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Wang Y, Chen J, Ni Y, Liu Y, Gao X, Tse MA, Panagiotou G, Xu A. Exercise-changed gut mycobiome as a potential contributor to metabolic benefits in diabetes prevention: an integrative multi-omics study. Gut Microbes 2024; 16:2416928. [PMID: 39473051 PMCID: PMC11533799 DOI: 10.1080/19490976.2024.2416928] [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: 07/22/2024] [Revised: 10/05/2024] [Accepted: 10/10/2024] [Indexed: 11/06/2024] Open
Abstract
BACKGROUND The importance of gut microbes in mediating the benefits of lifestyle intervention is increasingly recognized. However, compared to the bacterial microbiome, the role of intestinal fungi in exercise remains elusive. With our established randomized controlled trial of exercise intervention in Chinese males with prediabetes (n = 39, ClinicalTrials.gov:NCT03240978), we investigated the dynamics of human gut mycobiome and further interrogated their associations with exercise-elicited outcomes using multi-omics approaches. METHODS Clinical variations and biological samples were collected before and after training. Fecal fungal composition was analyzed using the internal transcribed spacer 2 (ITS2) sequencing and integrated with paired shotgun metagenomics, untargeted metabolomics, and Olink proteomics. RESULTS Twelve weeks of exercise training profoundly promoted fungal ecological diversity and intrakingdom connection. We further identified exercise-responsive genera with potential metabolic benefits, including Verticillium, Sarocladium, and Ceratocystis. Using multi-omics approaches, we elucidated comprehensive associations between changes in gut mycobiome and exercise-shaped metabolic phenotypes, bacterial microbiome, and circulating metabolomics and proteomics profiles. Furthermore, a machine-learning algorithm built using baseline microbial signatures and clinical characteristics predicted exercise responsiveness in improvements of insulin sensitivity, with an area under the receiver operating characteristic (AUROC) of 0.91 (95% CI: 0.85-0.97) in the discovery cohort and of 0.79 (95% CI: 0.74-0.86) in the independent validation cohort (n = 30). CONCLUSIONS Our findings suggest that intense exercise training significantly remodels the human fungal microbiome composition. Changes in gut fungal composition are associated with the metabolic benefits of exercise, indicating gut mycobiome is a possible molecular transducer of exercise. Moreover, baseline gut fungal signatures predict exercise responsiveness for diabetes prevention, highlighting that targeting the gut mycobiome emerges as a prospective strategy in tailoring personalized training for diabetes prevention.
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Affiliation(s)
- Yao Wang
- State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, China
- Department of Medicine, The University of Hong Kong, Hong Kong, China
- Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Hong Kong, China
| | - Jiarui Chen
- State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, China
- Department of Medicine, The University of Hong Kong, Hong Kong, China
| | - Yueqiong Ni
- Department of Microbiome Dynamics, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoll Institute, Jena, Germany
| | - Yan Liu
- State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, China
- Department of Medicine, The University of Hong Kong, Hong Kong, China
| | - Xiang Gao
- State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, China
| | - Michael Andrew Tse
- State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, China
- Centre for Sports and Exercise, The University of Hong Kong, Hong Kong, China
| | - Gianni Panagiotou
- State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, China
- Department of Medicine, The University of Hong Kong, Hong Kong, China
- Department of Microbiome Dynamics, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoll Institute, Jena, Germany
- Faculty of Biological Sciences, Friedrich Schiller University, Jena, Germany
- Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Aimin Xu
- State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong, China
- Department of Medicine, The University of Hong Kong, Hong Kong, China
- Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, China
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2
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Gupta D, Burstein AW, Schwalbe DC, Shankar K, Varshney S, Singh O, Paul S, Ogden SB, Osborne-Lawrence S, Metzger NP, Richard CP, Campbell JN, Zigman JM. Ghrelin deletion and conditional ghrelin cell ablation increase pancreatic islet size in mice. J Clin Invest 2023; 133:e169349. [PMID: 38099492 PMCID: PMC10721155 DOI: 10.1172/jci169349] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 10/05/2023] [Indexed: 12/18/2023] Open
Abstract
Ghrelin exerts key effects on islet hormone secretion to regulate blood glucose levels. Here, we sought to determine whether ghrelin's effects on islets extend to the alteration of islet size and β cell mass. We demonstrate that reducing ghrelin - by ghrelin gene knockout (GKO), conditional ghrelin cell ablation, or high-fat diet (HFD) feeding - was associated with increased mean islet size (up to 62%), percentage of large islets (up to 854%), and β cell cross-sectional area (up to 51%). In GKO mice, these effects were more apparent in 10- to 12-week-old mice than in 4-week-old mice. Higher β cell numbers from decreased β cell apoptosis drove the increase in β cell cross-sectional area. Conditional ghrelin cell ablation in adult mice increased the β cell number per islet by 40% within 4 weeks. A negative correlation between islet size and plasma ghrelin in HFD-fed plus chow-fed WT mice, together with even larger islet sizes in HFD-fed GKO mice than in HFD-fed WT mice, suggests that reduced ghrelin was not solely responsible for diet-induced obesity-associated islet enlargement. Single-cell transcriptomics revealed changes in gene expression in several GKO islet cell types, including upregulation of Manf, Dnajc3, and Gnas expression in β cells, which supports decreased β cell apoptosis and/or increased β cell proliferation. These effects of ghrelin reduction on islet morphology might prove useful when designing new therapies for diabetes.
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Affiliation(s)
- Deepali Gupta
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Avi W. Burstein
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Dana C. Schwalbe
- Department of Biology, University of Virginia, Charlottesville, Virginia, USA
| | - Kripa Shankar
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Salil Varshney
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Omprakash Singh
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Subhojit Paul
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Sean B. Ogden
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Sherri Osborne-Lawrence
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Nathan P. Metzger
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Corine P. Richard
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas, USA
| | - John N. Campbell
- Department of Biology, University of Virginia, Charlottesville, Virginia, USA
| | - Jeffrey M. Zigman
- Center for Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas, USA
- Division of Endocrinology and Metabolism, Department of Internal Medicine and
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, Texas, USA
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3
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St-Louis JL, El Jellas K, Velasco K, Slipp BA, Hu J, Helgeland G, Steine SJ, De Jesus DF, Kulkarni RN, Molven A. Deficiency of the metabolic enzyme SCHAD in pancreatic β-cells promotes amino acid-sensitive hypoglycemia. J Biol Chem 2023; 299:104986. [PMID: 37392854 PMCID: PMC10407745 DOI: 10.1016/j.jbc.2023.104986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 06/02/2023] [Accepted: 06/20/2023] [Indexed: 07/03/2023] Open
Abstract
Congenital hyperinsulinism of infancy (CHI) can be caused by a deficiency of the ubiquitously expressed enzyme short-chain 3-hydroxyacyl-CoA dehydrogenase (SCHAD). To test the hypothesis that SCHAD-CHI arises from a specific defect in pancreatic β-cells, we created genetically engineered β-cell-specific (β-SKO) or hepatocyte-specific (L-SKO) SCHAD knockout mice. While L-SKO mice were normoglycemic, plasma glucose in β-SKO animals was significantly reduced in the random-fed state, after overnight fasting, and following refeeding. The hypoglycemic phenotype was exacerbated when the mice were fed a diet enriched in leucine, glutamine, and alanine. Intraperitoneal injection of these three amino acids led to a rapid elevation in insulin levels in β-SKO mice compared to controls. Consistently, treating isolated β-SKO islets with the amino acid mixture potently enhanced insulin secretion compared to controls in a low-glucose environment. RNA sequencing of β-SKO islets revealed reduced transcription of β-cell identity genes and upregulation of genes involved in oxidative phosphorylation, protein metabolism, and Ca2+ handling. The β-SKO mouse offers a useful model to interrogate the intra-islet heterogeneity of amino acid sensing given the very variable expression levels of SCHAD within different hormonal cells, with high levels in β- and δ-cells and virtually absent α-cell expression. We conclude that the lack of SCHAD protein in β-cells results in a hypoglycemic phenotype characterized by increased sensitivity to amino acid-stimulated insulin secretion and loss of β-cell identity.
