title: MiR-690, a Runx2-targeted miRNA, regulates osteogenic differentiation of C2C12 myogenic progenitor cells by targeting NF-kappaB p65.
abstract: BACKGROUND
  The runt-related transcription factor 2 (Runx2) is a cell-fate-determining factor that controls osteoblast differentiation and bone formation. It has been previously demonstrated that microRNAs (miRNAs) play important roles in osteogenesis. However, the Runx2-regulated miRNAs that have been reported thus far are limited. In this study, we pursued to identify these miRNAs in Tet-on stable C2C12 cell line (C2C12/Runx2(Dox) subline).
  
  
  RESULTS
  Microarray analysis revealed that alterations in miRNA expression occur with 54 miRNAs. Among these miRNAs, miR-690 was identified as a positive regulator of Runx2-induced osteogenic differentiation of C2C12 cells through gain- and loss-of-function assays. Expression of miR-690 is induced by Runx2, which binds directly to the putative promoter of mir-690 (Mirn690). The miR-690 proceeds to inhibit translation of the messenger RNA encoding the nuclear factor kappa B (NF-κB) subunit p65 whose overexpression inhibits Runx2-induced osteogenic differentiation of C2C12 cells. Interleukin-6 (IL-6), a downstream target of NF-κB pathway, is upregulated by p65 overexpression but significantly downregulated during this differentiation process. Furthermore, overexpression of IL-6 impedes the expression of osteocalcin, a defined marker of late osteoblast differentiation.
  
  
  CONCLUSIONS
  Together, our results suggest that the miR-690 transactivated by Runx2 acts as a positive regulator of Runx2-induced osteogenic differentiation by inactivating the NF-κB pathway via the downregulation of the subunit p65.
authors.affiliation: Institute of Biomedicine, Jinan University, National Engineering Research Center of Genetic Medicine, Key Lab for Bioengineering Medicine of Guangdong Province, Guangzhou, Guangdong People's Republic of China.
authors.forename: Shouhe
authors.initials: S
authors.lastname: Yu
authors.affiliation: Institute of Biomedicine, Jinan University, National Engineering Research Center of Genetic Medicine, Key Lab for Bioengineering Medicine of Guangdong Province, Guangzhou, Guangdong People's Republic of China.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Geng
authors.affiliation: Central Laboratory, People's 10th Hospital, Shanghai, People's Republic of China.
authors.forename: Qiuhui
authors.initials: Q
authors.lastname: Pan
authors.affiliation: College of Life Science, Yangtze University, Jingzhou, Hubei People's Republic of China.
authors.forename: Zhongyu
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering, Jinan University, Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou, Guangdong People's Republic of China.
authors.forename: Shan
authors.initials: S
authors.lastname: Ding
authors.affiliation: Institute of Biomedicine, Jinan University, National Engineering Research Center of Genetic Medicine, Key Lab for Bioengineering Medicine of Guangdong Province, Guangzhou, Guangdong People's Republic of China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Xiang
authors.affiliation: Department of Medical Laboratory, People's 10th Hospital, Shanghai, People's Republic of China.
authors.forename: Fenyong
authors.initials: F
authors.lastname: Sun
authors.affiliation: College of Pharmacy, Jinan University, Guangzhou, Guangdong People's Republic of China.
authors.forename: Can
authors.initials: C
authors.lastname: Wang
authors.affiliation: Institute of Biomedicine, Jinan University, National Engineering Research Center of Genetic Medicine, Key Lab for Bioengineering Medicine of Guangdong Province, Guangzhou, Guangdong People's Republic of China.
authors.forename: Yadong
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Institute of Biomedicine, Jinan University, National Engineering Research Center of Genetic Medicine, Key Lab for Bioengineering Medicine of Guangdong Province, Guangzhou, Guangdong People's Republic of China.
authors.forename: An
authors.initials: A
authors.lastname: Hong
keywords: NF-κB pathway; Osteogenic differentiation; Runx2; miR-690; p65