Molecular Events of Cellular Apoptosis and Proliferation in the Early Tendon Healing Period
Molecular Events of Cellular Apoptosis and Proliferation in the Early Tendon Healing Period
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DOI：
10.1016/j.jhsa.2009.10.021
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发表时间：
2010-01-01
影响因子：
1.9
通讯作者：
Tang, Jin Bo
中科院分区：
文献类型：
--
作者：
Wu, Ya Fang;Chen, Chuan Hao;Tang, Jin Bo
目的细胞增殖伴随着细胞凋亡。在指屈肌腱愈合中，有关细胞凋亡的分子事件尚未被研究。本研究旨在探讨肌腱早期愈合过程中细胞凋亡与细胞增殖的关系。方法对25只鸡50根长趾的指深屈肌腱进行截断手术修复。在术后第3、7、14、21和28天，我们对肌腱进行原位末端脱氧核苷酸转移酶dUTP缺口末端标记（TUNEL）检测凋亡细胞，用增殖细胞核抗原抗体免疫荧光染色评估增殖情况，用抗凋亡蛋白Bcl-2评估抑制凋亡的反应。显微镜下对阳性标记的细胞计数并进行统计学比较。并用苏木精和伊红染色观察其愈合情况。另设12根肌腱（6只鸡）作为第0天对照。结果与第0天的肌腱相比，愈合后的肌腱外皮和内腱区细胞数量明显增加。细胞总数和tunel阳性细胞数在第3天达到峰值。在第7 ~ 21天，增殖细胞核抗原阳性细胞数量达到高峰。在第7天和第14天，Bcl-2阳性染色细胞达到高峰。第14 ~ 28天，细胞总数和tunel阳性细胞数较第3、7天明显减少，但仍高于第0天。结论愈合肌腱细胞凋亡在第3天达到高峰，10天后出现增殖高峰。由于Bcl-2起到抑制细胞凋亡的作用，Bcl-2阳性细胞的增加表明肌腱细胞凋亡受到抑制。这些结果表明，损伤后数天内，细胞凋亡加速，随后细胞增殖增加，并在2至4周内激活抑制细胞凋亡的分子事件。[J] .中华手外科杂志2010；35(1):2-10。美国手部外科学会版权所有(C) 2010。版权所有。)
Purpose Cellular proliferation is accompanied by cellular apoptosis. In the healing digital flexor tendon, molecular events concerning cellular apoptosis have not been investigated. This study aimed to investigate the relationship between cellular apoptosis and proliferation in early tendon healing.Methods The flexor digitorum profundus tendons of 50 long toes in 25 chickens were transected and were repaired surgically. On postoperative days 3, 7, 14, 21, and 28, we subjected tendons to in situ terminal deoxynucleotide transferase dUTP nick end labeling (TUNEL) assay to detect apoptotic cells, immunofluorescence staining with antibodies to proliferating cell nuclear antigen to assess proliferation, and Bcl-2, an anti-apoptotic protein, to assess responses suppressive to apoptosis. The positively labeled tenocytes were counted microscopically and compared statistically. We also stained sections with hematoxylin and eosin to observe their healing status. An additional 12 tendons (6 chickens) served as day 0 controls.Results Compared with tendons at day 0, the healing tendons had notably greater cellularity in both epitenon and endotenon areas. The total number of cells and number of TUNEL-positive cells peaked at day 3. At days 7 to 21, the number of proliferating cell nuclear antigen-positive cells peaked. At days 7 and 14, the cells positively stained with Bcl-2 peaked. At days 14 to 28, the total number of cells and TUNEL-positive cells decreased significantly compared with those at days 3 and 7, yet the numbers remained greater than those on day 0.Conclusions Apoptosis in the healing tendons peaks at day 3, followed about 10 days later by the peak proliferation period. Because Bcl-2 serves to inhibit apoptosis, a later increase in Bcl-2 positive cells indicates that tendon apoptosis is inhibited. These findings indicate that tenocyte apoptosis is accelerated within several days after injury, followed by increases in cellular proliferation and activation of molecular events to inhibit apoptosis in 2 to 4 weeks. (J Hand Surg 2010;35A:2-10. Copyright (C) 2010 by the American Society for Surgery of the Hand. All rights reserved.)