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Affiliation(s)
- Johanna L St-Louis
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, USA; Department of Clinical Medicine, Gade Laboratory for Pathology, University of Bergen, Bergen, Norway
| | - Khadija El Jellas
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, USA; Department of Clinical Medicine, Gade Laboratory for Pathology, University of Bergen, Bergen, Norway
| | - Kelly Velasco
- Department of Clinical Medicine, Gade Laboratory for Pathology, University of Bergen, Bergen, Norway
| | - Brittany A Slipp
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, USA
| | - Jiang Hu
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, USA
| | - Geir Helgeland
- Department of Clinical Medicine, Gade Laboratory for Pathology, University of Bergen, Bergen, Norway
| | - Solrun J Steine
- Department of Clinical Medicine, Gade Laboratory for Pathology, University of Bergen, Bergen, Norway
| | - Dario F De Jesus
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, USA; Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA; Harvard Stem Cell Institute, Boston, USA
| | - Rohit N Kulkarni
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, USA; Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA; Harvard Stem Cell Institute, Boston, USA
| | - Anders Molven
- Department of Clinical Medicine, Gade Laboratory for Pathology, University of Bergen, Bergen, Norway; Department of Pathology, Haukeland University Hospital, Bergen, Norway; Section for Cancer Genomics, Haukeland University Hospital, Bergen, Norway.
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The Potential Role of R4 Regulators of G Protein Signaling (RGS) Proteins in Type 2 Diabetes Mellitus. Cells 2022; 11:cells11233897. [PMID: 36497154 PMCID: PMC9739376 DOI: 10.3390/cells11233897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/26/2022] [Accepted: 11/30/2022] [Indexed: 12/05/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a complex and heterogeneous disease that primarily results from impaired insulin secretion or insulin resistance (IR). G protein-coupled receptors (GPCRs) are proposed as therapeutic targets for T2DM. GPCRs transduce signals via the Gα protein, playing an integral role in insulin secretion and IR. The regulators of G protein signaling (RGS) family proteins can bind to Gα proteins and function as GTPase-activating proteins (GAP) to accelerate GTP hydrolysis, thereby terminating Gα protein signaling. Thus, RGS proteins determine the size and duration of cellular responses to GPCR stimulation. RGSs are becoming popular targeting sites for modulating the signaling of GPCRs and related diseases. The R4 subfamily is the largest RGS family. This review will summarize the research progress on the mechanisms of R4 RGS subfamily proteins in insulin secretion and insulin resistance and analyze their potential value in the treatment of T2DM.
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5
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Tian M, Ma Y, Li T, Wu N, Li J, Jia H, Yan M, Wang W, Bian H, Tan X, Qi J. Functions of regulators of G protein signaling 16 in immunity, inflammation, and other diseases. Front Mol Biosci 2022; 9:962321. [PMID: 36120550 PMCID: PMC9478547 DOI: 10.3389/fmolb.2022.962321] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
Regulators of G protein signaling (RGS) act as guanosine triphosphatase activating proteins to accelerate guanosine triphosphate hydrolysis of the G protein α subunit, leading to the termination of the G protein-coupled receptor (GPCR) downstream signaling pathway. RGS16, which is expressed in a number of cells and tissues, belongs to one of the small B/R4 subfamilies of RGS proteins and consists of a conserved RGS structural domain with short, disordered amino- and carboxy-terminal extensions and an α-helix that classically binds and de-activates heterotrimeric G proteins. However, with the deepening of research, it has been revealed that RGS16 protein not only regulates the classical GPCR pathway, but also affects immune, inflammatory, tumor and metabolic processes through other signaling pathways including the mitogen-activated protein kinase, phosphoinositide 3-kinase/protein kinase B, Ras homolog family member A and stromal cell-derived factor 1/C-X-C motif chemokine receptor 4 pathways. Additionally, the RGS16 protein may be involved in the Hepatitis B Virus -induced inflammatory response. Therefore, given the continuous expansion of knowledge regarding its role and mechanism, the structure, characteristics, regulatory mechanisms and known functions of the small RGS proteinRGS16 are reviewed in this paper to prepare for diagnosis, treatment, and prognostic evaluation of different diseases such as inflammation, tumor, and metabolic disorders and to better study its function in other diseases.
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Affiliation(s)
- Miaomiao Tian
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Yan Ma
- Zibo Central Hospital, Zibo, China
| | - Tao Li
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Nijin Wu
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Jiaqi Li
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Huimin Jia
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Meizhu Yan
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Wenwen Wang
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Hongjun Bian
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Xu Tan
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
- *Correspondence: Jianni Qi, ; Xu Tan,
| | - Jianni Qi
- Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
- Shandong Provincial Engineering and Technological Research Center for Liver Diseases Prevention and Control, Jinan, China
- *Correspondence: Jianni Qi, ; Xu Tan,
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6
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Pipal KV, Mamtani M, Patel AA, Jaiswal SG, Jaisinghani MT, Kulkarni H. Susceptibility Loci for Type 2 Diabetes in the Ethnically Endogamous Indian Sindhi Population: A Pooled Blood Genome-Wide Association Study. Genes (Basel) 2022; 13:1298. [PMID: 35893037 PMCID: PMC9331904 DOI: 10.3390/genes13081298] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/15/2022] [Accepted: 07/19/2022] [Indexed: 12/10/2022] Open
Abstract
Type 2 diabetes (T2D) is a complex metabolic derangement that has a strong genetic basis. There is substantial population-specificity in the association of genetic variants with T2D. The Indian urban Sindhi population is at a high risk of T2D. The genetic basis of T2D in this population is unknown. We interrogated 28 pooled whole blood genomes of 1402 participants from the Diabetes In Sindhi Families In Nagpur (DISFIN) study using Illumina's Global Screening Array. From a total of 608,550 biallelic variants, 140 were significantly associated with T2D after adjusting for comorbidities, batch effects, pooling error, kinship status and pooling variation in a random effects multivariable logistic regression framework. Of the 102 well-characterized genes that these variants mapped onto, 70 genes have been previously reported to be associated with T2D to varying degrees with known functional relevance. Excluding open reading frames, intergenic non-coding elements and pseudogenes, our study identified 22 novel candidate genes in the Sindhi population studied. Our study thus points to the potential, interesting candidate genes associated with T2D in an ethnically endogamous population. These candidate genes need to be fully investigated in future studies.
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Affiliation(s)
- Kanchan V. Pipal
- Lata Medical Research Foundation, Nagpur 440002, India; (K.V.P.); (M.M.); (A.A.P.); (S.G.J.); (M.T.J.)
| | - Manju Mamtani
- Lata Medical Research Foundation, Nagpur 440002, India; (K.V.P.); (M.M.); (A.A.P.); (S.G.J.); (M.T.J.)
- M&H Research, LLC, San Antonio, TX 78249, USA
| | - Ashwini A. Patel
- Lata Medical Research Foundation, Nagpur 440002, India; (K.V.P.); (M.M.); (A.A.P.); (S.G.J.); (M.T.J.)
| | - Sujeet G. Jaiswal
- Lata Medical Research Foundation, Nagpur 440002, India; (K.V.P.); (M.M.); (A.A.P.); (S.G.J.); (M.T.J.)
| | - Manisha T. Jaisinghani
- Lata Medical Research Foundation, Nagpur 440002, India; (K.V.P.); (M.M.); (A.A.P.); (S.G.J.); (M.T.J.)
| | - Hemant Kulkarni
- Lata Medical Research Foundation, Nagpur 440002, India; (K.V.P.); (M.M.); (A.A.P.); (S.G.J.); (M.T.J.)
- M&H Research, LLC, San Antonio, TX 78249, USA
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Karimova MV, Gvazava IG, Vorotelyak EA. Overcoming the Limitations of Stem Cell-Derived Beta Cells. Biomolecules 2022; 12:biom12060810. [PMID: 35740935 PMCID: PMC9221417 DOI: 10.3390/biom12060810] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/06/2022] [Accepted: 06/07/2022] [Indexed: 12/13/2022] Open
Abstract
Great advances in type 1 diabetes (T1D) and type 2 diabetes (T2D) treatment have been made to this day. However, modern diabetes therapy based on insulin injections and cadaveric islets transplantation has many disadvantages. That is why researchers are developing new methods to regenerate the pancreatic hormone-producing cells in vitro. The most promising approach is the generation of stem cell-derived beta cells that could provide an unlimited source of insulin-secreting cells. Recent studies provide methods to produce beta-like cell clusters that display glucose-stimulated insulin secretion—one of the key characteristics of the beta cell. However, in comparison with native beta cells, stem cell-derived beta cells do not undergo full functional maturation. In this paper we review the development and current state of various protocols, consider advantages, and propose ways to improve them. We examine molecular pathways, epigenetic modifications, intracellular components, and the microenvironment as a possible leverage to promote beta cell functional maturation. A possibility to create islet organoids from stem cell-derived components, as well as their encapsulation and further transplantation, is also examined. We try to combine modern research on beta cells and their crosstalk to create a holistic overview of developing insulin-secreting systems.
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Affiliation(s)
- Mariana V. Karimova
- Koltzov Institute of Developmental Biology of Russian Academy of Sciences, 119334 Moscow, Russia; (M.V.K.); (I.G.G.)
| | - Inessa G. Gvazava
- Koltzov Institute of Developmental Biology of Russian Academy of Sciences, 119334 Moscow, Russia; (M.V.K.); (I.G.G.)
| | - Ekaterina A. Vorotelyak
- Koltzov Institute of Developmental Biology of Russian Academy of Sciences, 119334 Moscow, Russia; (M.V.K.); (I.G.G.)
