mRNA Levels Of P300 Research Articles

Prenatal Dexamethasone Exposure in Male Rats Alters Gene Expression Patterns of Epigenetic Enzymes in Hippocampus and Cortex

Objective: This study aimed to examine the effects of prenatal stress (PS) induced by dexamethasone exposure on gene expression levels of epigenetic enzymes in hippocampus and cerebral cortex of male rats through relative mRNA levels of histone acetyltransferases (activating transcription factor 2, P300), histone deacetylases (HDAC1, HDAC2), and DNA methyltransferases (DNMT1, DNMT3a, DNMT3b). Methods: Pregnant rats were daily injected subcutaneously with dexamethasone (0.2 mg/kg) or saline during the third week of gestation. After birth, male rats were killed at 90 days of age (n = 5 for control and dexamethasone groups). Hippocampal and cortical tissues were used for gene expression analyses. The effects of dexamethasone on epigenetic mechanisms were investigated by real-time polymerase chain reaction through relative mRNA levels of DNMT1, DNMT3a, DNMT3b, activating transcription factor 2, P300, HDAC1, and HDAC2. Statistical comparisons were performed with Student’s t-test. Results: Prenatal dexamethasone exposure (PDE) caused increased DNMT1, DNMT3a, DNMT3b, activating transcription factor 2 and decreased P300 mRNA levels in hippocampus while increased DNMT3a, DNMT3b, activating transcription factor 2, P300, HDAC1, and HDAC2 mRNA levels were achieved in cortex. Furthermore, no significant differences were obtained in cortical DNMT1 and hippocampal HDAC1 and HDAC2 gene expression levels between control and prenatally stressed rats. Conclusion: Our results emphasize the effect of prenatal dexamethasone exposure on gene expression levels of epigenetic enzymes involved in histone acety latio n/dea cetyl ation and DNA methylation in male rats and suggest that prenatal stress may lead to epigenetic dysregulation through alterations in hippocampal and cortical gene expression patterns of DNMT1, DNMT3a, DNMT3b, activating transcription factor 2, P300, HDAC1, and HDAC2.

Increased p300/CBP expression in acute respiratory distress syndrome is associated with interleukin-17 and prognosis.

Transcription co-activator p300/CBP, a histone acetyltransferase, has a central role in tumours, inflammation and neurodegenerative diseases. We investigated the effect of p300/CBP and its association with various IL-17-related indicators and prognosis in patients with acute respiratory distress syndrome (ARDS). We enrolled 45 adult ARDS patients who were followed for 28days and 22 healthy controls. The mRNA expression of p300, CBP, RORγt and Foxp3 and the plasma levels of several cytokines were measured. The mRNA levels of p300, CBP and RORγt, and plasma concentration of IL-17, IL-6, were higher in acute ARDS patients (P<0.05) compared with controls, and the mean levels of p300, CBP and IL-6 in non-survivors were higher than in survivors (P<0.05). The expression of p300 was associated with the level of RORγt, IL-17 and disease prognosis. The levels of p300, RORγt mRNA and plasma concentration of IL-6 and IL-17 in acute ARDS patients were increased compared with controls. Increased p300/CBP expression may be an independent risk factor for 28-day mortality in ARDS.

Gallic acid attenuates calcium calmodulin-dependent kinase II-induced apoptosis in spontaneously hypertensive rats.

Hypertension causes cardiac hypertrophy and leads to heart failure. Apoptotic cells are common in hypertensive hearts. Ca2+/calmodulin‐dependent protein kinase II (CaMKII) is associated with apoptosis. We recently demonstrated that gallic acid reduces nitric oxide synthase inhibition‐induced hypertension. Gallic acid is a trihydroxybenzoic acid and has been shown to have beneficial effects, such as anti‐cancer, anti‐calcification and anti‐oxidant activity. The purpose of this study was to determine whether gallic acid regulates cardiac hypertrophy and apoptosis in essential hypertension. Gallic acid significantly lowered systolic and diastolic blood pressure in spontaneously hypertensive rats (SHRs). Wheat germ agglutinin (WGA) and H&E staining revealed that gallic acid reduced cardiac enlargement in SHRs. Gallic acid treatment decreased cardiac hypertrophy marker genes, including atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), in SHRs. The four isoforms, α, β, δ and γ, of CaMKII were increased in SHRs and were significantly reduced by gallic acid administration. Gallic acid reduced cleaved caspase‐3 protein as well as bax, p53 and p300 mRNA levels in SHRs. CaMKII δ overexpression induced bax and p53 expression, which was attenuated by gallic acid treatment in H9c2 cells. Gallic acid treatment reduced DNA fragmentation and the TUNEL positive cells induced by angiotensin II. Taken together, gallic acid could be a novel therapeutic for the treatment of hypertension through suppression of CaMKII δ‐induced apoptosis.

