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Wright JJ, Eskaros A, Windon A, Bottino R, Jenkins R, Bradley AM, Aramandla R, Philips S, Kang H, Saunders DC, Brissova M, Powers AC. Exocrine Pancreas in Type 1 and Type 2 Diabetes: Different Patterns of Fibrosis, Metaplasia, Angiopathy, and Adiposity. Diabetes 2024; 73:1140-1152. [PMID: 37881846 DOI: 10.2337/db23-0009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 07/18/2023] [Indexed: 10/27/2023]
Abstract
The endocrine and exocrine compartments of the pancreas are spatially related but functionally distinct. Multiple diseases affect both compartments, including type 1 diabetes (T1D), pancreatitis, cystic fibrosis, and pancreatic cancer. To better understand how the exocrine pancreas changes with age, obesity, and diabetes, we performed a systematic analysis of well-preserved tissue sections from the pancreatic head, body, and tail of organ donors with T1D (n = 20) or type 2 diabetes (T2D) (n = 25) and donors with no diabetes (ND; n = 74). Among ND donors, we found that the incidence of acinar-to-ductal metaplasia (ADM), angiopathy, and pancreatic adiposity increased with age, and ADM and adiposity incidence also increased with BMI. Compared with age- and sex-matched ND organs, T1D pancreata had greater rates of acinar atrophy and angiopathy, with fewer intralobular adipocytes. T2D pancreata had greater rates of ADM and angiopathy and a higher total number of T lymphocytes, but no difference in adipocyte number, compared with ND organs. Although total pancreatic fibrosis was increased in both T1D and T2D, the patterns were different, with periductal and perivascular fibrosis occurring more frequently in T1D pancreata and lobular and parenchymal fibrosis occurring more frequently in T2D. Thus, the exocrine pancreas undergoes distinct changes as individuals age or develop T1D or T2D. ARTICLE HIGHLIGHTS
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Affiliation(s)
- Jordan J Wright
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN
| | - Adel Eskaros
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Annika Windon
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN
| | - Rita Bottino
- Imagine Islet Center, Imagine Pharma, Pittsburgh, PA
- Institute of Cellular Therapeutics, Allegheny-Singer Research Institute, Allegheny Health Network, Pittsburgh, PA
| | - Regina Jenkins
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Amber M Bradley
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Radhika Aramandla
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Sharon Philips
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN
| | - Hakmook Kang
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN
| | - Diane C Saunders
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Human Pancreas Analysis Program, Nashville, TN; Philadelphia, PA; and Gainesville, FL
| | - Marcela Brissova
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Human Pancreas Analysis Program, Nashville, TN; Philadelphia, PA; and Gainesville, FL
| | - Alvin C Powers
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN
- Human Pancreas Analysis Program, Nashville, TN; Philadelphia, PA; and Gainesville, FL
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN
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Gotvaldová K, Špačková J, Novotný J, Baslarová K, Ježek P, Rossmeislová L, Gojda J, Smolková K. BCAA metabolism in pancreatic cancer affects lipid balance by regulating fatty acid import into mitochondria. Cancer Metab 2024; 12:10. [PMID: 38532464 DOI: 10.1186/s40170-024-00335-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 03/07/2024] [Indexed: 03/28/2024] Open
Abstract
BACKGROUND Pancreatic ductal adenocarcinoma (PDAC) has been associated with the host dysmetabolism of branched-chain amino acids (BCAAs), however, the implications for the role of BCAA metabolism in PDAC development or progression are not clear. The mitochondrial catabolism of valine, leucine, and isoleucine is a multistep process leading to the production of short-chain R-CoA species. They can be subsequently exported from mitochondria as short-chain carnitines (SC-CARs), utilized in anabolic pathways, or released from the cells. METHODS We examined the specificities of BCAA catabolism and cellular adaptation strategies to BCAA starvation in PDAC cells in vitro. We used metabolomics and lipidomics to quantify major metabolic changes in response to BCAA withdrawal. Using confocal microscopy and flow cytometry we quantified the fluorescence of BODIPY probe and the level of lipid droplets (LDs). We used BODIPY-conjugated palmitate to evaluate transport of fatty acids (FAs) into mitochondria. Also, we have developed a protocol for quantification of SC-CARs, BCAA-derived metabolites. RESULTS Using metabolic profiling, we found that BCAA starvation leads to massive triglyceride (TG) synthesis and LD accumulation. This was associated with the suppression of activated FA transport into the mitochondrial matrix. The suppression of FA import into mitochondria was rescued with the inhibitor of the acetyl-CoA carboxylase (ACC) and the activator of AMP kinase (AMPK), which both regulate carnitine palmitoyltransferase 1A (CPT1) activation status. CONCLUSIONS Our data suggest that BCAA catabolism is required for the import of long chain carnitines (LC-CARs) into mitochondria, whereas the disruption of this link results in the redirection of activated FAs into TG synthesis and its deposition into LDs. We propose that this mechanism protects cells against mitochondrial overload with LC-CARs and it might be part of the universal reaction to amino acid perturbations during cancer growth, regulating FA handling and storage.
