Paracrine Effects of Adipose-Derived Cellular Therapies in an in Vitro Fibrogenesis Model of Human Vocal Fold Scarring.

ABSTRACT

OBJECTIVES/HYPOTHESIS: Vocal folds (VF) scarring leads to severe dysphonia which negatively impacts daily life of patients. Current therapeutic options are limited due in large part to the high complexity of the micro-structure of the VF. Innovative therapies derived from adipose tissue such as stromal vascular fraction (SVF) or adipose derived stromal/ stem cells (ASC) are currently being evaluated in this indication and paracrine anti-fibrotic effects are considered as predominant mechanisms. METHODS: The paracrine anti-fibrotic effects of SVF and ASC from healthy donors were tested in an innovative in vitro fibrogenesis model employing human VF fiboblasts (hVFF) and the principles of macromolecular crowding (MMC). Biosynthesis of collogen and alpha-smooth-muscle actin (αSMA) expression in hVFF were quantified after five days of indirect coculture with ASC or SVF using silver stain, western blot and RT-qPCR analysis. RESULTS: Fibrogenesis was promoted by addition of transforming growth factor beta 1 (TGFß1) combined with MMC characterized by an enhanced deposition of fibrillar collagens and the acquisition of a myofibroblast phenotype (overexpression of αSMA). Adipose-derived therapies led to a reduction in the αSMA expression and the collagen content was lower in hVFF co-cultivated with SVF. CONCLUSIONS: ASC and SVF promoted significant prevention of fibrosis in an in vitro fibrogenesis model through paracrine mechanisms, supporting further development of adipose-derived cellular therapies in VF scarring.