Exchange protein directly activated by cAMP (EPAC) promotes transcriptional activation of the decidual prolactin gene via CCAAT/enhancer-binding protein in human endometrial stromal cells

2018 ◽  
Vol 30 (11) ◽  
pp. 1454
Author(s):  
Kazuya Kusama ◽  
Kazuhiro Tamura ◽  
Hanako Bai ◽  
Toshihiro Sakurai ◽  
Hirotaka Nishi ◽  
...  
Keyword(s):  
Promoter Activity ◽  
Binding Protein ◽  
Luciferase Assay ◽  
Mrna Levels ◽  
Reporter Activity ◽  
Camp Analogue ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein ◽  
Decidual Prolactin ◽  
Exchange Protein

Protein kinase A (PKA) signalling accompanies elevated intracellular cAMP levels during endometrial stromal cell (ESC) decidualisation. Exchange protein directly activated by cAMP (EPAC), an alternate mediator of cAMP signalling, promotes PKA analogue-induced decidualisation; however, the precise mechanism by which EPAC and PKA co-operatively stimulate decidualisation has not been characterised. To examine the role of CCAAT/enhancer-binding protein (C/EBP) in EPAC- and PKA-mediated decidualisation of primary human ESCs, a reporter plasmid containing the 332 bp region upstream from the transcription initiation site of the decidual prolactin (dPRL) gene was generated and the promoter activity was evaluated using a luciferase assay. The dPRL promoter activity was increased by treatment of transfected ESCs with the PKA-selective cAMP analogue N6-phenyl-cAMP (Phe) and enhanced further by co-treatment with the EPAC-selective cAMP analogue 8-(4-chlorophenyltio)-2′-O-methyl cAMP (CPT). Treatment with forskolin, an adenylyl cyclase activator, had a similar effect on reporter activity. Site-directed mutagenesis of the C/EBPβ- and/or C/EBPδ-binding site in the dPRL promoter abolished Phe/CPT-mediated elevation of the reporter activity. EPAC2 knockdown markedly reduced Phe-stimulated C/EBPβ and C/EBPδ mRNA levels, as well as forkhead box O1 (FOXO1) protein levels. These results suggest that EPAC signalling enhances PKA-mediated dPRL expression in ESCs by acting on C/EBP response elements in the promoter region of the gene.

Overexpression of CCAAT Enhancer-Binding Protein α Inhibits the Growth of K562 Cells via the Foxo3a-Bim Pathway

2016 ◽  
Vol 136 (2) ◽  
pp. 65-70 ◽  
Author(s):  
Guili Zhang ◽  
Fei Dong ◽  
Caifu Luan ◽  
Xia Zhang ◽  
Huiyuan Shao ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Binding Protein ◽  
K562 Cells ◽  
Cell Counting ◽  
Stable Cell Line ◽  
Mrna Levels ◽  
Forkhead Transcription Factor ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein ◽  
Blood Specimens

We aimed to investigate the role of CCAAT enhancer-binding protein α (C/EBPα) in the pathogenesis of chronic myeloid leukemia (CML) and the mechanism underlying its effect. Bone marrow specimens from 50 patients with CML and peripheral blood specimens from 20 healthy individuals were collected. K562 cells were treated with imatinib. Subsequently, a stable cell line, K562-C/EBPα, was constructed. Cell proliferation was assayed with cell counting kit-8, and mRNA levels of C/EBPα, forkhead transcription factor FKHRL1 (Foxo3a) and Bim were detected by semiquantitative PCR. The correlation of C/EBPα and BCR-ABL was assessed by Spearman's correlation analysis. The results showed that C/EBPα mRNA levels were significantly reduced in CML patients compared with healthy subjects (p < 0.001) and were negatively correlated with BCR-ABL1 (r = -0.5046, p < 0.01). Additionally, imatinib enhanced the expression of C/EBPα in K562 cells compared with untreated cells (p < 0.05). Overexpression of C/EBPα significantly decreased cell proliferation and upregulated the expressions of the apoptosis-related genes Foxo3a (p < 0.01) and Bim (p < 0.05) in K562 cells. In conclusion, C/EBPα expression was decreased in patients with CML. Imatinib enhances the expression of C/EBPα in K562 cells, and the overexpression of C/EBPα inhibits cell proliferation and increases apoptosis via the Foxo3a-Bim pathway.

scholarly journals Intestinal maturation in mice lacking CCAAT/enhancer-binding protein α (C/EPBα)

