BioScience Trends. 2019;13(6):539-545. (DOI: 10.5582/bst.2019.01316)

The impact of apurinic-apyrimidinic endonuclease I on hepatocyte immuno-inflammatory factors and cell apoptosis.

Sawakami T, Sun ZP, Inagaki Y, Hasegawa K, Tang W, Xu GZ, Zhang NW

To explore the effect of apurinic-apyrimidinic endonuclease I (APE-1) on hepatocyte immune inflammatory factors and cell apoptosis. The gene expression profiles of peripheral blood of patients with or without immune tolerance after liver transplantation were obtained from the Gene Expression Omnibus (GEO). Differentially expressed genes were analyzed with a program in the R language, and the APE-1 gene was identified as a gene related to immune tolerance of liver transplantation. Four APE-1 shRNA vectors were constructed in parallel and verified as correct using plasmid sequencing, real-time PCR, and Western blotting. An APE-1 overexpression vector was similarly constructed and verified as correct. The STRING website predicted the protein-protein interaction network of APE-1. ELISA was used to detect the effects of APE-1 silencing and overexpression on inflammatory cytokines IL-1β, IL-10, TNFα, and INF-γ in the control group, APE-1-silenced group, and APE-1 overexpression group. Flow cytometry was used to detect apoptosis in each group. Forty differentially expressed genes related to immune tolerance after liver transplantation were screened, and the highly expressed gene APE-1 was selected. The best APE-1 shRNA_1 vector and APE-1 overexpression vector were obtained. APE-1 is predicted to interact with ANP32A, FEN1, HMGB2, LIG1, MUTYH, NTHL1, OGG1, PCNA, POLB, SET, and other proteins. APE-1 silencing resulted in a significant increase in the expression of the inflammatory factors IL-1β, IL-10, TNFα, and INF-γ in L-02 cells. In contrast, the expression of APE-1 led to a significant decrease in the expression of inflammatory factors. APE-1 silencing significantly increased the rate of apoptosis of L-02 cells, and APE-1 overexpression resulted in a significant decrease in the rate of apoptosis of L-02 cells. In conclusion APE-1 affects the expression of inflammatory factors and apoptosis in L-02 cells, so it may be a key gene in immune tolerance of liver transplantation.

Full Text: