title: Effect of 710-nm visible light irradiation on neuroprotection and immune function after stroke.
abstract: OBJECTIVE
  The phototherapeutic effects of low level infrared laser irradiation (808 nm) on brain neuronal cell protection after stroke have been presented recently. We previously reported that 710-nm wavelength visible light (VIS) increases total lymphocyte counts in vivo, especially CD4(+) T lymphocytes. In this study, we investigated the effects of 710-nm VIS irradiation on neuronal protection and recovery correlating with cellular immunity in stroke rats.
  
  
  METHODS
  Rats were subjected to 90-min middle cerebral artery occlusion (MCAO) followed by reperfusion and were divided into two groups: irradiation and no irradiation. The irradiation group had been exposed to 710-nm VIS for 3 weeks after MCAO establishment or sham operation. The helper T cell (CD4(+)) count in the whole blood and infarct volume were measured. Messenger RNA expression levels of IL-4 and IL-10 in peripheral blood mononuclear cells were measured, a histologic study including microglia activation and regulatory T (Treg) cell markers, neurological severity scoring and a parallel bar walking test were all performed.
  
  
  RESULTS
  CD4(+) cell count was reduced after MCAO but was significantly increased by 710-nm VIS irradiation. The infarct sizes were decreased in the MCAO + irradiation group compared with the MCAO control group. IL-10 mRNA expression and the immunoreactivity of Treg cells were increased in the MCAO + irradiation group compared with the MCAO control group. Increased microglia activation after MCAO was reduced by 710-nm VIS irradiation. The irradiation group also showed improved neurological severity score levels and step fault scores after MCAO.
  
  
  CONCLUSIONS
  Our data suggest that 710-nm VIS irradiation may activate cellular immunity, reduce brain infarction and ultimately induce functional recovery in a stroke animal model.
authors.affiliation: Center for Neuroscience Research, SMART Institute of Advanced Biomedical Science, Konkuk University School of Medicine, Seoul, Republic of Korea.
authors.forename: Dong-Hee
authors.initials: DH
authors.lastname: Choi
authors.forename: Jeong Hoon
authors.initials: JH
authors.lastname: Lim
authors.forename: Kyoung-Hee
authors.initials: KH
authors.lastname: Lee
authors.forename: Moon Young
authors.initials: MY
authors.lastname: Kim
authors.forename: Hahn Young
authors.initials: HY
authors.lastname: Kim
authors.forename: Chan Young
authors.initials: CY
authors.lastname: Shin
authors.forename: Seol-Heui
authors.initials: SH
authors.lastname: Han
authors.forename: Jongmin
authors.initials: J
authors.lastname: Lee
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D020520:Brain Infarction / Q000000981:diagnostic imaging* / Q000209:etiology; D049109:Cell Proliferation / Q000528:radiation effects; D004195:Disease Models, Animal; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000528:radiation effects; D020244:Infarction, Middle Cerebral Artery / Q000150:complications / Q000276:immunology* / Q000532:radiotherapy; D016753:Interleukin-10 / Q000235:genetics / Q000378:metabolism; D015847:Interleukin-4 / Q000235:genetics / Q000378:metabolism; D008297:Male; D009422:Nervous System Diseases / Q000000981:diagnostic imaging / Q000209:etiology; D018696:Neuroprotective Agents; D011859:Radiography; D011878:Radiotherapy / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D015424:Reperfusion; D013601:T-Lymphocytes / Q000528:radiation effects*
chemical_list: D015703:Antigens, CD; D018696:Neuroprotective Agents; D016753:Interleukin-10; D015847:Interleukin-4