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Affiliation(s)
- Klára Gotvaldová
- Institute of Physiology of the Czech Academy of Sciences, Laboratory of Mitochondrial Physiology, Vídeňská 1083, 142 20, Prague 4 - Krč, Czech Republic
| | - Jitka Špačková
- Institute of Physiology of the Czech Academy of Sciences, Laboratory of Mitochondrial Physiology, Vídeňská 1083, 142 20, Prague 4 - Krč, Czech Republic
| | - Jiří Novotný
- Institute of Physiology of the Czech Academy of Sciences, Laboratory of Mitochondrial Physiology, Vídeňská 1083, 142 20, Prague 4 - Krč, Czech Republic
| | - Kamila Baslarová
- Institute of Physiology of the Czech Academy of Sciences, Laboratory of Mitochondrial Physiology, Vídeňská 1083, 142 20, Prague 4 - Krč, Czech Republic
- First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Petr Ježek
- Institute of Physiology of the Czech Academy of Sciences, Laboratory of Mitochondrial Physiology, Vídeňská 1083, 142 20, Prague 4 - Krč, Czech Republic
| | - Lenka Rossmeislová
- Department of Pathophysiology, Center for Research on Nutrition, Metabolism, and Diabetes, Third Faculty of Medicine, Charles University, Prague, Czech Republic
- Third Faculty of Medicine, Franco-Czech Laboratory for Clinical Research on Obesity, Prague, Czech Republic
| | - Jan Gojda
- Third Faculty of Medicine, Franco-Czech Laboratory for Clinical Research on Obesity, Prague, Czech Republic
- Department of Internal Medicine, Královské Vinohrady University Hospital and Third Faculty of Medicine, Prague, Czech Republic
| | - Katarína Smolková
- Institute of Physiology of the Czech Academy of Sciences, Laboratory of Mitochondrial Physiology, Vídeňská 1083, 142 20, Prague 4 - Krč, Czech Republic.
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Thomas P, Gallagher MT, Da Silva Xavier G. Beta cell lipotoxicity in the development of type 2 diabetes: the need for species-specific understanding. Front Endocrinol (Lausanne) 2023; 14:1275835. [PMID: 38144558 PMCID: PMC10739424 DOI: 10.3389/fendo.2023.1275835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 11/13/2023] [Indexed: 12/26/2023] Open
Abstract
The propensity to develop type 2 diabetes (T2D) is known to have both environmental and hereditary components. In those with a genetic predisposition to T2D, it is widely believed that elevated concentrations of circulatory long-chain fatty acids (LC-FFA) significantly contribute towards the demise of insulin-producing pancreatic β-cells - the fundamental feature of the development of T2D. Over 25 years of research support that LC-FFA are deleterious to β-cells, through a process termed lipotoxicity. However, the work underpinning the theory of β-cell lipotoxicity is mostly based on rodent studies. Doubts have been raised as to whether lipotoxicity also occurs in humans. In this review, we examine the evidence, both in vivo and in vitro, for the pathogenic effects of LC-FFA on β-cell viability and function in humans, highlighting key species differences. In this way, we aim to uncover the role of lipotoxicity in the human pathogenesis of T2D and motivate the need for species-specific understanding.
