Regulation Of TLR7 On Smad Signal Pathway In Keloid

Objective To study the relevance between Smads and TLR7; investigate regulation of TLR7 on Smad signal pathway in keloid and effect of TLR7 on keloid formation.Methods After activation of TLR7 agonist Gardiquimod, the expression of Smad4 and Smad7 in cultured human fibroblasts in vitro were tested by Western Blot.Then animal models of keloid was constructed by implanting pieces of keloids with epidermis into subcutaneous pockets of nude mice. And in these models, expression of Smad4 and Smad7 were tested after subcutaneous injection of TLR7 agonist Gardiquimod by Western Blot separately. The relative gray value of gel blot images in each group was analysed with methods of single factor analysis of variance, LSD-t test and SNK-q test by setting P<0.05 as statistical significance. Histological changes of harvested tissues were observed after hematoxylin-eosin (HE) staining and Masson staining.Results Compared with control group, Smad4 and 7 protein expression showed no signs of significant change in vitro. Compared with control group, Smad4 expression showed no signs of significant change with an increased expression of Smad7,and the atrophy process of keloid was declined in the animal models.Conclusions In vitro, TLR7 has no direct effect on Smad4 and 7 protein expression in fibroblasts. In nude mouse model of human keloid, TLR7 upregulates the expression of Smad 7 with no influence on Smad4 and inhibits the atrophy process of implanted keloids.