Vocal fold myofibroblast profile of scarring

Objectives/HypothesisVocal fold fibroblasts (VFF) are responsible for extracellular matrix synthesis supporting lamina propria in normal and diseased conditions. When tissue is injured, VFF become activated and differentiate into myofibroblasts to facilitate wound healing response. We investigated if vocal fold myofibroblasts can be utilized as surrogate cells for scarred VFF. Study DesignIn vitro. MethodsNormal VFF cell lines from a 21-year-old male (N21), 59-year-old female (N59), and a scar VFF cell line from a 56-year-old female (S56) were used in this study. 10 ng/mL of transforming growth factor (TGF1) was applied for 5 days to normal VFF. Myofibroblast differentiation was determined with immunocytochemistry and western blot, measuring alpha smooth muscle actin (-SMA). Cell growth, proliferation, contractile properties, and gene expression profiles were evaluated. ResultsN21, N59, and S56 VFF presented elongated configuration. N21+ and N21- VFF demonstrated significantly greater proliferation compared to N59+, N59-, and S56 VFF at 6 days. -SMA was expressed in all cells. Fibronectin, alpha smooth actin, connective tissue growth factor, and metallopeptidase inhibitor were the highest genes expression in VFF treated with transforming growth factor 1 (TGF1). At 24 hours, S56 VFF showed lower contraction compared to N21+ and N59+ VFF, but at 60 hours S56 VFF had lower collagen contraction compared to all cell groups. Highest collagen contraction matrices were measured with VFF treated with TGF1 at 24 hours and N59- VFF at 60 hours. ConclusionVFF treated with TGF1 (myofibroblasts) appear to have similar phenotypic characteristics but different genotypic behavior compared to scar VFF.