The Study Of The Biological Characteristics Of Mandibular Condylar Chondrocyte And Nasal Septal Chondrocyte

[Objective] Establish primary culture model of SD rats mandibular condylar chondrocyte(MCC) and nasal septal chondrocyte(NSC). In order to explore chondrogenesis and provide a theoretical basis in maxillofacial growth mechanism in the development proceess differences in biological characteristics of MCC and NSC.[Methods] The primary MCC and NSC of1-3days neonatal SD rats were cultured in the same culture conditions after mechanical separation-enzymatic digestion combined method. On day3,5,8,15we observed the cells morphology and growth conditions by inverted microscope. Chondrocytes phenotype identification were examined by Type II collagen immunohistochemical staining and toluidine blue staining to observe the difference of the two cartilage extracellular matrix synthetsis. We observed chondrocytes growth curves by methyl thiazolyl tetraxolium(MTT) assay.Wound scratch assay experimental observation of MCC and NSC migration after24hours. Observed the expression differences of type II collagen (type Ⅱ collagen) and aggrecan mRNA by real-time quantitative polymerase chain reaction (RT-PCR) on day3,5,8,15.[Results] The primary MCC and NSC were successfully cultured in the same digestion and culture conditions. Morphological and biological characteristics in accordance with the characteristics of chondrocyteswere observed. Collagen Ⅱ immunohistochemical staining and toluidine blue staining were positive, which can prove the cultured cells were chondrocytes. Positive staining of these two cells were gradually increased with the culture days increased. On the same time point, NSC positive expression were higher than MCC. The two chondrocytes’growth curve were basically alike by MTT assay which indicate that the proliferation ability of NSC were stronger than MCC. After two chondrocytes were scratched after24h, more rs of NSCs migrated to the scratched area than MCCs, which indicated that migration ability of NSC were stronger than MCC. On day3,5,8,15collagen Ⅱ and aggrecan mRNA expression of two chondrocytes were detected. We found that collagen Ⅱ and aggrecan mRNA expression level of two chondrocytes of were increased on day3,5,8. On day15,collagen Ⅱ and aggrecan mRNA expression decreased; at the same time points,NSC synthesized more Ⅱ collagen and aggrecan than MCC.[Conclusions]1.In this study, primary MCC and NSC were successfully cultured in the same cell digestion and culture condition.2. NSC’migration and proliferation ability were stronger than MCC.3. MCC and NSC expression pattern of collagen Ⅱ and aggrecan mRNA were similar to the embryos’ chondrogenesis in vivo. NSC synthesis and secretion of collagen II and aggrecan were stronger than MCC, the difference of extracellular matrix was one of the causes which led to the difference of the partial response and biomechanical features. MCC and NSC were different in proliferation, migration, and the expression of extracellular matrix, which is closely related in the different of MCC and NSC formation mechanism and growth characteristics.