Endothelial GLP-1 (Glucagon-Like Peptide-1) Receptor Mediates Cardiovascular Protection by Liraglutide In Mice With Experimental Arterial Hypertension

Beyond Weight Loss: Added Benefits Could Guide the Choice of Anti-Obesity Medications

PURPOSE OF REVIEW

To highlight the added benefits of approved and upcoming, centrally-acting, anti-obesity drugs, focusing not only on the most common metabolic and cardiovascular effects but also on their less explored clinical benefits and drawbacks, in order to provide clinicians with a tool for more comprehensive, pharmacological management of obesity.

RECENT FINDINGS

Obesity is increasingly prevalent worldwide and has become a challenge for healthcare systems and societies. Reduced life expectancy and cardiometabolic complications are some of the consequences of this complex disease. Recent insights into the pathophysiology of obesity have led to the development of several promising pharmacologic targets, so that even more effective drugs are on the horizon. The perspective of having a wider range of treatments increases the chance to personalize therapy. This primarily has the potential to take advantage of the long-term use of anti-obesity medication for safe, effective and sustainable weight loss, and to concomitantly address obesity complications/comorbidities when already established. The evolving scenario of the availability of anti-obesity drugs and the increasing knowledge of their added effects on obesity complications will allow clinicians to move into a new era of precision medicine.

Liraglutide promotes angiogenesis in adipose tissue via suppression of adipocyte-derived IL-6

Accumulating evidence suggests that Liraglutide is a favorable treatment for obese people. Obesity induces cellular senescence and accumulated senescent adipocytes in adipose tissue. However, the role of Liraglutide in adipose tissue (AT) senescence and the underlying mechanisms remain obscure. In this study, we found that HFD induces adipocyte senescence and impaired angiogenesis in AT. The deleterious effects provoked unhealthy adipose tissue remodeling and metabolic disturbance. In contrast, treatment of Liraglutide promoted weight reduction, alleviated adipose tissue senescence, and improved angiogenesis in AT. Notably, we demonstrated that Liraglutide promotes angiogenesis in AT dependent on adipocyte-derived IL-6. These findings revealed distinctive roles of Liraglutide in the regulation of adipocyte senescence and provide a therapeutic potential to obesity-associated metabolic disorders.

Beyond the pancreas: contrasting cardiometabolic actions of GIP and GLP1

Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP1) exhibit incretin activity, meaning that they potentiate glucose-dependent insulin secretion. The emergence of GIP receptor (GIPR)-GLP1 receptor (GLP1R) co-agonists has fostered growing interest in the actions of GIP and GLP1 in metabolically relevant tissues. Here, we update concepts of how these hormones act beyond the pancreas. The actions of GIP and GLP1 on liver, muscle and adipose tissue, in the control of glucose and lipid homeostasis, are discussed in the context of plausible mechanisms of action. Both the GIPR and GLP1R are expressed in the central nervous system, wherein receptor activation produces anorectic effects enabling weight loss. In preclinical studies, GIP and GLP1 reduce atherosclerosis. Furthermore, GIPR and GLP1R are expressed within the heart and immune system, and GLP1R within the kidney, revealing putative mechanisms linking GIP and GLP1R agonism to cardiorenal protection. We interpret the clinical and mechanistic data obtained for different agents that enable weight loss and glucose control for the treatment of obesity and type 2 diabetes mellitus, respectively, by activating or blocking GIPR signalling, including the GIPR-GLP1R co-agonist tirzepatide, as well as the GIPR antagonist-GLP1R agonist AMG-133. Collectively, we update translational concepts of GIP and GLP1 action, while highlighting gaps, areas of uncertainty and controversies meriting ongoing investigation.

The blood pressure lowering effects of glucagon-like peptide-1 receptor agonists: A mini-review of the potential mechanisms

The incretin hormone glucagon-like peptide 1 (GLP-1) is a key component of the signaling mechanisms promoting glucose homeostasis. Clinical and experimental studies demonstrated that GLP-1 receptor agonists, including GLP-1 itself, have favorable effects on blood pressure and reduce the risk of major cardiovascular events, independently of their effect on glycemic control. GLP-1 receptors are present in the hypothalamus and brainstem, the carotid body, the vasculature, and the kidneys. These organs are involved in blood pressure regulation, have their function altered in hypertension, and are positively benefited by the treatment with GLP-1 receptor agonists. Here, we discuss the potential mechanisms whereby activation of GLP-1R signaling exerts blood pressure-lowering effects beyond glycemic control.

Weight-dependent and weight-independent effects of dulaglutide on blood pressure in patients with type 2 diabetes

BACKGROUND

Patients with type 2 diabetes (T2D) treated with glucagon-like peptide-1 receptor agonists may experience reductions in weight and blood pressure. The primary objective of the current study was to determine the weight-dependent and weight-independent effects of ~ 6 months treatment with dulaglutide 1.5 mg treatment in participants with T2D.

METHODS

Mediation analysis was conducted for five randomized, placebo-controlled trials of dulaglutide 1.5 mg to estimate the weight-dependent (i.e., mediated by weight) and weight-independent effects from dulaglutide vs. placebo on change from baseline for systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure. A random-effects meta-analysis combined these results. To investigate a dose response between dulaglutide 4.5 mg and placebo, mediation analysis was first conducted in AWARD-11 to estimate the weight-dependent and weight-independent effects of dulaglutide 4.5 mg vs. 1.5 mg, followed by an indirect comparison with the mediation result for dulaglutide 1.5 mg vs. placebo.

RESULTS

Baseline characteristics were largely similar across the trials. In the mediation meta-analysis of placebo-controlled trials, the total treatment effect of dulaglutide 1.5 mg after placebo-adjustment on SBP was - 2.6 mmHg (95% CI - 3.8, - 1.5; p < 0.001) and was attributed to both a weight-dependent effect (- 0.9 mmHg; 95% CI: - 1.4, - 0.5; p < 0.001) and a weight-independent effect (- 1.5 mmHg; 95% CI: - 2.6, - 0.3; p = 0.01), accounting for 36% and 64% of the total effect, respectively. For pulse pressure, the total treatment effect of dulaglutide (- 2.5 mmHg; 95% CI: - 3.5, - 1.5; p < 0.001) was 14% weight-dependent and 86% weight-independent. For DBP there was limited impact of dulaglutide treatment, with only a small weight-mediated effect. Dulaglutide 4.5 mg demonstrated an effect on reduction in SBP and pulse pressure beyond that of dulaglutide 1.5 mg which was primarily weight mediated.

CONCLUSIONS

Dulaglutide 1.5 mg reduced SBP and pulse pressure in people with T2D across the placebo-controlled trials in the AWARD program. While up to one third of the effect of dulaglutide 1.5 mg on SBP and pulse pressure was due to weight reduction, the majority was independent of weight. A greater understanding of the pleotropic effects of GLP-1 RA that contribute to reduction in blood pressure could support developing future approaches for treating hypertension. Trial registrations (clinicaltrials.gov) NCT01064687, NCT00734474, NCT01769378, NCT02597049, NCT01149421, NCT03495102.

Liraglutide Accelerates Ischemia-Induced Angiogenesis in a Murine Diabetic Model

Background Severe hindlimb ischemia is a chronic disease with poor prognosis that can lead to amputation or even death. This study aimed to assess the therapeutic effect of liraglutide on hind-limb ischemia in type 2 diabetic mice and to elucidate the underlying mechanism. Methods and Results Blood flow reperfusion and capillary densities after treatment with liraglutide or vehicle were evaluated in a mouse model of lower-limb ischemia in a normal background or a background of streptozotocin-induced diabetes. The proliferation, migration, and tube formation of human umbilical vein endothelial cells were analyzed in vitro upon treatment with liraglutide under normal-glucose and high-glucose conditions. Levels of phospho-Akt, phospho-endothelial nitric oxide synthase, and phospho-extracellular signal-related kinases 1 and 2 under different conditions in human umbilical vein endothelial cells and in ischemic muscle were determined by western blotting. Liraglutide significantly improved perfusion recovery and capillary density in both nondiabetic and diabetic mice. Liraglutide also promoted, in a concentration-dependent manner, the proliferation, migration, and tube formation of normal glucose- and high glucose-treated human umbilical vein endothelial cells, as well as the phosphorylation of Akt, endothelial nitric oxide synthase, and extracellular signal-related kinases 1 and 2 both in vitro and in vivo. The liraglutide antagonist exendin (9-39) reversed the promoting effects of liraglutide on human umbilical vein endothelial cell functions. Furthermore, exendin (9-39), LY294002, and PD98059 blocked the liraglutide-induced activation of Akt/endothelial nitric oxide synthase and extracellular signal-related kinases 1 and 2 signaling pathways. Conclusions These studies identified a novel role of liraglutide in modulating ischemia-induced angiogenesis, possibly through effects on endothelial cell function and activation of Akt/endothelial nitric oxide synthase and extracellular signal-related kinases 1 and 2 signaling, and suggested the glucagon-like peptide-1 receptor may be an important therapeutic target in diabetic hind-limb ischemia.

