glucagon-like-peptide-1 and Ischemia

Intestinal ischemia, also called mesenteric ischemia, is a severe gastrointestinal and vascular medical emergency caused by a sudden decrease of blood flow through the mesenteric vessels. It generates hypoperfusion of intestinal tissues and can rapidly progress to intestinal wall infarction, systemic inflammation or even death if not treated in time. The mortality of this condition is still considerably high despite all the medical advances of the past few years. This is partially due to the difficulty of diagnosing early stage mesenteric ischemia. Indeed, a speedy and correct diagnosis is decisive for suitable medical care. However, early symptoms are unspecific and conventional clinical markers are neither specific nor sensitive enough. In the last few years, significant clinical and preclinical efforts have been made to find biomarkers which could predict gastrointestinal damage before it becomes irreversible. Here, the gut-derived hormone glucagon-like peptide-1 (GLP-1) is described as a potential early biomarker of this severe condition. Indeed, GLP-1 plasma levels rise rapidly in both mice and humans with intestinal ischemia. This discovery could counter the cruel lack of clinical biomarkers available to diagnose and therefore manage intestinal ischemia efficiently in the early stages. GLP-1 could thus become part of a panel of biomarkers for intestinal ischemia and could help to reduce the associated high mortality rates.

Topics: Animals; Biomarkers; Glucagon-Like Peptide 1; Humans; Intestinal Diseases; Intestines; Ischemia

Testicular torsion is a serious emergency and a well-known cause of male infertility. It represents 10 %-15 % of scrotal diseases in children. Kisspeptin (KISS1) is a hormone secreted from the hypothalamic nuclei and testis, but its role in testis is not fully understood. Semaglutide is a novel antidiabetic glucagon-like peptide 1 (GLP-1) analog. Hence, we designed the current study to elucidate the possible ameliorative effect of semaglutide on ischemia/reperfusion-induced testicular dysfunction in rats and highlight the role of the testicular GLP-1/PCG-1α-PPAR-α-KISS1 signaling pathway. We randomly divided 50 male Sprague Dawley into five equal groups (10 rats each): SHAM, exendin 9-39 -treated (EX), testicular torsion/detorsion (T/D), testicular torsion/detorsion and semaglutide-treated (SEM + T/D), and testicular torsion/detorsion, exendin, and semaglutide-treated (EX + SEM + T/D). We quantified serum follicle-stimulating hormone, luteinizing hormone, total testosterone, testicular oxidative stress markers, testicular gene expression of GLP-1/KISS1 pathway-related genes (KISS1, KISS1R, GLP-1, GLP-1R, PGC-1α, PPAR-α), steroidogenesis pathway-related genes (STAR, CYP11A1, CYP17A1, HSD17B3, CYP19A1), HO-1, Nrf-2, and testicular protein expression of HIF-1α, TNF-α, NF-κβ, Caspase-3, FAS, proliferating cell nuclear antigen, and KISS1 through testicular histopathology and immunohistochemistry assays. Testicular torsion/detorsion markedly elevated proapoptotic, proinflammatory, and oxidative stress marker levels, noticeably downregulating the expression of GLP-1/KISS1 and steroidogenesis pathway-related proteins. Semaglutide administration significantly ameliorated all these deleterious effects. Nevertheless, injecting exendin, a GLP1-R antagonist, before semaglutide abolished all the documented improvements. We concluded that semaglutide ameliorated ischemia/reperfusion-induced testicular dysfunction by modulating the GLP-1/PGC-1α-PPAR-α/KISS1/steroidogenesis signaling pathway, improving testicular oxidative state, and suppressing testicular inflammation and apoptosis.

Topics: Animals; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Ischemia; Kisspeptins; Male; Oxidative Stress; PPAR alpha; Rats; Rats, Sprague-Dawley; Reperfusion; Reperfusion Injury; Signal Transduction; Testis

We assessed the effect of glucagon-like peptide 1 receptor agonists (GLP-1RAs) on ischemic stroke prevention in the Asian population with type 2 diabetes (T2D) without established cardiovascular disease.. This retrospective cohort study examined data obtained from the Taiwan National Health Insurance Research Database for the period from 1998 to 2018. The follow-up ended upon the occurrence of hospitalization for ischemic stroke. The median follow-up period was 3 years. The effect of GLP-1RA exposure time on the development of hospitalization for ischemic stroke was assessed.. The GLP-1RA and non-GLP-1RA user groups both included 6,534 patients. Approximately 53% of the patients were women, and the mean age was 49 ± 12 years. The overall risk of ischemic stroke hospitalization for GLP-1RA users was not significantly lower than that for GLP-1RA nonusers (adjusted hazard ratio [HR] 0.69 [95% CI 0.47-1.00]; P = 0.0506), but GLP-1RA users with a >251-day supply during the study period had a significantly lower risk of ischemic stroke hospitalization than GLP-1RA nonusers (adjusted HR 0.28 [95% CI 0.11-0.71]). Higher cumulative dose of GLP-1 RAs (>1,784 mg) was associated with significantly lower risk of ischemic stroke hospitalization. The subgroup analyses defined by various baseline features did not reveal significant differences in the observed effect of GLP-1RAs.. Longer use and higher dose of GLP-1 RAs were associated with a decreased risk of hospitalization for ischemic stroke among Asian patients with T2D who did not have established atherosclerotic cardiovascular diseases, but who did have dyslipidemia or hypertension.

