incretins and Fibrosis

The principle pathological drivers of metabolic dysfunction-associated steatohepatitis (MASH) are obesity and associated insulin resistance, rendering them key therapeutic targets. As glucagon-like peptide 1 receptor agonists (GLP-1RAs) have been licensed for the treatment of diabetes and obesity, they were one of the first drug types to be evaluated in patients with MASH, and successful phase IIa and IIb studies have resulted in progression to phase III clinical trials. Alongside GLP-1RAs, newer combinations with glucagon agonists and/or glucose-dependent insulinotropic peptide (GIP) agonists have been explored in related patient groups, with evidence of improvements in weight, insulin resistance and non-invasive liver parameters. Whether GLP-1RAs have direct, independent effects on MASH or whether they impact on pathophysiology through improvements in weight, insulin resistance and glycaemic control remains a matter of debate. Combinations are being explored, although the potential improvement in efficacy will need to be weighed against the cumulative side-effect burden, potential drug-drug interactions and costs. There is also uncertainty regarding the optimal ratio of glucagon and GIP agonism to GLP-1 agonism in combination agents, and as to whether GIP agonism or antagonism is the optimal approach. Finally, there are also multiple hypothetical permutations combining gut hormone agonists with other emerging assets in the field. Given that the likely dominant mode of action of gut hormone agonists is upstream on weight, initial combinations might focus on agents which have been shown to have a more direct effect on fibrosis, which would include FGF21 and pan-PPAR agonists.

Topics: Animals; Clinical Trials as Topic; Fatty Liver; Fibrosis; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Incretins; Molecular Targeted Therapy

Heart failure with preserved ejection fraction (HFpEF) is a multifactorial disease that constitutes several distinct phenotypes, including a common cardiometabolic phenotype with obesity and type 2 diabetes mellitus. Treatment options for HFpEF are limited, and development of novel therapeutics is hindered by the paucity of suitable preclinical HFpEF models that recapitulate the complexity of human HFpEF. Metabolic drugs, like glucagon-like peptide receptor agonist (GLP-1 RA) and sodium-glucose co-transporter 2 inhibitors (SGLT2i), have emerged as promising drugs to restore metabolic perturbations and may have value in the treatment of the cardiometabolic HFpEF phenotype. We aimed to develop a multifactorial HFpEF mouse model that closely resembles the cardiometabolic HFpEF phenotype, and evaluated the GLP-1 RA liraglutide (Lira) and the SGLT2i dapagliflozin (Dapa).. Aged (18-22 months old) female C57BL/6J mice were fed a standardized chow (CTRL) or high-fat diet (HFD) for 12 weeks. After 8 weeks HFD, angiotensin II (ANGII), was administered for 4 weeks via osmotic mini pumps. HFD + ANGII resulted in a cardiometabolic HFpEF phenotype, including obesity, impaired glucose handling, and metabolic dysregulation with inflammation. The multiple hit resulted in typical clinical HFpEF features, including cardiac hypertrophy and fibrosis with preserved fractional shortening but with impaired myocardial deformation, atrial enlargement, lung congestion, and elevated blood pressures. Treatment with Lira attenuated the cardiometabolic dysregulation and improved cardiac function, with reduced cardiac hypertrophy, less myocardial fibrosis, and attenuation of atrial weight, natriuretic peptide levels, and lung congestion. Dapa treatment improved glucose handling, but had mild effects on the HFpEF phenotype.. We developed a mouse model that recapitulates the human HFpEF disease, providing a novel opportunity to study disease pathogenesis and the development of enhanced therapeutic approaches. We furthermore show that attenuation of cardiometabolic dysregulation may represent a novel therapeutic target for the treatment of HFpEF.

