Role of gut-liver axis and glucagon-like peptide-1 receptor agonists in the treatment of metabolic dysfunction-associated fatty liver disease

Metabolic dysfunction-associated fatty liver disease(MAFLD)is a hepatic manifestation of the metabolic syndrome.It is one of the most common liver diseases worldwide and shows increasing prevalence rates in most countries.MAFLD is a progressive disease with the most severe cases presenting as advanced fibrosis or cirrhosis with an increased risk of hepatocellular carcinoma.Gut microbiota play a significant role in the pathogenesis and progression of MAFLD by disrupting the gut-liver axis.The mechanisms involved in maintaining gut-liver axis homeostasis are complex.One critical aspect involves preserving an appropriate intestinal barrier permeability and levels of intestinal lumen metabolites to ensure gutliver axis functionality.An increase in intestinal barrier permeability induces metabolic endotoxemia that leads to steatohepatitis.Moreover,alterations in the absorption of various metabolites can affect liver metabolism and induce liver steatosis and fibrosis.Glucagon-like peptide-1 receptor agonists(GLP-1 RAs)are a class of drugs developed for the treatment of type 2 diabetes mellitus.They are also commonly used to combat obesity and have been proven to be effective in reversing hepatic steatosis.The mechanisms reported to be involved in this effect include an improved regulation of glycemia,reduced lipid synthesis,β-oxidation of free fatty acids,and induction of autophagy in hepatic cells.Recently,multiple peptide receptor agonists have been introduced and are expected to increase the effectiveness of the treatment.A modulation of gut microbiota has also been observed with the use of these drugs that may contribute to the amelioration of MAFLD.This review presents the current understanding of the role of the gutliver axis in the development of MAFLD and use of members of the GLP-1 RA family as pleiotropic agents in the treatment of MAFLD.

Practical guide:Glucagon-like peptide-1 and dual glucosedependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonists in diabetes mellitus

Practical guide:Glucagon-like peptide-1 and dual glucosedependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonists in diabetes mellitus common second-line choice after metformin for treating T2DM.Various considerations can make selecting and switching between different GLP-1 RAs challenging.Our study aims to provide a comprehensive guide for the usage of GLP-1 RAs and dual GIP and GLP-1 RAs for the management of T2DM.

Glucagon-like peptide-1 receptor agonists as a possible intervention to delay the onset of type 1 diabetes:A new horizon

Type 1 diabetes(T1D)is a chronic autoimmune condition that destroys insulinproducing beta cells in the pancreas,leading to insulin deficiency and hyperglycemia.The management of T1D primarily focuses on exogenous insulin replacement to control blood glucose levels.However,this approach does not address the underlying autoimmune process or prevent the progressive loss of beta cells.Recent research has explored the potential of glucagon-like peptide-1 receptor agonists(GLP-1RAs)as a novel intervention to modify the disease course and delay the onset of T1D.GLP-1RAs are medications initially developed for treating type 2 diabetes.They exert their effects by enhancing glucose-dependent insulin secretion,suppressing glucagon secretion,and slowing gastric emptying.Emerging evidence suggests that GLP-1RAs may also benefit the treatment of newly diagnosed patients with T1D.This article aims to highlight the potential of GLP-1RAs as an intervention to delay the onset of T1D,possibly through their potential immunomodulatory and anti-inflammatory effects and preservation of beta-cells.This article aims to explore the potential of shifting the paradigm of T1D management from reactive insulin replacement to proactive disease modification,which should open new avenues for preventing and treating T1D,improving the quality of life and long-term outcomes for individuals at risk of T1D.

Cardioprotective effects of glucagon-like peptide 1 receptor agonists in heart failure: Myth or truth?

