Mice lacking matrilin-1 (cartilage matrix protein) have alterations in type II collagen fibrillogenesis and fibril organization

Involvement of extracellular matrix protein matrilin-2 in oval cell-mediated rat liver regeneration

AIM: To investigate possible involvement of extracellular matrix (ECM) protein matrilin-2 in oval cell-mediated liver regeneration in rats.

METHODS: A rat model of hepatic oval cell proliferation was established using the modified Soft-Farber protocol. The control group was fed normal saline. On days 2, 4, 6, 9, 12 and 15 after partial hepatectomy (PH), rat liver tissue samples were collected. The dynamic relationship between matrilin-2 protein expression and oval cell distribution during the proliferation and differentiation of oval cells was analyzed using immunohistochemistry and Western blot.

RESULTS: On day 2 after PH, oval cells began to proliferate around the portal area, and matrilin-2 deposition was observed in the hepatic sinusoids in the periportal area. On day 9, proliferating oval cells were present in the hepatic acini, and matrilin-2 upregulation was noted. On day 12, as oval cells differentiated to form hepatocellular nodules, matrilin-2 was distributed mainly in the periphery of the nodules, and little protein was present in the nodules. The expression level of matrilin-2 protein began to be upregulated on day 2 after PH, and reached the peak on day 9. After day 12, the protein level returned to physiological level.

CONCLUSION: The close relationship between matrilin-2 expression and oval cell distribution suggests a role for the protein in stem cell-fed liver regeneration.