1998 ◽  
Vol 330 (3) ◽  
pp. 1165-1171 ◽  
Author(s):  
J. Thomas OESTERREICHER ◽  
L. Lucy LEEPER ◽  
J. Milton FINEGOLD ◽  
J. Gretchen DARLINGTON ◽  
J. Susan HENNING
Keyword(s):  
Glucose Transporter ◽  
Binding Protein ◽  
Fatty Acid Binding Proteins ◽  
Mrna Levels ◽  
Fatty Acid Binding ◽  
Proliferative Zone ◽  
Glucose Transporter 2 ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein ◽  
Morphological Maturation

In rodents, there is a surge of intestinal expression of CCAAT/enhancer-binding protein α (C/EBPα) in the late fetal phase just before morphological maturation and the onset of expression of numerous epithelial genes. To investigate directly the hypothesis that C/EBPα plays a causal role in the latter phenomena, we have assessed both structural and functional maturation in neonatal intestine from C/EBPα-null mice and their littermates. No effects of C/EBPα genotype were observed on mucosal architecture or on the size of the proliferative zone in the intestinal crypts. Likewise, the mRNA levels for the glucose transporter 2 (GLUT2), intestinal and liver fatty acid-binding proteins, and apolipoprotein A-IV in newborn intestine were similar in all genotypes. Paradoxically, Na+/glucose co-transporter (SGLT1), lactase phlorizin-hydrolase and apolipoprotein B mRNAs were more abundant in the C/EBPα-deficient animals. In wild-type intestines, C/EBPβ and C/EBPΔ mRNAs were detectable throughout the late fetal period and increased toward term in parallel with C/EBPα mRNA. In newborn intestine, there was no compensatory up-regulation of these isoforms in the C/EBPα-deficient mice. We conclude that C/EBPα has no essential role in morphological maturation of the intestine, the pattern of proliferation of the epithelium, or the onset of expression of this cluster of epithelial mRNAs. However, since other C/EBP isoforms are present in the developing intestine, it is possible that there is a generic requirement for a member of the C/EBP family.

scholarly journals Epidermal Growth Factor-Induced GnRH-II Synthesis Contributes to Ovarian Cancer Cell Invasion

2009 ◽  
Vol 94 (9) ◽  
pp. 3618-3618
Author(s):  
Song Ling Poon ◽  
Gareth T. Hammond ◽  
Peter C. K. Leung
Keyword(s):  
Ovarian Cancer ◽  
Cancer Cells ◽  
Promoter Activity ◽  
Binding Protein ◽  
Ovarian Cancer Cells ◽  
Mrna Levels ◽  
Upstream Regulator ◽  
Enhancer Binding Protein ◽  
Responsive Element ◽  
Interfering Rna

GnRH-II modulates ovarian cancer cells invasion and is expressed in normal ovary and ovarian epithelial cancer cells; however, the upstream regulator(s) of GnRH-II expression in these cells remains unclear. We now demonstrate that epidermal growth factor (EGF) increases GnRH-II mRNA levels in several human ovarian carcinoma cell lines and up-regulates GnRH-II promoter activity in OVCAR-3 cells in a dose-dependent manner, whereas an EGF receptor inhibitor (AG148) abolishes EGF-induced increases in GnRH-II promoter activity and GnRH-II mRNA levels. EGF increases the phosphorylation of cAMP-responsive element-binding protein (p-CREB) and its association with the coregulator, CCAAT/enhancer binding protein β, whereas blocking the EGF-induced ERK1/2 phosphorylation with MAPK inhibitors (PD98059/U0126) markedly reduced these effects. Moreover, depletion of CREB using small interfering RNA attenuated EGF-induced GnRH-II promoter activity. Chromatin immunoprecipitation assays demonstrated that EGF induces p-CREB binding to a cAMP responsive-element within the GnRH-II promoter, likely in association with CCAAT/enhancer binding protein β, and mutagenesis of this cAMP responsive-element prevented EGF-induced GnRH-II promoter activity in OVCAR-3 cells. Importantly, GnRH-II acts additively with EGF to promote invasion of OVCAR-3 and CaOV-3 cells, but not SKOV-3 cells that express low levels of GnRH receptor (GnRHR). Treatment with GnRHR small interfering RNA also partially inhibited the EGF-induced invasion of OVCAR-3 and CaOV-3 cells. Furthermore, EGF treatment transiently increases GnRHR levels in OVCAR-3 and CaOV-3, which likely accentuates the effects of increase GnRH-II production on cell invasion. These results provide evidence that EGF is an upstream regulator of the autocrine actions of GnRH-II on the invasive properties of ovarian cancer cells.

scholarly journals Thapsigargin suppresses phorbol ester-dependent human involucrin promoter activity by suppressing CCAAT-enhancer-binding protein α (C/EBPα) DNA binding

