Chen Mei-Hsiu, Liao Shu-Lang, Chen Ming-Hong, Tsou Pei-Ling, Shih Mei-Ju, Chang Tien-Chun, Chuang Lee-Ming
Graduate Institute of Clinical Medicine, National Taiwan University Medical College, Taipei, Taiwan.
Invest Ophthalmol Vis Sci. 2008 Nov;49(11):4760-4. doi: 10.1167/iovs.08-2020. Epub 2008 Jun 14.
The molecular mechanism involved in the hypertrophy of the orbital fat in patients with Graves' ophthalmopathy or thyroid eye disease (TED) remains unclear. Comparison of genome-wide expression profiles may help in the search for the gene sets involved in TED.
Twenty-five orbital adipose tissue specimens were obtained, from which the RNA was isolated. Four of the tissue specimens (from four individuals, two with TED and two control subjects) were subjected to cDNA microarray analysis. The data were analyzed by the gene set enrichment analysis (GSEA) to survey the biological pathways involved in the pathogenesis of TED. Messenger RNA levels of some top-ranked genes in GSEA-selected pathways are validated by quantitative PCR (QPCR).
The expression of specific gene sets related to lytic vacuoles, lysosomes, and vacuoles were different between the specimens obtained from patients with TED and control subjects (P < 0.001). These three gene sets overlapped. For QPCR, four top-ranked genes were selected from these overlapping gene sets and another one that related to visual failure, using 21 independent samples of patients with TED (n = 15) and control subjects (n = 6). The results showed that ceroid-lipofuscinosis, neuronal 2, late infantile (CLN2; P = 0.044) and ceroid-lipofuscinosis, neuronal 3, juvenile (CLN3, which related to visual failure; P = 0.012) were significantly downregulated in the orbital fat of patients with TED. The expression of the beta subunit of hexosaminidase A (HEXB) was reduced as well, but the change did not reach statistical significance (P = 0.058).
Lysosome-related genes, such as CLN2, CLN3, and HEXB, may be involved in the pathogenesis of adipose tissue hypertrophy in TED.
格雷夫斯眼病或甲状腺眼病（TED）患者眼眶脂肪肥大所涉及的分子机制仍不清楚。全基因组表达谱的比较可能有助于寻找参与TED的基因集。
获取25份眼眶脂肪组织标本，并从中分离出RNA。对其中4份组织标本（来自4个人，2例TED患者和2例对照者）进行cDNA微阵列分析。通过基因集富集分析（GSEA）对数据进行分析，以探究参与TED发病机制的生物学途径。通过定量PCR（QPCR）验证GSEA选择途径中一些排名靠前的基因的信使RNA水平。
从TED患者和对照者获取的标本中，与溶酶泡、溶酶体和液泡相关的特定基因集的表达存在差异（P < 0.001）。这三个基因集有重叠。对于QPCR，从这些重叠基因集中选择了4个排名靠前的基因以及另一个与视力减退相关的基因，使用21份TED患者（n = 15）和对照者（n = 6）的独立样本。结果显示，在TED患者的眼眶脂肪中，神经元蜡样脂褐质沉积症2型（CLN2；P = 0.044）和神经元蜡样脂褐质沉积症3型（CLN3，与视力减退相关；P = 0.012）显著下调。己糖胺酶A（HEXB）的β亚基表达也降低，但变化未达到统计学意义（P = 0.058）。
CLN2、CLN3和HEXB等溶酶体相关基因可能参与TED脂肪组织肥大的发病机制。
