1
|
Wang T, Wang YY, Shi MY, Liu L. Mechanisms of action of natural products on type 2 diabetes. World J Diabetes 2023; 14:1603-1620. [DOI: 10.4239/wjd.v14.i11.1603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/14/2023] [Accepted: 10/23/2023] [Indexed: 11/14/2023] Open
Abstract
Over the past several decades, type 2 diabetes mellitus (T2DM) has been considered a global public health concern. Currently, various therapeutic modalities are available for T2DM management, including dietary modifications, moderate exercise, and use of hypoglycemic agents and lipid-lowering medications. Although the curative effect of most drugs on T2DM is significant, they also exert some adverse side effects. Biologically active substances found in natural medicines are important for T2DM treatment. Several recent studies have reported that active ingredients derived from traditional medicines or foods exert a therapeutic effect on T2DM. This review compiled important articles regarding the therapeutic effects of natural products and their active ingredients on islet β cell function, adipose tissue inflammation, and insulin resistance. Additionally, this review provided an in-depth understanding of the multiple regulatory effects on different targets and signaling pathways of natural medicines in the treatment of T2DM as well as a theoretical basis for clinical effective application.
Collapse
Affiliation(s)
- Tao Wang
- Clinical Molecular Immunology Center, Yangtze University, Jingzhou 434023, Hubei Province, China
| | - Yang-Yang Wang
- Clinical Molecular Immunology Center, Yangtze University, Jingzhou 434023, Hubei Province, China
| | - Meng-Yue Shi
- Clinical Molecular Immunology Center, Yangtze University, Jingzhou 434023, Hubei Province, China
| | - Lian Liu
- Department of Pharmacology, Yangtze University, Jingzhou 434023, Hubei Province, China
| |
Collapse
|
2
|
Sionov RV, Ahdut-HaCohen R. A Supportive Role of Mesenchymal Stem Cells on Insulin-Producing Langerhans Islets with a Specific Emphasis on The Secretome. Biomedicines 2023; 11:2558. [PMID: 37761001 PMCID: PMC10527322 DOI: 10.3390/biomedicines11092558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 09/06/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
Type 1 Diabetes (T1D) is a chronic autoimmune disease characterized by a gradual destruction of insulin-producing β-cells in the endocrine pancreas due to innate and specific immune responses, leading to impaired glucose homeostasis. T1D patients usually require regular insulin injections after meals to maintain normal serum glucose levels. In severe cases, pancreas or Langerhans islet transplantation can assist in reaching a sufficient β-mass to normalize glucose homeostasis. The latter procedure is limited because of low donor availability, high islet loss, and immune rejection. There is still a need to develop new technologies to improve islet survival and implantation and to keep the islets functional. Mesenchymal stem cells (MSCs) are multipotent non-hematopoietic progenitor cells with high plasticity that can support human pancreatic islet function both in vitro and in vivo and islet co-transplantation with MSCs is more effective than islet transplantation alone in attenuating diabetes progression. The beneficial effect of MSCs on islet function is due to a combined effect on angiogenesis, suppression of immune responses, and secretion of growth factors essential for islet survival and function. In this review, various aspects of MSCs related to islet function and diabetes are described.
Collapse
Affiliation(s)
- Ronit Vogt Sionov
- The Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Ronit Ahdut-HaCohen
- Department of Medical Neurobiology, Institute of Medical Research, Hadassah Medical School, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel;
- Department of Science, The David Yellin Academic College of Education, Jerusalem 9103501, Israel
| |
Collapse
|
3
|
Castell AL, Goubault C, Ethier M, Fergusson G, Tremblay C, Baltz M, Dal Soglio D, Ghislain J, Poitout V. β Cell mass expansion during puberty involves serotonin signaling and determines glucose homeostasis in adulthood. JCI Insight 2022; 7:160854. [PMID: 36107617 PMCID: PMC9675460 DOI: 10.1172/jci.insight.160854] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 09/14/2022] [Indexed: 01/07/2023] Open
Abstract
Puberty is associated with transient insulin resistance that normally recedes at the end of puberty; however, in overweight children, insulin resistance persists, leading to an increased risk of type 2 diabetes. The mechanisms whereby pancreatic β cells adapt to pubertal insulin resistance, and how they are affected by the metabolic status, have not been investigated. Here, we show that puberty is associated with a transient increase in β cell proliferation in rats and humans of both sexes. In rats, β cell proliferation correlated with a rise in growth hormone (GH) levels. Serum from pubertal rats and humans promoted β cell proliferation, suggesting the implication of a circulating factor. In pubertal rat islets, expression of genes of the GH/serotonin (5-hydroxytryptamine [5-HT]) pathway underwent changes consistent with a proliferative effect. Inhibition of the pro-proliferative 5-HT receptor isoform HTR2B blocked the increase in β cell proliferation in pubertal islets ex vivo and in vivo. Peripubertal metabolic stress blunted β cell proliferation during puberty and led to altered glucose homeostasis later in life. This study identifies a role of GH/GH receptor/5-HT/HTR2B signaling in the control of β cell mass expansion during puberty and identifies a mechanistic link between pubertal obesity and the risk of developing type 2 diabetes.
Collapse
Affiliation(s)
- Anne-Laure Castell
- Montreal Diabetes Research Center, Centre de recherche du centre hospitalier de l’Université de Montréal (CRCHUM), Montreal, Quebec, Canada.,Department of Medicine and
| | - Clara Goubault
- Montreal Diabetes Research Center, Centre de recherche du centre hospitalier de l’Université de Montréal (CRCHUM), Montreal, Quebec, Canada.,Department of Pharmacology and Physiology, University of Montreal, Quebec, Canada
| | - Mélanie Ethier
- Montreal Diabetes Research Center, Centre de recherche du centre hospitalier de l’Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Grace Fergusson
- Montreal Diabetes Research Center, Centre de recherche du centre hospitalier de l’Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Caroline Tremblay
- Montreal Diabetes Research Center, Centre de recherche du centre hospitalier de l’Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Marie Baltz
- Montreal Diabetes Research Center, Centre de recherche du centre hospitalier de l’Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Dorothée Dal Soglio
- CHU Sainte-Justine, Montreal, Quebec, Canada.,Department of Pathology and Cell Biology, University of Montreal, Montreal, Quebec, Canada
| | - Julien Ghislain
- Montreal Diabetes Research Center, Centre de recherche du centre hospitalier de l’Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Vincent Poitout
- Montreal Diabetes Research Center, Centre de recherche du centre hospitalier de l’Université de Montréal (CRCHUM), Montreal, Quebec, Canada.,Department of Medicine and
| |
Collapse
|
4
|
Fushimi Y, Obata A, Sanada J, Nogami Y, Ikeda T, Yamasaki Y, Obata Y, Shimoda M, Nakanishi S, Mune T, Kaku K, Kaneto H. Early combination therapy of empagliflozin and linagliptin exerts beneficial effects on pancreatic β cells in diabetic db/db mice. Sci Rep 2021; 11:16120. [PMID: 34373487 PMCID: PMC8352868 DOI: 10.1038/s41598-021-94896-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 07/19/2021] [Indexed: 12/17/2022] Open
Abstract
Effects of combination therapy of dipeptidyl peptidase-4 (DPP-4) inhibitor and sodium-glucose co-transporter 2 (SGLT2) inhibitor on β-cells are still unclear, although combination agent of these two drugs has become common in clinical practice. Therefore, we aimed to elucidate the effects of DPP-4 inhibitor and/or SGLT2 inhibitor on β-cell mass and function and compared their effects between in an early and advanced phase of diabetes. We used 7-week-old db/db mice as an early phase and 16-week-old mice as an advanced phase and treated them for 2 weeks with oral administration of linagliptin, empagliflozin, linagliptin + empagliflozin (L + E group), and 0.5% carboxymethylcellulose (Cont group). Blood glucose levels in Empa and L + E group were significantly lower than Cont group after treatment. In addition, β-cell mass in L + E group was significantly larger than Cont group only in an early phase, accompanied by increased Ki67-positive β-cell ratio. In isolated islets, mRNA expression levels of insulin and its transcription factors were all significantly higher only in L + E group in an early phase. Furthermore, mRNA expression levels related to β-cell differentiation and proliferation were significantly increased only in L + E group in an early phase. In conclusion, combination of DPP-4 inhibitor and SGLT2 inhibitor exerts more beneficial effects on β-cell mass and function, especially in an early phase of diabetes rather than an advanced phase.
Collapse
Affiliation(s)
- Yoshiro Fushimi
- Department of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192, Japan
| | - Atsushi Obata
- Department of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192, Japan.
| | - Junpei Sanada
- Department of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192, Japan
| | - Yuka Nogami
- Department of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192, Japan
| | - Tomoko Ikeda
- Department of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192, Japan
| | - Yuki Yamasaki
- Department of Clinical Nutrition, Kawasaki University of Medical Welfare, 288 Matsushima, Kurashiki, 701-0193, Japan
| | - Yoshiyuki Obata
- Department of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192, Japan
| | - Masashi Shimoda
- Department of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192, Japan
| | - Shuhei Nakanishi
- Department of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192, Japan
| | - Tomoatsu Mune
- Department of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192, Japan
| | - Kohei Kaku
- Department of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192, Japan
| | - Hideaki Kaneto
- Department of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki, 701-0192, Japan.
| |
Collapse
|
5
|
In silico approach to predict pancreatic β-cells classically secreted proteins. Biosci Rep 2021; 40:222021. [PMID: 32003782 PMCID: PMC7024845 DOI: 10.1042/bsr20193708] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 01/30/2020] [Accepted: 01/31/2020] [Indexed: 12/13/2022] Open
Abstract
Pancreatic β-cells, residents of the islets of Langerhans, are the unique insulin-producers in the body. Their physiology is a topic of intensive studies aiming to understand the biology of insulin production and its role in diabetes pathology. However, investigations about these cells' subset of secreted proteins, the secretome, are surprisingly scarce and a list describing islet/β-cell secretome upon glucose-stimulation is not yet available. In silico predictions of secretomes are an interesting approach that can be employed to forecast proteins likely to be secreted. In this context, using the rationale behind classical secretion of proteins through the secretory pathway, a Python tool capable of predicting classically secreted proteins was developed. This tool was applied to different available proteomic data (human and rodent islets, isolated β-cells, β-cell secretory granules, and β-cells supernatant), filtering them in order to selectively list only classically secreted proteins. The method presented here can retrieve, organize, search and filter proteomic lists using UniProtKB as a central database. It provides analysis by overlaying different sets of information, filtering out potential contaminants and clustering the identified proteins into functional groups. A range of 70-92% of the original proteomes analyzed was reduced generating predicted secretomes. Islet and β-cell signal peptide-containing proteins, and endoplasmic reticulum-resident proteins were identified and quantified. From the predicted secretomes, exemplary conservational patterns were inferred, as well as the signaling pathways enriched within them. Such a technique proves to be an effective approach to reduce the horizon of plausible targets for drug development or biomarkers identification.
Collapse
|
6
|
Yang H, Wang S, Ye Y, Xie M, Li Y, Jin H, Li J, Gao L. GLP-1 preserves β cell function via improvement on islet insulin signaling in high fat diet feeding mice. Neuropeptides 2021; 85:102110. [PMID: 33307381 DOI: 10.1016/j.npep.2020.102110] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 10/22/2022]
Abstract
BACKGROUND Numerous studies have shown that Glucagon like peptide-1 (GLP-1) treatment can protect β cell function, but the exact mechanism remains unclear. We hypothesized that GLP-1 may protect β cell function via its action on insulin signaling pathway. METHODS Mice were fed with high fat diet (HFD, 20 weeks) in the presence or absence of GLP-1 receptor agonist (exenatide) treatment. The islet structure was demonstrated by HE staining. Immunofluorescence antibodies targeting insulin and glucagon were used to illustrate α and β cell distribution. The insulin and glucagon abundance was measured by ELISA using pancreatic homogenates. The molecules involved in insulin signaling pathway (IRc, IRS1, IRS2, mTOR) in islet were examined with immunohistochemistry and immunoblotting. The effect of IRS1 silencing on mTOR and apoptosis were examined on NIT cells(β cell line)with immunoblotting and flow cytometry. RESULTS HE and immunofluorescence staining demonstrated that the normal structure of islet was deformed in HFD mice but preserved by exenatide. Insulin and glucagon contents were increased in islet and blood stream of HFD mice (HFD vs. Control, p<0.05) but resumed by exenatide. Meanwhile the expressions of IRc, IRS-1, mTOR from insulin signaling pathway and β cell apoptosis in the pancreas were significantly reduced (p<0.05) by HFD but reversed by exenatide. CONCLUSION Exenatide improved insulin signaling pathway that was suppressed by HFD in mice islet. Our results reveal a novel mechanism of the protective effects of GLP-1 on β cell function.
Collapse
Affiliation(s)
- Heng Yang
- Department of Endocrinology, Renmin Hospital of Wuhan University, 430060, China
| | - Shuo Wang
- Department of Endocrinology, Renmin Hospital of Wuhan University, 430060, China
| | - Yingchun Ye
- Department of Endocrinology, Renmin Hospital of Wuhan University, 430060, China
| | - Min Xie
- Department of Endocrinology, Renmin Hospital of Wuhan University, 430060, China
| | - Yubin Li
- Department of Endocrinology, Renmin Hospital of Wuhan University, 430060, China
| | - Hong Jin
- Department of Endocrinology, Renmin Hospital of Wuhan University, 430060, China
| | - Jing Li
- Department of Endocrinology, Renmin Hospital of Wuhan University, 430060, China
| | - Ling Gao
- Department of Endocrinology, Renmin Hospital of Wuhan University, 430060, China.
| |
Collapse
|
7
|
Engin AB, Engin A. Protein Kinases Signaling in Pancreatic Beta-cells Death and Type 2 Diabetes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1275:195-227. [PMID: 33539017 DOI: 10.1007/978-3-030-49844-3_8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Type 2 diabetes (T2D) is a worldwide serious public health problem. Insulin resistance and β-cell failure are the two major components of T2D pathology. In addition to defective endoplasmic reticulum (ER) stress signaling due to glucolipotoxicity, β-cell dysfunction or β-cell death initiates the deleterious vicious cycle observed in T2D. Although the primary cause is still unknown, overnutrition that contributes to the induction of the state of low-grade inflammation, and the activation of various protein kinases-related metabolic pathways are main factors leading to T2D. In this chapter following subjects, which have critical checkpoints regarding β-cell fate and protein kinases pathways are discussed; hyperglycemia-induced β-cell failure, chronic accumulation of unfolded protein in β-cells, the effect of intracellular reactive oxygen species (ROS) signaling to insulin secretion, excessive saturated free fatty acid-induced β-cell apoptosis, mitophagy dysfunction, proinflammatory responses and insulin resistance, and the reprogramming of β-cell for differentiation or dedifferentiation in T2D. There is much debate about selecting proposed therapeutic strategies to maintain or enhance optimal β-cell viability for adequate insulin secretion in T2D. However, in order to achieve an effective solution in the treatment of T2D, more intensive clinical trials are required on newer therapeutic options based on protein kinases signaling pathways.
