MicroRNA-185 inhibits the growth and proliferation of osteoblasts in fracture healing by targeting PTH gene through down-regulating Wnt/Œ≤ -catenin axis: In an animal experiment
Authors: Chang-Jiang Yao
Yang Lv
Jin Jiang
Ya-Yi Xia
Bin Geng
Cheng-Jun Zhang
Li-Hu Xu
Hong Li
Meng Wu
Jia-Xin Jin
Journal: Biochemical and Biophysical Research Communications (2018)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: Apoptosis; Fracture healing; MicroRNA-185; PTH gene; Proliferation
Affiliations: Orthopaedics Key Laboratory of Gansu Province, Lanzhou, 730000, PR China; Department of Orthopaedics, The Second Hospital of Lanzhou University, Lanzhou, 730000, PR China., Department of Ophthalmology, General Hospital of Lanzhou Military Command, Lanzhou, 730000, PR China; Department of Ophthalmology, Eye Institute of China PLA, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, PR China., Orthopaedics Key Laboratory of Gansu Province, Lanzhou, 730000, PR China; Department of Orthopaedics, The Second Hospital of Lanzhou University, Lanzhou, 730000, PR China. Electronic address: .

Abstract:  Fracture healing is a repair process of a mechanical discontinuity loss of force transmission, and pathological mobility of bone. Increasing evidence suggests that microRNA (miRNA) could regulate chondrocyte, osteoblast, and osteoclast differentiation and function, indicating miRNA as key regulators of bone formation, resorption, remodeling, and repair. Hence, during this study, we established a right femur fracture mouse model to explore the effect microRNA-185 (miR-185) has on osteoblasts in mice during fracture healing and its underlying mechanism. After successfully model establishment, osteoblasts were extracted and treated with a series of mimics or inhibitors of miR-185, or siRNA against PTH. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot analysis were performed to determine the levels of miR-185, PTH, Œ≤-catenin and Wnt5b. Cell viability, cycle distribution and apoptosis were detected by means of MTT and flow cytometry assays. Dual luciferase reporter gene assay verified that PTH is a target gene of miR-185. Osteoblasts transfected with miR-185 mimics or siRNA against PTH presented with decreased levels of PTH, Œ≤-catenin and Wnt5b which indicated that miR-185 blocks the Wnt/Œ≤ -catenin axis by inhibiting PTH. Moreover, miR-185 inhibitors promoted the osteoblast viability and reduced apoptosis with more cells arrested at the G1 stage. MiR-185 mimics were observed to have inhibitory effects on osteoblasts as opposed to those induced by miR-185 inhibitors. Above key results indicated that suppression of miR-185 targeting PTH could promote osteoblast growth and proliferation in mice during fracture healing through activating Wnt/Œ≤ -catenin axis. 

Retracted: No

PubPeer comments:
 Fig. 6A,  cell cycle of osteoblast in mice in six groups after 48-h transfection .  How did this happen?  , 
  Fig. 4. Protein expressions of PTH (A), b-catenin (B) and Wnt5b (C) in osteoblast after 48-h transfection in six groups .  The protein blobs appear to come from a restricted gamut of shapes, represented by several papers by otherwise-unrelated groups of authors. The distinctive loading control in B, with bubbles beneath one blob and providing another with an  eye , is particularly versatile.   ,