Disturbance of cardiac gene expression and cardiomyocyte structure predisposes Mecp2-null mice to arrhythmias

PubMed Central

Hara, Munetsugu; Takahashi, Tomoyuki; Mitsumasu, Chiaki; Igata, Sachiyo; Takano, Makoto; Minami, Tomoko; Yasukawa, Hideo; Okayama, Satoko; Nakamura, Keiichiro; Okabe, Yasunori; Tanaka, Eiichiro; Takemura, Genzou; Kosai, Ken-ichiro; Yamashita, Yushiro; Matsuishi, Toyojiro

2015-01-01

Methyl-CpG-binding protein 2 (MeCP2) is an epigenetic regulator of gene expression that is essential for normal brain development. Mutations in MeCP2 lead to disrupted neuronal function and can cause Rett syndrome (RTT), a neurodevelopmental disorder. Previous studies reported cardiac dysfunction, including arrhythmias in both RTT patients and animal models of RTT. In addition, recent studies indicate that MeCP2 may be involved in cardiac development and dysfunction, but its role in the developing and adult heart remains unknown. In this study, we found that Mecp2-null ESCs could differentiate into cardiomyocytes, but the development and further differentiation of cardiovascular progenitors were significantly affected in MeCP2 deficiency. In addition, we revealed that loss of MeCP2 led to dysregulation of endogenous cardiac genes and myocardial structural alterations, although Mecp2-null mice did not exhibit obvious cardiac functional abnormalities. Furthermore, we detected methylation of the CpG islands in the Tbx5 locus, and showed that MeCP2 could target these sequences. Taken together, these results suggest that MeCP2 is an important regulator of the gene-expression program responsible for maintaining normal cardiac development and cardiomyocyte structure. PMID:26073556

Selection of reference genes is critical for miRNA expression analysis in human cardiac tissue. A focus on atrial fibrillation.

PubMed

Masè, Michela; Grasso, Margherita; Avogaro, Laura; D'Amato, Elvira; Tessarolo, Francesco; Graffigna, Angelo; Denti, Michela Alessandra; Ravelli, Flavia

2017-01-24

MicroRNAs (miRNAs) are emerging as key regulators of complex biological processes in several cardiovascular diseases, including atrial fibrillation (AF). Reverse transcription-quantitative polymerase chain reaction is a powerful technique to quantitatively assess miRNA expression profile, but reliable results depend on proper data normalization by suitable reference genes. Despite the increasing number of studies assessing miRNAs in cardiac disease, no consensus on the best reference genes has been reached. This work aims to assess reference genes stability in human cardiac tissue with a focus on AF investigation. We evaluated the stability of five reference genes (U6, SNORD48, SNORD44, miR-16, and 5S) in atrial tissue samples from eighteen cardiac-surgery patients in sinus rhythm and AF. Stability was quantified by combining BestKeeper, delta-C q , GeNorm, and NormFinder statistical tools. All methods assessed SNORD48 as the best and U6 as the worst reference gene. Applications of different normalization strategies significantly impacted miRNA expression profiles in the study population. Our results point out the necessity of a consensus on data normalization in AF studies to avoid the emergence of divergent biological conclusions.

21 CFR 862.1163 - Cardiac allograft gene expression profiling test system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiac allograft gene expression profiling test... Chemistry Test Systems § 862.1163 Cardiac allograft gene expression profiling test system. (a) Identification. A cardiac allograft gene expression profiling test system is a device that measures the...

VANADIUM EXPOSURE ALTERS SPONTANEOUS BEAT RATE AND GENE EXPRESSION OF CULTURED CARDIAC MYOCYTES

EPA Science Inventory

Ambient air pollution particulate matter (PM) exposure is associated with increased morbidity and mortality. Recent toxicological studies report PM-induced changes in a number of cardiac parameters, including heart rate variability, arrhythmias, repolarization, and internal defib...

Cardiac I-1c overexpression with reengineered AAV improves cardiac function in swine ischemic heart failure.

PubMed

Ishikawa, Kiyotake; Fish, Kenneth M; Tilemann, Lisa; Rapti, Kleopatra; Aguero, Jaume; Santos-Gallego, Carlos G; Lee, Ahyoung; Karakikes, Ioannis; Xie, Chaoqin; Akar, Fadi G; Shimada, Yuichi J; Gwathmey, Judith K; Asokan, Aravind; McPhee, Scott; Samulski, Jade; Samulski, Richard Jude; Sigg, Daniel C; Weber, Thomas; Kranias, Evangelia G; Hajjar, Roger J

2014-12-01

Cardiac gene therapy has emerged as a promising option to treat advanced heart failure (HF). Advances in molecular biology and gene targeting approaches are offering further novel options for genetic manipulation of the cardiovascular system. The aim of this study was to improve cardiac function in chronic HF by overexpressing constitutively active inhibitor-1 (I-1c) using a novel cardiotropic vector generated by capsid reengineering of adeno-associated virus (BNP116). One month after a large anterior myocardial infarction, 20 Yorkshire pigs randomly received intracoronary injection of either high-dose BNP116.I-1c (1.0 × 10(13) vector genomes (vg), n = 7), low-dose BNP116.I-1c (3.0 × 10(12) vg, n = 7), or saline (n = 6). Compared to baseline, mean left ventricular ejection fraction increased by 5.7% in the high-dose group, and by 5.2% in the low-dose group, whereas it decreased by 7% in the saline group. Additionally, preload-recruitable stroke work obtained from pressure-volume analysis demonstrated significantly higher cardiac performance in the high-dose group. Likewise, other hemodynamic parameters, including stroke volume and contractility index indicated improved cardiac function after the I-1c gene transfer. Furthermore, BNP116 showed a favorable gene expression pattern for targeting the heart. In summary, I-1c overexpression using BNP116 improves cardiac function in a clinically relevant model of ischemic HF.

Cardiac I-1c Overexpression With Reengineered AAV Improves Cardiac Function in Swine Ischemic Heart Failure

PubMed Central

Ishikawa, Kiyotake; Fish, Kenneth M; Tilemann, Lisa; Rapti, Kleopatra; Aguero, Jaume; Santos-Gallego, Carlos G; Lee, Ahyoung; Karakikes, Ioannis; Xie, Chaoqin; Akar, Fadi G; Shimada, Yuichi J; Gwathmey, Judith K; Asokan, Aravind; McPhee, Scott; Samulski, Jade; Samulski, Richard Jude; Sigg, Daniel C; Weber, Thomas; Kranias, Evangelia G; Hajjar, Roger J

2014-01-01

Cardiac gene therapy has emerged as a promising option to treat advanced heart failure (HF). Advances in molecular biology and gene targeting approaches are offering further novel options for genetic manipulation of the cardiovascular system. The aim of this study was to improve cardiac function in chronic HF by overexpressing constitutively active inhibitor-1 (I-1c) using a novel cardiotropic vector generated by capsid reengineering of adeno-associated virus (BNP116). One month after a large anterior myocardial infarction, 20 Yorkshire pigs randomly received intracoronary injection of either high-dose BNP116.I-1c (1.0 × 1013 vector genomes (vg), n = 7), low-dose BNP116.I-1c (3.0 × 1012 vg, n = 7), or saline (n = 6). Compared to baseline, mean left ventricular ejection fraction increased by 5.7% in the high-dose group, and by 5.2% in the low-dose group, whereas it decreased by 7% in the saline group. Additionally, preload-recruitable stroke work obtained from pressure–volume analysis demonstrated significantly higher cardiac performance in the high-dose group. Likewise, other hemodynamic parameters, including stroke volume and contractility index indicated improved cardiac function after the I-1c gene transfer. Furthermore, BNP116 showed a favorable gene expression pattern for targeting the heart. In summary, I-1c overexpression using BNP116 improves cardiac function in a clinically relevant model of ischemic HF. PMID:25023328

Selection of reference genes is critical for miRNA expression analysis in human cardiac tissue. A focus on atrial fibrillation

PubMed Central

Masè, Michela; Grasso, Margherita; Avogaro, Laura; D’Amato, Elvira; Tessarolo, Francesco; Graffigna, Angelo; Denti, Michela Alessandra; Ravelli, Flavia

2017-01-01

MicroRNAs (miRNAs) are emerging as key regulators of complex biological processes in several cardiovascular diseases, including atrial fibrillation (AF). Reverse transcription-quantitative polymerase chain reaction is a powerful technique to quantitatively assess miRNA expression profile, but reliable results depend on proper data normalization by suitable reference genes. Despite the increasing number of studies assessing miRNAs in cardiac disease, no consensus on the best reference genes has been reached. This work aims to assess reference genes stability in human cardiac tissue with a focus on AF investigation. We evaluated the stability of five reference genes (U6, SNORD48, SNORD44, miR-16, and 5S) in atrial tissue samples from eighteen cardiac-surgery patients in sinus rhythm and AF. Stability was quantified by combining BestKeeper, delta-Cq, GeNorm, and NormFinder statistical tools. All methods assessed SNORD48 as the best and U6 as the worst reference gene. Applications of different normalization strategies significantly impacted miRNA expression profiles in the study population. Our results point out the necessity of a consensus on data normalization in AF studies to avoid the emergence of divergent biological conclusions. PMID:28117343

In Vitro Cardiomyogenic Potential of Human Amniotic Fluid Stem Cells

PubMed Central

Guan, Xuan; Delo, Dawn M.; Atala, Anthony; Soker, Shay

2010-01-01

Stem cell therapy for damaged cardiac tissue is currently limited by a number of factors, including the inability to obtain sufficient cell numbers, the potential tumorigenicity of certain types of stem cells, and the possible link between stem cell therapy and the development of malignant arrhythmias. In this study, we investigated whether human amniotic fluid-derived stem (hAFS) cells could be a potential source of cells for cardiac cell therapy by testing the in vitro differentiation capabilities. Undifferentiated hAFS cells express several cardiac genes, including the transcription factor mef2, the gap junction connexin43, and H- and N-cadherin. A 24-hour incubation with 5-aza-2′–deoxycytidine (5-AZA-dC) induced hAFS cell differentiation along the cardiac lineage. Evidence for this differentiation included morphological changes, up-regulation of cardiac-specific genes (cardiac troponin I and cardiac troponin T) and redistribution of connexin43, as well as down-regulation of the stem cell marker SRY-box 2 (sox2). When co-cultured with neonatal rat cardiomyocytes (NRCs), hAFS cells formed both mechanical and electrical connections with the NRCs. Dye transfer experiments showed that calcein dye could be transferred from NRCs to hAFS cells through cellular connections. The gap junction connexin 43 likely involved in the communication between the two cell types, because 12-O-Tetradecanoylphorbol 13-acetate (TPA) could partially block cellular crosstalk. We conclude that hAFS cells can be differentiated into a cardiomyocyte-like phenotype and can establish functional communication with NRCs. Thus, hAFS cells may potentially be used for cardiac cell therapy. PMID:20687122

In vitro cardiomyogenic potential of human amniotic fluid stem cells.

PubMed

Guan, Xuan; Delo, Dawn M; Atala, Anthony; Soker, Shay

2011-03-01

Stem cell therapy for damaged cardiac tissue is currently limited by a number of factors, including inability to obtain sufficient cell numbers, the potential tumorigenicity of certain types of stem cells and the possible link between stem cell therapy and the development of malignant arrhythmias. In this study, we investigated whether human amniotic fluid-derived stem (hAFS) cells could be a potential source of cells for cardiac cell therapy, by testing the in vitro differentiation capabilities. Undifferentiated hAFS cells express several cardiac genes, including the transcription factor mef2, the gap junction connexin43, and H- and N-cadherin. A 24 h incubation with 5-aza-2'-deoxycytidine (5-AZA-dC) induced hAFS cell differentiation along the cardiac lineage. Evidence for this differentiation included morphological changes, upregulation of cardiac-specific genes (cardiac troponin I and cardiac troponin T) and redistribution of connexin43, as well as downregulation of the stem cell marker SRY-box 2 (sox2). When co-cultured with neonatal rat cardiomyocytes (NRCs), hAFS cells formed both mechanical and electrical connections with the NRCs. Dye transfer experiments showed that calcein dye could be transferred from NRCs to hAFS cells through cellular connections. The gap junction connexin43 likely involved in the communication between the two cell types, because 12-O-tetradecanoylphorbol 13-acetate (TPA) could partially block cellular crosstalk. We conclude that hAFS cells can be differentiated into a cardiomyocyte-like phenotype and can establish functional communication with NRCs. Thus, hAFS cells may potentially be used for cardiac cell therapy. Copyright © 2010 John Wiley & Sons, Ltd.

The δA isoform of calmodulin kinase II mediates pathological cardiac hypertrophy by interfering with the HDAC4-MEF2 signaling pathway

PubMed Central

Li, Changlin; Cai, Xiangyu; Sun, Haili; Bai, Ting; Zheng, Xilong; Zhou, Xing Wang; Chen, Xiongwen; Gill, Donald L.; Li, Jing; Tang, Xiang D.

2011-01-01

Ca2+/calmodulin-dependent protein kinase II (CaMKII) is a new promising target for prevention and treatment of cardiac hypertrophy and heart failure. There are 3 δ isoforms of CaMKII in the heart and previous studies focused primarily on δB and δC types. Here we report the δA isoform of CaMKII is also critically involved in cardiac hypertrophy. We found that δA was significantly upregulated in pathological cardiac hypertrophy in both neonatal and adult models. Upregulation of δA was accompanied by cell enlargement, sarcomere reorganization and reactivation of various hypertrophic cardiac genes including atrial natriuretic factor (ANF) and β-myocin heavy chain (β-MHC). Studies further indicated the pathological changes were largely blunted by silencing the δA gene. These results provide new evidence for selective interfering cardiac hypertrophy and heart failure when CaMKII is considered as a therapeutic target. PMID:21554860

Impact of gestational chronodisruption on fetal cardiac genomics.

PubMed

Galdames, Hugo A; Torres-Farfan, Claudia; Spichiger, Carlos; Mendez, Natalia; Abarzua-Catalan, Lorena; Alonso-Vazquez, Pamela; Richter, Hans G

2014-01-01

We recently reported that gestational chronodisruption induces fetal growth restriction and marked effects on fetal adrenal physiology. Here, whole-transcriptome profiling was used to test whether gestational chronodisruption modifies gene expression in the fetal heart, potentially altering cardiac development. At day 10 of gestation (E10), pregnant rats were randomized in two groups: constant light (LL) and control 12 h light/12 h dark photoperiod (LD). RNA isolated from E18 heart was subjected to microarray analysis (Affymetrix platform for 28,000 genes). Integrated transcriptional changes were assessed by gene ontology and pathway analysis. Significant differential expression was found for 383 transcripts in LL relative to LD fetal heart (280 up-regulated and 103 down-regulated); with 42 of them displaying a 1.5-fold or greater change in gene expression. Deregulated markers of cardiovascular disease accounted for alteration of diverse gene networks in LL fetal heart, including local steroidogenesis and vascular calcification, as well as cardiac hypertrophy, stenosis and necrosis/cell death. DNA integrity was also overrepresented, including a 2.1-fold increase of Hmga1 mRNA, which encodes for a profuse architectural transcription factor. microRNA analysis revealed up-regulation of miRNAs 218-1 and 501 and concurrent down-regulation of their validated target genes. In addition, persistent down-regulation of Kcnip2 mRNA and hypertrophy of the left ventricle were found in the heart from 90 days-old offspring from LL mothers. The dysregulation of a relevant fraction of the fetal cardiac transcriptome, together with the diversity and complexity of the gene networks altered by gestational chronodisruption, suggest enduring molecular changes which may shape the hypertrophy observed in the left ventricle of adult LL offspring. © 2013.

Ecstasy (MDMA) Alters Cardiac Gene Expression and DNA Methylation: Implications for Circadian Rhythm Dysfunction in the Heart

PubMed Central

Koczor, Christopher A.; Ludlow, Ivan; Hight, Robert S.; Jiao, Zhe; Fields, Earl; Ludaway, Tomika; Russ, Rodney; Torres, Rebecca A.; Lewis, William

2015-01-01

MDMA (ecstasy) is an illicit drug that stimulates monoamine neurotransmitter release and inhibits reuptake. MDMA’s acute cardiotoxicity includes tachycardia and arrhythmia which are associated with cardiomyopathy. MDMA acute cardiotoxicity has been explored, but neither long-term MDMA cardiac pathological changes nor epigenetic changes have been evaluated. Microarray analyses were employed to identify cardiac gene expression changes and epigenetic DNA methylation changes. To identify permanent MDMA-induced pathogenetic changes, mice received daily 10- or 35-day MDMA, or daily 10-day MDMA followed by 25-day saline washout (10 + 25 days). MDMA treatment caused differential gene expression (p < .05, fold change >1.5) in 752 genes following 10 days, 558 genes following 35 days, and 113 genes following 10-day MDMA + 25-day saline washout. Changes in MAPK and circadian rhythm gene expression were identified as early as 10 days. After 35 days, circadian rhythm genes (Per3, CLOCK, ARNTL, and NPAS2) persisted to be differentially expressed. MDMA caused DNA hypermethylation and hypomethylation that was independent of gene expression; hypermethylation of genes was found to be 71% at 10 days, 68% at 35 days, and 91% at 10 + 25 days washout. Differential gene expression paralleled DNA methylation in 22% of genes at 10-day treatment, 17% at 35 days, and 48% at 10 + 25 days washout. We show here that MDMA induced cardiac epigenetic changes in DNA methylation where hypermethylation predominated. Moreover, MDMA induced gene expression of key elements of circadian rhythm regulatory genes. This suggests a fundamental organism-level event to explain some of the etiologies of MDMA dysfunction in the heart. PMID:26251327

Ecstasy (MDMA) Alters Cardiac Gene Expression and DNA Methylation: Implications for Circadian Rhythm Dysfunction in the Heart.

PubMed

Koczor, Christopher A; Ludlow, Ivan; Hight, Robert S; Jiao, Zhe; Fields, Earl; Ludaway, Tomika; Russ, Rodney; Torres, Rebecca A; Lewis, William

2015-11-01

MDMA (ecstasy) is an illicit drug that stimulates monoamine neurotransmitter release and inhibits reuptake. MDMA's acute cardiotoxicity includes tachycardia and arrhythmia which are associated with cardiomyopathy. MDMA acute cardiotoxicity has been explored, but neither long-term MDMA cardiac pathological changes nor epigenetic changes have been evaluated. Microarray analyses were employed to identify cardiac gene expression changes and epigenetic DNA methylation changes. To identify permanent MDMA-induced pathogenetic changes, mice received daily 10- or 35-day MDMA, or daily 10-day MDMA followed by 25-day saline washout (10 + 25 days). MDMA treatment caused differential gene expression (p < .05, fold change >1.5) in 752 genes following 10 days, 558 genes following 35 days, and 113 genes following 10-day MDMA + 25-day saline washout. Changes in MAPK and circadian rhythm gene expression were identified as early as 10 days. After 35 days, circadian rhythm genes (Per3, CLOCK, ARNTL, and NPAS2) persisted to be differentially expressed. MDMA caused DNA hypermethylation and hypomethylation that was independent of gene expression; hypermethylation of genes was found to be 71% at 10 days, 68% at 35 days, and 91% at 10 + 25 days washout. Differential gene expression paralleled DNA methylation in 22% of genes at 10-day treatment, 17% at 35 days, and 48% at 10 + 25 days washout. We show here that MDMA induced cardiac epigenetic changes in DNA methylation where hypermethylation predominated. Moreover, MDMA induced gene expression of key elements of circadian rhythm regulatory genes. This suggests a fundamental organism-level event to explain some of the etiologies of MDMA dysfunction in the heart. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Complete cardiac regeneration in a mouse model of myocardial infarction.

PubMed

Haubner, Bernhard Johannes; Adamowicz-Brice, Martyna; Khadayate, Sanjay; Tiefenthaler, Viktoria; Metzler, Bernhard; Aitman, Tim; Penninger, Josef M

2012-12-01

Cardiac remodeling and subsequent heart failure remain critical issues after myocardial infarction despite improved treatment and reperfusion strategies. Recently, complete cardiac regeneration has been demonstrated in fish and newborn mice following resection of the cardiac apex. However, it remained entirely unclear whether the mammalian heart can also completely regenerate following a complex cardiac ischemic injury. We established a protocol to induce a severe heart attack in one-day-old mice using left anterior descending artery (LAD) ligation. LAD ligation triggered substantial cardiac injury in the left ventricle defined by Caspase 3 activation and massive cell death. Ischemia-induced cardiomyocyte death was also visible on day 4 after LAD ligation. Remarkably, 7 days after the initial ischemic insult, we observed complete cardiac regeneration without any signs of tissue damage or scarring. This tissue regeneration translated into long-term normal heart functions as assessed by echocardiography. In contrast, LAD ligations in 7-day-old mice resulted in extensive scarring comparable to adult mice, indicating that the regenerative capacity for complete cardiac healing after heart attacks can be traced to the first week after birth. RNAseq analyses of hearts on day 1, day 3, and day 10 and comparing LAD-ligated and sham-operated mice surprisingly revealed a transcriptional programme of major changes in genes mediating mitosis and cell division between days 1, 3 and 10 postnatally and a very limited set of genes, including genes regulating cell cycle and extracellular matrix synthesis, being differentially regulated in the regenerating hearts. We present for the first time a mammalian model of complete cardiac regeneration following a severe ischemic cardiac injury. This novel model system provides the unique opportunity to uncover molecular and cellular pathways that can induce cardiac regeneration after ischemic injury, findings that one day could be translated to human heart attack patients.

Cardiomyocyte-Specific Ablation of Med1 Subunit of the Mediator Complex Causes Lethal Dilated Cardiomyopathy in Mice.

PubMed

Jia, Yuzhi; Chang, Hsiang-Chun; Schipma, Matthew J; Liu, Jing; Shete, Varsha; Liu, Ning; Sato, Tatsuya; Thorp, Edward B; Barger, Philip M; Zhu, Yi-Jun; Viswakarma, Navin; Kanwar, Yashpal S; Ardehali, Hossein; Thimmapaya, Bayar; Reddy, Janardan K

2016-01-01

Mediator, an evolutionarily conserved multi-protein complex consisting of about 30 subunits, is a key component of the polymerase II mediated gene transcription. Germline deletion of the Mediator subunit 1 (Med1) of the Mediator in mice results in mid-gestational embryonic lethality with developmental impairment of multiple organs including heart. Here we show that cardiomyocyte-specific deletion of Med1 in mice (csMed1-/-) during late gestational and early postnatal development by intercrossing Med1fl/fl mice to α-MyHC-Cre transgenic mice results in lethality within 10 days after weaning due to dilated cardiomyopathy-related ventricular dilation and heart failure. The csMed1-/- mouse heart manifests mitochondrial damage, increased apoptosis and interstitial fibrosis. Global gene expression analysis revealed that loss of Med1 in heart down-regulates more than 200 genes including Acadm, Cacna1s, Atp2a2, Ryr2, Pde1c, Pln, PGC1α, and PGC1β that are critical for calcium signaling, cardiac muscle contraction, arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy and peroxisome proliferator-activated receptor regulated energy metabolism. Many genes essential for oxidative phosphorylation and proper mitochondrial function such as genes coding for the succinate dehydrogenase subunits of the mitochondrial complex II are also down-regulated in csMed1-/- heart contributing to myocardial injury. Data also showed up-regulation of about 180 genes including Tgfb2, Ace, Atf3, Ctgf, Angpt14, Col9a2, Wisp2, Nppa, Nppb, and Actn1 that are linked to cardiac muscle contraction, cardiac hypertrophy, cardiac fibrosis and myocardial injury. Furthermore, we demonstrate that cardiac specific deletion of Med1 in adult mice using tamoxifen-inducible Cre approach (TmcsMed1-/-), results in rapid development of cardiomyopathy and death within 4 weeks. We found that the key findings of the csMed1-/- studies described above are highly reproducible in TmcsMed1-/- mouse heart. Collectively, these observations suggest that Med1 plays a critical role in the maintenance of heart function impacting on multiple metabolic, compensatory and reparative pathways with a likely therapeutic potential in the management of heart failure.

Sex-dimorphism in Cardiac Nutrigenomics: effect of Trans fat and/or Monosodium Glutamate consumption

PubMed Central

2011-01-01

Background A paucity of information on biological sex-specific differences in cardiac gene expression in response to diet has prompted this present nutrigenomics investigation. Sexual dimorphism exists in the physiological and transcriptional response to diet, particularly in response to high-fat feeding. Consumption of Trans-fatty acids (TFA) has been linked to substantially increased risk of heart disease, in which sexual dimorphism is apparent, with males suffering a higher disease rate. Impairment of the cardiovascular system has been noted in animals exposed to Monosodium Glutamate (MSG) during the neonatal period, and sexual dimorphism in the growth axis of MSG-treated animals has previously been noted. Processed foods may contain both TFA and MSG. Methods We examined physiological differences and changes in gene expression in response to TFA and/or MSG consumption compared to a control diet, in male and female C57BL/6J mice. Results Heart and % body weight increases were greater in TFA-fed mice, who also exhibited dyslipidemia (P < 0.05). Hearts from MSG-fed females weighed less than males (P < 0.05). 2-factor ANOVA indicated that the TFA diet induced over twice as many cardiac differentially expressed genes (DEGs) in males compared to females (P < 0.001); and 4 times as many male DEGs were downregulated including Gata4, Mef2d and Srebf2. Enrichment of functional Gene Ontology (GO) categories were related to transcription, phosphorylation and anatomic structure (P < 0.01). A number of genes were upregulated in males and downregulated in females, including pro-apoptotic histone deacetylase-2 (HDAC2). Sexual dimorphism was also observed in cardiac transcription from MSG-fed animals, with both sexes upregulating approximately 100 DEGs exhibiting sex-specific differences in GO categories. A comparison of cardiac gene expression between all diet combinations together identified a subset of 111 DEGs significant only in males, 64 DEGs significant in females only, and 74 transcripts identified as differentially expressed in response to dietary manipulation in both sexes. Conclusion Our model identified major changes in the cardiac transcriptional profile of TFA and/or MSG-fed mice compared to controls, which was reflected by significant differences in the physiological profile within the 4 diet groups. Identification of sexual dimorphism in cardiac transcription may provide the basis for sex-specific medicine in the future. PMID:22078008

AZT-induced mitochondrial toxicity: an epigenetic paradigm for dysregulation of gene expression through mitochondrial oxidative stress.

PubMed

Koczor, Christopher A; Jiao, Zhe; Fields, Earl; Russ, Rodney; Ludaway, Tomika; Lewis, William

2015-10-01

Mitochondrial dysfunction causes oxidative stress and cardiomyopathy. Oxidative stress also is a side effect of dideoxynucleoside antiretrovirals (NRTI) and is observed in NRTI-induced cardiomyopathy. We show here that treatment with the NRTI AZT {1-[(2R,4S,5S)-4-azido-5-(hydroxymethyl)oxolan-2-yl]-5-methylpyrimidine-2,4-dione} modulates cardiac gene expression epigenetically through production of mitochondrially derived reactive oxygen species. Transgenic mice with ubiquitous expression of mitochondrially targeted catalase (MCAT) and C57Bl/6 wild-type mice littermates (WT) were administered AZT (0.22 mg/day po, 35 days), and cardiac DNA and mRNA were isolated. In AZT-treated WT, 95 cardiac genes were differentially expressed compared with vehicle-treated WTs. When MCAT mice were treated with AZT, each of those 95 genes reverted toward the expression of vehicle-treated WTs. In AZT-treated WT hearts, Mthfr [5,10-methylenetetrahydrofolate reductase; a critical enzyme in synthesis of methionine cycle intermediates including S-adenosylmethionine (SAM)], was overexpressed. Steady-state abundance of SAM in cardiac extracts from AZT-treated MCAT mice increased 60% above that of vehicle-treated MCAT. No such change occurred in WT. AZT caused hypermethylation (47%) and hypomethylation (53%) of differentially methylated DNA regions in WT cardiac DNA. AZT-treated MCAT heart DNA exhibited greater hypermethylation (91%) and less hypomethylation (9%) compared with vehicle-treated MCAT controls. The gene encoding protein kinase C-α displayed multifocal epigenetic regulation caused by oxidative stress. Results show that mitochondrially derived oxidative stress in the heart hinders cardiac DNA methylation, alters steady-state abundance of SAM, alters cardiac gene expression, and promotes characteristic pathophysiological changes of cardiomyopathy. This mechanism for NRTI toxicity offers insight into long-term side effects from these commonly used antiviral agents. Copyright © 2015 the American Physiological Society.

Elevated expression of the metabolic regulator receptor-interacting protein 140 results in cardiac hypertrophy and impaired cardiac function.

PubMed

Fritah, Asmaà; Steel, Jennifer H; Nichol, Donna; Parker, Nadeene; Williams, Sharron; Price, Anthony; Strauss, Leena; Ryder, Timothy A; Mobberley, Margaret A; Poutanen, Matti; Parker, Malcolm; White, Roger

2010-06-01

Receptor-interacting protein 140 (RIP140) is a ligand-dependent cofactor for nuclear receptors that regulate networks of genes involved in cellular processes, including metabolism. An important role for RIP140 in metabolic control has been identified in RIP140 null mice, whose phenotypes include derepression of genes involved in energy mobilization or catabolism in adipocytes and a switch to more oxidative fibres in skeletal muscle. We hypothesized that ubiquitous expression of RIP140 would suppress metabolic processes, leading to defects in development or cellular function. The primary effect of exogenous expression of RIP140 mRNA (real-time PCR) and protein (western blotting) in transgenic mice is impaired postnatal heart function. There was rapid onset of cardiac hypertrophy and ventricular fibrosis, detected microscopically, in male RIP140 transgenic mice from 4 weeks of age, resulting in 25% mortality by 5 months. RIP140 exogenous expression in the heart leads to decreased mitochondria state III and state IV membrane potential and oxygen consumption. Quantitative PCR showed more than 50% reduced expression of genes involved in mitochondrial activity and fatty acid metabolism, including mitochondrial transcription factor A, cytochrome oxidase VIIa, cytochrome XII, CD36, medium-chain acyl dehydrogenase, and fatty acid transport protein, many of which are known targets for nuclear receptors, including peroxisome proliferator-activated receptors PPARalpha and PPARdelta and oestrogen-related receptors ERRalpha and ERRgamma. This study demonstrates that RIP140 is an important cofactor in postnatal cardiac function and that inhibition of the action of RIP140 may provide a model system to investigate specific interventions designed to prevent or delay the onset of cardiac disease.

Pharmacological inhibition of DNA methylation attenuates pressure overload-induced cardiac hypertrophy in rats.

PubMed

Stenzig, Justus; Schneeberger, Yvonne; Löser, Alexandra; Peters, Barbara S; Schaefer, Andreas; Zhao, Rong-Rong; Ng, Shi Ling; Höppner, Grit; Geertz, Birgit; Hirt, Marc N; Tan, Wilson; Wong, Eleanor; Reichenspurner, Hermann; Foo, Roger S-Y; Eschenhagen, Thomas

2018-07-01

Heart failure is associated with altered gene expression and DNA methylation. De novo DNA methylation is associated with gene silencing, but its role in cardiac pathology remains incompletely understood. We hypothesized that inhibition of DNA methyltransferases (DNMT) might prevent the deregulation of gene expression and the deterioration of cardiac function under pressure overload (PO). To test this hypothesis, we evaluated a DNMT inhibitor in PO in rats and analysed DNA methylation in cardiomyocytes. Young male Wistar rats were subjected to PO by transverse aortic constriction (TAC) or to sham surgery. Rats from both groups received solvent or 12.5 mg/kg body weight of the non-nucleosidic DNMT inhibitor RG108, initiated on the day of the intervention. After 4 weeks, we analysed cardiac function by MRI, fibrosis with Sirius Red staining, gene expression by RNA sequencing and qPCR, and DNA methylation by reduced representation bisulphite sequencing (RRBS). RG108 attenuated the ~70% increase in heart weight/body weight ratio of TAC over sham to 47% over sham, partially rescued reduced contractility, diminished the fibrotic response and the downregulation of a set of genes including Atp2a2 (SERCA2a) and Adrb1 (beta1-adrenoceptor). RG108 was associated with significantly lower global DNA methylation in cardiomyocytes by ~2%. The differentially methylated pathways were "cardiac hypertrophy", "cell death" and "xenobiotic metabolism signalling". Among these, "cardiac hypertrophy" was associated with significant methylation differences in the group comparison sham vs. TAC, but not significant between sham+RG108 and TAC+RG108 treatment, suggesting that RG108 partially prevented differential methylation. However, when comparing TAC and TAC+RG108, the pathway cardiac hypertrophy was not significantly differentially methylated. DNMT inhibitor treatment is associated with attenuation of cardiac hypertrophy and moderate changes in cardiomyocyte DNA methylation. The potential mechanistic link between these two effects and the role of non-myocytes need further clarification. Copyright © 2018 Elsevier Ltd. All rights reserved.

Cardiomyogenic Differentiation in Cardiac Myxoma Expressing Lineage-Specific Transcription Factors

PubMed Central

Kodama, Hiroaki; Hirotani, Takashi; Suzuki, Yusuke; Ogawa, Satoshi; Yamazaki, Kazuto

2002-01-01

We investigated five cases of cardiac myxoma and one case of cardiac undifferentiated sarcoma by light and electron microscopy, in situ hybridization, immunohistochemical staining, and reverse transcriptase-polymerase chain reaction for cardiomyocyte-specific transcription factors, Nkx2.5/Csx, GATA-4, MEF2, and eHAND. Conventional light microscopy revealed that cardiac myxoma and sarcoma cells presented variable cellular arrangements and different histological characteristics. Ultrastructurally, some of the myxoma cells exhibited endothelium-like or immature mesenchymal cell differentiation. Immunohistochemistry for Nkx2.5/Csx, GATA-4, and eHAND was slightly to intensely positive in all myxoma cases. MEF2 immunoreactivity was observed in all cases including the case of sarcoma, thus suggesting myogenic differentiation of myxoma or sarcoma cells. In situ hybridization for Nkx2.5/Csx also revealed that all myxoma cells, but not sarcoma cells, expressed mRNA of the cardiac homeobox gene, Nkx2.5/Csx. Furthermore, nested reverse transcriptase-polymerase chain reaction from formalin-fixed, paraffin-embedded tissue was performed and demonstrated that the Nkx2.5/Csx and eHAND gene product to be detected in all cases, and in three of six cases, respectively. In conclusion, cardiac myxoma cells were found to express various amounts of cardiomyocyte-specific transcription factor gene products at the mRNA and protein levels, thus suggesting cardiomyogenic differentiation. These results support the concept that cardiac myxoma might arise from mesenchymal cardiomyocyte progenitor cells. PMID:12163362

Kruppel-like Factor 4 Protein Regulates Isoproterenol-induced Cardiac Hypertrophy by Modulating Myocardin Expression and Activity*

PubMed Central

Yoshida, Tadashi; Yamashita, Maho; Horimai, Chihiro; Hayashi, Matsuhiko

2014-01-01

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. PMID:25100730

Contemporary genetic testing in inherited cardiac disease: tools, ethical issues, and clinical applications.

PubMed

Girolami, Francesca; Frisso, Giulia; Benelli, Matteo; Crotti, Lia; Iascone, Maria; Mango, Ruggiero; Mazzaccara, Cristina; Pilichou, Kalliope; Arbustini, Eloisa; Tomberli, Benedetta; Limongelli, Giuseppe; Basso, Cristina; Olivotto, Iacopo

2018-01-01

: Inherited cardiac diseases comprise a wide and heterogeneous spectrum of diseases of the heart, including the cardiomyopathies and the arrhythmic diseases in structurally normal hearts, that is, channelopathies. With a combined estimated prevalence of 3% in the general population, these conditions represent a relevant epidemiological entity worldwide, and are a major cause of cardiac morbidity and mortality in the young. The extraordinary progress achieved in molecular genetics over the last three decades has unveiled the complex molecular basis of many familial cardiac conditions, paving the way for routine use of gene testing in clinical practice. In current practice, genetic testing can be used in a clinically affected patient to confirm diagnosis, or to formulate a differential diagnosis among overlapping phenotypes or between hereditary and acquired (nongenetic) forms of disease. Although genotype-phenotype correlations are generally unpredictable, a precise molecular diagnosis can help predict prognosis in specific patient subsets and may guide management. In clinically unaffected relatives, genetic cascade testing is recommended, after the initial identification of a pathogenic variation, with the aim of identifying asymptomatic relatives who might be at risk of disease-related complications, including unexpected sudden cardiac death. Future implications include the identification of novel therapeutic targets and development of tailored treatments including gene therapy. This document reflects the multidisciplinary, 'real-world' experience required when implementing genetic testing in cardiomyopathies and arrhythmic syndromes, along the recommendations of various guidelines.

Contemporary genetic testing in inherited cardiac disease: tools, ethical issues, and clinical applications

PubMed Central

Girolami, Francesca; Frisso, Giulia; Benelli, Matteo; Crotti, Lia; Iascone, Maria; Mango, Ruggiero; Mazzaccara, Cristina; Pilichou, Kalliope; Arbustini, Eloisa; Tomberli, Benedetta; Limongelli, Giuseppe; Basso, Cristina; Olivotto, Iacopo

2018-01-01

Inherited cardiac diseases comprise a wide and heterogeneous spectrum of diseases of the heart, including the cardiomyopathies and the arrhythmic diseases in structurally normal hearts, that is, channelopathies. With a combined estimated prevalence of 3% in the general population, these conditions represent a relevant epidemiological entity worldwide, and are a major cause of cardiac morbidity and mortality in the young. The extraordinary progress achieved in molecular genetics over the last three decades has unveiled the complex molecular basis of many familial cardiac conditions, paving the way for routine use of gene testing in clinical practice. In current practice, genetic testing can be used in a clinically affected patient to confirm diagnosis, or to formulate a differential diagnosis among overlapping phenotypes or between hereditary and acquired (nongenetic) forms of disease. Although genotype–phenotype correlations are generally unpredictable, a precise molecular diagnosis can help predict prognosis in specific patient subsets and may guide management. In clinically unaffected relatives, genetic cascade testing is recommended, after the initial identification of a pathogenic variation, with the aim of identifying asymptomatic relatives who might be at risk of disease-related complications, including unexpected sudden cardiac death. Future implications include the identification of novel therapeutic targets and development of tailored treatments including gene therapy. This document reflects the multidisciplinary, ‘real-world’ experience required when implementing genetic testing in cardiomyopathies and arrhythmic syndromes, along the recommendations of various guidelines. PMID:29176389

78 FR 26794 - Prospective Grant of Start-Up Exclusive Evaluation Option License Agreement: Gene Therapy and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-08

...-Up Exclusive Evaluation Option License Agreement: Gene Therapy and Cell-Based Therapy for Cardiac... the field of use may be limited to ``Gene therapy and cell-based therapy for cardiac arrhythmias in...\\2+\\-activated adenylyl cyclase, as well as cardiac cells or cardiac-like cells derived from...

Cloning and characterization of the mouse alpha1C/A-adrenergic receptor gene and analysis of an alpha1C promoter in cardiac myocytes: role of an MCAT element that binds transcriptional enhancer factor-1 (TEF-1).

PubMed

O'Connell, T D; Rokosh, D G; Simpson, P C

2001-05-01

alpha1-Adrenergic receptor (AR) subtypes in the heart are expressed by myocytes but not by fibroblasts, a feature that distinguishes alpha1-ARs from beta-ARs. Here we studied myocyte-specific expression of alpha1-ARs, focusing on the subtype alpha1C (also called alpha1A), a subtype implicated in cardiac hypertrophic signaling in rat models. We first cloned the mouse alpha1C-AR gene, which consisted of two exons with an 18 kb intron, similar to the alpha1B-AR gene. The receptor coding sequence was >90% homologous to that of rat and human. alpha1C-AR transcription in mouse heart was initiated from a single Inr consensus sequence at -588 from the ATG; this and a putative polyadenylation sequence 8.5 kb 3' could account for the predominant 11 kb alpha1C mRNA in mouse heart. A 5'-nontranscribed fragment of 4.4 kb was active as a promoter in cardiac myocytes but not in fibroblasts. Promoter activity in myocytes required a single muscle CAT (MCAT) element, and this MCAT bound in vitro to recombinant and endogenous transcriptional enhancer factor-1. Thus, alpha1C-AR transcription in cardiac myocytes shares MCAT dependence with other cardiac-specific genes, including the alpha- and beta-myosin heavy chains, skeletal alpha-actin, and brain natriuretic peptide. However, the mouse alpha1C gene was not transcribed in the neonatal heart and was not activated by alpha1-AR and other hypertrophic agonists in rat myocytes, and thus differed from other MCAT-dependent genes and the rat alpha1C gene.

Genome-Wide Gene Expression Analysis Shows AKAP13-Mediated PKD1 Signaling Regulates the Transcriptional Response to Cardiac Hypertrophy.

PubMed

Johnson, Keven R; Nicodemus-Johnson, Jessie; Spindler, Mathew J; Carnegie, Graeme K

2015-01-01

In the heart, scaffolding proteins such as A-Kinase Anchoring Proteins (AKAPs) play a crucial role in normal cellular function by serving as a signaling hub for multiple protein kinases including protein kinase D1 (PKD1). Under cardiac hypertrophic conditions AKAP13 anchored PKD1 activates the transcription factor MEF2 leading to subsequent fetal gene activation and hypertrophic response. We used an expression microarray to identify the global transcriptional response in the hearts of wild-type mice expressing the native form of AKAP13 compared to a gene-trap mouse model expressing a truncated form of AKAP13 that is unable to bind PKD1 (AKAP13-ΔPKD1). Microarray analysis showed that AKAP13-ΔPKD1 mice broadly failed to exhibit the transcriptional profile normally associated with compensatory cardiac hypertrophy following trans-aortic constriction (TAC). The identified differentially expressed genes in WT and AKAP13-ΔPKD1 hearts are vital for the compensatory hypertrophic response to pressure-overload and include myofilament, apoptotic, and cell growth/differentiation genes in addition to genes not previously identified as affected by AKAP13-anchored PKD1. Our results show that AKAP13-PKD1 signaling is critical for transcriptional regulation of key contractile, cell death, and metabolic pathways during the development of compensatory hypertrophy in vivo.

Genome-Wide Gene Expression Analysis Shows AKAP13-Mediated PKD1 Signaling Regulates the Transcriptional Response to Cardiac Hypertrophy

PubMed Central

Johnson, Keven R.; Nicodemus-Johnson, Jessie; Spindler, Mathew J.

2015-01-01

In the heart, scaffolding proteins such as A-Kinase Anchoring Proteins (AKAPs) play a crucial role in normal cellular function by serving as a signaling hub for multiple protein kinases including protein kinase D1 (PKD1). Under cardiac hypertrophic conditions AKAP13 anchored PKD1 activates the transcription factor MEF2 leading to subsequent fetal gene activation and hypertrophic response. We used an expression microarray to identify the global transcriptional response in the hearts of wild-type mice expressing the native form of AKAP13 compared to a gene-trap mouse model expressing a truncated form of AKAP13 that is unable to bind PKD1 (AKAP13-ΔPKD1). Microarray analysis showed that AKAP13-ΔPKD1 mice broadly failed to exhibit the transcriptional profile normally associated with compensatory cardiac hypertrophy following trans-aortic constriction (TAC). The identified differentially expressed genes in WT and AKAP13-ΔPKD1 hearts are vital for the compensatory hypertrophic response to pressure-overload and include myofilament, apoptotic, and cell growth/differentiation genes in addition to genes not previously identified as affected by AKAP13-anchored PKD1. Our results show that AKAP13-PKD1 signaling is critical for transcriptional regulation of key contractile, cell death, and metabolic pathways during the development of compensatory hypertrophy in vivo. PMID:26192751

Systemic injection of AAV9 carrying a periostin promoter targets gene expression to a myofibroblast-like lineage in mouse hearts after reperfused myocardial infarction.

PubMed

Piras, B A; Tian, Y; Xu, Y; Thomas, N A; O'Connor, D M; French, B A

2016-05-01

Adeno-associated virus (AAV) has been used to direct gene transfer to a variety of tissues, including heart, liver, skeletal muscle, brain, kidney and lung, but it has not previously been shown to effectively target fibroblasts in vivo, including cardiac fibroblasts. We constructed expression cassettes using a modified periostin promoter to drive gene expression in a cardiac myofibroblast-like lineage, with only occasional spillover into cardiomyocyte-like cells. We compared AAV serotypes 6 and 9 and found robust gene expression when the vectors were delivered by systemic injection after myocardial infarction (MI), with little expression in healthy, non-infarcted mice. AAV9 provided expression in a greater number of cells than AAV6, with reporter gene expression visible in the cardiac infarct and border zones from 5 to 62 days post MI, as assessed by luciferase and Cre-activated green fluorescent protein expression. Although common myofibroblast markers were expressed in low abundance, most of the targeted cells expressed myosin IIb, an embryonic form of smooth muscle myosin heavy chain that has previously been associated with myofibroblasts after reperfused MI. This study is the first to demonstrate AAV-mediated expression in a potentially novel myofibroblast-like lineage in mouse hearts post MI and may open new avenues of gene therapy to treat patients surviving MI.

