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Li X, Tang X, Xiang Y, Zhao Z, Li Y, Ding Q, Zhang L, Xu J, Zhao L, Chen Y. N-glycosylation of SCAP exacerbates hepatocellular inflammation and lipid accumulation via ACSS2-mediated histone H3K27 acetylation. Am J Physiol Gastrointest Liver Physiol 2024. [PMID: 38591127 DOI: 10.1152/ajpgi.00273.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 03/25/2024] [Indexed: 04/10/2024]
Abstract
Sterol regulatory element binding protein (SREBP) cleavage-activating protein (SCAP) is a widely expressed membrane glycoprotein that acts as an important modulator of lipid metabolism and inflammatory stress. N-glycosylation of SCAP has been suggested to modulate cancer development, but its role in NASH is poorly understood. In this study, the N-glycosylation of SCAP was analyzed by using sequential trypsin proteolysis and glycosidase treatment. The liver cell lines expressing wild-type and N-glycosylation sites mutated SCAP were constructed to investigate the N-glycosylation role of SCAP in regulating inflammation and lipid accumulation as well as the underlying mechanisms. The hepatic SCAP protein levels were significantly increased in C57BL/6J mice fed with western diet and sweet water (WD+SW) and diabetic db/db mice, which exhibited typical liver steatosis and inflammation. In vitro, the enhanced N-glycosylation increased the protein stability of SCAP and hence increased its total protein levels, while the ablation of N-glycosylation significantly decreased SCAP protein stability and alleviated lipid accumulation and inflammation in hepatic cell lines. Mechanistically, the presence of SCAP N-glycosylation increased not only the SREBP1-mediated acetyl-CoA synthetase 2 (ACSS2) transcription but also the AMPK-mediated S659 phosphorylation of ACCS2 protein, causing the enhanced ACSS2 levels in nucleus and hence increasing the histone H3K27 acetylation (H3K27ac), which is a key epigenetic modification associated with NASH. Modulating ACSS2 expression or its location in cytoplasm abolished the effects of SCAP N-glycosylation on H3K27ac and lipid accumulation and inflammation. In conclusion, SCAP N-glycosylation aggravates inflammation and lipid accumulation through enhancing ACSS2-mediated H3K27ac in hepatocytes.
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Affiliation(s)
- Xuemei Li
- Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xiaoqin Tang
- Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yue Xiang
- Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Zhibo Zhao
- Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yanping Li
- Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Qiuying Ding
- Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Linkun Zhang
- Department of Endocrinology, First Affiliated Hospital of Chongqing Medical University, China
| | - Jingyuan Xu
- Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Lei Zhao
- Centre for Lipid Research, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yao Chen
- Centre for health medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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Zhu W, Zhang H, Niu T, Liu K, Fareeduddin Mohammed Farooqui H, Sun R, Chen X, Yuan Y, Wang S. Microglial SCAP deficiency protects against diabetes-associated cognitive impairment through inhibiting NLRP3 inflammasome-mediated neuroinflammation. Brain Behav Immun 2024; 119:154-170. [PMID: 38570101 DOI: 10.1016/j.bbi.2024.03.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 03/25/2024] [Accepted: 03/30/2024] [Indexed: 04/05/2024] Open
Abstract
Hyperglycemia-induced pathological microglial responses and subsequent neuronal damage are notable characteristics of diabetes-associated cognitive impairment (DACI). Cholesterol accumulation in the brain is a prevalent consequence of diabetes mellitus (DM), exacerbating pathological microglial responses. Regarding disordered glucose and lipid metabolism, the Sterol Regulatory Element-Binding Protein (SREBP) cleavage-activating protein (SCAP), a cholesterol sensor, exhibits increased expression and abnormal translocation from the endoplasmic reticulum to the Golgi, amplifying the inflammatory response. Therefore, we hypothesized that overexpression of microglia-SCAP and cholesterol accumulation in DM mice could induce pathological microglial responses associated with DACI. Our type 2 DM mice model presented an abnormal increase in microglial SCAP expression. The functional loss of microglia-specific SCAP in DM mice improved cognitive impairment, neuronal synaptic plasticity deficits, and abnormal microglial responses. Mechanistically, the accumulated SCAP directly bound to and enhanced the activation of the microglial-specific inflammatory amplifier, NLRP3 inflammasome, in Golgi, thereby increasing pathological microglial responses and promoting neuronal damage. These findings indicate an important regulatory axis of microglial responses from SCAP to the NLRP3 inflammasome pathway in microglia. These underscore the crosstalk between cholesterol disorders and pathological microglial responses, offering a promising avenue for pharmaceutical interventions in DACI.
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Affiliation(s)
- Wenwen Zhu
- Department of Endocrinology, Affiliated Zhongda Hospital of Southeast University, Nanjing 210009, China; School of Medicine, Southeast University, Nanjing 210009, China
| | - Haoqiang Zhang
- Department of Endocrinology, Center for Leading Medicine and Advanced Technologies of IHM, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230001, China
| | - Tong Niu
- Department of Endocrinology, Affiliated Zhongda Hospital of Southeast University, Nanjing 210009, China; School of Medicine, Southeast University, Nanjing 210009, China
| | - Kunyu Liu
- Department of Endocrinology, Affiliated Zhongda Hospital of Southeast University, Nanjing 210009, China; School of Medicine, Southeast University, Nanjing 210009, China
| | - Huzaifa Fareeduddin Mohammed Farooqui
- Department of Endocrinology, Affiliated Zhongda Hospital of Southeast University, Nanjing 210009, China; School of Medicine, Southeast University, Nanjing 210009, China
| | - Ruoyu Sun
- Department of Endocrinology, Affiliated Zhongda Hospital of Southeast University, Nanjing 210009, China; School of Medicine, Southeast University, Nanjing 210009, China
| | - Xiu Chen
- Department of Endocrinology, Affiliated Zhongda Hospital of Southeast University, Nanjing 210009, China; School of Medicine, Southeast University, Nanjing 210009, China
| | - Yang Yuan
- Department of Endocrinology, Affiliated Zhongda Hospital of Southeast University, Nanjing 210009, China.
| | - Shaohua Wang
- Department of Endocrinology, Affiliated Zhongda Hospital of Southeast University, Nanjing 210009, China.
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Liu MH, Lin XL, Xiao LL. SARS-CoV-2 nucleocapsid protein promotes TMAO-induced NLRP3 inflammasome activation by SCAP-SREBP signaling pathway. Tissue Cell 2024; 86:102276. [PMID: 37979395 DOI: 10.1016/j.tice.2023.102276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 11/12/2023] [Accepted: 11/12/2023] [Indexed: 11/20/2023]
Abstract
The sterol regulatory element-binding protein (SREBP) activation and cytokine level were significantly increased in coronavirus disease-19. The NLRP3 inflammasome is an amplifier for cellular inflammation. This study aimed to elucidate the modulatory effect of SARS-CoV-2 nucleocapsid protein (SARS-CoV-2 NP) on trimethylamine N-oxide (TMAO)-induced lipogenesis and NLRP3 inflammasome activation and the underlying mechanisms in vascular smooth muscle cells (VSMCs). Our data indicated that SARS-CoV-2 NP activates the dissociation of the SREBP cleavage activating protein (SCAP) from the endoplasmic reticulum, resulting in SREBP activation, increased lipogenic gene expression, and NLRP3 inflammasome activation. TMAO was applied to VSMC-induced NLRP3 inflammasome by promoting the SCAP-SREBP complex endoplasmic reticulum-to-Golgi translocation, which facilitates directly binding of SARS-CoV-2 NP to the NLRP3 protein for NLRP3 inflammasome assembly. SARS-CoV-2 NP amplified the TMAO-induced lipogenic gene expression and NLRP3 inflammasome. Knockdown of SCAP-SREBP2 can effectively reduce lipogenic gene expression and alleviate NLRP3 inflammasome-mediated systemic inflammation in VSMCs stimulated with TMAO and SARS-CoV-2 NP. These results reveal that SARS-CoV-2 NP amplified TMAO-induced lipogenesis and NLRP3 inflammasome activation via priming the SCAP-SREBP signaling pathway.
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Affiliation(s)
- Mi-Hua Liu
- Department of Clinical Laboratory, The Affiliated Ganzhou Hospital of Nanchang University, Ganzhou, Jiangxi 341000, People's Republic of China.
| | - Xiao-Long Lin
- Department of Pathology, Hui Zhou Third People's Hospital, Guangzhou Medical University, Huizhou City, Guangdong 516002, People's Republic of China
| | - Le-Le Xiao
- Intensive Care Unit, The Affiliated Ganzhou Hospital of Nanchang University, Ganzhou, Jiangxi 341000, People's Republic of China.
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Lu J, Ren Q, Qi W, Yang N, He Y. The Clinical Significance and the Potential Regulatory Mechanism of the LncRNA OIP5-AS1 in Paediatric Severe Community-Acquired Pneumonia Blood Through the MiR-150-5p/PDCD4 Axis. Immunol Invest 2024:1-18. [PMID: 38294019 DOI: 10.1080/08820139.2024.2309557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
BACKGROUND This study aimed to elucidate the clinical significance and regulatory mechanism of the long non-coding RNA OIP5-AS1 in severe community-acquired pneumonia (SCAP) among paediatric patients. METHODS qRT-PCR was used to assess the mRNA levels of OIP5-AS1. ROC curve analysis was used to assess the diagnostic significance of OIP5-AS1. Short-term prognostic significance was evaluated through Kaplan-Meier survival. An in vitro cell model was developed using LPS-induced MRC-5 cells. CCK-8, flow cytometry, and ELISA were conducted to measure cell viability, apoptosis, and inflammatory factor levels. The association between miR-150-5p and PDCD4 was confirmed through DLR assays. RESULTS Elevated OIP5-AS1 were observed in paediatric patients with SCAP, which enabled effective differentiation from healthy individuals. High expression of OIP5-AS1 correlated with reduced survival rates. OIP5-AS1 knockdown attenuated cell viability suppression and the promotion of apoptosis and inflammatory factors induced by LPS. However, this attenuation was reversed by reduced levels of miR-150-5p. miR-150-5p was identified as a target of PDCD4 and OIP5-AS1. CONCLUSION Increased OIP5-AS1 levels show potential as a valuable diagnostic and prognostic biomarker for paediatric patients with SCAP. This study illustrates its role in regulating cell viability, apoptosis, and the inflammatory response via the miR-150-5p/PDCD4 axis, acting as a ceRNA.
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Affiliation(s)
- Juan Lu
- Department of Pediatrics, Xingtai People's Hospital, Xingtai, Hebei, China
| | - Qingguo Ren
- Department of Pediatrics, Xingtai People's Hospital, Xingtai, Hebei, China
| | - Weiwei Qi
- Department of Pediatrics, Xingtai People's Hospital, Xingtai, Hebei, China
| | - Ning Yang
- Department of Pediatrics, Xingtai People's Hospital, Xingtai, Hebei, China
| | - Yuanyuan He
- Department of Pediatrics, Xingtai People's Hospital, Xingtai, Hebei, China
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Chandrasekaran P, Weiskirchen R. The Role of SCAP/SREBP as Central Regulators of Lipid Metabolism in Hepatic Steatosis. Int J Mol Sci 2024; 25:1109. [PMID: 38256181 PMCID: PMC10815951 DOI: 10.3390/ijms25021109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/09/2024] [Accepted: 01/14/2024] [Indexed: 01/24/2024] Open
Abstract
The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is rapidly increasing worldwide at an alarming pace, due to an increase in obesity, sedentary and unhealthy lifestyles, and unbalanced dietary habits. MASLD is a unique, multi-factorial condition with several phases of progression including steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Sterol element binding protein 1c (SREBP1c) is the main transcription factor involved in regulating hepatic de novo lipogenesis. This transcription factor is synthesized as an inactive precursor, and its proteolytic maturation is initiated in the membrane of the endoplasmic reticulum upon stimulation by insulin. SREBP cleavage activating protein (SCAP) is required as a chaperon protein to escort SREBP from the endoplasmic reticulum and to facilitate the proteolytic release of the N-terminal domain of SREBP into the Golgi. SCAP inhibition prevents activation of SREBP and inhibits the expression of genes involved in triglyceride and fatty acid synthesis, resulting in the inhibition of de novo lipogenesis. In line, previous studies have shown that SCAP inhibition can resolve hepatic steatosis in animal models and intensive research is going on to understand the effects of SCAP in the pathogenesis of human disease. This review focuses on the versatile roles of SCAP/SREBP regulation in de novo lipogenesis and the structure and molecular features of SCAP/SREBP in the progression of hepatic steatosis. In addition, recent studies that attempt to target the SCAP/SREBP axis as a therapeutic option to interfere with MASLD are discussed.
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Affiliation(s)
| | - Ralf Weiskirchen
- Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry (IFMPEGKC), Rheinisch-Westfälische Technische Hochschule (RWTH) University Hospital Aachen, D-52074 Aachen, Germany
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6
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Huang Y, Wang YF, Ruan XZ, Lau CW, Wang L, Huang Y. The role of KLF2 in regulating hepatic lipogenesis and blood cholesterol homeostasis via the SCAP/SREBP pathway. J Lipid Res 2024; 65:100472. [PMID: 37949368 PMCID: PMC10805670 DOI: 10.1016/j.jlr.2023.100472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 10/21/2023] [Accepted: 11/02/2023] [Indexed: 11/12/2023] Open
Abstract
Liver steatosis is a common metabolic disorder resulting from imbalanced lipid metabolism, which involves various processes such as de novo lipogenesis, fatty acid uptake, fatty acid oxidation, and VLDL secretion. In this study, we discovered that KLF2, a transcription factor, plays a crucial role in regulating lipid metabolism in the liver. Overexpression of KLF2 in the liver of db/db mice, C57BL/6J mice, and Cd36-/- mice fed on a normal diet resulted in increased lipid content in the liver. Additionally, transgenic mice (ALB-Klf2) that overexpressed Klf2 in the liver developed liver steatosis after being fed a normal diet. We found that KLF2 promotes lipogenesis by increasing the expression of SCAP, a chaperone that facilitates the activation of SREBP, the master transcription factor for lipogenic gene expression. Our mechanism studies revealed that KLF2 enhances lipogenesis in the liver by binding to the promoter of SCAP and increasing the expression of genes involved in fatty acid synthesis. Reduction of KLF2 expression led to a decrease in SCAP expression and a reduction in the expression of SREBP1 target genes involved in lipogenesis. Overexpression of KLF2 also increased the activation of SREBP2 and the mRNA levels of its downstream target SOAT1. In C57BL/6J mice fed a high-fat diet, overexpression of Klf2 increased blood VLDL secretion, while reducing its expression decreased blood cholesterol levels. Our study emphasizes the novelty that hepatic KLF2 plays a critical role in regulating lipid metabolism through the KLF2/SCAP/SREBPs pathway, which is essential for hepatic lipogenesis and maintaining blood cholesterol homeostasis.
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Affiliation(s)
- Yuhong Huang
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China; School of Biomedical Sciences, Chinese University of Hong Kong, Hong Kong, PR China; Shenzhen Research Institute and Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Shenzhen, China
| | - Yi Fan Wang
- School of Biomedical Sciences, Chinese University of Hong Kong, Hong Kong, PR China
| | - Xiong Zhong Ruan
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Chi Wai Lau
- School of Biomedical Sciences, Chinese University of Hong Kong, Hong Kong, PR China
| | - Li Wang
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Yu Huang
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China.