Therapy with glucagon-like peptide 1(GLP1)receptor agonists has raised great interest for its beneficial cardiovascular effects in preventing atherosclerosis and heart failure-related outcomes.However,while evidence about atherosclerosis consistently suggests a cardioprotective potential with class effect,controversies remain on its impact on heart failure.GLP1 receptor agonists appear to prevent hospitalization for new-onset heart failure and reduce symptoms in heart failure with preserved ejection fraction(as demonstrated by the recent STEP-HFpEF Trial).Still,GLP1 agonism has resulted in neutral or even harmful effects in patients with established heart failure with reduced ejection fraction(the LIVE trial).GLP1 receptor agonists benefit the cardiovascular system indirectly through their marked metabolic effects(improved weight management,glycemic control,blood pressure,systemic and tissue inflammation),while direct effects on the heart have been questioned.Nonetheless,weight loss alone achieved through GLP1 receptor agonists has failed in improving left ventricular functions.Tirzepatide is a dual agonist of GLP1 and glucose-dependent insulinotropic polypeptide,representing an innovative treatment option in diabetes with a major impact on weight loss and promising cardiovascular benefits.Whether this class of therapies is going to change the history of heart failure is an ongoing debate.

Fixed-ratio combinations of basal insulin and glucagon-like peptide-1 receptor agonists as a promising strategy for treating diabetes

The maintenance of appropriate glycemic control is important for the prevention of diabetic complications in people with type 2 diabetes(T2D). Numerous oral antidiabetic drugs are now clinically available, but in particular, the introduction of injection regimens using insulin and/or glucagon-like peptide-1 receptor agonist(GLP-1RA)s represents promising step-up options for oral antidiabetic drug treatment. The recently licensed fixed-ratio combination(FRC) products,which comprise basal insulin and a GLP-1RA, have potent anti-hyperglycemic effects and reduce the undesirable side-effects of each component, such as body weight gain, hypoglycemia, and gastrointestinal symptoms. Two FRCs-insulin degludec/Liraglutide and insulin glargine/Lixisenatide-are now clinically available and, to date, several phase Ⅱ/Ⅲ trials have been conducted in particular groups of subjects with T2D. However, their utility in real-world clinical settings is of interest for most clinicians. Recently reported real-world clinical trials of these two FRCs in various situations have demonstrated their efficacy regarding glycemic control and the quality of life of people with T2D. Their long-term safety and efficacy require confirmation, but a treatment strategy that includes an FRC may be compatible with the concept of “well-balanced” therapy in certain groups of patients with T2D who have inadequate glycemic control.

Effects of glucagon-like peptide-1 receptor agonists on glucose excursion and inflammation in overweight or obese type 2 diabetic patients

BACKGROUND Currently,the lack of comparative studies between weekly and daily formulations of glucagon-like peptide-1 receptor agonists(GLP-1RAs)for glucose excursion is worth investigation.AIM To investigate the effects of weekly and daily formulations of GLP-1RA on glucose excursion and inflammation in overweight and obese patients with type 2 diabetes.METHODS Seventy patients with type 2 diabetes mellitus who were treated at our hospital between January 2019 and January 2022 were enrolled in this retrospective analysis.All patients were treated with metformin.We evaluated changes in blood glucose levels and a series of important indicators in patients before and after treatment with either a weekly or daily preparation of GLP-1RA(group A;n=33 and group B;n=37).RESULTS The degree of decrease in the levels of fasting blood glucose,mean blood glucose,mean amplitude of glycemic excursions,total cholesterol,triglycerides,tumor necrosis factor-α,interleukin-6,and high-sensitivity C-reactive protein after treatment in group A was higher than that in group B(P<0.05),whereas the 2-h postprandial blood glucose levels decreased more so in group B than in group A(P<0.001).However,there were no statistically significant differences in the levels of glycated hemoglobin,standard deviation of blood glucose,coefficient of variation,absolute mean of daily differences,percentage of time with 3.9 mmol/L<glucose<10 mmol/L,and high-and low-density lipoproteins between the two groups(P>0.05).The incidence of adverse reactions was significantly lower in group A than in group B(P<0.05).CONCLUSION The effect of the weekly preparation of GLP-1RA in controlling blood glucose levels in the patients,suppressing inflammation,and reducing adverse reactions was significantly higher than that of the daily preparations,which is worthy of clinical promotion.

