Role of mature liver cells and oval cells in liver regeneration after liver injury / 中国组织工程研究

ABSTRACT

BACKGROUND: Retrorsine (RS) is a chemical agent for the long-term inhibition of mature liver cell division and proliferation. OBJECTIVE: To establish a rat model of liver injury by combined use of RS and 1/3 partial hepatectomy, to observe the proliferation of liver cells and oval cells in rats after liver injury, and to discuss the relationship between liver regeneration and mature liver cells and oval cells after liver injury. METHODS: Thirty male Sprague-Dawely rats were randomized into two groups (n=15 per group) RS group and control group. Rats in the RS group were subjected to intraperitoneal injection of RS, 30 mg/kg, twice in total, with 2 weeks in between; and rats in the control group were injected physiological saline instead of RS. Four weeks after the last injection, the 1/3 partial hepatectomy was performed in two groups of rats. Liver pathological and morphological changes as well as cell proliferation were observed, and CK19 and C-kit immunohistochemical detections of the rat liver in the two groups were conducted at different time points after operation. RESULTS AND CONCLUSION: At 20 days after operation, the body mass of the RS group rats was still lower than the baseline, and the liver increase was obviously less than that in the control group; there was cell body swelling shown by hematoxylin-eosin staining, loose cytoplasm, extensive vacuoles degeneration of liver cells, and clustered or scattered oval cells around the portal area of small bile duct and in the hepatic lobule. However, in the control group, the body mass was close to the baseline, liver damage was lighter than that in the RS group, a large number of mature liver cells proliferated under BrdU Immunofluorescence at 20 days after operation; liver oval cells proliferated and distributed in the liver cell line at 14 days after operation, with morphology and immunohistochemical markers consistent with oval cells in the RS group. These findings indicate that the rat model of acute liver injury is successfully established by combining retrorsine with 1/3 partial hepatectomy, liver poisoning and the proliferation of liver stem cells and mature liver cells after poisoning can be seen in the experiment, which firmly confirm that liver cell renewal and regeneration after injury is accredited to the combined action of liver stem cells in liver basin and mature liver cells.