The pseudokinase MLKL mediates programmed hepatocellular necrosis independently of RIPK3 during hepatitis

C Günther, GW He, AE Kremer, JM Murphy… - The Journal of clinical …, 2016 - jci.org
The Journal of clinical investigation, 2016jci.org
Although necrosis and necroinflammation are central features of many liver diseases, the
role of programmed necrosis in the context of inflammation-dependent hepatocellular death
remains to be fully determined. Here, we have demonstrated that the pseudokinase mixed
lineage kinase domain–like protein (MLKL), which plays a key role in the execution of
receptor-interacting protein (RIP) kinase–dependent necroptosis, is upregulated and
activated in human autoimmune hepatitis and in a murine model of inflammation-dependent …
Although necrosis and necroinflammation are central features of many liver diseases, the role of programmed necrosis in the context of inflammation-dependent hepatocellular death remains to be fully determined. Here, we have demonstrated that the pseudokinase mixed lineage kinase domain–like protein (MLKL), which plays a key role in the execution of receptor-interacting protein (RIP) kinase–dependent necroptosis, is upregulated and activated in human autoimmune hepatitis and in a murine model of inflammation-dependent hepatitis. Using genetic and pharmacologic approaches, we determined that hepatocellular necrosis in experimental hepatitis is driven by an MLKL-dependent pathway that occurs independently of RIPK3. Moreover, we have provided evidence that the cytotoxic activity of the proinflammatory cytokine IFN-γ in hepatic inflammation is strongly connected to induction of MLKL expression via activation of the transcription factor STAT1. In summary, our results reveal a pathway for MLKL-dependent programmed necrosis that is executed in the absence of RIPK3 and potentially drives the pathogenesis of severe liver diseases.
The Journal of Clinical Investigation