Subthreshold UV light-induced peroxide formation in cultured corneal epithelial cells

Shigeto Shimmura, M. Suematsu, M. Shimoyama, Kazuo Tsubota, Y. Oguchi, Y. Ishimura

Research output: Contribution to journalArticle

Abstract

Purpose: To demonstrate intracellular peroxide formation in cultured corneal epithelial cells by subthreshold ultraviolet (UV) light, and the protective effects of lactoferrin as an antioxidant. Methods: Intracellular oxidative insults and cell viability of rabbit corneal epithelial cells (RCEC) were assessed by dual-color digital microfluorography using carboxydichlorofluorescin (CDCFH) diacetate bis acetoxymethyl ester, a hydroperoxide-sensitive fluoroprobe, and propidium iodide (PI), respectively. The magnitude of UV-induced oxidative insults was calibrated by concentrations of exogenously applied H2O2 which evoke compatible levels of CDCFH oxidation. Inhibition of peroxide formation by lactoferrin, a potent iron-chelating protein present abundantly in tear fluids, was evaluated. Results: Exposure of RCEC to low dose UV-B (2.0 mJ/cm2) caused intracellular oxidative changes which were equivalent to those elicited by 250 μM hydrogen peroxide. The UV-induced changes were dose dependent, non-necrotic, and were partially inhibited by lactoferrin (1 mg/ml) but not by iron-saturated lactoferrin. Pretreatment with deferoxamine (2 mM) or catalase (100 u/ml) also attenuated the UV-induced oxidative stress. Conclusions: UV light comparable to solar irradiation levels caused significant intracellular peroxide formation in corneal epithelial cells. The UV-induced oxidative stress was suppressed by lactoferrin, indicating that lactoferrin in tears may have a physiological role in protecting the corneal epithelium from solar UV irradiation.

Original languageEnglish
JournalInvestigative Ophthalmology and Visual Science
Volume37
Issue number3
Publication statusPublished - 1996 Feb 15

Fingerprint

Lactoferrin
Peroxides
Ultraviolet Rays
Epithelial Cells
Tears
Hydrogen Peroxide
Oxidative Stress
Iron
Rabbits
Corneal Epithelium
Deferoxamine
Propidium
Catalase
Cell Survival
Esters
Color
Antioxidants
Proteins

ASJC Scopus subject areas

  • Ophthalmology

Cite this

Subthreshold UV light-induced peroxide formation in cultured corneal epithelial cells. / Shimmura, Shigeto; Suematsu, M.; Shimoyama, M.; Tsubota, Kazuo; Oguchi, Y.; Ishimura, Y.

In: Investigative Ophthalmology and Visual Science, Vol. 37, No. 3, 15.02.1996.

Research output: Contribution to journalArticle

@article{a9a9cecf853745698a5667b47c1e732a,
title = "Subthreshold UV light-induced peroxide formation in cultured corneal epithelial cells",
abstract = "Purpose: To demonstrate intracellular peroxide formation in cultured corneal epithelial cells by subthreshold ultraviolet (UV) light, and the protective effects of lactoferrin as an antioxidant. Methods: Intracellular oxidative insults and cell viability of rabbit corneal epithelial cells (RCEC) were assessed by dual-color digital microfluorography using carboxydichlorofluorescin (CDCFH) diacetate bis acetoxymethyl ester, a hydroperoxide-sensitive fluoroprobe, and propidium iodide (PI), respectively. The magnitude of UV-induced oxidative insults was calibrated by concentrations of exogenously applied H2O2 which evoke compatible levels of CDCFH oxidation. Inhibition of peroxide formation by lactoferrin, a potent iron-chelating protein present abundantly in tear fluids, was evaluated. Results: Exposure of RCEC to low dose UV-B (2.0 mJ/cm2) caused intracellular oxidative changes which were equivalent to those elicited by 250 μM hydrogen peroxide. The UV-induced changes were dose dependent, non-necrotic, and were partially inhibited by lactoferrin (1 mg/ml) but not by iron-saturated lactoferrin. Pretreatment with deferoxamine (2 mM) or catalase (100 u/ml) also attenuated the UV-induced oxidative stress. Conclusions: UV light comparable to solar irradiation levels caused significant intracellular peroxide formation in corneal epithelial cells. The UV-induced oxidative stress was suppressed by lactoferrin, indicating that lactoferrin in tears may have a physiological role in protecting the corneal epithelium from solar UV irradiation.",
author = "Shigeto Shimmura and M. Suematsu and M. Shimoyama and Kazuo Tsubota and Y. Oguchi and Y. Ishimura",
year = "1996",
month = "2",
day = "15",
language = "English",
volume = "37",
journal = "Investigative Ophthalmology and Visual Science",
issn = "0146-0404",
publisher = "Association for Research in Vision and Ophthalmology Inc.",
number = "3",

