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Tan YJ, Jin Y, Zhou J, Yang YF. Lipid droplets in pathogen infection and host immunity. Acta Pharmacol Sin 2024; 45:449-464. [PMID: 37993536 PMCID: PMC10834987 DOI: 10.1038/s41401-023-01189-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 10/30/2023] [Indexed: 11/24/2023] Open
Abstract
As the hub of cellular lipid metabolism, lipid droplets (LDs) have been linked to a variety of biological processes. During pathogen infection, the biogenesis, composition, and functions of LDs are tightly regulated. The accumulation of LDs has been described as a hallmark of pathogen infection and is thought to be driven by pathogens for their own benefit. Recent studies have revealed that LDs and their subsequent lipid mediators contribute to effective immunological responses to pathogen infection by promoting host stress tolerance and reducing toxicity. In this comprehensive review, we delve into the intricate roles of LDs in governing the replication and assembly of a wide spectrum of pathogens within host cells. We also discuss the regulatory function of LDs in host immunity and highlight the potential for targeting LDs for the diagnosis and treatment of infectious diseases.
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Affiliation(s)
- Yan-Jie Tan
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, 250014, China
| | - Yi Jin
- Research Center of Translational Medicine, Central Hospital Affiliated to Shandong First Medical University, Jinan, 250013, China
| | - Jun Zhou
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, 250014, China.
- State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, College of Life Sciences, Nankai University, Tianjin, 300071, China.
| | - Yun-Fan Yang
- Department of Cell Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China.
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Dai Y, Qiu C, Zhang D, Li M, Liu W. Yam Gruel alone and in combination with metformin regulates hepatic lipid metabolism disorders in a diabetic rat model by activating the AMPK/ACC/CPT-1 pathway. Lipids Health Dis 2024; 23:28. [PMID: 38273354 PMCID: PMC10809441 DOI: 10.1186/s12944-024-02014-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Accepted: 01/10/2024] [Indexed: 01/27/2024] Open
Abstract
BACKGROUND As independent and correctable risk factors, disturbances in lipid metabolism are significantly associated with type 2 diabetes mellitus (T2DM). This research investigated the mechanism underlying the lipid-regulating effects of Yam Gruel in diabetic rats. METHODS First, rats in the control group were given a normal diet, and a diabetic rat model was established via the consumption of a diet that was rich in both fat and sugar for six weeks followed by the intraperitoneal injection of streptozotocin (STZ). After the model was established, the rats were divided into five distinct groups: the control group, model group, Yam Gruel (SYZ) group, metformin (MET) group, and combined group; each treatment was administered for six weeks. The fasting blood glucose (FBG), body and liver weights as well as liver index of the rats were determined. Total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), aspartic acid transaminase (AST), alanine aminotransferase (ALT), and nonesterified fatty acid (NEFA) levels were measured. Oil Red O staining was used to assess hepatic steatosis. In addition, the levels of Phospho-acetyl-CoA carboxylase (p-ACC), acetyl coenzyme A carboxylase (ACC), AMP-activated protein kinase (AMPK), Phospho-AMPK (p-AMPK), carnitine palmitoyl transferase I (CPT-1), and Malonyl-CoA decarboxylase (MLYCD) in liver tissues were measured by real-time PCR (q-PCR) and western blotting. RESULTS After 6 weeks of treatment, Yam Gruel alone or in combination with metformin significantly reduced FBG level, liver weight and index. The concentrations of lipid indices (TG, TC, NEFA, and LDL-C), the levels of liver function indices (ALT and AST) and the degree of hepatic steatosis was improved in diabetic rats that were treated with Yam Gruel with or without metformin. Furthermore, Yam Gruel increased the protein levels of p-ACC/ACC, p-AMPK/AMPK, MLYCD, and CPT-1, which was consistent with the observed changes in gene expression. Additionally, the combination of these two agents was significantly more effective in upregulating the expression of AMPK pathway-related genes and proteins. CONCLUSIONS These results demonstrated that Yam Gruel may be a potential diet therapy for improving lipid metabolism in T2DM patients and that it may exert its effects via AMPK/ACC/CPT-1 pathway activation. In some respects, the combination of Yam Gruel and metformin exerted more benefits effects than Yam Gruel alone.
