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de Jong M, Lafeber HN, Cranendonk A, van Weissenbruch MM. Components of the metabolic syndrome in early childhood in very-low-birth-weight infants. Horm Res Paediatr 2015; 81:43-9. [PMID: 24281139 DOI: 10.1159/000355597] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 09/12/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Term small-for-gestational-age and preterm born infants have an increased prevalence of metabolic syndrome components already in childhood. Data in very-low-birth-weight (VLBW) children are limited. We investigated the prevalence of metabolic syndrome components in VLBW infants at 2 years of corrected age. METHODS We included 38 children, participating in the Neonatal Insulin Replacement Therapy in Europe (NIRTURE) trial, a randomized controlled trial of early insulin therapy in VLBW infants. Metabolic syndrome components were defined as: body mass index SDS >2; blood pressure (systolic and/or diastolic) ≥ 90th percentile; triglycerides ≥ 0.98 mmol/l; high-density lipoprotein (HDL) cholesterol ≤ 1.03 mmol/l; glucose ≥ 5.6 mmol/l. RESULTS Two children (5%) had three metabolic syndrome components, 13 children (34%) had two components, and 11 children (29%) one component. 63% had raised blood pressure (prevalence higher in boys), 32% low HDL, and 30% high triglycerides (prevalence lower in early insulin group). In children with body mass index SDS <0, insulin-treated children had higher HDL than children with standard care. Systolic blood pressure was correlated with growth between term and 2 years of corrected age. CONCLUSIONS VLBW infants already have a high prevalence of metabolic syndrome components at 2 years of corrected age. Early insulin treatment could have long-term benefits for some of these components.
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Affiliation(s)
- Miranda de Jong
- Department of Pediatrics, Albert Schweitzer Hospital, Dordrecht, The Netherlands
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Translational implications of the β-cell epigenome in diabetes mellitus. Transl Res 2015; 165:91-101. [PMID: 24686035 PMCID: PMC4162854 DOI: 10.1016/j.trsl.2014.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 03/04/2014] [Accepted: 03/06/2014] [Indexed: 12/12/2022]
Abstract
Diabetes mellitus is a disorder of glucose homeostasis that affects more than 24 million Americans and 382 million individuals worldwide. Dysregulated insulin secretion from the pancreatic β cells plays a central role in the pathophysiology of all forms of diabetes mellitus. Therefore, an enhanced understanding of the pathways that contribute to β-cell failure is imperative. Epigenetics refers to heritable changes in DNA transcription that occur in the absence of changes to the linear DNA nucleotide sequence. Recent evidence suggests an expanding role of the β-cell epigenome in the regulation of metabolic health. The goal of this review is to discuss maladaptive changes in β-cell DNA methylation patterns and chromatin architecture, and their contribution to diabetes pathophysiology. Efforts to modulate the β-cell epigenome as a means to prevent, diagnose, and treat diabetes are also discussed.
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Papaetis GS. Incretin-based therapies in prediabetes: Current evidence and future perspectives. World J Diabetes 2014; 5:817-834. [PMID: 25512784 PMCID: PMC4265868 DOI: 10.4239/wjd.v5.i6.817] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Revised: 09/10/2014] [Accepted: 11/10/2014] [Indexed: 02/05/2023] Open
Abstract
The prevalence of type 2 diabetes (T2D) is evolving globally at an alarming rate. Prediabetes is an intermediate state of glucose metabolism that exists between normal glucose tolerance (NGT) and the clinical entity of T2D. Relentless β-cell decline and failure is responsible for the progression from NGT to prediabetes and eventually T2D. The huge burden resulting from the complications of T2D created the need of therapeutic strategies in an effort to prevent or delay its development. The beneficial effects of incretin-based therapies, dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists, on β-cell function in patients with T2D, together with their strictly glucose-depended mechanism of action, suggested their possible use in individuals with prediabetes when greater β-cell mass and function are preserved and the possibility of β-cell salvage is higher. The present paper summarizes the main molecular intracellular mechanisms through which GLP-1 exerts its activity on β-cells. It also explores the current evidence of incretin based therapies when administered in a prediabetic state, both in animal models and in humans. Finally it discusses the safety of incretin-based therapies as well as their possible role in order to delay or prevent T2D.
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Cross-fostering and improved lactation ameliorates deficits in endocrine pancreatic morphology in growth-restricted adult male rat offspring. J Dev Orig Health Dis 2014; 1:234-44. [PMID: 25141871 DOI: 10.1017/s2040174410000383] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Uteroplacental insufficiency and poor postnatal nutrition impair adult glucose tolerance and insulin secretion in male rat offspring, which can be partially ameliorated by improving postnatal nutrition. Uteroplacental insufficiency was induced in the WKY rat on day 18 of pregnancy (Restricted) compared to sham-operated Controls. Pups were then cross-fostered onto Control or Restricted mothers one day after birth resulting in: (Pup-on-Mother) Control-on-Control, Control-on-Restricted, Restricted-on-Control and Restricted-on-Restricted. Endocrine pancreatic morphology and markers of intrinsic β-cell function and glucose homeostasis were assessed in male offspring at 6 months. Pancreatic and hepatic gene expression was quantified at postnatal day 7 and 6 months. Restricted pups were born 10-15% lighter than Controls and remained lighter at 6 months. Relative islet and β-cell mass were 51-65% lower in Restricted-on-Restricted compared to Controls at 6 months. Non-fasting plasma C-reactive protein levels were also increased, suggestive of an inflammatory response. Overall, the average number of islets, small islets and proportion of β-cells per islet correlated positively with birth weight. Intrinsic β-cell function, estimated by insulin secretion relative to β-cell mass, was unaffected by Restriction, suggesting that the in vivo functional deficit was attributable to reduced mass, not function. Importantly, these deficits were ameliorated when lactational nutrition was normalized in Restricted-on-Control offspring, who also showed increased pancreatic Igf1r, Pdx1 and Vegf mRNA expression at 7 days compared to Control-on-Control and Restricted-on-Restricted. This highlights lactation as a critical period for intervention following prenatal restraint, whereby deficits in endocrine pancreatic mass and associated impaired in vivo insulin secretion can be ameliorated.
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Abstract
In the last decades, the developmental origins of health and disease (DOHaD) have emerged as a vigorous field combining experimental, clinical, epidemiological and public health research. Its goal is to understand how events in early life shape later morbidity risk, especially of non-communicable chronic diseases. As these diseases become the major cause of morbidity and mortality worldwide, research arising from DOHaD is likely to gain significance to public health and economic development. But action may be hindered by the lack of a firm mechanistic explanation and of a conceptual basis, especially regarding the evolutionary significance of the DOHaD phenomenon. In this article, we provide a succinct historical review of the research into the relationship between development and later disease, consider the evolutionary and developmental significance and discuss the underlying mechanisms of the DOHaD phenomenon. DOHaD should be viewed as a part of a broader biological mechanism of plasticity by which organisms, in response to cues such as nutrition or hormones, adapt their phenotype to environment. These responses may be divided into those for immediate benefit and those aimed at prediction of a future environment: disease occurs in the mismatch between predicted and realized future. The likely mechanisms that enable plasticity involve epigenetic processes, affecting the expression of genes associated with regulatory pathways. There is now evidence that epigenetic marks may be inherited and so contribute to non-genomic heritable disease risk. We end by discussing the global significance of the DOHaD phenomenon and its potential applications for public health purposes.
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Agnoux AM, Antignac JP, Simard G, Poupeau G, Darmaun D, Parnet P, Alexandre-Gouabau MC. Time window-dependent effect of perinatal maternal protein restriction on insulin sensitivity and energy substrate oxidation in adult male offspring. Am J Physiol Regul Integr Comp Physiol 2014; 307:R184-97. [DOI: 10.1152/ajpregu.00015.2014] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Epidemiological and experimental evidence suggests that a suboptimal environment during perinatal life programs offspring susceptibility to the development of metabolic syndrome and Type 2 diabetes. We hypothesized that the lasting impact of perinatal protein deprivation on mitochondrial fuel oxidation and insulin sensitivity would depend on the time window of exposure. To improve our understanding of underlying mechanisms, an integrative approach was used, combining the assessment of insulin sensitivity and untargeted mass spectrometry-based metabolomics in the offspring. A hyperinsulinemic-euglycemic clamp was performed in adult male rats born from dams fed a low-protein diet during gestation and/or lactation, and subsequently exposed to a Western diet (WD) for 10 wk. Metabolomics was combined with targeted acylcarnitine profiling and analysis of liver gene expression to identify markers of adaptation to WD that influence the phenotype outcome evaluated by body composition analysis. At adulthood, offspring of protein-restricted dams had impaired insulin secretion when fed a standard diet. Moreover, rats who demonstrated catch-up growth at weaning displayed higher gluconeogenesis and branched-chain amino acid catabolism, and lower fatty acid β-oxidation compared with control rats. Postweaning exposure of intrauterine growth restriction-born rats to a WD exacerbated incomplete fatty acid β-oxidation and excess fat deposition. Control offspring nursed by protein-restricted mothers showed peculiar low-fat accretion through adulthood and preserved insulin sensitivity even after WD-exposure. Altogether, our findings suggest a testable hypothesis about how maternal diet might influence metabolic outcomes (insulin sensitivity) in the next generation such as mitochondrial overload and/or substrate oxidation inflexibility dependent on the time window of perinatal dietary manipulation.