- Department of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
- Correspondence:
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8
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Castell AL, Vivoli A, Tippetts TS, Frayne IR, Angeles ZE, Moullé VS, Campbell SA, Ruiz M, Ghislain J, Des Rosiers C, Holland WL, Summers SA, Poitout V. Very-Long-Chain Unsaturated Sphingolipids Mediate Oleate-Induced Rat β-Cell Proliferation. Diabetes 2022; 71:1218-1232. [PMID: 35287172 PMCID: PMC9163557 DOI: 10.2337/db21-0640] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 03/09/2022] [Indexed: 11/13/2022]
Abstract
Fatty acid (FA) signaling contributes to β-cell mass expansion in response to nutrient excess, but the underlying mechanisms are poorly understood. In the presence of elevated glucose, FA metabolism is shifted toward synthesis of complex lipids, including sphingolipids. Here, we tested the hypothesis that sphingolipids are involved in the β-cell proliferative response to FA. Isolated rat islets were exposed to FA and 16.7 mmol/L glucose for 48-72 h, and the contribution of the de novo sphingolipid synthesis pathway was tested using the serine palmitoyltransferase inhibitor myriocin, the sphingosine kinase (SphK) inhibitor SKI II, or knockdown of SphK, fatty acid elongase 1 (ELOVL1) and acyl-CoA-binding protein (ACBP). Rats were infused with glucose and the lipid emulsion ClinOleic and received SKI II by gavage. β-Cell proliferation was assessed by immunochemistry or flow cytometry. Sphingolipids were analyzed by liquid chromatography-tandem mass spectrometry. Among the FAs tested, only oleate increased β-cell proliferation. Myriocin, SKI II, and SphK knockdown all decreased oleate-induced β-cell proliferation. Oleate exposure did not increase the total amount of sphingolipids but led to a specific rise in 24:1 species. Knockdown of ACBP or ELOVL1 inhibited oleate-induced β-cell proliferation. We conclude that unsaturated very-long-chain sphingolipids produced from the available C24:1 acyl-CoA pool mediate oleate-induced β-cell proliferation in rats.
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Affiliation(s)
- Anne-Laure Castell
- Montreal Diabetes Research Center, CRCHUM, Montreal, Quebec, Canada
- Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Alexis Vivoli
- Montreal Diabetes Research Center, CRCHUM, Montreal, Quebec, Canada
- Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Trevor S. Tippetts
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT
| | | | - Zuraya Elisa Angeles
- Montreal Diabetes Research Center, CRCHUM, Montreal, Quebec, Canada
- Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Valentine S. Moullé
- Montreal Diabetes Research Center, CRCHUM, Montreal, Quebec, Canada
- Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Scott A. Campbell
- Montreal Diabetes Research Center, CRCHUM, Montreal, Quebec, Canada
- Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
| | - Matthieu Ruiz
- Metabolomic Platform, Montreal Heart Institute Research Center, Montreal, Quebec, Canada
| | - Julien Ghislain
- Montreal Diabetes Research Center, CRCHUM, Montreal, Quebec, Canada
| | - Christine Des Rosiers
- Metabolomic Platform, Montreal Heart Institute Research Center, Montreal, Quebec, Canada
- Department of Nutrition, Université de Montréal, Montreal, Quebec, Canada
| | - William L. Holland
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT
| | - Scott A. Summers
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT
| | - Vincent Poitout
- Montreal Diabetes Research Center, CRCHUM, Montreal, Quebec, Canada
- Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
- Corresponding author: Vincent Poitout,
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9
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Insulin is expressed by enteroendocrine cells during human fetal development. Nat Med 2021; 27:2104-2107. [PMID: 34887578 DOI: 10.1038/s41591-021-01586-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 10/22/2021] [Indexed: 12/23/2022]
Abstract
Generation of beta cells via transdifferentiation of other cell types is a promising avenue for the treatment of diabetes. Here we reconstruct a single-cell atlas of the human fetal and neonatal small intestine. We identify a subset of fetal enteroendocrine K/L cells that express high levels of insulin and other beta cell genes. Our findings highlight a potential extra-pancreatic source of beta cells and expose its molecular blueprint.
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10
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Bastin G, Luu L, Batchuluun B, Mighiu A, Beadman S, Zhang H, He C, Al Rijjal D, Wheeler MB, Heximer SP. RGS4-Deficiency Alters Intracellular Calcium and PKA-Mediated Control of Insulin Secretion in Glucose-Stimulated Beta Islets. Biomedicines 2021; 9:biomedicines9081008. [PMID: 34440212 PMCID: PMC8391461 DOI: 10.3390/biomedicines9081008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/04/2021] [Accepted: 08/05/2021] [Indexed: 11/16/2022] Open
Abstract
A number of diverse G-protein signaling pathways have been shown to regulate insulin secretion from pancreatic β-cells. Accordingly, regulator of G-protein signaling (RGS) proteins have also been implicated in coordinating this process. One such protein, RGS4, is reported to show both positive and negative effects on insulin secretion from β-cells depending on the physiologic context under which it was studied. We here use an RGS4-deficient mouse model to characterize previously unknown G-protein signaling pathways that are regulated by RGS4 during glucose-stimulated insulin secretion from the pancreatic islets. Our data show that loss of RGS4 results in a marked deficiency in glucose-stimulated insulin secretion during both phase I and phase II of insulin release in intact mice and isolated islets. These deficiencies are associated with lower cAMP/PKA activity and a loss of normal calcium surge (phase I) and oscillatory (phase II) kinetics behavior in the RGS4-deficient β-cells, suggesting RGS4 may be important for regulation of both Gαi and Gαq signaling control during glucose-stimulated insulin secretion. Together, these studies add to the known list of G-protein coupled signaling events that are controlled by RGS4 during glucose-stimulated insulin secretion and highlight the importance of maintaining normal levels of RGS4 function in healthy pancreatic tissues.
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Affiliation(s)
- Guillaume Bastin
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
- Ted Rogers Centre for Heart Research, Translational Biology and Engineering Program, University of Toronto, Toronto, ON M5G 1M1, Canada
- Heart and Stroke/Richard Lewar Centre of Excellence in Cardiovascular Research, Toronto, ON M5S 3H2, Canada
- Correspondence: ; Tel.: +33-658-469-334
| | - Lemieux Luu
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Battsetseg Batchuluun
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Alexandra Mighiu
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Stephanie Beadman
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Hangjung Zhang
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Changhao He
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Dana Al Rijjal
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Michael B. Wheeler
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
| | - Scott P. Heximer
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; (L.L.); (B.B.); (A.M.); (S.B.); (H.Z.); (C.H.); (D.A.R.); (M.B.W.); (S.P.H.)
- Ted Rogers Centre for Heart Research, Translational Biology and Engineering Program, University of Toronto, Toronto, ON M5G 1M1, Canada
- Heart and Stroke/Richard Lewar Centre of Excellence in Cardiovascular Research, Toronto, ON M5S 3H2, Canada
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11
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Iorio C, Rourke JL, Wells L, Sakamaki JI, Moon E, Hu Q, Kin T, Screaton RA. Silencing the G-protein coupled receptor 3-salt inducible kinase 2 pathway promotes human β cell proliferation. Commun Biol 2021; 4:907. [PMID: 34302056 PMCID: PMC8302759 DOI: 10.1038/s42003-021-02433-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 07/08/2021] [Indexed: 02/07/2023] Open
Abstract
Loss of pancreatic β cells is the hallmark of type 1 diabetes, for which provision of insulin is the standard of care. While regenerative and stem cell therapies hold the promise of generating single-source or host-matched tissue to obviate immune-mediated complications, these will still require surgical intervention and immunosuppression. Here we report the development of a high-throughput RNAi screening approach to identify upstream pathways that regulate adult human β cell quiescence and demonstrate in a screen of the GPCRome that silencing G-protein coupled receptor 3 (GPR3) leads to human pancreatic β cell proliferation. Loss of GPR3 leads to activation of Salt Inducible Kinase 2 (SIK2), which is necessary and sufficient to drive cell cycle entry, increase β cell mass, and enhance insulin secretion in mice. Taken together, our data show that targeting the GPR3-SIK2 pathway is a potential strategy to stimulate the regeneration of β cells.
