The Study Of The Biological Characteristics Of Mandibular Condylar Chondrocytes Under The Cells Co-cultured Condition With Tibial Growth Plate Chondrocytes

[Objective] Set up culture model of SD rats’ mandibular condylar chondrocytes (MCCs) and tibial growth plate(TGP) cartilage cell, to explore the impact of changes in the microenvironment of MCCs and their biological characteristics, to provide the basis for growth, development and tissue engineering of cartilage cell-derived.[Methods]Indirect co-culture via Transwell? Insert Culture Chamber and direct co-cultured via the same culture bottlesusing mixed3-week-old female SD rats MCCs and TGP chondrocytes in vitro. CFSE fluorescent dye, as the marker, wasbond with co-cultured MCCs in the system to effectively separate the two kinds of mixed cells. Set up the experimental groupsand control groups, observe the cell organization, proliferation and the amount of type I collagen (Col I), type II collagen (Col II) in matrix on each group with the second pass-generation cells line, using RT-PCR, histological, biochemical technique. Pure MCC, pure TGP chondrocytes and mixture of two were cultured in separate centrifuge tubes after centrifugation; observe the generation of cartilage tissue under optical microscope and transmission electron microscope.[Results]Indirect co-culture manner was no significant difference oncells apoptosis and proliferation compared with direct co-culture manner. RT-PCR, histological, biochemical techniqueresults showed that, with two independent culture groups as the control groups, the different mixed proportions of MCC and TGP cartilage cells increased the expression of type II collagen; type I collagen expression was reduced when added TGP cartilage cells increased.HE staining showed that the experimental group compared with the control group, the earlier onset of cell dedifferentiation and shuttle-like deformation.2weeks after the centrifuge tube culture in vitro, the co-cultured group showed the organizational structure of cartilage-like tissue, so does TGP cartilage cells independent culture group. And there tissue had the positive immunohistochemical staining with type II collagen expression. After4weeks, TGP group had no significant changes in the morphology of tissue, with a rare calcification; mixed cells group had disintegration of central necrosis, cell edema hypertrophy, apoptosis observing by electron microscopy.[Conclusions]In this study, the monolayer co-culture of the MCC and TGP cartilage cells grows well, secretion and synthesis function are normal, suggesting that co-culture environment may increase the content of the matrix type Ⅱ collagen. When the two types of cells cultured in the three-dimensional co-culture manner via centrifuge tubes, TGP cartilage cells may help MCC’s formation of cartilage structure.