incretins and Atherosclerosis

Cardiovascular events related to atherosclerosis are responsible for high morbidity and mortality among patients with type 2 diabetes. Improvement in care, especially in early stages, is crucial. Oral semaglutide, a glucagon-like peptide 1 analogue, controls blood glucose and results in significant body weight loss in patients with type 2 diabetes. Beyond these well-known effects, an interesting aspect of this drug is its antiatherogenic activity, which should be further explored in clinical practice. This paper reviews the evidence related to oral semaglutide decreasing cardiovascular risk in patients with type 2 diabetes, focusing on the drug's antiatherosclerotic properties. The glucagon-like peptide 1 analogue restores endothelial dysfunction, induces vasodilatation, and reduces plasma lipids. Oral semaglutide showed cardiovascular safety profile, with significant reduced risk of death from cardiovascular events. Based on current data, clinicians should consider oral semaglutide for type 2 diabetes management.

Topics: Administration, Oral; Animals; Atherosclerosis; Biomarkers; Blood Glucose; Cause of Death; Diabetes Mellitus, Type 2; Glucagon-Like Peptide-1 Receptor; Glucagon-Like Peptides; Glycemic Control; Humans; Hypoglycemic Agents; Incretins; Risk Assessment; Risk Factors; Treatment Outcome

Under healthy conditions, pancreatic β-cells produce and secrete the insulin hormone in response to blood glucose levels. Under diabetic conditions, however, β-cells are compelled to continuously secrete larger amounts of insulin to reduce blood glucose levels, and thereby, the β-cell function is debilitated in the long run. In the diabetic state, expression levels of insulin gene transcription factors and incretin receptors are downregulated, which we think is closely associated with β-cell failure. These data also suggest that it would be better to use incretin-based drugs at an early stage of diabetes when incretin receptor expression is preserved. Indeed, it was shown that incretin-based drugs exerted more protective effects on β-cells at an early stage. Furthermore, it was shown recently that endothelial cell dysfunction was also associated with pancreatic β-cell dysfunction. After ablation of insulin signaling in endothelial cells, the β-cell function and mass were substantially reduced, which was also accompanied by reduced expression of insulin gene transcription factors and incretin receptors in β-cells. On the other hand, it has been drawing much attention that incretin plays a protective role against the development of atherosclerosis. Many basic and clinical data have underscored the importance of incretin in arteries. Furthermore, it was shown recently that incretin receptor expression was downregulated in arteries under diabetic conditions, which likely diminishes the protective effects of incretin against atherosclerosis. Furthermore, a series of large-scale clinical trials (SPAED-A, SPIKE, LEADER, SUSTAIN-6, REWIND, PIONEER trials) have shown that various incretin-related drugs have beneficial effects against atherosclerosis and subsequent cardiovascular events. These data strengthen the hypothesis that incretin plays an important role in the arteries of humans, as well as rodents.

Topics: Animals; Atherosclerosis; Humans; Incretins; Insulin; Insulin-Secreting Cells; Signal Transduction

Atherosclerosis is a major underlying cause of ischemic heart diseases, ischemic stroke, and peripheral artery disease. Atherosclerotic plaque progression is characterized by chronic progressive inflammation of the arterial wall, endothelial cell dysfunction, and subendothelial lipoprotein retention. Incretin drugs, glucagon-like peptide-1 receptor (GLP-1R) agonists, and dipeptidyl peptidase-IV (DPP-IV) inhibitors, are promising anti-hyperglycemic agents used for the treatment of type 2 diabetes mellitus (T2DM). In addition to glucose-lowering effects, emerging data suggest that incretin drugs have anti-atherogenic effects with the potential to stabilize atherosclerotic plaques and treat arterial inflammation. Clinical and preclinical studies have reported a plethora of therapeutic benefits of incretin drugs, including modulation of inflammatory response, reduction of intima-media thickening, improvement in lipid profiles, endothelial and smooth muscle cell modulation. Despite extensive research and widespread clinical use of incretin-based therapies, the research on the incretin hormones continues to expand. This review outlines clinical studies, molecular aspects, and potential therapeutic implications of incretin drugs in attenuation of atherosclerosis.

Topics: Anti-Inflammatory Agents; Atherosclerosis; Blood Glucose; Blood Pressure; Cardiovascular Diseases; Carotid Intima-Media Thickness; Diabetes Complications; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Endothelium, Vascular; Glucagon-Like Peptide-1 Receptor; Homeostasis; Humans; Incretins; Inflammation; Lipids; Peptides

The increasing prevalence of atherosclerosis has become a worldwide health concern. Although significant progress has been made in the understanding of atherosclerosis pathogenesis, the underlying mechanisms are not fully understood. Recent studies suggest dipeptidyl peptidase-4 (DPP4), a regulator of inflammation and metabolism, may be involved in the development of atherosclerotic diseases. There has been increasing clinical and pre-clinical evidence showing DPP4-incretin axis is involved in cardiovascular disease. Although the cardiovascular outcome of DPP4 inhibition or incretin analogues has been or being evaluated by several large scale clinical trials, the exact role of DPP4 in atherosclerotic diseases is not completely understood. In the current review, we will summarize the recent advances in direct and indirect regulatory role of DPP4 in atherosclerosis.

