[The coordinated expression of laminin and its integrin receptor in hepatic sinusoidal capillarization].

OBJECTIVE

To explore the expression of laminin and its integrin receptor alpha 6 in sinusoidal capillaration.

METHODS

The rat hepatic fibrosis model was established by injection carbon tetrachloride subcutaneously. Liver sections were examined by scanning electron microscopy and special staining. Then expressions of laminin and integrin alpha 6 subunit were observed by immunohistochemistry and dot immuno-blotting.

RESULTS

The pathologic character of hepatic fibrosis-sinusoidal capillaration was observed. Sinusoidal capillaration is characterized by defenestration of sinusoidal endothelial cells (SEC) and basement membrane forming and phenotype transformation. By immunohistochemistry staining. The deposition of laminin surrounding sinusoids according to fibrosis stage was 0, 1.92%, 6.02%, 9.68%, 14.14% respectively, statistically different from each other (P < 0.05). In normal rat no expression of integrin alpha 6 were observed in SEC membranes. When capillaration integrin alpha 6 was detected in a continuous pattern along the sinusoidal in accordance with laminin assembly. The content of integrin alpha 6 in fibrotic liver tissues were significantly higher than in normal liver tissues as measured by dot immuno-blotting (P < 0.05).

CONCLUSIONS

During fibrogenesis laminin continuously accumulate in liver tissues and form basement membrane resulting in sinusoidal capillaration, meanwhile are company with induced expression of LN-binding-integrin alpha 6 on SEC membranes. These results suggest that coordinated expression of laminin and laminin-binding-integrin might be important in pathogenesis of sinusoidal capillaration and hepatic fibrosis.