Regulation of Sex-Hormone-Binding Globulin Production by Endogenous Estrogens in Vitro

1995 ◽  
Vol 206 (3) ◽  
pp. 895-901 ◽  
Author(s):  
M. Loukovaara ◽  
M. Carson ◽  
H. Adlercreutz
1981 ◽  
Vol 96 (1) ◽  
pp. 136-140 ◽  
Author(s):  
M. Egloff ◽  
N. Savouré ◽  
J. Tardivel-Lacombe ◽  
C. Massart ◽  
M. Nicol ◽  
...  

Abstract. The influence of human serum albumin and sex hormone binding globulin (SHBG) on the enzymic conversion of androstenedione to testosterone in human erythrocytes was investigated in vitro. Total plasma and albumin delayed the conversion rate of androstenedione, while SHBG increased it markedly. The effect of SHBG was largely abolished by heating to 60°C for 1 h and by saturating its binding sites by DHT. The effect of both proteins was found to be related to their concentration. It appears that the binding sites of albumin provide a mechanism for retarding androstenedione uptake by the erythrocytes and that the high binding affinity of SHBG for testosterone facilitates the diffusion of this steroid out of the cell and thus, displaces the chemical equilibrium within the cell.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Hiroki Yamazaki ◽  
Akifumi Kushiyama ◽  
Hideyuki Sakoda ◽  
Midori Fujishiro ◽  
Takeshi Yamamotoya ◽  
...  

Sex hormone-binding globulin (SHBG) is a serum protein released mainly by the liver, and a low serum level correlates with a risk for metabolic syndrome including diabetes, obesity, and cardiovascular events. However, the underlying molecular mechanism(s) linking SHBG and metabolic syndrome remains unknown. In this study, using adipocytes and macrophages, we focused on the in vitro effects of SHBG on inflammation as well as lipid metabolism. Incubation with 20 nM SHBG markedly suppressed lipopolysaccharide- (LPS-) induced inflammatory cytokines, such as MCP-1, TNFα, and IL-6 in adipocytes and macrophages, along with phosphorylations of JNK and ERK. Anti-inflammatory effects were also observed in 3T3-L1 adipocytes cocultured with LPS-stimulated macrophages. In addition, SHBG treatment for 18 hrs or longer significantly induced the lipid degradation of differentiated 3T3-L1 cells, with alterations in its corresponding gene and protein levels. Notably, these effects of SHBG were not altered by coaddition of large amounts of testosterone or estradiol. In conclusion, SHBG suppresses inflammation and lipid accumulation in macrophages and adipocytes, which might be among the mechanisms underlying the protective effect of SHBG, that is, its actions which reduce the incidence of metabolic syndrome.


Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 755
Author(s):  
Katarzyna Kornicka-Garbowska ◽  
Lynda Bourebaba ◽  
Michael Röcken ◽  
Krzysztof Marycz

Despite multiple research studies regarding metabolic syndrome and diabetes, the full picture of their molecular background and pathogenies remains elusive. The latest studies revealed that sex hormone-binding globulin (SHBG)—a serum protein released mainly by the liver—may participate in metabolic dysregulation, as its low serum level correlates with a risk for obesity, metabolic syndrome, and diabetes. Yet, the molecular phenomenon linking SHBG with these disorders remains unclear. In the presented study, we investigate how exogenous SHBG affects metabolically impaired hepatocytes with special attention to endoplasmic reticulum stress (ER stress) and lipid metabolism both in vitro and ex vivo. For that reason, palmitate-treated HepG2 cells and liver tissue samples collected post mortem were cultured in the presence of 50 nM and 100 nM SHBG. We found that SHBG protects against ER stress development and its progression. We have found that SHBG decreased the expression levels of inositol-requiring enzyme 1 (IRE1α), activating transcription factor 6 (ATF6), DNA damage-inducible transcript 3 (CHOP), and immunoglobulin heavy chain-binding protein (BIP). Furthermore, we have shown that it regulates lipolytic gene expression ex vivo. Additionally, herein, we deliver a novel large-animal model to study SHBG in translational research. Our data provide new insights into the cellular and molecular mechanisms by which SHBG modulates hepatocyte metabolism and offer a new experimental approach to study SHBG in human diseases.


1989 ◽  
Vol 12 (7) ◽  
pp. 489-493 ◽  
Author(s):  
L. Bartalena ◽  
E. Martino ◽  
A. Pacchiarotti ◽  
S. Balzano ◽  
M. Falcone ◽  
...  

1977 ◽  
Vol 86 (1) ◽  
pp. 200-215 ◽  
Author(s):  
M. Krieg ◽  
W. Bartsch ◽  
S. Herzer ◽  
H. Becker ◽  
K. D. Voigt

ABSTRACT The in vitro binding of 5α-dihydrotestosterone (5α-DHT) in benign prostatic hypertrophy (BPH), rectus abdominis muscle and plasma of 14 patients was characterized and quantified by agargel electrophoresis. The respective endogenous tissue and plasma levels of 5α-DHT and testosterone (T) were determined by radioimmunoassay, and the plasmatic sex hormone-binding globulin (SHBG) concentration was estimated in the 14 patients by an (NH4)2SO4 precipitation technique. Finally the in vitro conversion of 5α-DHT to the 5α-androstanediols in the BPH at 0°C after a 20–24 h incubation period was analyzed by thin-layer chromatography. The main results were as follows: (1) In 12 out of 14 BPH cytosols three charcoal resistant binding peaks were found, of which peak 1 represents SHBG, peak 2 the specific receptor protein and peak 3 a binding protein with relatively high binding capacity and low affinity for 5α-DHT. In two cases peak 2 was absent. In 11 out of 14 muscle cytosols three binding peaks are also present, resembling those of the BPH. (2) The receptor peak is reduced on average 38 % by unlabelled 5α-DHT, 23 % by cyproterone acetate (CYAC) and 29 % by oestradiol. The parallel data for the SHBG peak are: 62% by 5α-DHT, 22% by CYAC and 49% by oestradiol. (3) From displacement studies with unlabelled 5α-DHT the average concentration of receptor was calculated to be 12.3 fmol/mg cytosol protein (CP) in BPH, and 3.6 fmol/mg CP in muscle. Under identical conditions 39.9 fmol SHBG/mg CP and 24.1 fmol/mg CP were found in the BPH and muscle, respectively. The mean values are significantly different (P < 0.001). In plasma a mean value of 4.0 × 10−8 mol SHBG/1 was found. (4) In the BPH on average 4.43 ng 5α-DHT/g tissue and 0.23 ng T/g tissue are present, in muscle 0.45 ng 5α-DHT/g tissue and 0.71 ng T/g tissue, in plasma 0.47 ng 5α-DHT/ml and 3.89 ngT/ml. (5) Statistical calculations revealed (a) a significantly (P < 0.05) negative correlation between the endogenous 5α-DHT and T tissue levels and the available 5α-DHT receptor sites in BPH cytosol, (b) a positive correlation between plasmatic SHBG concentration and the available SHBG concentration in BPH cytosol. (6) Compared to the rat prostate, where 36 % of the incubated 5α-DHT was converted at 0°C within 20–24 h into the 5α-androstanediols, in the BPH conversion to 5α-androstanediols was negligible.


2016 ◽  
Vol 437 ◽  
pp. 280-291 ◽  
Author(s):  
Michaël R. Laurent ◽  
Christine Helsen ◽  
Leen Antonio ◽  
Dieter Schollaert ◽  
Steven Joniau ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document