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Updated: May 11, 2026
13:16
Characterization of Membrane Transporters by Heterologous Expression in E. coli and Production of Membrane Vesicles
Published on: December 31, 2019
Membrane transporters for sulfated steroids in the human testis--cellular localization, expression pattern and
Daniela Fietz1, Katharina Bakhaus, Britta Wapelhorst
1Institute for Veterinary Anatomy, Histology and Embryology, Justus Liebig University Giessen, Giessen, Germany. Daniela.Fietz@vetmed.uni-giessen.de
Plos One
|May 14, 2013
Summary
Sulfated steroid hormones can be reactivated to regulate reproductive functions. Researchers identified the Sodium-dependent Organic Anion Transporter (SOAT) as crucial for importing these hormones into testicular cells, with its expression reduced in infertility.
Area of Science:
- Reproductive biology
- Molecular endocrinology
- Cellular transport mechanisms
Background:
- Sulfated steroid hormones are generally inactive metabolites.
- Steroid sulfatase can reactivate sulfated steroids into active forms.
- Nuclear androgen and estrogen receptors in the testis mediate steroid hormone action.
Purpose of the Study:
- Investigate the role of carrier-mediated import in steroid sulfate reactivation within the testis.
- Identify specific transporters involved in steroid sulfate uptake in human testicular cells.
- Correlate transporter expression with spermatogenesis disorders.
Main Methods:
- Analysis of mRNA expression of transporters (SOAT, OATP6A1, OSPC1) in human testis biopsies.
- Immunohistochemical localization of SOAT in testicular germ cells.
- Liquid chromatography tandem mass spectrometry to analyze SOAT transport function for steroid sulfates.
Main Results:
- Predominant expression of SOAT, OATP6A1, and OSPC1 found in normal human testes.
- Significantly reduced or absent mRNA expression of these transporters in severe spermatogenesis disorders.
- SOAT localized to various germ cell types in normal testes.
- SOAT demonstrated inward transport of dehydroepiandrosterone sulfate and estrone-3-sulfate, and identified beta-estradiol-3-sulfate and androstenediol-3-sulfate as new substrates.
Conclusions:
- SOAT plays a critical role in the cellular uptake of steroid sulfates in the human testis.
- Reduced SOAT expression is linked to impaired spermatogenesis.
- SOAT facilitates the reactivation of steroid hormones, impacting reproductive function.
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