trichostatin-a and Cardiomegaly

People living with HIV (PLWH) have to take an antiretroviral therapy (ART) for life and show noncommunicable illnesses such as chronic inflammation, immune activation, and multiorgan dysregulation. Recent studies suggest that long-term use of ART induces comorbid conditions and is one of the leading causes of heart failure in PLWH. However, the molecular mechanism of antiretroviral drugs (ARVs) induced heart failure is unclear. To determine the mechanism of ARVs induced cardiac dysfunction, we performed global transcriptomic profiling of ARVs treated neonatal rat ventricular cardiomyocytes in culture. Differentially expressed genes were identified by RNA-sequencing. Our data show that ARVs treatment causes upregulation of several biological functions associated with cardiotoxicity, hypertrophy, and heart failure. Global gene expression data were validated in cardiac tissue isolated from HIV patients having a history of ART. Interestingly, we found that homeodomain-only protein homeobox (HOPX) expression was significantly increased in cardiomyocytes treated with ARVs and in the heart tissue of HIV patients. Furthermore, we found that HOPX plays a crucial role in ARVs mediated cellular hypertrophy. Mechanistically, we found that HOPX plays a critical role in epigenetic regulation, through deacetylation of histone, while the HDAC inhibitor, Trichostatin A, can restore the acetylation level of histone 3 in the presence of ARVs.

Topics: Acetylation; Animals; Anti-Retroviral Agents; Cardiomegaly; Disease Models, Animal; Epigenesis, Genetic; Gene Expression Regulation; Heart Failure; Histone Deacetylase Inhibitors; HIV; HIV Infections; Homeodomain Proteins; Humans; Hydroxamic Acids; Myocytes, Cardiac; Rats; RNA-Seq; Transcriptome; Tumor Suppressor Proteins

Pathological cardiac hypertrophy is a classical hallmark of heart failure. At the molecular level, inhibition of histone deacetylase (HDAC) enzymes attenuate pathological cardiac hypertrophy in vitro and in vivo. Emodin is an anthraquinone that has been implicated in cardiac protection. However, it is not known if the cardio-protective actions for emodin are mediated through HDAC-dependent regulation of gene expression. Therefore, we hypothesized that emodin would attenuate pathological cardiac hypertrophy via inhibition of HDACs, and that these actions would be reflected in an emodin-rich food like rhubarb. In this study, we demonstrate that emodin and Turkish rhubarb containing emodin inhibit HDAC activity in vitro, with fast-on, slow-off kinetics. Moreover, we show that emodin increased histone acetylation in cardiomyocytes concomitant to global changes in gene expression; gene expression changes were similar to the well-established pan-HDAC inhibitor trichostatin A (TSA). We additionally present evidence that emodin inhibited phenylephrine (PE) and phorbol myristate acetate (PMA)-induced hypertrophy in neonatal rat ventricular myocytes (NRVMs). Lastly, we demonstrate that the cardioprotective actions of emodin are translated to an angiotensin II (Ang) mouse model of cardiac hypertrophy and fibrosis and are linked to HDAC inhibition. These data suggest that emodin blocked pathological cardiac hypertrophy, in part, by inhibiting HDAC-dependent gene expression changes.

Topics: Acetylation; Angiotensin II; Animals; Animals, Newborn; Cardiomegaly; Cardiotonic Agents; Disease Models, Animal; Emodin; Female; Gene Expression; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Hydroxamic Acids; Male; Mice; Mice, Inbred C57BL; Myocytes, Cardiac; Rats; Rats, Sprague-Dawley; Rheum

