| 1. |
- Leong, Gary M, et al.
(författare)
-
Estrogen up-regulates hepatic expression of suppressors of cytokine signaling-2 and -3 in vivo and in vitro.
- 2004
-
Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 145:12, s. 5525-31
-
Tidskriftsartikel (refereegranskat)abstract
- Suppressors of cytokine signaling (SOCS) are important negative regulators of cytokine action. We recently reported that estrogen stimulates SOCS-2 expression and inhibits GH signaling in kidney cells. The effects of estrogen on SOCS expression in other tissues are unclear. The aim of this study was to investigate in vivo and in vitro whether estrogen affected SOCS expression in the liver, a major target organ of GH. The in vivo hepatic effects of estrogen on ovariectomized mice lacking estrogen receptor (ER)-alpha, ERbeta, or both and their wild-type littermates were examined by DNA microarray analysis. In vitro, the effects of estrogen on SOCS expression in human hepatoma cells were examined by reverse transcription quantitative PCR. Long-term (3 wk) estrogen treatment induced a 2- to 3-fold increase in hepatic expression of SOCS-2 and -3 in wild-type and ERbeta knockout mice but not in those lacking ERalpha or both ER subtypes. Short-term treatment (at 24 h) increased the mRNA level of SOCS-3 but not SOCS-2. In cultured hepatoma cells, estrogen increased SOCS-2 and -3 mRNA levels by 2-fold in a time- and dose-dependent manner (P < 0.05). Estrogen induced murine SOCS-3 promoter activity by 2-fold (P < 0.05) in constructs containing a region between nucleotides -1862 and -855. Moreover, estrogen and GH had additive effects on the SOCS-3 promoter activity. In summary, estrogen, via ERalpha, up-regulated hepatic expression of SOCS-2 and -3, probably through transcriptional activation. This indicates a novel mechanism of estrogen regulation of cytokine action.
|
|
| 2. |
- Lindberg, Marie K, 1975, et al.
(författare)
-
Estrogen receptor (ER)-beta reduces ERalpha-regulated gene transcription, supporting a "ying yang" relationship between ERalpha and ERbeta in mice.
- 2003
-
Ingår i: Molecular endocrinology (Baltimore, Md.). - : The Endocrine Society. - 0888-8809 .- 1944-9917. ; 17:2, s. 203-8
-
Tidskriftsartikel (refereegranskat)abstract
- Estrogen is of importance for the regulation of adult bone metabolism. The aim of the present study was to determine the role of estrogen receptor-beta (ERbeta) in vivo on global estrogen-regulated transcriptional activity in bone. The effect of estrogen in bone of ovariectomized mice was determined using microarray analysis including 9400 genes. Most of the genes (95% = 240 genes) that were increased by estrogen in wild-type (WT) mice were also increased by estrogen in ERbeta-inactivated mice. Interestingly, the average stimulatory effect of estrogen on the mRNA levels of these genes was 85% higher in ERbeta-inactivated than in WT mice, demonstrating that ERbeta reduces estrogen receptor-alpha (ERalpha)-regulated gene transcription in bone. The average stimulatory effect of estrogen on estrogen-regulated bone genes in ERalpha-inactivated mice was intermediate between that seen in WT and ERalphabeta double-inactivated mice. Thus, ERbeta inhibits ERalpha-mediated gene transcription in the presence of ERalpha, whereas, in the absence of ERalpha, it can partially replace ERalpha. In conclusion, our in vivo data indicate that an important physiological role of ERbeta is to modulate ERalpha-mediated gene transcription supporting a "Ying Yang" relationship between ERalpha and ERbeta in mice.
|
|
| 3. |
- Lindberg, Marie K, 1975, et al.
(författare)
-
Estrogen receptor specificity for the effects of estrogen in ovariectomized mice.
- 2002
-
Ingår i: The Journal of endocrinology. - : Bioscientifica. - 0022-0795 .- 1479-6805. ; 174:2, s. 167-78
-
Tidskriftsartikel (refereegranskat)abstract
- Estrogen exerts a variety of important physiological effects, which have been suggested to be mediated via the two known estrogen receptors (ERs), alpha and beta. Three-month-old ovariectomized mice, lacking one or both of the two estrogen receptors, were given estrogen subcutaneously (2.3 micro g/mouse per day) and the effects on different estrogen-responsive parameters, including skeletal effects, were studied. We found that estrogen increased the cortical bone dimensions in both wild-type (WT) and double ER knockout (DERKO) mice. DNA microarray analysis was performed to characterize this effect on cortical bone and it identified four genes that were regulated by estrogen in both WT and DERKO mice. The effect of estrogen on cortical bone in DERKO mice might either be due to remaining ERalpha activity or represent an ERalpha/ERbeta-independent effect. Other effects of estrogen, such as increased trabecular bone mineral density, thymic atrophy, fat reduction and increased uterine weight, were mainly ERalpha mediated.
|
|
| 4. |
- Lindberg, Marie K, 1975, et al.
(författare)
-
Identification of estrogen-regulated genes of potential importance for the regulation of trabecular bone mineral density.