Topics: Animals; Arteries; Atherosclerosis; Cardiovascular Agents; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Humans; Incretins; Plaque, Atherosclerotic; Signal Transduction

We reported that native incretins, liraglutide and dipeptidyl peptidase-4 inhibitors (DPP-4i) all confer an anti-atherosclerotic effect in apolipoprotein E-null (Apoe (-/-)) mice. We confirmed the anti-atherogenic property of incretin-related agents in the mouse wire injury model, in which the neointimal formation in the femoral artery is remarkably suppressed. Furthermore, we showed that DPP-4i substantially suppresses plaque formation in coronary arteries with a marked reduction in the accumulation of macrophages in cholesterol-fed rabbits. DPP-4i showed an anti-atherosclerotic effect in Apoe (-/-) mice mainly through the actions of glucagon-like peptide-1 and glucose-dependent insulinotropic polypepide. However, the dual incretin receptor antagonists partially attenuated the suppressive effect of DPP-4i on atherosclerosis in diabetic Apoe (-/-) mice, suggesting an incretin-independent mechanism. Exendin-4 and glucose-dependent insulinotropic polypepide elicited cyclic adenosine monophosphate generation, and suppressed the lipopolysaccharide-induced gene expression of inflammatory molecules, such as interleukin-1β, interleukin-6 and tumor necrosis factor-α, in U937 human monocytes. This suppressive effect, however, was attenuated by an inhibitor of adenylate cyclase and mimicked by 8-bromo-cyclic adenosine monophosphate or forskolin. DPP-4i substantially suppressed the lipopolysaccharide-induced expression of inflammatory cytokines without affecting cyclic adenosine monophosphate generation or cell proliferation. DPP-4i more strongly suppressed the lipopolysaccharide-induced gene expression of inflammatory molecules than incretins, most likely through inactivation of CD26. Glucagon-like peptide-1 and glucose-dependent insulinotropic polypepide suppressed oxidized low-density lipoprotein-induced macrophage foam cell formation in a receptor-dependent manner, which was associated with the downregulation of acyl-coenzyme A cholesterol acyltransferase-1 and CD36, as well as the up-regulation of adenosine triphosphate-binding cassette transporter A1. Our studies strongly suggest that incretin-related agents have favorable effects on macrophage-driven atherosclerosis in experimental animals.

Topics: Animals; Anti-Inflammatory Agents; Apolipoproteins E; Atherosclerosis; Coronary Restenosis; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Foam Cells; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hyperplasia; Incretins; Inflammation; Inflammation Mediators; Liraglutide; Macrophages; Mice; Mice, Knockout; Monocytes

Type 2 diabetes mellitus (T2DM) has become one of the most prevalent noncommunicable diseases in the past years. It is undoubtedly associated with atherosclerosis and increased risk for cardiovascular diseases. Incretins, which are intestinal peptides secreted during digestion, are able to increase insulin secretion and its impaired function and/or secretion is involved in the pathophysiology of T2DM. Dipeptidyl peptidase 4 (DPP4) is an ubiquitous enzyme that regulates incretins and consequently is related to the pathophysiology of T2DM. DPP4 is mainly secreted by endothelial cells and acts as a regulatory protease for cytokines, chemokines, and neuropeptides involved in inflammation, immunity, and vascular function. In T2DM, the activity of DPP4 seems to be increased and there are a growing number of in vitro and in vivo studies suggesting that this enzyme could be a new link between T2DM and atherosclerosis. Gliptins are a new class of pharmaceutical agents that acts by inhibiting DPP4. Thus, it is expected that gliptin represents a new pharmacological approach not only for reducing glycemic levels in T2DM, but also for the prevention and treatment of atherosclerotic cardiovascular disease in diabetic subjects. We aimed to review the evidences that reinforce the associations between DPP4, atherosclerosis, and T2DM.