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7
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Pay R, Sharrock AV, Elder R, Maré A, Bracegirdle J, Torres D, Malone N, Vorster J, Kelly L, Ryan A, Josephy PD, Allen-Vercoe E, Ackerley DF, Keyzers RA, Harvey JE. Preparation, analysis and toxicity characterisation of the redox metabolites of the azo food dye tartrazine. Food Chem Toxicol 2023; 182:114193. [PMID: 37980979 DOI: 10.1016/j.fct.2023.114193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 10/30/2023] [Accepted: 11/12/2023] [Indexed: 11/21/2023]
Abstract
Tartrazine (E102, FD&C Yellow 5) is a vibrant yellow azo dye added to many processed foods. The safety of this ubiquitous chemical has not been fully elucidated, and it has been linked to allergic reactions and ADHD in some individuals. In our study, bacterial species isolated from human stool decolourised tartrazine and, upon exposure to air, a purple compound formed. Tartrazine is known to undergo reduction in the gut to sulfanilic acid and 4-amino-3-carboxy-5-hydroxy-1-(4-sulfophenyl)pyrazole (SCAP). These metabolites and their derivatives are relevant to the toxicology of tartrazine. The toxicity of sulfanilic acid has been studied before, but the oxidative instability of SCAP has previously prevented full characterisation. We have verified the chemical identity of SCAP and confirmed that the purple-coloured oxidation derivative is 4-(3-carboxy-5-hydroxy-1-(4-sulfophenyl)-1H-pyrazol-4-yl)imino-5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazole-3-carboxylic acid (purpurazoic acid, PPA), as proposed by Westöö in 1965. A yellow derivative of SCAP is proposed to be the hydrolysed oxidation product, 4,5-dioxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazole-3-carboxylic acid. SCAP and PPA are moderately toxic to human cells (IC50 89 and 78 μM against HEK-293, respectively), but had no apparent effect on Escherichia coli and Bacillus subtilis bacteria. These results prompt further analyses of the toxicology of tartrazine and its derivatives.
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Affiliation(s)
- Ruth Pay
- School of Chemical and Physical Sciences, Centre for Biodiscovery, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand
| | - Abigail V Sharrock
- School of Biological Sciences, Centre for Biodiscovery, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand
| | - Riley Elder
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada
| | - Alaigne Maré
- School of Chemical and Physical Sciences, Centre for Biodiscovery, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand
| | - Joe Bracegirdle
- School of Chemical and Physical Sciences, Centre for Biodiscovery, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand
| | - Dan Torres
- School of Chemical and Physical Sciences, Centre for Biodiscovery, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand
| | - Niall Malone
- School of Chemical and Physical Sciences, Centre for Biodiscovery, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand
| | - Jan Vorster
- School of Chemical and Physical Sciences, Centre for Biodiscovery, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand
| | - Libusha Kelly
- Albert Einstein College of Medicine, 1301 Morris Park Avenue, Bronx, NY, 10461, USA
| | - Ali Ryan
- Department of Biology, University of Northumbria, Newcastle upon Tyne, NE1 8ST, UK
| | - P David Josephy
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada
| | - Emma Allen-Vercoe
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada
| | - David F Ackerley
- School of Biological Sciences, Centre for Biodiscovery, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand
| | - Robert A Keyzers
- School of Chemical and Physical Sciences, Centre for Biodiscovery, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand
| | - Joanne E Harvey
- School of Chemical and Physical Sciences, Centre for Biodiscovery, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand.
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Smoczer C, Park YK, Herrington JB, Askar MA, Plecha S, Krukonis E, Paurazas SB. A Potential Intracanal Medicament, 2-Hydroxyisocaproic Acid (HICA): Cytotoxicity, Genotoxicity, and Its Effect on SCAP Differentiation. Dent J (Basel) 2023; 11:270. [PMID: 38132408 PMCID: PMC10743052 DOI: 10.3390/dj11120270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/17/2023] [Accepted: 11/23/2023] [Indexed: 12/23/2023] Open
Abstract
Intracanal medicaments with maximal antimicrobial efficacy and minimal damage to resident stem cells are essential for successful regenerative endodontic procedures. 2-Hydroxyisocaproic acid (HICA) could have the attributes of a potential intracanal medicament. This study evaluates its cytotoxicity, genotoxicity, and effects on the odontogenic and osteogenic differentiation of the stem cells of the apical papilla (SCAP). Cytotoxicity and cell viability assays were performed on cells treated for 24, 48, and 72 h with varying concentrations of HICA and compared to the standard intracanal medicament, calcium hydroxide. The genotoxicity was assessed via immunofluorescence for two markers of DNA double-strand breaks: phosphorylated γH2AX and 53BP1. The SCAP differentiation was evaluated based on the alkaline phosphatase activity, Alizarin Red staining, and expression of odontogenic and osteogenic genes (DSPP1, BSP1, OCN, RUNX2) in the presence of selected HICA concentrations. HICA was not cytotoxic at concentrations up to 10 mg/mL, regardless of the exposure time, although it was cytostatic at all tested concentrations. HICA was not genotoxic at concentrations below 5 mg/mL. No difference in cytotoxicity or genotoxicity was found between HICA and calcium hydroxide at 1 mg/mL. HICA retained about 70% of the osteogenic differentiation potential at 1 mg/mL. Within the limitations of this in vitro study, we show that HICA at 1 mg/mL could be a potential intracanal medicament for REPs.
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Affiliation(s)
- Cristine Smoczer
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI 48208, USA; (C.S.); (S.P.); (E.K.)
| | - Yun K. Park
- Graduate Endodontics, University of Detroit Mercy School of Dentistry, Detroit, MI 48208, USA (M.A.A.)
| | - James B. Herrington
- Graduate Endodontics, University of Detroit Mercy School of Dentistry, Detroit, MI 48208, USA (M.A.A.)
| | - Mazin A. Askar
- Graduate Endodontics, University of Detroit Mercy School of Dentistry, Detroit, MI 48208, USA (M.A.A.)
| | - Sarah Plecha
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI 48208, USA; (C.S.); (S.P.); (E.K.)
| | - Eric Krukonis
- Division of Integrated Biomedical Sciences, University of Detroit Mercy School of Dentistry, Detroit, MI 48208, USA; (C.S.); (S.P.); (E.K.)
| | - Susan B. Paurazas
- Graduate Endodontics, University of Detroit Mercy School of Dentistry, Detroit, MI 48208, USA (M.A.A.)
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9
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Zymovets V, Rakhimova O, Wadelius P, Schmidt A, Brundin M, Kelk P, Landström M, Vestman NR. Exploring the impact of oral bacteria remnants on stem cells from the Apical papilla: mineralization potential and inflammatory response. Front Cell Infect Microbiol 2023; 13:1257433. [PMID: 38089810 PMCID: PMC10711090 DOI: 10.3389/fcimb.2023.1257433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 11/08/2023] [Indexed: 12/18/2023] Open
Abstract
Introduction Bacterial persistence is considered one of the main causal factors for regenerative endodontic treatment (RET) failure in immature permanent teeth. This interference is claimed to be caused by the interaction of bacteria that reside in the root canal with the stem cells that are one of the essentials for RET. The aim of the study was to investigate whether prolonged exposure of stem cells from the apical papilla (SCAP) to bacterial remnants of Fusobacterium nucleatum, Actinomyces gerensceriae, Slackia exigua, Enterococcus faecalis, Peptostreptococcaceae yurii, commonly found in infected traumatized root canals, and the probiotic bacteria Lactobacillus gasseri and Limosilactobacillus reuteri, can alter SCAP's inflammatory response and mineralization potential. Methods To assess the effect of bacterial remnants on SCAP, we used UV-C-inactivated bacteria (as cell wall-associated virulence factors) and bacterial DNA. Histochemical staining using Osteoimage Mineralization Assay and Alizarin Red analysis was performed to study SCAP mineralization, while inflammatory and osteo/odontogenic-related responses of SCAPs were assessed with Multiplex ELISA. Results We showed that mineralization promotion was greater with UV C-inactivated bacteria compared to bacterial DNA. Immunofluorescence analysis detected that the early mineralization marker alkaline phosphatase (ALP) was increased by the level of E. coli lipopolysaccharide (LPS) positive control in the case of UV-C-inactivated bacteria; meanwhile, DNA treatment decreased the level of ALP compared to the positive control. SCAP's secretome assessed with Multiplex ELISA showed the upregulation of pro-inflammatory factors IL-6, IL-8, GM-CSF, IL-1b, neurotrophic factor BDNF, and angiogenic factor VEGF, induced by UV-C-killed bacteria. Discussion The results suggest that long term stimulation (for 21 days) of SCAP with UV-C-inactivated bacteria stimulate their mineralization and inflammatory response, while DNA influence has no such effect, which opens up new ideas about the nature of RET failure.
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Affiliation(s)
| | | | - Philip Wadelius
- Department of Endodontics, Region of Västerbotten, Umeå, Sweden
| | - Alexej Schmidt
- Department of Medical Biosciences, Pathology, Umeå University, Umeå, Sweden
| | - Malin Brundin
- Department of Odontology, Umeå University, Umeå, Sweden
| | - Peyman Kelk
- Section for Anatomy, Department of Integrative Medical Biology (IMB), Umeå University, Umeå, Sweden
| | - Maréne Landström
- Department of Medical Biosciences, Pathology, Umeå University, Umeå, Sweden
| | - Nelly Romani Vestman
- Department of Odontology, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
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10
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Takimoto K, Widbiller M, Diogenes A. Expression of Toll-like Receptors in Stem Cells of the Apical Papilla and Its Implication for Regenerative Endodontics. Cells 2023; 12:2502. [PMID: 37887345 PMCID: PMC10605481 DOI: 10.3390/cells12202502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 10/16/2023] [Accepted: 10/18/2023] [Indexed: 10/28/2023] Open
Abstract
Regenerative therapies to replace cells and tissues damaged due to trauma and dental infections require temporal and spatial controlled recruitment and the differentiation of progenitor/stem cells. However, increasing evidence shows microbial antigens can interfere with this process. Toll-like receptors (TLRs) are crucial in recognizing pathogen-associated molecular patterns. Stem cells of the apical papilla (SCAP) are required for normal dental development and are intimately involved in the reparative and regenerative capacity of developing teeth. We hypothesized that TLRs are expressed in SCAP and that the activation of TLR2/TLR4 or TLR3 by different ligands results in differential cellular fate, impacting their differentiation into a mineralizing phenotype. We found that most TLRs are expressed as detected by PCR except TLR7 and TLR8; exposure to heat-killed E. coli results in upregulating TLR2 and TLR4 and reducing mineralization capacity. In addition, bacterial exposure resulted in the upregulation of 11 genes, of which 9 were chemokines whose proteins were also upregulated and released, promoting in vitro macrophage migration. On the other hand, TLR3 activation resulted in increased proliferation and a dramatic inhibition of osteogenic and odontoblastic differentiation, which was reversed by inhibition or the knockdown of TLR3 expression. The profound effects of TLR activation resulting in different cell fates that are ligand and receptor-specific warrants further evaluation and represents an important therapeutic target to make regenerative approaches more predictable following dental infections.
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Affiliation(s)
- Koyo Takimoto
- Department of Endodontics, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA; (K.T.); (M.W.)
| | - Matthias Widbiller
- Department of Endodontics, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA; (K.T.); (M.W.)
- Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, 93053 Regensburg, Germany
| | - Anibal Diogenes
- Department of Endodontics, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA; (K.T.); (M.W.)
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11
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Lu R, Yang H, Peng W, Tang H, Li Y, Lin F, Zhou A, Pan P. Serum Krebs von den Lungen-6 is associated with in-Hospital mortality of patients with severe Community-Acquired Pneumonia: A retrospective cohort study. Clin Chim Acta 2023; 548:117524. [PMID: 37633319 DOI: 10.1016/j.cca.2023.117524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 08/28/2023]
Abstract
BACKGROUND Currently, no ideal biomarker can accurately stratify the risk of patients with severe community-acquired pneumonia (SCAP). This study aimed to evaluate the role of serum Krebs von den Lungen-6 (sKL-6) in predicting in-hospital mortality in adults with SCAP. METHODS In this retrospective cohort study, 249 severe pneumonia adult patients were recruited between 6 May 2021 to 30 April 2023 in Xiangya Hospital of Central South University. The sKL-6 level within 48 h of admission was measured, and the primary outcome assessed was in-hospital mortality. Multivariable logistic regression analysis was performed to calculate adjusted odds ratios (OR) with 95% confidence intervals (CI). Survival curves were plotted and subgroup analyses were conducted, stratified by relevant covariates. RESULTS A total of 249 patients were included in the study,with 124 patients having normal sKL-6 levels, and 125 patients having abnormal sKL-6 levels. The overall in-hospital mortality rate was 28.9% (72 out of 249 patients). Univariate and multivariate logistic regression analysis revealed that the patients with abnormal sKL-6 levels had a higher risk of in-hospital mortality compared to those with normal sKL-6 levels, both in the total SCAP patient population (OR: 5.38, 95%CI: 2.41-12.01, P < 0.001) and the non-COVID-19 SCAP patients subgroup (OR: 8.12, 95%CI: 3.16-20.84, P < 0.001). Subgroup and interaction analyses confirmed the stability of the relationship between sKL-6 levels and in-hospital mortality(P for interaction > 0.05). Kaplan-Meier survival curves showed that patients with abnormal sKL-6 levels had a higher in-hospital mortality rate than those with normal sKL-6 levels (P < 0.05). However, the results of restricted cubic spline plots(RCS) analysis demonstrated a nonlinear association between sKL-6 levels (as a continuous variable) and in-hospital mortality in patients with SCAP. Similar results were observed in non-COVID-19 SCAP patients. Furthermore, the receiver operating characteristic curve (ROC) analysis revealed that sKL-6 had superior predictive performance compared to existing biomarkers (e.g., APACHE-II, SOFA, BUN/Cr, PCT, and D-dimer) for in-hospital mortality in non-COVID-19 SCAP patients. CONCLUSION sKL-6 is a practical and useful biomarker for predicting in-hospital mortality in patients with SCAP.
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Affiliation(s)
- Rongli Lu
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan 410008, China; Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan 410008, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, Hunan 410008, PR China
| | - Hang Yang
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan 410008, China; Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan 410008, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, Hunan 410008, PR China
| | - Wenzhong Peng
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan 410008, China; Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan 410008, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, Hunan 410008, PR China
| | - Haiyun Tang
- Department of Radiology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yi Li
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan 410008, China; Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan 410008, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, Hunan 410008, PR China
| | - Fengyu Lin
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan 410008, China; Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan 410008, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, Hunan 410008, PR China
| | - Aiyuan Zhou
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan 410008, China; Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan 410008, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, Hunan 410008, PR China.
| | - Pinhua Pan
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China; Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan 410008, China; Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan 410008, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, Hunan 410008, PR China.
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12
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Makokha GN, Chayama K, Hayes CN, Abe-Chayama H, Abuduwaili M, Makoto H. Deficiency of SCAP inhibits HBV pathogenesis via activation of the interferon signaling pathway. Virology 2023; 585:248-258. [PMID: 37437369 DOI: 10.1016/j.virol.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 06/15/2023] [Accepted: 07/03/2023] [Indexed: 07/14/2023]
Abstract
Hepatitis B virus (HBV) infects the liver and is a major risk factor for liver cirrhosis and hepatocellular carcinoma. Approaches for an effective cure are thwarted by limited knowledge of virus-host interactions. Herein, we identified SCAP as a novel host factor that regulates HBV gene expression. SCAP, sterol regulatory element-binding protein (SREBP) cleavage-activating protein, is an integral membrane protein located in the endoplasmic reticulum. The protein plays a central role in controlling lipid synthesis and uptake by cells. We found that gene silencing of SCAP significantly inhibited HBV replication; furthermore, knockdown of SREBP2 but not SREBP1, the downstream effectors of SCAP, reduced HBs antigen production from HBV infected primary hepatocytes. We also demonstrated that knockdown of SCAP resulted in activation of interferons (IFNs) and IFN stimulated genes (ISGs). Conversely, ectopic expression of SREBP2 in SCAP-deficient cells restored expression of IFNs and ISGs. Importantly, expression of SREBP2 restored HBV production in SCAP knockdown cells, suggesting that SCAP participates in HBV replication through an effect on IFN production via its downstream effector SREBP2. This observation was further confirmed by blocking IFN signaling by an anti-IFN antibody, which restored HBV infection in SCAP-deficient cells. This led to the conclusion that SCAP regulates the IFN pathway through SREBP, thereby affecting the HBV lifecycle. This is the first study to reveal the involvement of SCAP in regulation of HBV infection. These results may facilitate development of new antiviral strategies against HBV.
