视网膜衰老中的免疫激活：一项基因表达研究。

Immune activation in retinal aging: a gene expression study.

机构信息

Centre for Vision and Vascular Science, School of Medicine, Dentistry, and Biomedical Sciences, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom.

出版信息

Invest Ophthalmol Vis Sci. 2010 Nov;51(11):5888-96. doi: 10.1167/iovs.09-5103. Epub 2010 Jun 10.

DOI:10.1167/iovs.09-5103

PMID:20538981

Abstract

PURPOSE

To investigate changes in gene expression during aging of the retina in the mouse.

METHODS

Total RNA was extracted from the neuroretina of young (3-month-old) and old (20-month-old) mice and processed for microarray analysis. Age-related, differentially expressed genes were assessed by the empiric Bayes shrinkage-moderated t-statistics

METHOD

Statistical significance was based on dual criteria of a ratio of change in gene expression >2 and a P < 0.01. Differential expression in 11 selected genes was further verified by real-time PCR. Functional pathways involved in retinal aging were analyzed by an online software package (DAVID-2008) in differentially expressed gene lists. Age-related changes in differential expression in the identified retinal molecular pathways were further confirmed by immunohistochemical staining of retinal flat mounts and retinal cryosections.

RESULTS

With aging of the retina, 298 genes were upregulated and 137 genes were downregulated. Functional annotation showed that genes linked to immune responses (Ir genes) and to tissue stress/injury responses (TS/I genes) were most likely to be modified by aging. The Ir genes affected included those regulating leukocyte activation, chemotaxis, endocytosis, complement activation, phagocytosis, and myeloid cell differentiation, most of which were upregulated, with only a few downregulated. Increased microglial and complement activation in the aging retina was further confirmed by confocal microscopy of retinal tissues. The most strongly upregulated gene was the calcitonin receptor (Calcr; >40-fold in old versus young mice).

CONCLUSIONS

The results suggest that retinal aging is accompanied by activation of gene sets, which are involved in local inflammatory responses. A modified form of low-grade chronic inflammation (para-inflammation) characterizes these aging changes and involves mainly the innate immune system. The marked upregulation of Calcr in aging mice most likely reflects this chronic inflammatory/stress response, since calcitonin is a known systemic biomarker of inflammation/sepsis.

摘要

目的

研究小鼠视网膜衰老过程中基因表达的变化。

方法

从小鼠的神经视网膜中提取年轻（3 个月大）和年老（20 个月大）的总 RNA，并进行微阵列分析。使用经验贝叶斯收缩调节 t 统计量评估与年龄相关的差异表达基因。

方法

基于基因表达变化比 >2 和 P < 0.01 的双重标准来评估统计显著性。通过实时 PCR 进一步验证 11 个选定基因的差异表达。通过在线软件包（DAVID-2008）在差异表达基因列表中分析涉及视网膜衰老的功能途径。通过视网膜扁平膜和视网膜冷冻切片的免疫组织化学染色进一步确认鉴定的视网膜分子途径中差异表达的年龄相关变化。

结果

随着视网膜的衰老，有 298 个基因上调，137 个基因下调。功能注释表明，与免疫反应（Ir 基因）和组织应激/损伤反应（TS/I 基因）相关的基因最有可能被衰老修饰。受影响的 Ir 基因包括调节白细胞激活、趋化性、内吞作用、补体激活、吞噬作用和髓样细胞分化的基因，其中大多数基因上调，只有少数基因下调。通过对视网膜组织的共聚焦显微镜观察，进一步证实了衰老视网膜中微胶质细胞和补体的激活增加。上调最明显的基因是降钙素受体（Calcr；老年小鼠中>40 倍）。