Research Paper Volume 15, Issue 23 pp 14323—14332
Specific knockout of notch-1 attenuates non-alcoholic fatty liver disease by promoting SHP2 phosphorylation
- 1 Department of Endocrine and Metabolic Diseases, The Fourth Hospital of Hebei Medical University, Shijiazhuang 050000, China
- 2 Clinical Laboratory, Hebei General Hospital, Shijiazhuang 050000, China
Received: July 5, 2023 Accepted: November 3, 2023 Published: December 13, 2023
https://doi.org/10.18632/aging.205305How to Cite
Copyright: © 2023 Gao et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
Objective: To investigate the effect of Notch-1 signaling on NAFLD and its molecular mechanism.
Methods: The lipid deposition in liver tissues was detected by oil red O staining. Western blotting was performed to detect the expressions of SREBP1C, SREBP2, LXR, IL-1β, IL-18, NLRP3, Notch-1, NOX2, NOX4, p-PI3K and p-SHP2 in macrophages, and the expressions of ALIX, CD9, IL-1β and SREBP1C in exosomes. Macrophages in the Notch-1MAC-KO group and Notch-1WT group were treated with FFA, and those in the Notch-1WT+FFA group and Notch-1MAC-KO+FFA group were treated with SHP2 inhibitors PHPS1 and Relaxin.
Results: It was observed by oil red O staining that lipid deposition in mice with NAFLD was reduced in the Notch-1MAC-KO group. The results of Western blotting showed that the expressions of ALIX, CD9, IL-1β and SREBP1C in macrophage exosomes were significantly lower in the Notch-1MAC-KO group than in the Notch-1WT group. In macrophages, the expressions of SREBP1C, SREBP2, LXR, IL-1β, IL-18, Notch-1, NOX2, NOX4 and p-PI3K significantly decreased, while the expression of p-SHP2 significantly increased in the Notch-1MAC-KO group compared with the Notch-1WT group. The Notch-1MAC-KO+FFA group had significantly decreased expressions of SREBP1C, NLRP3, IL-1β, IL-18, SREBP2, NOX2, NOX4 and p-PI3K and a significantly increased expression of p-SHP2 compared with the Notch-1WT+FFA group. However, the differences in the above proteins were all eliminated after PHPS1 and Relaxin were added.
Conclusion: Specific knockout of Notch-1 attenuates NAFLD, and reduces inflammation and lipid deposition in the liver by promoting SHP2 phosphorylation.
Abbreviations
NAFLD: Non-alcoholic fatty liver disease; SREBP1C: Sterol regulatory element-binding protein-1C; LXR: Liver X receptor; IL-1β: Interleukin-1β; NLRP3: Nod-like receptor protein 3; NOX2: NADPH oxidase 2; p-PI3K: p-phosphatidylinositol 3-hydroxy kinase; p-SHP2: p-SH2 domain-containing tyrosine phosphatase-2; ALIX: ALG-2-interacting protein X; CD9: Cluster of differentiation 9; FFA: Free fatty acid; PHPS1: Phenylhydrazono pyrazolone sulfonate 1; HFD: High-fat diet; Notch-1: Notch homolog 1; ROS: Reactive oxygen species; PTP: Protein tyrosine phosphatase; D-PBS: Dulbecco’s Phosphate-Buffered Saline; BSA: Bovine serum albumin; BMDMs: Bone marrow-derived macrophages; DMEM: Dulbecco’s modified Eagle medium; SDS-PAGE: Sodium dodecyl sulfate-polyacrylamide gel electrophoresis; PVDF: Polyvinylidene fluoride; NICD: Notch-1 intracellular domain; NASH: Non-alcoholic steatohepatitis; HCC: Hepatocellular carcinoma.