Possible mechanisms of direct cardiovascular impact of GLP-1 agonists and DPP4 inhibitors

Animal models for development of anti-obesity drugs in the age of GLP-1 agents

INTRODUCTION

Obesity is a major health crisis globally, with prevalence escalating significantly in recent decades. Obesity is not merely excessive weight but is associated with myriad health complications. Ensuring the translational effectiveness of pre-clinical obesity models is paramount, and the success of GLP-1 therapies has highlighted important benchmarks for guiding drug development.

AREAS COVERED

The authors discuss the status of various animal models used for the development of anti-obesity drugs, with particular emphasis on rodent models and their validity of preclinical-to-clinical translation. They also highlight innovative animal model integration opportunities between obesity and other associated pathology. The article is based on literature searches using PubMed for content (up until February 2025).

EXPERT OPINION

The effectiveness of GLP-1 therapies in treating type 2 diabetes and obesity presents an opportunity to evaluate the translational relevance of animal models of obesity. Due to their compelling safety profiles, GLP-1(s) are being tested in a wide range of obesity-associated diseases. Optimization of the mechanistic qualities in this drug class requires the incorporation of new endpoints beyond body weight, including lean mass preservation, cardiovascular health, and anti-inflammatory activities. Finally, we are compelled by the intersection of non-obesity disease models into an obesogenic framework to understand the combinatorial effects of obesity on these other disease indications, including heart failure, neurodegenerative diseases, and cancer.

VPAC2 receptor mediates VIP-potentiated insulin secretion via ion channels in rat pancreatic β cells

Vasoactive intestinal peptide (VIP), a small neuropeptide composing of 28 amino acids, functions as a neuromodulator with insulinotropic effect on pancreatic β cells, in which it is of vital importance in regulating the levels of blood glucose. VIP potently agonizes VPAC2 receptor (VPAC2-R). Agonists of VPAC2-R stimulate glucose-dependent insulin secretion. The purpose of this study was to further investigate the possible ion channel mechanisms in VPAC2-R-mediated VIP-potentiated insulin secretion. The results of insulin secretion experiments showed that VIP augmented insulin secretion in a glucose-dependent manner. The insulinotropic effect was mediated by VPAC2-R rather than VPAC1 receptor (VPAC1-R), through the adenylyl cyclase (AC)/protein kinase A (PKA) signalling pathway. The calcium imaging analysis demonstrated that VIP increased intracellular Ca²⁺ concentration ([Ca²⁺]_i). In addition, in the whole-cell voltage-clamp mode, we found that VIP blocked the voltage-dependent potassium (Kv) channel currents, while this effect was reversed by inhibiting the VPAC2-R, AC or PKA respectively. Taken together, these findings suggest that VIP stimulates insulin secretion by inhibiting the Kv channels, activating the Ca²⁺ channels, and increasing [Ca²⁺]_i through the VPAC2-R and AC/PKA signalling pathway. These findings provide theoretical basis for the research of VPAC2-R as a novel therapeutic target.

Capillaries as a Therapeutic Target for Heart Failure

Prognosis of heart failure remains poor, and it is urgent to find new therapies for this critical condition. Oxygen and metabolites are delivered through capillaries; therefore, they have critical roles in the maintenance of cardiac function. With aging or age-related disorders, capillary density is reduced in the heart, and the mechanisms involved in these processes were reported to suppress capillarization in this organ. Studies with rodents showed capillary rarefaction has causal roles for promoting pathologies in failing hearts. Drugs used as first-line therapies for heart failure were also shown to enhance the capillary network in the heart. Recently, the approach with senolysis is attracting enthusiasm in aging research. Genetic or pharmacological approaches concluded that the specific depletion of senescent cells, senolysis, led to reverse aging phenotype. Reagents mediating senolysis are described to be senolytics, and these compounds were shown to ameliorate cardiac dysfunction together with enhancement of capillarization in heart failure models. Studies indicate maintenance of the capillary network as critical for inhibition of pathologies in heart failure.

