Curcumin targets CXCL16-mediated podocyte injury and lipid accumulation in diabetic kidney disease treatment.

Among the complications of diabetes, diabetic kidney disease (DKD) frequently emerges, typified by the detrimental effects on renal function, manifesting through inflammation, dysregulated lipid metabolism, and harm to podocytes. Existing research underscores the significance of the soluble form of C-X-C chemokine ligand 16 (CXCL16) within the context of renal impairments. However, whether CXCL16 is involved in the pathogenesis of DKD remains elusive. We report that CXCL16 levels in the serum and kidneys of individuals with DKD were elevated and correlated with various lipid parameters. The expression of CXCL16 in human podocytes subjected to high glucose or palmitic acid induction and exogenous CXCL16 administration in these cells were examined. Higher CXCL16 levels were linked to abnormal lipid metabolism. Exogenous CXCL16 administration induced lipid droplets, microfilament disorganization, apoptosis, oxidative stress, and inflammation, inhibited PPAR γ, up-regulated COX2 expression, and inhibited Nrf2 translocation in podocytes. Molecular analysis revealed that Curcumin (Cur), a polyphenolic compound derived from Curcuma longa and an Nrf2 agonist, targets the ATP-binding pocket of CXCL16, inhibiting its kinase activity. Meanwhile, Cur therapy alleviated podocyte injury, lipid accumulation, improved glomerulopathy, and reduced albuminuria. Furthermore, after silencing CXCL16 expression in podocytes using siRNA, the effects of exogenous CXCL16 were nullified, and Cur no longer exhibited any significant impact. Thus, CXCL16 participates in the pathogenesis of DKD. Inhibition of CXCL16 has shown promising results in experimental models, suggesting its beneficial effects in ameliorating DKD.