Aim: Depressor arm of the renin-angiotensin system (RAS) exerts reno-protective effects in chronic kidney diseases like diabetic nephropathy. However, same is still elusive under AKI and hyperglycaemia comorbidity. Hence, the present study delineates the role of angiotensin-II type 2 receptor (AT2R) and angiotensin-converting enzyme 2 (ACE2) in AKI under normal and hyperglycaemia condition.
Methods: Non-diabetic (ND) and Streptozotocin-induced diabetes mellitus (DM) rats were subjected to ischemic renal injury (IRI). Rats underwent IRI were treated with an AT2R agonist, C21 (0.3 mg/kg/day, i.p.) or ACE2 activator, Dize, (5 mg/kg/day, p.o.) either alone or as combination therapy. Renal histopathology and immunohistochemistry, proximal tubular fraction isolation, ELISA, immunoblotting and qRT-PCR were performed for subsequent analysis.
Key findings: Rats subjected to IRI displayed an increase in plasma ACE, AT1R, AT2R, Ang II, and reduction in ACE2, Ang-(1-7) expressions, with augmented renal inflammation and apoptosis. These changes were more prominent in diabetic rats with IRI. Co-administration of C21 and Dize augmented ACE2, Ang-(1-7), AT2R and MasR expressions, and attenuated tubular injury in both DM and ND rats.
Conclusion: We demonstrated that pharmacological activation of AT2R and ACE2 protects DM and ND rats from IRI by preventing oxidative stress, inflammation and apoptosis-mediated tubular damage.
Keywords: ACE2 activator; AT2R agonist; Diabetes; Ischemic renal injury; Renin-angiotensin system.
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