目的：本研究旨在验证环孢素A（CsA）对肺缺血再灌注（I/R）损伤具有保护作用的假说，并探讨其潜在机制。
方法：家兔分为4组：对照组，假手术,I/R,和I/R与CsA治疗。流式细胞术用于测量线粒体膜电位。采用激光扫描共聚焦显微镜分析线粒体通透性转换孔(MPTP)。通过TUNEL染色检测凋亡细胞。进行蛋白质印迹以分析蛋白质表达水平。
结果：CsA不仅减轻了I/R损伤后肺和线粒体的组织病理学改变，而且还通过增加MPP和抑制MPTP开放来减轻I/R损伤。此外,CsA通过抑制细胞色素C（CytC）的释放减轻I/R损伤，抑制细胞凋亡，降低亲环蛋白-D（Cyp-D）的表达水平，腺嘌呤核苷酸转位酶1(ANT1)和电压依赖性阴离子通道1(VDAC1)。最后,我们发现Cyp-D敲低抑制I/R损伤诱导的MPTP开放和细胞凋亡。
结论：我们的研究发现，CsA对肺I/R损伤的保护作用取决于对MPTP和CytC释放的抑制作用，抑制线粒体凋亡途径的激活和凋亡相关蛋白的表达，以及ANT1和VDAC1的表达水平降低。
OBJECTIVE: This
study is aimed at validating the hypothesis that administration of cyclosporine-A (CsA) would be protective in lung ischemia-reperfusion (I/R) injury and in exploring the underlying mechanism.
METHODS: Rabbits were divided into 4 groups: the control, sham operation, I/R, and I/R with CsA treatment. Flow cytometry was used to measure the mitochondrial membrane potential. Laser scanning confocal microscope was used to analyze mitochondrion permeability transition pore (MPTP). The apoptotic cell was detected by the TUNEL staining. Western blot was performed to analyze the protein expression levels.
RESULTS: CsA not only attenuated the histopathologic alterations in lung and mitochondria after I/R injury, but also attenuated I/R injury through increasing MPP and inhibiting MPTP opening. Besides, CsA attenuated I/R injury through suppressing the release of cytochrome-c (CytC), inhibiting cell apoptosis and decreasing the expression levels of cyclophilin-D (Cyp-D), adenine nucleotide translocase 1 (ANT1) and voltage-dependent anion channel 1 (VDAC1). Finally, we found that Cyp-D knockdown inhibits I/R injury-induced MPTP opening and cell apoptosis.
CONCLUSIONS: Our
study found that the protective role of CsA on lung I/R injury depends on the inhibition of MPTP and CytC release, suppression of the activation of mitochondrial apoptosis pathway and the expressions of apoptotic-related proteins, as well as the decreased expression levels of ANT1 and VDAC1.
