Tang Xu-Yun, Chen Pan-Bi, Du Di-Jia, Qin Zhong-Yin, Long Run-Jin
College of Acupuncture-moxibustion and Tuina, Guizhou University of Traditional Chinese Medicine, Guiyang 550025, China.
Zhen Ci Yan Jiu. 2022 Feb 25;47(2):129-34. doi: 10.13702/j.1000-0607.201279.
To observe the effect of acupoint catgut embedment(ACE) on expression of p38 mitogen activated protein kinase (p38MAPK), intercellular adhesion molecule-1(ICAM-1), interleukin-4 (IL-4) and eosinophils (EOS) in lung tissue of asthmatic rats, so as to explore its mechanism underlying improvement of asthma.
Forty male Wistar rats were randomly divided into control, model, ACE and dexamethasone (DEX) groups, with 10 rats in each group. The asthmatic model was established by intraperitoneal injection of mixture suspension (1 mL) of ovalbumin (OVA,10%) and 10% Al (OH)+ normal saline, followed by inhalation of atomized 1% OVA solution for 30 min, once daily for 2 weeks to trigger occurrence of asthmatic symptoms. The ACE was applied once to "Feishu" (BL13), "Dingchuan" (EX-B1) and "Danzhong" (CV17). Rats of the DEX group were given intraperitoneal injection of DEX once a day for 2 weeks. H.E. staining was used to evaluate histopathological changes of the lung tissue. The relative number of EOS in the bronchoalveolar lavage fluid (BALF) was detected by Wright Giemsa staining. The apoptosis level of EOS in the lung tissue was detected by TUNEL staining. The ultrastructural changes of EOS in the lung tissues were observed by transmission electron microscope (TEM). The expression of p38MAPK, ICAM-1 and IL-4 mRNAs in the lung tissue was detected by quantitative real-time PCR.
Findings of optical microscope and TEM showed obvious bronchial deformation and inflammatory cell infiltration, rupture of EOS cell membrane, uneven cytoplasm with swelling and uneven density of eosinophilic granules in EOS of the model group, which was relatively milder in the ACE and DEX groups. Compared with the control group, the EOS number in BALF and the expressions of p38MAPK, ICAM-1 and IL-4 mRNAs in the lung tissue were significantly increased (<0.01), and the apoptosis index of EOS in the lung tissue was significantly decreased (<0.01) in the model group. After intervention, the EOS number in BALF and expression levels of p38MAPK, ICAM-1 and IL-4 mRNAs in the lung tissue of ACE and DEX groups were significantly decreased (<0.01, <0.05), as well as the apoptosis index of EOS in the lung tissue was significantly increased in both ACE and DEX groups (<0.01) in comparison with the model group. The EOS number in BALF and expression of ICAM-1 mRNA were significantly lower in the DEX group than those in the ACE group (<0.05).
Catgut embedding at acupoints may alleviate the airway inflammatory response in asthma rats, which may be related with its effects in down-regulating p38MAPK signaling, ICAM-1 and IL-4 mRNA expression, reducing the aggregation of EOS, and promoting the apoptosis of EOS.
观察穴位埋线对哮喘大鼠肺组织中p38丝裂原活化蛋白激酶（p38MAPK）、细胞间黏附分子-1（ICAM-1）、白细胞介素-4（IL-4）及嗜酸性粒细胞（EOS）表达的影响，以探讨其改善哮喘的作用机制。
将40只雄性Wistar大鼠随机分为对照组、模型组、穴位埋线组和地塞米松（DEX）组，每组10只。采用腹腔注射卵白蛋白（OVA，10%）与10%氢氧化铝混合悬液（1 mL）加生理盐水的方法建立哮喘模型，随后雾化吸入1% OVA溶液30分钟，每天1次，连续2周以诱发哮喘症状。穴位埋线组于“肺俞”（BL13）、“定喘”（EX-B1）和“膻中”（CV17）埋线1次。DEX组大鼠每天腹腔注射DEX 1次，连续2周。采用苏木精-伊红（H.E.）染色评价肺组织的组织病理学变化。采用瑞氏-吉姆萨染色检测支气管肺泡灌洗液（BALF）中EOS的相对数量。采用TUNEL染色检测肺组织中EOS的凋亡水平。通过透射电子显微镜（TEM）观察肺组织中EOS的超微结构变化。采用实时定量PCR检测肺组织中p38MAPK、ICAM-1和IL-4 mRNA的表达。
光学显微镜和TEM观察结果显示，模型组可见明显的支气管变形和炎性细胞浸润，EOS细胞膜破裂，细胞质不均匀，肿胀，嗜酸性颗粒密度不均匀，穴位埋线组和DEX组相对较轻。与对照组相比，模型组BALF中EOS数量及肺组织中p38MAPK、ICAM-1和IL-4 mRNA表达显著增加（<0.01），肺组织中EOS凋亡指数显著降低（<0.01）。干预后，与模型组相比，穴位埋线组和DEX组BALF中EOS数量及肺组织中p38MAPK、ICAM-1和IL-4 mRNA表达水平显著降低（<0.01，<0.05），肺组织中EOS凋亡指数显著增加（<0.01）。DEX组BALF中EOS数量及ICAM-1 mRNA表达显著低于穴位埋线组（<0.05）。
穴位埋线可减轻哮喘大鼠的气道炎症反应，可能与其下调p38MAPK信号通路、ICAM-1和IL-4 mRNA表达、减少EOS聚集及促进EOS凋亡有关。