Topics: Atherosclerosis; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Humans; Incretins; Inflammation

Incretin peptides are a group of gastrointestinal hormones that play a prominent role in the regulation of glucose metabolism. Incretin-based therapies (IBTs) have recently emerged as an important treatment option for patients with type 2 diabetes mellitus (T2DM). These pharmaceutical agents may be specially well suited for patients who are overweight or obese with primarily post-meal glucose peaks, and in whom traditional first-line oral agents have failed to maintain adequate glycemic control. There are 2 classes of IBTs: the dipeptidyl peptidase-4 (DPP-4) inhibitors and the glucagon-like peptide 1 (GLP-1) receptor agonists. The ultimate effect of both types of agents is to augment GLP-1 signaling, which results in enhanced glucose-dependent insulin secretion, inhibition of glucagon secretion and decreased appetite. This leads to improved regulation of glucose homeostasis accompanied by either no increase in body weight (with DPP-4 inhibitors) or a reduction (with GLP-1 receptor agonists). GLP-1 inhibits food intake and the increased GLP-1 response may contribute as a satiety signal. Although data regarding the effect of GLP-1 agonists and DPP-4 inhibitors on levels of peptides involved in the regulation of food intake in T2DM are few, an indirect effect of IBT on weight loss is possible (e.g. Exendin-4 induces adiponectin secretion in vitro). Results from animal models indicate reduction of food intake and body weight by GLP-1 agonists, but follow-up studies are required. A growing amount of evidence suggests that these peptides may also impact the cardiovascular system, including beneficial effects on myocardial cells, lipid profiles and blood pressure as well as reduced markers of systemic inflammation and improved endothelial dysfunction. The potential role of these agents in improving components of the metabolic syndrome and retardation of atherosclerosis needs to be fully elucidated. Although IBTs are currently recommended only for use in the early treatment of T2DM, the 'non-glycemic' actions of these drugs may have far reaching therapeutic implications. It is hoped that future studies will elucidate their potential strengths and weaknesses for use in various metabolic conditions.

Topics: Animals; Atherosclerosis; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Incretins; Inflammation; Lipoproteins; Metabolic Syndrome

Overproduction of hepatic apoB100-containing VLDL particles has been well documented in animal models and in humans with insulin resistance such as the metabolic syndrome and type 2 diabetes, and contributes to the typical dyslipidemia of these conditions. In addition, postprandial hyperlipidemia and elevated plasma concentrations of intestinal apoB48-containing chylomicron and chylomicron remnant particles have been demonstrated in insulin resistant states. Intestinal lipoprotein production is primarily determined by the amount of fat ingested and absorbed. Until approximately 10 years ago, however, relatively little attention was paid to the role of the intestine itself in regulating the production of triglyceride-rich lipoproteins (TRL) and its dysregulation in pathological states such as insulin resistance. We and others have shown that insulin resistant animal models and humans are characterized by overproduction of intestinal apoB48-containing lipoproteins. Whereas various factors are known to regulate hepatic lipoprotein particle production, less is known about factors that regulate the production of intestinal lipoprotein particles. Monosacharides, plasma free fatty acids (FFA), resveratrol, intestinal peptides (e.g. GLP-1 and GLP-2), and pancreatic hormones (e.g. insulin) have recently been shown to be important regulators of intestinal lipoprotein secretion. Available evidence in humans and animal models strongly supports the concept that the small intestine is not merely an absorptive organ but rather plays an active role in regulating the rate of production of chylomicrons in fed and fasting states. Metabolic signals in insulin resistance and type 2 diabetes and in some cases an aberrant intestinal response to these factors contribute to the enhanced formation and secretion of TRL. Understanding the regulation of intestinal lipoprotein production is imperative for the development of new therapeutic strategies for the prevention and treatment of dyslipidemia. Here we review recent developments in this field and present evidence that intestinal lipoprotein production is a process with metabolic plasticity and that modulation of intestinal lipoprotein secretion may be a feasible therapeutic strategy in the treatment of dyslipidemia and possibly prevention of atherosclerosis.

Topics: Animals; Apolipoprotein B-100; Apolipoprotein B-48; Atherosclerosis; Bile Acids and Salts; Cholesterol; Chylomicrons; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dietary Carbohydrates; Dietary Fats; Dipeptidyl-Peptidase IV Inhibitors; Drug Evaluation, Preclinical; Dyslipidemias; Exenatide; Fatty Acids, Nonesterified; Glucagon-Like Peptide 1; Glucagon-Like Peptide 2; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Insulin; Insulin Resistance; Intestine, Small; Lipoproteins; Microbiota; Peptides; Receptors, Glucagon; Resveratrol; Secretory Rate; Stilbenes; Triglycerides; Venoms

Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are incretin hormones that control the secretion of insulin, glucagon, and somatostatin to facilitate glucose disposal. The actions of incretin hormones are terminated via enzymatic cleavage by dipeptidyl peptidase-4 (DPP-4) and through renal clearance. GLP-1 and GIP promote β-cell proliferation and survival in rodents. DPP-4 inhibitors expand β-cell mass, reduce α-cell mass, and inhibit glucagon secretion in preclinical studies; however, whether incretin-based therapies sustain functional β-cell mass in human diabetic subjects remains unclear. GLP-1 and GIP exert their actions predominantly through unique G protein-coupled receptors expressed on β-cells and other pancreatic cell types. Accurate localization of incretin receptor expression in pancreatic ductal or acinar cells in normal or diabetic human pancreas is challenging because antisera used for detection of the GLP-1 receptor often are neither sufficiently sensitive nor specific to yield reliable data. This article reviews recent advances and controversies in incretin hormone action in the pancreas and contrasts established mechanisms with areas of uncertainty. Furthermore, methodological challenges and pitfalls are highlighted and key areas requiring additional scientific investigation are outlined.

