Lipin3 deficiency promotes hepatocyte ferroptosis and pyroptosis via activating JAK1-STAT3 pathway during acetaminophen induced acute liver injury.

Lipin3 belongs to the Lipin protein family and is pivotal in modulating lipid homeostasis, inflammatory signaling, and lineage commitment. However, research on Lipin3 is limited, and its role in liver diseases remains poorly defined. This study investigated the function of Lipin3 in acetaminophen (APAP)-induced acute liver injury (ALI). Lipin3 expression was analyzed in public ALI datasets, ALI patients, APAP-challenged mouse models and primary hepatocytes. Lpin3-knockout (Lpin3-KO) mice and adeno-associated virus (AAV)-overexpressing Lpin3 mice were generated to assess the pathophysiological role of Lipin3. Mechanistic studies, including mass spectrometry, coimmunoprecipitation, and bioinformatics prediction, were conducted in primary hepatocytes and HepG2 cells. Our key findings were as follows: Lipin3 levels were markedly reduced in ALI patients, APAP-treated mice, and hepatocytes. Compared with wild-type mice, Lpin3-KO mice exhibited exacerbated ALI severity after post-APAP exposure. Lipin3 deficiency promoted hepatocyte ferroptosis (via lipid peroxidation/ACSL4) and pyroptosis (via GSDME cleavage). Mechanistically, Lipin3 directly interacts with JAK1 to suppress its phosphorylation, thereby inhibiting STAT3-driven activation of ACSL4 (ferroptosis) and GSDME (pyroptosis). Lipin3 overexpression mitigated APAP-induced hepatocyte ferroptosis and pyroptosis, thereby alleviating ALI. Our results demonstrate that Lipin3 depletion aggravates ALI through the dual regulation of ferroptosis and pyroptosis through the JAK1-STAT3 axis, suggesting that Lipin3 is a potential therapeutic target for APAP-induced liver injury.