The influence of Tribenoside on expression and deposition of epidermal laminins in HaCaT cells.

Tribenoside has been used clinically for hemorrhoidal disease associated with coagulation, inflammation, and wounds. However, the pharmacological mechanism of tribenoside activity has never been clear. In this study we examined whether tribenoside affected expression and deposition of laminins that are required for reconstruction of basement membranes (BMs) during wound healing in hemorrhoidal disease. HaCaT cells, which are derived from human epidermis, were treated in growth media supplemented with tribenoside. Reverse transcriptase-polymerase chain reaction (RT-PCR) using primers specific for laminin chains showed that HaCaT cells constitutively expressed laminin alpha3, alpha5, beta1, beta3, gamma1, and gamma2 chains. Tribenoside treatment of HaCaT cells did not induce expression of other laminin chains. We also quantified the expression of laminin chains in tribenoside-treated cells using real-time PCR. The expression level of laminin alpha3, beta1, beta3, gamma1, and gamma2 chains was not affected. In contrast, the expression of laminin alpha5 in the tribenoside-treated cells was four times higher than that of control cells. Immunocytochemistry also showed that tribenoside accelerated the focal deposition of laminin-332 (alpha3, beta3, gamma2). These results suggest that tribenoside interacts with epidermal cells and regulates the expression and localization of laminins to help reconstruct BMs in wound healing of hemorrhoids.