Topics: Acinar Cells; Animals; Atherosclerosis; Blotting, Western; Cell Proliferation; Cricetinae; Diabetes Mellitus; Dipeptidyl-Peptidase IV Inhibitors; Female; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Inflammation; Insulin-Secreting Cells; Male; Mice; Pancreas; Rats; Real-Time Polymerase Chain Reaction; Receptors, Gastrointestinal Hormone; Receptors, Glucagon

In addition to its effects on reproductive health, it is now well recognized that polycystic ovary syndrome (PCOS) is a metabolic disorder, characterized by decreased insulin sensitivity which leads to an excess lifetime risk of type 2 diabetes and cardiovascular disease. PCOS patients are often obese, hypertensive, dyslipidemic and insulin resistant; they have obstructive sleep apnea and have been reported to have higher aldosterone levels in comparison to normal healthy controls. These are all components of an adverse cardiovascular risk profile. Many studies exploring subclinical atherosclerosis using different methods (flow-mediated dilatation, intima media thickness, arterial stiffness, coronary artery calcification) as well as assessing circulating cardiovascular risk markers, point toward an increased cardiovascular risk and early atherogenesis in PCOS. The risk and early features of subclinical atherosclerosis can be reversed by non-medical (normalization of weight, healthy lifestyle) and medical (metformin, thiazolidinediones, spironolactone, and statins) interventions. However, the long-term risk for cardiovascular morbidity and mortality as well as the clinical significance of different interventions still need to be properly addressed in a large prospective study.

Topics: Adolescent; Adult; Androstenes; Atherosclerosis; Cardiovascular Diseases; Carotid Intima-Media Thickness; Coronary Artery Disease; Female; Humans; Hypertension; Incretins; Insulin Resistance; Life Style; Metformin; Middle Aged; Obesity; Polycystic Ovary Syndrome; Postmenopause; Renin-Angiotensin System; Risk Factors; Sleep Apnea, Obstructive; Thiazolidinediones; Vascular Stiffness; Weight Reduction Programs

Discovery of physiological and pharmacological characteristics of incretins (glucagon-like peptide-1 and glucose-dependent insulinotrop polypeptide), and the introduction of various products of those into the clinical practice has fundamentally changed blood glucose lowering therapy in type 2 diabetes. In addition to the antidiabetic properties more attention is paid to their favourable pleiotropic effects independent from the blood glucose lowering such as cardio-, vaso- and renoprotectiv, blood pressure lowering effects, as well as beneficial changes on blood lipid values and hepatic steatosis. These preferential changes prevail in slightly different way when incretin mimetics applied and dipeptidyl peptidase-4 inhibitors, furthermore, prolonged action of peptides metabolised by this enzyme may serve additional benefits in this latter mentioned group. The article overviews the currently known most important pleiotropic effects of incretins from the point of view of cardiorenal risk accompanying type 2 diabetes.

Topics: Animals; Atherosclerosis; Blood Glucose; Blood Vessels; Cardiotonic Agents; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Endothelium, Vascular; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Kidney; Lipids; Liver; Vasodilation

Type 2 diabetes is a chronic, progressive disease with a multi-faceted pathophysiology. Beyond the known defects of insulin resistance and beta-cell insufficiency, derangement of incretin hormones normally produced from the gut wall in response to food intake play an important role. In recent years, the 'incretin-based' therapies (IBTs) have been developed to address hyperglycemia through either mimicking the action of the endogenous incretin glucagon-like polypeptide (GLP-1) (GLP-1 receptor agonists) or by inhibiting the activity of the enzyme that degrades GLP-1 (the dipeptyl peptidase-4 inhibitors).. We reviewed available evidence on the glucose lowering and anti-atherogenic effects of IBT.. In addition to their glucose-lowering and weight-neutral or weight-reducing actions, IBT decrease systolic blood pressure and improve fasting and postprandial lipid parameters by reducing total-cholesterol, low-density lipoprotein-cholesterol and triglycerides concentrations, and increasing high-density lipoprotein-cholesterol values. Reduced high-sensitivity C-reactive protein levels and improved endothelial dysfunction have been reported too.. IBT have several beneficial effects on cardiovascular risk factors and, for this reason, it has been recently suggested to extend the use of these drugs in diabetic patients with cardiovascular complications. Yet, the long-term effects of IBT on subclinical or clinical atherosclerosis remain to be established by future studies.

