Department of Ophthalmology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, China.
Center of Clinical Research, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, China.
PeerJ. 2023 Dec 18;11:e16569. doi: 10.7717/peerj.16569. eCollection 2023.
Thyroid-associated orbitopathy (TAO) is a disease associated with autoimmune thyroid disorders and it can lead to proptosis, diplopia, and vision-threatening compressive optic neuropathy. To comprehensively understand the molecular mechanisms underlying orbital adipogenesis in TAO, we characterize the intrinsic molecular properties of orbital adipose/connective tissue from patients with TAO and control individuals.
RNA sequencing analysis (RNA-seq) was performed to measure the gene expression of orbital adipose/connective tissues of TAO patients. Differentially expressed genes (DEGs) were detected and analyzed through Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, and Gene Set Enrichment Analysis (GSEA). The protein-protein interaction (PPI) network was constructed using the STRING database, and hub genes were identified by the Cytoscape plug-in, cytoHubba. We validated several top DEGs through quantitative real-time polymerase chain reaction (qRT-PCR).
We identified 183 DEGs in adipose tissue between TAO patients ( = 3) and control patients ( = 3) through RNA sequencing, including 114 upregulated genes and 69 downregulated genes. The PPI network of these DEGs had 202 nodes and 743 edges. PCR-based validation results of orbital adipose tissue showed multiple top-ranked genes in TAO patients ( = 4) are immune and inflammatory response genes compared with the control individual ( = 4). They include ceruloplasmin isoform x3 (CP), alkaline tissue-nonspecific isozyme isoform x1 (ALPL), and angiotensinogen (AGT), which were overrepresented by 2.27- to 6.40-fold. Meanwhile, protein mab-21-like 1 (MAB21L1), phosphoinositide 3-kinase gamma-subunit (PIK3C2G), and clavesin-2 (CLVS2) decreased by 2.6% to 32.8%. R-spondin 1 (RSPO1), which is related to oogonia differentiation and developmental angiogenesis, was significantly downregulated in the orbital muscle tissues of patients with TAO compared with the control groups ( = 0.024).
Our results suggest that there are genetic differences in orbital adipose-connective tissues derived from TAO patients. The upregulation of the inflammatory response in orbital fat of TAO may be consistent with the clinical phenotype like eyelid edema, exophthalmos, and excess tearing. Downregulation of MAB21L1, PIK3C2G, and CLVS2 in TAO tissue demonstrates dysregulation of differentiation, oxidative stress, and developmental pathways.
甲状腺相关眼病（TAO）是一种与自身免疫性甲状腺疾病相关的疾病，可导致眼球突出、复视和威胁视力的压迫性视神经病变。为了全面了解 TAO 眼眶脂肪生成的分子机制，我们对 TAO 患者和对照个体的眼眶脂肪/结缔组织进行了内在分子特性的描述。
采用 RNA 测序分析（RNA-seq）测量 TAO 患者眼眶脂肪/结缔组织的基因表达。通过基因本体论（GO）、京都基因与基因组百科全书（KEGG）分析和基因集富集分析（GSEA）检测和分析差异表达基因（DEGs）。使用 STRING 数据库构建蛋白质-蛋白质相互作用（PPI）网络，并使用 Cytoscape 插件 cytoHubba 识别枢纽基因。我们通过实时定量聚合酶链反应（qRT-PCR）验证了几个顶级 DEGs。
通过 RNA 测序，我们在 3 名 TAO 患者（TAO 组）和 3 名对照患者（对照组）的脂肪组织中鉴定出 183 个 DEGs，包括 114 个上调基因和 69 个下调基因。这些 DEGs 的 PPI 网络有 202 个节点和 743 个边。基于 PCR 的眼眶脂肪组织验证结果显示，与对照个体相比，TAO 患者的多个顶级基因（TAO 组）是免疫和炎症反应基因。它们包括铜蓝蛋白同工型 x3（CP）、碱性组织非特异性同工酶同工型 x1（ALPL）和血管紧张素原（AGT），分别上调 2.27 倍至 6.40 倍。同时，蛋白 mab-21 样 1（MAB21L1）、磷酸肌醇 3-激酶γ亚基（PIK3C2G）和 clavesin-2（CLVS2）下降 2.6%至 32.8%。RSPO1，一种与卵母细胞分化和发育血管生成有关的基因，在 TAO 患者的眼眶肌肉组织中明显下调，与对照组相比（=0.024）。
我们的研究结果表明，TAO 患者的眼眶脂肪-结缔组织存在遗传差异。TAO 眼眶脂肪中炎症反应的上调可能与眼睑水肿、眼球突出和溢泪等临床表型一致。MAB21L1、PIK3C2G 和 CLVS2 在 TAO 组织中的下调表明分化、氧化应激和发育途径的失调。
