Basic Study On The Effect Of SOX9 Regulated By Platelet-rich Plasma On Knee Osteoarthritis In SD Rats

Objective: The aim of this experiment was to investigate the effect of receptor agonists of Platelet-rich plasma(PRP)and sex-determining gene region(SOX9)on Y chromosome on the remission of knee osteoarthritis(KOA)in SD rats.Method: SD rat chondrocytes were treated with different concentrations of PRP and SOX9 agonists by an in vitro lipopolysaccharide(LPS)-induced inflammation model of articular chondrocytes.The concentrations of IL-1β,IL-6,tumor epidermal necrosis suppressor α(TNF-α)and inducible nitric oxide activase(i NOS)were detected by enzyme-linked mediated immunosorbent cell therapy(ELISA),and real-time fluorescence qualitative gene assay(RT-PCR).The m RNA expression levels of pathogenic genes(MMP-3),MMP-13,IL-1β,IL-6,ADAMTS-4,ADAMTS-5,cyclophosphoxase-inhibitor-2(COX)-2,polyproteoglycan(ACAN)and collagenase type Ⅱ A1(COL2A1)could be quantitatively detected.The anterior cruciate ligament(ACL)of SD rats was severed under local anesthesia to establish a model of KOA.Rats in the experimental group were injected subcutaneously with activated PRP solution(PRP: calcium chloride=1:9)every other day,0.5ml each time.Control rats and sham operation rats were injected 0.9% sodium chloride solution in the anterior cavity of the same joint at the same time every other day,0.5ml each time.The experiment lasted for one month and was detected by HE staining,saffron solid green staining and ditoluidine blue staining.Matrix metalloproteinase-13(MMP-13)and polyproteinase-4(ADAMTS-4)were detected by immunohistochemical staining.Results:(1)The results of in vitro experiment showed that the concentrations of IL-1β,IL-6,TNF-α and i NOS were significantly increased under the effect of LPS,and the levels of inflammatory cytokines were significantly decreased after adding different concentrations of PRP(P<0.05),especially after adding SOX9 agonist(P<0.01).The results of RT-PCR showed that the m RNA expressions of MMP-3,MMP-13,ADAMTS-4,ADAMTS-5,IL-1β,IL-6 and COX-2 were also increased under the influence of LPS.After treatment with PRP and SOX9 agonists,the expression levels of ACAN and COLA2A1 were significantly decreased,and the changes were significantly improved at different concentrations,among which SOX9 agonists had the most prominent effect and the most significant influence(P < 0.01 for both).(2)In vivo pathological experiment.According to the results of gross inspection of knee cartilage and joint pathological tissue sections and staining,the local pathological soft tissue injury and degree of articular cartilage in the experimental group were significantly reduced compared with the control group.Conclusion: Platelet-rich plasma may reduce the loss of polyproteoglycan and inhibit the induced degradation of chondrocyte hypertrophy factor and type II collagen in chondrocyte matrix by regulating the expression of SOX9 receptor,and can directly and effectively inhibit the abnormal expression and induced release of various inflammatory factor proteins in cartilage caused by LPS,so as to reduce the foreign influx to chondrocytes The induced degradation of matrix factors can alleviate the course of osteoarthritis.