Mitochondrial involvement in Fas-mediated apoptosis of human lumbar disc cells
Mitochondrial involvement in Fas-mediated apoptosis of human lumbar disc cells
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DOI：
10.2106/jbjs.d.02527
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发表时间：
2005-06-01
影响因子：
5.3
通讯作者：
Riew, KD
中科院分区：
文献类型：
--
作者：
Park, JB;Li, JK;Riew, KD
背景资料：Fas介导的细胞凋亡有两条主要途径：I型（死亡诱导信号复合物）途径和II型（线粒体）途径。虽然凋亡性细胞死亡与腰椎退行性椎间盘疾病有关，但我们不知道有任何研究对手术切除的活体椎间盘进行了检查，以确定两种途径中哪一种参与了椎间盘细胞的凋亡。作为开发抑制椎间盘细胞不适当或过早凋亡的治疗方法的第一步，我们的目标是确定哪种途径参与其中。方法：我们检查了32个腰椎间盘突出组织样本，使用免疫组化染色和Western印迹分析来确定几种蛋白质的存在，包括caspase-8（与I型途径相关）; BID（BH 3相互作用结构域死亡激动剂）、细胞色素-c和半胱天冬酶-9（与II型途径相关）;和半胱天冬酶-3（细胞凋亡的执行者）。TUNEL（terminal deoxynucleotidyl transferase [TDT]-mediated dUTP nick end labeling）检测椎间盘细胞凋亡情况。结果：所有标本中与II型通路相关的蛋白（BID、cytochrome-c和caspase-9）均呈阳性染色。尽管免疫组化分析未检测到与I型途径相关的蛋白（半胱天冬酶-8），但Western印迹分析检测到少量半胱天冬酶-8。但Western blot分析显示，Ⅱ型蛋白的表达仍高于caspase-8的表达。免疫组化和Western blot分析结果显示，所有标本中caspase-3的表达均为阳性，所有标本中均检测到TUNEL阳性的椎间盘细胞。结论：本研究结果提示，人类椎间盘细胞为II型细胞，通过线粒体参与凋亡细胞死亡。未来的治疗方式，以抑制不适当的或过早的凋亡细胞死亡的退行性椎间盘应针对线粒体途径。
Background: Two main pathways of Fas-mediated apoptosis have been identified: the Type-I (death-inducing signaling complex) pathway and the Type-II (mitochondrial) pathway. While apoptotic cell death has been implicated in lumbar degenerative disc disease, we are not aware of any studies in which surgically removed discs from live humans have been examined to determine which of the two pathways is involved in the apoptosis of disc cells. As an initial step in the development of therapies to inhibit inappropriate or premature apoptosis of disc cells, our objective was to determine which pathway is involved.Methods: We examined thirty-two samples of herniated lumbar disc tissue with use of immunohistochemical staining and Western blot analysis to determine the presence of several proteins, including caspase-8 (associated with the Type-I pathway); BID (BH3 interacting domain death agonist), cytochrome-c, and caspase-9 (associated with the Type-II pathway); and caspase-3 (an executioner of apoptosis). The TUNEL (terminal deoxynucleotidyl transferase [TDT]-mediated dUTP nick end labeling) assay was performed to confirm the occurrence of apoptosis of the disc cells.Results: The proteins associated with the Type-II pathway (BID, cytochrome-c, and caspase-9) stained positively in all samples. Although the protein associated with the Type-I pathway (caspase-8) was not detected on immunohistochemical analysis, a small amount of caspase-8 was detected on Western blot analysis. However, the expression of Type-II proteins was still higher than the expression of caspase-8 on Western blot analysis. The expression of caspase-3 was identified in all samples with immunohistochemical and Western blot analysis, TUNEL-positive disc cells were identified in all samples.Conclusions: The results of the present study suggest that human disc cells are Type-II cells, which undergo apoptotic cell death through mitochondrial involvement.Clinical Relevance: Future therapeutic modalities to inhibit inappropriate or premature apoptotic cell death in degenerating discs should be directed to the mitochondrial pathway.