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Cai Z, Du S, Zhao N, Huang N, Yang K, Qi L. Periodontitis promotes the progression of diabetes mellitus by enhancing autophagy. Heliyon 2024; 10:e24366. [PMID: 38288023 PMCID: PMC10823111 DOI: 10.1016/j.heliyon.2024.e24366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 01/04/2024] [Accepted: 01/08/2024] [Indexed: 01/31/2024] Open
Abstract
Objective This study aims to identify the periodontitis factor that activates excessive autophagy in pancreatic β cells, resulting in organic lesions of pancreatic islet tissues and diminished insulin secretion, thereby accelerating the progression of diabetes mellitus (DM). Methods Sprague-Dawley (SD) rats were induced with periodontitis (PD), type 2 diabetes mellitus (T2DM), or the combination of T2DM and PD (DP) through a high-sugar/high-fat diet and ligation of the tooth neck with silk thread. Alveolar bone resorption was assessed using Micro-CT, blood glucose levels were measured with a blood glucose meter, pancreatic tissue pathology was examined through HE staining, and the expression of autophagy-related proteins Beclin1 and LC3II/LC3I was analyzed using Western blotting. Results Micro-CT results revealed more pronounced alveolar bone resorption and root bifurcation exposure in the PD and DP groups compared to the control group, with the DP group exhibiting the most severe condition. HE staining demonstrated the formation of periodontal pockets, severe alveolar bone destruction, and abnormal pancreatic islet tissue morphology in the PD and DP groups. The serum levels of IL-6, TNF-α, and IL-1β increased sequentially in the control, DM, PD, and DP groups (P < 0.05). Relative expressions of GCK and GLUT-2 mRNA decreased in the PD group compared to the control group (P > 0.05), while the mRNA expressions in the DP and DM groups increased (P < 0.05), with the DP group exhibiting higher levels than the DM group (P < 0.05). Western blot results indicated increased expression levels of autophagy proteins Beclin1 and LC3II/LC3I in the DM and DP groups compared to the control group (P < 0.05), with the DP group exhibiting higher levels than the DM group (P < 0.05). Conclusion The findings demonstrate that periodontal inflammatory factors may promote the enhancement of pancreatic cell autophagy in diabetic rats.
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Affiliation(s)
- Zhiguo Cai
- Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- Department of Periodontology, Stomatological Hospital Zunyi, Zunyi Medical University, Zunyi, Guizhou, China
- Honghuagang District Stomatological Hospital, Zunyi, Guizhou, China
| | - Shasha Du
- Department of Periodontology, Stomatological Hospital Zunyi, Zunyi Medical University, Zunyi, Guizhou, China
| | - Na Zhao
- Department of Periodontology, Stomatological Hospital Zunyi, Zunyi Medical University, Zunyi, Guizhou, China
| | - Nanqu Huang
- National Drug Clinical Trial Institution, Third Affiliated Hospital of Zunyi Medical University (The First People's Hospital of Zunyi), Zunyi, Guizhou, China
| | - Kun Yang
- Department of Periodontology, Stomatological Hospital Zunyi, Zunyi Medical University, Zunyi, Guizhou, China
| | - Liu Qi
- Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
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Cui K, Li Z. Identification and analysis of type 2 diabetes-mellitus-associated autophagy-related genes. Front Endocrinol (Lausanne) 2023; 14:1164112. [PMID: 37223013 PMCID: PMC10200926 DOI: 10.3389/fendo.2023.1164112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Accepted: 04/06/2023] [Indexed: 05/25/2023] Open
Abstract
Introduction Autophagy, an innate safeguard mechanism for protecting the organism against harmful agents, is implicated in the survival of pancreatic â cells and the development of type 2 diabetes mellitus (T2DM). Potential autophagy-related genes (ARGs) may serve as potential biomarkers for T2DM treatment. Methods The GSE25724 dataset was downloaded from the Gene Expression Omnibus (GEO) database, and ARGs were obtained from the Human Autophagy Database. The differentially expressed autophagy-related genes (DEARGs) were screened at the intersection of ARGs and differentially expressed genes (DEGs) between T2DM and non-diabetic islet samples, which were subjected to functional enrichment analyses. A protein-protein interaction (PPI) network was constructed to identify hub DEARGs. Expressions of top 10 DEARGs were validated in human pancreatic â-cell line NES2Y and rat pancreatic INS-1 cells using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Cell viability and insulin secretion were measured after cell transfection with lentiviral vector EIF2AK3 or RB1CC1 into islet cells. Results In total, we discovered 1,270 DEGs (266 upregulated and 1,004 downregulated genes) and 30 DEARGs enriched in autophagy- and mitophagy-related pathways. In addition, we identified GAPDH, ITPR1, EIF2AK3, FOXO3, HSPA5, RB1CC1, LAMP2, GABARAPL2, RAB7A, and WIPI1 genes as the hub ARGs. Next, qRT-PCR analysis revealed that expressions of hub DEARGs were consistent with findings from bioinformatics analysis. EIF2AK3, GABARAPL2, HSPA5, LAMP2, and RB1CC1 were both differentially expressed in the two cell types. Overexpression of EIF2AK3 or RB1CC1 promoted cell viability of islet cells and increased the insulin secretion. Discussion This study provides potential biomarkers as therapeutic targets for T2DM.
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Affiliation(s)
- Kun Cui
- Respiratory Medicine, Tangshan Gongren Hospital, Tangshan, Hebei, China
| | - Zhizheng Li
- Department of Respiratory and Critical Care Medicine, Tangshan Gongren Hospital, Tangshan, Hebei, China
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Mohammadi-Motlagh HR, Sadeghalvad M, Yavari N, Primavera R, Soltani S, Chetty S, Ganguly A, Regmi S, Fløyel T, Kaur S, Mirza AH, Thakor AS, Pociot F, Yarani R. β Cell and Autophagy: What Do We Know? Biomolecules 2023; 13:biom13040649. [PMID: 37189396 DOI: 10.3390/biom13040649] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 03/27/2023] [Accepted: 03/30/2023] [Indexed: 05/17/2023] Open
Abstract
Pancreatic β cells are central to glycemic regulation through insulin production. Studies show autophagy as an essential process in β cell function and fate. Autophagy is a catabolic cellular process that regulates cell homeostasis by recycling surplus or damaged cell components. Impaired autophagy results in β cell loss of function and apoptosis and, as a result, diabetes initiation and progress. It has been shown that in response to endoplasmic reticulum stress, inflammation, and high metabolic demands, autophagy affects β cell function, insulin synthesis, and secretion. This review highlights recent evidence regarding how autophagy can affect β cells' fate in the pathogenesis of diabetes. Furthermore, we discuss the role of important intrinsic and extrinsic autophagy modulators, which can lead to β cell failure.
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Affiliation(s)
- Hamid-Reza Mohammadi-Motlagh
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah 67155-1616, Iran
| | - Mona Sadeghalvad
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran 1416634793, Iran
| | - Niloofar Yavari
- Department of Cellular and Molecular Medicine, The Panum Institute, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Rosita Primavera
- Interventional Regenerative Innovation at Stanford (IRIS), Department of Radiology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Setareh Soltani
- Clinical Research Development Center, Taleghani and Imam Ali Hospital, Kermanshah University of Medical Sciences, Kermanshah 67145-1673, Iran
| | - Shashank Chetty
- Interventional Regenerative Innovation at Stanford (IRIS), Department of Radiology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Abantika Ganguly
- Interventional Regenerative Innovation at Stanford (IRIS), Department of Radiology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Shobha Regmi
- Interventional Regenerative Innovation at Stanford (IRIS), Department of Radiology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Tina Fløyel
- Translational Type 1 Diabetes Research, Department of Clinical Research, Steno Diabetes Center Copenhagen, 2730 Herlev, Denmark
| | - Simranjeet Kaur
- Translational Type 1 Diabetes Research, Department of Clinical Research, Steno Diabetes Center Copenhagen, 2730 Herlev, Denmark
| | - Aashiq H Mirza
- Translational Type 1 Diabetes Research, Department of Clinical Research, Steno Diabetes Center Copenhagen, 2730 Herlev, Denmark
- Department of Pharmacology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Avnesh S Thakor
- Interventional Regenerative Innovation at Stanford (IRIS), Department of Radiology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Flemming Pociot
- Translational Type 1 Diabetes Research, Department of Clinical Research, Steno Diabetes Center Copenhagen, 2730 Herlev, Denmark
- Institute for Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Reza Yarani
- Interventional Regenerative Innovation at Stanford (IRIS), Department of Radiology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
- Translational Type 1 Diabetes Research, Department of Clinical Research, Steno Diabetes Center Copenhagen, 2730 Herlev, Denmark
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Ren L, Cui H, Wang Y, Ju F, Cai Y, Gang X, Wang G. The role of lipotoxicity in kidney disease: From molecular mechanisms to therapeutic prospects. Biomed Pharmacother 2023; 161:114465. [PMID: 36870280 DOI: 10.1016/j.biopha.2023.114465] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/20/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023] Open
Abstract
Lipotoxicity is the dysregulation of the lipid environment and/or intracellular composition that leads to accumulation of harmful lipids and ultimately to organelle dysfunction, abnormal activation of intracellular signaling pathways, chronic inflammation and cell death. It plays an important role in the development of acute kidney injury and chronic kidney disease, including diabetic nephropathy, obesity-related glomerulopathy, age-related kidney disease, polycystic kidney disease, and the like. However, the mechanisms of lipid overload and kidney injury remain poorly understood. Herein, we discuss two pivotal aspects of lipotoxic kidney injury. First, we analyzed the mechanism of lipid accumulation in the kidney. Accumulating data indicate that the mechanisms of lipid overload in different kidney diseases are inconsistent. Second, we summarize the multiple mechanisms by which lipotoxic species affect the kidney cell behavior, including oxidative stress, endoplasmic reticulum stress, mitochondrial dysfunction, dysregulated autophagy, and inflammation, highlighting the central role of oxidative stress. Blocking the molecular pathways of lipid accumulation in the kidney and the damage of the kidney by lipid overload may be potential therapeutic targets for kidney disease, and antioxidant drugs may play a pivotal role in the treatment of kidney disease in the future.
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Affiliation(s)
- Linan Ren
- Department of Endocrinology and Metabolism, First Hospital of Jilin University, Changchun 130021, Jilin, China; Institute of Translational Medicine, First Hospital of Jilin University, Changchun 130021, Jilin, China
| | - Haiying Cui
- Department of Endocrinology and Metabolism, First Hospital of Jilin University, Changchun 130021, Jilin, China; Institute of Translational Medicine, First Hospital of Jilin University, Changchun 130021, Jilin, China
| | - Yao Wang
- Department of Orthopedics, The Second Hospital of Jilin University, Changchun 130021, Jilin, China
| | - Feng Ju
- Department of Orthopedics, Yuci District People's Hospital, Yuci 030600, Shanxi, China
| | - Yunjia Cai
- Department of Endocrinology and Metabolism, First Hospital of Jilin University, Changchun 130021, Jilin, China
| | - Xiaokun Gang
- Department of Endocrinology and Metabolism, First Hospital of Jilin University, Changchun 130021, Jilin, China.
| | - Guixia Wang
- Department of Endocrinology and Metabolism, First Hospital of Jilin University, Changchun 130021, Jilin, China.
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Type 2 Diabetes and Alzheimer's Disease: The Emerging Role of Cellular Lipotoxicity. Biomolecules 2023; 13:biom13010183. [PMID: 36671568 PMCID: PMC9855893 DOI: 10.3390/biom13010183] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/06/2023] [Accepted: 01/13/2023] [Indexed: 01/18/2023] Open
Abstract
Type 2 diabetes (T2D) and Alzheimer's diseases (AD) represent major health issues that have reached alarming levels in the last decades. Although growing evidence demonstrates that AD is a significant comorbidity of T2D, and there is a ~1.4-2-fold increase in the risk of developing AD among T2D patients, the involvement of possible common triggers in the pathogenesis of these two diseases remains largely unknown. Of note, recent mechanistic insights suggest that lipotoxicity could represent the missing ring in the pathogenetic mechanisms linking T2D to AD. Indeed, obesity, which represents the main cause of lipotoxicity, has been recognized as a major risk factor for both pathological conditions. Lipotoxicity can lead to inflammation, insulin resistance, oxidative stress, ceramide and amyloid accumulation, endoplasmic reticulum stress, ferroptosis, and autophagy, which are shared biological events in the pathogenesis of T2D and AD. In the current review, we try to provide a critical and comprehensive view of the common molecular pathways activated by lipotoxicity in T2D and AD, attempting to summarize how these mechanisms can drive future research and open the way to new therapeutic perspectives.
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Singh S, Bansal A, Singh V, Chopra T, Poddar J. Flavonoids, alkaloids and terpenoids: a new hope for the treatment of diabetes mellitus. J Diabetes Metab Disord 2022; 21:941-950. [PMID: 35673446 PMCID: PMC9167359 DOI: 10.1007/s40200-021-00943-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 11/24/2021] [Indexed: 01/11/2023]
Abstract
Diabetes mellitus is a metabolic syndrome characterized by a hyperglycemic state and multi-organ failure. Millions of people worldwide are suffering from this deadly disease taking a hit on their pocket and mental health in the name of its treatment. Modern medical practices with new technological advancements and discoveries have made revolutionary changes in the treatment. But, unfortunately, Glucose-lowering drugs used have many accompanying effects such as chronic vascular disease, renal malfunction, liver disease and, many skin problems. These complications have made us think about alternative treatments for diabetes with minimum or no side effects. Nowadays, in addition to modern medicine, herbal treatment has been suggested to treat diabetes mellitus. These herbal medicines contain biological macromolecules such as flavonoids, Terpenoids, glycosides, and alkaloids, which show versatile anti-diabetic effects. These phytochemicals are generally considered safe, and naturally occurring compounds have a potential role in preventing or controlling diabetes mellitus. The underlying mechanism of their anti-diabetic effects includes improvement in insulin secretion, decrease in insulin resistance, enhanced liver glycogen synthesis, antioxidant and anti-inflammatory activities. In this review, we have focused on the mechanism of various phytochemicals targeting hyperglycemia and its underlying pathogenesis.
