miR-let-7d-HMGA2通路调控缺氧诱导的类风湿关节炎滑膜成纤维样细胞增殖

目的 研究缺氧在类风湿关节炎（rheumatoid arthritis, RA）滑膜成纤维样细胞（fibroblast-like synoviocytes, FLS）增殖中的作用及机制。 方法 采用HE染色法检测RA和对照骨关节炎（osteoarthritis, OA）滑膜组织FLS增生情况。分离原代RA-FLS并采用流式细胞术鉴定；将RA-FLS置于常氧（21%O2）或缺氧环境（3%O2）中培养，CCK-8法检测细胞增殖水平的变化，RT-PCR检测miR-let-7d表达的变化。通过类似物或抑制物改变miR-let-7d的表达，观察其对RA-FLS增殖、凋亡的影响；探究miR-let-7d靶基因在缺氧诱导的RA-FLS增殖中的作用。 结果 FLS在RA滑膜中增生明显，在缺氧环境下RA-FLS增殖加快，miR-let-7d表达水平降低；过表达miR-let-7d抑制RA-FLS增殖，但对细胞凋亡水平无明显影响；进一步的研究证实miR-let-7d靶基因HMGA2参与缺氧诱导的RA-FLS增殖。 结论 miR-let-7d-HMGA2通路调控缺氧诱导的RA-FLS增殖。

miR-let-7d-HMGA2 signaling regulates hypoxia-induced cell proliferation of fibroblast-like synoviocytes from patients with rheumatoid arthritis

Objective To investigate the mechanisms of hypoxia-induced cell proliferation of rheumatoid arthritis fibroblast-like synoviocytes(RA-FLS). Methods FLS proliferation in the synovium tissues from patients with RA and osteoarthritis(OA) was detected by hematoxylin-eosin(HE) staining. Primary RA-FLSs were isolated and identified by flow cytometry. RA-FLS was cultured under normoxia(21%O2) or hypoxia(3%O2) condition, and CCK-8 assay was used to detect cell proliferation. The expression of miR-let-7d in FLS was detected with RT-PCR. The miR-let-7d mimic and inhibitor were transfected to RA-FLS, respectively. The role of HMGA2 gene in hypoxia-induced proliferation of RA-FLS was also investigated. Results Compared in OA synovium, the proliferation of FLS in RA synovium was increased significantly. Increased proliferation and down-regulation of miR-let-7d expression was found in RA-FLS under hypoxic environments. Overexpression of miR-let-7d inhibited RA-FLS proliferation, but had no effect in the apoptosis of RA-FLS. Further study indicated that, HMGA2 was a target gene of miR-let-7d in RA-FLS, and was found to be involved in hypoxia-induced proliferation of RA-FLS. Conclusion The miR-let-7d-HMGA2 signaling pathway may be involved in the proliferation of RA-FLS under hypoxia condition.