Kcne2 Deletion Creates a Multisystem Syndrome Predisposing to Sudden Cardiac Death

PubMed Central

Hu, Zhaoyang; Kant, Ritu; Anand, Marie; King, Elizabeth C.; Krogh-Madsen, Trine; Christini, David J.; Abbott, Geoffrey W.

2014-01-01

Background Sudden cardiac death (SCD) is the leading global cause of mortality, exhibiting increased incidence in diabetics. Ion channel gene perturbations provide a well-established ventricular arrhythmogenic substrate for SCD. However, most arrhythmia susceptibility genes - including the KCNE2 K+ channel β subunit - are expressed in multiple tissues, suggesting potential multiplex SCD substrates. Methods and Results Using “whole transcript” transcriptomics, we uncovered cardiac angiotensinogen upregulation and remodeling of cardiac angiotensinogen interaction networks in P21 Kcne2−/− mouse pups, and adrenal remodeling consistent with metabolic syndrome in adult Kcne2−/− mice. This led to the discovery that Kcne2 disruption causes multiple acknowledged SCD substrates of extracardiac origin: diabetes, hypercholesterolemia, hyperkalemia, anemia and elevated angiotensin II. Kcne2 deletion was also prerequisite for aging-dependent QT prolongation, ventricular fibrillation and SCD immediately following transient ischemia, and fasting-dependent hypoglycemia, myocardial ischemia and atrioventricular block. Conclusions Disruption of a single, widely expressed arrhythmia susceptibility gene can generate a multisystem syndrome comprising manifold electrical and systemic substrates and triggers of SCD. This paradigm is expected to apply to other arrhythmia susceptibility genes, the majority of which encode ubiquitously expressed ion channel subunits or regulatory proteins. PMID:24403551

Transcriptional alterations in the left ventricle of three hypertensive rat models.

PubMed

Cerutti, Catherine; Kurdi, Mazen; Bricca, Giampiero; Hodroj, Wassim; Paultre, Christian; Randon, Jacques; Gustin, Marie-Paule

2006-11-27

Left ventricular hypertrophy (LVH) is commonly associated with hypertension and represents an independent cardiovascular risk factor. The aim of this study was to test the hypothesis that the cardiac overload related to hypertension is associated to a specific gene expression pattern independently of genetic background. Gene expression levels were obtained with microarrays for 15,866 transcripts from RNA of left ventricles from 12-wk-old rats of three hypertensive models [spontaneously hypertensive rat (SHR), Lyon hypertensive rat (LH), and heterozygous TGR(mRen2)27 rat] and their respective controls. More than 60% of the detected transcripts displayed significant changes between the three groups of normotensive rats, showing large interstrain variability. Expression data were analyzed with respect to hypertension, LVH, and chromosomal distribution. Only four genes had significantly modified expression in the three hypertensive models among which a single gene, coding for sialyltransferase 7A, was consistently overexpressed. Correlation analysis between expression data and left ventricular mass index (LVMI) over all rats identified a larger set of genes whose expression was continuously related with LVMI, including known genes associated with cardiac remodeling. Positioning the detected transcripts along the chromosomes pointed out high-density regions mostly located within blood pressure and cardiac mass quantitative trait loci. Although our study could not detect a unique reprogramming of cardiac cells involving specific genes at early stage of LVH, it allowed the identification of some genes associated with LVH regardless of genetic background. This study thus provides a set of potentially important genes contained within restricted chromosomal regions involved in cardiovascular diseases.

Cardiogenic Genes Expressed in Cardiac Fibroblasts Contribute to Heart Development and Repair

PubMed Central

Furtado, Milena B.; Costa, Mauro W.; Pranoto, Edward Adi; Salimova, Ekaterina; Pinto, Alex; Lam, Nicholas T.; Park, Anthony; Snider, Paige; Chandran, Anjana; Harvey, Richard P.; Boyd, Richard; Conway, Simon J.; Pearson, James; Kaye, David M.; Rosenthal, Nadia A.

2014-01-01

Rationale Cardiac fibroblasts are critical to proper heart function through multiple interactions with the myocardial compartment but appreciation of their contribution has suffered from incomplete characterization and lack of cell-specific markers. Objective To generate an unbiased comparative gene expression profile of the cardiac fibroblast pool, identify and characterize the role of key genes in cardiac fibroblast function, and determine their contribution to myocardial development and regeneration. Methods and Results High-throughput cell surface and intracellular profiling of cardiac and tail fibroblasts identified canonical MSC and a surprising number of cardiogenic genes, some expressed at higher levels than in whole heart. Whilst genetically marked fibroblasts contributed heterogeneously to interstitial but not cardiomyocyte compartments in infarcted hearts, fibroblast-restricted depletion of one highly expressed cardiogenic marker, Tbx20, caused marked myocardial dysmorphology and perturbations in scar formation upon myocardial infarction. Conclusions The surprising transcriptional identity of cardiac fibroblasts, the adoption of cardiogenic gene programs and direct contribution to cardiac development and repair provokes alternative interpretations for studies on more specialized cardiac progenitors, offering a novel perspective for reinterpreting cardiac regenerative therapies. PMID:24650916

Myocardial Adeno-Associated Virus Serotype 6–βARKct Gene Therapy Improves Cardiac Function and Normalizes the Neurohormonal Axis in Chronic Heart Failure

PubMed Central

Rengo, Giuseppe; Lymperopoulos, Anastasios; Zincarelli, Carmela; Donniacuo, Maria; Soltys, Stephen; Rabinowitz, Joseph E.; Koch, Walter J.

2009-01-01

Background The upregulation of G protein–coupled receptor kinase 2 in failing myocardium appears to contribute to dysfunctional β-adrenergic receptor (βAR) signaling and cardiac function. The peptide βARKct, which can inhibit the activation of G protein–coupled receptor kinase 2 and improve βAR signaling, has been shown in transgenic models and short-term gene transfer experiments to rescue heart failure (HF). This study was designed to evaluate long-term βARKct expression in HF with the use of stable myocardial gene delivery with adeno-associated virus serotype 6 (AAV6). Methods and Results In HF rats, we delivered βARKct or green fluorescent protein as a control via AAV6-mediated direct intramyocardial injection. We also treated groups with concurrent administration of the β-blocker metoprolol. We found robust and long-term transgene expression in the left ventricle at least 12 weeks after delivery. βARKct significantly improved cardiac contractility and reversed left ventricular remodeling, which was accompanied by a normalization of the neurohormonal (catecholamines and aldosterone) status of the chronic HF animals, including normalization of cardiac βAR signaling. Addition of metoprolol neither enhanced nor decreased βARKct-mediated beneficial effects, although metoprolol alone, despite not improving contractility, prevented further deterioration of the left ventricle. Conclusions Long-term cardiac AAV6-βARKct gene therapy in HF results in sustained improvement of global cardiac function and reversal of remodeling at least in part as a result of a normalization of the neurohormonal signaling axis. In addition, βARKct alone improves outcomes more than a β-blocker alone, whereas both treatments are compatible. These findings show that βARKct gene therapy can be of long-term therapeutic value in HF. PMID:19103992

Gene transfer to promote cardiac regeneration.

PubMed

Collesi, Chiara; Giacca, Mauro

2016-12-01

There is an impelling need to develop new therapeutic strategies for patients with myocardial infarction and heart failure. Leading from the large quantity of new information gathered over the last few years on the mechanisms controlling cardiomyocyte proliferation during embryonic and fetal life, it is now possible to devise innovative therapies based on cardiac gene transfer. Different protein-coding genes controlling cell cycle progression or cardiomyocyte specification and differentiation, along with microRNA mimics and inhibitors regulating pre-natal and early post-natal cell proliferation, are amenable to transformation in potential therapeutics for cardiac regeneration. These gene therapy approaches are conceptually revolutionary, since they are aimed at stimulating the intrinsic potential of differentiated cardiac cells to proliferate, rather than relying on the implantation of exogenously expanded cells to achieve tissue regeneration. For efficient and prolonged cardiac gene transfer, vectors based on the Adeno-Associated Virus stand as safe, efficient and reliable tools for cardiac gene therapy applications.

Identification of genes regulated during mechanical load-induced cardiac hypertrophy

NASA Technical Reports Server (NTRS)

Johnatty, S. E.; Dyck, J. R.; Michael, L. H.; Olson, E. N.; Abdellatif, M.; Schneider, M. (Principal Investigator)

2000-01-01

Cardiac hypertrophy is associated with both adaptive and adverse changes in gene expression. To identify genes regulated by pressure overload, we performed suppressive subtractive hybridization between cDNA from the hearts of aortic-banded (7-day) and sham-operated mice. In parallel, we performed a subtraction between an adult and a neonatal heart, for the purpose of comparing different forms of cardiac hypertrophy. Sequencing more than 100 clones led to the identification of an array of functionally known (70%) and unknown genes (30%) that are upregulated during cardiac growth. At least nine of those genes were preferentially expressed in both the neonatal and pressure over-load hearts alike. Using Northern blot analysis to investigate whether some of the identified genes were upregulated in the load-independent calcineurin-induced cardiac hypertrophy mouse model, revealed its incomplete similarity with the former models of cardiac growth. Copyright 2000 Academic Press.

Expression of cardiac neural crest and heart genes isolated by modified differential display.

PubMed

Martinsen, Brad J; Groebner, Nathan J; Frasier, Allison J; Lohr, Jamie L

2003-08-01

The invasion of the cardiac neural crest (CNC) into the outflow tract (OFT) and subsequent outflow tract septation are critical events during vertebrate heart development. We have performed four modified differential display screens in the chick embryo to identify genes that may be involved in CNC, OFT, secondary heart field, and heart development. The screens included differential display of RNA isolated from three different axial segments containing premigratory cranial neural crest cells; of RNA from distal outflow tract, proximal outflow tract, and atrioventricular tissue of embryonic chick hearts; and of RNA isolated from left and right cranial tissues, including the early heart fields. These screens have resulted in the identification of the five cDNA clones presented here, which are expressed in the cardiac neural crest, outflow tract and developing heart in patterns that are unique in heart development.

Isoproterenol effects evaluated in heart slices of human and rat in comparison to rat heart in vivo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herrmann, Julia E.; Heale, Jason; Bieraugel, Mike

Human response to isoproterenol induced cardiac injury was evaluated by gene and protein pathway changes in human heart slices, and compared to rat heart slices and rat heart in vivo. Isoproterenol (10 and 100 μM) altered human and rat heart slice markers of oxidative stress (ATP and GSH) at 24 h. In this in vivo rat study (0.5 mg/kg), serum troponin concentrations increased with lesion severity, minimal to mild necrosis at 24 and 48 h. In the rat and the human heart, isoproterenol altered pathways for apoptosis/necrosis, stress/energy, inflammation, and remodeling/fibrosis. The rat and human heart slices were in anmore » apoptotic phase, while the in vivo rat heart exhibited necrosis histologically and further progression of tissue remodeling. In human heart slices genes for several heat shock 70 kD members were altered, indicative of stress to mitigate apoptosis. The stress response included alterations in energy utilization, fatty acid processing, and the up-regulation of inducible nitric oxide synthase, a marker of increased oxidative stress in both species. Inflammation markers linked with remodeling included IL-1α, Il-1β, IL-6 and TNFα in both species. Tissue remodeling changes in both species included increases in the TIMP proteins, inhibitors of matrix degradation, the gene/protein of IL-4 linked with cardiac fibrosis, and the gene Ccl7 a chemokine that induces collagen synthesis, and Reg3b a growth factor for cardiac repair. This study demonstrates that the initial human heart slice response to isoproterenol cardiac injury results in apoptosis, stress/energy status, inflammation and tissue remodeling at concentrations similar to that in rat heart slices. - Highlights: • Human response to isoproterenol induced cardiac injury evaluated in heart slices. • Isoproterenol altered apoptosis, energy, inflammation and remodeling pathways. • Human model verified by comparison to rat heart slices and rat heart in vivo. • Human and rat respond to isoproterenol at similar concentrations in vitro.« less

Cardiac Expression of ms1/STARS, a Novel Gene Involved in Cardiac Development and Disease, Is Regulated by GATA4

PubMed Central

Kobayashi, Satoru; Peterson, Richard E.; He, Aibin; Motterle, Anna; Samani, Nilesh J.; Menick, Donald R.; Pu, William T.; Liang, Qiangrong

2012-01-01

Ms1/STARS is a novel muscle-specific actin-binding protein that specifically modulates the myocardin-related transcription factor (MRTF)-serum response factor (SRF) regulatory axis within striated muscle. This ms1/STARS-dependent regulatory axis is of central importance within the cardiac gene regulatory network and has been implicated in cardiac development and postnatal cardiac function/homeostasis. The dysregulation of ms1/STARS is associated with and causative of pathological cardiac phenotypes, including cardiac hypertrophy and cardiomyopathy. In order to gain an understanding of the mechanisms governing ms1/STARS expression in the heart, we have coupled a comparative genomic in silico analysis with reporter, gain-of-function, and loss-of-function approaches. Through this integrated analysis, we have identified three evolutionarily conserved regions (ECRs), α, SINA, and DINA, that act as cis-regulatory modules and confer differential cardiac cell-specific activity. Two of these ECRs, α and DINA, displayed distinct regulatory sensitivity to the core cardiac transcription factor GATA4. Overall, our results demonstrate that within embryonic, neonatal, and adult hearts, GATA4 represses ms1/STARS expression with the pathologically associated depletion of GATA4 (type 1/type 2 diabetic models), resulting in ms1/STARS upregulation. This GATA4-dependent repression of ms1/STARS expression has major implications for MRTF-SRF signaling in the context of cardiac development and disease. PMID:22431517

Genome-wide computational analysis reveals cardiomyocyte-specific transcriptional Cis-regulatory motifs that enable efficient cardiac gene therapy.

PubMed

Rincon, Melvin Y; Sarcar, Shilpita; Danso-Abeam, Dina; Keyaerts, Marleen; Matrai, Janka; Samara-Kuko, Ermira; Acosta-Sanchez, Abel; Athanasopoulos, Takis; Dickson, George; Lahoutte, Tony; De Bleser, Pieter; VandenDriessche, Thierry; Chuah, Marinee K

2015-01-01

Gene therapy is a promising emerging therapeutic modality for the treatment of cardiovascular diseases and hereditary diseases that afflict the heart. Hence, there is a need to develop robust cardiac-specific expression modules that allow for stable expression of the gene of interest in cardiomyocytes. We therefore explored a new approach based on a genome-wide bioinformatics strategy that revealed novel cardiac-specific cis-acting regulatory modules (CS-CRMs). These transcriptional modules contained evolutionary-conserved clusters of putative transcription factor binding sites that correspond to a "molecular signature" associated with robust gene expression in the heart. We then validated these CS-CRMs in vivo using an adeno-associated viral vector serotype 9 that drives a reporter gene from a quintessential cardiac-specific α-myosin heavy chain promoter. Most de novo designed CS-CRMs resulted in a >10-fold increase in cardiac gene expression. The most robust CRMs enhanced cardiac-specific transcription 70- to 100-fold. Expression was sustained and restricted to cardiomyocytes. We then combined the most potent CS-CRM4 with a synthetic heart and muscle-specific promoter (SPc5-12) and obtained a significant 20-fold increase in cardiac gene expression compared to the cytomegalovirus promoter. This study underscores the potential of rational vector design to improve the robustness of cardiac gene therapy.

Analysis of the SWI/SNF chromatin-remodeling complex during early heart development and BAF250a repression cardiac gene transcription during P19 cell differentiation

PubMed Central

Singh, Ajeet Pratap; Archer, Trevor K.

2014-01-01

The regulatory networks of differentiation programs and the molecular mechanisms of lineage-specific gene regulation in mammalian embryos remain only partially defined. We document differential expression and temporal switching of BRG1-associated factor (BAF) subunits, core pluripotency factors and cardiac-specific genes during post-implantation development and subsequent early organogenesis. Using affinity purification of BRG1 ATPase coupled to mass spectrometry, we characterized the cardiac-enriched remodeling complexes present in E8.5 mouse embryos. The relative abundance and combinatorial assembly of the BAF subunits provides functional specificity to Switch/Sucrose NonFermentable (SWI/SNF) complexes resulting in a unique gene expression profile in the developing heart. Remarkably, the specific depletion of the BAF250a subunit demonstrated differential effects on cardiac-specific gene expression and resulted in arrhythmic contracting cardiomyocytes in vitro. Indeed, the BAF250a physically interacts and functionally cooperates with Nucleosome Remodeling and Histone Deacetylase (NURD) complex subunits to repressively regulate chromatin structure of the cardiac genes by switching open and poised chromatin marks associated with active and repressed gene expression. Finally, BAF250a expression modulates BRG1 occupancy at the loci of cardiac genes regulatory regions in P19 cell differentiation. These findings reveal specialized and novel cardiac-enriched SWI/SNF chromatin-remodeling complexes, which are required for heart formation and critical for cardiac gene expression regulation at the early stages of heart development. PMID:24335282

Murine T-box transcription factor Tbx20 acts as a repressor during heart development, and is essential for adult heart integrity, function and adaptation.

PubMed

Stennard, Fiona A; Costa, Mauro W; Lai, Donna; Biben, Christine; Furtado, Milena B; Solloway, Mark J; McCulley, David J; Leimena, Christiana; Preis, Jost I; Dunwoodie, Sally L; Elliott, David E; Prall, Owen W J; Black, Brian L; Fatkin, Diane; Harvey, Richard P

2005-05-01

The genetic hierarchies guiding lineage specification and morphogenesis of the mammalian embryonic heart are poorly understood. We now show by gene targeting that murine T-box transcription factor Tbx20 plays a central role in these pathways, and has important activities in both cardiac development and adult function. Loss of Tbx20 results in death of embryos at mid-gestation with grossly abnormal heart morphogenesis. Underlying these disturbances was a severely compromised cardiac transcriptional program, defects in the molecular pre-pattern, reduced expansion of cardiac progenitors and a block to chamber differentiation. Notably, Tbx20-null embryos showed ectopic activation of Tbx2 across the whole heart myogenic field. Tbx2 encodes a transcriptional repressor normally expressed in non-chamber myocardium, and in the atrioventricular canal it has been proposed to inhibit chamber-specific gene expression through competition with positive factor Tbx5. Our data demonstrate a repressive activity for Tbx20 and place it upstream of Tbx2 in the cardiac genetic program. Thus, hierarchical, repressive interactions between Tbx20 and other T-box genes and factors underlie the primary lineage split into chamber and non-chamber myocardium in the forming heart, an early event upon which all subsequent morphogenesis depends. Additional roles for Tbx20 in adult heart integrity and contractile function were revealed by in-vivo cardiac functional analysis of Tbx20 heterozygous mutant mice. These data suggest that mutations in human cardiac transcription factor genes, possibly including TBX20, underlie both congenital heart disease and adult cardiomyopathies.

Gene therapy to develop a genetically engineered cardiac pacemaker.

PubMed

Glenn, Christopher M; Pogwizd, Steven M

2003-01-01

While cardiac pacemakers are frequently used for the treatment of bradydysrhythmias (from diseases of the cardiac conduction system), their use is still limited by complications that can be life-threatening and expensive. Genetic engineering approaches offer an opportunity to modulate cellular automaticity in a manner that could have significant therapeutic potential. It is well known that ventricular myocytes exhibit a more negative diastolic potential than do pacemaker cells, in large part because of the inward rectifying potassium current/K1 (which pacemaker cells lack). Taking advantage of these intrinsic electrophysiological differences, a biological pacemaker has recently been developed by Miake et al (Nature 2002; 419:132-133) using adenoviral gene transfer approaches. By isolating the gene responsible for/K1 (the Kir2.1 gene), mutating it to make it a dysfunctional channel (a dominant-negative), inserting the mutated gene into an adenoviral vector, and delivering the virus to the hearts of guinea pigs, the investigators were able to successfully convert some ventricular myocytes to pacemaker cells. While issues of safety and long-term efficacy need to be further established, the results of these experiments provide proof of principle that gene transfer offers great promise for treatment of electrophysiological disorders including conduction system disease.

Design and testing of regulatory cassettes for optimal activity in skeletal and cardiac muscles.

PubMed

Himeda, Charis L; Chen, Xiaolan; Hauschka, Stephen D

2011-01-01

Gene therapy for muscular dystrophies requires efficient gene delivery to the striated musculature and specific, high-level expression of the therapeutic gene in a physiologically diverse array of muscles. This can be achieved by the use of recombinant adeno-associated virus vectors in conjunction with muscle-specific regulatory cassettes. We have constructed several generations of regulatory cassettes based on the enhancer and promoter of the muscle creatine kinase gene, some of which include heterologous enhancers and individual elements from other muscle genes. Since the relative importance of many control elements varies among different anatomical muscles, we are aiming to tailor these cassettes for high-level expression in cardiac muscle, and in fast and slow skeletal muscles. With the achievement of efficient intravascular gene delivery to isolated limbs, selected muscle groups, and heart in large animal models, the design of cassettes optimized for activity in different muscle types is now a practical goal. In this protocol, we outline the key steps involved in the design of regulatory cassettes for optimal activity in skeletal and cardiac muscle, and testing in mature muscle fiber cultures. The basic principles described here can also be applied to engineering tissue-specific regulatory cassettes for other cell types.

Forward Programming of Cardiac Stem Cells by Homogeneous Transduction with MYOCD plus TBX5

PubMed Central

Belian, Elisa; Noseda, Michela; Abreu Paiva, Marta S.; Leja, Thomas; Sampson, Robert; Schneider, Michael D.

2015-01-01

Adult cardiac stem cells (CSCs) express many endogenous cardiogenic transcription factors including members of the Gata, Hand, Mef2, and T-box family. Unlike its DNA-binding targets, Myocardin (Myocd)—a co-activator not only for serum response factor, but also for Gata4 and Tbx5—is not expressed in CSCs. We hypothesised that its absence was a limiting factor for reprogramming. Here, we sought to investigate the susceptibility of adult mouse Sca1+ side population CSCs to reprogramming by supplementing the triad of GATA4, MEF2C, and TBX5 (GMT), and more specifically by testing the effect of the missing co-activator, Myocd. Exogenous factors were expressed via doxycycline-inducible lentiviral vectors in various combinations. High throughput quantitative RT-PCR was used to test expression of 29 cardiac lineage markers two weeks post-induction. GMT induced more than half the analysed cardiac transcripts. However, no protein was detected for the induced sarcomeric genes Actc1, Myh6, and Myl2. Adding MYOCD to GMT affected only slightly the breadth and level of gene induction, but, importantly, triggered expression of all three proteins examined (α-cardiac actin, atrial natriuretic peptide, sarcomeric myosin heavy chains). MYOCD + TBX was the most effective pairwise combination in this system. In clonal derivatives homogenously expressing MYOCD + TBX at high levels, 93% of cardiac transcripts were up-regulated and all five proteins tested were visualized. In summary: (1) GMT induced cardiac genes in CSCs, but not cardiac proteins under the conditions used. (2) Complementing GMT with MYOCD induced cardiac protein expression, indicating a more complete cardiac differentiation program. (3) Homogeneous transduction with MYOCD + TBX5 facilitated the identification of differentiating cells and the validation of this combinatorial reprogramming strategy. Together, these results highlight the pivotal importance of MYOCD in driving CSCs toward a cardiac muscle fate. PMID:26047103

Forward Programming of Cardiac Stem Cells by Homogeneous Transduction with MYOCD plus TBX5.

PubMed

Belian, Elisa; Noseda, Michela; Abreu Paiva, Marta S; Leja, Thomas; Sampson, Robert; Schneider, Michael D

2015-01-01

Adult cardiac stem cells (CSCs) express many endogenous cardiogenic transcription factors including members of the Gata, Hand, Mef2, and T-box family. Unlike its DNA-binding targets, Myocardin (Myocd)-a co-activator not only for serum response factor, but also for Gata4 and Tbx5-is not expressed in CSCs. We hypothesised that its absence was a limiting factor for reprogramming. Here, we sought to investigate the susceptibility of adult mouse Sca1+ side population CSCs to reprogramming by supplementing the triad of GATA4, MEF2C, and TBX5 (GMT), and more specifically by testing the effect of the missing co-activator, Myocd. Exogenous factors were expressed via doxycycline-inducible lentiviral vectors in various combinations. High throughput quantitative RT-PCR was used to test expression of 29 cardiac lineage markers two weeks post-induction. GMT induced more than half the analysed cardiac transcripts. However, no protein was detected for the induced sarcomeric genes Actc1, Myh6, and Myl2. Adding MYOCD to GMT affected only slightly the breadth and level of gene induction, but, importantly, triggered expression of all three proteins examined (α-cardiac actin, atrial natriuretic peptide, sarcomeric myosin heavy chains). MYOCD + TBX was the most effective pairwise combination in this system. In clonal derivatives homogenously expressing MYOCD + TBX at high levels, 93% of cardiac transcripts were up-regulated and all five proteins tested were visualized. (1) GMT induced cardiac genes in CSCs, but not cardiac proteins under the conditions used. (2) Complementing GMT with MYOCD induced cardiac protein expression, indicating a more complete cardiac differentiation program. (3) Homogeneous transduction with MYOCD + TBX5 facilitated the identification of differentiating cells and the validation of this combinatorial reprogramming strategy. Together, these results highlight the pivotal importance of MYOCD in driving CSCs toward a cardiac muscle fate.

microRNA-133: expression, function and therapeutic potential in muscle diseases and cancer.

PubMed

Yu, Hao; Lu, Yinhui; Li, Zhaofa; Wang, Qizhao

2014-01-01

microRNAs (miRNAs) are a class of small non-coding RNAs that are 18-25 nucleotides (nt) in length and negatively regulate gene expression post-transcriptionally. miRNAs are known to mediate myriad processes and pathways. While many miRNAs are expressed ubiquitously, some are expressed in a tissue specific manner. miR-133 is one of the most studied and best characterized miRNAs to date. Specifically expressed in muscles, it has been classified as myomiRNAs and is necessary for proper skeletal and cardiac muscle development and function. Genes encoding miR-133 (miR-133a-1, miR-133a-2 and miR-133b) are transcribed as bicistronic transcripts together with miR-1-2, miR-1-1, and miR-206, respectively. However, they exhibit opposing impacts on muscle development. miR-133 gets involved in muscle development by targeting a lot of genes, including SFR, HDAC4, cyclin D2 and so on. Its aberrant expression has been linked to many diseases in skeletal muscle and cardiac muscle such as cardiac hypertrophy, muscular dystrophy, heart failure, cardiac arrhythmia. Beyond the study in muscle, miR-133 has been implicated in cancer and identified as a key factor in cancer development, including bladder cancer, prostate cancer and so on. Much more attention has been drawn to the versatile molecular functions of miR-133, making it a truly valuable therapeutic gene in miRNA-based gene therapy. In this review, we identified and summarized the results of studies of miR-133 with emphasis on its function in human diseases in muscle and cancer, and highlighted its therapeutic value. It might provide researchers a new insight into the biological significance of miR-133.

Chronomics of pressure overload-induced cardiac hypertrophy in mice reveals altered day/night gene expression and biomarkers of heart disease.

PubMed

Tsimakouridze, Elena V; Straume, Marty; Podobed, Peter S; Chin, Heather; LaMarre, Jonathan; Johnson, Ron; Antenos, Monica; Kirby, Gordon M; Mackay, Allison; Huether, Patsy; Simpson, Jeremy A; Sole, Michael; Gadal, Gerard; Martino, Tami A

2012-08-01

There is critical demand in contemporary medicine for gene expression markers in all areas of human disease, for early detection of disease, classification, prognosis, and response to therapy. The integrity of circadian gene expression underlies cardiovascular health and disease; however time-of-day profiling in heart disease has never been examined. We hypothesized that a time-of-day chronomic approach using samples collected across 24-h cycles and analyzed by microarrays and bioinformatics advances contemporary approaches, because it includes sleep-time and/or wake-time molecular responses. As proof of concept, we demonstrate the value of this approach in cardiovascular disease using a murine Transverse Aortic Constriction (TAC) model of pressure overload-induced cardiac hypertrophy in mice. First, microarrays and a novel algorithm termed DeltaGene were used to identify time-of-day differences in gene expression in cardiac hypertrophy 8 wks post-TAC. The top 300 candidates were further analyzed using knowledge-based platforms, paring the list to 20 candidates, which were then validated by real-time polymerase chain reaction (RTPCR). Next, we tested whether the time-of-day gene expression profiles could be indicative of disease progression by comparing the 1- vs. 8-wk TAC. Lastly, since protein expression is functionally relevant, we monitored time-of-day cycling for the analogous cardiac proteins. This approach is generally applicable and can lead to new understanding of disease.

Imaging approaches for the study of cell based cardiac therapies

PubMed Central

Lau, Joe F.; Anderson, Stasia A.; Adler, Eric; Frank, Joseph A.

2009-01-01

Despite promising preclinical data, the treatment of cardiovascular diseases using embryonic, bone-marrow-derived, and skeletal myoblast stem cells has not yet come to fruition within mainstream clinical practice. Major obstacles in cardiac stem cell investigations include the ability to monitor cell engraftment and survival following implantation within the myocardium. Several cellular imaging modalities, including reporter gene and MRI-based tracking approaches, have emerged that provide the means to identify, localize and monitor stem cells longitudinally in vivo following implantation. This Review will examine the various cardiac cellular tracking modalities, including the combinatorial use of several probes in multimodality imaging, with a focus on data from the last five years. PMID:20027188

Distinct gene-specific mechanisms of arrhythmia revealed by cardiac gene transfer of two long QT disease genes, HERG and KCNE1.

PubMed

Hoppe, U C; Marbán, E; Johns, D C

2001-04-24

The long QT syndrome (LQTS) is a heritable disorder that predisposes to sudden cardiac death. LQTS is caused by mutations in ion channel genes including HERG and KCNE1, but the precise mechanisms remain unclear. To clarify this situation we injected adenoviral vectors expressing wild-type or LQT mutants of HERG and KCNE1 into guinea pig myocardium. End points at 48-72 h included electrophysiology in isolated myocytes and electrocardiography in vivo. HERG increased the rapid component, I(Kr), of the delayed rectifier current, thereby accelerating repolarization, increasing refractoriness, and diminishing beat-to-beat action potential variability. Conversely, HERG-G628S suppressed I(Kr) without significantly delaying repolarization. Nevertheless, HERG-G628S abbreviated refractoriness and increased beat-to-beat variability, leading to early afterdepolarizations (EADs). KCNE1 increased the slow component of the delayed rectifier, I(Ks), without clear phenotypic sequelae. In contrast, KCNE1-D76N suppressed I(Ks) and markedly slowed repolarization, leading to frequent EADs and electrocardiographic QT prolongation. Thus, the two genes predispose to sudden death by distinct mechanisms: the KCNE1 mutant flagrantly undermines cardiac repolarization, and HERG-G628S subtly facilitates the genesis and propagation of premature beats. Our ability to produce electrocardiographic long QT in vivo with a clinical KCNE1 mutation demonstrates the utility of somatic gene transfer in creating genotype-specific disease models.

Perspective on Adeno-Associated Virus Capsid Modification for Duchenne Muscular Dystrophy Gene Therapy.

PubMed

Nance, Michael E; Duan, Dongsheng

2015-12-01

Duchenne muscular dystrophy (DMD) is a X-linked, progressive childhood myopathy caused by mutations in the dystrophin gene, one of the largest genes in the genome. It is characterized by skeletal and cardiac muscle degeneration and dysfunction leading to cardiac and/or respiratory failure. Adeno-associated virus (AAV) is a highly promising gene therapy vector. AAV gene therapy has resulted in unprecedented clinical success for treating several inherited diseases. However, AAV gene therapy for DMD remains a significant challenge. Hurdles for AAV-mediated DMD gene therapy include the difficulty to package the full-length dystrophin coding sequence in an AAV vector, the necessity for whole-body gene delivery, the immune response to dystrophin and AAV capsid, and the species-specific barriers to translate from animal models to human patients. Capsid engineering aims at improving viral vector properties by rational design and/or forced evolution. In this review, we discuss how to use the state-of-the-art AAV capsid engineering technologies to overcome hurdles in AAV-based DMD gene therapy.

Improving Interpretation of Cardiac Phenotypes and Enhancing Discovery With Expanded Knowledge in the Gene Ontology

PubMed Central

Roncaglia, Paola; Howe, Douglas G.; Laulederkind, Stanley J.F.; Khodiyar, Varsha K.; Berardini, Tanya Z.; Tweedie, Susan; Foulger, Rebecca E.; Osumi-Sutherland, David; Campbell, Nancy H.; Huntley, Rachael P.; Talmud, Philippa J.; Blake, Judith A.; Breckenridge, Ross; Riley, Paul R.; Lambiase, Pier D.; Elliott, Perry M.; Clapp, Lucie; Tinker, Andrew; Hill, David P.

2018-01-01

Background: A systems biology approach to cardiac physiology requires a comprehensive representation of how coordinated processes operate in the heart, as well as the ability to interpret relevant transcriptomic and proteomic experiments. The Gene Ontology (GO) Consortium provides structured, controlled vocabularies of biological terms that can be used to summarize and analyze functional knowledge for gene products. Methods and Results: In this study, we created a computational resource to facilitate genetic studies of cardiac physiology by integrating literature curation with attention to an improved and expanded ontological representation of heart processes in the Gene Ontology. As a result, the Gene Ontology now contains terms that comprehensively describe the roles of proteins in cardiac muscle cell action potential, electrical coupling, and the transmission of the electrical impulse from the sinoatrial node to the ventricles. Evaluating the effectiveness of this approach to inform data analysis demonstrated that Gene Ontology annotations, analyzed within an expanded ontological context of heart processes, can help to identify candidate genes associated with arrhythmic disease risk loci. Conclusions: We determined that a combination of curation and ontology development for heart-specific genes and processes supports the identification and downstream analysis of genes responsible for the spread of the cardiac action potential through the heart. Annotating these genes and processes in a structured format facilitates data analysis and supports effective retrieval of gene-centric information about cardiac defects. PMID:29440116

Improving Interpretation of Cardiac Phenotypes and Enhancing Discovery With Expanded Knowledge in the Gene Ontology.

PubMed

Lovering, Ruth C; Roncaglia, Paola; Howe, Douglas G; Laulederkind, Stanley J F; Khodiyar, Varsha K; Berardini, Tanya Z; Tweedie, Susan; Foulger, Rebecca E; Osumi-Sutherland, David; Campbell, Nancy H; Huntley, Rachael P; Talmud, Philippa J; Blake, Judith A; Breckenridge, Ross; Riley, Paul R; Lambiase, Pier D; Elliott, Perry M; Clapp, Lucie; Tinker, Andrew; Hill, David P

2018-02-01

A systems biology approach to cardiac physiology requires a comprehensive representation of how coordinated processes operate in the heart, as well as the ability to interpret relevant transcriptomic and proteomic experiments. The Gene Ontology (GO) Consortium provides structured, controlled vocabularies of biological terms that can be used to summarize and analyze functional knowledge for gene products. In this study, we created a computational resource to facilitate genetic studies of cardiac physiology by integrating literature curation with attention to an improved and expanded ontological representation of heart processes in the Gene Ontology. As a result, the Gene Ontology now contains terms that comprehensively describe the roles of proteins in cardiac muscle cell action potential, electrical coupling, and the transmission of the electrical impulse from the sinoatrial node to the ventricles. Evaluating the effectiveness of this approach to inform data analysis demonstrated that Gene Ontology annotations, analyzed within an expanded ontological context of heart processes, can help to identify candidate genes associated with arrhythmic disease risk loci. We determined that a combination of curation and ontology development for heart-specific genes and processes supports the identification and downstream analysis of genes responsible for the spread of the cardiac action potential through the heart. Annotating these genes and processes in a structured format facilitates data analysis and supports effective retrieval of gene-centric information about cardiac defects. © 2018 The Authors.

Elimination of remaining undifferentiated induced pluripotent stem cells in the process of human cardiac cell sheet fabrication using a methionine-free culture condition.

PubMed

Matsuura, Katsuhisa; Kodama, Fumiko; Sugiyama, Kasumi; Shimizu, Tatsuya; Hagiwara, Nobuhisa; Okano, Teruo

2015-03-01

Cardiac tissue engineering is a promising method for regenerative medicine. Although we have developed human cardiac cell sheets by integration of cell sheet-based tissue engineering and scalable bioreactor culture, the risk of contamination by induced pluripotent stem (iPS) cells in cardiac cell sheets remains unresolved. In the present study, we established a novel culture method to fabricate human cardiac cell sheets with a decreased risk of iPS cell contamination while maintaining viabilities of iPS cell-derived cells, including cardiomyocytes and fibroblasts, using a methionine-free culture condition. When cultured in the methionine-free condition, human iPS cells did not survive without feeder cells and could not proliferate or form colonies on feeder cells or in coculture with cells for cardiac cell sheet fabrication. When iPS cell-derived cells after the cardiac differentiation were transiently cultured in the methionine-free condition, gene expression of OCT3/4 and NANOG was downregulated significantly compared with that in the standard culture condition. Furthermore, in fabricated cardiac cell sheets, spontaneous and synchronous beating was observed in the whole area while maintaining or upregulating the expression of various cardiac and extracellular matrix genes. These findings suggest that human iPS cells are methionine dependent and a methionine-free culture condition for cardiac cell sheet fabrication might reduce the risk of iPS cell contamination.

Pregnancy as a cardiac stress model

PubMed Central

Chung, Eunhee; Leinwand, Leslie A.

2014-01-01

Cardiac hypertrophy occurs during pregnancy as a consequence of both volume overload and hormonal changes. Both pregnancy- and exercise-induced cardiac hypertrophy are generally thought to be similar and physiological. Despite the fact that there are shared transcriptional responses in both forms of cardiac adaptation, pregnancy results in a distinct signature of gene expression in the heart. In some cases, however, pregnancy can induce adverse cardiac events in previously healthy women without any known cardiovascular disease. Peripartum cardiomyopathy is the leading cause of non-obstetric mortality during pregnancy. To understand how pregnancy can cause heart disease, it is first important to understand cardiac adaptation during normal pregnancy. This review provides an overview of the cardiac consequences of pregnancy, including haemodynamic, functional, structural, and morphological adaptations, as well as molecular phenotypes. In addition, this review describes the signalling pathways responsible for pregnancy-induced cardiac hypertrophy and angiogenesis. We also compare and contrast cardiac adaptation in response to disease, exercise, and pregnancy. The comparisons of these settings of cardiac hypertrophy provide insight into pregnancy-associated cardiac adaptation. PMID:24448313

Endothelial Bmx tyrosine kinase activity is essential for myocardial hypertrophy and remodeling

PubMed Central

Holopainen, Tanja; Räsänen, Markus; Anisimov, Andrey; Tuomainen, Tomi; Zheng, Wei; Tvorogov, Denis; Hulmi, Juha J.; Andersson, Leif C.; Cenni, Bruno; Tavi, Pasi; Mervaala, Eero; Kivelä, Riikka; Alitalo, Kari

2015-01-01

Cardiac hypertrophy accompanies many forms of heart disease, including ischemic disease, hypertension, heart failure, and valvular disease, and it is a strong predictor of increased cardiovascular morbidity and mortality. Deletion of bone marrow kinase in chromosome X (Bmx), an arterial nonreceptor tyrosine kinase, has been shown to inhibit cardiac hypertrophy in mice. This finding raised the possibility of therapeutic use of Bmx tyrosine kinase inhibitors, which we have addressed here by analyzing cardiac hypertrophy in gene-targeted mice deficient in Bmx tyrosine kinase activity. We found that angiotensin II (Ang II)-induced cardiac hypertrophy is significantly reduced in mice deficient in Bmx and in mice with inactivated Bmx tyrosine kinase compared with WT mice. Genome-wide transcriptomic profiling showed that Bmx inactivation suppresses myocardial expression of genes related to Ang II-induced inflammatory and extracellular matrix responses whereas expression of RNAs encoding mitochondrial proteins after Ang II administration was maintained in Bmx-inactivated hearts. Very little or no Bmx mRNA was expressed in human cardiomyocytes whereas human cardiac endothelial cells expressed abundant amounts. Ang II stimulation of endothelial cells increased Bmx phosphorylation, and Bmx gene silencing inhibited downstream STAT3 signaling, which has been implicated in cardiac hypertrophy. Furthermore, activation of the mechanistic target of rapamycin complex 1 pathway by Ang II treatment was decreased in the Bmx-deficient hearts. Our results demonstrate that inhibition of the cross-talk between endothelial cells and cardiomyocytes by Bmx inactivation suppresses Ang II-induced signals for cardiac hypertrophy. These results suggest that the endothelial Bmx tyrosine kinase could provide a target to attenuate the development of cardiac hypertrophy. PMID:26430242

Cardiac Niche Influences the Direct Reprogramming of Canine Fibroblasts into Cardiomyocyte-Like Cells

PubMed Central

Palazzolo, Giacomo; Quattrocelli, Mattia; Toelen, Jaan; Dominici, Roberto; Tettamenti, Guido; Barthelemy, Inès; Blot, Stephane; Gijsbers, Rik; Cassano, Marco

2016-01-01

The Duchenne and Becker muscular dystrophies are caused by mutation of dystrophin gene and primarily affect skeletal and cardiac muscles. Cardiac involvement in dystrophic GRMD dogs has been demonstrated by electrocardiographic studies with the onset of a progressive cardiomyopathy similar to the cardiac disease in DMD patients. In this respect, GRMD is a useful model to explore cardiac and skeletal muscle pathogenesis and for developing new therapeutic protocols. Here we describe a protocol to convert GRMD canine fibroblasts isolated from heart and skin into induced cardiac-like myocytes (ciCLMs). We used a mix of transcription factors (GATA4, HAND2, TBX5, and MEF2C), known to be able to differentiate mouse and human somatic cells into ciCLMs. Exogenous gene expression was obtained using four lentiviral vectors carrying transcription factor genes and different resistance genes. Our data demonstrate a direct switch from fibroblast into ciCLMs with no activation of early cardiac genes. ciCLMs were unable to contract spontaneously, suggesting, differently from mouse and human cells, an incomplete differentiation process. However, when transplanted in neonatal hearts of SCID/Beige mice, ciCLMs participate in cardiac myogenesis. PMID:26681949

Cardiac Niche Influences the Direct Reprogramming of Canine Fibroblasts into Cardiomyocyte-Like Cells.

PubMed

Palazzolo, Giacomo; Quattrocelli, Mattia; Toelen, Jaan; Dominici, Roberto; Anastasia, Luigi; Tettamenti, Guido; Barthelemy, Inès; Blot, Stephane; Gijsbers, Rik; Cassano, Marco; Sampaolesi, Maurilio

2016-01-01

The Duchenne and Becker muscular dystrophies are caused by mutation of dystrophin gene and primarily affect skeletal and cardiac muscles. Cardiac involvement in dystrophic GRMD dogs has been demonstrated by electrocardiographic studies with the onset of a progressive cardiomyopathy similar to the cardiac disease in DMD patients. In this respect, GRMD is a useful model to explore cardiac and skeletal muscle pathogenesis and for developing new therapeutic protocols. Here we describe a protocol to convert GRMD canine fibroblasts isolated from heart and skin into induced cardiac-like myocytes (ciCLMs). We used a mix of transcription factors (GATA4, HAND2, TBX5, and MEF2C), known to be able to differentiate mouse and human somatic cells into ciCLMs. Exogenous gene expression was obtained using four lentiviral vectors carrying transcription factor genes and different resistance genes. Our data demonstrate a direct switch from fibroblast into ciCLMs with no activation of early cardiac genes. ciCLMs were unable to contract spontaneously, suggesting, differently from mouse and human cells, an incomplete differentiation process. However, when transplanted in neonatal hearts of SCID/Beige mice, ciCLMs participate in cardiac myogenesis.

Transgenic over-expression of YY1 induces pathologic cardiac hypertrophy in a sex-specific manner

PubMed Central

Stauffer, Brian L.; Dockstader, Karen; Russell, Gloria; Hijmans, Jamie; Walker, Lisa; Cecil, Mackenzie; Demos-Davies, Kimberly; Medway, Allen; McKinsey, Timothy A.; Sucharov, Carmen C.

2015-01-01

YY1 can activate or repress transcription of various genes. In cardiac myocytes in culture YY1 has been shown to regulate expression of several genes involved in myocyte pathology. YY1 can also acutely protect the heart against detrimental changes in gene expression. In this study we show that cardiac over-expression of YY1 induces pathologic cardiac hypertrophy in male mice, measured by changes in gene expression and lower ejection fraction/fractional shortening. In contrast, female animals are protected against pathologic gene expression changes and cardiac dysfunction. Furthermore, we show that YY1 regulates, in a sex-specific manner, the expression of mammalian enable (Mena), a factor that regulates cytoskeletal actin dynamics and whose expression is increased in several models of cardiac pathology, and that Mena expression in humans with heart failure is sex-dependent. Finally, we show that sex differences in YY1 expression are also observed in human heart failure. In summary, this is the first work to show that YY1 has a sex-specific effect in the regulation of cardiac pathology. PMID:25935483

Cell differentiation in cardiac myxomas: confocal microscopy and gene expression analysis after laser capture microdissection.

PubMed

Pucci, Angela; Mattioli, Claudia; Matteucci, Marco; Lorenzini, Daniele; Panvini, Francesca; Pacini, Simone; Ippolito, Chiara; Celiento, Michele; De Martino, Andrea; Dolfi, Amelio; Belgio, Beatrice; Bortolotti, Uberto; Basolo, Fulvio; Bartoloni, Giovanni

2018-05-22

Cardiac myxomas are rare tumors with a heterogeneous cell population including properly neoplastic (lepidic), endothelial and smooth muscle cells. The assessment of neoplastic (lepidic) cell differentiation pattern is rather difficult using conventional light microscopy immunohistochemistry and/or whole tissue extracts for mRNA analyses. In a preliminary study, we investigated 20 formalin-fixed and paraffin-embedded cardiac myxomas by means of conventional immunohistochemistry; in 10/20 cases, cell differentiation was also analyzed by real-time RT-PCR after laser capture microdissection of the neoplastic cells, whereas calretinin and endothelial antigen CD31 immunoreactivity was localized in 4/10 cases by double immunofluorescence confocal microscopy. Gene expression analyses of α-smooth muscle actin, endothelial CD31 antigen, alpha-cardiac actin, matrix metalloprotease-2 (MMP2) and tissue inhibitor of matrix metalloprotease-1 (TIMP1) was performed on cDNA obtained from either microdissected neoplastic cells or whole tumor sections. We found very little or absent CD31 and α-Smooth Muscle Actin expression in the microdissected cells as compared to the whole tumors, whereas TIMP1 and MMP2 genes were highly expressed in both ones, greater levels being found in patients with embolic phenomena. α-Cardiac Actin was not detected. Confocal microscopy disclosed two different signals corresponding to calretinin-positive myxoma cells and to endothelial CD31-positive cells, respectively. In conclusion, the neoplastic (lepidic) cells showed a distinct gene expression pattern and no consistent overlapping with endothelial and smooth muscle cells or cardiac myocytes; the expression of TIMP1 and MMP2 might be related to clinical presentation; larger series studies using also systematic transcriptome analysis might be useful to confirm the present results.

Postnatal Ablation of Foxm1 from Cardiomyocytes Causes Late Onset Cardiac Hypertrophy and Fibrosis without Exacerbating Pressure Overload-Induced Cardiac Remodeling

PubMed Central

Bolte, Craig; Zhang, Yufang; York, Allen; Kalin, Tanya V.; Schultz, Jo El J.; Molkentin, Jeffery D.; Kalinichenko, Vladimir V.

2012-01-01

Heart disease remains a leading cause of morbidity and mortality in the industrialized world. Hypertrophic cardiomyopathy is the most common genetic cardiovascular disorder and the most common cause of sudden cardiac death. Foxm1 transcription factor (also known as HFH-11B, Trident, Win or MPP2) plays an important role in the pathogenesis of various cancers and is a critical mediator of post-injury repair in multiple organs. Foxm1 has been previously shown to be essential for heart development and proliferation of embryonic cardiomyocytes. However, the role of Foxm1 in postnatal heart development and in cardiac injury has not been evaluated. To delete Foxm1 in postnatal cardiomyocytes, αMHC-Cre/Foxm1fl/fl mice were generated. Surprisingly, αMHC-Cre/Foxm1fl/fl mice exhibited normal cardiomyocyte proliferation at postnatal day seven and had no defects in cardiac structure or function but developed cardiac hypertrophy and fibrosis late in life. The development of cardiomyocyte hypertrophy and cardiac fibrosis in aged Foxm1-deficient mice was associated with reduced expression of Hey2, an important regulator of cardiac homeostasis, and increased expression of genes critical for cardiac remodeling, including MMP9, αSMA, fibronectin and vimentin. We also found that following aortic constriction Foxm1 mRNA and protein were induced in cardiomyocytes. However, Foxm1 deletion did not exacerbate cardiac hypertrophy or fibrosis following chronic pressure overload. Our results demonstrate that Foxm1 regulates genes critical for age-induced cardiomyocyte hypertrophy and cardiac fibrosis. PMID:23144938

Substance P acting via the neurokinin-1 receptor regulates adverse myocardial remodeling in a rat model of hypertension

PubMed Central

Dehlin, Heather M.; Manteufel, Edward J.; Monroe, Andrew L.; Reimer, Michael H.; Levick, Scott P.

2013-01-01

Background Substance P is a sensory nerve neuropeptide located near coronary vessels in the heart. Therefore, substance P may be one of the first mediators released in the heart in response to hypertension, and can contribute to adverse myocardial remodeling via interactions with the neurokinin-1 receptor. We asked: 1) whether substance P promoted cardiac hypertrophy, including the expression of fetal genes known to be re-expressed during pathological hypertrophy; and 2) the extent to which substance P regulated collagen production and fibrosis. Methods and Results Spontaneously hypertensive rats (SHR) were treated with the neurokinin-1 receptor antagonist L732138 (5 mg/kg/d) from 8 to 24 weeks of age. Age-matched WKY served as controls. The gene encoding substance P, TAC1, was up-regulated as blood pressure increased in SHR. Fetal gene expression by cardiomyocytes was increased in SHR and was prevented by L732138. Cardiac fibrosis also occurred in the SHR and was prevented by L732138. Endothelin-1 was up-regulated in the SHR and this was prevented by L732138. In isolated cardiac fibroblasts, substance P transiently up-regulated several genes related to cell-cell adhesion, cell-matrix adhesion, and extracellular matrix regulation, however, no changes in fibroblast function were observed. Conclusions Substance P activation of the neurokinin-1 receptor induced expression of fetal genes related to pathological hypertrophy in the hypertensive heart. Additionally, activation of the neurokinin-1 receptor was critical to the development of cardiac fibrosis. Since no functional changes were induced in isolated cardiac fibroblasts by substance P, we conclude that substance P mediates fibrosis via up-regulation of endothelin-1. PMID:23962787

Decoding the Long Noncoding RNA During Cardiac Maturation: A Roadmap for Functional Discovery.

PubMed

Touma, Marlin; Kang, Xuedong; Zhao, Yan; Cass, Ashley A; Gao, Fuying; Biniwale, Reshma; Coppola, Giovanni; Xiao, Xinshu; Reemtsen, Brian; Wang, Yibin

2016-10-01

Cardiac maturation during perinatal transition of heart is critical for functional adaptation to hemodynamic load and nutrient environment. Perturbation in this process has major implications in congenital heart defects. Transcriptome programming during perinatal stages is an important information but incomplete in current literature, particularly, the expression profiles of the long noncoding RNAs (lncRNAs) are not fully elucidated. From comprehensive analysis of transcriptomes derived from neonatal mouse heart left and right ventricles, a total of 45 167 unique transcripts were identified, including 21 916 known and 2033 novel lncRNAs. Among these lncRNAs, 196 exhibited significant dynamic regulation along maturation process. By implementing parallel weighted gene co-expression network analysis of mRNA and lncRNA data sets, several lncRNA modules coordinately expressed in a developmental manner similar to protein coding genes, while few lncRNAs revealed chamber-specific patterns. Out of 2262 lncRNAs located within 50 kb of protein coding genes, 5% significantly correlate with the expression of their neighboring genes. The impact of Ppp1r1b-lncRNA on the corresponding partner gene Tcap was validated in cultured myoblasts. This concordant regulation was also conserved in human infantile hearts. Furthermore, the Ppp1r1b-lncRNA/Tcap expression ratio was identified as a molecular signature that differentiated congenital heart defect phenotypes. The study provides the first high-resolution landscape on neonatal cardiac lncRNAs and reveals their potential interaction with mRNA transcriptome during cardiac maturation. Ppp1r1b-lncRNA was identified as a regulator of Tcap expression, with dynamic interaction in postnatal cardiac development and congenital heart defects. © 2016 American Heart Association, Inc.

Cardiac manifestations of congenital LMNA-related muscular dystrophy in children: three case reports and recommendations for care.

PubMed

Heller, Felice; Dabaj, Ivana; Mah, Jean K; Bergounioux, Jean; Essid, Aben; Bönnemann, Carsten G; Rutkowski, Anne; Bonne, Gisèle; Quijano-Roy, Susana; Wahbi, Karim

2017-08-01

Skeletal and cardiac muscle laminopathies, caused by mutations in the lamin A/C gene, have a clinical spectrum from congenital LMNA-related muscular dystrophy to later-onset Emery-Dreifuss muscular dystrophy, limb girdle muscular dystrophy, and dilated cardiomyopathy. Although cardiac involvement is observed at all ages, it has only been well described in adults. We present the evolution of cardiac disease in three children with congenital muscular dystrophy presentation of LMNA-related muscular dystrophy. In this series, atrial arrhythmia was the presenting cardiac finding in all three patients. Heart failure developed up to 5 years later. Symptoms of right heart failure, including diarrhoea and peripheral oedema, preceded a rapid decline in left ventricular ejection fraction. Recommendations for cardiac surveillance and management in these patients are made.

Caffeine exposure alters cardiac gene expression in embryonic cardiomyocytes

PubMed Central

Fang, Xiefan; Mei, Wenbin; Barbazuk, William B.; Rivkees, Scott A.

2014-01-01

Previous studies demonstrated that in utero caffeine treatment at embryonic day (E) 8.5 alters DNA methylation patterns, gene expression, and cardiac function in adult mice. To provide insight into the mechanisms, we examined cardiac gene and microRNA (miRNA) expression in cardiomyocytes shortly after exposure to physiologically relevant doses of caffeine. In HL-1 and primary embryonic cardiomyocytes, caffeine treatment for 48 h significantly altered the expression of cardiac structural genes (Myh6, Myh7, Myh7b, Tnni3), hormonal genes (Anp and BnP), cardiac transcription factors (Gata4, Mef2c, Mef2d, Nfatc1), and microRNAs (miRNAs; miR208a, miR208b, miR499). In addition, expressions of these genes were significantly altered in embryonic hearts exposed to in utero caffeine. For in utero experiments, pregnant CD-1 dams were treated with 20–60 mg/kg of caffeine, which resulted in maternal circulation levels of 37.3–65.3 μM 2 h after treatment. RNA sequencing was performed on embryonic ventricles treated with vehicle or 20 mg/kg of caffeine daily from E6.5-9.5. Differential expression (DE) analysis revealed that 124 genes and 849 transcripts were significantly altered, and differential exon usage (DEU) analysis identified 597 exons that were changed in response to prenatal caffeine exposure. Among the DE genes identified by RNA sequencing were several cardiac structural genes and genes that control DNA methylation and histone modification. Pathway analysis revealed that pathways related to cardiovascular development and diseases were significantly affected by caffeine. In addition, global cardiac DNA methylation was reduced in caffeine-treated cardiomyocytes. Collectively, these data demonstrate that caffeine exposure alters gene expression and DNA methylation in embryonic cardiomyocytes. PMID:25354728

Genetic engineering and therapy for inherited and acquired cardiomyopathies.

PubMed

Day, Sharlene; Davis, Jennifer; Westfall, Margaret; Metzger, Joseph

2006-10-01

The cardiac myofilaments consist of a highly ordered assembly of proteins that collectively generate force in a calcium-dependent manner. Defects in myofilament function and its regulation have been implicated in various forms of acquired and inherited human heart disease. For example, during cardiac ischemia, cardiac myocyte contractile performance is dramatically downregulated due in part to a reduced sensitivity of the myofilaments to calcium under acidic pH conditions. Over the last several years, the thin filament regulatory protein, troponin I, has been identified as an important mediator of this response. Mutations in troponin I and other sarcomere genes are also linked to several distinct inherited cardiomyopathic phenotypes, including hypertrophic, dilated, and restrictive cardiomyopathies. With the cardiac sarcomere emerging as a central player for such a diverse array of human heart diseases, genetic-based strategies that target the myofilament will likely have broad therapeutic potential. The development of safe vector systems for efficient gene delivery will be a critical hurdle to overcome before these types of therapies can be successfully applied. Nonetheless, studies focusing on the principles of acute genetic engineering of the sarcomere hold value as they lay the essential foundation on which to build potential gene-based therapies for heart disease.

Expression of homeobox genes Msx-1 (Hox-7) and Msx-2 (Hox-8) during cardiac development in the chick.

PubMed

Chan-Thomas, P S; Thompson, R P; Robert, B; Yacoub, M H; Barton, P J

1993-07-01

The vertebrate homeobox genes Msx-1 and Msx-2 are related to the Drosophila msh gene and are expressed in a variety of tissues during embryogenesis. We have examined their expression by in situ hybridisation during critical stages of cardiac development in the chick from stages 15+ to 37. Msx-1 expression is apparent in a number of non-myocardial cell populations, including cells undergoing an epithelial to mesenchymal transformation in the atrioventricular and the outflow tract regions that play an integral role in heart septation and valve formation. Msx-2 expression is restricted to a distinct subpopulation of myocardial cells that, in later stages, coincides morphologically with the cardiac conduction system. The timing of Msx-2 expression suggests that it plays a role in conduction system tissue formation and that it identifies precursor cells of this specialised myocardium. The pattern of Msx-2 expression is discussed with reference to current models of conduction tissue development.

Prenatal diagnosis of two fetuses with deletions of 8p23.1, critical region for congenital diaphragmatic hernia and heart defects.

PubMed

Keitges, Elisabeth A; Pasion, Romela; Burnside, Rachel D; Mason, Carla; Gonzalez-Ruiz, Antonio; Dunn, Teresa; Masiello, Meredith; Gebbia, Joseph A; Fernandez, Carlos O; Risheg, Hiba

2013-07-01

Microdeletions of 8p23.1 are mediated by low copy repeats and can cause congenital diaphragmatic hernia (CDH) and cardiac defects. Within this region, point mutations of the GATA4 gene have been shown to cause cardiac defects. However, the cause of CDH in these deletions has been difficult to determine due to the paucity of mutations that result in CDH, the lack of smaller deletions to refine the region and the reduced penetrance of CDH in these large deletions. Mice deficient for one copy of the Gata4 gene have been described with CDH and heart defects suggesting mutations in Gata4 can cause the phenotype in mice. We report on the SNP microarray analysis on two fetuses with deletions of 8p23.1. The first had CDH and a ventricular septal defect (VSD) on ultrasonography and a family history of a maternal VSD. Microarray analysis detected a 127-kb deletion which included the GATA4 and NEIL2 genes which was inherited from the mother. The second fetus had an incomplete atrioventricular canal defect on ultrasonography. Microarray analysis showed a 315-kb deletion that included seven genes, GATA4, NEIL2, FDFT1, CTSB, DEFB136, DEFB135, and DEFB134. These results suggest that haploinsufficiency of the two genes in common within 8p23.1; GATA4 and NEIL2 can cause CDH and cardiac defects in humans. Copyright © 2013 Wiley Periodicals, Inc.

Arrhythmogenic KCNE gene variants: current knowledge and future challenges

PubMed Central

Crump, Shawn M.; Abbott, Geoffrey W.

2014-01-01

There are twenty-five known inherited cardiac arrhythmia susceptibility genes, all of which encode either ion channel pore-forming subunits or proteins that regulate aspects of ion channel biology such as function, trafficking, and localization. The human KCNE gene family comprises five potassium channel regulatory subunits, sequence variants in each of which are associated with cardiac arrhythmias. KCNE gene products exhibit promiscuous partnering and in some cases ubiquitous expression, hampering efforts to unequivocally correlate each gene to specific native potassium currents. Likewise, deducing the molecular etiology of cardiac arrhythmias in individuals harboring rare KCNE gene variants, or more common KCNE polymorphisms, can be challenging. In this review we provide an update on putative arrhythmia-causing KCNE gene variants, and discuss current thinking and future challenges in the study of molecular mechanisms of KCNE-associated cardiac rhythm disturbances. PMID:24478792

Histone deacetylase inhibitor, CG200745, attenuates cardiac hypertrophy and fibrosis in DOCA-induced hypertensive rats

PubMed Central

Lee, Eunjo; Song, Min-ji; Lee, Hae-Ahm; Kang, Seol-Hee; Kim, Mina; Yang, Eun Kyoung; Lee, Do Young; Ro, Seonggu; Cho, Joong Myung

2016-01-01

CG200745 is a novel inhibitor of histone deacetylases (HDACs), initially developed for treatment of various hematological and solid cancers. Because it is water-soluble, it can be administered orally. We hypothesized that the HDAC inhibitor, CG200745, attenuates cardiac hypertrophy and fibrosis in deoxycorticosterone acetate (DOCA)-induced hypertensive rats. For establishment of hypertension, 40 mg/kg of DOCA was subcutaneously injected four times weekly into Sprague-Dawley rats. All the rats used in this study including those in the sham group had been unilaterally nephrectomized and allowed free access to drinking water containing 1% NaCl. Systolic blood pressure was measured by the tail-cuff method. Blood chemistry including sodium, potassium, glucose, triglyceride, and cholesterol levels was analyzed. Sections of the heart were visualized after trichrome and hematoxylin and eosin stain. The expression of hypertrophic genes such as atrial natriuretic peptide A (Nppa) and atrial natriuretic peptide B (Nppb) in addition to fibrotic genes such as Collagen-1, Collagen-3, connective tissue growth factor (Ctgf), and Fibronectin were measured by quantitative real-time PCR (qRT-PCR). Injection of DOCA increased systolic blood pressure, heart weight, and cardiac fibrosis, which was attenuated by CG200745. Neither DOCA nor CG200745 affected body weight, vascular contraction and relaxation responses, and blood chemistry. Injection of DOCA increased expression of both hypertrophic and fibrotic genes, which was abrogated by CG200745. These results indicate that CG200745 attenuates cardiac hypertrophy and fibrosis in DOCA-induced hypertensive rats. PMID:27610034

Histone deacetylase inhibitor, CG200745, attenuates cardiac hypertrophy and fibrosis in DOCA-induced hypertensive rats.

PubMed

Lee, Eunjo; Song, Min-Ji; Lee, Hae-Ahm; Kang, Seol-Hee; Kim, Mina; Yang, Eun Kyoung; Lee, Do Young; Ro, Seonggu; Cho, Joong Myung; Kim, Inkyeom

2016-09-01

CG200745 is a novel inhibitor of histone deacetylases (HDACs), initially developed for treatment of various hematological and solid cancers. Because it is water-soluble, it can be administered orally. We hypothesized that the HDAC inhibitor, CG200745, attenuates cardiac hypertrophy and fibrosis in deoxycorticosterone acetate (DOCA)-induced hypertensive rats. For establishment of hypertension, 40 mg/kg of DOCA was subcutaneously injected four times weekly into Sprague-Dawley rats. All the rats used in this study including those in the sham group had been unilaterally nephrectomized and allowed free access to drinking water containing 1% NaCl. Systolic blood pressure was measured by the tail-cuff method. Blood chemistry including sodium, potassium, glucose, triglyceride, and cholesterol levels was analyzed. Sections of the heart were visualized after trichrome and hematoxylin and eosin stain. The expression of hypertrophic genes such as atrial natriuretic peptide A (Nppa) and atrial natriuretic peptide B (Nppb) in addition to fibrotic genes such as Collagen-1, Collagen-3, connective tissue growth factor (Ctgf), and Fibronectin were measured by quantitative real-time PCR (qRT-PCR). Injection of DOCA increased systolic blood pressure, heart weight, and cardiac fibrosis, which was attenuated by CG200745. Neither DOCA nor CG200745 affected body weight, vascular contraction and relaxation responses, and blood chemistry. Injection of DOCA increased expression of both hypertrophic and fibrotic genes, which was abrogated by CG200745. These results indicate that CG200745 attenuates cardiac hypertrophy and fibrosis in DOCA-induced hypertensive rats.

Simple suspension culture system of human iPS cells maintaining their pluripotency for cardiac cell sheet engineering.

PubMed

Haraguchi, Yuji; Matsuura, Katsuhisa; Shimizu, Tatsuya; Yamato, Masayuki; Okano, Teruo

2015-12-01

In this study, a simple three-dimensional (3D) suspension culture method for the expansion and cardiac differentiation of human induced pluripotent stem cells (hiPSCs) is reported. The culture methods were easily adapted from two-dimensional (2D) to 3D culture without any additional manipulations. When hiPSCs were directly applied to 3D culture from 2D in a single-cell suspension, only a few aggregated cells were observed. However, after 3 days, culture of the small hiPSC aggregates in a spinner flask at the optimal agitation rate created aggregates which were capable of cell passages from the single-cell suspension. Cell numbers increased to approximately 10-fold after 12 days of culture. The undifferentiated state of expanded hiPSCs was confirmed by flow cytometry, immunocytochemistry and quantitative RT-PCR, and the hiPSCs differentiated into three germ layers. When the hiPSCs were subsequently cultured in a flask using cardiac differentiation medium, expression of cardiac cell-specific genes and beating cardiomyocytes were observed. Furthermore, the culture of hiPSCs on Matrigel-coated dishes with serum-free medium containing activin A, BMP4 and FGF-2 enabled it to generate robust spontaneous beating cardiomyocytes and these cells expressed several cardiac cell-related genes, including HCN4, MLC-2a and MLC-2v. This suggests that the expanded hiPSCs might maintain the potential to differentiate into several types of cardiomyocytes, including pacemakers. Moreover, when cardiac cell sheets were fabricated using differentiated cardiomyocytes, they beat spontaneously and synchronously, indicating electrically communicative tissue. This simple culture system might enable the generation of sufficient amounts of beating cardiomyocytes for use in cardiac regenerative medicine and tissue engineering. Copyright © 2013 John Wiley & Sons, Ltd.

Postnatal Cardiac Gene Editing Using CRISPR/Cas9 With AAV9-Mediated Delivery of Short Guide RNAs Results in Mosaic Gene Disruption.

PubMed

Johansen, Anne Katrine; Molenaar, Bas; Versteeg, Danielle; Leitoguinho, Ana Rita; Demkes, Charlotte; Spanjaard, Bastiaan; de Ruiter, Hesther; Akbari Moqadam, Farhad; Kooijman, Lieneke; Zentilin, Lorena; Giacca, Mauro; van Rooij, Eva

2017-10-27

CRISPR/Cas9 (clustered regularly interspaced palindromic repeats/CRISPR-associated protein 9)-based DNA editing has rapidly evolved as an attractive tool to modify the genome. Although CRISPR/Cas9 has been extensively used to manipulate the germline in zygotes, its application in postnatal gene editing remains incompletely characterized. To evaluate the feasibility of CRISPR/Cas9-based cardiac genome editing in vivo in postnatal mice. We generated cardiomyocyte-specific Cas9 mice and demonstrated that Cas9 expression does not affect cardiac function or gene expression. As a proof-of-concept, we delivered short guide RNAs targeting 3 genes critical for cardiac physiology, Myh6 , Sav1 , and Tbx20 , using a cardiotropic adeno-associated viral vector 9. Despite a similar degree of DNA disruption and subsequent mRNA downregulation, only disruption of Myh6 was sufficient to induce a cardiac phenotype, irrespective of short guide RNA exposure or the level of Cas9 expression. DNA sequencing analysis revealed target-dependent mutations that were highly reproducible across mice resulting in differential rates of in- and out-of-frame mutations. Finally, we applied a dual short guide RNA approach to effectively delete an important coding region of Sav1 , which increased the editing efficiency. Our results indicate that the effect of postnatal CRISPR/Cas9-based cardiac gene editing using adeno-associated virus serotype 9 to deliver a single short guide RNA is target dependent. We demonstrate a mosaic pattern of gene disruption, which hinders the application of the technology to study gene function. Further studies are required to expand the versatility of CRISPR/Cas9 as a robust tool to study novel cardiac gene functions in vivo. © 2017 American Heart Association, Inc.

Establishment of a PRKAG2 cardiac syndrome disease model and mechanism study using human induced pluripotent stem cells.

PubMed

Zhan, Yongkun; Sun, Xiaolei; Li, Bin; Cai, Huanhuan; Xu, Chen; Liang, Qianqian; Lu, Chao; Qian, Ruizhe; Chen, Sifeng; Yin, Lianhua; Sheng, Wei; Huang, Guoying; Sun, Aijun; Ge, Junbo; Sun, Ning

2018-04-01

PRKAG2 cardiac syndrome is a distinct form of human cardiomyopathy characterized by cardiac hypertrophy, ventricular pre-excitation and progressive cardiac conduction disorder. However, it remains unclear how mutations in the PRKAG2 gene give rise to such a complicated disease. To investigate the underlying molecular mechanisms, we generated disease-specific hiPSC-derived cardiomyocytes from two brothers both carrying a heterozygous missense mutation c.905G>A (R302Q) in the PRKAG2 gene and further corrected the R302Q mutation with CRISPR-Cas9 mediated genome editing. Disease-specific hiPSC-cardiomyocytes recapitulated many phenotypes of PRKAG2 cardiac syndrome including cellular enlargement, electrophysiological irregularities and glycogen storage. In addition, we found that the PRKAG2-R302Q mutation led to increased AMPK activities, resulting in extensive glycogen deposition and cardiomyocyte hypertrophy. Finally we confirmed that disrupted phenotypes of PRKAG2 cardiac syndrome caused by the specific PRKAG2-R302Q mutation can be alleviated by small molecules inhibiting AMPK activity and be rescued with CRISPR-Cas9 mediated genome correction. Our results showed that disease-specific hiPSC-CMs and genetically-corrected hiPSC-cardiomyocytes would be a very useful platform for understanding the pathogenesis of, and testing autologous cell-based therapies for, PRKAG2 cardiac syndrome. Copyright © 2018. Published by Elsevier Ltd.

Nandrolone and resistance training induce heart remodeling: role of fetal genes and implications for cardiac pathophysiology.

PubMed

Tanno, Ana Paula; das Neves, Vander José; Rosa, Kaleizu Teodoro; Cunha, Tatiana Sousa; Giordano, Fernanda Cristina Linarello; Calil, Caroline Morini; Guzzoni, Vinicius; Fernandes, Tiago; de Oliveira, Edilamar Menezes; Novaes, Pedro Duarte; Irigoyen, Maria Cláudia; Moura, Maria José Costa Sampaio; Marcondes, Fernanda Klein

2011-10-24

This study was conducted to assess the isolated and combined effects of nandrolone and resistance training on cardiac morphology, function, and mRNA expression of pathological cardiac hypertrophy markers. Wistar rats were randomly divided into four groups and submitted to 6 weeks of treatment with nandrolone and/or resistance training. Cardiac parameters were determined by echocardiography. Heart was analyzed for collagen infiltration. Real-time RT-PCR was used to assess the pathological cardiac hypertrophy markers. Both resistance training and nandrolone induced cardiac hypertrophy. Nandrolone increased the cardiac collagen content, and reduced the cardiac index in non-trained and trained groups, when compared with the respective vehicle-treated groups. Nandrolone reduced the ratio of maximum early to late transmitral flow velocity in non-trained and trained groups, when compared with the respective vehicle-treated groups. Nandrolone reduced the alpha-myosin heavy chain gene expression in both non-trained and trained groups, when compared with the respective vehicle-treated groups. Training reduced the beta-myosin heavy chain gene expression in the groups treated with vehicle and nandrolone. Only the association between training and nandrolone increased the expression of the skeletal alpha-actin gene and atrial natriuretic peptide in the left ventricle. This study indicated that nandrolone, whether associated with resistance training or not, induces cardiac hypertrophy, which is associated with enhanced collagen content, re-expression of fetal genes the in left ventricle, and impaired diastolic and systolic function. Copyright © 2011 Elsevier Inc. All rights reserved.

Expression profiling reveals distinct sets of genes altered during induction and regression of cardiac hypertrophy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Friddle, Carl J; Koga, Teiichiro; Rubin, Edward M.

2000-03-15

While cardiac hypertrophy has been the subject of intensive investigation, regression of hypertrophy has been significantly less studied, precluding large-scale analysis of the relationship between these processes. In the present study, using pharmacological models of hypertrophy in mice, expression profiling was performed with fragments of more than 3,000 genes to characterize and contrast expression changes during induction and regression of hypertrophy. Administration of angiotensin II and isoproterenol by osmotic minipump produced increases in heart weight (15% and 40% respectively) that returned to pre-induction size following drug withdrawal. From multiple expression analyses of left ventricular RNA isolated at daily time-points duringmore » cardiac hypertrophy and regression, we identified sets of genes whose expression was altered at specific stages of this process. While confirming the participation of 25 genes or pathways previously known to be altered by hypertrophy, a larger set of 30 genes was identified whose expression had not previously been associated with cardiac hypertrophy or regression. Of the 55 genes that showed reproducible changes during the time course of induction and regression, 32 genes were altered only during induction and 8 were altered only during regression. This study identified both known and novel genes whose expression is affected at different stages of cardiac hypertrophy and regression and demonstrates that cardiac remodeling during regression utilizes a set of genes that are distinct from those used during induction of hypertrophy.« less

Fndc5 knockdown induced suppression of mitochondrial integrity and significantly decreased cardiac differentiation of mouse embryonic stem cells.

PubMed

Nazem, Shima; Rabiee, Farzaneh; Ghaedi, Kamran; Babashah, Sadegh; Sadeghizadeh, Majid; Nasr-Esfahani, Mohammad Hossein

2018-06-01

Fibronectin type III domain-containing 5 protein (Fndc5) is a glycosylated protein with elevated expression in high energy demanded tissues as heart, brain, and muscle. It has been shown that upregulation of Fndc5 is regulated by peroxisome proliferator-activated receptor-γ coactivator-1 alpha (PGC-1α), which is known as a master regulator of mitochondrial function and biogenesis. Also, our group indicated that Fndc5 expression increases gradually during cardiac differentiation of mouse embryonic stem cells (mESCs). In this paper, to clarify the importance of Fndc5 in cardiac differentiation, we south to knock down Fndc5 expression by generation a stably transduced mESC line that derives the expression of a short hairpin RNA (shRNA) against Fndc5 gene following doxycycline (Dox) induction. Knock-down of Fndc5 demonstrated a considerable decrease in expression of cardiac progenitor and cardiomyocyte markers. Considering the fact that mitochondria play a crucial role in cardiac differentiation of ESCs, we investigated the role of Fndc5, as a downstream target of PGC1-α, on mitochondrial indices. Results showed that expression of nuclear encoded mitochondrial genes including PGC1-α, Atp5b, Ndufb5, and SOD2 significantly decreased. Moreover, mitochondrial membrane potential (ΔΨm) and relative ATP content of cardiomyocytes decreased markedly with relative ROS level increase. Together, our results suggest that Fndc5 attenuates process of cardiac differentiation of mESCs which is associated with modulation of mitochondrial function and gene expression. © 2017 Wiley Periodicals, Inc.

Angiogenic therapy for cardiac repair based on protein delivery systems.

PubMed

Formiga, F R; Tamayo, E; Simón-Yarza, T; Pelacho, B; Prósper, F; Blanco-Prieto, M J

2012-05-01

Cardiovascular diseases remain the first cause of morbidity and mortality in the developed countries and are a major problem not only in the western nations but also in developing countries. Current standard approaches for treating patients with ischemic heart disease include angioplasty or bypass surgery. However, a large number of patients cannot be treated using these procedures. Novel curative approaches under investigation include gene, cell, and protein therapy. This review focuses on potential growth factors for cardiac repair. The role of these growth factors in the angiogenic process and the therapeutic implications are reviewed. Issues including aspects of growth factor delivery are presented in relation to protein stability, dosage, routes, and safety matters. Finally, different approaches for controlled growth factor delivery are discussed as novel protein delivery platforms for cardiac regeneration.

Functional importance of cardiac enhancer-associated noncoding RNAs in heart development and disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ounzain, Samir; Pezzuto, Iole; Micheletti, Rudi

We report here that the key information processing units within gene regulatory networks are enhancers. Enhancer activity is associated with the production of tissue-specific noncoding RNAs, yet the existence of such transcripts during cardiac development has not been established. Using an integrated genomic approach, we demonstrate that fetal cardiac enhancers generate long noncoding RNAs (lncRNAs) during cardiac differentiation and morphogenesis. Enhancer expression correlates with the emergence of active enhancer chromatin states, the initiation of RNA polymerase II at enhancer loci and expression of target genes. Orthologous human sequences are also transcribed in fetal human hearts and cardiac progenitor cells. Throughmore » a systematic bioinformatic analysis, we identified and characterized, for the first time, a catalog of lncRNAs that are expressed during embryonic stem cell differentiation into cardiomyocytes and associated with active cardiac enhancer sequences. RNA-sequencing demonstrates that many of these transcripts are polyadenylated, multi-exonic long noncoding RNAs. Moreover, knockdown of two enhancer-associated lncRNAs resulted in the specific downregulation of their predicted target genes. Interestingly, the reactivation of the fetal gene program, a hallmark of the stress response in the adult heart, is accompanied by increased expression of fetal cardiac enhancer transcripts. Altogether, these findings demonstrate that the activity of cardiac enhancers and expression of their target genes are associated with the production of enhancer-derived lncRNAs.« less

Functional importance of cardiac enhancer-associated noncoding RNAs in heart development and disease

DOE PAGES

Ounzain, Samir; Pezzuto, Iole; Micheletti, Rudi; ...

2014-08-19

We report here that the key information processing units within gene regulatory networks are enhancers. Enhancer activity is associated with the production of tissue-specific noncoding RNAs, yet the existence of such transcripts during cardiac development has not been established. Using an integrated genomic approach, we demonstrate that fetal cardiac enhancers generate long noncoding RNAs (lncRNAs) during cardiac differentiation and morphogenesis. Enhancer expression correlates with the emergence of active enhancer chromatin states, the initiation of RNA polymerase II at enhancer loci and expression of target genes. Orthologous human sequences are also transcribed in fetal human hearts and cardiac progenitor cells. Throughmore » a systematic bioinformatic analysis, we identified and characterized, for the first time, a catalog of lncRNAs that are expressed during embryonic stem cell differentiation into cardiomyocytes and associated with active cardiac enhancer sequences. RNA-sequencing demonstrates that many of these transcripts are polyadenylated, multi-exonic long noncoding RNAs. Moreover, knockdown of two enhancer-associated lncRNAs resulted in the specific downregulation of their predicted target genes. Interestingly, the reactivation of the fetal gene program, a hallmark of the stress response in the adult heart, is accompanied by increased expression of fetal cardiac enhancer transcripts. Altogether, these findings demonstrate that the activity of cardiac enhancers and expression of their target genes are associated with the production of enhancer-derived lncRNAs.« less

Never in mitosis gene A related kinase-6 attenuates pressure overload-induced activation of the protein kinase B pathway and cardiac hypertrophy.

PubMed

Bian, Zhouyan; Liao, Haihan; Zhang, Yan; Wu, Qingqing; Zhou, Heng; Yang, Zheng; Fu, Jinrong; Wang, Teng; Yan, Ling; Shen, Difei; Li, Hongliang; Tang, Qizhu

2014-01-01

Cardiac hypertrophy appears to be a specialized form of cellular growth that involves the proliferation control and cell cycle regulation. NIMA (never in mitosis, gene A)-related kinase-6 (Nek6) is a cell cycle regulatory gene that could induce centriole duplication, and control cell proliferation and survival. However, the exact effect of Nek6 on cardiac hypertrophy has not yet been reported. In the present study, the loss- and gain-of-function experiments were performed in Nek6 gene-deficient (Nek6-/-) mice and Nek6 overexpressing H9c2 cells to clarify whether Nek6 which promotes the cell cycle also mediates cardiac hypertrophy. Cardiac hypertrophy was induced by transthoracic aorta constriction (TAC) and then evaluated by echocardiography, pathological and molecular analyses in vivo. We got novel findings that the absence of Nek6 promoted cardiac hypertrophy, fibrosis and cardiac dysfunction, which were accompanied by a significant activation of the protein kinase B (Akt) signaling in an experimental model of TAC. Consistent with this, the overexpression of Nek6 prevented hypertrophy in H9c2 cells induced by angiotonin II and inhibited Akt signaling in vitro. In conclusion, our results demonstrate that the cell cycle regulatory gene Nek6 is also a critical signaling molecule that helps prevent cardiac hypertrophy and inhibits the Akt signaling pathway.

Metabolic Dysfunction Consistent with Premature Aging Results from Deletion of Pim Kinases

PubMed Central

Din, Shabana; Konstandin, Mathias H; Johnson, Bevan; Emathinger, Jacqueline; Völkers, Mirko; Toko, Haruhiro; Collins, Brett; Ormachea, Lucy; Samse, Kaitlen; Kubli, Dieter A; De La Torre, Andrea; Kraft, Andrew S; Gustafsson, Asa B; Kelly, Daniel P; Sussman, Mark A

2014-01-01

Rationale The senescent cardiac phenotype is accompanied by changes in mitochondrial function and biogenesis causing impairment in energy provision. The relationship between myocardial senescence and Pim kinases deserves attention since Pim-1 kinase is cardioprotective, in part, by preservation of mitochondrial integrity. Study of the pathological effects resulting from genetic deletion of all Pim kinase family members could provide important insight regarding cardiac mitochondrial biology and the aging phenotype. Objective Demonstrate myocardial senescence is promoted by loss of Pim leading to premature aging and aberrant mitochondrial function. Methods and Results Cardiac myocyte senescence was evident at three months of age in Pim Triple KnockOut (PTKO) mice, where all three isoforms of Pim kinase family members are genetically deleted. Cellular hypertrophic remodeling and fetal gene program activation was followed by heart failure at six months in PTKO mice. Metabolic dysfunction is an underlying cause of cardiac senescence and instigates a decline in cardiac function. Altered mitochondrial morphology is evident consequential to Pim deletion together with decreased ATP levels and increased phosphorylated AMPK, exposing an energy deficiency in PTKO mice. Expression of the genes encoding master regulators of mitochondrial biogenesis, PPARγ coactivator-1 (PGC-1) α and β were diminished in PTKO hearts, as were downstream targets included in mitochondrial energy transduction, including fatty acid oxidation. Reversal of the dysregulated metabolic phenotype was observed by overexpressing c-Myc, a downstream target of Pim kinases. Conclusion Pim kinases prevent premature cardiac aging and maintain a healthy pool of functional mitochondria leading to efficient cellular energetics. PMID:24916111

Skeletal Muscle Laminopathies: A Review of Clinical and Molecular Features

PubMed Central

Maggi, Lorenzo; Carboni, Nicola; Bernasconi, Pia

2016-01-01

LMNA-related disorders are caused by mutations in the LMNA gene, which encodes for the nuclear envelope proteins, lamin A and C, via alternative splicing. Laminopathies are associated with a wide range of disease phenotypes, including neuromuscular, cardiac, metabolic disorders and premature aging syndromes. The most frequent diseases associated with mutations in the LMNA gene are characterized by skeletal and cardiac muscle involvement. This review will focus on genetics and clinical features of laminopathies affecting primarily skeletal muscle. Although only symptomatic treatment is available for these patients, many achievements have been made in clarifying the pathogenesis and improving the management of these diseases. PMID:27529282

Skeletal Muscle Laminopathies: A Review of Clinical and Molecular Features.

PubMed

Maggi, Lorenzo; Carboni, Nicola; Bernasconi, Pia

2016-08-11

LMNA-related disorders are caused by mutations in the LMNA gene, which encodes for the nuclear envelope proteins, lamin A and C, via alternative splicing. Laminopathies are associated with a wide range of disease phenotypes, including neuromuscular, cardiac, metabolic disorders and premature aging syndromes. The most frequent diseases associated with mutations in the LMNA gene are characterized by skeletal and cardiac muscle involvement. This review will focus on genetics and clinical features of laminopathies affecting primarily skeletal muscle. Although only symptomatic treatment is available for these patients, many achievements have been made in clarifying the pathogenesis and improving the management of these diseases.

Effects of hypertrophic and dilated cardiomyopathy mutations on power output by human β-cardiac myosin.

PubMed

Spudich, James A; Aksel, Tural; Bartholomew, Sadie R; Nag, Suman; Kawana, Masataka; Yu, Elizabeth Choe; Sarkar, Saswata S; Sung, Jongmin; Sommese, Ruth F; Sutton, Shirley; Cho, Carol; Adhikari, Arjun S; Taylor, Rebecca; Liu, Chao; Trivedi, Darshan; Ruppel, Kathleen M

2016-01-01

Hypertrophic cardiomyopathy is the most frequently occurring inherited cardiovascular disease, with a prevalence of more than one in 500 individuals worldwide. Genetically acquired dilated cardiomyopathy is a related disease that is less prevalent. Both are caused by mutations in the genes encoding the fundamental force-generating protein machinery of the cardiac muscle sarcomere, including human β-cardiac myosin, the motor protein that powers ventricular contraction. Despite numerous studies, most performed with non-human or non-cardiac myosin, there is no clear consensus about the mechanism of action of these mutations on the function of human β-cardiac myosin. We are using a recombinantly expressed human β-cardiac myosin motor domain along with conventional and new methodologies to characterize the forces and velocities of the mutant myosins compared with wild type. Our studies are extending beyond myosin interactions with pure actin filaments to include the interaction of myosin with regulated actin filaments containing tropomyosin and troponin, the roles of regulatory light chain phosphorylation on the functions of the system, and the possible roles of myosin binding protein-C and titin, important regulatory components of both cardiac and skeletal muscles. © 2016. Published by The Company of Biologists Ltd.

Utility of Genetic Testing in Elite Volleyball Players with Aortic Root Dilation.

PubMed

Herrick, Nicole; Davis, Christopher; Vargas, Lisa; Dietz, Hal; Grossfeld, Paul

2017-07-01

Basketball and volleyball attract individuals with a characteristic biophysical profile, mimicking features of Marfan syndrome. Consequently, identification of these abnormalities can be lifesaving. To determine how physical examination, echocardiography, and genetic screening can identify elite volleyball players with a previously undiagnosed aortopathy. We have performed cardiac screening on 90 US Volleyball National Team members and identified four individuals with dilated sinuses of Valsalva. This case series reports on three individuals who underwent a comprehensive genetics evaluation, including gene sequencing. Cardiac screening combined with genetic testing can identify previously undiagnosed tall athletes with an aortopathy, in the absence of noncardiac findings of a connective tissue disorder. Subject 1 had a revised Ghent systems (RGS) score of 2 and a normal aortopathy gene panel. Subject 2 had a RGS score of 1 and genetic testing revealed a de novo disease causing mutation in the gene encoding fibrillin-1 (FBN1). Subject 3 had an RGS score of 4.0 and had a normal aortopathy gene panel. Despite variable clinical features of Marfan syndrome, dilated sinuses of Valsalva were found in 4.9% of the athletes. A disease-causing mutation in the FBN1 gene was identified in subject 2, who had the lowest RGS but the largest aortic root measurement. Subjects 1 and 3, with the highest RGS, had a normal aortopathy gene panel. Our findings provide further evidence suggesting that a cardiac evaluation, including a screening echocardiogram, should be performed on all elite tall adult athletes independent of other physical findings. Genetic testing should be considered for athletes with dilated sinuses of Valsalva (male, >4.2 cm; female, >3.4 cm), regardless of other extracardiac findings.

Ablation of biglycan attenuates cardiac hypertrophy and fibrosis after left ventricular pressure overload.

PubMed

Beetz, Nadine; Rommel, Carolin; Schnick, Tilman; Neumann, Elena; Lother, Achim; Monroy-Ordonez, Elsa Beatriz; Zeeb, Martin; Preissl, Sebastian; Gilsbach, Ralf; Melchior-Becker, Ariane; Rylski, Bartosz; Stoll, Monika; Schaefer, Liliana; Beyersdorf, Friedhelm; Stiller, Brigitte; Hein, Lutz

2016-12-01

Biglycan, a small leucine-rich proteoglycan, has been shown to play an important role in stabilizing fibrotic scars after experimental myocardial infarction. However, the role of biglycan in the development and regression of cardiomyocyte hypertrophy and fibrosis during cardiac pressure overload and unloading remains elusive. Thus, the aim of the present study was to assess the effect of biglycan on cardiac remodeling in a mouse model of left ventricular pressure overload and unloading. Left ventricular pressure overload induced by transverse aortic constriction (TAC) in mice resulted in left ventricular dysfunction, fibrosis and increased biglycan expression. Fluorescence- and magnetic-assisted sorting of cardiac cell types revealed upregulation of biglycan in the fibroblast population, but not in cardiomyocytes, endothelial cells or leukocytes after TAC. Removal of the aortic constriction (rTAC) after short-term pressure overload (3weeks) improved cardiac contractility and reversed ventricular hypertrophy but not fibrosis in wild-type (WT) mice. Biglycan ablation (KO) enhanced functional recovery but did not resolve cardiac fibrosis. After long-term TAC for 9weeks, ablation of biglycan attenuated the development of cardiac hypertrophy and fibrosis. In vitro, biglycan induced hypertrophy of neonatal rat cardiomyocytes and led to activation of a hypertrophic gene program. Putative downstream mediators of biglycan signaling include Rcan1, Abra and Tnfrsf12a. These genes were concordantly induced by TAC in WT but not in biglycan KO mice. Left ventricular pressure overload induces biglycan expression in cardiac fibroblasts. Ablation of biglycan improves cardiac function and attenuates left ventricular hypertrophy and fibrosis after long-term pressure overload. In vitro biglycan induces hypertrophy of cardiomyocytes, suggesting that biglycan may act as a signaling molecule between cell types to modulate cardiac remodeling. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evolving targeted therapies for right ventricular failure.

PubMed

Di Salvo, Thomas G

2015-01-01

Although right and left ventricular embryological origins, morphology and cardiodynamics differ, the notion of selectively targeted right ventricular therapies remains controversial. This review focuses on both the currently evolving pharmacologic agents targeting right ventricular failure (metabolic modulators, phosphodiesterase type V inhibitors) and future therapeutic approaches including epigenetic modulation by miRNAs, chromatin binding complexes, long non-coding RNAs, genomic editing, adoptive gene transfer and gene therapy, cell regeneration via cell transplantation and cell reprogramming and cardiac tissue engineering. Strategies for adult right ventricular regeneration will require a more holistic approach than strategies for adult left ventricular failure. Instances of right ventricular failure requiring global reconstitution of right ventricular myocardium, attractive approaches include: i) myocardial patches seeded with cardiac fibroblasts reprogrammed into cardiomyocytes in vivo by small molecules, miRNAs or other epigenetic modifiers; and ii) administration of miRNAs, lncRNAs or small molecules by non-viral vector delivery systems targeted to fibroblasts (e.g., episomes) to stimulate in vivo reprogramming of fibroblasts into cardiomyocytes. For selected heritable genetic myocardial diseases, genomic editing affords exciting opportunities for allele-specific silencing by site-specific directed silencing, mutagenesis or gene excision. Genomic editing by adoptive gene transfer affords similarly exciting opportunities for restoration of myocardial gene expression.

Retinoic Acid Signaling Is Essential for Valvulogenesis by Affecting Endocardial Cushions Formation in Zebrafish Embryos.

PubMed

Li, Junbo; Yue, Yunyun; Zhao, Qingshun

2016-02-01

Retinoic acid (RA) plays important roles in many stages of heart morphogenesis. Zebrafish embryos treated with exogenous RA display defective atrio-ventricular canal (AVC) specification. However, whether endogenous RA signaling takes part in cardiac valve formation remains unknown. Herein, we investigated the role of RA signaling in cardiac valve development by knocking down aldh1a2, the gene encoding an enzyme that is mainly responsible for RA synthesis during early development, in zebrafish embryos. The results showed that partially knocking down aldh1a2 caused defective formation of primitive cardiac valve leaflets at 108 hpf (hour post-fertilization). Inhibiting endogenous RA signaling by 4-diethylaminobenzal-dehyde revealed that 16-26 hpf was a key time window when RA signaling affects the valvulogenesis. The aldh1a2 morphants had defective formation of endocardial cushion (EC) at 76 hpf though they had almost normal hemodynamics and cardiac chamber specification at early development. Examining the expression patterns of AVC marker genes including bmp4, bmp2b, nppa, notch1b, and has2, we found the morphants displayed abnormal development of endocardial AVC but almost normal development of myocardial AVC at 50 hpf. Being consistent with the reduced expression of notch1b in endocardial AVC, the VE-cadherin gene cdh5, the downstream gene of Notch signaling, was ectopically expressed in AVC of aldh1a2 morphants at 50 hpf, and overexpression of cdh5 greatly affected the formation of EC in the embryos at 76 hpf. Taken together, our results suggest that RA signaling plays essential roles in zebrafish cardiac valvulogenesis.

Molecular Cardiac Surgery with Recirculating Delivery (MCARD): Procedure and Vector Transfer.

PubMed

Katz, Michael G; Fargnoli, Anthony S; Kendle, Andrew P; Bridges, Charles R

2017-01-01

Despite progress in clinical treatment, cardiovascular diseases are still the leading cause of morbidity and mortality worldwide. Therefore, novel therapeutic approaches are needed, targeting the underlying molecular mechanisms of disease with improved outcomes for patients. Gene therapy is one of the most promising fields for the development of new treatments for the advanced stages of cardiovascular diseases. The establishment of clinically relevant methods of gene transfer remains one of the principal limitations on the effectiveness of gene therapy. Recently, there have been significant advances in direct and transvascular gene delivery methods. The ideal gene transfer method should be explored in clinically relevant large animal models of heart disease to evaluate the roles of specific molecular pathways in disease pathogenesis. Characteristics of the optimal technique for gene delivery include low morbidity, an increased myocardial transcapillary gradient, esxtended vector residence time in the myocytes, and the exclusion of residual vector from the systemic circulation after delivery to minimize collateral expression and immune response. Here we describe myocardial gene transfer techniques with molecular cardiac surgery with recirculating delivery in a large animal model of post ischemic heart failure.

Expression of cardiac function genes in adult stem cells is increased by treatment with nitric oxide agents.

PubMed

Rebelatto, Carmen K; Aguiar, Alessandra M; Senegaglia, Alexandra C; Aita, Carlos M; Hansen, Paula; Barchiki, Fabiane; Kuligovski, Crisciele; Olandoski, Márcia; Moutinho, José A; Dallagiovanna, Bruno; Goldenberg, Samuel; Brofman, Paulo S; Nakao, Lia S; Correa, Alejandro

2009-01-16

Mesenchymal stem cells (MSCs) have received special attention for cardiomyoplasty because several studies have shown that they differentiate into cardiomyocytes both in vitro and in vivo. Nitric oxide (NO) is a free radical signaling molecule that regulates several differentiation processes including cardiomyogenesis. Here, we report an investigation of the effects of two NO agents (SNAP and DEA/NO), able to activate both cGMP-dependent and -independent pathways, on the cardiomyogenic potential of bone marrow-derived mesenchymal stem cells (BM-MSCs) and adipose tissue-derived stem cells (ADSCs). The cells were isolated, cultured and treated with NO agents. Cardiac- and muscle-specific gene expression was analyzed by indirect immunofluorescence, flow cytometry, RT-PCR and real-time PCR. We found that untreated (control) ADSCs and BM-MSCs expressed some muscle markers and NO-derived intermediates induce an increased expression of some cardiac function genes in BM-MSCs and ADSCs. Moreover, NO agents considerably increased the pro-angiogenic potential mostly of BM-MSCs as determined by VEGF mRNA levels.

The ATP-sensitive potassium (KATP) channel-encoded dSUR gene is required for Drosophila heart function and is regulated by tinman

PubMed Central

Akasaka, Takeshi; Klinedinst, Susan; Ocorr, Karen; Bustamante, Erika L.; Kim, Seung K.; Bodmer, Rolf

2006-01-01

The homeobox transcription factor Tinman plays an important role in the initiation of heart development. Later functions of Tinman, including the target genes involved in cardiac physiology, are less well studied. We focused on the dSUR gene, which encodes an ATP-binding cassette transmembrane protein that is expressed in the heart. Mammalian SUR genes are associated with KATP (ATP-sensitive potassium) channels, which are involved in metabolic homeostasis. We provide experimental evidence that Tinman directly regulates dSUR expression in the developing heart. We identified a cis-regulatory element in the first intron of dSUR, which contains Tinman consensus binding sites and is sufficient for faithful dSUR expression in the fly’s myocardium. Site-directed mutagenesis of this element shows that these Tinman sites are critical to dSUR expression, and further genetic manipulations suggest that the GATA transcription factor Pannier is synergistically involved in cardiac-restricted dSUR expression in vivo. Physiological analysis of dSUR knock-down flies supports the idea that dSUR plays a protective role against hypoxic stress and pacing-induced heart failure. Because dSUR expression dramatically decreases with age, it is likely to be a factor involved in the cardiac aging phenotype of Drosophila. dSUR provides a model for addressing how embryonic regulators of myocardial cell commitment can contribute to the establishment and maintenance of cardiac performance. PMID:16882722

Unravelling the effects of mechanical physiological conditioning on cardiac adipose tissue-derived progenitor cells in vitro and in silico.

PubMed

Llucià-Valldeperas, Aida; Bragós, Ramon; Soler-Botija, Carolina; Roura, Santiago; Gálvez-Montón, Carolina; Prat-Vidal, Cristina; Perea-Gil, Isaac; Bayes-Genis, Antoni

2018-01-11

Mechanical conditioning is incompletely characterized for stimulating therapeutic cells within the physiological range. We sought to unravel the mechanism of action underlying mechanical conditioning of adipose tissue-derived progenitor cells (ATDPCs), both in vitro and in silico. Cardiac ATDPCs, grown on 3 different patterned surfaces, were mechanically stretched for 7 days at 1 Hz. A custom-designed, magnet-based, mechanical stimulator device was developed to apply ~10% mechanical stretching to monolayer cell cultures. Gene and protein analyses were performed for each cell type and condition. Cell supernatants were also collected to analyze secreted proteins and construct an artificial neural network. Gene and protein modulations were different for each surface pattern. After mechanostimulation, cardiac ATDPCs increased the expression of structural genes and there was a rising trend on cardiac transcription factors. Finally, secretome analyses revealed upregulation of proteins associated with both myocardial infarction and cardiac regeneration, such as regulators of the immune response, angiogenesis or cell adhesion. To conclude, mechanical conditioning of cardiac ATDPCs enhanced the expression of early and late cardiac genes in vitro. Additionally, in silico analyses of secreted proteins showed that mechanical stimulation of cardiac ATDPCs was highly associated with myocardial infarction and repair.

Divergent Requirements for EZH1 in Heart Development Versus Regeneration.

PubMed

Ai, Shanshan; Yu, Xianhong; Li, Yumei; Peng, Yong; Li, Chen; Yue, Yanzhu; Tao, Ge; Li, Chuanyun; Pu, William T; He, Aibin

2017-07-07

Polycomb repressive complex 2 is a major epigenetic repressor that deposits methylation on histone H3 on lysine 27 (H3K27me) and controls differentiation and function of many cells, including cardiac myocytes. EZH1 and EZH2 are 2 alternative catalytic subunits with partial functional redundancy. The relative roles of EZH1 and EZH2 in heart development and regeneration are unknown. We compared the roles of EZH1 versus EZH2 in heart development and neonatal heart regeneration. Heart development was normal in Ezh1 -/- ( Ezh 1 knockout) and Ezh2 f/f ::cTNT -Cre ( Ezh 2 knockout) embryos. Ablation of both genes in Ezh1 -/- ::Ezh2 f/f ::cTNT -Cre embryos caused lethal heart malformations, including hypertrabeculation, compact myocardial hypoplasia, and ventricular septal defect. Epigenome and transcriptome profiling showed that derepressed genes were upregulated in a manner consistent with total EZH dose. In neonatal heart regeneration, Ezh1 was required, but Ezh2 was dispensable. This finding was further supported by rescue experiments: cardiac myocyte-restricted re-expression of EZH1 but not EZH2 restored neonatal heart regeneration in Ezh 1 knockout. In myocardial infarction performed outside of the neonatal regenerative window, EZH1 but not EZH2 likewise improved heart function and stimulated cardiac myocyte proliferation. Mechanistically, EZH1 occupied and activated genes related to cardiac growth. Our work unravels divergent mechanisms of EZH1 in heart development and regeneration, which will empower efforts to overcome epigenetic barriers to heart regeneration. © 2017 American Heart Association, Inc.

MCAT elements and the TEF-1 family of transcription factors in muscle development and disease.

PubMed

Yoshida, Tadashi

2008-01-01

MCAT elements are located in the promoter-enhancer regions of cardiac, smooth, and skeletal muscle-specific genes including cardiac troponin T, beta-myosin heavy chain, smooth muscle alpha-actin, and skeletal alpha-actin, and play a key role in the regulation of these genes during muscle development and disease. The binding factors of MCAT elements are members of the transcriptional enhancer factor-1 (TEF-1) family. However, it has not been fully understood how these transcription factors confer cell-specific expression in muscle, because their expression patterns are relatively broad. Results of recent studies revealed multiple mechanisms whereby TEF-1 family members control MCAT element-dependent muscle-specific gene expression, including posttranslational modifications of TEF-1 family members, the presence of muscle-selective TEF-1 cofactors, and cell-selective control of TEF-1 accessibility to MCAT elements. In addition, of particular interest, recent studies regarding MCAT element-dependent transcription of the myocardin gene and the smooth muscle alpha-actin gene in muscle provide evidence for the transcriptional diversity among distinct cell types and subtypes. This article summarizes the role of MCAT elements and the TEF-1 family of transcription factors in muscle development and disease, and reviews recent progress in our understanding of the transcriptional regulatory mechanisms involved in MCAT element-dependent muscle-specific gene expression.

Purification of cardiac myocytes from human heart biopsies for gene expression analysis.

PubMed

Kosloski, L M; Bales, I K; Allen, K B; Walker, B L; Borkon, A M; Stuart, R S; Pak, A F; Wacker, M J

2009-09-01

The collection of gene expression data from human heart biopsies is important for understanding the cellular mechanisms of arrhythmias and diseases such as cardiac hypertrophy and heart failure. Many clinical and basic research laboratories conduct gene expression analysis using RNA from whole cardiac biopsies. This allows for the analysis of global changes in gene expression in areas of the heart, while eliminating the need for more complex and technically difficult single-cell isolation procedures (such as flow cytometry, laser capture microdissection, etc.) that require expensive equipment and specialized training. The abundance of fibroblasts and other cell types in whole biopsies, however, can complicate gene expression analysis and the interpretation of results. Therefore, we have designed a technique to quickly and easily purify cardiac myocytes from whole cardiac biopsies for RNA extraction. Human heart tissue samples were collected, and our purification method was compared with the standard nonpurification method. Cell imaging using acridine orange staining of the purified sample demonstrated that >98% of total RNA was contained within identifiable cardiac myocytes. Real-time RT-PCR was performed comparing nonpurified and purified samples for the expression of troponin T (myocyte marker), vimentin (fibroblast marker), and alpha-smooth muscle actin (smooth muscle marker). Troponin T expression was significantly increased, and vimentin and alpha-smooth muscle actin were significantly decreased in the purified sample (n = 8; P < 0.05). Extracted RNA was analyzed during each step of the purification, and no significant degradation occurred. These results demonstrate that this isolation method yields a more purified cardiac myocyte RNA sample suitable for downstream applications, such as real-time RT-PCR, and allows for more accurate gene expression changes in cardiac myocytes from heart biopsies.

Excessive training induces molecular signs of pathologic cardiac hypertrophy.

PubMed

da Rocha, Alisson L; Teixeira, Giovana R; Pinto, Ana P; de Morais, Gustavo P; Oliveira, Luciana da C; de Vicente, Larissa Gaioto; da Silva, Lilian E C M; Pauli, José R; Cintra, Dennys E; Ropelle, Eduardo R; de Moura, Leandro P; Mekary, Rania A; de Freitas, Ellen C; da Silva, Adelino S R

2018-05-24

Chronic exercise induces cardiac remodeling that promotes left ventricular hypertrophy and cardiac functional improvement, which are mediated by the mammalian or the mechanistic target of rapamycin (mTOR) as well as by the androgen and glucocorticoid receptors (GRs). However, pathological conditions (i.e., chronic heart failure, hypertension, and aortic stenosis, etc.) also induce cardiac hypertrophy, but with detrimental function, high levels of proinflammatory cytokines and myostatin, elevated fibrosis, reduced adenosine monophosphate-activated protein kinase (AMPK) activation, and fetal gene reactivation. Furthermore, recent studies have evidenced that excessive training induced an inflammatory status in the serum, muscle, hypothalamus, and liver, suggesting a pathological condition that could also be detrimental to cardiac tissue. Here, we verified the effects of three running overtraining (OT) models on the molecular parameters related to physiological and pathological cardiac hypertrophy. C57BL/6 mice performed three different OT protocols and were evaluated for molecular parameters related to physiological and pathological cardiac hypertrophy, including immunoblotting, reverse transcription polymerase chain reaction, histology, and immunohistochemistry analyses. In summary, the three OT protocols induced left ventricle (LV) hypertrophy with signs of cardiac fibrosis and negative morphological adaptations. These maladaptations were accompanied by reductions in AMPKalpha (Thr172) phosphorylation, androgen receptor, and GR expressions, as well as by an increase in interleukin-6 expression. Specifically, the downhill running-based OT model reduced the content of some proteins related to the mTOR signaling pathway and upregulated the β-isoform of myosin heavy-chain gene expression, presenting signs of LV pathological hypertrophy development. © 2018 Wiley Periodicals, Inc.

The long noncoding RNA Chaer defines an epigenetic checkpoint in cardiac hypertrophy.

PubMed

Wang, Zhihua; Zhang, Xiao-Jing; Ji, Yan-Xiao; Zhang, Peng; Deng, Ke-Qiong; Gong, Jun; Ren, Shuxun; Wang, Xinghua; Chen, Iris; Wang, He; Gao, Chen; Yokota, Tomohiro; Ang, Yen Sin; Li, Shen; Cass, Ashley; Vondriska, Thomas M; Li, Guangping; Deb, Arjun; Srivastava, Deepak; Yang, Huang-Tian; Xiao, Xinshu; Li, Hongliang; Wang, Yibin

2016-10-01

Epigenetic reprogramming is a critical process of pathological gene induction during cardiac hypertrophy and remodeling, but the underlying regulatory mechanisms remain to be elucidated. Here we identified a heart-enriched long noncoding (lnc)RNA, named cardiac-hypertrophy-associated epigenetic regulator (Chaer), which is necessary for the development of cardiac hypertrophy. Mechanistically, Chaer directly interacts with the catalytic subunit of polycomb repressor complex 2 (PRC2). This interaction, which is mediated by a 66-mer motif in Chaer, interferes with PRC2 targeting to genomic loci, thereby inhibiting histone H3 lysine 27 methylation at the promoter regions of genes involved in cardiac hypertrophy. The interaction between Chaer and PRC2 is transiently induced after hormone or stress stimulation in a process involving mammalian target of rapamycin complex 1, and this interaction is a prerequisite for epigenetic reprogramming and induction of genes involved in hypertrophy. Inhibition of Chaer expression in the heart before, but not after, the onset of pressure overload substantially attenuates cardiac hypertrophy and dysfunction. Our study reveals that stress-induced pathological gene activation in the heart requires a previously uncharacterized lncRNA-dependent epigenetic checkpoint.

Assessment of large copy number variants in patients with apparently isolated congenital left-sided cardiac lesions reveals clinically relevant genomic events.

PubMed

Hanchard, Neil A; Umana, Luis A; D'Alessandro, Lisa; Azamian, Mahshid; Poopola, Mojisola; Morris, Shaine A; Fernbach, Susan; Lalani, Seema R; Towbin, Jeffrey A; Zender, Gloria A; Fitzgerald-Butt, Sara; Garg, Vidu; Bowman, Jessica; Zapata, Gladys; Hernandez, Patricia; Arrington, Cammon B; Furthner, Dieter; Prakash, Siddharth K; Bowles, Neil E; McBride, Kim L; Belmont, John W

2017-08-01

Congenital left-sided cardiac lesions (LSLs) are a significant contributor to the mortality and morbidity of congenital heart disease (CHD). Structural copy number variants (CNVs) have been implicated in LSL without extra-cardiac features; however, non-penetrance and variable expressivity have created uncertainty over the use of CNV analyses in such patients. High-density SNP microarray genotyping data were used to infer large, likely-pathogenic, autosomal CNVs in a cohort of 1,139 probands with LSL and their families. CNVs were molecularly confirmed and the medical records of individual carriers reviewed. The gene content of novel CNVs was then compared with public CNV data from CHD patients. Large CNVs (>1 MB) were observed in 33 probands (∼3%). Six of these were de novo and 14 were not observed in the only available parent sample. Associated cardiac phenotypes spanned a broad spectrum without clear predilection. Candidate CNVs were largely non-recurrent, associated with heterozygous loss of copy number, and overlapped known CHD genomic regions. Novel CNV regions were enriched for cardiac development genes, including seven that have not been previously associated with human CHD. CNV analysis can be a clinically useful and molecularly informative tool in LSLs without obvious extra-cardiac defects, and may identify a clinically relevant genomic disorder in a small but important proportion of these individuals. © 2017 Wiley Periodicals, Inc.

Ultrasonic destruction of albumin microbubbles enhances gene transfection and expression in cardiac myocytes.

PubMed

Wang, Guo-zhong; Liu, Jing-hua; Lü, Shu-zheng; Lü, Yun; Guo, Cheng-jun; Zhao, Dong-hui; Fang, Dong-ping; He, Dong-fang; Zhou, Yuan; Ge, Chang-jiang

2011-05-01

It has been proven that ultrasonic destruction of microbubbles can enhance gene transfection efficiency into the noncardiac cells, but there are few reports about cardiac myocytes. Moreover, the exact mechanisms are not yet clear; whether the characteristic of microbubbles can affect the gene transfection efficiency or not is still controversial. This study was designed to investigate whether the ultrasound destruction of gene-loaded microbubbles could enhance the plasmids carried reporter gene transfection in primary cultured myocardial cell, and evaluate the effects of microbubbles characteristics on the transgene expression in cardiac myocytes. The β-galactosidase plasmids attached to the two types of microbubbles, air-contained sonicated dextrose albumin (ASDA) and perfluoropropane-exposed sonicated dextrose albumin (PESDA) were prepared. The gene transfection into cardiac myocytes was performed in vitro by naked plasmids, ultrasound exposure, ultrasonic destruction of gene-loaded microbubbles and calcium phosphate precipitation, and then the gene expression and cell viability were analyzed. The ultrasonic destruction of gene-loaded microbubbles enhanced gene expression in cardiac myocytes compared with naked plasmid transfection ((51.95 ± 2.41) U/g or (29.28 ± 3.65) U/g vs. (0.84 ± 0.21) U/g, P < 0.01), and ultrasonic destruction PESDA resulted in more significant gene expression than ASDA ((51.95 ± 2.41) U/g vs. (29.28 ± 3.65) U/g, P < 0.05). Ultrasonic destruction of microbubbles during calcium phosphate precipitation gene transfection enhanced β-galactosidase activity nearly 8-fold compared with calcium phosphate precipitation gene transfection alone ((111.35 ± 11.21) U/g protein vs. (14.13 ± 2.58) U/g protein, P < 0.01). Even 6 hours after calcium phosphate precipitation gene transfection, ultrasound-mediated microbubbles destruction resulted in more intense gene expression ((35.63 ± 7.65) U/g vs. (14.13 ± 2.58) U/g, P < 0.05). Ultrasonic destruction of microbubbles might be a promising method for the delivery of non-viral DNA into cardiac myocytes, and the gene tranfection is related to the characteristics of microbubbles.

CTCF counter-regulates cardiomyocyte development and maturation programs in the embryonic heart.

PubMed

Gomez-Velazquez, Melisa; Badia-Careaga, Claudio; Lechuga-Vieco, Ana Victoria; Nieto-Arellano, Rocio; Tena, Juan J; Rollan, Isabel; Alvarez, Alba; Torroja, Carlos; Caceres, Eva F; Roy, Anna R; Galjart, Niels; Delgado-Olguin, Paul; Sanchez-Cabo, Fatima; Enriquez, Jose Antonio; Gomez-Skarmeta, Jose Luis; Manzanares, Miguel

2017-08-01

Cardiac progenitors are specified early in development and progressively differentiate and mature into fully functional cardiomyocytes. This process is controlled by an extensively studied transcriptional program. However, the regulatory events coordinating the progression of such program from development to maturation are largely unknown. Here, we show that the genome organizer CTCF is essential for cardiogenesis and that it mediates genomic interactions to coordinate cardiomyocyte differentiation and maturation in the developing heart. Inactivation of Ctcf in cardiac progenitor cells and their derivatives in vivo during development caused severe cardiac defects and death at embryonic day 12.5. Genome wide expression analysis in Ctcf mutant hearts revealed that genes controlling mitochondrial function and protein production, required for cardiomyocyte maturation, were upregulated. However, mitochondria from mutant cardiomyocytes do not mature properly. In contrast, multiple development regulatory genes near predicted heart enhancers, including genes in the IrxA cluster, were downregulated in Ctcf mutants, suggesting that CTCF promotes cardiomyocyte differentiation by facilitating enhancer-promoter interactions. Accordingly, loss of CTCF disrupts gene expression and chromatin interactions as shown by chromatin conformation capture followed by deep sequencing. Furthermore, CRISPR-mediated deletion of an intergenic CTCF site within the IrxA cluster alters gene expression in the developing heart. Thus, CTCF mediates local regulatory interactions to coordinate transcriptional programs controlling transitions in morphology and function during heart development.

CTCF counter-regulates cardiomyocyte development and maturation programs in the embryonic heart

PubMed Central

Gomez-Velazquez, Melisa; Badia-Careaga, Claudio; Lechuga-Vieco, Ana Victoria; Nieto-Arellano, Rocio; Rollan, Isabel; Alvarez, Alba; Torroja, Carlos; Caceres, Eva F.; Roy, Anna R.; Galjart, Niels; Sanchez-Cabo, Fatima; Enriquez, Jose Antonio; Gomez-Skarmeta, Jose Luis

2017-01-01

Cardiac progenitors are specified early in development and progressively differentiate and mature into fully functional cardiomyocytes. This process is controlled by an extensively studied transcriptional program. However, the regulatory events coordinating the progression of such program from development to maturation are largely unknown. Here, we show that the genome organizer CTCF is essential for cardiogenesis and that it mediates genomic interactions to coordinate cardiomyocyte differentiation and maturation in the developing heart. Inactivation of Ctcf in cardiac progenitor cells and their derivatives in vivo during development caused severe cardiac defects and death at embryonic day 12.5. Genome wide expression analysis in Ctcf mutant hearts revealed that genes controlling mitochondrial function and protein production, required for cardiomyocyte maturation, were upregulated. However, mitochondria from mutant cardiomyocytes do not mature properly. In contrast, multiple development regulatory genes near predicted heart enhancers, including genes in the IrxA cluster, were downregulated in Ctcf mutants, suggesting that CTCF promotes cardiomyocyte differentiation by facilitating enhancer-promoter interactions. Accordingly, loss of CTCF disrupts gene expression and chromatin interactions as shown by chromatin conformation capture followed by deep sequencing. Furthermore, CRISPR-mediated deletion of an intergenic CTCF site within the IrxA cluster alters gene expression in the developing heart. Thus, CTCF mediates local regulatory interactions to coordinate transcriptional programs controlling transitions in morphology and function during heart development. PMID:28846746

Analyzing Gene Expression Profiles with Preliminary Validations in Cardiac Hypertrophy Induced by Pressure-overload.

PubMed

Gao, Jing; Li, Yuhong; Wang, Tongmei; Shi, Zhuo; Zhang, Yiqi; Liu, Shuang; Wen, Pushuai; Ma, Chunyan

2018-03-06

The aim of this study was to identify the key genes involved in the cardiac hypertrophy (CH) induced by pressure overload. mRNA microarray dataset GSE5500 and GSE18801 were downloaded from GEO database, and differentially expressed genes (DEGs) were screened using Limma package; then, functional and pathway enrichment analysis were performed for common DEGs using DAVID database. Furthermore, the top DEGs were further validated using qPCR in the hypertrophic heart tissue induced by Isoprenaline (ISO). A total of 113 common DEGs with absolute fold change >0.5, including 60 significantly up-regulated DEGs and 53 down-regulated DEGs were obtained. GO term enrichment analysis suggested that common up-regulated DEG mainly enriched in neutrophil chemotaxis, extracellular fibril organization and cell proliferation, and the common down-regulated genes were significantly enriched in ion transport, endoplasmic reticulum and dendritic spine. KEGG pathway analysis found that the common DEGs were mainly enriched in ECM-receptor interaction, phagosome, and focal adhesion. Additionally, the expression of Mfap4, Ltbp2, Aspn, Serpina3n, and Cnksr1 were up-regulated in the model of cardiac hypertrophy, while the expression of Anp32a was down-regulated. The current study identified the key deregulated genes and pathways involved in the CH, which could shed new light to understand the mechanism of CH.

Cardiac Expression of Microsomal Triglyceride Transfer Protein Is Increased in Obesity and Serves to Attenuate Cardiac Triglyceride Accumulation

PubMed Central

Bartels, Emil D.; Nielsen, Jan M.; Hellgren, Lars I.; Ploug, Thorkil; Nielsen, Lars B.

2009-01-01

Obesity causes lipid accumulation in the heart and may lead to lipotoxic heart disease. Traditionally, the size of the cardiac triglyceride pool is thought to reflect the balance between uptake and β-oxidation of fatty acids. However, triglycerides can also be exported from cardiomyocytes via secretion of apolipoproteinB-containing (apoB) lipoproteins. Lipoprotein formation depends on expression of microsomal triglyceride transfer protein (MTP); the mouse expresses two isoforms of MTP, A and B. Since many aspects of the link between obesity-induced cardiac disease and cardiac lipid metabolism remain unknown, we investigated how cardiac lipoprotein synthesis affects cardiac expression of triglyceride metabolism-controlling genes, insulin sensitivity, and function in obese mice. Heart-specific ablation of MTP-A in mice using Cre-loxP technology impaired upregulation of MTP expression in response to increased fatty acid availability during fasting and fat feeding. This resulted in cardiac triglyceride accumulation but unaffected cardiac insulin-stimulated glucose uptake. Long-term fat-feeding of male C57Bl/6 mice increased cardiac triglycerides, induced cardiac expression of triglyceride metabolism-controlling genes and attenuated heart function. Abolishing cardiac triglyceride accumulation in fat-fed mice by overexpression of an apoB transgene in the heart prevented the induction of triglyceride metabolism-controlling genes and improved heart function. The results suggest that in obesity, the physiological increase of cardiac MTP expression serves to attenuate cardiac triglyceride accumulation albeit without major effects on cardiac insulin sensitivity. Nevertheless, the data suggest that genetically increased lipoprotein secretion prevents development of obesity-induced lipotoxic heart disease. PMID:19390571

Seasonal and latitudinal acclimatization of cardiac transcriptome responses to thermal stress in porcelain crabs, Petrolisthes cinctipes.

PubMed

Stillman, Jonathon H; Tagmount, Abderrahmane

2009-10-01

Central predictions of climate warming models include increased climate variability and increased severity of heat waves. Physiological acclimatization in populations across large-scale ecological gradients in habitat temperature fluctuation is an important factor to consider in detecting responses to climate change related increases in thermal fluctuation. We measured in vivo cardiac thermal maxima and used microarrays to profile transcriptome heat and cold stress responses in cardiac tissue of intertidal zone porcelain crabs across biogeographic and seasonal gradients in habitat temperature fluctuation. We observed acclimatization dependent induction of heat shock proteins, as well as unknown genes with heat shock protein-like expression profiles. Thermal acclimatization had the largest effect on heat stress responses of extensin-like, beta tubulin, and unknown genes. For these genes, crabs acclimatized to thermally variable sites had higher constitutive expression than specimens from low variability sites, but heat stress dramatically induced expression in specimens from low variability sites and repressed expression in specimens from highly variable sites. Our application of ecological transcriptomics has yielded new biomarkers that may represent sensitive indicators of acclimatization to habitat temperature fluctuation. Our study also has identified novel genes whose further description may yield novel understanding of cellular responses to thermal acclimatization or thermal stress.

21 CFR 862.1163 - Cardiac allograft gene expression profiling test system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1163 Cardiac allograft gene expression profiling test system. (a...

21 CFR 862.1163 - Cardiac allograft gene expression profiling test system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1163 Cardiac allograft gene expression profiling test system. (a...

21 CFR 862.1163 - Cardiac allograft gene expression profiling test system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1163 Cardiac allograft gene expression profiling test system. (a...

21 CFR 862.1163 - Cardiac allograft gene expression profiling test system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1163 Cardiac allograft gene expression profiling test system. (a...

Congenital and childhood atrioventricular blocks: pathophysiology and contemporary management.

PubMed

Baruteau, Alban-Elouen; Pass, Robert H; Thambo, Jean-Benoit; Behaghel, Albin; Le Pennec, Solène; Perdreau, Elodie; Combes, Nicolas; Liberman, Leonardo; McLeod, Christopher J

2016-09-01

Atrioventricular block is classified as congenital if diagnosed in utero, at birth, or within the first month of life. The pathophysiological process is believed to be due to immune-mediated injury of the conduction system, which occurs as a result of transplacental passage of maternal anti-SSA/Ro-SSB/La antibodies. Childhood atrioventricular block is therefore diagnosed between the first month and the 18th year of life. Genetic variants in multiple genes have been described to date in the pathogenesis of inherited progressive cardiac conduction disorders. Indications and techniques of cardiac pacing have also evolved to allow safe permanent cardiac pacing in almost all patients, including those with structural heart abnormalities. Early diagnosis and appropriate management are critical in many cases in order to prevent sudden death, and this review critically assesses our current understanding of the pathogenetic mechanisms, clinical course, and optimal management of congenital and childhood AV block. • Prevalence of congenital heart block of 1 per 15,000 to 20,000 live births. AV block is defined as congenital if diagnosed in utero, at birth, or within the first month of life, whereas childhood AV block is diagnosed between the first month and the 18th year of life. As a result of several different etiologies, congenital and childhood atrioventricular block may occur in an entirely structurally normal heart or in association with concomitant congenital heart disease. Cardiac pacing is indicated in symptomatic patients and has several prophylactic indications in asymptomatic patients to prevent sudden death. • Autoimmune, congenital AV block is associated with a high neonatal mortality rate and development of dilated cardiomyopathy in 5 to 30 % cases. What is New: • Several genes including SCN5A have been implicated in autosomal dominant forms of familial progressive cardiac conduction disorders. • Leadless pacemaker technology and gene therapy for biological pacing are promising research fields. In utero percutaneous pacing appears to be at high risk and needs further development before it can be adopted into routine clinical practice. Cardiac resynchronization therapy is of proven value in case of pacing-induced cardiomyopathy.

Dmpk gene deletion or antisense knockdown does not compromise cardiac or skeletal muscle function in mice

PubMed Central

Carrell, Samuel T.; Carrell, Ellie M.; Auerbach, David; Pandey, Sanjay K.; Bennett, C. Frank; Dirksen, Robert T.; Thornton, Charles A.

2016-01-01

Myotonic dystrophy type 1 (DM1) is a genetic disorder in which dominant-active DM protein kinase (DMPK) transcripts accumulate in nuclear foci, leading to abnormal regulation of RNA processing. A leading approach to treat DM1 uses DMPK-targeting antisense oligonucleotides (ASOs) to reduce levels of toxic RNA. However, basal levels of DMPK protein are reduced by half in DM1 patients. This raises concern that intolerance for further DMPK loss may limit ASO therapy, especially since mice with Dmpk gene deletion reportedly show cardiac defects and skeletal myopathy. We re-examined cardiac and muscle function in mice with Dmpk gene deletion, and studied post-maturity knockdown using Dmpk-targeting ASOs in mice with heterozygous deletion. Contrary to previous reports, we found no effect of Dmpk gene deletion on cardiac or muscle function, when studied on two genetic backgrounds. In heterozygous knockouts, the administration of ASOs reduced Dmpk expression in cardiac and skeletal muscle by > 90%, yet survival, electrocardiogram intervals, cardiac ejection fraction and muscle strength remained normal. The imposition of cardiac stress by pressure overload, or muscle stress by myotonia, did not unmask a requirement for DMPK. Our results support the feasibility and safety of using ASOs for post-transcriptional silencing of DMPK in muscle and heart. PMID:27522499

Direct, Differential Effects of Tamoxifen, 4-Hydroxytamoxifen, and Raloxifene on Cardiac Myocyte Contractility and Calcium Handling

PubMed Central

Asp, Michelle L.; Martindale, Joshua J.; Metzger, Joseph M.

2013-01-01

Tamoxifen (Tam), a selective estrogen receptor modulator, is in wide clinical use for the treatment and prevention of breast cancer. High Tam doses have been used for treatment of gliomas and cancers with multiple drug resistance, but long QT Syndrome is a side effect. Tam is also used experimentally in mice for inducible gene knockout in numerous tissues, including heart; however, the potential direct effects of Tam on cardiac myocyte mechanical function are not known. The goal of this study was to determine the direct, acute effects of Tam, its active metabolite 4-hydroxytamoxifen (4OHT), and related drug raloxifene (Ral) on isolated rat cardiac myocyte mechanical function and calcium handling. Tam decreased contraction amplitude, slowed relaxation, and decreased Ca2+ transient amplitude. Effects were primarily observed at 5 and 10 μM Tam, which is relevant for high dose Tam treatment in cancer patients as well as Tam-mediated gene excision in mice. Myocytes treated with 4OHT responded similarly to Tam-treated cells with regard to both contractility and calcium handling, suggesting an estrogen-receptor independent mechanism is responsible for the effects. In contrast, Ral increased contraction and Ca2+ transient amplitudes. At 10 μM, all drugs had a time-dependent effect to abolish cellular contraction. In conclusion, Tam, 4OHT, and Ral adversely and differentially alter cardiac myocyte contractility and Ca2+ handling. These findings have important implications for understanding the Tam-induced cardiomyopathy in gene excision studies and may be important for understanding effects on cardiac performance in patients undergoing high-dose Tam therapy. PMID:24205315

Pathophysiology of cardiac hypertrophy and heart failure: signaling pathways and novel therapeutic targets.

PubMed

Tham, Yow Keat; Bernardo, Bianca C; Ooi, Jenny Y Y; Weeks, Kate L; McMullen, Julie R

2015-09-01

The onset of heart failure is typically preceded by cardiac hypertrophy, a response of the heart to increased workload, a cardiac insult such as a heart attack or genetic mutation. Cardiac hypertrophy is usually characterized by an increase in cardiomyocyte size and thickening of ventricular walls. Initially, such growth is an adaptive response to maintain cardiac function; however, in settings of sustained stress and as time progresses, these changes become maladaptive and the heart ultimately fails. In this review, we discuss the key features of pathological cardiac hypertrophy and the numerous mediators that have been found to be involved in the pathogenesis of cardiac hypertrophy affecting gene transcription, calcium handling, protein synthesis, metabolism, autophagy, oxidative stress and inflammation. We also discuss new mediators including signaling proteins, microRNAs, long noncoding RNAs and new findings related to the role of calcineurin and calcium-/calmodulin-dependent protein kinases. We also highlight mediators and processes which contribute to the transition from adaptive cardiac remodeling to maladaptive remodeling and heart failure. Treatment strategies for heart failure commonly include diuretics, angiotensin converting enzyme inhibitors, angiotensin II receptor blockers and β-blockers; however, mortality rates remain high. Here, we discuss new therapeutic approaches (e.g., RNA-based therapies, dietary supplementation, small molecules) either entering clinical trials or in preclinical development. Finally, we address the challenges that remain in translating these discoveries to new and approved therapies for heart failure.

Molecular evaluation of five cardiac genes in Doberman Pinschers with dilated cardiomyopathy.

PubMed

Meurs, Kathryn M; Hendrix, Kristina P; Norgard, Michelle M

2008-08-01

To sequence the exonic and splice site regions of 5 cardiac genes associated with the human form of familial dilated cardiomyopathy (DCM) in Doberman Pinschers with DCM and to identify a causative mutation. 5 unrelated Doberman Pinschers with DCM and 2 unaffected Labrador Retrievers (control dogs). Exonic and splice site regions of the 5 genes encoding the cardiac proteins troponin C, lamin A/C, cysteine- and glycine-rich protein 3, cardiac troponin T, and the beta-myosin heavy chain were sequenced. Sequences were compared for nucleotide changes between affected dogs and the published canine sequences and 2 control dogs. Base pair changes were considered to be causative for DCM if they were present in an affected dog but not in the control dogs or published sequences and if they involved a conserved amino acid and changed that amino acid to a different polarity, acid-base status, or structure. A causative mutation for DCM in Doberman Pinschers was not identified, although single nucleotide polymorphisms were detected in some dogs in the cysteine- and glycine-rich protein 3, beta-myosin heavy chain, and troponin T genes. Mutations in 5 of the cardiac genes associated with the development of DCM in humans did not appear to be causative for DCM in Doberman Pinschers. Continued evaluation of additional candidate genes or a focused approach with an association analysis is warranted to elucidate the molecular cause of this important cardiac disease in Doberman Pinschers.

In utero and lactational 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure: Effects on fetal and adult cardiac gene expression and adult cardiac and renal morphology

USDA-ARS?s Scientific Manuscript database

The mouse heart is a target of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during fetal development, and microarray analysis demonstrates significant changes in expression of cardiac genes involved in extracellular matrix (ECM) remodeling. We tested the hypothesis that developmental TCDD exposure wo...

Genetic investigation of 100 heart genes in sudden unexplained death victims in a forensic setting

PubMed Central

Christiansen, Sofie Lindgren; Hertz, Christin Løth; Ferrero-Miliani, Laura; Dahl, Morten; Weeke, Peter Ejvin; LuCamp; Ottesen, Gyda Lolk; Frank-Hansen, Rune; Bundgaard, Henning; Morling, Niels

2016-01-01

In forensic medicine, one-third of the sudden deaths remain unexplained after medico-legal autopsy. A major proportion of these sudden unexplained deaths (SUD) are considered to be caused by inherited cardiac diseases. Sudden cardiac death (SCD) may be the first manifestation of these diseases. The purpose of this study was to explore the yield of next-generation sequencing of genes associated with SCD in a cohort of SUD victims. We investigated 100 genes associated with cardiac diseases in 61 young (1–50 years) SUD cases. DNA was captured with the Haloplex target enrichment system and sequenced using an Illumina MiSeq. The identified genetic variants were evaluated and classified as likely, unknown or unlikely to have a functional effect. The criteria for this classification were based on the literature, databases, conservation and prediction of the effect of the variant. We found that 21 (34%) individuals carried variants with a likely functional effect. Ten (40%) of these variants were located in genes associated with cardiomyopathies and 15 (60%) of the variants in genes associated with cardiac channelopathies. Nineteen individuals carried variants with unknown functional effect. Our findings indicate that broad genetic investigation of SUD victims increases the diagnostic outcome, and the investigation should comprise genes involved in both cardiomyopathies and cardiac channelopathies. PMID:27650965

Non-human Primate and Rat Cardiac Fibroblasts show similar Extracellular Matrix-related and Cellular Adhesion Gene Responses to Substance P

PubMed Central

Meléndez, Giselle C.; Manteufel, Edward J.; Dehlin, Heather M.; Register, Thomas C.; Levick, Scott P.

2015-01-01

Background The sensory nerve neuropeptide substance P (SP) regulates cardiac fibrosis in rodents under pressure overload conditions. Interestingly, SP induces transient increase expression of specific genes in isolated rat cardiac fibroblasts, without resultant changes in cell function. This suggests that SP ‘primes’ fibroblasts, but does not directly activate them. We investigated whether these unusual findings are specific to rodent fibroblasts or are translatable to a larger animal model more closely related to humans. Methods We compared the effects of SP on genes associated with extracellular matrix (ECM) regulation, cell-cell adhesion, cell-matrix adhesion and ECM in cardiac fibroblasts isolated from a non-human primate and Sprague-Dawley rats. Results We found that rodent and non-human primate cardiac fibroblasts showed similar ECM regulation and cell adhesion gene expression responses to SP. There were, however, large discrepancies in ECM genes which did not result in collagen or laminin synthesis in rat or non-human primate fibroblasts in response to SP. Conclusions This study further supports the notion that SP serves as a ‘primer’ for fibroblasts rather than initiating direct effects and suggests that rodent fibroblasts are a suitable model for studying gene and functional responses to SP in the absence of human or non-human primate fibroblasts. PMID:25550118

Genetic investigation of 100 heart genes in sudden unexplained death victims in a forensic setting.

PubMed

Christiansen, Sofie Lindgren; Hertz, Christin Løth; Ferrero-Miliani, Laura; Dahl, Morten; Weeke, Peter Ejvin; LuCamp; Ottesen, Gyda Lolk; Frank-Hansen, Rune; Bundgaard, Henning; Morling, Niels

2016-12-01

In forensic medicine, one-third of the sudden deaths remain unexplained after medico-legal autopsy. A major proportion of these sudden unexplained deaths (SUD) are considered to be caused by inherited cardiac diseases. Sudden cardiac death (SCD) may be the first manifestation of these diseases. The purpose of this study was to explore the yield of next-generation sequencing of genes associated with SCD in a cohort of SUD victims. We investigated 100 genes associated with cardiac diseases in 61 young (1-50 years) SUD cases. DNA was captured with the Haloplex target enrichment system and sequenced using an Illumina MiSeq. The identified genetic variants were evaluated and classified as likely, unknown or unlikely to have a functional effect. The criteria for this classification were based on the literature, databases, conservation and prediction of the effect of the variant. We found that 21 (34%) individuals carried variants with a likely functional effect. Ten (40%) of these variants were located in genes associated with cardiomyopathies and 15 (60%) of the variants in genes associated with cardiac channelopathies. Nineteen individuals carried variants with unknown functional effect. Our findings indicate that broad genetic investigation of SUD victims increases the diagnostic outcome, and the investigation should comprise genes involved in both cardiomyopathies and cardiac channelopathies.

Preparation of rAAV9 to Overexpress or Knockdown Genes in Mouse Hearts

PubMed Central

Ding, Jian; Lin, Zhi-Qiang; Jiang, Jian-Ming; Seidman, Christine E.; Seidman, Jonathan G.; Pu, William T.; Wang, Da-Zhi

2016-01-01

Controlling the expression or activity of specific genes through the myocardial delivery of genetic materials in murine models permits the investigation of gene functions. Their therapeutic potential in the heart can also be determined. There are limited approaches for in vivo molecular intervention in the mouse heart. Recombinant adeno-associated virus (rAAV)-based genome engineering has been utilized as an essential tool for in vivo cardiac gene manipulation. The specific advantages of this technology include high efficiency, high specificity, low genomic integration rate, minimalimmunogenicity, and minimal pathogenicity. Here, a detailed procedure to construct, package, and purify the rAAV9 vectors is described. Subcutaneous injection of rAAV9 into neonatal pups results in robust expression or efficient knockdown of the gene(s) of interest in the mouse heart, but not in the liver and other tissues. Using the cardiac-specific TnnT2 promoter, high expression of GFP gene in the heart was obtained. Additionally, target mRNA was inhibited in the heart when a rAAV9-U6-shRNA was utilized. Working knowledge of rAAV9 technology may be useful for cardiovascular investigations. PMID:28060283

Preparation of rAAV9 to Overexpress or Knockdown Genes in Mouse Hearts.

