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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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Related in: MedlinePlus

Comet assay of Jurkat T cells treated with estrogen ± UVA where Y-axis is the Tail Length (μm) and x-axis is the different concentrations of estrogen used in comparison with controls which had no estrogen.
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f5-ijerph-02-00156: Comet assay of Jurkat T cells treated with estrogen ± UVA where Y-axis is the Tail Length (μm) and x-axis is the different concentrations of estrogen used in comparison with controls which had no estrogen.

Mentions: Figure 3 shows comet assay picture of cells ± UVA with estrogen at 5ng/mL. The nuclear DNA of untreated cells was round while estrogen + UVA were severely dispersed and fragmented. The percentages of DNA cleavage was approximately 8.5, 4.1 and 7% fragmentation (Figure 4), and the lengths of comet tail varied 37, 34 and 27% (Figure 5) while tail moment varied from 9.1, 2.7 and 5.8% (Figure 6) at 5, 10 and 20 ng/ml estrogen concentrations respectively. There are several ways to measure the severity of DNA fragmentation. In our study the variables studied were the percent of DNA fragmentation (percent of DNA in the Comet tail versus total DNA), tail moment and the length of the comet tail. Tail Length is the distance between the head and the last DNA fragment and Tail Moment is the product of % DNA and tail length mathematically written as (%DNA × Tail Length). The higher the percent of DNA fragments, the more severe is the damage. Similarly, the longer the comet tail, the smaller is the DNA fragment, the more severe is the damage.


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)

Comet assay of Jurkat T cells treated with estrogen ± UVA where Y-axis is the Tail Length (μm) and x-axis is the different concentrations of estrogen used in comparison with controls which had no estrogen.
© Copyright Policy
Related In: Results  -  Collection

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

f5-ijerph-02-00156: Comet assay of Jurkat T cells treated with estrogen ± UVA where Y-axis is the Tail Length (μm) and x-axis is the different concentrations of estrogen used in comparison with controls which had no estrogen.
Mentions: Figure 3 shows comet assay picture of cells ± UVA with estrogen at 5ng/mL. The nuclear DNA of untreated cells was round while estrogen + UVA were severely dispersed and fragmented. The percentages of DNA cleavage was approximately 8.5, 4.1 and 7% fragmentation (Figure 4), and the lengths of comet tail varied 37, 34 and 27% (Figure 5) while tail moment varied from 9.1, 2.7 and 5.8% (Figure 6) at 5, 10 and 20 ng/ml estrogen concentrations respectively. There are several ways to measure the severity of DNA fragmentation. In our study the variables studied were the percent of DNA fragmentation (percent of DNA in the Comet tail versus total DNA), tail moment and the length of the comet tail. Tail Length is the distance between the head and the last DNA fragment and Tail Moment is the product of % DNA and tail length mathematically written as (%DNA × Tail Length). The higher the percent of DNA fragments, the more severe is the damage. Similarly, the longer the comet tail, the smaller is the DNA fragment, the more severe is the damage.

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