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Affiliation(s)
- Sukhpal Singh
- Department of Biochemistry and Central Research Cell, M.M. Institute of Medical Sciences and Research, University Research Fellow, Maharishi Markandeswar (Deemed to be University, Mullana, Ambala, 133207 India
| | - Abhishek Bansal
- Department of Biochemistry, Government Medical College, RAJOURI, Rajouri, Jammu and Kashmir 185135 India
| | - Vikramjeet Singh
- Kalpana Chawla Government Medical College, Karnal, Haryana India
| | - Tanya Chopra
- Department Of Biochemistry and Central Research Cell, M.M. Institute of Medical Sciences and Research, Maharishi Markandeshwar (Deemed to be University), Mullana, Ambala, 133207 India
| | - Jit Poddar
- Department of Microbiology, RG Kar Medical College & Hospital, Kolkata, West Bengal 700003 India
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7
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Samir SM, Elalfy M, Nashar EME, Alghamdi MA, Hamza E, Serria MS, Elhadidy MG. Cardamonin exerts a protective effect against autophagy and apoptosis in the testicles of diabetic male rats through the expression of Nrf2 via p62-mediated Keap-1 degradation. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2021; 25:341-354. [PMID: 34187951 PMCID: PMC8255125 DOI: 10.4196/kjpp.2021.25.4.341] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 05/08/2021] [Accepted: 05/27/2021] [Indexed: 12/14/2022]
Abstract
Cardamonin (CARD) is a chalconoid with anti-inflammatory and antioxidant properties, and it is present in several plants. We sought to explore whether CARD exerts any positive effects against hyperglycemia-induced testicular dysfunction caused by type 2 diabetes and aimed to identify its possible intracellular pathways. Adult male rats were subdivided into six groups: control, CARD, diabetic (DM), DM + glibenclamide (GLIB), DM + CARD and DM + GLIB + CARD. Type 2 DM induced a significant increase in blood glucose and insulin resistance, along with diminished serum insulin, testosterone and gonadotropins levels, which were associated with the impairment of key testicular androgenic enzymes and cellular redox balance. Administration of CARD at a dose of 80 mg/kg for 4 weeks effectively normalized all of these alterations, and the improvement was confirmed by epididymal sperm analysis. After treatment with CARD, the pathological changes in spermatogenic tubules were markedly improved. Significantly, CARD upregulated testicular glucose transporter-8 (GLUT-8) expression and had inhibitory effects on elevated autophagy markers and caspase-3 immunoreactive cells. Furthermore, our results revealed that CARD was able to attenuate damage via activation of Nrf2 through the p62-dependent degradation of testicular anti-Kelch-like ECH-associated protein-1 (Keap-1). In conclusion, this study suggests that CARD provides protection against diabetic stress-mediated testicular damage. The use of CARD with conventional anti-diabetic therapy was associated with improved efficacy compared with conventional therapy alone.
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Affiliation(s)
- Shereen M Samir
- Department of Medical Physiology, College of Medicine, Mansoura University, Mansoura 35511, Egypt
| | - Mahmoud Elalfy
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35511, Egypt
| | - Eman Mohamad El Nashar
- Department of Anatomy, Faculty of Medicine, King Khalid University, Abha 61421, Saudi Arabia.,Department of Histology and Cell Biology, College of Medicine, Benha University, Benha 13511, Egypt
| | - Mansour A Alghamdi
- Department of Anatomy, College of Medicine, King Khalid University, Abha 61421, Saudi Arabia.,Genomics and Personalized Medicine Unit, College of Medicine, King Khalid University, Abha 61421, Saudi Arabia
| | - Eman Hamza
- Medical Biochemistry Department, College of Medicine, Mansoura University, Mansoura 35511, Egypt
| | - Mohamed Saad Serria
- Medical Biochemistry Department, College of Medicine, Mansoura University, Mansoura 35511, Egypt
| | - Mona G Elhadidy
- Department of Medical Physiology, College of Medicine, Mansoura University, Mansoura 35511, Egypt.,Department of Medical Physiology, College of Medicine, Al-Baha University, Al-Baha 65525, Saudi Arabia
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Bahramsoltani R, Farzaei MH, Sajadimajd S, Iranpanah A, Khazaei M, Pourjabar Z, Hajimahmoodi M, Rahimi R. In vitro and in vivo antidiabetic activity of Tamarix stricta Boiss.: Role of autophagy. JOURNAL OF ETHNOPHARMACOLOGY 2021; 269:113692. [PMID: 33321187 DOI: 10.1016/j.jep.2020.113692] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/07/2020] [Accepted: 12/10/2020] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Type 2 diabetes mellitus (DM) is a complicated metabolic disorder with no definite treatment. Different species of the genus Tamarix (tamarisk) are used by local people to treat DM. Tamarix stricta Boiss. is an endemic species to Iran with several traditional therapeutic uses in Persian Medicine. This study aimed to assess the antidiabetic activity of T. stricta. MATERIALS AND METHODS Hydroethanolic extract of the plant was prepared and analyzed by High-performance liquid chromatography (HPLC). The protective effect of the extract was evaluated in streptozotocin (STZ)-induced toxicity and markers of autophagy in pancreatic RIN-5F cells. The effect of intragastric 10 or 20 mg/kg of the extract was compared with negative control (water) or positive control (metformin) treatment during four weeks of administration in high-fat diet + STZ-induced DM in Balb/c mice. RESULTS Results showed the presence of 8.436 mg of gallic acid in each gram of the extract. A significant cytoprotective effect was observed by T. stricta in STZ-induced toxicity in RIN-5F cells, partially due to the modulation of autophagy. Also, animals treated with the extract showed a significant improvement in glycemic and lipid profiles, liver function, and histopathologic features of pancreas and liver compared with the negative control. CONCLUSION T. stricta demonstrated beneficial effects in animal model of DM; though, further studies are recommended to confirm the clinical use of this plant in DM.
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Affiliation(s)
- Roodabeh Bahramsoltani
- Department of Traditional Pharmacy, School of Persian Medicine, Tehran University of Medical Sciences, Tehran, Iran; PhytoPharmacology Interest Group (PPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran.
| | - Mohammad Hosein Farzaei
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran; Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran.
| | - Soraya Sajadimajd
- Department of Biology, Faculty of Science, Razi University, Kermanshah, Iran.
| | - Amin Iranpanah
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran; Student Research Committee, Kermanshah University of Medical Sciences, Kermanshah, Iran.
| | - Mozafar Khazaei
- Fertility and Infertility Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran.
| | - Zeinab Pourjabar
- Drug and Food Control Department, Faculty of Pharmacy, and Food and Drug Administration, Tehran University of Medical Sciences, Tehran, Iran.
| | - Mannan Hajimahmoodi
- Drug and Food Control Department, Faculty of Pharmacy, and Food and Drug Administration, Tehran University of Medical Sciences, Tehran, Iran.
| | - Roja Rahimi
- Department of Traditional Pharmacy, School of Persian Medicine, Tehran University of Medical Sciences, Tehran, Iran; PhytoPharmacology Interest Group (PPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran.
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9
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El-Shafey ES, Elsherbiny ES. The role of apoptosis and autophagy in the insulin-enhancing activity of oxovanadium(IV) bipyridine complex in streptozotocin-induced diabetic mice. Biometals 2020; 33:123-135. [PMID: 32318895 DOI: 10.1007/s10534-020-00237-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 04/09/2020] [Indexed: 12/25/2022]
Abstract
Metal-based therapies (e.g. Vanadium) possess an attractive proposition in medicinal treatment of diabetes mellitus. Defective insulin secretion can result from impaired β-cell function which is mediated by many process including apoptosis and autophagy. In this study. diabetes was induced by administration of streptozotocin then treatment was performed by vanadyl sulfate and [VO(bpy)2 Cl] Cl.H2O complex. Blood glucose level, AST, ALT, BUN, CR, TCHO, TG and total protein were determined in serum. MDA, NO, erythrocyte GSH and SOD were estimated. LC3 and Caspase 3 levels in pancreatic cells were assessed by flow cytometer. Histopathological investigation of pancreatic tissue was performed. Results of Diabetic group showed a significant increase in transaminases activities, TCHO, TG, MDA, NO and Caspase 3 levels and significant decrease in TP, GSH, SOD and LC3 levels. Oral administration of vanadium complex resulted in normoglycemia, significant increase in blood GSH, SOD, TP and LC3 levels, significant decrease in ALT, AST, BUN, TCHO, TG, MDA and NO and Caspase 3 levels. In addition, proliferative effect of complex prevents islet atrophy. From previous results, the insulin-enhancing effect induced by this complex indicated that this new complex can be a valuable candidate as insulin-enhancing and antioxidant compound than inorganic vanadyl sulfate.
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Affiliation(s)
- Eman Salah El-Shafey
- Biochemistry Department, Faculty of Science, Damietta University, New Damietta, Egypt.
| | - Eslam Samy Elsherbiny
- Biochemistry Department, Faculty of Science, Damietta University, New Damietta, Egypt
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10
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Bhattacharya D, Dutta M, Mukhopadhyay M, Bhattacharyya M, Chowdhury S, Karmakar P. The protective role of metformin in autophagic status in peripheral blood mononuclear cells of type 2 diabetic patients. Cell Biol Int 2020; 44:1628-1639. [PMID: 32237184 DOI: 10.1002/cbin.11355] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 03/20/2020] [Accepted: 03/29/2020] [Indexed: 11/11/2022]
Abstract
Autophagy plays an important role in the pathophysiology of type 2 diabetes (T2D). Metformin is the most common antidiabetic drug. The main objective of this study was to explore the molecular mechanism of metformin in starvation-induced autophagy in peripheral blood mononuclear cells (PBMCs) of type 2 diabetic patients. PBMCs were isolated from 10 diabetic patients and 7 non-diabetic healthy volunteers. The autophagic puncta and markers were measured with the help of monodansylcadaverine staining and western blot. Additionally, transmission electron microscopy was also performed. No significant changes were observed in the initial autophagy marker protein levels in PBMCs of T2D after metformin treatment though diabetic PBMCs showed a high level of phospho-mammalian target of rapamycin, p62 and reduced expression of phospho-AMP-activated protein kinase and lysosomal membrane-associated protein 2, indicating a defect in autophagy. Also, induction of autophagy by tunicamycin resulted in apoptosis in diabetic PBMCs as observed by caspase-3 cleavage and reduced expression of Bcl2. Inhibition of autophagy by bafilomycin rendered consistent expression of p62 indicating a defect in the final process of autophagy. Further, electron microscopic studies also confirmed massive vacuole overload and a sign of apoptotic cell death in PBMCs of diabetic patients, whereas metformin treatment reduced the number of autophagic vacuoles perhaps by lysosomal fusion. Thus, our results indicate that defective autophagy in T2D is associated with the fusion process of lysosomes which could be overcome by metformin.
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Affiliation(s)
| | - Moumita Dutta
- Division of Electron Microscopy, ICMR-NICED, Kolkata, West Bengal, India
| | - Mainak Mukhopadhyay
- Department of Biotechnology, JIS University, Agarpara, Kolkata, West Bengal, India
| | | | - Subhankar Chowdhury
- Department of Endocrinology & Metabolism, Institute of Postgraduate Medical Education and Research, Kolkata, West Bengal, India
| | - Parimal Karmakar
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata, West Bengal, India
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11
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Quan M, Hong MW, Ko MS, Kim YY. Relationships Between Disc Degeneration and Autophagy Expression in Human Nucleus Pulposus. Orthop Surg 2019; 12:312-320. [PMID: 31802633 PMCID: PMC7031585 DOI: 10.1111/os.12573] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 08/22/2019] [Accepted: 10/14/2019] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVES To elaborate on the relationship between degeneration grade and autophagy expression in human nucleus pulposus obtained from surgical procedures. METHODS For the 16 patients included in the present study, we determined the Pfirrmann classifications of degenerative lesions by MRI. Western blot analysis, LC3, LAMP2, and p62 protein expressions were quantified in different degeneration grades of disc nucleus pulposus. Double immunofluorescence staining was used to show co-localization of LC3 and LAMP2, and immunohistochemistry to show LC3 and p62 in the nucleus pulposus. RESULTS In the western blot analysis, LC3-II was highly expressed in grade III and decreased progressively from grade IV to V. In addition, LC3-II expression in grade III was significantly higher than in grade II, IV, and V (P < 0.05). LAMP2 expression in grade V was significantly higher than that in grade II, III, and IV (P < 0.05). P62 increased with decreasing autophagy expression up through grade V. In the double staining, the LC3 level was highly expressed in grade III and decreased progressively from grades IV to V, as in the western blot analysis. LAMP2 rose with increasing disc degeneration grade through grade V. In the quantitative analysis of colocalization, grade III is significantly higher than grade II and V (P < 0.05). Immunohistochemical staining showed that LC3 was highly expressed in grade III but weakly expressed in other grades, with few positive areas around the nucleus pulposus. However, p62 increased progressively with increasing disc degeneration grade. CONCLUSION Pfirrmann grade III disc degeneration showed that autophagosomes were formed, which led to the reversible decomposition of degenerative substances. Thus, by analyzing the effect of autophagy on degenerative discs, we showed the possibility of reversing degenerative changes, but only in grades III and lower.
