Fig. 5.

Tazarotene prevents spontaneous differentiation arising with extended culture time. TSCs were isolated from adult rat Achilles tendons and plated at low density for colony formation before being trypsinized and grown with or without tazarotene (TZ). Messenger RNA was collected at early (P1) and late passages (P4) for gene expression analysis a. In control conditions, several genes typical of TSC differentiation towards multiple lineages were found upregulated in late passage cells (P1 vs P4), confirming spontaneous differentiation during in vitro cell expansion b, d. Addition of tazarotene to the culture media was able to preserve TSC’s stemness as seen by cells from passage 4 having similar expression levels to those of passage 1 c. Values are given as the mean ± SD, n = 3