Resveratrol Improves Cardiomyopathy in Dystrophin-deficient Mice through SIRT1 Protein-mediated Modulation of p300 Protein*[S

Cardiomyopathy is the main cause of death in Duchenne muscular dystrophy. Here, we show that oral administration of resveratrol, which leads to activation of an NAD(+)-dependent protein deacetylase SIRT1, suppresses cardiac hypertrophy and fibrosis and restores cardiac diastolic function in dystrophin-deficient mdx mice. The pro-hypertrophic co-activator p300 protein but not p300 mRNA was up-regulated in the mdx heart, and resveratrol administration down-regulated the p300 protein level. In cultured cardiomyocytes, cardiomyocyte hypertrophy induced by the α(1)-agonist phenylephrine was inhibited by the overexpression of SIRT1 as well as resveratrol, both of which down-regulated p300 protein levels but not p300 mRNA levels. In addition, activation of atrial natriuretic peptide promoter by p300 was inhibited by SIRT1. We found that SIRT1 induced p300 down-regulation via the ubiquitin-proteasome pathway by deacetylation of lysine residues for ubiquitination. These findings indicate the pathological significance of p300 up-regulation in the dystrophic heart and indicate that SIRT1 activation has therapeutic potential for dystrophic cardiomyopathy.

Histone acetylation in peripheral blood mononuclear cells of type 2 diabetic patients

Objective To study histone acetylation patterns in peripheral boiood mononuclear cells (PBMC) from type 2 diabetic patients PBMC form 12type 2 diabetic patients and 12 healthy contrcl subiects were collecyed The global histone H3/H4 acetylation was determined by assay kit The differetial expression of the histone acetyltransferases and histone deacetylases were measured by real time PCR.Results increased H3/H4 acetylation was observed in PBMC of type 2 diabetic patients compared with control subjects (H3:0.134±0.035vs0.181±0.032,p<0.05;H4:0.266±0.070VS0.324±0.062,P<0.01).the mRNA levels of p300,CREBBP,HDAC2,HDAC7,and STRTL in patients PBMC compared with healthy control subieects were 3.11±0.38,2.78±0.45,3.55±0.30,0.77±0.37 and 0.40±0.25 folds respectively conclusion histone acetylation appears abnormal in PBMC of type 2 diabetic patients. Key words: Diabetes mellitus,type 2; Peripheral biood mononuclear cells; Histone acetylation

Abnormal histone modifications in PBMCs from patients with psoriasis vulgaris

Excessive keratinocyte proliferation is thought to be responsible for the formation and development of psoriasis vulgaris. Evidence indicates that epigenetic modifications are associated with aberrant gene expression, however, nothing is known about the status of histone modifications in psoriasis vulgaris. We investigated alterations in histone modifications in patients with psoriasis vulgaris. Global histone H3/H4 acetylation and H3K4/H3K27 methylation in peripheral blood mononuclear cells from 30 psoriatic patients and 20 healthy control subjects were quantified by the EpiQuik(TM) global histone H3/H4 acetylation and H3K4/H3K27 methylation assay kit. The mRNA levels of 12 members of 3 classes of chromatin modifier genes were measured by real-time quantitative polymerase chain reaction. Compared with normal controls, global histone H4 hypoacetylation was observed in PBMCs from psoriasis vulgaris patients. There was a negative correlation between the degree of histone H4 acetylation and disease activity in patients as measured by PASI. Global levels of H3 acetylation, H3K4/H3K27 methylation did not significantly differ between psoriatic patients and controls. mRNA levels of P300, CBP and SIRT1 were significantly reduced in PBMCs from patients with psoriasis vulgaris compared with healthy controls, while mRNA expression levels of HDAC1, SUV39H1 and EZH2 was significantly increased in psoriatic patients.We conclude that histone modifications are aberrant in the PBMCs of psoriasis vulgaris patients.

Transactivation of cytosolic alanine aminotransferase gene promoter by p300 and c-Myb