The Enhanced Cardiac Outcome of Conjugated SGLT2 Inhibitors and GLP-1RA Therapy in Diabetic Patients

PURPOSE OF REVIEW

Cardiovascular disease secondary to diabetes continues to threaten the survivability of many people all over the world. We assess the most recent findings of synergistic effects of combined glucagon-like peptide 1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter 2 (SGLT2) inhibitors in lowering cardiac complications in the diabetic population. We describe drug therapies' mechanism of action, postulated cardioprotective process, the additive value of conjugated therapy, and analyze recently reported study and its limitation.

RECENT FINDINGS

SGLT2 inhibitors and GLP-1RAs have gained popularity due to their ability to reduce major adverse cardiovascular events in diabetic patients. There is emerging evidence of the additional cardiovascular benefit from the combined application of SGLT2 inhibitors and GLP-1RAs therapy demonstrated by a recent real-world cohort study. Reducing cardiac mortality in patients with diabetes by administering dual antihyperglycemic therapies (GLP-1Rs and SGLT2 inhibitors) might play a key role in the future treatment of the diabetic population.

Exposure-Response Analysis of Cardiovascular Outcome Trials With Incretin-Based Therapies

Our study aimed to evaluate the exposure-response relationship between incretin-based medications and the risk of major adverse cardiovascular events (MACE) using cardiovascular outcome trials (CVOTs). Eleven CVOTs with incretin-based medications were included. The median follow-up time, percentage of time exposure, and hazard ratio (HR) of MACE were obtained from each CVOT. The pharmacokinetic parameters of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and dipeptidyl peptidase-4 inhibitor (DPP-4) were obtained from published studies. Regression analysis was performed to assess the relationship between drug exposure and MACE HR. Cutoff values were determined from the ROC curves. The linear regression results indicated that log C_max, log AUC_0-24h, and log AUC_CVOT are negatively correlated with MACE HR (R² = 0.8494, R² = 0.8728, and R² = 0.8372, respectively; all p < 0.0001). The relationship between drug exposure (log C_max, log AUC_0-24h, and log AUC_CVOT) and MACE HR strongly corresponded with the log (inhibitor) vs. response curve (R² = 0.8383, R² = 0.8430, and R² = 0.8229, respectively). The cutoff values in the ROC curves for log C_max, log AUC_0-24h, and log AUC_CVOT, were 2.556, 3.868, and 6.947, respectively (all p = 0.007). A Fisher's exact test revealed that these cutoff values were significantly related to cardiovascular benefits (all p < 0.05). Our study revealed a linear exposure-response relationship between drug exposure and MACE HR. We conclude that the cardiovascular benefits of incretin-based therapies may occur with higher doses of GLP-1 RAs and with increased exposure.

Type 2 Diabetes and Myocardial Infarction: Recent Clinical Evidence and Perspective

Type 2 diabetes mellitus (T2DM) and its complications are seriously affecting public health worldwide. Myocardial infarction (MI) is the primary cause of death in patients with T2DM. T2DM patients without a history of coronary artery disease (CAD) have the same risk of major coronary events as those with CAD; T2DM patients with a history of MI have >40% risk of recurrence of MI. Thus, CAD in patients with T2DM needs to be treated actively to reduce the risk of MI. The cardiology community focused on the role of T2DM in the development of CAD and on the related issues of T2DM and MI with respect to comorbidities, prognosis, drug therapy, and heredity. In this mini review, the latest progress of clinical evidence-based research between T2DM and MI in recent years was reviewed, and the possible research directions in this field were considered and prospected.

