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The Association between Depression and Type 1 Diabetes Mellitus: Inflammatory Cytokines as Ferrymen in between? Mediators Inflamm 2019; 2019:2987901. [PMID: 31049023 PMCID: PMC6458932 DOI: 10.1155/2019/2987901] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 02/14/2019] [Indexed: 12/16/2022] Open
Abstract
The depression incidence is much higher in patients with diabetes mellitus (DM), and the majority of these cases remain under-diagnosed. Type 1 diabetes mellitus (T1D) is now widely thought to be an organ-specific autoimmune disease. As a chronic autoimmune condition, T1D is characterized by T cell-mediated selective loss of insulin-producing β-cells. The age of onset of T1D is earlier than T2D, and T1D patients have an increased vulnerability to depression due to its diagnosis and treatment burden occurring in a period when the individuals are young. The literature has suggested that inflammatory cytokines play a wide role in both diseases. In this review, the mechanisms behind the initiation and propagation of the autoimmune response in T1D and depression are analyzed, and the contribution of cytokines to both conditions is discussed. This review outlines the immunological mechanism of T1D and depression, with a particular emphasis on the role of tumor necrosis factor-α (TNF-α), IL-1β, and interferon-γ (IFN-γ) cytokines and their signaling pathways. The purpose of this review is to highlight the possible pathways of the cytokines shared by these two diseases via deciphering their cytokine cascades. They may provide a basic groundwork for future study of the possible mechanism that links these two diseases and to develop new compounds that target the same pathway but can conquer two diseases.
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Niu B, Li C, Su H, Li Q, He Q, Liu L, Xue Y, Shen T, Xia X. Glucagon-like peptide-1 receptor agonist exendin-4 protects against interleukin-1β-mediated inhibition of glucose-stimulated insulin secretion by mouse insulinoma β cells. Exp Ther Med 2017; 14:2671-2676. [PMID: 28947919 DOI: 10.3892/etm.2017.4803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Accepted: 11/04/2016] [Indexed: 01/01/2023] Open
Abstract
The aim of the present study was to investigate the protective effect of the glucagon-like peptide-1 receptor agonist exendin-4 on the interleukin (IL)-1β-induced impairment of glucose-stimulated insulin secretion (GSIS) in β-TC-6 cells. β-TC-6 cells were pretreated with various concentrations of IL-1β (0.15, 1.5 or 15 ng/ml) and exendin-4 (0.1 or 1 mM). Exendin-4 was administered to β-TC-6 cells prior to, during and following pretreatment. Cells were stimulated with various concentrations of glucose (0, 1.38, 5.5 and 11.1 mM), and insulin was measured via radioimmunoassay of the supernatant; furthermore, western blot analysis was used to detect phosphorylated extracellular receptor kinase (ERK)1/2. The insulin levels (151.08±14.34 µIU/ml) and ERK1/2 phosphorylation in β-TC-6 cells peaked in response to 1.38 mM glucose stimulation compared with 0, 5.5 and 11.1 mM glucose stimulation. IL-1β inhibited GSIS in a dose-dependent manner: Insulin levels were 83.76±1.16 µIU/ml when 0.15 ng/ml IL-1β was added under GSIS, 59.46±3.20 µIU/ml when 1.5 ng/ml IL-1β was added under GSIS, and 56.98±1.19 µIU/ml when 15 ng/ml IL-1β was added under GSIS. Exendin-4 exerted a protective effect against IL-1β-induced GSIS inhibition in a dose-dependent manner. The greatest protective effect was observed when exendin-4 was added prior to IL-1β pretreatment, which was statistically significant (P<0.05). These findings suggested that exendin-4 was able to reverse the IL-1β-induced inhibition of ERK1/2 phosphorylation and serves a protective role by impairing GSIS induced by IL-1β in β-TC-6 cells. This mechanism may be associated with the recovery of ERK1/2 activation.