Liraglutide Lowers Endothelial Vascular Cell Adhesion Molecule-1 in Murine Atherosclerosis Independent of Glucose Levels

The authors determined the effect of the GLP-1 receptor agonist liraglutide on endothelial surface expression of vascular cell adhesion molecule (VCAM)-1 in murine apolipoprotein E knockout atherosclerosis. Contrast-enhanced ultrasound molecular imaging using microbubbles targeted to VCAM-1 and control microbubbles showed a 3-fold increase in endothelial surface VCAM-1 signal in vehicle-treated animals, whereas in the liraglutide-treated animals the signal ratio remained around 1 throughout the study. Liraglutide had no influence on low-density lipoprotein cholesterol or glycated hemoglobin, but reduced TNF-α, IL-1β, MCP-1, and OPN. Aortic plaque lesion area and luminal VCAM-1 expression on immunohistology were reduced under liraglutide treatment.

GLP-1 rescued gestational diabetes mellitus-induced suppression of fetal thalamus development

Diabetes can be classified as type 1, type 2, and gestational diabetes mellitus (GDM). It has been reported that children born from mothers with GDM present motor impairment, however, underlying mechanisms of GDM-induce fetal neurological diseases remain unknown. In this study, NOD (nonobese diabetic) mice were used to construct the GDM model; after 2 weeks of gestation, thalamocortical axon development of fetal was evaluated by immunofluorescence. PCR of LRRC4C was used to confirm axon development of the thalamus cortex. RNA array was used to predict possible targets affected by GDM during fetal neurodevelopment. Western blot was used to investigate the underlying mechanism, PI3K inhibitor, and MAPK inhibitor was used to determine key pathway involved in this model, in vitro axonal growth was evaluated using neural stem cells, tactile sensory behavior of offspring was assessed to confirm neurological influence further. The result shown that maternal diabetes significantly suppressed axonal development of fetal thalamus cortex, PCR array of GDM fetal brain indicated that upregulation of GLP-1R compared with normal fetal, ELISA confirmed that GLP-1 level was decreased in GDM maternal serum compared with that of wild type pregnant mice. In vitro study observed enhanced axonal elongation after supplements of GLP-1 analog, GLP-1 analog PI3K-dependently active ROCK1 activity, IP injection of GLP-1 analog could partly reverse GDM-induced suppression of fetal thalamocortical axon development and improve tactile sensory behavior of GDM offspring. Our study provided a novel mechanism of GDM induced-neurological diseases and predicted GLP-1 as possible prevention supplement during gestation.

Recent Pharmacological Options in Type 2 Diabetes and Synergic Mechanism in Cardiovascular Disease

Diabetes Mellitus is a multifactorial disease with a critical impact worldwide. During prediabetes, the presence of various inflammatory cytokines and oxidative stress will lead to the pathogenesis of type 2 diabetes. Furthermore, insulin resistance and chronic hyperglycemia will lead to micro- and macrovascular complications (cardiovascular disease, heart failure, hypertension, chronic kidney disease, and atherosclerosis). The development through the years of pharmacological options allowed us to reduce the persistence of chronic hyperglycemia and reduce diabetic complications. This review aims to highlight the specific mechanisms with which the new treatments for type 2 diabetes reduce oxidative stress and insulin resistance and improve cardiovascular outcomes.

Senescence-Associated Secretory Phenotype of Cardiovascular System Cells and Inflammaging: Perspectives of Peptide Regulation

A senescence-associated secretory phenotype (SASP) and a mild inflammatory response characteristic of senescent cells (inflammaging) form the conditions for the development of cardiovascular diseases: atherosclerosis, coronary heart disease, and myocardial infarction. The purpose of the review is to analyze the pool of signaling molecules that form SASP and inflammaging in cells of the cardiovascular system and to search for targets for the action of vasoprotective peptides. The SASP of cells of the cardiovascular system is characterized by a change in the synthesis of anti-proliferative proteins (p16, p19, p21, p38, p53), cytokines characteristic of inflammaging (IL-1α,β, IL-4, IL-6, IL-8, IL-18, TNFα, TGFβ1, NF-κB, MCP), matrix metalloproteinases, adhesion molecules, and sirtuins. It has been established that peptides are physiological regulators of body functions. Vasoprotective polypeptides (liraglutide, atrial natriuretic peptide, mimetics of relaxin, Ucn1, and adropin), KED tripeptide, and AEDR tetrapeptide regulate the synthesis of molecules involved in inflammaging and SASP-forming cells of the cardiovascular system. This indicates the prospects for the development of drugs based on peptides for the treatment of age-associated cardiovascular pathology.

GLP-1 Receptor Agonists for the Reduction of Atherosclerotic Cardiovascular Risk in Patients With Type 2 Diabetes

Patients with type 2 diabetes are at high risk for development of cardiovascular disease, including myocardial infarction, stroke, heart failure, and cardiovascular death. Multiple large cardiovascular outcome trials with novel glucose-lowering agents, namely SGLT2i (SGLT2 inhibitors) and GLP-1 RA (GLP-1 receptor agonists), have demonstrated robust and significant reductions of major adverse cardiovascular events and additional cardiovascular outcomes, such as hospitalizations for heart failure. This evidence has changed the landscape for treatment of patients with type 2 diabetes. Both diabetes and cardiology guidelines and professional societies have responded to this paradigm shift by including strong recommendations to use SGLT2i and/or GLP-1 RA, with evidence-based benefits to reduce cardiovascular risk in high-risk individuals with type 2 diabetes, independent of the need for additional glucose control. GLP-1 RA were initially developed as glucose-lowering drugs because activation of the GLP-1 receptor by these agents leads to a reduction in blood glucose and an improvement in postprandial glucose metabolism. By stimulating GLP-1R in hypothalamic neurons, GLP-1 RA additionally induce satiety and lead to weight loss. Data from cardiovascular outcome trials demonstrated a robust and consistent reduction in atherothrombotic events, particularly in patients with established atherosclerotic cardiovascular disease. Despite the consistent evidence of atherosclerotic cardiovascular disease benefit from these trials, the number of patients receiving these drugs remains low. This overview summarizes the experimental and clinical evidence of cardiovascular risk reduction offered by GLP-1 RA, and provides practical information on how these drugs should be implemented in the treatment of type 2 diabetes in the cardiology community.

Liraglutide Improves the Angiogenic Capability of EPC and Promotes Ischemic Angiogenesis in Mice under Diabetic Conditions through an Nrf2-Dependent Mechanism

The impairment in endothelial progenitor cell (EPC) functions results in dysregulation of vascular homeostasis and dysfunction of the endothelium under diabetic conditions. Improving EPC function has been considered as a promising strategy for ameliorating diabetic vascular complications. Liraglutide has been widely used as a therapeutic agent for diabetes. However, the effects and mechanisms of liraglutide on EPC dysfunction remain unclear. The capability of liraglutide in promoting blood perfusion and angiogenesis under diabetic conditions was evaluated in the hind limb ischemia model of diabetic mice. The effect of liraglutide on the angiogenic function of EPC was evaluated by cell scratch recovery assay, tube formation assay, and nitric oxide production. RNA sequencing was performed to assess the underlying mechanisms. Liraglutide enhanced blood perfusion and angiogenesis in the ischemic hindlimb of db/db mice and streptozotocin-induced type 1 diabetic mice. Additionally, liraglutide improved tube formation, cell migration, and nitric oxide production of high glucose (HG)-treated EPC. Assessment of liraglutide target pathways revealed a network of genes involved in antioxidant activity. Further mechanism study showed that liraglutide decreased the production of reactive oxygen species and increased the activity of nuclear factor erythroid 2-related factor 2 (Nrf2). Nrf2 deficiency attenuated the beneficial effects of liraglutide on improving EPC function and promoting ischemic angiogenesis under diabetic conditions. Moreover, liraglutide activates Nrf2 through an AKT/GSK3β/Fyn pathway, and inhibiting this pathway abolished liraglutide-induced Nrf2 activation and EPC function improvement. Overall, these results suggest that Liraglutide represents therapeutic potential in promoting EPC function and ameliorating ischemic angiogenesis under diabetic conditions, and these beneficial effects relied on Nrf2 activation.

