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Updated: Nov 4, 2025
Bile Duct Ligation in Mice: Induction of Inflammatory Liver Injury and Fibrosis by Obstructive Cholestasis
Published on: February 10, 2015
TLR4 Knockout Attenuates BDL-induced Liver Cholestatic Injury through Amino Acid and Choline Metabolic Pathways
Shou-Hua Zhang1, Meng-Jie Yu2, Jin-Long Yan3
1Department of General Surgery, Jiangxi Provincial Children's Hospital, Nanchang, 330006, China.
Abstract:
The exact mechanism by which knockout of Toll-like receptor 4 (TLR4) attenuates the liver injury remains unclear. The present study aimed to examine the role of TLR4 in the pathogenesis of bile duct ligation (BDL)-induced liver cholestatic injury and the underlying mechanism. Wild type (WT) mice and TLR4 knockout (TLR4-KO) mice were used for the establishment of the BDL model. Metabolomics were applied to analyze the changes of small molecular metabolites in the serum and liver of the two groups. The serum biochemical indexes and the HE staining results of liver tissue showed that liver damage was significantly reduced in TLR4-KO mice after BDL when compared with that in WT mice. The metabolite analysis results showed that TLR4 KO could maintain the metabolisms of amino acids- and choline-related metabolites. After BDL, the amino acids- and choline-related metabolites, especially choline and 3-hydroxybutyrate, were significantly increased in WT mice (both in serum and liver), but these metabolites in the liver of TLR4-KO mice after BLD were not significant different from those before BLD. In conclusion, TLR4 KO could attenuate BDL-induced liver cholestatic injury through regulating amino acid and choline metabolic pathways.
Insights
Toll-like receptor 4 (TLR4) knockout significantly reduces liver injury from bile duct ligation. This occurs by maintaining amino acid and choline metabolism, preventing harmful metabolite increases seen in wild-type mice.
Area of Science:
- Hepatology
- Immunology
- Metabolomics
Background:
- Bile duct ligation (BDL) is a model for cholestatic liver injury.
- The precise role of Toll-like receptor 4 (TLR4) in this injury is not fully understood.
Purpose of the Study:
- To investigate the role of TLR4 in BDL-induced liver injury.
- To elucidate the underlying mechanisms involving metabolic pathways.
Main Methods:
- Comparison of wild-type (WT) and TLR4 knockout (TLR4-KO) mice subjected to BDL.
- Analysis of serum and liver metabolites using metabolomics.
- Assessment of liver damage via biochemical markers and histology (HE staining).
Main Results:
- TLR4-KO mice exhibited significantly reduced liver injury post-BDL compared to WT mice.
- Metabolomic analysis revealed that TLR4 KO preserved amino acid and choline metabolism.
- WT mice showed increased serum and liver levels of amino acid and choline metabolites (e.g., choline, 3-hydroxybutyrate) after BDL, unlike TLR4-KO mice.
Conclusions:
- TLR4 knockout attenuates BDL-induced cholestatic liver injury.
- This protective effect is mediated by the regulation of amino acid and choline metabolic pathways.
