808 nm wavelength light induces a dose-dependent alteration in microglial polarization and resultant microglial induced neurite growth.

摘要: Background and Objective Despite the success of using photobiomodulation (PBM), also known as low level light therapy, in promoting recovery after central nervous system (CNS) injury, effect PBM on microglia, primary mediators immune inflammatory response CNS, remains unclear. Microglia exhibit a spectrum responses to with partial or full polarization into pro- anti-inflammatory phenotypes. Pro-inflammatory (M1 classically activated) microglia contribute chronic inflammation neuronal toxicity, while (M2 alternatively play role wound healing tissue repair; can fall anywhere along this stimulation. Materials Methods The microglial therefore was investigated colorimetric assays, immunocytochemistry, proteomic profiling RT-PCR vitro exposure BV2 cell line differing energy densities (0.2, 4, 10, 30 J/cm2, 808 nm wavelength, 50 mW output power). Results PBM has dose-dependent M1 M2 polarization. Specifically, between 4 30 J/cm2 induced expression markers microglia. Markers phenotype, including CD206 TIMP1, were observed at lower 0.2–10 J/cm2. In addition, co-culture control-treated cultures demonstrated microglial-induced growth neurite extension. Conclusion These data suggest that Arndt–Schulz law applied for specific bioassay does not hold true cells responses, alter phenotype across manner. These are important relevance only therapies CNS but understanding effects mechanisms. Lasers Surg. Med. © 2013 Wiley Periodicals, Inc.