Topics: Animals; Atherosclerosis; Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucose; Humans; Incretins; Risk Factors

The gut hormone glucose-dependent insulinotropic polypeptide (GIP) stimulates beta cell function and improves glycemia through its incretin actions. GIP also regulates endothelial function and suppresses adipose tissue inflammation through control of macrophage activity. Activation of the GIP receptor (GIPR) attenuates experimental atherosclerosis and inflammation in mice, however whether loss of GIPR signaling impacts the development of atherosclerosis is uncertain.. Atherosclerosis and related metabolic phenotypes were studied in Apoe. Body weight was lower, circulating myeloid cells were reduced, and glucose tolerance was not different, however, aortic atherosclerosis was increased in Apoe. Loss of the Gipr in mice results in increased aortic atherosclerosis and enhanced inflammation in aorta and liver, despite reduced weight gain and preserved glucose homeostasis. These findings extend concepts of GIPR in the suppression of inflammation-related pathophysiology beyond its classical incretin role in the control of metabolism.

Topics: Animals; Apolipoproteins E; Atherosclerosis; Blood Glucose; Body Weight; Gastric Inhibitory Polypeptide; Incretins; Inflammation; Mice; Proprotein Convertase 9; Receptors, G-Protein-Coupled; Receptors, Gastrointestinal Hormone; RNA, Messenger

The effect of GLP-1R agonists on DNA methylation levels of NF-κB and SOD2 genes in human aortic endothelial cells exposed to high glucose and in diabetic patients treated and not with incretin-based drugs, was evaluated. Methylation levels, mRNA and protein expression of NF-κB and SOD2 genes were measured in human endothelial cells exposed to high glucose for 7 days and treated with GLP-1R agonists. Methylation status of NF-κB and SOD2 promoter was also analyzed in 128 diabetics and 116 nondiabetics and correlated with intima media thickness (ITM), an early marker of atherosclerotic process. Cells exposed to high glucose showed lower NF-κB and SOD2 methylation levels, increased NF-κB and reduced SOD2 expression compared to normal glucose cells. Co-treatment with GLP-1 agonists prevented methylation and genes expression changes induced by high glucose. Both high glucose and incretins exposure increased DNA methyltransferases and demethylases levels. In diabetics, incretin treatment resulted a significant predictor of NF-κB DNA methylation, independently of age, sex, body mass index (BMI), glucose and plasma lipid levels. NF-κB DNA methylation inversely correlated with IMT after adjusting for multiple covariates. Our results firstly provide new evidences of an additional mechanism by which incretin drugs could prevent vascular diabetic complications.

Topics: Atherosclerosis; Blood Glucose; Body Mass Index; Carotid Intima-Media Thickness; Cell Line; Diabetes Complications; Diabetes Mellitus, Type 2; DNA Methylation; Endothelial Cells; Epigenesis, Genetic; Gene Expression; Glucagon-Like Peptide-1 Receptor; Glucose; Humans; Incretins; NF-kappa B; Superoxide Dismutase

Glucagon-like peptide-1 receptor (GLP1R) agonist is an incretin hormone and regulates glucose metabolism. However, phthalates, known as endocrine disruptors, can interfere with hormone homeostasis. In the present study, we aimed to estimate the impact of GLP1R agonist on di(2 ethylhexyl) phthalate (DEHP)-induced atherosclerosis. For this purpose, the effects of GLP1R agonist on various atherogenesis-related cellular processes and pathways were assessed in vascular smooth muscle cells (VSMCs). DEHP-induced cell proliferation and migration were significantly decreased by GLP1R agonist in VSMCs. Protein levels of matrix metalloproteinase (MMP)-2 and MMP-9 were significantly decreased in cells exposed to GLP1R agonist, compared with DEHP-treated cells. Expression levels of intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 were also reduced in GLP1R agonist-treated cells. Similarly, DEHP-associated phosphorylation of protein kinase B and extracellular signal-regulated kinase 1/2 was decreased in GLP1R agonist-treated cells, compared with DEHP-treated cells. Our findings suggest that treatment with GLP1R agonist counteracts the activation of pathways related to atherosclerosis.

Topics: Animals; Atherosclerosis; Cell Proliferation; Cells, Cultured; Diethylhexyl Phthalate; Glucagon-Like Peptide-1 Receptor; Incretins; Intercellular Adhesion Molecule-1; Mitogen-Activated Protein Kinase 3; Muscle, Smooth, Vascular; Plasticizers; Rats; Signal Transduction

Topics: Atherosclerosis; Constriction, Pathologic; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Dipeptidyl-Peptidase IV Inhibitors; Drug Design; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incidence; Incretins; Ischemia; Myocardial Infarction; Risk Factors; Signal Transduction; Stroke

Dipeptidyl peptidase-4 (DPP-4) inhibitors have various cellular effects that are associated with vascular protection. Here, we examined whether teneligliptin alters the pro-inflammatory phenotype of perivascular adipose tissue (PVAT) and inhibits atherogenesis.. Teneligliptin (60mg/kg/day) was administered orally to apolipoprotein-E-deficient (ApoE. Teneligliptin inhibited atherogenesis with attenuation of the inflammatory phenotype in PVAT. A GLP-1 analog suppressed pro-inflammatory activation of macrophages and adipocytes. Suppression of the pro-inflammatory phenotype of PVAT might contribute, at least partially, to the cardioprotective effects of teneligliptin.