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Affiliation(s)
- Meiling Quan
- Department of Orthopedics, Daejeon St. Mary's Hospital, College of Medicine, Daejeon, Korea.,Department of Orthopedics, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Myoung-Wha Hong
- Department of Orthopedics, Daejeon St. Mary's Hospital, College of Medicine, Daejeon, Korea
| | - Myung-Sup Ko
- Department of Orthopedics, Daejeon St. Mary's Hospital, College of Medicine, Daejeon, Korea
| | - Young-Yul Kim
- Department of Orthopedics, Daejeon St. Mary's Hospital, College of Medicine, Daejeon, Korea
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12
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Grizzanti J, Corrigan R, Casadesus G. Neuroprotective Effects of Amylin Analogues on Alzheimer's Disease Pathogenesis and Cognition. J Alzheimers Dis 2019; 66:11-23. [PMID: 30282360 DOI: 10.3233/jad-180433] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Type II diabetes (T2D) has been identified as a major risk factor for the development of Alzheimer's disease (AD). Interestingly, both AD and T2D have similar characteristics including amyloid peptide aggregation, decreased metabolism, and increased oxidative stress and inflammation. Despite their prevalence, therapies for these diseases are limited. To date, most therapies for AD have targeted amyloid-β or tau. Unfortunately, most of these clinical trials have been largely unsuccessful, creating a crucial need for novel therapies. A number of studies have shown that metabolic hormone therapies are effective at ameliorating high blood glucose levels in diabetics as well as improving cognitive function in AD and mild cognitive impairment patients. Pramlintide, a synthetic analogue of the pancreatic hormone amylin, has been developed and used for years now as a treatment for both type I diabetes and T2D due to the loss of β-islet cells responsible for producing amylin. Importantly, recent data demonstrates its potential therapeutic role for AD as well. This review aims at addressing parallels between T2D and AD at a pathological and functional level, focusing on amylin signaling as a key, overlapping mediator in both diseases. The potential therapeutic use of this hormone to treat AD will also be explored from a mechanistic viewpoint.
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Affiliation(s)
- John Grizzanti
- School of Biomedical Sciences, Kent State University, Kent, OH, USA
| | - Rachel Corrigan
- School of Biomedical Sciences, Kent State University, Kent, OH, USA
| | - Gemma Casadesus
- School of Biomedical Sciences, Kent State University, Kent, OH, USA.,Department of Biological Sciences, Kent State University, Kent, OH, USA
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13
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Zeng J, Shirihai OS, Grinstaff MW. Degradable Nanoparticles Restore Lysosomal pH and Autophagic Flux in Lipotoxic Pancreatic Beta Cells. Adv Healthc Mater 2019; 8:e1801511. [PMID: 30698920 DOI: 10.1002/adhm.201801511] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/09/2019] [Indexed: 01/07/2023]
Abstract
Chronic exposure to high levels of fatty acids (lipotoxicity) in pancreatic beta cells (β-cells) decreases lysosomal acidity and inhibits autophagic flux. Today, there are a lack of approaches to modify lysosomal acidity to determine whether impaired lysosomal acidification is causally inhibiting autophagic flux and cellular functions. Biodegradable poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) with diameters of ≈100 nm localize to lysosomes and serve as an ideal method to deliver lactic and glycolic acid to lysosomes upon NP polymer degradation. In this study, the ability of PLGA NPs to lower lysosomal pH and restore autophagic flux is investigated in pancreatic insulin secreting (INS1) β-cells. PLGA NPs display a concentration dependent performance with higher concentrations of PLGA NPs, lowering lysosomal pH, as well as restoring autophagic flux and insulin secretion in pancreatic β-cells. These results document that acidifying the lysosome, via an external perturbation, in lipotoxic pancreatic β-cells affords a specific biological outcome of improved cellular degradative activity.
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Affiliation(s)
- Jialiu Zeng
- Department of Biomedical EngineeringBoston University Boston MA 02215 USA
| | - Orian S. Shirihai
- Division of EndocrinologyDepartment of MedicineDavid Geffen School of MedicineUniversity of California, Los Angeles Los Angeles CA 90045 USA
- Department of MedicineBoston University School of Medicine Boston MA 02118 USA
| | - Mark W. Grinstaff
- Department of Biomedical EngineeringBoston University Boston MA 02215 USA
- Department of MedicineBoston University School of Medicine Boston MA 02118 USA
- Department of ChemistryBoston University Boston MA 02215 USA
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14
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Cheng STW, Li SYT, Leung PS. Fibroblast Growth Factor 21 Stimulates Pancreatic Islet Autophagy via Inhibition of AMPK-mTOR Signaling. Int J Mol Sci 2019; 20:ijms20102517. [PMID: 31121855 PMCID: PMC6567208 DOI: 10.3390/ijms20102517] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 05/17/2019] [Accepted: 05/21/2019] [Indexed: 12/13/2022] Open
Abstract
Background: Islet autophagy plays a role in glucose/lipid metabolism in type 2 diabetes mellitus. Meanwhile, fibroblast growth factor 21 (FGF21) has been found to regulate insulin sensitivity and glucose homeostasis. Whether FGF21 induces islet autophagy, remains to be elucidated. This study aimed to explore the physiological roles and signaling pathways involved in FGF21-stimulated islet autophagy under glucolipotoxic conditions. Methods: C57/BL6J mice were fed a standard diet or high-fat diet (HFD) for 12 weeks, and islets were isolated from normal and FGF21 knockout (KO) mice. Isolated islets and INS-1E cells were exposed to normal and high-concentration glucose and palmitic acid with/without FGF21 or AMPK inhibitor compound C. Real-time PCR, Western blot and immunohistochemistry/transmission electron microscopy were performed for the expression of targeted genes/proteins. Results: HFD-treated mice showed increases in fasting plasma glucose, body weight and impaired glucose tolerance; islet protein expression of FGF21 was induced after HFD treatment. Protein expression levels of FGF21 and LC3-II (autophagy marker) were induced in mouse islets treated with high concentrations of palmitic acid and glucose, while phosphorylation of AMPK was reduced, compared with controls. In addition, induction of LC3-II protein expression was reduced in islets isolated from FGF21 KO mice. Furthermore, exogenous administration of FGF21 diminished phosphorylation of AMPK and stimulated protein expression of LC3-II. Consistently, compound C significantly induced increased expression of LC3-II protein. Conclusions: Our data indicate that glucolipotoxicity-induced FGF21 activation mediates islet autophagy via AMPK inhibition, and further consolidate the evidence for the FGF21/analog being a pharmacotherapeutic target for obesity and its related T2DM.
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Affiliation(s)
- Sam Tsz Wai Cheng
- School of Biomedical Sciences, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China.
| | - Stephen Yu Ting Li
- School of Biomedical Sciences, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China.
| | - Po Sing Leung
- School of Biomedical Sciences, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China.
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15
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Li Q, Jia S, Xu L, Li B, Chen N. Metformin-induced autophagy and irisin improves INS-1 cell function and survival in high-glucose environment via AMPK/SIRT1/PGC-1α signal pathway. Food Sci Nutr 2019; 7:1695-1703. [PMID: 31139382 PMCID: PMC6526663 DOI: 10.1002/fsn3.1006] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Accepted: 03/04/2019] [Indexed: 12/15/2022] Open
Abstract
In order to explore the protective function of metformin on pancreatic β cells to alleviate insulin resistance and underlying mechanisms, INS-1 cells were cultured into normal control (N), high glucose (H), high glucose and metformin (H + Met), high glucose and chloroquine (H + CQ), and high glucose and Ex527 (H + Ex527) groups, respectively. Upon 24-hr cultivation, the proliferation and glucose-stimulated insulin secretion (GSIS) of INS-1 cells were determined, and the expression of irisin and other proteins associated with AMPK/SIRT1/PGC-1α signal pathway, autophagy, and apoptosis was evaluated. Compared with the N group, the cells from the H group revealed lower proliferation, GSIS, and expression of irisin and proteins associated with AMPK/SIRT1/PGC-1α signal pathway and autophagy, but higher expression of proteins associated with apoptosis; in contrast, metformin could significantly rescue lower cell proliferation, GSIS, and expression of proteins associated with AMPK/SIRT1/PGC-1α signal pathway and autophagy, as well as irisin, and suppress apoptosis in high-glucose environment. Meanwhile, autophagy inhibitor CQ and SIRT1 inhibitor Ex527 can block above functions of metformin. Therefore, metformin can promote INS-1 cell proliferation, enhance GSIS, and suppress apoptosis by activating AMPK/SIRT1/PGC-1α signal pathway, up-regulating irisin expression, and inducing autophagy in INS-1 cells in high-glucose environment.
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Affiliation(s)
- Qingxue Li
- Tianjiu Research and Development Center for Exercise Nutrition and Foods, Hubei Key Laboratory of Sport Training and Monitoring, College of Health ScienceWuhan Sports UniversityWuhanChina
- School of Sports and HealthLinyi UniversityLinyiChina
| | - Shaohui Jia
- Tianjiu Research and Development Center for Exercise Nutrition and Foods, Hubei Key Laboratory of Sport Training and Monitoring, College of Health ScienceWuhan Sports UniversityWuhanChina
| | - Lei Xu
- Graduate SchoolWuhan Sports UniversityWuhanChina
| | - Biao Li
- Graduate SchoolWuhan Sports UniversityWuhanChina
| | - Ning Chen
- Tianjiu Research and Development Center for Exercise Nutrition and Foods, Hubei Key Laboratory of Sport Training and Monitoring, College of Health ScienceWuhan Sports UniversityWuhanChina
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16
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Extensive mechanical tension promotes annulus fibrosus cell senescence through suppressing cellular autophagy. Biosci Rep 2019; 39:BSR20190163. [PMID: 30910846 PMCID: PMC6470409 DOI: 10.1042/bsr20190163] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 03/14/2019] [Accepted: 03/24/2019] [Indexed: 12/20/2022] Open
Abstract
Background: Mechanical load contributes a lot to the initiation and progression of disc degeneration. Annulus fibrosus (AF) cell biology under mechanical tension remains largely unclear. Objective: The present study was aimed to investigate AF cell senescence under mechanical tension and the potential role of autophagy. Methods: Rat AF cells were cultured and experienced different magnitudes (5% elongation and 20% elongation) of mechanical tension for 12 days. Control AF cells were kept static. Cell proliferation, telomerase activity, cell cycle fraction, and expression of senescence-related molecules (p16 and p53) and matrix macromolecules (aggrecan and collagen I) were analyzed to evaluate cell senescence. In addition, expression of Beclin-1 and LC3, and the ratio of LC3-II to LC3-I were analyzed to investigate cell autophagy. Results: Compared with the control group and 5% tension group, 20% tension group significantly decreased cell proliferation potency and telomerase activity, increased G1/G0 phase fraction, and up-regulated gene/protein expression of p16 and p53, whereas down-regulated gene/protein expression of aggrecan and collagen I. In addition, autophagy-related parameters such as gene/protein expression of Beclin-1 and LC3, and the ratio of LC3-II to LC3-I, were obviously suppressed in the 20% tension group. Conclusion: High mechanical tension promotes AF cell senescence though suppressing cellular autophagy. The present study will help us to better understand AF cell biology under mechanical tension and mechanical load-related disc degeneration.
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17
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FGF21 activation-mediated islet autophagy in Type 2 diabetes with pharmacotherapeutic potential. Future Med Chem 2019; 11:641-643. [PMID: 30920304 DOI: 10.4155/fmc-2018-0491] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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18
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Gut Microbiota, a Potential New Target for Chinese Herbal Medicines in Treating Diabetes Mellitus. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2019; 2019:2634898. [PMID: 30906411 PMCID: PMC6398116 DOI: 10.1155/2019/2634898] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 12/18/2018] [Accepted: 01/29/2019] [Indexed: 12/12/2022]
Abstract
The gut microbiota, as an important factor affecting host health, plays a significant role in the occurrence and development of diabetes mellitus (DM), and the mechanism may be related to excessive endotoxins, altered short-chain fatty acids (SCFAs), and disordered bile acid metabolism. Traditional Chinese medicine (TCM) has a long history of treating DM, but its mechanism is not very clear. Recent research has suggested that Chinese herbal medicine can improve glucose metabolism by remodeling the gut microbiota, which opens new avenues for further research on hypoglycemic mechanisms. This review presents the recent progress of Chinese herbs, herbal extracts, and herbal compound preparations in treating DM through regulating the gut microbiota and summarizes the main mechanisms involved, namely, anti-inflammatory and antioxidative effects, protecting the intestinal barrier and inhibiting lipotoxicity. In addition, some suggestions for improvement are also proposed.
