title: Neuroglobin - a potential biological marker of retinal damage induced by LED light.
abstract: Neuroglobin (NGB), a protein highly expressed in the retina, has been shown to be up-regulated to protect neurons from hypoxic and ischemic injuries. It exhibits neuroprotective functions and plays an important role in the survival of neurons. Recent studies show that light-emitting diode (LED) white light emitted significant amounts of blue light (short-wavelength), which may be harmful to retinal cells, but the studies about biomarkers for evaluating the damage from LED white light are still insufficient. In our study, we found that NGB levels in the retina showed a twofold increase and peaked at 1h after a 1-h exposure to blue light (453 nm) which did not cause damage to the retina. However, retinal damage was observed after 2h of blue-light irradiation, which induced an approximate sevenfold increase of NGB levels as confirmed by Western blot and RT-PCR analysis. Immunofluorescence study demonstrated that NGB was predominantly up-regulated in the ganglion cell layer (GCL), plexiform layer (PL) and photoreceptor layer (PRL). We also examined Ngb mRNA and protein expression in the damaged retina induced by light of other wavelengths given equal photon fluxes. The LED red light (625 nm), green light (527 nm) and blue light (453 nm) increased the expression of NGB and caused TdT-mediated dUTP nick-end labeling-positive cells, especially in the blue-light group. In addition, a negative correlation between NGB and rhodopsin was observed. These findings suggested that there was a correlation between NGB expression and the severity of the retinal damage, indicating NGB's potential function as a biological marker of retinal damage induced by LED light.
authors.affiliation: Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.
authors.forename: Z-L
authors.initials: ZL
authors.lastname: Yu
authors.affiliation: Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.
authors.forename: S
authors.initials: S
authors.lastname: Qiu
authors.affiliation: Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.
authors.forename: X-C
authors.initials: XC
authors.lastname: Chen
authors.affiliation: Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.
authors.forename: Z-H
authors.initials: ZH
authors.lastname: Dai
authors.affiliation: Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.
authors.forename: Y-C
authors.initials: YC
authors.lastname: Huang
authors.affiliation: School of Physics and Engineering, Sun Yat-sen University, Guangzhou, China.
authors.forename: Y-N
authors.initials: YN
authors.lastname: Li
authors.affiliation: Joinmax Display Technology Co., Ltd., Guangzhou, China.
authors.forename: R-H
authors.initials: RH
authors.lastname: Cai
authors.affiliation: Women and Childern Care Center of Luoyang, Henan Province, China.
authors.forename: H-T
authors.initials: HT
authors.lastname: Lei
authors.affiliation: Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China. Electronic address: guhuaiyusysu@yeah.net.
authors.forename: H-Y
authors.initials: HY
authors.lastname: Gu
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D015415:Biomarkers / Q000378:metabolism; D015153:Blotting, Western; D005260:Female; D005455:Fluorescent Antibody Technique; D005914:Globins / Q000378:metabolism*; D008027:Light / Q000009:adverse effects*; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D000078787:Neuroglobin; D010775:Photic Stimulation; D055668:Photochemical Processes; D017785:Photons / Q000009:adverse effects; D020419:Photoreceptor Cells, Vertebrate / Q000473:pathology / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D012160:Retina / Q000473:pathology / Q000528:radiation effects*; D012165:Retinal Ganglion Cells / Q000473:pathology / Q000502:physiology; D012243:Rhodopsin / Q000378:metabolism; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D009419:Nerve Tissue Proteins; D000078787:Neuroglobin; D012333:RNA, Messenger; D005914:Globins; D012243:Rhodopsin
keywords: LED light; biological marker; neuroglobin; retinal light damage