Sex steroids and leptin regulate 11β-hydroxysteroid dehydrogenase I and P450 aromatase expressions in human preadipocytes: Sex specificities

2006 ◽  
Vol 99 (4-5) ◽  
pp. 189-196 ◽  
Author(s):  
Marie-Noëlle Dieudonné ◽  
Anes Sammari ◽  
Esther Dos Santos ◽  
Marie-Christine Leneveu ◽  
Yves Giudicelli ◽  
...  
1974 ◽  
Vol 75 (4) ◽  
pp. 793-800
Author(s):  
A. O. Sogbesan ◽  
O. A. Dada ◽  
B. Kwaku Adadevoh

ABSTRACT The 17β-hydroxysteroid dehydrogenase activity in intact erythrocytes of Nigerian patients, in particular with regard to haemoglobin genotypes and G6PD* activity was studied. The G6PD activity of the erythrocyte did not affect the oxidative transformation of testosterone to androstenedione and of oestradiol to oestrone. The reduction (reverse transformation) was inhibited in G6PD-deficient erythrocytes but this inhibition was offset by the addition of 0.025 m glucose to the incubation medium. The per cent oxidation transformation of testosterone was higher in Hb-AA than in Hb-SS erythrocytes. It is suggested that the differences may be a result of either lower enzyme activity in the Hb-SS erythrocytes or of differences in the uptake and possibly binding of sex steroids by intact Hb-SS and Hb-AA erythrocytes.


2000 ◽  
Vol 165 (2) ◽  
pp. 217-222 ◽  
Author(s):  
M Bonenfant ◽  
PR Provost ◽  
R Drolet ◽  
Y Tremblay

The 17beta-hydroxysteroid dehydrogenases (17beta-HSDs) play a key role in the synthesis of sex steroids. The hallmark of this family of enzymes is the interconversion, through their oxydoreductive reactivity at position C17, of 17-keto- and 17beta-hydroxy-steroids. Because this reaction essentially transforms steroids having low binding activity for the steroid receptor to their more potent 17beta-hydroxysteroids isoforms, it is crucial to the control of the physiological activities of both estrogens and androgens. The human placenta produces large amounts of progesterone and estrogens throughout pregnancy. The placental type 1 17beta-HSD enzyme (E17beta-HSD) catalyzes the reduction of the low activity estrogen, estrone, into the potent estrogen, estradiol. We studied the cell-specific expression of type 1 17beta-HSD in human term placental villous tissue by combining in situ hybridization to localize type 1 17beta-HSD mRNA with immunohistochemistry using an antibody against human placental lactogen, a trophoblast marker. Immunolocalization of E17beta-HSD was also performed. To ascertain whether other steroidogenic enzymes are present in the same cell type, cytochrome P450 cholesterol side-chain cleavage (P450scc), P450 aromatase, and type 1 3beta-hydroxysteroid dehydrogenase (3beta-HSD) were also localized by immunostaining. Our results showed that the syncytium is the major steroidogenic unit of the fetal term villi. In fact, type 1 17beta-HSD mRNA and protein, as well as P450scc, P450 aromatase, and 3beta-HSD immunoreactivities were found in these cells. In addition, our results revealed undoubtedly that extravillous cytotrophoblasts (CTBs), e.g. those from which cell columns of anchoring villous originate, also express the type 1 17beta-HSD gene. However, CTBs lying beneath the syncytial layer, e.g. those from which syncytiotrophoblasts develop, contained barely detectable amounts of type 1 17beta-HSD mRNA as determined by in situ hybridization. These findings, along with those from other laboratories confirm the primordial role of the syncytium in the synthesis of steroids during pregnancy. In addition, our results indicate for the first time that CTBs differentiating along the invasive pathway contain type 1 17beta-HSD mRNA.


Endocrinology ◽  
2007 ◽  
Vol 148 (8) ◽  
pp. 3827-3836 ◽  
Author(s):  
Shen Zhongyi ◽  
Pia Rantakari ◽  
Tarja Lamminen ◽  
Jorma Toppari ◽  
Matti Poutanen

1966 ◽  
Vol 36 (1) ◽  
pp. 29-NP ◽  
Author(s):  
A. H. BAILLIE ◽  
M. M. FERGUSON ◽  
D. McK. HART

SUMMARY The human pronephros showed no hydroxysteroid dehydrogenase activity. The human mesonephros, like piscine and amphibian mesonephroi had 16β- and 17β-hydroxysteroid dehydrogenase activity and a possible function of the human mesonephros is suggested. Metanephric kidneys had 3α-, Δ5-3β-, 3β-, 6β-, 16α-, 16β-, and 17β-hydroxysteroid dehydrogenases; 11β-hydroxysteroid dehydrogenase was present in all adult mammalian metanephric kidneys surveyed. 3α-Hydroxysteroid dehydrogenase was selectively present and very active in the proximal and distal convoluted tubules, particularly of the juxta-medullary glomeruli. This function is thought to be related to the excretion of 3α-ketosteroids. 11β-Hydroxysteroid dehydrogenase was confined to the collecting tubules and its possible involvement in the metabolism of cortisol, aldosterone or androgens in the kidney is noted. 17β-Hydroxysteroid dehydrogenase may be concerned in the excretion of the sex steroids; it occurs throughout the nephron. Δ5-3β-, 16α-, and 16β-hydroxysteroid dehydrogenases were not as active histochemically in the kidney as the 3α-, 3β-, 11β- and 17β-hydroxysteroid dehydrogenases.


2001 ◽  
Vol 26 (1) ◽  
pp. 11-19 ◽  
Author(s):  
G Pelletier ◽  
V Luu-The ◽  
M El-Alfy ◽  
S Li ◽  
F Labrie

The subcellular distribution of steroidogenic enzymes has so far been studied mostly in classical endocrine glands and in the placenta. In the peripheral intracrine organs which synthesize sex steroids there is no indication about the organelles which contain the enzymes involved in steroid biosynthesis. We have thus investigated the subcellular localization of two enzymes involved in the production of sex steroids, namely 3beta-hydroxysteroid dehydrogenase (3beta-HSD) and type 5 17beta-hydroxysteroid dehydrogenase (17beta-HSD). Using specific antibodies to these enzymes, we conducted immunoelectron microscopic studies in two peripheral tissues, namely the human prostate and mammary gland. In the prostate, immunolabelling for both 3beta-HSD and type 5 17beta-HSD was detected in the basal cells of the tube-alveoli as well as in fibroblasts and endothelial cells lining the blood vessels. In all the labelled cell types, the gold particles were distributed throughout the cytoplasm. No obvious association with any specific organelle could be observed, although some concentration of gold particles was occasionally found over bundles of microfilaments. In mammary gland sections immunolabelled for 3beta-HSD or type 5 17beta-HSD localization, labelling was observed in the cytoplasm of the secretory epithelial cells in both the acini and terminal ducts. Immunolabelling was also found in the endothelial cells as well as in fibroblasts in stroma and blood vessels. The gold particles were not detected over any organelles, except with the occasional accumulation of gold particles over microfilaments. The present data on the localization of two steroidogenic enzymes leading to the synthesis of testosterone indicate that these enzymes are located not only in epithelial cells but also in stromal and endothelial cells in both tissues studied. The absence of any association of the enzymes with membrane-bound organelles appears as a common finding in the reactive cell types of two peripheral tissues.


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