Effect Of Electroacupuncture On The Expression Of Cartilage Cells MMP-13 In Rabbit Knee Osteoarthritis Model

bjective:Osteoarthritis (OA), a kind of degenerative joint disease, is characterized by synovitis and degradation of articular cartilage. The knee is the principle large joint affected by OA. Recent studies show that the synovial inflammatory response involved in the development of osteoarthritis. Matrix metalloproteinase-13 (MMP-13) is commonly recognized as a vital cytokines in the development of synovial inflammation and cartilage damage, which belongs to the family of matrix metalloproteinases (MMPs) in the collagenase subtypes. Clinical acupunctyre treatment is considered as the most effective method. When given electrical stimulation such as density waves, local muscles contract more, local blood circulate well, at the same time, they can also promote qi operation and help exudates absorption as well as cartilage repairment. The current experiment aims to investigate the influence of OA cartilage repairment with the intervention of electroacupuncture (EA) according to the observation of MMP-13 expression before and after the treatment by establishing rabbits' knees models. Methods:(1) Objects and interventions:30 New Zealand big-ear rabbits were randomized into normal group, model group and EA group,10 in each. The normal group do nothing, the other 20 were made knee osteoarthritis models by prolonged fixation of left-knee joint in extension with tubular plaster. Sacrificing the model group with air embolism 6 weeks later, and changes of indicators relating to left knee medial condyle cartilage were detected compeletely after model preparation. EA group selected 4 fixed points around the knee:"Liangqiu", "Zusanli" (Housanli), "Xuehai", "Yanglingquan". Stimulating the points with acupuncture needles and dense wave, sparse wave 4 Hz, density wave 20 Hz, pulse width 0.5 ms, each time 20 minutes, once a day, for 10 consecutive times. To kill the rabbits as above, observing changes in related indicators of the medial femoral condyle cartilage. (2) Observation index:â‘ The macroscopic observation of normal group, model group and EA group rabbits'left knee joints general morphology change by naked eyes;â‘¡Cut and seprate the rabbits'left knee medial condyle cartilages, after fixation of 10% neutral formaldehyde solution, embedding, sectioning paraffin HE dyeing and light microscopy toluidine blue staining cartilage cells form, scoring standards according to Mankin's of cartilage general form and light microscopy results.â‘¢The statistical treatment:all date mean differences, analysis the results with SPSS 13.0 plus or minus standard deviation of data statistics software, P<0.05 presents differences is significant. Results:(1) Cartilage general observation:normal group:no obvious joint effusion occurs, cartilage surface is smooth and deep bright bluish-white without any cracks; model group:joint effusion appears more, all the cartilage surfaces present gray and roughness with reduced glossiness, erosion occurs in some part places; EA group:part animals appear joint effusion and synovial hyperplasia with no obvious erosion, cartilage change major in roughness just to a lesser degree. EA group and model group Mankin's score by comparation of cartilage structure, said a significant difference (P<0.01). (2) HE and toluidine blue staining dyeing and pathological observation:normal group:cartilage surface becomes flat and cartilage layer'thickness is considerable, cartilage cells are all in order with fairly sizes, toluidine blue staining smooth, no lose dye matrix; model group: cartilage surface appears a little cankers, cartilage layer becomes thinner, cartilage cells decrease dramatically and in disorder, with little toluidine blue staining and occasional matrix dye loss; EA group:cartilage surface is regular with less crakes, cartilage layer is thicker than the model group, cells increased and all in order, weak toluidine blue staining. Differences represents significant meaning according to Mankin's score by comparation of normal group and model group, model group and EA group. (3) Immunohistochemical determination:MMP-13 in cartilage cells didn't express in normal group. While in the model group, MMP-13 expression appears in cartilage matrix and cytoplasm, obvious in every layers, especially in the table and middle ones with a peak density. Then for cell level, it appears to be deep brown particle, which can be found in more mature cartilage cells. In the EA group, light brown particles give a power evidence to prove MMP-13 expression in the dispersed cartilage cell matrix. The normal group and the model group, the model group and EA, when all the comparation are put into practice, differences make significant meaning (P<0.05). Conclusions:EA treatment can reduce MMP-13 expression in OA chondrocytes of rabbits, promote the rearrangement of cartilage cells, be a positive method to the treatment of OA.