Effect Of Electroacupuncture On Artilage Cartilage And Subchondral Bone In The Knee Of Ovariectomised Rat

Objective:To explore the effects of Electroacupuncture on articular cartilage and the subchondral bone in a rat model of knee osteoarthritis induced by ovarictomy,and investigate whether the mechanism of Electroacupuncture is via the RANKL/RANK/OPG signal pathway.Methods:90 three-month-old male SD rats were randomly divided into three groups(n=30 per group): Sham group,ovariectomized group(OVX group),ovariectomy with Electroacupuncture treatment group(EA treatment group).The OVX group and the EA treatment group were used to replicate the osteoarthritis(OA)model by bilateral ovariectomy.While the Sham group was treated with insision of back skin.The rats of treatment group were treated with electroacupuncture for 30 minutes each day and five times a week,once a day after the surgery,The total oftervention duration was 12 weeks;The Sham group and OVX group without treatment.Ten experimental rats were randomly killed in each group at 4,8 and 12 weeks after surgery.The levels of Serum 17?-estradiol,Urinary C-terminal cross-linking telopeptide of type I collagen(CTX-I)and C-terminal cross-linking telopeptide of type II collagen(CTX-II)concentrations were analyzed by using ELISA system;The histopathological grading of cartilage was performed using the modified Mankin scoring system;Micro-CT scanner was performed to evaluate the microstructure of the subchondral bone;Using RT-PCR to detected the expression of MMP-13 and RANKL/RANK/OPG signal pathway(RANKL?OPG).Results:1.At 4,8 and 12 weeks after surgery,the levels of serum 17?-estradiol in OVX group were significantly lower than the Sham group(P<0.05,P<0.01,P<0.01),while EA treatment group increased it compared to the OVX group(all P<0.01).2.At 4,8 and 12 weeks after surgery,The levels of CTX-I in OVX group were significantly higher than Sham group(P<0.01,P<0.01,P<0.01),The levels of CTX-II in OVX group were significantly higher than Sham group(P<0.05,P<0.01,P<0.01);The levels of CTX-I in EA treatment group was lower compared with OVX group at different examination time(all P<0.01);The levels of CTX-II were found no statistically significant difference between EA treatment group and OVX group at 4 weeks after surgery,while the levels of CTX-II in the EA treatment group were lower contrast with OVX group at 8,12 weeks after operation(all P<0.01).3.At 4,8 and 12 weeks after surgery,The bone volume ratio(BV/TV)and trabecular thickness(Tb.Th)in OVX group were significantly lower and trabecular separation(Tb.Sp)was significantly increased than Sham group(all P<0.01);No statistically difference was found between the two groups' trabecular number(Tb.N)at 4 weeks after surgery,but the trabecular number(Tb.N)in the OVX group were lower than that of in Sham group at 8,12 weeks after surgery(all P<0.01);The bone volume ratio(BV/TV)and trabecular thickness(Tb.Th)in EA treatment group were significantly increased contrast with OVX group at different examination time point(all P<0.01),while the trabecular separation(Tb.Sp)was significantly decreased compared with OVX group(P<0.01,P<0.05,P<0.01);The trabecular number(Tb.N)was found no statistically significant difference between EA treatment group and OVX group at 4 weeks after surgery,but EA increased trabecular number(Tb.N)at 8,12 weeks after surgery contrast with the OVX group(P<0.05,P<0.01).4.There are no statistically difference was found in Mankin scores at 4,8 weeks among the three groups after surgery;At 12 weeks after surgery,mankin scores was significantly higher in the OVX group contrast with Sham group(P<0.01),while the Mankin scores in EA treatment group were significantly lower than OVX group at 12 weeks after surgery(P<0.01).5.The m RNA expression of MMP-13 was significantly higher in the OVX group than that in Sham group at 8,12 weeks after surgery(P<0.05,P<0.01),while in the group of EA it was significantly lower compared with OVX group until 12 weeks after surgery(P<0.01);The expression of OPG in OVX group was significantly lower than that in the Sham group at 4,8 and 12 weeks after surgery(all P<0.01),while the expression of RANKL increased compared with Sham group(all P<0.01);At 4,8 and 12 weeks after surgery,Compared with the OVX group,the OPG expression increased significantly(all P<0.01),and the expression of RANKL decreased in EA treatment group group(P<0.01,P<0.01,P<0.05).Conclusion:1.Electroacupuncture may protect the knee of osteoarthritis rats articular cartilage;2.The mechanism of electroacupuncture in protecting the articular cartilage of the knee may be related to the increase of estrogen level,the influence of RANKL/RANK/OPG signaling pathway and the inhibition of MMP-13.