PubMed

Ding, Jian; Lin, Zhi-Qiang; Jiang, Jian-Ming; Seidman, Christine E; Seidman, Jonathan G; Pu, William T; Wang, Da-Zhi

2016-12-17

Controlling the expression or activity of specific genes through the myocardial delivery of genetic materials in murine models permits the investigation of gene functions. Their therapeutic potential in the heart can also be determined. There are limited approaches for in vivo molecular intervention in the mouse heart. Recombinant adeno-associated virus (rAAV)-based genome engineering has been utilized as an essential tool for in vivo cardiac gene manipulation. The specific advantages of this technology include high efficiency, high specificity, low genomic integration rate, minimal immunogenicity, and minimal pathogenicity. Here, a detailed procedure to construct, package, and purify the rAAV9 vectors is described. Subcutaneous injection of rAAV9 into neonatal pups results in robust expression or efficient knockdown of the gene(s) of interest in the mouse heart, but not in the liver and other tissues. Using the cardiac-specific TnnT2 promoter, high expression of GFP gene in the heart was obtained. Additionally, target mRNA was inhibited in the heart when a rAAV9-U6-shRNA was utilized. Working knowledge of rAAV9 technology may be useful for cardiovascular investigations.

Targeting Cardiac Fibroblasts to Treat Fibrosis of the Heart: Focus on HDACs

PubMed Central

Schuetze, Katherine B.; McKinsey, Timothy A.; Long, Carlin S.

2014-01-01

Cardiac fibrosis is implicated in numerous physiologic and pathologic conditions, including scar formation, heart failure and cardiac arrhythmias. However the specific cells and signaling pathways mediating this process are poorly understood. Lysine acetylation of nucleosomal histone tails is an important mechanism for the regulation of gene expression. Additionally, proteomic studies have revealed that thousands of proteins in all cellular compartments are subject to reversible lysine acetylation, and thus it is becoming clear that this post-translational modification will rival phosphorylation in terms of biological import. Acetyl groups are conjugated to lysine by histone acetyltransferases (HATs) and removed from lysine by histone deacetylases (HDACs). Recent studies have shown that pharmacologic agents that alter lysine acetylation by targeting HDACs have the remarkable ability to block pathological fibrosis. Here, we review the current understanding of cardiac fibroblasts and the fibrogenic process with respect to the roles of lysine acetylation in the control of disease-related cardiac fibrosis. Potential for small molecule HDAC inhibitors as antifibrotic therapeutics that target cardiac fibroblasts is highlighted. PMID:24631770

The cardiac TBX5 interactome reveals a chromatin remodeling network essential for cardiac septation

PubMed Central

Waldron, Lauren; Steimle, Jeffrey D.; Greco, Todd M.; Gomez, Nicholas C.; Dorr, Kerry M.; Kweon, Junghun; Temple, Brenda; Yang, Xinan Holly; Wilczewski, Caralynn M.; Davis, Ian J.; Cristea, Ileana M.; Moskowitz, Ivan P.; Conlon, Frank L.

2016-01-01

SUMMARY Human mutations in the cardiac transcription factor gene TBX5 cause Congenital Heart Disease (CHD), however the underlying mechanism is unknown. We report characterization of the endogenous TBX5 cardiac interactome and demonstrate that TBX5, long considered a transcriptional activator, interacts biochemically and genetically with the Nucleosome Remodeling and Deacetylase (NuRD) repressor complex. Incompatible gene programs are repressed by TBX5 in the developing heart. CHD missense mutations that disrupt the TBX5-NuRD interaction cause depression of a subset of repressed genes. Furthermore, the TBX5-NuRD interaction is required for heart development. Phylogenetic analysis showed that the TBX5-NuRD interaction domain evolved during early diversification of vertebrates, simultaneous with the evolution of cardiac septation. Collectively, this work defines a TBX5-NuRD interaction essential to cardiac development and the evolution of the mammalian heart, and when altered may contribute to human CHD. PMID:26859351

A Temporal Chromatin Signature in Human Embryonic Stem Cells Identifies Regulators of Cardiac Development

PubMed Central

Paige, Sharon L.; Thomas, Sean; Stoick-Cooper, Cristi L.; Wang, Hao; Maves, Lisa; Sandstrom, Richard; Pabon, Lil; Reinecke, Hans; Pratt, Gabriel; Keller, Gordon; Moon, Randall T.; Stamatoyannopoulos, John; Murry, Charles E.

2012-01-01

Summary Directed differentiation of human embryonic stem cells (ESCs) into cardiovascular cells provides a model for studying molecular mechanisms of human cardiovascular development. Though it is known that chromatin modification patterns in ESCs differ markedly from those in lineage-committed progenitors and differentiated cells, the temporal dynamics of chromatin alterations during differentiation along a defined lineage have not been studied. We show that differentiation of human ESCs into cardiovascular cells is accompanied by programmed temporal alterations in chromatin structure that distinguish key regulators of cardiovascular development from other genes. We used this temporal chromatin signature to identify regulators of cardiac development, including the homeobox gene MEIS2. We demonstrate using the zebrafish model that MEIS2 is critical for proper heart tube formation and subsequent cardiac looping. Temporal chromatin signatures should be broadly applicable to other models of stem cell differentiation to identify regulators and provide key insights into major developmental decisions. PMID:22981225

Molecular Pathogenesis of Familial Wolff-Parkinson-White Syndrome.

PubMed

Licht, Miyamotoa

2018-01-01

Familial Wolff-Parkinson-White (WPW) syndrome is an autosomal dominant inherited disease and consists of a small percentage of WPW syndrome which exhibits ventricular pre-excitation by development of accessory atrioventricular pathway. A series of mutations in PRKAG2 gene encoding gamma2 subunit of 5'AMP-activated protein kinase (AMPK) has been identified as the cause of familial WPW syndrome. AMPK is one of the most important metabolic regulators of carbohydrates and lipids in many types of tissues including cardiac and skeletal muscles. Patients and animals with the mutation in PRKAG2 gene exhibit aberrant atrioventricular conduction associated with cardiac glycogen overload. Recent studies have revealed "novel" significance of canonical pathways leading to glycogen synthesis and provided us profound insights into molecular mechanism of the regulation of glycogen metabolism by AMPK. This review focuses on the molecular basis of the pathogenesis of cardiac abnormality due to PRKAG2 mutation and will provide current overviews of the mechanism of glycogen regulation by AMPK. J. Med. Invest. 65:1-8, February, 2018.

Genetic factors contribute to bleeding after cardiac surgery.

PubMed

Welsby, I J; Podgoreanu, M V; Phillips-Bute, B; Mathew, J P; Smith, P K; Newman, M F; Schwinn, D A; Stafford-Smith, M

2005-06-01

Postoperative bleeding remains a common, serious problem for cardiac surgery patients, with striking inter-patient variability poorly explained by clinical, procedural, and biological markers. We tested the hypothesis that genetic polymorphisms of coagulation proteins and platelet glycoproteins are associated with bleeding after cardiac surgery. Seven hundred and eighty patients undergoing aortocoronary surgery with cardiopulmonary bypass were studied. Clinical covariates previously associated with bleeding were recorded and DNA isolated from preoperative blood. Matrix Assisted Laser Desorption/Ionization, Time-Of-Flight (MALDI-TOF) mass spectroscopy or polymerase chain reaction were used for genotype analysis. Multivariable linear regression modeling, including all genetic main effects and two-way gene-gene interactions, related clinical and genetic predictors to bleeding from the thorax and mediastinum. Nineteen candidate polymorphisms were assessed; seven [GPIaIIa-52C>T and 807C>T, GPIb alpha 524C>T, tissue factor-603A>G, prothrombin 20210G>A, tissue factor pathway inhibitor-399C>T, and angiotensin converting enzyme (ACE) deletion/insertion] demonstrate significant association with bleeding (P < 0.01). Adding genetic to clinical predictors results improves the model, doubling overall ability to predict bleeding (P < 0.01). We identified seven genetic polymorphisms associated with bleeding after cardiac surgery. Genetic factors appear primarily independent of, and explain at least as much variation in bleeding as clinical covariates; combining genetic and clinical factors double our ability to predict bleeding after cardiac surgery. Accounting for genotype may be necessary when stratifying risk of bleeding after cardiac surgery.

Angiotensin II promotes differentiation of mouse c-kit-positive cardiac stem cells into pacemaker-like cells

PubMed Central

XUE, CHENG; ZHANG, JUN; LV, ZHAN; LIU, HUI; HUANG, CONGXIN; YANG, JING; WANG, TEN

2015-01-01

Cardiac stem cells (CSCs) can differentiate into cardiac muscle-like cells; however, it remains unknown whether CSCs may possess the ability to differentiate into pacemaker cells. The aim of the present study was to determine whether angiotensin II (Ang II) could promote the specialization of CSCs into pacemaker-like cells. Mouse CSCs were treated with Ang II from day 3–5, after cell sorting. The differentiation potential of the cells was then analyzed by morphological analysis, flow cytometry, reverse transcription-polymerase chain reaction, immunohistochemistry and patch clamp analysis. Treatment with Ang II resulted in an increased number of cardiac muscle-like cells (32.7±4.8% vs. 21.5±4.8%; P<0.05), and inhibition of smooth muscle-like cells (6.2±7.3% vs. 20.5±5.1%; P<0.05). Following treatment with Ang II, increased levels of the cardiac progenitor-specific markers GATA4 and Nkx2.5 were observed in the cells. Furthermore, the transcript levels of pacemaker function-related genes, including hyperpolarization-activated cyclic nucleotide-gated (HCN)2, HCN4, T-box (Tbx)2 and Tbx3, were significantly upregulated. Immunofluorescence analysis confirmed the increased number of pacemaker-like cells. The pacemaker current (If) was recorded in the cells derived from CSCs, treated with Ang II. In conclusion, treatment of CSCs with Ang II during the differentiation process modified cardiac-specific gene expression and resulted in the enhanced formation of pacemaker-like cells. PMID:25572000

Apelin: an endogenous peptide essential for cardiomyogenic differentiation of mesenchymal stem cells via activating extracellular signal-regulated kinase 1/2 and 5.

PubMed

Wang, Li; Zhu, Zhi-Ming; Zhang, Ning-Kun; Fang, Zhi-Rong; Xu, Xiao-Hong; Zheng, Nan; Gao, Lian-Ru

2016-05-01

Growing evidence has shown that apelin/APJ system functions as a critical mediator of cardiac development as well as cardiovascular function. Here, we investigated the role of apelin in the cardiomyogenic differentiation of mesenchymal stem cells derived from Wharton's jelly of human umbilical cord in vitro. In this research, we used RNA interference methodology and gene transfection technique to regulate the expression of apelin in Wharton's jelly-derived mesenchymal stem cells and induced cells with a effective cardiac differentiation protocol including 5-azacytidine and bFGF. Four weeks after induction, induced cells assumed a stick-like morphology and myotube-like structures except apelin-silenced cells and the control group. The silencing expression of apelin in Wharton's jelly-derived mesenchymal stem cells decreased the expression of several critical cardiac progenitor transcription factors (Mesp1, Mef2c, NKX2.5) and cardiac phenotypes (cardiac α-actin, β-MHC, cTnT, and connexin-43). Meanwhile, endogenous compensation of apelin contributed to differentiating into cells with characteristics of cardiomyocytes in vitro. Further experiment showed that exogenous apelin peptide rescued the cardiomyogenic differentiation of apelin-silenced mesenchymal stem cells in the early stage (1-4 days) of induction. Remarkably, our experiment indicated that apelin up-regulated cardiac specific genes in Wharton's jelly-derived mesenchymal stem cells via activating extracellular signal-regulated kinase (ERK) 1/2 and 5. © 2016 International Federation for Cell Biology.

Mammalian enabled (Mena) is a critical regulator of cardiac function

PubMed Central

Aguilar, Frédérick; Belmonte, Stephen L.; Ram, Rashmi; Noujaim, Sami F.; Dunaevsky, Olga; Protack, Tricia L.; Jalife, Jose; Todd Massey, H.; Gertler, Frank B.

2011-01-01

Mammalian enabled (Mena) of the Drosophila enabled/vasodilator-stimulated phosphoprotein gene family is a cytoskeletal protein implicated in actin regulation and cell motility. Cardiac Mena expression is enriched in intercalated discs (ICD), the critical intercellular communication nexus between adjacent muscle cells. We previously identified Mena gene expression to be a key predictor of human and murine heart failure (HF). To determine the in vivo function of Mena in the heart, we assessed Mena protein expression in multiple HF models and characterized the effects of genetic Mena deletion on cardiac structure and function. Immunoblot analysis revealed significant upregulation of Mena protein expression in left ventricle tissue from patients with end-stage HF, calsequestrin-overexpressing mice, and isoproterenol-infused mice. Characterization of the baseline cardiac function of adult Mena knockout mice (Mena−/−) via echocardiography demonstrated persistent cardiac dysfunction, including a significant reduction in percent fractional shortening compared with wild-type littermates. Electrocardiogram PR and QRS intervals were significantly prolonged in Mena−/− mice, manifested by slowed conduction on optical mapping studies. Ultrastructural analysis of Mena−/− hearts revealed disrupted organization and widening of ICD structures, mislocalization of the gap junction protein connexin 43 (Cx43) to the lateral borders of cardiomyoycytes, and increased Cx43 expression. Furthermore, the expression of vinculin (an adherens junction protein) was significantly reduced in Mena−/− mice. We report for the first time that genetic ablation of Mena results in cardiac dysfunction, highlighted by diminished contractile performance, disrupted ICD structure, and slowed electrical conduction. PMID:21335464

Mammalian enabled (Mena) is a critical regulator of cardiac function.

PubMed

Aguilar, Frédérick; Belmonte, Stephen L; Ram, Rashmi; Noujaim, Sami F; Dunaevsky, Olga; Protack, Tricia L; Jalife, Jose; Todd Massey, H; Gertler, Frank B; Blaxall, Burns C

2011-05-01

Mammalian enabled (Mena) of the Drosophila enabled/vasodilator-stimulated phosphoprotein gene family is a cytoskeletal protein implicated in actin regulation and cell motility. Cardiac Mena expression is enriched in intercalated discs (ICD), the critical intercellular communication nexus between adjacent muscle cells. We previously identified Mena gene expression to be a key predictor of human and murine heart failure (HF). To determine the in vivo function of Mena in the heart, we assessed Mena protein expression in multiple HF models and characterized the effects of genetic Mena deletion on cardiac structure and function. Immunoblot analysis revealed significant upregulation of Mena protein expression in left ventricle tissue from patients with end-stage HF, calsequestrin-overexpressing mice, and isoproterenol-infused mice. Characterization of the baseline cardiac function of adult Mena knockout mice (Mena(-/-)) via echocardiography demonstrated persistent cardiac dysfunction, including a significant reduction in percent fractional shortening compared with wild-type littermates. Electrocardiogram PR and QRS intervals were significantly prolonged in Mena(-/-) mice, manifested by slowed conduction on optical mapping studies. Ultrastructural analysis of Mena(-/-) hearts revealed disrupted organization and widening of ICD structures, mislocalization of the gap junction protein connexin 43 (Cx43) to the lateral borders of cardiomyoycytes, and increased Cx43 expression. Furthermore, the expression of vinculin (an adherens junction protein) was significantly reduced in Mena(-/-) mice. We report for the first time that genetic ablation of Mena results in cardiac dysfunction, highlighted by diminished contractile performance, disrupted ICD structure, and slowed electrical conduction.

A Novel Mutation on RAF1 in Association with Fetal Findings Suggestive of Noonan Syndrome.

PubMed

Kneitel, Anna W; Norby, Audrey; Vettraino, Ivana; Treadwell, Marjorie C

2015-01-01

Noonan syndrome is a multisystem genetic disorder caused by genes encoding proteins involved in the RAS-MAPK pathway. Affected fetuses have variable presentations ranging from the absence of prenatal findings to increased nuchal fold, cystic hygromas, pleural effusions, cardiac malformations, or skin edema. We describe a male fetus who had features consistent with Noonan syndrome at the time of fetal anatomic survey, including hydrops and a possible cardiac defect. Subsequent scan revealed persistent bilateral pleural effusions (with predominance of lymphocytes). After bilateral thoracoamniotic shunt placement, the fetus did well and delivered at term. Prenatal testing revealed an S650F missense mutation in the RAF1 gene, which had not previously been associated with Noonan syndrome.

Calreticulin Induces Dilated Cardiomyopathy

PubMed Central

Lee, Dukgyu; Oka, Tatsujiro; Hunter, Beth; Robinson, Alison; Papp, Sylvia; Nakamura, Kimitoshi; Srisakuldee, Wattamon; Nickel, Barbara E.; Light, Peter E.; Dyck, Jason R. B.; Lopaschuk, Gary D.; Kardami, Elissavet; Opas, Michal; Michalak, Marek

2013-01-01

Background Calreticulin, a Ca2+-buffering chaperone of the endoplasmic reticulum, is highly expressed in the embryonic heart and is essential for cardiac development. After birth, the calreticulin gene is sharply down regulated in the heart, and thus, adult hearts have negligible levels of calreticulin. In this study we tested the role of calreticulin in the adult heart. Methodology/Principal Findings We generated an inducible transgenic mouse in which calreticulin is targeted to the cardiac tissue using a Cre/loxP system and can be up-regulated in adult hearts. Echocardiography analysis of hearts from transgenic mice expressing calreticulin revealed impaired left ventricular systolic and diastolic function and impaired mitral valve function. There was altered expression of Ca2+ signaling molecules and the gap junction proteins, Connexin 43 and 45. Sarcoplasmic reticulum associated Ca2+-handling proteins (including the cardiac ryanodine receptor, sarco/endoplasmic reticulum Ca2+-ATPase, and cardiac calsequestrin) were down-regulated in the transgenic hearts with increased expression of calreticulin. Conclusions/Significance We show that in adult heart, up-regulated expression of calreticulin induces cardiomyopathy in vivo leading to heart failure. This is due to an alternation in changes in a subset of Ca2+ handling genes, gap junction components and left ventricle remodeling. PMID:23437120

Necessity of angiotensin-converting enzyme-related gene for cardiac functions and longevity of Drosophila melanogaster assessed by optical coherence tomography

NASA Astrophysics Data System (ADS)

Liao, Fang-Tsu; Chang, Cheng-Yi; Su, Ming-Tsan; Kuo, Wen-Chuan

2014-01-01

Prior studies have established the necessity of an angiotensin-converting enzyme-related (ACER) gene for heart morphogenesis of Drosophila. Nevertheless, the physiology of ACER has yet to be comprehensively understood. Herein, we employed RNA interference to down-regulate the expression of ACER in Drosophila's heart and swept source optical coherence tomography to assess whether ACER is required for cardiac functions in living adult flies. Several contractile parameters of Drosophila heart, including the heart rate (HR), end-diastolic diameter (EDD), end-systolic diameter (ESD), percent fractional shortening (%FS), and stress-induced cardiac performance, are shown, which are age dependent. These age-dependent cardiac functions declined significantly when ACER was down-regulated. Moreover, the lifespans of ACER knock-down flies were significantly shorter than those of wild-type control flies. Thus, we posit that ACER, the Drosophila ortholog of mammalian angiotensin-converting enzyme 2 (ACE2), is essential for both heart physiology and longevity of animals. Since mammalian ACE2 controls many cardiovascular physiological features and is implicated in cardiomyopathies, our findings that ACER plays conserved roles in genetically tractable animals will pave the way for uncovering the genetic pathway that controls the renin-angiotensin system.

Selumetinib, an Oral Anti-Neoplastic Drug, May Attenuate Cardiac Hypertrophy via Targeting the ERK Pathway

PubMed Central

Yang, Hao; Luo, Fangbo; Chen, Lihong; Cai, Huawei; Li, Yajiao; You, Guiying; Long, Dan; Li, Shengfu; Zhang, Qiuping; Rao, Li

2016-01-01

Aims Although extracellular-regulated kinases (ERK) are a well-known central mediator in cardiac hypertrophy, no clinically available ERK antagonist has been tested for preventing cardiac hypertrophy. Selumetinib is a novel oral MEK inhibitor that is currently under Phase II and Phase III clinical investigation for advanced solid tumors. In this study, we investigated whether Selumetinib could inhibit the aberrant ERK activation of the heart in response to stress as well as prevent cardiac hypertrophy. Methods and Results In an in vitro model of PE-induced cardiac hypertrophy, Selumetinib significantly inhibited the ERK activation and prevented enlargement of cardiomyocytes or reactivation of certain fetal genes. In the pathologic cardiac hypertrophy model of ascending aortic constriction, Selumetinib provided significant ERK inhibition in the stressed heart but not in the other organs. This selective ERK inhibition prevented left ventricular (LV) wall thickening, LV mass increase, fetal gene reactivation and cardiac fibrosis. In another distinct physiologic cardiac hypertrophy model of a swimming rat, Selumetinib provided a similar anti-hypertrophy effect, except that no significant fetal gene reactivation or cardiac fibrosis was observed. Conclusions Selumetinib, a novel oral anti-cancer drug with good safety records in a number of Phase II clinical trials, can inhibit ERK activity in the heart and prevent cardiac hypertrophy. These promising results indicate that Selumetinib could potentially be used to treat cardiac hypertrophy. However, this hypothesis needs to be validated in human clinical trials. PMID:27438013

CARFMAP: A Curated Pathway Map of Cardiac Fibroblasts.

PubMed

Nim, Hieu T; Furtado, Milena B; Costa, Mauro W; Kitano, Hiroaki; Rosenthal, Nadia A; Boyd, Sarah E

2015-01-01

The adult mammalian heart contains multiple cell types that work in unison under tightly regulated conditions to maintain homeostasis. Cardiac fibroblasts are a significant and unique population of non-muscle cells in the heart that have recently gained substantial interest in the cardiac biology community. To better understand this renaissance cell, it is essential to systematically survey what has been known in the literature about the cellular and molecular processes involved. We have built CARFMAP (http://visionet.erc.monash.edu.au/CARFMAP), an interactive cardiac fibroblast pathway map derived from the biomedical literature using a software-assisted manual data collection approach. CARFMAP is an information-rich interactive tool that enables cardiac biologists to explore the large body of literature in various creative ways. There is surprisingly little overlap between the cardiac fibroblast pathway map, a foreskin fibroblast pathway map, and a whole mouse organism signalling pathway map from the REACTOME database. Among the use cases of CARFMAP is a common task in our cardiac biology laboratory of identifying new genes that are (1) relevant to cardiac literature, and (2) differentially regulated in high-throughput assays. From the expression profiles of mouse cardiac and tail fibroblasts, we employed CARFMAP to characterise cardiac fibroblast pathways. Using CARFMAP in conjunction with transcriptomic data, we generated a stringent list of six genes that would not have been singled out using bioinformatics analyses alone. Experimental validation showed that five genes (Mmp3, Il6, Edn1, Pdgfc and Fgf10) are differentially regulated in the cardiac fibroblast. CARFMAP is a powerful tool for systems analyses of cardiac fibroblasts, facilitating systems-level cardiovascular research.

Exome-based analysis of cardiac arrhythmia, respiratory control, and epilepsy genes in sudden unexpected death in epilepsy.

PubMed

Bagnall, Richard D; Crompton, Douglas E; Petrovski, Slavé; Lam, Lien; Cutmore, Carina; Garry, Sarah I; Sadleir, Lynette G; Dibbens, Leanne M; Cairns, Anita; Kivity, Sara; Afawi, Zaid; Regan, Brigid M; Duflou, Johan; Berkovic, Samuel F; Scheffer, Ingrid E; Semsarian, Christopher

2016-04-01

The leading cause of epilepsy-related premature mortality is sudden unexpected death in epilepsy (SUDEP). The cause of SUDEP remains unknown. To search for genetic risk factors in SUDEP cases, we performed an exome-based analysis of rare variants. Demographic and clinical information of 61 SUDEP cases were collected. Exome sequencing and rare variant collapsing analysis with 2,936 control exomes were performed to test for genes enriched with damaging variants. Additionally, cardiac arrhythmia, respiratory control, and epilepsy genes were screened for variants with frequency of <0.1% and predicted to be pathogenic with multiple in silico tools. The 61 SUDEP cases were categorized as definite SUDEP (n = 54), probable SUDEP (n = 5), and definite SUDEP plus (n = 2). We identified de novo mutations, previously reported pathogenic mutations, or candidate pathogenic variants in 28 of 61 (46%) cases. Four SUDEP cases (7%) had mutations in common genes responsible for the cardiac arrhythmia disease, long QT syndrome (LQTS). Nine cases (15%) had candidate pathogenic variants in dominant cardiac arrhythmia genes. Fifteen cases (25%) had mutations or candidate pathogenic variants in dominant epilepsy genes. No gene reached genome-wide significance with rare variant collapsing analysis; however, DEPDC5 (p = 0.00015) and KCNH2 (p = 0.0037) were among the top 30 genes, genome-wide. A sizeable proportion of SUDEP cases have clinically relevant mutations in cardiac arrhythmia and epilepsy genes. In cases with an LQTS gene mutation, SUDEP may occur as a result of a predictable and preventable cause. Understanding the genetic basis of SUDEP may inform cascade testing of at-risk family members. © 2016 American Neurological Association.

Myocardial gene delivery using molecular cardiac surgery with recombinant adeno-associated virus vectors in vivo

PubMed Central

White, JD; Thesier, DM; Swain, JBD; Katz, MG; Tomasulo, C; Henderson, A; Wang, L; Yarnall, C; Fargnoli, A; Sumaroka, M; Isidro, A; Petrov, M; Holt, D; Nolen-Walston, R; Koch, WJ; Stedman, HH; Rabinowitz, J; Bridges, CR

2013-01-01

We use a novel technique that allows for closed recirculation of vector genomes in the cardiac circulation using cardiopulmonary bypass, referred to here as molecular cardiac surgery with recirculating delivery (MCARD). We demonstrate that this platform technology is highly efficient in isolating the heart from the systemic circulation in vivo. Using MCARD, we compare the relative efficacy of single-stranded (ss) adeno-associated virus (AAV)6, ssAAV9 and self-complimentary (sc)AAV6-encoding enhanced green fluorescent protein, driven by the constitutive cytomegalovirus promoter to transduce the ovine myocardium in situ. MCARD allows for the unprecedented delivery of up to 48 green fluorescent protein genome copies per cell globally in the sheep left ventricular (LV) myocardium. We demonstrate that scAAV6-mediated MCARD delivery results in global, cardiac-specific LV gene expression in the ovine heart and provides for considerably more robust and cardiac-specific gene delivery than other available delivery techniques such as intramuscular injection or intracoronary injection; thus, representing a potential, clinically translatable platform for heart failure gene therapy. PMID:21228882

Comparative Analysis of mRNA Isoform Expression in Cardiac Hypertrophy and Development Reveals Multiple Post-Transcriptional Regulatory Modules

PubMed Central

Park, Ji Yeon; Li, Wencheng; Zheng, Dinghai; Zhai, Peiyong; Zhao, Yun; Matsuda, Takahisa; Vatner, Stephen F.; Sadoshima, Junichi; Tian, Bin

2011-01-01

Cardiac hypertrophy is enlargement of the heart in response to physiological or pathological stimuli, chiefly involving growth of myocytes in size rather than in number. Previous studies have shown that the expression pattern of a group of genes in hypertrophied heart induced by pressure overload resembles that at the embryonic stage of heart development, a phenomenon known as activation of the “fetal gene program”. Here, using a genome-wide approach we systematically defined genes and pathways regulated in short- and long-term cardiac hypertrophy conditions using mice with transverse aortic constriction (TAC), and compared them with those regulated at different stages of embryonic and postnatal development. In addition, exon-level analysis revealed widespread mRNA isoform changes during cardiac hypertrophy resulting from alternative usage of terminal or internal exons, some of which are also developmentally regulated and may be attributable to decreased expression of Fox-1 protein in cardiac hypertrophy. Genes with functions in certain pathways, such as cell adhesion and cell morphology, are more likely to be regulated by alternative splicing. Moreover, we found 3′UTRs of mRNAs were generally shortened through alternative cleavage and polyadenylation in hypertrophy, and microRNA target genes were generally de-repressed, suggesting coordinated mechanisms to increase mRNA stability and protein production during hypertrophy. Taken together, our results comprehensively delineated gene and mRNA isoform regulation events in cardiac hypertrophy and revealed their relations to those in development, and suggested that modulation of mRNA isoform expression plays an importance role in heart remodeling under pressure overload. PMID:21799842

Cardiac-specific overexpression of aldehyde dehydrogenase 2 exacerbates cardiac remodeling in response to pressure overload.

PubMed

Dassanayaka, Sujith; Zheng, Yuting; Gibb, Andrew A; Cummins, Timothy D; McNally, Lindsey A; Brittian, Kenneth R; Jagatheesan, Ganapathy; Audam, Timothy N; Long, Bethany W; Brainard, Robert E; Jones, Steven P; Hill, Bradford G

2018-06-01

Pathological cardiac remodeling during heart failure is associated with higher levels of lipid peroxidation products and lower abundance of several aldehyde detoxification enzymes, including aldehyde dehydrogenase 2 (ALDH2). An emerging idea that could explain these findings concerns the role of electrophilic species in redox signaling, which may be important for adaptive responses to stress or injury. The purpose of this study was to determine whether genetically increasing ALDH2 activity affects pressure overload-induced cardiac dysfunction. Mice subjected to transverse aortic constriction (TAC) for 12 weeks developed myocardial hypertrophy and cardiac dysfunction, which were associated with diminished ALDH2 expression and activity. Cardiac-specific expression of the human ALDH2 gene in mice augmented myocardial ALDH2 activity but did not improve cardiac function in response to pressure overload. After 12 weeks of TAC, ALDH2 transgenic mice had larger hearts than their wild-type littermates and lower capillary density. These findings show that overexpression of ALDH2 augments the hypertrophic response to pressure overload and imply that downregulation of ALDH2 may be an adaptive response to certain forms of cardiac pathology. Copyright © 2018. Published by Elsevier B.V.

Loss of microRNA-22 prevents high-fat diet induced dyslipidemia and increases energy expenditure without affecting cardiac hypertrophy.

PubMed

Diniz, Gabriela Placoná; Huang, Zhan-Peng; Liu, Jianming; Chen, Jinghai; Ding, Jian; Fonseca, Renata Inzinna; Barreto-Chaves, Maria Luiza; Donato, Jose; Hu, Xiaoyun; Wang, Da-Zhi

2017-12-15

Obesity is associated with development of diverse diseases, including cardiovascular diseases and dyslipidemia. MiRNA-22 (miR-22) is a critical regulator of cardiac function and targets genes involved in metabolic processes. Previously, we generated miR-22 null mice and we showed that loss of miR-22 blunted cardiac hypertrophy induced by mechanohormornal stress. In the present study, we examined the role of miR-22 in the cardiac and metabolic alterations promoted by high-fat (HF) diet. We found that loss of miR-22 attenuated the gain of fat mass and prevented dyslipidemia induced by HF diet, although the body weight gain, or glucose intolerance and insulin resistance did not seem to be affected. Mechanistically, loss of miR-22 attenuated the increased expression of genes involved in lipogenesis and inflammation mediated by HF diet. Similarly, we found that miR-22 mediates metabolic alterations and inflammation induced by obesity in the liver. However, loss of miR-22 did not appear to alter HF diet induced cardiac hypertrophy or fibrosis in the heart. Our study therefore establishes miR-22 as an important regulator of dyslipidemia and suggests it may serve as a potential candidate in the treatment of dyslipidemia associated with obesity. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Alteration at transcriptional level of cardiac renin-angiotensin system by letrozole treatment.

PubMed

Shekarforoush, Shahnaz; Koohpeyma, Farhad; Safari, Fatemeh

2018-06-17

The use of aromatase inhibitors (AIs) for breast cancer led to a marked change in ventricular function. Since accumulating evidence indicates that overactivation of the cardiac renin-angiotensin system (RAS) plays an important role in the development of cardiovascular diseases such as hypertrophy and remodelling, we aimed to investigate whether letrozole alters the transcription level of RAS related genes in the cardiac tissue. Twenty four rats were randomly divided into four groups (n = 6 per group): two groups were letrozole treated (1 and 2 mg/kg/day orally), one group was vehicle treated (DMSO) and one group was the control group without any treatment. 12 weeks after beginning treatment with letrozole, we examined the rate of transcription of renin, angiotensinogen, AngII type 1a and 1b (AT1a and AT1b) and type 2 receptors (AT2) in the rat heart using real-time polymerase chain reaction. The cardiac mRNA levels of several components of the RAS in the rats treated with letrozole were significantly increased including AT1a receptor (80%), renin (51%), and angiotensinogen (33%). Though not significant, AT2 receptor levels were observed to decrease with increasing doses of letrozole. Letrozole can induce significant changes in some RAS related genes. These alterations are important to understand the pathways and consequences beyond cardiac events induced by breast cancer treatments.

Exercise-Induced Changes in Glucose Metabolism Promote Physiological Cardiac Growth

PubMed Central

Gibb, Andrew A.; Epstein, Paul N.; Uchida, Shizuka; Zheng, Yuting; McNally, Lindsey A.; Obal, Detlef; Katragadda, Kartik; Trainor, Patrick; Conklin, Daniel J.; Brittian, Kenneth R.; Tseng, Michael T.; Wang, Jianxun; Jones, Steven P.; Bhatnagar, Aruni

2017-01-01

Background: Exercise promotes metabolic remodeling in the heart, which is associated with physiological cardiac growth; however, it is not known whether or how physical activity–induced changes in cardiac metabolism cause myocardial remodeling. In this study, we tested whether exercise-mediated changes in cardiomyocyte glucose metabolism are important for physiological cardiac growth. Methods: We used radiometric, immunologic, metabolomic, and biochemical assays to measure changes in myocardial glucose metabolism in mice subjected to acute and chronic treadmill exercise. To assess the relevance of changes in glycolytic activity, we determined how cardiac-specific expression of mutant forms of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase affect cardiac structure, function, metabolism, and gene programs relevant to cardiac remodeling. Metabolomic and transcriptomic screenings were used to identify metabolic pathways and gene sets regulated by glycolytic activity in the heart. Results: Exercise acutely decreased glucose utilization via glycolysis by modulating circulating substrates and reducing phosphofructokinase activity; however, in the recovered state following exercise adaptation, there was an increase in myocardial phosphofructokinase activity and glycolysis. In mice, cardiac-specific expression of a kinase-deficient 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase transgene (GlycoLo mice) lowered glycolytic rate and regulated the expression of genes known to promote cardiac growth. Hearts of GlycoLo mice had larger myocytes, enhanced cardiac function, and higher capillary-to-myocyte ratios. Expression of phosphatase-deficient 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase in the heart (GlycoHi mice) increased glucose utilization and promoted a more pathological form of hypertrophy devoid of transcriptional activation of the physiological cardiac growth program. Modulation of phosphofructokinase activity was sufficient to regulate the glucose–fatty acid cycle in the heart; however, metabolic inflexibility caused by invariantly low or high phosphofructokinase activity caused modest mitochondrial damage. Transcriptomic analyses showed that glycolysis regulates the expression of key genes involved in cardiac metabolism and remodeling. Conclusions: Exercise-induced decreases in glycolytic activity stimulate physiological cardiac remodeling, and metabolic flexibility is important for maintaining mitochondrial health in the heart. PMID:28860122

Initial deployment of the cardiogenic gene regulatory network in the basal chordate, Ciona intestinalis.

PubMed

Woznica, Arielle; Haeussler, Maximilian; Starobinska, Ella; Jemmett, Jessica; Li, Younan; Mount, David; Davidson, Brad

2012-08-01

The complex, partially redundant gene regulatory architecture underlying vertebrate heart formation has been difficult to characterize. Here, we dissect the primary cardiac gene regulatory network in the invertebrate chordate, Ciona intestinalis. The Ciona heart progenitor lineage is first specified by Fibroblast Growth Factor/Map Kinase (FGF/MapK) activation of the transcription factor Ets1/2 (Ets). Through microarray analysis of sorted heart progenitor cells, we identified the complete set of primary genes upregulated by FGF/Ets shortly after heart progenitor emergence. Combinatorial sequence analysis of these co-regulated genes generated a hypothetical regulatory code consisting of Ets binding sites associated with a specific co-motif, ATTA. Through extensive reporter analysis, we confirmed the functional importance of the ATTA co-motif in primary heart progenitor gene regulation. We then used the Ets/ATTA combination motif to successfully predict a number of additional heart progenitor gene regulatory elements, including an intronic element driving expression of the core conserved cardiac transcription factor, GATAa. This work significantly advances our understanding of the Ciona heart gene network. Furthermore, this work has begun to elucidate the precise regulatory architecture underlying the conserved, primary role of FGF/Ets in chordate heart lineage specification. Copyright © 2012 Elsevier Inc. All rights reserved.

Nkx2.5 enhances the efficacy of mesenchymal stem cells transplantation in treatment heart failure in rats.

PubMed

Deng, Bo; Wang, Jin Xin; Hu, Xing Xing; Duan, Peng; Wang, Lin; Li, Yang; Zhu, Qing Lei

2017-08-01

The aim of this study is to determine whether Nkx2.5 transfection of transplanted bone marrow mesenchymal stem cells (MSCs) improves the efficacy of treatment of adriamycin-induced heart failure in a rat model. Nkx2.5 was transfected in MSCs by lentiviral vector transduction. The expressions of Nkx2.5 and cardiac specific genes in MSCs and Nkx2.5 transfected mesenchymal stem cells (MSCs-Nkx2.5) were analyzed with quantitative real-time PCR and Western blot in vitro. Heart failure models of rats were induced by adriamycin and were then randomly divided into 3 groups: injected saline, MSCs or MSCs-Nkx2.5 via the femoral vein respectively. Four weeks after injection, the cardiac function, expressions of cardiac specific gene, fibrosis formation and collagen volume fraction in the myocardium as well as the expressions of GATA4 and MEF2 in rats were analyzed with echocardiography, immunohistochemistry, Masson staining, quantitative real-time PCR and Western blot, respectively. Nkx2.5 enhanced cardiac specific gene expressions including α-MHC, TNI, CKMB, connexin-43 in MSCs-Nkx2.5 in vitro. Both MSCs and MSCs-Nkx2.5 improved cardiac function, promoted the differentiation of transplanted MSCs into cardiomyocyte-like cells, decreased fibrosis formation and collagen volume fraction in the myocardium, as well as increased the expressions of GATA4 and MEF2 in adriamycin-induced rat heart failure models. Moreover, the effect was much more remarkable in MSCs-Nkx2.5 than in MSCs group. This study has found that Nkx2.5 enhances the efficacy of MSCs transplantation in treatment adriamycin-induced heart failure in rats. Nkx2.5 transfected to transplanted MSCs provides a potential effective approach to heart failure. Copyright © 2017 Elsevier Inc. All rights reserved.

Electromechanical Conditioning of Adult Progenitor Cells Improves Recovery of Cardiac Function After Myocardial Infarction

PubMed Central

Llucià‐Valldeperas, Aida; Soler‐Botija, Carolina; Gálvez‐Montón, Carolina; Roura, Santiago; Prat‐Vidal, Cristina; Perea‐Gil, Isaac; Sanchez, Benjamin; Bragos, Ramon; Vunjak‐Novakovic, Gordana

2016-01-01

Abstract Cardiac cells are subjected to mechanical and electrical forces, which regulate gene expression and cellular function. Therefore, in vitro electromechanical stimuli could benefit further integration of therapeutic cells into the myocardium. Our goals were (a) to study the viability of a tissue‐engineered construct with cardiac adipose tissue‐derived progenitor cells (cardiac ATDPCs) and (b) to examine the effect of electromechanically stimulated cardiac ATDPCs within a myocardial infarction (MI) model in mice for the first time. Cardiac ATDPCs were electromechanically stimulated at 2‐millisecond pulses of 50 mV/cm at 1 Hz and 10% stretching during 7 days. The cells were harvested, labeled, embedded in a fibrin hydrogel, and implanted over the infarcted area of the murine heart. A total of 39 animals were randomly distributed and sacrificed at 21 days: groups of grafts without cells and with stimulated or nonstimulated cells. Echocardiography and gene and protein analyses were also carried out. Physiologically stimulated ATDPCs showed increased expression of cardiac transcription factors, structural genes, and calcium handling genes. At 21 days after implantation, cardiac function (measured as left ventricle ejection fraction between presacrifice and post‐MI) increased up to 12% in stimulated grafts relative to nontreated animals. Vascularization and integration with the host blood supply of grafts with stimulated cells resulted in increased vessel density in the infarct border region. Trained cells within the implanted fibrin patch expressed main cardiac markers and migrated into the underlying ischemic myocardium. To conclude, synchronous electromechanical cell conditioning before delivery may be a preferred alternative when considering strategies for heart repair after myocardial infarction. Stem Cells Translational Medicine 2017;6:970–981 PMID:28297585

Electromechanical Conditioning of Adult Progenitor Cells Improves Recovery of Cardiac Function After Myocardial Infarction.

PubMed

Llucià-Valldeperas, Aida; Soler-Botija, Carolina; Gálvez-Montón, Carolina; Roura, Santiago; Prat-Vidal, Cristina; Perea-Gil, Isaac; Sanchez, Benjamin; Bragos, Ramon; Vunjak-Novakovic, Gordana; Bayes-Genis, Antoni

2017-03-01

Cardiac cells are subjected to mechanical and electrical forces, which regulate gene expression and cellular function. Therefore, in vitro electromechanical stimuli could benefit further integration of therapeutic cells into the myocardium. Our goals were (a) to study the viability of a tissue-engineered construct with cardiac adipose tissue-derived progenitor cells (cardiac ATDPCs) and (b) to examine the effect of electromechanically stimulated cardiac ATDPCs within a myocardial infarction (MI) model in mice for the first time. Cardiac ATDPCs were electromechanically stimulated at 2-millisecond pulses of 50 mV/cm at 1 Hz and 10% stretching during 7 days. The cells were harvested, labeled, embedded in a fibrin hydrogel, and implanted over the infarcted area of the murine heart. A total of 39 animals were randomly distributed and sacrificed at 21 days: groups of grafts without cells and with stimulated or nonstimulated cells. Echocardiography and gene and protein analyses were also carried out. Physiologically stimulated ATDPCs showed increased expression of cardiac transcription factors, structural genes, and calcium handling genes. At 21 days after implantation, cardiac function (measured as left ventricle ejection fraction between presacrifice and post-MI) increased up to 12% in stimulated grafts relative to nontreated animals. Vascularization and integration with the host blood supply of grafts with stimulated cells resulted in increased vessel density in the infarct border region. Trained cells within the implanted fibrin patch expressed main cardiac markers and migrated into the underlying ischemic myocardium. To conclude, synchronous electromechanical cell conditioning before delivery may be a preferred alternative when considering strategies for heart repair after myocardial infarction. Stem Cells Translational Medicine 2017;6:970-981. © 2016 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Cardiac gene transfer of short hairpin RNA directed against phospholamban effectively knocks down gene expression but causes cellular toxicity in canines.

PubMed

Bish, Lawrence T; Sleeper, Meg M; Reynolds, Caryn; Gazzara, Jeffrey; Withnall, Elanor; Singletary, Gretchen E; Buchlis, George; Hui, Daniel; High, Katherine A; Gao, Guangping; Wilson, James M; Sweeney, H Lee

2011-08-01

Derangements in calcium cycling have been described in failing hearts, and preclinical studies have suggested that therapies aimed at correcting this defect can lead to improvements in cardiac function and survival. One strategy to improve calcium cycling would be to inhibit phospholamban (PLB), the negative regulator of SERCA2a that is upregulated in failing hearts. The goal of this study was to evaluate the safety and efficacy of using adeno-associated virus (AAV)-mediated cardiac gene transfer of short hairpin RNA (shRNA) to knock down expression of PLB. Six dogs were treated with self-complementary AAV serotype 6 (scAAV6) expressing shRNA against PLB. Three control dogs were treated with empty AAV6 capsid, and two control dogs were treated with scAAV6 expressing dominant negative PLB. Vector was delivered via a percutaneously inserted cardiac injection catheter. PLB mRNA and protein expression were analyzed in three of six shRNA dogs between days 16 and 26. The other three shRNA dogs and five control dogs were monitored long-term to assess cardiac safety. PLB mRNA was reduced 16-fold, and PLB protein was reduced 5-fold, with treatment. Serum troponin elevation and depressed cardiac function were observed in the shRNA group only at 4 weeks. An enzyme-linked immunospot assay failed to detect any T cells reactive to AAV6 capsid in peripheral blood mononuclear cells, heart, or spleen. Microarray analysis revealed alterations in cardiac expression of several microRNAs with shRNA treatment. AAV6-mediated cardiac gene transfer of shRNA effectively knocks down PLB expression but is associated with severe cardiac toxicity. Toxicity may result from dysregulation of endogenous microRNA pathways.

