Exp Clin Endocrinol Diabetes 2004; 112 - P168
DOI: 10.1055/s-2004-819287

Existence of interindividual differences in 17ß-HSD-isoenzymes transcription profiles in peripheral blood cells

U Hoppe 1, PM Holterhus 1, C Marschke 1, O Hiort 1
  • 1Clinical Research Group „Intersexuality – From Gene to Gender“, Department of Pediatrics, University of Lübeck, Germany

Background: Sex steroid profiles are involved in the expression of sexual phenotype of an individual. The 17ß-Hydroxysteroid dehydrogenases (17ß-HSD)-isoenzymes play an essential role in both the activation and inactivation of androgens and estrogens in this process. To date, 12 distinct enzymes with 17ß-HSD activity have been identified. There is great interest in the expression-profiles of 17ß-HSD-isoenzymes because of their organ-specific regulating influences of the steriod action. Therefore, we investigated the messenger ribonucleic acid (mRNA) expression of four 17ß-HSD-isoenzymes (type 2, 4, 7, 10) in peripheral blood cells from males and females with quantitative RT-PCR to find possible coherences between steroid action and sexual phenotypic effects.

Methods: We studied blood samples from 10 healthy males and 13 healthy females. RNA was extracted from whole blood with the PAXgene Blood RNA Kit (Qiagen). Quality of RNA was examined with porphobilinogen deaminase (PBGD) house keeping gene transcription. Relative quantification of the different mRNA-transcription from the 17ß-HSD-isoenzymes type 2, 4, 7, 10 was achieved by real-time reverse transcription-PCR with the LightCycler system (Roche). The normalized ratio was calculated with the LightCycler Relative Quantification Software (Roche)

Results: While 17ß-HSD 2 transcription was not detectable, different transcription-profiles of the other three isoenzymes were found in all 23 samples. The normalized ration values of the 17ß-HSD 4 are between 0,28–2,05, of the 17ß-HSD 7 between 0,27–2,61 and of the 17ß-HSD 10 between 0,21–3,13. No sex- or age-specific regulation of mRNA-expression could be established.

Conclusions: The results of the transcription-profiles suggest a different steroid-spectrum in blood cells. Investigations of such specific steroid regulated target genes will lead to further understanding of steroid metabolism and action which may have consequences for the different sexual phenotypic expression.