Type-2 Diabetes Mellitus and Glucagon-Like Peptide-1 Receptor toward Predicting Possible Association

Aim: This study aimed to investigate the effect of non-synonymous SNPs (nsSNPs) of the Glucagon-like peptide-1 Receptor (GLP-1R) gene in protein function and structure using different computational software. Introduction: The GLP1R gene provides the necessary instruction for the synthesis of the insulin hormones which is needed for glucose catabolism. Polymorphisms in this gene are associated with diabetes. The protein is an important drug target for the treatment of type-2 diabetes and stroke. Material and Methods: Different nsSNPs and protein-related sequences were obtained from NCBI and ExPASY database. Gene associations and interactions were predicted using GeneMANIA software. Deleterious and damaging effects of nsSNPs were analyzed using SIFT, Provean, and Polyphen-2. The association of the nsSNPs with the disease was predicted using SNPs & GO software. Protein stability was investigated using I-Mutant and MUpro software. The structural and functional impact of point mutations was predicted using Project Hope software. Project Hope analyzes the mutations according to their size, charge, hydrophobicity, and conservancy. Results: The GLP1R gene was found to have an association with 20 other different genes. Among the most important ones is the GCG (glucagon) gene which is also a trans membrane protein. Overall 7229 variants were seen, and the missense variants or nsSNPs (146) were selected for further analysis. The total number of nsSNPs obtained in this study was 146. After being subjected to SIFT software (27 Deleterious and 119 Tolerated) were predicted. Analysis with Provean showed that (20 deleterious and 7 neutral). Analysis using Polyphen-2 revealed 17 probably damaging, 2 possibly damaging and 1 benign nsSNPs. Using two additional software SNPs & GO and PHD-SNPs showed that 14 and 17 nsSNPs had a disease effect, respectively. Project Hope software predicts the effect of the 14 nsSNPs on the protein function due to differences in charge, size, hydrophobicity, and conservancy between the wild and mutant types. Conclusion: In this study, the 14 nsSNPs which were highly affected the protein function. This protein is providing the necessary instruction for the synthesis of the insulin hormones which is needed for glucose catabolism. Polymorphisms in this gene are associated with diabetes and also affect the treatment of diabetic patients due to the fact that the protein acts as an important drug target.

Effects of glucagon-like peptide 1 analogs in combination with insulin on myocardial infarct size in rats with type 2 diabetes mellitus

AIM To evaluate the effects of glucagon-like peptide-1 analogs(GLP-1 a) combined with insulin on myocardial ischemiareperfusion injury in diabetic rats.METHODS Type 2 diabetes mellitus(T2 DM) was induced in maleWistar rats with streptozotocin(65 mg/kg) and verified using an oral glucose tolerance test. After anesthesia, the left coronary artery was occluded for 40 min followed by 80 min reperfusion. Blood glucose level was measured during surgery. Rats were randomized into six groups as follows:(1) control rats;(2) insulin(0.1 U/kg) treated rats prior to ischemia;(3) insulin(0.1 U/kg) treated rats at reperfusion;(4) GLP-1 a(140 mg/kg) treated rats prior to ischemia;(5) GLP-1 a(140 mg/kg) treated rats at reperfusion; and(6) rats treated with GLP-1 a(140 mg/kg) prior to ischemia plus insulin(0.1 U/kg) at reperfusion. Myocardial area at risk and infarct size was measured planimetrically using Evans blue and triphenyltetrazolium chloride staining, respectively.RESULTS There was no significant difference in the myocardial area at risk among groups. Insulin treatment before ischemia resulted in a significant increase in infarct size(34.7% ± 3.4% vs 18.6% ± 3.1% in the control rats, P < 0.05). Post-ischemic administration of insulin or GLP-1 a had no effect on infarct size. However, pre-ischemic administration of GLP-1 a reduced infarct size to 12% ± 2.2%(P < 0.05). The maximal infarct size reduction was observed in the group treated with GLP-1 a prior to ischemia and insulin at reperfusion(8% ± 1.6%, P < 0.05 vs the control and GLP-1 a alone treated groups).CONCLUSION GLP-1 a pre-administration results in myocardial infarct size reduction in rats with T2 DM. These effects are maximal in rats treated with GLP-1 a pre-ischemia plus insulin at reperfusion.

