scholarly journals Critical in Vivo Roles for Classical Estrogen Receptors in Rapid Estrogen Actions on Intracellular Signaling in Mouse Brain

Endocrinology ◽  
2004 ◽  
Vol 145 (7) ◽  
pp. 3055-3061 ◽  
Author(s):  
István M. Ábrahám ◽  
Martin G. Todman ◽  
Kenneth S. Korach ◽  
Allan E. Herbison

Abstract Estrogen exerts classical genomic as well as rapid nongenomic actions on neurons. The mechanisms involved in rapid estrogen signaling are poorly defined, and the roles of the classical estrogen receptors (ERs α and β) are unclear. We examined here the in vivo role of classical ERs in rapid estrogen actions by evaluating the estrogen-induced effects on two major signaling pathways within the brains of αER-, βER-, and double αβER-knockout (ERKO) ovariectomized female mice. Estrogen significantly (P < 0.05) increased the numbers of phospho-cAMP response element binding protein (phospho-CREB)-immunoreactive cells in specific brain regions of wild-type mice in a time-dependent manner beginning within 15 min. In brain areas that express predominantly ERβ, this response was absent in βERKO mice, whereas brain regions that express mostly ERα displayed no change in αERKO mice. In the medial preoptic nucleus (MPN), an area that expresses both ERs, the estrogen-induced phosphorylation of CREB was normal in both αERKO and βERKO mice. However, estrogen had no effect on CREB phosphorylation in the MPN, or any other brain region, in double αβERKO animals. Estrogen was also found to increase MAPK phosphorylation levels in a rapid (<15 min) manner within the MPN. In contrast to CREB signaling, this effect was lost in either αERKO or βERKO mice. These data show that ERα and ERβ play region- and pathway-specific roles in rapid estrogen actions throughout the brain. They further indicate an indispensable role for classical ERs in rapid estrogen actions in vivo and highlight the importance of ERs in coordinating both classical and rapid actions of estrogen.

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Chunfang Liu ◽  
Yanfang Zheng ◽  
Wen Xu ◽  
Hui Wang ◽  
Na Lin

Tannins, a group of major active components of Chinese rhubarb and widely distributed in nature, have a significant antidiarrhoeal activity. Aquaporins (AQPs) 2 and 3 play important roles in regulating water transfer during diarrhoea. The present study aims to determine the effect of the total tannins extract of rhubarb on aquaporins (AQPs) 2 and 3 in diarrhoea mice and HT-29 cells both induced by magnesium sulphate (MgSO4). Our results showed that rhubarb tannins extract (RTE) significantly decreased the faecal water content in colon and evaluation index of defecation of diarrhoea mice. Interestingly, RTE could markedly reduce the mRNA and protein expression levels of AQPs 2 and 3 in apical and lateral mucosal epithelial cells in the colons of diarrhoea mice and HT-29 cells both induced by MgSO4in a dose-dependent manner. Furthermore, RTE suppressed the production of cyclic monophosphate- (cAMP-) dependent protein kinase A catalytic subunitsα(PKA C-α) and phosphorylated cAMP response element-binding protein (p-CREB, Ser133) in MgSO4-induced HT-29 cells. Our data showed for the first time that RTE inhibit AQPs 2 and 3 expressionin vivoandin vitrovia downregulating PKA/p-CREB signal pathway, which accounts for the antidiarrhoeal effect of RTE.


Endocrinology ◽  
2003 ◽  
Vol 144 (3) ◽  
pp. 832-838 ◽  
Author(s):  
Christian B. Wade ◽  
Daniel M. Dorsa

The ability of estrogen to rapidly initiate a variety of signal transduction cascades is increasingly recognized as playing an important role in a number of tissue-specific transcriptional actions of the hormone. In vivo, estrogen rapidly elicits phosphorylation of cAMP response element-binding protein (CREB). We have previously shown that both ERα and ERβ are capable of activating the MAPK pathway in response to a low dose of 17β-estradiol. In the present study, the ability of estrogen to act through both ERα and ERβ to increase CREB phosphorylation was evaluated in an immortalized hippocampal cell line stably expressing either receptor. Estrogen treatment promoted rapid CREB phosphorylation, reaching a maximum by 15 min. This activation is completely blocked by the antiestrogen ICI 182,780, suggesting an estrogen receptor-dependent mechanism. The addition of the mitogen/ERK kinase-1 inhibitor, PD98059, also blocked the ability of estrogen to signal to CREB phosphorylation. Estrogen also caused an increase in p90Rsk activity, a critical mediator of MAPK effects. Surprisingly, blockade of the protein kinase A pathway in cells treated with estrogen did not affect estrogen-mediated CREB phosphorylation. Thus, MAPK and p90Rsk appear to be the primary mediators of estrogen-induced gene transcription through ERα and ERβ.


2019 ◽  
Vol 3 (12) ◽  
pp. 2326-2340 ◽  
Author(s):  
Luce Perie ◽  
Narendra Verma ◽  
Lingyan Xu ◽  
Xinran Ma ◽  
Elisabetta Mueller

Abstract Zinc finger factors are implicated in a variety of cellular processes, including adipose tissue differentiation and thermogenesis. We have previously demonstrated that zinc finger protein 638 (ZNF638) is a transcriptional coactivator acting as an early regulator of adipogenesis in vitro. In this study, we show, to our knowledge for the first time, that, in vivo, ZNF638 abounds selectively in mature brown and subcutaneous fat tissues and in fully differentiated thermogenic adipocytes. Furthermore, gene expression studies revealed that ZNF638 is upregulated by cAMP modulators in vitro and by cold exposure and by pharmacological stimulation of β-adrenergic signaling in vivo. In silico analysis of the upstream regulatory region of the ZNF638 gene identified two putative cAMP response elements within 500 bp of the ZNF638 transcription start site. Detailed molecular analysis involving EMSA and chromatin immunoprecipitation assays demonstrated that cAMP response element binding protein (CREB) binds to these cAMP response element regions of the ZNF638 promoter, and functional studies revealed that CREB is necessary and sufficient to regulate the levels of ZNF638 transcripts. Taken together, these results demonstrate that ZNF638 is selectively expressed in mature thermogenic adipocytes and tissues and that its induction in response to classic stimuli that promote heat generation is mediated via CREB signaling, pointing to a possible novel role of ZNF638 in brown and beige fat tissues.


