Abstract：
BACKGROUND: Adenosine A3 receptor (A3R) exerts analgesic, anti-inflammatory, and anti-nociceptive effects. In this study, we determined the analgesic mechanism of manual acupuncture (MA) in rats with complete Freund\'s adjuvant (CFA)-induced arthritis and explored whether MA ameliorates inflammation in these rats by upregulating A3R.
METHODS: Sixty Sprague Dawley (SD) rats were randomly divided into the following groups: Control, CFA, CFA + MA, CFA + sham MA, CFA + MA + DMSO, CFA + MA + IB-MECA, and CFA + MA + Reversine groups. The arthritis rat model was induced by injecting CFA into the left ankle joints. Thereafter, the rats were subjected to MA (ST36 acupoint) for 3 days. The clinical indicators paw withdrawal latency (PWL), paw withdrawal threshold (PWT), and open field test (OFT) were used to determine the analgesic effect of MA. In addition, to explore the effect of A3R on inflammation after subjecting arthritis rats to MA, IB-MECA (A3R agonist) and Reversine (A3R antagonist) were injected into ST36 before MA.
RESULTS: MA ameliorated the pathological symptoms of CFA-induced arthritis, including the pain indicators PWL and PWT, number of rearing, total ambulatory distance, and activity trajectory. Furthermore, after MA, the mRNA and protein expression of A3R was upregulated in CFA-induced arthritis rats. In contrast, the protein levels of TNF-α, IL-1β, Rap1, and p-p65 were downregulated after MA. Interestingly, the A3R agonist and antagonist further downregulated and upregulated inflammatory cytokine expression, respectively, after MA. Furthermore, the A3R antagonist increased the degree of ankle swelling after MA.
CONCLUSIONS: MA can alleviate inflammatory pain by inhibiting the NF-κB signaling pathway via upregulating A3R expression of the superficial fascia of the ST36 acupoint site in CFA-induced arthritis rats.
METHODS: Sixty Sprague Dawley (SD) rats were randomly divided into the following groups: Control, CFA, CFA + MA, CFA + sham MA, CFA + MA + DMSO, CFA + MA + IB-MECA, and CFA + MA + Reversine groups. The arthritis rat model was induced by injecting CFA into the left ankle joints. Thereafter, the rats were subjected to MA (ST36 acupoint) for 3 days. The clinical indicators paw withdrawal latency (PWL), paw withdrawal threshold (PWT), and open field test (OFT) were used to determine the analgesic effect of MA. In addition, to explore the effect of A3R on inflammation after subjecting arthritis rats to MA, IB-MECA (A3R agonist) and Reversine (A3R antagonist) were injected into ST36 before MA.
RESULTS: MA ameliorated the pathological symptoms of CFA-induced arthritis, including the pain indicators PWL and PWT, number of rearing, total ambulatory distance, and activity trajectory. Furthermore, after MA, the mRNA and protein expression of A3R was upregulated in CFA-induced arthritis rats. In contrast, the protein levels of TNF-α, IL-1β, Rap1, and p-p65 were downregulated after MA. Interestingly, the A3R agonist and antagonist further downregulated and upregulated inflammatory cytokine expression, respectively, after MA. Furthermore, the A3R antagonist increased the degree of ankle swelling after MA.
CONCLUSIONS: MA can alleviate inflammatory pain by inhibiting the NF-κB signaling pathway via upregulating A3R expression of the superficial fascia of the ST36 acupoint site in CFA-induced arthritis rats.
摘要：
背景：腺苷A3受体（A3R）发挥镇痛作用，抗炎,和抗伤害性作用。在这项研究中,我们确定了手动针刺（MA）对完全弗氏佐剂（CFA）诱导的关节炎大鼠的镇痛机制，并探讨了MA是否通过上调A3R改善这些大鼠的炎症。
方法:SD大鼠60只,随机分为对照组,CFA,CFA+MA,CFA+假MA,CFA+MA+DMSO,CFA+MA+IB-MECA,和CFA+MA+逆转组。左踝关节注射CFA诱导关节炎大鼠模型。此后,大鼠接受MA（ST36穴位）3天。临床指标爪退缩潜伏期（PWL），爪缩回阈值(PWT),和开放场试验（OFT）用于确定MA的镇痛作用。此外,探讨A3R对关节炎大鼠MA后炎症的影响,在MA之前将IB-MECA(A3R激动剂)和Reversine(A3R拮抗剂)注射到ST36中。
结果：MA改善了CFA诱导的关节炎的病理症状，包括疼痛指标PWL和PWT,饲养次数,总卧床距离,和活动轨迹。此外，在MA之后,在CFA诱导的关节炎大鼠中，A3R的mRNA和蛋白表达上调。相比之下,TNF-α的蛋白质水平，IL-1β,Rap1和p-p65在MA后下调。有趣的是,A3R激动剂和拮抗剂进一步下调和上调炎性细胞因子表达，分别,在MA之后。此外，A3R拮抗剂增加了MA后踝关节肿胀的程度。
结论：MA可通过上调CFA诱导的关节炎大鼠ST36穴位浅筋膜A3R的表达，抑制NF-κB信号通路减轻炎性疼痛。
方法:SD大鼠60只,随机分为对照组,CFA,CFA+MA,CFA+假MA,CFA+MA+DMSO,CFA+MA+IB-MECA,和CFA+MA+逆转组。左踝关节注射CFA诱导关节炎大鼠模型。此后,大鼠接受MA（ST36穴位）3天。临床指标爪退缩潜伏期（PWL），爪缩回阈值(PWT),和开放场试验（OFT）用于确定MA的镇痛作用。此外,探讨A3R对关节炎大鼠MA后炎症的影响,在MA之前将IB-MECA(A3R激动剂)和Reversine(A3R拮抗剂)注射到ST36中。
结果：MA改善了CFA诱导的关节炎的病理症状，包括疼痛指标PWL和PWT,饲养次数,总卧床距离,和活动轨迹。此外，在MA之后,在CFA诱导的关节炎大鼠中，A3R的mRNA和蛋白表达上调。相比之下,TNF-α的蛋白质水平，IL-1β,Rap1和p-p65在MA后下调。有趣的是,A3R激动剂和拮抗剂进一步下调和上调炎性细胞因子表达，分别,在MA之后。此外，A3R拮抗剂增加了MA后踝关节肿胀的程度。
结论：MA可通过上调CFA诱导的关节炎大鼠ST36穴位浅筋膜A3R的表达，抑制NF-κB信号通路减轻炎性疼痛。