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19
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Niu C, Chen Z, Kim KT, Sun J, Xue M, Chen G, Li S, Shen Y, Zhu Z, Wang X, Liang J, Jiang C, Cong W, Jin L, Li X. Metformin alleviates hyperglycemia-induced endothelial impairment by downregulating autophagy via the Hedgehog pathway. Autophagy 2019; 15:843-870. [PMID: 30653446 PMCID: PMC6526809 DOI: 10.1080/15548627.2019.1569913] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Studies regarding macroautophagic/autophagic regulation in endothelial cells (ECs) under diabetic conditions are very limited. Clinical evidence establishes an endothelial protective effect of metformin, but the underlying mechanisms remain unclear. We aimed to investigate whether metformin exerts its protective role against hyperglycemia-induced endothelial impairment through the autophagy machinery. db/db mice were treated with intravitreal metformin injections. Human umbilical vein endothelial cells (HUVECs) were cultured either in normal glucose (NG, 5.5 mM) or high glucose (HG, 33 mM) medium in the presence or absence of metformin for 72 h. We observed an obvious inhibition of hyperglycemia-triggered autophagosome synthesis in both the diabetic retinal vasculature and cultured HUVECs by metformin, along with restoration of hyperglycemia-impaired Hedgehog (Hh) pathway activity. Specifically, deletion of ATG7 in retinal vascular ECs of db/db mice and cultured HUVECs indicated a detrimental role of autophagy in hyperglycemia-induced endothelial dysfunction. Pretreatment with GANT61, a Hh pathway inhibitor, abolished the metformin-mediated downregulation of autophagy and endothelial protective action. Furthermore, GLI-family (transcription factors of the Hh pathway) knockdown in HUVECs and retinal vasculature revealed that downregulation of hyperglycemia-activated autophagy by the metformin-mediated Hh pathway activation was GLI1 dependent. Mechanistically, GLI1 knockdown-triggered autophagy was related to upregulation of BNIP3, which subsequently disrupted the association of BECN1/Beclin 1 and BCL2. The role of BNIP3 in BECN1 dissociation from BCL2 was further confirmed by BNIP3 overexpression or BNIP3 RNAi. Taken together, the endothelial protective effect of metformin under hyperglycemia conditions could be partly attributed to its role in downregulating autophagy via Hh pathway activation. Abbreviations: 3-MA = 3-methyladenine; 8×GLI BS-FL = 8×GLI-binding site firefly luciferase; AAV = adeno-associated virus; AAV-Cdh5-sh-Atg7 = AAV vectors carrying shRNA against murine Atg7 under control of murine Cdh5 promoter; AAV-Cdh5-sh-Gli1 = AAV vectors carrying shRNA against murine Gli1 under control of murine Cdh5 promoter; AAV-Cdh5-Gli1 = AAV vectors carrying murine Gli1 cDNA under the control of murine Cdh5 core promoter; ACAC = acetyl-CoA carboxylase; Ad-BNIP3 = adenoviruses harboring human BNIP3`; Ad-GLI1 = adenoviruses harboring human GLI1; Ad-sh-ATG7 = adenoviruses harboring shRNA against human ATG7; Ad-sh-BNIP3 = adenoviruses harboring shRNA against human BNIP3; Ad-sh-GLI = adenoviruses harboring shRNA against human GLI; AGEs = advanced glycation end products; ATG = autophagy-related; atg7flox/flox mice = mice bearing an Atg7flox allele, in which exon 14 of the Atg7 gene is flanked by 2 loxP sites; BafA1 = bafilomycin A1; BECN1 = beclin 1; CDH5/VE-cadherin = cadherin 5; CASP3 = caspase 3; CASP8 = caspase 8; CASP9 = caspase 9; ECs = endothelial cells; GAPDH = glyceraldehyde-3-phosphate dehydrogenase; GCL = ganglion cell layer; GFP-LC3B = green fluorescent protein labelled LC3B; HG = high glucose; Hh = Hedgehog; HHIP = hedgehog interacting protein; HUVECs = human umbilical vein endothelial cells; IB4 = isolectin B4; INL = inner nuclear layer; i.p. = intraperitoneal; MAP1LC3/LC3 = microtubule-associated protein 1 light chain 3; MAN = mannitol; MET = metformin; NG = normal glucose; ONL = outer nuclear layer; p-ACAC = phosphorylated acetyl-CoA carboxylase; PECAM1/CD31= platelet/endothelial cell adhesion molecule 1; PRKAA1/2 = protein kinase AMP-activated catalytic subunits alpha 1/2; p-PRKAA1/2 = phosphorylated PRKAA1/2; PTCH1 = patched 1; RAPA = rapamycin; RL = Renilla luciferase; SHH = sonic hedgehog; shRNA = short hairpin RNA; sh-PRKAA1/2 = short hairpin RNA against human PRKAA1/2; scrambled shRNA = the scrambled short hairpin RNA serves as a negative control for the target-specific short hairpin RNA, which has the same nucleotide composition as the input sequence and has no match with any mRNA of the selected organism database; SMO = smoothened, frizzled class receptor; sqRT-PCR = semi-quantitative RT-PCR; TEK/Tie2 = TEK receptor tyrosine kinase; Tek-Cre (+) mice = a mouse strain expressing Cre recombinase under the control of the promoter/enhancer of Tek, in a pan-endothelial fashion; TUNEL = terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling.
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Affiliation(s)
- Chao Niu
- Pediatric Research Institute, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, P.R. China,School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, P.R. China
| | - Zhiwei Chen
- Pediatric Research Institute, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, P.R. China,School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, P.R. China
| | - Kyoung Tae Kim
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, P.R. China
| | - Jia Sun
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, P.R. China
| | - Mei Xue
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, P.R. China
| | - Gen Chen
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, P.R. China
| | - Santie Li
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, P.R. China
| | - Yingjie Shen
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, P.R. China
| | - Zhongxin Zhu
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, P.R. China
| | - Xu Wang
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, P.R. China
| | - Jiaojiao Liang
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, P.R. China
| | - Chao Jiang
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, P.R. China,CONTACT Litai Jin ; Weitao Cong ; Chao Jiang School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou 325000, P.R. China
| | - Weitao Cong
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, P.R. China,CONTACT Litai Jin ; Weitao Cong ; Chao Jiang School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou 325000, P.R. China
| | - Litai Jin
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, P.R. China,CONTACT Litai Jin ; Weitao Cong ; Chao Jiang School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou 325000, P.R. China
| | - Xiaokun Li
- School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, P.R. China
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20
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Saleh A, Anwar MM, Zayed AE, Ezz Eldeen MES, Afifi G, Alnashiri HM, Gomaa AMS, Abd-Elkareem M, Abou-Elhamd AS, Shaheen ES, Mohamed GA, Hetta HF, Kotb AM. Impact of Ginkgo biloba extract and magnetized water on the survival rate and functional capabilities of pancreatic β-cells in type 2 diabetic rat model. Diabetes Metab Syndr Obes 2019; 12:1339-1347. [PMID: 31496771 PMCID: PMC6689767 DOI: 10.2147/dmso.s209856] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 07/16/2019] [Indexed: 12/15/2022] Open
Abstract
INTRODUCTION Type 2 diabetes (T2D) is a widely distributed disease that affects large population worldwide. This study aimed to verify the role of Ginkgo biloba (GB) extract and magnetized water (MW) on the survival rate and functional capabilities of pancreatic β-cells in type 2 diabetic rats. MATERIALS AND METHODS T2D was induced by feeding the rats on a high-fat diet (20% fat, 45% carbohydrate, 22% protein) for eight weeks followed by intra-peritoneal injection of a single low dose of streptozotocin (25mg/Kg). Forty rats were randomly assigned to four groups (n=10 rats) as follows: non treated control and three diabetic groups. One diabetic group served as a positive control (diabetic), while the other two groups were orally administered with water extract of GB leaves (0.11 g/kg/day) and MW (600 gauss) for four weeks, respectively. RESULTS The β-cell mass and insulin expression in these cells increased markedly after both treatments, particularly in GB treated group. In addition, the immune-expression of the two antioxidant enzymes; glutathione and superoxide dismutase 2 (SOD2) in the pancreatic tissue demonstrated a down-regulation in GB and MW treated groups as compared with the diabetic group. CONCLUSION A four-week treatment of GB and MW protected pancreatic β-cell cells and improved their insulin expression and antioxidant status in type 2 diabetic rats.
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Affiliation(s)
- Ahmed Saleh
- Department of Physics, Faculty of Science, Jazan University, Jazan, KSA
- Exploratory Center of Science and Technology
, Cairo, Egypt
| | - Mamdouh M Anwar
- Department of Pharmacology, Faculty of Pharmacy, Jazan University, Jazan, KSA
- Medical Physiology Department, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Ahmed E Zayed
- Department of Biology, Faculty of Science, Jazan University, Jazan, KSA
- Department of Anatomy and Histology, Faculty of Veterinary Medicine, Assiut University, Egypt
| | - Manal El Sayed Ezz Eldeen
- Endocrine Unit, Department of Internal Medicine, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Gamal Afifi
- Department of Physics, Faculty of Science, Jazan University, Jazan, KSA
- National Institute for Laser Enhanced Sciences, Cairo University
, Giza, Egypt
| | | | - Asmaa MS Gomaa
- Medical Physiology Department, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Mahmoud Abd-Elkareem
- Department of Anatomy and Histology, Faculty of Veterinary Medicine, Assiut University, Egypt
| | - Alaa Sayed Abou-Elhamd
- Department of Anatomy and Histology, Faculty of Veterinary Medicine, Assiut University, Egypt
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, Jazan University, Jazan, Saudi Arabia
| | | | - Ghada A Mohamed
- Endocrine Unit, Department of Internal Medicine, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Helal F Hetta
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Assiut University, Assiut, Egypt
- Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, USA
- Correspondence: Helal F HettaDepartment of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, 231 Albert B. Sabin Way, PO Box 670595, OH45267-0595, USAEmail
| | - Ahmed M Kotb
- Department of Anatomy and Histology, Faculty of Veterinary Medicine, Assiut University, Egypt
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21
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Klee NS, McCarthy CG, Lewis S, McKenzie JL, Vincent JE, Webb RC. Urothelial Senescence in the Pathophysiology of Diabetic Bladder Dysfunction-A Novel Hypothesis. Front Surg 2018; 5:72. [PMID: 30564582 PMCID: PMC6288180 DOI: 10.3389/fsurg.2018.00072] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 11/12/2018] [Indexed: 12/11/2022] Open
Abstract
Diabetic bladder dysfunction (DBD) is a well-recognized and common symptom affecting up to 50% of all diabetic patients. DBD has a broad range of clinical presentations ranging from overactive to underactive bladder symptoms that develops in middle-aged to elderly patients with long standing and poorly controlled diabetes. Low efficacy of current therapeutics and lifestyle interventions combined with high national healthcare costs highlight the need for more research into bladder dysfunction pathophysiology and novel treatment options. Cellular senescence is an age-related physiologic process in which cells undergo irreversible growth arrest induced by replicative exhaustion and damaging insults. While controlled senescence negatively regulates cell proliferation and promotes tissue regeneration, uncontrolled senescence is known to result in tissue dysfunction through enhanced secretion of inflammatory factors. This review presents previous scientific findings and current hypotheses that characterize diabetic bladder dysfunction. Further, we propose the novel hypothesis that cellular senescence within the urothelial layer of the bladder contributes to the pro-inflammatory/pro-oxidant environment and symptoms of diabetic bladder dysfunction. Our results show increased cellular senescence in the urothelial layer of the bladder; however, whether this phenomenon is the cause or effect of DBD is unknown. The urothelial layer of the bladder is made up of transitional epithelia specialized to contract and expand with demand and plays an active role in transmission by modulating afferent activity. Transition from normal functioning urothelial cells to secretory senescence cells would not only disrupt the barrier function of this layer but may result in altered signaling and sensation of bladder fullness; dysfunction of this layer is known to result in symptoms of frequency and urgency. Future DBD therapeutics may benefit from targeting and preventing early transition of urothelial cells to senescent cells.
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Affiliation(s)
- Nicole S Klee
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Cameron G McCarthy
- Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
| | - Steven Lewis
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Jaine L McKenzie
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, United States.,Department of Surgery, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Julie E Vincent
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - R Clinton Webb
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, United States
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Yang L, Guan G, Lei L, Lv Q, Liu S, Zhan X, Jiang Z, Gu X. Palmitic acid induces human osteoblast-like Saos-2 cell apoptosis via endoplasmic reticulum stress and autophagy. Cell Stress Chaperones 2018; 23:1283-1294. [PMID: 30194633 PMCID: PMC6237680 DOI: 10.1007/s12192-018-0936-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 08/27/2018] [Accepted: 09/01/2018] [Indexed: 12/30/2022] Open
Abstract
Palmitic acid (PA) is the most common saturated long-chain fatty acid in food that causes cell apoptosis. However, little is known about the molecular mechanisms of PA toxicity. In this study, we explore the effects of PA on proliferation and apoptosis in human osteoblast-like Saos-2 cells and uncover the signaling pathways involved in the process. Our study showed that endoplasmic reticulum (ER) stress and autophagy are involved in PA-induced Saos-2 cell apoptosis. We found that PA inhibited the viability of Saos-2 cells in a dose- and time-dependent manner. At the same time, PA induced the expression of ER stress marker genes (glucose-regulated protein 78 (GRP78) and CCAAT/enhancer binding protein homologous protein (CHOP)), altered autophagy-related gene expression (microtubule-associated protein 1 light chain 3 (LC3), ATG5, p62, and Beclin), promoted apoptosis-related gene expression (Caspase 3 and BAX), and affected autophagic flux. Inhibiting ER stress with 4-PBA diminished the PA-induced cell apoptosis, activated autophagy, and increased the expression of Caspase 3 and BAX. Inhibiting autophagy with 3-MA attenuated the PA and ER stress-induced cell apoptosis and the apoptosis-related gene expression (Caspase 3 and BAX), but seemed to have no obvious effects on ER stress, although the CHOP expression was downregulated. Taken together, our results suggest that PA-induced Saos-2 cell apoptosis is activated via ER stress and autophagy, and the activation of autophagy depends on the ER stress during this process.
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Affiliation(s)
- Lei Yang
- College of Basic Medical, Jiujiang University, Jiujiang, 332000, Jiangxi, China.
- Key Laboratory of System Bio-medicine of Jiangxi Province, Jiujiang University, Jiujiang, 332000, Jiangxi, China.
| | - Gaopeng Guan
- Key Laboratory of System Bio-medicine of Jiangxi Province, Jiujiang University, Jiujiang, 332000, Jiangxi, China
- Affiliated Hospital of Jiujiang University, Jiujiang University, Jiujiang, 332000, Jiangxi, China
- Medicine Graduate School, Nanchang University, Nanchang, 330006, China
| | - Lanjie Lei
- Affiliated Hospital of Jiujiang University, Jiujiang University, Jiujiang, 332000, Jiangxi, China
| | - Qizhuang Lv
- College of Biology & Pharmacy, Yulin Normal University, Yulin, 537000, Guangxi, China
| | - Shengyuan Liu
- Key Laboratory of System Bio-medicine of Jiangxi Province, Jiujiang University, Jiujiang, 332000, Jiangxi, China
- Affiliated Hospital of Jiujiang University, Jiujiang University, Jiujiang, 332000, Jiangxi, China
- Medicine Graduate School, Nanchang University, Nanchang, 330006, China
| | - Xiuwen Zhan
- Key Laboratory of System Bio-medicine of Jiangxi Province, Jiujiang University, Jiujiang, 332000, Jiangxi, China
- Affiliated Hospital of Jiujiang University, Jiujiang University, Jiujiang, 332000, Jiangxi, China
| | - Zhenzhen Jiang
- Medicine Graduate School, Nanchang University, Nanchang, 330006, China
| | - Xiang Gu
- Key Laboratory of System Bio-medicine of Jiangxi Province, Jiujiang University, Jiujiang, 332000, Jiangxi, China.
