scholarly journals Estradiol Regulates Corticotropin-Releasing Hormone Gene (crh) Expression in a Rapid and Phasic Manner that Parallels Estrogen Receptor-α and -β Recruitment to a 3′,5′-Cyclic Adenosine 5′-Monophosphate Regulatory Region of the Proximal crh Promoter

Endocrinology ◽  
2007 ◽  
Vol 149 (1) ◽  
pp. 346-357 ◽  
Author(s):  
Avin S. Lalmansingh ◽  
Rosalie M. Uht
Keyword(s):  
Molecular Mechanisms ◽  
Binding Protein ◽  
Regulatory Element ◽  
Regulatory Region ◽  
Steroid Receptor ◽  
Early Gene ◽  
Pcr Analysis ◽  
Mrna Levels ◽  
Steroid Receptor Coactivator ◽  
Histone 3

In the central nervous system, CRH regulates several affective states. Dysregulation of neuronal crh expression in the paraventricular nucleus of the hypothalamus correlates with some forms of depression, and amygdalar crh expression may modulate levels of anxiety. Because estrogens modulate these states, we sought to determine 17β-estradiol (E2) effects on crh expression. CRH mRNA levels were measured in the AR-5 amygdaloid cell line by RT-PCR analysis. They increased by 1 min of E2 treatment, suggesting that crh behaves as an immediate-early gene. After peaking at 3 min, CRH mRNA returned to basal levels and then increased by 60 min. To dissect some of the molecular mechanisms underlying these events, we measured occupancy of the crh promoter by estrogen receptors (ERs) and coactivators, using chromatin immunoprecipitation. Because this promoter does not contain palindromic estrogen response elements, we targeted the region of a cAMP regulatory element (CRE), implicated in crh regulation. The temporal pattern of the mRNA response was mimicked by recruitment of ERα and -β, phospho-CRE-binding protein, coactivators steroid receptor coactivator-1 and CRE-binding protein-binding protein (CBP), and an increase in histone 3 and 4 acetylation. Lastly, ERα and -β loading were temporally dissociated, peaking at 1 and 3 min, respectively. The ER peaks were associated with coactivators and acetylation patterns. ERα associated with phospho-CRE-binding protein, CBP, steroid receptor coactivator-1, and increased acetylated histone 3. ERβ associated with CBP and increased acetylated histone 4. The tight temporal correlation between E2-induced CRH mRNA levels and promoter occupancy by ERs strongly suggest that E2 regulates crh expression through an ERα- and/or ERβ-CRE alternate pathway.

scholarly journals Central Leptin Regulates Total Ceramide Content and Sterol Regulatory Element Binding Protein-1C Proteolytic Maturation in Rat White Adipose Tissue

Endocrinology ◽  
2008 ◽  
Vol 150 (1) ◽  
pp. 169-178 ◽  
Author(s):  
Elena Bonzón-Kulichenko ◽  
Dominik Schwudke ◽  
Nilda Gallardo ◽  
Eduardo Moltó ◽  
Teresa Fernández-Agulló ◽  
...  
Keyword(s):  
Nervous System ◽  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
White Adipose Tissue ◽  
Binding Protein ◽  
Regulatory Element ◽  
Mrna Levels ◽  
Element Binding Protein ◽  
Ceramide Content ◽  
Sterol Regulatory Element

Obesity and type 2 diabetes are associated with insulin and leptin resistance, and increased ceramide contents in target tissues. Because the adipose tissue has become a central focus in these diseases, and leptin-induced increases in insulin sensitivity may be related to effects of leptin on lipid metabolism, we investigated herein whether central leptin was able to regulate total ceramide levels and the expression of enzymes involved in ceramide metabolism in rat white adipose tissue (WAT). After 7 d central leptin treatment, the total content of ceramides was analyzed by quantitative shotgun lipidomics mass spectrometry. The effects of leptin on the expression of several enzymes of the sphingolipid metabolism, sterol regulatory element binding protein (SREBP)-1c, and insulin-induced gene 1 (INSIG-1) in this tissue were studied. Total ceramide levels were also determined after surgical WAT denervation. Central leptin infusion significantly decreased both total ceramide content and the long-chain fatty acid ceramide species in WAT. Concomitant with these results, leptin decreased the mRNA levels of enzymes involved in de novo ceramide synthesis (SPT-1, LASS2, LASS4) and ceramide production from sphingomyelin (SMPD-1/2). The mRNA levels of enzymes of ceramide degradation (Asah1/2) and utilization (sphingomyelin synthase, ceramide kinase, glycosyl-ceramide synthase, GM3 synthase) were also down-regulated. Ceramide-lowering effects of central leptin were prevented by local autonomic nervous system denervation of WAT. Finally, central leptin treatment markedly increased INSIG-1 mRNA expression and impaired SREBP-1c activation in epididymal WAT. These observations indicate that in vivo central leptin, acting through the autonomic nervous system, regulates total ceramide levels and SREBP-1c proteolytic maturation in WAT, probably contributing to improve the overall insulin sensitivity. Central leptin decreases total ceramide levels and prevents sterol regulatory element binding protein (SREBP-1C) proteolytic maturation in white adipose tissue, and probably, in this way, contributes to improve the overall insulin sensitivity.

