Targeting phosphorylation of 17β-hydroxysteroid dehydrogenase 13 at serine 33 to treat nonalcoholic steatohepatitis

ABSTRACT: 17β-hydroxysteroid dehydrogenase-13 (17β-HSD13) is a liver-rich lipid droplet associated protein, encoding by gene HSD17B13, that acted as an important regulator of hepatic lipid metabolism. Increased expression of 17β-HSD13 promotes hepatic lipid accumulation in rodents, and a common loss-of-function variant of HSD17B13 (rs72613567: TA) is related to better outcome in patients with various chronic liver diseases. To understand the role of 17β-HSD13 in liver lipid metabolism under normal and high-fat feeding conditions, we characterized the effect of protein phosphorylation of 17β-HSD13 on hepatic lipid homeostasis. We identify Ser33 as an important protein kinase A (PKA)-mediated phosphorylation site of 17β-HSD13 that physically interact with ATGL and facilitates its translocation to lipid droplets to enhance lipolysis. Mutation of Ser33 to Ala (S33A) in 17β-HSD13 reduces ATGL-dependent lipolysis and increases lipid droplet size in cultured hepatocytes by reducing CGI-58-mediated ATGL activation. Consistently, a transgenic knock-in mouse strain carrying HSD17B13 S33A mutation (HSD17B1333A/A) spontaneously develops liver steatosis with reduced lipolysis. Moreover, HSD17B1333A/A mice are more prone to high fat-induced hepatic steatosis and inflammation. Finally, we found Reproterol, a potential HSD17B13 modulator and FDA-approved drug, confers a protection against liver steatosis possibly through phosphorylation of 17β-HSD13 at Ser33 in a PKA-dependent manner. In summary, we demonstrate a critical role and the underlying mechanism of hepatic 17β-HSD13 phosphorylation in the pathogenesis of NAFLD. Our findings highlight the potential of targeting 17β-HSD13 phosphorylation as a novel therapeutic approach for NAFLD.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Epithelial Cell

DISEASE(S): Non-alcoholic Steatohepatitis

SUBMITTER: Rongfeng Lan  

LAB HEAD: Wen Su

PROVIDER: PXD037262 | Pride | 2023-03-11

REPOSITORIES: Pride