Collapse
Affiliation(s)
- Ayse Basak Engin
- Department of Toxicology, Faculty of Pharmacy, Gazi University, Ankara, Turkey.
| | - Atilla Engin
- Department of General Surgery, Faculty of Medicine, Gazi University, Ankara, Turkey
| |
Collapse
|
8
|
Modulation of Rab7a-mediated growth factor receptor trafficking inhibits islet beta cell apoptosis and autophagy under conditions of metabolic stress. Sci Rep 2020; 10:15741. [PMID: 32978479 PMCID: PMC7519639 DOI: 10.1038/s41598-020-72939-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 09/09/2020] [Indexed: 01/01/2023] Open
Abstract
Regenerative medicine approaches to enhancing beta cell growth and survival represent potential treatments for diabetes. It is known that growth factors such as insulin, IGF-1 and HGF support beta cell growth and survival, but in people with type 2 diabetes the destructive effects of metabolic stress predominate and beta cell death or dysfunction occurs. In this study we explore the novel hypothesis that regulation of growth factor receptor trafficking can be used to promote islet beta cell survival. Growth factor signalling is dependent on the presence of cell surface receptors. Endosomal trafficking and subsequent recycling or degradation of these receptors is controlled by the Rab GTPase family of proteins. We show that Rab7a siRNA inhibition enhances IGF-1 and HGF signalling in beta cells and increases expression of the growth factor receptors IGF-1R and c-Met. Furthermore, Rab7a inhibition promotes beta cell growth and islet survival, and protects against activation of apoptosis and autophagy pathways under conditions of metabolic stress. This study therefore demonstrates that Rab7a-mediated trafficking of growth factor receptors controls beta cell survival. Pharmaceutical Rab7a inhibition may provide a means to promote beta cell survival in the context of metabolic stress and prevent the onset of type 2 diabetes.
Collapse
|
9
|
Jara MA, Werneck-De-Castro JP, Lubaczeuski C, Johnson JD, Bernal-Mizrachi E. Pancreatic and duodenal homeobox-1 (PDX1) contributes to β-cell mass expansion and proliferation induced by Akt/PKB pathway. Islets 2020; 12:32-40. [PMID: 32876522 PMCID: PMC7527019 DOI: 10.1080/19382014.2020.1762471] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Maintenance of pancreatic β-cell mass and function is fundamental to glucose homeostasis and to prevent diabetes. The PI3 K-Akt-mTORC1 pathway is critical for β-cells mass and function, while PDX1 has been implicated in β-cell development, maturation, and function. Here we tested whether Akt signaling requires PDX1 expression to regulate β-cell mass, proliferation, and glucose homeostasis. In order to address that, we crossed a mouse model overexpressing constitutively active Akt mutant in β-cells (β-caAkt) with mice lacking one allele of PDX1gene (β-caAkt/pdx1+/-). While the β-caAkt mice exhibit higher plasma insulin levels, greater β-cell mass and improved glucose tolerance compared to control mice, the β-caAkt/pdx1+/- mice are hyperglycemic and intolerant to glucose. The changes in glucose homeostasis in β-caAkt/pdx1+/- were associated with a 60% reduction in β-cell mass compared to β-caAkt mice. The impaired β-cell mass in the β-caAkt/pdx1+/- mice can be explained by a lesser β-cell proliferation measured by the number of Ki67 positive β-cells. We did not observe any differences in apoptosis between β-caAkt/pdx1+/- and β-caAkt mice. In conclusion, PDX1 contributes to β-cell mass expansion and glucose metabolism induced by activation of Akt signaling.
Collapse
Affiliation(s)
- Mark Anthony Jara
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Joao Pedro Werneck-De-Castro
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, Miller School of Medicine, University of Miami, Miami, FL, USA
- Miami VA Health Care System, Miami, FL, USA
| | - Camila Lubaczeuski
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - James D. Johnson
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Ernesto Bernal-Mizrachi
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, Miller School of Medicine, University of Miami, Miami, FL, USA
- Miami VA Health Care System, Miami, FL, USA
- CONTACT Ernesto Bernal-Mizrachi Department Of Internal Medicine, Division Of Endocrinology, Diabetes and Metabolism, University of Miami Miller School of Medicine, Miami, FL33136, USA
| |
Collapse
|
10
|
Shapiro MR, Wasserfall CH, McGrail SM, Posgai AL, Bacher R, Muir A, Haller MJ, Schatz DA, Wesley JD, von Herrath M, Hagopian WA, Speake C, Atkinson MA, Brusko TM. Insulin-Like Growth Factor Dysregulation Both Preceding and Following Type 1 Diabetes Diagnosis. Diabetes 2020; 69:413-423. [PMID: 31826866 PMCID: PMC7034187 DOI: 10.2337/db19-0942] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 12/04/2019] [Indexed: 12/19/2022]
Abstract
Insulin-like growth factors (IGFs), specifically IGF1 and IGF2, promote glucose metabolism, with their availability regulated by IGF-binding proteins (IGFBPs). We hypothesized that IGF1 and IGF2 levels, or their bioavailability, are reduced during type 1 diabetes development. Total serum IGF1, IGF2, and IGFBP1-7 levels were measured in an age-matched, cross-sectional cohort at varying stages of progression to type 1 diabetes. IGF1 and IGF2 levels were significantly lower in autoantibody (AAb)+ compared with AAb- relatives of subjects with type 1 diabetes. Most high-affinity IGFBPs were unchanged in individuals with pre-type 1 diabetes, suggesting that total IGF levels may reflect bioactivity. We also measured serum IGFs from a cohort of fasted subjects with type 1 diabetes. IGF1 levels significantly decreased with disease duration, in parallel with declining β-cell function. Additionally, plasma IGF levels were assessed in an AAb+ cohort monthly for a year. IGF1 and IGF2 showed longitudinal stability in single AAb+ subjects, but IGF1 levels decreased over time in subjects with multiple AAb and those who progressed to type 1 diabetes, particularly postdiagnosis. In sum, IGFs are dysregulated both before and after the clinical diagnosis of type 1 diabetes and may serve as novel biomarkers to improve disease prediction.
Collapse
Affiliation(s)
- Melanie R Shapiro
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida Diabetes Institute, Gainesville, FL
| | - Clive H Wasserfall
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida Diabetes Institute, Gainesville, FL
| | - Sean M McGrail
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida Diabetes Institute, Gainesville, FL
| | - Amanda L Posgai
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida Diabetes Institute, Gainesville, FL
| | - Rhonda Bacher
- Department of Biostatistics, University of Florida, Gainesville, FL
| | - Andrew Muir
- Department of Pediatrics, Emory University, Atlanta, GA
| | - Michael J Haller
- Department of Pediatrics, University of Florida Diabetes Institute, Gainesville, FL
| | - Desmond A Schatz
- Department of Pediatrics, University of Florida Diabetes Institute, Gainesville, FL
| | | | | | | | - Cate Speake
- Benaroya Research Institute at Virginia Mason, Seattle, WA
| | - Mark A Atkinson
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida Diabetes Institute, Gainesville, FL
- Department of Pediatrics, University of Florida Diabetes Institute, Gainesville, FL
| | - Todd M Brusko
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida Diabetes Institute, Gainesville, FL
| |
Collapse
|
11
|
Đorđević M, Grdović N, Mihailović M, Arambašić Jovanović J, Uskoković A, Rajić J, Sinadinović M, Tolić A, Mišić D, Šiler B, Poznanović G, Vidaković M, Dinić S. Centaurium erythraea extract improves survival and functionality of pancreatic beta-cells in diabetes through multiple routes of action. JOURNAL OF ETHNOPHARMACOLOGY 2019; 242:112043. [PMID: 31252092 DOI: 10.1016/j.jep.2019.112043] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 06/24/2019] [Accepted: 06/24/2019] [Indexed: 06/09/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Centaurium erythraea Rafn (CE) is used as a traditional medicinal plant in Serbia to treat different ailments due to its antidiabetic, antipyretic, antiflatulent and detoxification effects. AIM OF THE STUDY Elucidation of the mechanisms that underlie the antioxidant and pro-survival effects of the CE extract (CEE) in beta-cells and pancreatic islets from streptozotocin (STZ)-treated diabetic rats. MATERIAL AND METHODS Diabetes was induced in rats by multiple applications of low doses of STZ (40 mg/kg intraperitoneally (i.p.), for five consecutive days). CEE (100 mg/kg) was administered orally, in the pre-treated group for two weeks before diabetes induction, during the treatments with STZ and for four weeks after diabetes onset, and in the post-treatment group for four weeks after diabetes induction. The impact of CEE on diabetic islets was estimated by histological and immunohistochemical examination of the pancreas. Molecular mechanisms of the effects of CEE were also analyzed in insulinoma Rin-5F cells treated with STZ (12 mM) and CEE (0.25 mg/mL). Oxidative stress was evaluated by assessing the levels of DNA damage, lipid peroxidation, protein S-glutathionylation and enzymatic activities and expression of CAT, MnSOD, CuZnSOD, GPx and GR in beta-cells. The presence and activities of the redox-sensitive and islet-enriched regulatory proteins were also analyzed. RESULTS Treatment with CEE ameliorated the insulin level and glycemic control in STZ-induced diabetic rats by improving the structural and functional properties of pancreatic islets through multiple routes of action. The disturbance of islet morphology and islet cell contents in diabetes was reduced by the CEE treatment and was associated with a protective effect of CEE on the levels of insulin, GLUT-2 and p-Akt in diabetic islets. The antioxidant effect of CEE on STZ-treated beta-cells was displayed as reduced DNA damage, lipid peroxidation, protein S-glutathionylation and alleviation of STZ-induced disruption in MnSOD, CuZnSOD and CAT enzyme activities. The oxidative stress-induced disturbance of the transcriptional regulation of CAT, MnSOD, CuZnSOD, GPx and GR enzymes in beta-cells was improved after the CEE treatment, and was observed as readjustment of the presence and activities of redox-sensitive NFκB-p65, FOXO3A, Sp1 and Nrf-2 transcription factors. The observed CEE-mediated induction of proliferative and pro-survival pathways and insulin expression/secretion after STZ-induced oxidative stress in beta-cells could be partially attributed to a fine-tuned modulation of the activities of pro-survival Akt, ERK and p38 kinases and islet-enriched Pdx-1 and MafA regulatory factors. CONCLUSIONS The results of this study provide evidence that CEE improves the structural and functional properties of pancreatic beta-cells by correcting the endogenous antioxidant regulatory mechanisms and by promoting proliferative and pro-survival pathways in beta-cells.
Collapse
Affiliation(s)
- Miloš Đorđević
- Department of Molecular Biology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060, Belgrade, Serbia.
| | - Nevena Grdović
- Department of Molecular Biology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060, Belgrade, Serbia.
| | - Mirjana Mihailović
- Department of Molecular Biology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060, Belgrade, Serbia.
| | - Jelena Arambašić Jovanović
- Department of Molecular Biology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060, Belgrade, Serbia.
| | - Aleksandra Uskoković
- Department of Molecular Biology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060, Belgrade, Serbia.
| | - Jovana Rajić
- Department of Molecular Biology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060, Belgrade, Serbia.
| | - Marija Sinadinović
- Department of Molecular Biology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060, Belgrade, Serbia.
| | - Anja Tolić
- Department of Molecular Biology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060, Belgrade, Serbia.
| | - Danijela Mišić
- Department of Plant Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060, Belgrade, Serbia.
| | - Branislav Šiler
- Department of Plant Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060, Belgrade, Serbia.
| | - Goran Poznanović
- Department of Molecular Biology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060, Belgrade, Serbia.
| | - Melita Vidaković
- Department of Molecular Biology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060, Belgrade, Serbia.
| | - Svetlana Dinić
- Department of Molecular Biology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060, Belgrade, Serbia.
| |
Collapse
|
12
|
Human Fetal Bone Marrow-Derived Mesenchymal Stem Cells Promote the Proliferation and Differentiation of Pancreatic Progenitor Cells and the Engraftment Function of Islet-Like Cell Clusters. Int J Mol Sci 2019; 20:ijms20174083. [PMID: 31438545 PMCID: PMC6747176 DOI: 10.3390/ijms20174083] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/19/2019] [Accepted: 08/20/2019] [Indexed: 12/11/2022] Open
Abstract
Pancreatic progenitor cells (PPCs) are the primary source for all pancreatic cells, including beta-cells, and thus the proliferation and differentiation of PPCs into islet-like cell clusters (ICCs) opens an avenue to providing transplantable islets for diabetic patients. Meanwhile, mesenchymal stem cells (MSCs) can enhance the development and function of different cell types of interest, but their role on PPCs remains unknown. We aimed to explore the mechanism-of-action whereby MSCs induce the in vitro and in vivo PPC/ICC development by means of our established co-culture system of human PPCs with human fetal bone marrow-derived MSCs. We examined the effect of MSC-conditioned medium on PPC proliferation and survival. Meanwhile, we studied the effect of MSC co-culture enhanced PPC/ICC function in vitro and in vivo co-/transplantation. Furthermore, we identified IGF1 as a critical factor responsible for the MSC effects on PPC differentiation and proliferation via IGF1-PI3K/Akt and IGF1-MEK/ERK1/2, respectively. In conclusion, our data indicate that MSCs stimulated the differentiation and proliferation of human PPCs via IGF1 signaling, and more importantly, promoted the in vivo engraftment function of ICCs. Taken together, our protocol may provide a mechanism-driven basis for the proliferation and differentiation of PPCs into clinically transplantable islets.
