Canagliflozin protects diabetic cardiomyopathy by mitigating fibrosis and preserving the myocardial integrity with improved mitochondrial function

Treatment with dapagliflozin increases FGF-21 gene expression and reduces triglycerides content in myocardial tissue of genetically obese mice

BACKGROUND

The association between obesity and some cardiovascular complications such as heart failure (HF) is well established, and drugs affecting adiposity are supposed to be promising treatments for these conditions. The sodium-glucose cotransporter-2 inhibitors (SGLT2i) are antidiabetic drugs showing benefits in patients with HF, despite the underlying mechanisms have not been completely understood yet. SGLT2i are supposed to promote systemic effects, such as triglycerides mobilization, through the enhancement of fibroblast growth factor-21 (FGF-21) activity. So, in this study, we evaluated the effects of dapagliflozin treatment on FGF-21 and related receptors (FGF-Rs) gene expression and on lipid content in myocardial tissue in an animal model of genetically induced obesity to unravel possible metabolic mechanisms accounting for the cardioprotection of SGLT2i.

METHODS

Six-week-old C57BL/6J wild-type mice and B6.V-LEP (ob/ob) mice were randomly assigned to the control or treatment group (14 animals/group). Treatment was based on the administration of dapagliflozin 0.15 mg/kg/day for 4 weeks. The gene expression of FGF-21 and related receptors (FGF-R1, FGF-R3, FGF-R4, and β-klotho co-receptor) was assessed at baseline and after treatment by real-time PCR. Similarly, cardiac triglycerides concentration was measured in the control group and treated animals.

RESULTS

At baseline, FGF-21 mRNA expression in the heart did not differ between lean and obese ob/ob mice. Dapagliflozin administration significantly increased heart FGF-21 gene expression, but only in ob/ob mice (p < 0.005). Consistently, when measuring the amount of triglycerides in the cardiac tissue, SGLT2i treatment reduced the lipid content in obese ob/ob mice, while no significant effects were observed in treated lean animals (p < 0.001). The overall expression of the FGF-21 receptors was only minimally affected by dapagliflozin treatment both in obese ob/ob mice and in lean controls.

CONCLUSIONS

Dapagliflozin administration increases FGF-21gene expression and reduces triglyceride content in myocardial tissue of ob/ob mice, while no significant effect was observed in lean controls. These results might help understand the cardiometabolic effects of SGLT2i inducing increased FGF-21 synthesis while reducing lipid content in cardiomyocytes as a possible expression of the switch to different energy substrates. This mechanism could represent a potential target of SGLT2i in obesity-related heart diseases.

Therapeutic strategies targeting mechanisms of macrophages in diabetic heart disease

Diabetic heart disease (DHD) is a serious complication in patients with diabetes. Despite numerous studies on the pathogenic mechanisms and therapeutic targets of DHD, effective means of prevention and treatment are still lacking. The pathogenic mechanisms of DHD include cardiac inflammation, insulin resistance, myocardial fibrosis, and oxidative stress. Macrophages, the primary cells of the human innate immune system, contribute significantly to these pathological processes, playing an important role in human disease and health. Therefore, drugs targeting macrophages hold great promise for the treatment of DHD. In this review, we examine how macrophages contribute to the development of DHD and which drugs could potentially be used to target macrophages in the treatment of DHD.

Research advances in the anti-inflammatory effects of SGLT inhibitors in type 2 diabetes mellitus

Diabetes mellitus is one of the most significant global burden diseases. It is well established that a chronic, systemic, low-grade inflammatory condition is strongly correlated with type 2 diabetes mellitus (T2D) and the development of target-organ damage (TOD). Sodium-glucose cotransporter inhibitors (SGLTis), novel oral drugs for the treatment of diabetes, act mainly by reducing glucose reabsorption in proximal renal tubules and/or the intestine. Several high-quality clinical trials and large observational studies have revealed that SGLTis significantly improve cardiovascular and renal outcomes in T2D patients. Increasing evidence suggests that this is closely related to their anti-inflammatory properties, which are mainly manifested by a reduction in plasma concentrations of inflammatory biomarkers. This review analyses the potential mechanisms behind the anti-inflammatory effects of SGLTis in diabetes and presents recent evidence of their therapeutic efficacy in treating diabetes and related TOD.

The influence of dapagliflozin on cardiac remodeling, myocardial function and metabolomics in type 1 diabetes mellitus rats

BACKGROUND

Sodium-glucose cotransporter (SGLT)2 inhibitors have displayed beneficial effects on the cardiovascular system in diabetes mellitus (DM) patients. As most clinical trials were performed in Type 2 DM, their effects in Type 1 DM have not been established.

OBJECTIVE

To evaluate the influence of long-term treatment with SGLT2 inhibitor dapagliflozin on cardiac remodeling, myocardial function, energy metabolism, and metabolomics in rats with Type 1 DM.

METHODS

Male Wistar rats were divided into groups: Control (C, n = 15); DM (n = 15); and DM treated with dapagliflozin (DM + DAPA, n = 15) for 30 weeks. DM was induced by streptozotocin. Dapagliflozin 5 mg/kg/day was added to chow.

STATISTICAL ANALYSIS

ANOVA and Tukey or Kruskal-Wallis and Dunn.

RESULTS

DM + DAPA presented lower glycemia and higher body weight than DM. Echocardiogram showed DM with left atrium dilation and left ventricular (LV) hypertrophy, dilation, and systolic and diastolic dysfunction. In LV isolated papillary muscles, DM had reduced developed tension, +dT/dt and -dT/dt in basal condition and after inotropic stimulation. All functional changes were attenuated by dapagliflozin. Hexokinase (HK), phosphofructokinase (PFK) and pyruvate kinase (PK) activity was lower in DM than C, and PFK and PK activity higher in DM + DAPA than DM. Metabolomics revealed 21 and 5 metabolites positively regulated in DM vs. C and DM + DAPA vs. DM, respectively; 6 and 3 metabolites were negatively regulated in DM vs. C and DM + DAPA vs. DM, respectively. Five metabolites that participate in cell membrane ultrastructure were higher in DM than C. Metabolites levels of N-oleoyl glutamic acid, chlorocresol and N-oleoyl-L-serine were lower and phosphatidylethanolamine and ceramide higher in DM + DAPA than DM.

CONCLUSION

Long-term treatment with dapagliflozin attenuates cardiac remodeling, myocardial dysfunction, and contractile reserve impairment in Type 1 diabetic rats. The functional improvement is combined with restored pyruvate kinase and phosphofructokinase activity and attenuated metabolomics changes.