To observe the effectiveness of short thrust needling (STN, close-to-bone needing) plus electroacupuncture (EA) in healing knee cartilage tissue and in regulating expressions of cartilage vitamin K dependent gamma-glutamyl carboxylase (GGCX), matrix metalloproteinase-13 (MMP 13) and serum uncarboxylated matrix gla protein (ucMGP) in rabbits with knee osteoarthritis (KOA), so as to reveal its mechanism underlying improvement of KOA.
Forty New Zealand rabbits were randomly divided into normal, model, EA and STN+ EA groups (n = 10 in each group). The KOA model was created by cutting the medial lateral ligament and medial parapatellar arthrotomy of rabbits as described by Hulth and colleagues. For rabbits in the STN+ EA group, "Neixiyan" (EX-LE 4) and "Waixiyan" (ST 35) were punctured with filiform needles by controlling the needle-tip obliquely to advance till the bone surface of the knee joint cavity, and "Yinlingquan" (SP 9) and "Zusanli" (ST 36) punctured by holding the filiform needles vertically along the tibia, and "Liangqiu" (ST 34) was punctured by controlling the filiform needle to advance till the thigh-bone, followed by EA stimulation. EA (2 Hz/100 Hz, 1-3 mA) was applied to unilateral EX-LE 4 and ST 35, and ST 36 and SP 9, separately for 20 min, once daily for 20 days except weekends. The pathological changes of the knee cartilage cells were observed using H. E. staining, Toluidine blue staining and electron transmission microscope, respectively. The immunoactivity of GGCX of the knee cartilage was determined by immunohistochemistry and the expression levels of GGCX and MMP 13 proteins in the cartilage were detected by Western blot, and the content of serum ucMGP was assayed by ELISA.
H. E. staining, Toluidine blue staining and electron transmission microscope results showed that pathological changes of knee cartilage cells in structure after modeling were improved in both the STN+ EA and EA groups, particularly the former group. In comparison with the normal group, the expression levels of GGCX protein in the cartilage tissue showed by both Western blot and immunohistochemistry were notably down-regulated (P<0.01), and the cartilage MMP 13 protein expression and serum ucMGP content were considerably up-regulated in the model group (P<0.01, P<0.05). After STN+ EA and simple EA, the decreased GGCX and the increased MMP 13 expression and serum ucMGP content were reversed (P<0.01, P<0.05). The effects of STN+EA were significantly superior to those of simple EA in down-regulating MMP13 and ucGLA levels, and upre-gulating GGCX expression.
Both STN+ EA and simple EA can effectively improve pathological changes of cartilage cells in KOA rabbits, which may be associated with their actions in up-regulating the expression of cartilage GGCX protein and lowering the levels of serum ucMGP content and cartilage MMP 13 protein expression, and the effects of STN+ EA are better.