P_(53)基因及P_(53)蛋白与人晶状体上皮细胞的增殖和凋亡的关系

Correlation of P_(53) expression with human lens epithelial cellular proliferation and apoptosis

目的研究抑癌基因P53及其表达产物P53蛋白在不同年龄组的晶状体上皮细胞(LECs)中的表达与晶状体上皮细胞凋亡和增殖的关系.方法收集手术切除的不同年龄组的晶状体前囊膜或晶状体标本42例,应用链霉菌亲生物素蛋白-过氧化物酶免疫组织化学染色测定P53蛋白和细胞增殖核抗原的表达;应用DNA末端转移酶介导的Bio-dUTP原位末端标记技术作凋亡细胞的定量检测;应用核酸分子原位杂交法检测P53 mRNA的表达,并分别定义凋亡指数和增殖指数.结果(1)正常胚胎组LECs中P53蛋白阳性率＜0.01%,在儿童白内障组和老年白内障组的LECs中其阳性表达率分别为1.21%～3.25%和12.83%～19.15%,两组之间有显著性差异(P＜0.01).(2)正常胚胎组和儿童白内障组的LECs中PCNA的表达显著高于老年白内障组(P＜0.01).(3)正常胚胎组的LECs中几乎未见凋亡细胞,老年白内障组的LECs中凋亡细胞阳性检出率为26.16%～27.80%,显著高于儿童组的1.52%～3.36%(P＜0.01).(4)正常胚胎组的LECs中P53 mRNA阳性表达率＜0.01%,老年白内障组阳性表达率为18.44%～20.10%,明显高于儿童白内障组的2.89%～5.05%(P＜0.01).(5)人LECs中凋亡指数AI和增殖指数PI之间无明显相关性,P53蛋白与AI呈显著正相关(γ=0.900,P＜0.01),与PI呈显著负相关(γ=-0.807,P＜0.01).结论白内障患者LECs中有P53蛋白高表达,且保持野生型P53蛋白促凋亡的作用,提示P53基因可能参与LECs凋亡的调控,有望作为治疗PCO的外源性抑癌基因.

Objective To investigate the relationship between expressions of antioncogene P53 mRNA and P53 protein in human lens epithelial cells (LECs) with LECs proliferation and apoptosis in human. Methods Forty-two surgical samples of LECs or lens in different ages were collected. P53 protein and proliferating cell nuclear antigen (PCNA) were detected by SP immunohistochemistry. TUNEL and in situ hybridization (ISH) techniques were separately applied to detect cell apoptosis and P53mRNA. The apoptotic index (AI) and proliferation index (PI) were defined. Results (1)The positive cells rate of P53 protein was 1. 21%-3. 25% and 12. 83% - 19. 15% respectively in LECs of the children cataract and senile cataract group with a significant difference between the two groups (P < 0. 01) , and no P53 protein was detected in LECs of the normal fetus lens. (2) Positive staining of PCNA in the normal fetus group and children cataract group was significantly higher than that of senile cataract group (P <0. 01). (3) The apoptotic cells were found in LECs of senile cataract group and children cataract group. (4) The positive cells rate of P53 mRNA expression was 2. 89% -5. 05% in children cataract group and 18.44%-20. 10% in senile cataract group and a lower P53 mRNA expression in the normal fetus lens. (5) There was a negative correlation in the expression rate of P53 protein with PI (γ= - 0. 807, P < 0. 01) and a positive correlation with AI (γ=0. 900,P <0. 01). Conclusion P53 gene might play a role in the regulation of cell apoptosis in LECs.