scholarly journals Interaction of Adenosine 3′,5′-Cyclic Monophosphate and Tumor Necrosis Factor-α on Serum Amyloid A3 Expression in Mouse Granulosa Cells: Dependence on CCAAT-Enhancing Binding Protein-β Isoform

Endocrinology ◽  
2010 ◽  
Vol 151 (7) ◽  
pp. 3407-3419 ◽  
Author(s):  
Deok-Soo Son ◽  
Paul F. Terranova ◽  
Katherine F. Roby
Keyword(s):  
Granulosa Cells ◽  
Promoter Activity ◽  
Binding Protein ◽  
Camp Response Element Binding ◽  
Dominant Negative ◽  
Serum Amyloid ◽  
Element Binding Protein ◽  
Granulose Cells ◽  
Factor Α ◽  
Interfering Rna

TNFα is an inflammatory-related cytokine that has inhibitory effects on gonadotropin- and cAMP-stimulated steroidogenesis and folliculogenesis. Because ovulation is an inflammatory reaction and TNF specifically induces serum amyloid A3 (SAA3) in mouse granulosa cells, the effect of cAMP on TNF-induced SAA3 promoter activity, mRNA and protein was investigated. Granulosa cells from immature mice were cultured with TNF and/or cAMP. TNF increased SAA3 promoter activity, mRNA, and protein, which were further increased by cAMP. cAMP alone increased SAA3 promoter activity, but SAA3 mRNA and protein remained undetectable. Thus, there appeared to be different mechanisms by which TNF and cAMP regulated SAA3 expression. SAA3 promoters lacking a nuclear factor (NF)-κB-like site or containing its mutant were not responsive to TNF but were responsive to cAMP. Among four CCAAT-enhancing binding protein (C/EBP) sites in the SAA3 promoter, the C/EBP site nearest the NF-κB-like site was required for TNF-induced SAA3. The C/EBP site at −75/−67 was necessary for responsiveness to cAMP. Dominant-negative C/EBP and cAMP response element-binding protein or short interfering RNA of C/EBPβ blocked TNF- or cAMP-induced SAA3 promoter activity. The combination of TNF and cAMP increased C/EBPβ protein above that induced by TNF or cAMP alone. Thus, cAMP in combination with TNF specifically induced C/EBPβ protein, leading to enhanced SAA3 expression but requiring NF-κB in mouse granulose cells. In addition, like TNF, SAA inhibited cAMP-induced estradiol accumulation and CYP19 levels. These data indicate SAA may play a role in events occurring during the ovulation process.

scholarly journals Regulation of Steroidogenesis and the Steroidogenic Acute Regulatory Protein by a Member of the cAMP Response-Element Binding Protein Family

2002 ◽  
Vol 16 (1) ◽  
pp. 184-199 ◽  
Author(s):  
Pulak R. Manna ◽  
Matthew T. Dyson ◽  
Darrell W. Eubank ◽  
Barbara J. Clark ◽  
Enzo Lalli ◽  
...  
Keyword(s):  
Family Member ◽  
Promoter Activity ◽  
Binding Protein ◽  
Camp Response Element Binding ◽  
Camp Response Element ◽  
Response Element ◽  
Star Protein ◽  
Element Binding Protein ◽  
Steroidogenic Acute Regulatory ◽  
Star Gene

