Ciccocioppo Rachele, Panelli Simona, Conti Bellocchi Maria C, Cangemi Giuseppina C, Frulloni Luca, Capelli Enrica, Corazza Gino R
Gastroenterology Unit, Department of Medicine, Azienda Ospedaliera Universitaria Integrata Verona, University of Verona Verona, Italy.
Pediatric Clinical Research Center "Invernizzi", University of Milano Milan, Italy.
Front Med (Lausanne). 2018 Jun 19;5:182. doi: 10.3389/fmed.2018.00182. eCollection 2018.
Celiac disease (CD), the most common chronic enteropathy worldwide, is triggered and sustained by a dysregulated immune response to dietary gluten in genetically susceptible individuals. Up to date either the role of environmental factors and the pathways leading to mucosal damage have been only partially unraveled. Therefore, we seized the unique opportunity to study a naturally-occurring experimental model of a family composed of both parents suffering from CD (one on a gluten-free diet) and two non-celiac daughters. The control group consisted in four unrelated cases, two celiac and two non-celiac subjects, all matching with family members for both disease status and genetic susceptibility. In this privileged setting, we sought to investigate gene expression in peripheral blood mononuclear cells (PBMCs), a population known to mirror the immune response state within the gut. To this purpose, PBMCs were obtained from the four biopsied-proven CD patients and the four non-celiac cases. Each group included two family members and two unrelated control subjects. After RNA purification and cDNA synthesis, each sample underwent a microarray screen on a whole-transcriptome scale, and the hybridization results were visualized by hierarchical clustering. Differentially expressed genes (DEG) were partitioned into clusters displaying comparable regulations among samples. These clusters were subjected to both functional and pathway analysis by using the Kyoto Encyclopedia of Genes and Genomes. Interestingly, on a global gene expression level, the family members clustered together, regardless of their disease status. A relevant fraction of DEG belonged to a limited number of pathways, and could be differentiated based on disease status: active CD vs. treated CD and CD vs. controls. These pathways were mainly involved in immune function regulation, cell-cell junctions, protein targeting and degradation, exosome trafficking, and signal transduction. Worth of noting, a small group of genes mapping on the male-specific region of the Y chromosome, and previously linked to cardiovascular risk, was found to be strongly upregulated in the active CD case belonging to the family, who suddenly died of a heart attack. Our results provide novel information on CD pathogenesis and may be useful in identifying new therapeutic tools and risk factors associated with this condition.
乳糜泻（CD）是全球最常见的慢性肠病，在基因易感个体中，对膳食麸质的免疫反应失调引发并维持该病。迄今为止，环境因素的作用以及导致黏膜损伤的途径仅得到部分揭示。因此，我们抓住了一个独特的机会，研究一个由父母均患有CD（一方采用无麸质饮食）和两个非乳糜泻女儿组成的家庭的自然发生的实验模型。对照组由四个无关个体组成，两个乳糜泻患者和两个非乳糜泻受试者，在疾病状态和遗传易感性方面均与家庭成员匹配。在这个特殊的环境中，我们试图研究外周血单核细胞（PBMC）中的基因表达，外周血单核细胞群体已知可反映肠道内的免疫反应状态。为此，从四名经活检证实的CD患者和四名非乳糜泻个体中获取PBMC。每组包括两名家庭成员和两名无关对照受试者。经过RNA纯化和cDNA合成后，每个样本在全转录组规模上进行微阵列筛选，并通过层次聚类可视化杂交结果。差异表达基因（DEG）被分为在样本间显示可比调控的簇。通过使用京都基因与基因组百科全书对这些簇进行功能和通路分析。有趣的是，在全球基因表达水平上，家庭成员聚集在一起，无论他们的疾病状态如何。相当一部分DEG属于有限数量的通路，并且可以根据疾病状态进行区分：活动期CD与经治疗的CD以及CD与对照。这些通路主要参与免疫功能调节、细胞间连接、蛋白质靶向和降解、外泌体运输以及信号转导。值得注意的是，在属于该家庭的活动期CD病例中，一小部分位于Y染色体男性特异性区域且先前与心血管风险相关的基因被发现强烈上调，该病例突然死于心脏病发作。我们的结果提供了关于CD发病机制的新信息，可能有助于识别与这种疾病相关的新治疗工具和风险因素。
