OBJECTIVETo observe the effects of close-to-bone needling (CBN) on the expressions of type-Ⅱcollagen, pro-collagen type Ⅱ C-terminal propeptide (PⅡCP) and C-telopeptide of type Ⅱ collagen (CTX-Ⅱ) in rabbits with knee osteoarthritis (KOA).

METHODSAmong 40 New Zealand rabbits, 10 rabbits were selected into a normal group; the remaining 30 rabbits were made into KOA model, and X-ray was used to evaluate the results of model establishment. After the model was successfully made, the rabbits were randomly divided into a model group, a CBN group and a regular acupuncture group, ten rabbits in each one.Rabbits in the CBN group and the regular acupuncture group were treated at "Neixiyan" (EX-LE 4), "Dubi" (ST 35), "Yinlingquan" (SP 9), "Zusanli" (ST 36) and "Liangqiu" (ST 34). The CBN group applied CBN, and the depth of needling was appropriate with needles reaching bone; the regular acupuncture group applied regular acupuncture. The electroacupuncture(EA) device was used in the two groups, 20 min per treatment, once a day.Five days of treatment were taken as one course, and totally 4 courses were given with an interval of 2 days between courses. The normal group received identical fixation as model group. After treatment, magnetic resonance imaging (MRI) was used to perform imaging observation on knee; transmission electron microscopy (TEM) was used to observe the cell structure of knee joint cartilage;HE staining was used to observe the pathological change of knee; TUNEL was used to observe the apoptotic index; the expressions of type-Ⅱ collagen proteins and mRNA were measured by Western-blot and reverse transcription-polymerase chain reaction (RT-PCR); the serum PⅡCP and CTX-Ⅱ levels were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTSAfter treatment, compared with the model group, in the CBN group and regular acupuncture group the articular cavity effusion was reduced without the subchondral bone edema; the cell structure of knee joint cartilage was regular with less apoptosis; the expressions of type-Ⅱ collagen proteins and mRNA were significantly increased (all<0.05), the PⅡCP levels were significantly increased (both<0.05), but the CTX-Ⅱ levels were significantly decreased (both<0.05).The differences of the expressions of type-Ⅱ collagen proteins and mRNA, the levels of PⅡCP and CTX-Ⅱ between the CBN group and the regular acupuncture group were significant (all<0.05); the differences between the CBN group and the normal group were non-significant (all>0.05).

CONCLUSIONSCBN can significantly improve the pathological status of cartilage of KOA, reduce apoptosis, and is likely to regulate the expressions of PⅡCP and CTX-Ⅱ to promote the type-Ⅱ collagen, which is superior to regular acupuncture.