- Affiliated Hospital of Jiujiang University, Jiujiang University, Jiujiang, 332000, Jiangxi, China.
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23
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Petcherski A, Trudeau KM, Wolf DM, Segawa M, Lee J, Taddeo EP, Deeney JT, Liesa M. Elamipretide Promotes Mitophagosome Formation and Prevents Its Reduction Induced by Nutrient Excess in INS1 β-cells. J Mol Biol 2018; 430:4823-4833. [PMID: 30389435 DOI: 10.1016/j.jmb.2018.10.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 09/22/2018] [Accepted: 10/24/2018] [Indexed: 11/28/2022]
Abstract
Elamipretide is a tetrapeptide that restores defects in mitochondrial function, binds to cardiolipin, and is being tested in clinical trials for mitochondria-related diseases. However, whether elamipretide modulates mitochondrial quality control and dynamics, processes essential to preserve mitochondrial function, is unclear. Thus, we tested the effects of elamipretide on mitochondrial morphology, mitophagosome formation, and their early disruption induced by excess nutrients in INS1 β-cells. Elamipretide treatment was sufficient to increase engulfment of mitochondria into autophagosomes in control INS1 β-cells, without inducing widespread changes in mitochondrial morphology or membrane potential. In an early pathogenic context mimicked by short-term exposure to nutrient excess, elamipretide treatment prevented both mitochondrial fragmentation and defects in the engulfment of mitochondria into autophagosomes. On the other hand, elamipretide did not prevent lysosomal defects induced by nutrient excess. Accordingly, elamipretide treatment did not entail benefits on pathogenic p62 and LC3II accumulation or on insulin secretory function. In conclusion, our data show that elamipretide selectively stimulates the engulfment of mitochondria into autophagosomes and prevents its defects induced by nutrient excess. Thus, we propose that improved selectivity of mitochondrial quality control processes might contribute to the benefits stemming from elamipretide treatments in other disease models.
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Affiliation(s)
- Anton Petcherski
- Departments of Medicine, Endocrinology and Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Kyle M Trudeau
- Department of Medicine, Evans Biomedical Research Center, Boston University School of Medicine, Boston, MA 02118, USA
| | - Dane M Wolf
- Departments of Medicine, Endocrinology and Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Department of Medicine, Evans Biomedical Research Center, Boston University School of Medicine, Boston, MA 02118, USA
| | - Mayuko Segawa
- Departments of Medicine, Endocrinology and Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Jennifer Lee
- Department of Medicine, Evans Biomedical Research Center, Boston University School of Medicine, Boston, MA 02118, USA
| | - Evan P Taddeo
- Departments of Medicine, Endocrinology and Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Jude T Deeney
- Department of Medicine, Evans Biomedical Research Center, Boston University School of Medicine, Boston, MA 02118, USA
| | - Marc Liesa
- Departments of Medicine, Endocrinology and Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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24
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Li Z, Liu H, Niu Z, Zhong W, Xue M, Wang J, Yang F, Zhou Y, Zhou Y, Xu T, Hou J. Temporal Proteomic Analysis of Pancreatic β-Cells in Response to Lipotoxicity and Glucolipotoxicity. Mol Cell Proteomics 2018; 17:2119-2131. [PMID: 30082485 DOI: 10.1074/mcp.ra118.000698] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 08/03/2018] [Indexed: 12/12/2022] Open
Abstract
Chronic hyperlipidemia causes the dysfunction of pancreatic β-cells, such as apoptosis and impaired insulin secretion, which are aggravated in the presence of hyperglycemia. The underlying mechanisms, such as endoplasmic reticulum (ER) stress, oxidative stress and metabolic disorders, have been reported before; however, the time sequence of these molecular events is not fully understood. Here, using isobaric labeling-based mass spectrometry, we investigated the dynamic proteomes of INS-1 cells exposed to high palmitate in the absence and presence of high glucose. Using bioinformatics analysis of differentially expressed proteins, including the time-course expression pattern, protein-protein interaction, gene set enrichment and KEGG pathway analysis, we analyzed the dynamic features of previously reported and newly identified lipotoxicity- and glucolipotoxicity-related molecular events in more detail. Our temporal data highlight cholesterol metabolism occurring at 4 h, earlier than fatty acid metabolism that started at 8 h and likely acting as an early toxic event highly associated with ER stress induced by palmitate. Interestingly, we found that the proliferation of INS-1 cells was significantly increased at 48 h by combined treatment of palmitate and glucose. Moreover, benefit from the time-course quantitative data, we identified and validated two new molecular targets: Setd8 for cell replication and Rhob for apoptosis, demonstrating that our temporal dataset serves as a valuable resource to identify potential candidates for mechanistic studies of lipotoxicity and glucolipotoxicity in pancreatic β-cells.
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Affiliation(s)
- Zonghong Li
- From the ‡National Laboratory of Biomacramolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,§Jilin Province Key Laboratory on Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, 130024, China
| | - Hongyang Liu
- From the ‡National Laboratory of Biomacramolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,‖Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhangjing Niu
- From the ‡National Laboratory of Biomacramolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,‖Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wen Zhong
- ***College of Life Science and Technology, HuaZhong University of Science and Technology, Wuhan 430074, China
| | - Miaomiao Xue
- From the ‡National Laboratory of Biomacramolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,¶College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jifeng Wang
- ‡‡Laboratory of Protein and Peptide Pharmaceuticals and Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Fuquan Yang
- ‡‡Laboratory of Protein and Peptide Pharmaceuticals and Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,¶College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yue Zhou
- §§ThermoFisher Scientific, Building 6, No. 27, Xin Jinqiao Rd, Pudong, Shanghai, 201206, China
| | - Yifa Zhou
- §Jilin Province Key Laboratory on Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, 130024, China;
| | - Tao Xu
- From the ‡National Laboratory of Biomacramolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; .,¶College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Junjie Hou
- From the ‡National Laboratory of Biomacramolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China;
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25
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Esterline RL, Vaag A, Oscarsson J, Vora J. MECHANISMS IN ENDOCRINOLOGY: SGLT2 inhibitors: clinical benefits by restoration of normal diurnal metabolism? Eur J Endocrinol 2018; 178:R113-R125. [PMID: 29371333 DOI: 10.1530/eje-17-0832] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 01/19/2018] [Indexed: 12/26/2022]
Abstract
Type 2 diabetes (T2D) is associated with inhibition of autophagic and lysosomal housekeeping processes that detrimentally affect key organ functioning; a process likely to be exacerbated by conventional insulin-driven anabolic therapies. We propose that the cardio-renal benefits demonstrated with sodium-glucose cotransporter-2 inhibitor (SGLT2i) treatment in T2D partly may be explained by their ability to drive consistent, overnight periods of increased catabolism brought about by constant glucosuria. Key steps driving this catabolic mechanism include: a raised glucagon/insulin ratio initially depleting glycogen in the liver and ultimately activating gluconeogenesis utilizing circulating amino acids (AAs); a general fuel switch from glucose to free fatty acids (accompanied by a change in mitochondrial morphology from a fission to a sustained fusion state driven by a decrease in AA levels); a decrease in circulating AAs and insulin driving inhibition of mammalian target of rapamycin complex 1 (mTORC1), which enhances autophagy/lysosomal degradation of dysfunctional organelles, eventually causing a change in mitochondrial morphology from a fission to a sustained fusion state. Resumption of eating in the morning restores anabolic biogenesis of new and fully functional organelles and proteins. Restoration of diurnal metabolic rhythms and flexibility by SGLT2is may have therapeutic implications beyond those already demonstrated for the cardio-renal axis and may therefore affect other non-diabetes disease states.
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Affiliation(s)
| | - Allan Vaag
- Cardiovascular and Metabolic Disease (CVMD) Translational Medicine Unit, Early Clinical Development, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden
| | - Jan Oscarsson
- AstraZeneca Pharmaceuticals, Gaithersburg, Maryland, USA
| | - Jiten Vora
- Royal Liverpool University Hospital, University of Liverpool, Liverpool, UK
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26
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Chen J, Xie JJ, Jin MY, Gu YT, Wu CC, Guo WJ, Yan YZ, Zhang ZJ, Wang JL, Zhang XL, Lin Y, Sun JL, Zhu GH, Wang XY, Wu YS. Sirt6 overexpression suppresses senescence and apoptosis of nucleus pulposus cells by inducing autophagy in a model of intervertebral disc degeneration. Cell Death Dis 2018; 9:56. [PMID: 29352194 PMCID: PMC5833741 DOI: 10.1038/s41419-017-0085-5] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Revised: 09/22/2017] [Accepted: 10/05/2017] [Indexed: 02/08/2023]
Abstract
Treatment of intervertebral disc degeneration (IDD) seeks to prevent senescence and death of nucleus pulposus (NP) cells. Previous studies have shown that sirt6 exerts potent anti-senescent and anti-apoptotic effects in models of age-related degenerative disease. However, it is not known whether sirt6 protects against IDD. Here, we explored whether sirt6 influenced IDD. The sirt6 level was reduced in senescent human NP cells. Sirt6 overexpression protected against apoptosis and both replicative and stress-induced premature senescence. Sirt6 also activated NP cell autophagy both in vivo and in vitro. 3-methyladenine (3-MA) and chloroquine (CQ)-mediated inhibition of autophagy partially reversed the anti-senescent and anti-apoptotic effects of sirt6, which regulated the expression of degeneration-associated proteins. In vivo, sirt6 overexpression attenuated IDD. Together, the data showed that sirt6 attenuated cell senescence, and reduced apoptosis, by triggering autophagy that ultimately ameliorated IDD. Thus, sirt6 may be a novel therapeutic target for IDD treatment.
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Affiliation(s)
- Jian Chen
- Department of Orthopaedic Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325027, People's Republic of China
| | - Jun-Jun Xie
- School of Pharmaceutical Sciences, Key Laboratory of Biotechnology and Pharmaceutical Engineering, Wenzhou Medical University, Wenzhou, 325027, People's Republic of China
| | - Meng-Yun Jin
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325027, People's Republic of China
| | - Yun-Tao Gu
- Department of Orthopaedic Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325027, People's Republic of China
| | - Cong-Cong Wu
- Department of Orthopaedic Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325027, People's Republic of China
| | - Wei-Jun Guo
- Department of Orthopaedic Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325027, People's Republic of China
| | - Ying-Zhao Yan
- Department of Orthopaedic Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325027, People's Republic of China
| | - Zeng-Jie Zhang
- Department of Orthopaedic Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325027, People's Republic of China
| | - Jian-Le Wang
- Department of Orthopaedic Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325027, People's Republic of China
| | - Xiao-Lei Zhang
- Department of Orthopaedic Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325027, People's Republic of China
| | - Yan Lin
- Department of Orthopaedic Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325027, People's Republic of China
| | - Jia-Li Sun
- Department of Orthopaedic Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325027, People's Republic of China
| | - Guang-Hui Zhu
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325027, People's Republic of China.
| | - Xiang-Yang Wang
- Department of Orthopaedic Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325027, People's Republic of China.
| | - Yao-Sen Wu
- Department of Orthopaedic Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325027, People's Republic of China.
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27
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Oh YS, Bae GD, Baek DJ, Park EY, Jun HS. Fatty Acid-Induced Lipotoxicity in Pancreatic Beta-Cells During Development of Type 2 Diabetes. Front Endocrinol (Lausanne) 2018; 9:384. [PMID: 30061862 PMCID: PMC6054968 DOI: 10.3389/fendo.2018.00384] [Citation(s) in RCA: 168] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 06/25/2018] [Indexed: 12/20/2022] Open
Abstract
Type 2 diabetes is caused by chronic insulin resistance and progressive decline in beta-cell function. Optimal beta-cell function and mass is essential for glucose homeostasis and beta-cell impairment leads to the development of diabetes. Elevated levels of circulating fatty acids (FAs) and disturbances in lipid metabolism regulation are associated with obesity, and they are major factors influencing the increase in the incidence of type 2 diabetes. Chronic free FA (FFA) treatment induces insulin resistance and beta-cell dysfunction; therefore, reduction of elevated plasma FFA levels might be an important therapeutic target in obesity and type 2 diabetes. Lipid signals via receptors, and intracellular mechanisms are involved in FFA-induced apoptosis. In this paper, we discuss lipid actions in beta cells, including effects on metabolic pathways and stress responses, to help further understand the molecular mechanisms of lipotoxicity-induced type 2 diabetes.
