کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1992845 | 1541091 | 2006 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Transfection with steroid-responsive reporter constructs shows glucocorticoid rather than androgen responsiveness in cultured Sertoli cells
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کلمات کلیدی
DHTPEMhGRMMTV5α-Dihydrotestosterone - 5α-دی هیدروتستوسترونHAR - اندTestis - بیضهTAT - تاتGene regulation - تنظیم ژنTyrosine aminotransferase - تیروزین آمینوترانسفرازDexamethasone - دگزامتازونAndrogen action - عمل آندروژنیfollicle-stimulating hormone - هورمون تحریک کننده فولیکولFSH - هورمون محرکه فولیکولی Mouse mammary tumor virus - ویروس تومور پستان موشAndrogen Receptor - گیرنده آندروژنیSteroid receptor - گیرنده استروئیدglucocorticoid receptor - گیرنده گلوکوکورتیکوئید
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
It remains unclear why it has proven so difficult to identify androgen target genes in cultured Sertoli cells. Given the lack of useful endogenous reporter genes, we studied the androgen and glucocorticoid responsiveness of these cells by transfection with three different steroid-responsive reporter constructs. The constructs were driven by the tyrosine aminotransferase steroid-responsive region (TAT-GRE4x-Luc), the mouse mammary tumor virus promoter (MMTV-Luc) and the Pem homeobox gene proximal promoter respectively (Pem-Luc). These constructs can be activated either by both the glucocorticoid receptor (GR) and the androgen receptor (AR) (TAT-GRE4x-Luc and MMTV-Luc) or selectively by the AR (Pem-Luc). Despite high transfection efficiency (30-40%) none of the constructs could be activated by treatment of the Sertoli cells with testosterone, 5α-dihydrotestosterone or synthetic androgens. Even pretreatment with follicle-stimulating hormone to raise AR levels (from 31 up to 82 fmol/mg protein) did not result in androgen responsiveness. In contrast, treatment with dexamethasone markedly stimulated TAT-GRE4x-Luc and MMTV-Luc activity. GR levels reached a value of 172 fmol/mg protein in the cultured cells and both AR and GR displayed homogeneous distribution by immunocytochemical evaluation. Androgen responsiveness was restored and glucocorticoid responsiveness was increased by cotransfection with AR or GR expression constructs. Under cotransfection conditions, 1 nM of testosterone (a concentration that is some 100 times lower than that estimated to be present in the testis) was sufficient to stimulate the TAT-GRE4x-Luc maximally. Our data indicate that cultured Sertoli cells respond better to glucocorticoids than to androgens and that one of the factors limiting androgen responsiveness is the availability of AR. Other factors limiting the transactivation capacity of the (endogenous) AR, however, cannot be excluded.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: The Journal of Steroid Biochemistry and Molecular Biology - Volume 98, Issues 2â3, February 2006, Pages 164-173
Journal: The Journal of Steroid Biochemistry and Molecular Biology - Volume 98, Issues 2â3, February 2006, Pages 164-173
نویسندگان
Evi Denolet, Karel De Gendt, Johannes V. Swinnen, Guy Verrijdt, Ludo Deboel, Tania Roskams, Guido Verhoeven,