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Affiliation(s)
- Grace Naswa Makokha
- Laboratory of Medical Innovation, Department of Collaborative Research, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
| | - Kazuaki Chayama
- Laboratory of Medical Innovation, Department of Collaborative Research, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - C Nelson Hayes
- Department of Gastroenterology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Hiromi Abe-Chayama
- Center for Medical Specialist Graduate Education and Research, Hiroshima University, Hiroshima, Japan
| | - Maidina Abuduwaili
- Laboratory of Medical Innovation, Department of Collaborative Research, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Hijikata Makoto
- Laboratory of Medical Innovation, Department of Collaborative Research, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
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13
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Quintino-Ottonicar GG, da Silva LR, Maria VLRDS, Pizzo EM, de Santana ACP, Lenharo NR, Pinho CF, Pereira S. Exposure to Dichlorvos pesticide alters the morphology of and lipid metabolism in the ventral prostate of rats. Front Toxicol 2023; 5:1207612. [PMID: 37469457 PMCID: PMC10352615 DOI: 10.3389/ftox.2023.1207612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 06/22/2023] [Indexed: 07/21/2023] Open
Abstract
Organophosphate pesticides are widely used in agriculture, leading to soil, water, and food contamination. Among these compounds is Dichlorvos [O,O-dimethyl O-(2,2-dichlorovinyl)phosphate, DDVP], which is listed as a highly toxic compound by the Environmental Protection Agency and World Health Organization. Exposure to DDVP can result in nervous, respiratory, hepatic, and reproductive abnormalities, in addition to endocrine disrupting, mutagenic, and carcinogenic effects. Little is known about the impacts of DDVP on the reprogramming of lipid metabolism, which is also associated with the development and progression of cancer, since the tumor cells need to recruit, capture, and use fatty acids to compose their building membranes. This study aimed to evaluate the influence of the pesticide DDVP on lipid metabolism in the prostate, after chemical induction by the carcinogen N-methyl-N-nitrosourea (MNU). For this, 32 Fischer rats aged 90 days were randomly divided into four experimental groups: Control, DDVP, MNU, and MNU + DDVP. The MNU and MNU + DDVP groups underwent chemical induction with MNU (15 mg/kg) and the DDVP and MNU + DDVP groups received a diet supplemented with DDVP (10 mg/kg). Histopathological analyses of the rat ventral prostate showed 100% incidence of epithelial hyperplasia in the MNU and MNU + DDVP groups. This finding was accompanied by an increase of the epithelial compartment in the MNU + DDVP group. Immunolocalization of important proteins linked to lipid metabolism has been established. In the MNU + DDVP group, Western blotting analyses pointed out an increased expression of the protein LIMP II (Lysosomal Integral Membrane Protein-II), which is correlated with the capture and distribution of lipids in tumor cells. Together, these results indicate that the association of a low dose of DDVP with MNU was able to promote alterations in the morphology and lipid metabolism of the rat ventral prostate, which may be related to tumor progression in this organ.
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14
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Lee JH, Lee SH, Lee EH, Cho JY, Song DK, Lee YJ, Kwon TK, Oh BC, Cho KW, Osborne TF, Jeon TI, Im SS. SCAP deficiency facilitates obesity and insulin resistance through shifting adipose tissue macrophage polarization. J Adv Res 2023; 45:1-13. [PMID: 35659922 PMCID: PMC10006517 DOI: 10.1016/j.jare.2022.05.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 05/13/2022] [Accepted: 05/26/2022] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION Sterol regulatory element binding protein (SREBP) cleavage-associating protein (SCAP) is a sterol-regulated escort protein that translocates SREBPs from the endoplasmic reticulum to the Golgi apparatus, thereby activating lipid metabolism and cholesterol synthesis. Although SCAP regulates lipid metabolism in metabolic tissues, such as the liver and muscle, the effect of macrophage-specific SCAP deficiency in adipose tissue macrophages (ATMs) of patients with metabolic diseases is not completely understood. OBJECTIVES Here, we examined the function of SCAP in high-fat/high-sucrose diet (HFHS)-fed mice and investigated its role in the polarization of classical activated macrophages in adipose tissue. METHODS Macrophage-specific SCAP knockout (mKO) mice were generated through crossbreeding lysozyme 2-cre mice with SCAP floxed mice which were then fed HFHS for 12 weeks. Primary macrophages were derived from bone marrow cells and analyzed further. RESULTS We found that fat accumulation and the appearance of proinflammatory M1 macrophages were both higher in HFHS-fed SCAP mKO mice relative to floxed control mice. We traced the effect to a defect in the lipopolysaccharide-mediated increase in SREBP-1a that occurs in control but not SCAP mKO mice. Mechanistically, SREBP-1a increased expression of cholesterol 25-hydroxylase transcription, resulting in an increase in the production of 25-hydroxycholesterol (25-HC), an endogenous agonist of liver X receptor alpha (LXRα) which increased expression of cholesterol efflux to limit cholesterol accumulation and M1 polarization. In the absence of SCAP mediated activation of SREBP-1a, increased M1 macrophage polarization resulted in reduced cholesterol efflux downstream from 25-HC-dependent LXRα activation. CONCLUSION Overall, the activation of the SCAP-SREBP-1a pathway in macrophages may provide a novel therapeutic strategy that ameliorates obesity by controlling cholesterol homeostasis in ATMs.
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Affiliation(s)
- Jae-Ho Lee
- Department of Physiology, Keimyung University School of Medicine, Daegu 42601, Republic of Korea
| | - Sun Hee Lee
- Department of Physiology, Keimyung University School of Medicine, Daegu 42601, Republic of Korea
| | - Eun-Ho Lee
- Department of Physiology, Keimyung University School of Medicine, Daegu 42601, Republic of Korea
| | - Jeong-Yong Cho
- Department of Food Science and Technology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Dae-Kyu Song
- Department of Physiology, Keimyung University School of Medicine, Daegu 42601, Republic of Korea
| | - Young Jae Lee
- Lee Gil Ya Cancer and Diabetes Institute, Department of Biochemistry, Gachon University School of Medicine, Younsoo-gu, Inchon 21999, Republic of Korea
| | - Taeg Kyu Kwon
- Department of Immunology, Keimyung University School of Medicine, Daegu 42601, Republic of Korea
| | - Byung-Chul Oh
- Lee Gil Ya Cancer and Diabetes Institute, Department of Physiology, Gachon University School of Medicine, Younsoo-gu, Inchon 21999, Republic of Korea
| | - Kae Won Cho
- Soonchunhyang Institute of Medi-bioScience (SIMS), Soonchunhyang University, Cheonan 31151, Republic of Korea
| | - Timothy F Osborne
- Institute for Fundamental Biomedical Research, Departments of Medicine and Biological Chemistry, Johns Hopkins University School of Medicine, St. Petersburg, FL 33701, USA
| | - Tae-Il Jeon
- Department of Animal Science, College of Agriculture and Life Science, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Seung-Soon Im
- Department of Physiology, Keimyung University School of Medicine, Daegu 42601, Republic of Korea.
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15
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Verma RR, Verma R. Syringocystadenocarcinoma Papilliferum of External Auditory Canal: First Case Report in English Literature. Indian J Otolaryngol Head Neck Surg 2022; 74:3700-3705. [PMID: 36742756 PMCID: PMC9895180 DOI: 10.1007/s12070-021-02434-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 02/02/2021] [Indexed: 02/07/2023] Open
Abstract
Malignant tumors of external auditory canal (EAC) constitute less than 0.2% of all head and neck cancers. The incidence of carcinoma of the EAC is estimated to be between one in six per million populations. Majority of cancers of EAC are squamous cell carcinomas and basal cell carcinomas. Some rare and unusual tumors do occur within the ear canal including malignant melanoma, merkel cell carcinoma, angiosarcoma, lymphoma and adnexal carcinomas like ceruminous adenocaricinoma and adenoid cystic carcinoma. Ceruminous glands tumors constitute about 5% of all external auditory canal tumors. Carcinoma of the external auditory canal is a difficult diagnosis unless the tumors presents as a fungating mass protruding from the external auditory canal. Syringocystadenocarcinoma Papilliferum (SCACP) is an extremely rare cutaneous adnexal neoplasm. Syringocystadenoma papilliferum (SCAP) is thought to be precursor of SCACP. About 50 cases of SCACP have been reported in literature all over the body. The diagnosis is difficult and excisional biopsy becomes mandatory for diagnosis and treatment. We present a case of SCACP in the external auditory canal in a middle-aged female. To the best of our knowledge and belief, this is the first case of SCACP in the external auditory canal in the English literature. This prompted us to report this case.
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Affiliation(s)
- Ravneet Ravinder Verma
- Department of Otorhinolaryngology, Head and Neck Surgery, Government Medical College and Hospital, Chandigarh, India
| | - Ravinder Verma
- Verma Hospital and Research Centre, Gujral Nagar, Jalandhar, 144001 India
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16
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Wang Y, Wang Y, Ding L, Ren X, Wang B, Wang L, Zhao S, Yue X, Wu Z, Li C, Liang X, Ma C, Gao L. Tim-4 reprograms cholesterol metabolism to suppress antiviral innate immunity by disturbing the Insig1- SCAP interaction in macrophages. Cell Rep 2022; 41:111738. [PMID: 36450259 DOI: 10.1016/j.celrep.2022.111738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 09/27/2022] [Accepted: 11/07/2022] [Indexed: 12/03/2022] Open
Abstract
Accumulating evidence indicates that macrophages reshape their cholesterol metabolism in response to pathogens to support host defense. Intervention of host cholesterol homeostasis has emerged as a promising strategy for antiviral therapy. T cell immunoglobulin and mucin domain-containing molecule 4 (Tim-4) is indispensable in maintaining the homeostasis of macrophages. However, its role in antiviral innate immunity and cholesterol metabolism remains unknown. Here, we report that Tim-4 deficiency results in boosted interferon (IFN) signaling and decreased viral load. Mechanistically, Tim-4 disturbs the Insig1-SCAP interaction and promotes SCAP-SREBP2 complex translocation to the Golgi apparatus, eventually leading to the upregulation of cholesterol biosynthesis in macrophages, which limits the type I IFN response. Our findings demonstrate that Tim-4 suppresses type I IFN signaling by enhancing SREBP2 activation, delineating the role of Tim-4 in antiviral innate immunity and cholesterol metabolism, which sheds light on the mechanism by which Tim-4 orchestrates macrophage homeostasis.
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Affiliation(s)
- Yingchun Wang
- Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Key Laboratory of Infection and Immunity, and Department of Immunology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Yuzhen Wang
- Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Key Laboratory of Infection and Immunity, and Department of Immunology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Lu Ding
- Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Key Laboratory of Infection and Immunity, and Department of Immunology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Xiaolei Ren
- Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Key Laboratory of Infection and Immunity, and Department of Immunology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Bo Wang
- Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Key Laboratory of Infection and Immunity, and Department of Immunology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Liyuan Wang
- Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Key Laboratory of Infection and Immunity, and Department of Immunology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Songbo Zhao
- Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Key Laboratory of Infection and Immunity, and Department of Immunology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Xuetian Yue
- Department of Cell Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Zhuanchang Wu
- Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Key Laboratory of Infection and Immunity, and Department of Immunology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Chunyang Li
- Key Laboratory for Experimental Teratology of Ministry of Education and Department of Histology and Embryology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Xiaohong Liang
- Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Key Laboratory of Infection and Immunity, and Department of Immunology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Chunhong Ma
- Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Key Laboratory of Infection and Immunity, and Department of Immunology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Lifen Gao
- Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Key Laboratory of Infection and Immunity, and Department of Immunology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China.
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17
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Kim JY, Wang LQ, Sladky VC, Oh TG, Liu J, Trinh K, Eichin F, Downes M, Hosseini M, Jacotot ED, Evans RM, Villunger A, Karin M. PIDDosome- SCAP crosstalk controls high-fructose-diet-dependent transition from simple steatosis to steatohepatitis. Cell Metab 2022; 34:1548-1560.e6. [PMID: 36041455 PMCID: PMC9547947 DOI: 10.1016/j.cmet.2022.08.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 06/17/2022] [Accepted: 08/07/2022] [Indexed: 02/06/2023]
Abstract
Sterol deficiency triggers SCAP-mediated SREBP activation, whereas hypernutrition together with ER stress activates SREBP1/2 via caspase-2. Whether these pathways interact and how they are selectively activated by different dietary cues are unknown. Here, we reveal regulatory crosstalk between the two pathways that controls the transition from hepatosteatosis to steatohepatitis. Hepatic ER stress elicited by NASH-inducing diets activates IRE1 and induces expression of the PIDDosome subunits caspase-2, RAIDD, and PIDD1, along with INSIG2, an inhibitor of SCAP-dependent SREBP activation. PIDDosome assembly activates caspase-2 and sustains IRE1 activation. PIDDosome ablation or IRE1 inhibition blunt steatohepatitis and diminish INSIG2 expression. Conversely, while inhibiting simple steatosis, SCAP ablation amplifies IRE1 and PIDDosome activation and liver damage in NASH-diet-fed animals, effects linked to ER disruption and preventable by IRE1 inhibition. Thus, the PIDDosome and SCAP pathways antagonistically modulate nutrient-induced hepatic ER stress to control non-linear transition from simple steatosis to hepatitis, a key step in NASH pathogenesis.
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Affiliation(s)
- Ju Youn Kim
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA.
| | - Lily Q Wang
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Valentina C Sladky
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Tae Gyu Oh
- Gene Expression Laboratory, Salk Institute of Biological Studies, La Jolla, CA 9037, USA
| | - Junlai Liu
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Kaitlyn Trinh
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Felix Eichin
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Michael Downes
- Gene Expression Laboratory, Salk Institute of Biological Studies, La Jolla, CA 9037, USA
| | - Mojgan Hosseini
- Department of Pathology, University of California San Diego, La Jolla, CA 92037, USA
| | - Etienne D Jacotot
- INSERM U1164 Sorbonne Université, Campus Pierre et Marie Curie, Paris 75005, France; Department of Pathology & Cell Biology and the Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY 10033, USA
| | - Ronald M Evans
- Gene Expression Laboratory, Salk Institute of Biological Studies, La Jolla, CA 9037, USA
| | - Andreas Villunger
- Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria; CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Michael Karin
- Laboratory of Gene Regulation and Signal Transduction, Departments of Pharmacology and Pathology, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA.
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18
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Limansubroto N, Chung WO, Johnson JD, Paranjpe A. Immunomodulatory effects of N-acetyl cysteine treated SCAP. J Endod 2022; 48:1055-1062. [PMID: 35588920 DOI: 10.1016/j.joen.2022.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 05/09/2022] [Accepted: 05/10/2022] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Stem cells of the apical papilla (SCAP) play an important role in regenerative endodontic procedures (REPs). Previous studies have shown that during REPs, bacteria can activate the innate immune system and cause indirect stem cell toxicity, leading to the lysis of SCAP. N-acetylcysteine (NAC) treated cells are resistant to apoptosis and have increased differentiation capabilities. The immunomodulatory properties of NAC treated SCAP are still unknown. Hence, the aim of this study is to evaluate the interactions of SCAP pre-treated with and without NAC with the immune system. METHODS Flow cytometric analysis was performed to assess the effects of NAC on SCAP viability. Human SCAP were then cultured and were either pre-treated with NAC or non-treated and co-cultured with human Peripheral blood mononuclear cells (PBMCs). A lactate dehydrogenase assay was performed to evaluate the levels of immune cell mediated apoptosis followed by an enzyme-linked immunosorbent assay (ELISA) to measure levels of pro-inflammatory cytokines for these co-cultures. Data were analyzed using an ANOVA with a post-hoc Tukey test. RESULTS Cells treated with NAC had similar levels of viability as the controls. SCAP pre-treated with NAC had a significantly lower immune cell-mediated cytotoxicity to non-activated and activated PBMCs. The ELISA results showed that SCAP pre-treated with NAC induced lower levels of proinflammatory cytokines. CONCLUSIONS SCAP pre-treated with NAC have a higher chance of surviving the activated immune system. This information may provide a better insight into the properties of these stem cells and may be the key to making REPs more predictable.
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Affiliation(s)
| | - Whasun Oh Chung
- Department of Oral Health Sciences, University of Washington, Seattle, Washington
| | - James D Johnson
- Department of Endodontics, University of Washington, Seattle, Washington
| | - Avina Paranjpe
- Department of Endodontics, University of Washington, Seattle, Washington.