scholarly journals A simple promoter containing two Sp1 sites controls the expression of sterol-regulatory-element-binding protein 1a (SREBP-1a)

2005 ◽  
Vol 386 (1) ◽  
pp. 161-168 ◽  
Author(s):  
Chengkang ZHANG ◽  
Dong-Ju SHIN ◽  
Timothy F. OSBORNE
Keyword(s):  
Transcriptional Activation ◽  
Binding Protein ◽  
Regulatory Element ◽  
Animal Experiments ◽  
Proximal Region ◽  
Mrna Levels ◽  
Relative Level ◽  
Transcriptional Activation Domain ◽  
Element Binding Protein ◽  
Sterol Regulatory Element

The mammalian gene for SREBP-1 (sterol-regulatory-element-binding protein 1) contains two promoters that control the production of two proteins, SREBP-1a and -1c, and each contains a unique N-terminal transcriptional activation domain, but they are otherwise identical. The relative level of each mRNA varies from tissue to tissue and they respond differently to regulatory stimuli. SREBP-1c is more abundantly expressed in liver, where its level is also regulated by insulin and liver X receptor activators, and it is also autoregulated by SREBPs. In contrast, SREBP-1a mRNA levels are relatively low and constant in different tissues and few studies have specifically analysed its pattern of expression and regulation. In the present study, we show that the promoter for SREBP-1a is contained in a very small promoter-proximal region containing two Sp1 sites. The small and relatively simple structure for its promoter provides an explanation for the low level of SREBP-1a expression. Additionally, since Sp1 has been implicated in the modest regulation of several genes by insulin, its involvement in the expression of the SREBP-1a promoter provides an explanation for the modest insulin regulation observed in animal experiments.

scholarly journals PURα Promotes the Transcriptional Activation of PCK2 in Oesophageal Squamous Cell Carcinoma Cells

Genes ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1301
Author(s):  
Yan Sun ◽  
Jiajia Gao ◽  
Zongpan Jing ◽  
Yan Zhao ◽  
Yulin Sun ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Rna Binding ◽  
Binding Protein ◽  
Luciferase Assay ◽  
Pcr Analysis ◽  
Mrna Levels ◽  
Gastrointestinal Malignancies

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal gastrointestinal malignancies due to its characteristics of local invasion and distant metastasis. Purine element binding protein α (PURα) is a DNA and RNA binding protein, and recent studies have showed that abnormal expression of PURα is associated with the progression of some tumors, but its oncogenic function, especially in ESCC progression, has not been determined. Based on the bioinformatic analysis of RNA-seq and ChIP-seq data, we found that PURα affected metabolic pathways, including oxidative phosphorylation and fatty acid metabolism, and we observed that it has binding peaks in the promoter of mitochondrial phosphoenolpyruvate carboxykinase (PCK2). Meanwhile, PURα significantly increased the activity of the PCK2 gene promoter by binding to the GGGAGGCGGA motif, as determined though luciferase assay and ChIP-PCR/qPCR. The results of Western blotting and qRT-PCR analysis showed that PURα overexpression enhances the protein and mRNA levels of PCK2 in KYSE510 cells, whereas PURα knockdown inhibits the protein and mRNA levels of PCK2 in KYSE170 cells. In addition, measurements of the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) indicated that PURα promoted the metabolism of ESCC cells. Taken together, our results help to elucidate the molecular mechanism by which PURα activates the transcription and expression of PCK2, which contributes to the development of a new therapeutic target for ESCC.