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Affiliation(s)
- Yoon S. Oh
- Department of Food and Nutrition, Eulji University, Seongnam, South Korea
- *Correspondence: Yoon S. Oh
| | - Gong D. Bae
- Department of Molecular Medicine, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, South Korea
| | - Dong J. Baek
- College of Pharmacy and Natural Medicine Research Institute, Mokpo National University, Jeonnam, South Korea
| | - Eun-Young Park
- College of Pharmacy and Natural Medicine Research Institute, Mokpo National University, Jeonnam, South Korea
| | - Hee-Sook Jun
- Department of Molecular Medicine, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, South Korea
- Gachon Institute of Pharmaceutical Science, College of Pharmacy, Gachon University, Incheon, South Korea
- Gachon University Gil Medical Center, Gachon Medical and Convergence Institute, Incheon, South Korea
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28
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Bhansali S, Bhansali A, Walia R, Saikia UN, Dhawan V. Alterations in Mitochondrial Oxidative Stress and Mitophagy in Subjects with Prediabetes and Type 2 Diabetes Mellitus. Front Endocrinol (Lausanne) 2017; 8:347. [PMID: 29326655 PMCID: PMC5737033 DOI: 10.3389/fendo.2017.00347] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 11/28/2017] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND AND AIM Hyperglycemia-mediated oxidative stress impedes cell-reparative process like autophagy, which has been implicated in impairment of β-cell function in type 2 diabetes mellitus (T2DM). However, the role of mitophagy (selective mitochondrial autophagy) in progression of hyperglycemia remains elusive. This study aimed to assess the impact of increasing severity of hyperglycemia on mitochondrial stress and mitophagy. DESIGN AND METHODS A case-control study included healthy controls, subjects with prediabetes, newly diagnosed T2DM (NDT2DM) and advanced duration of T2DM (ADT2DM) (n = 20 each). Mitochondrial stress indices, transcriptional and translational expression of mitophagy markers (PINK1, PARKIN, MFN2, NIX, LC3-II, and LAMP-2) and transmission electron microscopic (TEM) studies were performed in peripheral blood mononuclear cells. RESULTS With mild hyperglycemia in subjects with prediabetes, to moderate to severe hyperglycemia in NDT2DM and ADT2DM, a progressive rise in mitochondrial oxidative stress was observed. Prediabetic subjects exhibited significantly increased expression of mitophagy-related markers and showed a positive association with HOMA-β, whereas, patients with NDT2DM and ADT2DM demonstrated decreased expression, with a greater decline in ADT2DM subjects. TEM studies revealed significantly reduced number of distorted mitochondria in prediabetics, as compared to the T2DM patients. In addition, receiver operating characteristic analysis showed HbA1C > 7% (53 mmol/mol) was associated with attenuated mitophagy. CONCLUSION Increasing hyperglycemia is associated with progressive rise in oxidative stress and altered mitochondrial morphology. Sustenance of mitophagy at HbA1C < 7% (53 mmol/mol) strengthens the rationale of achieving HbA1C below this cutoff for good glycemic control. An "adaptive" increase in mitophagy may delay progression to T2DM by preserving the β-cell function in subjects with prediabetes.
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Affiliation(s)
- Shipra Bhansali
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Anil Bhansali
- Department of Endocrinology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Rama Walia
- Department of Endocrinology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Uma Nahar Saikia
- Department of Histopathology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Veena Dhawan
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
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29
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Abstract
Enlarged fat cells in obese adipose tissue diminish capacity to store fat and are resistant to the anti-lipolytic effect of insulin. Insulin resistance (IR)-associated S-nitrosylation of insulin-signaling proteins increases in obesity. In accordance with the inhibition of insulin-mediated anti-lipolytic action, plasma free fatty acid (FFA) levels increase. Additionally, endoplasmic reticulum stress stimuli induce lipolysis by activating cyclic adenosine monophosphate/Protein kinase A (cAMP/PKA) and extracellular signal-regulated kinase ½ (ERK1/2) signaling in adipocytes. Failure of packaging of excess lipid into lipid droplets causes chronic elevation of circulating fatty acids, which can reach to toxic levels within non-adipose tissues. Deleterious effects of lipid accumulation in non-adipose tissues are known as lipotoxicity. In fact, triglycerides may also serve a storage function for long-chain non-esterified fatty acids and their products such as ceramides and diacylglycerols (DAGs). Thus, excess DAG, ceramide and saturated fatty acids in obesity can induce chronic inflammation and have harmful effect on multiple organs and systems. In this context, chronic adipose tissue inflammation, mitochondrial dysfunction and IR have been discussed within the scope of lipotoxicity.
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30
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Yang JS, Lu CC, Kuo SC, Hsu YM, Tsai SC, Chen SY, Chen YT, Lin YJ, Huang YC, Chen CJ, Lin WD, Liao WL, Lin WY, Liu YH, Sheu JC, Tsai FJ. Autophagy and its link to type II diabetes mellitus. Biomedicine (Taipei) 2017; 7:8. [PMID: 28612706 PMCID: PMC5479440 DOI: 10.1051/bmdcn/2017070201] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 05/02/2017] [Indexed: 02/06/2023] Open
Abstract
Autophagy, a double-edged sword for cell survival, is the research object on 2016 Nobel Prize in Physiology or Medicine. Autophagy is a molecular mechanism for maintaining cellular physiology and promoting survival. Defects in autophagy lead to the etiology of many diseases, including diabetes mellitus (DM), cancer, neurodegeneration, infection disease and aging. DM is a metabolic and chronic disorder and has a higher prevalence in the world as well as in Taiwan. The character of diabetes mellitus is hyperglycemia resulting from defects in insulin secretion, insulin action, or both. Type 2 diabetes mellitus (T2DM) is characterized by insulin resistance and failure of producing insulin on pancreatic beta cells. In T2DM, autophagy is not only providing nutrients to maintain cellular energy during fasting, but also removes damaged organelles, lipids and miss-folded proteins. In addition, autophagy plays an important role in pancreatic beta cell dysfunction and insulin resistance. In this review, we summarize the roles of autophagy in T2DM.
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Affiliation(s)
- Jai-Sing Yang
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Department of Medical Research, China Medical University Hospital, China Medical University Taichung
404 Taiwan
| | - Chi-Cheng Lu
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Department of Medical Research, China Medical University Hospital, China Medical University Taichung
404 Taiwan
| | - Sheng-Chu Kuo
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School of Pharmacy, China Medical University Taichung
404 Taiwan
| | - Yuan-Man Hsu
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Department of Biological Science and Technology, China Medical University Taichung
404 Taiwan
| | - Shih-Chang Tsai
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Department of Biological Science and Technology, China Medical University Taichung
404 Taiwan
| | - Shih-Yin Chen
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Genetics Center, Department of Medical Research, China Medical University Hospital Taichung
404 Taiwan
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School of Chinese Medicine, China Medical University Taichung
404 Taiwan
| | - Yng-Tay Chen
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Genetics Center, Department of Medical Research, China Medical University Hospital Taichung
404 Taiwan
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School of Chinese Medicine, China Medical University Taichung
404 Taiwan
| | - Ying-Ju Lin
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Genetics Center, Department of Medical Research, China Medical University Hospital Taichung
404 Taiwan
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School of Chinese Medicine, China Medical University Taichung
404 Taiwan
| | - Yu-Chuen Huang
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Genetics Center, Department of Medical Research, China Medical University Hospital Taichung
404 Taiwan
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School of Chinese Medicine, China Medical University Taichung
404 Taiwan
| | - Chao-Jung Chen
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Genetics Center, Department of Medical Research, China Medical University Hospital Taichung
404 Taiwan
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School of Chinese Medicine, China Medical University Taichung
404 Taiwan
| | - Wei-De Lin
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Genetics Center, Department of Medical Research, China Medical University Hospital Taichung
404 Taiwan
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School of Chinese Medicine, China Medical University Taichung
404 Taiwan
| | - Wen-Lin Liao
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Genetics Center, Department of Medical Research, China Medical University Hospital Taichung
404 Taiwan
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School of Chinese Medicine, China Medical University Taichung
404 Taiwan
| | - Wei-Yong Lin
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Genetics Center, Department of Medical Research, China Medical University Hospital Taichung
404 Taiwan
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School of Chinese Medicine, China Medical University Taichung
404 Taiwan
| | - Yu-Huei Liu
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Genetics Center, Department of Medical Research, China Medical University Hospital Taichung
404 Taiwan
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School of Chinese Medicine, China Medical University Taichung
404 Taiwan
| | - Jinn-Chyuan Sheu
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Institute of Biomedical Sciences, National Sun Yat-sen University Kaohsiung
804 Taiwan
| | - Fuu-Jen Tsai
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Genetics Center, Department of Medical Research, China Medical University Hospital Taichung
404 Taiwan
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School of Chinese Medicine, China Medical University Taichung
404 Taiwan
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Department of Medical Genetics, China Medical University Hospital, China Medical University Taichung
404 Taiwan
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31
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Kung CP, Murphy ME. The role of the p53 tumor suppressor in metabolism and diabetes. J Endocrinol 2016; 231:R61-R75. [PMID: 27613337 PMCID: PMC5148674 DOI: 10.1530/joe-16-0324] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 09/08/2016] [Indexed: 12/12/2022]
Abstract
In the context of tumor suppression, p53 is an undisputedly critical protein. Functioning primarily as a transcription factor, p53 helps fend off the initiation and progression of tumors by inducing cell cycle arrest, senescence or programmed cell death (apoptosis) in cells at the earliest stages of precancerous development. Compelling evidence, however, suggests that p53 is involved in other aspects of human physiology, including metabolism. Indeed, recent studies suggest that p53 plays a significant role in the development of metabolic diseases, including diabetes, and further that p53's role in metabolism may also be consequential to tumor suppression. Here, we present a review of the literature on the role of p53 in metabolism, diabetes, pancreatic function, glucose homeostasis and insulin resistance. Additionally, we discuss the emerging role of genetic variation in the p53 pathway (single-nucleotide polymorphisms) on the impact of p53 in metabolic disease and diabetes. A better understanding of the relationship between p53, metabolism and diabetes may one day better inform the existing and prospective therapeutic strategies to combat this rapidly growing epidemic.
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Affiliation(s)
- Che-Pei Kung
- Department of Internal MedicineWashington University School of Medicine, St Louis, Missouri, USA
| | - Maureen E Murphy
- Department of Internal MedicineWashington University School of Medicine, St Louis, Missouri, USA
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Fetterman JL, Holbrook M, Flint N, Feng B, Bretón-Romero R, Linder EA, Berk BD, Duess MA, Farb MG, Gokce N, Shirihai OS, Hamburg NM, Vita JA. Restoration of autophagy in endothelial cells from patients with diabetes mellitus improves nitric oxide signaling. Atherosclerosis 2016; 247:207-17. [PMID: 26926601 DOI: 10.1016/j.atherosclerosis.2016.01.043] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 01/14/2016] [Accepted: 01/29/2016] [Indexed: 12/20/2022]
Abstract
BACKGROUND Endothelial dysfunction contributes to cardiovascular disease in diabetes mellitus. Autophagy is a multistep mechanism for the removal of damaged proteins and organelles from the cell. Under diabetic conditions, inadequate autophagy promotes cellular dysfunction and insulin resistance in non-vascular tissue. We hypothesized that impaired autophagy contributes to endothelial dysfunction in diabetes mellitus. METHODS AND RESULTS We measured autophagy markers and endothelial nitric oxide synthase (eNOS) activation in freshly isolated endothelial cells from diabetic subjects (n = 45) and non-diabetic controls (n = 41). p62 levels were higher in cells from diabetics (34.2 ± 3.6 vs. 20.0 ± 1.6, P = 0.001), indicating reduced autophagic flux. Bafilomycin inhibited insulin-induced activation of eNOS (64.7 ± 22% to -47.8 ± 8%, P = 0.04) in cells from controls, confirming that intact autophagy is necessary for eNOS signaling. In endothelial cells from diabetics, activation of autophagy with spermidine restored eNOS activation, suggesting that impaired autophagy contributes to endothelial dysfunction (P = 0.01). Indicators of autophagy initiation including the number of LC3-bound puncta and beclin 1 expression were similar in diabetics and controls, whereas an autophagy terminal phase indicator, the lysosomal protein Lamp2a, was higher in diabetics. In endothelial cells under diabetic conditions, the beneficial effect of spermidine on eNOS activation was blocked by autophagy inhibitors bafilomycin or 3-methyladenine. Blocking the terminal stage of autophagy with bafilomycin increased p62 (P = 0.01) in cells from diabetics to a lesser extent than in cells from controls (P = 0.04), suggesting ongoing, but inadequate autophagic clearance. CONCLUSION Inadequate autophagy contributes to endothelial dysfunction in patients with diabetes and may be a target for therapy of diabetic vascular disease.
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Affiliation(s)
- Jessica L Fetterman
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Monica Holbrook
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Nir Flint
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Bihua Feng
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Rosa Bretón-Romero
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Erika A Linder
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Brittany D Berk
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Mai-Ann Duess
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Melissa G Farb
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Noyan Gokce
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Orian S Shirihai
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
| | - Naomi M Hamburg
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA.
| | - Joseph A Vita
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA
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Abstract
Type 2 diabetes is a complex disease. It results from a failure of the body to maintain energy homoeostasis. Multicellular organisms have evolved complex strategies to preserve a relatively stable internal nutrient environment, despite fluctuations in external nutrient availability. This complex strategy involves the co-ordinated responses of multiple organs to promote storage or mobilization of energy sources according to the availability of nutrients and cellular bioenergetics needs. The endocrine pancreas plays a central role in these processes by secreting insulin and glucagon. When this co-ordinated effort fails, hyperglycaemia and hyperlipidaemia develops, characterizing a state of metabolic imbalance and ultimately overt diabetes. Although diabetes is most likely a collection of diseases, scientists are starting to identify genetic components and environmental triggers. Genome-wide association studies revealed that by and large, gene variants associated with type 2 diabetes are implicated in pancreatic β-cell function, suggesting that the β-cell may be the weakest link in the chain of events that results in diabetes. Thus, it is critical to understand how environmental cues affect the β-cell. Phosphoinositides are important 'decoders' of environmental cues. As such, these lipids have been implicated in cellular responses to a wide range of growth factors, hormones, stress agents, nutrients and metabolites. Here we will review some of the well-established and potential new roles for phosphoinositides in β-cell function/dysfunction and discuss how our knowledge of phosphoinositide signalling could aid in the identification of potential strategies for treating or preventing type 2 diabetes.
