Effect of prolyl endopeptidase expression inhibition on a mouse model of non-alcoholic steatohepatitis and its mechanism
- VernacularTitle:抑制脯氨酰内肽酶表达对非酒精性脂肪性肝炎小鼠模型的影响及作用机制
- Author:
Jingping XIONG
1
;
Yuexin ZHANG
2
Author Information
- Publication Type:Journal Article
- Keywords: Non-alcoholic Fatty Liver Disease; Prolyl Oligopeptidases; Mice， Inbred C57BL
- From: Journal of Clinical Hepatology 2025;41(6):1097-1104
- CountryChina
- Language:Chinese
- Abstract: ObjectiveTo investigate the effect and possible mechanism of prolyl endopeptidase （PREP） on a mouse model of non-alcoholic steatohepatitis （NASH） induced by high-fat diet. MethodsA total of 18 healthy male C57BL/6J mice， aged 6 — 8 weeks， were randomly divided into normal control group， NASH group， and NASH+rosmarinic acid （RA） group， with 6 mice in each group. The mice in the control group were fed with normal diet for 16 weeks， and those in the NASH group and the NASH+RA group were fed with high-fat diet for 16 weeks； the mice in the NASH+RA group were given the PREP inhibitor RA by gavage since week 9 at a dose of 100 mg/kg， once a day for 8 weeks. The mice were sacrificed after modeling and intervention， and each group of mice was observed in terms of serum inflammatory indicators， the concentration of triglyceride in the liver， and the changes in liver lipids/inflammation/liver fibrosis； NAFLD activity score （NAS） was calculated. Western blot and quantitative real-time PCR were used to measure the protein and mRNA expression levels of PREP， peroxisome proliferator-activated receptor-γ （PPAR-γ）， fibroblast growth factor 21 （FGF21）， and silent information regulator 1 （SIRT1） in liver tissue. A one-way analysis of variance was used for comparison of normally distributed continuous data between multiple groups， while the least significant difference t-test and the Dunnett’s-T3 test were used for further comparison between two groups. The Kruskal-Wallis H test was used for comparison of non-normally distributed continuous data between multiple groups and further comparison between two groups. ResultsCompared with the NASH group， the NASH+RA group had significant reductions in the serum levels of interleukin-6， tumor necrosis factor-α， and triglyceride （all P<0.05）， as well as significant improvements in hepatic steatosis， hepatocyte edema， inflammatory cell infiltration， and liver tissue lesion. The NASH+RA group had a significant reduction in NAS compared with the NASH group （P<0.05）， and the NASH group had an increase in perivascular collagen fiber with occasional fiber bridging， while the NASH+RA group had a slight reduction in perivascular collagen fiber compared with the NASH group. Compared with the normal control group， the NASH group had a significant increase in collagen area percentage in the liver （P<0.05）， while the NASH+RA group had no significant reduction in collagen area percentage compared with the NASH group. Compared with the NASH group， the NASH+RA group had significant increases in the relative protein expression levels of PPAR-γ， FGF21， and SIRT1 （all P<0.05） and a significant reduction in the relative protein expression level of PREP （P<0.05）. Compared with the NASH group， the NASH+RA group had significant increases in the relative mRNA expression levels of PPAR-γ， FGF21， and SIRT1 （P<0.05） and a significant reduction in the relative mRNA expression level of PREP （P<0.05）. ConclusionPREP reduces the level of inflammation and improves NASH in mice by regulating the PPAR-γ/FGF21/SIRT1 signaling pathway.
