title: Differential expression of miR-672-5p and miR-146a-5p in osteoblasts in rats after steroid intervention.
abstract: BACKGROUND
  Apoptosis of osteoblasts and osteocytes is one cause of steroid-induced osteonecrosis of the femoral head; however, the molecular mechanism of steroid affecting osteoblasts at the genetic level is unclear. The aim of the present work is to examine differential expression of osteoblasts in rats after steroid intervention and to verify expression by real-time polymerase chain reaction (RT-PCR).
  
  
  METHODS
  Primary culture, passaging and identification of osteoblasts of SD neonatal rats were conducted; osteoblasts were divided into two groups, the control group, and the steroid group. Total RNA was extracted separately, and quality control was performed; by means of RNA labeling and microarray hybridization, data were collected and then standardized to ascertain differences in miRNA expression between the two groups. The gene expression spectrum was analyzed. Obvious differential expression of miR-672-5p and miR-146a-5p was verified by RT-PCR. Miranda, microcosm and mirdb bioinformatics software were used to predict target genes.
  
  
  RESULTS
  Compared with the control group, morphologically, the osteoblasts in the steroid group were more irregular and showed various shapes. The number of miRNAs (fold change >2) in the steroid group was six. Four miRNAs were upregulated and two miRNAs were downregulated. In particular, upregulated miR-672-5p expression and downregulated miR-146a-5p expression were significant. RT-PCR results showed that the 2(-△△) CT value of miR-672-5p in the steroid group was 3.743-fold of that in the control group, and the 2(-△△) CT value of miR-146a-5p in the steroid group was 0.322-fold of that in the control group. Angptl4, Ccdc51, Ssbp3 and RGD1306991 were predicted as the target gene of miR-672-5p, while Hrp12 was that of miR-146a-5p.
  
  
  CONCLUSIONS
  Expression profiles of miR-672-5p and miR-146a-5p had the most significant changes in the osteoblasts of rats with steroid intervention, which may provide a new viewpoint to pathogenesis of osteonecrosis of the femoral head.
authors.affiliation: Guangzhou University of Chinese Medicine, Guangzhou, China.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Li
authors.affiliation: Guangzhou University of Chinese Medicine, Guangzhou, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Sun
authors.affiliation: Deparment of orthopedics, The First Affiliated Hospital of Guangzhou university of Chinese Medicine, Guangzhou, China.
authors.forename: Jianchun
authors.initials: J
authors.lastname: Zeng
authors.affiliation: Deparment of orthopedics, The First Affiliated Hospital of Guangzhou university of Chinese Medicine, Guangzhou, China.
authors.forename: Yirong
authors.initials: Y
authors.lastname: Zeng
authors.affiliation: Deparment of orthopedics, The First Affiliated Hospital of Guangzhou university of Chinese Medicine, Guangzhou, China. Electronic address: luckypaper@yeah.net.
authors.forename: Yueguang
authors.initials: Y
authors.lastname: Fan
authors.affiliation: Deparment of orthopedics, The First Affiliated Hospital of Guangzhou university of Chinese Medicine, Guangzhou, China.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Feng
authors.affiliation: Deparment of orthopedics, The First Affiliated Hospital of Guangzhou university of Chinese Medicine, Guangzhou, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Li
mesh_terms: D000818:Animals; D020869:Gene Expression Profiling; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D009691:Nucleic Acid Denaturation / Q000187:drug effects; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D013256:Steroids / Q000494:pharmacology*
chemical_list: C554180:MIRN146 microRNA, rat; C000613789:MIRN672 microRNA, rat; D035683:MicroRNAs; D013256:Steroids
keywords: Osteoblasts; Steroid-induced osteonecrosis of the femoral head; miRNA expression