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19
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De Berdt P, Vanvarenberg K, Ucakar B, Bouzin C, Paquot A, Gratpain V, Loriot A, Payen V, Bearzatto B, Muccioli GG, Gatto L, Diogenes A, des Rieux A. The human dental apical papilla promotes spinal cord repair through a paracrine mechanism. Cell Mol Life Sci 2022; 79:252. [PMID: 35445984 DOI: 10.1007/s00018-022-04210-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/13/2022] [Accepted: 02/15/2022] [Indexed: 11/03/2022]
Abstract
Traumatic spinal cord injury is an overwhelming condition that strongly and suddenly impacts the patient's life and her/his entourage. There are currently no predictable treatments to repair the spinal cord, while many strategies are proposed and evaluated by researchers throughout the world. One of the most promising avenues is the transplantation of stem cells, although its therapeutic efficiency is limited by several factors, among which cell survival at the lesion site. In our previous study, we showed that the implantation of a human dental apical papilla, residence of stem cells of the apical papilla (SCAP), supported functional recovery in a rat model of spinal cord hemisection. In this study, we employed protein multiplex, immunohistochemistry, cytokine arrays, RT- qPCR, and RNAseq technology to decipher the mechanism by which the dental papilla promotes repair of the injured spinal cord. We found that the apical papilla reduced inflammation at the lesion site, had a neuroprotective effect on motoneurons, and increased the apoptosis of activated macrophages/ microglia. This therapeutic effect is likely driven by the secretome of the implanted papilla since it is known to secrete an entourage of immunomodulatory or pro-angiogenic factors. Therefore, we hypothesize that the secreted molecules were mainly produced by SCAP, and that by anchoring and protecting them, the human papilla provides a protective niche ensuring that SCAP could exert their therapeutic actions. Therapeutic abilities of the papilla were demonstrated in the scope of spinal cord injury but could very well be beneficial to other types of tissue.
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20
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Huang X, Yao Y, Hou X, Wei L, Rao Y, Su Y, Zheng G, Ruan XZ, Li D, Chen Y. Macrophage SCAP Contributes to Metaflammation and Lean NAFLD by Activating STING-NF-κB Signaling Pathway. Cell Mol Gastroenterol Hepatol 2022; 14:1-26. [PMID: 35367665 PMCID: PMC9117819 DOI: 10.1016/j.jcmgh.2022.03.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/23/2022] [Accepted: 03/24/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND & AIMS Sterol regulatory element binding protein cleavage-activating protein (SCAP) is a cholesterol sensor that confers a broad range of functional effects in metabolic diseases. Lean nonalcoholic fatty liver disease (NAFLD) is characterized by a decrease in subcutaneous fat and ectopic fat deposition in the liver. SCAP may mediate the development of lean NAFLD, but the mechanism of action remains unclear. METHODS C57BL/6J wild-type and macrophage SCAP-specific knockout mice (SCAPΔMϕ) were subjected to Paigen diet (PD) feeding induced lean NAFLD. Inflammation and lipid metabolism of adipose and liver were evaluated. The STING-NF-κB signaling pathway was examined in vivo and in vitro to explore the underlying mechanism of macrophage SCAP on metaflammation. RESULTS The data showed heterogeneity of lipid metabolic processes in liver and epididymal white adipose tissue due to inflammation mediated by macrophage infiltration. Meanwhile, we found that the macrophage SCAP was abnormally increased in the adipose and liver tissues of PD-fed mice. Intriguingly, the SCAPΔMϕ mice attenuated PD-induced metaflammation and ectopic lipid deposition by reducing hepatic stimulator of interferon gene (STING)-nuclear factor kappa B (NF-κB) pathway activation. In-depth molecular analysis revealed that SCAP specifically recruits the STING and tank-binding kinase 1 onto the Golgi to activate the NF-κB in macrophages, thereby promoting the release of inflammatory factors. This process ultimately led to an increased lipolysis in adipocytes and lipid uptake and synthesis in hepatocytes. CONCLUSIONS Our findings suggest that SCAP acts as a novel regulator of the macrophage inflammatory response and the pathogenesis of lean NAFLD by activating the STING-NF-κB signaling pathway. Inhibition of macrophage SCAP may represent a new therapeutic strategy for the treatment of lean NAFLD.
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Affiliation(s)
- Xinyu Huang
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Yingcheng Yao
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Xiaoli Hou
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Li Wei
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Yuhan Rao
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Yu Su
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Guo Zheng
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Xiong Z. Ruan
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, Second Affiliated Hospital, Chongqing Medical University, Chongqing, China,John Moorhead Research Laboratory, Centre for Nephrology, University College London Medical School, Royal Free Campus, University College London, London, United Kingdom
| | - Danyang Li
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, Second Affiliated Hospital, Chongqing Medical University, Chongqing, China,Correspondence Address correspondence to: Danyang Li, PhD or Yaxi Chen, PhD, Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, Second Affiliated Hospital, Chongqing Medical University, 400016 Chongqing, China. fax: +86-23-68486780.
| | - Yaxi Chen
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, Second Affiliated Hospital, Chongqing Medical University, Chongqing, China,Correspondence Address correspondence to: Danyang Li, PhD or Yaxi Chen, PhD, Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, Second Affiliated Hospital, Chongqing Medical University, 400016 Chongqing, China. fax: +86-23-68486780.
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21
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Li D, Yao Y, Rao Y, Huang X, Wei L, You Z, Zheng G, Hou X, Su Y, Varghese Z, Moorhead JF, Chen Y, Ruan XZ. Cholesterol sensor SCAP contributes to sorafenib resistance by regulating autophagy in hepatocellular carcinoma. J Exp Clin Cancer Res 2022; 41:116. [PMID: 35354475 PMCID: PMC8966370 DOI: 10.1186/s13046-022-02306-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/28/2022] [Indexed: 01/08/2023]
Abstract
Background Hepatocellular carcinoma (HCC) is one of the most malignant tumors and the fourth leading cause of cancer-related death worldwide. Sorafenib is currently acknowledged as a standard therapy for advanced HCC. However, acquired resistance substantially limits the clinical efficacy of sorafenib. Therefore, further investigations of the associated risk factors are highly warranted. Methods We analysed a group of 78 HCC patients who received sorafenib treatment after liver resection surgery. The expression of SCAP and its correlation with sorafenib resistance in HCC clinical samples were determined by immunohistochemical analyses. Overexpression and knockdown approaches in vitro were used to characterize the functional roles of SCAP in regulating sorafenib resistance. The effects of SCAP inhibition in HCC cell lines were analysed in proliferation, apoptosis, and colony formation assays. Autophagic regulation by SCAP was assessed by immunoblotting, immunofluorescence and immunoprecipitation assays. The combinatorial effect of a SCAP inhibitor and sorafenib was tested using nude mice. Results Hypercholesterolemia was associated with sorafenib resistance in HCC treatment. The degree of sorafenib resistance was correlated with the expression of the cholesterol sensor SCAP and consequent deposition of cholesterol. SCAP is overexpressed in HCC tissues and hepatocellular carcinoma cell lines with sorafenib resistance, while SCAP inhibition could improve sorafenib sensitivity in sorafenib-resistant HCC cells. Furthermore, we found that SCAP-mediated sorafenib resistance was related to decreased autophagy, which was connected to decreased AMPK activity. A clinically significant finding was that lycorine, a specific SCAP inhibitor, could reverse acquired resistance to sorafenib in vitro and in vivo. Conclusions SCAP contributes to sorafenib resistance through AMPK-mediated autophagic regulation. The combination of sorafenib and SCAP targeted therapy provides a novel personalized treatment to enhance sensitivity in sorafenib-resistant HCC. Supplementary Information The online version contains supplementary material available at 10.1186/s13046-022-02306-4.
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Affiliation(s)
- Danyang Li
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, 400016, Chongqing, China
| | - Yingcheng Yao
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, 400016, Chongqing, China
| | - Yuhan Rao
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, 400016, Chongqing, China
| | - Xinyu Huang
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, 400016, Chongqing, China
| | - Li Wei
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, 400016, Chongqing, China
| | - Zhimei You
- Department of General Medicine, Affiliated Cancer Hospital of Chongqing University, Chongqing, 400016, China
| | - Guo Zheng
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, 400016, Chongqing, China
| | - Xiaoli Hou
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, 400016, Chongqing, China
| | - Yu Su
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, 400016, Chongqing, China
| | - Zac Varghese
- John Moorhead Research Laboratory, Centre for Nephrology, University College London Medical School, Royal Free Campus, University College London, London, NW3 2PF, UK
| | - John F Moorhead
- John Moorhead Research Laboratory, Centre for Nephrology, University College London Medical School, Royal Free Campus, University College London, London, NW3 2PF, UK
| | - Yaxi Chen
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, 400016, Chongqing, China.
| | - Xiong Z Ruan
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, 400016, Chongqing, China. .,John Moorhead Research Laboratory, Centre for Nephrology, University College London Medical School, Royal Free Campus, University College London, London, NW3 2PF, UK.
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22
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Hsieh J, Molusky MM, McCabe KM, Fotakis P, Xiao T, Tascau L, Zeana-Schliep L, DaSilva-Jardine P, Tall AR. TTC39B destabilizes retinoblastoma protein promoting hepatic lipogenesis in a sex-specific fashion. J Hepatol 2022; 76:383-393. [PMID: 34600974 PMCID: PMC8766887 DOI: 10.1016/j.jhep.2021.09.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 09/20/2021] [Accepted: 09/21/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND & AIMS Molecular mechanisms underlying the different susceptibility of men and women to non-alcoholic fatty liver disease (NAFLD) are poorly understood. The TTC39B locus encodes a scaffolding protein, associates with gynecological disorders and its deletion protects mice from diet-induced steatohepatitis. This study aimed to elucidate the molecular mechanisms linking TTC39B (T39) to the expression of lipogenic genes and to explore sex-specific effects. METHODS Co-expression in HEK293A cells validated the novel T39/pRb interaction predicted by a protein-protein interaction algorithm. T39 was knocked down using an antisense oligonucleotide (ASO) in mice with dietary NAFLD and a genetic deficiency of pRb or its downstream effector E2F1, as well as in primary human hepatocytes. RESULTS T39 interacts with pRb via its C-terminal TPR domain and promotes its proteasomal degradation. In female mice, T39 deficiency reduces the mRNA of lipogenic genes, especially Pnpla3, in a pRb- and E2F1-dependent manner. In contrast, in male mice, T39 deficiency results in a much smaller reduction in lipogenic gene expression that is independent of pRb/E2F1. T39 also interacts with VAPB via an N-terminal FFAT motif and stabilizes the interaction of VAPB with SCAP. Ovariectomy abolishes the effect of T39 knockdown on the hepatic pRb/E2F1/Pnpla3 axis. In both sexes T39 knockdown reduces SCAP independently of pRb. In primary human hepatocytes, T39 knockdown reduces expression of PNPLA3 and other lipogenic genes in women but not men. CONCLUSIONS We have uncovered a conserved sexual dimorphism in the regulation of hepatic lipogenic genes, with effects of T39 mediated through pRb/E2F1 in females and VAPB/SCAP in both sexes. T39 inhibition could be a novel strategy to downregulate PNPLA3 and treat NAFLD in women. LAY SUMMARY In females, the protein TTC39B degrades a tumor suppressor in the liver to promote the synthesis of new fat and the expression of a major genetic risk factor for non-alcoholic fatty liver disease. TTC39B is a potential therapeutic target for non-alcoholic fatty liver disease, especially in women.
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Affiliation(s)
- Joanne Hsieh
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, NY, 10032, USA.
| | - Matthew M. Molusky
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, NY, 10032, USA
| | - Kristin M. McCabe
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, NY, 10032, USA
| | - Panagiotis Fotakis
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, NY, 10032, USA
| | - Tong Xiao
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, NY, 10032, USA
| | - Liana Tascau
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, NY, 10032, USA
| | - Lars Zeana-Schliep
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, NY, 10032, USA
| | | | - Alan R. Tall
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, NY, 10032, USA
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23
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Li D, Liu M, Li Z, Zheng G, Chen A, Zhao L, Yang P, Wei L, Chen Y, Ruan XZ. Sterol-resistant SCAP Overexpression in Vascular Smooth Muscle Cells Accelerates Atherosclerosis by Increasing Local Vascular Inflammation through Activation of the NLRP3 Inflammasome in Mice. Aging Dis 2021; 12:747-763. [PMID: 34094640 PMCID: PMC8139202 DOI: 10.14336/ad.2020.1120] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 11/20/2020] [Indexed: 12/01/2022] Open
Abstract
Atherosclerosis is a serious age-related pathology, and one of its hallmarks is the presence of chronic inflammation. Sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP) is a cholesterol sensor that plays an essential role in regulating intracellular cholesterol homeostasis. Accordingly, dysregulation of the SCAP-SREBP pathway has been reported to be closely associated with an increased risk of obesity, hypercholesterolemia, and cardiovascular disease. In this study, we explored whether sterol-resistant SCAP (D443N mutation) in vascular smooth muscle cells (VSMCs) of mice promotes vascular inflammation and accelerates the occurrence and progression of atherosclerosis. We established a transgenic knock-in mouse model of atherosclerosis with an activating D443N mutation at the sterol-sensing domain of SCAP (SCAPD443N) by microinjection. Next, SCAPD443N/ApoE-/- mice were generated by crossing SCAPD443N mice with apolipoprotein E-/- (ApoE-/-) background mice. We found that sterol-resistant SCAP markedly amplified and accelerated the progression of atherosclerotic plaques in SCAPD443N/ApoE-/- mice compared with that in control ApoE-/- mice. Similarly, in SCAPD443N mice, aortic atherosclerotic plaques both appeared earlier and were greater in number than that in control SCAP+/+ mice, both of which were fed a Western diet for 12 or 24 weeks. Moreover, we observed that sterol-resistant SCAP significantly increased local inflammation and induced endothelial dysfunction in the aortas of SCAPD443N mice and SCAPD443N/ApoE-/- mice. In vitro, we also found that sterol-resistant SCAP overexpression in VSMCs increased the release of inflammatory cytokines and induced endothelial cell injury when both cell types were cocultured. Furthermore, we demonstrated that sterol-resistant SCAP overexpression in VSMCs promoted SCAP and NLRP3 inflammasome cotranslocation to the Golgi and increased the activation of the NLRP3 inflammasome pathway. These findings suggested that sterol-resistant SCAP in VSMCs of mice induced vascular inflammation and endothelial dysfunction, consequently accelerating atherosclerosis by activating the NLRP3 inflammasome pathway.
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Affiliation(s)
- Danyang Li
- 1Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Mihua Liu
- 1Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Zhe Li
- 1Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Guo Zheng
- 1Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Amei Chen
- 1Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Lei Zhao
- 1Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Ping Yang
- 1Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Li Wei
- 1Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Yaxi Chen
- 1Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Xiong Z Ruan
- 1Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China.,2National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China.,3John Moorhead Research Laboratory, Centre for Nephrology, University College London Medical School, Royal Free Campus, University College London, London, United Kingdom
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Driesen RB, Gervois P, Vangansewinkel T, Lambrichts I. Unraveling the Role of the Apical Papilla During Dental Root Maturation. Front Cell Dev Biol 2021; 9:665600. [PMID: 34026757 PMCID: PMC8134663 DOI: 10.3389/fcell.2021.665600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/13/2021] [Indexed: 12/12/2022] Open
Abstract
The apical papilla is a stem cell rich tissue located at the base of the developing dental root and is responsible for the progressive elongation and maturation of the root. The multipotent stem cells of the apical papilla (SCAP) are extensively studied in cell culture since they demonstrate a high capacity for osteogenic, adipogenic, and chondrogenic differentiation and are thus an attractive stem cell source for stem cell-based therapies. Currently, only few studies are dedicated to determining the role of the apical papilla in dental root development. In this review, we will focus on the architecture of the apical papilla and describe the specific SCAP signaling pathways involved in root maturation. Furthermore, we will explore the heterogeneity of the SCAP phenotype within the tissue and determine their micro-environmental interaction. Understanding the mechanism of postnatal dental root growth could further aid in developing novel strategies in dental root regeneration.
