Objectives: To observe the similarities and differences of effects of moxibustion at "Zusanli" (ST36) on target tissues and macrophages polarization in knee osteoarthritis (KOA) and rheumatoid arthritis (RA) rats, and to summarize its efficacy and characteristics.
Methods: Thirty rats were equally and randomly divided into control, KOA, RA, KOA+Moxi and RA+Moxi groups. The KOA model and RA model were induced by injection of sodium monoiodoacetate or Freund's complete adjuvant into the rats' knee joints, respectively. Rats of the KOA+Moxi and RA+Moxi groups received moxibustion stimulation at bilateral ST36 for 30 min, once a day for 21 days, beginning from the 7th day on after modeling. The contents of serum interleukin(IL)-1β and IL-10 were detected by ELISA. Histopathological changes (Markin score of the knee cartilage and synovial pathology score) of the knee joints were observed after HE staining. The polarization state of M1 and M2 macrophages in the synovial tissue of the knee joints was assessed by detecting the expression of CD86 and CD206 after immunofluorescence staining.
Results: Compared with the control group, the content of serum IL-1β, synovial pathology score, and synovial CD86 expression were significantly increased (P<0.01, P<0.05), while the content of serum IL-10 and synovial CD206 expression markedly decreased (P<0.01) in both KOA and RA groups；the Markin score was increased (P<0.01) in the KOA group. In comparison with the KOA group, the Markin score was obviously decreased (P<0.01), while the content of serum IL-10 and CD206 expression were apparently increased (P<0.01) in the KOA+Moxi group. No significant changes were found in the content of serum IL-1β, synovial pathology score and CD86 expression in the KOA+Moxi group relevant to the KOA group. In comparison with the RA group, the content of serum IL-1β, synovial pathology score, and CD86 expression were considerably decreased (P<0.01) in the RA+Moxi group. No marked differences were found in the serum IL-10 level, Markin score, and CD206 expression between RA+Moxi and RA model groups. The increased Markin score was significantly higher in the KOA group than in the RA group (P<0.01), but the increased synovial pathology score was significantly lower in the KOA group than in the RA group (P<0.01). Correspondingly, the effect of moxibustion at ST36 was significantly better in RA model than in KOA model in reducing serum IL-1β (P<0.05).
Conclusions: Moxibustion at ST36 can effectively reduce cartilage injury of knee joint in rats with KOA and reduce synovial injury in rats with RA, which may be related with its effects in lowering IL-1β level in RA model by inhibiting the polarization of M1 macrophages, and up-regulating level of IL-10 in KOA model by promoting the polarization of M2 macrophages. However, the relevant mechanism needs to be further studied.
目的: 通过艾灸膝关节骨关节炎（KOA）与类风湿性关节炎（RA）大鼠“足三里”，观察膝关节滑膜巨噬细胞极化情况的异同，并归纳腧穴功效特点。方法: 雄性SD大鼠随机分为对照组、KOA组、RA组、KOA+艾灸组、RA+艾灸组，每组6只。采用膝关节注射单碘乙酸钠建立KOA模型，膝关节注射弗氏完全佐剂建立RA模型。造模后7 d给予KOA+艾灸组与RA+艾灸组大鼠艾灸“足三里”治疗，30 min/次，1 次/d，连续21 d。治疗结束后，采用ELISA法检测大鼠血清白细胞介素（IL）-1β、IL-10含量；HE染色法观察大鼠膝关节组织形态学变化，分别采用Markin评分和膝关节滑膜病理评分评价大鼠膝关节软骨和滑膜病理情况；免疫荧光染色法检测大鼠膝关节滑膜CD86、CD206表达，分析M1、M2巨噬细胞极化情况。结果: 与对照组相比，KOA组及RA组大鼠血清IL-1β含量、膝关节滑膜病理评分、滑膜CD86表达水平显著升高（P<0.01，P<0.05），血清IL-10含量及滑膜CD206表达水平显著降低（P<0.01）；KOA组膝关节Markin评分显著升高（P<0.01）。与KOA组比较，KOA+艾灸组大鼠血清IL-10含量和滑膜CD206表达显著升高（P<0.01），Markin评分显著降低（P<0.01）。与RA组比较，RA+艾灸组大鼠血清IL-1β含量、滑膜病理评分和CD86表达显著降低（P<0.01）。KOA组膝关节Markin评分显著高于RA组（P<0.01），滑膜病理评分和CD86表达显著低于RA组（P<0.01）。KOA+艾灸组血清IL-1β含量、膝关节Markin评分显著高于RA+艾灸组（P<0.05，P<0.01），滑膜病理评分显著低于RA+艾灸组（P<0.01）。结论: 艾灸“足三里”能有效减轻KOA大鼠与RA大鼠膝关节炎性损伤，调控炎性反应，但对KOA来说主要通过促进M2型巨噬细胞极化以提高抑炎因子IL-10含量，而对RA则是抑制M1型巨噬细胞极化从而降低促炎因子IL-1β，这可能与“足三里”能随着不同机体状态对相应靶器官进行靶向性调节有关。.
Keywords: Efficacy of acupoints; Knee osteoarthritis; Macrophage polarization; Moxibustion; Reheumatoid arthritis; Zusanli (ST36).