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Affiliation(s)
| | - Jillian L Rourke
- Sunnybrook Research Institute, Toronto, Canada
- Mount Allison University, Sackville, NB, Canada
| | - Lisa Wells
- Sunnybrook Research Institute, Toronto, Canada
| | - Jun-Ichi Sakamaki
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Japan
| | - Emily Moon
- Sunnybrook Research Institute, Toronto, Canada
- Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Queenie Hu
- Sunnybrook Research Institute, Toronto, Canada
| | - Tatsuya Kin
- Clinical Islet Laboratory, University of Alberta Hospital, Edmonton, Canada
| | - Robert A Screaton
- Sunnybrook Research Institute, Toronto, Canada.
- Department of Biochemistry, University of Toronto, Toronto, Canada.
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12
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Inoue R, Nishiyama K, Li J, Miyashita D, Ono M, Terauchi Y, Shirakawa J. The Feasibility and Applicability of Stem Cell Therapy for the Cure of Type 1 Diabetes. Cells 2021; 10:cells10071589. [PMID: 34202521 PMCID: PMC8304653 DOI: 10.3390/cells10071589] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/18/2021] [Accepted: 06/22/2021] [Indexed: 12/25/2022] Open
Abstract
Stem cell therapy using islet-like insulin-producing cells derived from human pluripotent stem cells has the potential to allow patients with type 1 diabetes to withdraw from insulin therapy. However, several issues exist regarding the use of stem cell therapy to treat type 1 diabetes. In this review, we will focus on the following topics: (1) autoimmune responses during the autologous transplantation of stem cell-derived islet cells, (2) a comparison of stem cell therapy with insulin injection therapy, (3) the impact of the islet microenvironment on stem cell-derived islet cells, and (4) the cost-effectiveness of stem cell-derived islet cell transplantation. Based on these various viewpoints, we will discuss what is required to perform stem cell therapy for patients with type 1 diabetes.
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Affiliation(s)
- Ryota Inoue
- Laboratory of Diabetes and Metabolic Disorders, Institute for Molecular and Cellular Regulation (IMCR), Gunma University, Maebashi 371-8512, Japan; (R.I.); (K.N.); (J.L.)
| | - Kuniyuki Nishiyama
- Laboratory of Diabetes and Metabolic Disorders, Institute for Molecular and Cellular Regulation (IMCR), Gunma University, Maebashi 371-8512, Japan; (R.I.); (K.N.); (J.L.)
| | - Jinghe Li
- Laboratory of Diabetes and Metabolic Disorders, Institute for Molecular and Cellular Regulation (IMCR), Gunma University, Maebashi 371-8512, Japan; (R.I.); (K.N.); (J.L.)
| | - Daisuke Miyashita
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama City University, Yokohama 236-0004, Japan; (D.M.); (M.O.); (Y.T.)
| | - Masato Ono
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama City University, Yokohama 236-0004, Japan; (D.M.); (M.O.); (Y.T.)
| | - Yasuo Terauchi
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama City University, Yokohama 236-0004, Japan; (D.M.); (M.O.); (Y.T.)
| | - Jun Shirakawa
- Laboratory of Diabetes and Metabolic Disorders, Institute for Molecular and Cellular Regulation (IMCR), Gunma University, Maebashi 371-8512, Japan; (R.I.); (K.N.); (J.L.)
- Correspondence: ; Tel.: +81-27-220-8850
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13
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Maachi H, Ghislain J, Tremblay C, Poitout V. Pronounced proliferation of non-beta cells in response to beta-cell mitogens in isolated human islets of Langerhans. Sci Rep 2021; 11:11283. [PMID: 34050242 PMCID: PMC8163757 DOI: 10.1038/s41598-021-90643-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 05/06/2021] [Indexed: 11/09/2022] Open
Abstract
The potential to treat diabetes by increasing beta-cell mass is driving a major effort to identify beta-cell mitogens. Demonstration of mitogen activity in human beta cells is frequently performed in ex vivo assays. However, reported disparities in the efficacy of beta-cell mitogens led us to investigate the sources of this variability. We studied 35 male (23) and female (12) human islet batches covering a range of donor ages and BMI. Islets were kept intact or dispersed into single cells and cultured in the presence of harmine, glucose, or heparin-binding epidermal growth factor-like growth factor (HB-EGF), and subsequently analyzed by immunohistochemistry or flow cytometry. Proliferating cells were identified by double labeling with EdU and Ki67 and glucagon, c-peptide or Nkx6.1, and cytokeratin-19 to respectively label alpha, beta, and ductal cells. Harmine and HB-EGF stimulated human beta-cell proliferation, but the effect of glucose was dependent on the assay and the donor. Harmine potently stimulated alpha-cell proliferation and both harmine and HB-EGF increased proliferation of insulin- and glucagon-negative cells, including cytokeratin 19-positive cells. Given the abundance of non-beta cells in human islet preparations, our results suggest that assessment of beta-cell mitogens requires complementary approaches and rigorous identification of cell identity using multiple markers.
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Affiliation(s)
- Hasna Maachi
- Montreal Diabetes Research Center, CRCHUM, 900 rue St Denis, Montreal, QC, H2X 0A9, Canada.,Department of Pharmacology and Physiology, University of Montreal, Montreal, QC, Canada
| | - Julien Ghislain
- Montreal Diabetes Research Center, CRCHUM, 900 rue St Denis, Montreal, QC, H2X 0A9, Canada
| | - Caroline Tremblay
- Montreal Diabetes Research Center, CRCHUM, 900 rue St Denis, Montreal, QC, H2X 0A9, Canada
| | - Vincent Poitout
- Montreal Diabetes Research Center, CRCHUM, 900 rue St Denis, Montreal, QC, H2X 0A9, Canada. .,Department of Medicine, University of Montreal, Montreal, QC, Canada.
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14
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Rajagopalan S, Park B, Palanivel R, Vinayachandran V, Deiuliis JA, Gangwar RS, Das L, Yin J, Choi Y, Al-Kindi S, Jain MK, Hansen KD, Biswal S. Metabolic effects of air pollution exposure and reversibility. J Clin Invest 2021; 130:6034-6040. [PMID: 32780721 DOI: 10.1172/jci137315] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 07/29/2020] [Indexed: 12/29/2022] Open
Abstract
Air pollution involving particulate matter smaller than 2.5 μm in size (PM2.5) is the world's leading environmental risk factor contributing to mortality through cardiometabolic pathways. In this study, we modeled early life exposure using chow-fed C57BL/6J male mice that were exposed to real-world inhaled, concentrated PM2.5 (~10 times ambient levels/~60-120 μg/m3) or filtered air over a 14-week period. We investigated the effects of PM2.5 on phenotype, the transcriptome, and chromatin accessibility and compared these with the effects of a prototypical high-fat diet (HFD) as well as cessation of exposure on phenotype reversibility. Exposure to PM2.5 impaired glucose and insulin tolerance and reduced energy expenditure and 18FDG-PET uptake in brown adipose tissue. Multiple differentially expressed gene clusters in pathways involving metabolism and circadian rhythm were noted in insulin-responsive tissues. Although the magnitude of transcriptional change detected with PM2.5 exposure was lower than that observed with a HFD, the degree of alteration in chromatin accessibility after PM2.5 exposure was significant. The novel chromatin remodeler SMARCA5 (SWI/SNF complex) was regulated in response to PM2.5 exposure, the cessation of which was associated with a reversal of insulin resistance and restoration of chromatin accessibility and nucleosome positioning near transcription start sites, as well as a reversal of exposure-induced changes in the transcriptome, including SMARCA5. These changes indicate pliable epigenetic control mechanisms following cessation of exposure.