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Affiliation(s)
- Patricia Thomas
- Centre for Systems Modelling and Quantitative Biomedicine, University of Birmingham, Birmingham, United Kingdom
- Institute for Metabolism and Systems Research, Birmingham Medical School, University of Birmingham, Birmingham, United Kingdom
| | - Meurig T. Gallagher
- Centre for Systems Modelling and Quantitative Biomedicine, University of Birmingham, Birmingham, United Kingdom
- Institute for Metabolism and Systems Research, Birmingham Medical School, University of Birmingham, Birmingham, United Kingdom
| | - Gabriela Da Silva Xavier
- Institute for Metabolism and Systems Research, Birmingham Medical School, University of Birmingham, Birmingham, United Kingdom
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Řezanka T, Kyselová L, Murphy DJ. Archaeal lipids. Prog Lipid Res 2023; 91:101237. [PMID: 37236370 DOI: 10.1016/j.plipres.2023.101237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 04/25/2023] [Accepted: 05/19/2023] [Indexed: 05/28/2023]
Abstract
The major archaeal membrane glycerolipids are distinguished from those of bacteria and eukaryotes by the contrasting stereochemistry of their glycerol backbones, and by the use of ether-linked isoprenoid-based alkyl chains rather than ester-linked fatty acyl chains for their hydrophobic moieties. These fascinating compounds play important roles in the extremophile lifestyles of many species, but are also present in the growing numbers of recently discovered mesophilic archaea. The past decade has witnessed significant advances in our understanding of archaea in general and their lipids in particular. Much of the new information has come from the ability to screen large microbial populations via environmental metagenomics, which has revolutionised our understanding of the extent of archaeal biodiversity that is coupled with a strict conservation of their membrane lipid compositions. Significant additional progress has come from new culturing and analytical techniques that are gradually enabling archaeal physiology and biochemistry to be studied in real time. These studies are beginning to shed light on the much-discussed and still-controversial process of eukaryogenesis, which probably involved both bacterial and archaeal progenitors. Puzzlingly, although eukaryotes retain many attributes of their putative archaeal ancestors, their lipid compositions only reflect their bacterial progenitors. Finally, elucidation of archaeal lipids and their metabolic pathways have revealed potentially interesting applications that have opened up new frontiers for biotechnological exploitation of these organisms. This review is concerned with the analysis, structure, function, evolution and biotechnology of archaeal lipids and their associated metabolic pathways.
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Affiliation(s)
- Tomáš Řezanka
- Institute of Microbiology, Czech Academy of Sciences, Vídeňská 1083, 142 00 Prague, Czech Republic
| | - Lucie Kyselová
- Research Institute of Brewing and Malting, Lípová 511, 120 44 Prague, Czech Republic
| | - Denis J Murphy
- School of Applied Sciences, University of South Wales, Pontypridd, CF37 1DL, United Kingdom.