}

TY - JOUR

T1 - Subthreshold UV light-induced peroxide formation in cultured corneal epithelial cells

AU - Shimmura, Shigeto

AU - Suematsu, M.

AU - Shimoyama, M.

AU - Tsubota, Kazuo

AU - Oguchi, Y.

AU - Ishimura, Y.

PY - 1996/2/15

Y1 - 1996/2/15

N2 - Purpose: To demonstrate intracellular peroxide formation in cultured corneal epithelial cells by subthreshold ultraviolet (UV) light, and the protective effects of lactoferrin as an antioxidant. Methods: Intracellular oxidative insults and cell viability of rabbit corneal epithelial cells (RCEC) were assessed by dual-color digital microfluorography using carboxydichlorofluorescin (CDCFH) diacetate bis acetoxymethyl ester, a hydroperoxide-sensitive fluoroprobe, and propidium iodide (PI), respectively. The magnitude of UV-induced oxidative insults was calibrated by concentrations of exogenously applied H2O2 which evoke compatible levels of CDCFH oxidation. Inhibition of peroxide formation by lactoferrin, a potent iron-chelating protein present abundantly in tear fluids, was evaluated. Results: Exposure of RCEC to low dose UV-B (2.0 mJ/cm2) caused intracellular oxidative changes which were equivalent to those elicited by 250 μM hydrogen peroxide. The UV-induced changes were dose dependent, non-necrotic, and were partially inhibited by lactoferrin (1 mg/ml) but not by iron-saturated lactoferrin. Pretreatment with deferoxamine (2 mM) or catalase (100 u/ml) also attenuated the UV-induced oxidative stress. Conclusions: UV light comparable to solar irradiation levels caused significant intracellular peroxide formation in corneal epithelial cells. The UV-induced oxidative stress was suppressed by lactoferrin, indicating that lactoferrin in tears may have a physiological role in protecting the corneal epithelium from solar UV irradiation.

AB - Purpose: To demonstrate intracellular peroxide formation in cultured corneal epithelial cells by subthreshold ultraviolet (UV) light, and the protective effects of lactoferrin as an antioxidant. Methods: Intracellular oxidative insults and cell viability of rabbit corneal epithelial cells (RCEC) were assessed by dual-color digital microfluorography using carboxydichlorofluorescin (CDCFH) diacetate bis acetoxymethyl ester, a hydroperoxide-sensitive fluoroprobe, and propidium iodide (PI), respectively. The magnitude of UV-induced oxidative insults was calibrated by concentrations of exogenously applied H2O2 which evoke compatible levels of CDCFH oxidation. Inhibition of peroxide formation by lactoferrin, a potent iron-chelating protein present abundantly in tear fluids, was evaluated. Results: Exposure of RCEC to low dose UV-B (2.0 mJ/cm2) caused intracellular oxidative changes which were equivalent to those elicited by 250 μM hydrogen peroxide. The UV-induced changes were dose dependent, non-necrotic, and were partially inhibited by lactoferrin (1 mg/ml) but not by iron-saturated lactoferrin. Pretreatment with deferoxamine (2 mM) or catalase (100 u/ml) also attenuated the UV-induced oxidative stress. Conclusions: UV light comparable to solar irradiation levels caused significant intracellular peroxide formation in corneal epithelial cells. The UV-induced oxidative stress was suppressed by lactoferrin, indicating that lactoferrin in tears may have a physiological role in protecting the corneal epithelium from solar UV irradiation.

UR - http://www.scopus.com/inward/record.url?scp=33750163415&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33750163415&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:33750163415

VL - 37

JO - Investigative Ophthalmology and Visual Science

JF - Investigative Ophthalmology and Visual Science

SN - 0146-0404

IS - 3

ER -