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Affiliation(s)
- Ronald B Driesen
- Faculty of Medicine, Hasselt University, Biomedical Research Institute, Cardio and Organ Systems, Hasselt, Belgium
| | - Pascal Gervois
- Faculty of Medicine, Hasselt University, Biomedical Research Institute, Cardio and Organ Systems, Hasselt, Belgium
| | - Tim Vangansewinkel
- Faculty of Medicine, Hasselt University, Biomedical Research Institute, Cardio and Organ Systems, Hasselt, Belgium
| | - Ivo Lambrichts
- Faculty of Medicine, Hasselt University, Biomedical Research Institute, Cardio and Organ Systems, Hasselt, Belgium
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25
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Yi B, Ding T, Jiang S, Gong T, Chopra H, Sha O, Dissanayaka WL, Ge S, Zhang C. Conversion of stem cells from apical papilla into endothelial cells by small molecules and growth factors. Stem Cell Res Ther 2021; 12:266. [PMID: 33941255 PMCID: PMC8091697 DOI: 10.1186/s13287-021-02350-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 04/19/2021] [Indexed: 12/16/2022] Open
Abstract
Objectives Recently, a new strategy has been developed to directly reprogram one cell type towards another targeted cell type using small molecule compounds. Human fibroblasts have been chemically reprogrammed into neuronal cells, Schwann cells and cardiomyocyte-like cells by different small molecule combinations. This study aimed to explore whether stem cells from apical papilla (SCAP) could be reprogrammed into endothelial cells (ECs) using the same strategy. Materials and methods The expression level of endothelial-specific genes and proteins after chemical induction of SCAP was assessed by RT-PCR, western blotting, flow cytometry and immunofluorescence. The in vitro functions of SCAP-derived chemical-induced endothelial cells (SCAP-ECs) were evaluated by tube-like structure formation assay, acetylated low-density lipoprotein (ac-LDL) uptake and NO secretion detection. The proliferation and the migration ability of SCAP-ECs were evaluated by CCK-8 and Transwell assay. LPS stimulation was used to mimic the inflammatory environment in demonstrating the ability of SCAP-ECs to express adhesion molecules. The in vivo Matrigel plug angiogenesis assay was performed to assess the function of SCAP-ECs in generating vascular structures using the immune-deficient mouse model. Results SCAP-ECs expressed upregulated endothelial-specific genes and proteins; displayed endothelial transcriptional networks; exhibited the ability to form functional tubular-like structures, uptake ac-LDL and secrete NO in vitro; and contributed to generate blood vessels in vivo. The SCAP-ECs could also express adhesion molecules in the pro-inflammatory environment and have a similar migration and proliferation ability as HUVECs. Conclusions Our study demonstrates that the set of small molecules and growth factors could significantly promote endothelial transdifferentiation of SCAP, which provides a promising candidate cell source for vascular engineering and treatment of ischemic diseases. Supplementary Information The online version contains supplementary material available at 10.1186/s13287-021-02350-5.
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Affiliation(s)
- Baicheng Yi
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region, China.,Shenzhen Institute of Research and Innovation, The University of Hong Kong, Shenzhen, China
| | - Tian Ding
- Department of Periodontology, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University; Shandong Key Laboratory of Oral Tissue Regeneration; Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, No.44-1 Wenhua Road West, Jinan, Shandong, China
| | - Shan Jiang
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Ting Gong
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Hitesh Chopra
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Ou Sha
- School of Dentistry, Shenzhen University Health Science Center, Shenzhen, China
| | - Waruna Lakmal Dissanayaka
- Applied Oral Sciences & Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Shaohua Ge
- Department of Periodontology, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University; Shandong Key Laboratory of Oral Tissue Regeneration; Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, No.44-1 Wenhua Road West, Jinan, Shandong, China.
| | - Chengfei Zhang
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region, China. .,Shenzhen Institute of Research and Innovation, The University of Hong Kong, Shenzhen, China.
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Rakhimova O, Schmidt A, Landström M, Johansson A, Kelk P, Romani Vestman N. Cytokine Secretion, Viability, and Real-Time Proliferation of Apical-Papilla Stem Cells Upon Exposure to Oral Bacteria. Front Cell Infect Microbiol 2021; 10:620801. [PMID: 33718256 PMCID: PMC7945949 DOI: 10.3389/fcimb.2020.620801] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 12/31/2020] [Indexed: 01/09/2023] Open
Abstract
The use of stem cells from the apical papilla (SCAPs) has been proposed as a means of promoting root maturation in permanent immature teeth, and plays a significant role in regenerative dental procedures. However, the role of SCAPs may be compromised by microenvironmental factors, such as hypoxic conditions and the presence of bacteria from infected dental root canals. We aim to investigate oral bacterial modulation of SCAP in terms of binding capacity using flow cytometry and imaging, real-time cell proliferation monitoring, and cytokine secretion (IL-6, IL-8, and TGF-β isoforms) under anaerobic conditions. SCAPs were exposed to key species in dental root canal infection, namely Actinomyces gerensceriae, Slackia exigua, Fusobacterium nucleatum, and Enterococcus faecalis, as well as two probiotic strains, Lactobacillus gasseri strain B6 and Lactobacillus reuteri (DSM 17938). We found that A. gerensceriae, S. exigua, F. nucleatum, and E. faecalis, but not the Lactobacillus probiotic strains bind to SCAPs on anaerobic conditions. Enterococcus faecalis and F. nucleatum exhibited the strongest binding capacity, resulting in significantly reduced SCAP proliferation. Notably, F. nucleatum, but not E. faecalis, induce production of the proinflammatory chemokine IL-8 and IL-10 from SCAPs. Production of TGF-β1 and TGF-β2 by SCAPs was dependent on species, cell line, and time, but secretion of TGF-β3 did not vary significantly over time. In conclusion, SCAP response is compromised when exposed to bacterial stimuli from infected dental root canals in anaerobic conditions. Thus, stem cell-mediated endodontic regenerative studies need to include microenvironmental conditions, such as the presence of microorganisms to promote further advantage in the field.
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Affiliation(s)
| | - Alexej Schmidt
- Department of Medical Biosciences, Pathology, Umeå University, Umeå, Sweden
| | - Maréne Landström
- Department of Medical Biosciences, Pathology, Umeå University, Umeå, Sweden
| | | | - Peyman Kelk
- Section for Anatomy, Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
| | - Nelly Romani Vestman
- Department of Endodontics, County Council of Västerbotten, Umeå, Sweden.,Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
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Li Z, Li D, Rao Y, Wei L, Liu M, Zheng G, Yao Y, Hou X, Chen Y, Ruan XZ. SCAP knockout in SM22α-Cre mice induces defective angiogenesis in the placental labyrinth. Biomed Pharmacother 2021; 133:111011. [PMID: 33227706 DOI: 10.1016/j.biopha.2020.111011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/04/2020] [Accepted: 11/09/2020] [Indexed: 12/12/2022] Open
Abstract
The placental labyrinth is important for the exchange of nutrients and gases between the mother and the embryo in mice. This interface contains cells of both trophoblast and allantoic mesodermal origin that together produce maternal blood sinuses and placental blood vessels. However, the molecular mechanisms that take place during process of placental labyrinth development, especially concerning fetal capillaries, are not well understood. SREBP cleavage-activating protein (SCAP), a membrane protein, is required for the synthesis of fatty acids and cholesterol. Recently, when we crossed the offspring of the cross between smooth muscle 22 alpha (SM22α)- Cre recombinase (Cre) mice and SCAPloxp/loxp mice to research the function of SCAP in vascular smooth muscle cells (VSMCs) during certain pathological processes, we found that there were no resultant SM22α-Cre-specific SCAP knockout (KO) pups (SM22α-Cre+SCAPflox/flox; hereafter referred to as SCAP KO). Through anatomic studies of these embryos and placentas, we found that SCAP KO resulted in defective placental vessels and abnormal fetal morphology. Further immunohistochemical and immunocytochemical analyses suggested that SCAP is knocked out in the pericytes of the placental labyrinth. Compared to wildtype mice, SCAP KO placentas had abnormal vasculature in the labyrinth and lower levels of angiogenesis. By using RNA-seq and western blotting, we found that the expression of some genes and proteins in SCAP KO placentas was changed, including those related to pericyte/endothelial interactions genes and angiogenesis. Our results suggest that the proper organizational structure of the placental labyrinth depends on SCAP expression in pericytes.
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Affiliation(s)
- Zhe Li
- Centre for Lipid Research, Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Danyang Li
- Centre for Lipid Research, Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Yuhan Rao
- Centre for Lipid Research, Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Li Wei
- Centre for Lipid Research, Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Mihua Liu
- Centre for Lipid Research, Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Guo Zheng
- Centre for Lipid Research, Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Yingcheng Yao
- Centre for Lipid Research, Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Xiaoli Hou
- Centre for Lipid Research, Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Yaxi Chen
- Centre for Lipid Research, Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China.
| | - Xiong Z Ruan
- Centre for Lipid Research, Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China; National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China; John Moorhead Research Laboratory, Centre for Nephrology, University College London Medical School, Royal Free Campus, University College London, London, United Kingdom.
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Charles KN, Shackelford JE, Faust PL, Fliesler SJ, Stangl H, Kovacs WJ. Functional Peroxisomes Are Essential for Efficient Cholesterol Sensing and Synthesis. Front Cell Dev Biol 2020; 8:560266. [PMID: 33240873 PMCID: PMC7677142 DOI: 10.3389/fcell.2020.560266] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 09/22/2020] [Indexed: 01/14/2023] Open
Abstract
Cholesterol biosynthesis is a multi-step process involving several subcellular compartments, including peroxisomes. Cells adjust their sterol content by both transcriptional and post-transcriptional feedback regulation, for which sterol regulatory element-binding proteins (SREBPs) are essential; such homeostasis is dysregulated in peroxisome-deficient Pex2 knockout mice. Here, we compared the regulation of cholesterol biosynthesis in Chinese hamster ovary (CHO-K1) cells and in three isogenic peroxisome-deficient CHO cell lines harboring Pex2 gene mutations. Peroxisome deficiency activated expression of cholesterogenic genes, however, cholesterol levels were unchanged. 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) protein levels were increased in mutant cells, whereas HMGCR activity was significantly decreased, resulting in reduced cholesterol synthesis. U18666A, an inhibitor of lysosomal cholesterol export, induced cholesterol biosynthetic enzymes; yet, cholesterol synthesis was still reduced. Interestingly, peroxisome deficiency promoted ER-to-Golgi SREBP cleavage-activating protein (SCAP) trafficking even when cells were cholesterol-loaded. Restoration of functional peroxisomes normalized regulation of cholesterol synthesis and SCAP trafficking. These results highlight the importance of functional peroxisomes for maintaining cholesterol homeostasis and efficient cholesterol synthesis.
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Affiliation(s)
- Khanichi N Charles
- Department of Biology, San Diego State University, San Diego, CA, United States
| | - Janis E Shackelford
- Department of Biology, San Diego State University, San Diego, CA, United States
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States
| | - Steven J Fliesler
- Departments of Ophthalmology and Biochemistry and Gradate Program in Neuroscience, University at Buffalo-The State University of New York (SUNY), Buffalo, NY, United States.,Research Service, Veterans Administration Western New York Healthcare System, Buffalo, NY, United States
| | - Herbert Stangl
- Department of Medical Chemistry, Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria
| | - Werner J Kovacs
- Institute of Molecular Health Sciences, ETH Zurich, Zurich, Switzerland
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Queiroz A, Wada MT, Rosin FCP, Pelissari C, Trierveiler M. Effects of serum-free culture media on human apical papilla cells properties. Arch Oral Biol 2020; 121:104962. [PMID: 33171394 DOI: 10.1016/j.archoralbio.2020.104962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/11/2020] [Accepted: 10/19/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVE Aiming at more effective and safer cell therapies, the objective of this study was to evaluate the biological properties of human apical papilla cells cultured in the absence of serum supplementation in comparison to cells cultured with fetal bovine serum (FBS). DESIGN Two apical papilla cell populations were isolated from third molars with incomplete rhizogenesis, and cultured in four different media: minimum essential Eagle medium - alpha modification (alpha-MEM); alpha-MEM supplemented with FBS (alpha-MEM + FBS); Dulbecco's modified Eagle medium/nutrient mixture F-12 (DMEM/F12); and DMEM/F12 supplemented with FBS (DMEM/F12 + FBS). We evaluated their proliferation, clonogenicity, and in vitro osteogenic and chondrogenic differentiation potential. RESULTS Apical papilla cells cultured in DMEM/F12 + FBS and alpha-MEM + FBS were more proliferative than those grown in serum-free media, and also exhibited greater efficiency in colony cell formation. Despite this, all study groups showed immunostaining for the marker of mitosis anti-PHH3. Also, alpha-MEM + FBS, alpha-MEM, and DMEM/F12 + FBS exhibited higher amount of mineralized deposits in vitro than DMEM/F12, while only cells cultured with FBS were able to form spheres in chondrogenic differentiation assay. CONCLUSIONS Our results showed that, although the cultivation of apical papilla cells in a serum-free medium has reduced the properties of cell proliferation and differentiation, these cells are still capable of maintaining their desirable characteristics.
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Affiliation(s)
- Aline Queiroz
- Laboratory of Stem Cell Biology in Dentistry - LABITRON, Oral and Maxillofacial Pathology Department, School of Dentistry, University of São Paulo, Av Professor Lineu Prestes, 2227, 05508-000, São Paulo, SP, Brazil.
| | - Mariana Taira Wada
- Laboratory of Stem Cell Biology in Dentistry - LABITRON, Oral and Maxillofacial Pathology Department, School of Dentistry, University of São Paulo, Av Professor Lineu Prestes, 2227, 05508-000, São Paulo, SP, Brazil.
| | - Flávia Cristina Perillo Rosin
- General Pathology Department, School of Dentistry, University of São Paulo, Av Professor Lineu Prestes, 2227, 05508-000, São Paulo, SP, Brazil.
| | - Cibele Pelissari
- Laboratory of Stem Cell Biology in Dentistry - LABITRON, Oral and Maxillofacial Pathology Department, School of Dentistry, University of São Paulo, Av Professor Lineu Prestes, 2227, 05508-000, São Paulo, SP, Brazil.
| | - Marília Trierveiler
- Laboratory of Stem Cell Biology in Dentistry - LABITRON, Oral and Maxillofacial Pathology Department, School of Dentistry, University of São Paulo, Av Professor Lineu Prestes, 2227, 05508-000, São Paulo, SP, Brazil.
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30
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Dong G, Huang X, Jiang S, Ni L, Ma L, Zhu C, Chen S. SCAP Mediated GDF15-Induced Invasion and EMT of Esophageal Cancer. Front Oncol 2020; 10:564785. [PMID: 33123476 PMCID: PMC7573169 DOI: 10.3389/fonc.2020.564785] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 09/01/2020] [Indexed: 11/24/2022] Open
Abstract
Background: GDF15 is a potential biomarker for patients with esophageal cancer (EC). However, the mechanistic role of GDF15 in the invasion and metastasis of EC remains poorly understood. Methods: We determined the expression and function of GDF15 in esophageal cancer cells (ESCCs) and in patient tissue samples using western blotting, migration, and invasion assays, immunohistochemistry, Co-IP assays, and quantitative real-time-PCR. In addition, a pulmonary metastatic nude mouse model was used to determine the function of GDF15. We then supplemented our experimental results with database analysis to validate our findings. Results: GDF15 was upregulated in EC, and was associated with poor differentiation, high metastasis rates, and worse prognosis. GDF15 knock-down reduced the migration and invasion of ESCCs. Co-IP assays demonstrated its association with SCAP, while GDF15 knock-down decreased SCAP levels. SCAP overexpression reversed the migration, invasion and EMT in GDF15-siRNA ESCCs. However, after incubation with β-cyclodextrin (β-CD), the ability of migration and invasion was weakened, EMT was reversed again. Migration, invasion, and EMT were enhanced in GDF15-siRNA ESCCs cultured in the presence of cholesterol and were similar to GDF15-siRNA ESCCs overexpressing SCAP. In vivo, knockdown of GDF15 inhibited lung metastasis of ESCCs and was reversed by SCAP overexpression or high cholesterol diet. Increased lung metastasis after SCAP overexpression was partially suppressed by intraperitoneal injection of β-CD. In addition, we determined that GDF15 was a direct target of miR-1324, miR-1324 was down-regulated in EC tissues. MiR-1324 upregulation resulted in decreased GDF15 expression and metastasis in ESCCs. Conclusions: We demonstrated that SCAP mediated GDF15-induced the invasion and metastasis of EC by regulating cholesterol metabolism. In addition, GDF15 was shown to be a direct target of miR-1324.
