Effect mechanism of acupuncture for anti-asthmatic airway remodeling based on TGF-β1 / Smad3 signaling pathway

Abstract

To observe the effect of acupuncture at "Feishu" (BL 13) + "Dingchuan" (EX-B 1) and "Kongzui" (LU 6) + "Yuji" (LU 10) for the airway remodeling in asthma rats based on the transforming growth factor-β1 (TGF-β1)/ Smad family member 3 (Smad3) signaling pathway; and explore the efficacy difference between the two acupoint combinations. Forty SPF male SD rats, aged 4 weeks, were randomly divided into a blank group (n = 10) and a modeling group (n = 30). The ovalbumin (OVA) sensitization method was used to establish asthma model in the modeling group. After successful model preparation, the rats of the modeling group were randomized into a model group, an acupuncture at "Feishu" (BL 13) + "Dingchuan" (EX-B 1) (AAF) group, and acupuncture at "Kongzui" (LU 6)+"Yuji" (LU 10) (AAK) group, with 10 rats in each one. Starting from day 15 of the experiment, 5 min after motivating, acupuncture was applied to "Feishu" (BL 13) + "Dingchuan" (EX-B 1) and "Kongzui" (LU 6)+"Yuji" (LU 10) in the AAF group and the AAK group respectively. The intervention was delivered for 30 min each time, once daily, lasting 3 weeks consecutively. Using lung function detector, the airway resistance (RL) and dynamic compliance (Cdyn) of the lungs were detected. The histomorphology of lung tissues was detected with HE staining and Masson staining, and the mRNA and protein expression of TGF-β1 and Smad3 in lung tissues was detected with the real-time PCR and Western blot methods. Compared with the blank group, RL was increased and Cdyn was decreased in the rats of the model group (P<0.01); and RL was reduced and Cdyn was increased in the AAF group and the AAK group when compared with those in the model group (P<0.01, P<0.05). The rats of the model group had bronchial lumen stenosis, inflammatory cell infiltration, collagen fibre hyperplasia and thickened smooth muscle in the lung tissues when compared with those in the blank group; and in comparison with the model group, all of the above morphological changes were attenuated in the AAF group and the AAK group. Besides, these morphological changes of the lung tissues were more alleviated in the AAF group when compared with those in the AAK group. In comparison with the blank group, the mRNA and protein expression of TGF-β1 and Smad3 of the lung tissues was increased in the model group (P<0.01), and it was reduced in the AAF group and the AAK group when compared with that in the model group (P<0.05, P<0.01). The mRNA expression of TGF-β1 and Smad3 was lower in the AAF group when compared with that in the AAK group (P<0.05). Acupuncture at either "Feishu" (BL 13)+"Dingchuan" (EX-B 1) or "Kongzui" (LU 6)+"Yuji" (LU 10) reduces the airway remodeling in the rats with asthma, which may be related to the down-regulation of mRNA and protein expression of TGF-β1 and Smad3. The better efficacy is obtained with acupuncture at "Feishu" (BL 13)+"Dingchuan" (EX-B 1).