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Affiliation(s)
- Aurore Martin Agnoux
- Institut National de la Recherche Agronomique (INRA), UMR 1280, Physiologie des Adaptations Nutritionnelles, Institut des maladies de l'appareil digestif (IMAD), Centre de Recherche en Nutrition Humaine Ouest (CRNH), Nantes, France
- Université de Nantes, UMR 1280, Physiologie des Adaptations Nutritionnelles, IMAD, CRNH, Nantes, France
| | - Jean-Philippe Antignac
- L'Université Nantes Angers Le Mans (LUNAM) université, Oniris, Laboratoire d'Etude des Résidus et Contaminants dans les Aliments, Unité Sous Contrat (USC) INRA, Nantes, France
| | - Gilles Simard
- LUNAM Université, Angers, France
- Institut National de la Santé et de la Recherche Médicale U1063, Angers, France; and
- Université d'Angers, Centre Hospitalier Universitaire (CHU) Angers, Department of Biochemistry, Angers, France
| | - Guillaume Poupeau
- Institut National de la Recherche Agronomique (INRA), UMR 1280, Physiologie des Adaptations Nutritionnelles, Institut des maladies de l'appareil digestif (IMAD), Centre de Recherche en Nutrition Humaine Ouest (CRNH), Nantes, France
- Université de Nantes, UMR 1280, Physiologie des Adaptations Nutritionnelles, IMAD, CRNH, Nantes, France
| | - Dominique Darmaun
- Institut National de la Recherche Agronomique (INRA), UMR 1280, Physiologie des Adaptations Nutritionnelles, Institut des maladies de l'appareil digestif (IMAD), Centre de Recherche en Nutrition Humaine Ouest (CRNH), Nantes, France
- Université de Nantes, UMR 1280, Physiologie des Adaptations Nutritionnelles, IMAD, CRNH, Nantes, France
| | - Patricia Parnet
- Institut National de la Recherche Agronomique (INRA), UMR 1280, Physiologie des Adaptations Nutritionnelles, Institut des maladies de l'appareil digestif (IMAD), Centre de Recherche en Nutrition Humaine Ouest (CRNH), Nantes, France
- Université de Nantes, UMR 1280, Physiologie des Adaptations Nutritionnelles, IMAD, CRNH, Nantes, France
| | - Marie-Cécile Alexandre-Gouabau
- Institut National de la Recherche Agronomique (INRA), UMR 1280, Physiologie des Adaptations Nutritionnelles, Institut des maladies de l'appareil digestif (IMAD), Centre de Recherche en Nutrition Humaine Ouest (CRNH), Nantes, France
- Université de Nantes, UMR 1280, Physiologie des Adaptations Nutritionnelles, IMAD, CRNH, Nantes, France
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Tasyurek HM, Altunbas HA, Balci MK, Sanlioglu S. Incretins: their physiology and application in the treatment of diabetes mellitus. Diabetes Metab Res Rev 2014; 30:354-71. [PMID: 24989141 DOI: 10.1002/dmrr.2501] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 11/06/2013] [Accepted: 11/12/2013] [Indexed: 12/18/2022]
Abstract
Therapies targeting the action of incretin hormones have been under close scrutiny in recent years. The incretin effect has been defined as postprandial enhancement of insulin secretion by gut-derived factors. Likewise, incretin mimetics and incretin effect amplifiers are the two different incretin-based treatment strategies developed for the treatment of diabetes. Although, incretin mimetics produce effects very similar to those of natural incretin hormones, incretin effect amplifiers act by inhibiting dipeptidyl peptidase-4 (DPP-4) enzyme to increase plasma concentration of incretins and their biologic effects. Because glucagon-like peptide-1 (GLP-1) is an incretin hormone with various anti-diabetic actions including stimulation of glucose-induced insulin secretion, inhibition of glucagon secretion, hepatic glucose production and gastric emptying, it has been evaluated as a novel therapeutic agent for the treatment of type 2 diabetes mellitus (T2DM). GLP-1 also manifests trophic effects on pancreas such as pancreatic beta cell growth and differentiation. Because DPP-4 is the enzyme responsible for the inactivation of GLP-1, DPP-4 inhibition represents another potential strategy to increase plasma concentration of GLP-1 to enhance the incretin effect. Thus, anti-diabetic properties of these two classes of drugs have stimulated substantial clinical interest in the potential of incretin-based therapeutic agents as a means to control glucose homeostasis in T2DM patients. Despite this fact, clinical use of GLP-1 mimetics and DPP-4 inhibitors have raised substantial concerns owing to possible side effects of the treatments involving increased risk for pancreatitis, and C-cell adenoma/carcinoma. Thus, controversial issues in incretin-based therapies under development are reviewed and discussed in this manuscript.
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Maternal diabetes, programming of beta-cell disorders and intergenerational risk of type 2 diabetes. DIABETES & METABOLISM 2014; 40:323-30. [PMID: 24948417 DOI: 10.1016/j.diabet.2014.02.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 01/31/2014] [Accepted: 02/05/2014] [Indexed: 01/01/2023]
Abstract
A substantial body of evidence suggests that an abnormal intra-uterine milieu elicited by maternal metabolic disturbances as diverse as malnutrition, placental insufficiency, diabetes and obesity may be able to programme susceptibility of the foetus to later develop chronic degenerative diseases such as obesity, hypertension, cardiovascular diseases and type 2 diabetes (T2D). As insulin-producing cells have been placed centre stage in the development of T2D, this review examines developmental programming of the beta-cell mass (BCM) in various rodent models of maternal protein restriction, calorie restriction, overnutrition and diabetes. The main message is that whatever the initial maternal insult (F0 generation) and whether alone or in combination, it gives rise to the same programmed BCM outcome in the daughter generation (F1). The altered BCM phenotype in F1 females prohibits normal BCM adaptation during pregnancy and, thus, diabetes (gestational diabetes) ensues. This gestational diabetes is then passed from one generation (F1) to the next (F2, F3 and so on). This review highlights a number of studies that have identified epigenetic mechanisms that may contribute to altered BCM development and beta-cell failure, as observed in diabetes. In addition to their role in instilling the programmed defect, these non-genomic mechanisms may also be involved in its intergenerational transmission.
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Ge ZJ, Zhang CL, Schatten H, Sun QY. Maternal Diabetes Mellitus and the Origin of Non-Communicable Diseases in Offspring: The Role of Epigenetics1. Biol Reprod 2014; 90:139. [DOI: 10.1095/biolreprod.114.118141] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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Gatford KL, Kaur G, Falcão-Tebas F, Wadley GD, Wlodek ME, Laker RC, Ebeling PR, McConell GK. Exercise as an intervention to improve metabolic outcomes after intrauterine growth restriction. Am J Physiol Endocrinol Metab 2014; 306:E999-1012. [PMID: 24619880 DOI: 10.1152/ajpendo.00456.2013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Individuals born after intrauterine growth restriction (IUGR) are at an increased risk of developing diabetes in their adult life. IUGR impairs β-cell function and reduces β-cell mass, thereby diminishing insulin secretion. IUGR also induces insulin resistance, with impaired insulin signaling in muscle in adult humans who were small for gestational age (SGA) and in rodent models of IUGR. There is epidemiological evidence in humans that exercise in adults can reduce the risk of metabolic disease following IUGR. However, it is not clear whether adult IUGR individuals benefit to the same extent from exercise as do normal-birth-weight individuals, as our rat studies suggest less of a benefit in those born IUGR. Importantly, however, there is some evidence from studies in rats that exercise in early life might be able to reverse or reprogram the long-term metabolic effects of IUGR. Studies are needed to address gaps in current knowledge, including determining the mechanisms involved in the reprogramming effects of early exercise in rats, whether exercise early in life or in adulthood has similar beneficial metabolic effects in larger animal models in which insulin resistance develops after IUGR. Human studies are also needed to determine whether exercise training improves insulin secretion and insulin sensitivity to the same extent in IUGR adults as in control populations. Such investigations will have implications for customizing the recommended level and timing of exercise to improve metabolic health after IUGR.
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Affiliation(s)
- Kathryn L Gatford
- Robinson Institute and School of Paediatrics and Reproductive Health, University of Adelaide, Adelaide, South Australia, Australia
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Jaeckle Santos LJ, Li C, Doulias PT, Ischiropoulos H, Worthen GS, Simmons RA. Neutralizing Th2 inflammation in neonatal islets prevents β-cell failure in adult IUGR rats. Diabetes 2014; 63:1672-84. [PMID: 24408314 PMCID: PMC3994952 DOI: 10.2337/db13-1226] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Intrauterine growth restriction (IUGR) leads to development of type 2 diabetes (T2D) in adulthood. The mechanisms underlying this phenomenon have not been fully elucidated. Inflammation is associated with T2D; however, it is unknown whether inflammation is causal or secondary to the altered metabolic state. Here we show that the mechanism by which IUGR leads to the development of T2D in adulthood is via transient recruitment of T-helper 2 (Th) lymphocytes and macrophages in fetal islets resulting in localized inflammation. Although this immune response is short-lived, it results in a permanent reduction in islet vascularity and impaired insulin secretion. Neutralizing interleukin-4 antibody therapy given only in the newborn period ameliorates inflammation and restores vascularity and β-cell function into adulthood, demonstrating a novel role for Th2 immune responses in the induction and progression of T2D. In the neonatal stage, inflammation and vascular changes are reversible and may define an important developmental window for therapeutic intervention to prevent adult-onset diabetes.
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Affiliation(s)
- Lane J. Jaeckle Santos
- Division of Neonatology, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- The Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Changhong Li
- Division of Neonatology, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- The Children’s Hospital of Philadelphia, Philadelphia, PA
| | | | - Harry Ischiropoulos
- Division of Neonatology, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- The Children’s Hospital of Philadelphia, Philadelphia, PA
| | - G. Scott Worthen
- Division of Neonatology, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- The Children’s Hospital of Philadelphia, Philadelphia, PA
- Corresponding author: Rebecca A. Simmons, , or G. Scott Worthen,
| | - Rebecca A. Simmons
- Division of Neonatology, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- The Children’s Hospital of Philadelphia, Philadelphia, PA
- Corresponding author: Rebecca A. Simmons, , or G. Scott Worthen,
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Fetale und perinatale Programmierung der Nierenfunktion. GYNAKOLOGISCHE ENDOKRINOLOGIE 2014. [DOI: 10.1007/s10304-013-0593-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Lamont BJ, Andrikopoulos S. Hope and fear for new classes of type 2 diabetes drugs: is there preclinical evidence that incretin-based therapies alter pancreatic morphology? J Endocrinol 2014; 221:T43-61. [PMID: 24424288 DOI: 10.1530/joe-13-0577] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Incretin-based therapies appear to offer many advantages over other approaches for treating type 2 diabetes. Some preclinical studies have suggested that chronic activation of glucagon-like peptide 1 receptor (GLP1R) signalling in the pancreas may result in the proliferation of islet β-cells and an increase in β-cell mass. This provided hope that enhancing GLP1 action could potentially alter the natural progression of type 2 diabetes. However, to date, there has been no evidence from clinical trials suggesting that GLP1R agonists or dipeptidyl peptidase-4 (DPP4) inhibitors can increase β-cell mass. Nevertheless, while the proliferative capacity of these agents remains controversial, some studies have raised concerns that they could potentially contribute to the development of pancreatitis and hence increase the risk of pancreatic cancer. Currently, there are very limited clinical data to directly assess these potential benefits and risks of incretin-based therapies. However, a review of the preclinical studies indicates that incretin-based therapies probably have only a limited capacity to regenerate pancreatic β-cells, but may be useful for preserving any remaining β-cells in type 2 diabetes. In addition, the majority of preclinical evidence does not support the notion that GLP1R agonists or DPP4 inhibitors cause pancreatitis.