Collapse
|
13
|
Xiao D, Kou H, Gui S, Ji Z, Guo Y, Wu Y, Wang H. Age-Characteristic Changes of Glucose Metabolism, Pancreatic Morphology and Function in Male Offspring Rats Induced by Prenatal Ethanol Exposure. Front Endocrinol (Lausanne) 2019; 10:34. [PMID: 30778335 PMCID: PMC6369175 DOI: 10.3389/fendo.2019.00034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 01/16/2019] [Indexed: 01/05/2023] Open
Abstract
Intrauterine growth restricted offspring suffer from abnormal glucose homeostasis and β cell dysfunction. In this study, we observed the dynamic changes of glucose metabolic phenotype, pancreatic morphology, and insulin synthesis in prenatal ethanol exposure (PEE) male offspring rats, and to explore the potential intrauterine programming mechanism of the glucocorticoid-insulin-like growth factor 1 (GC-IGF1) axis. Ethanol (4 g/kg·d) was administered through oral gavage during gestational day (GD) 9-20. Serum glucose and insulin levels, pancreatic β cell mass, and expression of glucocorticoid receptor (GR), IGF1 and insulin were determined on GD20, postnatal week (PW) 6, PW12 with/without chronic stress (CS), and PW24, respectively. Both intraperitoneal glucose and insulin tolerance tests were conducted at PW12 and PW24. Results showed that the serum glucose and insulin levels as well as pancreatic β cell mass were reduced on GD20 in PEE males compared with the controls, while pancreatic GR expression was enhanced but IGF1 and INS1/2 expression were suppressed. After birth, compared with the controls, β cell mass in the PEE males was initially decreased at PW6 and gradually recovered from PW12 to PW24, which was accompanied by increased serum glucose/insulin levels and insulin resistance index (IRI) at PW6 and decreased serum glucose contents at PW12, as well as unchanged serum glucose/insulin concentrations at PW24. In addition, both improved glucose tolerance and impaired insulin sensitivity of the PEE males at PW12 were inversed at PW24. Moreover, at PW6 and PW12, pancreatic GR expression in the PEE group was decreased, while IGF1 expression was reversely increased, resulting in a compensatory increase of insulin expression. Moreover, CS induced pancreatic GR activation and inhibited IGF1 expression, resulting in impaired insulin biosynthesis. Conclusively, the above changes were associated with age and the intrauterine programming alteration of GC-IGF1 axis may be involved in prenatal and postnatal pancreatic dysplasia and impaired insulin biosynthesis in PEE male offspring.
Collapse
Affiliation(s)
- Di Xiao
- Department of Pharmacology, School of Basic Medical Sciences of Wuhan University, Wuhan, China
| | - Hao Kou
- Department of Pharmacy, Zhongnan Hospital, Wuhan University, Wuhan, China
- Hubei Provincial Key Laboratory of Developmentally Originated Diseases, Wuhan, China
| | - Shuxia Gui
- Department of Pharmacology, School of Basic Medical Sciences of Wuhan University, Wuhan, China
| | - Zhenyu Ji
- Department of Pharmacology, School of Basic Medical Sciences of Wuhan University, Wuhan, China
| | - Yu Guo
- Department of Pharmacology, School of Basic Medical Sciences of Wuhan University, Wuhan, China
- Hubei Provincial Key Laboratory of Developmentally Originated Diseases, Wuhan, China
| | - Yin Wu
- Department of Pharmacology, School of Basic Medical Sciences of Wuhan University, Wuhan, China
- Hubei Provincial Key Laboratory of Developmentally Originated Diseases, Wuhan, China
| | - Hui Wang
- Department of Pharmacology, School of Basic Medical Sciences of Wuhan University, Wuhan, China
- Hubei Provincial Key Laboratory of Developmentally Originated Diseases, Wuhan, China
- *Correspondence: Hui Wang
| |
Collapse
|
14
|
Baeyens L, Lemper M, Staels W, De Groef S, De Leu N, Heremans Y, German MS, Heimberg H. (Re)generating Human Beta Cells: Status, Pitfalls, and Perspectives. Physiol Rev 2018; 98:1143-1167. [PMID: 29717931 DOI: 10.1152/physrev.00034.2016] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Diabetes mellitus results from disturbed glucose homeostasis due to an absolute (type 1) or relative (type 2) deficiency of insulin, a peptide hormone almost exclusively produced by the beta cells of the endocrine pancreas in a tightly regulated manner. Current therapy only delays disease progression through insulin injection and/or oral medications that increase insulin secretion or sensitivity, decrease hepatic glucose production, or promote glucosuria. These drugs have turned diabetes into a chronic disease as they do not solve the underlying beta cell defects or entirely prevent the long-term complications of hyperglycemia. Beta cell replacement through islet transplantation is a more physiological therapeutic alternative but is severely hampered by donor shortage and immune rejection. A curative strategy should combine newer approaches to immunomodulation with beta cell replacement. Success of this approach depends on the development of practical methods for generating beta cells, either in vitro or in situ through beta cell replication or beta cell differentiation. This review provides an overview of human beta cell generation.
Collapse
Affiliation(s)
- Luc Baeyens
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Brussels , Belgium ; Diabetes Center, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, and Department of Medicine, University of California San Francisco , San Francisco, California ; Genentech Safety Assessment, South San Francisco, California ; Investigative Toxicology, UCB BioPharma, Braine-l'Alleud, Belgium ; Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University, Hospital and Department of Pediatrics and Genetics , Ghent , Belgium ; Department of Endocrinology, Universitair Ziekenhuis Brussel, Brussels , Belgium ; and Department of Endocrinology, Algemeen Stedelijk Ziekenhuis Aalst, Aalst, Belgium
| | - Marie Lemper
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Brussels , Belgium ; Diabetes Center, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, and Department of Medicine, University of California San Francisco , San Francisco, California ; Genentech Safety Assessment, South San Francisco, California ; Investigative Toxicology, UCB BioPharma, Braine-l'Alleud, Belgium ; Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University, Hospital and Department of Pediatrics and Genetics , Ghent , Belgium ; Department of Endocrinology, Universitair Ziekenhuis Brussel, Brussels , Belgium ; and Department of Endocrinology, Algemeen Stedelijk Ziekenhuis Aalst, Aalst, Belgium
| | - Willem Staels
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Brussels , Belgium ; Diabetes Center, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, and Department of Medicine, University of California San Francisco , San Francisco, California ; Genentech Safety Assessment, South San Francisco, California ; Investigative Toxicology, UCB BioPharma, Braine-l'Alleud, Belgium ; Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University, Hospital and Department of Pediatrics and Genetics , Ghent , Belgium ; Department of Endocrinology, Universitair Ziekenhuis Brussel, Brussels , Belgium ; and Department of Endocrinology, Algemeen Stedelijk Ziekenhuis Aalst, Aalst, Belgium
| | - Sofie De Groef
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Brussels , Belgium ; Diabetes Center, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, and Department of Medicine, University of California San Francisco , San Francisco, California ; Genentech Safety Assessment, South San Francisco, California ; Investigative Toxicology, UCB BioPharma, Braine-l'Alleud, Belgium ; Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University, Hospital and Department of Pediatrics and Genetics , Ghent , Belgium ; Department of Endocrinology, Universitair Ziekenhuis Brussel, Brussels , Belgium ; and Department of Endocrinology, Algemeen Stedelijk Ziekenhuis Aalst, Aalst, Belgium
| | - Nico De Leu
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Brussels , Belgium ; Diabetes Center, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, and Department of Medicine, University of California San Francisco , San Francisco, California ; Genentech Safety Assessment, South San Francisco, California ; Investigative Toxicology, UCB BioPharma, Braine-l'Alleud, Belgium ; Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University, Hospital and Department of Pediatrics and Genetics , Ghent , Belgium ; Department of Endocrinology, Universitair Ziekenhuis Brussel, Brussels , Belgium ; and Department of Endocrinology, Algemeen Stedelijk Ziekenhuis Aalst, Aalst, Belgium
| | - Yves Heremans
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Brussels , Belgium ; Diabetes Center, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, and Department of Medicine, University of California San Francisco , San Francisco, California ; Genentech Safety Assessment, South San Francisco, California ; Investigative Toxicology, UCB BioPharma, Braine-l'Alleud, Belgium ; Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University, Hospital and Department of Pediatrics and Genetics , Ghent , Belgium ; Department of Endocrinology, Universitair Ziekenhuis Brussel, Brussels , Belgium ; and Department of Endocrinology, Algemeen Stedelijk Ziekenhuis Aalst, Aalst, Belgium
| | - Michael S German
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Brussels , Belgium ; Diabetes Center, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, and Department of Medicine, University of California San Francisco , San Francisco, California ; Genentech Safety Assessment, South San Francisco, California ; Investigative Toxicology, UCB BioPharma, Braine-l'Alleud, Belgium ; Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University, Hospital and Department of Pediatrics and Genetics , Ghent , Belgium ; Department of Endocrinology, Universitair Ziekenhuis Brussel, Brussels , Belgium ; and Department of Endocrinology, Algemeen Stedelijk Ziekenhuis Aalst, Aalst, Belgium
| | - Harry Heimberg
- Beta Cell Neogenesis (BENE), Vrije Universiteit Brussel, Brussels , Belgium ; Diabetes Center, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, and Department of Medicine, University of California San Francisco , San Francisco, California ; Genentech Safety Assessment, South San Francisco, California ; Investigative Toxicology, UCB BioPharma, Braine-l'Alleud, Belgium ; Department of Pediatrics, Division of Pediatric Endocrinology, Ghent University, Hospital and Department of Pediatrics and Genetics , Ghent , Belgium ; Department of Endocrinology, Universitair Ziekenhuis Brussel, Brussels , Belgium ; and Department of Endocrinology, Algemeen Stedelijk Ziekenhuis Aalst, Aalst, Belgium
| |
Collapse
|
15
|
Jiang Y, Fischbach S, Xiao X. The Role of the TGFβ Receptor Signaling Pathway in Adult Beta Cell Proliferation. Int J Mol Sci 2018; 19:ijms19103136. [PMID: 30322036 PMCID: PMC6212884 DOI: 10.3390/ijms19103136] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 10/09/2018] [Accepted: 10/10/2018] [Indexed: 12/19/2022] Open
Abstract
Diabetes is a global epidemic and affects millions of individuals in the United States. Devising novel treatments for diabetes continues to be a great medical challenge. Postnatal beta cell growth or compensation is largely attributed to beta cell proliferation, which declines continuously with age. To boost beta cell proliferation to regenerate an adequate functional mass, there is a need to understand the signaling pathways that regulate beta cell proliferation for creating practical strategies to promote the process. Transforming growth factor β (TGFβ) belongs to a signaling superfamily that governs pancreatic development and the regeneration of beta cells after pancreatic diseases. TGFβ exerts its functions by activation of downstream Smad proteins and through its crosstalk with other pathways. Accumulating data demonstrate that the TGFβ receptor signaling pathway also participates in the control of beta cell proliferation. This review details the role of the TGFβ receptor signaling pathway in beta cell proliferation physiologically and in the pathogenesis of diabetes.
Collapse
Affiliation(s)
- Yinan Jiang
- Division of Pediatric Surgery, Department of Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, 4401 Penn Ave, Pittsburgh, PA 15224, USA.
| | - Shane Fischbach
- Division of Pediatric Surgery, Department of Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, 4401 Penn Ave, Pittsburgh, PA 15224, USA.
- The Warren Alpert Medical School of Brown University, 222 Richmond Street, Providence, RI 02903, USA.
| | - Xiangwei Xiao
- Division of Pediatric Surgery, Department of Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, 4401 Penn Ave, Pittsburgh, PA 15224, USA.
| |
Collapse
|
16
|
Evaluation of vitrification protocol of mouse ovarian tissue by effect of DNA methyltransferase-1 and paternal imprinted growth factor receptor-binding protein 10 on signaling pathways. Cryobiology 2017; 80:89-95. [PMID: 29180273 DOI: 10.1016/j.cryobiol.2017.11.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Revised: 10/27/2017] [Accepted: 11/21/2017] [Indexed: 10/18/2022]
Abstract
Transplantation of cryopreserved ovarian tissue has been considered as a promising way of fertility preservation for women. however, this cryopreservation method is prone to post-resuscitation follicle proliferation and oocyte development stagnation, affecting late transplant survival. To evaluate current vitrification works, we investigated the critical pathway alternations in vitrified-warmed juvenile 10-day-old mouse ovary. We showed a significant decrease of protein kinase B (Akt) and Mitogen-activated protein kinase (Mapk) phosphorylation, during which serine/threonine kinases play central roles in coordinating follicle and oocyte development and stress response. Inhibition of Akt and Mapk activity were associated with one of the imprinted insulin pathway negative regulatory genes, Growth factor receptor-binding protein 10 (Grb10) which remarkably increased in vitrified-warmed juvenile mouse ovary than that of fresh group (p < 0.05). RNAi-induced Grb10 down-regulation reversed the decrease in Akt and Mapk phosphorylation. The increase of Grb10 expression was partially caused by the hyper-methylation of the promoter region, associated with the decrease of follicular DNA methyltransferase (Dnmt) 1 protein in different stages of vitrified-warmed group, compared to fresh group (p < 0.05). The mRNA and protein expression of Dnmt1 in ovary of vitrified-warmed juvenile mouse were remarkably lower than those in fresh group (p < 0.05). Dnmt1 overexpression dramatically reversed Grb10 up-regulation and Akt and Mapk phosphorylation reduction. Taken together, our findings suggest that Grb10 expression might be helpful in evaluation of effectiveness of vitrification, and considered as a potential target for further vitrification protocols improvement in the future.
Collapse
|
17
|
Chen C, Wu S, Lin X, Wu D, Fischbach S, Xiao X. ERK5 plays an essential role in gestational beta-cell proliferation. Cell Prolif 2017; 51:e12410. [PMID: 29159830 DOI: 10.1111/cpr.12410] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 10/24/2017] [Indexed: 12/25/2022] Open
Abstract
OBJECTIVES Restoring a functional beta-cell mass is a fundamental goal in treating diabetes. A complex signalling pathway network coordinates the regulation of beta-cell proliferation, although a role for ERK5 in this network has not been reported. This question was addressed in this study. MATERIALS AND METHODS We studied the activation of extracellular-signal-regulated kinase 5 (ERK5) in pregnant mice, a well-known mouse model of increased beta-cell proliferation. A specific inhibitor of ERK5 activation, BIX02189, was intraperitoneally injected into the pregnant mice to suppress ERK5 signalling. Beta-cell proliferation was determined by quantification of Ki-67+ beta cells. Beta-cell apoptosis was determined by TUNEL assay. The extent of beta-cell proliferation was determined by beta-cell mass. The alteration of ERK5 activation and CyclinD1 levels in purified mouse islets was examined by Western blotting. RESULTS Extracellular-signal-regulated kinase 5 phosphorylation, which represents ERK5 activation, was significantly upregulated in islets from pregnant mice. Suppression of ERK5 activation by BIX02189 in pregnant mice significantly reduced beta-cell proliferation, without affecting beta-cell apoptosis, resulting in increases in random blood glucose levels and impairment of glucose response of the mice. ERK5 seemed to activate CyclinD1 to promote gestational beta-cell proliferation. CONCLUSIONS Extracellular-signal-regulated kinase 5 plays an essential role in the gestational augmentation of beta-cell proliferation. ERK5 may be a promising target for increasing beta-cell mass in diabetes patients.