Glucagon-like Peptide-1 receptor Tie2+ cells are essential for the cardioprotective actions of liraglutide in mice with experimental myocardial infarction

OBJECTIVES

Glucagon-like peptide-1 receptor (GLP-1R) agonists reduce the rates of major cardiovascular events, including myocardial infarction in people with type 2 diabetes, and decrease infarct size while preserving ventricular function in preclinical studies. Nevertheless, the precise cellular sites of GLP-1R expression that mediate the cardioprotective actions of GLP-1 in the setting of ischemic cardiac injury are uncertain.

METHODS

Publicly available single cell RNA sequencing (scRNA-seq) datasets on mouse and human heart cells were analyzed for Glp1r/GLP1R expression. Fluorescent activated cell sorting was used to localize Glp1r expression in cell populations from the mouse heart. The importance of endothelial and hematopoietic cells for the cardioprotective response to liraglutide in the setting of acute myocardial infarction (MI) was determined by inactivating the Glp1r in Tie2+ cell populations. Cardiac gene expression profiles regulated by liraglutide were examined using RNA-seq to interrogate mouse atria and both infarcted and non-infarcted ventricular tissue after acute coronary artery ligation.

RESULTS

In mice, cardiac Glp1r mRNA transcripts were exclusively detected in endocardial cells by scRNA-seq. In contrast, analysis of human heart by scRNA-seq localized GLP1R mRNA transcripts to populations of atrial and ventricular cardiomyocytes. Moreover, very low levels of GIPR, GCGR and GLP2R mRNA transcripts were detected in the human heart. Cell sorting and RNA analyses detected cardiac Glp1r expression in endothelial cells (ECs) within the atria and ventricle in the ischemic and non-ischemic mouse heart. Transcriptional responses to liraglutide administration were not evident in wild type mouse ventricles following acute MI, however liraglutide differentially regulated genes important for inflammation, cardiac repair, cell proliferation, and angiogenesis in the left atrium, while reducing circulating levels of IL-6 and KC/GRO within hours of acute MI. Inactivation of the Glp1r within the Tie2+ cell expression domain encompassing ECs revealed normal cardiac structure and function, glucose homeostasis and body weight in Glp1r^Tie2-/- mice. Nevertheless, the cardioprotective actions of liraglutide to reduce infarct size, augment ejection fraction, and improve survival after experimental myocardial infarction (MI), were attenuated in Glp1r^Tie2-/- mice.

CONCLUSIONS

These findings identify the importance of the murine Tie2+ endothelial cell GLP-1R as a target for the cardioprotective actions of GLP-1R agonists and support the importance of the atrial and ventricular endocardial GLP-1R as key sites of GLP-1 action in the ischemic mouse heart. Hitherto unexplored species-specific differences in cardiac GLP-1R expression challenge the exclusive use of mouse models for understanding the mechanisms of GLP-1 action in the normal and ischemic human heart.

Bariatric surgery for diabetic comorbidities: A focus on hepatic, cardiac and renal fibrosis

Continuously rising trends in diabetes render this disease spectrum an epidemic proportion worldwide. As the disease progresses, the pathological effects of diabetes may impair the normal function of several vital organs, eventually leading to increase the risk of other diabetic comorbidities with advanced fibrosis such as non-alcoholic fatty liver disease, diabetic cardiomyopathy, and diabetic kidney disease. Currently, lifestyle changes and drug therapies of hypoglycemic and lipid-lowering are effective in improving multi-organ function, but therapeutic efficacy is difficult to maintain due to poor compliance and drug reactions. Bariatric surgery, including sleeve gastrectomy and Roux-en-Y gastric bypass surgery, has shown better results in terms of prognosis for diabetes through long-term follow-up. Moreover, bariatric surgery has significant long-term benefits on the function of the heart, liver, kidneys, and other organs through mechanisms associated with reversal of tissue fibrosis. The aim of this review is to describe the impact of type 2 diabetes mellitus on hepatic, cardiac and renal fibrosis and to summarize the potential mechanisms by which bariatric surgery improves multiple organ function, particularly reversal of fibrosis.

Divergent roles for the gut intraepithelial lymphocyte GLP-1R in control of metabolism, microbiota, and T cell-induced inflammation

Gut intraepithelial lymphocytes (IELs) are thought to calibrate glucagon-like peptide 1 (GLP-1) bioavailability, thereby regulating systemic glucose and lipid metabolism. Here, we show that the gut IEL GLP-1 receptor (GLP-1R) is not required for enteroendocrine L cell GLP-1 secretion and glucose homeostasis nor for the metabolic benefits of GLP-1R agonists (GLP-1RAs). Instead, the gut IEL GLP-1R is essential for the full effects of GLP-1RAs on gut microbiota. Moreover, independent of glucose control or weight loss, the anti-inflammatory actions of GLP-1RAs require the gut IEL GLP-1R to selectively restrain local and systemic T cell-induced, but not lipopolysaccharide-induced, inflammation. Such effects are mediated by the suppression of gut IEL effector functions linked to the dampening of proximal T cell receptor signaling in a protein-kinase-A-dependent manner. These data reposition key roles of the L cell-gut IEL GLP-1R axis, revealing mechanisms linking GLP-1R activation in gut IELs to modulation of microbiota composition and control of intestinal and systemic inflammation.

Endogenous Vasoactive Peptides and Vascular Aging-Related Diseases

Vascular aging is a specific type of organic aging that plays a central role in the morbidity and mortality of cardiovascular and cerebrovascular diseases among the elderly. It is essential to develop novel interventions to prevent/delay age-related vascular pathologies by targeting fundamental cellular and molecular aging processes. Endogenous vasoactive peptides are compounds formed by a group of amino acids connected by peptide chains that exert regulatory roles in intercellular interactions involved in a variety of biological and pathological processes. Emerging evidence suggests that a variety of vasoactive peptides play important roles in the occurrence and development of vascular aging and related diseases such as atherosclerosis, hypertension, vascular calcification, abdominal aortic aneurysms, and stroke. This review will summarize the cumulative roles and mechanisms of several important endogenous vasoactive peptides in vascular aging and vascular aging-related diseases. In addition, we also aim to explore the promising diagnostic function as biomarkers and the potential therapeutic application of endogenous vasoactive peptides in vascular aging-related diseases.

Novel Therapies for Cardiometabolic Disease: Recent Findings in Studies with Hormone Peptide-Derived G Protein Coupled Receptor Agonists

The increasing prevalence of obesity and type 2 diabetes (T2DM) is provoking an important socioeconomic burden mainly in the form of cardiovascular disease (CVD). One successful strategy is the so-called metabolic surgery whose beneficial effects are beyond dietary restrictions and weight loss. One key underlying mechanism behind this surgery is the cooperative improved action of the preproglucagon-derived hormones, glucagon, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) which exert their functions through G protein-coupled receptors (GPCR). Great success has been reached with therapies based on the GLP-1 receptor monoagonism; therefore, a logical and rational approach is the use of the dual and triagonism of GCPC to achieve complete metabolic homeostasis. The present review describes novel findings regarding the complex biology of the preproglucagon-derived hormones, their signaling, and the drug development of their analogues, especially those acting as dual and triagonists. Moreover, the main investigations into animal models and ongoing clinical trials using these unimolecular dual and triagonists are included which have demonstrated their safety, efficacy, and beneficial effects on the CV system. These therapeutic strategies could greatly impact the treatment of CVD with unprecedented benefits which will be revealed in the next years.

Modulatory role of gut microbiota in cholesterol and glucose metabolism: Potential implications for atherosclerotic cardiovascular disease Atherosclerosis

Accumulating evidence suggests an important role of gut microbiota in physiological processes of host metabolism as well as cardiometabolic disease. Recent advances in metagenomic and metabolomic research have led to discoveries of novel pathways in which intestinal microbial metabolism of dietary nutrients is linked to metabolic profiles and cardiovascular disease risk. A number of metaorganismal circuits have been identified by microbiota transplantation studies and experimental models using germ-free rodents. Many of these pathways involve gut microbiota-related bioactive metabolites that impact host metabolism, in particular lipid and glucose homeostasis, partly via specific host receptors. In this review, we summarize the current knowledge of how the gut microbiome can impact cardiometabolic phenotypes and provide an overview of recent advances of gut microbiome research. Finally, the potential of modulating intestinal microbiota composition and/or targeting microbiota-related pathways for novel preventive and therapeutic strategies in cardiometabolic and cardiovascular diseases will be discussed.