Influence of Nitrous Oxide Anesthesia, B-Vitamins, and MTHFR gene polymorphisms on Perioperative Cardiac Events: The Vitamins in Nitrous Oxide (VINO) Randomized Trial

PubMed Central

Nagele, Peter; Brown, Frank; Francis, Amber; Scott, Mitchell G.; Gage, Brian F.; Miller, J. Philip

2013-01-01

Background Nitrous oxide causes an acute increase in plasma homocysteine that is more pronounced in patients with the MTHFR C677T or A1298C gene variant. In this randomized controlled trial we sought to determine if patients carrying the MTHFR C677T or A1298C variant had a higher risk for perioperative cardiac events after nitrous oxide anesthesia and if this risk could be mitigated by B-vitamins. Methods We randomized adult patients with cardiac risk factors undergoing noncardiac surgery to receive nitrous oxide plus intravenous B-vitamins before and after surgery or to nitrous oxide and placebo. Serial cardiac biomarkers and 12-lead electrocardiograms were obtained. The primary study endpoint was the incidence of myocardial injury, as defined by cardiac troponin I elevation within the first 72 hours after surgery. Results A total of 500 patients completed the trial. Patients who were homozygous for either MTHFR C677T or A1298C gene variant (n= 98; 19.6%) had no increased rate of postoperative cardiac troponin I elevation compared to wild-type and heterozygous patients (11.2% vs. 14.0%; relative risk 0.96, 95% CI 0.85 to 1.07, p=0.48). B-vitamins blunted the rise in homocysteine, but had no effect on cardiac troponin I elevation compared to patients receiving placebo (13.2% vs. 13.6%; relative risk 1.02, 95% CI 0.78 to 1.32, p=0.91). Conclusions Neither MTHFR C677T and A1298C gene variant nor acute homocysteine increase are associated with perioperative cardiac troponin elevation after nitrousoxide anesthesia. B-vitamins blunt nitrous oxide-induced homocysteine increase but have no effect on cardiac troponin elevation. PMID:23856660

Induction of human cardiomyocyte-like cells from fibroblasts by defined factors.

PubMed

Wada, Rie; Muraoka, Naoto; Inagawa, Kohei; Yamakawa, Hiroyuki; Miyamoto, Kazutaka; Sadahiro, Taketaro; Umei, Tomohiko; Kaneda, Ruri; Suzuki, Tomoyuki; Kamiya, Kaichiro; Tohyama, Shugo; Yuasa, Shinsuke; Kokaji, Kiyokazu; Aeba, Ryo; Yozu, Ryohei; Yamagishi, Hiroyuki; Kitamura, Toshio; Fukuda, Keiichi; Ieda, Masaki

2013-07-30

Heart disease remains a leading cause of death worldwide. Owing to the limited regenerative capacity of heart tissue, cardiac regenerative therapy has emerged as an attractive approach. Direct reprogramming of human cardiac fibroblasts (HCFs) into cardiomyocytes may hold great potential for this purpose. We reported previously that induced cardiomyocyte-like cells (iCMs) can be directly generated from mouse cardiac fibroblasts in vitro and vivo by transduction of three transcription factors: Gata4, Mef2c, and Tbx5, collectively termed GMT. In the present study, we sought to determine whether human fibroblasts also could be converted to iCMs by defined factors. Our initial finding that GMT was not sufficient for cardiac induction in HCFs prompted us to screen for additional factors to promote cardiac reprogramming by analyzing multiple cardiac-specific gene induction with quantitative RT-PCR. The addition of Mesp1 and Myocd to GMT up-regulated a broader spectrum of cardiac genes in HCFs more efficiently compared with GMT alone. The HCFs and human dermal fibroblasts transduced with GMT, Mesp1, and Myocd (GMTMM) changed the cell morphology from a spindle shape to a rod-like or polygonal shape, expressed multiple cardiac-specific proteins, increased a broad range of cardiac genes and concomitantly suppressed fibroblast genes, and exhibited spontaneous Ca(2+) oscillations. Moreover, the cells matured to exhibit action potentials and contract synchronously in coculture with murine cardiomyocytes. A 5-ethynyl-2'-deoxyuridine assay revealed that the iCMs thus generated do not pass through a mitotic cell state. These findings demonstrate that human fibroblasts can be directly converted to iCMs by defined factors, which may facilitate future applications in regenerative medicine.

Cardiac Gene Transfer of Short Hairpin RNA Directed Against Phospholamban Effectively Knocks Down Gene Expression but Causes Cellular Toxicity in Canines

PubMed Central

Sleeper, Meg M.; Reynolds, Caryn; Gazzara, Jeffrey; Withnall, Elanor; Singletary, Gretchen E.; Buchlis, George; Hui, Daniel; High, Katherine A.; Gao, Guangping; Wilson, James M.; Sweeney, H. Lee

2011-01-01

Abstract Derangements in calcium cycling have been described in failing hearts, and preclinical studies have suggested that therapies aimed at correcting this defect can lead to improvements in cardiac function and survival. One strategy to improve calcium cycling would be to inhibit phospholamban (PLB), the negative regulator of SERCA2a that is upregulated in failing hearts. The goal of this study was to evaluate the safety and efficacy of using adeno-associated virus (AAV)-mediated cardiac gene transfer of short hairpin RNA (shRNA) to knock down expression of PLB. Six dogs were treated with self-complementary AAV serotype 6 (scAAV6) expressing shRNA against PLB. Three control dogs were treated with empty AAV6 capsid, and two control dogs were treated with scAAV6 expressing dominant negative PLB. Vector was delivered via a percutaneously inserted cardiac injection catheter. PLB mRNA and protein expression were analyzed in three of six shRNA dogs between days 16 and 26. The other three shRNA dogs and five control dogs were monitored long-term to assess cardiac safety. PLB mRNA was reduced 16-fold, and PLB protein was reduced 5-fold, with treatment. Serum troponin elevation and depressed cardiac function were observed in the shRNA group only at 4 weeks. An enzyme-linked immunospot assay failed to detect any T cells reactive to AAV6 capsid in peripheral blood mononuclear cells, heart, or spleen. Microarray analysis revealed alterations in cardiac expression of several microRNAs with shRNA treatment. AAV6-mediated cardiac gene transfer of shRNA effectively knocks down PLB expression but is associated with severe cardiac toxicity. Toxicity may result from dysregulation of endogenous microRNA pathways. PMID:21542669

Angiotensin-converting enzyme gene polymorphism in arrhythmogenic right ventricular dysplasia: is DD genotype helpful in predicting syncope risk?

PubMed

Ozben, Beste; Altun, Ibrahim; Sabri Hancer, Veysel; Bilge, Ahmet Kaya; Tanrikulu, Azra Meryem; Diz-Kucukkaya, Reyhan; Fak, Ali Serdar; Yilmaz, Ercument; Adalet, Kamil

2008-12-01

Arrhythmogenic right ventricular dysplasia (ARVD) is a heritable disorder characterised by fibrofatty replacement of right ventricular myocytes and increased risk of ventricular arrhythmias and sudden cardiac death. Angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism affects myocardial ACE levels. DD genotype favours myocardial fibrosis and is associated with malignant ventricular tachycardia. The aim of this study was to explore ACE gene polymorphism in ARVD patients. Twenty-nine patients with ARVD and 24 controls were included. All ARVD patients had documented sustained ventricular tachycardia. Thirteen patients had syncopal episodes. Six patients were resuscitated from sudden cardiac death. ACE gene polymorphism was identified by polymerase chain reaction technique. There was no significant difference in DD genotype frequency between ARVD patients and controls (44.8% vs. 45.8%, p=0.94). However, DD genotype frequency was significantly higher in ARVD patients with syncopal episodes compared to those without syncope (69.2% vs. 25.0%, p=0.017, odds ratio:6.750, 95% confidence interval: 1.318-34.565). DD genotype was detected in higher frequency also in patients with a family history of sudden cardiac death (66.7% vs. 39.1%,p=0.36). High prevalence of DD genotype in ARVD patients with syncope suggests that ACE I/D polymorphism might be useful in identifying high-risk patients for syncope.

AFos Dissociates Cardiac Myocyte Hypertrophy and Expression of the Pathological Gene Program

PubMed Central

Jeong, Mark Y.; Kinugawa, Koichiro; Vinson, Charles; Long, Carlin S.

2005-01-01

Background Although induction of activator protein-1 (AP-1) transcription factor activity has been observed in cardiac hypertrophy, a direct role for AP-1 in myocardial growth and gene expression remains obscure. Methods and Results Hypertrophy was induced in cultured neonatal rat cardiomyocytes with phenylephrine or overexpression of a constitutively active MAP3K, MKK6. In both treatment groups, induction of the pathological gene profile was observed, ie, expression of β-myosin heavy chain (βMHC), atrial/brain natriuretic peptides (ANP/BNP), and skeletal α-actin (sACT) was increased, whereas expression for α-myosin heavy chain (αMHC) and the sarcoplasmic reticulum Ca2+-ATPase (SERCA) genes was repressed. The role of AP-1 in the hypertrophic phenotype was evaluated with the use of an adenoviral construct expressing a dominant negative mutant of the c-Fos proto-oncogene (AdAFos). Although AFos did not change the myocyte growth response, it abrogated the gene profile to both agonists, including the upregulation of both αMHC and SERCA expression. Conclusions Although c-Fos/AP-1 is necessary for induction of the pathological/fetal gene program, it does not appear to be critical for cardiomyocyte hypertrophy. PMID:15795322

Deletion of ETS-1, a gene in the Jacobsen syndrome critical region, causes ventricular septal defects and abnormal ventricular morphology in mice

PubMed Central

Ye, Maoqing; Coldren, Chris; Liang, Xingqun; Mattina, Teresa; Goldmuntz, Elizabeth; Benson, D. Woodrow; Ivy, Dunbar; Perryman, M.B.; Garrett-Sinha, Lee Ann; Grossfeld, Paul

2010-01-01

Congenital heart defects comprise the most common form of major birth defects, affecting 0.7% of all newborn infants. Jacobsen syndrome (11q-) is a rare chromosomal disorder caused by deletions in distal 11q. We have previously determined that a wide spectrum of the most common congenital heart defects occur in 11q-, including an unprecedented high frequency of hypoplastic left heart syndrome (HLHS). We identified an ∼7 Mb ‘cardiac critical region’ in distal 11q that contains a putative causative gene(s) for congenital heart disease. In this study, we utilized chromosomal microarray mapping to characterize three patients with 11q- and congenital heart defects that carry interstitial deletions overlapping the 7 Mb cardiac critical region. We propose that this 1.2 Mb region of overlap harbors a gene(s) that causes at least a subset of the congenital heart defects that occur in 11q-. We demonstrate that one gene in this region, ETS-1 (a member of the ETS family of transcription factors), is expressed in the endocardium and neural crest during early mouse heart development. Gene-targeted deletion of ETS-1 in mice in a C57/B6 background causes, with high penetrance, large membranous ventricular septal defects and a bifid cardiac apex, and less frequently a non-apex-forming left ventricle (one of the hallmarks of HLHS). Our results implicate an important role for the ETS-1 transcription factor in mammalian heart development and should provide important insights into some of the most common forms of congenital heart disease. PMID:19942620

Influences of the G2350A polymorphism in the ACE Gene on cardiac structure and function of ball game players

PubMed Central

2012-01-01

Background Except for the I/D polymorphism in the angiotensin I-converting enzyme (ACE) gene, there were few reports about the relationship between other genetic polymorphisms in this gene and the changes in cardiac structure and function of athletes. Thus, we investigated whether the G2350A polymorphism in the ACE gene is associated with the changes in cardiac structure and function of ball game players. Total 85 healthy ball game players were recruited in this study, and they were composed of 35 controls and 50 ball game players, respectively. Cardiac structure and function were measured by 2-D echocardiography, and the G2350A polymorphism in the ACE gene analyzed by the SNaPshot method. Results There were significant differences in left ventricular mass index (LVmassI) value among each sporting discipline studied. Especially in the athletes of basketball disciplines, indicated the highest LVmassI value than those of other sporting disciplines studied (p < 0.05). However, there were no significant association between any echocardiographic data and the G2350A polymorphism in the ACE gene in the both controls and ball game players. Conclusions Our data suggests that the G2350A polymorphism in the ACE gene may not significantly contribute to the changes in cardiac structure and function of ball game players, although sporting disciplines of ball game players may influence the changes in LVmassI value of these athletes. Further studies using a larger sample size and other genetic markers in the ACE gene will be needed. PMID:22239999

Transcriptional profile of isoproterenol-induced cardiomyopathy and comparison to exercise-induced cardiac hypertrophy and human cardiac failure

PubMed Central

2009-01-01

Background Isoproterenol-induced cardiac hypertrophy in mice has been used in a number of studies to model human cardiac disease. In this study, we compared the transcriptional response of the heart in this model to other animal models of heart failure, as well as to the transcriptional response of human hearts suffering heart failure. Results We performed microarray analyses on RNA from mice with isoproterenol-induced cardiac hypertrophy and mice with exercise-induced physiological hypertrophy and identified 865 and 2,534 genes that were significantly altered in pathological and physiological cardiac hypertrophy models, respectively. We compared our results to 18 different microarray data sets (318 individual arrays) representing various other animal models and four human cardiac diseases and identified a canonical set of 64 genes that are generally altered in failing hearts. We also produced a pairwise similarity matrix to illustrate relatedness of animal models with human heart disease and identified ischemia as the human condition that most resembles isoproterenol treatment. Conclusion The overall patterns of gene expression are consistent with observed structural and molecular differences between normal and maladaptive cardiac hypertrophy and support a role for the immune system (or immune cell infiltration) in the pathology of stress-induced hypertrophy. Cross-study comparisons such as the results presented here provide targets for further research of cardiac disease that might generally apply to maladaptive cardiac stresses and are also a means of identifying which animal models best recapitulate human disease at the transcriptional level. PMID:20003209

The evolution of heart gene delivery vectors.

PubMed

Wasala, Nalinda B; Shin, Jin-Hong; Duan, Dongsheng

2011-10-01

Gene therapy holds promise for treating numerous heart diseases. A key premise for the success of cardiac gene therapy is the development of powerful gene transfer vehicles that can achieve highly efficient and persistent gene transfer specifically in the heart. Other features of an ideal vector include negligible toxicity, minimal immunogenicity and easy manufacturing. Rapid progress in the fields of molecular biology and virology has offered great opportunities to engineer various genetic materials for heart gene delivery. Several nonviral vectors (e.g. naked plasmids, plasmid lipid/polymer complexes and oligonucleotides) have been tested. Commonly used viral vectors include lentivirus, adenovirus and adeno-associated virus. Among these, adeno-associated virus has shown many attractive features for pre-clinical experimentation in animal models of heart diseases. We review the history and evolution of these vectors for heart gene transfer. Copyright © 2011 John Wiley & Sons, Ltd.

The evolution of heart gene delivery vectors

PubMed Central

Wasala, Nalinda B.; Shin, Jin-Hong; Duan, Dongsheng

2012-01-01

Gene therapy holds promise for treating numerous heart diseases. A key premise for the success of cardiac gene therapy is the development of powerful gene transfer vehicles that can achieve highly efficient and persistent gene transfer specifically in the heart. Other features of an ideal vector include negligible toxicity, minimal immunogenicity and easy manufacturing. Rapid progress in the fields of molecular biology and virology has offered great opportunities to engineer various genetic materials for heart gene delivery. Several nonviral vectors (e.g. naked plasmids, plasmid lipid/polymer complexes and oligonucleotides) have been tested. Commonly used viral vectors include lentivirus, adenovirus and adeno-associated virus. Among these, adeno-associated virus has shown many attractive features for pre-clinical experimentation in animal models of heart diseases. We review the history and evolution of these vectors for heart gene transfer. PMID:21837689

A role for peroxisome proliferator-activated receptor γ coactivator-1 in the control of mitochondrial dynamics during postnatal cardiac growth.

PubMed

Martin, Ola J; Lai, Ling; Soundarapandian, Mangala M; Leone, Teresa C; Zorzano, Antonio; Keller, Mark P; Attie, Alan D; Muoio, Deborah M; Kelly, Daniel P

2014-02-14

Increasing evidence has shown that proper control of mitochondrial dynamics (fusion and fission) is required for high-capacity ATP production in the heart. Transcriptional coactivators, peroxisome proliferator-activated receptor γ coactivator-1 (PGC-1) α and PGC-1β, have been shown to regulate mitochondrial biogenesis in the heart at the time of birth. The function of PGC-1 coactivators in the heart after birth has been incompletely understood. Our aim was to assess the role of PGC-1 coactivators during postnatal cardiac development and in adult hearts in mice. Conditional gene targeting was used in mice to explore the role of PGC-1 coactivators during postnatal cardiac development and in adult hearts. Marked mitochondrial structural derangements were observed in hearts of PGC-1α/β-deficient mice during postnatal growth, including fragmentation and elongation, associated with the development of a lethal cardiomyopathy. The expression of genes involved in mitochondrial fusion (Mfn1, Opa1) and fission (Drp1, Fis1) was altered in the hearts of PGC-1α/β-deficient mice. PGC-lα was shown to directly regulate Mfn1 gene transcription by coactivating the estrogen-related receptor α on a conserved DNA element. Surprisingly, PGC-1α/β deficiency in the adult heart did not result in evidence of abnormal mitochondrial dynamics or heart failure. However, transcriptional profiling demonstrated that PGC-1 coactivators are required for high-level expression of nuclear- and mitochondrial-encoded genes involved in mitochondrial dynamics and energy transduction in the adult heart. These results reveal distinct developmental stage-specific programs involved in cardiac mitochondrial dynamics.

Cardiac fibroblast transcriptome analyses support a role for interferogenic, profibrotic, and inflammatory genes in anti-SSA/Ro-associated congenital heart block.

PubMed

Clancy, Robert M; Markham, Androo J; Jackson, Tanisha; Rasmussen, Sara E; Blumenberg, Miroslav; Buyon, Jill P

2017-09-01

The signature lesion of SSA/Ro autoantibody-associated congenital heart block (CHB) is fibrosis and a macrophage infiltrate, supporting an experimental focus on cues influencing the fibroblast component. The transcriptomes of human fetal cardiac fibroblasts were analyzed using two complementary approaches. Cardiac injury conditions were simulated in vitro by incubating human fetal cardiac fibroblasts with supernatants from macrophages transfected with the SSA/Ro-associated noncoding Y ssRNA. The top 10 upregulated transcripts in the stimulated fibroblasts reflected a type I interferon (IFN) response [e.g., IFN-induced protein 44-like (IFI44L), of MX dynamin-like GTPase (MX)1, MX2, and radical S -adenosyl methionine domain containing 2 (Rsad2)]. Within the fibrotic pathway, transcript levels of endothelin-1 (EDN1), phosphodiesterase (PDE)4D, chemokine (C-X-C motif) ligand (CXCL)2, and CXCL3 were upregulated, while others, including adenomedullin, RAP guanine nucleotide exchange factor 3 (RAPGEF3), tissue inhibitor of metalloproteinase (TIMP)1, TIMP3, and dual specificity phosphatase 1, were downregulated. Agnostic Database for Annotation, Visualization and Integrated Discovery analysis revealed a significant increase in inflammatory genes, including complement C3A receptor 1 (C3AR1), F2R-like thrombin/trypsin receptor 3, and neutrophil cytosolic factor 2. In addition, stimulated fibroblasts expressed high levels of phospho-MADS box transcription enhancer factor 2 [a substrate of MAPK5 (ERK5)], which was inhibited by BIX-02189, a specific inhibitor of ERK5. Translation to human disease leveraged an unprecedented opportunity to interrogate the transcriptome of fibroblasts freshly isolated and cell sorted without stimulation from a fetal heart with CHB and a matched healthy heart. Consistent with the in vitro data, five IFN response genes were among the top 10 most highly expressed transcripts in CHB fibroblasts. In addition, the expression of matrix-related genes reflected fibrosis. These data support the novel finding that cardiac injury in CHB may occur secondary to abnormal remodeling due in part to upregulation of type 1 IFN response genes. NEW & NOTEWORTHY Congenital heart block is a rare disease of the fetal heart associated with maternal anti-Ro autoantibodies which can result in death and for survivors, lifelong pacing. This study provides in vivo and in vitro transcriptome-support that injury may be mediated by an effect of Type I Interferon on fetal fibroblasts. Copyright © 2017 the American Physiological Society.

Advances in gene therapy for heart failure.

PubMed

Fish, Kenneth M; Ishikawa, Kiyotake

2015-04-01

Chronic heart failure is expected to increase its social and economic burden as a consequence of improved survival in patients with acute cardiac events. Cardiac gene therapy holds significant promise in heart failure treatment for patients with currently very limited or no treatment options. The introduction of adeno-associated virus (AAV) gene vector changed the paradigm of cardiac gene therapy, and now it is the primary vector of choice for chronic heart failure gene therapy in clinical and preclinical studies. Recently, there has been significant progress towards clinical translation in this field spearheaded by AAV-1 mediated sarcoplasmic reticulum Ca2+ ATPase (SERCA2a) gene therapy targeting chronic advanced heart failure patients. Meanwhile, several independent laboratories are reporting successful gene therapy approaches in clinically relevant large animal models of heart failure and some of these approaches are expected to enter clinical trials in the near future. This review will focus on gene therapy approaches targeting heart failure that is in clinical trials and those close to its initial clinical trial application.

A distinct subgroup of cardiomyopathy patients characterized by transcriptionally active cardiotropic erythrovirus and altered cardiac gene expression.

PubMed

Kuhl, U; Lassner, D; Dorner, A; Rohde, M; Escher, F; Seeberg, B; Hertel, E; Tschope, C; Skurk, C; Gross, U M; Schultheiss, H-P; Poller, W

2013-09-01

Recent studies have detected erythrovirus genomes in the hearts of cardiomyopathy and cardiac transplant patients. Assessment of the functional status of viruses may provide clinically important information beyond detection of the viral genomes. Here, we report transcriptional activation of cardiotropic erythrovirus to be associated with strongly altered myocardial gene expression in a distinct subgroup of cardiomyopathy patients. Endomyocardial biopsies (EMBs) from 415 consecutive cardiac erythrovirus (B19V)-positive patients with clinically suspected cardiomyopathy were screened for virus-encoded VP1/VP2 mRNA indicating transcriptional activation of the virus, and correlated with cardiac host gene expression patterns in transcriptionally active versus latent infections, and in virus-free control hearts. Transcriptional activity was detected in baseline biopsies of only 66/415 patients (15.9 %) harbouring erythrovirus. At the molecular level, significant differences between cardiac B19V-positive patients with transcriptionally active versus latent virus were revealed by expression profiling of EMBs. Importantly, latent B19V infection was indistinguishable from controls. Genes involved encode proteins of antiviral immune response, B19V receptor complex, and mitochondrial energy metabolism. Thus, functional mapping of erythrovirus allows definition of a subgroup of B19V-infected cardiomyopathy patients characterized by virus-encoded VP1/VP2 transcripts and anomalous host myocardial transcriptomes. Cardiac B19V reactivation from latency, as reported here for the first time, is a key factor required for erythrovirus to induce altered cardiac gene expression in a subgroup of cardiomyopathy patients. Virus genome detection is insufficient to assess pathogenic potential, but additional transcriptional mapping should be incorporated into future pathogenetic and therapeutic studies both in cardiology and transplantation medicine.

Induction of cardiomyocyte-like cells in infarct hearts by gene transfer of Gata4, Mef2c, and Tbx5.

PubMed

Inagawa, Kohei; Miyamoto, Kazutaka; Yamakawa, Hiroyuki; Muraoka, Naoto; Sadahiro, Taketaro; Umei, Tomohiko; Wada, Rie; Katsumata, Yoshinori; Kaneda, Ruri; Nakade, Koji; Kurihara, Chitose; Obata, Yuichi; Miyake, Koichi; Fukuda, Keiichi; Ieda, Masaki

2012-10-12

After myocardial infarction (MI), massive cell death in the myocardium initiates fibrosis and scar formation, leading to heart failure. We recently found that a combination of 3 cardiac transcription factors, Gata4, Mef2c, and Tbx5 (GMT), reprograms fibroblasts directly into functional cardiomyocytes in vitro. To investigate whether viral gene transfer of GMT into infarcted hearts induces cardiomyocyte generation. Coronary artery ligation was used to generate MI in the mouse. In vitro transduction of GMT retrovirus converted cardiac fibroblasts from the infarct region into cardiomyocyte-like cells with cardiac-specific gene expression and sarcomeric structures. Injection of the green fluorescent protein (GFP) retrovirus into mouse hearts, immediately after MI, infected only proliferating noncardiomyocytes, mainly fibroblasts, in the infarct region. The GFP expression diminished after 2 weeks in immunocompetent mice but remained stable for 3 months in immunosuppressed mice, in which cardiac induction did not occur. In contrast, injection of GMT retrovirus into α-myosin heavy chain (αMHC)-GFP transgenic mouse hearts induced the expression of αMHC-GFP, a marker of cardiomyocytes, in 3% of virus-infected cells after 1 week. A pooled GMT injection into the immunosuppressed mouse hearts induced cardiac marker expression in retrovirus-infected cells within 2 weeks, although few cells showed striated muscle structures. To transduce GMT efficiently in vivo, we generated a polycistronic retrovirus expressing GMT separated by 2A "self-cleaving" peptides (3F2A). The 3F2A-induced cardiomyocyte-like cells in fibrotic tissue expressed sarcomeric α-actinin and cardiac troponin T and had clear cross striations. Quantitative RT-PCR also demonstrated that FACS-sorted 3F2A-transduced cells expressed cardiac-specific genes. GMT gene transfer induced cardiomyocyte-like cells in infarcted hearts.

Cardiovascular progenitor-derived extracellular vesicles recapitulate the beneficial effects of their parent cells in the treatment of chronic heart failure.

PubMed

Kervadec, Anaïs; Bellamy, Valérie; El Harane, Nadia; Arakélian, Lousineh; Vanneaux, Valérie; Cacciapuoti, Isabelle; Nemetalla, Hany; Périer, Marie-Cécile; Toeg, Hadi D; Richart, Adèle; Lemitre, Mathilde; Yin, Min; Loyer, Xavier; Larghero, Jérôme; Hagège, Albert; Ruel, Marc; Boulanger, Chantal M; Silvestre, Jean-Sébastien; Menasché, Philippe; Renault, Nisa K E

2016-06-01

Cell-based therapies are being explored as a therapeutic option for patients with chronic heart failure following myocardial infarction. Extracellular vesicles (EV), including exosomes and microparticles, secreted by transplanted cells may orchestrate their paracrine therapeutic effects. We assessed whether post-infarction administration of EV released by human embryonic stem cell-derived cardiovascular progenitors (hESC-Pg) can provide equivalent benefits to administered hESC-Pg and whether hESC-Pg and EV treatments activate similar endogenous pathways. Mice underwent surgical occlusion of their left coronary arteries. After 2-3 weeks, 95 mice included in the study were treated with hESC-Pg, EV, or Minimal Essential Medium Alpha Medium (alpha-MEM; vehicle control) delivered by percutaneous injections under echocardiographic guidance into the peri-infarct myocardium. functional and histologic end-points were blindly assessed 6 weeks later, and hearts were processed for gene profiling. Genes differentially expressed between control hearts and hESC-Pg-treated and EV-treated hearts were clustered into functionally relevant pathways. At 6 weeks after hESC-Pg administration, treated mice had significantly reduced left ventricular end-systolic (-4.20 ± 0.96 µl or -7.5%, p = 0.0007) and end-diastolic (-4.48 ± 1.47 µl or -4.4%, p = 0.009) volumes compared with baseline values despite the absence of any transplanted hESC-Pg or human embryonic stem cell-derived cardiomyocytes in the treated mouse hearts. Equal benefits were seen with the injection of hESC-Pg-derived EV, whereas animals injected with alpha-MEM (vehicle control) did not improve significantly. Histologic examination suggested a slight reduction in infarct size in hESC-Pg-treated animals and EV-treated animals compared with alpha-MEM-treated control animals. In the hESC-Pg-treated and EV-treated groups, heart gene profiling identified 927 genes that were similarly upregulated compared with the control group. Among the 49 enriched pathways associated with these up-regulated genes that could be related to cardiac function or regeneration, 78% were predicted to improve cardiac function through increased cell survival and/or proliferation or DNA repair as well as pathways related to decreased fibrosis and heart failure. In this post-infarct heart failure model, either hESC-Pg or their secreted EV enhance recovery of cardiac function and similarly affect cardiac gene expression patterns that could be related to this recovery. Although the mechanisms by which EV improve cardiac function remain to be determined, these results support the idea that a paracrine mechanism is sufficient to effect functional recovery in cell-based therapies for post-infarction-related chronic heart failure. Copyright © 2016 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Pan-histone deacetylase inhibitors regulate signaling pathways involved in proliferative and pro-inflammatory mechanisms in H9c2 cells

PubMed Central

2012-01-01

Background 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. Results 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. Conclusions 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. PMID:23249388

Apoptosis in neural crest cells by functional loss of APC tumor suppressor gene

PubMed Central

Hasegawa, Sumitaka; Sato, Tomoyuki; Akazawa, Hiroshi; Okada, Hitoshi; Maeno, Akiteru; Ito, Masaki; Sugitani, Yoshinobu; Shibata, Hiroyuki; Miyazaki, Jun-ichi; Katsuki, Motoya; Yamauchi, Yasutaka; Yamamura, Ken-ichi; Katamine, Shigeru; Noda, Tetsuo

2002-01-01

Apc is a gene associated with familial adenomatous polyposis coli (FAP) and its inactivation is a critical step in colorectal tumor formation. The protein product, adenomatous polyposis coli (APC), acts to down-regulate intracellular levels of β-catenin, a key signal transducer in the Wnt signaling. Conditional targeting of Apc in the neural crest of mice caused massive apoptosis of cephalic and cardiac neural crest cells at about 11.5 days post coitum, resulting in craniofacial and cardiac anomalies at birth. Notably, the apoptotic cells localized in the regions where β-catenin had accumulated. In contrast to its role in colorectal epithelial cells, inactivation of APC leads to dysregulation of β-catenin/Wnt signaling with resultant apoptosis in certain tissues including neural crest cells. PMID:11756652

The first missense mutation of NHS gene in a Tunisian family with clinical features of NHS syndrome including cardiac anomaly

PubMed Central

Chograni, Manèl; Rejeb, Imen; Jemaa, Lamia Ben; Châabouni, Myriam; Bouhamed, Habiba Chaabouni

2011-01-01

Nance-Horan Syndrome (NHS) or X-linked cataract-dental syndrome is a disease of unknown gene action mechanism, characterized by congenital cataract, dental anomalies, dysmorphic features and, in some cases, mental retardation. We performed linkage analysis in a Tunisian family with NHS in which affected males and obligate carrier female share a common haplotype in the Xp22.32-p11.21 region that contains the NHS gene. Direct sequencing of NHS coding exons and flanking intronic sequences allowed us to identify the first missense mutation (P551S) and a reported SNP-polymorphism (L1319F) in exon 6, a reported UTR–SNP (c.7422 C>T) and a novel one (c.8239 T>A) in exon 8. Both variations P551S and c.8239 T>A segregate with NHS phenotype in this family. Although truncations, frame-shift and copy number variants have been reported in this gene, no missense mutations have been found to segregate previously. This is the first report of a missense NHS mutation causing NHS phenotype (including cardiac defects). We hypothesize also that the non-reported UTR–SNP of the exon 8 (3′-UTR) is specific to the Tunisian population. PMID:21559051

The first missense mutation of NHS gene in a Tunisian family with clinical features of NHS syndrome including cardiac anomaly.

PubMed

Chograni, Manèl; Rejeb, Imen; Jemaa, Lamia Ben; Châabouni, Myriam; Bouhamed, Habiba Chaabouni

2011-08-01

Nance-Horan Syndrome (NHS) or X-linked cataract-dental syndrome is a disease of unknown gene action mechanism, characterized by congenital cataract, dental anomalies, dysmorphic features and, in some cases, mental retardation. We performed linkage analysis in a Tunisian family with NHS in which affected males and obligate carrier female share a common haplotype in the Xp22.32-p11.21 region that contains the NHS gene. Direct sequencing of NHS coding exons and flanking intronic sequences allowed us to identify the first missense mutation (P551S) and a reported SNP-polymorphism (L1319F) in exon 6, a reported UTR-SNP (c.7422 C>T) and a novel one (c.8239 T>A) in exon 8. Both variations P551S and c.8239 T>A segregate with NHS phenotype in this family. Although truncations, frame-shift and copy number variants have been reported in this gene, no missense mutations have been found to segregate previously. This is the first report of a missense NHS mutation causing NHS phenotype (including cardiac defects). We hypothesize also that the non-reported UTR-SNP of the exon 8 (3'-UTR) is specific to the Tunisian population.

Cardiac Paraganglioma Arising From the Right Atrioventricular Groove in a Paraganglioma-Pheochromocytoma Family Syndrome With Evidence of SDHB Gene Mutation: An Unusual Presentation.

PubMed

Del Forno, Benedetto; Zingaro, Carlo; Di Palma, Enza; Capestro, Filippo; Rescigno, Giuseppe; Torracca, Lucia

2016-09-01

Primary cardiac paragangliomas are extremely rare. Recently this neoplasm has been associated with a familiar syndrome as a result of mutation of genes that encode proteins in the mitochondrial complex II. We report a case of a 46-year-old woman having cases of vertebral paraganglioma in her family showing an unusual anatomic and clinical presentation of cardiac paraganglioma and expressing a genetic mutation never associated before with cardiac localization of this neoplasm. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Prediction and characterisation of a highly conserved, remote and cAMP responsive enhancer that regulates Msx1 gene expression in cardiac neural crest and outflow tract.

PubMed

Miller, Kerry Ann; Davidson, Scott; Liaros, Angela; Barrow, John; Lear, Marissa; Heine, Danielle; Hoppler, Stefan; MacKenzie, Alasdair

2008-05-15

Double knockouts of the Msx1 and Msx2 genes in the mouse result in severe cardiac outflow tract malformations similar to those frequently found in newborn infants. Despite the known role of the Msx genes in cardiac formation little is known of the regulatory systems (ligand receptor, signal transduction and protein-DNA interactions) that regulate the tissue-specific expression of the Msx genes in mammals during the formation of the outflow tract. In the present study we have used a combination of multi-species comparative genomics, mouse transgenic analysis and in-situ hybridisation to predict and validate the existence of a remote ultra-conserved enhancer that supports the expression of the Msx1 gene in migrating mouse cardiac neural crest and the outflow tract primordia. Furthermore, culturing of embryonic explants derived from transgenic lines with agonists of the PKC and PKA signal transduction systems demonstrates that this remote enhancer is influenced by PKA but not PKC dependent gene regulatory systems. These studies demonstrate the efficacy of combining comparative genomics and transgenic analyses and provide a platform for the study of the possible roles of Msx gene mis-regulation in the aetiology of congenital heart malformation.

Single-Cell Sequencing of the Healthy and Diseased Heart Reveals Ckap4 as a New Modulator of Fibroblasts Activation.

PubMed

Gladka, Monika M; Molenaar, Bas; de Ruiter, Hesther; van der Elst, Stefan; Tsui, Hoyee; Versteeg, Danielle; Lacraz, Grègory P A; Huibers, Manon M H; van Oudenaarden, Alexander; van Rooij, Eva

2018-01-31

Background -Genome-wide transcriptome analysis has greatly advanced our understanding of the regulatory networks underlying basic cardiac biology and mechanisms driving disease. However, so far, the resolution of studying gene expression patterns in the adult heart has been limited to the level of extracts from whole tissues. The use of tissue homogenates inherently causes the loss of any information on cellular origin or cell type-specific changes in gene expression. Recent developments in RNA amplification strategies provide a unique opportunity to use small amounts of input RNA for genome-wide sequencing of single cells. Methods -Here, we present a method to obtain high quality RNA from digested cardiac tissue from adult mice for automated single-cell sequencing of both the healthy and diseased heart. Results -After optimization, we were able to perform single-cell sequencing on adult cardiac tissue under both homeostatic conditions and after ischemic injury. Clustering analysis based on differential gene expression unveiled known and novel markers of all main cardiac cell types. Based on differential gene expression we were also able to identify multiple subpopulations within a certain cell type. Furthermore, applying single-cell sequencing on both the healthy and the injured heart indicated the presence of disease-specific cell subpopulations. As such, we identified cytoskeleton associated protein 4 ( Ckap4 ) as a novel marker for activated fibroblasts that positively correlates with known myofibroblast markers in both mouse and human cardiac tissue. Ckap4 inhibition in activated fibroblasts treated with TGFβ triggered a greater increase in the expression of genes related to activated fibroblasts compared to control, suggesting a role of Ckap4 in modulating fibroblast activation in the injured heart. Conclusions -Single-cell sequencing on both the healthy and diseased adult heart allows us to study transcriptomic differences between cardiac cells, as well as cell type-specific changes in gene expression during cardiac disease. This new approach provides a wealth of novel insights into molecular changes that underlie the cellular processes relevant for cardiac biology and pathophysiology. Applying this technology could lead to the discovery of new therapeutic targets relevant for heart disease.

The relationship between changes in functional cardiac parameters following anthracycline therapy and carbonyl reductase 3 and glutathione S transferase Pi polymorphisms.

PubMed

Volkan-Salanci, Bilge; Aksoy, Hakan; Kiratli, Pınar Özgen; Tülümen, Erol; Güler, Nilüfer; Öksüzoglu, Berna; Tokgözoğlu, Lale; Erbaş, Belkıs; Alikaşifoğlu, Mehmet

2012-10-01

The aim of this prospective clinical study is to evaluate the relationship between changes in functional cardiac parameters following anthracycline therapy and carbonyl reductase 3 (CBR3p.V244M) and glutathione S transferase Pi (GSTP1p.I105V) polymorphisms. Seventy patients with normal cardiac function and no history of cardiac disease scheduled to undergo anthracycline chemotherapy were included in the study. The patients' cardiac function was evaluated by gated blood pool scintigraphy and echocardiography before and after chemotherapy, as well as 1 year following therapy. Gene polymorphisms were genotyped in 70 patients using TaqMan probes, validated by DNA sequencing. A deteriorating trend was observed in both systolic and diastolic parameters from GG to AA in CBR3p.V244M polymorphism. Patients with G-allele carriers of GSTP1p.I105V polymorphism were common (60%), with significantly decreased PFR compared to patiens with AA genotype. Variants of CBR3 and GSTP1 enzymes may be associated with changes in short-term functional cardiac parameters.

Strategies for Analyzing Cardiac Phenotypes in the Zebrafish Embryo

PubMed Central

Houk, Andrew R.; Yelon, Deborah

2017-01-01

The molecular mechanisms underlying cardiogenesis are of critical biomedical importance due to the high prevalence of cardiac birth defects. Over the past two decades, the zebrafish has served as a powerful model organism for investigating heart development, facilitated by its powerful combination of optical access to the embryonic heart and plentiful opportunities for genetic analysis. Work in zebrafish has identified numerous factors that are required for various aspects of heart formation, including the specification and differentiation of cardiac progenitor cells, the morphogenesis of the heart tube, cardiac chambers, and atrioventricular canal, and the establishment of proper cardiac function. However, our current roster of regulators of cardiogenesis is by no means complete. It is therefore valuable for ongoing studies to continue pursuit of additional genes and pathways that control the size, shape, and function of the zebrafish heart. An extensive arsenal of techniques is available to distinguish whether particular mutations, morpholinos, or small molecules disrupt specific processes during heart development. In this chapter, we provide a guide to the experimental strategies that are especially effective for the characterization of cardiac phenotypes in the zebrafish embryo. PMID:27312497

Myeloid mineralocorticoid receptor deficiency inhibits aortic constriction-induced cardiac hypertrophy in mice.

PubMed

Li, Chao; Zhang, Yu Yao; Frieler, Ryan A; Zheng, Xiao Jun; Zhang, Wu Chang; Sun, Xue Nan; Yang, Qing Zhen; Ma, Shu Min; Huang, Baozhuan; Berger, Stefan; Wang, Wang; Wu, Yong; Yu, Ying; Duan, Sheng Zhong; Mortensen, Richard M

2014-01-01

Mineralocorticoid receptor (MR) blockade has been shown to suppress cardiac hypertrophy and remodeling in animal models of pressure overload (POL). This study aims to determine whether MR deficiency in myeloid cells modulates aortic constriction-induced cardiovascular injuries. Myeloid MR knockout (MMRKO) mice and littermate control mice were subjected to abdominal aortic constriction (AAC) or sham operation. We found that AAC-induced cardiac hypertrophy and fibrosis were significantly attenuated in MMRKO mice. Expression of genes important in generating reactive oxygen species was decreased in MMRKO mice, while that of manganese superoxide dismutase increased. Furthermore, expression of genes important in cardiac metabolism was increased in MMRKO hearts. Macrophage infiltration in the heart was inhibited and expression of inflammatory genes was decreased in MMRKO mice. In addition, aortic fibrosis and inflammation were attenuated in MMRKO mice. Taken together, our data indicated that MR deficiency in myeloid cells effectively attenuated aortic constriction-induced cardiac hypertrophy and fibrosis, as well as aortic fibrosis and inflammation.

COUP-TF1 antagonizes Nkx2.5-mediated activation of the calreticulin gene during cardiac development.

PubMed

Guo, L; Lynch, J; Nakamura, K; Fliegel, L; Kasahara, H; Izumo, S; Komuro, I; Agellon, L B; Michalak, M

2001-01-26

Calreticulin, a Ca(2+) binding chaperone of the endoplasmic reticulum, is also highly expressed in the embryonic heart, and knockout of the calreticulin gene is lethal during embryogenesis because of impaired cardiac development. The protein is down-regulated after birth, and elevated expression of calreticulin in newborn hearts is associated with severe cardiac pathology and death. Here we show that the transcription factor Nkx2.5 activates expression of the calreticulin gene in the heart. Binding of chicken ovalbumin upstream promoter-transcription factor 1 to the Nkx2.5 binding site suppresses transcription from the calreticulin promoter. Nkx2.5 and chicken ovalbumin upstream promoter-transcription factor 1 play antagonistic roles in regulating the expression of calreticulin during cardiac development. These studies indicate that cardiac-specific transcription factor Nkx2.5 plays a central role in activating calreticulin expression and that there is a cooperation between chicken ovalbumin upstream promoter-transcription factor 1 and Nkx2.5 at the calreticulin promoter.

Unbiased compound screening with a reporter gene assay highlights the role of p13 in the cardiac cellular stress response.

PubMed

Inoue, Naoki; Hirouchi, Taisei; Kasai, Atsushi; Higashi, Shintaro; Hiraki, Natsumi; Tanaka, Shota; Nakazawa, Takanobu; Nunomura, Kazuto; Lin, Bangzhong; Omori, Akiko; Hayata-Takano, Atsuko; Kim, Yoon-Jeong; Doi, Takefumi; Baba, Akemichi; Hashimoto, Hitoshi; Shintani, Norihito

2018-01-08

We recently showed that a 13-kDa protein (p13), the homolog protein of formation of mitochondrial complex V assembly factor 1 in yeast, acts as a potential protective factor in pancreatic islets under diabetes. Here, we aimed to identify known compounds regulating p13 mRNA expression to obtain therapeutic insight into the cellular stress response. A luciferase reporter system was developed using the putative promoter region of the human p13 gene. Overexpression of peroxisome proliferator-activated receptor gamma coactivator 1α, a master player regulating mitochondrial metabolism, increased both reporter activity and p13 expression. Following unbiased screening with 2320 known compounds in HeLa cells, 12 pharmacological agents (including 8 cardiotonics and 2 anthracyclines) that elicited >2-fold changes in p13 mRNA expression were identified. Among them, four cardiac glycosides decreased p13 expression and concomitantly elevated cellular oxidative stress. Additional database analyses showed highest p13 expression in heart, with typically decreased expression in cardiac disease. Accordingly, our results illustrate the usefulness of unbiased compound screening as a method for identifying novel functional roles of unfamiliar genes. Our findings also highlight the importance of p13 in the cellular stress response in heart. Copyright © 2017. Published by Elsevier Inc.

A lentiviral vector with a short troponin-I promoter for tracking cardiomyocyte differentiation of human embryonic stem cells.

PubMed

Gallo, P; Grimaldi, S; Latronico, M V G; Bonci, D; Pagliuca, A; Gallo, P; Ausoni, S; Peschle, C; Condorelli, G

2008-02-01

Human embryonic stem cells (hESCs) may become important for cardiac repair due to their potentially unlimited ability to generate cardiomyocytes (CMCs). Moreover, genetic manipulation of hESC-derived CMCs would be a very promising technique for curing myocardial disorders. At the present time, however, inducing the differentiation of hESCs into CMCs is extremely difficult and, therefore, an easy and standardizable technique is needed to evaluate differentiation strategies. Vectors driving cardiac-specific expression may represent an important tool not only for monitoring new cardiac-differentiation strategies, but also for the manipulation of cardiac differentiation of ESCs. To this aim, we generated cardiac-specific lentiviral vectors (LVVs) in which expression is driven by a short fragment of the cardiac troponin-I proximal promoter (TNNI3) with a human cardiac alpha-actin enhancer, and tested its suitability in inducing tissue-specific gene expression and ability to track the CMC lineage during differentiation of ESCs. We determined that (1) TNNI3-LVVs efficiently drive cardiac-specific gene expression and mark the cardiomyogenic lineage in human and mouse ESC differentiation systems (2) the cardiac alpha-actin enhancer confers a further increase in gene-expression specificity of TNNI3-LVVs in hESCs. Although this technique may not be useful in tracking small numbers of cells, data suggested that TNNI3-based LVVs are a powerful tool for manipulating human ESCs and modifying hESC-derived CMCs.