Abstract The mitochondrial phosphoprotein, the steroidogenic acute regulatory (StAR) protein, is an essential component in the regulation of steroid biosynthesis in adrenal and gonadal cells through cAMP-dependent pathways. In many cases transcriptional induction by cAMP is mediated through the interaction of a cAMP response-element binding protein (CREB) family member with a consensus cAMP response element (CRE; 5′-TGACGTCA-3′) found in the promoter of target genes. The present investigation was carried out to determine whether a CRE-binding protein (CREB) family member [CREB/CRE modulator (CREM) family] was involved in the regulation of steroidogenesis and StAR protein expression. Transient expression of wild- type CREB in MA-10 mouse Leydig tumor cells further increased the levels of (Bu)2cAMP-induced progesterone synthesis, StAR promoter activity, StAR mRNA, and StAR protein. These responses were significantly inhibited by transfection with a dominant-negative CREB (A-CREB), or with a CREB mutant that cannot be phosphorylated (CREB-M1), the latter observation indicating the importance of phosphorylation of a CREB/CREM family member in steroidogenesis and StAR expression. The CREB/CREM-responsive region in the mouse StAR gene was located between −110 and −67 bp upstream of the transcriptional start site. An oligonucleotide probe (−96/−67 bp) containing three putative half-sites for 5′-canonical CRE sequences (TGAC) demonstrated the formation of protein-DNA complexes in EMSAs with recombinant CREB protein as well as with nuclear extracts from MA-10 or Y-1 mouse adrenal tumor cells. The predominant binding factor observed with EMSA was found to be the CREM protein as demonstrated using specific antibodies and RT-PCR analyses. The CRE elements identified within the− 96/−67 bp region were tested for cAMP responsiveness by generating mutations in each of the CRE half-sites either alone or in combination. Although each of the CRE sites contribute in part to the CREM response, the CRE2 appears to be the most important site as determined by EMSA and by reporter gene analyses. Binding specificity was further assessed using specific antibodies to CREB/CREM family members, cold competitors, and mutations in the target sites that resulted in either supershift and/or inhibition of these complexes. We also demonstrate that the inducible cAMP early repressor markedly diminished the endogenous effects of CREM on cAMP-induced StAR promoter activity and on StAR mRNA expression. These are the first observations to provide evidence for the functional involvement of a CREB/CREM family member in the acute regulation of trophic hormone-stimulated steroidogenesis and StAR gene expression.

MMP28 gene expression is regulated by Sp1 transcription factor acetylation

2010 ◽  
Vol 427 (3) ◽  
pp. 391-400 ◽  
Author(s):  
Tracey E. Swingler ◽  
Lara Kevorkian ◽  
Kirsty L. Culley ◽  
Sara A. Illman ◽  
David A. Young ◽  
...  
Keyword(s):  
Histone Deacetylase Inhibitors ◽  
Binding Protein ◽  
Trichostatin A ◽  
Camp Response Element Binding ◽  
Camp Response Element ◽  
Receptor Associated Protein ◽  
Sp1 Transcription Factor ◽  
Basal Expression ◽  
Element Binding Protein ◽  
Interfering Rna

MMP-28 (epilysin) is a recently cloned member of the MMP (matrix metalloproteinase) family. It is highly expressed in the skin by keratinocytes, the developing and regenerating nervous system and a number of other normal human tissues, as well as a number of carcinomas. The MMP28 promoter has previously been cloned and characterized identifying a conserved GT-box that binds Sp1/Sp3 (specificity proteins 1 and 3) proteins and is essential for the basal expression of the gene. The present study demonstrates that MMP28 expression is induced by HDAC (histone deacetylase) inhibitors and that this effect is mediated through the GT-box. Transient transfection assays have shown that the induction of MMP28 expression by the HDAC inhibitior TSA (trichostatin A) is mediated via Sp1 at the GT-box. Immunoprecipitation experiments have shown that the acetylation of Sp1 and Sp3 is increased by TSA treatment; however, no effect on DNA binding was observed. Histone acetyltransferases such as p300 and P/CAF [p300/CREB (cAMP-response-element-binding protein)-binding protein-associated factor] increased induction of the MMP28 promoter by Sp1. Knockdown of HDAC1 using siRNA (small interfering RNA) also induces the MMP28 promoter. Oligonucleotide pulldown identified STRAP (serine/threonine kinase receptor-associated protein) as a further protein recruited to the MMP28 promoter and acting functionally with Sp1.

scholarly journals Glucose-Dependent Insulinotropic Polypeptide-Mediated Up-Regulation of β-Cell Antiapoptotic Bcl-2 Gene Expression Is Coordinated by Cyclic AMP (cAMP) Response Element Binding Protein (CREB) and cAMP-Responsive CREB Coactivator 2

2007 ◽  
Vol 28 (5) ◽  
pp. 1644-1656 ◽  
Author(s):  
Su-Jin Kim ◽  
Cuilan Nian ◽  
Scott Widenmaier ◽  
Christopher H. S. McIntosh
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Binding Protein ◽  
Camp Response Element Binding ◽  
Β Cells ◽  
Β Cell ◽  
Camp Response Element ◽  
Response Element ◽  
Element Binding Protein ◽  
Interfering Rna

