Molecular Regulation of Wound Contraction and Scar Formation Using a Three-Dimensional Connective Tissue Model

Kern, Jami RaDel, Molecular Regulation of Wound Contraction and Scar Formation Using a Three-Dimensional Connective Tissue Model. Doctor of Philosophy (Biomedical Sciences, Biochemistry and Molecular Biology), December 2002, 156 pp., 1 table, 27 illustrations, references, 112 titles. The focus of these studies was to characterize a novel connective tissue model for use in experiments examining possible contraction initiators in the wound healing process, i.e. endothelin-1 (ET-1). Through these studies, it has been shown that use of a telomerized dermal fibroblast cell line addresses the concerns relating to variations due to heterogeneity of normal human cells cultured in vitro, without creating a cancerous cell line or interfering with normal phenotypic changes. In addition, the incorporation of telomerized cells into our TE, which does not spontaneously contract (US Patent #6471958), provides a unique model to study the contraction and scar formation process. Using the TE populated with hTERT fibroblasts, an innovative technique was developed to identify the initiation of tissue contraction using an optical fiber interferometry system. The process allows observation of contraction within five minutes of stimulus addition and also enables continuous data capture over a period of several hours. The greatest strength of this system is its sensitivity, since optic interferometer allows measurement of displacement (contraction) to the tens of nanometers. Along those lines, the current studies have identified ET-1 as a potential early initiator in wound healing and suggest a novel pathway through which it functions. This proposed mechanism includes both direct effects of ET-1 through the Rho-associated kinase pathway and indirect effects potentiated by TGF-β. Future studies addressing whether TGF-β converges on the Rho-associated kinase pathway or acts independently through other signaling mechanisms should be initiated. The discovery of early initiators of tissue contraction is essential in the identification of potential therapeutic targets in the quest to reduce prolonged and severe tissue contracture and scaring.