Genome-Nuclear Lamina Interactions Regulate Cardiac Stem Cell Lineage Restriction.

PubMed

Poleshko, Andrey; Shah, Parisha P; Gupta, Mudit; Babu, Apoorva; Morley, Michael P; Manderfield, Lauren J; Ifkovits, Jamie L; Calderon, Damelys; Aghajanian, Haig; Sierra-Pagán, Javier E; Sun, Zheng; Wang, Qiaohong; Li, Li; Dubois, Nicole C; Morrisey, Edward E; Lazar, Mitchell A; Smith, Cheryl L; Epstein, Jonathan A; Jain, Rajan

2017-10-19

Progenitor cells differentiate into specialized cell types through coordinated expression of lineage-specific genes and modification of complex chromatin configurations. We demonstrate that a histone deacetylase (Hdac3) organizes heterochromatin at the nuclear lamina during cardiac progenitor lineage restriction. Specification of cardiomyocytes is associated with reorganization of peripheral heterochromatin, and independent of deacetylase activity, Hdac3 tethers peripheral heterochromatin containing lineage-relevant genes to the nuclear lamina. Deletion of Hdac3 in cardiac progenitor cells releases genomic regions from the nuclear periphery, leading to precocious cardiac gene expression and differentiation into cardiomyocytes; in contrast, restricting Hdac3 to the nuclear periphery rescues myogenesis in progenitors otherwise lacking Hdac3. Our results suggest that availability of genomic regions for activation by lineage-specific factors is regulated in part through dynamic chromatin-nuclear lamina interactions and that competence of a progenitor cell to respond to differentiation signals may depend upon coordinated movement of responding gene loci away from the nuclear periphery. Copyright © 2017 Elsevier Inc. All rights reserved.

Cardiomyocyte-enriched protein CIP protects against pathophysiological stresses and regulates cardiac homeostasis.

PubMed

Huang, Zhan-Peng; Kataoka, Masaharu; Chen, Jinghai; Wu, Gengze; Ding, Jian; Nie, Mao; Lin, Zhiqiang; Liu, Jianming; Hu, Xiaoyun; Ma, Lixin; Zhou, Bin; Wakimoto, Hiroko; Zeng, Chunyu; Kyselovic, Jan; Deng, Zhong-Liang; Seidman, Christine E; Seidman, J G; Pu, William T; Wang, Da-Zhi

2015-11-02

Cardiomyopathy is a common human disorder that is characterized by contractile dysfunction and cardiac remodeling. Genetic mutations and altered expression of genes encoding many signaling molecules and contractile proteins are associated with cardiomyopathy; however, how cardiomyocytes sense pathophysiological stresses in order to then modulate cardiac remodeling remains poorly understood. Here, we have described a regulator in the heart that harmonizes the progression of cardiac hypertrophy and dilation. We determined that expression of the myocyte-enriched protein cardiac ISL1-interacting protein (CIP, also known as MLIP) is reduced in patients with dilated cardiomyopathy. As CIP is highly conserved between human and mouse, we evaluated the effects of CIP deficiency on cardiac remodeling in mice. Deletion of the CIP-encoding gene accelerated progress from hypertrophy to heart failure in several cardiomyopathy models. Conversely, transgenic and AAV-mediated CIP overexpression prevented pathologic remodeling and preserved cardiac function. CIP deficiency combined with lamin A/C deletion resulted in severe dilated cardiomyopathy and cardiac dysfunction in the absence of stress. Transcriptome analyses of CIP-deficient hearts revealed that the p53- and FOXO1-mediated gene networks related to homeostasis are disturbed upon pressure overload stress. Moreover, FOXO1 overexpression suppressed stress-induced cardiomyocyte hypertrophy in CIP-deficient cardiomyocytes. Our studies identify CIP as a key regulator of cardiomyopathy that has potential as a therapeutic target to attenuate heart failure progression.

Cardiomyocyte-enriched protein CIP protects against pathophysiological stresses and regulates cardiac homeostasis

PubMed Central

Huang, Zhan-Peng; Kataoka, Masaharu; Chen, Jinghai; Wu, Gengze; Ding, Jian; Nie, Mao; Lin, Zhiqiang; Liu, Jianming; Hu, Xiaoyun; Ma, Lixin; Zhou, Bin; Wakimoto, Hiroko; Zeng, Chunyu; Kyselovic, Jan; Deng, Zhong-Liang; Seidman, Christine E.; Seidman, J.G.; Pu, William T.; Wang, Da-Zhi

2015-01-01

Cardiomyopathy is a common human disorder that is characterized by contractile dysfunction and cardiac remodeling. Genetic mutations and altered expression of genes encoding many signaling molecules and contractile proteins are associated with cardiomyopathy; however, how cardiomyocytes sense pathophysiological stresses in order to then modulate cardiac remodeling remains poorly understood. Here, we have described a regulator in the heart that harmonizes the progression of cardiac hypertrophy and dilation. We determined that expression of the myocyte-enriched protein cardiac ISL1-interacting protein (CIP, also known as MLIP) is reduced in patients with dilated cardiomyopathy. As CIP is highly conserved between human and mouse, we evaluated the effects of CIP deficiency on cardiac remodeling in mice. Deletion of the CIP-encoding gene accelerated progress from hypertrophy to heart failure in several cardiomyopathy models. Conversely, transgenic and AAV-mediated CIP overexpression prevented pathologic remodeling and preserved cardiac function. CIP deficiency combined with lamin A/C deletion resulted in severe dilated cardiomyopathy and cardiac dysfunction in the absence of stress. Transcriptome analyses of CIP-deficient hearts revealed that the p53- and FOXO1-mediated gene networks related to homeostasis are disturbed upon pressure overload stress. Moreover, FOXO1 overexpression suppressed stress-induced cardiomyocyte hypertrophy in CIP-deficient cardiomyocytes. Our studies identify CIP as a key regulator of cardiomyopathy that has potential as a therapeutic target to attenuate heart failure progression. PMID:26436652

Cardiac CaM Kinase II genes δ and γ contribute to adverse remodeling but redundantly inhibit calcineurin-induced myocardial hypertrophy.

PubMed

Kreusser, Michael M; Lehmann, Lorenz H; Keranov, Stanislav; Hoting, Marc-Oscar; Oehl, Ulrike; Kohlhaas, Michael; Reil, Jan-Christian; Neumann, Kay; Schneider, Michael D; Hill, Joseph A; Dobrev, Dobromir; Maack, Christoph; Maier, Lars S; Gröne, Hermann-Josef; Katus, Hugo A; Olson, Eric N; Backs, Johannes

2014-10-07

Ca(2+)-dependent signaling through CaM Kinase II (CaMKII) and calcineurin was suggested to contribute to adverse cardiac remodeling. However, the relative importance of CaMKII versus calcineurin for adverse cardiac remodeling remained unclear. We generated double-knockout mice (DKO) lacking the 2 cardiac CaMKII genes δ and γ specifically in cardiomyocytes. We show that both CaMKII isoforms contribute redundantly to phosphorylation not only of phospholamban, ryanodine receptor 2, and histone deacetylase 4, but also calcineurin. Under baseline conditions, DKO mice are viable and display neither abnormal Ca(2+) handling nor functional and structural changes. On pathological pressure overload and β-adrenergic stimulation, DKO mice are protected against cardiac dysfunction and interstitial fibrosis. But surprisingly and paradoxically, DKO mice develop cardiac hypertrophy driven by excessive activation of endogenous calcineurin, which is associated with a lack of phosphorylation at the auto-inhibitory calcineurin A site Ser411. Likewise, calcineurin inhibition prevents cardiac hypertrophy in DKO. On exercise performance, DKO mice show an exaggeration of cardiac hypertrophy with increased expression of the calcineurin target gene RCAN1-4 but no signs of adverse cardiac remodeling. We established a mouse model in which CaMKII's activity is specifically and completely abolished. By the use of this model we show that CaMKII induces maladaptive cardiac remodeling while it inhibits calcineurin-dependent hypertrophy. These data suggest inhibition of CaMKII but not calcineurin as a promising approach to attenuate the progression of heart failure. © 2014 American Heart Association, Inc.

Vinpocetine Attenuates Pathological Cardiac Remodeling by Inhibiting Cardiac Hypertrophy and Fibrosis

PubMed Central

Wu, Mei-ping; Zhang, Yi-shuai; Xu, Xiangbin; Zhou, Qian

2017-01-01

Purpose Pathological cardiac remodeling, characterized by cardiac hypertrophy and fibrosis, is a pathological feature of many cardiac disorders that leads to heart failure and cardiac arrest. Vinpocetine, a derivative of the alkaloid vincamine, has been used for enhancing cerebral blood flow to treat cognitive impairment. However, its role in pathological cardiac remodeling remains unknown. The aim of this study is to examine the effect of vinpocetine on pathological cardiac remodeling induced by chronic stimulation with angiotensin II (Ang II). Methods Mice received Ang II infusion via osmotic pumps in the presence of vehicle or vinpocetine. Cardiac hypertrophy and fibrosis were assessed by morphological, histological, and biochemical analyses. Mechanistic studies were carried out in vitro with isolated mouse adult cardiac myocytes and fibroblasts. Results We showed that chronic Ang II infusion caused cardiac hypertrophy and fibrosis, which were all significantly attenuated by systemic administration of vinpocetine. In isolated adult mouse cardiomyocytes, vinpocetine suppressed Ang II-stimulated myocyte hypertrophic growth. In cultured cardiac fibroblasts, vinpocetine suppressed TGFβ-induced fibroblast activation and matrix gene expression, consistent with its effect in attenuating cardiac fibrosis. The effects of vinpocetine on cardiac myocyte hypertrophy and fibroblast activation are likely mediated by targeting cyclic nucleotide phosphodiesterase 1 (PDE1). Conclusions Our results reveal a novel protective effect of vinpocetine in attenuating pathological cardiac remodeling through suppressing cardiac myocyte hypertrophic growth and fibroblast activation and fibrotic gene expression. These studies may also shed light on developing novel therapeutic agents for antagonizing pathological cardiac remodeling. PMID:28321644

Vinpocetine Attenuates Pathological Cardiac Remodeling by Inhibiting Cardiac Hypertrophy and Fibrosis.

PubMed

Wu, Mei-Ping; Zhang, Yi-Shuai; Xu, Xiangbin; Zhou, Qian; Li, Jian-Dong; Yan, Chen

2017-04-01

Pathological cardiac remodeling, characterized by cardiac hypertrophy and fibrosis, is a pathological feature of many cardiac disorders that leads to heart failure and cardiac arrest. Vinpocetine, a derivative of the alkaloid vincamine, has been used for enhancing cerebral blood flow to treat cognitive impairment. However, its role in pathological cardiac remodeling remains unknown. The aim of this study is to examine the effect of vinpocetine on pathological cardiac remodeling induced by chronic stimulation with angiotensin II (Ang II). Mice received Ang II infusion via osmotic pumps in the presence of vehicle or vinpocetine. Cardiac hypertrophy and fibrosis were assessed by morphological, histological, and biochemical analyses. Mechanistic studies were carried out in vitro with isolated mouse adult cardiac myocytes and fibroblasts. We showed that chronic Ang II infusion caused cardiac hypertrophy and fibrosis, which were all significantly attenuated by systemic administration of vinpocetine. In isolated adult mouse cardiomyocytes, vinpocetine suppressed Ang II-stimulated myocyte hypertrophic growth. In cultured cardiac fibroblasts, vinpocetine suppressed TGFβ-induced fibroblast activation and matrix gene expression, consistent with its effect in attenuating cardiac fibrosis. The effects of vinpocetine on cardiac myocyte hypertrophy and fibroblast activation are likely mediated by targeting cyclic nucleotide phosphodiesterase 1 (PDE1). Our results reveal a novel protective effect of vinpocetine in attenuating pathological cardiac remodeling through suppressing cardiac myocyte hypertrophic growth and fibroblast activation and fibrotic gene expression. These studies may also shed light on developing novel therapeutic agents for antagonizing pathological cardiac remodeling.

Different gene expression in human heart tissue and progenitor cells from control and diabetic subjects: relevance to the pathogenesis of human diabetic cardiomyopathy.

PubMed

de Cillis, Emanuela; Leonardini, Anna; Laviola, Luigi; Giorgino, Francesco; Tupputi Schinosa, Luigi de Luca; Bortone, Alessandro Santo

2010-04-01

The The aim of our study is to investigate the molecular mechanisms of diabetic cardiomyopathy through the identification of remarkable genes for the myocardial function that are expressed differently between diabetic and normal subjects. Moreover, we intend to characterize both in human myocardial tissue and in the related cardiac progenitor cells the pattern of gene expression and the levels of expression and protein activation of molecular effectors involved in the regulation of the myocardial function and differentiation to clarify whether in specific human pathological conditions (type 2 diabetes mellitus, cardiac failure, coronary artery disease) specific alterations of the aforementioned factors could take place. Thirty-five patients scheduled for coronary artery bypass grafting (CABG) or for aortic or mitral valve replacement were recruited into the study. There were 13 men and 22 women with a mean age of 64.8 +/- 13.4 years. A list of anamnestic, anthropometric, clinical, and instrumental data required for an optimal phenotypical characterization of the patients is reported. The small cardiac biopsy specimens were placed in the nourishing buffer, in a sterile tube provided the day of the procedure, to maintain the stability of the sample for several hours at room temperature. The cells were isolated by a dedicated protocol and then cultured in vitro. The sample was processed for total RNA extraction and levels of gene expression and protein activation of molecular effectors involved in the regulation of function and differentiation of human myocardium was analyzed. In particular, cardiac genes that modulate the oxidative stress response or the stress induced by pro-inflammatory cytokines (p66Shc, SOCS-1, SOCS-3) were analyzed. From a small sample of myocardium cardiac stem cells and cardiomyoblasts were also isolated and characterized. These cells showed a considerable proliferative capacity due to the fact that they demonstrate stability up to the eleventh passage. Analysis of gene expression in a subgroup of subjects showed the trend of a decrease in levels of expression of cardiac-specific transcription genes and oxidative stress-related proteins in tissues of diabetic patients compared with controls subjects. This trend is not confirmed in isolated cells. As for the coronary artery disease, diabetic cardiomyopathy could be associated with a reduction of the cardiac stem and progenitor cells pool. The expansion of the cardiac resident cells pool could be associated with a preservation of cardiac performance, suggesting that a preserved stamina compartment can counteract the impact of diabetes on the myocardium.

Use of RNA-seq to identify cardiac genes and gene pathways differentially expressed between dogs with and without dilated cardiomyopathy.

PubMed

Friedenberg, Steven G; Chdid, Lhoucine; Keene, Bruce; Sherry, Barbara; Motsinger-Reif, Alison; Meurs, Kathryn M

2016-07-01

OBJECTIVE To identify cardiac tissue genes and gene pathways differentially expressed between dogs with and without dilated cardiomyopathy (DCM). ANIMALS 8 dogs with and 5 dogs without DCM. PROCEDURES Following euthanasia, samples of left ventricular myocardium were collected from each dog. Total RNA was extracted from tissue samples, and RNA sequencing was performed on each sample. Samples from dogs with and without DCM were grouped to identify genes that were differentially regulated between the 2 populations. Overrepresentation analysis was performed on upregulated and downregulated gene sets to identify altered molecular pathways in dogs with DCM. RESULTS Genes involved in cellular energy metabolism, especially metabolism of carbohydrates and fats, were significantly downregulated in dogs with DCM. Expression of cardiac structural proteins was also altered in affected dogs. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that RNA sequencing may provide important insights into the pathogenesis of DCM in dogs and highlight pathways that should be explored to identify causative mutations and develop novel therapeutic interventions.

Mutations in the Katnb1 gene cause left-right asymmetry and heart defects.

PubMed

Furtado, Milena B; Merriner, D Jo; Berger, Silke; Rhodes, Danielle; Jamsai, Duangporn; O'Bryan, Moira K

2017-12-01

The microtubule-severing protein complex katanin is composed two subunits, the ATPase subunit, KATNA1, and the noncatalytic regulatory subunit, KATNB1. Recently, the Katnb1 gene has been linked to infertility, regulation of centriole and cilia formation in fish and mammals, as well as neocortical brain development. KATNB1 protein is expressed in germ cells in humans and mouse, mitotic/meiotic spindles and cilia, although the full expression pattern of the Katnb1 gene has not been described. Using a knockin-knockout mouse model of Katnb1 dysfunction we demonstrate that Katnb1 is ubiquitously expressed during embryonic development, although a stronger expression is seen in the crown cells of the gastrulation organizer, the murine node. Furthermore, null and hypomorphic Katnb1 gene mutations show a novel correlation between Katnb1 dysregulation and the development of impaired left-right signaling, including cardiac malformations. Katanin function is a critical regulator of heart development in mice. These findings are potentially relevant to human cardiac development. Developmental Dynamics 246:1027-1035, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Mef2c Regulates Transcription of the Extracellular Matrix Protein Cartilage Link Protein 1 in the Developing Murine Heart

PubMed Central

Phelps, Aimee L.; Ghatnekar, Angela V.; Barth, Jeremy L.; Norris, Russell A.; Wessels, Andy

2013-01-01

Cartilage Link Protein 1 (Crtl1) is an extracellular matrix (ECM) protein that stabilizes the interaction between hyaluronan and versican and is expressed in endocardial and endocardially-derived cells in the developing heart, including cells in the atrioventricular (AV) and outflow tract (OFT) cushions. Previous investigations into the transcriptional regulation of the Crtl1 gene have shown that Sox9 regulates Crtl1 expression in both cartilage and the AV valves. The cardiac transcription factor Mef2c is involved in the regulation of gene expression in cardiac and skeletal muscle cell lineages. In this study we have investigated the potential role of Mef2c in the regulation of ECM production in the endocardial and mesenchymal cell lineages of the developing heart. We demonstrate that the Crtl1 5′ flanking region contains two highly conserved Mef2 binding sites and that Mef2c is able to bind to these sites in vivo during cardiovascular development. Additionally, we show that Crtl1 transcription is dependent on Mef2c expression in fetal mitral valve interstitial cells (VICs). Combined, these findings highlight a new role for Mef2c in cardiac development and the regulation of cardiac extracellular matrix protein expression. PMID:23468913

Id4 functions downstream of Bmp signaling to restrict TCF function in endocardial cells during atrioventricular valve development.

PubMed

Ahuja, Suchit; Dogra, Deepika; Stainier, Didier Y R; Reischauer, Sven

2016-04-01

The atrioventricular canal (AVC) connects the atrial and ventricular chambers of the heart and its formation is critical for the development of the cardiac valves, chamber septation and formation of the cardiac conduction system. Consequently, problems in AVC formation can lead to congenital defects ranging from cardiac arrhythmia to incomplete cardiac septation. While our knowledge about early heart tube formation is relatively comprehensive, much remains to be investigated about the genes that regulate AVC formation. Here we identify a new role for the basic helix-loop-helix factor Id4 in zebrafish AVC valve development and function. id4 is first expressed in the AVC endocardium and later becomes more highly expressed in the atrial chamber. TALEN induced inactivation of id4 causes retrograde blood flow at the AV canal under heat induced stress conditions, indicating defects in AV valve function. At the molecular level, we found that id4 inactivation causes misexpression of several genes important for AVC and AV valve formation including bmp4 and spp1. We further show that id4 appears to control the number of endocardial cells that contribute to the AV valves by regulating Wnt signaling in the developing AVC endocardium. Copyright © 2016 Elsevier Inc. All rights reserved.

The Representation of Heart Development in the Gene Ontology

PubMed Central

Khodiyar, Varsha K.; Hill, David P.; Howe, Doug; Berardini, Tanya Z.; Tweedie, Susan; Talmud, Philippa J.; Breckenridge, Ross; Bhattarcharya, Shoumo; Riley, Paul; Scambler, Peter; Lovering, Ruth C.

2012-01-01

An understanding of heart development is critical in any systems biology approach to cardiovascular disease. The interpretation of data generated from high-throughput technologies (such as microarray and proteomics) is also essential to this approach. However, characterizing the role of genes in the processes underlying heart development and cardiovascular disease involves the non-trivial task of data analysis and integration of previous knowledge. The Gene Ontology (GO) Consortium provides structured controlled biological vocabularies that are used to summarize previous functional knowledge for gene products across all species. One aspect of GO describes biological processes, such as development and signaling. In order to support high-throughput cardiovascular research, we have initiated an effort to fully describe heart development in GO; expanding the number of GO terms describing heart development from 12 to over 280. This new ontology describes heart morphogenesis, the differentiation of specific cardiac cell types, and the involvement of signaling pathways in heart development and aligns GO with the current views of the heart development research community and its representation in the literature. This extension of GO allows gene product annotators to comprehensively capture the genetic program leading to the developmental progression of the heart. This will enable users to integrate heart development data across species, resulting in the comprehensive retrieval of information about this subject. The revised GO structure, combined with gene product annotations, should improve the interpretation of data from high-throughput methods in a variety of cardiovascular research areas, including heart development, congenital cardiac disease, and cardiac stem cell research. Additionally, we invite the heart development community to contribute to the expansion of this important dataset for the benefit of future research in this area. PMID:21419760

Interplay between cardiac transcription factors and non-coding RNAs in predisposing to atrial fibrillation.

PubMed

Mikhailov, Alexander T; Torrado, Mario

2018-05-12

There is growing evidence that putative gene regulatory networks including cardio-enriched transcription factors, such as PITX2, TBX5, ZFHX3, and SHOX2, and their effector/target genes along with downstream non-coding RNAs can play a potentially important role in the process of adaptive and maladaptive atrial rhythm remodeling. In turn, expression of atrial fibrillation-associated transcription factors is under the control of upstream regulatory non-coding RNAs. This review broadly explores gene regulatory mechanisms associated with susceptibility to atrial fibrillation-with key examples from both animal models and patients-within the context of both cardiac transcription factors and non-coding RNAs. These two systems appear to have multiple levels of cross-regulation and act coordinately to achieve effective control of atrial rhythm effector gene expression. Perturbations of a dynamic expression balance between transcription factors and corresponding non-coding RNAs can provoke the development or promote the progression of atrial fibrillation. We also outline deficiencies in current models and discuss ongoing studies to clarify remaining mechanistic questions. An understanding of the function of transcription factors and non-coding RNAs in gene regulatory networks associated with atrial fibrillation risk will enable the development of innovative therapeutic strategies.

Issues in solid-organ transplantation in children: translational research from bench to bedside

PubMed Central

Lipshultz, Steven E.; Chandar, Jayanthi J.; Rusconi, Paolo G.; Fornoni, Alessia; Abitbol, Carolyn L.; Burke III, George W.; Zilleruelo, Gaston E.; Pham, Si M.; Perez, Elena E.; Karnik, Ruchika; Hunter, Juanita A.; Dauphin, Danielle D.; Wilkinson, James D.

2014-01-01

In this review, we identify important challenges facing physicians responsible for renal and cardiac transplantation in children based on a review of the contemporary medical literature. Regarding pediatric renal transplantation, we discuss the challenge of antibody-mediated rejection, focusing on both acute and chronic antibody-mediated rejection. We review new diagnostic approaches to antibody-mediated rejection, such as panel-reactive antibodies, donor-specific cross-matching, antibody assays, risk assessment and diagnosis of antibody-mediated rejection, the pathology of antibody-mediated rejection, the issue of ABO incompatibility in renal transplantation, new therapies for antibody-mediated rejection, inhibiting of residual antibodies, the suppression or depletion of B-cells, genetic approaches to treating acute antibody-mediated rejection, and identifying future translational research directions in kidney transplantation in children. Regarding pediatric cardiac transplantation, we discuss the mechanisms of cardiac transplant rejection, including the role of endomyocardial biopsy in detecting graft rejection and the role of biomarkers in detecting cardiac graft rejection, including biomarkers of inflammation, cardiomyocyte injury, or stress. We review cardiac allograft vasculopathy. We also address the role of genetic analyses, including genome-wide association studies, gene expression profiling using entities such as AlloMap®, and adenosine triphosphate release as a measure of immune function using the Cylex® ImmuKnow™ cell function assay. Finally, we identify future translational research directions in heart transplantation in children. PMID:24860861

Heterogeneity of adult masseter muscle satellite cells with cardiomyocyte differentiation potential.

PubMed

Huang, Wei; Liang, Jialiang; Feng, Yuliang; Jia, Zhanfeng; Jiang, Lin; Cai, Wenfeng; Paul, Christian; Gu, Jianguo G; Stambrook, Peter J; Millard, Ronald W; Zhu, Xiao-Lan; Zhu, Ping; Wang, Yigang

2018-05-26

Although resident cardiac stem cells have been reported, regeneration of functional cardiomyocytes (CMs) remains a challenge. The present study identifies an alternative progenitor source for CM regeneration without the need for genetic manipulation or invasive heart biopsy procedures. Unlike limb skeletal muscles, masseter muscles (MM) in the mouse head are developed from Nkx2-5 mesodermal progenitors. Adult masseter muscle satellite cells (MMSCs) display heterogeneity in developmental origin and cell phenotypes. The heterogeneous MMSCs that can be characterized by cell sorting based on stem cell antigen-1 (Sca1) show different lineage potential. While cardiogenic potential is preserved in Sca1 + MMSCs as shown by expression of cardiac progenitor genes (including Nkx2-5), skeletal myogenic capacity is maintained in Sca1 - MMSCs with Pax7 expression. Sca1 + MMSC-derived beating cells express cardiac genes and exhibit CM-like morphology. Electrophysiological properties of MMSC-derived CMs are demonstrated by calcium transients and action potentials. These findings show that MMSCs could serve as a novel cell source for cardiomyocyte replacement. Copyright © 2018. Published by Elsevier Inc.

Fabry disease: A fundamental genetic modifier of cardiac function.

PubMed

Tadevosyan, A

Fabry disease (FD) is an inherited X-linked metabolic storage disorder triggered by abnormalities in the GLA gene at Xq22, which leads to a deficiency in α-galactosidase A and massive accumulation of intralysosomal glycosphingolipids. Cardiac complications are very common in FD and are the main cause of late morbidity, as well as early mortality in both hemizygous men and heterozygous women. There is a need for a multidisciplinary approach to evaluation and management of FD patients as there is a wide range of presentation of FD, which varies with mutation and other organ involvement/dysfunction. An overview of common cardiac involvement and clinical characteristics in FD including: left ventricular hypertrophy (LVH), conduction abnormalities and arrhythmias, coronary artery disease and valvular infiltrative myopathy are provided in this review. Current therapeutic approaches such as enzyme replacement therapy as well as the emergence of novel therapeutic options such as gene therapy to optimize disease outcomes in FD patients will be highlighted in this paper. Crown Copyright © 2016. Published by Elsevier Masson SAS. All rights reserved.

A Systematic Review of Fetal Genes as Biomarkers of Cardiac Hypertrophy in Rodent Models of Diabetes

PubMed Central

2014-01-01

Pathological cardiac hypertrophy activates a suite of genes called the fetal gene program (FGP). Pathological hypertrophy occurs in diabetic cardiomyopathy (DCM); therefore, the FGP is widely used as a biomarker of DCM in animal studies. However, it is unknown whether the FGP is a consistent marker of hypertrophy in rodent models of diabetes. Therefore, we analyzed this relationship in 94 systematically selected studies. Results showed that diabetes induced with cytotoxic glucose analogs such as streptozotocin was associated with decreased cardiac weight, but genetic or diet-induced models of diabetes were significantly more likely to show cardiac hypertrophy (P<0.05). Animal strain, sex, age, and duration of diabetes did not moderate this effect. There were no correlations between the heart weight:body weight index and mRNA or protein levels of the fetal genes α-myosin heavy chain (α-MHC) or β-MHC, sarco/endoplasmic reticulum Ca2+-ATPase, atrial natriuretic peptide (ANP), or brain natriuretic peptide. The only correlates of non-indexed heart weight were the protein levels of α-MHC (Spearman's ρ = 1, P<0.05) and ANP (ρ = −0.73, P<0.05). These results indicate that most commonly measured genes in the FGP are confounded by diabetogenic methods, and are not associated with cardiac hypertrophy in rodent models of diabetes. PMID:24663494

Revealing New Mouse Epicardial Cell Markers through Transcriptomics

PubMed Central

Bochmann, Lars; Sarathchandra, Padmini; Mori, Federica; Lara-Pezzi, Enrique; Lazzaro, Domenico; Rosenthal, Nadia

2010-01-01

Background The epicardium has key functions during myocardial development, by contributing to the formation of coronary endothelial and smooth muscle cells, cardiac fibroblasts, and potentially cardiomyocytes. The epicardium plays a morphogenetic role by emitting signals to promote and maintain cardiomyocyte proliferation. In a regenerative context, the adult epicardium might comprise a progenitor cell population that can be induced to contribute to cardiac repair. Although some genes involved in epicardial function have been identified, a detailed molecular profile of epicardial gene expression has not been available. Methodology Using laser capture microscopy, we isolated the epicardial layer from the adult murine heart before or after cardiac infarction in wildtype mice and mice expressing a transgenic IGF-1 propeptide (mIGF-1) that enhances cardiac repair, and analyzed the transcription profile using DNA microarrays. Principal Findings Expression of epithelial genes such as basonuclin, dermokine, and glycoprotein M6A are highly enriched in the epicardial layer, which maintains expression of selected embryonic genes involved in epicardial development in mIGF-1 transgenic hearts. After myocardial infarct, a subset of differentially expressed genes are down-regulated in the epicardium representing an epicardium-specific signature that responds to injury. Conclusion This study presents the description of the murine epicardial transcriptome obtained from snap frozen tissues, providing essential information for further analysis of this important cardiac cell layer. PMID:20596535

Transcriptome profiling reveals novel BMI- and sex-specific gene expression signatures for human cardiac hypertrophy.

PubMed

Newman, Mackenzie S; Nguyen, Tina; Watson, Michael J; Hull, Robert W; Yu, Han-Gang

2017-07-01

How obesity or sex may affect the gene expression profiles of human cardiac hypertrophy is unknown. We hypothesized that body-mass index (BMI) and sex can affect gene expression profiles of cardiac hypertrophy. Human heart tissues were grouped according to sex (male, female), BMI (lean<25 kg/m 2 , obese>30 kg/m 2 ), or left ventricular hypertrophy (LVH) and non-LVH nonfailed controls (NF). We identified 24 differentially expressed (DE) genes comparing female with male samples. In obese subgroup, there were 236 DE genes comparing LVH with NF; in lean subgroup, there were seven DE genes comparing LVH with NF. In female subgroup, we identified 1,320 significant genes comparing LVH with NF; in male subgroup, there were 1,383 significant genes comparing LVH with NF. There were seven significant genes comparing obese LVH with lean NF; comparing male obese LVH with male lean NF samples we found 106 significant genes; comparing female obese LVH with male lean NF, we found no significant genes. Using absolute value of log 2 fold-change > 2 or extremely small P value (10 -20 ) as a criterion, we identified nine significant genes (HBA1, HBB, HIST1H2AC, GSTT1, MYL7, NPPA, NPPB, PDK4, PLA2G2A) in LVH, also found in published data set for ischemic and dilated cardiomyopathy in heart failure. We identified a potential gene expression signature that distinguishes between patients with high BMI or between men and women with cardiac hypertrophy. Expression of established biomarkers atrial natriuretic peptide A (NPPA) and B (NPPB) were already significantly increased in hypertrophy compared with controls. Copyright © 2017 the American Physiological Society.

Class I HDACs Regulate Angiotensin II-Dependent Cardiac Fibrosis via Fibroblasts and Circulating Fibrocytes

PubMed Central

Williams, Sarah M.; Golden-Mason, Lucy; Ferguson, Bradley S.; Douglas, Katherine B.; Cavasin, Maria A.; Demos-Davies, Kim; Yeager, Michael E.; Stenmark, Kurt R.; McKinsey, Timothy A.

2014-01-01

Fibrosis, which is defined as excessive accumulation of fibrous connective tissue, contributes to the pathogenesis of numerous diseases involving diverse organ systems. Cardiac fibrosis predisposes individuals to myocardial ischemia, arrhythmias and sudden death, and is commonly associated with diastolic dysfunction. Histone deacetylase (HDAC) inhibitors block cardiac fibrosis in pre-clinical models of heart failure. However, which HDAC isoforms govern cardiac fibrosis, and the mechanisms by which they do so, remains unclear. Here, we show that selective inhibition of class I HDACs potently suppresses angiotensin II (Ang II)-mediated cardiac fibrosis by targeting two key effector cell populations, cardiac fibroblasts and bone marrow-derived fibrocytes. Class I HDAC inhibition blocks cardiac fibroblast cell cycle progression through derepression of the genes encoding the cyclin-dependent kinase (CDK) inhibitors, p15 and p57. In contrast, class I HDAC inhibitors block agonist-dependent differentiation of fibrocytes through a mechanism involving repression of ERK1/2 signaling. These findings define novel roles for class I HDACs in the control of pathological cardiac fibrosis. Furthermore, since fibrocytes have been implicated in the pathogenesis of a variety of human diseases, including heart, lung and kidney failure, our results suggest broad utility for isoform-selective HDAC inhibitors as anti-fibrotic agents that function, in part, by targeting these circulating mesenchymal cells. PMID:24374140

TRPM4 channels in the cardiovascular system: physiology, pathophysiology, and pharmacology.

PubMed

Abriel, Hugues; Syam, Ninda; Sottas, Valentin; Amarouch, Mohamed Yassine; Rougier, Jean-Sébastien

2012-10-01

The transient receptor potential channel (TRP) family comprises at least 28 genes in the human genome. These channels are widely expressed in many different tissues, including those of the cardiovascular system. The transient receptor potential channel melastatin 4 (TRPM4) is a Ca(2+)-activated non-specific cationic channel, which is impermeable to Ca(2+). TRPM4 is expressed in many cells of the cardiovascular system, such as cardiac cells of the conduction pathway and arterial and venous smooth muscle cells. This review article summarizes the recently described roles of TRPM4 in normal physiology and in various disease states. Genetic variants in the human gene TRPM4 have been linked to several cardiac conduction disorders. TRPM4 has also been proposed to play a crucial role in secondary hemorrhage following spinal cord injuries. Spontaneously hypertensive rats with cardiac hypertrophy were shown to over-express the cardiac TRPM4 channel. Recent studies suggest that TRPM4 plays an important role in cardiovascular physiology and disease, even if most of the molecular and cellular mechanisms have yet to be elucidated. We conclude this review article with a brief overview of the compounds that have been shown to either inhibit or activate TRPM4 under experimental conditions. Based on recent findings, the TRPM4 channel can be proposed as a future target for the pharmacological treatment of cardiovascular disorders, such as hypertension and cardiac arrhythmias. Copyright © 2012 Elsevier Inc. All rights reserved.

Aldosterone Promotes Cardiac Endothelial Cell Proliferation In Vivo

PubMed Central

Gravez, Basile; Tarjus, Antoine; Pelloux, Véronique; Ouvrard‐Pascaud, Antoine; Delcayre, Claude; Samuel, Janelise; Clément, Karine; Farman, Nicolette; Jaisser, Fréderic; Messaoudi, Smail

2015-01-01

Background Experimentally, aldosterone in association with NaCl induces cardiac fibrosis, oxidative stress, and inflammation through mineralocorticoid receptor activation; however, the biological processes regulated by aldosterone alone in the heart remain to be identified. Methods and Results Mice were treated for 7 days with aldosterone, and then cardiac transcriptome was analyzed. Aldosterone regulated 60 transcripts (51 upregulated and 9 downregulated) in the heart (fold change ≥1.5, false discovery rate <0.01). To identify the biological processes modulated by aldosterone, a gene ontology analysis was performed. The majority of aldosterone‐regulated genes were involved in cell division. The cardiac Ki‐67 index (an index of proliferation) of aldosterone‐treated mice was higher than that of nontreated mice, confirming microarray predictions. Costaining of Ki‐67 with vinculin, CD68, α‐smooth muscle actin, CD31, or caveolin 1 revealed that the cycling cells were essentially endothelial cells. Aldosterone‐induced mineralocorticoid receptor–dependent proliferation was confirmed ex vivo in human endothelial cells. Moreover, pharmacological‐specific blockade of mineralocorticoid receptor by eplerenone inhibited endothelial cell proliferation in a preclinical model of heart failure (transverse aortic constriction). Conclusions Aldosterone modulates cardiac gene expression and induces the proliferation of cardiac endothelial cells in vivo. PMID:25564371

Human relaxin gene expression delivered by bioreducible dendrimer polymer for post-infarct cardiac remodeling in rats

PubMed Central

Lee, Young Sook; Choi, Joung-Woo; Oh, Jung-Eun; Yun, Chae-Ok; Kim, Sung Wan

2017-01-01

In consensus, myocardial infarction (MI) is defined as irreversible cell death secondary to prolonged ischemia in heart. The aim of our study was to evaluate the therapeutic potential of anti-fibrotic human Relaxin-expressing plasmid DNA with hypoxia response element (HRE) 12 copies (HR1) delivered by a dendrimer type PAM-ABP polymer G0 (HR1/G0) after MI on functional, hemodynamic, geometric, and cardiac extracellular matrix (ECM) remodeling in rats. HR1/G0 demonstrated significantly improved LV systolic function, hemodynamic parameters, and geometry on 1 wk and 4 wks after MI in rats, compared with I/R group. The resolution of regional wall motional abnormalities and the increased blood flow of infarct-related coronary artery supported functional improvements of HR1/G0. Furthermore, HR1/G0 polyplex showed favorable post-infarct cardiac ECM remodeling reflected on the favorable cardiac ECM compositions. Overall, this is the first study, which presented an advanced platform for the gene therapy that reverses adverse cardiac remodeling after MI with a HR1 gene delivered by a bioreducible dendrimer polymer in the cardiac ECM. PMID:27174688

Responses of Cardiac Tissue to Simulated Weightlessness

NASA Technical Reports Server (NTRS)

Tahimic, Candice; Steczina, Sonette; Terada, Masahiro; Shirazi-Fard, Yasaman; Schreurs, Ann-Sofie; Goukassian, David; Globus, Ruth

2017-01-01

Our current study aims to determine the molecular mechanisms that underlie these cardiac changes in response to spaceflight. The central hypothesis of our study is that long duration simulated weightlessness and subsequent recovery causes select and persistent changes in gene expression and oxidative defense-related pathways. In this study, we will first conduct general analyses of three-month old male and female animals, focusing on two key long-duration time points, (i.e. after 90 days of simulated weightlessness (HU) and after 90 days recovery from 90 days of HU. Both rat-specific gene arrays and qPCR will be performed focusing on genes already implicated in oxidative stress responses and cardiac disease. Gene expression analyses will be complemented by biochemical tests of frozen tissue lysates for select markers of oxidative damage.

Loss of RNA expression and allele-specific expression associated with congenital heart disease

PubMed Central

McKean, David M.; Homsy, Jason; Wakimoto, Hiroko; Patel, Neil; Gorham, Joshua; DePalma, Steven R.; Ware, James S.; Zaidi, Samir; Ma, Wenji; Patel, Nihir; Lifton, Richard P.; Chung, Wendy K.; Kim, Richard; Shen, Yufeng; Brueckner, Martina; Goldmuntz, Elizabeth; Sharp, Andrew J.; Seidman, Christine E.; Gelb, Bruce D.; Seidman, J. G.

2016-01-01

Congenital heart disease (CHD), a prevalent birth defect occurring in 1% of newborns, likely results from aberrant expression of cardiac developmental genes. Mutations in a variety of cardiac transcription factors, developmental signalling molecules and molecules that modify chromatin cause at least 20% of disease, but most CHD remains unexplained. We employ RNAseq analyses to assess allele-specific expression (ASE) and biallelic loss-of-expression (LOE) in 172 tissue samples from 144 surgically repaired CHD subjects. Here we show that only 5% of known imprinted genes with paternal allele silencing are monoallelic versus 56% with paternal allele expression—this cardiac-specific phenomenon seems unrelated to CHD. Further, compared with control subjects, CHD subjects have a significant burden of both LOE genes and ASE events associated with altered gene expression. These studies identify FGFBP2, LBH, RBFOX2, SGSM1 and ZBTB16 as candidate CHD genes because of significantly altered transcriptional expression. PMID:27670201

SYSTEMIC BIOMARKERS AND CARDIAC GENE EXPRESSION PROFILES OF RAT DISEASE MODELS EMPLOYED IN AIR POLLUTION STUDIES

EPA Science Inventory

Cardiovascular disease (CVD) models are used for identification of mechanisms of susceptibility to air pollution. We hypothesized that baseline systemic biomarkers and cardiac gene expression in CVD rat models will have influence on their ozone-induced lung inflammation. Male 12-...

Disruption of canonical TGFβ-signaling in murine coronary progenitor cells by low level arsenic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allison, Patrick; Huang, Tianfang; Broka, Derrick

2013-10-01

Exposure to arsenic results in several types of cancers as well as heart disease. A major contributor to ischemic heart pathologies is coronary artery disease, however the influences by environmental arsenic in this disease process are not known. Similarly, the impact of toxicants on blood vessel formation and function during development has not been studied. During embryogenesis, the epicardium undergoes proliferation, migration, and differentiation into several cardiac cell types including smooth muscle cells which contribute to the coronary vessels. The TGFβ family of ligands and receptors is essential for developmental cardiac epithelial to mesenchymal transition (EMT) and differentiation into coronarymore » smooth muscle cells. In this in vitro study, 18 hour exposure to 1.34 μM arsenite disrupted developmental EMT programming in murine epicardial cells causing a deficit in cardiac mesenchyme. The expression of EMT genes including TGFβ2, TGFβ receptor-3, Snail, and Has-2 are decreased in a dose-dependent manner following exposure to arsenite. TGFβ2 cell signaling is abrogated as detected by decreases in phosphorylated Smad2/3 when cells are exposed to 1.34 μM arsenite. There is also loss of nuclear accumulation pSmad due to arsenite exposure. These observations coincide with a decrease in vimentin positive mesenchymal cells invading three-dimensional collagen gels. However, arsenite does not block TGFβ2 mediated smooth muscle cell differentiation by epicardial cells. Overall these results show that arsenic exposure blocks developmental EMT gene programming in murine coronary progenitor cells by disrupting TGFβ2 signals and Smad activation, and that smooth muscle cell differentiation is refractory to this arsenic toxicity. - Highlights: • Arsenic blocks TGFβ2 induced expression of EMT genes. • Arsenic blocks TGFβ2 triggered Smad2/3 phosphorylation and nuclear translocation. • Arsenic blocks epicardial cell differentiation into cardiac mesenchyme. • Arsenic does not block TGFβ2 induced smooth muscle cell differentiation.« less

Testing the burden of rare variation in arrhythmia-susceptibility genes provides new insights into molecular diagnosis for Brugada syndrome.

PubMed

Le Scouarnec, Solena; Karakachoff, Matilde; Gourraud, Jean-Baptiste; Lindenbaum, Pierre; Bonnaud, Stéphanie; Portero, Vincent; Duboscq-Bidot, Laëtitia; Daumy, Xavier; Simonet, Floriane; Teusan, Raluca; Baron, Estelle; Violleau, Jade; Persyn, Elodie; Bellanger, Lise; Barc, Julien; Chatel, Stéphanie; Martins, Raphaël; Mabo, Philippe; Sacher, Frédéric; Haïssaguerre, Michel; Kyndt, Florence; Schmitt, Sébastien; Bézieau, Stéphane; Le Marec, Hervé; Dina, Christian; Schott, Jean-Jacques; Probst, Vincent; Redon, Richard

2015-05-15

The Brugada syndrome (BrS) is a rare heritable cardiac arrhythmia disorder associated with ventricular fibrillation and sudden cardiac death. Mutations in the SCN5A gene have been causally related to BrS in 20-30% of cases. Twenty other genes have been described as involved in BrS, but their overall contribution to disease prevalence is still unclear. This study aims to estimate the burden of rare coding variation in arrhythmia-susceptibility genes among a large group of patients with BrS. We have developed a custom kit to capture and sequence the coding regions of 45 previously reported arrhythmia-susceptibility genes and applied this kit to 167 index cases presenting with a Brugada pattern on the electrocardiogram as well as 167 individuals aged over 65-year old and showing no history of cardiac arrhythmia. By applying burden tests, a significant enrichment in rare coding variation (with a minor allele frequency below 0.1%) was observed only for SCN5A, with rare coding variants carried by 20.4% of cases with BrS versus 2.4% of control individuals (P = 1.4 × 10(-7)). No significant enrichment was observed for any other arrhythmia-susceptibility gene, including SCN10A and CACNA1C. These results indicate that, except for SCN5A, rare coding variation in previously reported arrhythmia-susceptibility genes do not contribute significantly to the occurrence of BrS in a population with European ancestry. Extreme caution should thus be taken when interpreting genetic variation in molecular diagnostic setting, since rare coding variants were observed in a similar extent among cases versus controls, for most previously reported BrS-susceptibility genes. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effect of siRNA silencing of inducible co-stimulatory molecule on myocardial cell hypertrophy after cardiac infarction in rats.

