Effects of melatonin and its receptor antagonist on retinal pigment epithelial cells against hydrogen peroxide damage

Richard B. Rosen; Dan Ning Hu; Min Chen; Steven A. McCormick; Joseph Walsh; Joan E. Roberts

Effects of melatonin and its receptor antagonist on retinal pigment epithelial cells against hydrogen peroxide damage

Richard B. Rosen
, Dan Ning Hu
, Min Chen
, Steven A. McCormick
, Joseph Walsh
, Joan E. Roberts

Research output: Contribution to journal › Article › peer-review

55 Scopus citations

Abstract

Purpose: Recently, we reported finding that circulating melatonin levels in age-related macular degeneration patients were significantly lower than those in age-matched controls. The purpose of this study was to investigate the hypothesis that melatonin deficiency may play a role in the oxidative damage of the retinal pigment epithelium (RPE) by testing the protective effect of melatonin and its receptor antagonist on RPE cells exposed to H ₂O ₂ damage. Methods: Cultured human RPE cells were subjected to oxidative stress induced by 0.5 mM H ₂O ₂. Cell viability was measured using the microculture tetrazoline test (MTT) assay. Cells were pretreated with or without melatonin for 24 h. Luzindole (50 μM), a melatonin membrane-receptor antagonist, was added to the culture 1 h before melatonin to distinguish direct antioxidant effects from indirect receptor-dependent effects. All tests were performed in triplicate. Results: H ₂O ₂ at 0.5 mM decreased cell viability to 20% of control levels. Melatonin showed dose-dependent protective effects on RPE cells against H ₂O ₂. Cell viability of RPE cells pretreated with 10 ^-10, 10 ^-8, 10 ^-6, and 10 ^-4 M melatonin for 24 h was 130%, 160%, 187%, and 230% of cells treated with H ₂O ₂ alone (all p<0.05). Using cells cultured without H ₂O ₂ as the control, cell viability of cells treated with H ₂O ₂ after pretreatment with 10 ^-10-10 ^-4 M melatonin was still significantly lower than that of the controls, suggesting that melatonin significantly decreased but did not completely abolish the in vitro cytotoxic effects of H ₂O ₂. Luzindole completely blocked melatonin's protective effects at low concentrations of melatonin (10 ^-10-10 ^-8 M) but not at high concentrations (10 ^-6-10 ^-4 M). Conclusions: Melatonin has a partial protective effect on RPE cells against H ₂O ₂ damage across a wide range of concentrations (10 ^-10-10 ^-4 M). This protective effect occurs through the activation of melatonin membrane receptors at low concentrations (10 ^-10-10 ^-8 M) and through both the direct antioxidant and indirect receptor activation effects at high concentrations (10 ^-6-10 ^-4 M).

Original language	English
Pages (from-to)	1640-1648
Number of pages	9
Journal	Molecular Vision
Volume	18
State	Published - 20 Jun 2012
Externally published	Yes

Cite this

@article{ab27e52fca444b3d96d0af9b394ac615,

title = "Effects of melatonin and its receptor antagonist on retinal pigment epithelial cells against hydrogen peroxide damage",

abstract = "Purpose: Recently, we reported finding that circulating melatonin levels in age-related macular degeneration patients were significantly lower than those in age-matched controls. The purpose of this study was to investigate the hypothesis that melatonin deficiency may play a role in the oxidative damage of the retinal pigment epithelium (RPE) by testing the protective effect of melatonin and its receptor antagonist on RPE cells exposed to H 2O 2 damage. Methods: Cultured human RPE cells were subjected to oxidative stress induced by 0.5 mM H 2O 2. Cell viability was measured using the microculture tetrazoline test (MTT) assay. Cells were pretreated with or without melatonin for 24 h. Luzindole (50 μM), a melatonin membrane-receptor antagonist, was added to the culture 1 h before melatonin to distinguish direct antioxidant effects from indirect receptor-dependent effects. All tests were performed in triplicate. Results: H 2O 2 at 0.5 mM decreased cell viability to 20\% of control levels. Melatonin showed dose-dependent protective effects on RPE cells against H 2O 2. Cell viability of RPE cells pretreated with 10 -10, 10 -8, 10 -6, and 10 -4 M melatonin for 24 h was 130\%, 160\%, 187\%, and 230\% of cells treated with H 2O 2 alone (all p<0.05). Using cells cultured without H 2O 2 as the control, cell viability of cells treated with H 2O 2 after pretreatment with 10 -10-10 -4 M melatonin was still significantly lower than that of the controls, suggesting that melatonin significantly decreased but did not completely abolish the in vitro cytotoxic effects of H 2O 2. Luzindole completely blocked melatonin's protective effects at low concentrations of melatonin (10 -10-10 -8 M) but not at high concentrations (10 -6-10 -4 M). Conclusions: Melatonin has a partial protective effect on RPE cells against H 2O 2 damage across a wide range of concentrations (10 -10-10 -4 M). This protective effect occurs through the activation of melatonin membrane receptors at low concentrations (10 -10-10 -8 M) and through both the direct antioxidant and indirect receptor activation effects at high concentrations (10 -6-10 -4 M).",

author = "Rosen, \{Richard B.\} and Hu, \{Dan Ning\} and Min Chen and McCormick, \{Steven A.\} and Joseph Walsh and Roberts, \{Joan E.\}",

year = "2012",

month = jun,

day = "20",

language = "English",

volume = "18",

pages = "1640--1648",

journal = "Molecular Vision",

issn = "1090-0535",

publisher = "Molecular Vision",

}

TY - JOUR

T1 - Effects of melatonin and its receptor antagonist on retinal pigment epithelial cells against hydrogen peroxide damage

AU - Rosen, Richard B.

