Abstract P362: Gata4 Dimerization May Be A Target For Heart Failure Therapy

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Satoshi Shimizu ◽  
Kodai Hara ◽  
Asami Hishiki ◽  
Yoichi Sunagawa ◽  
Yasufumi Katanasaka ◽  
...  
Keyword(s):  
Heart Failure ◽  
Dna Binding ◽  
Transcriptional Activation ◽  
Binding Capacity ◽  
Activation Mechanism ◽  
Cardiomyocyte Hypertrophy ◽  
Heart Failure Therapy ◽  
Post Translational Modification ◽  
X Ray ◽  
Acetylation Site

Introduction: Cardiac hypertrophy is regulated by activation of GATA4. Although GATA4 post-translational modification such as acetylation by p300 is well examined, the details of the activation mechanism of GATA4 are still unclear. The purpose of this study is to investigate whether GATA4 dimerization involved in transcriptional activation and cardiomyocyte hypertrophic responses. Methods and Results: A GST pull-down assay using GST fusion GATA4 full-length and deletion mutants demonstrated that GATA4 308-326, including the acetylation site, was required for the dimerization of GATA4. A DNA pull down assay showed that the C-zinc finger motif (256-295) and the acetylation site were required for the DNA binding capacity of GATA4. IP-WB using nuclear extract from HEK293T cells expressing FLAG- or HA-tagged GATA4 showed that co-expression of p300 increased the formation of the homo-dimer as well as acetylation of GATA4. The GATA4 homo-dimer was disrupted by both acetyl-deficient GATA4 and HAT-deficient p300. This result indicates that acetylation of GATA4 is important for dimerization of GATA4. Overexpression of the deletion mutant containing a GATA4 308-326 (G4D) prevented p300-induced GATA4 dimerization but not the p300 binding nor acetylation of GATA4. ChIP assay and DNA pulldown assay showed that G4D did not inhibit the p300-induced DNA binding of GATA4. In cardiomyocytes, the G4D inhibited phenylephrine-induced ANF and ET-1 promoter activities and cardiomyocyte hypertrophy. To perform the X-ray crystal structure analysis, recombinant GATA4 fragment including GATA4 308-326 was highly purified. The X-ray diffraction data of obtained crystals was collected. Resolution of the crystal was 3.1Å, which was insufficient for phase determine. To obtain a high-quality crystal, GATA4 fragment was crystallized in international space station, in collaboration with JAXA. Resolution of the crystal was 3.16Å, which was similar to the best data before obtained. Conclusions: These results suggest that GATA4 dimerization may play an important role in hypertrophy-response gene transcription. It is expected to elucidate the GATA4 dimerization mechanism and targeted this dimerization will lead to the development of a noble heart failure therapy.

P1608Inhibition of GATA4 dimerization suppress hypertrophic responses

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
S Shimizu ◽  
Y Sunagawa ◽  
K Hara ◽  
A Hishiki ◽  
Y Katanasaka ◽  
...  
Keyword(s):  
Heart Failure ◽  
Dna Binding ◽  
Cardiac Hypertrophy ◽  
Zinc Finger ◽  
Therapeutic Target ◽  
Transcriptional Activity ◽  
Luciferase Assay ◽  
Zinc Finger Motif ◽  
Zinc Finger Domain ◽  
Acetylation Site

