Department of Spinal Surgery, Qilu Hospital of ShanDong University, No. 107, Cultural West Road, Jinan City, Shandong Province, 250012, China; Department Of Orthopedics, Liaocheng People's Hospital, No. 67, Dongchang West Road, Liaocheng City, Shandong Province, 252000, China.
Department Of Orthopedics, Liaocheng People's Hospital, No. 67, Dongchang West Road, Liaocheng City, Shandong Province, 252000, China.
Pathol Res Pract. 2020 Feb;216(2):152766. doi: 10.1016/j.prp.2019.152766. Epub 2019 Nov 26.
The aim of this study was to investigate the effect of Toll like receptor 4 (TLR4) on fracture healing.
The open tibial fracture models in TLR4 knockout (TLR4) and wild type (WT) C57BL-6 J mice were established. The radiological examination, tartrate-resistant acid phosphatase (TRAP) staining, Micro-CT scan and biological torsion test were performed on 7, 14 and 21 days after operation. Enzyme Linked Immunosorbent Assay (ELISA) kit was used to detect the expression levels of tumor necrosis factor-α (TNF-α), interleukin-1 beta (IL-1β) and interleukin 6 (IL-6). Western blotting was used to detect the expression of β-catenin, Wingless-type MMTV integration site family, member 4 and 5B (Wnt4 and Wnt5B), proliferating cell nuclear antigen (PCNA) and bone morphogenetic protein-2 (BMP-2) of the callus tissue obtained from mice.
TLR4 knockout promoted fracture healing, reduced the number of osteoclasts, increased bone callus volume (BV) and callus mineralized volume fraction (BV/TV%) (P < 0.05), increased the maximum torque and torsional stiffness of callus (P < 0.05), reduced TNF-α, IL-1β and IL-6 expression (P < 0.01), and increased the expression levels of β-catenin, Wnt4, Wnt5B, PCNA and BMP-2 (P < 0.01).
TLR4 knockout reduced inflammatory and promoted fracture healing by activating Wnt/β-catenin signaling pathway.
本研究旨在探讨 Toll 样受体 4（TLR4）对骨折愈合的影响。
建立 TLR4 敲除（TLR4）和野生型（WT）C57BL-6J 小鼠开放性胫骨骨折模型。术后 7、14 和 21 天分别进行影像学检查、抗酒石酸酸性磷酸酶（TRAP）染色、Micro-CT 扫描和生物扭转试验。采用酶联免疫吸附试验（ELISA）试剂盒检测肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）和白细胞介素 6（IL-6）的表达水平。采用 Western blot 法检测取自小鼠骨痂组织中β-连环蛋白（β-catenin）、Wingless 型 MMV 整合位点家族成员 4 和 5B（Wnt4 和 Wnt5B）、增殖细胞核抗原（PCNA）和骨形态发生蛋白-2（BMP-2）的表达。
TLR4 敲除促进骨折愈合，减少破骨细胞数量，增加骨痂体积（BV）和骨痂矿化体积分数（BV/TV%）（P<0.05），增加骨痂最大扭矩和扭转刚度（P<0.05），降低 TNF-α、IL-1β 和 IL-6 的表达（P<0.01），增加β-catenin、Wnt4、Wnt5B、PCNA 和 BMP-2 的表达水平（P<0.01）。
TLR4 敲除通过激活 Wnt/β-catenin 信号通路减少炎症反应，促进骨折愈合。
