人年龄相关性白内障中 SIRT1 表达及其下游途径的变化。

Changes in SIRT1 expression and its downstream pathways in age-related cataract in humans.

机构信息

Department of Ophthalmology, Eye & ENT Hospital of Fudan University, Shanghai, China.

出版信息

Curr Eye Res. 2011 May;36(5):449-55. doi: 10.3109/02713683.2011.559301.

DOI:10.3109/02713683.2011.559301

PMID:21501079

Abstract

PURPOSE

SIRT1, the most well-known sirtuin family (class III histone deacetylases) member, is involved in many age-related diseases. However, no study has demonstrated its relationship with age-related cataract (ARC). This study was to investigate the expression of SIRT1 in human lens epithelial cells, and to observe the changes in SIRT1 expression and its downstream P53 and forkhead box class O (FOXO) proteins at the onset of ARC.

METHODS

The anterior lens capsule specimens from 360 normal human donor eyes (age 19-91 years) were divided into three groups: group A of young lens (younger than age 49 without cataract), group B of old but normal lens (older than age 50 without cataract), and group C of ARC lens (older than age 50 with ARC). Real-time quantitative reverse transcription of SIRT1 mRNA; Western blot analysis by anti-SIRT1, anti-p53, anti-p53 (acetyl K379), anti-FOXO3a, anti-FOXO4, anti-p27kip1, anti-p130, and anti-Bim; immunofluorescence of SIRT1; and TUNEL assay were performed in each group.

RESULTS

SIRT1 expression was significantly decreased in group B compared with group A, but increased in group C compared with group B. P53 expression increased with age and topped in group C; however, there was a decrease in active acetyl-P53 expression in group C compared with group B. The expression of both FOXO3a and FOXO4 decreased with age, but in group C, their expression level is equivalent to group A. Accordingly, the downstream p27kip1 and p130 showed the similar changes among three groups. In contrast, the expression of Bim was lowest in the ARC lens, and TUNEL assay showed significantly increased apoptosis incidence in group C.

CONCLUSIONS

The expression of SIRT1 increased in ARC in humans. Its downstream p53 was inhibited, and FOXO pathway was activated, indicating that SIRT1 may play a protective role in ARC formation.

摘要

目的

SIRT1 是最著名的 sirtuin 家族（III 类组蛋白去乙酰化酶）成员之一，与许多与年龄相关的疾病有关。然而，尚无研究表明其与年龄相关性白内障（ARC）有关。本研究旨在探讨 SIRT1 在人晶状体上皮细胞中的表达，并观察 ARC 发生时 SIRT1 表达及其下游 P53 和叉头框 O（FOXO）蛋白的变化。

方法

将 360 例正常人晶状体前囊标本（年龄 19-91 岁）分为三组：A 组为年轻晶状体（年龄<49 岁且无白内障），B 组为年老但正常晶状体（年龄>50 岁且无白内障），C 组为 ARC 晶状体（年龄>50 岁且有 ARC）。采用实时定量逆转录聚合酶链反应检测 SIRT1 mRNA，Western blot 分析抗 SIRT1、抗 p53、抗 p53（乙酰化 K379）、抗 FOXO3a、抗 FOXO4、抗 p27kip1、抗 p130 和抗 Bim，免疫荧光检测 SIRT1，TUNEL 检测。

结果

与 A 组相比，B 组 SIRT1 表达显著降低，C 组 SIRT1 表达升高。随着年龄的增长，p53 表达增加，在 C 组达到峰值；然而，与 B 组相比，C 组活性乙酰化 p53 表达减少。FOXO3a 和 FOXO4 的表达均随年龄增长而降低，但在 C 组，其表达水平与 A 组相当。相应地，下游的 p27kip1 和 p130 在三组中也有类似的变化。相比之下，Bim 在 ARC 晶状体中的表达最低，TUNEL 检测显示 C 组细胞凋亡发生率显著增加。