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Affiliation(s)
- Benjamin J Lamont
- Department of Medicine (Austin Health), The University of Melbourne, Melbourne, Victoria, Australia
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Islet inflammation, hemosiderosis, and fibrosis in intrauterine growth-restricted and high fat-fed Sprague-Dawley rats. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:1446-57. [PMID: 24631026 DOI: 10.1016/j.ajpath.2014.01.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Revised: 01/03/2014] [Accepted: 01/28/2014] [Indexed: 12/27/2022]
Abstract
Prenatal and postnatal factors such as intrauterine growth restriction (IUGR) and high-fat (HF) diet contribute to type 2 diabetes. Our aim was to determine whether IUGR and HF diets interact in type 2 diabetes pathogenesis, with particular attention focused on pancreatic islet morphology including assessment for inflammation. A surgical model of IUGR (bilateral uterine artery ligation) in Sprague-Dawley rats with sham controls was used. Pups were fed either HF or chow diets after weaning. Serial measures of body weight and glucose tolerance were performed. At 25 weeks of age, rat pancreases were harvested for histologic assessment. The birth weight of IUGR pups was 13% lower than that of sham pups. HF diet caused excess weight gain, dyslipidemia, hyperinsulinemia, and mild glucose intolerance, however, this was not aggravated further by IUGR. Markedly abnormal islet morphology was evident in 0 of 6 sham-chow, 5 of 8 sham-HF, 4 of 8 IUGR-chow, and 8 of 9 IUGR-HF rats (chi-square, P = 0.007). Abnormal islets were characterized by larger size, irregular shape, inflammation with CD68-positive cells, marked fibrosis, and hemosiderosis. β-Cell mass was not altered by IUGR. In conclusion, HF and IUGR independently contribute to islet injury characterized by inflammation, hemosiderosis, and fibrosis. This suggests that both HF and IUGR can induce islet injury via converging pathways. The potential pathogenic or permissive role of iron in this process of islet inflammation warrants further investigation.
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Abstract
Intrauterine growth restriction (IUGR) impairs insulin secretion in humans and in animal models of IUGR. Several underlying mechanisms have been implicated, including decreased expression of molecular regulators of β-cell mass and function, in some cases shown to be due to epigenetic changes initiated by an adverse fetal environment. Alterations in cell cycle progression contribute to loss of β-cell mass, whereas decreased islet vascularity and mitochondrial dysfunction impair β-cell function in IUGR rodents. Animal models of IUGR sharing similar insulin secretion outcomes as the IUGR human are allowing underlying mechanisms to be identified. This review will focus on models of uteroplacental insufficiency.
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66
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Abstract
Gestational diabetes mellitus (GDM) is a common medical complication in pregnancy. Offspring exposed to maternal hyperglycemia have a higher birth weight and are prone to develop metabolic disease in adult life. The intrauterine environmental or nutritional status seems to be involved in the fetal programing. The concept of "Developmental Origins of Health and Disease" (DOHaD) has been widely accepted and it brings new insights into the molecular pathogenesis of human diseases. The underlying mechanism is still under discussion and epigenetic mechanisms may provide an explanation for the phenomenon. The aim of this review is to illustrate the role of epigenetic modifications in the development of insulin resistance in metabolic diseases induced by adverse intrauterine exposures. Changes in epigenetic mechanism may be an early event in pathogenesis and progression of the metabolic disease in humans. Studies on epigenetic modifications contribute to our understanding of long-term effects of in utero exposure and shed light on the disease prevention and treatment by modulating epigenetic changes.
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Affiliation(s)
- Jie Yan
- Department of Obstetrics and Gynecology, Peking University First Hospital , Beijing , China
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67
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Barella LF, de Oliveira JC, Mathias PCDF. Pancreatic islets and their roles in metabolic programming. Nutrition 2013; 30:373-9. [PMID: 24206821 DOI: 10.1016/j.nut.2013.07.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 07/03/2013] [Accepted: 07/08/2013] [Indexed: 12/13/2022]
Abstract
Experimental and epidemiologic data have confirmed that undernutrition or overnutrition during critical periods of life can result in metabolic dysfunction, leading to the development of obesity, hypertension, and type 2 diabetes, later in life. These studies have contributed to the concept of the developmental origins of health and disease (DOHaD), which involves metabolic programming patterns. Beyond the earlier phases of development, puberty can be an additional period of plasticity, during which any insult can lead to changes in metabolism. Impaired brain development, associated with imbalanced autonomous nervous system activity due to metabolic programming, is pivotal to the creation of pathophysiology. Excess glucocorticoid exposure, due to hypothalamic-pituitary-adrenal axis deregulation, is also involved in malprogramming in early life. Additionally, the pancreatic islets appear to play a decisive role in the setup and maintenance of these metabolic dysfunctions as key targets of metabolic programming, and epigenetic mechanisms may underlie these changes. Moreover, studies have indicated the possibility that deprogramming renders the islets able to recover their functioning after malprogramming. In this review, we discuss the key roles of the pancreatic islets as targets of malprogramming; however, we also discuss their roles as important targets for the treatment and prevention of metabolic diseases.
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Affiliation(s)
- Luiz Felipe Barella
- Laboratory of Secretion Cell Biology, Department of Cell Biology and Genetics, State University of Maringá, Maringá, PR, Brazil.
| | - Júlio Cezar de Oliveira
- Laboratory of Secretion Cell Biology, Department of Cell Biology and Genetics, State University of Maringá, Maringá, PR, Brazil
| | - Paulo Cezar de Freitas Mathias
- Laboratory of Secretion Cell Biology, Department of Cell Biology and Genetics, State University of Maringá, Maringá, PR, Brazil
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Portha B, Fournier A, Kioon MDA, Mezger V, Movassat J. Early environmental factors, alteration of epigenetic marks and metabolic disease susceptibility. Biochimie 2013; 97:1-15. [PMID: 24139903 DOI: 10.1016/j.biochi.2013.10.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 10/07/2013] [Indexed: 12/11/2022]
Abstract
The environmental conditions that are experienced in early life can profoundly influence human biology and long-term health. Early-life nutrition and stress are among the best documented examples of such conditions because they influence the adult risk of developing metabolic diseases, such as type 2 diabetes mellitus (T2D) and cardiovascular diseases. It is now becoming increasingly accepted that environmental compounds including nutrients can produce changes in the genome activity that in spite of not altering DNA sequence can produce important, stable and transgenerational alterations in the phenotype. Epigenetic changes, in particular DNA methylation and histone acetylation/methylation, provide a 'memory' of developmental plastic responses to early environment and are central to the generation of phenotypes and their stability throughout the life course. Their effects may only become manifest later in life, e.g. in terms of altered responses to environmental challenges.
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Affiliation(s)
- B Portha
- Université Paris-Diderot, Sorbonne-Paris-Cité, Laboratoire B2PE (Biologie et Pathologie du Pancréas Endocrine), Unité BFA (Biologie Fonctionnelle et Adaptive), CNRS EAC 4413, Bâtiment BUFFON, 5ème étage, 4 Rue Lagroua Weill Hallé, Case 7126, F-75205 Paris Cedex 13, France.
| | - A Fournier
- Univ ParisDiderot, Sorbonne-Paris-Cité, Unité EDC (Epigénétique et Destin Cellulaire), CNRS UMR7216, F-75205 Paris Cedex 13, Paris, France
| | - M D Ah Kioon
- Université Paris-Diderot, Sorbonne-Paris-Cité, Laboratoire B2PE (Biologie et Pathologie du Pancréas Endocrine), Unité BFA (Biologie Fonctionnelle et Adaptive), CNRS EAC 4413, Bâtiment BUFFON, 5ème étage, 4 Rue Lagroua Weill Hallé, Case 7126, F-75205 Paris Cedex 13, France
| | - V Mezger
- Univ ParisDiderot, Sorbonne-Paris-Cité, Unité EDC (Epigénétique et Destin Cellulaire), CNRS UMR7216, F-75205 Paris Cedex 13, Paris, France
| | - J Movassat
- Université Paris-Diderot, Sorbonne-Paris-Cité, Laboratoire B2PE (Biologie et Pathologie du Pancréas Endocrine), Unité BFA (Biologie Fonctionnelle et Adaptive), CNRS EAC 4413, Bâtiment BUFFON, 5ème étage, 4 Rue Lagroua Weill Hallé, Case 7126, F-75205 Paris Cedex 13, France
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69
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Abstract
Pancreatic beta-cell mass expands through beta-cell proliferation and neogenesis while it decreases mainly via apoptosis. The loss of balance between beta-cell death and regeneration leads to a reduction of beta-cell functional mass, thus contributing to the pathogenesis of type 2 diabetes mellitus (T2DM). The pathogenetic mechanisms causing T2DM are complex, and also include a significant reduction of the incretin effect. A better understanding of the role of incretin hormones in glucose homeostasis has led to the development of incretin-based therapies. Recently, incretin hormones have been shown to stimulate the beta-cell growth and differentiation from pancreas-derived stem/progenitor cells, as well as to exert cytoprotective, antiapoptotic effects on beta-cells. However, the role and the molecular mechanisms by which GLP-1 and its agonists regulate beta-cell mass have not been fully investigated. This review focuses the current findings and the missing understanding of the effects of incretin hormones on beta-cell mass expansion.
