Acupuncture inhibits epithelial mesenchymal transition in allergic asthma rats by activating the PI3K/AKT pathway through DEK activation

To observe the effect of acupuncture at “Dazhui” (GV14) and “Shenzhu” (GV12) on DEK/phosphorylated phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway and epithelial-mesenchymal transition related factors in rats with allergic asthma (AA), so as to explore its potential mechanism in the treatment of AA.

Sixty SD rats were randomly divided into normal, model, acupuncture, dexamethasone (DEX) and sham-acupuncture groups, with 12 rats in each group. The AA model was made by intraperitoneal injection of mixture solution of ovalbumin and aluminium hydroxide gel (on day 1 and 7) and followed by inhalation of atomized 1% ovalbumin (30 min, from day 15, once daily for 14 days). Rats in the acupuncture group received acupuncture at GV14 and GV12, while rats in the sham-acupuncture group received acupuncture at the non-meridian and non-acupoint point, both for 20 min, once daily for 14 days. Rats of the DEX group received intraperitoneal injection of DEX (0.5 mg/kg), once daily for 14 days. H.E. staining was used to observe the changes of pathological morphology in lung tissue. ELISA was used to detect the levels of interleukin (IL)-4 and IL-5 in broncho alveolar lavage fluid (BALF), and serum immunoglobulin IgE and IgM. Western blot was used to detect the expressions of DEK, PI3K, AKT, phosphorylated (p)-PI3K, p-AKT, and E-cadherin in lung tissue. Immunofluorescence staining was used to detect the positive expressions of DEK, p-PI3K, p-AKT, and E-cadherin in lung tissue.

Compared with the normal group, the levels of IL-4, IL-5 in BALF and serum IgE and IgM, the protein expression levels of DEK, p-PI3K and p-AKT in lung tissue, the positive expression levels of DEK, p-PI3K and p-AKT were increased in the model group (P<0.01), while the protein expression and positive expression levels of E-cadherin were decreased (P<0.01). In comparison with the model group, the contents of IL-4, IL-5 in BALF and serum IgE and IgM, the protein expressions of DEK, p-PI3K and p-AKT, the positive expression levels of DEK and p-PI3K in the acupuncture and DEX groups were decreased (P<0.01, P<0.05), while the positive expression of E-cadherin was increased (P<0.05). The positive expression level of p-AKT in the acupuncture group was decreased (P<0.05). The level of IL-5 in BALF was decreased (P<0.01) in the shamacupuncture grourp relative to the model group. H.E. staining showed that the rats in the model and sham-acupuncture groups exhibited thickened bronchial walls and increased infiltration of inflammatory cells, while these situations were obviously milder in both acupuncture and DEX groups.

Acupuncture can improve the airway remodeling of AA rats induced by ovalbumin, which may be associated with its functions in down-regulating the expression of DEK, inhibiting the activation of PI3K/AKT, and delaying the process of epithelial-mesenchymal transition.