血浆微小RNA-146a在骨关节炎早期诊断中的作用及机制

The role and mechanism of plasma microRNA - 146a in the early diagnosis of osteoarthritis

目的观察微小RNA（miRNA，miR）-146a-3p在不同分级骨关节炎（OA）患者血浆中含量差异，探究其在OA早期发生发展过程中的作用机制。方法应用实时荧光定量聚合酶链反应（FQ-PCR）方法检测不同分级OA患者血浆和OA细胞中miR-146a-3p的表达量。进一步检测在人关节软骨细胞中瞬时过表达/抑制miR-146a-3p后软骨寡聚基质蛋白（COMP）、基质金属蛋白酶（MMP）-13、Ⅱ型胶原α1链（COL2A1）和含Ⅳ型血小板结合蛋白基序的解聚蛋白样金属蛋白酶（ADAMTS-5）等OA相关因子表达量变化，联合生物信息学方法预测miR-146a-3p的靶基因。 结果随着OA分级的升高，血浆miR-146a-3p相对表达量逐渐降低（F＝3.15，P＝0.012），亚临床OA组miR-146a-3p相对表达量（4.41±2.55）介于对照组（2.79±1.59）和OA Ⅰ级组（5.52±2.48）之间。人关节软骨细胞中，miR-146a-3p的表达量随IL-1β处理时间延长而显著降低（F＝24.32，P＝0.000）。瞬时过表达/抑制miR-146a-3p后，人关节软骨细胞中COMP和MMP-13基因的表达量变化分别与miR-146a-3p表达量变化的趋势相反，miRanda数据库预测发现COMP和MMP-13可能是miR-146a-3p的靶基因。 结论miR-146a-3p参与了早期OA的形成过程，可能通过下调MMP-13和COMP而发挥其生物学功能。

Objective To investigate the difference of microRNA （miRNA, miR）-146a-3p in plasma of patients with different grades of osteoarthritis （OA）, and explore its molecular mechanism in the early development of OA. Methods The expression of miR-146a-3p was detected by real-time fluorescent quantitative polymerase chain reaction （FQ-PCR） both in plasma of patients with different grades of OA and OA cell models. The mRNA expression of OA related factors, such as cartilage oligomeric matrix protein （COMP）, matrix metalloproteinase-13 （MMP-13）, collagen type Ⅱ alpha 1 （COL2A1） and a disintegrin and metalloproteinase with thrombospondin motifs 5 （ADAMTS-5）, was detected in human articular chondrocytes after transient transfection of miR-146a-3p mimics/inhibitor. The miR-146a-3p target genes were predicted by bioinformatics methods.Results With the increase of OA grades, the plasma miR-146a-3p content was gradually decreased （F=3.15, P=0.012）. The miR-146a-3p level in pre-OA group （4.41±2.55） was between the control group （2.79±1.59） and OA I group （5.52±2.48）. The expression of miR-146a-3p in human articular chondrocytes was decreased significantly with the time of IL-1β treatment （F=24.32, P=0.000）. After transient transfection of miR-146a-3p mimics/inhibitor, the expression of COMP and MMP-13 gene in human articular chondrocytes changed reversely with miR-146a-3p expression levels. MiRanda database predicts that COMP and MMP-13 may be the target genes of miR-146a-3p.Conclusion MiR-146a-3p is involved in the early development of OA. It may play a biological role by down-regulating MMP-13 and COMP, which provids a new biomarker and therapeutic target for early OA diagnosis and treatment.