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Affiliation(s)
- Federica Tortosa
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari School of Medicine , Bari , Italy and
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70
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Bruin JE, Rezania A, Xu J, Narayan K, Fox JK, O'Neil JJ, Kieffer TJ. Maturation and function of human embryonic stem cell-derived pancreatic progenitors in macroencapsulation devices following transplant into mice. Diabetologia 2013; 56:1987-98. [PMID: 23771205 DOI: 10.1007/s00125-013-2955-4] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 05/07/2013] [Indexed: 12/21/2022]
Abstract
AIMS/HYPOTHESIS Islet transplantation is a promising cell therapy for patients with diabetes, but it is currently limited by the reliance upon cadaveric donor tissue. We previously demonstrated that human embryonic stem cell (hESC)-derived pancreatic progenitor cells matured under the kidney capsule in a mouse model of diabetes into glucose-responsive insulin-secreting cells capable of reversing diabetes. However, the formation of cells resembling bone and cartilage was a major limitation of that study. Therefore, we developed an improved differentiation protocol that aimed to prevent the formation of off-target mesoderm tissue following transplantation. We also examined how variation within the complex host environment influenced the development of pancreatic progenitors in vivo. METHODS The hESCs were differentiated for 14 days into pancreatic progenitor cells and transplanted either under the kidney capsule or within Theracyte (TheraCyte, Laguna Hills, CA, USA) devices into diabetic mice. RESULTS Our revised differentiation protocol successfully eliminated the formation of non-endodermal cell populations in 99% of transplanted mice and generated grafts containing >80% endocrine cells. Progenitor cells developed efficiently into pancreatic endocrine tissue within macroencapsulation devices, despite lacking direct contact with the host environment, and reversed diabetes within 3 months. The preparation of cell aggregates pre-transplant was critical for the formation of insulin-producing cells in vivo and endocrine cell development was accelerated within a diabetic host environment compared with healthy mice. Neither insulin nor exendin-4 therapy post-transplant affected the maturation of macroencapsulated cells. CONCLUSIONS/INTERPRETATION Efficient differentiation of hESC-derived pancreatic endocrine cells can occur in a macroencapsulation device, yielding glucose-responsive insulin-producing cells capable of reversing diabetes.
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Affiliation(s)
- Jennifer E Bruin
- Laboratory of Molecular and Cellular Medicine, Department of Cellular & Physiological Sciences, Life Sciences Institute, University of British Columbia, Room 5308-2350 Health Sciences Mall, Vancouver, BC, Canada V6T 1Z3
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71
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Cox AR, Beamish CA, Carter DE, Arany EJ, Hill DJ. Cellular mechanisms underlying failed beta cell regeneration in offspring of protein-restricted pregnant mice. Exp Biol Med (Maywood) 2013; 238:1147-59. [PMID: 23986224 DOI: 10.1177/1535370213493715] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Low birth weight and poor foetal growth following low protein (LP) exposure are associated with altered islet development and glucose intolerance in adulthood. Additionally, LP-fed offspring fail to regenerate their β-cells following depletion with streptozotocin (STZ) in contrast to control-fed offspring that restore β-cell mass. Our objective was to identify signalling pathways and cellular functions that may be critically altered in LP offspring rendering them susceptible to developing long-term glucose intolerance and decreased β-cell plasticity. Pregnant Balb/c mice were fed a control (C; 20% protein) or an isocaloric LP (8% protein) diet throughout gestation and C diet thereafter. Female offspring were injected intraperitoneally with 35 mg/kg STZ or vehicle on days 1 to 5 for each dietary treatment. At 30 days of age, total RNA was extracted from pancreatic tissue for microarray analysis using the Affymetrix GeneChip Mouse Genome 430 2.0. Gene and protein expression were quantified from isolated islets. Finally, β-cell proliferation was determined in vitro following REG1α treatment. The microarray data and GO enrichment analysis indicated that foetal protein restriction alters the early expression of genes necessary for many cell functions, such as oxidative phosphorylation and free radical scavenging. Expression of Reg1 was upregulated following STZ, whereas protein content was decreased in LP + STZ islets. Furthermore, REG1α failed to stimulate β-cell proliferation in vitro in LP + STZ islets. Therefore, early nutritional insults may programme the Reg1 pathway resulting in a limited ability to increase β-cell mass during metabolic stress. In conclusion, this study implicates the Reg1 pathway in β-cell regeneration and describes altered programming of gene expression in LP offspring, which underlies later development of cell dysfunction and glucose intolerance in adulthood.
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Affiliation(s)
- Aaron R Cox
- Lawson Health Research Institute, St. Joseph's Health Care, London, Ontario, Canada, N6A 4V2
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72
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Lacroix IME, Li-Chan ECY. Overview of food products and dietary constituents with antidiabetic properties and their putative mechanisms of action: a natural approach to complement pharmacotherapy in the management of diabetes. Mol Nutr Food Res 2013; 58:61-78. [PMID: 23943383 DOI: 10.1002/mnfr.201300223] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 06/10/2013] [Accepted: 06/13/2013] [Indexed: 01/05/2023]
Abstract
Diabetes is one of the fastest growing chronic, noncommunicable diseases worldwide. Currently, 11 major classes of pharmacotherapy are available for the management of this metabolic disorder. However, the usage of these drugs is often associated with undesirable side effects, including weight gain and hypoglycemia. There is thus a need for new, safe and effective treatment strategies. Diet is known to play a major role in the prevention and management of diabetes. Numerous studies have reported the putative association of the consumption of specific food products, or their constituents, with the incidence of diabetes, and mounting evidence now suggests that some dietary factors can improve glycemic regulation. Foods and dietary constituents, similar to synthetic drugs, have been shown to modulate hormones, enzymes, and organ systems involved in carbohydrate metabolism. The present article reviews the major classes and modes of action of antidiabetic drugs, and examines the evidence on food products and dietary factors with antidiabetic properties as well as their plausible mechanisms of action. The findings suggest potential use of dietary constituents as a complementary approach to pharmacotherapy in the prevention and/or management of diabetes, but further research is necessary to identify the active components and evaluate their efficacy and safety.
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Affiliation(s)
- Isabelle M E Lacroix
- Faculty of Land & Food Systems, Food Nutrition & Health Program, The University of British Columbia, Vancouver, BC, Canada
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73
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Zhao TC. Glucagon-like peptide-1 (GLP-1) and protective effects in cardiovascular disease: a new therapeutic approach for myocardial protection. Cardiovasc Diabetol 2013; 12:90. [PMID: 23777457 PMCID: PMC3700838 DOI: 10.1186/1475-2840-12-90] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 06/05/2013] [Indexed: 12/14/2022] Open
Abstract
Glucagon-like peptide-1 (GLP-1) is a member of the proglucagon incretin family implicated in the control of appetite and satiety. GLP-1 has insulinotropic, insulinomimetic, and glucagonostatic effects, thereby exerting multiple complementary actions to lower blood glucose in subjects with type 2 diabetes mellitus. A major advantage over conventional insulin is the fact that the insulinotropic actions of GLP-1 are dependent upon ambient glucose concentration, mitigating the risks of hypoglycemia. Recently, the crucial role of GLP-1 in cardiovascular disease has been suggested in both preclinical and clinical studies. The experimental data indicate GLP-1 and its analogs to have direct effects on the cardiovascular system, in addition to their classic glucoregulatory actions. Clinically, beneficial effects of GLP-1 have also been demonstrated in patients with myocardial ischemia and heart failure. GLP-1 has recently been demonstrated to be a more effective alternative in treating myocardial injury. This paper provides a review on the current evidence supporting the use of GLP-1 in experimental animal models and human trials with the ischemic and non-ischemic heart and discusses their molecular mechanisms and potential as a new therapeutic approach.
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Affiliation(s)
- Ting C Zhao
- Cardiovascular Research laboratory, Department of Surgery, Roger Williams Medical Center, Boston University Medical School, 50 Maude Street, Providence, RI 02908, USA.
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74
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Abstract
Intrauterine growth retardation has been linked to the development of type 2 diabetes later in life and the mechanisms underlying this phenomena are unknown. Epidemiological studies in humans show a distinct link with the exposure to an intrauterine insult that results in low birth weight and the development of type 2 diabetes in adulthood. Intrauterine growth retardation can be induced in rodent models by exposing the pregnant rat to a low protein diet, total calorie restriction, high dose glucocorticoids or inducing uteroplacental insufficiency, all which result in abnormalities in glucose homeostasis in the offspring later in life. Animal models of intrauterine growth retardation allow for a better characterization of changes in glucose homeostasis and corresponding changes in gene expression that can provide insight in the mechanisms by which intrauterine growth retardation leads to type 2 diabetes.
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75
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Herold KC, Vignali DAA, Cooke A, Bluestone JA. Type 1 diabetes: translating mechanistic observations into effective clinical outcomes. Nat Rev Immunol 2013; 13:243-56. [PMID: 23524461 DOI: 10.1038/nri3422] [Citation(s) in RCA: 167] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Type 1 diabetes (T1D) remains an important health problem, particularly in western countries, where the incidence has been increasing in younger children. In 1986, Eisenbarth described T1D as a chronic autoimmune disease. Work over the past three-and-a-half decades has identified many of the genetic, immunological and environmental factors that are involved in the disease and have led to hypotheses concerning its pathogenesis. Clinical trials have been conducted to test these hypotheses but have had mixed results. Here, we discuss the findings that have led to our current concepts of the disease mechanisms involved in T1D and the clinical studies promoted by these studies. The findings from preclinical and clinical studies support the original proposed model for how T1D develops but have also suggested that this disease is more complex than was originally thought and will require broader treatment approaches.
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Affiliation(s)
- Kevan C Herold
- Department of Immunobiology, Yale University, New Haven, Connecticut 06520, USA.
