Dehydroepiandrosterone and Its CYP7B1 Metabolite 7α-Hydroxydehydroepiandrosterone Regulates 11β-Hydroxysteroid Dehydrogenase 1 Directions in Rat Leydig Cells

Abstract

Background: The purpose of this study was to investigate cytochrome P450-7B1 (CYP7B1) in the human and rat testes to regulate 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) activity. We hypothesized that dehydroepiandrosterone (DHEA) and its product 7α-hydroxydehydroepiandrosterone (7αOHD) after catalysis of CYP7B1 played a critical role in driving the direction of 11β-HSD1, because 7αOHD is an alternative substrate for 11β-HSD1. Methods: We examined the influence of DHEA and 7αOHD on 11β-HSD1 activities in both intact Leydig cells and microsomes using radioactive substrates and identified the location of CYP7B1 in Leydig cells using immunohistochemical staining, Western blot, and qPCR. Results: We found that DHEA stimulated 11β-HSD1 oxidase activity in intact cells (EC 50 = 0.97 ± 0.11 µM) and inhibited its reductase activity (IC 50 = 1.04 ± 0.06 µM). In microsomes, DHEA was a competitive inhibitor of the reductase activity. The 11β-HSD1 oxidase activity in intact cells was inhibited by 7αOHD (IC 50 = 1.18 ± 0.12 µM), and the reductase activity was enhanced (EC 50 = 0.7 ± 0.04 µM). 7αOHD was a competitive inhibitor of 11β-HSD1 oxidase. CYP7B1 was present in rat Leydig cells, as shown by immunohistochemistry, Western blotting, and qPCR analysis. Conclusion: Our results are consistent with a conclusion that DHEA in the circulation driving 11β-HSD1 toward an oxidase in Leydig cells mainly through inhibiting the reductase of the enzyme, while 7αOHD (CYP7B1 catalytic product of DHEA) drives the enzyme toward the opposite direction.

Impact of Fetal Exposure to Endocrine Disrupting Chemical Mixtures on FOXA3 Gene and Protein Expression in Adult Rat Testes

“…Cytochromes 7B1, 7A1, and 2R1 were also found to be decreased in the study. Cytochrome P450s in the testes are important for metabolizing cholesterol into testosterone [ 34 ]. Cytochrome P450 family 7 subfamily B1 has been found to regulate 11 beta-hydroxysteroid dehydrogenase 1 (11b-HSD1) in rat Leydig cells [ 34 ].…”

“…Cytochrome P450s in the testes are important for metabolizing cholesterol into testosterone [ 34 ]. Cytochrome P450 family 7 subfamily B1 has been found to regulate 11 beta-hydroxysteroid dehydrogenase 1 (11b-HSD1) in rat Leydig cells [ 34 ]. CYP7A1 and CYP2R1 are also part of the cholesterol synthesis network.…”

Investigation of dichlorodiphenyltrichloroethane (DDT) on xenobiotic enzyme disruption and metabolomic bile acid biosynthesis in DDT-sprayed areas using wild rats

“…The primer data are summarized in Supplementary Table 2 and some primers used were based on previous reports [2,16,22,23,27,28,31,40,51,52]. Gene expression was normalized using the housekeeping gene (beta-actin) and calculated using the comparative Ct method (ΔΔCT) in both liver and testis.…”

Physiological and pathophysiological role of dehydroepiandrosterone in cardiovascular disease

“…Описано е и свързване на DHEA към нуклеарните рецептори за естроген α и β, андрогенни рецептори, както и PPAR (Peroxisome proliferatoractivated receptor) с много по-нисък афинитет от специфичните им лиганди (11,18). При проучвания през последните години е установено, че един от метаболитите на DHEA (7алфа-хидроксиепиандростерон) има възможността да увеличава редуктазната активност на 11-бета-хидроксистероид дехидрогеназата (11βHSD), докато ДХЕА повишава оксидазната й активност (инактивиране на кортизол до кортизон) (19). Теоретично се допуска неблагоприятно влияние на свръхекспресията на 11βHSD тип 1 върху развитието на сърдечносъдовите заболявания, в частност исхемичната болест на сърцето (20).…”