Chronic heart failure (CHF) is a complex clinical syndrome, and a serious stage of various heart diseases. Dysfunction of histone acetylation is involved in pathogenesis of CHF. Lujiao is a clinical and traditional prescription that has been previously used in the treatment of heart failure. The objective of our study was to explore the effects of traditional Chinese Medicine intervention with Lujiao prescription on hypertrophic cardiomyocytes with histone acetylation abnormality.. Myocardial cells from neonatal rats were stimulated via phenylephrine (PE) and then randomly divided into seven groups: normal group (without any treatment), model group (treated with saline), TSA group (treated with trichostatin A), perindopril group (treated with perindopril), and the high, medium, and low dose of Lujiao groups (treated with 2.4 g/mL, 1.2 g/mL, and 0.6 g/mL of Lujiao, respectively). The test drug of perindopril group or Lujiao group was derived from serum after drug treatment in rats. Real-time polymerase chain reaction and Western blot were performed to analyze expression of myocyte enhancer factor 2 (MEF-2), α-major histocompatibility complex (MHC), and β-MHC and acetylation level of histone H3.. Expressions of MEF-2 and β-MHC were significantly increased after PE treatment and decreased after drug treatment. Expression of α-MHC mRNA was significantly reduced after PE treatment and increased after being treated with Lujiao prescription, perindopril, and TSA. The acetylation level of histone H3 decreased in rat myocardial cells stimulated by PE 48 for hours and this decrease was reversed after treatment with high and medium doses of Lujiao prescription, perindopril and TSA.. Histone acetylation-MEF-2-α-MHC/β-MHC axis was discovered in myocardial hypertrophy, and intervention of Lujiao prescription exhibited good effects.

Topics: Acetylation; Animals; Cardiomegaly; Cells, Cultured; Histones; Hydroxamic Acids; Male; Medicine, Chinese Traditional; MEF2 Transcription Factors; Myocytes, Cardiac; Myosin Heavy Chains; Perindopril; Rats; Rats, Sprague-Dawley

Pharmacological histone deacetylase (HDAC) inhibitors attenuate pathological cardiac remodeling and hypertrophic gene expression; yet, the direct histone targets remain poorly characterized. Since the inhibition of HDAC activity is associated with suppressing hypertrophy, we hypothesized histone acetylation would target genes implicated in cardiac remodeling. Trichostatin A (TSA) regulates cardiac gene expression and attenuates transverse aortic constriction (TAC) induced hypertrophy. We used chromatin immunoprecipitation (ChIP) coupled with massive parallel sequencing (ChIP-seq) to map, for the first time, genome-wide histone acetylation changes in a preclinical model of pathological cardiac hypertrophy and attenuation of pathogenesis with TSA. Pressure overload-induced cardiac hypertrophy was associated with histone acetylation of genes implicated in cardiac contraction, collagen deposition, inflammation, and extracellular matrix identified by ChIP-seq. Gene set enrichment analysis identified NF-kappa B (NF-κB) transcription factor activation with load induced hypertrophy. Increased histone acetylation was observed on the promoters of NFκB target genes (Icam1, Vcam1, Il21r, Il6ra, Ticam2, Cxcl10) consistent with gene activation in the hypertrophied heart. Surprisingly, TSA attenuated pressure overload-induced cardiac hypertrophy and the suppression of NFκB target genes by broad histone deacetylation. Our results suggest a mechanism for cardioprotection subject to histone deacetylation as a previously unknown target, implicating the importance of inflammation by pharmacological HDAC inhibition. The results of this study provides a framework for HDAC inhibitor function in the heart and argues the long held views of acetylation is subject to more flexibility than previously thought.

Topics: Acetylation; Animals; Aorta; Cardiomegaly; Gene Expression Regulation; Histone Deacetylase Inhibitors; Histone Deacetylases; Histones; Hydroxamic Acids; Male; Mice, Inbred C57BL; Myocardium; NF-kappa B

The Polycomb-group protein, Ezh2, is required for epigenetic gene silencing in the adult heart by unknown mechanism. We investigated the role of Ezh2 and non-coding RNAs in a mouse model of pressure overload using transverse aortic constriction (TAC) attenuated by the prototypical histone deacetylase inhibitor, trichostatin A (TSA). Chromatin immunoprecipitation of TAC and TAC+TSA hearts suggests interaction of Ezh2 and primary microRNA-208b (pri-miR-208b) in the regulation of hypertrophic gene expression. RNAi silencing of pri-miR-208b and Ezh2 validate pri-miR-208b-mediated transcriptional silencing of genes implicated in cardiac hypertrophy including the suppression of the bi-directional promoter (bdP) of the cardiac myosin heavy chain genes. In TAC mouse heart, TSA attenuated Ezh2 binding to bdP and restored antisense β-MHC and α-MHC gene expression. RNA-chromatin immunoprecipitation experiments in TAC hearts also show increased pri-miR-208b dependent-chromatin binding. These results are the first description by which primary miR interactions serve to integrate chromatin modifications and the transcriptional response to distinct signaling cues in the heart. These studies provide a framework for MHC expression and regulation of genes implicated in pathological remodeling of ventricular hypertrophy.

