Huang Jianhou, Meng Yake, Liu Yan, Chen Yu, Yang Haisong, Chen Deyu, Shi Jiangang, Guo Yongfei
Department of Orthopedics, The 188th Hospital of PLA, ChaoZhou, GuangDong Province, China.
Cell Physiol Biochem. 2016;38(1):40-8. doi: 10.1159/000438607. Epub 2016 Jan 8.
BACKGROUND/AIMS: Human bone marrow-derived mesenchymal stem cells (hMSCs) are a promising cell source for bone engineering owing to their high potential to differentiate into osteoblasts. The bone morphogenetic protein-inducible gene homeobox a10 (HOXA10) is a critical regulator of osteogenesis. The objective of the present study was to identify microR-NAs (miRNAs) targeting HOXA10 and examine the effects on the osteogenic differentiation of hMSCs.
Based on in silico analysis, HOXA10-targeting miRNAs were selected and their regulatory roles in osteoblast differentiation were investigated.
Six HOXA10-targeting miRNAs were identifIed by computational analysis, of which miR-320a was selected for further analysis because it was downregulated during osteogenic induction. Overexpression of miR-320a downregulated HOXA10 and significantly inhibited osteogenesis in hMSCs, as determined by the downregulation of the osteogenic markers Runx2, ALP, and OC and the inhibition of ALP activity and matrix mineralization, whereas miR-320a inhibition had the opposite effects. Furthermore, ectopic expression of HOXA10 (not including 3'-UTR) rescued the effects of miR-320a on osteogenic differentiation.
These results suggest that miR-320a acts as a critical regulator of osteogenic differentiation of hMSCs by repressing its target HOXA10.
背景/目的：人骨髓间充质干细胞（hMSCs）因其具有向成骨细胞分化的高潜力，是骨组织工程中一种很有前景的细胞来源。骨形态发生蛋白诱导基因同源框a10（HOXA10）是成骨作用的关键调节因子。本研究的目的是鉴定靶向HOXA10的微小RNA（miRNAs），并研究其对hMSCs成骨分化的影响。
基于计算机分析，选择靶向HOXA10的miRNAs，并研究它们在成骨细胞分化中的调节作用。
通过计算机分析鉴定出6种靶向HOXA10的miRNAs，其中选择miR-320a进行进一步分析，因为它在成骨诱导过程中表达下调。miR-320a的过表达下调了HOXA10，并显著抑制了hMSCs的成骨作用，这通过成骨标志物Runx2、碱性磷酸酶（ALP）和骨钙素（OC）的下调以及ALP活性和基质矿化的抑制来确定，而抑制miR-320a则产生相反的效果。此外，HOXA10（不包括3'-UTR）的异位表达挽救了miR-320a对成骨分化的影响。
这些结果表明，miR-320a通过抑制其靶标HOXA10，作为hMSCs成骨分化的关键调节因子。
