Aigner T, Zhu Y, Chansky H H, Matsen F A, Maloney W J, Sandell L J
Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, Germany.
Arthritis Rheum. 1999 Jul;42(7):1443-50. doi: 10.1002/1529-0131(199907)42:7<1443::AID-ANR18>3.0.CO;2-A.
To test for the reexpression of the chondroprogenitor splice variant of the gene COL2A1, type IIA procollagen (containing a cysteine-rich NH2 propeptide), in adult articular chondrocytes in osteoarthritic (OA) joint disease.
In situ hybridization and immunohistochemical localization were performed on normal and OA articular cartilage specimens. The presence of type IIA procollagen messenger RNA (mRNA) expression was confirmed by Northern blot analysis.
In normal articular cartilage, no expression of mRNA or presence of type IIA procollagen was found. In OA articular cartilage, focally intense staining for type IIA protein was detected. Consistent with this, chondrocytes, particularly in the middle zones of articular cartilage, expressed type IIA procollagen mRNA. OA repair cartilage typically showed a broad zone of cells expressing type IIA mRNA and protein.
Type IIA procollagen is reexpressed by adult articular chondrocytes in OA cartilage degeneration, indicating the potential reversion of the cells to a chondroprogenitor cellular phenotype. The absence of type IIA mRNA and protein in normal adult articular cartilage and its onset in the diseased state suggests type IIA procollagen as a marker of OA.
检测骨关节炎（OA）关节疾病中成年关节软骨细胞中基因COL2A1的软骨前体细胞剪接变体（含富含半胱氨酸的NH2前肽的IIA型原胶原）的重新表达情况。
对正常和OA关节软骨标本进行原位杂交和免疫组化定位。通过Northern印迹分析确认IIA型原胶原信使核糖核酸（mRNA）表达的存在。
在正常关节软骨中，未发现mRNA表达或IIA型原胶原的存在。在OA关节软骨中，检测到IIA型蛋白的局灶性强染色。与此一致的是，软骨细胞，尤其是在关节软骨中间区域的软骨细胞，表达IIA型原胶原mRNA。OA修复软骨通常显示出一个表达IIA型mRNA和蛋白的广泛细胞区域。
成年关节软骨细胞在OA软骨退变中重新表达IIA型原胶原，表明细胞可能逆转为软骨前体细胞表型。正常成年关节软骨中不存在IIA型mRNA和蛋白，而在疾病状态下出现，提示IIA型原胶原可作为OA的标志物。
