Lysine-specific histone demethylase 1A mediates the up-regulation of NADPH oxidase expression in the kidney of diabetic mice

Background and Aims: Epigenetic alterations have been increasingly connected to the pathology of diabetic kidney disease (DKD), a degenerative disorder leading to kidney failure that is characterized by structural-functional alterations of the glomerular microvascular system. NADPH oxidase (Nox) represents a major source of oxidative stress in DKD. We aimed at elucidating the potential implication of lysine-specific histone demethylase 1A (LSD1) in the up-regulation of Nox expression in diabetic kidney. Methods: Male non-diabetic and streptozotocin-induced diabetic C57BL/6J mice (n=10/group) were treated with 5 mg/kg GSK2879552, a specific LSD1 inhibitor, or its vehicle, for 4 weeks. Human endothelial cells (EA.hy926, EC) were exposed to normal (5 mM) or high (25 mM) concentrations of glucose in the absence/presence of 5 μM GSK2879552, or subjected to transient transfection. Fluorescence microscopy, real-time PCR and Western blot techniques were used. Results: Significant increases in LSD1 mRNA and protein levels correlated with elevated Nox subunit mRNA/protein expression were detected in the kidney of diabetic mice, 4 weeks after installation of hyperglycemia. A marked immunostaining of LSD1 was detected in the glomeruli of diabetic mice. Pharmacological inhibition of LSD1 suppressed the up-regulation of Nox subunit (Nox1, Nox2, Nox4, p22phox) mRNA/protein levels in the kidney of diabetic mice. LSD1 blockade significantly reduced the up-regulation of Nox subtype expression levels in high glucose-exposed EC. Overexpression of LSD1 increased the mRNA levels of Nox subunits in cultured EC. Conclusions: LSD1-oriented pharmacological inhibitors could become important therapeutic tools to prevent epigenetic instability and oxidative stress in DKD. Acknowledgements: Work supported by UEFISCDI (PN-III-P1-1.1-TE-2021-0180, PN-III-P4-ID-PCE-2020-1898).