ABSTRACT
Objective To investigate the effect of POSTN protein on the proliferation of chondrocytes of tibial plateau in old rats.Methods Cartilage cells collected from the tibial plateau of old rats were cultured in vitro to the third generation.Then the cells were divided into 3 groups:POSTN group,PBS group and POSTN antibody group.The proliferations of the three groups at 24 h,48 h and 72 h were determined by EDU method.The expression of Notch1 protein was detected by immunohistochemistry in all groups at the same time.Female 20-month-old Sprague-Dawley rats were randomly divided into 3 groups:POSTN protein injection group,Phosphate Buffered Saline (PBS) injection group and POSTN antibody injection group.Twelve weeks after the operation,related reagents were injected 3 times consecutively at day 1,day 3,day 5 and EDU was injected into joints at day 1.At 2 weeks after injection,the rats were killed and the knee tibial plateau was taken to observe the proliferation of the cartilage cells.Results At 24 h,there were differences between the three groups O(F=27.32,P=0.017).The proliferation rates of POSTN group [(23±8)％] and PBS group [(21±10)％] were higher than that of POSTN antibody group (16±5)(P=0.003,P=0.011).At 48 h,there were differences between the three groups (F=35.34,P＜0.01).The proliferation rate of POSTN group [(36±11)％] was higher than that of the other groups [(22±6)％],(18±6)％(P=0.021,P＜0.01).At 72h,there were differences between the three groups (F=52.62,P=0.000).The proliferation rate of POSTN group [(56±17)％] was the highest one,the proliferation rate of PBS group [(31±8)％] was the medium,and the POSTN antibody group [(26±7)％] was the lowest one (all P＜0.05).As for Notch1 protein expression in chondrocytes,there were differences between the three groups (F=26.72,P＜0.01).The Notch1 protein was the most frequently expressed in POSTN protein-injection group and the least in the anti-POSTN group.In rats,the proliferation rate of the chondrocytes in the medial tibia plateau of the knee of POSTN protein injection group [(36±14)％],which was the highest,and that of the POSTN antibody injection group [(10 ±4)％] was the lowest (all P＜0.05).Conclusion POSTN protein can promote the proliferation of chondrocytes knee OA rats.POSTN antibody injection has been shown to induce the proliferation of chondrocytes.The POSTN protein may promote the proliferation of chondrocytes by activating the Notch signaling pathway.
ABSTRACT
Objective We performed comprehensive proteomic analyses of synovial fluid by using the isobaric tags for relative and absolute quantitation (iTRAQ) method and LC-MS/MS, and searched for candidate biomarkers for osteoarthritis. Methods Synovial fluid was collected from patients with late-stage OA, earlystage OA and the control group. Molecular variations were detected by the iTRAQ method. T test was used for statistical analysis. Results Using the iTRAQ method, we identified 1 283 proteins from synovial fluid of patients with osteoarthritis, of which 268 proteins were not reported previously. There were 72 proteins upregulated and 249 proteins down-regulated between moderate OA group and controls. One hundred and twentyeight proteins were up-regulated and 141 proteins were down-regulated between severe OA group and controls.One hundred and ninety-two proteins were up-regulated and 76 proteins were down-regulated between severe OA group and moderate OA group. Eight proteins were found to be up-regulated in the three groups.Conclusion This is an in-depth analysis of the synovial fluid proteome from patients with osteoarthritis by iTRAQ method. The catalog of proteins generated in this study will further expand our knowledge regarding the pathophysiology of osteoarthritis and help us in identifying good biomarkers for early diagnosis.
ABSTRACT
Objective We performed comprehensive proteomic analyses of synovial fluid by using the isobaric tags for relative and absolute quantitation (iTRAQ) method and LC-MS/MS, and searched for candidate biomarkers for osteoarthritis. Methods Synovial fluid was collected from patients with late-stage OA, earlystage OA and the control group. Molecular variations were detected by the iTRAQ method. T test was used for statistical analysis. Results Using the iTRAQ method, we identified 1 283 proteins from synovial fluid of patients with osteoarthritis, of which 268 proteins were not reported previously. There were 72 proteins upregulated and 249 proteins down-regulated between moderate OA group and controls. One hundred and twentyeight proteins were up-regulated and 141 proteins were down-regulated between severe OA group and controls.One hundred and ninety-two proteins were up-regulated and 76 proteins were down-regulated between severe OA group and moderate OA group. Eight proteins were found to be up-regulated in the three groups.Conclusion This is an in-depth analysis of the synovial fluid proteome from patients with osteoarthritis by iTRAQ method. The catalog of proteins generated in this study will further expand our knowledge regarding the pathophysiology of osteoarthritis and help us in identifying good biomarkers for early diagnosis.