Human chondrocyte apoptosis in response to mechanical injury
Human chondrocyte apoptosis in response to mechanical injury
复制标题
DOI：
10.1053/joca.2001.0468
复制
发表时间：
2001-11-01
影响因子：
7
通讯作者：
Lotz, MK
中科院分区：
文献类型：
--
作者：
D'Lima, DD;Hashimoto, S;Lotz, MK
目的：研究机械损伤对软骨细胞活力和基质降解的影响。有人提出，人体软骨外植体的机械损伤导致软骨细胞凋亡，并伴有糖胺聚糖的丢失。设计：全层人软骨外植体，直径5mm，在径向无侧限压缩下承受14mpa的单次静态机械应力500ms。在损伤后96 h测定糖胺聚糖（GAG）释放量和细胞凋亡率。为了确定细胞凋亡的时间过程，外植体在损伤后以30%的浓度培养，并在不同的时间间隔培养至7天。一组负载的外植体也用广谱aspase抑制剂z-Vad处理。受伤后的FMK。结果：在14 MPa的机械载荷作用下，96 h时，34%的软骨细胞（sd +/- 11）出现核体间DNA断裂，而在未加载的外体中，这一比例为4% （sd +/- 2）。通过电镜和caspase切割细胞角蛋白也获得了细胞凋亡诱导细胞死亡的证据。外植体的GAG释放量也高于对照，平均为0.8% (SD, +/- 0.28)，平均为1.9% （SD +/- 0.14）。凋亡细胞的百分比也与向培养基中释放GAG的水平相关。损伤后6小时至7天，软骨细胞凋亡百分比呈渐进式增加。加载后外植体在z-Vad中培养。FMK损伤后，细胞凋亡率降低50%。结论：机械损伤可诱导软骨细胞凋亡和GAG从基质中释放，时间过程提示可能存在抑制细胞凋亡的治疗窗口期。这可能确定一种新的软骨保护方法。(C) 2001国际骨关节炎研究学会。
Objective: The effect of mechanical injury on chondrocyte viability and matrix degradation was studied. It was proposed that mechanical injury to human cartilage explants results in chondrocyte apoptosis with associated loss of glycosaminoglycans.Design: Full thickness human cartilage explants, 5 mm in diameter were subjected to a single static mechanical stress of 14 MPa for 500 ms under radially unconfined compression. Glycosaminoglycan (GAG) release and percentage of cells undergoing apoptosis were measured at 96 h after injury. To establish the time course of apoptosis, explants were subjected to 30% strain and cultured for varying intervals up to 7 days after injury. A group of loaded explants were also treated with the broad spectrum aspase inhibitor z-Vad.fmk after injury.Results: Internucleosomal DNA fragmentation as one indicator of apoptosis was observed in 34% (S.D +/- 11) of chondrocytes at 96 h in response to mechanical loading at 14 MPa, compared to 4% (S.D. +/- 2) in the non-loaded explants. Evidence for cell death induction via apoptosis was also obtained by electron microscopy and caspase cleavage of cytokeratin. GAG release was also higher for the loaded explants, mean 1.9% (S.D. +/- 0.14) of total GAG content, compared to control explants, mean 0.8% (SD, +/- 0.28). The percentage of apoptotic cells also correlated with the level of GAG release into the culture media. The percentage of apoptotic, chondrocytes demonstrated a progressive increase from 6 h to 7 days post-injury. When loaded explants were cultured in z-Vad.fmk after injury, a 50% reduction in apoptosis rates was seen.Conclusions: These results demonstrate that mechanical injury induces chondrocyte apoptosis and release of GAG from the matrix, The time course suggests that a therapeutic window may exist where apoptosis could be inhibited. This potentially identifies a new approach to chondroprotection. (C) 2001 OsteoArthritis Research Society International.