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Affiliation(s)
- Gang Dong
- Department of Gastroenterology and Hepatology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xiaoquan Huang
- Department of Gastroenterology and Hepatology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Siyu Jiang
- Department of Gastroenterology and Hepatology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Liyuan Ni
- Department of Gastroenterology and Hepatology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Lili Ma
- Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Chouwen Zhu
- Department of Gastroenterology and Hepatology, Zhongshan Hospital, Fudan University, Shanghai, China.,Center of Evidence-Based Medicine, Fudan University, Shanghai, China
| | - Shiyao Chen
- Department of Gastroenterology and Hepatology, Zhongshan Hospital, Fudan University, Shanghai, China.,Endoscopy Center and Endoscopy Research Institute, Zhongshan Hospital, Fudan University, Shanghai, China.,Center of Evidence-Based Medicine, Fudan University, Shanghai, China
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31
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Lei T, Zhang X, Chen P, Li Q, Du H. Proteomic profile of human dental follicle stem cells and apical papilla stem cells. J Proteomics 2020; 231:103928. [PMID: 32800794 DOI: 10.1016/j.jprot.2020.103928] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 07/30/2020] [Indexed: 12/17/2022]
Abstract
Dental stem cells have great potential in clinical practice as an adult mesenchymal stem cell, such as dental follicle and the apical papilla, have strong proliferation and differentiation characteristics. The developmental relevance and discrimination of them in the niche is not clear, which limits their application scenarios. The aim of this study was to investigate the intrinsical differences in cellular contents of DFSCs and SCAP by Tandem mass tag (TMT) labeling quantitative proteomics. Cell lysates were labeled and tracked by the combined use of TMT and LC-MS/MS. A total of 1622 proteins were detected, of which 421 were different and 12 were significantly up-regulated and 4 were significantly down-regulated. The results of proteomics support the application of stem cells in the treatment of neurodegenerative diseases such as Huntington's disease, Alzheimer's disease, Parkinson's disease and so on. The difference is related to cell proliferation and protection of neurons from inflammation and autophagy damage. Highly expressed proteins predict the special ability of DFSCs to stably proliferate and differentiate through CD13, MARCKS, and PAST1. The strong immune stability of SCAP is supported by NPC1.This study expands our understanding on the molecular mechanisms of tooth development and regeneration, and provide basic support for dental stem cells in clinical applications such as neurological and immune diseases.
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Affiliation(s)
- Tong Lei
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, 112 Lab, Beijing 100083, China
| | - Xiaoshuang Zhang
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, 112 Lab, Beijing 100083, China
| | - Peng Chen
- Beijing Key Laboratory of Traditional Chinese Medicine Basic Research on Prevention and Treatment for Major Diseases, Experimental Research Center, China Academy of Chinese Medical Sciences, Dongcheng District, Beijing 100700, China
| | - Qihong Li
- Department of Stomatology, the Fifth Medical Centre, Chinese PLA General Hospital, Former 307th Hospital of the PLA, Dongda Street, Beijing 100071, China.
| | - Hongwu Du
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, 112 Lab, Beijing 100083, China.
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32
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van den Boomen DJH, Volkmar N, Lehner PJ. Ubiquitin-mediated regulation of sterol homeostasis. Curr Opin Cell Biol 2020; 65:103-111. [PMID: 32580085 DOI: 10.1016/j.ceb.2020.04.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 04/03/2020] [Accepted: 04/26/2020] [Indexed: 11/19/2022]
Abstract
Cholesterol is an essential component of mammalian membranes, and its homeostasis is strictly regulated, with imbalances causing atherosclerosis, Niemann Pick disease, and familial hypercholesterolemia. Cellular cholesterol supply is mediated by LDL-cholesterol import and de novo cholesterol biosynthesis, and both pathways are adjusted to cellular demand by the cholesterol-sensitive SREBP2 transcription factor. Cholesterol homeostasis is modulated by a wide variety of metabolic pathways and the ubiquitination machinery, in particular E3 ubiquitin ligases. In this article, we review recent progress in understanding the role of E3 ubiquitin ligases in the metabolic control of cellular sterol homeostasis.
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Affiliation(s)
- Dick J H van den Boomen
- Cambridge Institute of Therapeutic Immunology & Infectious Disease, University of Cambridge, Cambridge, United Kingdom
| | - Norbert Volkmar
- Cambridge Institute of Therapeutic Immunology & Infectious Disease, University of Cambridge, Cambridge, United Kingdom
| | - Paul J Lehner
- Cambridge Institute of Therapeutic Immunology & Infectious Disease, University of Cambridge, Cambridge, United Kingdom.
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33
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Zheng ZG, Zhu ST, Cheng HM, Zhang X, Cheng G, Thu PM, Wang SP, Li HJ, Ding M, Qiang L, Chen XW, Zhong Q, Li P, Xu X. Discovery of a potent SCAP degrader that ameliorates HFD-induced obesity, hyperlipidemia and insulin resistance via an autophagy-independent lysosomal pathway. Autophagy 2020; 17:1592-1613. [PMID: 32432943 DOI: 10.1080/15548627.2020.1757955] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
SCAP (SREBF chaperone) regulates SREBFs (sterol regulatory element binding transcription factors) processing and stability, and, thus, becomes an emerging drug target to treat dyslipidemia and fatty liver disease. However, the current known SCAP inhibitors, such as oxysterols, induce endoplasmic reticulum (ER) stress and NR1H3/LXRα (nuclear receptor subfamily 1 group H member 3)-SREBF1/SREBP-1 c-mediated hepatic steatosis, which severely limited the clinical application of this inhibitor. In this study, we identified a small molecule, lycorine, which binds to SCAP, which suppressed the SREBF pathway without inducing ER stress or activating NR1H3. Mechanistically, lycorine promotes SCAP lysosomal degradation in a macroautophagy/autophagy-independent pathway, a mechanism completely distinct from current SCAP inhibitors. Furthermore, we determined that SQSTM1 captured SCAP after its exit from the ER. The interaction of SCAP and SQSTM1 requires the WD40 domain of SCAP and the TB domain of SQSTM1. Interestingly, lycorine triggers the lysosome translocation of SCAP independent of autophagy. We termed this novel protein degradation pathway as the SQSTM1-mediated autophagy-independent lysosomal degradation (SMAILD) pathway. In vivo, lycorine ameliorates high-fat diet-induced hyperlipidemia, hepatic steatosis, and insulin resistance in mice. Our study demonstrated that the inhibition of SCAP through the SMAILD pathway could be employed as a useful therapeutic strategy for treating metabolic diseases.Abbreviation: 25-OHD: 25-hydroxyvitamin D; 3-MA: 3-methyladenine; ABCG5: ATP binding cassette subfamily G member 5; ABCG8: ATP binding cassette subfamily G member 8; ACACA: acetyl-CoA carboxylase alpha; AEBSF: 4-(2-aminoethyl) benzenesulfonyl fluoride hydrochloride; AHI: anhydroicaritin; AKT/protein kinase B: AKT serine/threonine kinase; APOE: apolipoprotein E; ATF6: activating transcription factor 6; ATG: autophagy-related; BAT: brown adipose tissue; CD274/PD-L1: CD274 molecule; CETSA: cellular thermal shift assay; CMA: chaperone-mediated autophagy; COPII: cytoplasmic coat protein complex-II; CQ: chloroquine; DDIT3/CHOP: DNA damage inducible transcript 3; DNL: de novo lipogenesis; EE: energy expenditure; EGFR: epithelial growth factor receptor; eMI: endosomal microautophagy; ERN1/IRE1α: endoplasmic reticulum to nucleus signaling 1; FADS2: fatty acid desaturase 2; FASN: fatty acid synthase; GOT1/AST: glutamic-oxaloacetic transaminase 1; GPT/ALT: glutamic-pyruvate transaminase; HMGCR: 3-hydroxy-3-methylglutaryl-CoA reductase; HMGCS1: 3-hydroxy-3-methylglutaryl-CoA synthase 1; HSP90B1/GRP94: heat shock protein 90 beta family member 1; HSPA5/GRP78: heat hock protein family A (Hsp70) member 5; HSPA8/HSC70: heat shock protein family A (Hsp70) member 8; INSIG1: insulin induced gene 1; LAMP2A: lysosomal associated membrane protein 2A; LDLR: low density lipoprotein receptor; LyTACs: lysosome targeting chimeras; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MBTPS1: membrane bound transcription factor peptidase, site 1; MEF: mouse embryonic fibroblast; MST: microscale thermophoresis; MTOR: mechanistic target of rapamycin kinase; MVK: mevalonate kinase; PROTAC: proteolysis targeting chimera; RQ: respiratory quotient; SCAP: SREBF chaperone; SCD1: stearoyl-coenzemy A desaturase 1; SMAILD: sequestosome 1 mediated autophagy-independent lysosomal degradation; SQSTM1: sequestosome 1; SREBF: sterol regulatory element binding transcription factor; TNFRSF10B/DR5: TNF receptor superfamily member 10b; TRAF6: TNF receptor associated factor 6; UPR: unfolded protein response; WAT: white adipose tissue; XBP1: X-box binding protein 1.
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Affiliation(s)
- Zu-Guo Zheng
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Si-Tong Zhu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China.,Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Hui-Min Cheng
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Xin Zhang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Gang Cheng
- Beijing Kanglisheng Pharmaceutical Technology Development Co., Ltd, Beijing, China
| | - Pyone Myat Thu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China
| | | | - Hui-Jun Li
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Ming Ding
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Lei Qiang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Xiao-Wei Chen
- State Key Laboratory of Membrane Biology, Center for Life Sciences, Institute of Molecular Medicine, Peking University, Beijing, China
| | - Qing Zhong
- School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Ping Li
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Xiaojun Xu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China.,Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, China Pharmaceutical University, Nanjing, Jiangsu, China
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Teixeira GR, Mendes LO, Veras ASC, Thorpe HHA, Fávaro WJ, de Almeida Chuffa LG, Pinheiro PFF, Martinez FE. Physical resistance training-induced changes in lipids metabolism pathways and apoptosis in prostate. Lipids Health Dis 2020; 19:14. [PMID: 31996229 PMCID: PMC6990525 DOI: 10.1186/s12944-020-1195-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 01/15/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Altered lipid metabolism is an important characteristic of neoplastic cells, with androgens and growth factors being major regulatory agents of the lipid metabolism process. We investigated the effect of physical resistance training on lipid metabolism and apoptosis in the adult Wistar rat prostate. METHODS Two experimental groups represented sedentary and physical resistance training. Three days per week for 13 weeks, rats performed jumps in water carrying a weight load strapped to their chests as part of a physical resistance exercise protocol. Two days after the last training session, rats were anesthetized and sacrificed for blood and prostate analysis. RESULTS Physical exercise improved feeding efficiency, decreased weight gain, regulated the serum-lipid profile, and modulated insulin-like growth factor-1 (IGF-1) and free testosterone concentration. Furthermore, upregulation of cluster of differentiation 36 (CD36), sterol regulatory element binding protein-1 (SREBP-1), sterol regulatory element-binding protein cleavage-activating protein (SCAP), and reduced lysosome membrane protein (LIMPII) expression were also observed in the blood and prostates of trained rats. Consistent with these results, caspase-3 expression was upregulating and the BCL-2/Bax index ratio was decreased in trained rats relative to sedentary animals. CONCLUSIONS In this work, physical resistance training can alter lipid metabolism and increase markers of apoptosis in the prostate, suggesting physical resistance training as a potential novel therapeutic strategy for treating prostate cancer.
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Affiliation(s)
- Giovana Rampazzo Teixeira
- Department of Physiotherapy, School of Technology and Sciences, UNESP, campus of Presidente Prudente, São Paulo, SP, Brazil.
- Postgraduate Program in Movement Sciences, Sao Paulo State University-UNESP, Presidente Prudente, SP, Brazil.
- Multicenter Graduate Program in Physiological Sciences, SBFis, São Paulo State University (UNESP), Araçatuba, SP, Brazil.
| | - Leonardo Oliveira Mendes
- Postgraduate Program in Animal Science and Postgraduate Program in Health Sciences University of Western São Paulo-UNOESTE, Presidente Prudente, SP, Brazil
| | - Allice Santos Cruz Veras
- Postgraduate Program in Movement Sciences, Sao Paulo State University-UNESP, Presidente Prudente, SP, Brazil
| | | | - Wagner José Fávaro
- Department of Structural and Functional Biology, State University of Campinas - UNICAMP, Institute of Biology, Campinas, SP, Brazil
| | | | | | - Francisco Eduardo Martinez
- Department of Anatomy, São Paulo State University, UNESP - Institute of Biosciences, Botucatu, SP, Brazil
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Han L, Pang K, Li XL, Loor JJ, Yang GY, Gao T. Lipidomic profiling analysis of the phospholipid molecules in SCAP-induced lipid droplet formation in bovine mammary epithelial cells. Prostaglandins Other Lipid Mediat 2020; 149:106420. [PMID: 31953015 DOI: 10.1016/j.prostaglandins.2020.106420] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 12/15/2019] [Accepted: 01/10/2020] [Indexed: 12/12/2022]
Abstract
The accumulation of lipid droplets (LDs) in the cytoplasm plays an important role in energy balance, membrane synthesis and cell signal transduction. The aim of this study was to investigate the profile of phospholipids after SCAP-induced LD formation in bovine mammary epithelial cells (BMECs). A shRNA-SCAP vector and a SCAP/SREBP vector were used to knock down and overexpress the SCAP gene in BMECs prior to evaluating the effects on LDs using Western blotting, real-time PCR, LD staining and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The average LD diameter was determined following oil red O staining. The overexpression of SCAP increased the abundance of SCD, ACACA and FASN genes and nuclear SREBP1a. In contrast, knocking down SCAP decreased the abundance of the nuclear SREBP1a protein and downregulated the abundance of target genes. Lipid droplet staining revealed that knocking down SCAP reduced LD formation and average LD diameter. In contrast, overexpression of SCAP increased the formation and size of the LDs. The results from an analysis of cellular lipids revealed that phospholipids are the predominant species in the profile of cell lipids. phosphatidylethanolamine (PE) and phosphatidylcholine (PC) are important for determining the size of LDs. The LD formation induced by SCAP gene overexpression and knockdown underscored the role of phospholipids involved in lipid droplet formation and fusion.
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Liu Y, Hua W, Li Y, Xian X, Zhao Z, Liu C, Zou J, Li J, Fang X, Zhu Y. Berberine suppresses colon cancer cell proliferation by inhibiting the SCAP/SREBP-1 signaling pathway-mediated lipogenesis. Biochem Pharmacol 2019; 174:113776. [PMID: 31874145 DOI: 10.1016/j.bcp.2019.113776] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 12/19/2019] [Indexed: 02/07/2023]
Abstract
Lipid metabolism is a significant section of energy homeostasis, and it affects the development of various cancers. Previous studies have revealed that berberine has strong anticancer and blood lipid-lowering effects. Here, we further investigated the effects of berberine on cell proliferation and lipogenesis in colon cancer cells and the relationship between the two effects. We found that berberine inhibited cell proliferation by inducing G0/G1 phase cell cycle arrest in colon cancer cells. Moreover, the expressions of key lipogenic enzymes were down-regulated by berberine and led to the suppressed lipid synthesis, which was linked to cell proliferation via Wnt/β-catenin pathway. Importantly, berberine inhibited sterol regulatory element-binding protein-1 (SREBP-1) activation and SREBP cleavage-activating protein (SCAP) expression, resulting in the downregulation of these lipogenic enzymes. Knockdown of SCAP by shRNA could abolish the effect of berberine on SREBP-1 activation. Besides the inhibitory effects in vitro, berberine suppressed the growth and lipogenesis of colon cancer xenograft in a SCAP-dependent manner as well. Together, our results suggest that berberine may serve as a candidate against tumor growth of colon cancer partially through targeting SCAP/SREBP-1 pathway driving lipogenesis.