ABSTRACT The cyclic AMP (cAMP)/protein kinase A (PKA) cascade plays a central role in β-cell proliferation and apoptosis. Here, we show that the incretin hormone glucose-dependent insulinotropic polypeptide (GIP) stimulates expression of the antiapoptotic Bcl-2 gene in pancreatic β cells through a pathway involving AMP-activated protein kinase (AMPK), cAMP-responsive CREB coactivator 2 (TORC2), and cAMP response element binding protein (CREB). Stimulation of β-INS-1 (clone 832/13) cells with GIP resulted in increased Bcl-2 promoter activity. Analysis of the rat Bcl-2 promoter revealed two potential cAMP response elements, one of which (CRE-I [GTGACGTAC]) was shown, using mutagenesis and deletion analysis, to be functional. Subsequent studies established that GIP increased the nuclear localization of TORC2 and phosphorylation of CREB serine 133 through a pathway involving PKA activation and reduced AMPK phosphorylation. At the nuclear level, phospho-CREB and TORC2 were demonstrated to bind to CRE-I of the Bcl-2 promoter, and GIP treatment resulted in increases in their interaction. Furthermore, GIP-mediated cytoprotection was partially reversed by small interfering RNA-mediated reduction in BCL-2 or TORC2/CREB or by pharmacological activation of AMPK. The antiapoptotic effect of GIP in β cells is therefore partially mediated through a novel mode of transcriptional regulation of Bcl-2 involving cAMP/PKA/AMPK-dependent regulation of CREB/TORC2 activity.

scholarly journals Involvement of Transducer of Regulated cAMP Response Element-Binding Protein Activity on Corticotropin Releasing Hormone Transcription

Endocrinology ◽  
2010 ◽  
Vol 151 (3) ◽  
pp. 1109-1118 ◽  
Author(s):  
Ying Liu ◽  
Ana G. Coello ◽  
Valery Grinevich ◽  
Greti Aguilera
Keyword(s):  
Promoter Activity ◽  
Nuclear Translocation ◽  
Binding Protein ◽  
Primary Cultures ◽  
Camp Response Element Binding ◽  
Neuronal Cultures ◽  
Dependent Manner ◽  
Camp Response Element ◽  
Response Element ◽  
Element Binding Protein

We have recently shown that phospho-cAMP response element-binding protein (CREB) is essential but not sufficient for activation of CRH transcription, suggesting the requirement of a coactivator. Here, we test the hypothesis that the CREB coactivator, transducer of regulated CREB activity (TORC), is required for activation of CRH transcription, using the cell line 4B and primary cultures of hypothalamic neurons. Immunohistochemistry and Western blot experiments in 4B cells revealed time-dependent nuclear translocation of TORC1,TORC 2, and TORC3 by forskolin [but not by the phorbol ester, phorbol 12-myristate 13-acetate (PMA)] in a concentration-dependent manner. In reporter gene assays, cotransfection of TORC1 or TORC2 potentiated the stimulatory effect of forskolin on CRH promoter activity but had no effect in cells treated with PMA. Knockout of endogenous TORC using silencing RNA markedly inhibited forskolin-activated CRH promoter activity in 4B cells, as well as the induction of endogenous CRH primary transcript by forskolin in primary neuronal cultures. Coimmunoprecipitation and chromatin immunoprecipitation experiments in 4B cells revealed association of CREB and TORC in the nucleus, and recruitment of TORC2 by the CRH promoter, after 20-min incubation with forskolin. These studies demonstrate a correlation between nuclear translocation of TORC with association to the CRH promoter and activation of CRH transcription. The data suggest that TORC is required for transcriptional activation of the CRH promoter by acting as a CREB coactivator. In addition, cytoplasmic retention of TORC during PMA treatment is likely to explain the failure of phorbolesters to activate CRH transcription in spite of efficiently phosphorylating CREB.

