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Effect of light irradiation and sex hormones on jurkat T cells: 17beta-estradiol but not testosterone enhances UVA-induced cytotoxicity in Jurkat lymphocytes.

Cohly HH, Graham-Evans B, Ndebele K, Jenkins JK, McMurray R, Yan J, Yu H, Angel MF - Int J Environ Res Public Health (2005)

Bottom Line: The effects of EST and TE were investigated between 1 and 20 ng/mL.We found that EST alone, without UVA, enhanced Jurkat T cell survival.Since TE did not alter cell viability in the presence of UVA further damaging studies were not performed.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, Division of Plastic Surgery, University of Mississippi Medical Center, 2500 North State Street, Jackson, Mississippi, 39216-4505, USA. hcohly2004@yahoo.com

ABSTRACT
In Eastern cultures, such as India, it is traditionally recommended that women but not men cover their heads while working in the scorching sun. The purpose of this pilot study was to determine whether there was any scientific basis for this cultural tradition. We examined the differential cytotoxic effects of ultraviolet A light (UVA) on an established T cell line treated with female and male sex hormones. CD4+ Jurkat T cells were plated in 96 well plates at 2 x 106 cells/ml and treated with 17beta-estradiol (EST) or testosterone (TE). These cells were irradiated by UVA light with an irradiance of 170 J/cm2 for 15min at a distance of 6 cm from the surface of the 96-well plate. Controls included cells not treated with hormones or UVA. The effects of EST and TE were investigated between 1 and 20 ng/mL. Cytotoxicity by fluorescein-diacetate staining and COMET assay generating single strand DNA cleavage, tail length and tail moment measurements were examined. The effect of estrogen (5ng/mL) on apoptosis and its mediators was further studied using DNA laddering and western blotting for bcl-2 and p53. We found that EST alone, without UVA, enhanced Jurkat T cell survival. However, EST exhibited a dose-related cytotoxicity in the presence of UVA; up to 28% at 20 ng/ml. TE did not alter UVA-induced cytotoxicity. Since TE did not alter cell viability in the presence of UVA further damaging studies were not performed. COMET assay demonstrated the harmful effects of EST in the presence of UVA while EST without UVA. had no significant effect on the nuclear damage. Apoptosis was not present as indicated by the absence of DNA laddering on agarose gel electrophoresis at 5ng/ml EST or TE +/- UVA. Western blot showed that estrogen down regulated bcl-2 independently of UVA radiation while p53 was down regulated in the presence of UVA treatment. EST and TE have differential effects on UVA-induced cytotoxicity in Jurkat T-lymphocyte which suggested that women may be more susceptible to the harmful effects of solar irradiation than men.

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DNA laddering of cells treated with estrogen ± UVA.
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f7-ijerph-02-00156: DNA laddering of cells treated with estrogen ± UVA.

Mentions: Apoptosis was determined by electrophoresis of nucleosomal fragments using a standard procedure for precipitating cytosolic nucleic acid [7]. Briefly, 1 × 106 cells were pelleted (1200 × g, 5min) and lysed for 15 min (250μl, 0.4% Triton-X, 20mM Tris, 0.4mM Na2EDTA) at 4ºC. Nuclei were then pelleted (13,000 × g, 5 min, 4ºC) and the supernatant was transferred to a clean microfuge tube. Nucleosomal fragments were precipitated overnight with an equal volume of isopropanol after adjusting to 0.5 M NaCl. The pellet which represents precipitated cytosolic DNA, was washed twice in 70% ethanol, dried briefly, and re-suspended in 40 μL TE (10 mM Tris-HCl, 1 mM Na2EDTA) with 1 mg/ml DNase-free RNase. Results were identical to those in which total DNA was prepared, but this modification facilitates resuspension of the DNA fragments which are transported from the nuclear location to the cytosol. A total of 15 μl was electrophoresed on a 1.8% agarose gel and stained with ethidium bromide for visualization. A representative experiment is shown in Figure 7. The picture of the gel in Figure 7 is the consequence of one of three experiments.