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Bresgen N, Kovacs M, Lahnsteiner A, Felder TK, Rinnerthaler M. The Janus-Faced Role of Lipid Droplets in Aging: Insights from the Cellular Perspective. Biomolecules 2023; 13:912. [PMID: 37371492 DOI: 10.3390/biom13060912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 05/22/2023] [Accepted: 05/29/2023] [Indexed: 06/29/2023] Open
Abstract
It is widely accepted that nine hallmarks-including mitochondrial dysfunction, epigenetic alterations, and loss of proteostasis-exist that describe the cellular aging process. Adding to this, a well-described cell organelle in the metabolic context, namely, lipid droplets, also accumulates with increasing age, which can be regarded as a further aging-associated process. Independently of their essential role as fat stores, lipid droplets are also able to control cell integrity by mitigating lipotoxic and proteotoxic insults. As we will show in this review, numerous longevity interventions (such as mTOR inhibition) also lead to strong accumulation of lipid droplets in Saccharomyces cerevisiae, Caenorhabditis elegans, Drosophila melanogaster, and mammalian cells, just to name a few examples. In mammals, due to the variety of different cell types and tissues, the role of lipid droplets during the aging process is much more complex. Using selected diseases associated with aging, such as Alzheimer's disease, Parkinson's disease, type II diabetes, and cardiovascular disease, we show that lipid droplets are "Janus"-faced. In an early phase of the disease, lipid droplets mitigate the toxicity of lipid peroxidation and protein aggregates, but in a later phase of the disease, a strong accumulation of lipid droplets can cause problems for cells and tissues.
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Affiliation(s)
- Nikolaus Bresgen
- Department of Biosciences and Medical Biology, Paris-Lodron University Salzburg, 5020 Salzburg, Austria
| | - Melanie Kovacs
- Department of Biosciences and Medical Biology, Paris-Lodron University Salzburg, 5020 Salzburg, Austria
| | - Angelika Lahnsteiner
- Department of Biosciences and Medical Biology, Paris-Lodron University Salzburg, 5020 Salzburg, Austria
| | - Thomas Klaus Felder
- Department of Laboratory Medicine, Paracelsus Medical University, 5020 Salzburg, Austria
| | - Mark Rinnerthaler
- Department of Biosciences and Medical Biology, Paris-Lodron University Salzburg, 5020 Salzburg, Austria
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Janikiewicz J, Dobosz AM, Majzner K, Bernas T, Dobrzyn A. Stearoyl-CoA desaturase 1 deficiency exacerbates palmitate-induced lipotoxicity by the formation of small lipid droplets in pancreatic β-cells. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166711. [PMID: 37054998 DOI: 10.1016/j.bbadis.2023.166711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 03/28/2023] [Accepted: 03/30/2023] [Indexed: 04/15/2023]
Abstract
The accelerating accumulation of surplus lipids in the pancreas triggers structural and functional changes in type 2 diabetes-affected islets. Pancreatic β-cells exhibit a restricted capacity to store fat reservoirs in lipid droplets (LDs), which act as transient buffers to prevent lipotoxic stress. With the increasing incidence of obesity, growing interest has been seen in the intracellular regulation of LD metabolism for β-cell function. Stearoyl-CoA desaturase 1 (SCD1) is critical for producing unsaturated fatty acyl moieties for fluent storage into and out of LDs, likely affecting the overall rate of β-cell survival. We explored LD-associated composition and remodeling in SCD1-deprived INS-1E cells and in pancreatic islets in wildtype and SCD1-/- mice in the lipotoxic milieu. Deficiency in the enzymatic activity of SCD1 led to decrease in the size and number of LDs and the lower accumulation of neutral lipids. This occurred in parallel with a higher compactness and lipid order inside LDs, followed by changes in the saturation status and composition of fatty acids within core lipids and the phospholipid coat. The lipidome of LDs was enriched in 18:2n-6 and 20:4n-6 in β-cells and pancreatic islets. These rearrangements markedly contributed to differences in protein association with the LD surface. Our findings highlight an unexpected molecular mechanism by which SCD1 activity affects the morphology, composition and metabolism of LDs. We demonstrate that SCD1-dependent disturbances in LD enrichment can impact proper pancreatic β-cells and islet functioning, which may have considerable therapeutic value for the management of type 2 diabetes.
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Affiliation(s)
- Justyna Janikiewicz
- Laboratory of Cell Signaling and Metabolic Disorders, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland.
| | - Aneta M Dobosz
- Laboratory of Cell Signaling and Metabolic Disorders, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Katarzyna Majzner
- Faculty of Chemistry, Jagiellonian University, Cracow, Poland; Jagiellonian University, Jagiellonian Centre for Experimental Therapeutics (JCET), Cracow, Poland
| | - Tytus Bernas
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, USA
| | - Agnieszka Dobrzyn
- Laboratory of Cell Signaling and Metabolic Disorders, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland.