scholarly journals CREB (cAMP response element binding protein) and C/EBPα (CCAAT/enhancer binding protein) are required for the superstimulation of phosphoenolpyruvate carboxykinase gene transcription by adenoviral E1a and cAMP

2000 ◽  
Vol 352 (2) ◽  
pp. 335-342 ◽  
Author(s):  
John M. ROUTES ◽  
Lillester A. COLTON ◽  
Sharon RYAN ◽  
Dwight J. KLEMM
Keyword(s):  
Gene Transcription ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Binding Protein ◽  
Gene Promoter ◽  
Camp Response Element Binding ◽  
Dominant Negative ◽  
Camp Response Element ◽  
Response Element ◽  
Element Binding Protein ◽  
In Cells

In the present study, we observed superstimulated levels of cAMP-stimulated transcription from the phosphoenolpyruvate carboxykinase (PEPCK) gene promoter in cells infected with wild-type adenovirus expressing 12S and 13S E1a proteins, or in cells expressing 13S E1a alone. cAMP-stimulated transcription was inhibited in cells expressing only 12S E1a, but slightly elevated in cells expressing E1a proteins with mutations in conserved regions 1 or 2, leading us to conclude that the superstimulation was mediated by conserved region 3 of 13S E1a. E1a failed to enhance cAMP-stimulated transcription from promoters containing mutations that abolish binding by cAMP response element binding protein (CREB) or CCAAT/enhancer binding proteins (C/EBPs). This result was supported by experiments in which expression of dominant-negative CREB and/or C/EBP proteins repressed E1a- and cAMP-stimulated transcription from the PEPCK gene promoter. In reconstitution experiments using a Gal4-responsive promoter, E1a enhanced cAMP-stimulated transcription when chimaeric Gal4–CREB and Gal4–C/EBPα were co-expressed. Phosphorylation of CREB on serine-133 was stimulated in cells treated with dibutyryl cAMP, whereas phosphorylation of C/EBPα was increased by E1a expression. Our data support a model in which cAMP agonists increase CREB activity and stimulate PEPCK gene transcription, a process that is enhanced by E1a through the phosphorylation of C/EBPα.

scholarly journals Adenovirus-Directed Expression of a Nonphosphorylatable Mutant of CREB (cAMP Response Element-Binding Protein) Adversely Affects the Survival, but Not the Differentiation, of Rat Granulosa Cells

1999 ◽  
Vol 13 (8) ◽  
pp. 1364-1372 ◽  
Author(s):  
Jeremy P. Somers ◽  
Julie A. DeLoia ◽  
Anthony J. Zeleznik
Keyword(s):  
Granulosa Cells ◽  
Fluorescent Protein ◽  
Binding Protein ◽  
Primary Cultures ◽  
Adenovirus Vector ◽  
Camp Response Element Binding ◽  
Camp Response Element ◽  
Response Element ◽  
Luteal Cells ◽  
Element Binding Protein

Abstract Although usually considered to be a constitutively expressed protein, in the primate ovary the expression of CREB (cAMP response element-binding protein) is extinguished after ovulation, and its loss is temporally associated with the cessation of proliferation of luteal cells and the ultimate commitment of the corpus luteum to undergo regression. To determine the cellular consequences of the loss of CREB expression, we expressed a nonphosphorylatable mutant of CREB (CREB M1) in primary cultures of rat granulosa cells using a replication-defective adenovirus vector. Expression of CREB M1 did not block granulosa cell differentiation as assessed by acquisition of the ability to produce estrogen and progesterone in response to FSH or forskolin. However, granulosa cells expressing CREB M1, but not adenovirus-directed β-galactosidase or enhanced green fluorescent protein, exhibited a 35% reduction in viability that was further reduced to 65% after stimulation with 10 μm forskolin. These results demonstrate that the trophic effects of cAMP (proliferation and survival) on ovarian granulosa cells are functionally separate from the effects of cAMP on differentiation and provide novel evidence that CREB may function as a cell survival factor in the ovary. The separation of signaling pathways that govern differentiation and survival in the ovary thereby provides a mechanism by which progesterone production, which is absolutely essential for the maintenance of pregnancy, can continue despite the cessation of proliferation of luteal cells and their commitment to cell death (luteolysis).

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