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Affiliation(s)
- Lucia E Rameh
- Department of Medicine, Boston University School of Medicine, 650 Albany Street, Boston, MA 02118, U.S.A.
| | - Jude T Deeney
- Department of Medicine, Boston University School of Medicine, 650 Albany Street, Boston, MA 02118, U.S.A
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Lin Y, Sun Z. In vivo pancreatic β-cell-specific expression of antiaging gene Klotho: a novel approach for preserving β-cells in type 2 diabetes. Diabetes 2015; 64:1444-58. [PMID: 25377875 PMCID: PMC4375073 DOI: 10.2337/db14-0632] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Protein expression of an antiaging gene, Klotho, was depleted in pancreatic islets in patients with type 2 diabetes mellitus (T2DM) and in db/db mice, an animal model of T2DM. The objective of this study was to investigate whether in vivo expression of Klotho would preserve pancreatic β-cell function in db/db mice. We report for the first time that β-cell-specific expression of Klotho attenuated the development of diabetes in db/db mice. β-Cell-specific expression of Klotho decreased hyperglycemia and enhanced glucose tolerance. The beneficial effects of Klotho were associated with significant improvements in T2DM-induced decreases in number of β-cells, insulin storage levels in pancreatic islets, and glucose-stimulated insulin secretion from pancreatic islets, which led to increased blood insulin levels in diabetic mice. In addition, β-cell-specific expression of Klotho decreased intracellular superoxide levels, oxidative damage, apoptosis, and DNAJC3 (a marker for endoplasmic reticulum stress) in pancreatic islets. Furthermore, β-cell-specific expression of Klotho increased expression levels of Pdx-1 (insulin transcription factor), PCNA (a marker of cell proliferation), and LC3 (a marker of autophagy) in pancreatic islets in db/db mice. These results reveal that β-cell-specific expression of Klotho improves β-cell function and attenuates the development of T2DM. Therefore, in vivo expression of Klotho may offer a novel strategy for protecting β-cells in T2DM.
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Affiliation(s)
- Yi Lin
- Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Zhongjie Sun
- Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK
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35
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Chon S, Riveline JP, Blondeau B, Gautier JF. Incretin-based therapy and pancreatic beta cells. DIABETES & METABOLISM 2014; 40:411-22. [DOI: 10.1016/j.diabet.2014.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 05/19/2014] [Accepted: 05/21/2014] [Indexed: 01/09/2023]
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Di Ciaula A, Portincasa P. Fat, epigenome and pancreatic diseases. Interplay and common pathways from a toxic and obesogenic environment. Eur J Intern Med 2014; 25:865-73. [PMID: 25457435 DOI: 10.1016/j.ejim.2014.10.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Revised: 10/08/2014] [Accepted: 10/10/2014] [Indexed: 02/07/2023]
Abstract
The worldwide obesity epidemic is paralleled by a rise in the incidence of pancreatic disorders ranging from "fatty" pancreas to pancreatitis and cancer. Body fat accumulation and pancreatic dysfunctions have common pathways, mainly acting through insulin resistance and low-grade inflammation, frequently mediated by the epigenome. These mechanisms are affected by lifestyle and by the toxic effects of fat and pollutants. An early origin is common, starting in pediatric age or during the fetal life in response to nutritional factors, endocrine disruptor chemicals (EDCs) or parental exposure to toxics. A "fatty pancreas" is frequent in obese and is able to induce pancreatic damage. The fat is a target of EDCs and of the cytotoxic/mutagenic effects of heavy metals, and is the site of bioaccumulation of lipophilic and persistent pollutants related with insulin resistance and able to promote pancreatic cancer. Increased Body Mass Index (BMI) can act as independent risk factor for a more severe course of acute pancreatitis and obesity is also a well-known risk factor for pancreatic cancer, that is related with BMI, insulin resistance, and duration of exposure to the toxic effects of fat and/or of environmental pollutants. All these mechanisms involve gene-environment interactions through epigenetic factors, and might be manipulated by primary prevention measures. Further studies are needed, pointing to better assess the interplays of modifiable factors on both obesity and pancreatic diseases, and to verify the efficacy of primary prevention strategies involving lifestyle and environmental exposure to toxics.
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Affiliation(s)
| | - Piero Portincasa
- Department of Biomedical Sciences and Human Oncology, Clinica Medica "A. Murri", University of Bari Medical School, Bari, Italy.
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Zhu XX, Yao XF, Jiang LP, Geng CY, Zhong LF, Yang G, Zheng BL, Sun XC. Sodium arsenite induces ROS-dependent autophagic cell death in pancreatic β-cells. Food Chem Toxicol 2014; 70:144-50. [PMID: 24859355 DOI: 10.1016/j.fct.2014.05.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 05/09/2014] [Accepted: 05/10/2014] [Indexed: 12/14/2022]
Abstract
Inorganic arsenic is a worldwide environmental pollutant. Inorganic arsenic's positive relationship with the incidence of type 2 diabetes mellitus arouses concerns associated with its etiology in diabetes among the general human population. In this study, the inhibitor of autophagosome formation, 3-methyladenine, protected the cells against sodium arsenite cytotoxicity, and the autophagy stimulator rapamycin further decreased the cell viability of sodium arsenite-treated INS-1 cells. These finding suggested the hypothesis that autophagic cell death contributed to sodium arsenite-induced cytotoxicity in INS-1 cells. Sodium arsenite increased the autophagosome-positive puncta in INS-1 cells observed under a fluorescence microscope, and this effect was confirmed by the elevated LC3-II levels detected through Western blot. The LC3 turnover assay indicated that the accumulation of autophagosomes in the arsenite-treated INS-1 cells was due to increased formation rather than impaired degradation. The pretreatment of INS-1 cells with the ROS inhibitor NAC reduced autophagosome formation and reversed the sodium arsenite cytotoxicity, indicating that sodium arsenite-induced autophagic cell death was ROS-dependent. In summary, the precise molecular mechanisms through which arsenic is related to diabetes have not been completely elucidated, but the ROS-dependent autophagic cell death of pancreatic β-cells described in this study may help to elucidate the underlying mechanism.
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Affiliation(s)
- Xue-Xin Zhu
- Department of Occupational and Environmental Health, Dalian Medical University, 9 W Lvshun South Road, Dalian 116044, PR China
| | - Xiao-Feng Yao
- Department of Occupational and Environmental Health, Dalian Medical University, 9 W Lvshun South Road, Dalian 116044, PR China
| | - Li-Ping Jiang
- Liaoning Anti-Degenerative Diseases Natural Products Engineering Research Center, 9 W Lvshun South Road, Dalian 116044, PR China
| | - Cheng-Yan Geng
- Liaoning Anti-Degenerative Diseases Natural Products Engineering Research Center, 9 W Lvshun South Road, Dalian 116044, PR China
| | - Lai-Fu Zhong
- Liaoning Anti-Degenerative Diseases Natural Products Engineering Research Center, 9 W Lvshun South Road, Dalian 116044, PR China
| | - Guang Yang
- Liaoning Anti-Degenerative Diseases Natural Products Engineering Research Center, 9 W Lvshun South Road, Dalian 116044, PR China
| | - Bai-Lu Zheng
- Department of Occupational and Environmental Health, Dalian Medical University, 9 W Lvshun South Road, Dalian 116044, PR China
| | - Xian-Ce Sun
- Department of Occupational and Environmental Health, Dalian Medical University, 9 W Lvshun South Road, Dalian 116044, PR China; Liaoning Anti-Degenerative Diseases Natural Products Engineering Research Center, 9 W Lvshun South Road, Dalian 116044, PR China.
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38
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Type 2 diabetes and congenital hyperinsulinism cause DNA double-strand breaks and p53 activity in β cells. Cell Metab 2014; 19:109-21. [PMID: 24332968 DOI: 10.1016/j.cmet.2013.11.007] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 03/30/2013] [Accepted: 11/06/2013] [Indexed: 01/09/2023]
Abstract
β cell failure in type 2 diabetes (T2D) is associated with hyperglycemia, but the mechanisms are not fully understood. Congenital hyperinsulinism caused by glucokinase mutations (GCK-CHI) is associated with β cell replication and apoptosis. Here, we show that genetic activation of β cell glucokinase, initially triggering replication, causes apoptosis associated with DNA double-strand breaks and activation of the tumor suppressor p53. ATP-sensitive potassium channels (KATP channels) and calcineurin mediate this toxic effect. Toxicity of long-term glucokinase overactivity was confirmed by finding late-onset diabetes in older members of a GCK-CHI family. Glucagon-like peptide-1 (GLP-1) mimetic treatment or p53 deletion rescues β cells from glucokinase-induced death, but only GLP-1 analog rescues β cell function. DNA damage and p53 activity in T2D suggest shared mechanisms of β cell failure in hyperglycemia and CHI. Our results reveal membrane depolarization via KATP channels, calcineurin signaling, DNA breaks, and p53 as determinants of β cell glucotoxicity and suggest pharmacological approaches to enhance β cell survival in diabetes.
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39
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Abstract
Autophagy plays a key role in maintaining pancreatic β-cell homeostasis. Deregulation of this process is associated with loss of β-cell mass and function, and it is likely to be involved in type 2 diabetes development and progression. Evidence that modulation of autophagy may be beneficial to preserve β-cell mass and function is beginning to accumulate although the complexity of this process, the intricate link between autophagy and apoptosis, and the fine balance between the protective and the disruptive role of autophagy make it very difficult to develop interventional strategies. This chapter provides an overview of the role of constitutive and adaptive autophagy in pancreatic β-cell and in the context of type 2 diabetes.
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Affiliation(s)
- Simona Mazza
- Queen Mary University of London, Barts and The London School of Medicine and Dentistry, Blizard Institute, Centre for Diabetes, Inositide Signalling Group, London, United Kingdom
| | - Tania Maffucci
- Queen Mary University of London, Barts and The London School of Medicine and Dentistry, Blizard Institute, Centre for Diabetes, Inositide Signalling Group, London, United Kingdom.
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40
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Cerf ME. Beta cell dynamics: beta cell replenishment, beta cell compensation and diabetes. Endocrine 2013; 44:303-11. [PMID: 23483434 DOI: 10.1007/s12020-013-9917-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 03/01/2013] [Indexed: 12/19/2022]
Abstract
Type 2 diabetes, characterized by persistent hyperglycemia, arises mostly from beta cell dysfunction and insulin resistance and remains a highly complex metabolic disease due to various stages in its pathogenesis. Glucose homeostasis is primarily regulated by insulin secretion from the beta cells in response to prevailing glycemia. Beta cell populations are dynamic as they respond to fluctuating insulin demand. Beta cell replenishment and death primarily regulate beta cell populations. Beta cells, pancreatic cells, and extra-pancreatic cells represent the three tiers for replenishing beta cells. In rodents, beta cell self-replenishment appears to be the dominant source for new beta cells supported by pancreatic cells (non-beta islet cells, acinar cells, and duct cells) and extra-pancreatic cells (liver, neural, and stem/progenitor cells). In humans, beta cell neogenesis from non-beta cells appears to be the dominant source of beta cell replenishment as limited beta cell self-replenishment occurs particularly in adulthood. Metabolic states of increased insulin demand trigger increased insulin synthesis and secretion from beta cells. Beta cells, therefore, adapt to support their physiology. Maintaining physiological beta cell populations is a strategy for targeting metabolic states of persistently increased insulin demand as in diabetes.
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Affiliation(s)
- Marlon E Cerf
- Diabetes Discovery Platform, South African Medical Research, PO Box 19070, Tygerberg, 7505, South Africa,
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Lin Y, Kuro-o M, Sun Z. Genetic deficiency of anti-aging gene klotho exacerbates early nephropathy in STZ-induced diabetes in male mice. Endocrinology 2013; 154:3855-63. [PMID: 23928372 PMCID: PMC3776873 DOI: 10.1210/en.2013-1053] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Klotho is a recently discovered anti-aging gene and is primarily expressed in kidneys. In humans, the klotho level decreases with age whereas the prevalence of chronic kidney disease (CKD) increases with age. Diabetic nephropathy is the most common form of CKD, which leads to end-stage renal disease. A decrease in klotho has been found in kidneys of patients with diabetic nephropathy. The purpose of this study is to assess whether klotho gene deficiency affects early diabetic nephropathy in a mouse of model of type 1 diabetes induced by streptozotocin (STZ). Male KL(+/-) mutant and wild-type mice (6-8 weeks) were injected with multiple low doses of STZ. Renal functions and renal blood flow were assessed. Kidneys were collected for histological examination and molecular assays of TGFβ1 and mammalian targets of rapamycin (mTOR) signaling. Klotho deficiency in KL(+/-) mutant mice exacerbated STZ-induced increases in urine albumin, blood urea nitrogen, expansion of mesangial matrix in renal glomeruli, and kidney hypertrophy, suggesting a protective role of klotho in kidney function and structure. Klotho deficiency did not affect renal blood flow. Notably, klotho deficiency significantly increased phosphorylation of Smad2, indicating enhanced TGFβ1 signaling in kidneys. Klotho deficiency also increased phosphorylation of mTOR and S6 (a downstream effector of mTOR), indicating enhanced mTOR signaling in kidneys of early diabetic mice. Thus, klotho gene deficiency may make kidneys more susceptible to diabetic injury. Klotho gene deficiency exacerbated early diabetic nephropathy via enhancing both TGFβ1 and mTOR signaling in kidneys.
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Affiliation(s)
- Yi Lin
- MD, PhD, FAHA, Professor of Physiology, Director, The Robert and Mary Cade Laboratory, BMSB 662A, Box 26901, Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, 940 S. L. Young Boulevard, Oklahoma City, OK 73126-0901.
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Nesca V, Guay C, Jacovetti C, Menoud V, Peyot ML, Laybutt DR, Prentki M, Regazzi R. Identification of particular groups of microRNAs that positively or negatively impact on beta cell function in obese models of type 2 diabetes. Diabetologia 2013; 56:2203-12. [PMID: 23842730 DOI: 10.1007/s00125-013-2993-y] [Citation(s) in RCA: 174] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 06/19/2013] [Indexed: 01/11/2023]
Abstract
AIMS/HYPOTHESIS MicroRNAs are key regulators of gene expression involved in health and disease. The goal of our study was to investigate the global changes in beta cell microRNA expression occurring in two models of obesity-associated type 2 diabetes and to assess their potential contribution to the development of the disease. METHODS MicroRNA profiling of pancreatic islets isolated from prediabetic and diabetic db/db mice and from mice fed a high-fat diet was performed by microarray. The functional impact of the changes in microRNA expression was assessed by reproducing them in vitro in primary rat and human beta cells. RESULTS MicroRNAs differentially expressed in both models of obesity-associated type 2 diabetes fall into two distinct categories. A group including miR-132, miR-184 and miR-338-3p displays expression changes occurring long before the onset of diabetes. Functional studies indicate that these expression changes have positive effects on beta cell activities and mass. In contrast, modifications in the levels of miR-34a, miR-146a, miR-199a-3p, miR-203, miR-210 and miR-383 primarily occur in diabetic mice and result in increased beta cell apoptosis. These results indicate that obesity and insulin resistance trigger adaptations in the levels of particular microRNAs to allow sustained beta cell function, and that additional microRNA deregulation negatively impacting on insulin-secreting cells may cause beta cell demise and diabetes manifestation. CONCLUSIONS/INTERPRETATION We propose that maintenance of blood glucose homeostasis or progression toward glucose intolerance and type 2 diabetes may be determined by the balance between expression changes of particular microRNAs.