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Basu L, Bhagat V, Ching MEA, Di Giandomenico A, Dostie S, Greenberg D, Greenberg M, Hahm J, Hilton NZ, Lamb K, Jentz EM, Larsen M, Locatelli CAA, Maloney M, MacGibbon C, Mersali F, Mulchandani CM, Najam A, Singh I, Weisz T, Wong J, Senior PA, Estall JL, Mulvihill EE, Screaton RA. Recent Developments in Islet Biology: A Review With Patient Perspectives. Can J Diabetes 2023; 47:207-221. [PMID: 36481263 PMCID: PMC9640377 DOI: 10.1016/j.jcjd.2022.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 10/24/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022]
Abstract
Navigating the coronavirus disease-2019 (COVID-19, now COVID) pandemic has required resilience and creativity worldwide. Despite early challenges to productivity, more than 2,000 peer-reviewed articles on islet biology were published in 2021. Herein, we highlight noteworthy advances in islet research between January 2021 and April 2022, focussing on 5 areas. First, we discuss new insights into the role of glucokinase, mitogen-activated protein kinase-kinase/extracellular signal-regulated kinase and mitochondrial function on insulin secretion from the pancreatic β cell, provided by new genetically modified mouse models and live imaging. We then discuss a new connection between lipid handling and improved insulin secretion in the context of glucotoxicity, focussing on fatty acid-binding protein 4 and fetuin-A. Advances in high-throughput "omic" analysis evolved to where one can generate more finely tuned genetic and molecular profiles within broad classifications of type 1 diabetes and type 2 diabetes. Next, we highlight breakthroughs in diabetes treatment using stem cell-derived β cells and innovative strategies to improve islet survival posttransplantation. Last, we update our understanding of the impact of severe acute respiratory syndrome-coronavirus-2 infection on pancreatic islet function and discuss current evidence regarding proposed links between COVID and new-onset diabetes. We address these breakthroughs in 2 settings: one for a scientific audience and the other for the public, particularly those living with or affected by diabetes. Bridging biomedical research in diabetes to the community living with or affected by diabetes, our partners living with type 1 diabetes or type 2 diabetes also provide their perspectives on these latest advances in islet biology.
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Affiliation(s)
- Lahari Basu
- Department of Biology and Institute of Biochemistry, Carleton University, Ottawa, Ontario, Canada
| | - Vriti Bhagat
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Ma Enrica Angela Ching
- Department of Biology and Institute of Biochemistry, Carleton University, Ottawa, Ontario, Canada
| | | | - Sylvie Dostie
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | - Dana Greenberg
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | - Marley Greenberg
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | - Jiwon Hahm
- Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
| | - N Zoe Hilton
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | - Krista Lamb
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | - Emelien M Jentz
- School of Pharmacy, University of Waterloo, Kitchener, Ontario, Canada
| | - Matt Larsen
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | - Cassandra A A Locatelli
- University of Ottawa Heart Institute, Energy Substrate Laboratory, Ottawa, Ontario, Canada; Department of Biochemistry, Immunology and Microbiology, University of Ottawa, Ottawa, Ontario, Canada
| | - MaryAnn Maloney
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | | | - Farida Mersali
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | | | - Adhiyat Najam
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | - Ishnoor Singh
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Tom Weisz
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | - Jordan Wong
- Alberta Diabetes Institute and Department of Pharmacology, Li Ka Shing Centre for Health Research Innovation, University of Alberta, Edmonton, Alberta, Canada; Alberta Diabetes Institute and Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Peter A Senior
- Alberta Diabetes Institute and Department of Medicine, Edmonton, Alberta, Canada
| | - Jennifer L Estall
- Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada; Institut de recherches cliniques de Montréal, Center for Cardiometabolic Health, Montréal, Québec, Canada
| | - Erin E Mulvihill
- University of Ottawa Heart Institute, Energy Substrate Laboratory, Ottawa, Ontario, Canada; Department of Biochemistry, Immunology and Microbiology, University of Ottawa, Ottawa, Ontario, Canada
| | - Robert A Screaton
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada; Sunnybrook Research Institute, Toronto, Ontario, Canada.