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Affiliation(s)
- Ben Niu
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, P.R. China.,Department of Endocrinology, The Affiliated Hospital of Kunming University of Science and Technology, The First People's Hospital of Yunnan, Kunming, Yunnan 650032, P.R. China
| | - Chao Li
- Department of Emergency Medicine, The People's Hospital of Yuxi City, Yuxi, Yunnan 653100, P.R. China
| | - Heng Su
- Department of Endocrinology, The Affiliated Hospital of Kunming University of Science and Technology, The First People's Hospital of Yunnan, Kunming, Yunnan 650032, P.R. China
| | - Qingzhu Li
- Department of Endocrinology, The Affiliated Hospital of Kunming University of Science and Technology, The First People's Hospital of Yunnan, Kunming, Yunnan 650032, P.R. China
| | - Qiu He
- Department of Endocrinology, The Affiliated Hospital of Kunming University of Science and Technology, The First People's Hospital of Yunnan, Kunming, Yunnan 650032, P.R. China
| | - Lijuan Liu
- Department of Cadre Ward, WISCO General Hospital, Wuhan, Hubei 430080, P.R. China
| | - Yuanming Xue
- Department of Endocrinology, The Affiliated Hospital of Kunming University of Science and Technology, The First People's Hospital of Yunnan, Kunming, Yunnan 650032, P.R. China
| | - Tao Shen
- Institute of Basic and Clinical Medicine, Center of Clinical Molecular Biology of Yunnan, Affiliated Hospital of Kunming University of Science and Technology, First People's Hospital of Yunnan, Kunming, Yunnan 650032, P.R. China
| | - Xueshan Xia
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan 650500, P.R. China
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Abstract
In 1974, the discovery of a mouse and a rat that spontaneously developed hyperglycemia led to the development of 2 autoimmune diabetes models: nonobese diabetic (NOD) mouse and Bio-Breeding rat. These models have contributed to our understanding of autoimmune diabetes, provided tools to dissect autoimmune islet damage, and facilitated development of early detection, prevention, and treatment of type 1 diabetes. The genetic characterization, monoclonal antibodies, and congenic strains have made NOD mice especially useful.Although the establishment of the inbred NOD mouse strain was documented by Makino et al (Jikken Dobutsu. 1980;29:1-13), this review will focus on the not-as-well-known history leading to the discovery of a glycosuric female mouse by Yoshihiro Tochino. This discovery was spearheaded by years of effort by Japanese scientists from different disciplines and dedicated animal care personnel and by the support of the Shionogi Pharmaceutical Company, Osaka, Japan. The history is based on the early literature, mostly written in Japanese, and personal communications especially with Dr Tochino, who was involved in diabetes animal model development and who contributed to the release of NOD mice to the international scientific community. This article also reviews the scientific contributions made by the Bio-Breeding rat to autoimmune diabetes.
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Baena-Nieto G, Lomas-Romero IM, Mateos RM, Leal-Cosme N, Perez-Arana G, Aguilar-Diosdado M, Segundo C, Lechuga-Sancho AM. Ghrelin mitigates β-cell mass loss during insulitis in an animal model of autoimmune diabetes mellitus, the BioBreeding/Worcester rat. Diabetes Metab Res Rev 2017; 33. [PMID: 27103341 DOI: 10.1002/dmrr.2813] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 03/06/2016] [Accepted: 04/07/2016] [Indexed: 12/24/2022]
Abstract
BACKGROUND Ghrelin is a peptide hormone with pleiotropic effects. It stimulates cell proliferation and inhibits apoptosis-mediated cell death. It prevents diabetes mellitus in several models of chemical, surgical and biological toxic insults to pancreas in both in vivo and in vitro models and promotes glucose-stimulated insulin secretion under cytotoxic conditions. It has not yet been tested in vivo in an autoimmune model of diabetes with a persistent insult to the β-cell. Given the immunomodulating effects of ghrelin and its trophic effects on β-cells, we hypothesized that ghrelin treatment during the early stages of insulitis would delay diabetes onset. METHODS BioBreeding/Worcester male rats received ghrelin (10 ng/kg/day) before insulitis development. Glucose metabolism was characterized by glucose and insulin tolerance tests. β-cell mass, islet area, islet number, β-cell clusters, proliferation and apoptosis and degree of insulitis were analysed by histomorphometry. A Kaplan-Meier survival curve was plotted and analysed applying the log-rank (Mantel-Cox) test. RESULTS Ghrelin treatment significantly reduced the probability of developing diabetes in our model (p < 0.0001). It decreased islet infiltration and partially prevented β-cell mass loss, enabling the maintenance of β-cell neogenesis and proliferation rates. Furthermore, ghrelin treatment did not induce any metabolic perturbations. CONCLUSIONS These findings support the hypothesis that ghrelin delays the development of autoimmune diabetes by attenuating insulitis and supporting β-cell mass. GENERAL SIGNIFICANCE Ghrelin promotes β-cell viability and function through diverse mechanisms that may have significant implications for diabetes prevention, therapy and also transplant success of both islets and complete pancreas. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Gloria Baena-Nieto
- Department of Endocrinology and Nutrition, Puerta del Mar University Hospital, Cadiz, Spain
