Underlying mechanism on intra-articular injection of dexmedetomidine in alleviating cartilage damage and pain in monosodium iodoacetate-induced osteoarthritis rats by regulating the NF-κB/CX3CL1 signaling pathway
Objective To explore the molecular mechanism underlying the role of dexmedetomidine(Dex)in alleviating cartilage damage and pain in monosodium iodoacetate(MIA)-induced osteoarthritis rats by regulating the NF-κB(nuclear factor kappa-B)/CX3CL1(CX3C chemokine ligand 1)signaling pathway.Methods The cellular model of osteoarthritis was established by stimulating chondrocytes with IL-1β at 10ng/mL for 24h.The chondrocytes were divided into four groups,including the control group,model group(stimulation of chondrocytes with IL-1β),model + si-negative control(NC)group(transfection with NC siRNA for 48h followed by IL-1β stimulation),and IL-1β + MIR155HG group(transfection with MIR155HG siRNA for 48h followed by IL-1β stimulation).The expression level of MIR155HG was examined using the real-time quantitative reverse transcription polymerase chain reaction(RT-qPCR).The survival rate of chondrocytes was detected using the Calcein acetoxymethyl ester(Calcein AM)cell viability assay kit.The apoptosis of chondrocytes was evaluated using the TdT-mediated dUTP nick end labeling(TUNEL)assay.The protein levels of Bcl-2-associated X protein(Bcl-2),Bcl-2-associated X protein(Bax),matrix metalloproteinase-13(MMP-13),collagen type Ⅱ alpha 1(COL2A1),NLR family pyrin domain containing protein 3(NLRP3),apoptosis associated speck like protein containing a CARD(ASC),and Caspase-1 were measured by Western blotting.The concentrations of interleukin-6(IL-6),tumor necrosis factor-α(TNF-α),and interleukin-18(IL-18)were quantified by the enzyme-linked immunosorbent assay(ELISA)kits.Results Before treatment,there were no significant differences in thermal withdrawal latency(TWL)and mechanical withdrawal threshold(MWT)in rats among the five groups(P>0.05).After treatment,TWL and MWT in all groups except for control group were significantly reduced(P<0.05).Compared with those of Control group,TWL and MWT were significantly lower in Model group(P<0.05).Compared with those of Model group,TWL and MWT were significantly higher in Dex group and PDTC group,especially in Dex+PDTC group(P<0.05).Compared with those of Control group,relative levels of MMP-1,MMP-13,COX-2 and IL-1 in rat articular fluid were significantly higher in Model group(P<0.05),which were significantly reduced by Dex and PDTC(P<0.05),especially in Dex+PDTC group(P<0.05).Compared with those of Control group,rats in the Model group presented significant rupture and extensive proliferation of inflammatory cells on the articular surface of the cartilage,and higher Mankin score(P<0.05).Dex and PDTC significantly alleviated rupture and extensive proliferation of inflammatory cells on the articular surface of the cartilage,and decreased the Mankin score(P<0.05),which were much pronounced by Dex combined with PDTC(P<0.05).Compared with those of Control group,rats in the Model group presented significantly higher protein levels of cleaved-caspase-3,Bax,NF-κB and CX3CL1(P<0.05),which were significantly reduced by Dex and PDTC(P<0.05),especially in Dex+PDTC group(P<0.05).Conclusion Intra-articular injection of dexmedetomidine can significantly alleviate cartilage damage,apoptosis in cartilage tissue and pain in MIA-induced osteoarthritis rats by inhibiting the inflammatory response and the NF-κB/CX3CL1 signaling pathway.However,the mechanism is still worth further studying.
NETL
NSTL
万方数据
维普