Abstract Introduction Hypertrophic signals eventually reach the nuclei of cardiomyocytes, change patterns of gene expression, and cause the development of heart failure. During the development of heart failure, intrinsic histone acetyltransferase called p300 induce GATA4 acetylation. Acetylated GATA4 increases its DNA binding, up-regulates cardiac hypertrophic response genes, and lead to heart failure. A zinc finger protein, GATA4 is the transcription factor that expression level is high in heart. It has been reported that GATA1, the same GATA family, regulates transcriptional activity through its homo-dimerization. However, GATA4 homo-dimerization and its relationship to hypertrophic responses are still unknown. Purpose To clarify the relationship between GATA4 homo-dimerization and transcriptional activity and investigate whether inhibition of this homo-dimerization become therapeutic target for cardiac hypertrophy. Methods GST pull-down and DNA pull-down assay were performed using GST fusion full length and deletion mutants of GATA4 and biotin-conjugated ET-1 promoter probe including a GATA element. Recombinant C-zinc finger domain (256–326), including C-zinc finger motif (256–295) and acetylation site (308–326) was cross-linked using glutaraldehyde and subjected to silver staining. An expression plasmid with three GATA4-acetylation site mutant-conjugated with nuclear localization sequence (3xG4D) was constructed. Immunoprecipitation and western blotting were performed using nuclear extract from HEK293T cells expressing p300, GATA4, and 3xG4D. Luciferase assay was using ANF and ET-1 promoter sequences. Neonatal rat cultured cardiomyocyte expressed 3xG4D and then stimulated with phenylephrine (PE) for 48 hours. Next cardiomyocytes stained with α-actinin antibody and measured the cell surface area. Results The acetylation site of GATA4 was required for the dimerization of GATA4. But, C-zinc finger motif (256–295) and the acetylation site were required for the DNA binding. Recombinant C-zinc finger domain formed not only a homo-dimer but also a multimer. Co-expression of p300 increased the formation of homo-dimer as well as the acetylation of GATA4 in HEK293T cells. The GATA4 homo-dimer was disrupted by acetyl-deficient GATA4 or HAT-deficient p300 mutant. Overexpression of 3xG4D prevented the dimerization of GATA4, but not acetylation of GATA4. The result of luciferase assay showed that overexpression of 3xG4D prevented p300/GATA-induced ANF and ET-1 promoter activities. Furthermore, overexpression of 3xG4D inhibited phenylephrine-induced cardiomyocyte hypertrophy. Conclusions These results suggest that GATA4 dimerization may play an important role in hypertrophy-response gene activation. Thus, it is likely that inhabitation of GATA4 dimerization become therapeutic target for cardiac hypertrophy.

Abstract 1465: Cardiomyocyte Hypertrophy Induces O-linked-β-N-acetylglucosamine Modification of PGC-1α and Augments its Transcriptional Activity

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Heberty T Facundo ◽  
Charles R Pratridge ◽  
Sumanth D Prabhu ◽  
Steven P Jones
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Metabolism ◽  
Transcriptional Activation ◽  
Acid Metabolism ◽  
Mechanical Stretch ◽  
Neonatal Rat ◽  
Cardiomyocyte Hypertrophy ◽  
Mrna Levels ◽  
Post Translational Modification ◽  
Rat Cardiomyocytes

Background and Hypothesis: PGC-1α (peroxisome proliferator activated receptor-gamma coactivator-1α) coordinately regulates fatty acid metabolism. The O-linked β-N-acetylglucosamine post-translational modification (O-GlcNAc) of proteins is a glucose-derived metabolic signal. We hypothesized that metabolic changes during cardiomyocyte hypertrophy might involve interaction between glycolysis and fatty acid metabolism, specifically via O-GlcNAc modification of PGC-1α. Methods and Results: Mechanical stretch (24 h at 4%; Flexercell FX-4000) in neonatal rat cardiomyocytes (n > 4/group) induced a significant (p<0.05) increase (113 ± 35% over No Stretch) in ANP mRNA, confirming induction of hypertrophy. Mechanical stretch significantly augmented (p<0.001; n = 5) global O-GlcNAcylation of several proteins, which was completely reversed by adenoviral overexpression of the deglycosylating enzyme (O-GlcNAcase). Mechanical stretch also augmented mRNA levels of O-GlcNAc transferase (OGT: adds O-GlcNAc to proteins) and glutamine:fructose aminotransferase (GFAT: rate-limiting step for the O-GlcNAc sugar donor), further indicating recruitment of O-GlcNAc signaling. Immunoprecipitation identified PGC-1α as an O-GlcNAc target in this cardiomyocyte hypertrophy model. Real-time (q)-PCR revealed that O-GlcNAc modification of PGC-1α correlated with elevated mRNA levels (n=4/group) of MCAD and COXIV-5b, implying transcriptional activation of PGC-1α. Conclusions: Cardiomyocyte hypertrophy induces O-GlcNAcylation of PGC-1α and represents a surprising and novel potential regulatory interaction between glycolytic and fatty acid metabolism. This research has received full or partial funding support from the American Heart Association, AHA National Center.

scholarly journals Regulation of Cardiac Transcription Factor GATA4 by Post-Translational Modification in Cardiomyocyte Hypertrophy and Heart Failure

2016 ◽  
Vol 57 (6) ◽  
pp. 672-675 ◽  
Author(s):  
Yasufumi Katanasaka ◽  
Hidetoshi Suzuki ◽  
Yoichi Sunagawa ◽  
Koji Hasegawa ◽  
Tatsuya Morimoto
Keyword(s):  
Heart Failure ◽  
Transcription Factor ◽  
Cardiomyocyte Hypertrophy ◽  
Post Translational Modification

Cardiac tamponade from anticoagulant-related spontaneous haemopericardium in a patient with ischaemic cardiomyopathy and heart failure

2020 ◽  
Vol 13 (12) ◽  
pp. e238047
Author(s):  
Alicia Lefas ◽  
Neil Bodagh ◽  
Jiliu Pan ◽  
Ali Vazir
Keyword(s):  
Heart Failure ◽  
Cardiac Tamponade ◽  
Ventricular Dysfunction ◽  
Oral Anticoagulants ◽  
Direct Oral Anticoagulants ◽  
Left Ventricular ◽  
Heart Failure Therapy ◽  
Severe Left Ventricular Dysfunction ◽  
Ischaemic Cardiomyopathy ◽  
Common Causes

We describe the case of an 86-year-old man with a background of severe left ventricular dysfunction and ischaemic cardiomyopathy who, having been optimised for heart failure therapy in hospital, unexpectedly deteriorated again with hypotension and progressive renal failure over the course of 2 days. Common causes of decompensation were ruled out and a bedside echocardiogram unexpectedly diagnosed new pericardial effusion with tamponade physiology. The patient underwent urgent pericardiocentesis and 890 mL of haemorrhagic fluid was drained. Common causes for haemopericardium were ruled out, and the spontaneous haemopericardium was thought to be related to introduction of rivaroxaban anticoagulation. The patient made a full recovery and was well 2 months following discharge. This case highlights the challenges of diagnosing cardiac tamponade in the presence of more common disorders that share similar non-specific clinical features. In addition, this case adds to growing evidence that therapy with direct oral anticoagulants can be complicated by spontaneous haemopericardium, especially when coadministered with other agents that affect clotting, renal dysfunction and cytochrome P3A5 inhibitors.

scholarly journals Doubling the Carbonate-Binding Capacity of Nanojars by the Formation of Expanded Nanojars

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3083
Author(s):  
Wisam A. Al Isawi ◽  
Gellert Mezei
Keyword(s):  
Co2 Fixation ◽  
Binding Capacity ◽  
Coordination Complexes ◽  
Anion Binding ◽  
Ionization Mass ◽  
X Ray ◽  
Carbonate Ion ◽  
Carbonate Ions ◽  
Supramolecular Coordination ◽  
Hydration Energies

Anion binding and extraction from solutions is currently a dynamic research topic in the field of supramolecular chemistry. A particularly challenging task is the extraction of anions with large hydration energies, such as the carbonate ion. Carbonate-binding complexes are also receiving increased interest due to their relevance to atmospheric CO2 fixation. Nanojars are a class of self-assembled, supramolecular coordination complexes that have been shown to bind highly hydrophilic anions and to extract even the most hydrophilic ones, including carbonate, from water into aliphatic solvents. Here we present an expanded nanojar that is able to bind two carbonate ions, thus doubling the previously reported carbonate-binding capacity of nanojars. The new nanojar is characterized by detailed single-crystal X-ray crystallographic studies in the solid state and electrospray ionization mass spectrometric (including tandem MS/MS) studies in solution.

Protective action of the microbial metabolite butyrate against cardiomyocyte hypertrophy

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M Umei ◽  
H Akazawa ◽  
A Saga-Kamo ◽  
H Yagi ◽  
Q Liu ◽  
...  
Keyword(s):  
Heart Failure ◽  
Short Chain Fatty Acid ◽  
Short Chain Fatty Acids ◽  
Chain Fatty Acid ◽  
G Protein Coupled Receptors ◽  
Short Chain ◽  
Cardiomyocyte Hypertrophy ◽  
Cell Transcriptome ◽  
Single Cell Transcriptome ◽  
G Protein Coupled

Abstract Introduction Short-chain fatty acids are one of the gut microbial metabolites that may influence host physiology. We previously reported that gut dysbiosis was associated with heart failure, and that the proportions of butyrate-producing bacteria diminished prominently in the gut of patients with heart failure. Purpose We investigated the molecular mechanism of butyrate and investigated the protective mechanism against heart failure. Methods We searched for G protein-coupled receptors for short-chain fatty acids using single-cell transcriptome analysis of cardiomyocytes and non-cardiomyocytes isolated from murine hearts. In addition, we examined the effects of butyrate on endothelin-1 (ET1) or isoproterenol-induced hypertrophic responses and histone deacetylase (HDAC) activities in cultured neonatal rat cardiomyocytes. Results Single-cell transcriptome analysis and co-expression network analysis revealed that G protein-coupled receptors for short-chain fatty acid receptors were not expressed in cardiomyocytes and that Olfr78 was expressed in vascular smooth muscle cells in the heart. Treatment with butyrate inhibited ET1-induced hypertrophic growth and up-regulation of the genes such as Nppa, Acta1, and Myh7 in cultured rat neonatal cardiomyocytes. Moreover, butyrate increased the acetylation levels of histone H3, indicating that butyrate has an inhibitory effect on HDAC in cardiomyocytes. In addition, treatment with butyrate caused up-regulation of Inpp5f, encoding inositol polyphosphate-5-phosphatase f, which was associated with a significant decrease in the phosphorylation levels of Akt. These results suggest that butyrate may act as HDAC inhibitor to increase Inpp5f gene expression, leading to the activation of Akt-glycogen synthase kinase 3beta (Gsk3beta) pathway, and thereby protect against hypertrophic responses. Conclusion There was no known GPCR for short-chain fatty acid expressed in cardiomyocytes. However, butyrate suppressed cardiomyocyte hypertrophy through epigenetic modification of gene expression. Our results may uncover a potential role of the dysbiosis of intestinal microbiota in the pathogenesis of cardiac hypertrophy and failure. Funding Acknowledgement Type of funding source: None

scholarly journals Pulmonary Congestion Assessment in Heart Failure: Traditional and New Tools

Diagnostics ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1306
Author(s):  
Filippo Pirrotta ◽  
Benedetto Mazza ◽  
Luigi Gennari ◽  
Alberto Palazzuoli
Keyword(s):  
Heart Failure ◽  
Adverse Outcome ◽  
Volume Overload ◽  
Pulmonary Congestion ◽  
X Ray ◽  
Persistent Symptoms ◽  
Biochemical Evaluation ◽  
Cardiac Filling ◽  
Symptoms And Signs

Congestion related to cardiac pressure and/or volume overload plays a central role in the pathophysiology, presentation, and prognosis of heart failure (HF). Most HF exacerbations are related to a progressive rise in cardiac filling pressures that precipitate pulmonary congestion and symptomatic decompensation. Furthermore, persistent symptoms and signs of congestion at discharge or among outpatients are strong predictors of an adverse outcome. Pulmonary congestion is also one of the most important diagnostic and therapeutic targets in chronic heart failure. The aim of this review is to analyze the importance of clinical, instrumental, and biochemical evaluation of congestion in HF by describing old and new tools. Lung ultrasonography (LUS) is an emerging method to assess pulmonary congestion. Accordingly, we describe the additive prognostic role of chest ultrasound with respect to traditional clinical and X-ray assessment in acute and chronic HF setting.

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