Inflammatory cell activation drives diverse cellular programming during hepatic diseases. Hypoxia-inducible factors (HIFs) have recently been identified as important regulators of immunity and inflammation. In nonalcoholic steatohepatitis (NASH), HIF-1 alpha is upregulated in hepatocytes, where it induces steatosis; however, the role of HIF-1 alpha in macrophages under metabolic stress has not been explored. In this study, we found increased HIF-1 alpha levels in hepatic macrophages in methionine-choline-deficient (MCD) diet-fed mice and in macrophages of patients with NASH compared with controls. The HIF-1 alpha increase was concomitant with elevated levels of autophagy markers BNIP3, Beclin-1, LC3-II, and p62 in both mouse and human macrophages. LysM(Cre) HIF(dPA)fl/fl mice, which have HIF-1 alpha levels stabilized in macrophages, showed higher steatosis and liver inflammation compared with HIF(dPA)fl/fl mice on MCD diet. In vitro and ex vivo experiments reveal that saturated fatty acid, palmitic acid (PA), both induces HIF-1 alpha and impairs autophagic flux in macrophages. Using small interfering RNA-mediated knock-down and overexpression of HIF-1 alpha in macrophages, we demonstrated that PA impairs autophagy via HIF-1 alpha. We found that HIF-1 alpha mediates NF-kappa B activation and MCP-1 production and that HIF-1 alpha-mediated impairment of macrophage autophagy increases IL-1 beta production, contributing to MCD diet-induced NASH. Conclusion: Palmitic acid impairs autophagy via HIF-1 alpha activation in macrophages. HIF-1 alpha and impaired autophagy are present in NASH in vivo in mouse macrophages and in human blood monocytes. We identified that HIF-1 alpha activation and decreased autophagic flux stimulate inflammation in macrophages through upregulation of NF-kappa B activation. These results suggest that macrophage activation in NASH involves a complex interplay between HIF-1 alpha and autophagy as these pathways promote proinflammatory overactivation in MCD diet-induced NASH.
基金:
NIH [R01AA011576, R01AA020744]; NSFC [81500452, F30 AA024680, F31 AA025545, F30 AA022283]; NIH Liver Tissue Cell Distribution System (Minneapolis, MN) [NIH N01-DK-7-004/HHSN267007004C]; NIH Liver Tissue Cell Distribution System (Pittsburgh, PA) [NIH N01-DK-7-004/HHSN267007004C]; NIH Liver Tissue Cell Distribution System (Richmond, VA) [NIH N01-DK-7-004/HHSN267007004C]
第一作者单位:[1]Univ Massachusetts, Med Sch, Dept Med, LRB 215,364 Plantat St, Worcester, MA 01605 USA[2]Huazhong Univ Sci & Technol,Tongji Hosp,Tongji Med Coll,Inst & Dept Infect Dis,Wuhan,Hubei,Peoples R China
通讯作者:
推荐引用方式(GB/T 7714):
Wang Xiaojing,Ribeiro Marcelle de Carvalho,Iracheta-Vellve Arvin,et al.Macrophage-Specific Hypoxia-Inducible Factor-1α Contributes to Impaired Autophagic Flux in Nonalcoholic Steatohepatitis[J].HEPATOLOGY.2019,69(2):545-563.doi:10.1002/hep.30215.
APA:
Wang, Xiaojing,Ribeiro, Marcelle de Carvalho,Iracheta-Vellve, Arvin,Lowe, Patrick,Ambade, Aditya...&Szabo, Gyongyi.(2019).Macrophage-Specific Hypoxia-Inducible Factor-1α Contributes to Impaired Autophagic Flux in Nonalcoholic Steatohepatitis.HEPATOLOGY,69,(2)
MLA:
Wang, Xiaojing,et al."Macrophage-Specific Hypoxia-Inducible Factor-1α Contributes to Impaired Autophagic Flux in Nonalcoholic Steatohepatitis".HEPATOLOGY 69..2(2019):545-563