背景:ERAP2是一种参与抗原加工和呈递的氨肽酶,并带有与几种炎症性疾病有关的遗传变异,例如炎症性肠病(IBD)。小鼠缺乏ERAP2基因同源物阻碍了功能研究,大多数人类研究都集中在造血细胞上。使用IBD生物样本库作为有利位置,这项研究探讨了ERAP2的遗传变异如何在促炎性刺激后影响人源上皮类器官的基因表达。
方法:对IBD患者队列进行了基因分型,分析了与ERAP2表达水平相关的两个单核苷酸多态性(SNP)(rs2910686/rs2248374),我们检查了结肠基因表达和基因型之间的相关性,专门旨在建立与ERAP2表达能力的关系。建立了具有已知ERAP2基因型的人源结肠类器官(结肠样),并用于探索在促炎性反应时ERAP2缺陷(n=4)和熟练(n=4)供体之间的全基因组基因表达差异。
结果:考虑rs2910686基因型时,ERAP2基因表达在IBD患者发炎的结肠中上调。结肠样蛋白在IFNü刺激后上调ERAP2,和ERAP2表达水平依赖于rs2910686基因型。克隆样基因分型证实,独立于经常研究的SNPrs2248374的机制可以导致ERAP2缺乏症。共有586个涉及各种分子机制的基因在促炎刺激时在ERAP2高发和缺乏的结肠样之间差异表达,包括编码具有以下分子功能的蛋白质的基因:催化活性(AOC1,CPE,ANPEP和MEP1A),调节活性(TNFSF9、MDK、GDF15、ILR6A、LGALS3和FLNA),跨膜转运蛋白活性(SLC40A1和SLC5A1),和细胞外基质结构成分(FGL2、HMCN2和MUC17)。
结论:ERAP2在发炎的IBD结肠粘膜中上调,表达能力与rs2910686基因型高度相关。虽然SNPrs2248374通常用于确定ERAP2表达能力,我们的数据证实,独立于该SNP的机制可导致ERAP2缺陷.我们的数据表明上皮ERAP2的存在会影响结肠的炎症反应,表明ERAP2的多效性作用超出了MHCI类抗原加工。
BACKGROUND: ERAP2 is an aminopeptidase involved in antigen processing and presentation, and harbor genetic variants linked to several inflammatory diseases such as Inflammatory Bowel Disease (IBD). The lack of an ERAP2 gene homologue in mice has hampered functional studies, and most human studies have focused on cells of hematopoietic origin. Using an IBD biobank as vantage point, this study explores how genetic variation in ERAP2 affects gene expression in human-derived epithelial organoids upon proinflammatory stimulation.
METHODS: An IBD patient cohort was genotyped with regards to two single nucleotide polymorphisms (SNP) (rs2910686/rs2248374) associated with ERAP2 expression levels, and we examined the correlation between colon gene expression and genotype, specifically aiming to establish a relationship with ERAP2 expression proficiency. Human-derived colon organoids (
colonoids) with known ERAP2 genotype were established and used to explore differences in whole genome gene expression between ERAP2-deficient (n = 4) and -proficient (n = 4) donors upon pro-inflammatory encounter.
RESULTS: When taking rs2910686 genotype into account, ERAP2 gene expression is upregulated in the inflamed colon of IBD patients.
Colonoids upregulate ERAP2 upon IFNɣ stimulation, and ERAP2 expression proficiency is dependent on rs2910686 genotype. Colonoid genotyping confirms that mechanisms independent of the frequently studied SNP rs2248374 can cause ERAP2-deficiency. A total of 586 genes involved in various molecular mechanisms are differentially expressed between ERAP2 proficient- and deficient
colonoids upon proinflammatory stimulation, including genes encoding proteins with the following molecular function: catalytic activity (AOC1, CPE, ANPEP and MEP1A), regulator activity (TNFSF9, MDK, GDF15, ILR6A, LGALS3 and FLNA), transmembrane transporter activity (SLC40A1 and SLC5A1), and extracellular matrix structural constituents (FGL2, HMCN2, and MUC17).
CONCLUSIONS: ERAP2 is upregulated in the inflamed IBD colon mucosa, and expression proficiency is highly correlated with genotype of rs2910686. While the SNP rs2248374 is commonly used to determine ERAP2 expressional proficiency, our data confirms that mechanisms independent of this SNP can lead to ERAP2 deficiency. Our data demonstrates that epithelial ERAP2 presence affects the inflammatory response in
colonoids, suggesting a pleiotropic role of ERAP2 beyond MHC class I antigen processing.