Groen Kira, Maltby Vicki E, Scott Rodney J, Tajouri Lotti, Lechner-Scott Jeannette
School of Medicine and Public Health, University of Newcastle, Callaghan, New South Wales, Australia.
Centre for Brain and Mental Health Research, Hunter Medical Research Institute, New Lambton Heights, New South Wales, Australia.
Clin Transl Med. 2020 Jan;10(1):74-90. doi: 10.1002/ctm2.22. Epub 2020 Apr 10.
Multiple sclerosis is a demyelinating autoimmune disease, for which there is no blood-borne biomarker. Erythrocytes may provide a source of such biomarkers as they contain microRNAs. MicroRNAs regulate protein translation through complementary binding to messenger RNA. As erythrocytes are transcriptionally inactive, their microRNA profiles may be less susceptible to variation. The aim of this study was to assess the biomarker potential of erythrocyte microRNAs for multiple sclerosis and assess the potential contribution of erythrocyte-derived extracellular vesicle microRNAs to pathology.
Erythrocytes were isolated from whole blood by density gradient centrifugation. Erythrocyte microRNAs of a discovery cohort (23 multiple sclerosis patients and 22 healthy controls) were sequenced. Increased expression of miR-183 cluster microRNAs (hsa-miR-96-5p, hsa-miR-182-5p and hsa-miR-183-5p) was validated in an independent cohort of 42 patients and 45 healthy and pathological (migraine) controls. Erythrocyte-derived extracellular vesicles were created ex vivo and their microRNAs were sequenced. Targets of microRNAs were predicted using miRDIP.
Hsa-miR-182-5p and hsa-miR-183-5p were able to discriminate relapsing multiple sclerosis patients from migraine patients and/or healthy controls with 89-94% accuracy and around 90% specificity. Hsa-miR-182-5p and hsa-miR-183-5p expression correlated with measures of physical disability and hsa-miR-96-5p expression correlated with measures of cognitive disability in multiple sclerosis. Erythrocytes were found to selectively package microRNAs into extracellular vesicles and 34 microRNAs were found to be differentially packaged between healthy controls and multiple sclerosis patients. Several gene targets of differentially expressed and packaged erythrocyte microRNAs overlapped with multiple sclerosis susceptibility genes. Gene enrichment analysis indicated involvement in nervous system development and histone H3-K27 demethylation.
Erythrocyte miR-183 cluster members may be developed into specific multiple sclerosis biomarkers that could assist with diagnosis and disability monitoring. Erythrocyte and their extracellular microRNAs were shown to target multiple sclerosis susceptibility genes and may be contributing to the pathophysiology via previously identified routes.
多发性硬化症是一种脱髓鞘自身免疫性疾病，目前尚无血液中的生物标志物。红细胞可能提供此类生物标志物的来源，因为它们含有微小RNA。微小RNA通过与信使RNA的互补结合来调节蛋白质翻译。由于红细胞在转录上是无活性的，它们的微小RNA谱可能较不易发生变化。本研究的目的是评估红细胞微小RNA作为多发性硬化症生物标志物的潜力，并评估红细胞衍生的细胞外囊泡微小RNA对病理过程的潜在贡献。
通过密度梯度离心从全血中分离红细胞。对一个发现队列（23例多发性硬化症患者和22例健康对照）的红细胞微小RNA进行测序。在一个由42例患者以及45例健康和病理（偏头痛）对照组成的独立队列中验证了miR-183簇微小RNA（hsa-miR-96-5p、hsa-miR-182-5p和hsa-miR-183-5p）表达的增加。体外制备红细胞衍生的细胞外囊泡，并对其微小RNA进行测序。使用miRDIP预测微小RNA的靶标。
hsa-miR-182-5p和hsa-miR-183-5p能够以89%-94%的准确率和大约90%的特异性区分复发型多发性硬化症患者与偏头痛患者和/或健康对照。在多发性硬化症中，hsa-miR-182-5p和hsa-miR-183-5p的表达与身体残疾程度相关，hsa-miR-96-5p的表达与认知残疾程度相关。发现红细胞会选择性地将微小RNA包装到细胞外囊泡中，并且发现34种微小RNA在健康对照和多发性硬化症患者之间存在差异包装。差异表达和包装的红细胞微小RNA的几个基因靶标与多发性硬化症易感基因重叠。基因富集分析表明其参与神经系统发育和组蛋白H3-K27去甲基化。
红细胞miR-183簇成员可能发展成为特定的多发性硬化症生物标志物，有助于诊断和残疾监测。红细胞及其细胞外微小RNA被证明靶向多发性硬化症易感基因，并且可能通过先前确定的途径对病理生理过程产生影响。