- Research Unit, Puerta del Mar University Hospital, Cadiz, Spain
| | - Isabel M Lomas-Romero
- Research Unit, Puerta del Mar University Hospital, Cadiz, Spain
- Andalusian Cellular Reprogramming Laboratory, Sevilla, Spain
| | - Rosa M Mateos
- Research Unit, Puerta del Mar University Hospital, Cadiz, Spain
- Department of Biotechnology, Biomedicine and Public Health, Cadiz University Medical School, Cadiz, Spain
| | - Noelia Leal-Cosme
- Department of Child and Mother Health and Radiology, Cadiz University Medical School, Cadiz, Spain
| | | | | | - Carmen Segundo
- "Salus Infirmorum" Faculty of Nursing, Cadiz University, Cadiz, Spain
| | - Alfonso M Lechuga-Sancho
- Research Unit, Puerta del Mar University Hospital, Cadiz, Spain
- Department of Child and Mother Health and Radiology, Cadiz University Medical School, Cadiz, Spain
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Berchtold LA, Prause M, Størling J, Mandrup-Poulsen T. Cytokines and Pancreatic β-Cell Apoptosis. Adv Clin Chem 2016; 75:99-158. [PMID: 27346618 DOI: 10.1016/bs.acc.2016.02.001] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The discovery 30 years ago that inflammatory cytokines cause a concentration, activity, and time-dependent bimodal response in pancreatic β-cell function and viability has been a game-changer in the fields of research directed at understanding inflammatory regulation of β-cell function and survival and the causes of β-cell failure and destruction in diabetes. Having until then been confined to the use of pathophysiologically irrelevant β-cell toxic chemicals as a model of β-cell death, researchers could now mimic endocrine and paracrine effects of the cytokine response in vitro by titrating concentrations in the low to the high picomolar-femtomolar range and vary exposure time for up to 14-16h to reproduce the acute regulatory effects of systemic inflammation on β-cell secretory responses, with a shift to inhibition at high picomolar concentrations or more than 16h of exposure to illustrate adverse effects of local, chronic islet inflammation. Since then, numerous studies have clarified how these bimodal responses depend on discrete signaling pathways. Most interest has been devoted to the proapoptotic response dependent upon mainly nuclear factor κ B and mitogen-activated protein kinase activation, leading to gene expressional changes, endoplasmic reticulum stress, and triggering of mitochondrial dysfunction. Preclinical studies have shown preventive effects of cytokine antagonism in animal models of diabetes, and clinical trials demonstrating proof of concept are emerging. The full clinical potential of anticytokine therapies has yet to be shown by testing the incremental effects of appropriate dosing, timing, and combinations of treatments. Due to the considerable translational importance of enhancing the precision, specificity, and safety of antiinflammatory treatments of diabetes, we review here the cellular, preclinical, and clinical evidence of which of the death pathways recently proposed in the Nomenclature Committee on Cell Death 2012 Recommendations are activated by inflammatory cytokines in the pancreatic β-cell to guide the identification of antidiabetic targets. Although there are still scarce human data, the cellular and preclinical studies point to the caspase-dependent intrinsic apoptosis pathway as the prime effector of inflammatory β-cell apoptosis.
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Affiliation(s)
| | - M Prause
- University of Copenhagen, Copenhagen, Denmark
| | - J Størling
- Copenhagen Diabetes Research Center, Beta Cell Biology Group, Copenhagen University Hospital Herlev, Herlev, Denmark
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Ogbourne SM, Parsons PG. The value of nature's natural product library for the discovery of New Chemical Entities: the discovery of ingenol mebutate. Fitoterapia 2014; 98:36-44. [PMID: 25016953 DOI: 10.1016/j.fitote.2014.07.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 07/03/2014] [Accepted: 07/04/2014] [Indexed: 11/15/2022]
Abstract
In recent decades, 'Big Pharma' has invested billions of dollars into ingenious and innovative strategies designed to develop drugs using high throughput screening of small molecule libraries generated on the laboratory bench. Within the same time frame, screening of natural products by pharmaceutical companies has suffered an equally significant reduction. This is despite the fact that the complexity, functional diversity and druggability of nature's natural product library are considered by many to be superior to any library any team of scientists can prepare. It is therefore no coincidence that the number of New Chemical Entities reaching the market has also suffered a substantial decrease, leading to a productivity crisis within the pharmaceutical sector. In fact, the current dearth of New Chemical Entities reaching the market in recent decades might be a direct consequence of the strategic decision to move away from screening of natural products. Nearly 700 novel drugs derived from natural product New Chemical Entities were approved between 1981 and 2010; more than 60% of all approved drugs over the same time. In this review, we use the example of ingenol mebutate, a natural product identified from Euphorbia peplus and later approved as a therapy for actinic keratosis, as why nature's natural product library remains the most valuable library for discovery of New Chemical Entities and of novel drug candidates.
