电针“委中”穴对腰多裂肌损伤大鼠血小板衍生生长因子CC及受体α表达的影响

Effect of electroacupuncture at “Weizhong” (BL40) on expression of muscular PDGF-CC, PDGFR-α and MMP-1 in rats with lumbar multifidus muscle injury

目的:观察电针"委中"穴对腰多裂肌损伤大鼠血小板衍生生长因子CC(PDGF-CC)、血小板衍生生长因子受体α(PDGFR-α)、基质金属蛋白酶-1(MMP-1)表达的影响,从骨骼肌损伤后修复的角度研究电针及不同治疗周期对其的影响。方法:SD大鼠按随机数字表法分为正常组6只、模型组24只和电针组24只。其中,模型组和电针组再分1、3、5、7 d 4个亚组,每组6只,采用布比卡因致腰多裂肌损伤。电针组电针"委中"穴,每次治疗20 min,每日治疗1次,分别干预1、3、5、7 d。取大鼠左侧多裂肌用于HE染色观察多裂肌损伤变化,右侧多裂肌用于Western blot检测PDGF-CC、PDGFR-α、MMP-1的含量。结果:造模后,与正常组相比,模型组肌纤维出现大面积变形,肌间隙增大;同一时点,电针组肌纤维恢复程度优于模型组;电针5、7 d组肌纤维恢复程度优于电针1、3 d组。与同时点正常组相比,模型1、3、7 d组PDGF-CC表达降低(P<0.05),模型5 d组升高(P<0.05);模型5、7 d组PDGFR-α表达升高(P<0.05);模型3 d组MMP-1表达降低(P<0.05),模型5、7 d组表达升高(P<0.05)。与各时点模型组相比,电针3、5、7 d组PDGF-CC表达升高(P<0.05);电针5 d组PDGFR-α表达升高(P<0.05);电针3、5 d组MMP-1表达升高(P<0.05)。电针组各亚组比较,电针5 d组PDGF-CC、PDGFR-α表达高于电针1、3、7 d组(P<0.05);电针5、7 d组MMP-1表达高于电针1、3 d组(P<0.05)。结论:电针"委中"穴能促进损伤多裂肌的修复,并且在治疗5 d时有较好疗效,其机制可能与提高多裂肌中PDGF-CC、PDGFR-α和MMP-1的表达相关。

Objective To observe the effect of electroacupuncture(EA) of "Weizhong"(BL40) on the expression of platelet-derived growth factor(PDGF)-CC, PDGF receptor(PDGFR)α and matrix metalloproteinase-1(MMP-1) in rats with lumbar multifidus muscle injury(LMMI) so as to study its mechanisms underlying improvement of skeletal muscle injury. Methods Fifty-four male SD rats were randomly divided into normal group(n=6), model group(n=24) and EA group(n=24), and the latter two groups were further divided into four subgroups(1, 3, 5 and 7 days), with 6 rats in each group. The LMMI model was established by injection of 0.5% bupivacaine(BPVC, 100 μL×4) into the multifidus along the L4 and L5 spinous process. EA(2 Hz/50 Hz, 1 mA) was applied to bilateral "Weizhong"(BL40) for 20 min, once daily for 1, 3, 5 and 7 days respectively, from the first day on after modeling. Histopathological changes of the left multifidus muscle were observed after H.E. staining, and the expression of PDGF-CC, PDGFR-α and MMP-1 proteins in the right multifidus was observed by Western blot. Results Compared with the normal group, the expression levels of PDGF-CC protein in the model subgroup 1 d, 3 d and 7 d were significantly decreased(P<0.05), and those of PDGFR-α and MMP-1 proteins in the model subgroup 5 d and 7 d, and PDGF-CC protein in the model subgroup 5 d significantly increased(P<0.05). In comparison with the model subgroups, the expression levels of PDGF-CC in the EA subgroup 3 d, 5 d and 7 d, PDGFR-α in the EA subgroup 5 d, and MMP-1 in the EA group 3 d and 5 d were significantly increased or significantly further increased(P<0.05). H.E. staining showed different shapes and uneven sizes, with large area of damage, enlarged muscle space and inflammatory cell infiltration in the model group, which was relatively milder in the EA subgroups particularly in subgroup 5 d and 7 d. Conclusion EA stimulation of BL40 for about 5 days has a positive effect in promoting the repair of the injured multifidus muscle in LMMI rats, which may be related to its function in up-regulating the expression of muscular PDGF-CC, PDGFR-α and MMP-1 proteins.