RESUMO
The beneficial effects of photobiomodulation (PBM) on function recovery after stroke have been well-established, while its molecular and cellular mechanisms remain to be elucidated. The current study was designed to investigate the effect of PBM on synaptic proteins and astrocyte polarization of photothrombotic (PT)-stroke induced rats in vivo, and explore the possible effect of PBM treatment on oxygen-glucose deprivation (OGD)-induced neurotoxic astrocytic polarization in vitro. We reported that 2-min PBM treatment (808 nm) for 7 days significantly increased synaptic proteins and neuroprotective astrocytic marker S100 Calcium Binding Protein A10 (S100A10) and inhibited neurotoxic astrocytic marker C3d in the peri-infarct region after ischemic stroke. Cell culture studies of primary cortical neurons and N2a cells showed that single-dose PBM treatment could increase cellular viability, regulate the apoptotic proteins (Caspase 9, Bcl-xL and BAX) and preserve synaptic proteins following OGD exposure. Additionly, PBM decreased the levels of C3d, inducible nitric oxide synthase (iNOS) and interleukin 1ß (IL-1ß) on astrocytes exposed to OGD. In summary, we demonstrated that PBM could inhibit neurotoxic astrocytic polarization, preserve synaptic integrity and protect neurons against stroke injury both in vitro and in vivo.
