Neuroglobin – A potential biological marker of retinal damage induced by LED light

• Published in: Neuroscience Vol. 270; pp. 158 - 167
• Main Authors: Yu, Z.-L., Qiu, S., Chen, X.-C., Dai, Z.-H., Huang, Y.-C., Li, Y.-N., Cai, R.-H., Lei, H.-T., Gu, H.-Y.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 13.06.2014; Elsevier
• Subjects: Animals; Apoptosis - physiology; Biological and medical sciences; biological marker; Biomarkers - metabolism; Blotting, Western; Eye and associated structures. Visual pathways and centers. Vision; Female; Fluorescent Antibody Technique; Fundamental and applied biological sciences. Psychology; Globins - metabolism; LED light; Light - adverse effects; Male; Nerve Tissue Proteins - metabolism; neuroglobin; Neurology; Photic Stimulation; Photochemical Processes; Photons - adverse effects; Photoreceptor Cells, Vertebrate - pathology; Photoreceptor Cells, Vertebrate - physiology; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Retina - pathology; Retina - radiation effects; Retinal Ganglion Cells - pathology; Retinal Ganglion Cells - physiology; retinal light damage; Rhodopsin - metabolism; RNA, Messenger - metabolism; Severity of Illness Index; Vertebrates: nervous system and sense organs; PBS; OCT; retinal light damage; TBS; NGB; LED light; LED; PRL; RIPA; GCL; TUNEL; biological marker; PL; GAPDH; neuroglobin; plexiform layer; photoreceptor layer; radioimmunoprecipitation assay; phosphate-buffered saline; TdT-mediated dUTP nick-end labeling; Tris-buffered saline; glyceraldehyde-3-phosphate dehydrogenase; light-emitting diode; ganglion cell layer; Neuroglobin; optimum cutting temperature compound; Eye; Visual system; Biological marker; Retina
• ISSN: 0306-4522; 1873-7544; 1873-7544
• DOI: 10.1016/j.neuroscience.2014.04.013

[Display omitted] •LED light exposure up-regulated NGB expression in the rat retina.•Alteration is induced predominantly by blue light compared to green or red light.•The increased NGB level is correlated with the severity of retinal light damage.•NGB may be a marker of retinal damage induced by LED light. 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 (453nm) 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 (625nm), green light (527nm) and blue light (453nm) 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.