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Updated: Jun 26, 2025
Induction of Drug-Induced, Autoimmune Hepatitis in BALB/c Mice for the Study of Its Pathogenic Mechanisms
Published on: May 29, 2020
PIM1 inhibitor SMI-4a attenuated concanavalin A-induced acute hepatitis through suppressing inflammatory responses
Xinwan Wu1, Yuwei Chen2, Meiru Jiang1
1Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Background:
Serine/threonine kinase 1 (PIM1) plays a crucial role in cell growth, differentiation, and apoptosis. However, its role in the pathogenesis of concanavalin A (ConA)-induced acute hepatitis is not well understood. PIM1 kinase inhibitor can reduce the expression of PIM1. This study aims to investigate the effects of PIM1 kinase inhibitor and its protective mechanism in ConA-induced acute hepatitis.
Methods:
C57/BL six mice were injected with ConA (20, 15, and 12 mg/kg) to induce acute hepatitis, and PIM1 kinase inhibitor SMI-4a (60 mg/kg) was administered orally 24 h before ConA injection. The survival rate of the mice was observed after ConA injection. The levels of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured. Serum inflammatory factors were detected by enzyme-linked immunosorbent assay (ELISA). Hematoxylin-eosin (HE) staining was performed on liver tissue collected at different time points. The major cytokines expression in liver tissue was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The number of macrophages, T-cell and neutrophils in liver tissue were detected by flow cytometry (FCM). PIM1 in liver tissue was detected by western blot (WB) and qRT-PCR. SMI-4a (80 µM) was pretreated for 24 h and ConA (400 µg/mL) was stimulated for 12 h in RAW264.7 cell model. Phosphorylated p65 (p-p65) and cleaved caspase-3 (c-caspase-3) in liver tissue and macrophages were detected by WB.
Results:
Different concentrations of ConA caused different acute hepatitis mortality, 12 mg/kg concentration within 24 h of the mortality showed a gradient increase. The levels of AST and ALT increased significantly at 12 h after ConA injection. PIM1 expression was upregulated at 12 h. SMI-4a can suppress the PIM1 expression. SMI-4a suppressed cytokines production, AST, and ALT in ConA-treated serum. SMI-4a suppressed the major cytokines in liver tissue. Tests in liver tissue showed that SMI-4a reduced the number of T cells, neutrophils, and macrophages. SMI-4a inhibited the inflammatory response by downregulating the expression of p-p65. Meanwhile, apoptosis was decreased by decreasing the expression of c-caspase-3.
Conclusions:
In conclusion, the protective effect of SMI-4a against acute hepatitis is by reducing the inflammatory response and apoptosis. These findings suggest that SMI-4a may have therapeutic potential in the treatment of autoimmune hepatitis.
Insights
The PIM1 kinase inhibitor SMI-4a protects against concanavalin A-induced acute hepatitis by reducing inflammation and apoptosis. This study suggests SMI-4a as a potential therapeutic for autoimmune hepatitis.
Area of Science:
- Immunology
- Hepatology
- Pharmacology
Background:
- Serine/threonine kinase 1 (PIM1) is vital for cell growth, differentiation, and apoptosis.
- The role of PIM1 in concanavalin A (ConA)-induced acute hepatitis remains unclear.
- PIM1 kinase inhibitors can decrease PIM1 expression.
Purpose of the Study:
- To investigate the therapeutic effects of the PIM1 kinase inhibitor SMI-4a in a mouse model of ConA-induced acute hepatitis.
- To elucidate the protective mechanisms of SMI-4a against ConA-induced liver injury.
Main Methods:
- ConA was used to induce acute hepatitis in C57/BL6 mice, with SMI-4a administered pre-treatment.
- Liver injury markers (AST, ALT), inflammatory cytokines, immune cell infiltration (T cells, neutrophils, macrophages), PIM1 expression, and apoptosis markers were assessed.
- In vitro studies used RAW264.7 cells stimulated with ConA and treated with SMI-4a.
Main Results:
- SMI-4a treatment significantly reduced mortality, liver enzymes (AST, ALT), and inflammatory cytokine levels in ConA-induced hepatitis.
- SMI-4a suppressed PIM1 expression, decreased infiltration of T cells, neutrophils, and macrophages in the liver.
- SMI-4a inhibited the inflammatory signaling pathway by downregulating phosphorylated p65 (p-p65) and reduced apoptosis by decreasing cleaved caspase-3 (c-caspase-3) expression.
Conclusions:
- SMI-4a demonstrates a protective effect against ConA-induced acute hepatitis.
- The mechanism involves the suppression of inflammatory responses and apoptosis.
- SMI-4a holds potential as a therapeutic agent for autoimmune hepatitis.