Topics: Angiotensin II; Animals; Benzhydryl Compounds; Blood Glucose; Diet, High-Fat; Disease Models, Animal; Female; Fibrosis; Gene Expression Regulation; Glucagon-Like Peptide-1 Receptor; Glucosides; Heart Failure, Diastolic; Hypertrophy, Left Ventricular; Incretins; Liraglutide; Mice, Inbred C57BL; Myocardium; Signal Transduction; Sodium-Glucose Transporter 2 Inhibitors; Ventricular Function, Left; Ventricular Remodeling

Studies evaluating endocrine and exocrine functions in fibrocalculous pancreatic diabetes (FCPD) are scarce.. Insulin, C-peptide, glucagon, incretin hormones (glucagon-like peptide 1 [GLP-1] and gastric inhibitory peptide [GIP]), and dipeptidyl peptidase IV (DPP-IV) were estimated in patients with FCPD (n = 20), type 2 diabetes mellitus (T2DM) (n = 20), and controls (n = 20) in fasting and 60 minutes after 75 g glucose.. Fasting and post-glucose C-peptide and insulin in FCPD were lower than that of T2DM and controls. Plasma glucagon decreased after glucose load in controls (3.72, 2.29), but increased in T2DM (4.01, 5.73), and remained unchanged in FCPD (3.44, 3.44). Active GLP-1 (pmol/L) after glucose load increased in FCPD (6.14 to 9.72, P = <.001), in T2DM (2.87 to 4.62, P < .001), and in controls (3.91 to 6.13, P < .001). Median active GLP-1 in FCPD, both in fasting and post-glucose state (6.14, 9.72), was twice that of T2DM (2.87, 4.62) and 1.5 times that of controls (3.91, 6.13) (P < .001 for all). Post-glucose GIP (pmol/L) increased in all: FCPD (15.83 to 94.14), T2DM (21.85 to 88.29), and control (13.00 to 74.65) (P < .001 for all). GIP was not different between groups. DPP-IV concentration (ng/mL) increased in controls (1578.54, 3012.00) and FCPD (1609.95, 1995.42), but not in T2DM (1204.50, 1939.50) (P = .131). DPP-IV between the three groups was not different. Fecal elastase was low in FCPD compared with T2DM controls.. In FCPD, basal C-peptide and glucagon are low, and glucagon does not increase after glucose load. GLP-1, but not GIP, in FCPD increases 1.5 to 2 times as compared with T2DM and controls (fasting and post glucose) without differences in DPP-IV.. 背景: 评价纤维结石性胰腺糖尿病(FCPD)内分泌和外分泌功能的研究很少。 方法: 测定FCPD组(n=20)、2型糖尿病(T2 DM)组(n=20)和对照组(n=20)空腹和75g葡萄糖后60min的胰岛素、C肽、胰高血糖素、肠泌素(胰高血糖素样肽1[GLP-1]和胃抑制肽[GIP])、二肽基肽酶IV(DPP-IV)水平。 结果: FCPD组空腹和糖负荷后C肽、胰岛素水平均低于T2 DM组和对照组。对照组糖负荷后胰高血糖素(pmol/L)降低(3.72; 2.29); T2 DM组升高(4.01; 5.73); FCPD组(3.44; 3.44)无明显变化。FCPD组(6.14~9.72; P=<0.001)、T2 DM组(2.87~4.62; P<0.001)和对照组(3.91~6.13; P<0.001)糖负荷后活性GLP-1(pmol/L)升高。FCPD组空腹和糖负荷后GLP-1(pmol/L)活性中位数(6.14; 9.72)是T2 DM组(2.87; 4.62)的两倍; 是对照组(3.91; 6.13)的1.5倍(P<0.001)。糖负荷后GIP(pmol/L)在所有组别中都升高:FCPD(15.83~94.14)、T2DM(21.85~88.29)、对照组(13.00~74.65), P<0.01。不同组间GIP差异无统计学意义。对照组(1578.54,3012.00)和FCPD组(1609.95,1995.42)的DPP-IV浓度(ng/mL)升高; 而T2 DM组(1204.50,1939.50)的DPP-IV浓度无明显变化(P=0.131)。DPP-IV于三组间差异无统计学意义。FCPD组中粪弹性蛋白酶低于T2 DM组对照组。 结论: FCPD患者糖负荷后基础C肽和胰高血糖素降低; 在糖负荷后胰高血糖素不升高。FCPD的GLP-1; 而不是GIP; 与T2 DM和对照组(空腹和糖负荷后)相比升高了1.5-2倍; 而DPP-IV没有差异.