Dipeptidyl Peptidase-4 at the Interface Between Inflammation and Metabolism

Dipeptidyl peptidase-4 (DPP4) is a serine protease that rapidly inactivates the incretin peptides, glucagon-like peptide-1, and glucose-dependent insulinotropic polypeptide to modulate postprandial islet hormone secretion and glycemia. Dipeptidyl peptidase-4 also has nonglycemic effects by controlling the progression of inflammation, which may be mediated more through direct protein-protein interactions than catalytic activity in the context of nonalcoholic fatty liver disease (NAFLD), obesity, and type 2 diabetes (T2D). Failure to resolve inflammation resulting in chronic subclinical activation of the immune system may influence the development of metabolic dysregulation. Thus, through both its cleavage and regulation of the bioactivity of peptide hormones and its influence on inflammation, DPP4 exhibits a diverse array of effects that can influence the progression of metabolic disease. Here, we highlight our current understanding of the complex biology of DPP4 at the intersection of inflammation, obesity, T2D, and NAFLD. We compare and review new mechanisms identified in basic laboratory and clinical studies, which may have therapeutic application and relevance to the pathogenesis of obesity and T2D.

Neuromodulatory effects of anti-diabetes medications: A mechanistic review

Diabetes mellitus is a potent upstream event in the molecular pathophysiology which gives rise to various diabetes-related complications. There are several classes of anti-diabetic medications that have been developed to normalize blood glucose concentrations through a variety of molecular mechanisms. Beyond glucose-lowering effects, these agents may also provide further therapeutic potential. For instance, there is a high incidence of diabetes-induced neuronal disorders among patients with diabetes, who may also develop neurodegenerative and psychological complications. If anti-diabetic agents can modify the molecular mechanisms involved in the pathophysiology of neuronal comorbidities, this could potentially be translated to reducing the risk of other neurological conditions such as Alzheimer's disease, Parkinson's disease, depression, memory deficits and cognition impairments among patients with diabetes. This review aimed to shed light on some of the potentially beneficial aspects of anti-diabetic agents in lowering the risk or treating neuronal disorders by reviewing the molecular mechanisms by which these agents can potentially modulate neuronal behaviors.

Association of Glycemic Indices (Hyperglycemia, Glucose Variability, and Hypoglycemia) with Oxidative Stress and Diabetic Complications

Oxidative stress (OS) is defined as a disturbance in the prooxidant-antioxidant balance of the cell, in favor of the former, which results in the antioxidant capacity of the cell to be overpowered. Excess reactive oxygen species (ROS) production is very harmful to cell constituents, especially proteins, lipids, and DNA, thus causing damage to the cell. Oxidative stress has been associated with a variety of pathologic conditions, including diabetes mellitus (DM), cancer, atherosclerosis, neurodegenerative diseases, rheumatoid arthritis, ischemia/reperfusion injury, obstructive sleep apnea, and accelerated aging. Regarding DM specifically, previous experimental and clinical studies have pointed to the fact that oxidative stress probably plays a major role in the pathogenesis and development of diabetic complications. It is postulated that hyperglycemia induces free radicals and impairs endogenous antioxidant defense systems through several different mechanisms. In particular, hyperglycemia promotes the creation of advanced glycation end-products (AGEs), the activation of protein kinase C (PKC), and the hyperactivity of hexosamine and sorbitol pathways, leading to the development of insulin resistance, impaired insulin secretion, and endothelial dysfunction, by inducing excessive ROS production and OS. Furthermore, glucose variability has been associated with OS as well, and recent evidence suggests that also hypoglycemia may be playing an important role in favoring diabetic vascular complications through OS, inflammation, prothrombotic events, and endothelial dysfunction. The association of these diabetic parameters (i.e., hyperglycemia, glucose variability, and hypoglycemia) with oxidative stress will be reviewed here.

Inhibition of voltage-gated K+ channels mediates docosahexaenoic acid-stimulated insulin secretion in rat pancreatic β-cells

Kv channels play a vital role in DHA-augmented insulin secretion through GPR40/AC/cAMP/PLC signaling pathway in rat pancreatic β-cells.