Enhanced glucose homeostasis via Clostridium symbiosummediated glucagon-like peptide 1 inhibition of hepatic gluconeogenesis in mid-intestinal bypass surgery

BACKGROUND The small intestine is known to play a crucial role in the development and remission of diabetes mellitus(DM).However,the exact mechanism by which mid-small intestinal bypass improves glucose metabolism in diabetic rats is not fully understood.AIM To elucidate the mechanisms by which mid-small intestinal bypass improves glucose metabolism.METHODS Streptozotocin(STZ)was used to induce DM in Sprague-Dawley(SD)rats at a dose of 60 mg/kg.The rats were then randomly divided into two groups:The mid-small intestine bypass(MSIB)group and the sham group(underwent switch laparotomy).Following a 6-wk recovery period post-surgery,the rats underwent various assessments,including metabolic parameter testing,analysis of liver glycogen levels,measurement of key gluconeogenic enzyme activity,characterization of the gut microbiota composition,evaluation of hormone levels,determination of bile acid concentrations,and assessment of the expression of the intestinal receptors Takeda G protein-coupled receptor 5 and farnesoid X receptor.RESULTS The MSIB group of rats demonstrated improved glucose metabolism and lipid metabolism,along with increased hepatic glycogen content.Furthermore,there was a decrease in the expression of the key gluconeogenic enzymes phosphoenolpyruvate carboxykinase 1 and glucose-6-phosphatase.Importantly,the MSIB group exhibited a substantial increase in the abundances of intestinal Lactobacillus,Clostridium symbiosum,Ruminococcus gnavus,and Bilophila.Moreover,higher levels of secondary bile acids,such as intestinal lithocholic acid,were observed in this group.Remarkably,the changes in the gut microbiota showed a significant correlation with the expression of key gluconeogenic enzymes and glucagon-like peptide 1(GLP-1)at 6 wk postoperatively,highlighting their potential role in glucose regulation.These findings highlight the beneficial effects of mid-small intestine bypass on glucose metabolism and the associated modulation of the gut microbiota.CONCLUSION The findings of this study demonstrate that the introduction of postoperative intestinal Clostridium symbiosum in the mid-small intestine contributes to the enhancement of glucose metabolism in nonobese diabetic rats.This improvement is attributed to the increased inhibition of hepatic gluconeogenesis mediated by GLP-1,resulting in a favorable modulation of glucose homeostasis.

Effects of glucagon-like peptide-1 receptor agonists on non-alcoholic fatty liver disease and inflammation

Glucagon-like peptide1(GLP-1)is secreted from Langerhans cells in response to oral nutrient intake.Glucagon-like peptide-1 receptor agonists(GLP-1RAs)are a new class of incretin-based anti-diabetic drugs.They function to stimulate insulin secretion while suppressing glucagon secretion.GLP-1-based therapies are now well established in the management of type 2 diabetes mellitus(T2DM),and recent literature has suggested potential applications of these drugs in the treatment of obesity and for protection against cardiovascular and neurological diseases.As we know,along with change in lifestyles,the prevalence of non-alcoholic fatty liver disease(NAFLD)in China is rising more than that of viral hepatitis and alcoholic fatty liver disease,and NAFLD has become the most common chronic liver disease in recent years.Recent studies further suggest that GLP-1RAs can reduce transaminase levels to improve NAFLD by improving blood lipid levels,cutting down the fatcontent to promote fat redistribution,directly decreasing fatty degeneration of the liver,reducing the degree of liver fibrosis and improving inflammation.This review shows the NAFLD-associated effects of GLP-1RAs in animal models and in patients with T2DM or obesity who are participants in clinical trials.

Coagonist of glucagon-like peptide-1 and glucagon receptors ameliorates kidney injury in murine models of obesity and diabetes mellitus

AIM To investigate the role of glucagon-like peptide-1(GLP-1)/glucagon receptors coagonist on renal dysfunction associated with diabetes and obesity. METHODS Chronic high-fat diet fed C57 BL/6 J mice, streptozotocintreated high-fat diet fed C57 BL/6 J mice and diabeticC57 BLKS/J db/db mice were used as models of diabetes-induced renal dysfunction. The streptozotocintreated high-fat diet fed mice and db/db mice were treated with the GLP-1 and glucagon receptors coagonist(Aib2 C24 Chimera2, 150 μg/kg, sc) for twelve weeks, while in chronic high-fat diet fed mice, coagonist(Aib2 C24 Chimera2, 150 μg/kg, sc) treatment was continued for forty weeks. Kidney function, histology, fibrosis, inflammation, and plasma biochemistry were assessed at the end of the treatment. RESULTS Coagonist treatment decreased body weight, plasma lipids, insulin resistance, creatinine, blood urea nitrogen, urinary albumin excretion rate and renal lipids. In kidney, expression of lipogenic genes(SREBP-1 C, FAS, and SCD-1) was decreased, and expression of genes involved in β-oxidation(CPT-1 and PPAR-α) was increased due to coagonist treatment. In plasma, coagonist treatment increased adiponectin and FGF21 and decreased IL-6 and TNF-?. Coagonist treatment reduced expression of inflammatory(TNF-α, MCP-1, and MMP-9) and pro-fibrotic(TGF-β, COL1 A1, and α-SMA) genes and also improved histological derangement in renal tissue.CONCLUSION Coagonist of GLP-1 and glucagon receptors alleviated diabetes and obesity-induced renal dysfunction by reducing glucose intolerance, obesity, and hyperlipidemia.

Glucagon-like peptide-1 receptor agonists in non-alcoholic fatty liver disease: An update

Non-alcoholic fatty liver disease(NAFLD)is the predominant cause of chronic liver disease worldwide.NAFLD progresses in some cases to non-alcoholic steatohepatitis(NASH),which is characterized,in addition to liver fat deposition,by hepatocyte ballooning,inflammation and liver fibrosis,and in some cases may lead to hepatocellular carcinoma.NAFLD prevalence increases along with the rising incidence of type 2 diabetes mellitus(T2DM).Currently,lifestyle interventions and weight loss are used as the major therapeutic strategy in the vast majority of patients with NAFLD.Glucagon-like peptide-1 receptor agonists(GLP-1RAs)are used in the management of T2DM and do not have major side effects like hypoglycemia.In patients with NAFLD,the GLP-1 receptor production is down-regulated.Recently,several animal and human studies have emphasized the role of GLP-1RAs in ameliorating liver fat accumulation,alleviating the inflammatory environment and preventing NAFLD progression to NASH.In this review,we summarize the updated literature data on the beneficial effects of GLP-1RAs in NAFLD/NASH.Finally,as GLP-1RAs seem to be an attractive therapeutic option for T2DM patients with concomitant NAFLD,we discuss whether GLP-1RAs should represent the first line pharmacotherapy for these patients.

Significance of serum glucagon-like peptide-1 and matrix Gla protein levels in patients with diabetes and osteoporosis

BACKGROUND Osteoporosis is a systemic bone disease characterized by decreased bone mass,impaired bone mass,and reduced bone strength that leads to increased bone fragility and fracture.Type 2 diabetes mellitus(T2DM)complicated with osteoporosis is a common systemic metabolic bone disease,and reduced bone mass and bone strength are considered the main clinical features;however,the pathogenesis of this disease has not been fully clarified.Its occurrence is considered related to sex,age,and genetic factors.There are many risk factors for diabetes complicated with osteoporosis.Therefore,exploring these risk factors will help prevent it.AIM To investigate the relationships among serum glucagon-like peptide-1(GLP-1)levels,matrix Gla protein(MGP)levels,and diabetes with osteoporosis.METHODS Sixty patients with T2DM complicated with osteoporosis confirmed by the endocrinology department of our hospital were selected as the case group.Sixty T2DM patients with bone loss were selected as the control group.Sixty healthy participants were selected as the healthy group.The general data,bone mineral density index,and bone metabolic markers of the three groups were compared.The relationships among GLP-1 levels,MGP levels,and the bone mineral density index of the case group were analyzed using linear correlation analysis and a logistic regression model.RESULTS Differences in sex,smoking,and drinking among the case group,control group,and healthy group were not statistically significant(P>0.05).The mean age of the case group was older than those of the control and healthy groups(P<0.05).The body mass index,fasting plasma glucose level,HbA1c level,hypertension rate,and coronary heart disease rate of the case and control groups were higher than those of the healthy group(P<0.05).The serum GLP-1 and MGP levels of the case group were lower than those of the control and healthy groups;these differences were statistically significant(P<0.05).The serum GLP-1 and MGP levels of the control group were lower than those of the healthy group;these differences were statistically significant(P<0.05).The serum GLP-1 and MGP levels of the case group were significantly positively correlated with the bone mineral density values of the hip and lumbar spine(P<0.05).The results of the logistic regression model showed that age and duration of diabetes were independent risk factors for osteoporosis in diabetic patients(P<0.05)and that increased GLP-1 and MGP values were protective factors against osteoporosis in diabetic patients(P<0.05).CONCLUSION Serum GLP-1 and MGP levels of diabetic patients with osteoporosis were significantly decreased and positively correlated with bone mineral density and were independent risk factors for osteoporosis in diabetic patients.

