Soluble Epoxide Hydrolase Inhibition Attenuates Proteinuria by Alleviating Renal Inflammation and Podocyte Injuries in Adriamycin-Induced Nephropathy

Soluble epoxide hydrolase (sEH) has previously been demonstrated to play an important part in kidney diseases by hydrolyzing renoprotective epoxyeicosatrienoic acids to their less active diols. However, little is known about the role of sEH in primary glomerular diseases. Here, we investigated the effects of sEH inhibition on proteinuria in primary glomerular diseases and the underlying mechanism. The expression of sEH in the renal tubules of patients with minimal change disease, IgA nephropathy, and membranous nephropathy was significantly increased. Renal sEH expression level was positively correlated with the 24 h urine protein excretion and negatively correlated with serum albumin. In the animal model of Adriamycin (ADR)-induced nephropathy, renal sEH mRNA and protein expression increased significantly. Pharmacological inhibition of sEH with AUDA effectively reduced urine protein excretion and attenuated renal pathological damage. Furthermore, sEH inhibition markedly abrogated the abnormal expressions of nephrin and desmin in glomerular podocytes induced by ADR. More importantly, AUDA treatment inhibited renal NF-kappa B activation and reduced TNF-alpha levels in rats with ADR-induced nephropathy. Overall, our findings suggest that sEH inhibition ameliorates renal inflammation and podocyte injury, thus reducing proteinuria and exerting renoprotective effects. Targeting sEH might be a potential strategy for the treatment of proteinuria in primary glomerular diseases.