Department of Ophthalmology, The Chinese People's Liberation Army General Hospital, Beijing, China.
Medical Department, The First Hospital Affiliated to General Hospital of the Chinese People's Liberation Army, Beijing, China.
Exp Eye Res. 2018 Apr;169:68-78. doi: 10.1016/j.exer.2018.01.023. Epub 2018 Jan 31.
Mitochondrial components are of great importance for the maintenance of lens transparency. In our previous work, we confirmed that carbon monoxide (CO) can protect human and rabbit lens epithelial cells (LECs) from hydrogen peroxide (HO)-mediated apoptosis, while the mechanism remains undefined. Because CO can bind to mitochondrial cytochrome c oxidase (COX), we evaluated the effect of CO on the regulation of mitochondrial biogenesis and function in HO-treated rabbit LECs. To evaluate mitochondrial biogenesis, several mitochondrial transcription factors (PGC-1α, NRF-1, and mtTFA) were detected by western blot analysis. To assess cellular metabolism, adenosine triphosphate (ATP) levels and COX enzymatic activity were measured. In addition, mitochondrial permeability transition pores (mPTP) opening, dissipation of mitochondrial membrane potential (ΔΨm), cytochrome c mitochondrial translocation, and apoptotic molecules were also detected to evaluate mitochondrial apoptosis pathway. Furthermore, the interaction of Bcl-2 and COX was assessed by co-immunoprecipitation. Finally, CO-mediated regulation of cellular function was detected in Bcl-2-knockdown cells. Our results confirmed that CO pretreatment restored HO-induced down-regulation of mitochondrial transcription factors expression, COX activity and ATP production. Moreover, CO pretreatment attenuated mPTP opening, ΔΨm loss, cytochrome c mitochondrial translocation, and activation of apoptotic molecules. Bcl-2 was identified to bind to COX, and silence of Bcl-2 expression prevented CO-regulated cellular metabolism and cytoprotection. These data suggest that CO modulates HO-induced cellular dysfunction by increasing mitochondrial biogenesis, enhancing cellular metabolism, and attenuating mitochondrial apoptosis cascade. Moreover, Bcl-2 expression was vital for CO to regulate cellular metabolism and cytoprotection in LECs.
线粒体成分对于维持晶状体透明度非常重要。在我们之前的工作中，我们证实一氧化碳（CO）可以保护人眼和兔眼晶状体上皮细胞（LEC）免受过氧化氢（HO）介导的细胞凋亡，但其机制尚不清楚。因为 CO 可以与线粒体细胞色素 c 氧化酶（COX）结合，所以我们评估了 CO 对 HO 处理的兔 LEC 中线粒体生物发生和功能的调节作用。为了评估线粒体生物发生，我们通过 Western blot 分析检测了几种线粒体转录因子（PGC-1α、NRF-1 和 mtTFA）。为了评估细胞代谢，测量了三磷酸腺苷（ATP）水平和 COX 酶活性。此外，还检测了线粒体通透性转换孔（mPTP）开放、线粒体膜电位（ΔΨm）耗散、细胞色素 c 线粒体易位和凋亡分子，以评估线粒体凋亡途径。此外，还通过共免疫沉淀评估了 Bcl-2 和 COX 的相互作用。最后，在 Bcl-2 敲低细胞中检测了 CO 介导的细胞功能调节作用。我们的结果证实，CO 预处理恢复了 HO 诱导的线粒体转录因子表达、COX 活性和 ATP 产生的下调。此外，CO 预处理减弱了 mPTP 开放、ΔΨm 丧失、细胞色素 c 线粒体易位和凋亡分子的激活。Bcl-2 被鉴定与 COX 结合，沉默 Bcl-2 表达可防止 CO 调节的细胞代谢和细胞保护。这些数据表明，CO 通过增加线粒体生物发生、增强细胞代谢和减弱线粒体凋亡级联来调节 HO 诱导的细胞功能障碍。此外，Bcl-2 的表达对于 CO 调节 LEC 中的细胞代谢和细胞保护至关重要。