2008 ◽  
Vol 413 (2) ◽  
pp. 349-357 ◽  
Author(s):  
Chia-Wei Li ◽  
Gia Khanh Dinh ◽  
Aihua Zhang ◽  
J. Don Chen

ANCO (ankyrin repeats-containing cofactor)-1 and ANCO-2 are a family of unique transcriptional co-regulators with dual properties: they interact with both the co-activators and the co-repressors [Zhang, Yeung, Li, Tsai, Dinh, Wu, Li and Chen (2004) J. Biol. Chem. 279, 33799–33805]. Specifically, ANCO-1 is thought to recruit HDACs (histone deacetylases) to the p160 co-activator to repress transcriptional activation by nuclear receptors. In the present study, we provide new evidence to suggest further that ANCO-1 and ANCO-2 also interact with the co-activator ADA3 (alteration/deficiency in activation 3). The interaction occurs between the conserved C-terminal domain of ANCO-1 and the N-terminal transactivation domain of ADA3. Several subunits of the P/CAF {p300/CBP [CREB (cAMP-response-element-binding protein)-binding protein]-associated factor} complex, including ADA3, ADA2α/β and P/CAF, showed co-localization with ANCO-1 nuclear dots, indicating an in vivo association of ANCO-1 with the P/CAF complex. Furthermore, a transient reporter assay revealed that both ANCO-1 and ANCO-2 repress ADA3-mediated transcriptional co-activation on nuclear receptors, whereas ANCO-1 stimulated p53-mediated transactivation. These data suggest that ADA3 is a newly identified target of the ANCO proteins, which may modulate co-activator function in a transcription-factor-specific manner.


1999 ◽  
Vol 13 (8) ◽  
pp. 1338-1352
Author(s):  
W. Rachel Duan ◽  
Jennifer L. Shin ◽  
J. Larry Jameson

Abstract Estradiol acts on the hypothalamus and pituitary gland to modulate the synthesis and secretion of gonadotropins. We recently reported that GnRH-induced transcription of the human gonadotropin α-gene promoter is increased markedly in transfected pituitary cells derived from animals treated with estradiol. Because the cAMP response element binding (CREB) protein plays an important role in the transcriptional regulation of this promoter and is highly regulated by posttranslational phosphorylation, we hypothesized that it might serve as a target for estradiol-induced sensitivity to GnRH. In this study, we assessed the roles of estradiol and GnRH in the regulation of CREB phosphorylation in the rat pituitary. Using an antibody that specifically recognizes phosphorylated CREB (pCREB), we found that the pituitary content of pCREB was inversely related to the level of estradiol during the estrous cycle. Ovariectomy increased the level of pCREB, and treatment with estradiol for 10 days decreased the content of pCREB dramatically (93% inhibition). A similar reduction of pCREB was seen when ovariectomized rats were treated with a GnRH receptor antagonist for 10 days. This result indicates that the ovariectomy-induced increase in pCREB is GnRH-dependent. In αT3 gonadotrope cells, estradiol had no direct effect on CREB phosphorylation, whereas GnRH increased CREB phosphorylation 4- to 5-fold within 5 min. We conclude that estradiol inhibits CREB phosphorylation in the gonadotrope, probably by inhibiting GnRH production. The estradiol-induced decrease in CREB phosphorylation is proposed to lower basalα -promoter activity and increase its responsiveness to GnRH. (Molecular Endocrinology 13: 1338–1352, 1999)


Blood ◽  
2000 ◽  
Vol 95 (8) ◽  
pp. 2552-2558 ◽  
Author(s):  
Evelyn M. Kwon ◽  
Maribeth A. Raines ◽  
John Blenis ◽  
Kathleen M. Sakamoto

Abstract Granulocyte-macrophage colony-stimulating factor (GM-CSF) activates several kinases and transcription factors through interaction with a heterodimeric receptor complex. We previously demonstrated that phosphorylation of the cyclic adenosine monophosphate (cAMP) response element-binding protein, CREB, occurs through a protein kinase A-independent pathway and is required for GM-CSF–induced transcriptional activation of the immediate early gene, early growth response-1 (egr-1). Recent reports indicate that receptor tyrosine kinases can induce CREB phosphorylation through activation of pp90RSK. We performed immune complex kinase assays in the human myeloid leukemic cell line, TF-1, which revealed that GM-CSF induced pp90RSK activation and phosphorylation of CREB within 5 minutes of stimulation. Transfection with the kinase-defective pp90RSK expression plasmid demonstrated a statistically significant decrease in transcriptional activation of a −116 CAT/egr-1 promoter construct in response to GM-CSF. Furthermore, activation of pp90RSK, CREB and egr-1in GM-CSF–treated cells was inhibited by the presence of the inhibitor, PD98059. In this study, we report that GM-CSF induces CREB phosphorylation and egr-1 transcription by activating pp90RSK through an MEK-dependent signaling pathway.


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