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Affiliation(s)
- Yanling Dai
- School of Nursing, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, China
| | - Chen Qiu
- Department of Endocrine, People's Hospital Affiliated to Fujian University of Traditional Chinese Medicine, Fuzhou, 350004, China
| | - Diandian Zhang
- School of Nursing, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, China
| | - Mianli Li
- School of Nursing, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, China
| | - Weinan Liu
- Department of Orthopedics, People's Hospital Affiliated to Fujian University of Traditional Chinese Medicine, Fuzhou, 350004, China.
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Dempsey JL, Ioannou GN, Carr RM. Mechanisms of Lipid Droplet Accumulation in Steatotic Liver Diseases. Semin Liver Dis 2023; 43:367-382. [PMID: 37799111 DOI: 10.1055/a-2186-3557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/07/2023]
Abstract
The steatotic diseases of metabolic dysfunction-associated steatotic liver disease (MASLD), alcohol-associated liver disease (ALD), and chronic hepatitis C (HCV) account for the majority of liver disease prevalence, morbidity, and mortality worldwide. While these diseases have distinct pathogenic and clinical features, dysregulated lipid droplet (LD) organelle biology represents a convergence of pathogenesis in all three. With increasing understanding of hepatocyte LD biology, we now understand the roles of LD proteins involved in these diseases but also how genetics modulate LD biology to either exacerbate or protect against the phenotypes associated with steatotic liver diseases. Here, we review the history of the LD organelle and its biogenesis and catabolism. We also review how this organelle is critical not only for the steatotic phenotype of liver diseases but also for their advanced phenotypes. Finally, we summarize the latest attempts and challenges of leveraging LD biology for therapeutic gain in steatotic diseases. In conclusion, the study of dysregulated LD biology may lead to novel therapeutics for the prevention of disease progression in the highly prevalent steatotic liver diseases of MASLD, ALD, and HCV.
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Affiliation(s)
- Joseph L Dempsey
- Division of Gastroenterology, Department of Medicine, School of Medicine, University of Washington, Seattle, Washington
| | - George N Ioannou
- Division of Gastroenterology, Department of Medicine, School of Medicine, University of Washington, Seattle, Washington
- Division of Gastroenterology, Veterans Affairs Puget Sound Healthcare System Seattle, Washington
| | - Rotonya M Carr
- Division of Gastroenterology, Department of Medicine, School of Medicine, University of Washington, Seattle, Washington
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Schelbert S, Schindeldecker M, Drebber U, Witzel HR, Weinmann A, Dries V, Schirmacher P, Roth W, Straub BK. Lipid Droplet-Associated Proteins Perilipin 1 and 2: Molecular Markers of Steatosis and Microvesicular Steatotic Foci in Chronic Hepatitis C. Int J Mol Sci 2022; 23:ijms232415456. [PMID: 36555099 PMCID: PMC9778710 DOI: 10.3390/ijms232415456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/29/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
Chronic infection with hepatitis C (HCV) is a major risk factor in the development of cirrhosis and hepatocellular carcinoma. Lipid metabolism plays a major role in the replication and deposition of HCV at lipid droplets (LDs). We have demonstrated the importance of LD-associated proteins of the perilipin family in steatotic liver diseases. Using a large collection of 231 human liver biopsies with HCV, perilipins 1 and 2 have been localized to LDs of hepatocytes that correlate with the degree of steatosis and specific HCV genotypes, but not significantly with the HCV viral load. Perilipin 1- and 2-positive microvesicular steatotic foci were observed in 36% of HCV liver biopsies, and also in chronic hepatitis B, autoimmune hepatitis and mildly steatotic or normal livers, but less or none were observed in normal livers of younger patients. Microvesicular steatotic foci did not frequently overlap with glycogenotic/clear cell foci as determined by PAS stain in serial sections. Steatotic foci were detected in all liver zones with slight architectural disarrays, as demonstrated by immunohistochemical glutamine synthetase staining of zone three, but without elevated Ki67-proliferation rates. In conclusion, microvesicular steatotic foci are frequently found in chronic viral hepatitis, but the clinical significance of these foci is so far not clear.