Effects of gender and GH secretory pattern on sterol regulatory element-binding protein-1c and its target genes in rat liver

2004 ◽  
Vol 287 (6) ◽  
pp. E1039-E1048 ◽  
Author(s):  
Caroline Améen ◽  
Daniel Lindén ◽  
Britt-Mari Larsson ◽  
Agneta Mode ◽  
Agneta Holmäng ◽  
...  
Keyword(s):  
Insulin Sensitivity ◽  
Continuous Infusion ◽  
Target Genes ◽  
Binding Protein ◽  
Regulatory Element ◽  
Female Rats ◽  
Mrna Levels ◽  
Element Binding Protein ◽  
Sterol Regulatory Element ◽  
Secretory Pattern

We investigated whether the sexually dimorphic secretory pattern of growth hormone (GH) in the rat regulates hepatic gene expression of sterol regulatory element-binding protein-1c (SREBP-1c) and its target genes. SREBP-1c, fatty acid synthase (FAS), and glycerol-3-phosphate acyltransferase (GPAT) mRNA were more abundant in female than in male livers, whereas acetyl-CoA carboxylase-1 (ACC1) and stearoyl-CoA desaturase-1 (SCD-1) were similarly expressed in both sexes. Hypophysectomized female rats were given GH as a continuous infusion or as two daily injections for 7 days to mimic the female- and male-specific GH secretory patterns, respectively. The female pattern of GH administration increased the expression of SREBP-1c, ACC1, FAS, SCD-1, and GPAT mRNA, whereas the male pattern of GH administration increased only SCD-1 mRNA. FAS and SCD-1 protein levels were regulated in a similar manner by GH. Incubation of primary rat hepatocytes with GH increased SCD-1 mRNA levels and decreased FAS and GPAT mRNA levels but had no effect on SREBP-1c mRNA. GH decreased hepatic liver X receptor-α (LXRα) mRNA levels both in vivo and in vitro. Feminization of the GH plasma pattern in male rats by administration of GH as a continuous infusion decreased insulin sensitivity and increased expression of FAS and GPAT mRNA but had no effect on SREBP-1c, ACC1, SCD-1, or LXRα mRNA. In conclusion, FAS and GPAT are specifically upregulated by the female secretory pattern of GH. This regulation is not a direct effect of GH on hepatocytes and does not involve changed expression of SREBP-1c or LXRα mRNA but is associated with decreased insulin sensitivity.

scholarly journals Ergosterol Peroxide from the Medicinal Mushroom Ganoderma lucidum Inhibits Differentiation and Lipid Accumulation of 3T3-L1 Adipocytes

2020 ◽  
Vol 21 (2) ◽  
pp. 460 ◽  
Author(s):  
Yong-Un Jeong ◽  
Young-Jin Park
Keyword(s):  
Transcription Factors ◽  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Metabolic Diseases ◽  
Binding Protein ◽  
Regulatory Element ◽  
Peroxisome Proliferator ◽  
Mrna Levels ◽  
Medicinal Mushrooms ◽  
Ergosterol Peroxide

Ergosterol peroxide is a natural compound of the steroid family found in many fungi, and it possesses antioxidant, anti-inflammatory, anticancer and antiviral activities. The anti-obesity activity of several edible and medicinal mushrooms has been reported, but the effect of mushroom-derived ergosterol peroxide on obesity has not been studied. Therefore, we analyzed the effect of ergosterol peroxide on the inhibition of triglyceride synthesis at protein and mRNA levels and differentiation of 3T3-L1 adipocytes. Ergosterol peroxide inhibited lipid droplet synthesis of differentiated 3T3-L1 cells, expression of peroxisome proliferator-activated receptor gamma (PPARγ) and CCAT/enhancer-binding protein alpha (C/EBPα), the major transcription factors of differentiation, and also the expression of sterol regulatory element-binding protein-1c (SREBP-1c), which promotes the activity of PPARγ, resulting in inhibition of differentiation. It further inhibited the expression of fatty acid synthase (FAS), fatty acid translocase (FAT), and acetyl-coenzyme A carboxylase (ACC), which are lipogenic factors. In addition, it inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs) involved in cell proliferation and activation of early differentiation transcription factors in the mitotic clonal expansion (MCE) stage. As a result, ergosterol peroxide significantly inhibited the synthesis of triglycerides and differentiation of 3T3-L1 cells, and is, therefore, a possibile prophylactic and therapeutic agent for obesity and related metabolic diseases.

scholarly journals Effects on Liver Lipid Metabolism of the Naturally Occurring Dietary Flavone Luteolin-7-glucoside

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Carla Sá ◽  
Ana Rita Oliveira ◽  
Cátia Machado ◽  
Marisa Azevedo ◽  
Cristina Pereira-Wilson
Keyword(s):  
Lipid Metabolism ◽  
Fatty Acid Synthase ◽  
Molecular Mechanisms ◽  
Metabolic Diseases ◽  
Regulatory Element ◽  
Lipid Lowering ◽  
Whole Body ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Hepatic Expression

