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Damage of photoreceptor-derived cells in culture induced by light emitting diode-derived blue light.

Kuse Y, Ogawa K, Tsuruma K, Shimazawa M, Hara H - Sci Rep (2014)

Bottom Line: Our eyes are increasingly exposed to light from the emitting diode (LED) light of video display terminals (VDT) which contain much blue light.VDTs are equipped with televisions, personal computers, and smart phones.Murine cone photoreceptor-derived cells (661 W) were exposed to blue, white, or green LED light (0.38 mW/cm(2)).

View Article: PubMed Central - PubMed

Affiliation: Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan.

ABSTRACT
Our eyes are increasingly exposed to light from the emitting diode (LED) light of video display terminals (VDT) which contain much blue light. VDTs are equipped with televisions, personal computers, and smart phones. The present study aims to clarify the mechanism underlying blue LED light-induced photoreceptor cell damage. Murine cone photoreceptor-derived cells (661 W) were exposed to blue, white, or green LED light (0.38 mW/cm(2)). In the present study, blue LED light increased reactive oxygen species (ROS) production, altered the protein expression level, induced the aggregation of short-wavelength opsins (S-opsin), resulting in severe cell damage. While, blue LED light damaged the primary retinal cells and the damage was photoreceptor specific. N-Acetylcysteine (NAC), an antioxidant, protected against the cellular damage induced by blue LED light. Overall, the LED light induced cell damage was wavelength-, but not energy-dependent and may cause more severe retinal photoreceptor cell damage than the other LED light.

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NAC suppressed the blue LED light-induced damage and inhibited NF-κB activation.(A–C) Evaluation of the cell viability by the CCK-8assay and the rate of cell death by Hoechst and PI staining. The rate of cell death indicates by the ratio of PI (red) stained cells per Hoechst (blue) stained cells. NAC at 1 mM significantly improved the cell viability reduced by blue LED light. (D) NAC reduced the ROS level elevated by blue LED light. (E–H) The effect of NAC against blue LED light-induced changes in protein expression was assessed by Western blots. NAC suppressed the blue LED light-induced increase in activated NF-κB levels, but did not suppress activated p38. NAC did not alter the reduced ERK level. Data are expressed as mean ± SEM (n = 5 or 6). ** indicates p < 0.01 vs. vehicle; ## indicates p < 0.01 vs. control (one-way ANOVA followed by Tukey's test). The scale bar represents 50 μm. The cropped blots are used in this Figure and the full-length blots are presented in Supplementary Figure S8.
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f6: NAC suppressed the blue LED light-induced damage and inhibited NF-κB activation.(A–C) Evaluation of the cell viability by the CCK-8assay and the rate of cell death by Hoechst and PI staining. The rate of cell death indicates by the ratio of PI (red) stained cells per Hoechst (blue) stained cells. NAC at 1 mM significantly improved the cell viability reduced by blue LED light. (D) NAC reduced the ROS level elevated by blue LED light. (E–H) The effect of NAC against blue LED light-induced changes in protein expression was assessed by Western blots. NAC suppressed the blue LED light-induced increase in activated NF-κB levels, but did not suppress activated p38. NAC did not alter the reduced ERK level. Data are expressed as mean ± SEM (n = 5 or 6). ** indicates p < 0.01 vs. vehicle; ## indicates p < 0.01 vs. control (one-way ANOVA followed by Tukey's test). The scale bar represents 50 μm. The cropped blots are used in this Figure and the full-length blots are presented in Supplementary Figure S8.

Mentions: Our findings suggested that blue LED light damaged photoreceptor-derived cell most severely compared to the other LED lights. Then, we investigated the protective effects of an antioxidant against blue LED light-induced photoreceptor-derived cell damage. Representative photomicrographs of cell morphology, with Hoechst 33342 and PI staining shows the control, as well as cells treated with vehicle and NAC at 1 mM (Figure 6A). The number of dead cells (PI-positive) was increased in the vehicle-treated group. The treatment with NAC at 1 mM increased the number of viable cells and inhibited photoreceptor-derived cell death (Figure 6A). Furthermore, NAC improved cell viability, and markedly suppressed cell death and ROS production (Figure 6B–D). NAC at 1 mM suppressed the activation of NF-κB caused by blue LED light exposure, but did not affect the blue light-induced phosphorylation of p38 MAPK or ERK (Figure 6E–H).


