Acupuncture regulates macrophage polarization in COPD mice model by activating dopamine D2 receptor

Introduction: Activation of dopamine D2 receptor is involved in inhibition of macrophage (Mø) polarization. Acupuncture (Acup) reportedly inhibits Mø polarization in COPD model, but whether D2 receptor is involved in it remains unknown. Methods: BALB/c mice were equally allocated to controls, COPD models, Acup group, sham Acup group, CPZ group, D1 blocking group (D1) and D2 blocking group (D2). COPD model was induced by exposure of CS and mice were injected and acupunctured as described previously. Morphology, Mø polarization and expression of protein were determined. Results: Slighter alveolar destruction, elevated Arg-1 and decreased CD11c were seen in Acup and D1 groups. Compared to controls, iNOS, pSTAT3 and p-p65 elevated in sham Acup and model groups (p‹0.05), whereas Arg-1, DRD2 and SOCS3 decreased (p‹0.05). This effect reversed with varying degrees after Acup, which was more significant in Acup and D1 groups than in CPZ and D2 groups. Conclusions: Acupuncture shifts Mø polarization from M1 to M2 by D2 receptor in COPD mice model, which might be involved in the alleviation of pathological damage of COPD.