Crosstalk between incretin hormones, Th17 and Treg cells in inflammatory diseases

Intestinal epithelial cells constantly crosstalk with the gut microbiota and immune cells of the gut lamina propria. Enteroendocrine cells, secrete hormones, such as incretin hormones, which participate in host physiological events, such as stimulating insulin secretion, satiety, and glucose homeostasis. Interestingly, evidence suggests that the incretin pathway may influence immune cell activation. Consequently, drugs targeting the incretin hormone signaling pathway may ameliorate inflammatory diseases such as inflammatory bowel diseases, cancer, and autoimmune diseases. In this review, we discuss how these hormones may modulate two subsets of CD4 + T cells, the regulatory T cells (Treg)/Th17 axis important for gut homeostasis: thus, preventing the development and progression of inflammatory diseases. We also summarize the main experimental and clinical findings using drugs targeting the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide (GLP-1) signaling pathways and their great impact on conditions in which the Treg/Th17 axis is disturbed such as inflammatory diseases and cancer. Understanding the role of incretin stimulation in immune cell activation and function, might contribute to new therapeutic designs for the treatment of inflammatory diseases, autoimmunity, and tumors.

Reactive Oxygen Species Scavenging Nanomedicine for the Treatment of Ischemic Heart Disease

Ischemic heart disease (IHD) is the leading cause of disability and mortality worldwide. Reactive oxygen species (ROS) have been shown to play key roles in the progression of diabetes, hypertension, and hypercholesterolemia, which are independent risk factors that lead to atherosclerosis and the development of IHD. Engineered biomaterial-based nanomedicines are under extensive investigation and exploration, serving as smart and multifunctional nanocarriers for synergistic therapeutic effect. Capitalizing on cell/molecule-targeting drug delivery, nanomedicines present enhanced specificity and safety with favorable pharmacokinetics and pharmacodynamics. Herein, the roles of ROS in both IHD and its risk factors are discussed, highlighting cardiovascular medications that have antioxidant properties, and summarizing the advantages, properties, and recent achievements of nanomedicines that have ROS scavenging capacity for the treatment of diabetes, hypertension, hypercholesterolemia, atherosclerosis, ischemia/reperfusion, and myocardial infarction. Finally, the current challenges of nanomedicines for ROS-scavenging treatment of IHD and possible future directions are discussed from a clinical perspective.

GLP-1 Agonist to Treat Obesity and Prevent Cardiovascular Disease: What Have We Achieved so Far?

PURPOSE OF REVIEW

To discuss evidence supporting the use of glucagon-like peptide 1 receptor agonists (GLP-1RA) to treat obesity and their role as a cardioprotective drug. Obesity is not just a hypertrophy of the adipose tissue because it may become dysfunctional and inflamed resulting in increased insulin resistance. Being overweight is associated with increased incidence of cardiovascular events and weight loss achieved through lifestyle changes lowers risk factors, but has no clear effect on cardiovascular outcomes. In contrast, treating obesity with GLP-1RA decreases cardiovascular risk and the possible mechanisms of cardioprotection achieved by this class of drugs are discussed. GLP-1RA were initially developed to treat type 2 diabetes patients, in whom the effects upon glycemia and, moreover, weight loss, especially with long-acting GLP-1RA, were evident. However, cardiovascular safety trials in type 2 diabetes patients, the majority presenting cardiovascular disease and excess weight, showed that GLP-1 receptor agonists were indeed capable of decreasing cardiovascular risk.

RECENT FINDINGS

Type 2 diabetes treatment with GLP-1RA liraglutide and semaglutide paved way to a ground-breaking therapy specific for obesity, as shown with the SCALE 3 mg/day liraglutide program and the STEP 2.4 mg/week semaglutide program. A novel molecule with superior performance is tirzepatide, a GLP-1 and GIP (Gastric Inhibitory Peptide) receptor agonist and recent results from the SURPASS and SURMOUNT programs are briefly described. Liraglutide was approved without a CVOT (Cardiovascular Outcome Trial) because authorities accepted the results from the LEADER study, designed for superiority. The SELECT study with semaglutide will report results only in 2023 and tirzepatide is being tested in patients with diabetes in the SURPASS-CVOT. Clinical studies highlight that GLP-1RA to treat obesity, alongside their concomitant cardioprotective effects, have become a hallmark in clinical science.

Obesity-related vascular dysfunction persists after weight loss and is associated with decreased vascular glucagon-like peptide (GLP-1) receptor in female rats

Obesity-related cardiovascular complications are a major health problem worldwide. Overconsumption of the Western diet is a well-known culprit for the development of obesity. While short-term weight loss through switching from a Western diet to a normal diet is known to promote metabolic improvement, its short-term effects on vascular parameters are not well-characterized. Glucagon-like peptide 1 (GLP-1), an incretin with vasculo-protective properties, is decreased in plasma from obese patients. We hypothesize that obesity causes persistent vascular dysfunction in association with downregulation of vascular GLP-1R. Female Wistar rats were randomized into three groups: lean received a chow diet for 28 weeks, obese received a Western diet for 28 weeks, and reverse obese received a Western diet for 18 weeks followed by 12 weeks of standard chow diet. The obese group exhibited increased body weight and body mass index, while the reverse obese group lost weight. Weight loss failed to reverse impaired vasodilation and high systolic blood pressure in obese rats. Strikingly, our results show that obese rats exhibit decreased serum levels of GLP-1 accompanied by decreased vascular GLP-1R expression. Weight loss recovered GLP-1 serum levels, however GLP-1R expression remained downregulated. Decreased Akt phosphorylation was observed in the obese and reverse obese group, suggesting that GLP-1/Akt signaling is persistently downregulated. Our results support that GLP-1 signaling is associated with obesity-related vascular dysfunction in females and short-term weight loss does not guarantee recovery of vascular function. This study suggests that GLP-1R may be a potential target for therapeutic intervention in obesity-related hypertension in females.

Polyethylene Glycol Loxenatide Injection (GLP-1) Protects Vascular Endothelial Cell Function in Middle-Aged and Elderly Patients With Type 2 Diabetes by Regulating Gut Microbiota

Objective: To evaluate the protective effect of Polyethylene Glycol Loxenatide Injection (Glucagon-like peptide-1, GLP-1) on endothelial cells from middle-aged and elderly patients with newly diagnosed or poorly controlled type 2 diabetes mellitus (T2DM). GLP-1 weekly formulation was analyzed for cardiovascular disease protection and correlated with intestinal flora. Design: Stool samples were collected from middle-aged and elderly patients with new-onset or poorly controlled type 2 diabetes in Longhu People's Hospital and Shantou Central Hospital from June 2019 to November 2019. Samples were collected at week 0, 4, and 8 of treatment with GLP-1 weekly formulations. Samples were analyzed for metagenomic sequencing. Analysis was performed to compare the characteristics of the gut microbiota at week 0, 4, and 8 of GLP-1 treatment and to correlate different microbiota with characteristic clinical parameters. Results: Statistical differences were found in blood glucose lowering, cardiovascular endothelial, and inflammation-related indices between week 0 and W4 and in blood glucose lowering and cardiovascular endothelial indices from week 0 to 8 in the newly diagnosed or poorly controlled type 2 diabetic patients treated with GLP-1. Changes in gut microbiota at week 0, 4, and 8 after using GLP-1 were not statistically different, but had an overall trend of rising and then falling, and with different bacteria, that were correlated with different clinical indicators. Conclusion: GLP-1 improves endothelial cell function indicators in middle-aged and elderly diabetic patients, which may be related to its alteration of the population numbers of gut microbiota such as Acinetobacter, Eubacterium ramulus ATCC 29099, and Bacteroides_faecis. This study provides a guidance for the treatment of type 2 diabetic patients.

Nonalcoholic Steatohepatitis (NASH) and Atherosclerosis: Explaining Their Pathophysiology, Association and the Role of Incretin-Based Drugs

Nonalcoholic steatohepatitis (NASH) is the most severe manifestation of nonalcoholic fatty liver disease (NAFLD), a common complication of type 2 diabetes, and may lead to cirrhosis and hepatocellular carcinoma. Oxidative stress and liver cell damage are the major triggers of the severe hepatic inflammation that characterizes NASH, which is highly correlated with atherosclerosis and coronary artery disease. Regarding drug therapy, research on the role of GLP-1 analogues and DPP4 inhibitors, novel classes of antidiabetic drugs, is growing. In this review, we outline the association between NASH and atherosclerosis, the underlying molecular mechanisms, and the effects of incretin-based drugs, especially GLP-1 RAs, for the therapeutic management of these conditions.

