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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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ROS production by blue, white, and green LED light exposure.(A–C) Blue LED light and white LED light exposure increased each 1.4-fold and 1.2-fold ROS production, and green LED light did not increase ROS level. Data are expressed as mean ± SEM (n = 6). ## indicates p < 0.01 vs. control (ANOVA). (D) Representative images show JC-1 stained cells. The healthy cells with mainly JC-1 J-aggregates (red) and apoptotic or unhealthy cells with mainly JC-1 monomers (green). Merged cells (yellow) were considered to be pre-apoptotic (early or middle state of transition to cell death) cells. Scale bar represents 50 μm. (E) The number of cells with red or yellow color were counted. The ratio of merged cells to red color cells was increased by blue LED light exposure for 12 h or 24 h. Data are expressed as mean ± SEM (n = 6). ## indicates p < 0.01 vs. control (ANOVA).
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f2: ROS production by blue, white, and green LED light exposure.(A–C) Blue LED light and white LED light exposure increased each 1.4-fold and 1.2-fold ROS production, and green LED light did not increase ROS level. Data are expressed as mean ± SEM (n = 6). ## indicates p < 0.01 vs. control (ANOVA). (D) Representative images show JC-1 stained cells. The healthy cells with mainly JC-1 J-aggregates (red) and apoptotic or unhealthy cells with mainly JC-1 monomers (green). Merged cells (yellow) were considered to be pre-apoptotic (early or middle state of transition to cell death) cells. Scale bar represents 50 μm. (E) The number of cells with red or yellow color were counted. The ratio of merged cells to red color cells was increased by blue LED light exposure for 12 h or 24 h. Data are expressed as mean ± SEM (n = 6). ## indicates p < 0.01 vs. control (ANOVA).

Mentions: First, we evaluated the relationship between ROS generation and exposure to three different colored LED lights for 24 h at 2,500 lux. We found that blue LED light induced a higher ROS production than white and green LED lights (see Supplementary Fig. S2 and S4C online). Then, we investigated these changes under unified LED energy (0.38 mW/cm2). Blue LED light induced ROS increase (see Supplementary Fig. S4A online). White and green LED lights also increased the ROS generation but at lower levels compared to blue LED light (see Supplementary Fig. S4B and S4C online). The direct comparison in each LED exposed groups showed blue LED light-induced ROS production was most severely than the other LED light-induced ROS production (see Supplementary Fig. S4D online). Moreover, we examined whether the LED light exposure for 6 h induced ROS production. Blue LED light exposure for 6 h induced 1.4-fold ROS increase, and white LED light exposure for 6 h induced 1.2-fold ROS increase (Figure 2A, B). Green LED light exposure for 6 h did not induce ROS increase (Figure 2C). The photoreceptor cell death is promoted by oxidative stress induced the generation of ROS12, and it is confirmed that the damage induced by light exposure reduces the mitochondrial membrane potential in vivo light-induced retinal degeneration model22. Therefore, we evaluated the mitochondrial membrane potential. The healthy cells were detected with mainly JC-1 J-aggregates (red) and apoptotic or unhealthy cells with mainly JC-1 monomers (green). Merged cells (yellow) were considered to be pre-apoptotic (early or middle state of transition to cell death) cells19. Control cells were almost stained with red (Figure 2D). Blue LED light increased the pro-apoptotic cells (yellow) in time dependent manner (Figure 2E). The ratio of merged cells to red stained cells was significantly increased by blue LED exposure for 12 or 24 h (Figure 2E).


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)

ROS production by blue, white, and green LED light exposure.(A–C) Blue LED light and white LED light exposure increased each 1.4-fold and 1.2-fold ROS production, and green LED light did not increase ROS level. Data are expressed as mean ± SEM (n = 6). ## indicates p < 0.01 vs. control (ANOVA). (D) Representative images show JC-1 stained cells. The healthy cells with mainly JC-1 J-aggregates (red) and apoptotic or unhealthy cells with mainly JC-1 monomers (green). Merged cells (yellow) were considered to be pre-apoptotic (early or middle state of transition to cell death) cells. Scale bar represents 50 μm. (E) The number of cells with red or yellow color were counted. The ratio of merged cells to red color cells was increased by blue LED light exposure for 12 h or 24 h. Data are expressed as mean ± SEM (n = 6). ## indicates p < 0.01 vs. control (ANOVA).
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4048889&req=5

f2: ROS production by blue, white, and green LED light exposure.(A–C) Blue LED light and white LED light exposure increased each 1.4-fold and 1.2-fold ROS production, and green LED light did not increase ROS level. Data are expressed as mean ± SEM (n = 6). ## indicates p < 0.01 vs. control (ANOVA). (D) Representative images show JC-1 stained cells. The healthy cells with mainly JC-1 J-aggregates (red) and apoptotic or unhealthy cells with mainly JC-1 monomers (green). Merged cells (yellow) were considered to be pre-apoptotic (early or middle state of transition to cell death) cells. Scale bar represents 50 μm. (E) The number of cells with red or yellow color were counted. The ratio of merged cells to red color cells was increased by blue LED light exposure for 12 h or 24 h. Data are expressed as mean ± SEM (n = 6). ## indicates p < 0.01 vs. control (ANOVA).
Mentions: First, we evaluated the relationship between ROS generation and exposure to three different colored LED lights for 24 h at 2,500 lux. We found that blue LED light induced a higher ROS production than white and green LED lights (see Supplementary Fig. S2 and S4C online). Then, we investigated these changes under unified LED energy (0.38 mW/cm2). Blue LED light induced ROS increase (see Supplementary Fig. S4A online). White and green LED lights also increased the ROS generation but at lower levels compared to blue LED light (see Supplementary Fig. S4B and S4C online). The direct comparison in each LED exposed groups showed blue LED light-induced ROS production was most severely than the other LED light-induced ROS production (see Supplementary Fig. S4D online). Moreover, we examined whether the LED light exposure for 6 h induced ROS production. Blue LED light exposure for 6 h induced 1.4-fold ROS increase, and white LED light exposure for 6 h induced 1.2-fold ROS increase (Figure 2A, B). Green LED light exposure for 6 h did not induce ROS increase (Figure 2C). The photoreceptor cell death is promoted by oxidative stress induced the generation of ROS12, and it is confirmed that the damage induced by light exposure reduces the mitochondrial membrane potential in vivo light-induced retinal degeneration model22. Therefore, we evaluated the mitochondrial membrane potential. The healthy cells were detected with mainly JC-1 J-aggregates (red) and apoptotic or unhealthy cells with mainly JC-1 monomers (green). Merged cells (yellow) were considered to be pre-apoptotic (early or middle state of transition to cell death) cells19. Control cells were almost stained with red (Figure 2D). Blue LED light increased the pro-apoptotic cells (yellow) in time dependent manner (Figure 2E). The ratio of merged cells to red stained cells was significantly increased by blue LED exposure for 12 or 24 h (Figure 2E).

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