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Affiliation(s)
- Yunxin Liu
- Department of Pharmacy, Nanjing First Hospital, Nanjing Medical University, Nanjing 210029, PR China; School of Basic Medicine & Clinical Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China
| | - Weiwei Hua
- School of Basic Medicine & Clinical Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China; Department of Pharmacy, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing 210042, PR China
| | - Yao Li
- School of Basic Medicine & Clinical Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China
| | - Xirui Xian
- School of Basic Medicine & Clinical Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China
| | - Zheng Zhao
- Department of Pharmacy, Nanjing First Hospital, Nanjing Medical University, Nanjing 210029, PR China; School of Basic Medicine & Clinical Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China
| | - Chao Liu
- Department of Pharmacy, Nanjing First Hospital, Nanjing Medical University, Nanjing 210029, PR China; School of Basic Medicine & Clinical Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China
| | - Jianjun Zou
- Department of Pharmacy, Nanjing First Hospital, Nanjing Medical University, Nanjing 210029, PR China; School of Basic Medicine & Clinical Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China
| | - Jun Li
- Department of Pharmacy, Nanjing First Hospital, Nanjing Medical University, Nanjing 210029, PR China; School of Basic Medicine & Clinical Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China
| | - Xianjun Fang
- Department of Pharmacy, The First Affiliated Hospital of Anhui Medical University, Hefei 230022, PR China.
| | - Yubing Zhu
- Department of Pharmacy, Nanjing First Hospital, Nanjing Medical University, Nanjing 210029, PR China; School of Basic Medicine & Clinical Pharmacy, China Pharmaceutical University, Nanjing 211198, PR China.
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Hadjichristou C, Papachristou E, Bonovolias I, Bakopoulou A. Three-dimensional tissue engineering-based Dentin/Pulp tissue analogue as advanced biocompatibility evaluation tool of dental restorative materials. Dent Mater 2019; 36:229-248. [PMID: 31791732 DOI: 10.1016/j.dental.2019.11.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 11/04/2019] [Accepted: 11/15/2019] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Two-dimensional (2D) in vitro models have been extensively utilized for cytotoxicity assessment of dental materials, but with certain limitations in terms of direct in vitro-in vivo extrapolation (IVIVE). Three-dimensional (3D) models seem more appropriate, recapitulating the structure of human tissues. This study established a 3D dentin/pulp analogue, as advanced cytotoxicity assessment tool of dental restorative materials (DentCytoTool). METHODS DentCytoTool comprised two compartments: the upper, representing the dentin component, with a layer of odontoblast-like cells expanded on microporous membrane of a cell culture insert and covered by a treated dentin matrix; and the lower, representing a pulp analogue, incorporating HUVEC/SCAP co-cultures into collagen I/fibrin hydrogels. Representative resinous monomers (HEMA: 1-8mM; TEGDMA: 0.5-5mM) and bacterial components (LPS: 1μg/ml) were applied into the construct. Cytotoxicity was assessed by MTT and LDH assays, live/dead staining and real-time PCR for odontogenesis- and angiogenesis-related markers. RESULTS DentCytoTool supported cell viability and promoted capillary-like network formation inside the pulp analogue. LPS induced expression of odontogenesis-related markers (RUNX2, ALP, DSPP) without compromising viability of the odontoblast-like cells, while co-treatment with LPS and resin monomers induced cytotoxic effects (live/dead staining, MTT and LDH assays) in cells of both upper and lower compartments and reduced expression angiogenesis-related markers (VEGF, VEGFR2, ANGPT-1, Tie-2, PECAM-1) in a concentration- and time- dependent manner. LPS treatment aggravated TEGDMA-induced and -in certain concentrations (2-4mM)- HEMA-induced cytotoxicity. SIGNIFICANCE DentCytoTool represents a promising tissue-engineering-based cytotoxicity assessment tool, providing more insight into the mechanistic aspects of interactions of dental materials to the dentin/pulp complex.
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Affiliation(s)
- Christina Hadjichristou
- Department of Prosthodontics, School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th), GR-54124 Thessaloniki, Greece
| | - Eleni Papachristou
- Department of Prosthodontics, School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th), GR-54124 Thessaloniki, Greece
| | - Ioannis Bonovolias
- Department of Prosthodontics, School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th), GR-54124 Thessaloniki, Greece
| | - Athina Bakopoulou
- Department of Prosthodontics, School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th), GR-54124 Thessaloniki, Greece.
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Guo D, Wang Y, Wang J, Song L, Wang Z, Mao B, Tan N. RA-XII Suppresses the Development and Growth of Liver Cancer by Inhibition of Lipogenesis via SCAP-dependent SREBP Supression. Molecules 2019; 24:E1829. [PMID: 31083642 DOI: 10.3390/molecules24091829] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 04/29/2019] [Accepted: 05/01/2019] [Indexed: 12/23/2022] Open
Abstract
Lipogenesis plays a critical role in the growth and metastasis of tumors, which is becoming an attractive target for anti-tumor drugs. RA-XII, one of the cyclopeptide glycosides isolated from Rubia yunnanensis, exerts anti-tumor effects on liver cancer. However, the underlying mechanisms are not clear. In the present study, the effects of RA-XII on lipogenesis were evaluated and the underlying mechanisms were investigated. The results indicated that RA-XII strongly inhibited tumor growth and lipogenesis (triglycerides and lipid droplets) in HepG2 cells, and the expression of key factors involved in lipogenesis (SREBP, SCD, FASN) was also obviously downregulated. Further investigation showed that the anti-tumor effects of RA-XII were attenuated by SREBP knockdown. Moreover, RA-XII downregulated the expression of SREBP cleavage-activating protein (SCAP), an upstream regulator of SREBP, and siRNA of SCAP prevented its restrained effects on tumor growth and lipogenesis. In addition, the in vivo experiment showed that RA-XII strongly restrained the lipogenesis and growth of liver tumor in nude mice xenograft model. Taken together, these results indicate that RA-XII suppresses the liver cancer growth by inhibition of lipogenesis via SCAP-dependent SREBP suppression. The findings reveal the potentials of RA-XII to be used in a novel therapeutic approach for treating liver cancer.
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Zhao Z, Zhong L, He K, Qiu C, Li Z, Zhao L, Gong J. Cholesterol attenuated the progression of DEN-induced hepatocellular carcinoma via inhibiting SCAP mediated fatty acid de novo synthesis. Biochem Biophys Res Commun 2019; 509:855-861. [PMID: 30638930 DOI: 10.1016/j.bbrc.2018.12.181] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 12/29/2018] [Indexed: 01/06/2023]
Abstract
Worldwide, hepatocellular carcinoma (HCC) remains a top instigator of cancer mortality. Previous clinical studies have revealed that low serum cholesterol predicts a poor outcome in HCC patients, but the potential role of cholesterol in the progression of HCC remains controversial. In the present study,we tested the influence of cholesterol on the progression of DEN-induced HCC by feeding mice with a high cholesterol diet (HCD) and by depriving cholesterol with atorvastatin, a widely used inhibitor of the mevalonate pathway. We found that HCD induced more and larger liver tumors and an increased occurrence of lung metastasis in DEN-injected mice. These effects could be prevented by cholesterol deprivation with atorvastatin. In vitro, cholesterol loading repressed the proliferation, migration, and the invasion of SK hep1 cells, which was additionally prevented by cholesterol deprivation. Both in vivo and in vitro, cholesterol loading decreased the expression of Sterol regulatory element-binding protein cleavage-activating protein (SCAP), the translocation of sterol regulatory element-binding protein1 (SREBP1) to the nucleolus, and the genetic expression of FAS and ACC-1. Over-expression of SCAP in cholesterol-loaded SK hep1 cells promoted the nuclear translocation of SREBP1 and the expression of FAS and ACC-1, which promoted the proliferation, migration, and the invasion of SK hep1 cells. Knockdown of SCAP also restrained the cholesterol deletion-mediated up-regulation of fatty acid de novo synthesis in SK hep1 cells, inhibiting the atorvastatin-mediated proliferation, migration, and invasion of SK hep1 cells. In conclusion, cholesterol inhibited the progression of HCC through restraining SCAP-mediated fatty acid de novo synthesis.
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Affiliation(s)
- Zhibo Zhao
- Department of Hepatobiliary Surgery, the Second Affiliated Hospital & Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education) of Chongqing Medical University, 40016, Chongqing, China
| | - Li Zhong
- Health Management Center, The First Affiliated Hospital of Chongqing Medical University, 400016, Chongqing, China
| | - Kun He
- Department of Hepatobiliary Surgery, the Second Affiliated Hospital & Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education) of Chongqing Medical University, 40016, Chongqing, China
| | - Chan Qiu
- Department of Hepatobiliary Surgery, the Second Affiliated Hospital & Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education) of Chongqing Medical University, 40016, Chongqing, China
| | - Zhi Li
- Department of Hepatobiliary Surgery, the Second Affiliated Hospital & Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education) of Chongqing Medical University, 40016, Chongqing, China
| | - Lei Zhao
- Department of Hepatobiliary Surgery, the Second Affiliated Hospital & Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education) of Chongqing Medical University, 40016, Chongqing, China.
| | - Jianping Gong
- Department of Hepatobiliary Surgery, the Second Affiliated Hospital & Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education) of Chongqing Medical University, 40016, Chongqing, China.
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Wang WA, Agellon LB, Michalak M. Endoplasmic reticulum calcium dictates the distribution of intracellular unesterified cholesterol. Cell Calcium 2018; 76:116-121. [PMID: 30463032 DOI: 10.1016/j.ceca.2018.11.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 11/07/2018] [Accepted: 11/07/2018] [Indexed: 01/06/2023]
Abstract
Endoplasmic reticulum (ER) luminal Ca2+ influences many functions of this organelle, notably the synthesis and quality control of proteins and lipids. Cholesterol is an essential component of biological membranes and a precursor for many biologically important signaling molecules. The sterol regulatory element-binding proteins (SREBPs) are key regulators of lipid metabolism. These transcription factors are synthesized as ER membrane-bound precursor proteins that are proteolytically processed in response to cellular cholesterol status. Recently, ER Ca2+ status was shown to be an important determinant of the basal sensitivity of the sterol sensing mechanism inherent to the SREBP processing pathway. This article discusses the emerging relationship between cellular Ca2+ and cholesterol metabolism.
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Affiliation(s)
- Wen-An Wang
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2S7, Canada
| | - Luis B Agellon
- School of Human Nutrition, McGill University, Ste. Anne de Bellevue, Quebec, H9X 3V9, Canada.
| | - Marek Michalak
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2S7, Canada.
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Guo C, Chi Z, Jiang D, Xu T, Yu W, Wang Z, Chen S, Zhang L, Liu Q, Guo X, Zhang X, Li W, Lu L, Wu Y, Song BL, Wang D. Cholesterol Homeostatic Regulator SCAP-SREBP2 Integrates NLRP3 Inflammasome Activation and Cholesterol Biosynthetic Signaling in Macrophages. Immunity 2018; 49:842-856.e7. [PMID: 30366764 DOI: 10.1016/j.immuni.2018.08.021] [Citation(s) in RCA: 158] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 07/25/2018] [Accepted: 08/27/2018] [Indexed: 11/28/2022]
Abstract
Cholesterol metabolism has been linked to immune functions, but the mechanisms by which cholesterol biosynthetic signaling orchestrates inflammasome activation remain unclear. Here, we have shown that NLRP3 inflammasome activation is integrated with the maturation of cholesterol master transcription factor SREBP2. Importantly, SCAP-SREBP2 complex endoplasmic reticulum-to-Golgi translocation was required for optimal activation of the NLRP3 inflammasome both in vitro and in vivo. Enforced cholesterol biosynthetic signaling by sterol depletion or statins promoted NLPR3 inflammasome activation. However, this regulation did not predominantly depend on changes in cholesterol homeostasis controlled by the transcriptional activity of SREBP2, but relied on the escort activity of SCAP. Mechanistically, NLRP3 associated with SCAP-SREBP2 to form a ternary complex which translocated to the Golgi apparatus adjacent to a mitochondrial cluster for optimal inflammasome assembly. Our study reveals that, in addition to controlling cholesterol biosynthesis, SCAP-SREBP2 also serves as a signaling hub integrating cholesterol metabolism with inflammation in macrophages.
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Affiliation(s)
- Chuansheng Guo
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China; Program in Molecular and Cellular Biology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China
| | - Zhexu Chi
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China; Program in Molecular and Cellular Biology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China
| | - Danlu Jiang
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China; Program in Molecular and Cellular Biology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China
| | - Ting Xu
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China; Program in Molecular and Cellular Biology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China
| | - Weiwei Yu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, P.R. China
| | - Zhen Wang
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China; Program in Molecular and Cellular Biology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China
| | - Sheng Chen
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China; Program in Molecular and Cellular Biology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China
| | - Li Zhang
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China; Program in Molecular and Cellular Biology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China
| | - Qianyun Liu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, P.R. China
| | - Xingchen Guo
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, P.R. China
| | - Xue Zhang
- Program in Molecular and Cellular Biology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China; Department of Pathology and Pathophysiology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China
| | - Wenxin Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, P.R. China
| | - Linrong Lu
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China; Program in Molecular and Cellular Biology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China
| | - Yingliang Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, P.R. China
| | - Bao-Liang Song
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan 430072, P.R. China
| | - Di Wang
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China; Program in Molecular and Cellular Biology, Zhejiang University School of Medicine, Hangzhou 310058, P.R. China.
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Cheng X, Li J, Guo D. SCAP/SREBPs are Central Players in Lipid Metabolism and Novel Metabolic Targets in Cancer Therapy. Curr Top Med Chem 2018; 18:484-493. [PMID: 29788888 DOI: 10.2174/1568026618666180523104541] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 12/02/2017] [Accepted: 01/03/2018] [Indexed: 01/09/2023]
Abstract
Lipid metabolism reprogramming emerges as a new hallmark of malignancies. Sterol regulatory element-binding proteins (SREBPs), which are central players in lipid metabolism, are endoplasmic reticulum (ER)-bound transcription factors that control the expression of genes important for lipid synthesis and uptake. Their transcriptional activation requires binding to SREBP cleavageactivating protein (SCAP) to translocate their inactive precursors from the ER to the Golgi to undergo cleavage and subsequent nucleus translocation of their NH2-terminal forms. Recent studies have revealed that SREBPs are markedly upregulated in human cancers, providing the mechanistic link between lipid metabolism alterations and malignancies. Pharmacological or genetic inhibition of SCAP or SREBPs significantly suppresses tumor growth in various cancer models, demonstrating that SCAP/SREBPs could serve as promising metabolic targets for cancer therapy. In this review, we will summarize recent progress in our understanding of the underlying molecular mechanisms regulating SCAP/SREBPs and lipid metabolism in malignancies, discuss new findings about SREBP trafficking, which requires SCAP N-glycosylation, and introduce a newly identified microRNA-29-mediated negative feedback regulation of the SCAP/SREBP pathway. Moreover, we will review recently developed inhibitors targeting the SCAP/SREBP pathway for cancer treatment.
