Hepatic interleukin 32 attenuates liver injury through repression of necroptosis in cholestasis

Aim: In our research, we sought to evaluate the impact of interleukin 32(IL32) and the relationship between IL32 and Necroptosis in cholestatic liver injury.

Methods: We measured the levels of Necroptosis related markers in cholestatic and control patients, including the receptor-interacting serine-threonine kinase 3(RIPK3), receptor-interacting serine-threonine kinase 1(RIPK1) and Mixed Lineage Kinase domain-like(MLKL). Then we performed experiments with C57BL/6J and IL32β/γ overexpression mice to confirm the effect of IL32 on Necroptosis in cholestatic liver injury, which induced by α-naphthylisothiocyanate (ANIT) and 1% lithocholic acid (LCA). PLC/PRF/5-ASBT and primary mouse hepatocytes were utilized for studying the regulation and mechanism of IL32 in cholestasis.

Results: In the liver tissues of cholestatic patients, the expression levels of RIPK1/RIPK3/MLKL were considerably higher and highly connected with IL32 expression(p < 0.05). Besides, The levels in the liver of 1%LCA and ANIT model groups were significantly increased, while they were markedly decreased in hIL32β/γLTg mice (p < 0.05). After bile acid stimulation, IL32 and p-Akt expression significantly elevated in a dose-dependent manner. In addition, after TNF-α stimulation, IL32 prevented the expression of MLKL in primary mouse hepatocytes(p < 0.05).

Conclusions: In conclusion, IL32 is negatively correlated with Necroptosis in cholestatic patients. What's more, IL32 is induced by p-Akt and effectively attenuates Necroptosis in the mouse models of ANIT/1%LCA-induced cholestasis.

Cholestasis; Interleukin 32; Liver injury; Necroptosis; p-Akt.