Expression and mechanism of gp73 in liver tissue of mouse liver fibrosis

Abstract

Objective To investigate the changes and mechanism of golgi protein 73 (gp73) in mouse with liver fibrosis. Methods The model of hepatic fibrosis was developed by intraperitoneal injection of CCl4 in C57BL6/J mice. Serum level of gp73 was determined by ELISA. The expression of gp73 in liver tissues was detected by immuno-histochemical staining. Hepatic stellate cell (HSC) was isolated by density gradient centrifugation and gp73 expression was detected. The expression of insulin like growth factor 2 mRNA binding protein 3 (IGF2BP3) in liver tissues was detected by immuno-histochemical staining. Next, IGF2BP3 over-expression and knock down plasmids were transfected, and the changes of GOLM1, which encodes gp73, were detected by RT-PCR. Furthermore, the expression of gp73 in hepatic stellate cells of fibrotic IGF2BP3 knockout mice was detected by flow cytometry. Results A higere expression of gp73 protein increased in serum(P＜0.01), liver (P＜0.05) and primary hepatic stellatecells (P＜0.001) in the fibrotic mice model was found as compared to the control animals. Along with that, the protein level of IGF2BP3 in the liver was also increased (P＜0.05). After over-expressing or knocking down IGF2BP3 by transient transfection, the mRNA expression of GOLM1 was also up-regulated (P＜0.001) and down-regulated (P＜0.01). Respectively, compared with the wide type group, the expression of gp73 was decreased in the hepatic stellate cells of fibrotic IGF2BP3 conditional knockout mice (P＜0.01). Conclusions In the CCl4 induced liver fibrosis mice, the protein level of gp73 protein in hepatic stellate cells is increased, and RNA binding protein IGF2BP3 is a potential regulatory factor to promote its expression.

Keywords

• hepatic fibrosis|gp73|igf2bp3