Is there a role for glucagon-like peptide-1 receptor agonists in the management of diabetic nephropathy?

Chronic kidney disease constitutes a major microvascular complication of diabetes mellitus.Accumulating data suggest that glucagon-like peptide-1 receptor agonists(GLP-1 RAs)might have a role in the management of diabetic kidney disease(DKD).GLP-1 RAs appear to reduce the incidence of persistent macro-albuminuria in patients with type 2 diabetes mellitus.This beneficial effect appears to be mediated not only by the glucose-lowering action of these agents but also on their blood pressure lowering,anti-inflammatory and antioxidant effects.On the other hand,GLP-1 RAs do not appear to affect the rate of decline of glomerular filtration rate.However,this might be due to the relatively short duration of the trials that evaluated their effects on DKD.Moreover,these trials were not designed nor powered to assess renal outcomes.Given than macrolbuminuria is a strong risk factor for the progression of DKD,it might be expected that GLP-1 RAs will prevent the deterioration in renal function in the long term.Nevertheless,this remains to be shown in appropriately designed randomized controlled trials in patients with DKD.

Correlation between gut microbiota and glucagon-like peptide-1 in patients with gestational diabetes mellitus

BACKGROUND Gestational diabetes mellitus(GDM)places both the mother and offspring at high risk of complications.Increasing evidence suggests that the gut microbiota plays a role in the pathogenesis of GDM.However,it is still unclear whether the gut microbiota is related to blood biochemical traits,particularly glucagon-like peptide-1(GLP-1),in GDM patients.AIM To explore the correlation between the gut microbiota and blood biochemical traits,particularly GLP-1,in GDM patients.METHODS The V4 region of the 16S ribosomal ribonucleic acid(rRNA)gene was sequenced based on the fecal samples of 35 pregnant women with GDM and was compared to that of 25 pregnant women with normal glucose tolerance(NGT).RESULTS The results showed that Ruminococcaceae_UCG-002,Ruminococcaceae_UCG-005,Clostridium_sensu_stricto_1,and Streptococcus were more abundant in the NGT group than in the GDM group.Bacteroides and Lachnoclostridium were more abundant in the GDM group than in the NGT group.Spearman’s correlation analysis was performed to identify the relationships between microbiota genera and blood biochemical traits.Paraprevotella,Roseburia,Faecalibacterium,and Ruminococcaceae_UCG-002 were significantly negatively correlated with glucose.Ruminococcaceae_UCG-002 was significantly negatively correlated with hemoglobin A1c.Bacteroides was significantly positively correlated with glucose.Sutterella,Oscillibacter,and Bifidobacterium were significantly positively correlated with GLP-1.A random forest model showed that 20 specific genera plus glucose provided the best discriminatory power,as indicated by the area under the receiver operating characteristic curve(0.94).CONCLUSION The results of this study reveal novel relationships between the gut microbiome,blood biochemical traits,particularly GLP-1,and GDM status.These findings suggest that some genera are crucial for controlling blood glucose-related indices and may be beneficial for GDM treatment.Alteration in the microbial composition of the gut may potentially serve as a marker for identifying individuals at risk of GDM.

Review on the Effect of Glucagon-Like Peptide-1 Receptor Agonists and Dipeptidyl Peptidase-4 Inhibitors for the Treatment of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease（NAFLD） is a common liver disease and it represents the hepatic manifestation of metabolic syndrome, which includes type 2 diabetes mellitus（T2DM）, dyslipidemia, central obesity and hypertension. Glucagon-like peptide-1（GLP-1） analogues and dipeptidyl peptidase-4（DPP-4） inhibitors were widely used to treat T2 DM. These agents improve glycemic control, promote weight loss and improve lipid metabolism. Recent studies have demonstrated that the GLP-1 receptor（GLP-1R） is present and functional in human and rat hepatocytes. In this review, we present data from animal researches and human clinical studies that showed GLP-1 analogues and DPP-4 inhibitors can decrease hepatic triglyceride（TG） content and improve hepatic steatosis, although some effects could be a result of improvements in metabolic parameters. Multiple hepatocyte signal transduction pathways and m RNA from key enzymes in fatty acid metabolism appear to be activated by GLP-1 and its analogues. Thus, the data support the need for more rigorous prospective clinical trials to further investigate the potential of incretin therapies to treat patients with NAFLD.