Topics: Animals; Cardiomegaly; Cells, Cultured; Chromatin; Enhancer of Zeste Homolog 2 Protein; Gene Expression Regulation; Histone Deacetylase Inhibitors; Hydroxamic Acids; Male; Mice; Mice, Inbred C57BL; MicroRNAs; Myocardium; Myocytes, Cardiac; Myosin Heavy Chains; Polycomb Repressive Complex 2; Promoter Regions, Genetic; RNA, Antisense; RNA, Untranslated

Kruppel-like factor 4 (KLF4) plays an important role in vascular diseases, including atherosclerosis and vascular injury. Although KLF4 is expressed in the heart in addition to vascular cells, the role of KLF4 in cardiac disease has not been fully determined. The goals of this study were to investigate the role of KLF4 in cardiac hypertrophy and to determine the underlying mechanisms. Cardiomyocyte-specific Klf4 knockout (CM Klf4 KO) mice were generated by the Cre/LoxP technique. Cardiac hypertrophy was induced by chronic infusion of the β-adrenoreceptor agonist isoproterenol (ISO). Results showed that ISO-induced cardiac hypertrophy was enhanced in CM Klf4 KO mice compared with control mice. Accelerated cardiac hypertrophy in CM Klf4 KO mice was accompanied by the augmented cellular enlargement of cardiomyocytes as well as the exaggerated expression of fetal cardiac genes, including atrial natriuretic factor (Nppa). Additionally, induction of myocardin, a transcriptional cofactor regulating fetal cardiac genes, was enhanced in CM Klf4 KO mice. Interestingly, KLF4 regulated Nppa expression by modulating the expression and activity of myocardin, providing a mechanical basis for accelerated cardiac hypertrophy in CM Klf4 KO mice. Moreover, we showed that KLF4 mediated the antihypertrophic effect of trichostatin A, a histone deacetylase inhibitor, because ISO-induced cardiac hypertrophy in CM Klf4 KO mice was attenuated by olmesartan, an angiotensin II type 1 antagonist, but not by trichostatin A. These results provide novel evidence that KLF4 is a regulator of cardiac hypertrophy by modulating the expression and the activity of myocardin.

Topics: Angiotensin II; Animals; Antihypertensive Agents; Atrial Natriuretic Factor; Cardiomegaly; Cell Line; Gene Expression; Gene Expression Regulation; Histone Deacetylase Inhibitors; Hydroxamic Acids; Imidazoles; Isoproterenol; Kruppel-Like Factor 4; Kruppel-Like Transcription Factors; Mice, Inbred C57BL; Mice, Knockout; MicroRNAs; Myocytes, Cardiac; Natriuretic Peptide, C-Type; Nuclear Proteins; Protein Precursors; Tetrazoles; Trans-Activators

Pressure overload induces cardiac hypertrophy through activation of Janus kinase 2 (Jak2), however, the underlying mechanisms remain largely unknown. In the current study, we tested whether histone deacetylase 2 (HDAC2) was involved in the process. We found that angiotensin II (Ang-II)-induced re-expression of fetal genes (Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP)) in cultured cardiomyocytes was prevented by the Jak2 inhibitor AG-490 and HDAC2 inhibitor Trichostatin-A (TSA), or by Jak2/HDAC2 siRNA knockdown. On the other hand, myocardial cells with Jak2 or HDAC2 over-expression were hyper-sensitive to Ang-II. In vivo, pressure overload by transverse aorta binding (AB) induced a significant cardiac hypertrophic response as well as re-expression of ANP and BNP in mice heart, which were markedly reduced by AG-490 and TSA. Significantly, AG-490, the Jak2 inhibitor, largely suppressed pressure overload-/Ang-II-induced HDAC2 nuclear exportation in vivo and in vitro. Meanwhile, TSA or HDAC2 siRNA knockdown reduced Ang-II-induced ANP/BNP expression in Jak2 over-expressed H9c2 cardiomyocytes. Together, these results suggest that HDAC2 might be a downstream effector of Jak2 to mediate cardiac hypertrophic response by pressure overload or Ang-II.

