Imidazolines increase the levels of the autophagosomal marker LC3-II in macrophage-like RAW264.7 cells.

This study evaluated whether imidazolines can induce autophagy in the murine macrophage-like cell line RAW264.7. Idazoxan increased the content of LC3-II, an autophagosomal marker, in RAW264.7 cells. To determine whether this effect was due to the induction of its synthesis or inhibition of its degradation, idazoxan treatment was performed in the presence of bafilomycin A1, which blocks autophagosome-lysosome fusion, as well as Pepstatin A and E-64d, both of which block protein degradation in autolysosomes. An increased content of LC3-II was observed in the presence of bafilomycin A1 as well as the protease inhibitors. Furthermore, an increased number of autophagosomes was observed following idazoxan treatment using an autophagosome-specific dye. This indicated that idazoxan induced autophagy. Other imidazolines, such as efaroxan, clonidine, and 2-(2-benzofuranyl)-2-imidazoline, also increased the LC3-II content in RAW264.7 cells in the presence of bafilomycin A1. Taken together, these results indicate that some imidazolines, including idazoxan, can induce autophagy in RAW264.7 cells.