HIF-2α drives hepatic Kupffer cell death and proinflammatory recruited macrophage activation in nonalcoholic steatohepatitis

Sci Transl Med. 2024 Sep 11;16(764):eadi0284. doi: 10.1126/scitranslmed.adi0284. Epub 2024 Sep 11.

Abstract

Proinflammatory hepatic macrophage activation plays a key role in the development of nonalcoholic steatohepatitis (NASH). This involves increased embryonic hepatic Kupffer cell (KC) death, facilitating the replacement of KCs with bone marrow-derived recruited hepatic macrophages (RHMs) that highly express proinflammatory genes. Moreover, phago/efferocytic activity of KCs is diminished in NASH, enhancing liver inflammation. However, the molecular mechanisms underlying these changes in KCs are not known. Here, we show that hypoxia-inducible factor 2α (HIF-2α) mediates NASH-associated decreased KC growth and efferocytosis by enhancing lysosomal stress. At the molecular level, HIF-2α stimulated mammalian target of rapamycin (mTOR)- and extracellular signal-regulated kinase-dependent inhibitory transcription factor EB (TFEB) phosphorylation, leading to decreased lysosomal and phagocytic gene expression. With increased metabolic stress and phago/efferocytic burden in NASH, these changes were sufficient to increase lysosomal stress, causing decreased efferocytosis and lysosomal cell death. Of interest, HIF-2α-dependent TFEB regulation only occurred in KCs but not RHMs. Instead, in RHMs, HIF-2α promoted mitochondrial reactive oxygen species production and proinflammatory activation by increasing ANT2 expression and mitochondrial permeability transition. Consequently, myeloid lineage-specific or KC-specific HIF-2α depletion or the inhibition of mTOR-dependent TFEB inhibition using antisense oligonucleotide treatment protected against the development of NASH in mice. Moreover, treatment with an HIF-2α-specific inhibitor reduced inflammatory and fibrogenic gene expression in human liver spheroids cultured under a NASH-like condition. Together, our results suggest that macrophage subtype-specific effects of HIF-2α collectively contribute to the proinflammatory activation of liver macrophages, leading to the development of NASH.

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / metabolism
  • Basic Helix-Loop-Helix Transcription Factors* / metabolism
  • Cell Death
  • Humans
  • Inflammation / metabolism
  • Inflammation / pathology
  • Kupffer Cells* / metabolism
  • Liver* / metabolism
  • Liver* / pathology
  • Lysosomes / metabolism
  • Macrophage Activation*
  • Macrophages / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mitochondria / metabolism
  • Non-alcoholic Fatty Liver Disease* / metabolism
  • Non-alcoholic Fatty Liver Disease* / pathology
  • Phagocytosis
  • Reactive Oxygen Species / metabolism
  • TOR Serine-Threonine Kinases / metabolism

Substances

  • endothelial PAS domain-containing protein 1
  • Basic Helix-Loop-Helix Transcription Factors
  • Reactive Oxygen Species
  • TOR Serine-Threonine Kinases
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • Tcfeb protein, mouse