Topics: Adult; Atherosclerosis; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Ischemia; Ischemic Stroke; Male; Middle Aged; Retrospective Studies

Previous studies have reported that glucagon-like peptide-1 (GLP-1) may play a critical role in the development of intestinal ischemia-reperfusion (I/R) injury. The present study aimed to investigate whether liraglutide (GLP-1 analog) protects against intestinal I/R injury and reveals the possible underlying mechanism.. Temporary superior mesenteric artery occlusion was performed to establish an intestinal I/R injury mouse model. Different doses of liraglutide were administered in vivo. Then, the survival rate of mice exposed to different ischemia times, the histopathology, intestinal barrier index, cytokine production, intestinal tissue apoptosis, and the levels of several proteins were detected in each group.. Pretreatment with liraglutide significantly alleviated the pathological changes induced by I/R and increased the overall survival of mice exposed to intestinal I/R injury. Moreover, liraglutide attenuated neutrophil infiltration of intestinal tissues, pro-inflammatory cytokine production (including IL-1β, IL-6, and TNF-α), and apoptosis of intestinal tissues caused by intestinal I/R injury. In addition, liraglutide inhibited the nuclear translocation of nuclear factor-κB (NF-κB) and up-regulated the phosphorylation levels of phosphoinositide 3-kinase (PI3K) and protein kinase B (Akt) in the I/R group.. Liraglutide may attenuate the inflammatory response and the apoptosis of intestinal tissues via the NF-κB and PI3K/Akt pathway, protecting against intestinal I/R.

Topics: Animals; Apoptosis; Glucagon-Like Peptide 1; Interleukin-6; Ischemia; Liraglutide; Mesenteric Ischemia; Mice; NF-kappa B; Phosphatidylinositol 3-Kinase; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Reperfusion Injury; Tumor Necrosis Factor-alpha

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

Inflammation associated with blood-retinal barrier (BRB) breakdown is a common feature of several retinal diseases. Therefore, the development of novel nonsteroidal anti-inflammatory approaches may provide important therapeutic options. Previous studies demonstrated that inhibition of dipeptidyl peptidase-IV, the enzyme responsible for the degradation of glucagon-like peptide-1 (GLP-1), led to insulin-independent prevention of diabetes-induced increases in BRB permeability, suggesting that incretin-based drugs may have beneficial pleiotropic effects in the retina. In the current study, the barrier protective and anti-inflammatory properties of exendin-4 (Ex-4), an analog of GLP-1, after ischemia-reperfusion (IR) injury were examined.. Ischemia-reperfusion injury was induced in rat retinas by increasing the intraocular pressure for 45 minutes followed by 48 hours of reperfusion. Rats were treated with Ex-4 prior to and following IR. Blood-retinal barrier permeability was assessed by Evans blue dye leakage. Retinal inflammatory gene expression and leukocytic infiltration were measured by qRT-PCR and immunofluorescence, respectively. A microglial cell line was used to determine the effects of Ex-4 on lipopolysaccharide (LPS)-induced inflammatory response.. Exendin-4 dramatically reduced the BRB permeability induced by IR injury, which was associated with suppression of inflammatory gene expression. Moreover, in vitro studies showed that Ex-4 also reduced the inflammatory response to LPS and inhibited NF-κB activation.. The present work suggests that Ex-4 can prevent IR injury-induced BRB breakdown and inflammation through inhibition of inflammatory cytokine production by activated microglia and may provide a novel option for therapeutic intervention in diseases involving retinal inflammation.

Topics: Animals; Blood-Retinal Barrier; Cattle; Cells, Cultured; Disease Models, Animal; Exenatide; Glucagon-Like Peptide 1; Immunoblotting; Immunohistochemistry; Incretins; Inflammation; Ischemia; Male; Peptides; Rats; Rats, Long-Evans; Reperfusion Injury; Retinal Diseases; Venoms