Collapse
Affiliation(s)
- Congde Chen
- Department of Pediatric Surgery, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Suichun Wu
- Reproductive Medicine Centre, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xiaokun Lin
- Department of Pediatric Surgery, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Dazhou Wu
- Department of Pediatric Surgery, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Shane Fischbach
- Department of Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, USA
| | - Xiangwei Xiao
- Department of Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, USA
| |
Collapse
|
18
|
Chirivella L, Kirstein M, Ferrón SR, Domingo-Muelas A, Durupt FC, Acosta-Umanzor C, Cano-Jaimez M, Pérez-Sánchez F, Barbacid M, Ortega S, Burks DJ, Fariñas I. Cyclin-Dependent Kinase 4 Regulates Adult Neural Stem Cell Proliferation and Differentiation in Response to Insulin. Stem Cells 2017; 35:2403-2416. [DOI: 10.1002/stem.2694] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 06/25/2017] [Accepted: 07/11/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Laura Chirivella
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Spain
- Departamento de Biología Celular; Biología Funcional y Antropología Física and Estructura de Recerca Interdisciplinar en Biotecnología i Biomedicina (ERI BIOTECMED), Universidad de Valencia; Burjassot Spain
| | - Martina Kirstein
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Spain
- Departamento de Biología Celular; Biología Funcional y Antropología Física and Estructura de Recerca Interdisciplinar en Biotecnología i Biomedicina (ERI BIOTECMED), Universidad de Valencia; Burjassot Spain
| | - Sacri R. Ferrón
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Spain
- Departamento de Biología Celular; Biología Funcional y Antropología Física and Estructura de Recerca Interdisciplinar en Biotecnología i Biomedicina (ERI BIOTECMED), Universidad de Valencia; Burjassot Spain
| | - Ana Domingo-Muelas
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Spain
- Departamento de Biología Celular; Biología Funcional y Antropología Física and Estructura de Recerca Interdisciplinar en Biotecnología i Biomedicina (ERI BIOTECMED), Universidad de Valencia; Burjassot Spain
| | - Fabrice C. Durupt
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Spain
- Departamento de Biología Celular; Biología Funcional y Antropología Física and Estructura de Recerca Interdisciplinar en Biotecnología i Biomedicina (ERI BIOTECMED), Universidad de Valencia; Burjassot Spain
| | - Carlos Acosta-Umanzor
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), Centro de Investigación Príncipe Felipe; Valencia Spain
| | - Marifé Cano-Jaimez
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), Centro de Investigación Príncipe Felipe; Valencia Spain
| | - Francisco Pérez-Sánchez
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Spain
- Departamento de Biología Celular; Biología Funcional y Antropología Física and Estructura de Recerca Interdisciplinar en Biotecnología i Biomedicina (ERI BIOTECMED), Universidad de Valencia; Burjassot Spain
| | - Mariano Barbacid
- Centro Nacional de Investigaciones Oncológicas (CNIO); Madrid Spain
| | - Sagrario Ortega
- Centro Nacional de Investigaciones Oncológicas (CNIO); Madrid Spain
| | - Deborah J. Burks
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), Centro de Investigación Príncipe Felipe; Valencia Spain
| | - Isabel Fariñas
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Spain
- Departamento de Biología Celular; Biología Funcional y Antropología Física and Estructura de Recerca Interdisciplinar en Biotecnología i Biomedicina (ERI BIOTECMED), Universidad de Valencia; Burjassot Spain
| |
Collapse
|
19
|
Mallol C, Casana E, Jimenez V, Casellas A, Haurigot V, Jambrina C, Sacristan V, Morró M, Agudo J, Vilà L, Bosch F. AAV-mediated pancreatic overexpression of Igf1 counteracts progression to autoimmune diabetes in mice. Mol Metab 2017; 6:664-680. [PMID: 28702323 PMCID: PMC5485311 DOI: 10.1016/j.molmet.2017.05.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 05/09/2017] [Accepted: 05/12/2017] [Indexed: 12/31/2022] Open
Abstract
Objective Type 1 diabetes is characterized by autoimmune destruction of β-cells leading to severe insulin deficiency. Although many improvements have been made in recent years, exogenous insulin therapy is still imperfect; new therapeutic approaches, focusing on preserving/expanding β-cell mass and/or blocking the autoimmune process that destroys islets, should be developed. The main objective of this work was to test in non-obese diabetic (NOD) mice, which spontaneously develop autoimmune diabetes, the effects of local expression of Insulin-like growth factor 1 (IGF1), a potent mitogenic and pro-survival factor for β-cells with immunomodulatory properties. Methods Transgenic NOD mice overexpressing IGF1 specifically in β-cells (NOD-IGF1) were generated and phenotyped. In addition, miRT-containing, IGF1-encoding adeno-associated viruses (AAV) of serotype 8 (AAV8-IGF1-dmiRT) were produced and administered to 4- or 11-week-old non-transgenic NOD females through intraductal delivery. Several histological, immunological, and metabolic parameters were measured to monitor disease over a period of 28–30 weeks. Results In transgenic mice, local IGF1 expression led to long-term suppression of diabetes onset and robust protection of β-cell mass from the autoimmune insult. AAV-mediated pancreatic-specific overexpression of IGF1 in adult animals also dramatically reduced diabetes incidence, both when vectors were delivered before pathology onset or once insulitis was established. Transgenic NOD-IGF1 and AAV8-IGF1-dmiRT-treated NOD animals had much less islet infiltration than controls, preserved β-cell mass, and normal insulinemia. Transgenic and AAV-treated islets showed less expression of antigen-presenting molecules, inflammatory cytokines, and chemokines important for tissue-specific homing of effector T cells, suggesting IGF1 modulated islet autoimmunity in NOD mice. Conclusions Local expression of Igf1 by AAV-mediated gene transfer counteracts progression to diabetes in NOD mice. This study suggests a therapeutic strategy for autoimmune diabetes in humans. Local pancreatic IGF1 expression prevents spontaneous autoimmune diabetes. Protection achieved after one-time local administration of IGF1-encoding AAV vectors. Efficacious in animals treated early or once autoimmunity is already established. Protection through maintenance of β-cell mass and endogenous insulin secretion. Treatment leads to reduced infiltration and expression of immunity genes in islets.
Collapse
Affiliation(s)
- Cristina Mallol
- Center of Animal Biotechnology and Gene Therapy (CBATEG), Spain.,Department of Biochemistry and Molecular Biology, School of Veterinary Medicine, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.,CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08017 Madrid, Spain
| | - Estefania Casana
- Center of Animal Biotechnology and Gene Therapy (CBATEG), Spain.,Department of Biochemistry and Molecular Biology, School of Veterinary Medicine, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Veronica Jimenez
- Center of Animal Biotechnology and Gene Therapy (CBATEG), Spain.,Department of Biochemistry and Molecular Biology, School of Veterinary Medicine, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.,CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08017 Madrid, Spain
| | - Alba Casellas
- Center of Animal Biotechnology and Gene Therapy (CBATEG), Spain.,Department of Biochemistry and Molecular Biology, School of Veterinary Medicine, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.,CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08017 Madrid, Spain
| | - Virginia Haurigot
- Center of Animal Biotechnology and Gene Therapy (CBATEG), Spain.,Department of Biochemistry and Molecular Biology, School of Veterinary Medicine, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.,CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08017 Madrid, Spain
| | - Claudia Jambrina
- Center of Animal Biotechnology and Gene Therapy (CBATEG), Spain.,Department of Biochemistry and Molecular Biology, School of Veterinary Medicine, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Victor Sacristan
- Center of Animal Biotechnology and Gene Therapy (CBATEG), Spain.,Department of Biochemistry and Molecular Biology, School of Veterinary Medicine, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Meritxell Morró
- Center of Animal Biotechnology and Gene Therapy (CBATEG), Spain.,Department of Biochemistry and Molecular Biology, School of Veterinary Medicine, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.,CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08017 Madrid, Spain
| | - Judith Agudo
- Center of Animal Biotechnology and Gene Therapy (CBATEG), Spain.,Department of Biochemistry and Molecular Biology, School of Veterinary Medicine, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.,CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08017 Madrid, Spain
| | - Laia Vilà
- Center of Animal Biotechnology and Gene Therapy (CBATEG), Spain.,Department of Biochemistry and Molecular Biology, School of Veterinary Medicine, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.,CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08017 Madrid, Spain
| | - Fatima Bosch
- Center of Animal Biotechnology and Gene Therapy (CBATEG), Spain.,Department of Biochemistry and Molecular Biology, School of Veterinary Medicine, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.,CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 08017 Madrid, Spain
| |
Collapse
|
20
|
Wei S, Han C, He F, Song Q, Kang B, Liu H, Li L, Xu H, Zeng X. Inhibition of PI3K-Akt-mTOR signal pathway dismissed the stimulation of glucose on goose liver cell growth. J Anim Physiol Anim Nutr (Berl) 2016; 101:e133-e143. [DOI: 10.1111/jpn.12574] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Accepted: 06/16/2016] [Indexed: 12/28/2022]
Affiliation(s)
- S. Wei
- College of life science; Sichuan Agricultural University; Ya'an Sichuan China
| | - C. Han
- Institute of Animal Breeding & Genetic; Sichuan Agricultural University; Chengdu Sichuan China
| | - F. He
- Institute of Animal Breeding & Genetic; Sichuan Agricultural University; Chengdu Sichuan China
| | - Q. Song
- Institute of Animal Breeding & Genetic; Sichuan Agricultural University; Chengdu Sichuan China
| | - B. Kang
- Institute of Animal Breeding & Genetic; Sichuan Agricultural University; Chengdu Sichuan China
| | - H. Liu
- Institute of Animal Breeding & Genetic; Sichuan Agricultural University; Chengdu Sichuan China
| | - L. Li
- Institute of Animal Breeding & Genetic; Sichuan Agricultural University; Chengdu Sichuan China
| | - H. Xu
- Institute of Animal Breeding & Genetic; Sichuan Agricultural University; Chengdu Sichuan China
| | - X. Zeng
- College of life science; Sichuan Agricultural University; Ya'an Sichuan China
| |
Collapse
|
21
|
Nagaraju R, Rajini PS. Adaptive response of rat pancreatic β-cells to insulin resistance induced by monocrotophos: Biochemical evidence. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2016; 134:39-48. [PMID: 27914538 DOI: 10.1016/j.pestbp.2016.04.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 04/28/2016] [Accepted: 04/29/2016] [Indexed: 06/06/2023]
Abstract
Our previous findings clearly suggested the role of duration of exposure to monocrotophos (MCP) in the development of insulin resistance. Rats exposed chronically to MCP developed insulin resistance with hyperinsulinemia without overt diabetes. In continuation of this vital observation, we sought to delineate the biochemical mechanisms that mediate heightened pancreatic β-cell response in the wake of MCP-induced insulin resistance in rats. Adult rats were orally administered (0.9 and 1.8mg/kgb.w/d) MCP for 180days. Terminally, MCP-treated rats exhibited glucose intolerance, hyperinsulinemia, and potentiation of glucose-induced insulin secretion along with elevated levels of circulating IGF1, free fatty acids, corticosterone, and paraoxonase activity. Biochemical analysis of islet extracts revealed increased levels of insulin, malate, pyruvate and ATP with a concomitant increase in activities of cytosolic and mitochondrial enzymes that are known to facilitate insulin secretion and enhanced shuttle activities. Interestingly, islets from MCP-treated rats exhibited increased insulin secretory potential ex vivo compared to those isolated from control rats. Further, MCP-induced islet hypertrophy was associated with increased insulin-positive cells. Our study demonstrates the impact of the biological interaction between MCP and components of metabolic homeostasis on pancreatic beta cell function/s. We speculate that the heightened pancreatic beta cell function evidenced may be mediated by increased IGF1 and paraoxonase activity, which effectively counters insulin resistance induced by chronic exposure to MCP. Our findings emphasize the need for focused research to understand the confounding environmental risk factors which may modulate heightened beta cell functions in the case of organophosphorus insecticide-induced insulin resistance. Such an approach may help us to explain the sharp increase in the prevalence of type II diabetes worldwide.
Collapse
Affiliation(s)
- Raju Nagaraju
- Food Protectants and Infestation Control Department, CSIR- Central Food Technological Research Institute, Mysuru 570 020, India
| | - Padmanabhan Sharda Rajini
- Food Protectants and Infestation Control Department, CSIR- Central Food Technological Research Institute, Mysuru 570 020, India.
| |
Collapse
|
22
|
Breuer TGK, Borker L, Quast DR, Tannapfel A, Schmidt WE, Uhl W, Meier JJ. Impact of proton pump inhibitor treatment on pancreatic beta-cell area and beta-cell proliferation in humans. Eur J Endocrinol 2016; 175:467-76. [PMID: 27562401 DOI: 10.1530/eje-16-0320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 08/24/2016] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Gastrin has been shown to promote beta-cell proliferation in rodents, but its effects in adult humans are largely unclear. Proton pump inhibitors (PPIs) lead to endogenous hypergastrinaemia, and improved glucose control during PPI therapy has been reported in patients with diabetes. Therefore, we addressed whether PPI treatment is associated with improved glucose homoeostasis, islet cell hyperplasia or increased new beta-cell formation in humans. PATIENTS AND METHODS Pancreatic tissue specimens from 60 patients with and 33 patients without previous PPI therapy were examined. The group was subdivided into patients without diabetes (n = 27), pre-diabetic patients (n = 31) and patients with diabetes (n = 35). RESULTS Fasting glucose and HbA1c levels were not different between patients with and without PPI therapy (P = 0.34 and P = 0.30 respectively). Beta-cell area was higher in patients without diabetes than in patients with pre-diabetes or diabetes (1.33 ± 0.12%, 1.05 ± 0.09% and 0.66 ± 0.07% respectively; P < 0.0001). There was no difference in beta-cell area between patients with and without PPI treatment (1.05 ± 0.08% vs 0.87 ± 0.08%, respectively; P = 0.16). Beta-cell replication was rare and not different between patients with and without PPI therapy (P = 0.20). PPI treatment was not associated with increased duct-cell replication (P = 0.18), insulin expression in ducts (P = 0.28) or beta-cell size (P = 0.63). CONCLUSIONS These results suggest that in adult humans, chronic PPI treatment does not enhance beta-cell mass or beta-cell function to a relevant extent.
