Combination of Linagliptin and Empagliflozin Preserves Cardiac Systolic Function in an Ischemia-Reperfusion Injury Mice With Diabetes Mellitus

Pathophysiological basis of the cardiological benefits of SGLT-2 inhibitors: a narrative review

In recent years, GLP-1 receptor agonists (GLP-1RA), and SGLT-2 inhibitors (SGLT-2i) have become available, which have become valuable additions to therapy for type 2 diabetes as they are associated with low risk for hypoglycemia and cardiovascular benefits. Indeed, SGLT-2i have emerged as a promising class of agents to treat heart failure (HF). By inhibiting SGLT-2, these agents lead to excretion of glucose in urine with subsequent lowering of plasma glucose, although it is becoming clear that the observed benefits in HF cannot be explained by glucose-lowering alone. In fact, multiple mechanisms have been proposed to explain the cardiovascular and renal benefits of SGLT-2i, including hemodynamic, anti-inflammatory, anti-fibrotic, antioxidant, and metabolic effects. Herein, we review the available evidence on the pathophysiology of the cardiological benefits of SGLT-2i. In diabetic heart disease, in both clinical and animal models, the effect of SGLT-2i have been shown to improve diastolic function, which is even more evident in HF with preserved ejection fraction. The probable pathogenic mechanisms likely involve damage from free radicals, apoptosis, and inflammation, and therefore fibrosis, many of which have been shown to be improved by SGLT-2i. While the effects on systolic function in models of diabetic heart disease and HF with preserved ejection fraction is limited and contrasting, it is a key element in patients with HF and reduced ejection fraction both with and without diabetes. The significant improvement in systolic function appears to lead to subsequent structural remodeling of the heart with a reduction in left ventricle volume and a consequent reduction in pulmonary pressure. While the effects on cardiac metabolism and inflammation appear to be consolidated, greater efforts are still warranted to further define the entity to which these mechanisms contribute to the cardiovascular benefits of SGLT-2i.

Empagliflozin activates JAK2/STAT3 signaling and protects cardiomyocytes from hypoxia/reoxygenation injury under high glucose conditions

The morbidity and mortality rates of cardiovascular disease are markedly higher in patients with diabetes than in non-diabetic patients, including patients with ischemia-reperfusion injury (IRI). However, the cardiovascular protective effects of Empagliflozin (EMPA) on IRI in diabetes mellitus have rarely been studied. In this study, we established a cardiomyocyte hypoxia/reoxygenation (H/R) injury model to mimic myocardial I/R injuries that occur in vivo. H9C2 cells were subjected to high glucose (HG) treatment plus H/R injury to mimic myocardial I/R injuries that occur in diabetes mellitus. Next, different concentrations of EMPA were added to the H9C2 cells and its protective effect was detected. STAT3 knockdown with recombinant plasmids was used to determine its roles. Our results showed that H/R injury-induced cell apoptosis, necroptosis, oxidative stress, and endoplasmic reticulum stress were further promoted by HG conditions, and HG treatment plus an H/R injury inhibited the activation of JAK2/STAT3 signaling. EMPA was found to protect against H/R-induced cardiomyocyte injury under HG conditions and activate JAK2/STAT3 signaling, while down-regulation of STAT3 reversed the protective effect of EMPA. When taken together, these findings indicate that EMPA protects against I/R-induced cardiomyocyte injury by activating JAK2/STAT3 signaling under HG conditions. Our results clarified the mechanisms that underlie the cardiovascular protective effects of EMPA in diabetes mellitus and provide new therapeutic targets for IRI in diabetes mellitus.

Cardiovascular protection by DPP-4 inhibitors in preclinical studies: an updated review of molecular mechanisms

Dipeptidyl peptidase 4 (DPP4) inhibitors are a class of antidiabetic medications that cause glucose-dependent increase in incretins in diabetic patients. One of the two incretins, glucagon-like peptide-1 (GLP-1), beside its insulinotropic activity, has been studied for extra pancreatic effects. Most of DPP4 inhibitors (DPP4i) have been investigated in in vivo and in vitro models of diabetic and nondiabetic cardiovascular diseases including heart failure, hypertension, myocardial ischemia or infarction, atherosclerosis, and stroke. Results of preclinical studies proved prominent therapeutic potential of DPP4i in cardiovascular diseases, regardless the presence of diabetes. This review aims to present an updated summary of the cardiovascular protective and therapeutic effects of DPP4 inhibitors through the past 5 years focusing on the molecular mechanisms beneath these effects. Additionally, based on the results summary presented here, future studies may be conducted to elucidate or illustrate some of these findings which can add clinical benefits towards management of diabetic cardiovascular complications.