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Affiliation(s)
- Steven M Ogbourne
- GeneCology Research Centre, Faculty of Science, Health, Engineering and Education, University of the Sunshine Coast, Maroochydore DC, QLD 4558, Australia.
| | - Peter G Parsons
- QIMR Berghofer Medical Research Institute, Locked Bag 2000, Post Office Royal Brisbane Hospital, QLD 4029, Australia.
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Liu XH, Wang YP, Wang LX, Chen Z, Liu XY, Liu LB. Exendin-4 protects murine MIN6 pancreatic β-cells from interleukin-1β-induced apoptosis via the NF-κB pathway. J Endocrinol Invest 2013; 36:803-11. [PMID: 23609920 DOI: 10.3275/8938] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Glucagon-like peptide-1 (GLP-1) and its potent analog, exendin-4, are well known to inhibit β- cell apoptosis and promote β-cell proliferation. Meanwhile, cytokines, such as interleukin-1β (IL-1β), stimulate inducible nitric oxide synthase (iNOS) expression and nitric oxide overproduction leading to β-cell damage. However, the protective mechanisms of GLP-1 in β-cells exposed to cytokines have not been fully elucidated. AIMS In this study, the protective effects of exendin-4 on IL-1β-induced apoptosis were investigated in murine MIN6 pancreatic β-cells. The role of nuclear factor-κB (NF-κB) signaling in this process was also explored. METHODS The effects of exendin-4 pre-treatment on IL-1β-induced apoptosis were investigated by Hoechst/PI and Annexin V/PI staining. Levels of iNOS and NF-κB proteins were investigated by Western blotting and cytoplasmic nitrite levels were determined using Griess reagent. RESULTS IL-1β treatment (range, 5-40 ng/ml) for 24 h was positively correlated with nitrite production (R2=0.9668, p<0.01), a significant increase in the percentage of apoptotic cells (p<0.01) and a concomitant dose-dependent increase in cytoplasmic levels of iNOS and NF-κB p65 activation. N-acetyl- L-cysteine (NAC), NG-nitro-L-arginine methyl ester (L-NAME) and pyrrolidine dithiocarbamate (PDTC), partially rescued apoptotic β-cells, suggesting involvement of NF-κB-iNOS-nitrite in this process. Exendin-4 (100 nM) treatment significantly decreased IL-1β-induced apoptosis (p<0.01), downregulated NF-κB activation and subsequently decreased iNOS and nitrite levels in IL-1β-induced β-cells (p<0.001), in a similar manner to L-NAME, PDTC and NAC. CONCLUSIONS These results suggest that exendin-4 protects against IL-1β- induced apoptosis in β-cells via downregulation of the NF- κB-iNOS-nitrite pathway.
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Affiliation(s)
- X H Liu
- Department of Endocrinology, Fujian Institute of Endocrinology, Union Hospital of Fujian Medical University, 29 Xinquan Road, Fuzhou, Fujian 350001, People's Republic of China
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Nitric oxide is a mediator of antiproliferative effects induced by proinflammatory cytokines on pancreatic beta cells. Mediators Inflamm 2013; 2013:905175. [PMID: 23840099 PMCID: PMC3694487 DOI: 10.1155/2013/905175] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 05/21/2013] [Accepted: 05/23/2013] [Indexed: 01/02/2023] Open
Abstract
Nitric oxide (NO) is involved in several biological processes. In type 1 diabetes mellitus (T1DM), proinflammatory cytokines activate an inducible isoform of NOS (iNOS) in β cells, thus increasing NO levels and inducing apoptosis. The aim of the current study is to determine the role of NO (1) in the antiproliferative effect of proinflammatory cytokines IL-1β, IFN-γ, and TNF-α on cultured islet β cells and (2) during the insulitis stage prior to diabetes onset using the Biobreeding (BB) rat strain as T1DM model. Our results indicate that NO donors exert an antiproliferative effect on β cell obtained from cultured pancreatic islets, similar to that induced by proinflammatory cytokines. This cytokine-induced antiproliferative effect can be reversed by L-NMMA, a general NOS inhibitor, and is independent of guanylate cyclase pathway. Assays using NOS isoform specific inhibitors suggest that the NO implicated in the antiproliferative effect of proinflammatory cytokines is produced by inducible NOS, although not in an exclusive way. In BB rats, early treatment with L-NMMA improves the initial stage of insulitis. We conclude that NO is an important mediator of antiproliferative effect induced by proinflammatory cytokines on cultured β cell and is implicated in β-cell proliferation impairment observed early from initial stage of insulitis.