Alanine aminotransferase (Alt) provides a molecular link between carbohydrate and amino acid metabolism. In the cell context, the predominant Alt isozyme is located in the cytosol. To gain insight into the transcriptional regulation of the cytosolic alt gene (calt), we cloned and characterized the calt promoter from gilthead sea bream (Sparus aurata). Transient transfection of sea bass larvae cells with deleted calt promoter constructs and electrophoretic mobility shift assays allowed us to identify p300 and c-Myb as new factors in the transcriptional regulation of calt expression. Transfection studies carried out with an acetylase-deficient mutant p300 (p300DY) revealed that the acetyltransferase activity of p300 is essential for the p300-mediated transcriptional activation of S. aurata calt. We had previously found up-regulation of liver cAlt2, an alternatively spliced isoform of calt, under gluconeogenic conditions and in streptozotocin (STZ)-treated S. aurata. Quantitative RT-PCR assays showed that increased p300 and c-Myb mRNA levels in the liver of starved S. aurata contribute to enhancing the transcription of cAlt2. Consistently, the administration of insulin decreased both p300 and c-Myb expression. The mRNA levels of p300 and c-Myb were also analyzed in the liver of STZ-induced diabetic S. aurata. Treatment with STZ increased the expression of p300, whereas it decreased c-Myb. Our findings suggest an involvement of p300 and c-Myb in up-regulation of cAlt2 in the liver of S. aurata under starvation. In addition, these results provide evidence for a role of p300 in diabetes.

ERCC1 and XPF mediated upregulation of Fibronectin (FN) in Diabetes.

ERCC1 and XPF mediated upregulation of Fibronectin (FN) in Diabetes. BIJU GEORGE*, SHALI CHEN, BIAO FENG, JANE CHIU AND SUBRATA CHAKRABARTI. Dept. of Pathology, Univ. of Western Ontario, London, ON. Excision Repair Cross Complimenting1 (ERCC-1) and Xeroderma Pigmentosum group F (XPF) are important DNA repair enzymes. They play important roles in aging, glucose metabolism and oxidative stress and demonstrate interactive relationships with Poly (ADP-Ribose) polymerase (PARP), another DNA repair protein, upregulated in diabetes. We studied the role of ERCC1 and XPF in glucose induced FN production. Human Umbilical Vein endothelial cells were grown in low (5mM) and high glucose (25mM) containing media. They were also exposed to siRNA against ERCC1 and XPF, histone deacetylase blocker TSA, PARP blocker ABA and p300 blocker Curcumin. Quantitative RT-PCR were performed for ERCC1, XPF, FN, PARP and p300 mRNA. High glucose led to upregulation of ERCC1, XPF, FN, PAPR, p300 mRNA levels compared to the cells in low glucose. ERCC1 and XPF silencing reduced such upregulation. ABA and curcumin also reduced both basal and glucose induced ERCC1 and XPF expression. TSA however, only prevented glucose induced ERCC1 and XPF upregulation. Western blots of ERCC1 and XPF from the nuclear proteins showed similar changes. Data from this study indicated that glucose induced upregulation of ERCC1 and XPF may lead to increased FN production via PARP, P300 pathway. These novel mechanisms may play important roles in diabetic complications. These studies were supported in part by CDA and CIHR 116

Glucose-induced Alteration of Endothelial microRNA

ERCC1 and XPF mediated upregulation of Fibronectin (FN) in Diabetes. BIJU GEORGE*, SHALI CHEN, BIAO FENG, JANE CHIU AND SUBRATA CHAKRABARTI. Dept. of Pathology, Univ. of Western Ontario, London, ON. Excision Repair Cross Complimenting1 (ERCC-1) and Xeroderma Pigmentosum group F (XPF) are important DNA repair enzymes. They play important roles in aging, glucose metabolism and oxidative stress and demonstrate interactive relationships with Poly (ADP-Ribose) polymerase (PARP), another DNA repair protein, upregulated in diabetes. We studied the role of ERCC1 and XPF in glucose induced FN production. Human Umbilical Vein endothelial cells were grown in low (5mM) and high glucose (25mM) containing media. They were also exposed to siRNA against ERCC1 and XPF, histone deacetylase blocker TSA, PARP blocker ABA and p300 blocker Curcumin. Quantitative RT-PCR were performed for ERCC1, XPF, FN, PARP and p300 mRNA. High glucose led to upregulation of ERCC1, XPF, FN, PAPR, p300 mRNA levels compared to the cells in low glucose. ERCC1 and XPF silencing reduced such upregulation. ABA and curcumin also reduced both basal and glucose induced ERCC1 and XPF expression. TSA however, only prevented glucose induced ERCC1 and XPF upregulation. Western blots of ERCC1 and XPF from the nuclear proteins showed similar changes. Data from this study indicated that glucose induced upregulation of ERCC1 and XPF may lead to increased FN production via PARP, P300 pathway. These novel mechanisms may play important roles in diabetic complications. These studies were supported in part by CDA and CIHR 116

Expression of HDAC1 and CBP/p300 in human colorectal carcinomas

Background:The histone-modifying enzymes histone deacetylase (HDAC) and histone acetyltransferase (HAT) control gene transcriptional activation and repression in human malignancies.Aims:To analyse the expression of HDAC/HAT-associated molecules such as HDAC1, CREB-binding protein...