Inhibition of SDF-1α/CXCR4 Signalling in Subchondral Bone Attenuates Post-Traumatic Osteoarthritis
Authors: Xuejun Zhang
Hui Huang
Qing Yang
Peng Cheng
Fei Xu
Liang Qin
Fengjing Guo
Anmin Chen
Yonghui Dong
Hui Liu
Journal: International journal of molecular sciences (2016)
Discipline: CHEMISTRY
Keywords: MAPK pathway; SDF-1α/CXCR4; articular cartilage; osteoclast; post-traumatic osteoarthritis (PTOA)
Affiliations: Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China. .

Abstract:  Previous studies showed that SDF-1α is a catabolic factor that can infiltrate cartilage, decrease proteoglycan content, and increase MMP-13 activity. Inhibiting the SDF-1α/CXCR4 signalling pathway can attenuate the pathogenesis of osteoarthritis (OA). Recent studies have also shown that SDF-1α enhances chondrocyte proliferation and maturation. These results appear to be contradictory. In the current study, we used a destabilisation OA animal model to investigate the effects of SDF-1α/CXCR4 signalling in the tibial subchondral bone and the OA pathological process. Post-traumatic osteoarthritis (PTOA) mice models were prepared by transecting the anterior cruciate ligament (ACLT), or a sham surgery was performed, in a total of 30 mice. Mice were treated with phosphate buffer saline (PBS) or AMD3100 (an inhibitor of CXCR4) and sacrificed at 30 days post ACLT or sham surgery. Tibial subchondral bone status was quantified by micro-computed tomography (μCT). Knee-joint histology was analysed to examine the articular cartilage and joint degeneration. The levels of SDF-1α and collagen type I c-telopeptidefragments (CTX-I) were quantified by ELISA. Bone marrow mononuclear cells (BMMCs) were used to clarify the effects of SDF-1α on osteoclast formation and activity in vivo. μCT analysis revealed significant loss of trabecular bone from tibial subchondral bone post-ACLT, which was effectively prevented by AMD3100. AMD3100 could partially prevent bone loss and articular cartilage degeneration. Serum biomarkers revealed an increase in SDF-1α and bone resorption, which were also reduced by AMD3100. SDF-1α can promote osteoclast formation and the expression oftartrate resistant acid phosphatase (TRAP), cathepsin K (CK), and matrix metalloproteinase (MMP)-9 in osteoclasts by activating the MAPK pathway, including ERK and p38, but not JNK. In conclusion, inhibition of SDF-1α/CXCR4signalling was able to prevent trabecular bone loss and attenuated cartilage degeneration in PTOA mice. 

Retracted: No

PubPeer comments:
 In Figure 5A, a micrograph has been duplicated and presented as something else. ![file] , 
 #1 Dear Dr. Rosea: I appreciate your interest in our work and your comment on our article in the article. I have carefully re-examined our manuscript and lab records. There was indeed technical error in Figure 5A of this article. When writing the manuscript, a TRAP staining picture of 30 ng ml SDF-1u03b1 group was wrongly placed in 10 ng ml SDF-1u03b1 group. I will contact the journal and MDPI magazine for correction as soon as possible. Thank you again for reading my article carefully, and I apologize for the mistake in my work. ,