Expression of angiotensin-converting enzyme 2 is increased during preservation injury of liver transplantation in rats / 第二军医大学学报

ABSTRACT

Objective: To observe the expression of local angiotensin-converting enzyme 2 (ACE-2) in rat liver and its relationship with preservation injury (PI) after transplantation, so as to determine the possible role of local renin-angiotensin system (RAS) in PI caused by the cold-preservation in liver transplantation. Methods: The donor liver grafts were divided into cold preservation (CP) and non-cold preservation (NCP) groups; we also included a sham operation group without transplantation. The mRNA and protein levels of ACE-2 in the transplanted livers were detected by quantitative real-time PCR and Western blotting assay, respectively. The location of ACE-2 protein and pimonidazole in liver was detected by immunohistochemistry. Furthermore, histological evaluation was applied to verify the extent of liver damage. Results: Histological injuries of different degrees existed after liver transplantation; the injury was more obvious in the CP group. Compared with the sham operation group, the mRNA and protein expression of ACE-2 was significantly increased after liver transplantation (P<0.05 or P<0.01), and the expression of the CP group was significantly higher than that of the NCP group (P<0.05). Pimonidazole staining was positive around the hepatic veins in the transplantation groups, and the intensity of staining was positively correlated with the expression of ACE-2 mRNA (r=0. 78, P<0.001). Conclusion: It is indicated that ACE-2 expression is closely associated with tissue hypoxia during cold preservation-induced PI, and local RAS may play an important role in PI during liver transplantation.