incretins and Liver-Diseases

In the past decade, G protein-coupled receptors have emerged as drug targets, and their physiological and pathological effects have been extensively studied. Among these receptors, GPR119 is expressed in multiple organs, including the liver. It can be activated by a variety of endogenous and exogenous ligands. After GPR119 is activated, the cell secretes a variety of incretins, including glucagon-like peptide-1 and glucagon-like peptide-2, which may attenuate the metabolic dysfunction associated with fatty liver disease, including improving glucose and lipid metabolism, inhibiting inflammation, reducing appetite, and regulating the intestinal microbial system. GPR119 has been a potential therapeutic target for diabetes mellitus type 2 for many years, but its role in metabolic dysfunction associated fatty liver disease deserves further attention. In this review, we discuss relevant research and current progress in the physiology and pharmacology of the GPR119/incretin axis and speculate on the potential therapeutic role of this axis in metabolic dysfunction associated with fatty liver disease, which provides guidance for transforming experimental research into clinical applications.

Topics: Animals; Fatty Liver; Humans; Incretins; Liver Diseases; Molecular Targeted Therapy; Receptors, G-Protein-Coupled

Incretin contains two peptides named glucagon-like peptide-1(GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). Drug therapy using incretin has become a new strategy for diabetic treatments due to its significant effects on improving insulin receptors and promoting insulinotropic secretion. Considering the fact that diabetes millitus is a key risk factor for almost all age-related diseases, the extensive protective roles of incretin in chronic diseases have received great attention. Based on the evidence from animal experiments, where incretin can protect against the pathophysiological processes of neurodegenerative diseases, clinical trials for the treatments of Alzheimer's disease (AD) and Parkinson's disease (PD) patients are currently ongoing. Moreover, the protective effect of incretin on heart has been observed in cardiac myocytes, smooth muscle cells and endothelial cells of vessels. Meanwhile, incretin can also inhibit the proliferation of aortic vascular smooth muscle cells, which can induce atherosclerogenesis. Incretin is also beneficial for diabetic microvascular complications, including nephropathy, retinopathy and gastric ulcer, as well as the hepatic-related diseases such as NAFLD and NASH. Besides, the anti-tumor properties of incretin have been proven in diverse cancers including ovarian cancer, pancreas cancer, prostate cancer and breast cancer.

Topics: Aging; Animals; Cardiovascular Diseases; Diabetes Mellitus; Humans; Incretins; Liver Diseases; Neoplasms; Neurodegenerative Diseases; Stomach Ulcer

Recent findings indicate that incretin hormones and incretin-based therapies may affect the metabolism of lipoproteins, although the corresponding mechanisms are not clearly defined.. To summarize the available data on the mechanisms linking incretins with the characteristics of serum lipoproteins and discuss the clinical implications of these relationships.. PubMed was searched using the terms "incretins", "GLP-1", "GIP" and "lipids", "dyslipidemia", "triglycerides", "apolipoprotein B48". All articles published in the English language until June 2016 were assessed and the relevant information is presented here.. GLP-1, and therapies that increase its activity, exert a beneficial effect on lipoprotein metabolism that is translated in a reduction in the fasting and postprandial concentration of triglycerides and a small improvement in the concentration and function of HDLs. In addition, a shift towards larger, less atherogenic particles usually follows the administration of GLP-1 receptor agonists. The mechanisms that underlie these changes involve a direct effect of GLP- 1 on the hepatic and intestinal production of triglyceride-rich lipoproteins, the GLP-1 induced increase in the production and function of insulin, the activation of specific areas of central nervous system as well as the increase in the peripheral utilization of triglycerides for energy production. On the other hand, GLP-2 increases the absorption of dietary fat and the production of triglyceride-rich lipoproteins while the role of GIP on lipid metabolism remains indeterminate.. GLP-1 and incretin-based therapies favorably affect lipid metabolism. These effects may contribute to the beneficial effects of incretin-based therapies on atherosclerosis and fatty liver disease.

Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Lipoproteins, HDL; Lipoproteins, LDL; Liver Diseases; Triglycerides

Patients with type 2 diabetes mellitus have an increased risk of chronic liver disease (CLD) such as non-alcoholic fatty liver disease and steatohepatitis, and about one-third of cirrhotic patients have diabetes. However, the use of several antidiabetic agents, such as metformin and sulphonylureas, may be a concern in case of hepatic impairment (HI). New glucose-lowering agents targeting the incretin system are increasingly used for the management of type 2 diabetes. Incretin-based therapies comprise oral inhibitors of dipeptidyl peptidase-4 (DPP-4) (gliptins) or injectable glucagon-like peptide-1 (GLP-1) receptor agonists. This narrative review summarises the available data regarding the use of both incretin-based therapies in patients with HI. In contrast to old glucose-lowering agents, they were evaluated in specifically designed acute pharmacokinetic studies in patients with various degrees of HI and their hepatic safety was carefully analysed in large clinical trials. Only mild changes in pharmacokinetic characteristics of DPP-4 inhibitors were observed in patients with different degrees of HI, presumably without major clinical relevance. GLP-1 receptor agonists have a renal excretion rather than liver metabolism. Specific pharmacokinetic data in patients with HI are only available for liraglutide. No significant changes in liver enzymes were reported with DPP-4 inhibitors or GLP-1 receptor agonists, alone or in combination with various other glucose-lowering agents, in clinical trials up to 2 years in length. On the contrary, preliminary data suggested that incretin-based therapies may be beneficial in patients with CLD, more particularly in the presence of non-alcoholic fatty liver disease. Nevertheless, caution should be recommended, especially in patients with advanced cirrhosis, because of a lack of clinical experience with incretin-based therapies in these vulnerable patients.

Topics: Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Liver; Liver Diseases; Receptors, Glucagon

The wide ubiquity of GLP-1 receptors in the body has stimulated the search for different extrapancreatic actions of GLP-1 and its receptor agonists. Thus, severe cardioprotective effects directed on myocardial ischaemia and dysfunction as well as diverse antiaterogenic actions have been reported. Also, native and GLP-1 receptor agonists have demonstrated significant beneficial effects on liver steatosis and fibrosis and on neuronal protection in experimental models of Alzheimer, and Parkinson's disease as well as on cerebral ischaemia. Recent evidences suggest that these drugs may also be useful for prevention and treatment of diabetic retinopathy, nephropathy and peripheral neuropathy. Good results have also been reported in psoriasis. Despite we still need confirmation that these promising effects can be applied to clinical practice, they offer new interesting perspectives for treatment of type 2 diabetes associated complications and give to GLP-1 receptor agonists an even more integral position in diabetes therapy.

Topics: Alzheimer Disease; Brain Ischemia; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Diabetic Neuropathies; Diabetic Retinopathy; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Incretins; Liver Diseases; Parkinson Disease; Patient Care Planning

Effects of glucagonlike peptide 1 (GLP1) on liver cells are very intensively studied. In the metabolism of saccharides GLP1 stimulates synthesis of glycogen and reduces glucose production -  thus acting like insulin. In the lipid metabolism it enhances fatty acid oxidation and lipid transport from hepatocytes while reducing de novo lipogenesis -  effects more similar to glucagon action. Some studies suggest beneficial effects of GLP1 on oxidative stress, endoplasmic reticulum stress, production of inflammatory mediators and dysfunction of biliary secretion. Current results suggest that drugs affecting incretin system could be used in the treatment of certain liver diseases (e.g. NAFLD and NASH) in the future. In the following article we mention the known effects of GLP 1 on liver functions and liver metabolism and we point out its possible future therapeutic use in the treatment of liver diseases.

Topics: Animals; Glucagon; Glucagon-Like Peptide 1; Hepatocytes; Humans; Hypoglycemic Agents; Incretins; Insulin; Lipid Metabolism; Liver Diseases; Non-alcoholic Fatty Liver Disease; Oxidative Stress

Topics: Animals; Chronic Disease; Dipeptidyl Peptidase 4; Glucagon-Like Peptide 1; Glucose Intolerance; Hepatitis C, Chronic; Humans; Incretins; Liver Diseases