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76
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Abstract
The prevalence of type 2 diabetes mellitus has increased at an alarming rate in recent years. Recent estimations project that 366 million people could have diabetes by 2030. The incretin system emerges as a new target for type 2 diabetes therapy, and new molecules are being approved for its use in humans since the year 2005. These agents could be divided into 2 main groups, glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 inhibitors. Endogenous GLP-1 is an incretin hormone composed by a 30-amino acid peptide and is secreted from L-cells in distal small intestine in response to calorie intake, causing a glucose-dependent β-cell response resulting in a restoration of the first-phase insulin response. Additionally, GLP-1 regulates glucagon production, which leads to inhibition of glucogenolysis and gluconeogenesis in the liver. Synthetic molecules such as exenatide and liraglutide have been developed to bind GLP-1 receptor and mimic GLP-1 effects in pancreatic cells and other target organs.
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77
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Bhavsar S, Mudaliar S, Cherrington A. Evolution of exenatide as a diabetes therapeutic. Curr Diabetes Rev 2013; 9:161-93. [PMID: 23256660 PMCID: PMC3664512 DOI: 10.2174/1573399811309020007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 12/12/2012] [Accepted: 12/14/2012] [Indexed: 12/18/2022]
Abstract
Type 2 diabetes (T2DM) is a disease of epidemic proportion associated with significant morbidity and excess mortality. Optimal glucose control reduces the risk of microvascular and possibly macrovascular complications due to diabetes. However, glycemic control is rarely optimal and several therapeutic interventions for the treatment of diabetes cause hypoglycemia and weight gain; some may exacerbate cardiovascular risk. Exenatide (synthetic exendin-4) is a glucagon- like peptide-1 receptor (GLP-1R) agonist developed as a first-in-class diabetes therapy. This review presents an overview of the evolution of exenatide as a T2DM treatment, beginning with the seminal preclinical discoveries and continuing through to clinical pharmacology investigations and phase 3 clinical trials. In patients with T2DM, exenatide enhanced glucose-dependent insulin secretion, suppressed inappropriately elevated glucagon secretion, slowed gastric emptying, and enhanced satiety. In controlled phase 3 clinical trials ranging from 12 to 52 weeks, 10-mcg exenatide twice daily (ExBID) reduced mean HbA1c by -0.8% to -1.7% as monotherapy or in combination with metformin (MET), sulfonylureas (SFU), and/or thiazolidinediones (TZD); with mean weight losses of -1.2 kg to -8.0 kg. In controlled phase 3 trials ranging from 24 to 30 weeks, a 2-mg once-weekly exenatide formulation (ExQW) reduced mean HbA1c by -1.3% to -1.9%, with mean weight reductions of -2.3 to -3.7 kg. Exenatide was generally well-tolerated. The most common side effects were gastrointestinal in nature, mild, and transient. Nausea was the most prevalent adverse event. The incidence of hypoglycemia was generally low. By building upon early observations exenatide was successfully developed into an effective diabetes therapy.
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Affiliation(s)
- Sunil Bhavsar
- Amylin Pharmaceuticals, Inc., San Diego CA
- Address correspondence to these authors at the Amylin Pharmaceuticals, Inc., San Diego CA; VA San Diego Healthcare System and University of California at San Diego, San Diego CA; Vanderbilt University, Nashville TN, USA; Fax: 615-343-0490, 858-642-6242; E-mails: , , ,
| | - Sunder Mudaliar
- VA San Diego Healthcare System and University of California at San Diego, San Diego CA
- Address correspondence to these authors at the Amylin Pharmaceuticals, Inc., San Diego CA; VA San Diego Healthcare System and University of California at San Diego, San Diego CA; Vanderbilt University, Nashville TN, USA; Fax: 615-343-0490, 858-642-6242; E-mails: , , ,
| | - Alan Cherrington
- Vanderbilt University, Nashville TN, USA
- Address correspondence to these authors at the Amylin Pharmaceuticals, Inc., San Diego CA; VA San Diego Healthcare System and University of California at San Diego, San Diego CA; Vanderbilt University, Nashville TN, USA; Fax: 615-343-0490, 858-642-6242; E-mails: , , ,
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78
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Thompson RF, Einstein FH. Epigenetic basis for fetal origins of age-related disease. J Womens Health (Larchmt) 2013; 19:581-7. [PMID: 20136551 DOI: 10.1089/jwh.2009.1408] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The current concept of fetal origins of adult diseases describes in utero programming, or adaptation to a spectrum of adverse environmental conditions that ultimately leads to increased susceptibility to age-related diseases (e.g., type 2 diabetes and cardiovascular disease) later in life. Although the precise mechanism of this biological memory remains unclear, mounting evidence suggests an epigenetic basis. The increased susceptibility to chronic disease and involvement of multiple organ systems that is observed is analogous to the decline in resistance to disease that is typical of normal aging. Although the cumulative environment over the course of a lifetime can induce increasing epigenetic dysregulation, we propose that adverse events that occur during early development can induce significant additional dysregulation of the epigenome. Here, we describe the current evidence for fetal origins of adult disease and the associated role of epigenetic dysregulation. In addition, we present a new perspective on the induction of epigenetic alterations in utero, which subsequently lead to an aging phenotype marked by increased susceptibility to age-related diseases.
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79
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Gatford KL, Sulaiman SA, Mohammad SNB, De Blasio MJ, Harland ML, Simmons RA, Owens JA. Neonatal exendin-4 reduces growth, fat deposition and glucose tolerance during treatment in the intrauterine growth-restricted lamb. PLoS One 2013; 8:e56553. [PMID: 23424667 PMCID: PMC3570470 DOI: 10.1371/journal.pone.0056553] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 01/15/2013] [Indexed: 11/24/2022] Open
Abstract
Background IUGR increases the risk of type 2 diabetes mellitus (T2DM) in later life, due to reduced insulin sensitivity and impaired adaptation of insulin secretion. In IUGR rats, development of T2DM can be prevented by neonatal administration of the GLP-1 analogue exendin-4. We therefore investigated effects of neonatal exendin-4 administration on insulin action and β-cell mass and function in the IUGR neonate in the sheep, a species with a more developed pancreas at birth. Methods Twin IUGR lambs were injected s.c. daily with vehicle (IUGR+Veh, n = 8) or exendin-4 (1 nmol.kg-1, IUGR+Ex-4, n = 8), and singleton control lambs were injected with vehicle (CON, n = 7), from d 1 to 16 of age. Glucose-stimulated insulin secretion and insulin sensitivity were measured in vivo during treatment (d 12–14). Body composition, β-cell mass and in vitro insulin secretion of isolated pancreatic islets were measured at d 16. Principal Findings IUGR+Veh did not alter in vivo insulin secretion or insulin sensitivity or β-cell mass, but increased glucose-stimulated insulin secretion in vitro. Exendin-4 treatment of the IUGR lamb impaired glucose tolerance in vivo, reflecting reduced insulin sensitivity, and normalised glucose-stimulated insulin secretion in vitro. Exendin-4 also reduced neonatal growth and visceral fat accumulation in IUGR lambs, known risk factors for later T2DM. Conclusions Neonatal exendin-4 induces changes in IUGR lambs that might improve later insulin action. Whether these effects of exendin-4 lead to improved insulin action in adult life after IUGR in the sheep, as in the PR rat, requires further investigation.
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Affiliation(s)
- Kathryn L Gatford
- Robinson Institute, University of Adelaide, Adelaide, South Australia, Australia.
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80
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Parkes DG, Mace KF, Trautmann ME. Discovery and development of exenatide: the first antidiabetic agent to leverage the multiple benefits of the incretin hormone, GLP-1. Expert Opin Drug Discov 2012; 8:219-44. [PMID: 23231438 DOI: 10.1517/17460441.2013.741580] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
INTRODUCTION The GLP-1 receptor agonist exenatide is synthetic exendin-4, a peptide originally isolated from the salivary secretions of the Gila monster. Exenatide was developed as a first-in-class diabetes therapy, with immediate- and extended-release formulations. In preclinical diabetes models, exenatide enhanced glucose-dependent insulin secretion, suppressed inappropriately elevated glucagon secretion, slowed gastric emptying, reduced body weight, enhanced satiety, and preserved pancreatic β-cell function. In clinical trials, both exenatide formulations reduced hyperglycemia in patients with type 2 diabetes mellitus (T2DM) and were associated with weight loss. AREAS COVERED This article reviews the development of exenatide from its discovery and preclinical investigations, to the elucidation of its pharmacological mechanisms of action in mammalian systems. The article also presents the pharmacokinetic profiling and toxicology studies of exenatide, as well as its validation in clinical trials. EXPERT OPINION GLP-1 receptor agonists represent a new paradigm for the treatment of patients with T2DM. By leveraging incretin physiology, a natural regulatory system that coordinates oral nutrient intake with mechanisms of metabolic control, these agents address multiple core defects in the pathophysiology of T2DM. Studies have identified unique benefits including improvements in glycemic control and weight, and the potential for beneficial effects on the cardiometabolic system without the increased risk of hypoglycemia associated with insulin therapy. Peptide hormone therapeutics can offer significant advantages over small molecule drug targets when it comes to specificity, potency, and more predictable side effects. As exemplified by exenatide, injectable peptides can be important drugs for the treatment of chronic diseases, such as T2DM.
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Affiliation(s)
- David G Parkes
- Amylin Pharmaceuticals, Inc., 9360 Towne Centre Drive, San Diego, CA 92121, USA.
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81
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Lee SA, Ding C. The dysfunctional placenta epigenome: causes and consequences. Epigenomics 2012; 4:561-9. [DOI: 10.2217/epi.12.49] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The placenta is a fetal–maternal endocrine organ responsible for ensuring proper fetal development throughout pregnancy. Adverse insults to the intrauterine environment often lead to expression level changes in placental genes, many of which are epigenetically regulated by DNA methylation, histone modifications and ncRNA interference. These epigenetic alterations may cause placental dysfunction, resulting in offspring of low birthweight owing to adverse pregnancy complications such as intrauterine growth restriction. Numerous epidemiological studies have shown a strong correlation between low birthweight and increased risk of developing metabolic diseases and neurological imbalances in adulthood, and in subsequent generations, indicating that epigenetic regulation of gene expression can be propagated stably with long-term effects on health. This article provides an overview of the various environmental factors capable of inducing detrimental changes to the placental epigenome, as well as the corresponding mechanisms that prime the offspring for onset of disease later in life.