Protective effect of alogliptin against cyclophosphamide-induced lung toxicity in rats: Impact on PI3K/Akt/FoxO1 pathway and downstream inflammatory cascades

Cyclophosphamide (CP)-induced lung toxicity is a remaining obstacle against the beneficial use of this chemotherapeutic agent. More considerations were given to the role of Alogliptin (ALO) in ameliorating CP-induced toxicities in many tissues. We designed this study to clarify the protective potential of ALO against CP-induced lung toxicity in rats. ALO was administered for 7 days. Single-dose CP was injected on the 2nd day (200 mg/kg: i.p.) to induce lung toxicity. Rats were divided into four groups: control, ALO-treated, CP-treated and ALO + CP-treated group. Leucocytic count, total proteins, LDH activity, TNF-α, and IL-6 were estimated in the bronchoalveolar lavage fluid (BALF). The oxidative/antioxidants (MDA, Nrf2, TAO and GSH), inflammatory (NFκB), fibrotic (TGF-β1) and apoptotic (PI3K/Akt/FoxO1) markers in pulmonary homogenates were biochemically evaluated. Rat lung sections were examined histologically (light and electron microscopic examination) and immunohistochemically (for iNOS and CD68 positive alveolar macrophages). CP significantly increased oxidative stress, inflammation, fibrosis, and apoptosis markers as well as deteriorated the histopathological pulmonary architecture. These hazardous effects were significantly ameliorated by ALO treatment. ALO protected against CP-induced lung toxicity by mitigating the oxidative, inflammatory and fibrotic impacts making it a promising pharmacological therapy for mitigating CP-induced lung toxicity.

Prediction of the Effects of Liraglutide on Kidney and Cardiovascular Outcomes Based on Short-Term Changes in Multiple Risk Markers

Aims: The LEADER trial demonstrated that the glucagon-like peptide-1 receptor agonist (GLP1-RA) liraglutide reduces kidney and cardiovascular (CV) risk in patients with type 2 diabetes. We previously developed a Parameter Response Efficacy (PRE) score that translates multiple short-term risk marker changes, from baseline to first available follow-up measurement, into a predicted long-term drug effect on clinical outcomes. The objective of this study was to assess the accuracy of the PRE score in predicting the efficacy of liraglutide in reducing the risk of kidney and CV outcomes.

Methods: Short-term changes in glycated hemoglobin (HbA1c), systolic blood pressure (BP), urinary-albumin-creatinine-ratio (UACR), hemoglobin, body weight, high-density-lipoprotein (HDL) cholesterol, low-density-lipoprotein (LDL) cholesterol, and potassium were monitored in the LEADER trial. Associations between risk markers and kidney or CV outcomes were established using a multivariable Cox proportional hazards model in a separate pooled database of 6,355 patients with type 2 diabetes. The regression coefficients were then applied to the short-term risk markers in the LEADER trial to predict the effects of liraglutide on kidney (defined as a composite of doubling of serum creatinine or end-stage kidney disease) and CV (defined as a composite of non-fatal myocardial infarction, non-fatal stroke, and CV death) outcomes.

Results: Liraglutide compared to placebo reduced HbA1c (1.4%), systolic BP (3.0 mmHg), UACR (13.2%), body weight (2.3 kg), hemoglobin (2.6 g/L), and increased HDL-cholesterol (0.01 mmol/L) (all p-values <0.01). Integrating multiple risk marker changes in the PRE score resulted in a predicted relative risk reduction (RRR) of 16.2% (95% CI 13.7–18.6) on kidney outcomes which was close to the observed RRR of 15.5% (95% CI -9.0–34.6). For the CV outcome, the PRE score predicted a 7.6% (95% CI 6.8–8.3) RRR, which was less than the observed 13.2% (95% CI 3.2–22.2) RRR.

Conclusion: Integrating multiple short-term risk markers using the PRE score adequately predicted the effect of liraglutide on the composite kidney outcome. However, the PRE score underestimated the effect of liraglutide for the composite CV outcome, suggesting that the risk markers included in the PRE score do not fully capture the CV benefit of liraglutide.

Metformin exerts synergistic anti-proliferative effects with liraglutide in human umbilical vein endothelial cells (HUVECs)

Objectives

Metformin (Met) and liraglutide (Lira) have been approved to treat type 2 diabetes mellitus and have cardioprotective effects.

Materials and Methods

Human umbilical vein endothelial cells (HUVECs) were incubated with Met, Lira, or their combination in this study.

Results

Results showed that the synergistic inhibitory effect of the two drugs on HUVECs proliferation was significant (75%) after 48 hr drug exposure. In addition, either Lira or Met alone had a marked tendency to inhibit the migration of HUVECs (42% and 39%). Almost a complete inhibition (97%) was demonstrated in combinational use after 48 hr treatment. After combining these two drugs, the apoptosis rate raised to 68%, which was a significant approval of synergistic apoptosis induction of Met and Lira. The combinational group indicated a substantial increase in VEGF, PDGF, and MMP-9 at 24 hr compared with the control.

Conclusion

This study showed that combination therapy with Lira and Met could effectively reduce cell proliferation, induce apoptosis, and inhibit cell migration in the HUVECs. This study provides evidence to support using Met in combination with Lira as a treatment option for patients with type-2 diabetes and cancer.

Cardiovascular effects of GLP-1 receptor agonism

Glucagon-like peptide-1 (GLP-1) receptor agonists are extensively used in type 2 diabetic patients for the effective control of hyperglycemia. It is now clear from outcomes trials that this class of drugs offers important additional benefits to these patients due to reducing the risk of developing major adverse cardiac events (MACE). This risk reduction is, in part, due to effective glycemic control in patients; however, the various outcomes trials, further validated by subsequent meta-analysis of the outcomes trials, suggest that the risk reduction in MACE is also dependent on glycemic-independent mechanisms operant in cardiovascular tissues. These glycemic-independent mechanisms are likely mediated by GLP-1 receptors found throughout the cardiovascular system and by the complex signaling cascades triggered by the binding of agonists to the G-protein coupled receptors. This heterogeneity of signaling pathways underlying different downstream effects of GLP-1 agonists, and the discovery of biased agonists favoring specific signaling pathways, may have import in the future treatment of MACE in these patients. We review the evidence supporting the glycemic-independent evidence for risk reduction of MACE by the GLP-1 receptor agonists and highlight the putative mechanisms underlying these benefits. We also comment on the different signaling pathways which appear important for mediating these effects.

GLP1 Exerts Paracrine Activity in the Intestinal Lumen of Human Colon

GLP1 produced in the upper part of the gut is released after food intake and acts by activating insulin secretion, but the role of GLP1 in the colon, where it is predominantly produced, remains unknown. Here we characterized the apical versus basolateral secretion of GLP1 and PYY and the paracrine mechanisms of action of these enterohormones in the human colon. We stimulated human colon tissue in different ex vivo models with meat peptone and we used immunofluorescence to study the presence of canonical and non-canonical receptors of GLP1. We found that PYY and GLP1 are secreted mainly at the gut lumen in unstimulated and stimulated conditions. We detected DPP4 activity and found that GLP1R and GCGR are widely expressed in the human colon epithelium. Unlike GLP1R, GCGR is not expressed in the lamina propria, but it is located in the crypts of Lieberkühn. We detected GLP1R expression in human colon cell culture models. We show that the apical secretion of PYY and GLP1 occurs in humans, and we provide evidence that GLP1 has a potential direct paracrine function through the expression of its receptors in the colon epithelium, opening new therapeutic perspectives in the use of enterohormones analogues in metabolic pathologies.

Recent advance in treatment of atherosclerosis: Key targets and plaque-positioned delivery strategies

Atherosclerosis, a chronic inflammatory disease of vascular wall, is a progressive pathophysiological process with lipids oxidation/depositing initiation and innate/adaptive immune responses. The coordination of multi systems covering oxidative stress, dysfunctional endothelium, diseased lipid uptake, cell apoptosis, thrombotic and pro-inflammatory responding as well as switched SMCs contributes to plaque growth. In this circumstance, inevitably, targeting these processes is considered to be effective for treating atherosclerosis. Arriving, retention and working of payload candidates mediated by targets in lesion direct ultimate therapeutic outcomes. Accumulating a series of scientific studies and clinical practice in the past decades, lesion homing delivery strategies including stent/balloon/nanoparticle-based transportation worked as the potent promotor to ensure a therapeutic effect. The objective of this review is to achieve a very brief summary about the effective therapeutic methods cooperating specifical targets and positioning-delivery strategies in atherosclerosis for better outcomes.

