Chondrogenic transdifferentiation of human dermal fibroblasts stimulated with cartilage-derived morphogenetic protein 1.

This study aimed to investigate the chondrogenic transdifferentiation potential of human dermal fibroblasts (DFs) by stimulation with cartilage-derived morphogenetic protein 1 (CDMP1). Using CDMP1 (100 ng/mL) we induced human DFs at passage 5 in both monolayer and micromass culture. Chondrogenic-specific markers were detected via immunochemistry, reverse transcription-polymerase chain reaction, and Western blot analysis in the collected specimens. The expression profile of adhesion molecules including integrin alpha5, beta1, and N-cadherin of DFs accompanying with chondrogenesis was further investigated. After 7 days of induction in monolayer culture, DFs acquired the polygonal chondrocyte-like shape with positive expression of chondrogenic-specific markers. Such a phenotypic transition of DFs was lost at 14 days. However, in micromass culture the chondrogenic transdifferentiation of DFs can be maintained even at 14 days. No chondrogenesis was detected in DFs without CDMP1 treatment under both culture conditions. By neutralization assay with blocking antibodies, it was further revealed that integrin alpha5 expression was in direct proportion to the degree of chondrogenic differentiation. Based on our findings, it can be ascertained that DFs are capable of transdifferentiating into a chondrogenic lineage by stimulation with CDMP1 in vitro. The integrin alpha5 mediating cell-cell and cell-matrix interactions is required for maintaining the chondrogenic phenotype of DFs.