Influence of muscle-derived soluble factors on embryonic tendon progenitor cells

Tendon repair after injury poses a significant problem due to variable success rates. Consequently, tissue engineering with stem cells has been explored to enable replacement of damaged tendon with regenerated, living tissue. Interestingly, there are no known growth factors available to induce and guide stem cell differentiation toward the tendon lineage in a tissue engineering system. This is due largely to limited understanding of the role of growth factors in tendon development. We propose to identify and characterize these candidate growth factors, and derive new growth factor-directed tendon tissue regeneration strategies. In this study, we investigated the effects of muscle-derived growth factors on embryonic tendon cells in an in vitro culture system. Our results demonstrated that apparent soluble muscle signaling factors downregulated proliferation, increased metabolic activity, and induced morphological changes in the ETCs. Identification of signaling molecules capable of enhancing and guiding stem cell differentiation into tendon fibroblasts and development into new tissue will lead to innovative new tendon tissue engineering strategies.