Effect of light irradiation and sex hormones on jurkat T cells: 17beta-estradiol but not testosterone enhances UVA-induced cytotoxicity in Jurkat lymphocytes.

Cohly HH, Graham-Evans B, Ndebele K, Jenkins JK, McMurray R, Yan J, Yu H, Angel MF - Int J Environ Res Public Health (2005)

DNA laddering of cells treated with estrogen ± UVA.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3814710&req=5

f7-ijerph-02-00156: DNA laddering of cells treated with estrogen ± UVA.
Mentions: Apoptosis was determined by electrophoresis of nucleosomal fragments using a standard procedure for precipitating cytosolic nucleic acid [7]. Briefly, 1 × 106 cells were pelleted (1200 × g, 5min) and lysed for 15 min (250μl, 0.4% Triton-X, 20mM Tris, 0.4mM Na2EDTA) at 4ºC. Nuclei were then pelleted (13,000 × g, 5 min, 4ºC) and the supernatant was transferred to a clean microfuge tube. Nucleosomal fragments were precipitated overnight with an equal volume of isopropanol after adjusting to 0.5 M NaCl. The pellet which represents precipitated cytosolic DNA, was washed twice in 70% ethanol, dried briefly, and re-suspended in 40 μL TE (10 mM Tris-HCl, 1 mM Na2EDTA) with 1 mg/ml DNase-free RNase. Results were identical to those in which total DNA was prepared, but this modification facilitates resuspension of the DNA fragments which are transported from the nuclear location to the cytosol. A total of 15 μl was electrophoresed on a 1.8% agarose gel and stained with ethidium bromide for visualization. A representative experiment is shown in Figure 7. The picture of the gel in Figure 7 is the consequence of one of three experiments.

Bottom Line: The effects of EST and TE were investigated between 1 and 20 ng/mL.We found that EST alone, without UVA, enhanced Jurkat T cell survival.Since TE did not alter cell viability in the presence of UVA further damaging studies were not performed.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery, Division of Plastic Surgery, University of Mississippi Medical Center, 2500 North State Street, Jackson, Mississippi, 39216-4505, USA. hcohly2004@yahoo.com

ABSTRACT
In Eastern cultures, such as India, it is traditionally recommended that women but not men cover their heads while working in the scorching sun. The purpose of this pilot study was to determine whether there was any scientific basis for this cultural tradition. We examined the differential cytotoxic effects of ultraviolet A light (UVA) on an established T cell line treated with female and male sex hormones. CD4+ Jurkat T cells were plated in 96 well plates at 2 x 106 cells/ml and treated with 17beta-estradiol (EST) or testosterone (TE). These cells were irradiated by UVA light with an irradiance of 170 J/cm2 for 15min at a distance of 6 cm from the surface of the 96-well plate. Controls included cells not treated with hormones or UVA. The effects of EST and TE were investigated between 1 and 20 ng/mL. Cytotoxicity by fluorescein-diacetate staining and COMET assay generating single strand DNA cleavage, tail length and tail moment measurements were examined. The effect of estrogen (5ng/mL) on apoptosis and its mediators was further studied using DNA laddering and western blotting for bcl-2 and p53. We found that EST alone, without UVA, enhanced Jurkat T cell survival. However, EST exhibited a dose-related cytotoxicity in the presence of UVA; up to 28% at 20 ng/ml. TE did not alter UVA-induced cytotoxicity. Since TE did not alter cell viability in the presence of UVA further damaging studies were not performed. COMET assay demonstrated the harmful effects of EST in the presence of UVA while EST without UVA. had no significant effect on the nuclear damage. Apoptosis was not present as indicated by the absence of DNA laddering on agarose gel electrophoresis at 5ng/ml EST or TE +/- UVA. Western blot showed that estrogen down regulated bcl-2 independently of UVA radiation while p53 was down regulated in the presence of UVA treatment. EST and TE have differential effects on UVA-induced cytotoxicity in Jurkat T-lymphocyte which suggested that women may be more susceptible to the harmful effects of solar irradiation than men.

Show MeSH
Related in: MedlinePlus