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Affiliation(s)
- Selina Schelbert
- Institute of Pathology, University Medical Center Mainz, 55131 Mainz, Germany
- Institute of Pathology, University Hospital Wuerzburg, 97080 Wuerzburg, Germany
| | | | - Uta Drebber
- Institute of Pathology, University Clinic Cologne, 50931 Cologne, Germany
| | - Hagen Roland Witzel
- Institute of Pathology, University Medical Center Mainz, 55131 Mainz, Germany
| | - Arndt Weinmann
- Department of Internal Medicine, University Medical Center, 55131 Mainz, Germany
| | - Volker Dries
- Institute of Pathology, University Clinic Cologne, 50931 Cologne, Germany
| | - Peter Schirmacher
- Institute of Pathology, University Medical Center Heidelberg, 69120 Heidelberg, Germany
| | - Wilfried Roth
- Institute of Pathology, University Medical Center Mainz, 55131 Mainz, Germany
| | - Beate Katharina Straub
- Institute of Pathology, University Medical Center Mainz, 55131 Mainz, Germany
- Correspondence: ; Tel.: +49-6131-17-7307
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Huo K, Ma KG, Guo QY, Duan P, Xu J. Perilipin 5 protects against oxygen-glucose deprivation/reoxygenation-elicited neuronal damage by inhibiting oxidative stress and inflammatory injury via the Akt-GSK-3β-Nrf2 pathway. Int Immunopharmacol 2022; 108:108718. [DOI: 10.1016/j.intimp.2022.108718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/02/2022] [Accepted: 03/17/2022] [Indexed: 11/05/2022]
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Perilipin 5 ameliorates high-glucose-induced podocyte injury via Akt/GSK-3β/Nrf2-mediated suppression of apoptosis, oxidative stress, and inflammation. Biochem Biophys Res Commun 2021; 544:22-30. [PMID: 33516878 DOI: 10.1016/j.bbrc.2021.01.069] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 01/20/2021] [Indexed: 12/18/2022]
Abstract
Hyperglycemia-induced podocyte damage contributes to the onset of diabetic nephropathy, a severe complication of diabetes. Perilipin 5 (Plin5) exerts a vital role in numerous pathological conditions via affecting cell apoptosis, oxidative stress, and inflammation. However, whether Plin5 plays a role in regulating podocyte damage of diabetic nephropathy has not been fully determined. This work aimed to explore the role of Plin5 in mediating high glucose (HG)-induced injury of podocytes in vitro. Our results demonstrated that Plin5 expression was markedly decreased in mouse podocytes challenged with HG. Plin5 overexpression markedly suppressed HG-induced apoptosis, reactive oxygen species (ROS) production, and the pro-inflammatory response in podocytes. On the contrary, Plin5 silencing produced the opposite effects. Further mechanistic analysis demonstrated that Plin5 upregulation remarkably increased the levels of phospho-Akt and phospho-glycogen synthase kinase-3β (GSK-3β) in HG-exposed podocytes. Moreover, Plin5 overexpression increased the levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and enhanced the activation of Nrf2 signaling. Akt inhibition markedly blocked Plin5-mediated activation of Nrf2, while GSK-3β inhibition reversed Plin5-silencing-induced suppressive effects on Nrf2 activation. Notably, Nrf2 suppression significantly blocked Plin5-mediated protective effects against HG-induced podocyte injury. In summary, our work indicates a vital role for Plin5 in protecting against HG-induced apoptosis, oxidative stress, and inflammation in podocytes via modulation of Akt/GSK-3β/Nrf2 signaling. This study suggests that Plin5 may participate in modulating podocyte damage in diabetic nephropathy.