Collapse
Affiliation(s)
- Thomas G K Breuer
- Diabetes DivisionSt. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Laura Borker
- Diabetes DivisionSt. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Daniel R Quast
- Diabetes DivisionSt. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany
| | | | - Wolfgang E Schmidt
- Diabetes DivisionSt. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Waldemar Uhl
- Department of SurgerySt. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Juris J Meier
- Diabetes DivisionSt. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany
| |
Collapse
|
23
|
Benthuysen JR, Carrano AC, Sander M. Advances in β cell replacement and regeneration strategies for treating diabetes. J Clin Invest 2016; 126:3651-3660. [PMID: 27694741 DOI: 10.1172/jci87439] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In the past decade, new approaches have been explored that are aimed at restoring functional β cell mass as a treatment strategy for diabetes. The two most intensely pursued strategies are β cell replacement through conversion of other cell types and β cell regeneration by enhancement of β cell replication. The approach closest to clinical implementation is the replacement of β cells with human pluripotent stem cell-derived (hPSC-derived) cells, which are currently under investigation in a clinical trial to assess their safety in humans. In addition, there has been success in reprogramming developmentally related cell types into β cells. Reprogramming approaches could find therapeutic applications by inducing β cell conversion in vivo or by reprogramming cells ex vivo followed by implantation. Finally, recent studies have revealed novel pharmacologic targets for stimulating β cell replication. Manipulating these targets or the pathways they regulate could be a strategy for promoting the expansion of residual β cells in diabetic patients. Here, we provide an overview of progress made toward β cell replacement and regeneration and discuss promises and challenges for clinical implementation of these strategies.
Collapse
|
24
|
Schmidt SF, Madsen JGS, Frafjord KØ, Poulsen LLC, Salö S, Boergesen M, Loft A, Larsen BD, Madsen MS, Holst JJ, Maechler P, Dalgaard LT, Mandrup S. Integrative Genomics Outlines a Biphasic Glucose Response and a ChREBP-RORγ Axis Regulating Proliferation in β Cells. Cell Rep 2016; 16:2359-72. [PMID: 27545881 DOI: 10.1016/j.celrep.2016.07.063] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/26/2016] [Accepted: 07/25/2016] [Indexed: 12/27/2022] Open
Abstract
Glucose is an important inducer of insulin secretion, but it also stimulates long-term adaptive changes in gene expression that can either promote or antagonize the proliferative potential and function of β cells. Here, we have generated time-resolved profiles of enhancer and transcriptional activity in response to glucose in the INS-1E pancreatic β cell line. Our data outline a biphasic response with a first transcriptional wave during which metabolic genes are activated, and a second wave where cell-cycle genes are activated and β cell identity genes are repressed. The glucose-sensing transcription factor ChREBP directly activates first wave enhancers, whereas repression and activation of second wave enhancers are indirect. By integrating motif enrichment within late-regulated enhancers with expression profiles of the associated transcription factors, we have identified multiple putative regulators of the second wave. These include RORγ, the activity of which is important for glucose-induced proliferation of both INS-1E and primary rat β cells.
Collapse
Affiliation(s)
- Søren Fisker Schmidt
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Jesper Grud Skat Madsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark; NNF Center of Basic Metabolic Research, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Kari Østerli Frafjord
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Lars la Cour Poulsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Sofia Salö
- Department of Science and Environment, Roskilde University, 4000 Roskilde, Denmark
| | - Michael Boergesen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Anne Loft
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Bjørk Ditlev Larsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Maria Stahl Madsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Jens Juul Holst
- NNF Center of Basic Metabolic Research, University of Copenhagen, 2200 Copenhagen N, Denmark; Department of Biomedical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Pierre Maechler
- Department of Cell Physiology and Metabolism, University of Geneva, 1211 Geneva, Switzerland
| | - Louise Torp Dalgaard
- Department of Science and Environment, Roskilde University, 4000 Roskilde, Denmark
| | - Susanne Mandrup
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark.
| |
Collapse
|
25
|
Stamateris RE, Sharma RB, Kong Y, Ebrahimpour P, Panday D, Ranganath P, Zou B, Levitt H, Parambil NA, O'Donnell CP, García-Ocaña A, Alonso LC. Glucose Induces Mouse β-Cell Proliferation via IRS2, MTOR, and Cyclin D2 but Not the Insulin Receptor. Diabetes 2016; 65:981-95. [PMID: 26740601 PMCID: PMC5314707 DOI: 10.2337/db15-0529] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 12/29/2015] [Indexed: 12/21/2022]
Abstract
An important goal in diabetes research is to understand the processes that trigger endogenous β-cell proliferation. Hyperglycemia induces β-cell replication, but the mechanism remains debated. A prime candidate is insulin, which acts locally through the insulin receptor. Having previously developed an in vivo mouse hyperglycemia model, we tested whether glucose induces β-cell proliferation through insulin signaling. By using mice lacking insulin signaling intermediate insulin receptor substrate 2 (IRS2), we confirmed that hyperglycemia-induced β-cell proliferation requires IRS2 both in vivo and ex vivo. Of note, insulin receptor activation was not required for glucose-induced proliferation, and insulin itself was not sufficient to drive replication. Glucose and insulin caused similar acute signaling in mouse islets, but chronic signaling differed markedly, with mammalian target of rapamycin (MTOR) and extracellular signal-related kinase (ERK) activation by glucose and AKT activation by insulin. MTOR but not ERK activation was required for glucose-induced proliferation. Cyclin D2 was necessary for glucose-induced β-cell proliferation. Cyclin D2 expression was reduced when either IRS2 or MTOR signaling was lost, and restoring cyclin D2 expression rescued the proliferation defect. Human islets shared many of these regulatory pathways. Taken together, these results support a model in which IRS2, MTOR, and cyclin D2, but not the insulin receptor, mediate glucose-induced proliferation.
Collapse
Affiliation(s)
- Rachel E Stamateris
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Rohit B Sharma
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Yahui Kong
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Pantea Ebrahimpour
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Deepika Panday
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Pavana Ranganath
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Baobo Zou
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Helena Levitt
- Division of Endocrinology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | | | - Christopher P O'Donnell
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Adolfo García-Ocaña
- Diabetes, Obesity and Metabolism Institute, Division of Endocrinology, Diabetes and Bone Disease, The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Laura C Alonso
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| |
Collapse
|
26
|
mTOR Inhibition: Reduced Insulin Secretion and Sensitivity in a Rat Model of Metabolic Syndrome. Transplant Direct 2016; 2:e65. [PMID: 27500257 PMCID: PMC4946492 DOI: 10.1097/txd.0000000000000576] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 12/22/2015] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Sirolimus (SRL) has been associated with new-onset diabetes mellitus after transplantation. The aim was to determine the effect of SRL on development of insulin resistance and β -cell toxicity. METHODS Lean Zucker rat (LZR) and obese Zucker rat (OZR) were distributed into groups: vehicle and SRL (0.25, 0.5, or 1.0 mg/kg) during 12 or 28 days. Intraperitoneal glucose tolerance test (IPGTT) was evaluated at days 0, 12, 28, and 45. Islet morphometry, β-cell proliferation, and apoptosis were analyzed at 12 days. Islets were isolated to analyze insulin content, insulin secretion, and gene expression. RESULTS After 12 days, SRL treatment only impaired IPGTT in a dose-dependent manner in OZR. Treatment prolongation induced increase of area under the curve of IPGTT in LZR and OZR; however, in contrast to OZR, LZR normalized glucose levels after 2 hours. The SRL reduced pancreas weight and islet proliferation in LZR and OZR as well as insulin content. Insulin secretion was only affected in OZR. Islets from OZR + SRL rats presented a downregulation of Neurod1, Pax4, and Ins2 gene. Genes related with insulin secretion remained unchanged or upregulated. CONCLUSIONS In conditions that require adaptive β -cell proliferation, SRL might reveal harmful effects by blocking β -cell proliferation, insulin production and secretion. These effects disappeared when removing the therapy.
Collapse
|
27
|
Beneficial effects of growth hormone-releasing hormone agonists on rat INS-1 cells and on streptozotocin-induced NOD/SCID mice. Proc Natl Acad Sci U S A 2015; 112:13651-6. [PMID: 26474831 DOI: 10.1073/pnas.1518540112] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Agonists of growth hormone-releasing hormone (GHRH) have been previously reported to promote growth, function, and engraftment of islet cells following transplantation. Here we evaluated recently synthesized GHRH agonists on the proliferation and biological functions of rat pancreatic β-cell line (INS-1) and islets. In vitro treatment of INS-1 cells with GHRH agonists increased cell proliferation, the expression of cellular insulin, insulin-like growth factor-1 (IGF1), and GHRH receptor, and also stimulated insulin secretion in response to glucose challenge. Exposure of INS-1 cells to GHRH agonists, MR-356 and MR-409, induced activation of ERK and AKT pathways. Agonist MR-409 also significantly increased the levels of cellular cAMP and the phosphorylation of cAMP response element binding protein (CREB) in INS-1 cells. Treatment of rat islets with agonist, MR-409 significantly increased cell proliferation, islet size, and the expression of insulin. In vivo daily s.c. administration of 10 μg MR-409 for 3 wk dramatically reduced the severity of streptozotocin (STZ)-induced diabetes in nonobese diabetic severe combined immunodeficiency (NOD/SCID) mice. The maximal therapeutic benefits with respect to the efficiency of engraftment, ability to reach normoglycemia, gain in body weight, response to high glucose challenge, and induction of higher levels of serum insulin and IGF1 were observed when diabetic mice were transplanted with rat islets preconditioned with GHRH agonist, MR-409, and received additional treatment with MR-409 posttransplantation. This study provides an improved approach to the therapeutic use of GHRH agonists in the treatment of diabetes mellitus.
Collapse
|
28
|
Arous C, Halban PA. The skeleton in the closet: actin cytoskeletal remodeling in β-cell function. Am J Physiol Endocrinol Metab 2015; 309:E611-20. [PMID: 26286869 DOI: 10.1152/ajpendo.00268.2015] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 08/11/2015] [Indexed: 01/13/2023]
Abstract
Over the last few decades, biomedical research has considered not only the function of single cells but also the importance of the physical environment within a whole tissue, including cell-cell and cell-extracellular matrix interactions. Cytoskeleton organization and focal adhesions are crucial sensors for cells that enable them to rapidly communicate with the physical extracellular environment in response to extracellular stimuli, ensuring proper function and adaptation. The involvement of the microtubular-microfilamentous cytoskeleton in secretion mechanisms was proposed almost 50 years ago, since when the evolution of ever more sensitive and sophisticated methods in microscopy and in cell and molecular biology have led us to become aware of the importance of cytoskeleton remodeling for cell shape regulation and its crucial link with signaling pathways leading to β-cell function. Emerging evidence suggests that dysfunction of cytoskeletal components or extracellular matrix modification influences a number of disorders through potential actin cytoskeleton disruption that could be involved in the initiation of multiple cellular functions. Perturbation of β-cell actin cytoskeleton remodeling could arise secondarily to islet inflammation and fibrosis, possibly accounting in part for impaired β-cell function in type 2 diabetes. This review focuses on the role of actin remodeling in insulin secretion mechanisms and its close relationship with focal adhesions and myosin II.
Collapse
Affiliation(s)
- Caroline Arous
- Department of Genetic Medicine and Development, University of Geneva Medical Center, Geneva, Switzerland
| | - Philippe A Halban
- Department of Genetic Medicine and Development, University of Geneva Medical Center, Geneva, Switzerland
| |
Collapse
|
29
|
Hirukawa H, Kaneto H, Shimoda M, Kimura T, Okauchi S, Obata A, Kohara K, Hamamoto S, Tawaramoto K, Hashiramoto M, Kaku K. Combination of DPP-4 inhibitor and PPARγ agonist exerts protective effects on pancreatic β-cells in diabetic db/db mice through the augmentation of IRS-2 expression. Mol Cell Endocrinol 2015; 413:49-60. [PMID: 26116826 DOI: 10.1016/j.mce.2015.06.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 06/05/2015] [Accepted: 06/07/2015] [Indexed: 11/29/2022]
Abstract
We investigated the effects of long- and short-term treatment with pioglitazone (Pio) and/or alogliptin (Alo) on β-cells in diabetic db/db mice. Six-week-old male db/db mice received Pio (25 mg/kg, oral) and/or Alo (30 mg/kg, oral) for 4 weeks and for 2 days. Blood glucose levels were decreased after 4-week intervention, but not after 2-day intervention. Pio increased adiponectin levels, and Alo decreased glucagon levels and increased active GlP-1 levels. Insulin sensitivity was restored by Pio. After 4-week treatment, β-cell mass was increased (over 2-fold increase) and expression levels of various β-cell-related factors were restored. Expression levels of IRS-2 and various downstream factors were up-regulated by Pio and Alo after 2-day and 4-week intervention. In addition, mRNA and protein levels of IRS-2 and various downstream factors were up-regulated in MIN6 cells after 24-h exposure to Pio and exendin-4. These results suggest that Pio and Alo additively up-regulate IRS-2 expression independently of the alteration of glycemic control. Taken together, combination of Pio and Alo exerts protective effects on β-cells in diabetic db/db mice, at least in part, through the augmentation of IRS-2 expression.
Collapse
Affiliation(s)
- Hidenori Hirukawa
- Division of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki-city, Okayama 701-0192, Japan.
| | - Hideaki Kaneto
- Division of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki-city, Okayama 701-0192, Japan
| | - Masashi Shimoda
- Division of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki-city, Okayama 701-0192, Japan
| | - Tomohiko Kimura
- Division of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki-city, Okayama 701-0192, Japan
| | - Seizo Okauchi
- Division of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki-city, Okayama 701-0192, Japan
| | - Atsushi Obata
- Division of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki-city, Okayama 701-0192, Japan
| | - Kenji Kohara
- Division of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki-city, Okayama 701-0192, Japan
| | - Sumiko Hamamoto
- Division of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki-city, Okayama 701-0192, Japan
| | - Kazuhito Tawaramoto
- Division of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki-city, Okayama 701-0192, Japan
| | - Mitsuru Hashiramoto
- Division of Diabetes and Endocrinology, Yodogawa Christian Hospital, Osaka, Japan
| | - Kohei Kaku
- Division of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki-city, Okayama 701-0192, Japan; Department of General Internal Medicine 1, Kawasaki Hospital, Kawasaki Medical School, Okayama, Japan
| |
Collapse
|
30
|
Escribano O, Gómez-Hernández A, Díaz-Castroverde S, Nevado C, García G, Otero YF, Perdomo L, Beneit N, Benito M. Insulin receptor isoform A confers a higher proliferative capability to pancreatic beta cells enabling glucose availability and IGF-I signaling. Mol Cell Endocrinol 2015; 409:82-91. [PMID: 25797178 DOI: 10.1016/j.mce.2015.03.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 02/16/2015] [Accepted: 03/14/2015] [Indexed: 11/29/2022]
Abstract
The main compensatory response to insulin resistance is the pancreatic beta cell hyperplasia to account for increased insulin secretion. In fact, in a previous work we proposed a liver-pancreas endocrine axis with IGF-I (insulin-like growth factor type I) secreted by the liver acting on IRA insulin receptor in beta cells from iLIRKO mice (inducible Liver Insulin Receptor KnockOut) that showed a high IRA/IRB ratio. However, the role of insulin receptor isoforms in the IGF-I-induced beta cell proliferation as well as the underlying molecular mechanisms remain poorly understood. For this purpose, we have used four immortalized mouse beta cell lines: bearing IR (IRLoxP), lacking IR (IRKO), expressing exclusively IRA (IRA), or alternatively expressing IRB (IRB). Pancreatic beta cell proliferation studies showed that IRA cells are more sensitive than those expressing IRB to the mitogenic response induced by IGF-I, acting through the pathway IRA/IRS-1/2/αp85/Akt/mTORC1/p70S6K. More importantly, IRA beta cells, but not IRB, showed an increased glucose uptake as compared with IRLoxP cells, this effect being likely owing to an enhanced association between Glut-1 and Glut-2 with IRA. Overall, our results strongly suggest a prevalent role of IRA in glucose availability and IGF-I-induced beta cell proliferation mainly through mTORC1. These results could explain, at least partially, the role played by the liver-secreted IGF-I in the compensatory beta cell hyperplasia observed in response to severe hepatic insulin resistance in iLIRKO mice.