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Affiliation(s)
- Xiang Cheng
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, Columbus, OH 43210, United States
| | - Jianying Li
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, Columbus, OH 43210, United States
| | - Deliang Guo
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, Columbus, OH 43210, United States
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Abstract
The success of tissue engineering inevitably depends on the fabrication of tissue constructs that can be vascularized and that anastomose with the host vasculature. In this report, we studied the effects of light-emitting diode (LED) photopolymerized gelatin methacryloyl hydrogels (GelMA), encapsulated with stem cells from the apical papilla (SCAP) and human umbilical vein endothelial cells (HUVECs), in promoting vasculature network formation as a function of hydrogel physical and mechanical properties, as well as total cell density. Lithium acylphosphinate (LAP) was used as the photoinitiator in concentrations of 0.05, 0.075, 0.1% (w/v). GelMA hydrogel precursors of 5% (w/v) were encapsulated with cocultures of SCAPs and HUVECs at different cell densities (1×, 5×, and 10 × 106 cells/mL) and photo-cross-linked for 5 s. Results suggested that the compressive modulus of GelMA hydrogels increased as a function of LAP concentration, and had a maximum stiffness of 3.2 kPa. GelMA hydrogels photopolymerized using 0.05 or 0.075% LAP, which had an average of 1.5 and 1.6 kPa of elastic modulus respectively, had the most efficient vasculature formation after 5 days, and these results were further enhanced when the highest cell density (10 × 106 cells/mL) was used. Immunofluorescence images showed that SCAP cells spread in close contact with endothelial networks and expressed alpha smooth muscle actin (αSMA), which is suggestive of their differentiation into pericyte-like cells. αSMA expression was also apparently higher in hydrogels polymerized with 0.05% LAP and 10 × 106 cells/mLl. In conclusion, photopolymerization of GelMA hydrogels using an LED-light source can be an effective method for potential chair-side/in situ procedures for engineering of vascularized tissue constructs in regenerative medicine.
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Affiliation(s)
- Nelson Monteiro
- Division of Biomaterials and Biomechanics, Department of Restorative Dentistry, OHSU School of Dentistry, 2730 Southwest Moody Avenue, Portland, Oregon 97201, United States
| | - Wenting He
- Division of Biomaterials and Biomechanics, Department of Restorative Dentistry, OHSU School of Dentistry, 2730 Southwest Moody Avenue, Portland, Oregon 97201, United States
| | - Cristiane Miranda Franca
- Division of Biomaterials and Biomechanics, Department of Restorative Dentistry, OHSU School of Dentistry, 2730 Southwest Moody Avenue, Portland, Oregon 97201, United States
| | - Avathamsa Athirasala
- Division of Biomaterials and Biomechanics, Department of Restorative Dentistry, OHSU School of Dentistry, 2730 Southwest Moody Avenue, Portland, Oregon 97201, United States
| | - Luiz E Bertassoni
- Division of Biomaterials and Biomechanics, Department of Restorative Dentistry, OHSU School of Dentistry, 2730 Southwest Moody Avenue, Portland, Oregon 97201, United States
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Abstract
In eukaryotes, the synthesis and uptake of sterols undergo stringent multivalent regulation. Both individual enzymes and transcriptional networks are controlled to meet changing needs of the many sterol pathway products. Regulation is tailored by evolution to match regulatory constraints, which can be very different in distinct species. Nevertheless, a broadly conserved feature of many aspects of sterol regulation is employment of proteostasis mechanisms to bring about control of individual proteins. Proteostasis is the set of processes that maintain homeostasis of a dynamic proteome. Proteostasis includes protein quality control pathways for the detection, and then the correction or destruction, of the many misfolded proteins that arise as an unavoidable feature of protein-based life. Protein quality control displays not only the remarkable breadth needed to manage the wide variety of client molecules, but also extreme specificity toward the misfolded variants of a given protein. These features are amenable to evolutionary usurpation as a means to regulate proteins, and this approach has been used in sterol regulation. We describe both well-trod and less familiar versions of the interface between proteostasis and sterol regulation and suggest some underlying ideas with broad biological and clinical applicability.
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Affiliation(s)
- Margaret A Wangeline
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093;
| | - Nidhi Vashistha
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093;
| | - Randolph Y Hampton
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093;
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Deng T, Ma X, Pang C, Liang S, Lu X, Duan A, Liang X. Molecular characterisation of the buffalo SCAP gene and its association with milk production traits in water buffaloes. J DAIRY RES 2018; 85:133-7. [PMID: 29785906 DOI: 10.1017/S0022029918000195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The study reported in this Research Communication was conducted to investigate the molecular characterisation of buffalo SCAP gene, expression analysis, and the association between single nucleotide polymorphisms and milk production traits in 384 buffaloes. Sequence analysis revealed the SCAP gene had an open reading frame of 3837 bp encoding 1279 amino acids. A ubiquitous expression profile of SCAP gene was detected in various tissues with extreme predominance in the mammary gland during early lactation. Moreover, eleven SNPs in buffalo SCAP gene were identified, six of them (g.1717600A>G, g.1757922C>T, g.1758953G>A, g.1759142C>T, g.1760740G>A, and g.1766036T>C) were found to be significantly associated with 305-day milk yield. Thus, buffalo SCAP could sever as a candidate gene affecting milk production traits in buffalo and the identified SNPs might potentially be genetic markers.
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Abstract
Reprogramming of lipid metabolism is a newly recognized hallmark of malignancy. Increased lipid uptake, storage and lipogenesis occur in a variety of cancers and contribute to rapid tumor growth. Lipids constitute the basic structure of membranes and also function as signaling molecules and energy sources. Sterol regulatory element-binding proteins (SREBPs), a family of membrane-bound transcription factors in the endoplasmic reticulum, play a central role in the regulation of lipid metabolism. Recent studies have revealed that SREBPs are highly up-regulated in various cancers and promote tumor growth. SREBP cleavage-activating protein is a key transporter in the trafficking and activation of SREBPs as well as a critical glucose sensor, thus linking glucose metabolism and de novo lipid synthesis. Targeting altered lipid metabolic pathways has become a promising anti-cancer strategy. This review summarizes recent progress in our understanding of lipid metabolism regulation in malignancy, and highlights potential molecular targets and their inhibitors for cancer treatment.
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Affiliation(s)
- Chunming Cheng
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, Columbus, OH, 43210, USA
| | - Feng Geng
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, Columbus, OH, 43210, USA
| | - Xiang Cheng
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, Columbus, OH, 43210, USA
| | - Deliang Guo
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, Columbus, OH, 43210, USA.
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El Ayachi I, Zhang J, Zou XY, Li D, Yu Z, Wei W, O’Connell KM, Huang GTJ. Human dental stem cell derived transgene-free iPSCs generate functional neurons via embryoid body-mediated and direct induction methods. J Tissue Eng Regen Med 2018; 12:e1836-e1851. [PMID: 29139614 PMCID: PMC6482049 DOI: 10.1002/term.2615] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 10/02/2017] [Accepted: 11/02/2017] [Indexed: 12/17/2022]
Abstract
Induced pluripotent stem cells (iPSCs) give rise to neural stem/progenitor cells, serving as a good source for neural regeneration. Here, we established transgene-free (TF) iPSCs from dental stem cells (DSCs) and determined their capacity to differentiate into functional neurons in vitro. Generated TF iPSCs from stem cells of apical papilla and dental pulp stem cells underwent two methods-embryoid body-mediated and direct induction, to guide TF-DSC iPSCs along with H9 or H9 Syn-GFP (human embryonic stem cells) into functional neurons in vitro. Using the embryoid body-mediated method, early stage neural markers PAX6, SOX1, and nestin were detected by immunocytofluorescence or reverse transcription-real time polymerase chain reaction (RT-qPCR). At late stage of neural induction measured at Weeks 7 and 9, the expression levels of neuron-specific markers Nav1.6, Kv1.4, Kv4.2, synapsin, SNAP25, PSD95, GAD67, GAP43, and NSE varied between stem cells of apical papilla iPSCs and H9. For direct induction method, iPSCs were directly induced into neural stem/progenitor cells and guided to become neuron-like cells. The direct method, while simpler, showed cell detachment and death during the differentiation process. At early stage, PAX6, SOX1 and nestin were detected. At late stage of differentiation, all five genes tested, nestin, βIII-tubulin, neurofilament medium chain, GFAP, and Nav, were positive in many cells in cultures. Both differentiation methods led to neuron-like cells in cultures exhibiting sodium and potassium currents, action potential, or spontaneous excitatory postsynaptic potential. Thus, TF-DSC iPSCs are capable of undergoing guided neurogenic differentiation into functional neurons in vitro, thereby may serve as a cell source for neural regeneration.
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Affiliation(s)
- Ikbale El Ayachi
- Department of Bioscience Research, College of Dentistry, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Jun Zhang
- Department of Bioscience Research, College of Dentistry, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Xiao-Ying Zou
- Department of Endodontics, Boston University Henry M. Goldman School of Dental Medicine, Boston, MA 02118, USA
- Department of Cariology, Endodontology and Operative Dentistry, School and Hospital of Stomatology, Peking University, Beijing, 100081, P. R. China
| | - Dong Li
- Department of Bioscience Research, College of Dentistry, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Zongdong Yu
- Department of Bioscience Research, College of Dentistry, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Wei Wei
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
- The Jackson Laboratory, Bar Harbor, ME, USA
| | - Kristen M.S. O’Connell
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
- The Jackson Laboratory, Bar Harbor, ME, USA
| | - George T.-J. Huang
- Department of Bioscience Research, College of Dentistry, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Endodontics, Boston University Henry M. Goldman School of Dental Medicine, Boston, MA 02118, USA
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Murphy BA, Tadin-Strapps M, Jensen K, Mogg R, Liaw A, Herath K, Bhat G, McLaren DG, Previs SF, Pinto S. siRNA-mediated inhibition of SREBP cleavage-activating protein reduces dyslipidemia in spontaneously dysmetabolic rhesus monkeys. Metabolism 2017; 71:202-212. [PMID: 28521874 DOI: 10.1016/j.metabol.2017.02.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 02/26/2017] [Accepted: 02/27/2017] [Indexed: 01/07/2023]
Abstract
BACKGROUND SREBP cleavage-activating protein (SCAP) is a cholesterol binding endoplasmic reticulum (ER) membrane protein that is required to activate SREBP transcription factors. SREBPs regulate genes involved in lipid biosynthesis. They also influence lipid clearance by modulating the expression of LDL receptor (LDLR) and proprotein convertase subtilisin/kexin type 9 (PCSK9) genes. Inhibiting SCAP decreases circulating PCSK9, triglycerides (TG), and LDL-cholesterol (LDL-C), both in vitro and in vivo. Type 2 diabetics with dyslipidemia are at high risk for cardiovascular diseases. These patients present a unique pathophysiological lipid profile characterized by moderately elevated LDL-C, elevated TG and reduced HDL-cholesterol (HDL-C). The spontaneous dysmetabolic rhesus monkey model (DysMet RhM) recapitulates this human dyslipidemia and therefore is an attractive preclinical model to evaluate SCAP inhibition as a therapy for this disease population. The objective to of this study was to assess the effect of SCAP inhibition on the lipid profile of DysMet RhM. METHOD We assessed the effect of inhibiting hepatic SCAP on the lipid profile of DysMet RhM using an siRNA encapsulated lipid nanoparticle (siRNA-LNP). RESULTS The SCAP siRNA-LNP significantly reduced LDL-C, PCSK9 and TG in DysMet RhM; LDL-C was reduced by ≥20%, circulating PCSK9 by 30-40% and TG by >25%. These changes by the SCAP siRNA-LNP agree with the predicted effect of SCAP inhibition and reduced SREBP tone on these endpoints. CONCLUSION These data demonstrate that a SCAP siRNA-LNP improved the lipid profile in a clinically relevant preclinical disease model and provide evidence for SCAP inhibition as a therapy for diabetic dyslipidemic patients.
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Affiliation(s)
- Beth Ann Murphy
- Pharmacology, Merck &Co. Inc., 2000 Galloping Hill Rd., Kenilworth, NJ 07033, USA.
| | - Marija Tadin-Strapps
- Genetics and Pharmacogenomics, Merck & Co. Inc., 33 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Kristian Jensen
- Cardiometabolic Disease, Merck & Co. Inc., 2000 Galloping Hill Rd., Kenilworth, NJ 07033, USA
| | - Robin Mogg
- Biostatistics, Merck & Co. Inc., 351 North Sumneytown Pike, North Wales, PA 19454, USA
| | - Andy Liaw
- Biostatistics, Merck & Co. Inc., 126 E. Lincoln Avenue, PO Box 2000, Rahway, NJ 07065, USA
| | - Kithsiri Herath
- Cardiometabolic Disease, Merck & Co. Inc., 2000 Galloping Hill Rd., Kenilworth, NJ 07033, USA
| | - Gowri Bhat
- Cardiometabolic Disease, Merck & Co. Inc., 2000 Galloping Hill Rd., Kenilworth, NJ 07033, USA
| | - David G McLaren
- Pharmacology, Merck &Co. Inc., 2000 Galloping Hill Rd., Kenilworth, NJ 07033, USA
| | - Stephen F Previs
- Cardiometabolic Disease, Merck & Co. Inc., 2000 Galloping Hill Rd., Kenilworth, NJ 07033, USA
| | - Shirly Pinto
- Cardiometabolic Disease, Merck & Co. Inc., 2000 Galloping Hill Rd., Kenilworth, NJ 07033, USA
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Liu H, Zhang L, Sun J, Chen W, Li S, Wang Q, Yu H, Xia Z, Jin X, Wang C. Endoplasmic Reticulum Protein SCAP Inhibits Dengue Virus NS2B3 Protease by Suppressing Its K27-Linked Polyubiquitylation. J Virol 2017; 91:e02234-16. [PMID: 28228593 DOI: 10.1128/JVI.02234-16] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 02/14/2017] [Indexed: 01/11/2023] Open
Abstract
Dengue viruses (DENVs) are an emerging threat to global public health. The NS2B3 protease complex of DENV has recently been shown to cleave the antiviral protein STING and thereby subvert the innate immune signaling to facilitate virus replication. Whether host cells have a mechanism to counteract this virus-mediated immunosuppression is unclear. We discovered that the K27-linked polyubiquitination of NS3 protein facilitates its recruitment of NS2B, the formation of NS2B3, and consequently the enhanced cleavage of STING. However, an endoplasmic reticulum (ER) protein, SCAP, through binding to NS2B protein, inhibits the ubiquitination of NS3, rendering NS2B3 protease incapable of binding and cleaving STING. Importantly, ectopic expression of SCAP impaired DENV infection, whereas silencing of SCAP potentiated DENV infection. Collectively, this study uncovered a novel function of SCAP of counteracting the inhibitory action of DENV NS2B3 protease on STING signaling, suggesting that modulation of SCAP levels may have therapeutic implications.IMPORTANCE This study reports the first ubiquitylation target protein in DENV, the NS3 protein, and the unique role of K27-linked polyubiquitylation in NS3's ability to recruit NS2B and formation of the NS2B3 protease complex. Additionally, this study identified novel functions of the ER protein SCAP: one is to compete with NS2B for binding to STING, and the other is to inhibit the ubiquitination of NS3. Both of these functions protect STING from being cleaved by the NS2B3 protease and thus contribute to host antiviral response.
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Abstract
The membrane-bound transcription factors, SREBPs (sterol regulatory element-binding proteins), play a central role in regulating lipid metabolism. The transcriptional activation of SREBPs requires the key protein SCAP (SREBP-cleavage activating protein) to translocate their precursors from the endoplasmic reticulum to the Golgi for subsequent proteolytic activation, a process tightly regulated by a cholesterol-mediated negative feedback loop. Our previous work showed that the SCAP/SREBP-1 pathway is significantly upregulated in human glioblastoma (GBM), the most deadly brain cancer, and that glucose-mediated N-glycosylation of SCAP is a prerequisite step for SCAP/SREBP trafficking. More recently, we demonstrated that microRNA-29 (miR-29) mediates a previously unrecognized negative feedback loop in SCAP/SREBP-1 signaling to control lipid metabolism. We found that SREBP-1, functioning as a transcription factor, promotes the expression of the miR-29 family members, miR-29a, -29b and -29c. In turn, the miR-29 isoforms reversely repress the expression of SCAP and SREBP-1. Moreover, treatment with miR-29 mimics effectively suppressed GBM tumor growth by inhibiting SCAP/SREBP-1 and de novo lipid synthesis. These findings, recently published in Cell Reports, strongly suggest that delivery of miR-29 in vivo may be a promising approach to treat cancer and metabolic diseases by suppressing SCAP/SREBP-1-regulated lipid metabolism.
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Affiliation(s)
- Peng Ru
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, Columbus, OH 43210, USA
| | - Deliang Guo
- Department of Radiation Oncology, The Ohio State University James Comprehensive Cancer Center and College of Medicine, Columbus, OH 43210, USA
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