Graphene compounds modulate autophagy combined with PU.1 change in the macrophages

The graphene, an allotrope of carbon, has the honeycombing structure of one-atom-thick planar sheets, is widely used for the modern electronics, informative technologies including medical devices. It may provoke immune response within the human beings. We tested the cellular response of macrophages by examination of change of autophagy and PU.1 which is monocyte-macrophage specific transcription factor. Raw264.7 cells were treated with GO, reduced GO(rGO), SDS-rGO, dodecyl amine(DA)-GO. MTT assay and Western blotting for PU.1, mTOR, NBR1, p62, Beclin-1 and LC3-A/B-I/II. Cell viability was reduced after treatment of 4 kinds of GO compounds in macrophages in light microscopy and MTT assay. PU.1 expression was remarkably decremented in response to treatment of GO compounds. LC3-A/B-I to LC3A/B-II conversion and NBR1 were decreased after treatment of GO. P62 expression induced by GO. Actin and Beclin-1 changed similarly. GAPDH expression was constant in 4 kinds of GO treatment. In case of DA-GO, rGO, SDS-rGO, PU.1 and LC3A/B-I to LC3A/B-II conversion was not remarkable. Taken together, these data might suggest the inter-relation between PU.1 and autophagy in macrophages. Further research should be mandatory for delving into association of PU.1 regulated autophagy in graphene-treated macrophages to explain the mechanism of immune response to graphene compounds.