Mushrooms of the Genus Ganoderma Used to Treat Diabetes and Insulin Resistance

Pharmacotherapy using natural substances can be currently regarded as a very promising future alternative to conventional therapy of diabetes mellitus, especially in the case of chronic disease when the body is no longer able to produce adequate insulin or when it cannot use the produced insulin effectively. This minireview summarizes the perspectives, recent advances, and major challenges of medicinal mushrooms from Ganoderma genus with reference to their antidiabetic activity. The most active ingredients of those mushrooms are polysaccharides and triterpenoids. We hope this review can offer some theoretical basis and inspiration for the mechanism study of the bioactivity of those compounds.

GLP-1 receptor agonists and cardiovascular outcome trials: An update

Major cardiovascular (CV) outcome trials with glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are currently available. These agonists have proven their CV safety, in harmony with the US Food and Drug Administration (FDA) recommendation for antidiabetic drugs. The potential cardioprotective effect of incretin-based therapies is attributed to their multiple non-glycaemic actions in the CV system, including changes in insulin resistance, weight loss, reduction in blood pressure, improved lipid profile and direct effects on the heart and vascular endothelium. Liraglutide, semaglutide and albiglutide have been demonstrated to reduce the risk of major adverse cardiac events (MACE), whereas lixisenatide and extended-release exenatide had a neutral effect. Thus, it is conceivable that there are different drug-specific properties across the class of GLP-1 RAs. In this review, we discuss the results of the five recently published randomised CV outcome trials with GLP-1 RAs, along with the potential differences and the pleiotropic actions of these agents on the CV system.

Glucagon-Like Peptide-1 Receptor Agonists in Adult Patients With Type 2 Diabetes: Review of Cardiovascular Outcome Trials

People with type 2 diabetes are at heightened risk for developing cardiovascular (CV) events. CV disease is the leading cause of premature death among adults with type 2 diabetes. Unfortunately, historically, some antidiabetes agents were implicated in worsening CV function, despite improving glycemic and metabolic control. Accordingly, over a decade ago, health regulatory bodies modified approval requirements for novel antidiabetes pharmacotherapies, requiring prospective evaluation of CV safety through cardiovascular outcome trials (CVOTs). To meet regulatory requirements, CVOTs were primarily designed around establishing CV safety by demonstrating noninferiority to placebo in addition to standard of care, without significant differences in blood glucose. If appropriately designed and powered, however, these CVOTs could also determine superiority, and hence CV protection. Although many of these CVOTs were initiated several years ago, the recent reporting of the results for these CVOTs has been pivotal and practice-changing. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are one such class of antidiabetes therapies, wherein multiple GLP-1RA CVOTs, but interestingly, not all, have demonstrated CV benefits. In this review, we provide a comprehensive summary of all the reported CVOTs completed with GLP-1RAs to date. Although it remains unclear why some GLP-1RAs are associated with reducing CV events, whereas others have been consistent with CV safety alone, we highlight and provide an overview of some key differences between the various GLP-1RAs and their respective CVOTs and possible implications of study design differences. We also speculate on potential mechanisms of action for glucagon-like peptide-1 receptor signalling in the CV system.

Glucagon Receptor Antagonism Ameliorates Progression of Heart Failure

Mice were treated with a fully human monoclonal glucagon receptor antagonistic antibody REMD2.59 following myocardial infarction or pressure overload. REMD2.59 treatment blunted cardiac hypertrophy and fibrotic remodeling, and attenuated contractile dysfunction at 4 weeks after myocardial infarction. In addition, REMD2.59 treatment at the onset of pressure overload significantly suppressed cardiac hypertrophy and chamber dilation with marked preservation of cardiac systolic and diastolic function. Initiation of REMD2.59 treatment 2 weeks after pressure overload significantly blunted the progression of cardiac pathology. These results provide the first in vivo proof-of-concept evidence that glucagon receptor antagonism is a potentially efficacious therapy to ameliorate both onset and progression of heart failure.