The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou 510230, Guangdong, China.
Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Center for Human Genome Research, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China.
Aging (Albany NY). 2020 Jun 17;12(13):13594-13617. doi: 10.18632/aging.103474.
The general transcription factor, CREB has been shown to play an essential role in promoting cell proliferation, neuronal survival and synaptic plasticity in the nervous system. However, its function in stress response remains to be elusive. In the present study, we demonstrated that CREB plays a major role in mediating stress response. In both rat lens organ culture and mouse lens epithelial cells (MLECs), CREB promotes oxidative stress-induced apoptosis. To confirm that CREB is a major player mediating the above stress response, we established stable lines of MLECs stably expressing CREB and found that they are also very sensitive to oxidative stress-induced apoptosis. To define the underlying mechanism, RNAseq analysis was conducted. It was found that CREB significantly suppressed expression of the αB-crystallin gene to sensitize CREB-expressing cells undergoing oxidative stress-induced apoptosis. CREB knockdown via CRISPR/CAS9 technology led to upregulation of αB-crystallin and enhanced resistance against oxidative stress-induced apoptosis. Moreover, overexpression of exogenous human αB-crystallin can restore the resistance against oxidative stress-induced apoptosis. Finally, we provided first evidence that CREB directly regulates αB-crystallin gene. Together, our results demonstrate that CREB is an important transcription factor mediating stress response, and it promotes oxidative stress-induced apoptosis by suppressing αB-crystallin expression.
一般转录因子 CREB 已被证明在促进神经系统中的细胞增殖、神经元存活和突触可塑性方面发挥着重要作用。然而,其在应激反应中的功能仍然难以捉摸。在本研究中,我们证明 CREB 在介导应激反应中起着主要作用。在大鼠晶状体器官培养物和小鼠晶状体上皮细胞(MLECs)中,CREB 促进氧化应激诱导的细胞凋亡。为了证实 CREB 是介导上述应激反应的主要参与者,我们建立了稳定表达 CREB 的 MLECs 稳定系,发现它们对氧化应激诱导的细胞凋亡也非常敏感。为了定义潜在的机制,进行了 RNAseq 分析。结果发现,CREB 显著抑制αB-晶状体蛋白基因的表达,使表达 CREB 的细胞对氧化应激诱导的细胞凋亡敏感。通过 CRISPR/CAS9 技术敲低 CREB 导致αB-晶状体蛋白上调,并增强对氧化应激诱导的细胞凋亡的抵抗能力。此外,过表达外源人αB-晶状体蛋白可以恢复对氧化应激诱导的细胞凋亡的抵抗能力。最后,我们提供了 CREB 直接调节αB-晶状体蛋白基因的第一个证据。总之,我们的结果表明 CREB 是一种重要的转录因子,介导应激反应,通过抑制αB-晶状体蛋白的表达来促进氧化应激诱导的细胞凋亡。