Topics: Adolescent; Adult; Biomarkers; Blood Glucose; C-Peptide; Calcinosis; Case-Control Studies; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Female; Fibrosis; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin; Male; Middle Aged; Pancreatitis, Chronic; Time Factors; Young Adult

The role of exendin-4 in brown adipose tissue (BAT) activation was not very clear. This study is to verify the role of BAT involved in renal benefits of exendin-4 in diabetes mellitus (DM).. In vivo, C57BL/6 mice were randomly divided into nondiabetic (control) and diabetic groups (DM). The diabetic mice were randomized into a control group (DM-Con), BAT-excision group (DM+Exc), exendin-4-treated group (DM+E4), and BAT-excision plus exendin-4-treated group (DM+Exc+E4). The weight, blood glucose and lipids, 24 h urine albumin and 8-OH-dG, and renal fibrosis were analyzed. In vitro, we investigated the role of exendin-4 in the differentiation process of 3T3-L1 and brown preadipocytes and its effect on the rat mesangial cells induced by oleate.. The expressions of UCP-1, PGC-1. Exendin-4 could decrease the renal lipid deposit and improve diabetic nephropathy via activating the renal AMPK pathway independent of BAT activation.

Topics: 3T3-L1 Cells; 8-Hydroxy-2'-Deoxyguanosine; Adenylate Kinase; Adipocytes, Brown; Adipogenesis; Adipose Tissue, Brown; Albuminuria; Animals; Blood Glucose; Blotting, Western; Body Weight; CD36 Antigens; Cholesterol, HDL; Cholesterol, LDL; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Disease Models, Animal; Exenatide; Fibrosis; Gene Expression; Incretins; Kidney; Lipase; Mesangial Cells; Mice; Mice, Inbred C57BL; Myofibroblasts; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Random Allocation; Rats; Real-Time Polymerase Chain Reaction; Triglycerides; Uncoupling Protein 1

Sirt1 is a potent inhibitor of both poly(ADP-ribose) polymerases1 (PARP1) and NF-kB. This study investigated the cardioprotective effect of exendin-4 on cardiac function and remodeling in rats after an expreimentally-induced myocardial infarction (MI) and explored if this protection involves SIRT1/PARP1 axis. Rats were divided into five groups (n = 10/each): sham, sham + exendin-4 (25 nmol/kg/day i.p.), MI (induced by LAD occlusion), MI + exendin-4, and sham + exendin-4 + EX527 (5 mg/2×/week) (a SIRT1 inhibitor). All treatments were given for 6 weeks post the induction of MI. In sham-operated and MI-induced rats, exendin-4 significantly upregulated Bcl-2 levels, enhanced activity, mRNA, and levels of SIRT1, inhibited activity, mRNA, and levels of PARP1, and reduced ROS generation and PARP1 acetylation. In MI-treated rats, these effects were associated with improved cardiac architectures and LV function, reduced collagen deposition, and reduced mRNA and total levels of TNF-α and IL-6, as well as, the activation of NF-κB p65. In addition, exendin-4 inhibited the interaction of PARP1 with p300, TGF-β1, Smad3, and NF-κB p65 and signficantly reduced mRNA and protein levels of collagen I/III and protein levels of MMP2/9. In conclusion, exendin-4 is a potent cardioprotective agent that prevents post-MI inflammation and cardiac remodeling by activating SIRT1-induced inhibition of PARP1.

