Discoidin domain receptor 2 activation of p38 mitogen-activated protein kinase as an important pathway for osteonectin-regulating osteoblast mineralization

Journal of Orthopaedic Surgery and Research

Liang Chen¹  Ting-Ting Mo²  Yun-Sen Zhu²  Chang Jiang²  Ru-Chao Ma²  Jiang-Nan Zhang² 

[1] Department of Orthopaedic Surgery, The First Affiliated Hospital of Soochow University, 215000, Suzhou, Jiangsu, China;Department of Orthopaedic Surgery, The First People’s Hospital of Wenling, Chuan’an Nan Road NO 333, 317500, Wenling, Zhejiang, China;

关键词: Osteonectin;    p38 MAPK signaling pathway;    Discoidin domain receptor 2;    Mineralization;   

DOI  :  10.1186/s13018-021-02860-1

来源: Springer

【 摘 要 】

ObjectiveThe present study aimed to determine the role of the discoidin domain receptor 2 (DDR2) in the osteonectin (ON) regulation of osteoblast mineralization through the activation of p38 mitogen-activated protein kinase (MAPK).MethodsFour groups were established: the ON group, the inhibitor group, the Ddr2-small interfering ribonucleic acid (siRNA) group, and the control group. Osteoblasts from the parietal bones of neonatal Sprague–Dawley rats were isolated and cultured. In the ON group, 1 µg/mL ON was added to the osteoblasts. The gene expressions of collagen 1 (Col 1) and Ddr2 were detected using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). In the inhibitor group, the osteoblasts were added to WRG-28 (a specific DDR2 inhibitor), and in the Ddr2-siRNA group, the osteoblasts were transfected with Ddr2-siRNA. The gene and protein expressions of DDR2, bone sialoprotein, osteocalcin, osteopontin, and p38 MAPK were determined using RT-qPCR and western blot analysis. Alizarin red staining and transmission electron microscopy were used to detect mineralization.ResultsThe results showed that ON enhanced the osteoblast Col 1 and Ddr2 gene expressions, while the use of a Ddr2-siRNA/DDR2-blocker decreased the OPN, BSP, OCN, and P38 gene and protein expressions and reduced osteoblast cellular activity and mineralized nodules.ConclusionThe present study demonstrated that DDR2 activation of p38 MAPK is an important approach to ON-regulating osteoblast mineralization.

【 授权许可】

CC BY