Tissue stretch decreases soluble TGF-β1 and type-1 procollagen in mouse subcutaneous connective tissue: Evidence from ex vivo and in vivo models

• Published in: Journal of cellular physiology 2008-02, Vol.214 (2), p.389-395
• Main Authors: Bouffard, Nicole A., Cutroneo, Kenneth R., Badger, Gary J., White, Sheryl L., Buttolph, Thomas R., Ehrlich, H. Paul, Stevens-Tuttle, Debbie, Langevin, Helene M.
• Format: Article
• Language: English
• ISSN: 0021-9541; 1097-4652
• DOI: 10.1002/jcp.21209

Transforming growth factor beta 1 (TGF‐β1) plays a key role in connective tissue remodeling, scarring, and fibrosis. The effects of mechanical forces on TGF‐β1 and collagen deposition are not well understood. We tested the hypothesis that brief (10 min) static tissue stretch attenuates TGF‐β1‐mediated new collagen deposition in response to injury. We used two different models: (1) an ex vivo model in which excised mouse subcutaneous tissue (N = 44 animals) was kept in organ culture for 4 days and either stretched (20% strain for 10 min 1 day after excision) or not stretched; culture media was assayed by ELISA for TGF‐β1; (2) an in vivo model in which mice (N = 22 animals) underwent unilateral subcutaneous microsurgical injury on the back, then were randomized to stretch (20–30% strain for 10 min twice a day for 7 days) or no stretch; subcutaneous tissues of the back were immunohistochemically stained for Type‐1 procollagen. In the ex vivo model, TGF‐β1 protein was lower in stretched versus non‐stretched tissue (repeated measures ANOVA, P