Topics: Acetylation; Animals; Anti-Inflammatory Agents; Apoptosis; Disease Models, Animal; Exenatide; Fibrosis; Glucagon-Like Peptide-1 Receptor; Incretins; Male; Myocardial Infarction; Myocytes, Cardiac; NF-kappa B; Poly (ADP-Ribose) Polymerase-1; Rats, Wistar; Signal Transduction; Sirtuin 1; Ventricular Function, Left; Ventricular Remodeling

Mammalian target of rapamycin (mTOR) and a ribosomal protein S6 kinase (p70S6K) mediate tissue fibrosis and negatively regulate autophagy. This study aims to investigate whether glucagon-like peptide-1 (GLP-1) analog liraglutide protects the heart against aortic banding-induced cardiac fibrosis and dysfunction through inhibiting mTOR/p70S6K signaling and promoting autophagy activity. Male SD rats were randomly divided into four groups (n = 6/each group): sham operated control; abdominal aortic constriction (AAC); liraglutide treatment during AAC (0.3 mg/kg, injected subcutaneously twice daily); rapamycin treatment during AAC (0.2 mg/kg/day, administered by gastric gavage). Relative to the animals with AAC on week 16, liraglutide treatment significantly reduced heart/body weight ratio, inhibited cardiomyocyte hypertrophy, and augmented plasma GLP-1 level and tissue GLP-1 receptor expression. Phosphorylation of mTOR/p70S6K, populations of myofibroblasts and synthesis of collagen I/III in the myocardium were simultaneously inhibited. Furthermore, autophagy regulating proteins: LC3-II/LC3-I ratio and Beclin-1 were upregulated, and p62 was downregulated by liraglutide. Compared with liraglutide group, treatment with rapamycin, a specific inhibitor of mTOR, compatibly augmented GLP-1 receptor level, inhibited phosphorylation of mTOR/p70S6K and expression of p62 as well as increased level of LC3-II/LC3-I ratio and Beclin-1, suggesting that there is an interaction between GLP-1 and mTOR/p70S6K signaling in the regulation of autophagy. In line with these modifications, treatment with liraglutide and rapamycin significantly reduced perivascular/interstitial fibrosis, and preserved systolic/diastolic function. These results suggest that the inhibitory effects of liraglutide on cardiac fibrosis and dysfunction are potentially mediated by inhibiting mTOR/p70S6K signaling and enhancing autophagy activity.

Topics: Animals; Aorta, Abdominal; Autophagy; Autophagy-Related Proteins; Disease Models, Animal; Fibrosis; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Hypertrophy, Left Ventricular; Incretins; Ligation; Male; Myocytes, Cardiac; Myofibroblasts; Phosphorylation; Protein Kinase Inhibitors; Rats, Sprague-Dawley; Ribosomal Protein S6 Kinases, 70-kDa; Signal Transduction; TOR Serine-Threonine Kinases; Ventricular Function, Left; Ventricular Remodeling

Glucagon-like peptide-1 (GLP-1) reduces cardiovascular events in diabetic patients; however, its counter-protective effects have also been suggested in patients with heart failure and the clear explanation for its mechanisms have not yet been offered.. The effects of GLP-1 analog on cardiac function and energy metabolism, especially glycemic and lipid metabolisms were elucidated using non-diabetic J2N-k hamsters which showed spontaneous dilated cardiomyopathy. J2N-k hamsters were treated with PBS (HF group), low-dose (HF-L group) or high-dose liraglutide (HF-H group).. In failing heart, GLP-1 analog exerted further deteriorated cardiac function (e.g. positive and negative dP/dt; p = 0.01 and p = 0.002, respectively) with overt fibrosis and cardiac enlargement (heart/body weight, 5.7 ± 0.2 in HF group versus 7.6 ± 0.2 in HF-H group; p = 0.02). The protein expression of cardiac muscles indicated the energy starvation status. Indirect calorimetry showed that failing hearts consumed higher energy and carbohydrate than normal hearts; moreover, this tendency was augmented by GLP-1 analog administration. Upon 10% glucose solution loading with GLP-1 analog administration (HF-H-G group) as complementary experiments, the cardiac function and fibrosis significantly ameliorated, whereas carbohydrate utilization augmented further and lipid utilization reduced more. The prognosis of HF-H-G group also significantly improved (p = 0.025).. Glucagon-like peptide-1 analog caused the relative but desperate shortage of glycemic energy source for the failing cardiac muscles and it may restrict ATP synthesis, resulting in cardiac function deterioration. Therefore, appropriate energy supply and amount of carbohydrate intake should be carefully considered when administrating incretin-related drugs to patients with heart failure.