Topics: 3T3-L1 Cells; Adipose Tissue; Animals; Anti-Inflammatory Agents; Aorta; Aortic Diseases; Apolipoproteins E; Atherosclerosis; Cytokines; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Exenatide; Female; Genetic Predisposition to Disease; Incretins; Inflammation Mediators; Macrophage Activation; Macrophages; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Oxidative Stress; Peptides; Phenotype; Plaque, Atherosclerotic; Pyrazoles; RAW 264.7 Cells; Signal Transduction; Thiazolidines; Time Factors; Vasodilation; Venoms

Exposure to psychosocial stress is a risk factor for cardiovascular disorders. Because the glucagon-like peptide-1 (GLP-1) receptor (GLP-1R) agonist prevents cardiovascular injury, we investigated the beneficial effects and mechanism of the GLP-1 analogue exenatide on stress-related vascular senescence and atherosclerosis in apolipoprotein E-deficient (ApoE. ApoE. Chronic stress enhanced vascular endothelial senescence and atherosclerotic plaque growth. The stress increased the levels of plasma depeptidyl peptidase-4 activity and decreased the levels of plasma GLP-1 and both plasma and adipose adiponectin (APN). As compared with the mice subjected to stress alone, the exenatide-treated mice had decreased plaque microvessel density, macrophage accumulation, broken elastin, and enhanced plaque collagen volume, and lowered levels of peroxisome proliferator-activated receptor-α, gp91phox osteopontin, C-X-C chemokine receptor-4, toll-like receptor-2 (TLR2), TLR4, and cathepsins K, L, and S mRNAs and/or proteins. Exenatide reduced aortic matrix metalloproteinase-9 (MMP-9) and MMP-2 gene expression and activities. Exenatide also stimulated APN expression of preadipocytes and inhibited ox-low density lipoprotein-induced foam cell formation of monocytes in stressed mice.. These results indicate that the exenatide-mediated beneficial vascular actions are likely attributable, at least in part, to the enhancement of APN production and the attenuation of plaque oxidative stress, inflammation, and proteolysis in ApoE

Topics: Adiponectin; Age Factors; Animals; Aorta; Aortic Diseases; Atherosclerosis; Cells, Cultured; Cellular Senescence; Chronic Disease; Diet, High-Fat; Dipeptidyl Peptidase 4; Disease Models, Animal; Endothelial Cells; Exenatide; Foam Cells; Genetic Predisposition to Disease; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Incretins; Inflammation Mediators; Male; Mice, Knockout, ApoE; Oxidative Stress; Peptide Hydrolases; Peptides; Phenotype; Plaque, Atherosclerotic; Proteolysis; Signal Transduction; Stress, Psychological; Venoms

Glipitins are widely used for the treatment of type 2 diabetic patients. In addition to their improvement of glycemic control, animal studies have suggested an independent anti-atherosclerotic effect of gliptins. Nevertheless, recent clinical trials regarding long-term effects of gliptin therapy on vascular events have been disappointing. This discrepancy led us to better dissect the functional role of SDF-1/CXCR4 signaling as a potential mechanism underlying gliptin action. The study should give improved understanding of the potential of gliptin therapy in the prevention and treatment of atherosclerosis.. In an ApoE-/- mouse model on high cholesterol diet, long-term treatment with the DPP-4 inhibitor Sitagliptin significantly reduced atherosclerosic plaque load in the aorta. Flow cytometry analyses showed an enrichment of M2 macrophages in the aortic wall under gliptin therapy. Importantly, the number of recruited CD206+ macrophages was inversely correlated with total plaque area while no correlation was found for the overall macrophage population or M1 macrophages. Blockade of CXCR4/SDF-1 signaling by AMD3100 inhibited aortic M2 accumulation and the therapeutic effect of Sitagliptin. Correspondingly, Sitagliptin shifted the polarization profile of macrophages towards a M2-like phenotype.. Sitagliptin-mediated inhibition of early atherosclerosis is based on M2-polarization during monocyte differentiation via the SDF-1/CXCR4 signaling. In contrast to earlier assumptions gliptin treatment might be especially effective in prevention of atherosclerosis.

