中国神经再生研究(英文版)

中国神经再生研究(英文版) ›› 2017, Vol. 12 ›› Issue (4): 644-653.doi: 10.4103/1673-5374.205106

• 原著:神经损伤修复保护与再生 • 上一篇    下一篇

丝裂霉素C诱导脊髓损伤减压术后硬膜外瘢痕成纤维细胞的凋亡

  

  • 收稿日期:2017-03-12 出版日期:2017-04-15 发布日期:2017-04-15
  • 基金资助:

    国家自然科基金（81401791, 81371968, 81672152）

Mitomycin C induces apoptosis in human epidural scar fibroblasts after surgical decompression for spinal cord injury

Tao Sui1, Da-wei Ge1, Lei Yang1, Jian Tang1, Xiao-jian Cao1, Ying-bin Ge2   

  1. 1 Department of Orthopedics, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China; 2 Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu Province, China
  • Received:2017-03-12 Online:2017-04-15 Published:2017-04-15
  • Contact: Xiao-jian Cao, Ph.D. or Ying-bin Ge, Ph.D., xiaojiancao001@163.com or ybge@njmu.edu.cn.
  • Supported by:

    This research was supported by the National Natural Science Foundation of China, No. 81401791, 81371968, 81672152.

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摘要：

有研究证实，脊髓损伤后减压手术后局部应用丝裂霉素C可有效减轻瘢痕粘连，但具体机制不明。为此，实验设计探讨丝裂霉素C对人硬膜外瘢痕成纤维细胞增殖和凋亡的作用机制。用丝裂霉素C(1，5，10，20，40 μg/mL)干预培养人硬膜外瘢痕成纤维细胞，处理12，24，48 h，发现丝裂霉素C剂量、时间依赖性地抑制人硬膜外瘢痕成纤维细胞生长。丝裂霉素C可显著提高细胞中促凋亡蛋白-Fas，DR4，DR5，cleaved caspase-8/9，Bax，Bim和 cleaved-3表达，同时显著降低细胞抑制凋亡蛋白-Bcl-2和Bcl-xL的表达，但caspase-8/9抑制剂(Z-IETD-FMK 和 Z-LETD-FMK)并不能完全抑制丝裂霉素C诱导的细胞凋亡。同时，丝裂霉素C可剂量依赖性增加细胞中GRP78、内质网应激通路相关蛋白(CHOP)和caspase-4蛋白的表达，从而激发内质网应激。实验中采用的内质网应激抑制因子Salubrinal (Sal)显著抑制了丝裂霉素C处理后细胞的活性，同时降低细胞内CHOP的表达而抑制凋亡。结果证实，丝裂霉素C可部分地通过内质网应激通路诱导硬膜外瘢痕形成中成纤维细胞的凋亡。

ORCID:0000-0003-3603-3448(Xiao-jian Cao); 0000-0003-1471-9000(Ying-bin Ge)

关键词: 神经再生, 脊髓损伤, 丝裂霉素C, 成纤维细胞, 凋亡, 内质网应激, 椎板减压, 硬膜外瘢痕, 纤维化, CHOP, GRP78蛋白

Abstract:

Numerous studies have shown that topical application of mitomycin C after surgical decompression effectively reduces scar adhesion. However, the underlying mechanisms remain unclear. In this study, we investigated the effect of mitomycin C on the proliferation and apoptosis of human epidural scar fibroblasts. Human epidural scar fibroblasts were treated with various concentrations of mitomycin C (1, 5, 10, 20, 40 μg/mL) for 12, 24 and 48 hours. Mitomycin C suppressed the growth of these cells in a dose- and time-dependent manner. Mitomycin C upregulated the expression levels of Fas, DR4, DR5, cleaved caspase-8/9, Bax, Bim and cleaved caspase-3 proteins, and it downregulated Bcl-2 and Bcl-xL expression. In addition, inhibitors of caspase-8 and caspase-9 (Z-IETD-FMK and Z-LEHD-FMK, respectively) did not fully inhibit mitomycin C-induced apoptosis. Furthermore, mitomycin C induced endoplasmic reticulum stress by increasing the expression of glucose-regulated protein 78, CAAT/enhancer-binding protein homologous protein (CHOP) and caspase-4 in a dose-dependent manner. Salubrinal significantly inhibited the mitomycin C-induced cell viability loss and apoptosis, and these effects were accompanied by a reduction in CHOP expression. Our results support the hypothesis that mitomycin C induces human epidural scar fibroblast apoptosis, at least in part, via the endoplasmic reticulum stress pathway.

Key words: nerve regeneration, spinal cord injury, mitomycin C, fibroblasts, apoptosis, endoplasmic reticulum stress, surgical decompression, epidural scar, fibrosis, CAAT/enhancer-binding protein homologous protein, glucose-regulated protein 78, neural regeneration