Expression of Fas system and apoptosis in rat allografted liver / 中国普通外科杂志

ABSTRACT

Objective To investigate the effects of apoptosis, Fas/FasL and Bax/Bcl-2 in rat liver allograft immune response. MethodsDifferent rat allograft models were established(1)Acute liver allograft rejection group PVG liver to Lewis rats; (2) Liver allograft tolerance group PVG liver→DA rats; (3) F1(P/D)→D group F1(PVG-DA) liver to DA rats; (4)HLTx(P/2→D)group PVG/2 liver→DA rats. Liver samples were collected on days 1, 3, 5, 7 postoperatively (each n=3). Apoptosis was monitored by TUNEL(terminal deoxynucleotidyl transferase(TdT) mediated dUTP nick-end-labeling). The expressions of Fas/FasL and Bcl-2/Bax mRNA were examined by means of immunohistochemistry and in situ-hybridization respectively. Results Compared with liver allograft tolerance group, in acute liver allograft rejection group, the apoptosis cell numbers increased in hepatocytes, FasL expression was high in infiltrated cells in portal tract areas and low in hepatocytes, and the expression of Fas and Bax mRNA increased. The expression of molecules detected in F1(P/D)→D group was similar with those in acute liver allograft rejection. The expression of molecules detected in HLTx(P/2→D)group was similar with those in liver allograft tolerance group. On the fifth day postoperatively, the apoptosis index in portal tract areas had a positive correlation with the expression of FasL in hepatocyte and a negative correlation with the expression of Fas and Bax. Conclusions The high expression of FasL in infiltrated cells of portal tract areas, Fas and Bax in hepatocytes may be involved in rejection response. The high expression of apoptosis in infiltrated cells of portal areas, FasL in hepatocytes may relate with the establishment of tolerance.