Effects of liraglutide vs. lifestyle changes on soluble suppression of tumorigenesis-2 (sST2) and galectin-3 in obese subjects with prediabetes or type 2 diabetes after comparable weight loss

BACKGROUND

Soluble suppression of tumorigenesis-2 (sST2) and galectin (Gal)-3 are two biomarkers related to inflammation, metabolic disturbances and to myocardial fibrosis that characterize several cardiac pathological conditions. Increased circulating levels of these molecules have been associated with risk of cardiovascular death. Treatment with liraglutide, a glucagon-like peptide 1 analog, is associated with weight loss, improved glycemic control, and reduced cardiovascular risk. We wanted to assess (I) potential differences between subjects with prediabetes or type 2 diabetes mellitus (T2DM) and healthy controls in sST2 and Gal-3 circulating levels, and their relationship with glycemic control and markers of beta cell function and myocardial injury; (II) whether liraglutide treatment modulates these markers in subjects with prediabetes or early T2DM independently of weight loss; (III) whether baseline levels of any of these two molecules may predict the response to liraglutide treatment.

METHODS

Forty metformin-treated obese subjects (BMI ≥ 30) with prediabetes [impaired fasting glucose (IFG) or impaired glucose tolerance (IGT) or both (n = 23)] or newly diagnosed T2DM (n = 17), were randomized to liraglutide or lifestyle counseling until achieving a comparable weight loss (7% of initial body weight). Thirteen subjects were enrolled as healthy controls for baseline sST2 and Gal-3 levels.

RESULTS

Baseline sST2 levels were comparable between controls and obese patients (p = 0.79) whereas Gal-3 levels were significantly higher in patients as compared to controls (p < 0.001). Liraglutide treatment, but not weight loss achieved by lifestyle counseling, decreased plasma sST2 levels (- 9%, beta = - 14.9, standard deviation 6.9, p = 0.037) while Gal-3 levels did not change. A reduction in serum hs-Troponin I was observed after intervention, due to a 19% (p = 0.29) increase in the lifestyle arm, and a 25% decrease (p = 0.033) in the liraglutide arm (between-group difference p = 0.083). Lower baseline Gal-3 levels predicted a better improvement in beta cell function after liraglutide treatment.

CONCLUSIONS

Liraglutide-induced reduction in sST2 and possibly hs-TnI suggests that in obese patients with prediabetes or early T2DM this drug may have a positive effect on (cardiac) fibrosis, whereas plasma level of Gal-3 before liraglutide initiation may predict response to the drug in terms of beta cell function improvement. Trial registration Eudract: 2013-001356-36.

Plaque-targeted, proteolysis-resistant, activatable and MRI-visible nano-GLP-1 receptor agonist targets smooth muscle cell differentiation in atherosclerosis

Background: Glucagon-like peptide-1 receptor (GLP-1R) agonists are powerful glycemia-lowering agents, which have systematically been shown to lower cardiovascular events and mortality. These beneficial effects were difficult to pinpoint within atherosclerotic plaque due to lack of particular specificity of such agonists to the vascular cells and an inadequate understanding of the GLP-1R expression in atherosclerosis. Here, we hypothesized that the direct engagement of the GLP-1R in atherosclerosis by targeted agonists will alleviate vascular inflammation and plaque burden, even at a very low dose. Methods: The expression of GLP-1 receptor (GLP-1R, Glp1r mRNA) in human lesions with pathologic intimal thickening, Apoe-/- mouse atheroma and cultured immune/non-immune cells was investigated using genetic lineage tracing, Southern blotting and validated antisera against human GLP-1R. Protease-resistant and "activatable" nanoparticles (NPs) carrying GLP-1R agonist liraglutide (GlpNP) were engineered and synthesized. Inclusion of gadolinium chelates into GlpNP allowed for imaging by MRI. Atherosclerotic Apoe-/- mice were treated intravenously with a single dose (30 µg/kg of liraglutide) or chronically (1 µg/kg, 6 weeks, 2x/week) with GlpNP, liraglutide or control NPs, followed by assessment of metabolic parameters, atheroma burden, inflammation and vascular function. Results: Humal plaque specimens expressed high levels of GLP-1R within the locus of de-differentiated smooth muscle cells that also expressed myeloid marker CD68. However, innate immune cells under a variety of conditions expressed very low levels of Glp1r, as seen in lineage tracing and Southern blotting experiments examining full-length open reading frame mRNA transcripts. Importantly, de-differentiated vascular smooth muscle cells demonstrated significant Glp1r expression levels, suggesting that these could represent the cells with predominant Glp1r-positivity in atherosclerosis. GlpNP resisted proteolysis and demonstrated biological activity including in vivo glycemia lowering at 30 µg/kg and in vitro cholesterol efflux. Activatable properties of GlpNP were confirmed in vitro by imaging cytometry and in vivo using whole organ imaging. GlpNP targeted CD11b+/CD11c+ cells in circulation and smooth muscle cells in aortic plaque in Apoe-/- mice when assessed by MRI and fluorescence imaging. At a very low dose of 1 µg/kg, previously known to have little effect on glycemia and weight loss, GlpNP delivered i.v. for six weeks reduced triglyceride-rich lipoproteins in plasma, plaque burden and plaque cholesterol without significant effects on weight, glycemia and plasma cholesterol levels. Conclusions: GlpNP improves atherosclerosis at weight-neutral doses as low as 1 µg/kg with the effects independent from the pancreas or the central nervous system. Our study underlines the importance of direct actions of GLP-1 analogs on atherosclerosis, involving cholesterol efflux and inflammation. Our findings are the first to suggest the therapeutic modulation of vascular targets by GlpNP, especially in the context of smooth muscle cell inflammation.

Comparison of Sodium-Glucose Cotransporter 2 Inhibitors and Glucagon-like Peptide Receptor Agonists for Atrial Fibrillation in Type 2 Diabetes Mellitus: Systematic Review With Network Meta-analysis of Randomized Controlled Trials

ABSTRACT

Atrial fibrillation (AF) is a major public health concern with a rising prevalence. Although sodium-glucose cotransporter 2 inhibitors (SGLT2is) and glucagon-like peptide-1 receptor agonists (GLP-1RAs) have shown the respective favorable effects on reducing the occurrence of AF/atrial flutter (AFL), comparative protective AF/AFL effects between above 2 novel antidiabetic agents remain unavailable. Thus, we aimed to evaluate the comparative efficacy of SGLT2is and GLP-1RAs in reducing the risk of AF/AFL in patients with type 2 diabetes and estimate relative rankings of interventions. PubMed, Embase, and ClinicalTrials.gov were searched up to December 1, 2020. All available randomized controlled trials comparing SGLT2is and GLP-1RAs with one another or placebo in patients with type 2 diabetes were included. Pooled results were shown as risk ratios (RRs) with 95% confidence intervals (CIs). We used a frequentist network meta-analysis to evaluate the outcomes of interests. Thirty-six randomized controlled trials including 85,701 participants with type 2 diabetes were identified. Compared with placebo, both SGLT2is (RR: 0.82, 95% CI, 0.68-0.99) and GLP-1RAs (RR: 0.86, 95% CI, 0.76-0.97; RR long-acting ones: 0.87, 95% CI, 0.76-0.99; RR short-acting ones: 0.72, 95% CI, 0.45-1.14) significantly reduced AF/AFL risk. No significant difference between SGLT2is and GLP-1RAs was noted (RR: 0.95, 95% CI, 0.76-1.2). Compared with placebo, results from the analysis showed an RR of 0.72 (95% CI, 0.45-1.14) for short-acting GLP-1RAs and 0.87 (95% CI, 0.76-0.99) for long-acting GLP-1RAs in reducing the risk of AF/AFL. Compared with placebo, both SGLT2is and GLP-1RAs possessed favorable effects on reducing the risk of AF/AFL. However, no difference was observed when comparisons were made between them. In addition, long-acting ones may confer a more pronounced AF/AFL reduction benefit compared with placebo.

Cardiovascular Effects of Incretin-Based Therapies: Integrating Mechanisms With Cardiovascular Outcome Trials

As the worldwide prevalence of diabetes and obesity continues to rise, so does the risk of debilitating cardiovascular complications. Given the significant association between diabetes and cardiovascular risk, the actions of glucose-lowering therapies within the cardiovascular system must be clearly defined. Incretin hormones, including GLP-1 (glucagon-like peptide 1) and GIP (glucose-dependent insulinotropic polypeptide), are gut hormones secreted in response to nutrient intake that maintain glycemic control by regulating insulin and glucagon release. GLP-1 receptor agonists (GLP-1Ras) and dipeptidyl peptidase 4 inhibitors (DPP-4is) represent two drug classes used for the treatment of type 2 diabetes mellitus (T2DM) that improve glucose regulation through stimulating the actions of gut-derived incretin hormones or inhibiting their degradation, respectively. Despite both classes acting to potentiate the incretin response, the potential cardioprotective benefits afforded by GLP-1Ras have not been recapitulated in cardiovascular outcome trials (CVOTs) evaluating DPP-4is. This review provides insights through discussion of clinical and preclinical studies to illuminate the physiological mechanisms that may underlie and reconcile observations from GLP-1Ra and DPP-4i CVOTs. Furthermore, critical knowledge gaps and areas for further investigation will be emphasized to guide future studies and, ultimately, facilitate improved clinical management of cardiovascular disease in T2DM.

