Abstract
Background Although VEGF can maintain the normal phenotype of liver sinusoidal endothelial cells (LSECs), it has also been reported that VEGF exacerbates cirrhosis. The role of VEGF in the progression and recovery of cirrhosis has still remained controversial.Methods We established a cirrhotic rat model by thioacetamide that was used as drinking water; besides, 0, 1, 2, and 4 μg VEGF165 were then continuously injected into the rats. The serum level of hyaluronic acid was measured by ELISA at 0, 1, and 4 weeks, separately. Serum levels of ALT, AST, direct bilirubin, indirect bilirubin, and ALB were detected by an automatic biochemical analyzer. In addition, the levels of VEGF165, CD44, MMP9, MMP2, HIF-1α, and endothelin were detected by Western blotting. The expression level of CD44 in LSECs was detected by immunohistochemistry. Changes of fenestrations of LSECs and basement membranes of blood vessels were observed by transmission electron microscopy. Results With the increase of dosage and duration of VEGF treatment, the levels of liver function markers in the serum, the levels of CD44, HIF-1α, hydroxyproline and endothelin were significantly improved. With determination of the serum level of hydroxyproline in the blood, it was disclosed that the mentioned level was markedly decreased. In the Sirius Red staining, the stained red area was gradually reduced. Images captured by transmission electron microscopy also confirmed that the ultrastructure of LSECs tended to be normal.Conclusion VEGF165 can accelerate the resolution of liver fibrosis by promoting fenestration structure formation in LSECs, as well as promoting material exchange between sinusoids and hepatocytes. Our findings may provide a new insight for the study of the role of VEGF in liver fibrosis.
Key role of liver sinusoidal endothelial cells in liver fibrosis