Damage of photoreceptor-derived cells in culture induced by light emitting diode-derived blue light.

Kuse Y, Ogawa K, Tsuruma K, Shimazawa M, Hara H - Sci Rep (2014)

NAC suppressed the blue LED light-induced damage and inhibited NF-κB activation.(A–C) Evaluation of the cell viability by the CCK-8assay and the rate of cell death by Hoechst and PI staining. The rate of cell death indicates by the ratio of PI (red) stained cells per Hoechst (blue) stained cells. NAC at 1 mM significantly improved the cell viability reduced by blue LED light. (D) NAC reduced the ROS level elevated by blue LED light. (E–H) The effect of NAC against blue LED light-induced changes in protein expression was assessed by Western blots. NAC suppressed the blue LED light-induced increase in activated NF-κB levels, but did not suppress activated p38. NAC did not alter the reduced ERK level. Data are expressed as mean ± SEM (n = 5 or 6). ** indicates p < 0.01 vs. vehicle; ## indicates p < 0.01 vs. control (one-way ANOVA followed by Tukey's test). The scale bar represents 50 μm. The cropped blots are used in this Figure and the full-length blots are presented in Supplementary Figure S8.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4048889&req=5

f6: NAC suppressed the blue LED light-induced damage and inhibited NF-κB activation.(A–C) Evaluation of the cell viability by the CCK-8assay and the rate of cell death by Hoechst and PI staining. The rate of cell death indicates by the ratio of PI (red) stained cells per Hoechst (blue) stained cells. NAC at 1 mM significantly improved the cell viability reduced by blue LED light. (D) NAC reduced the ROS level elevated by blue LED light. (E–H) The effect of NAC against blue LED light-induced changes in protein expression was assessed by Western blots. NAC suppressed the blue LED light-induced increase in activated NF-κB levels, but did not suppress activated p38. NAC did not alter the reduced ERK level. Data are expressed as mean ± SEM (n = 5 or 6). ** indicates p < 0.01 vs. vehicle; ## indicates p < 0.01 vs. control (one-way ANOVA followed by Tukey's test). The scale bar represents 50 μm. The cropped blots are used in this Figure and the full-length blots are presented in Supplementary Figure S8.
Mentions: Our findings suggested that blue LED light damaged photoreceptor-derived cell most severely compared to the other LED lights. Then, we investigated the protective effects of an antioxidant against blue LED light-induced photoreceptor-derived cell damage. Representative photomicrographs of cell morphology, with Hoechst 33342 and PI staining shows the control, as well as cells treated with vehicle and NAC at 1 mM (Figure 6A). The number of dead cells (PI-positive) was increased in the vehicle-treated group. The treatment with NAC at 1 mM increased the number of viable cells and inhibited photoreceptor-derived cell death (Figure 6A). Furthermore, NAC improved cell viability, and markedly suppressed cell death and ROS production (Figure 6B–D). NAC at 1 mM suppressed the activation of NF-κB caused by blue LED light exposure, but did not affect the blue light-induced phosphorylation of p38 MAPK or ERK (Figure 6E–H).

Bottom Line: Our eyes are increasingly exposed to light from the emitting diode (LED) light of video display terminals (VDT) which contain much blue light.VDTs are equipped with televisions, personal computers, and smart phones.Murine cone photoreceptor-derived cells (661 W) were exposed to blue, white, or green LED light (0.38 mW/cm(2)).

View Article: PubMed Central - PubMed

Affiliation: Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan.

ABSTRACT
Our eyes are increasingly exposed to light from the emitting diode (LED) light of video display terminals (VDT) which contain much blue light. VDTs are equipped with televisions, personal computers, and smart phones. The present study aims to clarify the mechanism underlying blue LED light-induced photoreceptor cell damage. Murine cone photoreceptor-derived cells (661 W) were exposed to blue, white, or green LED light (0.38 mW/cm(2)). In the present study, blue LED light increased reactive oxygen species (ROS) production, altered the protein expression level, induced the aggregation of short-wavelength opsins (S-opsin), resulting in severe cell damage. While, blue LED light damaged the primary retinal cells and the damage was photoreceptor specific. N-Acetylcysteine (NAC), an antioxidant, protected against the cellular damage induced by blue LED light. Overall, the LED light induced cell damage was wavelength-, but not energy-dependent and may cause more severe retinal photoreceptor cell damage than the other LED light.

Show MeSH
Related in: MedlinePlus