2000 ◽  
Vol 350 (3) ◽  
pp. 791-796 ◽  
Author(s):  
Sivaprakasam BALASUBRAMANIAN ◽  
Chapla AGARWAL ◽  
Tatiana EFIMOVA ◽  
George R. DUBYAK ◽  
Eric BANKS ◽  
...  
Keyword(s):  
Promoter Activity ◽  
Binding Protein ◽  
Regulatory Region ◽  
Keratinocyte Differentiation ◽  
Calcium Stores ◽  
Mrna Levels ◽  
Promoter Activation ◽  
Protein Levels ◽  
Enhancer Binding Protein ◽  
Differentiation Marker

Human involucrin (hINV) is a keratinocyte differentiation marker expressed in the suprabasal epidermal layers. In cultured keratinocytes hINV mRNA levels are increased 10-fold by a 24-h treatment with 50ng/ml PMA, an agent that promotes keratinocyte differentiation. Previous studies show that thapsigargin (TGN), an agent that depletes intracellular calcium stores, inhibits keratinocyte differentiation. In the present study we show that TGN inhibits the PMA-dependent, differentiation-associated, increase in hINV mRNA levels and hINV promoter activity. Inhibition is half-maximal at 10nM and maximal at 100nM TGN. Neither basal hINV promoter activity nor glyceraldehyde-3-phosphate dehydrogenase mRNA levels are inhibited. Mutation of a functionally important CAATT-enhancer-binding protein (C/EBP) site within the hINV promoter proximal regulatory region eliminates the regulation, suggesting that TGN may effect C/EBP-dependent promoter activation. Consistent with this hypothesis, TGN inhibits C/EBPα-dependent promoter activation via a mechanism that involves inhibition of C/EBPα binding to DNA without changing C/EBPα protein levels. These results suggest that TGN interferes with hINV expression by interfering with C/EBP transcription-factor function.

scholarly journals Knockdown of LXRα Inhibits Goat Intramuscular Preadipocyte Differentiation

2018 ◽  
Vol 19 (10) ◽  
pp. 3037 ◽  
Author(s):  
Yan Xiong ◽  
Qing Xu ◽  
Sen Lin ◽  
Yong Wang ◽  
Yaqiu Lin ◽  
...  
Keyword(s):  
Lipid Accumulation ◽  
Early Stage ◽  
Binding Protein ◽  
Regulatory Element ◽  
Adipogenic Differentiation ◽  
Mrna Level ◽  
Peroxisome Proliferator ◽  
Mrna Levels ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein

Goat intramuscular fat (IMF) content is mainly determined by the processes of intramuscular preadipocytes adipogenic differentiation and mature adipocyte lipid accumulation. However, the underlying regulators of these biological processes remain largely unknown. Here, we report that the expression of Liver X receptor alpha (LXRα) reaches a peak at early stage and then gradually decreases during goat intramuscular adipogenesis. Knockdown of LXRα mediated by two independent siRNAs significantly inhibits intramuscular adipocytes lipid accumulation and upregulates preadipocytes marker- preadipocyte factor 1 (pref1) expression. Consistently, siRNA treatments robustly decrease mRNA level of adipogenic related genes, including CCAAT enhancer binding protein alpha (Cebpα), Peroxisome proliferator activated receptor gamma (Pparg), Sterol regulatory element binding protein isoform 1c (Srebp1c), Fatty acids binding protein (aP2) and Lipoprotein lipase (Lpl). Next, adenovirus overexpression of LXRα does not affect intramuscular adipocytes adipogenesis manifested by Oil Red O signal measurement and adipogenic specific genes detection. Mechanically, we found that both CCAAT enhancer binding protein beta (Cebpβ) and Kruppel like factor 8 (Klf8) are potential targets of LXRα, indicated by having putative binding sites of LXRα at the promoter of these genes and similar expression pattern during adipogenesis comparing to LXRα. Importantly, mRNA levels of Cebpβ and Klf8 are downregulated significantly in goat LXRα knockdown intramuscular adipocyte. These results demonstrate that loss function of LXRα inhibits intramuscular adipogenesis possibly through down-regulation of Cebpβ and Klf8. Our research will provide new insights into mechanical regulation of goat IMF deposition.

scholarly journals Thapsigargin suppresses phorbol ester-dependent human involucrin promoter activity by suppressing CCAAT-enhancer-binding protein α (C/EBPα) DNA binding

2000 ◽  
Vol 350 (3) ◽  
pp. 791 ◽  
Author(s):  
Sivaprakasam BALASUBRAMANIAN ◽  
Chapla AGARWAL ◽  
Tatiana EFIMOVA ◽  
George R. DUBYAK ◽  
Eric BANKS ◽  
...  
Keyword(s):  
Dna Binding ◽  
Phorbol Ester ◽  
Promoter Activity ◽  
Binding Protein ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein ◽  
Involucrin Promoter
Sign in / Sign up

Export Citation Format

Share Document