Chinese Journal of Tissue Engineering Research ›› 2017, Vol. 21 ›› Issue (4): 538-544.doi: 10.3969/j.issn.2095-4344.2017.04.008

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miR-155 regulates the osteogenic differentiation of osteoblasts by inhibiting SMAD5 expression

Qiu Shi-yang1, Fu Xi-jia2, Bai Xiao-xue3, Yang Jun1   

  1. 1Department of Orthopedics and Traumatology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China; 2Department of Neurology, Chaoyang Central Hospital, Chaoyang 122000, Liaoning Province, China; 3Department of Cadre’s Ward, the First Hospital of Jilin University, Changchun 130021, Jilin Province, China
  • Received:2016-12-07 Online:2017-02-08 Published:2017-03-13
  • Contact: Corresponding author: Yang Jun, M.D., Associate professor, Department of Orthopedics and Traumatology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
  • About author:Qiu Shi-yang, Studying for master’s degree, Department of Orthopedics and Traumatology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
  • Supported by:

    the National Natural Science Foundation of China, No. 81600016

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Abstract:

Abstract
BACKGROUND: Induction of osteoblasts differentiating into osteocytes is a hot spot in tissue engineering; however, the regulatory mechanism underlying differentiation has not been fully elucidated. MicroRNA, as an endogenous small RNA molecule, can regulate post-transcriptional gene expression by binding to the 3’ nontranslated region of the target gene mRNA, which also has been found to play an important regulatory role in osteocyte differentiation.
OBJECTIVE: To study the regulation of miR-155 on osteoblast differentiation and the underlying mechanism.
METHODS: The mouse osteoblast cell lines MC3T3-E1 were selected and induced by mouse bone morphogenetic protein-2 (BMP2, 200 ng/mL) and then the miR-155 mRNA expression was determined by quantitative real-time PCR at 1, 3, 7 and 14 days. MC3T3-E1 cells were divided into control, BMP2, miR-155 and miR-155 inhibitor groups, followed by cultured with α-MEM medium, BMP2, miR-155 and miR-155 inhibitor, respectively, for 2 weeks.
RESULTS AND CONCLUSION: After induction using BMP2, miR-155 expression was downregulated in a time dependent manner. The staining intensity of alizarin red in the BMP2 group was significantly higher than that of the control group, and the activity of alkaline phosphatase and mRNA expression were also significantly higher than those in the control group (P < 0.01). The staining intensity of alizarin red, activity of alkaline phosphatase and mRNA expression in the miR-155 group were significantly lower than those in the control group (P < 0.01), while all above measurements were reversed significantly by miR-155 inhibitor (P < 0.05). miR-155 could bind to the 3’ untranslated region of SMAD5 mRNA and significantly downregulated the expressions of SMAD5 protein and mRNA in MC3T3-E1 cells (P < 0.01). These results show that miR-155 can inhibit MC3T3-E1osteogenic differentiation by downregulating SMAD5 expression.

中国组织工程研究杂志出版内容重点：组织构建；骨细胞；软骨细胞；细胞培养；成纤维细胞；血管内皮细胞；骨质疏松；组织工程

Key words: Tissue Engineering, Alkaline Phosphatase, Bone Morphogenetic Proteins

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