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Abstract
Unfortunately, the only approved medical treatment for type 1 diabetes mellitus (DM) is insulin, despite the fact that tight control cannot be reached without some serious side effects such as hypoglycemia and weight gain. More and more importance is now shifted towards developing new drugs that can reach a better glycemic control with lesser side effects. Some of these promising drugs are the glucagon-like peptides 1 (GLP-1) and their agonists, which have been FDA approved for the treatment of type 2 DM. The purpose of this article is to review all of the relevant literature on the potential role of GLP-1 in the treatment of type 1 DM. The major source of data acquisition included Medline search strategies, using the words "type 1 diabetes mellitus" and "GLP-1." Articles published in the last 20 years were screened. GLP-1 increases insulin secretion in humans with existing beta cells; it also decreases glucagon secretion, and blunts appetite. Of note, new animal studies demonstrate a role in beta cell-proliferation and decreased apoptosis. Because of all the effects mentioned above, GLP-1 seems to be a promising drug for type 1 DM treatment, but more studies are still needed before solid conclusions can be drawn.
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Affiliation(s)
- Claire M Issa
- Department of Internal Medicine, Division of Endocrinology and Metabolism, American University of Beirut-Medical Center, New York, NY 10017, USA
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10
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Abstract
Type 1 diabetes (T1D) is a serious disease with increasing incidence worldwide, with fatal consequences if untreated. Traditional therapies require direct or indirect insulin replacement, which involves numerous limitations and complications. While insulin is the major regulator of blood glucose, recent reports demonstrate the ability of several extra-pancreatic hormones to decrease blood glucose and improve metabolic homeostasis. Such hormones mainly include adipokines originating from adipose tissue (AT), while specific factors from the gut and liver also contribute to glucose homeostasis. Correction of T1D with adipokines is progressively becoming a realistic option, with the potential to overcome many problems associated with insulin replacement. Several recent studies demonstrate insulin-independent reversal or amelioration of T1D through administration of specific adipokines. Our recent work demonstrates the ability of healthy AT to compensate for the function of endocrine pancreas in long-term correction of T1D. This review discusses the potential of AT-related therapies for T1D as viable alternatives to insulin replacement.
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Affiliation(s)
- Subhadra C Gunawardana
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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11
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The development of Byetta (exenatide) from the venom of the Gila monster as an anti-diabetic agent. Toxicon 2012; 59:464-71. [DOI: 10.1016/j.toxicon.2010.12.016] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2010] [Accepted: 12/21/2010] [Indexed: 12/19/2022]
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Activation of the GLP-1 receptor signalling pathway: a relevant strategy to repair a deficient beta-cell mass. EXPERIMENTAL DIABETES RESEARCH 2011; 2011:376509. [PMID: 21716694 PMCID: PMC3118608 DOI: 10.1155/2011/376509] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Accepted: 02/25/2011] [Indexed: 12/18/2022]
Abstract
Recent preclinical studies in rodent models of diabetes suggest that exogenous GLP-1R agonists and DPP-4 inhibitors have the ability to increase islet mass and preserve beta-cell function, by immediate reactivation of beta-cell glucose competence, as well as enhanced beta-cell proliferation and neogenesis and promotion of beta-cell survival. These effects have tremendous implication in the treatment of T2D because they directly address one of the basic defects in T2D, that is, beta-cell failure. In human diabetes, however, evidence that the GLP-1-based drugs alter the course of beta-cell function remains to be found. Several questions surrounding the risks and benefits of GLP-1-based therapy for the diabetic beta-cell mass are discussed in this review and require further investigation.