Collapse
Affiliation(s)
- Oscar Escribano
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain; Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain; Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain.
| | - Almudena Gómez-Hernández
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain; Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain; Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain
| | - Sabela Díaz-Castroverde
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain; Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain; Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain
| | - Carmen Nevado
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain; Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain; Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain
| | - Gema García
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain; Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain; Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain
| | - Yolanda F Otero
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain; Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain; Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain
| | - Liliana Perdomo
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain; Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain; Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain
| | - Nuria Beneit
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain; Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain; Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain
| | - Manuel Benito
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain; Health Research Institute of San Carlos Clinic Hospital (IdISSC), Madrid, Spain; Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain
| |
Collapse
|
31
|
Stewart AF, Hussain MA, García-Ocaña A, Vasavada RC, Bhushan A, Bernal-Mizrachi E, Kulkarni RN. Human β-cell proliferation and intracellular signaling: part 3. Diabetes 2015; 64:1872-85. [PMID: 25999530 PMCID: PMC4439562 DOI: 10.2337/db14-1843] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
This is the third in a series of Perspectives on intracellular signaling pathways coupled to proliferation in pancreatic β-cells. We contrast the large knowledge base in rodent β-cells with the more limited human database. With the increasing incidence of type 1 diabetes and the recognition that type 2 diabetes is also due in part to a deficiency of functioning β-cells, there is great urgency to identify therapeutic approaches to expand human β-cell numbers. Therapeutic approaches might include stem cell differentiation, transdifferentiation, or expansion of cadaver islets or residual endogenous β-cells. In these Perspectives, we focus on β-cell proliferation. Past Perspectives reviewed fundamental cell cycle regulation and its upstream regulation by insulin/IGF signaling via phosphatidylinositol-3 kinase/mammalian target of rapamycin signaling, glucose, glycogen synthase kinase-3 and liver kinase B1, protein kinase Cζ, calcium-calcineurin-nuclear factor of activated T cells, epidermal growth factor/platelet-derived growth factor family members, Wnt/β-catenin, leptin, and estrogen and progesterone. Here, we emphasize Janus kinase/signal transducers and activators of transcription, Ras/Raf/extracellular signal-related kinase, cadherins and integrins, G-protein-coupled receptors, and transforming growth factor β signaling. We hope these three Perspectives will serve to introduce these pathways to new researchers and will encourage additional investigators to focus on understanding how to harness key intracellular signaling pathways for therapeutic human β-cell regeneration for diabetes.
Collapse
Affiliation(s)
- Andrew F Stewart
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Mehboob A Hussain
- Departments of Medicine and Pediatrics, Johns Hopkins School of Medicine, Baltimore, MD
| | - Adolfo García-Ocaña
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Rupangi C Vasavada
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Anil Bhushan
- Diabetes Center, University of California, San Francisco, San Francisco, CA
| | - Ernesto Bernal-Mizrachi
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, and VA Ann Arbor Healthcare System, Ann Arbor, MI
| | - Rohit N Kulkarni
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA
| |
Collapse
|
32
|
Oh YS. Mechanistic insights into pancreatic beta-cell mass regulation by glucose and free fatty acids. Anat Cell Biol 2015; 48:16-24. [PMID: 25806118 PMCID: PMC4371177 DOI: 10.5115/acb.2015.48.1.16] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Accepted: 02/04/2015] [Indexed: 01/14/2023] Open
Abstract
Pancreatic islets are responsible for blood glucose homeostasis. Reduced numbers of functional (insulin-secreting) beta-cells in pancreatic islets underlies diabetes. Restoration of the secretion of the proper amount of insulin is a goal. Beta-cell mass is increased by neogenesis, proliferation and cell hypertrophy, and is decreased by beta-cell death primarily through apoptosis. Many hormones and nutrients affect beta-cell mass, and glucose and free fatty acid are thought to be the most important determinants of beta-cell equilibrium. A number of molecular pathways have been implicated in beta-cell mass regulation and have been studied. This review will focus on the role of the principle metabolites, glucose and free fatty acid, and the downstream signaling pathways regulating beta-cell mass by these metabolites.
Collapse
Affiliation(s)
- Yoon Sin Oh
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea. ; Gachon Medical Research Institute, Gil Hospital, Incheon, Korea
| |
Collapse
|
33
|
Human fetal liver stromal cell co-culture enhances the differentiation of pancreatic progenitor cells into islet-like cell clusters. Stem Cell Rev Rep 2014; 10:280-94. [PMID: 24395006 DOI: 10.1007/s12015-013-9491-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Recent advance in directed differentiation of pancreatic stem cells offers potential to the development of replacement therapy for diabetic patients. However, the existing differentiation protocols are complex, time-consuming, and costly; thus there is a need for alternative protocols. Given the common developmental origins of liver and pancreas, we sought to develop a novel protocol, devoid of growth factors, by using liver stromal cells (LSCs) derived from human fetal liver. We examined the effects of the LSCs on the differentiation of pancreatic progenitor cells (PPCs) into islet-like cell clusters (ICCs). PPCs and LSCs isolated from 1st to 2nd trimester human fetal tissues underwent co-cultures; differentiation and functionality of ICCs were determined by examining expression of critical markers and secretion of insulin. Co-culture with 2nd but not 1st trimester LSCs enhanced ICC differentiation and functionality without the use of exogenous differentiation 'cocktails'. Differential expression profiles of growth factors from 1st versus 2nd trimester fetal liver were compared. Many morphogenic factors were expressed by LSCs, while insulin-like growth factor 1 (IGF1) was identified as one of the key molecules responsible for the ICC differentiation. This is the first report showing that an LSC-induced microenvironment can enhance ICC differentiation and functionality. Further modifications of the stroma microenvironment may offer an alternative, efficient and cost-effective approach to providing islets for transplantation.
Collapse
|
34
|
Schvartz D, Couté Y, Sanchez JC. Quantitative proteomics reveals the link between minichromosome maintenance complex and glucose-induced proliferation of rat pancreatic INS-1E β-cells. J Proteomics 2014; 108:163-70. [DOI: 10.1016/j.jprot.2014.05.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 05/16/2014] [Accepted: 05/19/2014] [Indexed: 12/21/2022]
|
35
|
Alismail H, Jin S. Microenvironmental stimuli for proliferation of functional islet β-cells. Cell Biosci 2014; 4:12. [PMID: 24594290 PMCID: PMC3974598 DOI: 10.1186/2045-3701-4-12] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 01/29/2014] [Indexed: 12/31/2022] Open
Abstract
Diabetes is characterized by high blood glucose level due to either autoimmune destruction of islet β-cells or insufficient insulin secretion or glucose non-responsive production of insulin by β-cells. It is highly desired to replace biological functional β-cells for the treatment of diabetes. Unfortunately, β-cells proliferate with an extremely low rate. This cellular property hinders cell-based therapy for clinical application. Many attempts have been made to develop techniques that allow production of large quantities of clinically relevant islet β-cells in vitro. A line of studies evidently demonstrate that β-cells can proliferate under certain circumstances, giving the hopes for generating and expanding these cells in vitro and transplanting them to the recipient. In this review, we discuss the requirements of microenvironmental stimuli that stimulate β-cell proliferation in cell cultures. We highlight advanced approaches for augmentation of β-cell expansion that have recently emerged in this field. Furthermore, knowing the signaling pathways and molecular mechanisms would enable manipulating cell proliferation and optimizing its insulin secretory function. Thus, signaling pathways involved in the enhancement of cell proliferation are discussed as well.
Collapse
Affiliation(s)
| | - Sha Jin
- Department of Bioengineering, Thomas J, Watson School of Engineering and Applied Sciences, State University of New York in Binghamton, Binghamton, NY 13902, USA.
| |
Collapse
|
36
|
Huang Y, Chang Y. Regulation of pancreatic islet beta-cell mass by growth factor and hormone signaling. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 121:321-49. [PMID: 24373242 DOI: 10.1016/b978-0-12-800101-1.00010-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Dysfunction and destruction of pancreatic islet beta cells is a hallmark of diabetes. Better understanding of cellular signals in beta cells will allow development of therapeutic strategies for diabetes, such as preservation and expansion of beta-cell mass and improvement of beta-cell function. During the past several decades, the number of studies analyzing the molecular mechanisms, including growth factor/hormone signaling pathways that impact islet beta-cell mass and function, has increased exponentially. Notably, somatolactogenic hormones including growth hormone (GH), prolactin (PRL), and insulin-like growth factor-1 (IGF-1) and their receptors (GHR, PRLR, and IGF-1R) are critically involved in beta-cell growth, survival, differentiation, and insulin secretion. In this chapter, we focus more narrowly on GH, PRL, and IGF-1 signaling, and GH-IGF-1 cross talk. We also discuss how these signaling aspects contribute to the regulation of beta-cell proliferation and apoptosis. In particular, our novel findings of GH-induced formation of GHR-JAK2-IGF-1R protein complex and synergistic effects of GH and IGF-1 on beta-cell signaling, proliferation, and antiapoptosis lead to a new concept that IGF-1R may serve as a proximal component of GH/GHR signaling.
Collapse
Affiliation(s)
- Yao Huang
- Department of Obstetrics and Gynecology, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA
| | - Yongchang Chang
- Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA
| |
Collapse
|
37
|
DeNardo BD, Holloway MP, Ji Q, Nguyen KT, Cheng Y, Valentine MB, Salomon A, Altura RA. Quantitative phosphoproteomic analysis identifies activation of the RET and IGF-1R/IR signaling pathways in neuroblastoma. PLoS One 2013; 8:e82513. [PMID: 24349301 PMCID: PMC3859635 DOI: 10.1371/journal.pone.0082513] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 10/24/2013] [Indexed: 12/20/2022] Open
Abstract
Neuroblastoma is an embryonal tumor of childhood with a heterogenous clinical presentation that reflects differences in activation of complex biological signaling pathways. Protein phosphorylation is a key component of cellular signal transduction and plays a critical role in processes that control cancer cell growth and survival. We used shotgun LC/MS to compare phosphorylation between a human MYCN amplified neuroblastoma cell line (NB10), modeling a resistant tumor, and a human neural precursor cell line (NPC), modeling a normal baseline neural crest cell. 2181 unique phosphorylation sites representing 1171 proteins and 2598 phosphopeptides were found. Protein kinases accounted for 6% of the proteome, with a predominance of tyrosine kinases, supporting their prominent role in oncogenic signaling pathways. Highly abundant receptor tyrosine kinase (RTK) phosphopeptides in the NB10 cell line relative to the NPC cell line included RET, insulin-like growth factor 1 receptor/insulin receptor (IGF-1R/IR), and fibroblast growth factor receptor 1 (FGFR1). Multiple phosphorylated peptides from downstream mediators of the PI3K/AKT/mTOR and RAS pathways were also highly abundant in NB10 relative to NPC. Our analysis highlights the importance of RET, IGF-1R/IR and FGFR1 as RTKs in neuroblastoma and suggests a methodology that can be used to identify potential novel biological therapeutic targets. Furthermore, application of this previously unexploited technology in the clinic opens the possibility of providing a new wide-scale molecular signature to assess disease progression and prognosis.
Collapse
Affiliation(s)
- Bradley D. DeNardo
- Division of Pediatric Hematology-Oncology, Department of Pediatrics, The Warren Albert School of Medicine at Brown University, Providence, Rhode Island, United States of America
| | - Michael P. Holloway
- Division of Pediatric Hematology-Oncology, Department of Pediatrics, The Warren Albert School of Medicine at Brown University, Providence, Rhode Island, United States of America
| | - Qinqin Ji
- Department of Chemistry, Brown University, Providence, Rhode Island, United States of America
| | - Kevin T. Nguyen
- Division of Pediatric Hematology-Oncology, Department of Pediatrics, The Warren Albert School of Medicine at Brown University, Providence, Rhode Island, United States of America
| | - Yan Cheng
- Division of Pediatric Hematology-Oncology, Department of Pediatrics, The Warren Albert School of Medicine at Brown University, Providence, Rhode Island, United States of America
| | - Marcus B. Valentine
- St. Jude Comprehensive Cancer Center Cytogenetic Shared Resource, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Arthur Salomon
- Department of Molecular and Cellular Biochemistry, Brown University, Providence, Rhode Island, United States of America
| | - Rachel A. Altura
- Division of Pediatric Hematology-Oncology, Department of Pediatrics, The Warren Albert School of Medicine at Brown University, Providence, Rhode Island, United States of America
| |
Collapse
|
38
|
Oh YS, Lee YJ, Park K, Choi HH, Yoo S, Jun HS. Treatment with glucokinase activator, YH-GKA, increases cell proliferation and decreases glucotoxic apoptosis in INS-1 cells. Eur J Pharm Sci 2013; 51:137-45. [PMID: 24056026 DOI: 10.1016/j.ejps.2013.09.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 08/31/2013] [Accepted: 09/09/2013] [Indexed: 12/17/2022]
Abstract
Glucokinase (GK), an enzyme that phosphorylates glucose to form glucose-6-phosphate, has a role in regulating insulin secretion and proliferation in beta cells. GK activators (GKAs) have been developed as new therapies for type 2 diabetes. In this study, we evaluated the proliferation and anti-apoptotic actions of YH-GKA, a novel and potent GKA, in INS-1 pancreatic β-cells. YH-GKA treatment increased cell numbers at 3 mM glucose via upregulation of insulin receptor substrate-2 and subsequent activation of AKT/protein kinase B phosphorylation. YH-GKA also increased beta-catenin and cyclin D2 mRNA expression and inactivated GSK3β by increasing phosphorylation. These proliferative effects of YH-GKA were attenuated by IRS-2 downregulation. Moreover, YH-GKA reduced annexin-V-stained cells and expression levels of cleaved poly (ADP-ribose) polymerase and caspase-3 induced by glucotoxicity. YH-GKA inhibited apoptotic signaling via induction of ATP content, mitochondrial membrane potential, and citrate synthase activity and was correlated with changes of the mitochondrial function-related genes. YH-GKA also increased interaction between GK and voltage-dependent anion-selective channel protein. Our results suggest that the novel GKA, YH-GKA, promotes beta cell growth and prevents glucotoxic beta cell apoptosis. Therefore, YH-GKA may provide a therapy that compensates for beta cell loss in patients with type 2 diabetes.