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Affiliation(s)
- Sue-Ann Lee
- Singapore Institute for Clinical Sciences, Agency for Science, Technology & Research (A*STAR), Brenner Center for Molecular Medicine, 30 Medical Drive, Singapore, 117609
| | - Chunming Ding
- Singapore Institute for Clinical Sciences, Agency for Science, Technology & Research (A*STAR), Brenner Center for Molecular Medicine, 30 Medical Drive, Singapore, 117609
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82
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The fetal origins of the metabolic syndrome: can we intervene? J Pregnancy 2012; 2012:482690. [PMID: 23029616 PMCID: PMC3457612 DOI: 10.1155/2012/482690] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 07/23/2012] [Accepted: 08/08/2012] [Indexed: 12/15/2022] Open
Abstract
Epidemiological studies have suggested that metabolic programming begins during fetal life and adverse events in utero are a critical factor in the etiology of chronic diseases and overall health. While the underlying molecular mechanisms linking impaired fetal development to these adult diseases are being elucidated, little is known about how we can intervene early in life to diminish the incidence and severity of these long-term diseases. This paper highlights the latest clinical and pharmaceutical studies addressing how dietary intervention in fetal and neonatal life may be able to prevent aspects of the metabolic syndrome associated with IUGR pregnancies.
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83
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Kent AL. Developmental origins of health and adult disease: what should neonatologists/paediatricians be considering about the long-term health of their patients? J Paediatr Child Health 2012; 48:730-4. [PMID: 22970665 DOI: 10.1111/j.1440-1754.2012.02541.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The developmental origins of health and disease hypothesis is now strongly supported by both animal and human evidence, and as a consequence, obstetricians, neonatologists and paediatricians need to consider the impact that the in utero and early post-natal environment can have on later renal, cardiovascular and metabolic health. Four common clinical scenarios were provided along with animal and human evidence identifying long-term health implications. Suggestions as to how we should translate this growing body of evidence into practice are provided.
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Affiliation(s)
- Alison L Kent
- Department of Neonatology, Canberra Hospital, Woden, Australian Capital Territory, Australia.
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84
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Gilbert ER, Liu D. Epigenetics: the missing link to understanding β-cell dysfunction in the pathogenesis of type 2 diabetes. Epigenetics 2012; 7:841-52. [PMID: 22810088 PMCID: PMC3427279 DOI: 10.4161/epi.21238] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Type 2 diabetes (T2D) is a growing health problem worldwide. While peripheral insulin resistance is common during obesity and aging in both animals and people, progression to T2D is largely due to insulin secretory dysfunction and significant apoptosis of functional β-cells, leading to an inability to compensate for insulin resistance. It is recognized that environmental factors and nutrition play an important role in the pathogenesis of diabetes. However, our knowledge surrounding molecular mechanisms by which these factors trigger β-cell dysfunction and diabetes is still limited. Recent discoveries raise the possibility that epigenetic changes in response to environmental stimuli may play an important role in the development of diabetes. In this paper, we review emerging knowledge regarding epigenetic mechanisms that may be involved in β-cell dysfunction and pathogenesis of diabetes, including the role of nutrition, oxidative stress and inflammation. We will mainly focus on the role of DNA methylation and histone modifications but will also briefly review data on miRNA effects on the pancreatic islets. Further studies aimed at better understanding how epigenetic regulation of gene expression controls β-cell function may reveal potential therapeutic targets for prevention and treatment of diabetes.
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Affiliation(s)
- Elizabeth R. Gilbert
- Department of Animal and Poultry Sciences; College of Agriculture and Life Sciences; Virginia Tech; Blacksburg, VA USA
| | - Dongmin Liu
- Department of Human Nutrition, Foods and Exercise; College of Agriculture and Life Sciences; Virginia Tech; Blacksburg, VA USA
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85
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Vickers MH, Sloboda DM. Strategies for reversing the effects of metabolic disorders induced as a consequence of developmental programming. Front Physiol 2012; 3:242. [PMID: 22783205 PMCID: PMC3387724 DOI: 10.3389/fphys.2012.00242] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 06/13/2012] [Indexed: 01/21/2023] Open
Abstract
Obesity and the metabolic syndrome have reached epidemic proportions worldwide with far-reaching health care and economic implications. The rapid increase in the prevalence of these disorders suggests that environmental and behavioral influences, rather than genetic causes, are fueling the epidemic. The developmental origins of health and disease hypothesis has highlighted the link between the periconceptual, fetal, and early infant phases of life and the subsequent development of metabolic disorders in later life. In particular, the impact of poor maternal nutrition on susceptibility to later life metabolic disease in offspring is now well documented. Several studies have now shown, at least in experimental animal models, that some components of the metabolic syndrome, induced as a consequence of developmental programming, are potentially reversible by nutritional or targeted therapeutic interventions during windows of developmental plasticity. This review will focus on critical windows of development and possible therapeutic avenues that may reduce metabolic and obesogenic risk following an adverse early life environment.
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Affiliation(s)
- M H Vickers
- National Research Centre for Growth and Development, Liggins Institute, University of Auckland Auckland, New Zealand
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86
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Roth CL, Sathyanarayana S. Mechanisms affecting neuroendocrine and epigenetic regulation of body weight and onset of puberty: potential implications in the child born small for gestational age (SGA). Rev Endocr Metab Disord 2012; 13:129-40. [PMID: 22415297 DOI: 10.1007/s11154-012-9212-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Signaling peptides produced in peripheral tissues such as gut, adipose tissue, and pancreas communicate with brain centers, such as hypothalamus and hindbrain to manage energy homeostasis. These regulatory mechanisms of energy intake and storage have evolved during long periods of hunger in the evolution of man to protect the species from extinction. It is now clear that these circuitries are influenced by prenatal and postnatal environmental factors including endocrine disruptive chemicals. Hypothalamic appetite regulatory systems develop and mature in utero and early infancy, and involve signaling pathways that are important also for the regulation of puberty onset. Recent studies in humans and animals have shown that metabolic pathways involved in regulation of growth, body weight gain and sexual maturation are largely affected by epigenetic programming that can impact both current and future generations. In particular, intrauterine and early infantile developmental phases of high plasticity are susceptible to factors that affect metabolic programming that therefore, affect metabolic function throughout life. In children born small for gestational age, poor nutritional conditions during gestation can modify metabolic systems to adapt to expectations of chronic undernutrition. These children are potentially poorly equipped to cope with energy-dense diets and are possibly programmed to store as much energy as possible, leading to later obesity, metabolic syndrome, disturbed regulation of normal puberty and early onset of cardiovascular disease. Most cases of disturbed energy balance are likely a result of a combination of genetics, epigenetics and environment. This review will discuss potential mechanisms linking intrauterine growth retardation with changes in growth, energy homeostasis and sexual maturation.
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Affiliation(s)
- Christian L Roth
- Division of Endocrinology, Seattle Children's Hospital Research Institute, 1900 Ninth Avenue, Seattle, WA 98101, USA.
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87
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Bramswig NC, Kaestner KH. Epigenetics and diabetes treatment: an unrealized promise? Trends Endocrinol Metab 2012; 23:286-91. [PMID: 22424897 PMCID: PMC3367121 DOI: 10.1016/j.tem.2012.02.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 01/30/2012] [Accepted: 02/02/2012] [Indexed: 01/19/2023]
Abstract
Epigenetic mechanisms may contribute to the pathogenesis of complex diseases. Early or late environmental influences such as intrauterine malnutrition or sedentary lifestyle have been shown to lead to an increased risk of diabetes. Recently, epigenetic mechanisms were shown to be involved in endocrine cell differentiation and islet function. Genomic profiling of pancreatic islets in non-diabetic and diabetic states is needed in order to dissect the contribution of epigenetic mechanisms to the declining proliferation potential of β cells that we see with aging or the β-cell failure observed in diabetes. In-depth understanding of epigenetic landscapes can help to improve protocols for in vitro differentiation towards the β-cell fate, enhance β-cell proliferation, and lead to the discovery of novel therapeutic targets.
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Affiliation(s)
- Nuria C Bramswig
- Department of Genetics and Institute of Diabetes, Obesity & Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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88
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Vo T, Hardy DB. Molecular mechanisms underlying the fetal programming of adult disease. J Cell Commun Signal 2012; 6:139-53. [PMID: 22623025 DOI: 10.1007/s12079-012-0165-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Accepted: 05/02/2012] [Indexed: 12/30/2022] Open
Abstract
Adverse events in utero can be critical in determining quality of life and overall health. It is estimated that up to 50 % of metabolic syndrome diseases can be linked to an adverse fetal environment. However, the mechanisms linking impaired fetal development to these adult diseases remain elusive. This review uncovers some of the molecular mechanisms underlying how normal physiology may be impaired in fetal and postnatal life due to maternal insults in pregnancy. By understanding the mechanisms, which include epigenetic, transcriptional, endoplasmic reticulum (ER) stress, and reactive oxygen species (ROS), we also highlight how intervention in fetal and neonatal life may be able to prevent these diseases long-term.