AU - Hu, Dan Ning

AU - Chen, Min

AU - McCormick, Steven A.

AU - Walsh, Joseph

AU - Roberts, Joan E.

PY - 2012/6/20

Y1 - 2012/6/20

N2 - Purpose: Recently, we reported finding that circulating melatonin levels in age-related macular degeneration patients were significantly lower than those in age-matched controls. The purpose of this study was to investigate the hypothesis that melatonin deficiency may play a role in the oxidative damage of the retinal pigment epithelium (RPE) by testing the protective effect of melatonin and its receptor antagonist on RPE cells exposed to H 2O 2 damage. Methods: Cultured human RPE cells were subjected to oxidative stress induced by 0.5 mM H 2O 2. Cell viability was measured using the microculture tetrazoline test (MTT) assay. Cells were pretreated with or without melatonin for 24 h. Luzindole (50 μM), a melatonin membrane-receptor antagonist, was added to the culture 1 h before melatonin to distinguish direct antioxidant effects from indirect receptor-dependent effects. All tests were performed in triplicate. Results: H 2O 2 at 0.5 mM decreased cell viability to 20% of control levels. Melatonin showed dose-dependent protective effects on RPE cells against H 2O 2. Cell viability of RPE cells pretreated with 10 -10, 10 -8, 10 -6, and 10 -4 M melatonin for 24 h was 130%, 160%, 187%, and 230% of cells treated with H 2O 2 alone (all p<0.05). Using cells cultured without H 2O 2 as the control, cell viability of cells treated with H 2O 2 after pretreatment with 10 -10-10 -4 M melatonin was still significantly lower than that of the controls, suggesting that melatonin significantly decreased but did not completely abolish the in vitro cytotoxic effects of H 2O 2. Luzindole completely blocked melatonin's protective effects at low concentrations of melatonin (10 -10-10 -8 M) but not at high concentrations (10 -6-10 -4 M). Conclusions: Melatonin has a partial protective effect on RPE cells against H 2O 2 damage across a wide range of concentrations (10 -10-10 -4 M). This protective effect occurs through the activation of melatonin membrane receptors at low concentrations (10 -10-10 -8 M) and through both the direct antioxidant and indirect receptor activation effects at high concentrations (10 -6-10 -4 M).

AB - Purpose: Recently, we reported finding that circulating melatonin levels in age-related macular degeneration patients were significantly lower than those in age-matched controls. The purpose of this study was to investigate the hypothesis that melatonin deficiency may play a role in the oxidative damage of the retinal pigment epithelium (RPE) by testing the protective effect of melatonin and its receptor antagonist on RPE cells exposed to H 2O 2 damage. Methods: Cultured human RPE cells were subjected to oxidative stress induced by 0.5 mM H 2O 2. Cell viability was measured using the microculture tetrazoline test (MTT) assay. Cells were pretreated with or without melatonin for 24 h. Luzindole (50 μM), a melatonin membrane-receptor antagonist, was added to the culture 1 h before melatonin to distinguish direct antioxidant effects from indirect receptor-dependent effects. All tests were performed in triplicate. Results: H 2O 2 at 0.5 mM decreased cell viability to 20% of control levels. Melatonin showed dose-dependent protective effects on RPE cells against H 2O 2. Cell viability of RPE cells pretreated with 10 -10, 10 -8, 10 -6, and 10 -4 M melatonin for 24 h was 130%, 160%, 187%, and 230% of cells treated with H 2O 2 alone (all p<0.05). Using cells cultured without H 2O 2 as the control, cell viability of cells treated with H 2O 2 after pretreatment with 10 -10-10 -4 M melatonin was still significantly lower than that of the controls, suggesting that melatonin significantly decreased but did not completely abolish the in vitro cytotoxic effects of H 2O 2. Luzindole completely blocked melatonin's protective effects at low concentrations of melatonin (10 -10-10 -8 M) but not at high concentrations (10 -6-10 -4 M). Conclusions: Melatonin has a partial protective effect on RPE cells against H 2O 2 damage across a wide range of concentrations (10 -10-10 -4 M). This protective effect occurs through the activation of melatonin membrane receptors at low concentrations (10 -10-10 -8 M) and through both the direct antioxidant and indirect receptor activation effects at high concentrations (10 -6-10 -4 M).

UR - https://www.scopus.com/pages/publications/84863336535

M3 - Article

C2 - 22773902

AN - SCOPUS:84863336535

SN - 1090-0535

VL - 18

SP - 1640

EP - 1648

JO - Molecular Vision

JF - Molecular Vision

ER -

Effects of melatonin and its receptor antagonist on retinal pigment epithelial cells against hydrogen peroxide damage

Abstract

Fingerprint

Cite this