Topics: Active Transport, Cell Nucleus; Angiotensin II; Animals; Atrial Natriuretic Factor; Cardiomegaly; Cell Nucleus; Cells, Cultured; Histone Deacetylase 2; Hydroxamic Acids; Janus Kinase 2; Male; Mice, Inbred C57BL; Myocytes, Cardiac; Natriuretic Peptide, Brain; Peptide Fragments; Pressure; Rats; Signal Transduction; Tyrphostins

We have shown previously that pan-HDAC inhibitors (HDACIs) m-carboxycinnamic acid bis-hydroxamide (CBHA) and trichostatin A (TSA) attenuated cardiac hypertrophy in BALB/c mice by inducing hyper-acetylation of cardiac chromatin that was accompanied by suppression of pro-inflammatory gene networks. However, it was not feasible to determine the precise contribution of the myocytes- and non-myocytes to HDACI-induced gene expression in the intact heart. Therefore, the current study was undertaken with a primary goal of elucidating temporal changes in the transcriptomes of cardiac myocytes exposed to CBHA and TSA.. We incubated H9c2 cardiac myocytes in growth medium containing either of the two HDACIs for 6h and 24h and analyzed changes in gene expression using Illumina microarrays. H9c2 cells exposed to TSA for 6h and 24h led to differential expression of 468 and 231 genes, respectively. In contrast, cardiac myocytes incubated with CBHA for 6h and 24h elicited differential expression of 768 and 999 genes, respectively. We analyzed CBHA- and TSA-induced differentially expressed genes by Ingenuity Pathway (IPA), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Core_TF programs and discovered that CBHA and TSA impinged on several common gene networks. Thus, both HDACIs induced a repertoire of signaling kinases (PTEN-PI3K-AKT and MAPK) and transcription factors (Myc, p53, NFkB and HNF4A) representing canonical TGFβ, TNF-α, IFNγ and IL-6 specific networks. An overrepresentation of E2F, AP2, EGR1 and SP1 specific motifs was also found in the promoters of the differentially expressed genes. Apparently, TSA elicited predominantly TGFβ- and TNF-α-intensive gene networks regardless of the duration of treatment. In contrast, CBHA elicited TNF-α and IFNγ specific networks at 6 h, followed by elicitation of IL-6 and IFNγ-centered gene networks at 24h.. Our data show that both CBHA and TSA induced similar, but not identical, time-dependent, gene networks in H9c2 cardiac myocytes. Initially, both HDACIs impinged on numerous genes associated with adipokine signaling, intracellular metabolism and energetics, and cell cycle. A continued exposure to either CBHA or TSA led to the emergence of a number of apoptosis- and inflammation-specific gene networks that were apparently suppressed by both HDACIs. Based on these data we posit that the anti-inflammatory and anti-proliferative actions of HDACIs are myocyte-intrinsic. These findings advance our understanding of the mechanisms of actions of HDACIs on cardiac myocytes and reveal potential signaling pathways that may be targeted therapeutically.

