Abstract

Background

Osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs) is essential for bone formation, and its dysfunction is reported to be associated with osteoporosis (OP). Recent researches have determined that lncRNA PART1 participates in the pathogenesis of multiple diseases. However, its role in modulating osteogenic differentiation of hBMSCs is unclear.

Methods

PART1, miR-185-5p, and RUNX3 levels were assessed via RT-qPCR. The protein levels of OCN, OSN, and COL1A1 were measured by western blotting. The osteoblastic phenotype was evaluated via ALP activity and ARS staining. The relationship between miR-185-5p and PART1 or RUNX3 was validated by luciferase reporter, RIP assays.

Results

PART1 and RUNX3 expression were enhanced during hBMSC osteogenic differentiation. PART1 deletion decreased OCN, OSN, and COL1A1 levels and weakened ALP activity, but promoted the apoptosis of hBMSCs. Moreover, PART1 served as a ceRNA to influence the RUNX3 level via targeting miR-185-5p. In addition, RUNX3 was verified to activate the transcription of PART1 in hBMSCs. Finally, rescue assays indicated that suppression of miR-185-5p or addition of RUNX3 partially abolished the effects of PART1 knockdown on the levels of OCN, OSX, and COL1A1 levels, ALP activity, and apoptosis.

Conclusion

Our study elaborated that PART1/miR-185-5p/RUNX3 feedback contributed to osteogenic differentiation and inhibited the hBMSCs apoptosis, suggesting that PART1 might be a novel target for OP treatment.

中文翻译：

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LncRNA PART1/miR-185-5p/RUNX3反馈环调节骨髓间充质干细胞的成骨分化

摘要

背景

人骨髓间充质干细胞 (hBMSCs) 的成骨分化对骨形成至关重要，据报道其功能障碍与骨质疏松症 (OP) 相关。近期研究确定lncRNA PART1参与多种疾病的发病机制。然而，其在调节 hBMSCs 成骨分化中的作用尚不清楚。

方法

通过RT-qPCR评估 PART1、miR-185-5p 和 RUNX3 水平。通过蛋白质印迹测量 OCN、OSN 和 COL1A1 的蛋白质水平。通过ALP 活性和 ARS 染色评估成骨细胞表型。miR-185-5p 与 PART1 或 RUNX3 之间的关系已通过荧光素酶报告基因 RIP 测定进行验证。

结果

在 hBMSC 成骨分化过程中 PART1 和 RUNX3 表达增强。PART1缺失降低了OCN、OSN和COL1A1水平，削弱了ALP活性，但促进了hBMSCs的凋亡。此外，PART1 作为 ceRNA通过靶向 miR-185-5p 影响 RUNX3 水平。此外，RUNX3 被证实可激活 hBMSCs 中 PART1 的转录。最后，救援分析表明抑制 miR-185-5p 或添加 RUNX3 部分消除了 PART1 敲低对 OCN、OSX 和 COL1A1 水平、ALP 活性和细胞凋亡水平的影响。

结论

我们的研究阐述了 PART1/miR-185-5p/RUNX3 反馈有助于成骨分化并抑制 hBMSCs 凋亡，表明 PART1 可能是 OP 治疗的新靶点。