title: Blue Light Modulates Murine Microglial Gene Expression in the Absence of Optogenetic Protein Expression.
abstract: Neural optogenetic applications over the past decade have steadily increased; however the effects of commonly used blue light paradigms on surrounding, non-optogenetic protein-expressing CNS cells are rarely considered, despite their simultaneous exposure. Here we report that blue light (450 nm) repetitively delivered in both long-duration boluses and rapid optogenetic bursts gene-specifically altered basal expression of inflammatory and neurotrophic genes in immortalized and primary murine wild type microglial cultures. In addition, blue light reduced pro-inflammatory gene expression in microglia activated with lipopolysaccharide. These results demonstrate previously unreported, off-target effects of blue light in cells not expressing optogenetic constructs. The unexpected gene modulatory effects of blue light on wild type CNS resident immune cells have novel and important implications for the neuro-optogenetic field. Further studies are needed to elucidate the molecular mechanisms and potential therapeutic utility of blue light modulation of the wild type CNS.
authors.affiliation: Departments of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706.
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Cheng
authors.affiliation: Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Kiernan
authors.affiliation: Departments of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706.
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Eliceiri
authors.affiliation: Departments of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706.
authors.forename: Justin C
authors.initials: JC
authors.lastname: Williams
authors.affiliation: Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706.
authors.forename: Jyoti J
authors.initials: JJ
authors.lastname: Watters
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics / Q000528:radiation effects; D002460:Cell Line; D002470:Cell Survival / Q000235:genetics / Q000528:radiation effects; D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D053960:DNA Breaks / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005786:Gene Expression Regulation / Q000528:radiation effects*; D007249:Inflammation / Q000235:genetics / Q000378:metabolism; D008027:Light; D008070:Lipopolysaccharides / Q000009:adverse effects / Q000276:immunology; D051379:Mice; D017628:Microglia / Q000378:metabolism* / Q000528:radiation effects*; D062308:Optogenetics / Q000379:methods
chemical_list: D016207:Cytokines; D008070:Lipopolysaccharides