Disruptions in whole-body lipid metabolism can lead to the onset of several pathologies such as nonalcoholic fatty liver disease (NAFLD) and cardiovascular diseases (CVDs). The present study aimed at elucidating the molecular mechanisms behind the lipid-lowering effects of the flavone luteolin-7-glucoside (L7G) which we previously showed to improve plasma lipid profile in rats. L7G is abundant in plant foods of Mediterranean diet such as aromatic plants used as herbs. Results show that dietary supplementation with L7G for one week induced the expression of peroxisome proliferator-activated receptor-alpha (PPAR-α) and of its target gene carnitine palmitoyl transferase 1 (CPT-1) in rat liver. L7G showed a tendency to decrease the hepatic expression of sterol regulatory element-binding protein-1 (SREBP-1), without affecting fatty acid synthase (FAS) protein levels. Although SREBP-2 and LDLr mRNA levels did not change, the expression of HMG CoA reductase (HMGCR) was significantly repressed by L7G. L7G also inhibited this enzyme’sin vitroactivity in a dose dependent manner, but only at high and not physiologically relevant concentrations. These results add new evidence that the flavone luteolin-7-glucoside may help in preventing metabolic diseases and clarify the mechanisms underlying the beneficial health effects of diets rich in fruits and vegetables.

Increased hepatic lipogenesis in insulin resistance and Type 2 diabetes is associated with AMPK signalling pathway up-regulation in Psammomys obesus

2009 ◽  
Vol 29 (5) ◽  
pp. 283-292 ◽  
Author(s):  
Ali Ben Djoudi Ouadda ◽  
Emile Levy ◽  
Ehud Ziv ◽  
Geneviève Lalonde ◽  
Alain T. Sané ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Protein Expression ◽  
Body Weight Gain ◽  
Binding Protein ◽  
Regulatory Element ◽  
Mrna Levels ◽  
Psammomys Obesus ◽  
Element Binding Protein

AMPK (AMP-activated protein kinase) has been suggested to be a central player regulating FA (fatty acid) metabolism through its ability to regulate ACC (acetyl-CoA carboxylase) activity. Nevertheless, its involvement in insulin resistance- and TD2 (Type 2 diabetes)-associated dyslipidaemia remains enigmatic. In the present study, we employed the Psammomys obesus gerbil, a well-established model of insulin resistance and TD2, in order to appreciate the contribution of the AMPK/ACC pathway to the abnormal hepatic lipid synthesis and increased lipid accumulation in the liver. Our investigation provided evidence that the development of insulin resistance/diabetic state in P. obesus is accompanied by (i) body weight gain and hyperlipidaemia; (ii) elevations of hepatic ACC-Ser79 phosphorylation and ACC protein levels; (iii) a rise in the gene expression of cytosolic ACC1 concomitant with invariable mitochondrial ACC2; (iv) an increase in hepatic AMPKα-Thr172 phosphorylation and protein expression without any modification in the calculated ratio of phospho-AMPKα to total AMPKα; (v) a stimulation in ACC activity despite increased AMPKα phosphorylation and protein expression; and (vi) a trend of increase in mRNA levels of key lipogenic enzymes [SCD-1 (stearoyl-CoA desaturase-1), mGPAT (mitochondrial isoform of glycerol-3-phosphate acyltransferase) and FAS (FA synthase)] and transcription factors [SREBP-1 (sterol-regulatory-element-binding protein-1) and ChREBP (carbohydrate responsive element-binding protein)]. Altogether, our findings suggest that up-regulation of the AMPK pathway seems to be a natural response in order to reduce lipid metabolism abnormalities, thus supporting the role of AMPK as a promising target for the treatment of TD2-associated dyslipidaemia.

Effect of insulin on transcription of lipogenic and lipolytic-related genes and lipid metabolism in primary porcine adipocytes

2006 ◽  
Vol 3 (2) ◽  
pp. 135-140
Author(s):  
Lu Jian-Xiong ◽  
Chen Fen-Fen ◽  
Yang Gong-She
Keyword(s):  
Fatty Acid Synthase ◽  
Lipolytic Activity ◽  
Binding Protein ◽  
Regulatory Element ◽  
Mrna Level ◽  
Hormone Sensitive Lipase ◽  
Mrna Levels ◽  
Tissue Samples ◽  
Element Binding Protein ◽  
High Insulin