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Affiliation(s)
- Sanjay Rajagopalan
- Cardiovascular Research Institute, Case Western Reserve University, Cleveland, Ohio, USA.,Harrington Heart and Vascular Institute, University Hospital Cleveland Medical Center, Cleveland, Ohio, USA
| | - Bongsoo Park
- Department of Environmental Health and Engineering and
| | - Rengasamy Palanivel
- Cardiovascular Research Institute, Case Western Reserve University, Cleveland, Ohio, USA
| | - Vinesh Vinayachandran
- Cardiovascular Research Institute, Case Western Reserve University, Cleveland, Ohio, USA
| | - Jeffrey A Deiuliis
- Cardiovascular Research Institute, Case Western Reserve University, Cleveland, Ohio, USA
| | - Roopesh Singh Gangwar
- Cardiovascular Research Institute, Case Western Reserve University, Cleveland, Ohio, USA
| | - Lopa Das
- Cardiovascular Research Institute, Case Western Reserve University, Cleveland, Ohio, USA
| | - Jinhu Yin
- Department of Environmental Health and Engineering and
| | | | - Sadeer Al-Kindi
- Cardiovascular Research Institute, Case Western Reserve University, Cleveland, Ohio, USA
| | - Mukesh K Jain
- Cardiovascular Research Institute, Case Western Reserve University, Cleveland, Ohio, USA.,Harrington Heart and Vascular Institute, University Hospital Cleveland Medical Center, Cleveland, Ohio, USA
| | - Kasper D Hansen
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| | - Shyam Biswal
- Department of Environmental Health and Engineering and
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15
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Vazquez-Jimenez JG, Corpus-Navarro MS, Rodriguez-Chavez JM, Jaramillo-Ramirez HJ, Hernandez-Aranda J, Galindo-Hernandez O, Machado-Contreras JR, Trejo-Trejo M, Guerrero-Hernandez A, Olivares-Reyes JA. The Increased Expression of Regulator of G-Protein Signaling 2 (RGS2) Inhibits Insulin-Induced Akt Phosphorylation and Is Associated with Uncontrolled Glycemia in Patients with Type 2 Diabetes. Metabolites 2021; 11:91. [PMID: 33562475 PMCID: PMC7915073 DOI: 10.3390/metabo11020091] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 01/23/2021] [Accepted: 01/29/2021] [Indexed: 12/17/2022] Open
Abstract
Experimental evidence in mice models has demonstrated that a high regulator of G-protein signaling 2 (RSG2) protein levels precede an insulin resistance state. In the same context, a diet rich in saturated fatty acids induces an increase in RGS2 protein expression, which has been associated with decreased basal metabolism in mice; however, the above has not yet been analyzed in humans. For this reason, in the present study, we examined the association between RGS2 expression and insulin resistance state. The incubation with palmitic acid (PA), which inhibits insulin-mediated Akt Ser473 phosphorylation, resulted in the increased RGS2 expression in human umbilical vein endothelial-CS (HUVEC-CS) cells. The RGS2 overexpression without PA was enough to inhibit insulin-mediated Akt Ser473 phosphorylation in HUVEC-CS cells. Remarkably, the platelet RGS2 expression levels were higher in type 2 diabetes mellitus (T2DM) patients than in healthy donors. Moreover, an unbiased principal component analysis (PCA) revealed that RGS2 expression level positively correlated with glycated hemoglobin (HbA1c) and negatively with age and high-density lipoprotein cholesterol (HDL) in T2DM patients. Furthermore, PCA showed that healthy subjects segregated from T2DM patients by having lower levels of HbA1c and RGS2. These results demonstrate that RGS2 overexpression leads to decreased insulin signaling in a human endothelial cell line and is associated with poorly controlled diabetes.
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Affiliation(s)
- J. Gustavo Vazquez-Jimenez
- Department of Biochemistry, Center for Research and Advanced Studies of the National Polytechnic Institute, CINVESTAV-IPN, Mexico City 07360, Mexico; (J.G.V.-J.); (J.H.-A.); (A.G.-H.)
- Laboratory of Molecular Pathogenesis, School of Medicine, Campus Mexicali, Autonomous University of Baja California, Mexicali, Baja California 21000, Mexico; (M.S.C.-N.); (J.M.R.-C.); (J.R.M.-C.)
| | - M. Stephanie Corpus-Navarro
- Laboratory of Molecular Pathogenesis, School of Medicine, Campus Mexicali, Autonomous University of Baja California, Mexicali, Baja California 21000, Mexico; (M.S.C.-N.); (J.M.R.-C.); (J.R.M.-C.)
| | - J. Miguel Rodriguez-Chavez
- Laboratory of Molecular Pathogenesis, School of Medicine, Campus Mexicali, Autonomous University of Baja California, Mexicali, Baja California 21000, Mexico; (M.S.C.-N.); (J.M.R.-C.); (J.R.M.-C.)
| | | | - Judith Hernandez-Aranda
- Department of Biochemistry, Center for Research and Advanced Studies of the National Polytechnic Institute, CINVESTAV-IPN, Mexico City 07360, Mexico; (J.G.V.-J.); (J.H.-A.); (A.G.-H.)
| | - Octavio Galindo-Hernandez
- Laboratory of Biochemistry, School of Medicine, Campus Mexicali, Autonomous University of Baja California, Mexicali, Baja California 21000, Mexico;
| | - J. Rene Machado-Contreras
- Laboratory of Molecular Pathogenesis, School of Medicine, Campus Mexicali, Autonomous University of Baja California, Mexicali, Baja California 21000, Mexico; (M.S.C.-N.); (J.M.R.-C.); (J.R.M.-C.)
| | - Marina Trejo-Trejo
- School of Sports, Campus Mexicali, Autonomous University of Baja California, Mexicali, Baja California 21000, Mexico;
| | - Agustin Guerrero-Hernandez
- Department of Biochemistry, Center for Research and Advanced Studies of the National Polytechnic Institute, CINVESTAV-IPN, Mexico City 07360, Mexico; (J.G.V.-J.); (J.H.-A.); (A.G.-H.)
| | - J. Alberto Olivares-Reyes
- Department of Biochemistry, Center for Research and Advanced Studies of the National Polytechnic Institute, CINVESTAV-IPN, Mexico City 07360, Mexico; (J.G.V.-J.); (J.H.-A.); (A.G.-H.)
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16
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Avrahami D, Wang YJ, Schug J, Feleke E, Gao L, Liu C, Naji A, Glaser B, Kaestner KH. Single-cell transcriptomics of human islet ontogeny defines the molecular basis of β-cell dedifferentiation in T2D. Mol Metab 2020; 42:101057. [PMID: 32739450 PMCID: PMC7471622 DOI: 10.1016/j.molmet.2020.101057] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 07/20/2020] [Accepted: 07/27/2020] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVE Dedifferentiation of pancreatic β-cells may reduce islet function in type 2 diabetes (T2D). However, the prevalence, plasticity and functional consequences of this cellular state remain unknown. METHODS We employed single-cell RNAseq to detail the maturation program of α- and β-cells during human ontogeny. We also compared islets from non-diabetic and T2D individuals. RESULTS Both α- and β-cells mature in part by repressing non-endocrine genes; however, α-cells retain hallmarks of an immature state, while β-cells attain a full β-cell specific gene expression program. In islets from T2D donors, both α- and β-cells have a less mature expression profile, de-repressing the juvenile genetic program and exocrine genes and increasing expression of exocytosis, inflammation and stress response signalling pathways. These changes are consistent with the increased proportion of β-cells displaying suboptimal function observed in T2D islets. CONCLUSIONS These findings provide new insights into the molecular program underlying islet cell maturation during human ontogeny and the loss of transcriptomic maturity that occurs in islets of type 2 diabetics.
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Affiliation(s)
- Dana Avrahami
- Endocrinology and Metabolism Department, Hadassah-Hebrew University Medical Centre, Jerusalem, Israel
| | - Yue J Wang
- Department of Genetics and Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Jonathan Schug
- Department of Genetics and Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Eseye Feleke
- Endocrinology and Metabolism Department, Hadassah-Hebrew University Medical Centre, Jerusalem, Israel
| | - Long Gao
- Department of Genetics and Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Chengyang Liu
- Department of Surgery and Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ali Naji
- Department of Surgery and Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Benjamin Glaser
- Endocrinology and Metabolism Department, Hadassah-Hebrew University Medical Centre, Jerusalem, Israel.
| | - Klaus H Kaestner
- Department of Genetics and Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
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17
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Hernandez KR, Karim ZA, Qasim H, Druey KM, Alshbool FZ, Khasawneh FT. Regulator of G-Protein Signaling 16 Is a Negative Modulator of Platelet Function and Thrombosis. J Am Heart Assoc 2020; 8:e011273. [PMID: 30791801 PMCID: PMC6474914 DOI: 10.1161/jaha.118.011273] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Background Members of the regulator of G‐protein signaling (RGS) family inhibit G‐protein coupled receptor signaling by modulating G‐protein activity. In platelets, there are 3 different RGS isoforms that are expressed at the protein level, including RGS16. Recently, we have shown that CXCL12 regulates platelet function via RGS16. However, the role of RGS16 in platelet function and thrombus formation is poorly defined. Methods and Results We used a genetic knockout mouse model approach to examine the role(s) of RGS16 in platelet activation by using a host of in vitro and in vivo assays. We observed that agonist‐induced platelet aggregation, secretion, and integrin activation were much more pronounced in platelets from the RGS16 knockout (Rgs16−/−) mice relative to their wild type (Rgs16+/+) littermates. Furthermore, the Rgs16−/− mice had a markedly shortened bleeding time and were more susceptible to vascular injury–associated thrombus formation than the controls. Conclusions These findings support a critical role for RGS16 in regulating hemostatic and thrombotic functions of platelets in mice. Hence, RGS16 represents a potential therapeutic target for modulating platelet function.