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Affiliation(s)
- Thin Vo
- The Department of Physiology & Pharmacology, University of Western Ontario, London, Ontario, Canada, N6A 5C1
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89
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Dötsch J, Plank C, Amann K. Fetal programming of renal function. Pediatr Nephrol 2012; 27:513-20. [PMID: 21298502 DOI: 10.1007/s00467-011-1781-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Revised: 12/09/2010] [Accepted: 12/15/2010] [Indexed: 01/10/2023]
Abstract
Results from large epidemiological studies suggest a clear relation between low birth weight and adverse renal outcome evident as early as during childhood. Such adverse outcomes may include glomerular disease, hypertension, and renal failure and contribute to a phenomenon called fetal programming. Other factors potentially leading to an adverse renal outcome following fetal programming are maternal diabetes mellitus, smoking, salt overload, and use of glucocorticoids during pregnancy. However, clinical data on the latter are scarce. Here, we discuss potential underlying mechanisms of fetal programming, including reduced nephron number via diminished nephrogenesis and other renal (e.g., via the intrarenal renin-angiotensin-aldosterone system) and non-renal (e.g., changes in endothelial function) alterations. It appears likely that the outcomes of fetal programming may be influenced or modified postnatally, for example, by the amount of nutrients given at critical times.
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Affiliation(s)
- Jörg Dötsch
- Department of Pediatrics, University of Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
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90
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Turner syndrome and metabolic derangements: another example of fetal programming. Early Hum Dev 2012; 88:99-102. [PMID: 21802870 DOI: 10.1016/j.earlhumdev.2011.07.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Revised: 07/08/2011] [Accepted: 07/11/2011] [Indexed: 01/15/2023]
Abstract
BACKGROUND AND AIM Turner syndrome (TS) patients have an increased risk of weight gain and metabolic syndrome. To date, it is unknown what factors are involved in this metabolic process, even though it is recognized that TS patients are frequently born small-for-gestational age. The aim of this study was to evaluate the correlation between lipid and glucose profiles with being overweight and birth weight and length in TS patients. STUDY DESIGN This was a cross-sectional study. SUBJECTS AND OUTCOME MEASURES Serum glucose, insulin (HOMA-IR), total cholesterol, and triglycerides were measured in 64 patients with TS. Data regarding birth weight and length and current body mass index (BMI) were also evaluated. RESULTS Total cholesterol showed a significant negative correlation with birth weight and a positive correlation with BMI; triglycerides showed significant negative correlation with birth weight and length and a positive correlation with BMI; and HOMA-IR showed a significant negative correlation with birth weight and length. Low birth weight and a high BMI were predictive for 28% of total cholesterol and triglycerides; and low birth weight for 22% of HOMA-IR. CONCLUSIONS Lipid profile was correlated with a high current BMI and low birth weight and length in TS patients and glucose profile only with low birth weight. Thus far, growth retardation may play a role in metabolic derangements in this group of patients, being considered another example of fetal programming.
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Abstract
The link between an adverse intrauterine environment and the development of disease later in life has been observed in offspring of pregnancies complicated by obesity and diabetes, but the molecular mechanisms underlying this phenomenon are unknown. In this review, we highlight recent publications exploring the role of gestational diabetes mellitus in the programming of disease in the offspring. We also review recent publications aiming to identify mechanisms responsible for the "programming effect" that results from exposure to diabetes in utero. Finally, we highlight research on the role of epigenetic regulation of gene expression in an animal model of uteroplacental insufficiency where the offspring develop diabetes as a model by which an exposure to the mother can alter epigenetic modifications that affect expression of key genes and ultimately lead to the development of diabetes in the offspring.
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Affiliation(s)
- Sara E Pinney
- Division of Endocrinology and Diabetes, Department of Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA.
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Calderari S, Chougnet C, Clemessy M, Kempf H, Corvol P, Larger E. Angiopoietin 2 alters pancreatic vascularization in diabetic conditions. PLoS One 2012; 7:e29438. [PMID: 22272235 PMCID: PMC3260141 DOI: 10.1371/journal.pone.0029438] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Accepted: 11/28/2011] [Indexed: 01/25/2023] Open
Abstract
Aims/hypothesis Islet vascularization, by controlling beta-cell mass expansion in response to increased insulin demand, is implicated in the progression to glucose intolerance and type 2 diabetes. We investigated how hyperglycaemia impairs expansion and differentiation of the growing pancreas. We have grafted xenogenic (avian) embryonic pancreas in severe combined immuno-deficient (SCID) mouse and analyzed endocrine and endothelial development in hyperglycaemic compared to normoglycaemic conditions. Methods 14 dpi chicken pancreases were grafted under the kidney capsule of normoglycaemic or hyperglycaemic, streptozotocin-induced, SCID mice and analyzed two weeks later. Vascularization was analyzed both quantitatively and qualitatively using either in situ hybridization with both mouse- and chick-specific RNA probes for VEGFR2 or immunohistochemistry with an antibody to nestin, a marker of endothelial cells that is specific for murine cells. To inhibit angiopoietin 2 (Ang2), SCID mice were treated with 4 mg/kg IP L1–10 twice/week. Results In normoglycaemic condition, chicken-derived endocrine and exocrine cells developed well and intragraft vessels were lined with mouse endothelial cells. When pancreases were grafted in hyperglycaemic mice, growth and differentiation of the graft were altered and we observed endothelial discontinuities, large blood-filled spaces. Vessel density was decreased. These major vascular anomalies were associated with strong over-expression of chick-Ang2. To explore the possibility that Ang2 over-expression could be a key step in vascular disorganization induced by hyperglycaemia, we treated mice with L1–10, an Ang-2 specific inhibitor. Inhibition of Ang2 improved vascularization and beta-cell density. Conclusions This work highlighted an important role of Ang2 in pancreatic vascular defects induced by hyperglycaemia.
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Laker RC, Gallo LA, Wlodek ME, Siebel AL, Wadley GD, McConell GK. Short-term exercise training early in life restores deficits in pancreatic β-cell mass associated with growth restriction in adult male rats. Am J Physiol Endocrinol Metab 2011; 301:E931-40. [PMID: 21810930 DOI: 10.1152/ajpendo.00114.2011] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Fetal growth restriction is associated with reduced pancreatic β-cell mass, contributing to impaired glucose tolerance and diabetes. Exercise training increases β-cell mass in animals with diabetes and has long-lasting metabolic benefits in rodents and humans. We studied the effect of exercise training on islet and β-cell morphology and plasma insulin and glucose, following an intraperitoneal glucose tolerance test (IPGTT) in juvenile and adult male Wistar-Kyoto rats born small. Bilateral uterine vessel ligation performed on day 18 of pregnancy resulted in Restricted offspring born small compared with sham-operated Controls and also sham-operated Reduced litter offspring that had their litter size reduced to five pups at birth. Restricted, Control, and Reduced litter offspring remained sedentary or underwent treadmill running from 5 to 9 or 20 to 24 wk of age. Early life exercise increased relative islet surface area and β-cell mass across all groups at 9 wk, partially restoring the 60-68% deficit (P < 0.05) in Restricted offspring. Remarkably, despite no further exercise training after 9 wk, β-cell mass was restored in Restricted at 24 wk, while sedentary littermates retained a 45% deficit (P = 0.05) in relative β-cell mass. Later exercise training also restored Restricted β-cell mass to Control levels. In conclusion, early life exercise training in rats born small restored β-cell mass in adulthood and may have beneficial consequences for later metabolic health and disease.
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Affiliation(s)
- Rhianna C Laker
- Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia
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94
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Early-life origins of type 2 diabetes: fetal programming of the beta-cell mass. EXPERIMENTAL DIABETES RESEARCH 2011; 2011:105076. [PMID: 22110471 PMCID: PMC3202114 DOI: 10.1155/2011/105076] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 08/02/2011] [Accepted: 08/02/2011] [Indexed: 12/13/2022]
Abstract
A substantial body of evidence suggests that an abnormal intrauterine milieu elicited by maternal metabolic disturbances as diverse as undernutrition, placental insufficiency, diabetes or obesity, may program susceptibility in the fetus to later develop chronic degenerative diseases, such as obesity, hypertension, cardiovascular diseases and diabetes. This paper examines the developmental programming of glucose intolerance/diabetes by disturbed intrauterine metabolic condition experimentally obtained in various rodent models of maternal protein restriction, caloric restriction, overnutrition or diabetes, with a focus on the alteration of the developing beta-cell mass. In most of the cases, whatever the type of initial maternal metabolic stress, the beta-cell adaptive growth which normally occurs during gestation, does not take place in the pregnant offspring and this results in the development of gestational diabetes. Therefore gestational diabetes turns to be the ultimate insult targeting the offspring beta-cell mass and propagates diabetes risk to the next generation again. The aetiology and the transmission of spontaneous diabetes as encountered in the GK/Par rat model of type 2 diabetes, are discussed in such a perspective. This review also discusses the non-genomic mechanisms involved in the installation of the programmed effect as well as in its intergenerational transmission.
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95
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Moutzouri E, Tsimihodimos V, Rizos E, Elisaf M. Prediabetes: to treat or not to treat? Eur J Pharmacol 2011; 672:9-19. [PMID: 22020287 DOI: 10.1016/j.ejphar.2011.10.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 09/27/2011] [Accepted: 10/02/2011] [Indexed: 02/07/2023]
Abstract
The incidence of diabetes is continuously increasing worldwide. Pre-diabetes (defined as impaired glucose tolerance, impaired fasting glucose or both) represents an intermediate state, which often progresses to overt diabetes within a few years. In addition, pre-diabetes may be associated with increased risk of microvascular and macrovascular complications. Thus, reverting a pre-diabetic state as well as preventing the development of diabetes represents enormous challenge for the clinician. Lifestyle modification in pre-diabetic individuals was found particularly effective in the prevention of diabetes. However, compliance to lifestyle modification measures can be a crucial problem in the everyday clinical practice, especially in developing countries. During the last decade many studies support the use of anti-diabetic treatment schemes in pre-diabetic subjects to be advantageous. The American Diabetes Prevention Program (DPP) as well as other minor studies and meta-analyses has convincingly demonstrated the efficacy of metformin in this patient group. In addition, results of the 10 year DPP follow up have recently been published, demonstrating the long term safety and sustainability of metformin treatment benefits in this population. In contrast to metformin, the evidence from the use of other anti-diabetic agents (thiazolidinediones, a-glucosidase inhibitors, incretin mimetics) in pre-diabetic individuals is rather inadequate and prospective data is further needed. Furthermore, large scale studies with hard clinical endpoints are needed to delineate the effect of pre-diabetes treatment on macro- and microvascular complications. In conclusion, several strategies of patient management, mainly lifestyle modification and pharmacological interventions can prevent diabetes development in subjects diagnosed with pre-diabetes or even revert pre-diabetic state. However, whether this biochemical improvement can be translated into actual clinical benefit remains to be established.