- 2002
-
Ingår i: Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research. - : Wiley. - 0884-0431. ; 17:12, s. 2183-95
-
Tidskriftsartikel (refereegranskat)abstract
- Estrogen is of importance for the regulation of trabecular bone mineral density (BMD). The aim of this study was to search for possible mechanisms of action of estrogen on bone. Ovariectomized (OVX) mice were treated with 17beta-estradiol. Possible effects of estrogen on the expression of 125 different bone-related genes in humerus were analyzed using the microarray technique. Estrogen regulated 12 of these genes, namely, two growth factor-related genes, 8 cytokines, and 2 bone matrix-related genes. Five of the 12 genes are known to be estrogen-regulated, and the remaining 7 genes are novel estrogen-regulated genes. Seven genes, including interleukin-1 receptor antagonist (IL-1ra), IL-1receptor type II (IL-1RII), insulin-like growth factor-binding protein 4 (IGFBP-4), transforming growth factor beta (TGF-beta), granulocyte colony-stimulating factor receptor (G-CSFR), leukemia inhibitory factor receptor (LIFR), and soluble IL-4 receptor (sIL-4R) were selected as probable candidate genes for the trabecular bone-sparing effect of estrogen, as the mRNA levels of these genes were highly correlated (r2 > 0.65) to the trabecular BMD. The regulation of most of these seven genes was predominantly estrogen receptor alpha (ER-alpha)-mediated (5/7) while some genes (2/7) were regulated both via ER-alpha and ER-beta. In conclusion, by using the microarray technique, we have identified four previously known and three novel estrogen-regulated genes of potential importance for the trabecular bone-sparing effect of estrogen.
|
|
| 5. |
- Lundholm, Lovisa, et al.
(författare)
-
Gene expression profiling identifies liver X receptor alpha as an estrogen-regulated gene in mouse adipose tissue.
- 2004
-
Ingår i: Journal of molecular endocrinology. - : Bioscientifica. - 0952-5041 .- 1479-6813. ; 32:3, s. 879-92
-
Tidskriftsartikel (refereegranskat)abstract
- Estrogens reduce adipose tissue mass in both humans and animals. The molecular mechanisms for this effect are, however, not well characterized. We took a gene expression profiling approach to study the direct effects of estrogen on mouse white adipose tissue (WAT). Female ovariectomized mice were treated for 10, 24 and 48 h with 17beta-estradiol or vehicle. RNA was extracted from gonadal fat and hybridized to Affymetrix MG-U74Av2 arrays. 17beta-Estradiol was shown to decrease mRNA expression of liver X receptor (LXR) alpha after 10 h of treatment compared with the vehicle control. The expression of several LXRalpha target genes, such as sterol regulatory element-binding protein 1c, apolipoprotein E, phospholipid transfer protein, ATP-binding cassette A1 and ATP-binding cassette G1, was similarly decreased. We furthermore identified a 1.5 kb LXRalpha promoter fragment that is negatively regulated by estrogen. Several genes involved in lipogenesis and lipolysis were identified as novel targets that could mediate estrogenic effects on adipose tissue. Finally, we show that ERalpha is the main estrogen receptor expressed in mouse white adipose tissue (WAT) with mRNA levels several hundred times higher than those of ERbeta mRNA.
|
|
| 6. |
- Movérare, Sofia, et al.
(författare)
-
Estrogen increases coagulation factor V mRNA levels via both estrogen receptor-alpha and -beta in murine bone marrow/bone.
- 2004
-
Ingår i: European journal of endocrinology / European Federation of Endocrine Societies. - : Oxford University Press (OUP). - 0804-4643 .- 1479-683X. ; 151:2, s. 259-63
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Both oral estrogen-based hormone-replacement therapy and contraceptives increase the risk of venous thromboembolism. Several circulating factors involved in coagulation/fibrinolysis are expressed mainly in the liver whilst some are expressed in extrahepatic tissues, including bone marrow. The aim of this study was to identify estrogen-responsive target genes involved in the pathogenesis of estrogen-induced venous thromboembolism. METHODS: Ovariectomized mice were treated with 17beta-estradiol and possible effects on the expression of genes related to coagulation/fibrinolysis were investigated using DNA microarray analyses. RESULTS: None of the selected genes was regulated by 17beta-estradiol in the liver. Interestingly, 17beta-estradiol increased mRNA levels of coagulation factor V in the bone marrow/bone. Furthermore, this stimulatory effect of 17beta-estradiol on coagulation factor V expression can be mediated via both estrogen receptor-alpha and -beta. CONCLUSIONS: The expression of bone marrow-derived, but not liver-derived, coagulation factor V is increased by estrogen treatment in mice. The pathophysiological importance of this finding for estrogen-induced venous thromboembolism remains to be determined.
|
|
| 7. |
- Otsuki, Michio, et al.
(författare)
-
Specific regulation of lipocalin-type prostaglandin D synthase in mouse heart by estrogen receptor beta.
- 2003
-
Ingår i: Molecular endocrinology (Baltimore, Md.). - : The Endocrine Society. - 0888-8809 .- 1944-9917. ; 17:9, s. 1844-55
-
Tidskriftsartikel (refereegranskat)abstract
- Estrogens have important physiological roles in the cardiovascular system. We use DNA microarray technology to study the molecular mechanism of estrogen action in the heart and to identify novel estrogen-regulated genes. In this investigation we identify genes that are regulated by chronic estrogen treatment of mouse heart. We present our detailed characterization of one of these genes, lipocalin-type prostaglandin D synthase (L-PGDS). Northern and Western blot analysis revealed that L-PGDS was induced both by acute and chronic estrogen treatment. Northern blot analysis, using estrogen receptor (ER)-disrupted mice, suggests that L-PGDS is specifically induced by ERbeta in vivo. In further support of ERbeta-selective regulation, we identify a functional estrogen-responsive element in the L-PGDS promoter, the activity of which is up-regulated by ERbeta, but not by ERalpha. We demonstrate that a one-nucleotide change (A to C) in the L-PGDS estrogen-responsive element affects receptor selectivity.
|
|