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Abstract
Type 2 diabetes occurs due to a relative deficit in β-cell mass or function. Glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), cholecystokinin (CCK), and gastrin are gastrointestinal hormones that are secreted in response to nutrient intake, regulating digestion, insulin secretion, satiety, and β-cell mass. In this review, we focus upon β-cell mass regulation. β-cell mass expands through β-cell proliferation and islet neogenesis; β-cell mass is lost via apoptosis. GLP-1 and GIP are well-studied gastrointestinal hormones and influence β-cell proliferation, apoptosis, and islet neogenesis. CCK regulates β-cell apoptosis and mitogenesis, and gastrin stimulates islet neogenesis. GLP-1 and GIP bind to G protein-coupled receptors and regulate β-cell mass via multiple signaling pathways. The protein kinase A pathway is central to this process because it directly regulates proliferative and anti-apoptotic genes and transactivates several signaling cascades, including Akt and mitogen-activated protein kinases. However, the signaling pathways downstream of G protein-coupled CCK receptors that influence β-cell mass remain unidentified. Gastrointestinal hormones integrate nutrient signals from the gut to the β-cell, regulating insulin secretion and β-cell mass adaptation.
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Affiliation(s)
- Jeremy A Lavine
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
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14
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Riedel MJ, Kieffer TJ. Treatment of diabetes with glucagon-like peptide-1 gene therapy. Expert Opin Biol Ther 2010; 10:1681-92. [PMID: 21029027 DOI: 10.1517/14712598.2010.532786] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
IMPORTANCE OF THE FIELD Glucagon-like peptide (GLP)-1 receptor agonists are in widespread clinical use for the treatment of diabetes. While effective, these peptides require frequent injections to maintain efficacy. Therefore, alternative delivery methods including gene therapy are currently being evaluated. AREAS COVERED IN THIS REVIEW Here, we review the biology of GLP-1, evidence supporting the clinical use of the native peptide as well as synthetic GLP-1 receptor agonists, and the rationale for their delivery by gene therapy. We then review progress made in the field of GLP-1 gene therapy for both type 1 and type 2 diabetes. WHAT THE READER WILL GAIN Efforts to improve the biological half-life of GLP-1 receptor agonists are discussed. We focus on the development of both viral and non-viral gene delivery methods, highlighting vector designs and the strengths and weaknesses of these approaches. We also discuss the utility of targeting regulated GLP-1 production to tissues including the liver, muscle, islet and gut. TAKE HOME MESSAGE GLP-1 is a natural peptide possessing several actions that effectively combat diabetes. Current delivery methods for GLP-1-based drugs are cumbersome and do not recapitulate the normal secretion pattern of the native hormone. Gene therapy offers a useful method for directing long-term production and secretion of the native peptide. Targeted production of GLP-1 using tissue-specific promoters and delivery methods may improve therapeutic efficacy, while also eliminating the burden of frequent injections.
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Affiliation(s)
- Michael J Riedel
- University of British Columbia, Department of Cellular and Physiological Sciences, Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
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15
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Moore F, Naamane N, Colli ML, Bouckenooghe T, Ortis F, Gurzov EN, Igoillo-Esteve M, Mathieu C, Bontempi G, Thykjaer T, Ørntoft TF, Eizirik DL. STAT1 is a master regulator of pancreatic {beta}-cell apoptosis and islet inflammation. J Biol Chem 2010; 286:929-41. [PMID: 20980260 DOI: 10.1074/jbc.m110.162131] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cytokines produced by islet-infiltrating immune cells induce β-cell apoptosis in type 1 diabetes. The IFN-γ-regulated transcription factors STAT1/IRF-1 have apparently divergent effects on β-cells. Thus, STAT1 promotes apoptosis and inflammation, whereas IRF-1 down-regulates inflammatory mediators. To understand the molecular basis for these differential outcomes within a single signal transduction pathway, we presently characterized the gene networks regulated by STAT1 and IRF-1 in β-cells. This was done by using siRNA approaches coupled to microarray analysis of insulin-producing cells exposed or not to IL-1β and IFN-γ. Relevant microarray findings were further studied in INS-1E cells and primary rat β-cells. STAT1, but not IRF-1, mediates the cytokine-induced loss of the differentiated β-cell phenotype, as indicated by decreased insulin, Pdx1, MafA, and Glut2. Furthermore, STAT1 regulates cytokine-induced apoptosis via up-regulation of the proapoptotic protein DP5. STAT1 and IRF-1 have opposite effects on cytokine-induced chemokine production, with IRF-1 exerting negative feedback inhibition on STAT1 and downstream chemokine expression. The present study elucidates the transcriptional networks through which the IFN-γ/STAT1/IRF-1 axis controls β-cell function/differentiation, demise, and islet inflammation.
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Affiliation(s)
- Fabrice Moore
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, B-1070 Brussels, Belgium
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