Topics: Animals; Binding Sites; Cardiomegaly; Cell Line; Cell Proliferation; Cinnamates; Gene Regulatory Networks; Genomics; Histone Deacetylase Inhibitors; Histone Deacetylases; Hydroxamic Acids; Inflammation; Myocytes, Cardiac; Rats; Signal Transduction; Sirtuins; Software; Time Factors; Transcription Factors; Transcriptome

We investigated the genome-wide consequences of pan-histone deacetylase inhibitors (HDACIs) trichostatin A (TSA) and m-carboxycinnamic acid bis-hydroxamide (CBHA) in the hearts of BALB/c mice eliciting hypertrophy in response to interleukin-18 (IL-18). Both TSA and CBHA profoundly altered cardiac chromatin structure that occurred concomitantly with normalization of IL-18-induced gene expression and amelioration of cardiac hypertrophy. The hearts of mice exposed to IL-18+/-TSA or CBHA elicited distinct gene expression profiles. Of 184 genes that were differentially regulated by IL-18 and TSA, 33 were regulated in an opposite manner. The hearts of mice treated with IL-18 and/or CBHA elicited 147 differentially expressed genes (DEGs), a third of which were oppositely regulated by IL-18 and CBHA. Ingenuity Pathways and Kyoto Encyclopedia of Genes and Genomes analyses of DEGs showed that IL-18 impinged on TNF-α- and IFNγ-specific gene networks relegated to controlling immunity and inflammation, cardiac metabolism and energetics, and cell proliferation and apoptosis. These TNF-α- and IFNγ-specific gene networks, extensively connected with PI3K, MAPK, and NF-κB signaling pathways, were oppositely regulated by IL-18 and pan-HDACIs. Evidently, both TSA and CBHA caused a two- to fourfold induction of phosphatase and tensin homolog expression to counteract IL-18-induced proinflammatory signaling and cardiac hypertrophy.

Topics: Animals; Cardiomegaly; Chromatin Assembly and Disassembly; Cinnamates; Cluster Analysis; Gene Expression Profiling; Gene Expression Regulation; Gene Regulatory Networks; Histone Deacetylase Inhibitors; Histones; Hydroxamic Acids; Inflammation; Interleukin-18; Intracellular Space; Male; Mice; Mice, Inbred BALB C; Myocardium; Oligonucleotide Array Sequence Analysis; Protein Processing, Post-Translational; Reproducibility of Results; Signal Transduction

Histone deacetylase inhibitors represent a new class of anticancer therapeutics and the expectation is that they will be most effective when used in combination with conventional cancer therapies, such as the anthracycline, doxorubicin. The dose-limiting side effect of doxorubicin is severe cardiotoxicity and evaluation of the effects of combinations of the anthracycline with histone deacetylase inhibitors in relevant models is important. We used a well-established in vitro model of doxorubicin-induced hypertrophy to examine the effects of the prototypical histone deacetylase inhibitor, Trichostatin A. Our findings indicate that doxorubicin modulates the expression of the hypertrophy-associated genes, ventricular myosin light chain-2, the alpha isoform of myosin heavy chain and atrial natriuretic peptide, an effect which is augmented by Trichostatin A. Furthermore, we show that Trichostatin A amplifies doxorubicin-induced DNA double strand breaks, as assessed by γH2AX formation. More generally, our findings highlight the importance of investigating potential side effects that may be associated with emerging combination therapies for cancer.

Topics: Animals; Atrial Natriuretic Factor; Cardiac Myosins; Cardiomegaly; Cell Differentiation; Cell Enlargement; Cell Line; Cell Size; DNA Damage; Doxorubicin; Drug Synergism; Gene Expression; Histone Deacetylase Inhibitors; Histones; Hydroxamic Acids; Myoblasts, Cardiac; Myocytes, Cardiac; Myosin Heavy Chains; Myosin Light Chains; Phosphorylation; Proteins; Rats; Tretinoin

Topics: Angiotensin II; Animals; Atrial Fibrillation; Cardiomegaly; Connexins; Enzyme Inhibitors; Fibrosis; Gap Junction alpha-5 Protein; Histone Deacetylase Inhibitors; Histone Deacetylases; Homeodomain Proteins; Hydroxamic Acids; Mice; Mice, Transgenic; Time Factors