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Affiliation(s)
- Keziah R Hernandez
- 1 Pharmaceutical Sciences, School of Pharmacy The University of Texas at El Paso TX
| | - Zubair A Karim
- 1 Pharmaceutical Sciences, School of Pharmacy The University of Texas at El Paso TX
| | - Hanan Qasim
- 1 Pharmaceutical Sciences, School of Pharmacy The University of Texas at El Paso TX
| | - Kirk M Druey
- 2 Molecular Signal Transduction Section Laboratory of Allergic Diseases NIAID/NIH Bethesda MD
| | - Fatima Z Alshbool
- 1 Pharmaceutical Sciences, School of Pharmacy The University of Texas at El Paso TX
| | - Fadi T Khasawneh
- 1 Pharmaceutical Sciences, School of Pharmacy The University of Texas at El Paso TX
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18
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Sakloth F, Polizu C, Bertherat F, Zachariou V. Regulators of G Protein Signaling in Analgesia and Addiction. Mol Pharmacol 2020; 98:739-750. [PMID: 32474445 DOI: 10.1124/mol.119.119206] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 05/19/2020] [Indexed: 12/11/2022] Open
Abstract
Regulator of G protein signaling (RGS) proteins are multifunctional proteins expressed in peripheral and neuronal cells, playing critical roles in development, physiologic processes, and pharmacological responses. RGS proteins primarily act as GTPase accelerators for activated Gα subunits of G-protein coupled receptors, but they may also modulate signal transduction by several other mechanisms. Over the last two decades, preclinical work identified members of the RGS family with unique and critical roles in intracellular responses to drugs of abuse. New information has emerged on the mechanisms by which RGS proteins modulate the efficacy of opioid analgesics in a brain region- and agonist-selective fashion. There has also been progress in the understanding of the protein complexes and signal transduction pathways regulated by RGS proteins in addiction and analgesia circuits. In this review, we summarize findings on the mechanisms by which RGS proteins modulate functional responses to opioids in models of analgesia and addiction. We also discuss reports on the regulation and function of RGS proteins in models of psychostimulant addiction. Using information from preclinical studies performed over the last 20 years, we highlight the diverse mechanisms by which RGS protein complexes control plasticity in response to opioid and psychostimulant drug exposure; we further discuss how the understanding of these pathways may lead to new opportunities for therapeutic interventions in G protein pathways. SIGNIFICANCE STATEMENT: Regulator of G protein signaling (RGS) proteins are signal transduction modulators, expressed widely in various tissues, including brain regions mediating addiction and analgesia. Evidence from preclinical work suggests that members of the RGS family act by unique mechanisms in specific brain regions to control drug-induced plasticity. This review highlights interesting findings on the regulation and function of RGS proteins in models of analgesia and addiction.
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Affiliation(s)
- Farhana Sakloth
- Nash Family Department of Neuroscience, and Friedman Brain Institute (F.S., C.P., F.B., V.Z.) and Department of Pharmacological Sciences (V.Z.), Icahn School of Medicine at Mount Sinai, New York, New York
| | - Claire Polizu
- Nash Family Department of Neuroscience, and Friedman Brain Institute (F.S., C.P., F.B., V.Z.) and Department of Pharmacological Sciences (V.Z.), Icahn School of Medicine at Mount Sinai, New York, New York
| | - Feodora Bertherat
- Nash Family Department of Neuroscience, and Friedman Brain Institute (F.S., C.P., F.B., V.Z.) and Department of Pharmacological Sciences (V.Z.), Icahn School of Medicine at Mount Sinai, New York, New York
| | - Venetia Zachariou
- Nash Family Department of Neuroscience, and Friedman Brain Institute (F.S., C.P., F.B., V.Z.) and Department of Pharmacological Sciences (V.Z.), Icahn School of Medicine at Mount Sinai, New York, New York
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19
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Huang R, Li G, Zhao Z, Zeng F, Zhang K, Liu Y, Wang K, Hu H. RGS16 promotes glioma progression and serves as a prognostic factor. CNS Neurosci Ther 2020; 26:791-803. [PMID: 32319728 PMCID: PMC7366748 DOI: 10.1111/cns.13382] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 03/27/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
Background RGS protein family members have recently became new potentially promising therapeutic targets in many cancers. However, as a key member of RGS family, RGS16 has seldom been studied in glioma. The present study was designed to investigate the prognostic value and biological function of RGS16 based on large‐scale databases and functional assays in vitro. Methods Here, we performed comprehensive analysis for the expression characteristic of RGS16 in Chinese Glioma Genome Atlas (CGGA) microarray database with 301 patients and validated in The Cancer Genome Atlas (TCGA) microarray and RNA sequencing database. Student's t‐test, one‐way ANOVA test and long‐rank test were used to assess differences between groups. Kaplan‐Meier survival, univariate and multivariate Cox analysis and ROC curve were used to estimate the survival distributions. Biological implication of abnormal expression of RGS16 in glioma was also explored. Functional analysis of RGS16 was performed in several glioblastoma (GBM) cell lines. R language and SPSS were used for statistical analysis and graphical work. Results We found that the expression of RGS16 was positively related to the grade of glioma. High level of RGS16 commonly gathered in glioma of mesenchymal subtype and wild‐type IDH1. Moreover, higher expression level of RGS16 was found to be significantly correlated with poor prognosis. The univariate and multivariate Cox regression analysis and ROC curve showed that RGS16 was an independent prognostic factor for glioma patients. Gene ontology analysis, gene set enrichment analysis, and gene set variation analysis suggested that the overexpression of RGS16 tightly related to cell proliferation, migration, epithelial‐mesenchymal transition (EMT), immune and inflammatory response of glioma. Knockdown of RGS16 in glioma cell lines also showed that RGS16 promoted the malignant progress of glioma cell lines. Conclusions RGS16 plays an important role in glioma progression and serves as an independent prognostic factor, especially in GBM patients.
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Affiliation(s)
- Ruoyu Huang
- Department of Molecular Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.,Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,Chinese Glioma Cooperative Group (CGCG), Beijing, China
| | - Guanzhang Li
- Department of Molecular Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.,Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,Chinese Glioma Cooperative Group (CGCG), Beijing, China
| | - Zheng Zhao
- Department of Molecular Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.,Chinese Glioma Cooperative Group (CGCG), Beijing, China
| | - Fan Zeng
- Department of Molecular Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.,Chinese Glioma Cooperative Group (CGCG), Beijing, China
| | - Kenan Zhang
- Department of Molecular Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.,Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,Chinese Glioma Cooperative Group (CGCG), Beijing, China
| | - Yanwei Liu
- Chinese Glioma Cooperative Group (CGCG), Beijing, China.,Department of Radiotherapy, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Kuanyu Wang
- Chinese Glioma Cooperative Group (CGCG), Beijing, China.,Department of Gamma Knife Center, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Huimin Hu
- Department of Molecular Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.,Chinese Glioma Cooperative Group (CGCG), Beijing, China
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20
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Abstract
Glucose-induced (physiological) insulin secretion from the islet β-cell involves interplay between cationic (i.e., changes in intracellular calcium) and metabolic (i.e., generation of hydrophobic and hydrophilic second messengers) events. A large body of evidence affirms support for novel regulation, by G proteins, of specific intracellular signaling events, including actin cytoskeletal remodeling, transport of insulin-containing granules to the plasma membrane for fusion, and secretion of insulin into the circulation. This article highlights the following aspects of GPCR-G protein biology of the islet. First, it overviews our current understanding of the identity of a wide variety of G protein regulators and their modulatory roles in GPCR-G protein-effector coupling, which is requisite for optimal β-cell function under physiological conditions. Second, it describes evidence in support of novel, noncanonical, GPCR-independent mechanisms of activation of G proteins in the islet. Third, it highlights the evidence indicating that abnormalities in G protein function lead to islet β-cell dysregulation and demise under the duress of metabolic stress and diabetes. Fourth, it summarizes observations of potential beneficial effects of GPCR agonists in preventing/halting metabolic defects in the islet β-cell under various pathological conditions (e.g., metabolic stress and inflammation). Lastly, it identifies knowledge gaps and potential avenues for future research in this evolving field of translational islet biology. Published 2020. Compr Physiol 10:453-490, 2020.
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Affiliation(s)
- Anjaneyulu Kowluru
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Center for Translational Research in Diabetes, Biomedical Research Service, John D. Dingell VA Medical Center, Wayne State University, Detroit, Michigan, USA
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21
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Hartig SM, Cox AR. Paracrine signaling in islet function and survival. J Mol Med (Berl) 2020; 98:451-467. [PMID: 32067063 DOI: 10.1007/s00109-020-01887-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 02/05/2020] [Accepted: 02/11/2020] [Indexed: 02/06/2023]
Abstract
The pancreatic islet is a dense cellular network comprised of several cell types with endocrine function vital in the control of glucose homeostasis, metabolism, and feeding behavior. Within the islet, endocrine hormones also form an intricate paracrine network with supportive cells (endothelial, neuronal, immune) and secondary signaling molecules regulating cellular function and survival. Modulation of these signals has potential consequences for diabetes development, progression, and therapeutic intervention. Beta cell loss, reduced endogenous insulin secretion, and dysregulated glucagon secretion are hallmark features of both type 1 and 2 diabetes that not only impact systemic regulation of glucose, but also contribute to the function and survival of cells within the islet. Advancing research and technology have revealed new islet biology (cellular identity and transcriptomes) and identified previously unrecognized paracrine signals and mechanisms (somatostatin and ghrelin paracrine actions), while shifting prior views of intraislet communication. This review will summarize the paracrine signals regulating islet endocrine function and survival, the disruption and dysfunction that occur in diabetes, and potential therapeutic targets to preserve beta cell mass and function.