Topics: Animals; Aorta; Apolipoproteins E; Atherosclerosis; Chemokine CXCL12; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Flow Cytometry; Hypercholesterolemia; Incretins; Insulin Resistance; Macrophages; Male; Mice; Monocytes; Plaque, Atherosclerotic; Receptors, CXCR4; Repetition Priming; Sitagliptin Phosphate

Folk medicine stories accredited the aptitude of camel milk (CMK) as a hypoglycemic agent and recent studies have confirmed this in the diabetic patients and experimental animals. However, the mechanism(s) by which CMK influences glucose homeostasis is yet unclear. The current study investigated the changes in the glucose homeostatic parameters, the incretin hormones, and the inflammatory cytokines in the CMK-treated diabetic animals. A model of type 2 diabetes mellitus was induced in rats by intraperitoneal injection of streptozotocin 40 mg/kg/day for 4 repeated doses. Camel milk treatment was administered for 8 weeks. The changes in glucagon like peptide-1 (GLP-1), glucose dependent insulinotropic peptide (GIP), glucose tolerance, fasting and glucose-stimulated insulin secretion, insulin resistance (IR), TNF-α, TGF-β1, lipid profile, atherogenic index (AI), and body weight were investigated. The untreated diabetic animals showed hyperglycemia, increased HOMA-IR, hyperlipidemia, elevated AI, high serum incretins [GLP-1 and GIP], TNF-α, and TGF-β1 levels and weight loss as compared with the control group. Camel milk treatment to the diabetic animals resulted in significant lowered fasting glucose level, hypolipidemia, decreased HOMA-IR, recovery of insulin secretion, weight gain, and no mortality during the study. Additionally, CMK inhibits the diabetes-induced elevation in incretin hormones, TNF-α and TGF-β1 levels. The increase in glucose-stimulated insulin secretion, decreased HOMA-IR, modulation of the secretion and/or the action of incretins, and the anti-inflammatory effect are anticipated mechanisms to the antidiabetic effect of CMK and suggest it as a valuable adjuvant antidiabetic therapy.

Topics: Animals; Atherosclerosis; Blood Glucose; Body Weight; Camelus; Cytokines; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Fasting; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hypoglycemic Agents; Incretins; Inflammation Mediators; Insulin; Insulin Resistance; Lipids; Male; Milk; Rats, Wistar; Transforming Growth Factor beta1; Tumor Necrosis Factor-alpha

Several recent reports have revealed that dipeptidyl peptidase (DPP)-4 inhibitors have suppressive effects on atherosclerosis in apolipoprotein E-null (Apoe (-/-)) mice. It remains to be seen, however, whether this effect stems from increased levels of the two active incretins, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP).. Nontreated Apoe (-/-) mice, streptozotocin-induced diabetic Apoe (-/-) mice, and db/db diabetic mice were administered the DPP-4 inhibitor vildagliptin in drinking water and co-infused with either saline, the GLP-1 receptor blocker, exendin(9-39), the GIP receptor blocker, (Pro(3))GIP, or both via osmotic minipumps for 4 weeks. Aortic atherosclerosis and oxidized low-density lipoprotein-induced foam cell formation in exudate peritoneal macrophages were determined.. Vildagliptin increased plasma GLP-1 and GIP levels without affecting food intake, body weight, blood pressure, or plasma lipid profile in any of the animals tested, though it reduced HbA1c in the diabetic mice. Diabetic Apoe (-/-) mice exhibited further-progressed atherosclerotic lesions and foam cell formation compared with nondiabetic counterparts. Nondiabetic and diabetic Apoe (-/-) mice showed a comparable response to vildagliptin, namely, remarkable suppression of atherosclerotic lesions with macrophage accumulation and foam cell formation in peritoneal macrophages. Exendin(9-39) or (Pro(3))GIP partially attenuated the vildagliptin-induced suppression of atherosclerosis. The two blockers in combination abolished the anti-atherosclerotic effect of vildagliptin in nondiabetic mice but only partly attenuated it in diabetic mice. Vildagliptin suppressed macrophage foam cell formation in nondiabetic and diabetic mice, and this suppressive effect was abolished by infusions with exendin(9-39)+(Pro(3))GIP. Incubation of DPP-4 or vildagliptin in vitro had no effect on macrophage foam cell formation.. Vildagliptin confers a substantial anti-atherosclerotic effect in both nondiabetic and diabetic mice, mainly via the action of the two incretins. However, the partial attenuation of atherosclerotic lesions by the dual incretin receptor antagonists in diabetic mice implies that vildagliptin confers a partial anti-atherogenic effect beyond that from the incretins.