E-Selectin Is Associated with Daytime and 24-Hour Diastolic Blood Pressure Variability in Type 2 Diabetes

E-selectin is an endothelial cell adhesion molecule involved in vascular inflammation. Elevated E-selectin has been reported in patients with high blood pressure and diabetes. Given the increasing clinical relevance of parameters derived from ambulatory blood pressure monitoring, further investigation of their relationships with E-selectin is of interest. In this study, we aimed to investigate the association between serum E-selectin, office blood pressure and 24 h ambulatory blood pressure parameters in patients with type 2 diabetes. Blood pressure variability was assessed by computing the standard deviation of mean systolic and diastolic blood pressure separately for daytime and nighttime during 24 h ambulatory blood pressure monitoring in a cohort of patients with type 2 diabetes (n = 132). Additionally, were assessed nighttime systolic dipping and pulse pressure separately for daytime, nighttime, and 24 h. Serum E-selectin was measured using the enzyme-linked immunosorbent assay technique. We found that E-selectin was consistently associated with 24 h diastolic blood pressure variability (r = 0.238; p = 0.019) and daytime diastolic blood pressure variability (r = 0.258; p = 0.012), after adjustment for confounding factors. No association of E-selectin with office blood pressure and other 24 h ambulatory blood pressure parameters was observed. In conclusion, endothelial activation indicated by elevated serum E-selectin is associated with increased ambulatory diastolic blood pressure variability in patients with type 2 diabetes.

Targeting the GLP-1/GLP-1R axis to treat osteoarthritis: A new opportunity?

Osteoarthritis (OA) is a degenerative joint disease affecting millions of people worldwide. In OA, chondrocytes, synovial cells and other joint cells become activated when exposed to an abnormal environment, including mechanical stress, inflammatory cytokines or disorganization of matrix proteins. Several analogues of the hormones called incretins have been developed and are used notably for treating type 2 diabetes mellitus. Data has accumulated to suggest that incretinomimetics, which bind to the glucagon-like peptide-1 receptor (GLP-1R), have beneficial pleiotropic effects such as immunomodulation, anti-inflammation and neuronal protection. Thus, because of their anti-inflammatory properties, GLP-1-based therapies could benefit OA patients. This review focuses on the GLP-1R pathway, molecular mechanisms and phenotypes related to OA pathogenesis.

The translational potential of this article

The search for new therapeutic targets to treat people suffering from OA remains urgent as there is currently no disease-modifyingtherapy available for this disease. This review discusses how GLP-1 analogues could be potential DMOADs for treating OA thanks to their anti-inflammatory, immunoregulatory and differentiation properties.

The molecular link between oxidative stress, insulin resistance, and type 2 diabetes: A target for new therapies against cardiovascular diseases

Type 2 Diabetes Mellitus (T2D) is a chronic disease with a pandemic incidence whose pathogenesis has not yet been clarified. Raising evidence highlighted the role of oxidative stress in inducing insulin resistance, pancreatic beta-cell dysfunction, and leading to cardiovascular disease (CVD). Therefore, understanding the link between oxidative stress, T2D and CVD may help to further understand the pathological processes beyond this association, to personalize the algorithm of the cure, and to find new therapeutic targets. Here, we discussed the role of oxidative stress and the decrease of antioxidant defenses in the pathogenesis of T2D. Furthermore, some aspects of hypoglycemic therapies and their potential role as antioxidant agents were examined, which might be pivotal in preventing CVD in T2D patients.

An Overview of Glycosylation and its Impact on Cardiovascular Health and Disease

The cardiovascular system is a complex and well-organized system in which glycosylation plays a vital role. The heart and vascular wall cells are constituted by an array of specific receptors; most of them are N- glycosylated and mucin-type O-glycosylated. There are also intracellular signaling pathways regulated by different post-translational modifications, including O-GlcNAcylation, which promote adequate responses to extracellular stimuli and signaling transduction. Herein, we provide an overview of N-glycosylation and O-glycosylation, including O-GlcNAcylation, and their role at different levels such as reception of signal, signal transduction, and exogenous molecules or agonists, which stimulate the heart and vascular wall cells with effects in different conditions, like the physiological status, ischemia/reperfusion, exercise, or during low-grade inflammation in diabetes and aging. Furthermore, mutations of glycosyltransferases and receptors are associated with development of cardiovascular diseases. The knowledge on glycosylation and its effects could be considered biochemical markers and might be useful as a therapeutic tool to control cardiovascular diseases.

Vascular repair and regeneration in cardiometabolic diseases

Chronic cardiometabolic assaults during type 2 diabetes (T2D) and obesity induce a progenitor cell imbalance in the circulation characterized by overproduction and release of pro-inflammatory monocytes and granulocytes from the bone marrow alongside aberrant differentiation and mobilization of pro-vascular progenitor cells that generate downstream progeny for the coordination of blood vessel repair. This imbalance can be detected in the peripheral blood of individuals with established T2D and severe obesity using multiparametric flow cytometry analyses to discern pro-inflammatory vs. pro-angiogenic progenitor cell subsets identified by high aldehyde dehydrogenase activity, a conserved progenitor cell protective function, combined with lineage-restricted cell surface marker analyses. Recent evidence suggests that progenitor cell imbalance can be reversed by treatment with pharmacological agents or surgical interventions that reduce hyperglycaemia or excess adiposity. In this state-of-the-art review, we present current strategies to assess the progression of pro-vascular regenerative cell depletion in peripheral blood samples of individuals with T2D and obesity and we summarize novel clinical data that intervention using sodium-glucose co-transporter 2 inhibition or gastric bypass surgery can efficiently restore cell-mediated vascular repair mechanisms associated with profound cardiovascular benefits in recent outcome trials. Collectively, this thesis generates a compelling argument for early intervention using current pharmacological agents to prevent or restore imbalanced circulating progenitor content and maintain vascular regenerative cell trafficking to sites of ischaemic damage. This conceptual advancement may lead to the design of novel therapeutic approaches to prevent or reverse the devastating cardiovascular comorbidities currently associated with T2D and obesity.

Differential importance of endothelial and hematopoietic cell GLP-1Rs for cardiometabolic versus hepatic actions of semaglutide

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are used to treat diabetes and obesity and reduce rates of major cardiovascular events, such as stroke and myocardial infarction. Nevertheless, the identity of GLP-1R–expressing cell types mediating the cardiovascular benefits of GLP-1RA remains incompletely characterized. Herein, we investigated the importance of murine Glp1r expression within endothelial and hematopoietic cells. Mice with targeted inactivation of Glp1r in Tie2⁺ cells exhibited reduced levels of Glp1r mRNA transcripts in aorta, liver, spleen, blood, and gut. Glp1r expression in bone marrow cells was very low and not further reduced in Glp1r^Tie2–/– mice. The GLP-1RA semaglutide reduced the development of atherosclerosis induced by viral PCSK9 expression in both Glp1r^Tie2+/+ and Glp1r^Tie2–/– mice. Hepatic Glp1r mRNA transcripts were reduced in Glp1r^Tie2–/– mice, and liver Glp1r expression was localized to γδ T cells. Moreover, semaglutide reduced hepatic Tnf, Abcg1, Tgfb1, Cd3g, Ccl2, and Il2 expression; triglyceride content; and collagen accumulation in high-fat, high-cholesterol diet–fed Glp1r^Tie2+/+ mice but not Glp1r^Tie2–/– mice. Collectively, these findings demonstrate that Tie2⁺ endothelial or hematopoietic cell GLP-1Rs are dispensable for the antiatherogenic actions of GLP-1RA, whereas Tie2-targeted GLP-1R⁺ cells are required for a subset of the antiinflammatory actions of semaglutide in the liver.

The Application of Single-Cell Technologies in Cardiovascular Research

Cardiovascular diseases (CVDs) are the leading cause of deaths in the world. The intricacies of the cellular composition and tissue microenvironment in heart and vasculature complicate the dissection of molecular mechanisms of CVDs. Over the past decade, the rapid development of single-cell omics technologies generated vast quantities of information at various biological levels, which have shed light on the cellular and molecular dynamics in cardiovascular development, homeostasis and diseases. Here, we summarize the latest single-cell omics techniques, and show how they have facilitated our understanding of cardiovascular biology. We also briefly discuss the clinical value and future outlook of single-cell applications in the field.