Mutated recombinant human glucagon-like peptide-1 induces differentiation of PC12 cells

Glucagon-like peptide-1 （GLP-1） and its long-acting analogues have neuroprotective and neurotrophic properties and are emerging as potential treatments for neurodegenerative diseases. Its short half-life has limited the application of GLP-1 in the clinic. We generated a mutated form of human GLP-1 （mGLP-1） using site-directed mutagenesis and gene recombination techniques, and found that these modifications significantly prolonged the biological half-life of GLP-1 compared with native GLP-1 （nGLP-1）. This study investigated the role of mGLP-1 on inducing PC12 cell differentiation, mGLP-1 induced PC12 cell differentiation with neurite outgrowth and increased the expression of growth-associated protein-43 and neuronal class III I^-tubulin, and significantly increased cyclic adenosine monophosphate level. No significant difference was found between mGLP-1 and nGLP-I. The results indicate that mGLP-1 activates the GLP-1 receptor, induces PC12 cell differentiation, and has neurotrophic effects.

Exercise and glucagon-like peptide-1: Does exercise potentiate the effect of treatment?

Recently, glucagon-like peptide-1(GLP-1) receptor agonists have become a cornerstone for the treatment of obese patients with type 2 diabetes(T2D), exhibiting favorable effects on the cardiovascular outcome. In T2D, impaired GLP-1 secretion/function is observed, and gut microbiota dysbiosis is related to the GLP-1 resistance. Prior research has revealed that exercise increases GLP-1 levels in healthy and obese individuals; however, the efficacy of exercise on GLP-1 levels in patients with T2D remains unclear. Exercise may improve GLP-1 resistance rather than GLP-1 secretion in patients with T2D. Exercise increases the gut microbiota diversity, which could contribute to improving the GLP-1 resistance of T2D. Furthermore, the gut microbiota may play a role in the correlation between exercise and GLP-1. The combination of exercise and GLP-1-based therapy may have a synergistic effect on the treatment of T2D. Although the underlying mechanism remains unknown, exercise potentiates the efficacy of GLP-1 receptor agonist treatment in patients with T2D.

Efficacy of glucagon-like peptide-1 mimetics for neural regeneration

Glucagon-like peptide 1（GLP-1）is secreted from enteroendocrine L cells in response to nutrient ingestion and exhibits insulinotropic properties by stimulating specific G protein-linked receptors（GLP-1Rs）on pancreaticβcells.Several GLP-1 mimetics,such as exenatide（exendin-4（Ex-4））,liraglutide,and lixisenatide,have been developed and approved as treatments for patients with type 2 diabetes.These peptides show bioactiv-ities almost identical to those of GLP- 1 and have a substantially longer plasma half-life than GLP-1 because of their resistance to dipeptidyl peptidase-4, a GLP-1 degrading enzyme.

Development of therapeutic options on type 2 diabetes in years:Glucagon-like peptide-1 receptor agonist’s role intreatment; from the past to future

Diabetes mellitus (DM) is a chronic metabolic disease characterized by hyperglycemia.Type 2 diabetes (T2DM) accounting for 90% of cases globally.The worldwide prevalence of DM is rising dramatically over the last decades,from 30 million cases in 1985 to 382 million cases in 2013.It’s estimated that 451 million people had diabetes in 2017.As the pathophysiology was understood over the years,treatment options for diabetes increased.Incretin-based therapy is one of them.Glucagon-like peptide-1 receptor agonist (GLP-1 RA) not only significantly lower glucose level with minimal risk of hypoglycemia but also,they have an important advantage in themanagement of cardiovascular risk and obesity.Thus,we will review here GLP-1 RAsrole in the treatment of diabetes.