Topics: Adamantane; Alternative Splicing; Animals; Apolipoproteins E; Atherosclerosis; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Foam Cells; Gene Expression Profiling; Gene Expression Regulation; Gene Order; Glucagon-Like Peptide-1 Receptor; Glucose Tolerance Test; Incretins; Macrophages; Male; Mice; Mice, Inbred NOD; Mice, Knockout; Nitriles; Pyrrolidines; Receptors, Glucagon; Vildagliptin

[corrected] Glucagon-like peptide-1 (GLP-1) based therapies are new treatment options for patients with type 2 diabetes. Recent reports suggest vasoprotective actions of GLP-1. Similar beneficial effects might be reached by GLP-1(9-37) and the c-terminal GLP-1 split product (28-37) although both peptides do not activate the GLP-1 receptor. We therefore investigated the actions of GLP-1(7-37), GLP-1(9-37) as well as GLP-1(28-37) on vascular lesion formation in a mouse model of atherosclerosis.. GLP-1(7-37), GLP-1(9-37) and GLP-1(28-37) and LacZ (control) were overexpressed for a period of 12 weeks in apoe(-/-) mice on high-fat diet (n = 10/group) using an adeno-associated viral vector system. Neither of the constructs changed overall lesion size. However, GLP-1(7-37), GLP-1(9-37) and GLP-1(28-37) significantly reduced plaque macrophage infiltration (GLP-1(7-37): 40.6%, GLP-1(9-37): 47.0%, GLP-1(28-37): 40.1% decrease, p < 0.05) and plaque MMP-9 expression (GLP-1(7-37): 41.6%, GLP-1(9-37): 50.2%, GLP-1(28-37): 44.0% decrease, p < 0.05) compared to LacZ in the aortic arch. Moreover, all GLP-1 constructs increased plaque collagen content (GLP-1(7-37): 49.3%, GLP-1(9-37): 86.0%, GLP-1(28-37): 81.9% increase, p < 0.05) and increased fibrous cap thickness (GLP-1(7-37): 188.0%, GLP-1(9-37): 179.9% GLP-1(28-37): 111.0% increase, p < 0.05). These effects of GLP-1(7-37), GLP-1(9-37) and GLP-1(28-37) on plaque macrophage infiltration, MMP-9 expression and plaque collagen content were confirmed in the aortic root.. GLP-1(7-37), GLP-1(9-37) and GLP-1(28-37) reduce plaque inflammation and increase phenotypic characteristics of plaque stability in a murine model of atherosclerosis. Future studies are needed to determine whether these effects translate into improved plaque stability and less cardiovascular events in high-risk patients with type 2 diabetes.

Topics: Animals; Apolipoproteins E; Atherosclerosis; Blood Glucose; Collagen; Diet, High-Fat; Disease Models, Animal; Gene Expression Regulation; Glucagon-Like Peptide 1; Incretins; Inflammation; Lipids; Macrophages; Matrix Metalloproteinase 9; Mice; Mice, Inbred C57BL; Mice, Knockout; Peptide Fragments; Phenotype; Plaque, Atherosclerotic; Transgenes

Several lines of evidence suggest that incretin-based therapies suppress the development of cardiovascular disease in type 2 diabetes. We investigated the possibility that glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) can prevent the development of atherosclerosis in Apoe (-/-) mice.. Apoe (-/-) mice (17 weeks old) were administered GLP-1(7-36)amide, GLP-1(9-36)amide, GIP(1-42) or GIP(3-42) for 4 weeks. Aortic atherosclerosis, oxidised LDL-induced foam cell formation and related gene expression in exudate peritoneal macrophages were determined.. Administration of GLP-1(7-36)amide or GIP(1-42) significantly suppressed atherosclerotic lesions and macrophage infiltration in the aortic wall, compared with vehicle controls. These effects were cancelled by co-infusion with specific antagonists for GLP-1 and GIP receptors, namely exendin(9-39) or Pro(3)(GIP). The anti-atherosclerotic effects of GLP-1(7-36)amide and GIP(1-42) were associated with significant decreases in foam cell formation and downregulation of CD36 and acyl-coenzyme A:cholesterol acyltransferase-1 (ACAT-1) in macrophages. GLP-1 and GIP receptors were both detected in Apoe (-/-) mouse macrophages. Ex vivo incubation of macrophages with GLP-1(7-36)amide or GIP(1-42) for 48 h significantly suppressed foam cell formation. This effect was wholly abolished in macrophages pretreated with exendin(9-39) or (Pro(3))GIP, or with an adenylate cyclase inhibitor, MDL12,330A, and was mimicked by incubation with an adenylate cyclase activator, forskolin. The inactive forms, GLP-1(9-36)amide and GIP(3-42), had no effects on atherosclerosis and macrophage foam cell formation.. Our study is the first to demonstrate that active forms of GLP-1 and GIP exert anti-atherogenic effects by suppressing macrophage foam cell formation via their own receptors, followed by cAMP activation. Molecular mechanisms underlying these effects are associated with the downregulation of CD36 and ACAT-1 by incretins.

Topics: Acetyl-CoA C-Acetyltransferase; Animals; Apolipoproteins E; Atherosclerosis; Blotting, Western; CD36 Antigens; Cell Line; Cells, Cultured; Foam Cells; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Incretins; Male; Mice; Mice, Knockout; Microscopy, Confocal; Peptide Fragments; Peptides; Real-Time Polymerase Chain Reaction