The gut-cardiovascular connection: new era for cardiovascular therapy

Our gut microbiome is constituted by trillions of microorganisms including bacteria, archaea and eukaryotic microbes. Nowadays, gut microbiome has been gradually recognized as a new organ system that systemically and biochemically interact with the host. Accumulating evidence suggests that the imbalanced gut microbiome contributes to the dysregulation of immune system and the disruption of cardiovascular homeostasis. Specific microbiome profiles and altered intestinal permeability are often observed in the pathophysiology of cardiovascular diseases. Gut-derived metabolites, toxins, peptides and immune cell-derived cytokines play pivotal roles in the induction of inflammation and the pathogenesis of dysfunction of heart and vasculature. Impaired crosstalk between gut microbiome and multiple organ systems, such as gut-vascular, heart-gut, gut-liver and brain-gut axes, are associated with higher cardiovascular risks. Medications and strategies that restore healthy gut microbiome might therefore represent novel therapeutic options to lower the incidence of cardiovascular and metabolic disorders.

Glucose-lowering Drugs and Hospitalization for Heart Failure: A Systematic Review and Additive-effects Network Meta-analysis With More Than 500 000 Patient-years

BACKGROUND

Sodium glucose co-transporter 2 inhibitors (SGLT2is) prevent hospitalization resulting from heart failure (HHF). However, patients with type 2 diabetes mellitus use multiple antihyperglycemic drugs to achieve glycosylated hemoglobin (HbA1c) targets. In these drug combinations, the risk of HHF is unpredictable and so is the parallel effect of glucose-lowering.

PURPOSE

To examine the impact of antihyperglycemic drugs and their association on HHF.

DATA SOURCES

Forty randomized controlled trials (RCTs) reporting HHF.

STUDY SELECTION

Published RCTs were the data source.

DATA EXTRACTION

Incidence rates of HHF.

DATA SYNTHESIS

Random additive-effects network meta-analysis showed that metformin (P = 0.55), sulfonylureas (P = 0.51), glucagon-like peptide-1 receptor-agonist (P = 0.16), and dipeptidyl peptidase 4 inhibitors (DPP4is; P = 0.54) were neutral on the risk of HHF. SGLT2is and SGLT2is + DPP4is reduced the risk of HHF with a hazard ratio (HR) of 0.68 (95% CI, 0.60-0.76; P < 0.0001) and 0.70 (95% CI, 0.60-0.81; P < 0.0001), respectively. Increased risk of HHF was associated with thiazolidinediones (TZDs) as monotherapy or in combination with DPP4is (HR: 1.45; 95% CI, 1.18-1.78; P = 0.0004) and 1.49 (95% CI, 1.18-1.88; P = 0.0008), respectively. Regardless of the therapy, a 1% reduction in HbA1c reduced the risk of HHF by 31.3% (95% CI, 9-48; P = 0.009).

LIMITATIONS

There are no data to verify drug combinations available for clinical use and to discriminate the effect of drugs within each of the therapeutic classes.

CONCLUSIONS

The risk of HHF is reduced by SGLT2is as monotherapy or in combination with DPP4is and increased by TZDs as monotherapy or in combination. Glucose-lowering provides an additive effect of reducing HHF.

Understanding the place for GLP-1RA therapy: Translating guidelines for treatment of type 2 diabetes into everyday clinical practice and patient selection

Since the first glucagon-like peptide 1 (GLP-1) receptor agonist (GLP-1RA) was approved in 2005 (exenatide twice daily) for type 2 diabetes (T2D), the class has developed with newer compounds having more pronounced effects on glycaemic control and body weight. Also, administration regimes have become more convenient with once weekly injections, and recently an oral administration has become available. Large-scale randomized controlled cardiovascular (CV) outcome trials (CVOTs) have shown that GLP-1RA therapy can reduce the risk of CV disease (CVD) in high-risk individuals with T2D. In addition, GLP-1RAs may have renal benefits driven by new-onset macroalbuminuria, although no effect on hard renal endpoints has been found. Subsequently, the place for GLP-1RA therapy has changed over recent years, with most societies endorsing GLP-1RA therapy in patients with established or high risk of CVD independently of glycaemia. Initiation of GLP-1RA therapy can be complex due to differences in efficacy, side effects and safety profiles as well as administration forms within the class. Implementing guideline recommendations into ideal patient selection may be challenging both in specialty and non-specialty settings. To ensure adequate and proactive use of modern glucose-lowering medications in the treatment of T2D, it is essential to recognize patients with high risk or documented CVD. The present review provides an overview of the efficacy and benefits of the currently available GLP-1RA compounds. Furthermore, we review the results from recent large-scale CVOTs in a clinical context and suggest improving the implementation of GLP-1RA therapy across specialties to improve overall patient selection.

CARDIOVASCULAR EFFECTS OF NON-INSULIN GLUCOSE-LOWERING AGENTS: A COMPREHENSIVE REVIEW OF TRIAL EVIDENCE AND POTENTIAL CARDIOPROTECTIVE MECHANISMS

Type 2 diabetes mellitus (T2DM) is highly prevalent and associated with a 2-fold increased mortality, mostly explained by cardiovascular diseases. Trial evidence on older glucose-lowering agents such as metformin and sulfonylureas is limited in terms of cardiovascular efficacy. Since 2008, after rosiglitazone was observed to increase the risk of myocardial infarction and heart failure (HF), cardiovascular outcome trials (CVOT) have been required by regulators for licensing new glucose-lowering agents. In the following CVOTs, dipeptidyl peptidase 4 inhibitors (DPP4i) have been shown to be safe but not to improve morbidity/mortality, except for saxagliptin which increased the risk of HF. Several glucagon-like peptide-1 receptor agonists (GLP1-Ra) and sodium-glucose cotransporter-2 inhibitors (SGLT2i) have been demonstrated to reduce the risk of cardiovascular morbidity and mortality. SGLT2i have shown a class effect for the reduction in risk of HF events in patients with T2DM, leading to trials testing their efficacy/safety in HF regardless of T2DM. In the DAPA-HF and the EMPEROR-Reduced trials dapagliflozin and empagliflozin, respectively, improved cardiovascular mortality/morbidity in patients with HF and reduced ejection fraction (HFrEF), with and without T2DM. Therefore, these drugs are now key part of HFrEF pharmacotherapy. In the SOLOIST-WHF, sotagliflozin reduced cardiovascular mortality/morbidity in patients with T2DM and a recent acute episode of HF regardless of EF. The DELIVER and the EMPEROR-Preserved are testing dapagliflozin and empagliflozin, respectively, in patients with HF with mildly reduced and preserved EF. A strong renal protective role of SGLT2i has also emerged in trials enrolling patients with and without T2DM.

Effect of Liraglutide on Vascular Inflammation Evaluated by [64Cu]DOTATATE

Quantification of vascular inflammation before and after treatment with glucagon-like peptide-1 receptor agonists (GLP-1 RAs) may help reveal mechanistic pathways underlying the cardiovascular benefits of these drugs. We assessed change in vascular inflammation in the carotid arteries over 26 weeks by copper-64-labeled [1,4,7,10-tetraazacyclododecane-N,N′,N″,N‴-tetraacetic acid]-D-Phe1, Tyr3-octreotate ([⁶⁴Cu]DOTATATE) PET in 30 participants included in a substudy of a double-blind trial where persons with type 2 diabetes (T2D) were randomized to liraglutide (n = 15) or placebo (n = 15) for 26 weeks. Mean age (SD) was 66.4 (7.2) years, HbA_1c 56.4 (9.2) mmol/mol and BMI 28.9 (4.6) kg/m². Weight and HbA_1c were significantly reduced by liraglutide vs. placebo (p ≤ 0.01). The [⁶⁴Cu]DOTATATE uptake (mean standardized uptake values) was significantly reduced in the liraglutide-treated group (−0.11 [95% confidence interval −0.19 to −0.03], p = 0.01) and not changed significantly in the placebo group (−0.07 [−0.14 to 0.01], p = 0.08). The mean difference between groups did not reach significance (−0.04 [−0.15 to 0.07], p = 0.44). In conclusion, [⁶⁴Cu]DOTATATE uptake was reduced in persons with T2D treated with liraglutide. However, the reduction compared to placebo did not reach statistical significance, perhaps due to limited power. A reduction in vascular inflammation with liraglutide could help explain the cardiovascular protection observed with GLP-1 RAs in outcome studies but warrants further and larger studies.