17 beta-estradiol increases Ca(2+) influx and down regulates interleukin-2 receptor in mouse thymocytes.
The influx of Ca(2+) across the T lymphocyte membrane is an essential triggering signal for activation and proliferation by an antigen. The aim of this study was to determine if Ca(2+) influx through estradiol receptor (ER) operated channels of Ca(2+) entry induced activation of lymphoid cells. Mouse thymocytes were incubated with 17 beta-estradiol (E) and in the presence or absence of the mitogen, phytohemagglutinin (PHA). Despite evidence of an enhanced binding of E to ER on thymocyte membranes, and an E dose-related influx of Ca(2+), there was a consistent down regulation of IL-2 receptor expression (P < 0.001). Incubation of thymocytes with PHA enhanced IL-2 receptor expression although the down regulatory effect of E was still evident. The results suggest that the Ca(2+) channel activated by E may have a down regulatory effect on the IL-2 receptor in thymus cells leading to the dampening of cell activation process.
Azenabor
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Department of Health Studies and Gerontology, University of Waterloo, Waterloo, Ontario, Canada.
Hoffman-Goetz
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D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D004958:Estradiol / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010835:Phytohemagglutinins / Q000494:pharmacology; D015375:Receptors, Interleukin-2 / Q000187:drug effects* / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism
D010835:Phytohemagglutinins; D015375:Receptors, Interleukin-2; D004958:Estradiol; D002118:Calcium