Immunohistochemical study of the apoptosis process in epidermal epithelial cells of rats under a physiological condition
Immunohistochemical study of the apoptosis process in epidermal epithelial cells of rats under a physiological condition
复制标题
DOI：
10.14670/hh-26.811
复制
发表时间：
2011-07-01
影响因子：
2
通讯作者：
Kitagawa, H.
中科院分区：
文献类型：
--
作者：
Udayanga, K. G. S.;Miyata, H.;Kitagawa, H.
表皮的稳态是由基底层（SB）中的上皮细胞增殖和生理条件下上皮细胞的凋亡来维持的。本研究在生理条件下，利用细胞凋亡相关蛋白，对Wistar大鼠掌跖表皮细胞凋亡的诱导和调控机制进行了化学研究。结果表明，Fas和Fas-L表达于棘层（SS）细胞膜，而TNF-R1在表皮各层均不表达。在表皮中未观察到TNF-α。Caspase-10、切割的Caspase-3和DNase-1在从SS到颗粒层（SG）的上皮细胞中被发现，而Caspase-8在表皮中未检测到。XIAP和巴克在SS至SG的胞浆中均有表达，且Bak在SG的表达强度强于SS，而Bid、Apaf-1和切割的caspase-9在SG中表达受限。Bcl-2在SB中呈均匀的胞浆免疫反应性，从SB到SG强度逐渐减弱。细胞色素C的颗粒-细胞质免疫阳性逐渐改变为在SG的上半部分的同质细胞质表达。在SG的上部很少检测到单链DNA。这些结果表明，表皮细胞凋亡是由Fas和Fas-L之间的相互作用和caspase-10的激活，并可能最初进行通过一个细胞的非依赖性途径，并最终在生理条件下加速细胞的依赖性途径。
Epidermal homeostasis is maintained by both epithelial proliferation in the stratum basale (SB) and the apoptosis of epithelial cells under physiological conditions. In this study, the induction and regulation mechanisms of epidermal apoptosis were immunohistochemically investigated in the epidermis from Wistar rat's palm and foot pad by using several apoptotic related proteins under a physiological condition. The results showed that Fas and Fas-L were expressed in cellular membranes of the stratum spinosum (SS), whereas TNF-R1 did not show any membranous expression in any epidermal layers. TNF-alpha was not observed in the epidermis. Caspase-10, cleaved caspase-3 and DNase-1 were found in the epithelial cytoplasms from the SS to stratum granulosum (SG), whereas caspase-8 was not detected in the epidermis. XIAP and Bak were found in the cytoplasm from the SS to SG, and the intensity of Bak-positivity was stronger in the SG than the SS, whereas Bid, Apaf-1 and cleaved caspase-9 were restricted in the SG. Homogenous cytoplasmic immunoreactivity of Bcl-2 was found in the SB and the intensity was gradually decreased from the SB to the SG. The granular-cytoplasmic immuno-positivity of cytochrome C gradually altered into homogenous cytoplasmic expression in the upper half of the SG. Single-stranded DNA was rarely detected in the upper portion of the SG. These results suggest that epidermal apoptosis is induced by the interaction between Fas and Fas-L and the activation of caspase-10, and might initially proceed through a mitochondrial-independent pathway, and that a mitochondrial-dependent pathway finally accelerated under physiological conditions.