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Affiliation(s)
- Sean M Hartig
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Aaron R Cox
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, 77030, USA.
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22
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Yip L, Fuhlbrigge R, Alkhataybeh R, Fathman CG. Gene Expression Analysis of the Pre-Diabetic Pancreas to Identify Pathogenic Mechanisms and Biomarkers of Type 1 Diabetes. Front Endocrinol (Lausanne) 2020; 11:609271. [PMID: 33424774 PMCID: PMC7793767 DOI: 10.3389/fendo.2020.609271] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 11/16/2020] [Indexed: 12/28/2022] Open
Abstract
Type 1 Diabetes (T1D) occurs as a result of the autoimmune destruction of pancreatic β-cells by self-reactive T cells. The etiology of this disease is complex and difficult to study due to a lack of disease-relevant tissues from pre-diabetic individuals. In this study, we performed gene expression analysis on human pancreas tissues obtained from the Network of Pancreatic Organ Donors with Diabetes (nPOD), and showed that 155 genes were differentially expressed by ≥2-fold in the pancreata of autoantibody-positive (AA+) at-risk individuals compared to healthy controls. Only 48 of these genes remained changed by ≥2-fold in the pancreata of established T1D patients. Pathway analysis of these genes showed a significant association with various immune pathways. We were able to validate the differential expression of eight disease-relevant genes by QPCR analysis: A significant upregulation of CADM2, and downregulation of TRPM5, CRH, PDK4, ANGPL4, CLEC4D, RSG16, and FCGR2B was confirmed in the pancreata of AA+ individuals versus controls. Studies have already implicated FCGR2B in the pathogenesis of disease in non-obese diabetic (NOD) mice. Here we showed that CADM2, TRPM5, PDK4, and ANGPL4 were similarly changed in the pancreata of pre-diabetic 12-week-old NOD mice compared to NOD.B10 controls, suggesting a possible role for these genes in the pathogenesis of both T1D and NOD disease. The loss of the leukocyte-specific gene, FCGR2B, in the pancreata of AA+ individuals, is particularly interesting, as it may serve as a potential whole blood biomarker of disease progression. To test this, we quantified FCGR2B expression in peripheral blood samples of T1D patients, and AA+ and AA- first-degree relatives of T1D patients enrolled in the TrialNet Pathway to Prevention study. We showed that FCGR2B was significantly reduced in the peripheral blood of AA+ individuals compared to AA- controls. Together, these findings demonstrate that gene expression analysis of pancreatic tissue and peripheral blood samples can be used to identify disease-relevant genes and pathways and potential biomarkers of disease progression in T1D.
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23
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Abstract
The somatostatin-secreting δ-cells comprise ~5% of the cells of the pancreatic islets. The δ-cells have complex morphology and might interact with many more islet cells than suggested by their low numbers. δ-Cells contain ATP-sensitive potassium channels, which open at low levels of glucose but close when glucose is elevated. This closure initiates membrane depolarization and electrical activity and increased somatostatin secretion. Factors released by neighbouring α-cells or β-cells amplify the glucose-induced effects on somatostatin secretion from δ-cells, which act locally within the islets as paracrine or autocrine inhibitors of insulin, glucagon and somatostatin secretion. The effects of somatostatin are mediated by activation of somatostatin receptors coupled to the inhibitory G protein, which culminates in suppression of the electrical activity and exocytosis in α-cells and β-cells. Somatostatin secretion is perturbed in animal models of diabetes mellitus, which might explain the loss of appropriate hypoglycaemia-induced glucagon secretion, a defect that could be mitigated by somatostatin receptor 2 antagonists. Somatostatin antagonists or agents that suppress somatostatin secretion have been proposed as an adjunct to insulin therapy. In this Review, we summarize the cell physiology of somatostatin secretion, what might go wrong in diabetes mellitus and the therapeutic potential of agents targeting somatostatin secretion or action.
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Affiliation(s)
- Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, Churchill Hospital, University of Oxford, Oxford, UK.
- Department of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden.
| | - Mark O Huising
- Department of Neurobiology, Physiology and Behavior, College of Biological Sciences, University of California, Davis, Davis, CA, USA
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, Davis, CA, USA
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24
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Depletion of regulator-of-G-protein signaling-10 in mice exaggerates high-fat diet-induced insulin resistance and inflammation, and this effect is mitigated by dietary green tea extract. Nutr Res 2018; 70:50-59. [PMID: 30032988 DOI: 10.1016/j.nutres.2018.06.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 06/11/2018] [Accepted: 06/24/2018] [Indexed: 12/25/2022]
Abstract
The interaction between insulin resistance and inflammation plays a central role in the development of chronic diseases, although the mechanism is not fully understood. We previously demonstrated that regulator of G-protein signaling-10 (RGS10) protein is a negative modulator of the inflammatory response in macrophages and microglia. Because inflammation is a critical component in the development of high fat diet-induced insulin resistance, in this study we investigated whether RGS10 is involved in the diet-dependent regulation of glucose tolerance and insulin sensitivity. We hypothesized that the absence of RGS10 would exaggerate high-fat diet (HFD)-induced insulin resistance and inflammation response. Our results showed that RGS10 knockout (KO) mice fed a HFD gained significantly more weight and developed severe insulin resistance compared to wild-type (WT) mice fed HFD. Furthermore, compared to WT HFD-fed mice, KO mice fed the HFD displayed inflammatory phenotypes such as decreased adipose tissue expression of the anti-inflammatory M2 markers YM1 and Fizz1 and increased expression of the proinflammatory M1 cytokine interleukin 6 in adipose and CD11b, CD68 and interleukin 1β in liver tissues. The impact of RGS10 deficiency on the exaggeration of HFD-induced insulin resistance and inflammation was ameliorated by oral consumption of green tea extract. Our results demonstrate that RGS10 is an important part of a protective mechanism involved in in regulating metabolic homeostasis by reducing inflammatory responses, which could potentially lead to an innovative new approach targeting inflammation and insulin resistance.
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25
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The somatostatin-secreting pancreatic δ-cell in health and disease. NATURE REVIEWS. ENDOCRINOLOGY 2018. [PMID: 29773871 DOI: 10.1038/s41574‐018‐0020‐6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The somatostatin-secreting δ-cells comprise ~5% of the cells of the pancreatic islets. The δ-cells have complex morphology and might interact with many more islet cells than suggested by their low numbers. δ-Cells contain ATP-sensitive potassium channels, which open at low levels of glucose but close when glucose is elevated. This closure initiates membrane depolarization and electrical activity and increased somatostatin secretion. Factors released by neighbouring α-cells or β-cells amplify the glucose-induced effects on somatostatin secretion from δ-cells, which act locally within the islets as paracrine or autocrine inhibitors of insulin, glucagon and somatostatin secretion. The effects of somatostatin are mediated by activation of somatostatin receptors coupled to the inhibitory G protein, which culminates in suppression of the electrical activity and exocytosis in α-cells and β-cells. Somatostatin secretion is perturbed in animal models of diabetes mellitus, which might explain the loss of appropriate hypoglycaemia-induced glucagon secretion, a defect that could be mitigated by somatostatin receptor 2 antagonists. Somatostatin antagonists or agents that suppress somatostatin secretion have been proposed as an adjunct to insulin therapy. In this Review, we summarize the cell physiology of somatostatin secretion, what might go wrong in diabetes mellitus and the therapeutic potential of agents targeting somatostatin secretion or action.
