Differential expression and bioinformatics analysis of circRNA expression in migraine patients. Differential expression and bioinformatics analysis of circRNA expression in migraine patients

Background：CircRNAs are non-coding RNA molecules that have recently been described and shown to regulate miRNA functionality. While recent studies have suggested such circRNAs to be associated with pain related diseases in humans, no comprehensive migraine-related circRNA profiles have been generated and there is currently no clear understanding of whether they can serve as regulators of migraine pathology. Methods:We initially conducted a circRNA microarray analysis of the plasma of migraine patients and healthy controls. Based upon these data, we then selected 8 differentially expressed circRNAs and confirmed their expression in more migraine patient plasma samples via real-time PCR. We then performed functional and pathway enrichment analyses. Lastly, using a robust rank aggregation approach, we constructed a ceRNA network according to predicted circRNA–miRNA and miRNA–mRNA pairs in these migraine patient samples. Results:we were able to detect 2039 circRNAs in our patient samples, with and 794 of 1245 these circRNAs being up- and down-regulated in migraine patients relative to controls, respectively (fold change ≥1.5, P < 0.01). A qRT-PCR analysis confirmed that the expression of hsa_circRNA_100236, hsa_circRNA_102413, and hsa_circRNA_000367 was significantly enhanced in migraine patients, whereas the expression of hsa_circRNA_103809, hsa_circRNA_103670, and hsa_circRNA_101833 was significantly reduced in these individuals relative to healthy controls. We found these differentially regulated circRNAs to be associated with numerous predicted biological processes, with enrichment analyses suggesting that they may modulate PI3K-Akt signaling so as to promote inflammation to drive migraine development. However, further research will be needed to formally test these mechanistic possibilities and to validate these circRNAs as potential biomarkers of migraine patients.Conclusions: our results offer new potential insights into the mechanistic basis of this condition, and suggest that hsa_circRNA_000367 and hsa_circRNA_102413 may offer value as regulators of migraine pathology. Overall design: We obtained peripheral blood samples for 4 migraine patients and 3 healthy control patients.

背景：环状RNA（CircRNA）是一类近年被发现并证实可调控微小RNA（miRNA）功能的非编码RNA分子。尽管已有研究提示此类环状RNA与人类疼痛相关疾病存在关联，但目前尚未构建出全面的偏头痛相关环状RNA表达谱，且尚不明确其是否可作为偏头痛病理过程的调控因子。
方法：本研究首先对偏头痛患者与健康对照的血浆样本开展环状RNA芯片分析；基于该芯片数据，筛选出8个差异表达的环状RNA，并通过实时PCR在更多偏头痛患者血浆样本中验证其表达水平。随后进行功能富集与通路富集分析；最后，基于本研究中偏头痛患者样本内预测得到的环状RNA-微小RNA及微小RNA-信使RNA（mRNA）配对关系，采用稳健秩聚集法构建内源竞争RNA（ceRNA）网络。
结果：本研究在患者样本中共检测到2039个环状RNA，其中1245个环状RNA在偏头痛患者与健康对照间存在差异表达，分别有794个在偏头痛患者中上调、451个下调（倍数变化≥1.5，P<0.01）。实时定量PCR（qRT-PCR）验证结果显示，hsa_circRNA_100236、hsa_circRNA_102413及hsa_circRNA_000367在偏头痛患者中的表达水平显著升高，而hsa_circRNA_103809、hsa_circRNA_103670及hsa_circRNA_101833的表达水平则显著低于健康对照。本研究发现这些差异表达的环状RNA参与多种预测的生物学过程，富集分析结果提示其可能通过调控PI3K-Akt信号通路促进炎症反应，进而参与偏头痛的发生发展。不过，仍需开展进一步研究以正式验证上述机制假说，并验证这些环状RNA作为偏头痛患者潜在生物标志物的价值。
结论：本研究结果为偏头痛的发病机制提供了新的潜在视角，并提示hsa_circRNA_000367与hsa_circRNA_102413可作为偏头痛病理过程的调控因子。
整体实验设计：本研究收集了4名偏头痛患者与3名健康对照的外周血样本。