1. Academic Validation
  2. The Annexin A2-Notch regulatory loop in hepatocytes promotes liver fibrosis in NAFLD by increasing osteopontin expression

The Annexin A2-Notch regulatory loop in hepatocytes promotes liver fibrosis in NAFLD by increasing osteopontin expression

  • Biochim Biophys Acta Mol Basis Dis. 2022 Aug 1;1868(8):166413. doi: 10.1016/j.bbadis.2022.166413.
Guangyan Wang 1 Jinjie Duan 1 Guangyin Pu 1 Chenji Ye 2 Yue Li 3 Wenjing Xiu 1 Jingwen Xu 1 Ben Liu 1 Yi Zhu 1 Chunjiong Wang 4
Affiliations

Affiliations

  • 1 Department of Physiology and Pathophysiology, The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, NHC Key Laboratory of Hormones and Development, Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Key Laboratory of Medical Epigenetics, Tianjin Medical University, Tianjin, China.
  • 2 Henan Key Laboratory of Medical Tissue Regeneration, Xinxiang Medical University, Xinxiang, China.
  • 3 Department of Pathology, Beijing Ditan Hospital, Capital Medical University, Beijing, China.
  • 4 Department of Physiology and Pathophysiology, The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, NHC Key Laboratory of Hormones and Development, Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Key Laboratory of Medical Epigenetics, Tianjin Medical University, Tianjin, China; School of Nursing, Tianjin Medical University, Tianjin, China. Electronic address: wangchunjiong@tmu.edu.cn.
Abstract

Background: The mechanisms underlying the progression of liver disease from simple hepatic steatosis to advanced nonalcoholic steatohepatitis (NASH) and liver fibrosis warrant further investigation. Increased mRNA levels of Annexin A2 protein (Anxa2) have been observed in patients with NASH. However, the role of Anxa2 in NASH remains unclear.

Methods: The protein levels of Anxa2 were analyzed in the livers of mice and patients with NASH. Anxa2-knockout and -knockdown mice were generated, and NASH was induced through a high fructose, palmitate, and Cholesterol (FPC) diet or methionine- and choline-deficient (MCD) diet.

Findings: We found elevated expression of Anxa2 in the livers of patients and mice with NASH. Anxa2 knockdown but not knockout ameliorated liver fibrosis in both FPC and MCD diet-fed mice. Liver-specific Anxa2 overexpression increased collagen deposition in mice fed a normal diet. Mechanistically, Anxa2 overexpression in hepatocytes promoted hepatic stellate cell activation in a paracrine manner by increasing osteopontin expression. Notch inhibition suppressed the exogenous overexpression of Anxa2-induced osteopontin and endogenous Anxa2 expression. Additionally, Anxa2 overexpression accelerated the progression of nonalcoholic fatty liver disease (NAFLD) in mice fed a high-fat diet. Moreover, Anxa2 levels were higher in NAFLD patients with advanced liver fibrosis than in those with mild liver fibrosis, as determined using the Gene Expression Omnibus database.

Interpretation: In conclusion, we found increased Anxa2 expression in hepatocytes promoted liver fibrosis in NASH mice by increasing osteopontin expression. The Anxa2-Notch positive regulatory loop contributes to this process and represents a novel target for the treatment of NASH-related liver fibrosis.

Keywords

Anxa2; Fibrosis; NASH; Notch; Osteopontin.

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