<b>Inhibition of ACSS2-mediated </b><b> crotonylation alleviates kidney fibrosis via IL-1β-dependent macrophage activation and tubular cell senescence</b>

Histone lysine crotonylation (Kcr), as a novel posttranslational modification, is widespread as acetylation (Kac); however, its roles are largely unknown in kidney fibrosis. In this study, we reported that histone Kcr of tubular epithelial cells wasis abnormally elevated in fibrotic kidneys. By screening these crotonylated/acetylated factors, a crotonyl-CoA-producing enzyme ACSS2 (acyl-CoA synthetase short chain family member 2) wasis found to remarkably increase histone 3 lysine 9 crotonylation (H3K9cr) level without influencing H3K9ac in kidneys and tubular epithelial cells. The integrated analysis of ChIP-seq and RNA-seq of fibrotic kidneys revealed that the hub proinflammatory cytokine IL-1β, which is regulated by H3K9cr, play crucial roles in fibrogenesis. Furthermore, genetic and pharmacologic inhibition of ACSS2 both suppressed H3K9cr-mediated IL-1β expression, which thereby alleviated IL-1β-dependent macrophage activation and tubular cell senescence to delay renal fibrosis. Collectively, our findings uncover that H3K9cr exerts a critical, previously unrecognized role in kidney fibrosis, where ACSS2 represents an attractive drug target to slow fibrotic kidney disease progression.