Remote photobiomodulation: an emerging strategy for neuroprotection

Luke C. Gordon; Daniel M. Johnstone

doi:10.4103/1673-5374.262573

摘要：Photobiomodulation (PBM) - the irradiation of cells or tissues with low-intensity red to near-infrared light - is emerging as an effec-tive means of enhancing cell and tissue resilience and repair. As reviewed elsewhere (Gordon et al., 2019), the intracellular effects of PBM appear to be primarily mediated by cytochrome C oxidase, a key enzyme in the mitochondrial respiratory chain and a primary photoacceptor of red to near-infrared light. Absorption of light by cytochrome C oxidase alters its redox state, resulting in increased ATP production, the liberation of nitric oxide and a transient burst in reactive oxygen species. This, in turn, triggers a cascade of secondary downstream effects that collectively enhance cell and tissue resilience, including the reactive oxygen species-mediated activation of key transcription factors and consequent effects on the expression of genes involved in cell proliferation and migration and in the production of cytokines and growth factors. In the context of neurodegenerative diseases, the disease-modifying or "neuropro-tective" effects of PBM have been demonstrated in animal models of retinal degeneration, stroke, traumatic brain injury, Alzheimer’s disease, frontotemporal dementia and Parkinson’s disease (PD) (Johnstone et al., 2016; Gordon et al., 2019).