AbstractPrimary adipocytes from subcutaneous adipose tissue samples obtained from 7-day-old Yorkshire×Landrace crossbreed piglets were exposed to 0–400 nmol/l of insulin for 48 h. The accumulated triglyceride was measured through Oil Red O staining and the cumulative glycerol released was determined to assess lipolytic activity in adipocytes. Transcription levels of sterol regulatory element binding protein (SREBP)-1c, carbohydrate response element binding protein (ChREBP), acetyl-CoA carboxylase 1 (ACC1), fatty acid synthase (FAS), and hormone-sensitive lipase (HSL) were assessed using reverse transcriptase-polymerase chain reaction (RT-PCR). The results showed that ChREBP and ACC1 mRNA levels were not influenced by insulin alone under low glucose (5 nmol/l). FAS mRNA level was markedly stimulated by all doses of insulin except 200 nmol/l, and SREBP-1c mRNA level increased with 100–300 nmol/l insulin. High insulin doses (300 and 400 nmol/l) increased the HSL mRNA level as well as lipolytic activity.

scholarly journals Phospholipid-Binding Protein EhC2A Mediates Calcium-Dependent Translocation of Transcription Factor URE3-BP to the Plasma Membrane of Entamoeba histolytica

2009 ◽  
Vol 9 (5) ◽  
pp. 695-704 ◽  
Author(s):  
Heriberto Moreno ◽  
Alicia S. Linford ◽  
Carol A. Gilchrist ◽  
William A. Petri
Keyword(s):  
Transcription Factor ◽  
Plasma Membrane ◽  
Entamoeba Histolytica ◽  
Binding Protein ◽  
Regulatory Element ◽  
Direct Interaction ◽  
Immunofluorescent Staining ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Phospholipid Liposomes

ABSTRACT The Entamoeba histolytica upstream regulatory element 3-binding protein (URE3-BP) is a transcription factor that binds DNA in a Ca2+-inhibitable manner. The protein is located in both the nucleus and the cytoplasm but has also been found to be enriched in the plasma membrane of amebic trophozoites. We investigated the reason for the unusual localization of URE3-BP at the amebic plasma membrane. Here we identify and characterize a 22-kDa Ca2+-dependent binding partner of URE3-BP, EhC2A, a novel member of the C2-domain superfamily. Immunoprecipitations of URE3-BP and EhC2A showed that the proteins interact and that such interaction was enhanced in the presence of Ca2+. Recombinant and native EhC2A bound phospholipid liposomes in a Ca2+-dependent manner, with half-maximal binding occurring at 3.4 μM free Ca2+. A direct interaction between EhC2A and URE3-BP was demonstrated by the ability of recombinant EhC2A to recruit recombinant URE3-BP to phospholipid liposomes in a Ca2+-dependent manner. URE3-BP and EhC2A were observed to translocate to the amebic plasma membrane upon an increase in the intracellular Ca2+ concentration of trophozoites, as revealed by subcellular fractionation and immunofluorescent staining. Short hairpin RNA-mediated knockdown of EhC2A protein expression significantly modulated the mRNA levels of URE3-BP-regulated transcripts. Based on these results, we propose a model for EhC2A-mediated regulation of the transcriptional activities of URE3-BP via Ca2+-dependent anchoring of the transcription factor to the amebic plasma membrane.

Novel Deletion and Insertion Mutations Cause Splicing Defects, Leading to Severe Reduction in mRNA Levels of the A Subunit in Severe Factor XIII Deficiency

1998 ◽  
Vol 79 (03) ◽  
pp. 479-485 ◽  
Author(s):  
Tomonori Izumi ◽  
Utako Nagaoka ◽  
Tetsuo Saito ◽  
Junki Takamatsu ◽  
Hidehiko Saito ◽  
...  
Keyword(s):  
Factor Xiii ◽  
Molecular Mechanisms ◽  
Donor Site ◽  
Pcr Analysis ◽  
Nucleotide Sequence Analysis ◽  
Mrna Levels ◽  
Factor Xiii Deficiency ◽  
Dna And Rna ◽  
Severe Reduction ◽  
A Subunit

SummaryIn order to explore molecular mechanisms for factor XIII deficiency, a patient (Nagoya I) was examined at the DNA and RNA levels. Nucleotide sequence analysis of the patient’s DNA amplified by PCR revealed that he had a 20 bp deletion at the boundary of exon I/intron A, and an insertion of T in the invariant GT dinucleotide at the splicing donor site of exon IV/intron D. The presence of these heterozygous mutations was confirmed by restriction digestion of the amplified fragments of the proband and his parents. RT-PCR analysis demonstrated that only one kind of mRNA without exon IV was detected in Nagoya I, although its level was greatly reduced to less than 5% of normal. The other defective allele of the A subunit gene containing the 20 bp deletion was not detected. Thus, both mutations impaired normal processing of mRNA for the A subunit, resulting in his severe factor XIII deficiency.

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