[Chondrogenesis of adipose derived stem cells induced by misshapen auricular chondrocytes from microtia in vitro].

OBJECTIVE: To investigate the effects of the misshapen auricular chondrocytes from microtia in inducing.

METHODS: Human ADSCs at passage 3 and misshapen chondrogenesis of human adipose derived stem cells (ADSCs) in vitro. auricular chondrocytes at passage 2 were harvested and mixed at a ratio of 7:3 as experimental group (group A, 1.0 x 10(6) mixed cells). Misshapen auricular chondrocytes or ADSCs at the same cell number served as control groups (groups B and C, respectively). All samples were incubated in the centrifuge tubes. At 28 days after incubation, the morphological examination was done and the wet weight was measured; the content of glycosaminoglycan (GAG) was detected by Alcian blue colorimetry; the expressions of collagen type II and Aggrecan were determined with RT-PCR; and HE staining, toluidine blue staining, Safranin O staining of GAG, and collagen type II immunohistochemical staining were used for histological and immunohistochemical observations.

RESULTS: At 28 days after incubation, all specimens formed disc tissue that was translucent and white with smooth surface and good elasticity in groups A and B; the specimens shrank into yellow spherical tissue without elasticity in group C. The wet weight and GAG content of specimens in groups A and B were significantly higher than those in group C (P < 0.05), but no significant difference was found between groups A and B in the wet weight (t = 1.8203, P = 0.0687) and in GAG content (t = 1.8614, P = 0.0627). In groups A and B, obvious expressions of collagen type II and Aggrecan mRNA could be detected by RT-PCR, but no obvious expressions were observed in group C; the expressions in groups A and B were significantly higher than those in group C (P < 0.05), but no significant difference was found between groups A and B in collagen type II mRNA expression (t = 1.4576, P = 0.1449) and Aggrecan mRNA expression (t = 1.5195, P = 0.1286). Mature cartilage lacunas and different degrees of dyeing for the extracellular matrix could be observed in groups A and B; no mature cartilage lacunas or collagen type II could be observed in group C. The expression of collagen type II around cartilage lacuna was observed in groups A and B, but no expression in group C; the gray values of groups A and B were significantly lower than that of group C (P < 0.01), but no significant difference was found between groups A and B (t = 1.6615, P = 0.0970).

CONCLUSION: Misshapen auricular chondrocytes from microtia can induce chondrogenic differentiation of human ADSCs in vitro.