Gerstenfeld L C, Kelly C M, Von Deck M, Lian J B
Department of Orthopedic Surgery, Harvard Medical School, Boston, Massachusetts.
Connect Tissue Res. 1990;24(1):29-39. doi: 10.3109/03008209009152420.
A comparative study of Type X collagen expression, chondrocyte morphology, and the expression of two genes controlling chondrocyte morphology (beta-actin and fibronectin) was carried out on chondrocytes derived from a tissue that remains as permanent hyaline cartilage in vivo (embryonic chicken caudal sterna), from a tissue that undergoes endochondral replacement (embryonic chicken ventral vertebrae) and caudal sternal chondrocytes treated with 1,25(OH)2D3. Under identical in vitro growth conditions and times, sternal chondrocytes grew as rounded non-adherent cells, and vertebral chondrocytes grew as adherent polygonal cells. Upon treatment with 10(-8) M 1,25(OH)2D3 over a twelve day period the sternal chondrocytes showed complete adherence and took on an identical appearance as the vertebral chondrocytes. Cellular adherence of both vertebral and 1,25(OH)2D3 treated sternal chondrocytes was associated with 10 X increased beta-actin, fibronectin and their corresponding mRNA's. Changes in connective tissue expression were observed with altered cellular morphology. Total collagen synthesis was 35-50% lower in both hormone treated and vertebral chondrocytes. Type II collagen was the major collagen type produced by all chondrocyte cultures; however, in both vertebral and 1,25(OH)2D3 treated sternal chondrocytes, a 60 kD collagenous protein was identified. This short chain collagen was determined to be Type X collagen based on its molecular weight and its CNBr peptide maps. Analysis of Type X mRNA levels using a 33 base pair anti sense oligonucleotide sequence to Type X, demonstrated that vertebral cells showed six to seven times more mRNA than sternal chondrocytes. However, the low mRNA levels of type X mRNA in sternal chondrocytes were increased two to three times by 1,25(OH)2D3 treatment. These studies demonstrate that the steroid hormone 1,25(OH)2 vitamin D3 induced morphological, biochemical and molecular changes indicative of chondrocyte maturation from a hyaline to a more hypertrophic phenotype.
对来自在体内保持为永久性透明软骨的组织（胚胎鸡尾胸骨）、经历软骨内替代的组织（胚胎鸡颈椎）以及用1,25(OH)₂D₃处理的尾胸骨软骨细胞的软骨细胞进行了X型胶原蛋白表达、软骨细胞形态以及控制软骨细胞形态的两个基因（β-肌动蛋白和纤连蛋白）表达的比较研究。在相同的体外生长条件和时间下，胸骨软骨细胞呈圆形非贴壁细胞生长，而椎骨软骨细胞呈贴壁多边形细胞生长。在12天的时间里用10⁻⁸ M 1,25(OH)₂D₃处理后，胸骨软骨细胞表现出完全贴壁，并呈现出与椎骨软骨细胞相同的外观。椎骨和经1,25(OH)₂D₃处理的胸骨软骨细胞的细胞贴壁与β-肌动蛋白、纤连蛋白及其相应mRNA增加10倍有关。随着细胞形态的改变，观察到结缔组织表达的变化。激素处理的软骨细胞和椎骨软骨细胞中的总胶原蛋白合成均降低了
