Pim-1 kinase protects the liver from ischemia reperfusion injury by regulating dynamics-related protein 1

Area of Science:

• Hepatology
• Molecular Biology
• Cellular Biology

Background:

• Hepatic ischemia-reperfusion (IR) injury is a major challenge in liver transplantation.
• Current treatments for hepatic IR injury are insufficient, necessitating novel therapeutic strategies.

Purpose of the Study:

• To investigate the role of Proto-oncogene serine/threonine-protein kinase (Pim-1) in hepatic IR injury.
• To elucidate the molecular mechanisms underlying Pim-1's function in liver IR.

Main Methods:

• Established mouse liver IR *in vivo* and MIHA cell hypoxia-reoxygenation *in vitro* models.
• Assessed Pim-1 expression levels and correlated them with liver injury markers (ALT, AST).
• Investigated the impact of Pim-1 on mitochondrial dynamics (Drp1 phosphorylation, fission) and apoptosis.
• Examined the epigenetic regulation of Pim-1, specifically histone H3 lysine 9 trimethylation.

Main Results:

• Pim-1 expression was upregulated following hepatic IR.
• Increased Pim-1 expression correlated inversely with serum ALT and AST levels, indicating a protective effect.
• Pim-1 modulated Drp1 phosphorylation, leading to mitochondrial membrane stabilization, reduced fission, and decreased apoptosis.
• Elevated Pim-1 expression was found to be dependent on histone H3 lysine 9 trimethylation during liver IR.

Conclusions:

• Pim-1 plays a critical protective role in mitigating hepatic IR injury.
• Pim-1 exerts its protective effects by regulating mitochondrial integrity and reducing apoptosis.
• Epigenetic modifications, specifically histone H3 lysine 9 trimethylation, are involved in regulating Pim-1 expression in response to IR.
• Targeting Pim-1 represents a promising novel therapeutic strategy for managing hepatic IR injury.