The effects of chitosan oligosaccharides on OPG and RANKL expression in a rat osteoarthritis model
Authors: Qing Chen
Qi Liao
Shi-Qing Liu
Jiang-Hua Ming
Ge-Liang Hu
Ya-Ming Li
Chun Zhang
Journal: Acta Cirurgica Brasileira (2017)
Discipline: CLINICAL MEDICINE
Keywords: chitosan oligosaccharides; osteoarthritis; osteoprotegerin; RANKL; RANK
Affiliations: PhD, Department of Orthopedics, Renmin Hospital, Wuhan University, China. Conception and design of the study, acquisition and interpretation of data, manuscript writing., PhD, Department of Orthopedics, Renmin Hospital, Wuhan University, China. Design of the study, critical revision, supervised all phases of the study., PhD, Department of Orthopedics, Renmin Hospital, Wuhan University, China. Acquisition of data, critical revision., Full Professor, Master, Department of Orthopedics, Renmin Hospital, Wuhan University, China. Acquisition of data.

Abstract:  Purpose:: To investigate the effect of chitosan oligosaccharides (COS) against osteoarthritis (OA) and preliminarily discuss the osteoprotegerin (OPG), receptor activator of NF-κB ligand (RANKL) and RANK expression in a rat OA model. Methods:: Thirty-six 6-week-old Male SD rats were randomly divided into three groups: sham-operated group(CON), OA-induction group(OA), COS intervention group(n=12/group). At 4 weeks after the operation, COS (50 ul) intervention weekily for consecutive 5 weeks. The OA and CON groups received an injection of 50 ul physiological saline. At death, 11 weeks following surgery, cartilage was harvested and total RNA and protein were extracted. Both the morphological changes of the cartilage were observed and harvested the total RNA and protein. Meanwhile, the expression of OPG, RANKL and RANK in cartilage were determined. Results:: The expression of OPG and RANKL were both enhanced in the cartilage of the OA model. Compared with the OA group, COS treatment improved the cartilage damage (both extent and grade). Furthermore, the COS group showed highly OPG and lower RANKL. Simultaneously, COS treatment upregulated the ratio of OPG/RANKL and downregulated the RANKL/RANK. Conclusion:: Chitosan oligosaccharides may be used as a unique biological agent to prevent and treat osteoarthritis, and this effect is associated with modulation of the expression of osteoprotegerin and receptor activator of NF-κB ligand. 

Retracted: No

PubPeer comments:
 Figures 4 and 5 appear to show the same panels, although the legends are different. Could the authors please check? ![file] , 
 Dear Dr. Bik, Thanks for your comment and your responsible attitude towards scientific research. After receiving your query, we carefully checked our original data and experimental records. Regarding your comment on Figures 4 and 5 appear to show the same panels, we have conducted a careful and detailed check. Duplicate image uploaded due to our negligence and lack of rigour. We also failed to discover the problems during the submission process. Under no circumstances will we intentionally falsify and tamper with experimental data to mislead reviewers and readers. We are so sorry about the lack of rigour or negligence. We will contact the editor of the journal to resubmit the corrected images. We will take this lesson as a valuable learning opportunity to do better in the future research work. Thanks again! Yours sincerely, Shiqing Liu ,