Acylglycerol Kinase 2-mediated Inhibition of Sirtuin 2 Restores AMPK/AKT/mTOR Signaling Balance in Podocytes: A...

Diabetic nephropathy is a major cause of end-stage renal disease, driven in part by molecular dysfunctions in podocytes. Sirtuin 2 (Sirt2), a cytoplasmic NAD⁺-dependent deacetylase, has emerged as a potential regulator of key metabolic pathways, but its specific role in podocyte biology remains poorly defined.

This study aimed to investigate the function of Sirt2 in human podocytes (hPodo), delineate its interaction with histone deacetylase 6 (HDAC6), and evaluate the therapeutic potential of Sirt2 inhibition in restoring metabolic balance and protecting against diabetic nephropathy-associated podocyte stress.

Comparative expression analysis was performed between hPodo and HEK293T kidney cells. Pharmacological inhibition of Sirt2 was carried out using acylglycerol kinase 2 (AGK2), alongside siRNA-mediated Sirt2 knockdown. AMPK/AKT/mTOR signaling activity was assessed by Western blotting and functional assays to determine metabolic and growth responses.

Human podocytes exhibited significantly elevated Sirt2 expression and high levels of HDAC6, forming a unique Sirt2-HDAC6 regulatory complex. Inhibition or silencing of Sirt2 induced robust AMPK activation while suppressing AKT/mTOR signaling. This signaling reprogramming restored energy sensing and attenuated hyperactive growth pathways, alleviating podocyte stress. Acylglycerol kinase 2 treatment reestablished metabolic homeostasis by disrupting Sirt2-mediated repression of AMPK.

Sirtuin 2 inhibition, particularly through AGK2, emerges as a novel pharmacological strategy to protect podocytes, restore metabolic regulation, and potentially slow the progression of diabetic nephropathy. Significance Statement By inhibiting one of the important intracellular signaling pathways in human kidney cells, we could reduce the cellular stress that is commonly observed in diabetic kidney injury. This could serve as a drug target to slow the progression of kidney disease associated with diabetes mellitus.