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Perilipin 2 Protects against Lipotoxicity-Induced Islet Fibrosis by Inducing Islet Stellate Cell Activation Phenotype Changes. BIOMED RESEARCH INTERNATIONAL 2022; 2022:4581405. [PMID: 35845956 PMCID: PMC9279040 DOI: 10.1155/2022/4581405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 06/20/2022] [Indexed: 11/17/2022]
Abstract
Aims We explored whether and how perilipin 2 (Plin2) protected islets against lipotoxicity-induced islet dysfunction by regulating islet stellate cells (ISCs) activation. Methods Six-week-old male rats were given a high-fat diet or a control diet for 28 weeks. Glucose metabolic phenotypes were assessed using glucose/insulin tolerance tests, masson, and immunohistochemical staining. ISCs activation levels were assessed from rats and palmitic acid- (PA-) treated cultured ISCs by immunofluorescence, Oil red O staining, electron microscopy, quantitative PCR, and western blotting. Changes in ISCs phenotype of activation degree and its underlying mechanisms were assessed by target gene lentiviral infection, high-performance liquid chromatography (HPLC), and western blotting. Results Obese rats showed glucose intolerance, decreased endocrine hormone profiles, and elevated expression of α-smooth muscle actin (α-SMA), a polygonal appearance without cytoplasmic lipid droplets of ISCs in rats and isolated islets. PA-treated cultured ISCs exhibited faster proliferation and migration abilities with the induction of mRNA levels of lipid metabolism proteins, especially Plin2. The overexpression of Plin2 resulted in ISCs “re-quiescent” phenotypes associated with inhibition of the Smad3-TGF-β signaling pathways. Conclusions Our observations suggest a protective role of Plin2 in weakening ISCs activation. It may serve as a novel therapeutic target for preventing islet fibrosis for T2DM.
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Differential routing and disposition of the long-chain saturated fatty acid palmitate in rodent vs human beta-cells. Nutr Diabetes 2022; 12:22. [PMID: 35443738 PMCID: PMC9021209 DOI: 10.1038/s41387-022-00199-y] [Citation(s) in RCA: 4] [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: 02/03/2021] [Revised: 03/15/2022] [Accepted: 03/28/2022] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Rodent and human β-cells are differentially susceptible to the "lipotoxic" effects of long-chain saturated fatty acids (LC-SFA) but the factors accounting for this are unclear. Here, we have studied the intracellular disposition of the LC-SFA palmitate in human vs rodent β-cells and present data that reveal new insights into the factors regulating β-cell lipotoxicity. METHODS The subcellular distribution of the LC-SFA palmitate was studied in rodent (INS-1E and INS-1 823/13 cells) and human (EndoC-βH1) β-cells using confocal fluorescence and electron microscopy (EM). Protein expression was assessed by Western blotting and cell viability, by vital dye staining. RESULTS Exposure of INS-1 cells to palmitate for 24 h led to loss of viability, whereas EndoC-βH1 cells remained viable even after 72 h of treatment with a high concentration (1 mM) of palmitate. Use of the fluorescent palmitate analogue BODIPY FL C16 revealed an early localisation of the LC-SFA to the Golgi apparatus in INS-1 cells and this correlated with distention of intracellular membranes, visualised under the EM. Despite this, the PERK-dependent ER stress pathway was not activated under these conditions. By contrast, BODIPY FL C16 did not accumulate in the Golgi apparatus in EndoC-βH1 cells but, rather, co-localised with the lipid droplet-associated protein, PLIN2, suggesting preferential routing into lipid droplets. When INS-1 cells were treated with a combination of palmitate plus oleate, the toxic effects of palmitate were attenuated and BODIPY FL C16 localised primarily with PLIN2 but not with a Golgi marker. CONCLUSION In rodent β-cells, palmitate accumulates in the Golgi apparatus at early time points whereas, in EndoC- βH1 cells, it is routed preferentially into lipid droplets. This may account for the differential sensitivity of rodent vs human β-cells to "lipotoxicity" since manoeuvres leading to the incorporation of palmitate into lipid droplets is associated with the maintenance of cell viability in both cell types.
