Year-end Sale % OFF 
Abstract
ObjectivesThe aim of this study was to investigate the effect of Toll like receptor 4 (TLR4) on fracture healing. MethodsThe 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. ResultsTLR4 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). ConclusionTLR4 knockout reduced inflammatory and promoted fracture healing by activating Wnt/β-catenin signaling pathway.
Highlights
The aim of this study was to investigate the effect of Toll like receptor 4 (TLR4) on fracture healing
Our study aimed to reveal the effect of TLR4 on callus remodeling and biomechanical properties in the late stage of fracture healing
X ray results on the remaining 36 mice showed that the fracture lines of the tibia in wild type (WT) mice and TLR4-/- mice were clear on 7 days after the operation
Summary
The aim of this study was to investigate the effect of Toll like receptor 4 (TLR4) on fracture healing. Fracture healing is a complex physiologic process that involves the coordinated participation of several cell types 3. It is influenced by many factors (such as inflammation), which leading to delay union or nonunion with a incidence rate of 3–10% 4,5. The overexpression of TLR4 activates the downstream signaling pathways, induces inflammation related genes expression, and further leading to inflammatory reaction 10. Some researchers suggested that Wnt/β-catenin signaling pathway plays an important role in bone embryonic development 12–14. Wnt signaling pathway plays an important role in inflammatory bone diseases such as rheumatoid arthritis and chronic periodontitis 17. Whether there is an effect of TLR4 on fracture healing via Wnt/β-catenin signaling pathway is still unclear
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
