Effects of alginate gel-encapsulated adenoviruses expressing relaxin on scar remodeling in a pig model

Abstract

To evaluate the effects of relaxin on scar remodeling, we investigated the scar remodeling process after injecting alginate gel-encapsulated adenoviruses expressing relaxin using a pig scar model.In this study, we divided the scars into three groups and the injection was done according to the groups, respectively. Group I: alginate gel alone, group II: alginate gel + adenoviruses not containing the relaxin gene (dE1-RGD/LacZ), group III: alginate gel + adenoviruses expressing the relaxin gene (dE1-RGD/LacZ/RLX). The surface areas, color and pliability of scars were compared, and various factors influencing scar formation, collagen arrangement, and mast cell counts were quantitatively analyzed using RT-PCR and immunohistochemical staining.The surface areas of scars decreased, color was improved, pliability increased, mast cell number decreased, and a more mature collagen arrangement was observed in the group III. The expression levels of transforming growth factor (TGF)-β1, tissue inhibitor of metalloproteinase (TIMP)1, and α-smooth muscle actin (SMA) were reduced in the tissues of the group III, whereas the expression levels of TGF-β3 and matrix metalloproteinase (MMP)1 increased. Additionally, the expression of major extracellular matrix (ECM) components was decreased.Alginate gel-encapsulated adenoviruses expressing relaxin improved the surface area, color, and pliability of scars. Myofibroblasts were likely inhibited by relaxin, which either reduces the expression of TGF-β1 and TIMP1, or increases the expression of TGF-β3 and MMP1; scar remodeling was also enhanced as mast cell number decreased.