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26
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Kowluru A. Role of G-proteins in islet function in health and diabetes. Diabetes Obes Metab 2017; 19 Suppl 1:63-75. [PMID: 28880478 PMCID: PMC5657296 DOI: 10.1111/dom.13011] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 05/03/2017] [Accepted: 05/12/2017] [Indexed: 12/17/2022]
Abstract
Glucose-stimulated insulin secretion (GSIS) involves interplay between metabolic and cationic events. Seminal contributions from multiple laboratories affirm essential roles for small G-proteins (Rac1, Cdc42, Arf6, Rab27A) in GSIS. Activation of these signalling proteins promotes cytoskeletal remodeling, transport and docking of insulin granules on the plasma membrane for exocytotic secretion of insulin. Evidence in rodent and human islets suggests key roles for lipidation (farnesylation and geranylgeranylation) of these G-proteins for their targeting to appropriate cellular compartments for optimal regulation of effectors leading to GSIS. Interestingly, however, inhibition of prenylation appears to cause mislocalization of non-prenylated, but (paradoxically) activated G-proteins, in "inappropriate" compartments leading to activation of stress kinases and onset of mitochondrial defects, loss in GSIS and apoptosis of the islet β-cell. This review highlights our current understanding of roles of G-proteins and their post-translational lipidation (prenylation) signalling networks in islet function in normal health, metabolic stress (glucolipotoxicity and ER stress) and diabetes. Critical knowledge gaps that need to be addressed for the development of therapeutics to halt defects in these signalling steps in β-cells in models of impaired insulin secretion and diabetes are also highlighted and discussed.
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Affiliation(s)
- Anjaneyulu Kowluru
- β-Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, and Department of Pharmaceutical Sciences, Wayne State University, Detroit, Michigan
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27
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Carboneau BA, Allan JA, Townsend SE, Kimple ME, Breyer RM, Gannon M. Opposing effects of prostaglandin E 2 receptors EP3 and EP4 on mouse and human β-cell survival and proliferation. Mol Metab 2017; 6:548-559. [PMID: 28580285 PMCID: PMC5444094 DOI: 10.1016/j.molmet.2017.04.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 03/30/2017] [Accepted: 04/03/2017] [Indexed: 01/02/2023] Open
Abstract
OBJECTIVE Hyperglycemia and systemic inflammation, hallmarks of Type 2 Diabetes (T2D), can induce the production of the inflammatory signaling molecule Prostaglandin E2 (PGE2) in islets. The effects of PGE2 are mediated by its four receptors, E-Prostanoid Receptors 1-4 (EP1-4). EP3 and EP4 play opposing roles in many cell types due to signaling through different G proteins, Gi and GS, respectively. We previously found that EP3 and EP4 expression are reciprocally regulated by activation of the FoxM1 transcription factor, which promotes β-cell proliferation and survival. Our goal was to determine if EP3 and EP4 regulate β-cell proliferation and survival and, if so, to elucidate the downstream signaling mechanisms. METHODS β-cell proliferation was assessed in mouse and human islets ex vivo treated with selective agonists and antagonists for EP3 (sulprostone and DG-041, respectively) and EP4 (CAY10598 and L-161,982, respectively). β-cell survival was measured in mouse and human islets treated with the EP3- and EP4-selective ligands in conjunction with a cytokine cocktail to induce cell death. Changes in gene expression and protein phosphorylation were analyzed in response to modulation of EP3 and EP4 activity in mouse islets. RESULTS Blockade of EP3 enhanced β-cell proliferation in young, but not old, mouse islets in part through phospholipase C (PLC)-γ1 activity. Blocking EP3 also increased human β-cell proliferation. EP4 modulation had no effect on ex vivo proliferation alone. However, blockade of EP3 in combination with activation of EP4 enhanced human, but not mouse, β-cell proliferation. In both mouse and human islets, EP3 blockade or EP4 activation enhanced β-cell survival in the presence of cytokines. EP4 acts in a protein kinase A (PKA)-dependent manner to increase mouse β-cell survival. In addition, the positive effects of FoxM1 activation on β-cell survival are inhibited by EP3 and dependent on EP4 signaling. CONCLUSIONS Our results identify EP3 and EP4 as novel regulators of β-cell proliferation and survival in mouse and human islets ex vivo.
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Key Words
- COX-2, cyclooxygenase-2
- Cell death
- DAG, diacylglycerol
- EP1-4, E-Prostanoid Receptors 1-4
- GPCR, G protein-coupled receptor
- IP3, inositol 1,4,5-trisphosphate
- PGE2, prostaglandin E2
- PKA, protein kinase A
- PL, placental lactogen
- PLC, phospholipase C
- PT, pertussis toxin
- Pancreatic β-cell
- Proliferation
- Prostaglandin E2
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Affiliation(s)
- Bethany A Carboneau
- Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.,Program in Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Jack A Allan
- School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Shannon E Townsend
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Michelle E Kimple
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA.,William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Richard M Breyer
- Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN, USA.,Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Maureen Gannon
- Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.,Program in Developmental Biology, Vanderbilt University, Nashville, TN, USA.,Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.,Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
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28
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Remsberg JR, Ediger BN, Ho WY, Damle M, Li Z, Teng C, Lanzillotta C, Stoffers DA, Lazar MA. Deletion of histone deacetylase 3 in adult beta cells improves glucose tolerance via increased insulin secretion. Mol Metab 2016; 6:30-37. [PMID: 28123935 PMCID: PMC5220396 DOI: 10.1016/j.molmet.2016.11.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 11/14/2016] [Accepted: 11/17/2016] [Indexed: 12/25/2022] Open
Abstract
Objective Histone deacetylases are epigenetic regulators known to control gene transcription in various tissues. A member of this family, histone deacetylase 3 (HDAC3), has been shown to regulate metabolic genes. Cell culture studies with HDAC-specific inhibitors and siRNA suggest that HDAC3 plays a role in pancreatic β-cell function, but a recent genetic study in mice has been contradictory. Here we address the functional role of HDAC3 in β-cells of adult mice. Methods An HDAC3 β-cell specific knockout was generated in adult MIP-CreERT transgenic mice using the Cre-loxP system. Induction of HDAC3 deletion was initiated at 8 weeks of age with administration of tamoxifen in corn oil (2 mg/day for 5 days). Mice were assayed for glucose tolerance, glucose-stimulated insulin secretion, and islet function 2 weeks after induction of the knockout. Transcriptional functions of HDAC3 were assessed by ChIP-seq as well as RNA-seq comparing control and β-cell knockout islets. Results HDAC3 β-cell specific knockout (HDAC3βKO) did not increase total pancreatic insulin content or β-cell mass. However, HDAC3βKO mice demonstrated markedly improved glucose tolerance. This improved glucose metabolism coincided with increased basal and glucose-stimulated insulin secretion in vivo as well as in isolated islets. Cistromic and transcriptomic analyses of pancreatic islets revealed that HDAC3 regulates multiple genes that contribute to glucose-stimulated insulin secretion. Conclusions HDAC3 plays an important role in regulating insulin secretion in vivo, and therapeutic intervention may improve glucose homeostasis. HDAC3 ablation in adult mouse β-cells improves glucose tolerance. Improved glucose tolerance is due to increased insulin secretion. HDAC3 targets multiple genes involved in potentiating insulin secretion.
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Affiliation(s)
- Jarrett R Remsberg
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Benjamin N Ediger
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Wesley Y Ho
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Manashree Damle
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Zhenghui Li
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Christopher Teng
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Cristina Lanzillotta
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Doris A Stoffers
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mitchell A Lazar
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
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29
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Okano S. Unique Aspects of Cryptochrome in Chronobiology and Metabolism, Pancreatic β-Cell Dysfunction, and Regeneration: Research into Cysteine414-Alanine Mutant CRY1. J Diabetes Res 2016; 2016:3459246. [PMID: 28105441 PMCID: PMC5220486 DOI: 10.1155/2016/3459246] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Accepted: 11/27/2016] [Indexed: 01/05/2023] Open
Abstract
Cryptochrome proteins (CRYs), which can bind noncovalently to cofactor (chromophore) flavin adenine dinucleotide (FAD), occur widely among organisms. CRYs play indispensable roles in the generation of circadian rhythm in mammals. Transgenic mice (Tg mice), ubiquitously expressing mouse CRY1 having a mutation in which cysteine414 (the zinc-binding site of CRY1) being replaced with alanine, display unique phenotypes in their circadian rhythms. Moreover, male Tg mice exhibit symptoms of diabetes characterized by beta-cell dysfunction, resembling human maturity onset diabetes of the young (MODY). The lowered proliferation of β-cells is a primary cause of age-dependent β-cell loss. Furthermore, unusually enlarged duct-like structures developed prominently in the Tg mice pancreases. The duct-like structures contained insulin-positive cells, suggesting neogenesis of β-cells in the Tg mice. This review, based mainly on the author's investigation of the unique features of Tg mice, presents reported results and recent findings related to molecular processes associated with mammalian cryptochromes, especially their involvement in the regulation of metabolism. New information is described with emphasis on the aspects of islet architecture, pancreatic β-cell dysfunction, and regeneration.
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Affiliation(s)
- Satoshi Okano
- Research Center for Molecular Genetics, Institute for Promotion of Medical Science Research, Yamagata University Faculty of Medicine, Yamagata 990-9585, Japan
- *Satoshi Okano:
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