Abstract: Objective To investigate the feasibility of the differentiation of scar fibroblasts into chondrogenic phenotype in vitro induced by Cartilage-derived morphogenetic protein 1(CDMP1) for the reconstruction of ear defect.Methods Scar fibroblasts were extracted from hypertrophic scar and cultured in momo-layer in vitro.Scar fibroblasts of the 4th passage were induced by CDMP1(100 ng/mL in medium of F12+2%FBS).Negative and positive control groups were also set up.After 7 days of induction,morphological change of cells was observed by Image Plus software.Expression of col Ⅰ,col Ⅱ,sox 9 and aggrecan were detected by immunofluorescence,RT-PCR and western blot.Micromass cultured scar fibroblasts were induced and cultured.The results were analyzed by HE staining,immunohistochemistry and Safranine-O staining.Results After induction,the morphology of the cells changed from spindle to polygon shape.By Image Plus software analysis,the length/width ratio changed from(7.21±1.54):1 of pre-induction to(1.48±0.21):1 of post-induction(P<0.05).No significant difference was found between post-induction fibroblasts and normal chondrocytes(P>0.05).Col Ⅱ,sox9,aggrecan were expressed in post-inductive cells by immunofluorescence,RT-PCR and western blot.HE staining,immunohistochemistry and Safranine-O staining revealed cartilage specific structure and deposition of cartilage extracellular matrix in micromass cultured scar fibroblasts.Conclusion Scar fibroblasts could be differentiated into chondrogenic phenotype by CDMP1 induction and induced scar fibroblasts can be used as the seed cells for the reconstruction of ear defect.

Key words: Scar fibroblasts, Chondrocytes, CDMP1, Differentiation