Resistin regulates AMPK/mTOR pathway activity in PAECs. (a) PAECs were co-cultured with wild-type or resistin knockout PAMs, and the PAMs were infected by H. parasuis (100 MOI) for 2 h. Lysates of PAECs were collected and subsequently analysed for the protein levels of phospho-AMPK (S458), AMPK, phospho-mTOR (S2448), and mTOR using western blot analysis. β-actin served as a loading control. (b) PAECs were stimulated or unstimulated with recombined resistin protein (2.5, 5, or 0 nM) for 2 h. The expression of related proteins was analysed the same as above. The antibodies against phospho-AMPK (S458), AMPK, phospho-mTOR (S2448), and mTOR were diluted at 1/1000, and the antibody against β-actin was diluted at 1/50000. β-actin served as a loading control, and the relative protein level was calculated with ImageJ software and normalized to β-actin. **p<0.01 compared with the wild-type group (a) or the untreated group (b). Error bars represent the mean ± SEM (n = 3).