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Tong X, Liu S, Stein R, Imai Y. Lipid Droplets' Role in the Regulation of β-Cell Function and β-Cell Demise in Type 2 Diabetes. Endocrinology 2022; 163:6516108. [PMID: 35086144 PMCID: PMC8826878 DOI: 10.1210/endocr/bqac007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Indexed: 01/29/2023]
Abstract
During development of type 2 diabetes (T2D), excessive nutritional load is thought to expose pancreatic islets to toxic effects of lipids and reduce β-cell function and mass. However, lipids also play a positive role in cellular metabolism and function. Thus, proper trafficking of lipids is critical for β cells to maximize the beneficial effects of these molecules while preventing their toxic effects. Lipid droplets (LDs) are organelles that play an important role in the storage and trafficking of lipids. In this review, we summarize the discovery of LDs in pancreatic β cells, LD lifecycle, and the effect of LD catabolism on β-cell insulin secretion. We discuss factors affecting LD formation such as age, cell type, species, and nutrient availability. We then outline published studies targeting critical LD regulators, primarily in rat and human β-cell models, to understand the molecular effect of LD formation and degradation on β-cell function and health. Furthermore, based on the abnormal LD accumulation observed in human T2D islets, we discuss the possible role of LDs during the development of β-cell failure in T2D. Current knowledge indicates that proper formation and clearance of LDs are critical to normal insulin secretion, endoplasmic reticulum homeostasis, and mitochondrial integrity in β cells. However, it remains unclear whether LDs positively or negatively affect human β-cell demise in T2D. Thus, we discuss possible research directions to address the knowledge gap regarding the role of LDs in β-cell failure.
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Affiliation(s)
- Xin Tong
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, Tennessee 37232, USA
| | - Siming Liu
- Department of Internal Medicine Carver College of Medicine, Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa 52242, USA
| | - Roland Stein
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, Tennessee 37232, USA
| | - Yumi Imai
- Department of Internal Medicine Carver College of Medicine, Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa 52242, USA
- Iowa City Veterans Affairs Medical Center, Iowa City, Iowa 52246, USA
- Correspondence: Yumi Imai, MD, Department of Internal Medicine Carver College of Medicine, Fraternal Order of Eagles Diabetes Research Center, University of Iowa, 200 Hawkins Dr, PBDB Rm 3318, Iowa City, IA 52242, USA.
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Yang M, Luo S, Yang J, Chen W, He L, Liu D, Zhao L, Wang X. Lipid droplet - mitochondria coupling: A novel lipid metabolism regulatory hub in diabetic nephropathy. Front Endocrinol (Lausanne) 2022; 13:1017387. [PMID: 36387849 PMCID: PMC9640443 DOI: 10.3389/fendo.2022.1017387] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 10/04/2022] [Indexed: 11/13/2022] Open
Abstract
Diabetic nephropathy (DN) involves serious lipid metabolism disorder, and renal ectopic lipid deposition aggravates DN progression. However, the molecular mechanism of renal lipid deposition in DN remains unclear. Lipid droplets (LDs) are lipid pools in cells that change dynamically in response to the cellular energy needs. The LDs and mitochondria are connected through a part of the mitochondria known as the peridroplet mitochondria (PDM). In this review, we summarize the definition, detection methods, and function of the PDM. Finally, we discuss the research status of PDM in DN and the possibility of its use as a therapeutic target.
