Does renin angiotensin system blockade deserve preferred status over other anti-hypertensive medications for the treatment of people with diabetes?

Potential of Renin-Angiotensin-Aldosterone System Modulations in Diabetic Kidney Disease: Old Players to New Hope!

Due to a tragic increase in the incidences of diabetes globally, diabetic kidney disease (DKD) has emerged as one of the leading causes of end-stage renal diseases (ESRD). Hyperglycaemia-mediated overactivation of the renin-angiotensin-aldosterone system (RAAS) is key to the development and progression of DKD. Consequently, RAAS inhibition by angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARBs) is the first-line therapy for the clinical management of DKD. However, numerous clinical and preclinical evidences suggested that RAAS inhibition can only halt the progression of the DKD to a certain extent, and they are inadequate to cure DKD completely. Recent studies have improved understanding of the complexity of the RAAS. It consists of two counter-regulatory arms, the deleterious pressor arm (ACE/angiotensin II/AT1 receptor axis) and the beneficial depressor arm (ACE2/angiotensin-(1-7)/Mas receptor axis). These advances have paved the way for the development of new therapies targeting the RAAS for better treatment of DKD. In this review, we aimed to summarise the involvement of the depressor arm of the RAAS in DKD. Moreover, in modern drug discovery and development, an advance approach is the bispecific therapeutics, targeting two independent signalling pathways. Here, we discuss available reports of these bispecific drugs involving the RAAS as well as propose potential treatments based on neurohormonal balance as credible therapeutic strategies for DKD.

Telmisartan and esculetin combination ameliorates type 2 diabetic cardiomyopathy by reversal of H3, H2A, and H2B histone modifications

OBJECTIVES:

Although cardioprotective effects of telmisartan are well explored, its effects on epigenetic alterations associated with type 2 diabetic (T2D) cardiomyopathy remain unmapped. Thus, the present study was designed to evaluate the potential of esculetin and telmisartan combination to reverse histone posttranslational modifications (PTMs) in curbing T2D cardiomyopathy.

MATERIALS AND METHODS:

T2D was induced by high-fat diet feeding along with low dose of streptozotocin (35 mg/kg, I.P) in male Wistar rats. T2D rats were treated with either telmisartan (10 mg/kg/day, P.O) or esculetin (50 mg/kg/day doses, P.O) or their combination for 2 weeks. Biochemical estimations, vascular reactivity, immunohistochemistry, and western blotting experiments were performed to evaluate the effects of the treatment in T2D cardiomyopathy.

RESULTS:

Esculetin and telmisartan combination alleviated the pathological features of T2D cardiomyopathy including metabolic perturbations, morphometric alterations, altered vascular reactivity, increased Keap1 and fibronectin expression more effectively than their respective monotherapy. This is the first report showing that telmisartan attenuates increased level of histone PTMs such as H3K9me2, H3K9Ac, H2AK119Ub, and H2BK120Ub in heart of T2D rats. The combination regimen showed a more significant reduction in augmented histone PTMs associated with T2D cardiomyopathy than their independent treatments.

CONCLUSIONS:

The present study demonstrates that esculetin and telmisartan combination can be an advanced pharmacological approach to ameliorate T2D cardiomyopathy which could be partially attributed to its ability to reverse the epigenetic alterations.