Collapse
Affiliation(s)
- Yoon Sin Oh
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, 7-45 Songdo-dong, Yeonsu-ku, Incheon, Republic of Korea; Gachon Medical Research Institute, Gil Hospital, 1198, Guwol-dong, Namdong-Gu, Incheon, Republic of Korea
| | | | | | | | | | | |
Collapse
|
39
|
Xiao X, Wiersch J, El-Gohary Y, Guo P, Prasadan K, Paredes J, Welsh C, Shiota C, Gittes GK. TGFβ receptor signaling is essential for inflammation-induced but not β-cell workload-induced β-cell proliferation. Diabetes 2013; 62:1217-26. [PMID: 23248173 PMCID: PMC3609557 DOI: 10.2337/db12-1428] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Protection and restoration of a functional β-cell mass are fundamental strategies for prevention and treatment of diabetes. Consequently, knowledge of signals that determine the functional β-cell mass is of immense clinical relevance. Transforming growth factor β (TGFβ) superfamily signaling pathways play a critical role in development and tissue specification. Nevertheless, the role of these pathways in adult β-cell homeostasis is not well defined. Here, we ablated TGFβ receptor I and II genes in mice undergoing two surgical β-cell replication models (partial pancreatectomy or partial duct ligation), representing two triggers for β-cell proliferation, increased β-cell workload and local inflammation, respectively. Our data suggest that TGFβ receptor signaling is necessary for baseline β-cell proliferation. By either provision of excess glucose or treatment with exogenous insulin, we further demonstrated that inflammation and increased β-cell workload are both stimulants for β-cell proliferation but are TGFβ receptor signaling dependent and independent, respectively. Collectively, by using a pancreas-specific TGFβ receptor-deleted mouse model, we have identified two distinct pathways that regulate adult β-cell proliferation. Our study thus provides important information for understanding β-cell proliferation during normal growth and in pancreatic diseases.
Collapse
Affiliation(s)
- Xiangwei Xiao
- Division of Pediatric Surgery, Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Sathanoori R, Olde B, Erlinge D, Göransson O, Wierup N. Cocaine- and amphetamine-regulated transcript (CART) protects beta cells against glucotoxicity and increases cell proliferation. J Biol Chem 2012; 288:3208-18. [PMID: 23250745 DOI: 10.1074/jbc.m112.437145] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cocaine- and amphetamine-regulated transcript (CART) is an islet peptide that promotes glucose-stimulated insulin secretion in beta cells via cAMP/PKA-dependent pathways. In addition, CART is a regulator of neuronal survival. In this study, we examined the effect of exogenous CART 55-102 on beta cell viability and dissected its signaling mechanisms. Evaluation of DNA fragmentation and chromatin condensation revealed that CART 55-102 reduced glucotoxicity-induced apoptosis in both INS-1 (832/13) cells and isolated rat islets. Glucotoxicity in INS-1 (832/13) cells also caused a 50% reduction of endogenous CART protein. We show that CART increased proliferation in INS-1 (832/13) cells, an effect that was blocked by PKA, PKB, and MEK1 inhibitors. In addition, CART induced phosphorylation of CREB, IRS, PKB, FoxO1, p44/42 MAPK, and p90RSK in INS-1 (832/13) cells and isolated rat islets, all key mediators of cell survival and proliferation. Thus, we demonstrate that CART 55-102 protects beta cells against glucotoxicity and promotes proliferation. Taken together our data point to the potential use of CART in therapeutic interventions targeted at enhancing functional beta cell mass and long-term insulin secretion in T2D.
Collapse
|
41
|
Blandino-Rosano M, Chen AY, Scheys JO, Alejandro EU, Gould AP, Taranukha T, Elghazi L, Cras-Méneur C, Bernal-Mizrachi E. mTORC1 signaling and regulation of pancreatic β-cell mass. Cell Cycle 2012; 11:1892-902. [PMID: 22544327 DOI: 10.4161/cc.20036] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The capacity of β cells to expand in response to insulin resistance is a critical factor in the development of type 2 diabetes. Proliferation of β cells is a major component for these adaptive responses in animal models. The extracellular signals responsible for β-cell expansion include growth factors, such as insulin, and nutrients, such as glucose and amino acids. AKT activation is one of the important components linking growth signals to the regulation of β-cell expansion. Downstream of AKT, tuberous sclerosis complex 1 and 2 (TSC1/2) and mechanistic target of rapamycin complex 1 (mTORC1) signaling have emerged as prime candidates in this process, because they integrate signals from growth factors and nutrients. Recent studies demonstrate the importance of mTORC1 signaling in β cells. This review will discuss recent advances in the understanding of how this pathway regulates β-cell mass and present data on the role of TSC1 in modulation of β-cell mass. Herein, we also demonstrate that deletion of Tsc1 in pancreatic β cells results in improved glucose tolerance, hyperinsulinemia and expansion of β-cell mass that persists with aging.
Collapse
Affiliation(s)
- Manuel Blandino-Rosano
- Department of Internal Medicine; Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center; Ann Arbor, MI, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Zumsteg A, Caviezel C, Pisarsky L, Strittmatter K, García-Echeverría C, Hofmann F, Christofori G. Repression of malignant tumor progression upon pharmacologic IGF1R blockade in a mouse model of insulinoma. Mol Cancer Res 2012; 10:800-9. [PMID: 22562956 DOI: 10.1158/1541-7786.mcr-11-0522] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
NVP-AEW541, a specific ATP-competitive inhibitor of the insulin-like growth factor-1 receptor (IGF1R) tyrosine kinase, has been reported to interfere with tumor growth in various tumor transplantation models. We have assessed the efficacy of NVP-AEW541 in repressing tumor growth and tumor progression in the Rip1Tag2 transgenic mouse model of pancreatic β-cell carcinogenesis. In addition, we have tested NVP-AEW541 in Rip1Tag2;RipIGF1R double-transgenic mice which show accelerated tumor growth and increased tumor malignancy compared with Rip1Tag2 single-transgenic mice. Previously, we have shown that high levels of IGF-2, a high-affinity ligand for IGF1R, are required for Rip1Tag2 tumor cell survival and tumor growth. Unexpectedly, treatment of Rip1Tag2 mice with NVP-AEW541 in prevention and intervention trials neither did affect tumor growth nor tumor cell proliferation and apoptosis. Yet, it significantly repressed progression to tumor malignancy, that is, the rate of the transition from differentiated adenoma to invasive carcinoma. Treatment of Rip1Tag2;RipIGF1R double-transgenic mice resulted in moderately reduced tumor volumes and increased rates of tumor cell apoptosis. Sustained expression of IGF-2 and of the IGF-2-binding form of insulin receptor (IR-A) in tumor cells suggests a compensatory role of IR-A upon IGF1R blockade. The results indicate that inhibition of IGF1R alone is not sufficient to efficiently block insulinoma growth and imply an overlapping role of IGF1R and insulin receptor in executing mitogenic and survival stimuli elicited by IGF-2. The reduction of tumor invasion upon IGF1R blockade on the other hand indicates a critical function of IGF1R signaling for the acquisition of a malignant phenotype.
Collapse
Affiliation(s)
- Adrian Zumsteg
- Institute of Biochemistry and Genetics, Department of Biomedicine, University of Basel, Mattenstrasse 28, Basel 4058, Switzerland
| | | | | | | | | | | | | |
Collapse
|
43
|
Doiron B, Hu W, Norton L, DeFronzo RA. Lentivirus shRNA Grb10 targeting the pancreas induces apoptosis and improved glucose tolerance due to decreased plasma glucagon levels. Diabetologia 2012; 55:719-28. [PMID: 22222503 DOI: 10.1007/s00125-011-2414-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 11/24/2011] [Indexed: 01/09/2023]
Abstract
AIMS/HYPOTHESIS The physiological significance of growth factor receptor-bound protein-10 (GRB10) in the pancreas is unclear. We hypothesised that GRB10 is involved in pancreatic apoptosis, as GRB10 binds with a family of cell-survival-related proteins implicated in apoptosis. METHODS Lentiviral vector small hairpin RNA (shRNA) targeting Grb10 was injected in vivo via an intraductal pancreatic route to target pancreatic tissues in adult mice, which were studied 2 weeks post-injection. RESULTS Using the TUNEL assay, we demonstrated for the first time that in vivo injection of lentivirus shRNA Grb10 directly into the adult mouse pancreas induced apoptosis in both exocrine and endocrine (alpha and beta) cells. This effect was more pronounced in alpha cells. Levels of the pro-apoptotic protein BCL2-interacting mediator of cell death (BIM) in islets was higher in lentivirus shRNA Grb10 than in lentivirus shRNA scramble mice. In the apoptotic pathway, BIM initiates apoptosis signalling, leading to activation of the caspase cascade. We propose that, when complexed with GRB10, BIM is inactive. On activation by stress signalling or, in the present study, following injection of lentivirus shRNA Grb10 into pancreas, BIM becomes unbound from GRB10 and activates the caspase cascade. Indeed, caspase-3 activity in islets was higher in the experimental than in the control group. Apoptosis induced by shRNA Grb10 resulted in a 34% decrease in fasting plasma glucagon. Mice injected with shRNA Grb10 had improved glucose tolerance despite reduced insulin secretion compared with shRNA scramble control mice. CONCLUSIONS/INTERPRETATION GRB10 is critically involved in alpha cell survival and, as a result, plays an important role in regulating basal glucagon secretion and glucose tolerance in adult mice.
Collapse
Affiliation(s)
- B Doiron
- Diabetes Division, University of Texas Health Science Center at San Antonio, Mail Code 7886, 7703 Floyd Curl Drive, San Antonio, TX 78299, USA.
| | | | | | | |
Collapse
|
44
|
Palau N, Rebuffat SA, Altirriba J, Piquer S, Hanzu FA, Gomis R, Barbera A. Role of IGFBP-3 in the regulation of β-cell mass during obesity: adipose tissue/β-cell cross talk. Endocrinology 2012; 153:177-87. [PMID: 22067319 DOI: 10.1210/en.2011-0181] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In obesity an increase in β-cell mass occurs to cope with the rise in insulin demand. This β-cell plasticity is essential to avoid the onset of hyperglycemia, although the molecular mechanisms that regulate this process remain unclear. This study analyzed the role of adipose tissue in the control of β-cell replication. Using a diet-induced model of obesity, we obtained conditioned media from three different white adipose tissue depots. Only in the adipose tissue depot surrounding the pancreas did the diet induce changes that led to an increase in INS1E cells and the islet replication rate. To identify the factors responsible for this proliferative effect, adipose tissue gene expression analysis was conducted by microarrays and quantitative RT-PCR. Of all the differentially expressed proteins, only the secreted ones were studied. IGF binding protein 3 (Igfbp3) was identified as the candidate for this effect. Furthermore, in the conditioned media, although the blockage of IGFBP3 led to an increase in the proliferation rate, the blockage of IGF-I receptor decreased it. Taken together, these data show that obesity induces specific changes in the expression profile of the adipose tissue depot surrounding the pancreas, leading to a decrease in IGFBP3 secretion. This decrease acts in a paracrine manner, stimulating the β-cell proliferation rate, probably through an IGF-I-dependent mechanism. This cross talk between the visceral-pancreatic adipose tissue and β-cells is a novel mechanism that participates in the control of β-cell plasticity.
Collapse
Affiliation(s)
- Nuria Palau
- Diabetes and Obesity Laboratory, Institut d'Investigations Biomediques August Pi i Sunyer, Rosselló 149-153, E-08036 Barcelona, Spain
| | | | | | | | | | | | | |
Collapse
|
45
|
Ranta F, Leveringhaus J, Theilig D, Schulz-Raffelt G, Hennige AM, Hildebrand DG, Handrick R, Jendrossek V, Bosch F, Schulze-Osthoff K, Häring HU, Ullrich S. Protein kinase C delta (PKCδ) affects proliferation of insulin-secreting cells by promoting nuclear extrusion of the cell cycle inhibitor p21Cip1/WAF1. PLoS One 2011; 6:e28828. [PMID: 22216119 PMCID: PMC3246440 DOI: 10.1371/journal.pone.0028828] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 11/15/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND High fat diet-induced hyperglycemia and palmitate-stimulated apoptosis was prevented by specific inhibition of protein kinase C delta (PKCδ) in β-cells. To understand the role of PKCδ in more detail the impact of changes in PKCδ activity on proliferation and survival of insulin-secreting cells was analyzed under stress-free conditions. METHODOLOGY AND PRINCIPAL FINDINGS Using genetic and pharmacological approaches, the effect of reduced and increased PKCδ activity on proliferation, apoptosis and cell cycle regulation of insulin secreting cells was examined. Proteins were analyzed by Western blotting and by confocal laser scanning microscopy. Increased expression of wild type PKCδ (PKCδWT) significantly stimulated proliferation of INS-1E cells with concomitant reduced expression and cytosolic retraction of the cell cycle inhibitor p21(Cip1/WAF1). This nuclear extrusion was mediated by PKCδ-dependent phosphorylation of p21(Cip1/WAF1) at Ser146. In kinase dead PKCδ (PKCδKN) overexpressing cells and after inhibition of endogenous PKCδ activity by rottlerin or RNA interference phosphorylation of p21(Cip1/WAF1) was reduced, which favored its nuclear accumulation and apoptotic cell death of INS-1E cells. Human and mouse islet cells express p21(Cip1/WAF1) with strong nuclear accumulation, while in islet cells of PKCδWT transgenic mice the inhibitor resides cytosolic. CONCLUSIONS AND SIGNIFICANCE These observations disclose PKCδ as negative regulator of p21(Cip1/WAF1), which facilitates proliferation of insulin secreting cells under stress-free conditions and suggest that additional stress-induced changes push PKCδ into its known pro-apoptotic role.