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Affiliation(s)
- Valeria Nesca
- Department of Fundamental Neurosciences, Faculty of Biology and Medicine, University of Lausanne, Rue du Bugnon 9, CH-1005 Lausanne, Switzerland
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Wu J, Wu JJ, Yang LJ, Wei LX, Zou DJ. Rosiglitazone protects against palmitate-induced pancreatic beta-cell death by activation of autophagy via 5'-AMP-activated protein kinase modulation. Endocrine 2013; 44:87-98. [PMID: 23109223 DOI: 10.1007/s12020-012-9826-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 10/19/2012] [Indexed: 01/20/2023]
Abstract
Promoting beta-cell survival is crucial for the prevention of beta-cell failure in diabetes. Thiazolidinediones, a widely used drug to improve insulin sensitivity in clinical practice, is found to have a protective effect on islet beta-cell. To date, the mechanism underlying the protective role of thiazolidinedione on beta-cell survival remain largely unknown. Activation of autophagy was detected by transmission electron microscopy, western blot, and GFP-LC3 transfection. Cell viability was examined by WST-8. Cell apoptosis was demonstrated by DAPI and Annexin V/PI staining. Colony formation assay was used to detect long-term cell viability. We demonstrated that rosiglitazone-treated beta-cells were more resistant to palmitate-induced apoptosis. The conversion of LC3-I to LC3-II and accumulated autophagosomes were found to be upregulated in rosiglitazone-treated cells. Inhibition of autophagy augmented palmitate-induced apoptosis with rosiglitazone treatment, suggesting that autophagy plays an important role in the survival function of rosiglitazone on beta-cells. Furthermore, we showed that rosiglitazone could induce AMP-activated protein kinase (AMPK) phosphorylation and reduce p70S6 kinase phosphorylation. Inhibition of AMPK impaired autophagy activation and enhanced palmitate-induced apoptosis during rosiglitazone treatment. These findings reveal that rosiglitazone-induced autophagy contributes to its protective function on beta-cells during palmitate treatment.
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Affiliation(s)
- Jie Wu
- Department of Endocrinology, Chang Hai Hospital, The Second Military Medical University, 168 Changhai Road, Shanghai, 200438, People's Republic of China
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44
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Jiang L, Zhang X, Zheng X, Ru A, Ni X, Wu Y, Tian N, Huang Y, Xue E, Wang X, Xu H. Apoptosis, senescence, and autophagy in rat nucleus pulposus cells: Implications for diabetic intervertebral disc degeneration. J Orthop Res 2013; 31:692-702. [PMID: 23238821 DOI: 10.1002/jor.22289] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2012] [Accepted: 11/09/2012] [Indexed: 02/04/2023]
Abstract
This research was aimed to study the mechanisms by which diabetes aggravates intervertebral disc degeneration (IDD) and to discuss the relationship between autophagy and IDD in nucleus pulposus (NP) cells. Sixteen weeks after injecting streptozotocin (STZ), the intervertebral discs (IVDs) were studied by histology, Alcian blue, 1,9-dimethylmethylene blue (DMMB), immunohistochemistry, and RT-PCR to explore the IDD. The apoptosis and senescence of NP cells was investigated by terminal deoxyribonucleotidyl transferase (TDT)-mediated dUTP-digoxigenin nick end labeling (TUNEL) assay, immunohistochemistry, and Western blot for caspase3, caspase8, caspase9, and p16lnk4A (increased in cellular senescence). The level of autophagy in NP cells was detected by Western blot, immunohistochemistry, and transmission electron microscopy (TEM). The proteoglycan and collagen II in the extracellular matrix and the aggrecan and collagen II mRNA expression in NP cells of diabetic rats were decreased compared with the control group. Diabetes increased apoptosis of NP cells and led to activations of initiators of intrinsic (caspases-9) and extrinsic (caspase-8) pathways as well as their common executioner (caspase-3). Cellular senescence was increased about twofold in NP of diabetic rats. In addition, the Western blot, immunohistochemistry, and TEM demonstrated higher level of autophagy in NP cells of diabetic rats than control rats to a statistically significant extent. These findings support that diabetes induced by STZ can cause IDD by accelerating the apoptosis and senescence of NP cells excluding the overweight influence. And the results suggest that the autophagy may be a response mechanism to the change of NP cells in diabetic rats.
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Affiliation(s)
- Libo Jiang
- Department of Orthopaedics, The Second Affiliated Hospital of Wenzhou Medical College, 109 Western Xueyuan Road, Wenzhou, China
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Abstract
Beta cell dysfunction and insulin resistance are inherently complex with their interrelation for triggering the pathogenesis of diabetes also somewhat undefined. Both pathogenic states induce hyperglycemia and therefore increase insulin demand. Beta cell dysfunction results from inadequate glucose sensing to stimulate insulin secretion therefore elevated glucose concentrations prevail. Persistently elevated glucose concentrations above the physiological range result in the manifestation of hyperglycemia. With systemic insulin resistance, insulin signaling within glucose recipient tissues is defective therefore hyperglycemia perseveres. Beta cell dysfunction supersedes insulin resistance in inducing diabetes. Both pathological states influence each other and presumably synergistically exacerbate diabetes. Preserving beta cell function and insulin signaling in beta cells and insulin signaling in the glucose recipient tissues will maintain glucose homeostasis.
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Affiliation(s)
- Marlon E. Cerf
- Diabetes Discovery Platform, South African Medical Research CouncilCape Town, South Africa
- *Correspondence: Marlon E. Cerf, Diabetes Discovery Platform, South African Medical Research Council, PO Box 19070, Tygerberg, Cape Town 7505, South Africa. e-mail:
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Park CH, Tanaka T, Yokozawa T. Anti-diabetic Action of 7- O-Galloyl-d-sedoheptulose, a Polyphenol from Corni Fructus, through Ameliorating Inflammation and Inflammation-Related Oxidative Stress in the Pancreas of Type 2 Diabetics. Biol Pharm Bull 2013; 36:723-32. [DOI: 10.1248/bpb.b12-00543] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | - Takashi Tanaka
- Graduate School of Biomedical Sciences, Nagasaki University
| | - Takako Yokozawa
- Institute of Natural Medicine, University of Toyama
- Organization for Promotion of Regional Collaboration, University of Toyama
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Lei X, Bone RN, Ali T, Wohltmann M, Gai Y, Goodwin KJ, Bohrer AE, Turk J, Ramanadham S. Genetic modulation of islet β-cell iPLA₂β expression provides evidence for its impact on β-cell apoptosis and autophagy. Islets 2013; 5:29-44. [PMID: 23411472 PMCID: PMC3662380 DOI: 10.4161/isl.23758] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
β-cell apoptosis is a significant contributor to β-cell dysfunction in diabetes and ER stress is among the factors that contributes to β-cell death. We previously identified that the Ca²⁺-independent phospholipase A₂β (iPLA₂β), which in islets is localized in β-cells, participates in ER stress-induced β-cell apoptosis. Here, direct assessment of iPLA₂β role was made using β-cell-specific iPLA₂β overexpressing (RIP-iPLA₂β-Tg) and globally iPLA₂β-deficient (iPLA₂β-KO) mice. Islets from Tg, but not KO, express higher islet iPLA₂β and neutral sphingomyelinase, decrease in sphingomyelins, and increase in ceramides, relative to WT group. ER stress induces iPLA₂β, ER stress factors, loss of mitochondrial membrane potential (∆Ψ), caspase-3 activation, and β-cell apoptosis in the WT and these are all amplified in the Tg group. Surprisingly, β-cells apoptosis while reduced in the KO is higher than in the WT group. This, however, was not accompanied by greater caspase-3 activation but with larger loss of ∆Ψ, suggesting that iPLA₂β deficiency impacts mitochondrial membrane integrity and causes apoptosis by a caspase-independent manner. Further, autophagy, as reflected by LC3-II accumulation, is increased in Tg and decreased in KO, relative to WT. Our findings suggest that (1) iPLA₂β impacts upstream (UPR) and downstream (ceramide generation and mitochondrial) pathways in β-cells and (2) both over- or under-expression of iPLA₂β is deleterious to the β-cells. Further, we present for the first time evidence for potential regulation of autophagy by iPLA₂β in islet β-cells. These findings support the hypothesis that iPLA₂β induction under stress, as in diabetes, is a key component to amplifying β-cell death processes.
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Affiliation(s)
- Xiaoyong Lei
- Department of Cell, Developmental, and Integrative Biology; University of Alabama at Birmingham; Birmingham, AL USA
| | - Robert N. Bone
- Department of Pathology; University of Alabama at Birmingham; Birmingham, AL USA
| | - Tomader Ali
- Department of Cell, Developmental, and Integrative Biology; University of Alabama at Birmingham; Birmingham, AL USA
| | - Mary Wohltmann
- Department of Medicine; Mass Spectrometry Resource; Division of Endocrinology, Metabolism and Lipid Research; Washington University School of Medicine; St. Louis, MO USA
| | - Ying Gai
- Department of Cell, Developmental, and Integrative Biology; University of Alabama at Birmingham; Birmingham, AL USA
| | - Karen J. Goodwin
- Department of Cell, Developmental, and Integrative Biology; University of Alabama at Birmingham; Birmingham, AL USA
| | - Alan E. Bohrer
- Department of Medicine; Mass Spectrometry Resource; Division of Endocrinology, Metabolism and Lipid Research; Washington University School of Medicine; St. Louis, MO USA
| | - John Turk
- Department of Medicine; Mass Spectrometry Resource; Division of Endocrinology, Metabolism and Lipid Research; Washington University School of Medicine; St. Louis, MO USA
| | - Sasanka Ramanadham
- Department of Cell, Developmental, and Integrative Biology; University of Alabama at Birmingham; Birmingham, AL USA
- Correspondence to: Sasanka Ramanadham,
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Xu X, Ren J. Unmasking the janus faces of autophagy in obesity-associated insulin resistance and cardiac dysfunction. Clin Exp Pharmacol Physiol 2012; 39:200-8. [PMID: 22053892 DOI: 10.1111/j.1440-1681.2011.05638.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Autophagy is an intracellular, lysosomal-dependent process involved in the turnover of long-lived proteins, damaged organelles and other subcellular structures. The autophagic process is known to play an essential role in the maintenance of cellular homeostasis. Results from recent studies also indicate an important role for the autophagic process in the pathogenesis of human diseases, including cancer, cardiovascular diseases, obesity, diabetes mellitus and ageing. Because of the pivotal role of autophagy in the regulation of adipogenesis, obesity and insulin sensitization, research efforts have focused on elucidating the role of autophagy in metabolic syndrome. Mammalian target of rapamycin (mTOR) is a key regulator of cell growth and is characterized by a complex signalling mechanism that affects protein synthesis and autophagy. Results from experimental and clinical studies reveal some interesting, but conflicting, findings regarding the mTOR signalling pathway and autophagy in adipocytes in metabolic syndrome. Although the pivotal role of autophagy in obesity and other metabolic diseases has been established, its involvement in obesity-induced cardiac dysfunction remains unknown, as do the upstream signalling regulators of autophagy. The present minireview discusses the molecular mechanisms of autophagy in the regulation of cardiac function in overweight and obesity. Further studies using appropriate models are needed to better unravel the complex intracellular mechanisms involved in the regulation of autophagy in obesity-induced cardiac dysfunction.
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Affiliation(s)
- Xihui Xu
- Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY, USA
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Salminen A, Ojala J, Kaarniranta K, Kauppinen A. Mitochondrial dysfunction and oxidative stress activate inflammasomes: impact on the aging process and age-related diseases. Cell Mol Life Sci 2012; 69:2999-3013. [PMID: 22446749 PMCID: PMC11114788 DOI: 10.1007/s00018-012-0962-0] [Citation(s) in RCA: 194] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 02/23/2012] [Accepted: 03/12/2012] [Indexed: 12/20/2022]
Abstract
Oxidative stress and low-grade inflammation are the hallmarks of the aging process and are even more enhanced in many age-related degenerative diseases. Mitochondrial dysfunction and oxidative stress can provoke and potentiate inflammatory responses, but the mechanism has remained elusive. Recent studies indicate that oxidative stress can induce the assembly of multiprotein inflammatory complexes called the inflammasomes. Nod-like receptor protein 3 (NLRP3) is the major immune sensor for cellular stress signals, e.g., reactive oxygen species, ceramides, and cathepsin B. NLRP3 activation triggers the caspase-1-mediated maturation of the precursors of IL-1β and IL-18 cytokines. During aging, the autophagic clearance of mitochondria declines and dysfunctional mitochondria provoke chronic oxidative stress, which disturbs the cellular redox balance. Moreover, increased NF-κB signaling observed during aging could potentiate the expression of NLRP3 and cytokine proforms enhancing the priming of NLRP3 inflammasomes. Recent studies have demonstrated that NLRP3 activation is associated with several age-related diseases, e.g., the metabolic syndrome. We will review here the emerging field of inflammasomes in the appearance of the proinflammatory phenotype during the aging process and in age-related diseases.
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Affiliation(s)
- Antero Salminen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FIN-70211, Kuopio, Finland.
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