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

Objectives: 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.

Methods: 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.

Results: 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 (<0.01), while the protein expression and positive expression levels of E-cadherin were decreased (<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 (<0.01, <0.05), while the positive expression of E-cadherin was increased (<0.05). The positive expression level of p-AKT in the acupuncture group was decreased (<0.05). The level of IL-5 in BALF was decreased (<0.01) in the sham-acupuncture 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.

Conclusions: 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.