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Affiliation(s)
- Elisavet Moutzouri
- Department of Internal Medicine, Medical School, University of Ioannina, Ioannina, Greece
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96
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Pinney SE, Jaeckle Santos LJ, Han Y, Stoffers DA, Simmons RA. Exendin-4 increases histone acetylase activity and reverses epigenetic modifications that silence Pdx1 in the intrauterine growth retarded rat. Diabetologia 2011; 54:2606-14. [PMID: 21779870 PMCID: PMC4461231 DOI: 10.1007/s00125-011-2250-1] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 06/10/2011] [Indexed: 01/04/2023]
Abstract
AIMS/HYPOTHESIS The abnormal intrauterine milieu of intrauterine growth retardation (IUGR) permanently alters gene expression and function of pancreatic beta cells leading to the development of diabetes in adulthood. Expression of the pancreatic homeobox transcription factor Pdx1 is permanently reduced in IUGR islets suggesting an epigenetic mechanism. Exendin-4 (Ex-4), a long-acting glucagon-like peptide-1 (GLP-1) analogue, given in the newborn period increases Pdx1 expression and prevents the development of diabetes in the IUGR rat. METHODS IUGR was induced by bilateral uterine artery ligation in fetal life. Ex-4 was given on postnatal days 1-6 of life. Islets were isolated at 1 week and at 3-12 months. Histone modifications, PCAF, USF1 and DNA methyltransferase (Dnmt) 1 binding were assessed by chromatin immunoprecipitation (ChIP) assays and DNA methylation was quantified by pyrosequencing. RESULTS Phosphorylation of USF1 was markedly increased in IUGR islets in Ex-4 treated animals. This resulted in increased USF1 and PCAF association at the proximal promoter of Pdx1, thereby increasing histone acetyl transferase (HAT) activity. Histone H3 acetylation and trimethylation of H3K4 were permanently increased, whereas Dnmt1 binding and subsequent DNA methylation were prevented at the proximal promoter of Pdx1 in IUGR islets. Normalisation of these epigenetic modifications reversed silencing of Pdx1 in islets of IUGR animals. CONCLUSIONS/INTERPRETATION These studies demonstrate a novel mechanism whereby a short treatment course of Ex-4 in the newborn period permanently increases HAT activity by recruiting USF1 and PCAF to the proximal promoter of Pdx1 which restores chromatin structure at the Pdx1 promoter and prevents DNA methylation, thus preserving Pdx1 transcription.
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Affiliation(s)
- S. E. Pinney
- Department of Pediatrics, The Children’s Hospital of Philadelphia, University of Pennsylvania School of Medicine Philadelphia, Philadelphia, PA, USA
- Biomedical Research Building II/III 1308, University of Pennsylvania School of Medicine, 421 Curie Boulevard, Philadelphia, PA 19104, USA
| | - L. J. Jaeckle Santos
- Department of Pediatrics, The Children’s Hospital of Philadelphia, University of Pennsylvania School of Medicine Philadelphia, Philadelphia, PA, USA
- Biomedical Research Building II/III 1308, University of Pennsylvania School of Medicine, 421 Curie Boulevard, Philadelphia, PA 19104, USA
| | - Y. Han
- Department of Pediatrics, The Children’s Hospital of Philadelphia, University of Pennsylvania School of Medicine Philadelphia, Philadelphia, PA, USA
- Biomedical Research Building II/III 1308, University of Pennsylvania School of Medicine, 421 Curie Boulevard, Philadelphia, PA 19104, USA
| | - D. A. Stoffers
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
- Institute of Diabetes, Obesity and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - R. A. Simmons
- Department of Pediatrics, The Children’s Hospital of Philadelphia, University of Pennsylvania School of Medicine Philadelphia, Philadelphia, PA, USA
- Biomedical Research Building II/III 1308, University of Pennsylvania School of Medicine, 421 Curie Boulevard, Philadelphia, PA 19104, USA
- Institute of Diabetes, Obesity and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
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97
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Maternal obesity and developmental programming of metabolic disorders in offspring: evidence from animal models. EXPERIMENTAL DIABETES RESEARCH 2011; 2011:592408. [PMID: 21969822 PMCID: PMC3182397 DOI: 10.1155/2011/592408] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 07/22/2011] [Indexed: 01/21/2023]
Abstract
The incidence of obesity and overweight has reached epidemic proportions in the developed world as well as in those countries transitioning to first world economies, and this represents a major global health problem. Concern is rising over the rapid increases in childhood obesity and metabolic disease that will translate into later adult obesity. Although an obesogenic nutritional environment and increasingly sedentary lifestyle contribute to our risk of developing obesity, a growing body of evidence links early life nutritional adversity to the development of long-term metabolic disorders. In particular, the increasing prevalence of maternal obesity and excess maternal weight gain has been associated with a heightened risk of obesity development in offspring in addition to an increased risk of pregnancy-related complications. The mechanisms that link maternal obesity to obesity in offspring and the level of gene-environment interactions are not well understood, but the early life environment may represent a critical window for which intervention strategies could be developed to curb the current obesity epidemic. This paper will discuss the various animal models of maternal overnutrition and their importance in our understanding of the mechanisms underlying altered obesity risk in offspring.
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Vickers MH. Developmental programming of the metabolic syndrome - critical windows for intervention. World J Diabetes 2011; 2:137-48. [PMID: 21954418 PMCID: PMC3180526 DOI: 10.4239/wjd.v2.i9.137] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 08/15/2011] [Accepted: 08/31/2011] [Indexed: 02/05/2023] Open
Abstract
Metabolic disease results from a complex interaction of many factors, including genetic, physiological, behavioral and environmental influences. The recent rate at which these diseases have increased suggests that environmental and behavioral influences, rather than genetic causes, are fuelling the present epidemic. In this context, the developmental origins of health and disease hypothesis has highlighted the link between the periconceptual, fetal and early infant phases of life and the subsequent development of adult obesity and the metabolic syndrome. Although the mechanisms are yet to be fully elucidated, this programming was generally considered an irreversible change in developmental trajectory. Recent work in animal models suggests that developmental programming of metabolic disorders is potentially reversible by nutritional or targeted therapeutic interventions during the period of developmental plasticity. This review will discuss critical windows of developmental plasticity and possible avenues to ameliorate the development of postnatal metabolic disorders following an adverse early life environment.
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Affiliation(s)
- Mark H Vickers
- Mark H Vickers, Liggins Institute and the National Research Centre for Growth and Development, University of Auckland, Auckland 1023, New Zealand
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Lotfy M, Singh J, Kalász H, Tekes K, Adeghate E. Medicinal Chemistry and Applications of Incretins and DPP-4 Inhibitors in the Treatment of Type 2 Diabetes Mellitus. THE OPEN MEDICINAL CHEMISTRY JOURNAL 2011; 5:82-92. [PMID: 21966329 PMCID: PMC3174521 DOI: 10.2174/1874104501105010082] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2011] [Revised: 03/27/2011] [Accepted: 03/30/2011] [Indexed: 12/25/2022]
Abstract
Diabetes mellitus (DM) is a major metabolic disorder currently affecting over 200 million people worldwide. Approximately 90% of all diabetic patients suffer from Type 2 diabetes mellitus (T2DM). The world's economy coughs out billions of dollars annually to diagnose, treat and manage patients with diabetes. It has been shown that the naturally occurring gut hormones incretins, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) can preserve the morphology and function of pancreatic beta cell. In addition, GIP and GLP-1 act on insulin receptors to facilitate insulin-receptor binding, resulting in optimal glucose metabolism. This review examines the medicinal chemistry and roles of incretins, specifically, GLP-1 and drugs which can mimic its actions and prevent its enzymatic degradation. The review discussed GLP-1 agonists such as exenatide, liraglutide, taspoglutide and albiglutide. The paper also identified and reviewed a number of inhibitors, which can block dipeptidyl peptidase 4 (DPP-4), the enzyme responsible for the rapid degradation of GLP-1. These DPP-4 inhibitors include sitagliptin, saxagliptin, vildagliptin and many others which are still in the experimental phase.
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Affiliation(s)
- Mohamed Lotfy
- Department of Biology, Faculty of Science, UAE University
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100
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Abstract
The metabolic syndrome (MetS) represents a cluster of cardiometabolic risk factors, including central obesity, insulin resistance, glucose intolerance, dyslipidemia, hypertension, hyperinsulinemia and microalbuminuria, and more recently, nonalcoholic fatty liver disease (NAFLD), polycystic ovarian syndrome (PCOS) and atherosclerosis. Although the concept of the MetS is subject to debate due to lack of a unifying underlying mechanism, the prevalence of a metabolic syndrome phenotype is rapidly increasing worldwide. Moreover, it is increasingly prevalent in children and adolescents of obese mothers. Evidence from both epidemiological and experimental animal studies now demonstrates that MetS onset is increasingly likely following exposure to suboptimal nutrition during critical periods of development, as observed in maternal obesity. Thus, the developmental priming of the MetS provides a common origin for this multifactorial disorder. Consequently, the mechanisms leading to this developmental priming have recently been the subject of intensive investigation. This review discusses recent data regarding the epigenetic modifications resulting from nutrition during early development that mediate persistent changes in the expression of key metabolic genes and contribute toward an adult metabolic syndrome phenotype. In addition, this review considers the role of the endogenous molecular circadian clock system, which has the potential to act at the interface between nutrient sensing and epigenetic processing. A continued and greater understanding of these mechanisms will eventually aid in the identification of individuals at high risk of cardiovascular disease (CVD) and type 2 diabetes, and help develop therapeutic interventions, in accordance with current global government strategy.
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Affiliation(s)
- Kimberley D Bruce
- Developmental Origins of Health and Disease Division, Institute of Developmental Sciences, University of Southampton School of Medicine, Southampton, UK.
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