Iron-rich Kupffer cells exhibit phenotypic changes during the development of liver fibrosis in NASH

Although recent evidence suggests the involvement of iron accumulation in the pathogenesis of nonalcoholic steatohepatitis (NASH), the underlying mechanisms remain poorly understood. Previously, we reported a unique histological structure termed crown-like structure (CLS), where liver-resident macrophages (Kupffer cells) surround dead hepatocytes, scavenge their debris, and induce inflammation and fibrosis in NASH. In this study, using magnetic column separation, we show that iron-rich Kupffer cells exhibit proinflammatory and profibrotic phenotypic changes during the development of NASH, at least partly, through activation of MiT/TFE transcription factors. Activation of MiT/TFE transcription factors is observed in Kupffer cells forming CLSs in murine and human NASH. Iron chelation effectively attenuates liver fibrosis in a murine NASH model. This study provides insight into the pathophysiologic role of iron in NASH. Our data also shed light on a unique macrophage subset rich in iron that contributes to CLS formation and serves as a driver of liver fibrosis.

Automated summary

The study reveals that iron accumulation can lead to proinflammatory and profibrotic phenotypic changes in iron-rich Kupffer cells during the development of NASH by activating MiT/TFE transcription factors. Iron chelation effectively attenuates liver fibrosis in a murine NASH model, shedding light on the pathophysiologic role of iron in NASH and a unique macrophage subset rich in iron contributing to CLS formation and liver fibrosis.