Collapse
Affiliation(s)
- Felicia Ranta
- Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Department of Internal Medicine, University of Tübingen, Tübingen, Germany
| | - Johannes Leveringhaus
- Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Department of Internal Medicine, University of Tübingen, Tübingen, Germany
| | - Dorothea Theilig
- Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Department of Internal Medicine, University of Tübingen, Tübingen, Germany
| | - Gabriele Schulz-Raffelt
- Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Department of Internal Medicine, University of Tübingen, Tübingen, Germany
| | - Anita M. Hennige
- Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Department of Internal Medicine, University of Tübingen, Tübingen, Germany
| | - Dominic G. Hildebrand
- Interfaculty Institute for Biochemistry (IFIB), University of Tübingen, Tübingen, Germany
| | - René Handrick
- Institute for Pharmaceutical Biotechnology, Biberach University of Applied Sciences, Biberach, Germany
| | | | - Fatima Bosch
- Center of Animal Biotechnology and Gene Therapy, Universita Autònoma Barcelona, Bellaterra and CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | - Klaus Schulze-Osthoff
- Interfaculty Institute for Biochemistry (IFIB), University of Tübingen, Tübingen, Germany
| | - Hans-Ulrich Häring
- Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Department of Internal Medicine, University of Tübingen, Tübingen, Germany
| | - Susanne Ullrich
- Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Department of Internal Medicine, University of Tübingen, Tübingen, Germany
- * E-mail:
| |
Collapse
|
46
|
Tsunekawa S, Demozay D, Briaud I, McCuaig J, Accili D, Stein R, Rhodes CJ. FoxO feedback control of basal IRS-2 expression in pancreatic β-cells is distinct from that in hepatocytes. Diabetes 2011; 60:2883-91. [PMID: 21933986 PMCID: PMC3198101 DOI: 10.2337/db11-0340] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Appropriate regulation of insulin receptor substrate 2 (IRS-2) expression in pancreatic β-cells is essential to adequately compensate for insulin resistance. In liver, basal IRS-2 expression is controlled via a temporal negative feedback of sterol regulatory element-binding protein 1 (SREBP-1) to antagonize transcription factors forkhead box class O (FoxO)1/FoxO3a at an insulin response element (IRE) on the IRS-2 promoter. The purpose of the study was to examine if a similar mechanism controlled IRS-2 expression in β-cells. RESEARCH DESIGN AND METHODS IRS-2 mRNA and protein expression, as well as IRS-2 gene promoter activity, were examined in isolated rat islets. Specific transcription factor association with the IRE on the IRS-2 promoter was examined by chromatin immunoprecipitation (ChIP) assay, and their nuclear translocation was examined by immunofluorescence. A direct in vivo effect of insulin on control of IRS-2 expression in liver and pancreatic islets was also investigated. RESULTS In IRS-2 promoter-reporter assays conducted in isolated islets, removal of the IRE decreased basal IRS-2 promoter activity in β-cells up to 80%. Activation of IRS signaling in isolated rat islets by insulin/IGF-I (used as an experimental in vitro tool) or downstream constitutive activation of protein kinase B (PKB) significantly decreased IRS-2 expression. In contrast, inhibition of phosphatidylinositol 3-kinase (PI3K) or PKB significantly increased IRS-2 levels in β-cells. ChIP assays indicated that transcription factors FoxO1 and FoxO3a associated with the IRE on the IRS-2 promoter in β-cells in a PI3K/PKB-dependent manner, whereas others, such as SREBP-1, the transcription factor binding to immunoglobulin heavy chain enhancer 3', and the aryl hydrocarbon receptor nuclear translocator (ARNT), did not. However, only FoxO3a, not FoxO1, was capable of driving IRS-2 promoter activity via the IRE in β-cells. In vivo studies showed insulin was able to suppress IRS-2 expression via activation of SREBP-1 in the liver, but this mechanism was not apparent in pancreatic islets from the same animal. CONCLUSIONS The molecular mechanism for feedback control of IRS signaling to decrease IRS-2 expression in liver and β-cells is quite distinct, with a predominant role played by FoxO3a in β-cells.
Collapse
Affiliation(s)
- Shin Tsunekawa
- Kovler Diabetes Center, Department of Medicine, University of Chicago, Chicago, Illinois
| | - Damien Demozay
- Kovler Diabetes Center, Department of Medicine, University of Chicago, Chicago, Illinois
| | | | - Jill McCuaig
- Kovler Diabetes Center, Department of Medicine, University of Chicago, Chicago, Illinois
| | - Domenico Accili
- Naomi Berrie Diabetes Center and Department of Medicine, Columbia University, New York City, New York
| | - Roland Stein
- Departments of Molecular Physiology and Biophysics and Cell Biology and Development, Vanderbilt University, Nashville, Tennessee
| | - Christopher J. Rhodes
- Kovler Diabetes Center, Department of Medicine, University of Chicago, Chicago, Illinois
- Corresponding author: Christopher J. Rhodes,
| |
Collapse
|
47
|
Gannon MC, Nuttall FQ. Effect of a high-protein diet on ghrelin, growth hormone, and insulin-like growth factor-I and binding proteins 1 and 3 in subjects with type 2 diabetes mellitus. Metabolism 2011; 60:1300-11. [PMID: 21406307 DOI: 10.1016/j.metabol.2011.01.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 01/19/2011] [Accepted: 01/29/2011] [Indexed: 01/12/2023]
Abstract
We have developed a diet that over 5 weeks dramatically lowers plasma glucose in people with type 2 diabetes mellitus. This diet consists of 30% carbohydrate, 30% protein, and 40% fat and is referred to as a Low Biologically Available Glucose (LoBAG) diet. The diet also resulted in an approximately 30% increase in fasting insulin-like growth factor-I (IGF-I). Thus, we were interested in determining if the IGF-I elevation was due to an increase in ghrelin and growth hormone (GH) or to a change in IGF-I binding proteins (IGFBPs). Eight men with type 2 diabetes mellitus ingested a control diet (15% protein, 55% carbohydrate, and 30% fat) and a LoBAG(30) diet for 5 weeks in a randomized crossover design with a washout period in between. Before and after each 5-week period, subjects had blood drawn for total glycated hemoglobin and, at several time points over 24 hours, for GH, IGF-I, IGFBP-1, IGFBP-3, ghrelin, glucose, and insulin. Fasting and 24-hour glucose concentrations and total glycated hemoglobin were decreased, as expected (all Ps < .05). Fasting IGF-I increased by approximately 30% (P = .05) and remained unchanged throughout 24 hours. Ghrelin, GH, IGFBP-1, IGFBP-3, and insulin were not different between diets. Insulin and IGFBP-1 concentrations were reciprocal, as expected. Insulin-like growth factor-I binding protein 1 decreased as insulin increased to greater than approximately 30 to 40 μU/mL. Ingestion of a LoBAG(30) diet by weight-stable subjects with type 2 diabetes mellitus resulted in an increase in total IGF-I without an increase in ghrelin, GH, and IGFBP-3 or a change in IGFBP-1 regulation. The mechanism remains to be determined.
Collapse
Affiliation(s)
- Mary Carol Gannon
- Section of Endocrinology, Metabolism and Nutrition and the Metabolic Research Laboratory, Minneapolis VA Medical Center, Minneapolis, MN 55417, USA.
| | | |
Collapse
|
48
|
Kang HM, Park S, Kim H. Insulin-like growth factor 2 enhances insulinogenic differentiation of human eyelid adipose stem cells via the insulin receptor. Cell Prolif 2011; 44:254-63. [PMID: 21535266 DOI: 10.1111/j.1365-2184.2011.00755.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
OBJECTIVES Previously, we have isolated stem cells (HEAC) from human eyelid adipose tissue and functionally differentiated them into insulin-secreting cells. In the present study, we examined whether insulin family members might influence insulinogenic differentiation of HEAC. MATERIALS AND METHODS Following culture in differentiation media containing insulin family member or not, cells were examined for gene expression, protein expression and, particularly, insulin and C-peptide secretion, in response to high glucose challenge. Using antibodies against the specific receptor, target receptor mediating effect of the insulin family member was investigated. RESULTS Insulin treatment during culture had little effect on either insulin or C-peptide secretion from HEAC, against high glucose challenge after culture. However, insulin-like growth factor (IGF) 1 treatment decreased both secretions, and interestingly, IGF2 greatly increased the secretions. HEAC treated with IGF2 had strong expression of Pdx1, Isl1, Pax6 and PC1/3 genes, and distinct staining after insulin and C-peptide antibodies, and dithizone. IGF2-enhanced insulinogenic differentiation was totally blocked by antibody against insulin receptor (IR), but not by anti-IGF1 receptor (IGF1R). Differentiated HEAC expressed both IR and IGF1R genes, whereas they expressed neither IGF2 nor IGF2R genes. CONCLUSIONS From these results, it is suggested that IGF1 might inhibit insulinogenic differentiation of HEAC, whereas IGF2 enhances differentiation, and that enhancement of IGF2 appeared to be mediated via IR.
Collapse
Affiliation(s)
- H M Kang
- Department of Biotechnology, Seoul Women's University, Kongnung-dong, Nowon-gu, Seoul, Korea
| | | | | |
Collapse
|
49
|
Meur G, Qian Q, da Silva Xavier G, Pullen TJ, Tsuboi T, McKinnon C, Fletcher L, Tavaré JM, Hughes S, Johnson P, Rutter GA. Nucleo-cytosolic shuttling of FoxO1 directly regulates mouse Ins2 but not Ins1 gene expression in pancreatic beta cells (MIN6). J Biol Chem 2011; 286:13647-56. [PMID: 21335550 PMCID: PMC3075709 DOI: 10.1074/jbc.m110.204248] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 02/14/2011] [Indexed: 01/26/2023] Open
Abstract
The Forkhead box transcription factor FoxO1 regulates metabolic gene expression in mammals. FoxO1 activity is tightly controlled by phosphatidylinositol 3-kinase (PI3K) signaling, resulting in its phosphorylation and nuclear exclusion. We sought here to determine the mechanisms involved in glucose and insulin-stimulated nuclear shuttling of FoxO1 in pancreatic β cells and its consequences for preproinsulin (Ins1, Ins2) gene expression. Nuclear-localized endogenous FoxO1 translocated to the cytosol in response to elevated glucose (3 versus 16.7 mM) in human islet β cells. Real-time confocal imaging of nucleo-cytosolic shuttling of a FoxO1-EGFP chimera in primary mouse and clonal MIN6 β cells revealed a time-dependent glucose-responsive nuclear export, also mimicked by exogenous insulin, and blocked by suppressing insulin secretion. Constitutively active PI3K or protein kinase B/Akt exerted similar effects, while inhibitors of PI3K, but not of glycogen synthase kinase-3 or p70 S6 kinase, blocked nuclear export. FoxO1 overexpression reversed the activation by glucose of pancreatic duodenum homeobox-1 (Pdx1) transcription. Silencing of FoxO1 significantly elevated the expression of mouse Ins2, but not Ins1, mRNA at 3 mM glucose. Putative FoxO1 binding sites were identified in the distal promoter of rodent Ins2 genes and direct binding of FoxO1 to the Ins2 promoter was demonstrated by chromatin immunoprecipitation. A 915-bp glucose-responsive Ins2 promoter was inhibited by constitutively active FoxO1, an effect unaltered by simultaneous overexpression of PDX1. We conclude that nuclear import of FoxO1 contributes to the suppression of Pdx1 and Ins2 gene expression at low glucose, the latter via a previously unsuspected and direct physical interaction with the Ins2 promoter.
Collapse
Affiliation(s)
- Gargi Meur
- From the Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Imperial College London, London SW7 2AZ, United Kingdom
| | - Qingwen Qian
- From the Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Imperial College London, London SW7 2AZ, United Kingdom
| | - Gabriela da Silva Xavier
- From the Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Imperial College London, London SW7 2AZ, United Kingdom
| | - Timothy J. Pullen
- From the Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Imperial College London, London SW7 2AZ, United Kingdom
| | - Takashi Tsuboi
- the Department of Life Sciences, University of Tokyo, Tokyo 153-8902, Japan
| | - Caroline McKinnon
- From the Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Imperial College London, London SW7 2AZ, United Kingdom
- the Henry Wellcome Laboratories for Integrated Cell Signalling and Department of Biochemistry, School of Medical Sciences, University Walk, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Laura Fletcher
- the Henry Wellcome Laboratories for Integrated Cell Signalling and Department of Biochemistry, School of Medical Sciences, University Walk, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Jeremy M. Tavaré
- the Henry Wellcome Laboratories for Integrated Cell Signalling and Department of Biochemistry, School of Medical Sciences, University Walk, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Stephen Hughes
- the Nuffield Department of Surgery, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom, and
| | - Paul Johnson
- the Nuffield Department of Surgery, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom, and
| | - Guy A. Rutter
- From the Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Imperial College London, London SW7 2AZ, United Kingdom
| |
Collapse
|
50
|
Bouzakri K, Plomgaard P, Berney T, Donath MY, Pedersen BK, Halban PA. Bimodal effect on pancreatic β-cells of secretory products from normal or insulin-resistant human skeletal muscle. Diabetes 2011; 60:1111-21. [PMID: 21378173 PMCID: PMC3064085 DOI: 10.2337/db10-1178] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
OBJECTIVE Type 2 diabetes is characterized by insulin resistance with a relative deficiency in insulin secretion. This study explored the potential communication between insulin-resistant human skeletal muscle and primary (human and rat) β-cells. RESEARCH DESIGN AND METHODS Human skeletal muscle cells were cultured for up to 24 h with tumor necrosis factor (TNF)-α to induce insulin resistance, and mRNA expression for cytokines was analyzed and compared with controls (without TNF-α). Conditioned media were collected and candidate cytokines were measured by antibody array. Human and rat primary β-cells were used to explore the impact of exposure to conditioned media for 24 h on apoptosis, proliferation, short-term insulin secretion, and key signaling protein phosphorylation and expression. RESULTS Human myotubes express and release a different panel of myokines depending on their insulin sensitivity, with each panel exerting differential effects on β-cells. Conditioned medium from control myotubes increased proliferation and glucose-stimulated insulin secretion (GSIS) from primary β-cells, whereas conditioned medium from TNF-α-treated insulin-resistant myotubes (TMs) exerted detrimental effects that were either independent (increased apoptosis and decreased proliferation) or dependent on the presence of TNF-α in TM (blunted GSIS). Knockdown of β-cell mitogen-activated protein 4 kinase 4 prevented these effects. Glucagon-like peptide 1 protected β-cells against decreased proliferation and apoptosis evoked by TMs, while interleukin-1 receptor antagonist only prevented the latter. CONCLUSIONS Taken together, these data suggest a possible new route of communication between skeletal muscle and β-cells that is modulated by insulin resistance and could contribute to normal β-cell functional mass in healthy subjects, as well as the decrease seen in type 2 diabetes.
Collapse
Affiliation(s)
- Karim Bouzakri
- Department of Genetic Medicine and Development, University Medical Center, University of Geneva, Geneva, Switzerland.
| | | | | | | | | | | |
Collapse
|