Wang Ying, Yuan Zhigang, You Caiyun, Han Jindong, Li Haiyan, Zhang Zhuhong, Yan Hua
Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin 300052, China.
BMC Ophthalmol. 2014 Nov 25;14:144. doi: 10.1186/1471-2415-14-144.
P21 is one kind of cyclin-dependent kinase inhibitor that can prevent cells from going through the G1/S phase checkpoint and inhibit cell proliferation. Proliferative vitreoretinopathy (PVR) is a proliferative response in the eye. The aim of this study was to determine whether p21Waf1/Cip1 (p21) suppresses the proliferation and migration of retinal pigment epithelial (RPE) cells in vitro and controls PVR development in vivo.
Cell cycle analyses and transwell assays were conducted to assess cell proliferation characteristics and the migration ability of RPE cells after transfection with p21. Western blot and reverse-transcription polymerase chain reaction technologies were used to detect the expression of p21, CDK2 and cyclinE in RPE cells and rabbit retinal tissues. The impact of increasing p21 expression on PVR development was conducted by implantation of an adenovirus vector containing rabbit p21 (rAd-p21) in a PVR rabbit model. The prevalence of PVR and retinal detachment was determined by indirect ophthalmoscopy on days 3, 7, 14, and 21 after the injection of rAd-p21 into the vitreous. B scans and hematoxylin-eosin staining were employed to check rabbit retinas on day 21.
Cell cycle analyses and transwell assays showed that p21 inhibited the proliferation and migration of RPE cells. Increased expression of p21 was detected in cultured RPE cells and rabbit retinas after transfection with the p21 gene, whereas levels of CDK2 and cyclinE were decreased. The increase in p21 expression effectively suppressed the development of PVR in a rabbit model.
The increase in p21 expression in RPE cells not only inhibits the proliferation and migration of RPE cells in vitro, but also suppresses the development of PVR in vivo, which indicates its therapeutic potential in treating PVR.
P21是一种细胞周期蛋白依赖性激酶抑制剂，可阻止细胞通过G1/S期检查点并抑制细胞增殖。增殖性玻璃体视网膜病变（PVR）是眼部的一种增殖性反应。本研究的目的是确定p21Waf1/Cip1（p21）是否在体外抑制视网膜色素上皮（RPE）细胞的增殖和迁移，并在体内控制PVR的发展。
进行细胞周期分析和Transwell实验，以评估转染p21后RPE细胞的增殖特性和迁移能力。采用蛋白质印迹法和逆转录聚合酶链反应技术检测RPE细胞和兔视网膜组织中p21、CDK2和细胞周期蛋白E的表达。通过在PVR兔模型中植入含兔p21的腺病毒载体（rAd-p21），研究增加p21表达对PVR发展的影响。在玻璃体注射rAd-p21后的第3、7、14和21天，通过间接检眼镜检查确定PVR和视网膜脱离的发生率。在第21天采用B超扫描和苏木精-伊红染色检查兔视网膜。
细胞周期分析和Transwell实验表明，p21抑制RPE细胞的增殖和迁移。转染p21基因后，在培养的RPE细胞和兔视网膜中检测到p21表达增加，而CDK2和细胞周期蛋白E的水平降低。p21表达的增加有效抑制了兔模型中PVR的发展。
RPE细胞中p21表达的增加不仅在体外抑制RPE细胞的增殖和迁移，而且在体内抑制PVR的发展，这表明其在治疗PVR方面具有治疗潜力。