Dipeptidyl peptidase-4 inhibitors are known to lower glucose levels and are also beneficial in the management of cardiovascular disease. Here, we investigated whether a dipeptidyl peptidase-4 inhibitor, vildagliptin, modulates endothelial cell network formation and revascularization processes in vitro and in vivo. Treatment with vildagliptin enhanced blood flow recovery and capillary density in the ischemic limbs of wild-type mice, with accompanying increases in phosphorylation of Akt and endothelial nitric-oxide synthase (eNOS). In contrast to wild-type mice, treatment with vildagliptin did not improve blood flow in ischemic muscles of eNOS-deficient mice. Treatment with vildagliptin increased the levels of glucagon-like peptide-1 (GLP-1) and adiponectin, which have protective effects on the vasculature. Both vildagliptin and GLP-1 increased the differentiation of cultured human umbilical vein endothelial cells (HUVECs) into vascular-like structures, although vildagliptin was less effective than GLP-1. GLP-1 and vildagliptin also stimulated the phosphorylation of Akt and eNOS in HUVECs. Pretreatment with a PI3 kinase or NOS inhibitor blocked the stimulatory effects of both vildagliptin and GLP-1 on HUVEC differentiation. Furthermore, treatment with vildagliptin only partially increased the limb flow of ischemic muscle in adiponectin-deficient mice in vivo. GLP-1, but not vildagliptin, significantly increased adiponectin expression in differentiated 3T3-L1 adipocytes in vitro. These data indicate that vildagliptin promotes endothelial cell function via eNOS signaling, an effect that may be mediated by both GLP-1-dependent and GLP-1-independent mechanisms. The beneficial activity of GLP-1 for revascularization may also be partially mediated by its ability to increase adiponectin production.

Topics: 3T3-L1 Cells; Adamantane; Adipocytes; Adiponectin; Animals; Cell Differentiation; Dipeptidyl-Peptidase IV Inhibitors; Glucagon-Like Peptide 1; Hindlimb; Human Umbilical Vein Endothelial Cells; Ischemia; Mice; Mice, Knockout; Muscle, Skeletal; Neovascularization, Physiologic; Nitric Oxide Synthase Type III; Nitriles; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Pyrrolidines; Signal Transduction; Vildagliptin

Current methods used to treat critical limb ischaemia (CLI) are hampered by a lack of effective strategies, therefore, therapeutic vasculogenesis may open up a new field for the treatment of CLI. In this study we investigated the ability of the DPP-4 inhibitor, sitagliptin, originally used as a hypoglycaemic agent, to induce vasculogenesis in vivo.. Sitagliptin were administered daily to C57CL/B6 mice and eGFP transgenic mouse bone marrow-transplanted ICR mice that had undergone hindlimb ischaemic surgery. Laser Doppler imaging and flow cytometry were used to evaluate the degree of neovasculogenesis and circulating levels of endothelial progenitor cells (EPCs) respectively. Cell surface markers of EPCs and endothelial NOS (eNOS) in vessels were studied.. Sitagliptin elevated plasma glucagon-like peptide-1 (GLP-1) levels in mice subjected to ischaemia, decreased plasma dipeptidyl peptidase-4 (DPP-4) concentration, and augmented ischaemia-induced increases in stromal cell-derived factor-1 (SDF-1) in a dose-dependent manner. Blood flow in the ischaemic limb was significantly improved in mice treated with sitagliptin. Circulating levels of EPCs were also increased after sitagliptin treatment. Sitagliptin also enhanced the expression of CD 34 and eNOS in ischaemic muscle. In addition, sitagliptin promoted EPC mobilization and homing to ischaemic tissue in eGFP transgenic mouse bone marrow-transplanted ICR mice.. Circulating EPC levels and neovasculogenesis were augmented by the DPP-4 inhibitor, sitagliptin and this effect was dependent on an eNOS-related pathway in a mouse model of hindlimb ischaemia. The results indicate that oral administration of sitagliptin has therapeutic potential as an inducer of vasculogenesis.

Topics: Animals; Chemokine CXCL12; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Endothelial Cells; Glucagon-Like Peptide 1; Hindlimb; Ischemia; Male; Mice; Mice, Inbred ICR; Mice, Transgenic; Neovascularization, Physiologic; Nitric Oxide Synthase Type III; Platelet Endothelial Cell Adhesion Molecule-1; Pyrazines; Sitagliptin Phosphate; Stem Cells; Triazoles

Glucagon-like peptide-1 (7-36) amide (GLP-1) has been studied as a treatment option in diabetic patients. We investigated the effect of recombinant GLP-1 infusion on hemodynamic parameters, myocardial metabolism, and infarct size during normoxic conditions as well as during ischemia and reperfusion using an open-chest porcine heart model. In the presence of rGLP-1, interstitial levels of pyruvate and lactate decreased during ischemia and reperfusion both in ischemic and non-ischemic tissue. Moreover, rGLP-1 infusion resulted in increased plasma insulin levels and decreased blood glucose levels. Neither hemodynamic variables nor the consequent infarct size were influenced by rGLP-1 infusion. We conclude that rGLP-1 altered myocardial glucose utilization during ischemia and reperfusion. It did not exert any untoward hemodynamic effects.

Topics: Animals; Area Under Curve; Blood Glucose; Cardiovascular System; Glucagon; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Ischemia; Lactic Acid; Microdialysis; Myocardial Infarction; Myocardium; Peptide Fragments; Protein Precursors; Pyruvic Acid; Reperfusion Injury; Swine; Time Factors