Atrial fibrosis influences the development of atrial fibrillation (AF), particularly in the setting of structural heart disease where angiotensin-inhibition is partially effective for reducing atrial fibrosis and AF. Histone-deacetylase inhibition reduces cardiac hypertrophy and fibrosis, so we sought to determine if the HDAC inhibitor trichostatin A (TSA) could reduce atrial fibrosis and arrhythmias. Mice over-expressing homeodomain-only protein (HopX(Tg)), which recruits HDAC activity to induce cardiac hypertrophy were investigated in 4 groups (aged 14-18 weeks): wild-type (WT), HopX(Tg), HopX(Tg) mice treated with TSA for 2 weeks (TSA-HopX) and wild-type mice treated with TSA for 2 weeks (TSA-WT). These groups were characterized using invasive electrophysiology, atrial fibrosis measurements, atrial connexin immunocytochemistry and myocardial angiotensin II measurements. Invasive electrophysiologic stimulation, using the same attempts in each group, induced more atrial arrhythmias in HopX(Tg) mice (48 episodes in 13 of 15 HopX(Tg) mice versus 5 episodes in 2 of 15 TSA-HopX mice, P<0.001; versus 9 episodes in 2 of 15 WT mice, P<0.001; versus no episodes in any TSA-WT mice, P<0.001). TSA reduced atrial arrhythmia duration in HopX(Tg) mice (1307+/-289 ms versus 148+/-110 ms, P<0.01) and atrial fibrosis (8.1+/-1.5% versus 3.9+/-0.4%, P<0.001). Atrial connexin40 was lower in HopX(Tg) compared to WT mice, and TSA normalized the expression and size distribution of connexin40 gap junctions. Myocardial angiotensin II levels were similar between WT and HopX(Tg) mice (76.3+/-26.0 versus 69.7+/-16.6 pg/mg protein, P=NS). Therefore, it appears HDAC-inhibition reverses atrial fibrosis, connexin40 remodeling and atrial arrhythmia vulnerability independent of angiotensin II in cardiac hypertrophy.

Topics: Angiotensin II; Animals; Arrhythmias, Cardiac; Cardiomegaly; Connexins; Enzyme Inhibitors; Fibrosis; Gap Junction alpha-5 Protein; Histone Deacetylase Inhibitors; Histone Deacetylases; Homeodomain Proteins; Hydroxamic Acids; Mice; Mice, Transgenic; Time Factors

Recent work has demonstrated the importance of chromatin remodeling, especially histone acetylation, in the control of gene expression in the heart. In cell culture models of cardiac hypertrophy, pharmacological suppression of histone deacetylases (HDACs) can either blunt or amplify cell growth. Thus, HDAC inhibitors hold promise as potential therapeutic agents in hypertrophic heart disease.. In the present investigation, we studied 2 broad-spectrum HDAC inhibitors in a physiologically relevant banding model of hypertrophy, observing dose-responsive suppression of ventricular growth that was well tolerated in terms of both clinical outcome and cardiac performance measures. In both short-term (3-week) and long-term (9-week) trials, cardiomyocyte growth was blocked by HDAC inhibition, with no evidence of cell death or apoptosis. Fibrotic change was diminished in hearts treated with HDAC inhibitors, and collagen synthesis in isolated cardiac fibroblasts was blocked. Preservation of systolic function in the setting of blunted hypertrophic growth was documented by echocardiography and by invasive pressure measurements. The hypertrophy-associated switch of adult and fetal isoforms of myosin heavy chain expression was attenuated, which likely contributed to the observed preservation of systolic function in HDAC inhibitor-treated hearts.. Together, these data suggest that HDAC inhibition is a viable therapeutic strategy that holds promise in the treatment of load-induced heart disease.

Topics: Acetylation; Animals; Apoptosis; Cardiomegaly; Cell Proliferation; Dose-Response Relationship, Drug; Enzyme Inhibitors; Gene Expression; Histone Deacetylase 1; Histone Deacetylase 2; Histone Deacetylase Inhibitors; Histone Deacetylases; Histones; Hydroxamic Acids; Hydroxylamines; Male; Mice; Mice, Inbred C57BL; Myocytes, Cardiac; Myosin Heavy Chains; Natriuretic Peptides; Protein Isoforms; Quinolines; Repressor Proteins; Time Factors; Ultrasonography; Ventricular Function