Stress-responsive gene FKBP5 mediates alcohol-induced liver injury through the hippo pathway and CXCL1 signaling

Abstract

Chronic alcohol drinking is a major risk factor for alcohol-associated liver disease (ALD). FK506-binding protein 51 (FKBP5), a co-chaperone protein, is involved in many key regulatory pathways. It is known to be involved in stress-related disorders but there are no reports regarding its role in ALD. This present study aimed to examine the molecular mechanism of FKBP5 in ALD. We found a significant increase in hepatic FKBP5 transcripts and protein expression in patients with ALD and mice fed with chronic-plus-single binge ethanol. Loss of Fkbp5 in mice protected against alcohol-induced hepatic steatosis and inflammation. Transcriptomic analysis revealed a significant reduction of Tead1 and Cxcl1 mRNA in ethanol-fed Fkbp5-/- mice. Ethanol-induced Fkbp5 expression was secondary to downregulation of methylation level at its 5′ UTR promoter region. The increase in Fkbp5 expression led to induction in transcription factor Tead1 through Hippo signaling pathway. Fkbp5 can interact with YAP upstream kinase, MST1, affecting its ability to phosphorylate YAP and the inhibitory effect of hepatic YAP phosphorylation by ethanol leading to YAP nuclear translocation and TEAD1 activation. Activation of TEAD1 led to increased expression of its novel target, CXCL1, a chemokine-mediated neutrophil recruitment, causing hepatic inflammation and neutrophil infiltration in our mouse model. Conclusion We identified a novel FKBP5-YAP-TEAD1-CXCL1 axis in the pathogenesis of ALD. Loss of FKBP5 ameliorates alcohol-induced liver injury through the Hippo pathway and CXCL1 signaling, suggesting its potential role as a target for the treatment of ALD.