Department of Biomedical Engineering, College of Engineering, Peking University, Beijing 100871, China.
Chin Med J (Engl). 2011 Dec;124(24):4245-53.
There is a difficulty in evaluating the in vivo functionality of individual chondrocytes, and there is much heterogeneity among cartilage affected by osteoarthritis (OA). In this study, in vitro cultured chondrocytes harvested from varying stages of degeneration were studied as a projective model to further understand the pathogenesis of osteoarthritis.
Cartilage of varying degeneration of end-stage OA was harvested, while cell yield and matrix glycosaminoglycan (GAG) content were measured. Cell morphology, proliferation, and gene expression of collagen type I, II, and X, aggrecan, matrix metalloproteinase 13 (MMP-13), and ADAMTS5 of the acquired chondrocytes were measured during subsequent in vitro culture.
Both the number of cells and the GAG content increased with increasing severity of OA. Cell spreading area increased and gradually showed spindle-like morphology during in vitro culture. Gene expression of collagen type II, collagen type X as well as GAG decreased with severity of cartilage degeneration, while expression of collagen type I increased. Expression of MMP-13 increased with severity of cartilage degeneration, while expression of ADAMTS-5 remained stable. Expression of collagen type II, X, GAG, and MMP-13 substantially decreased with in vitro culture. Expression of collagen type I increased with in vitro cultures, while expression of ADAMTS 5 remained stable.
Expression of functional genes such as collagen type II and GAG decreased during severe degeneration of OA cartilage and in vitro dedifferentiation. Gene expression of collagen I and MMP-13 increased with severity of cartilage degeneration.
评估单个软骨细胞的体内功能存在困难，且受骨关节炎（OA）影响的软骨存在很大的异质性。本研究中，体外培养的取自不同退变阶段的软骨细胞被作为研究模型，以进一步了解骨关节炎的发病机制。
采集终末期 OA 不同退变程度的软骨，同时测量细胞产量和基质糖胺聚糖（GAG）含量。在随后的体外培养过程中，测量获得的软骨细胞的细胞形态、增殖和 I 型、II 型和 X 型胶原、聚集蛋白聚糖、基质金属蛋白酶 13（MMP-13）和 ADAMTS5 的基因表达。
细胞数量和 GAG 含量均随 OA 严重程度的增加而增加。细胞铺展面积增加，并在体外培养过程中逐渐呈现出梭形形态。随着软骨退变严重程度的增加，II 型胶原、X 型胶原和 GAG 的基因表达减少，而 I 型胶原的表达增加。MMP-13 的表达随软骨退变的严重程度增加而增加，而 ADAMTS-5 的表达保持稳定。II 型、X 型胶原、GAG 和 MMP-13 的表达随体外培养而显著下降。I 型胶原的表达随体外培养而增加，而 ADAMTS5 的表达保持稳定。
OA 软骨严重退变和体外去分化过程中，II 型胶原和 GAG 等功能基因的表达减少。I 型胶原和 MMP-13 的基因表达随软骨退变的严重程度增加。