Topics: Adenosine Triphosphate; Animals; Cardiomyopathy, Dilated; Cricetinae; Disease Models, Animal; Energy Metabolism; Fibrosis; Heart Failure; Incretins; Liraglutide; Male; Myocytes, Cardiac; Risk Assessment; Stroke Volume; Ventricular Function, Left; Ventricular Pressure; Ventricular Remodeling

Glucagon-like peptide-1 receptor agonists may have a role in modulation of cardiac fibrosis. Our study aimed to determine the effect of the glucagon-like peptide-1 receptor agonist liraglutide in obesity, hypertension and age-induced murine models of cardiac fibrosis and identify associated molecular mechanisms.. C57Bl/6J mice on a high-fat diet and C57Bl/6J mice on a normal chow diet treated with angiotensin II were used to induce obesity and hypertension-mediated cardiac fibrosis, respectively. C57Bl/6J mice 20 months old were used to study age-induced cardiac fibrosis. Liraglutide treatment of 30 µg/kg/day-300 µg/kg s.c. twice daily was administered for 4 weeks.. Liraglutide treatment attenuated obesity, hypertension and age-induced increases in interstitial cardiac fibrosis and expression of inflammatory and oxidative stress markers.. These observations identify a potential role for liraglutide in the prevention of cardiac fibrosis and identify molecular mechanisms associated with these effects.

Topics: Aging; Angiotensin II; Animals; Aorta; Blood Pressure; Body Weight; Chemokine CCL2; Diet, High-Fat; Disease Models, Animal; Endothelium, Vascular; Fibrosis; Glucagon-Like Peptide-1 Receptor; Heart; Heart Diseases; Hypertension; I-kappa B Proteins; Immunohistochemistry; Incretins; Inflammation; Interleukin-10; Liraglutide; Macrophages; Male; Mice; Mice, Inbred C57BL; Myocardium; NF-kappa B p50 Subunit; Obesity; Oxidative Stress; Real-Time Polymerase Chain Reaction; Vasoconstrictor Agents; Vimentin

Dramatic improvement of type 2 diabetes is commonly observed after bariatric surgery. However, the mechanisms behind the alterations in glucose homeostasis are still elusive. We examined the effect of duodenal-jejunal bypass (DJB), which maintains the gastric volume intact while bypassing the entire duodenum and the proximal jejunum, on glycemic control, β-cell mass, islet morphology, and changes in enteroendocrine cell populations in nonobese diabetic Goto-Kakizaki (GK) rats and nondiabetic control Wistar rats. We performed DJB or sham surgery in GK and Wistar rats. Blood glucose levels and glucose tolerance were monitored, and the plasma insulin, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) levels were measured. β-Cell area, islet fibrosis, intestinal morphology, and the density of enteroendocrine cells expressing GLP-1 and/or GIP were quantified. Improved postprandial glycemia was observed from 3 mo after DJB in diabetic GK rats, persisting until 12 mo after surgery. Compared with the sham-GK rats, the DJB-GK rats had an increased β-cell area and a decreased islet fibrosis, increased insulin secretion with increased GLP-1 secretion in response to a mixed meal, and an increased population of cells coexpressing GIP and GLP-1 in the jejunum anastomosed to the stomach. In contrast, DJB impaired glucose tolerance in nondiabetic Wistar rats. In conclusion, although DJB worsens glucose homeostasis in normal nondiabetic Wistar rats, it can prevent long-term aggravation of glucose homeostasis in diabetic GK rats in association with changes in intestinal enteroendocrine cell populations, increased GLP-1 production, and reduced β-cell deterioration.

Topics: Animals; Bariatric Surgery; Blood Glucose; Body Composition; Body Weight; Diabetes Mellitus, Type 2; Duodenum; Endocrine System; Enzyme-Linked Immunosorbent Assay; Fibrosis; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hyperglycemia; Immunohistochemistry; Incretins; Insulin-Secreting Cells; Islets of Langerhans; Jejunum; Male; Rats; Rats, Wistar