High-Intensity Interval Training and Semaglutide Ameliorate Metabolic Dysfunction-Associated Steatotic Liver Disease via the IL-17/CXCL1 Pathway

This study was to explore the molecular mechanisms underlying the effects of 8-week highintensity interval training and semaglutide on hepatic inflammation in db/db mice with type 2 diabetes mellitus complicated with metabolic dysfunction-associated steatotic liver disease. A total of 10 healthy 8-week-old db/db mice were assigned to the control group, and another 30 age-matched db/db mice were randomly divided into DE group, DM group and EM group, with 10 mice in each group. Mice in DE and EM groups received 8-week HIIT intervention; mice in DM and EM groups were subjected to subcutaneous neck injection of semaglutide at a dose of 0.05 mg/kg for 8 consecutive weeks. Body mass and fasting blood glucose of mice were regularly monitored every week throughout the experiment. After intervention, three liver tissue samples were selected from each group for transcriptome sequencing to screen differentially expressed genes, followed by Gene Set Enrichment Analysis and protein-protein interaction network analysis. Oil red O and hematoxylin-eosin staining were used to observe hepatic pathological changes, and Masson staining was applied to evaluate liver fibrosis. Liver function indexes were detected using commercial assay kits. The mRNA expression levels of inflammation-related genes were determined by quantitative real-time polymerase chain reaction. Western blot was performed to detect the protein levels of inflammatory factors, IL-17 signaling pathway molecules and fibrosis-related proteins in liver tissues. The results show that compared with the DC group, the body mass, fasting blood glucose, food intake, liver mass, as well as serum levels of TG, TC, AST, ALT, HDL-C and LDL-C were significantly decreased in DE, DM and EM groups. HE, oil red O and Masson staining results revealed severe hepatocellular ballooning degeneration, massive lipid deposition, inflammatory cell infiltration and partial collagen deposition in the portal area of DC group. In contrast, hepatocellular ballooning degeneration, inflammatory infiltration and collagen deposition were markedly ameliorated in DE, DM and EM groups. Transcriptomic analysis indicated that the IL-17 signaling pathway and the differential gene Cxcl1 were significantly downregulated in DE, DM and EM groups. qRT-PCR results further verified that the mRNA expression of Cxcl1 was notably reduced in the three intervention groups relative to the DC group. Western blot results showed that the protein expressions of TNF-α, IL-6, Pro-IL-1β, Cleaved-IL-1β, IL-17A, the ratio of p-NF-κB/NF-κB and chemokine CXCL1 were dramatically lowered in the DE group vs the DC group. The DM and EM groups also downregulate the p-NF-κB/NF-κB ratio as well as the expressions of multiple inflammatory factors (TNF-α、 IL-6、IL-1β、IL-17A) and CXCL1 to varying degrees. Compared with the DE group, the p-NF-κB/NF-κB ratio and the expressions of IL-6, IL-1β, IL-17A and CXCL1 were obviously elevated in the DM group. Only the p-NF-κB/NF-κB ratio and CXCL1 expression were increased in the EM group, with no significant differences in other inflammatory indicators. Further detection of TGF-β/Smad signaling pathway-related proteins demonstrated that the protein levels of TGF-β1, α-SMA and p-Smad2/3 were prominently downregulated in DE, DM and EM groups compared with the DC group, while the total protein expression of Smad2/3 showed no significant difference among all groups. Compared with the DE group, TGF-β1 expression was upregulated in the DM group, and α-SMA expression was increased in both DM and EM groups. In conclusion, 8-week HIIT and semaglutide interventions can effectively retard the pathological progression of MASLD in db/db mice by ameliorating liver dysfunction, suppressing hepatic inflammation, and attenuating hepatic fibrosis. The underlying mechanism may be attributed to the inhibition of the excessive activation of the IL-17/NF-κB/CXCL1 signaling axis.

CSTR: 32200.14.cjcb.2026.09.0005