MicroRNA-218, microRNA-191*, microRNA-3070a and microRNA-33 are responsive to mechanical strain exerted on osteoblastic cells.
MicroRNA (miRNA) is an important regulator of cell differentiation and function. Mechanical strain is important in the growth and differentiation of osteoblasts. Therefore, mechanresponsive miRNA may be important in the response of osteoblasts to mechanical strain. The purpose of the present study was to select and identify the mechanoresponsive miRNAs of osteoblasts. Mouse osteoblastic MC3T3-E1 cells were cultured in cell culture dishes and stimulated with a mechanical tensile strain of 2,50 με at 0.5 Hz, and the activity of alkaline phosphatase (ALP), mRNA levels of ALP, osteocalcin (OCN), and collagen type I (Col I), and protein levels of bone morphogenetic proteins (BMPs) in the cell culture medium were assayed. Following miRNA microarray and reverse transcription-quantitative polymerase chain reaction analyses, differentially expressed miRNAs in the mechanically strained cells and unstrained cells were selected and identified. Using bioinformatics analysis, the target genes of the miRNAs were then predicted. The results revealed that the mechanical strain of 2,500 με increased the activity of ALP, the mRNA levels of ALP, OCN and Col I, and the protein levels of bone morphogenetic protein(BMP)-2 and BMP-4 Continuous mechanical stimulation for 8 h had the most marked stimulant effects. miR-218, miR-191*, miR-3070a and miR-33 were identified as differentially expressed miRNAs in the mechanically strained MC3T3-E1 cells. Certain target genes of these four miRNAs were involved in osteoblastic differentiation. These findings indicated that a mechanical strain of 2,500 με, particularly for a period of 8 h, promoted osteoblastic differentiation, and the four mechanoresponsive miRNAs identified may be a potential regulator of osteoblastic differentiation and their response to mechanical strain.
Department of Biomedical Engineering, College of Biotechnology, Guilin Medical University, Guilin, Guangxi 541004, P.R. China.
Yong
Y
Guo
Department of Biomedical Engineering, College of Biotechnology, Guilin Medical University, Guilin, Guangxi 541004, P.R. China.
Yang
Y
Wang
Department of Biomedical Engineering, College of Biotechnology, Guilin Medical University, Guilin, Guangxi 541004, P.R. China.
Yinqin
Y
Liu
Department of Biomedical Engineering, College of Biotechnology, Guilin Medical University, Guilin, Guangxi 541004, P.R. China.
Yongming
Y
Liu
Shandong Provincial Key Laboratory of Functional Macromolecular Biophysics, Institute of Biophysics, Dezhou University, Dezhou, Shandong 253000, P.R. China.
Qiangcheng
Q
Zeng
Department of Biomedical Engineering, College of Biotechnology, Guilin Medical University, Guilin, Guangxi 541004, P.R. China.
Yumin
Y
Zhao
Lab of Biomechanics, Institute of Medical Equipment, Academy of Military Medical Sciences, Tianjin 300161, P.R. China.
Xinchang
X
Zhang
Lab of Biomechanics, Institute of Medical Equipment, Academy of Military Medical Sciences, Tianjin 300161, P.R. China.
Xizheng
X
Zhang
D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism; D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000032:analysis; D055415:Bone Morphogenetic Protein 4 / Q000032:analysis; D002454:Cell Differentiation; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D051379:Mice; D035683:MicroRNAs / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism; D015675:Osteocalcin / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D013314:Stress, Mechanical
D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D024042:Collagen Type I; D035683:MicroRNAs; D012333:RNA, Messenger; D015675:Osteocalcin; D000469:Alkaline Phosphatase