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Affiliation(s)
- Ming Yang
- Department of Nutrition, Xiangya Hospital, Central South University, Changsha, China
- Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Shilu Luo
- Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Jinfei Yang
- Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Wei Chen
- Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Liyu He
- Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Di Liu
- Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Li Zhao
- Department of Reproduction and Genetics, The First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Xi Wang
- Department of Nutrition, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
- *Correspondence: Xi Wang,
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Horii T, Kozawa J, Fujita Y, Kawata S, Ozawa H, Ishibashi C, Yoneda S, Nammo T, Miyagawa JI, Eguchi H, Shimomura I. Lipid droplet accumulation in β cells in patients with type 2 diabetes is associated with insulin resistance, hyperglycemia and β cell dysfunction involving decreased insulin granules. Front Endocrinol (Lausanne) 2022; 13:996716. [PMID: 36204103 PMCID: PMC9530467 DOI: 10.3389/fendo.2022.996716] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/05/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND OBJECTIVE Pancreatic fat is a form of ectopic fat. Lipid droplets (LDs) are also observed in β cells; however, the pathophysiological significance, especially for β cell function, has not been elucidated. Our aim was to assess LD accumulation in β cells in various stages of glucose intolerance and to clarify its relationship with clinical and histological parameters. METHODS We examined 42 Japanese patients who underwent pancreatectomy. The BODIPY493/503-positive (BODIPY-positive) area in β cells was measured in pancreatic sections from 32 patients. The insulin granule numbers were counted in an additional 10 patients using electron microscopy. RESULTS The BODIPY-positive area in β cells in preexisting type 2 diabetes patients was higher than that in normal glucose tolerance patients (p = 0.031). The BODIPY-positive area in β cells was positively correlated with age (r = 0.45, p = 0.0097), HbA1c (r = 0.38, p = 0.0302), fasting plasma glucose (r = 0.37, p = 0.045), and homeostasis model assessment insulin resistance (r = 0.41, p = 0.049) and negatively correlated with an increase in the C-peptide immunoreactivity level by the glucagon test (r = -0.59, p = 0.018). The ratio of mature insulin granule number to total insulin granule number was reduced in the patients with rich LD accumulation in β cells (p = 0.039). CONCLUSIONS Type 2 diabetes patients had high LD accumulation in β cells, which was associated with insulin resistance, hyperglycemia, aging and β cell dysfunction involving decreased mature insulin granules.
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Affiliation(s)
- Tomomi Horii
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Junji Kozawa
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
- Department of Diabetes Care Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
- *Correspondence: Junji Kozawa,
| | - Yukari Fujita
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
- Department of Community Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Satoshi Kawata
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Harutoshi Ozawa
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
- Department of Lifestyle Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Chisaki Ishibashi
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Sho Yoneda
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
- Yoneda Clinic, Osaka, Japan
| | - Takao Nammo
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
- Department of Diabetes Care Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
| | | | - Hidetoshi Eguchi
- Department of Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Iichiro Shimomura
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Suita, Japan
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Abstract
Pancreatic islets are the body's central rheostat that regulates glucose homeostasis through the production of different hormones, including β cell-derived insulin. During obesity-induced type 2 diabetes (T2D), islet β cells become dysfunctional and inadequate insulin secretion no longer ensures glycemic control. T2D is associated with a chronic low-grade inflammation that manifests in several metabolic organs including the pancreatic islets. Growing evidence suggests that components of the innate immune system, and especially macrophages, play a crucial role in regulating islet homeostasis. Yet, the phenotypes and functions of islet macrophages in physiology and during T2D have only started to attract attention and remain unclear. In this review, the current knowledge about islet inflammation and macrophages will be summarized in humans and rodent models. Recent findings on the cellular and molecular mechanisms involved in islet remodeling and β cell function during obesity and T2D will be discussed.
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Affiliation(s)
- Joyceline Cuenco
- Centre de Recherche des Cordeliers, INSERM, IMMEDIAB Laboratory, Sorbonne Université, Université de Paris, Paris, France
| | - Elise Dalmas
- Centre de Recherche des Cordeliers, INSERM, IMMEDIAB Laboratory, Sorbonne Université, Université de Paris, Paris, France.
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