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Isocitrate dehydrogenase 1 mutation enhances 24(S)-hydroxycholesterol production and alters cholesterol homeostasis in glioma. Oncogene 2020; 39:6340-6353. [PMID: 32855525 DOI: 10.1038/s41388-020-01439-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 08/10/2020] [Accepted: 08/17/2020] [Indexed: 01/08/2023]
Abstract
Isocitrate dehydrogenase (IDH) mutation is the most important initiating event in gliomagenesis, and the increasing evidence shows that IDH mutation is associated with the metabolic reprogramming in the tumor. Dysregulated cholesterol metabolism is a hallmark of tumor cells, but the cholesterol homeostasis in IDH-mutated glioma is still unknown. In this study, we found that astrocyte-specific mutant IDH1(R132H) knockin reduced the cholesterol contents and damaged the structure of myelin in mouse brains. In U87 and U251 cells, the expression of mutant IDH1 consistently reduced the cholesterol levels. Furthermore, we found that IDH1 mutation enhanced the production of 24(S)-hydroxycholesterol (24-OHC), which is not only the metabolite of cholesterol elimination, but also functions as an endogenous ligand for the liver X receptors (LXRs). In IDH1-mutant glioma cells, the elevated 24-OHC activated LXRs, which consequently accelerated the low-density lipoprotein receptor (LDLR) degradation by upregulating the inducible degrader of the LDLR (IDOL). The reduced LDLR expressions in IDH1-mutant glioma cells abated the uptakes of low-density lipoprotein (LDL) to decrease the cholesterol influx. In addition, the activated LXRs also promoted the cholesterol efflux by elevating the ATP-binding cassette transporter A1 (ABCA1), ABCG1, and apolipoprotein E (ApoE) in both IDH1-mutant astrocytes and glioma cells. As a feedback, the reduced cholesterol levels stimulated the cholesterol biosynthesis, which made IDH1-mutated glioma cells more sensitive to atorvastatin, an inhibitor of 3-hydroxy-3-methylglutaryl-CoA reductase. The altered cholesterol homeostasis regulated by mutant IDH provides a pivotal therapeutical strategy for the IDH-mutated gliomas.
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Meng Z, Liu Q, Sun F, Qiao L. Hepatitis C virus nonstructural protein 5A perturbs lipid metabolism by modulating AMPK/SREBP-1c signaling. Lipids Health Dis 2019; 18:191. [PMID: 31684957 PMCID: PMC6829953 DOI: 10.1186/s12944-019-1136-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 10/20/2019] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Steatosis is an important clinical manifestation associated with chronic hepatitis C virus (HCV) infection. AMP-activated protein kinase (AMPK), a major mediator of lipid metabolism, regulates HCV-associated hepatic steatosis, but the underlying mechanisms remain obscure. Here we investigated the mechanism of HCV nonstructural protein 5A (NS5A)-induced lipid accumulation by the AMPK/SREBP-1c pathway. METHODS We generated model mice by injecting recombinant lentiviral particles expressing the NS5A protein (genotype 3a) via the tail vein. The serum levels of alanine aminotransferase (ALT), free fatty acids (FFAs) and triglycerides (TG) were examined. H&E and Oil Red O staining were used to examine lipid droplets. Immunohistochemistry staining, quantitative real-time PCR and Western blotting were used to determine the expression of lipogenic genes. RESULTS Our results showed that the serum levels of ALT, FFAs and TG, as well as the accumulation of hepatic lipid droplets, were increased significantly in mice infected with NS5A-expressing lentiviral particles. NS5A inhibited AMPK phosphorylation and increased the expression levels of sterol regulatory element binding protein-1c (SREBP-1c), acetyl-coenzyme A carboxylase 1 (ACC1) and fatty acid synthase (FASN) in vivo and in vitro. Further investigation revealed that pharmacological activation or ectopic expression of AMPK neutralized the upregulation of SREBP-1c, ACC1 and FASN, and ameliorated hepatic lipid accumulation induced by NS5A. Ectopic expression of SREBP-1c enhanced NS5A-induced hepatic lipid accumulation, which was dramatically reversed by pharmacological activation of AMPK. CONCLUSIONS Collectively, we demonstrate that NS5A induces hepatic lipid accumulation via the AMPK/SREBP-1c pathway.
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Affiliation(s)
- Ziyu Meng
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin, 300134, China
| | - Qiang Liu
- Vaccine and Infectious Disease Organization-International Vaccine Centre (VIDO-InterVac), School of Public Health Vaccinology and Immunotherapeutics, Department of Veterinary Microbiology, University of Saskatchewan, S7N5E3, Saskatoon, Canada
| | - Fujun Sun
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin, 300134, China
| | - Ling Qiao
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital & Tianjin Institute of Endocrinology, Tianjin, 300134, China.
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