PubMed

Wang, W M; Liu, Z; Chen, G

2016-05-20

As the most common cardiac disease, myocardial infarction is followed by hypertrophy of cardiac myocytes and reconstruction of ventricular structure. The up-regulation of a series of factors including metalloproteinases, inflammatory factors, and growth factors after primary infarction lead to the hypertrophy, apoptosis, necrosis, and fibroblast proliferation in cardiac muscle tissues. Recent studies have reported on the potency of small interfering RNA (siRNA) in treating cardiac diseases. We thus investigated the efficacy of inducible co-stimulatory molecule (ICOS)-specific siRNA silencing in myocardial hypertrophy in a cardiac infarction rat model. This cardiac infarction model was prepared by ligating the left anterior descending coronary artery. ICOS-siRNA treatment was administered in parallel with non-sense siRNA. After 18 days, the cross-sectional area of cardiac muscle tissues and the left ventricle weight index were measured, along with ICOS mRNA and protein expression levels, and pathological staining. Compared to those in the control groups, in myocardial infarcted rats, the application of ICOS-siRNA effectively decreased the left ventricle weight index, as well as the surface area of cardiac myocytes. Both mRNA and protein levels of ICOS were also significantly decreased. HE staining was consistent with these results. In conclusion, ICOS-targeted siRNA can effectively silence gene expression of ICOS, and provided satisfactory treatment efficacy for myocardial cell hypertrophy after infarction.

Effects of temperature acclimation on Pacific bluefin tuna (Thunnus orientalis) cardiac transcriptome.

PubMed

Jayasundara, Nishad; Gardner, Luke D; Block, Barbara A

2013-11-01

Little is known about the mechanisms underpinning thermal plasticity of vertebrate hearts. Bluefin tuna hearts offer a unique model to investigate processes underlying thermal acclimation. Their hearts, while supporting an endothermic physiology, operate at ambient temperature, and are presented with a thermal challenge when migrating to different thermal regimes. Here, we examined the molecular responses in atrial and ventricular tissues of Pacific bluefin tuna acclimated to 14°C, 20°C, and 25°C. Quantitative PCR studies showed an increase in sarcoplasmic reticulum Ca(2+) ATPase gene expression with cold acclimation and an induction of Na(+)/Ca(2+)-exchanger gene at both cold and warm temperatures. These data provide evidence for thermal plasticity of excitation-contraction coupling gene expression in bluefin tunas and indicate an increased capacity for internal Ca(2+) storage in cardiac myocytes at 14°C. Transcriptomic analysis showed profound changes in cardiac tissues with acclimation. A principal component analysis revealed that temperature effect was greatest on gene expression in warm-acclimated atrium. Overall data showed an increase in cardiac energy metabolism at 14°C, potentially compensating for cold temperature to optimize bluefin tuna performance in colder oceans. In contrast, metabolic enzyme activity and gene expression data suggest a decrease in ATP production at 25°C. Expression of genes involved in protein turnover and molecular chaperones was also decreased at 25°C. Expression of genes involved in oxidative stress response and programmed cell death suggest an increase in oxidative damage and apoptosis at 25°C, particularly in the atrium. These findings provide insights into molecular processes that may characterize cardiac phenotypes at upper thermal limits of teleosts.

p63 Silencing induces reprogramming of cardiac fibroblasts into cardiomyocyte-like cells.

PubMed

Patel, Vivekkumar; Singh, Vivek P; Pinnamaneni, Jaya Pratap; Sanagasetti, Deepthi; Olive, Jacqueline; Mathison, Megumi; Cooney, Austin; Flores, Elsa R; Crystal, Ronald G; Yang, Jianchang; Rosengart, Todd K

2018-04-13

Reprogramming of fibroblasts into induced cardiomyocytes represents a potential new therapy for heart failure. We hypothesized that inactivation of p63, a p53 gene family member, may help overcome human cell resistance to reprogramming. p63 Knockout ( -/- ) and knockdown murine embryonic fibroblasts (MEFs), p63 -/- adult murine cardiac fibroblasts, and human cardiac fibroblasts were assessed for cardiomyocyte-specific feature changes, with or without treatment by the cardiac transcription factors Hand2-Myocardin (HM). Flow cytometry revealed that a significantly greater number of p63 -/- MEFs expressed the cardiac-specific marker cardiac troponin T (cTnT) in culture compared with wild-type (WT) cells (38% ± 11% vs 0.9% ± 0.9%, P < .05). HM treatment of p63 -/- MEFs increased cTnT expression to 74% ± 3% of cells but did not induce cTnT expression in wild-type murine embryonic fibroblasts. shRNA-mediated p63 knockdown likewise yielded a 20-fold increase in cTnT microRNA expression compared with untreated MEFs. Adult murine cardiac fibroblasts demonstrated a 200-fold increase in cTnT gene expression after inducible p63 knockout and expressed sarcomeric α-actinin as well as cTnT. These p63 -/- adult cardiac fibroblasts exhibited calcium transients and electrically stimulated contractions when co-cultured with neonatal rat cardiomyocytes and treated with HM. Increased expression of cTnT and other marker genes was also observed in p63 knockdown human cardiac fibroblasts procured from patients undergoing procedures for heart failure. Downregulation of p63 facilitates direct cardiac cellular reprogramming and may help overcome the resistance of human cells to reprogramming. Copyright © 2018 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Silencing Genes in the Heart.

PubMed

Fechner, Henry; Vetter, Roland; Kurreck, Jens; Poller, Wolfgang

2017-01-01

Silencing of cardiac genes by RNA interference (RNAi) has developed into a powerful new method to treat cardiac diseases. Small interfering (si)RNAs are the inducers of RNAi, but cultured primary cardiomyocytes and heart are highly resistant to siRNA transfection. This can be overcome by delivery of small hairpin (sh)RNAs or artificial microRNA (amiRNAs) by cardiotropic adeno-associated virus (AAV) vectors. Here we describe as example of the silencing of a cardiac gene, the generation and cloning of shRNA, and amiRNAs directed against the cardiac protein phospholamban. We further describe the generation of AAV shuttle plasmids with self complementary vector genomes, the production of AAV vectors in roller bottles, and their purification via iodixanol gradient centrifugation and concentration with filter systems. Finally we describe the preparation of primary neonatal rat cardiomyocytes (PNRC), the transduction of PNRC with AAV vectors, and the maintenance of the transduced cell culture.

Fibrin patch-based insulin-like growth factor-1 gene-modified stem cell transplantation repairs ischemic myocardium.

PubMed

Li, Jun; Zhu, Kai; Yang, Shan; Wang, Yulin; Guo, Changfa; Yin, Kanhua; Wang, Chunsheng; Lai, Hao

2015-05-01

Bone marrow mesenchymal stem cells (BMSCs), tissue-engineered cardiac patch, and therapeutic gene have all been proposed as promising therapy strategies for cardiac repair after myocardial infarction. In our study, BMSCs were modified with insulin-like growth factor-1 (IGF-1) gene, loaded into a fibrin patch, and then transplanted into a porcine model of ischemia/reperfusion (I/R) myocardium injury. The results demonstrated that IGF-1 gene overexpression could promote proliferation of endothelial cells and cardiomyocyte-like differentiation of BMSCs in vitro. Four weeks after transplantation of fibrin patch loaded with gene-modified BMSCs, IGF-1 overexpression could successfully promote angiogenesis, inhibit remodeling, increase grafted cell survival and reduce apoptosis. In conclusion, the integrated strategy, which combined fibrin patch with IGF-1 gene modified BMSCs, could promote the histological cardiac repair for a clinically relevant porcine model of I/R myocardium injury. © 2015 by the Society for Experimental Biology and Medicine.

Dynamic changes in genes related to glucose uptake and utilization during pig skeletal and cardiac muscle development.

PubMed

Guo, Yanqin; Jin, Long; Wang, Fengjiao; He, Mengnan; Liu, Rui; Li, Mingzhou; Shuai, Surong

2014-01-01

Skeletal and cardiac muscle have important roles in glucose uptake and utilization. However, changes in expression of protein coding genes and miRNAs that participate in glucose metabolism during development are not fully understood. In this study, we investigated the expression of genes related to glucose metabolism during muscle development. We found an age-dependent increase in gene expression in cardiac muscle, with enrichment in heart development- and energy-related metabolic processes. A subset of genes that were up-regulated until 30 or 180 days postnatally, and then down-regulated in psoas major muscle was significantly enriched in mitochondrial oxidative-related processes, while genes that up-regulated in longissimus doris muscle was significantly enriched in glycolysis-related processes. Meanwhile, expression of energy-related microRNAs decreased with increasing age. In addition, we investigated the correlation between microRNAs and mRNAs in three muscle types across different stages of development and found many potential microRNA-mRNA pairs involved in regulating glucose metabolism.

Induction of cardiac Angptl4 by dietary fatty acids is mediated by peroxisome proliferator-activated receptor beta/delta and protects against fatty acid-induced oxidative stress.

PubMed

Georgiadi, Anastasia; Lichtenstein, Laeticia; Degenhardt, Tatjana; Boekschoten, Mark V; van Bilsen, Marc; Desvergne, Beatrice; Müller, Michael; Kersten, Sander

2010-06-11

Although dietary fatty acids are a major fuel for the heart, little is known about the direct effects of dietary fatty acids on gene regulation in the intact heart. To study the effect of dietary fatty acids on cardiac gene expression and explore the functional consequences. Oral administration of synthetic triglycerides composed of one single fatty acid altered cardiac expression of numerous genes, many of which are involved in the oxidative stress response. The gene most significantly and consistently upregulated by dietary fatty acids encoded Angiopoietin-like protein (Angptl)4, a circulating inhibitor of lipoprotein lipase expressed by cardiomyocytes. Induction of Angptl4 by the fatty acid linolenic acid was specifically abolished in peroxisome proliferator-activated receptor (PPAR)beta/delta(-/-) and not PPARalpha(-/-) mice and was blunted on siRNA-mediated PPARbeta/delta knockdown in cultured cardiomyocytes. Consistent with these data, linolenic acid stimulated binding of PPARbeta/delta but not PPARalpha to the Angptl4 gene. Upregulation of Angptl4 resulted in decreased cardiac uptake of plasma triglyceride-derived fatty acids and decreased fatty acid-induced oxidative stress and lipid peroxidation. In contrast, Angptl4 deletion led to enhanced oxidative stress in the heart, both after an acute oral fat load and after prolonged high fat feeding. Stimulation of cardiac Angptl4 gene expression by dietary fatty acids and via PPARbeta/delta is part of a feedback mechanism aimed at protecting the heart against lipid overload and consequently fatty acid-induced oxidative stress.

A comprehensive gene expression analysis at sequential stages of in vitro cardiac differentiation from isolated MESP1-expressing-mesoderm progenitors

PubMed Central

den Hartogh, Sabine C.; Wolstencroft, Katherine; Mummery, Christine L.; Passier, Robert

2016-01-01

In vitro cardiac differentiation of human pluripotent stem cells (hPSCs) closely recapitulates in vivo embryonic heart development, and therefore, provides an excellent model to study human cardiac development. We recently generated the dual cardiac fluorescent reporter MESP1mCherry/wNKX2-5eGFP/w line in human embryonic stem cells (hESCs), allowing the visualization of pre-cardiac MESP1+ mesoderm and their further commitment towards the cardiac lineage, marked by activation of the cardiac transcription factor NKX2-5. Here, we performed a comprehensive whole genome based transcriptome analysis of MESP1-mCherry derived cardiac-committed cells. In addition to previously described cardiac-inducing signalling pathways, we identified novel transcriptional and signalling networks indicated by transient activation and interactive network analysis. Furthermore, we found a highly dynamic regulation of extracellular matrix components, suggesting the importance to create a versatile niche, adjusting to various stages of cardiac differentiation. Finally, we identified cell surface markers for cardiac progenitors, such as the Leucine-rich repeat-containing G-protein coupled receptor 4 (LGR4), belonging to the same subfamily of LGR5, and LGR6, established tissue/cancer stem cells markers. We provide a comprehensive gene expression analysis of cardiac derivatives from pre-cardiac MESP1-progenitors that will contribute to a better understanding of the key regulators, pathways and markers involved in human cardiac differentiation and development. PMID:26783251

G protein-coupled estrogen receptor (GPER) deficiency induces cardiac remodeling through oxidative stress.

PubMed

Wang, Hao; Sun, Xuming; Lin, Marina S; Ferrario, Carlos M; Van Remmen, Holly; Groban, Leanne

2018-04-25

Oxidative stress has been implicated in the unfavorable changes in cardiac function and remodeling that occur after ovarian estrogen loss. Using ovariectomized rat models, we previously reported that the cardioprotective actions of estrogen are mediated by the G protein-coupled estrogen receptor (GPER). Here, in 9-month-old, female cardiomyocyte-specific GPER knockout (KO) mice vs sex- and age-matched wild-type (WT) mice, we found increased cardiac oxidative stress and oxidant damage, measured as a decreased ratio of reduced glutathione to oxidized glutathione, increased 4-hydroxynonenal and 8-hydroxy-2'-deoxyguanosine (8-oxo-DG) staining, and increased expression of oxidative stress-related genes. GPER KO mice also displayed increased heart weight, cardiac collagen deposition, and Doppler-derived filling pressure, and decreased percent fractional shortening and early mitral annular velocity compared with WT controls. Treatment of GPER KO mice for 8 weeks with phosphonium [10-(4,5-dimethoxy-2-methyl 3,6-dioxo-1,4-cyclohexadien-1-yl)decyl] triphenyl-,mesylate (MitoQ), a mitochondria-targeted antioxidant, significantly attenuated these measures of cardiac dysfunction, and MitoQ decreased 8-oxo-DG intensity compared with treatment with an inactive comparator compound, (1-decyl)triphenylphosphonium bromide (P <0.05). A real-time polymerase chain reaction array analysis of 84 oxidative stress and antioxidant defense genes revealed that MitoQ attenuates the increase in NADPH oxidase 4 and prostaglandin-endoperoxide synthase 2 and the decrease in uncoupling protein 3 and glutathione S-transferase kappa 1 seen in GPER KO mice. Our findings suggest that the cardioprotective effects of GPER include an antioxidant role and that targeted strategies to limit oxidative stress after early noncancerous surgical extirpation of ovaries or menopause may help limit alterations in cardiac structure and function related to estrogen loss. Copyright © 2018 Elsevier Inc. All rights reserved.

Optogenetics-enabled assessment of viral gene and cell therapy for restoration of cardiac excitability

PubMed Central

Ambrosi, Christina M.; Boyle, Patrick M.; Chen, Kay; Trayanova, Natalia A.; Entcheva, Emilia

2015-01-01

Multiple cardiac pathologies are accompanied by loss of tissue excitability, which leads to a range of heart rhythm disorders (arrhythmias). In addition to electronic device therapy (i.e. implantable pacemakers and cardioverter/defibrillators), biological approaches have recently been explored to restore pacemaking ability and to correct conduction slowing in the heart by delivering excitatory ion channels or ion channel agonists. Using optogenetics as a tool to selectively interrogate only cells transduced to produce an exogenous excitatory ion current, we experimentally and computationally quantify the efficiency of such biological approaches in rescuing cardiac excitability as a function of the mode of application (viral gene delivery or cell delivery) and the geometry of the transduced region (focal or spatially-distributed). We demonstrate that for each configuration (delivery mode and spatial pattern), the optical energy needed to excite can be used to predict therapeutic efficiency of excitability restoration. Taken directly, these results can help guide optogenetic interventions for light-based control of cardiac excitation. More generally, our findings can help optimize gene therapy for restoration of cardiac excitability. PMID:26621212

Identification of novel mutations including a double mutation in patients with inherited cardiomyopathy by a targeted sequencing approach using the Ion Torrent PGM system.

PubMed

Zhao, Yue; Cao, Hong; Song, Yindi; Feng, Yue; Ding, Xiaoxue; Pang, Mingjie; Zhang, Yunmei; Zhang, Hong; Ding, Jiahuan; Xia, Xueshan

2016-06-01

Inherited cardiomyopathy is the major cause of sudden cardiac death (SCD) and heart failure (HF). The disease is associated with extensive genetic heterogeneity; pathogenic mutations in cardiac sarcomere protein genes, cytoskeletal protein genes and nuclear envelope protein genes have been linked to its etiology. Early diagnosis is conducive to clinical monitoring and allows for presymptomatic interventions as needed. In the present study, the entire coding sequences and flanking regions of 12 major disease (cardiomyopathy)-related genes [namely myosin, heavy chain 7, cardiac muscle, β (MYH7); myosin binding protein C, cardiac (MYBPC3); lamin A/C (LMNA); troponin I type 3 (cardiac) (TNNI3); troponin T type 2 (cardiac) (TNNT2); actin, α, cardiac muscle 1 (ACTC1); tropomyosin 1 (α) (TPM1); sodium channel, voltage gated, type V alpha subunit (SCN5A); myosin, light chain 2, regulatory, cardiac, slow (MYL2); myosin, heavy chain 6, cardiac muscle, α (MYH6); myosin, light chain 3, alkali, ventricular, skeletal, slow (MYL3); and protein kinase, AMP-activated, gamma 2 non-catalytic subunit  (PRKAG2)] in 8 patients with dilated cardiomyopathy (DCM) and in 8 patients with hypertrophic cardiomyopathy (HCM) were amplified and then sequenced using the Ion Torrent Personal Genome Machine (PGM) system. As a result, a novel heterozygous mutation (MYH7, p.Asn885Thr) and a variant of uncertain significance (TNNT2, p.Arg296His) were identified in 2 patients with HCM. These 2 missense mutations, which were absent in the samples obtained from the 200 healthy control subjects, altered the amino acid that was evolutionarily conserved among a number of vertebrate species; this illustrates that these 2 non-synonymous mutations play a role in the pathogenesis of HCM. Moreover, a double heterozygous mutation (PRKAG2, p.Gly100Ser plus MYH7, p.Arg719Trp) was identified in a patient with severe familial HCM, for the first time to the best of our knowledge. This patient provided us with more information regarding the genotype-phenotype correlation between mutations of MYH7 and PRKAG2. Taken together, these findings provide insight into the molecular mechanisms underlying inherited cardiomyopathy. The mutations identified in this study may be further investigated in the future in order to improve the diagnosis and treatment of patients with inherited cardiomyopathy. Furthermore, our findings indicated that sequencing using the Ion Torrent PGM system is a useful approach for the identification of pathogenic mutations associated with inherited cardiomyopathy, and it may be used for the risk evaluation of individuals with a possible susceptibility to inherited cardiomyopathy.

High-fat feeding in cardiomyocyte-restricted PPARdelta knockout mice leads to cardiac overexpression of lipid metabolic genes but fails to rescue cardiac phenotypes.

PubMed

Li, Yuquan; Cheng, Lihong; Qin, Qianhong; Liu, Jian; Lo, Woo-kuen; Brako, Lowrence A; Yang, Qinglin

2009-10-01

Peroxisome proliferator-activated receptor delta (PPARdelta) is an essential determinant of basal myocardial fatty acid oxidation (FAO) and bioenergetics. We wished to determine whether increased lipid loading affects the PPARdelta deficient heart in transcriptional regulation of FAO and in the development of cardiac pathology. Cardiomyocyte-restricted PPARdelta knockout (CR-PPARdelta(-/-)) and control (alpha-MyHC-Cre) mice were subjected to 48 h of fasting and to a long-term maintenance on a (28 weeks) high-fat diet (HFD). The expression of key FAO proteins in heart was examined. Serum lipid profiles, cardiac pathology, and changes of various transduction signaling pathways were also examined. Mice subjected to fasting exhibited upregulated transcript expression of FAO genes in the CR-PPARdelta(-/-) hearts. Moreover, long-term HFD in CR-PPARdelta(-/-) mice induced a strikingly greater transcriptional response. After HFD, genes encoding key FAO enzymes were expressed remarkably more in CR-PPARdelta(-/-) hearts than in those of control mice. Despite the marked rise of FAO gene expression, corresponding protein expression remained low in the CR-PPARdelta(-/-) heart, accompanied by abnormalities in sarcomere structures and mitochondria that were similar to those of CR-PPARdelta(-/-) hearts with regular chow feeding. The CR-PPARdelta(-/-) mice displayed increased expression of PPARgamma co-activator-1alpha (PGC-1alpha) and PPARalpha in the heart with deactivated Akt and p42/44 MAPK signaling in response to HFD. We conclude that PPARdelta is an essential determinant of myocardial FAO. Increased lipid intake activates cardiac expression of FAO genes via PPARalpha/PGC-1alpha pathway, albeit it is not sufficient to improve cardiac pathology due to PPARdelta deficiency.

Cardiac AAV9-S100A1 gene therapy rescues postischemic heart failure in a preclinical large animal model

PubMed Central

Pleger, Sven T.; Shan, Changguang; Ksienzyk, Jan; Bekeredjian, Raffi; Boekstegers, Peter; Hinkel, Rabea; Schinkel, Stefanie; Leuchs, Barbara; Ludwig, Jochen; Qiu, Gang; Weber, Christophe; Kleinschmidt, Jürgen A.; Raake, Philip; Koch, Walter J.; Katus, Hugo A.; Müller, Oliver J.; Most, Patrick

2014-01-01

As a prerequisite to clinical application, we determined the long-term therapeutic effectiveness and safety of adeno-associated viral (AAV) S100A1 gene therapy in a preclinical, large animal model of heart failure. S100A1, a positive inotropic regulator of myocardial contractility, becomes depleted in failing cardiomyocytes in humans and various animal models, and myocardial-targeted S100A1 gene transfer rescues cardiac contractile function by restoring sarcoplasmic reticulum calcium Ca2+ handling in acutely and chronically failing hearts in small animal models. We induced heart failure in domestic pigs by balloon-occlusion of the left circumflex coronary artery, resulting in myocardial infarction. After 2 weeks, when the pigs displayed significant left ventricular contractile dysfunction, we administered through retrograde coronary venous delivery, AAV9-S100A1 to the left ventricular non-infarcted myocardium. AAV9-luciferase and saline treatment served as control. At 14 weeks, both control groups showed significantly decreased myocardial S100A1 protein expression along with progressive deterioration of cardiac performance and left ventricular remodeling. AAV9-S100A1 treatment prevented and reversed this phenotype by restoring cardiac S100A1 protein levels. S100A1 treatment normalized cardiomyocyte Ca2+ cycling, sarcoplasmic reticulum calcium handling and energy homeostasis. Transgene expression was restricted to cardiac tissue and extra-cardiac organ function was uncompromised indicating a favorable safety profile. This translational study shows the pre-clinical feasibility, long-term therapeutic effectiveness and a favorable safety profile of cardiac AAV9-S100A1 gene therapy in a preclinical model of heart failure. Our study presents a strong rational for a clinical trial of S100A1 gene therapy for human heart failure that could potentially complement current strategies to treat end-stage heart failure. PMID:21775667

Simultaneous regulation of apoptotic gene silencing and angiogenic gene expression for myocardial infarction therapy: Single-carrier delivery of SHP-1 siRNA and VEGF-expressing pDNA.

PubMed

Kim, Dongkyu; Ku, Sook Hee; Kim, Hyosuk; Jeong, Ji Hoon; Lee, Minhyung; Kwon, Ick Chan; Choi, Donghoon; Kim, Sun Hwa

2016-12-10

Gene therapy is aimed at selectively knocking up or knocking down the target genes involved in the development of diseases. In many human diseases, dysregulation of disease-associated genes is occurred concurrently: some genes are abnormally turned up and some are turned down. In the field of non-viral gene therapy, plasmid DNA (pDNA) and small interfering RNA (siRNA) are suggested as representative regulation tools for activating and silencing the expression of genes of interest, representatively. Herein, we simultaneously loaded both siRNA (Src homology region 2 domain-containing tyrosine phosphatase-1 siRNA, siSHP-1) for anti-apoptosis and pDNA (hypoxia-inducible vascular endothelial growth factor expression vector, pHI-VEGF) for angiogenesis in a single polymeric nanocarrier and used to synergistically attenuate ischemia-reperfusion (IR)-induced myocardial infarction, which is mainly caused by dysregulating of cardiac apoptosis and angiogenesis. For dual-modality cardiac gene delivery, siSHP-1 and pHI-VEGF were sequentially incorporated into a stable nanocomplex by using deoxycholic acid-modified polyethylenimine (DA-PEI). The resulting DA-PEI/siSHP-1/pHI-VEGF complexes exhibited the high structural stability against polyanion competition and the improved resistance to digestion by nucleases. The cardiac administration of DA-PEI/siSHP-1/pHI-VEGF reduced cardiomyocyte apoptosis and enhanced cardiac microvessel formation, thereby reducing infarct size in rat ischemia-reperfusion model. The simultaneous anti-apoptotic and angiogenic gene therapies synergized the cardioprotective effects of each strategy; thus our dual-modal single-carrier gene delivery system can be considered as a promising candidate for treating ischemic heart diseases. Copyright © 2016 Elsevier B.V. All rights reserved.

Gene Regulatory Networks in Cardiac Conduction System Development

PubMed Central

Munshi, Nikhil V.

2014-01-01

The cardiac conduction system is a specialized tract of myocardial cells responsible for maintaining normal cardiac rhythm. Given its critical role in coordinating cardiac performance, a detailed analysis of the molecular mechanisms underlying conduction system formation should inform our understanding of arrhythmia pathophysiology and affect the development of novel therapeutic strategies. Historically, the ability to distinguish cells of the conduction system from neighboring working myocytes presented a major technical challenge for performing comprehensive mechanistic studies. Early lineage tracing experiments suggested that conduction cells derive from cardiomyocyte precursors, and these claims have been substantiated by using more contemporary approaches. However, regional specialization of conduction cells adds an additional layer of complexity to this system, and it appears that different components of the conduction system utilize unique modes of developmental formation. The identification of numerous transcription factors and their downstream target genes involved in regional differentiation of the conduction system has provided insight into how lineage commitment is achieved. Furthermore, by adopting cutting-edge genetic techniques in combination with sophisticated phenotyping capabilities, investigators have made substantial progress in delineating the regulatory networks that orchestrate conduction system formation and their role in cardiac rhythm and physiology. This review describes the connectivity of these gene regulatory networks in cardiac conduction system development and discusses how they provide a foundation for understanding normal and pathological human cardiac rhythms. PMID:22628576

The road ahead: working towards effective clinical translation of myocardial gene therapies

PubMed Central

Katz, Michael G; Fargnoli, Anthony S; Williams, Richard D; Bridges, Charles R

2014-01-01

During the last two decades the fields of molecular and cellular cardiology, and more recently molecular cardiac surgery, have developed rapidly. The concept of delivering cDNA encoding a therapeutic gene to cardiomyocytes using a vector system with substantial cardiac tropism, allowing for long-term expression of a therapeutic protein, has moved from hypothesis to bench to clinical application. However, the clinical results to date are still disappointing. The ideal gene transfer method should be explored in clinically relevant animal models of heart disease to evaluate the relative roles of specific molecular pathways in disease pathogenesis, helping to validate the potential targets for therapeutic intervention. Successful clinical cardiovascular gene therapy also requires the use of nonimmunogenic cardiotropic vectors capable of expressing the requisite amount of therapeutic protein in vivo and in situ. Depending on the desired application either regional or global myocardial gene delivery is required. Cardiac-specific delivery techniques incorporating mapping technologies for regional delivery and highly efficient methodologies for global delivery should improve the precision and specificity of gene transfer to the areas of interest and minimize collateral organ gene expression. PMID:24341816

Use of RNA-seq to identify cardiac genes and gene pathways differentially expressed between dogs with and without dilated cardiomyopathy

PubMed Central

Friedenberg, Steven G.; Chdid, Lhoucine; Keene, Bruce; Sherry, Barbara; Motsinger-Reif, Alison; Meurs, Kathryn M.

2017-01-01

OBJECTIVE To identify cardiac tissue genes and gene pathways differentially expressed between dogs with and without dilated cardiomyopathy (DCM). ANIMALS 8 dogs with and 5 dogs without DCM. PROCEDURES Following euthanasia, samples of left ventricular myocardium were collected from each dog. Total RNA was extracted from tissue samples, and RNA sequencing was performed on each sample. Samples from dogs with and without DCM were grouped to identify genes that were differentially regulated between the 2 populations. Overrepresentation analysis was performed on upregulated and downregulated gene sets to identify altered molecular pathways in dogs with DCM. RESULTS Genes involved in cellular energy metabolism, especially metabolism of carbohydrates and fats, were significantly downregulated in dogs with DCM. Expression of cardiac structural proteins was also altered in affected dogs. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that RNA sequencing may provide important insights into the pathogenesis of DCM in dogs and highlight pathways that should be explored to identify causative mutations and develop novel therapeutic interventions. PMID:27347821

Gene therapy in large animal models of human cardiovascular genetic disease.

PubMed

Sleeper, Meg M; Bish, Lawrence T; Sweeney, H Lee

2009-01-01

Several naturally occurring animal models for human genetic heart diseases offer an excellent opportunity to evaluate potential novel therapies, including gene therapy. Some of these diseases--especially those that result in a structural defect during development (e.g., patent ductus arteriosus, pulmonic stenosis)--would likely be difficult to treat with a therapeutic gene transfer approach. However, the ability to transduce a significant proportion of the myocardial cells should make the various forms of inherited cardiomyopathy amenable to a therapeutic gene transfer approach. Adeno-associated virus may be the ideal vector for cardiac gene therapy since its low immunogenicity allows for stable transgene expression, a crucial factor when considering treatment of a chronic disease. Cardiomyopathies are a major cause of morbidity and mortality in both children and adults, and large animal models are available for the major forms of inherited cardiomyopathy (dilated cardiomyopathy, hypertrophic cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy). One of these animal models, juvenile dilated cardiomyopathy of Portuguese water dogs, offers an effective means to assess the efficacy of therapeutic gene transfer to alter the course of cardiomyopathy and heart failure. Correction of the abnormal metabolic processes that occur with heart failure (e.g., calcium metabolism, apoptosis) could normalize diseased myocardial function. Gene therapy may offer a promising new approach for the treatment of cardiac disease in both veterinary and human clinical settings.

c-Abl tyrosine kinase regulates cardiac growth and development.

PubMed

Qiu, Zhaozhu; Cang, Yong; Goff, Stephen P

2010-01-19

The c-Abl protein is a ubiquitously expressed nonreceptor tyrosine kinase involved in the development and function of many mammalian organ systems, including the immune system and bone. Here we show that homozygous Abl mutant embryos and newborns on the C57BL/6J background, but not on other backgrounds, display dramatically enlarged hearts and die perinatally. The heart defects can be largely rescued by cardiomyocyte-specific restoration of the full-length c-Abl protein. The cardiac hyperplasia phenotype is not caused by decreased apoptosis, but rather by abnormally increased cardiomyocyte proliferation during later stages of embryogenesis. Genes involved in cardiac stress and remodeling and cell cycle regulation are also up-regulated in the mutant hearts. These findings reveal an essential role for c-Abl in mammalian heart growth and development.

c-Abl tyrosine kinase regulates cardiac growth and development

PubMed Central

Qiu, Zhaozhu; Cang, Yong; Goff, Stephen P.

2009-01-01

The c-Abl protein is a ubiquitously expressed nonreceptor tyrosine kinase involved in the development and function of many mammalian organ systems, including the immune system and bone. Here we show that homozygous Abl mutant embryos and newborns on the C57BL/6J background, but not on other backgrounds, display dramatically enlarged hearts and die perinatally. The heart defects can be largely rescued by cardiomyocyte-specific restoration of the full-length c-Abl protein. The cardiac hyperplasia phenotype is not caused by decreased apoptosis, but rather by abnormally increased cardiomyocyte proliferation during later stages of embryogenesis. Genes involved in cardiac stress and remodeling and cell cycle regulation are also up-regulated in the mutant hearts. These findings reveal an essential role for c-Abl in mammalian heart growth and development. PMID:20080568

Lmcd1/Dyxin, a novel Z-disc associated LIM protein, mediates cardiac hypertrophy in vitro and in vivo.

PubMed

Frank, Derk; Frauen, Robert; Hanselmann, Christiane; Kuhn, Christian; Will, Rainer; Gantenberg, Johanne; Füzesi, Laszlo; Katus, Hugo A; Frey, Norbert

2010-10-01

To identify new mediators of cardiac hypertrophy, we performed a genome-wide mRNA screen of stretched neonatal rat cardiomyocytes (NRCMs). In addition to known members of the hypertrophic gene program, we found the novel sarcomeric Z-disc LIM protein Lmcd1/Dyxin markedly upregulated. Consistently, Lmcd1 was also induced in several mouse models of myocardial hypertrophy suggesting a causal role in cardiac hypertrophy. We overexpressed Lmcd1 in NRCM, which led to cardiomyocyte hypertrophy and induction of the hypertrophic gene program. Likewise, the calcineurin-responsive gene RCAN1-4 was found significantly upregulated. Conversely, knockdown of Lmcd1 blunted the response to hypertrophic stimuli such as stretch and phenylephrine (PE), suggesting that Lmcd1 is required for the hypertrophic response. Furthermore, PE-mediated activation of calcineurin was completely blocked by knockdown of Lmcd1. To confirm these results in vivo, we generated transgenic mice with cardiac-restricted overexpression of Lmcd1. Despite normal cardiac function, adult transgenic mice displayed significant cardiac hypertrophy, again accompanied by induction of hypertrophic marker genes such as ANF and alpha-skeletal actin. Likewise, Rcan1-4 was found upregulated. Moreover, when crossed with transgenic mice overexpressing constitutionally active calcineurin, Lmcd1 transgenic mice revealed an exacerbated cardiomyopathic phenotype with depressed contractile function and further increased cardiomyocyte hypertrophy. We show that the novel z-disc protein Lmcd1/Dyxin is significantly upregulated in several models of cardiac hypertrophy. Lmcd1/Dyxin potently induces cardiomyocyte hypertrophy both in vitro and in vivo, while knockdown of this molecule prevents hypertrophy. Mechanistically, Lmcd1/Dyxin appears to signal through the calcineurin pathway. Lmcd1/Dyxin may thus represent an attractive target for novel antihypertrophic strategies. Copyright 2010 Elsevier Ltd. All rights reserved.

Short-Term Subclinical Zinc Deficiency in Weaned Piglets Affects Cardiac Redox Metabolism and Zinc Concentration.

PubMed

Brugger, Daniel; Windisch, Wilhelm M

2017-04-01

Background: Subclinical zinc deficiency (SZD) represents the common zinc malnutrition phenotype. However, its association with oxidative stress is not well understood. The heart muscle may be a promising target for studying early changes in redox metabolism. Objective: We investigated the effects of short-term SZD on cardiac redox metabolism in weaned piglets. Methods: Forty-eight weaned German Large White × Landrace × Piétrain piglets (50% castrated males and 50% females; body weight of 8.5 kg) were fed diets with different zinc concentrations for 8 d. Measurements included cardiac parameters of antioxidative capacity, stress-associated gene expression, and tissue zinc status. Analyses comprised (linear, broken-line) regression models and Pearson correlation coefficients. Results: Glutathione and α-tocopherol concentrations as well as catalase, glutathione reductase, B-cell lymphoma 2-associated X protein, and caspase 9 gene expression plateaued in response to reduction in dietary zinc from 88.0 to 57.6, 36.0, 36.5, 41.3, 55.3, and 33.8 mg/kg, respectively ( P < 0.0001). Further reduction in dietary zinc promoted a linear decrease of glutathione and α-tocopherol (30 and 0.6 nmol/mg dietary Zn, respectively; P < 0.05) and a linear increase of gene expression [0.02, 0.01, 0.003, and 0.02 Log 10 (2 -ΔΔCt )/mg dietary Zn, respectively; P < 0.05)]. Tissue zinc declined linearly with reduction in dietary zinc (0.21 mg tissue Zn/mg dietary Zn; P = 0.004) from 88.0 to 42.7 mg/kg ( P < 0.0001), below which it linearly increased inversely to further reduction in dietary zinc (0.57 mg tissue Zn/mg dietary Zn; P = 0.006). H 2 O 2 -detoxification activity and metallothionein 1A gene expression decreased linearly with reduction in dietary zinc from 88.0 to 28.1 mg/kg [0.02 mU and 0.008 Log 10 (2 -ΔΔCt )/mg dietary Zn, respectively; P < 0.05]. Fas cell-surface death receptor, etoposide-induced 2.4 and cyclin-dependent kinase inhibitor 1A gene expression correlated positively to cardiac zinc in piglets fed ≤42.7 mg Zn/kg ( r ≥ 0.97; P < 0.05). Conclusions: Short-term SZD decreased cardiac antioxidative capacity of weaned piglets while simultaneously increasing stress-associated gene expression and zinc concentration. This is the first report to our knowledge on the effects of SZD on redox metabolism. © 2017 American Society for Nutrition.

Cardiac transcriptome profiling of diabetic Akita mice using microarray and next generation sequencing

PubMed Central

Kesherwani, Varun; Shahshahan, Hamid R.

2017-01-01

Although diabetes mellitus (DM) causes cardiomyopathy and exacerbates heart failure, the underlying molecular mechanisms for diabetic cardiomyopathy/heart failure are poorly understood. Insulin2 mutant (Ins2+/-) Akita is a mouse model of T1DM, which manifests cardiac dysfunction. However, molecular changes at cardiac transcriptome level that lead to cardiomyopathy remain unclear. To understand the molecular changes in the heart of diabetic Akita mice, we profiled cardiac transcriptome of Ins2+/- Akita and Ins2+/+ control mice using next generation sequencing (NGS) and microarray, and determined the implications of differentially expressed genes on various heart failure signaling pathways using Ingenuity pathway (IPA) analysis. First, we validated hyperglycemia, increased cardiac fibrosis, and cardiac dysfunction in twelve-week male diabetic Akita. Then, we analyzed the transcriptome levels in the heart. NGS analyses on Akita heart revealed 137 differentially expressed transcripts, where Bone Morphogenic Protein-10 (BMP10) was the most upregulated and hairy and enhancer of split-related (HELT) was the most downregulated gene. Moreover, twelve long non-coding RNAs (lncRNAs) were upregulated. The microarray analyses on Akita heart showed 351 differentially expressed transcripts, where vomeronasal-1 receptor-180 (Vmn1r180) was the most upregulated and WD Repeat Domain 83 Opposite Strand (WDR83OS) was the most downregulated gene. Further, miR-101c and H19 lncRNA were upregulated but Neat1 lncRNA was downregulated in Akita heart. Eleven common genes were upregulated in Akita heart in both NGS and microarray analyses. IPA analyses revealed the role of these differentially expressed genes in key signaling pathways involved in diabetic cardiomyopathy. Our results provide a platform to initiate focused future studies by targeting these genes and/or non-coding RNAs, which are differentially expressed in Akita hearts and are involved in diabetic cardiomyopathy. PMID:28837672

Effects of Hypertension and Exercise on Cardiac Proteome Remodelling

PubMed Central

Petriz, Bernardo A.; Franco, Octavio L.

2014-01-01

Left ventricle hypertrophy is a common outcome of pressure overload stimulus closely associated with hypertension. This process is triggered by adverse molecular signalling, gene expression, and proteome alteration. Proteomic research has revealed that several molecular targets are associated with pathologic cardiac hypertrophy, including angiotensin II, endothelin-1 and isoproterenol. Several metabolic, contractile, and stress-related proteins are shown to be altered in cardiac hypertrophy derived by hypertension. On the other hand, exercise is a nonpharmacologic agent used for hypertension treatment, where cardiac hypertrophy induced by exercise training is characterized by improvement in cardiac function and resistance against ischemic insult. Despite the scarcity of proteomic research performed with exercise, healthy and pathologic heart proteomes are shown to be modulated in a completely different way. Hence, the altered proteome induced by exercise is mostly associated with cardioprotective aspects such as contractile and metabolic improvement and physiologic cardiac hypertrophy. The present review, therefore, describes relevant studies involving the molecular characteristics and alterations from hypertensive-induced and exercise-induced hypertrophy, as well as the main proteomic research performed in this field. Furthermore, proteomic research into the effect of hypertension on other target-demerged organs is examined. PMID:24877123

Contribution of rare inherited and de novo variants in 2,871 congenital heart disease probands

PubMed Central

Jin, Sheng Chih; Homsy, Jason; Zaidi, Samir; Lu, Qiongshi; Morton, Sarah; DePalma, Steven R.; Zeng, Xue; Qi, Hongjian; Chang, Weni; Sierant, Michael C.; Hung, Wei-Chien; Haider, Shozeb; Zhang, Junhui; Knight, James; Bjornson, Robert D.; Castaldi, Christopher; Tikhonoa, Irina R.; Bilguvar, Kaya; Mane, Shrikant M.; Sanders, Stephan J.; Mital, Seema; Russell, Mark; Gaynor, William; Deanfield, John; Giardini, Alessandro; Porter, George A.; Srivastava, Deepak; Lo, Cecelia W.; Shen, Yufeng; Watkins, W. Scott; Yandell, Mark; Yost, H. Joseph; Tristani-Firouzi, Martin; Newburger, Jane W.; Roberts, Amy E.; Kim, Richard; Zhao, Hongyu; Kaltman, Jonathan R.; Goldmuntz, Elizabeth; Chung, Wendy K.; Seidman, Jonathan G.; Gelb, Bruce D.; Seidman, Christine E.; Lifton, Richard P.; Brueckner, Martina

2017-01-01

Congenital heart disease (CHD) is the leading cause of mortality from birth defects. Exome sequencing of a single cohort of 2,871 CHD probands including 2,645 parent-offspring trios implicated rare inherited mutations in 1.8%, including a recessive founder mutation in GDF1 accounting for ~5% of severe CHD in Ashkenazim, recessive genotypes in MYH6 accounting for ~11% of Shone complex, and dominant FLT4 mutations accounting for 2.3% of Tetralogy of Fallot. De novo mutations (DNMs) accounted for 8% of cases, including ~3% of isolated CHD patients and ~28% with both neurodevelopmental and extra-cardiac congenital anomalies. Seven genes surpassed thresholds for genome-wide significance and 12 genes not previously implicated in CHD had > 70% probability of being disease-related; DNMs in ~440 genes are inferred to contribute to CHD. There was striking overlap between genes with damaging DNMs in probands with CHD and autism. PMID:28991257

Complete Genome Sequence of Germline Chromosomally Integrated Human Herpesvirus 6A and Analyses Integration Sites Define a New Human Endogenous Virus with Potential to Reactivate as an Emerging Infection.

PubMed

Tweedy, Joshua; Spyrou, Maria Alexandra; Pearson, Max; Lassner, Dirk; Kuhl, Uwe; Gompels, Ursula A

2016-01-15

Human herpesvirus-6A and B (HHV-6A, HHV-6B) have recently defined endogenous genomes, resulting from integration into the germline: chromosomally-integrated "CiHHV-6A/B". These affect approximately 1.0% of human populations, giving potential for virus gene expression in every cell. We previously showed that CiHHV-6A was more divergent than CiHHV-6B by examining four genes in 44 European CiHHV-6A/B cardiac/haematology patients. There was evidence for gene expression/reactivation, implying functional non-defective genomes. To further define the relationship between HHV-6A and CiHHV-6A we used next-generation sequencing to characterize genomes from three CiHHV-6A cardiac patients. Comparisons to known exogenous HHV-6A showed CiHHV-6A genomes formed a separate clade; including all 85 non-interrupted genes and necessary cis-acting signals for reactivation as infectious virus. Greater single nucleotide polymorphism (SNP) density was defined in 16 genes and the direct repeats (DR) terminal regions. Using these SNPs, deep sequencing analyses demonstrated superinfection with exogenous HHV-6A in two of the CiHHV-6A patients with recurrent cardiac disease. Characterisation of the integration sites in twelve patients identified the human chromosome 17p subtelomere as a prevalent site, which had specific repeat structures and phylogenetically related CiHHV-6A coding sequences indicating common ancestral origins. Overall CiHHV-6A genomes were similar, but distinct from known exogenous HHV-6A virus, and have the capacity to reactivate as emerging virus infections.

Complete Genome Sequence of Germline Chromosomally Integrated Human Herpesvirus 6A and Analyses Integration Sites Define a New Human Endogenous Virus with Potential to Reactivate as an Emerging Infection

PubMed Central

Tweedy, Joshua; Spyrou, Maria Alexandra; Pearson, Max; Lassner, Dirk; Kuhl, Uwe; Gompels, Ursula A.

2016-01-01

Human herpesvirus-6A and B (HHV-6A, HHV-6B) have recently defined endogenous genomes, resulting from integration into the germline: chromosomally-integrated “CiHHV-6A/B”. These affect approximately 1.0% of human populations, giving potential for virus gene expression in every cell. We previously showed that CiHHV-6A was more divergent than CiHHV-6B by examining four genes in 44 European CiHHV-6A/B cardiac/haematology patients. There was evidence for gene expression/reactivation, implying functional non-defective genomes. To further define the relationship between HHV-6A and CiHHV-6A we used next-generation sequencing to characterize genomes from three CiHHV-6A cardiac patients. Comparisons to known exogenous HHV-6A showed CiHHV-6A genomes formed a separate clade; including all 85 non-interrupted genes and necessary cis-acting signals for reactivation as infectious virus. Greater single nucleotide polymorphism (SNP) density was defined in 16 genes and the direct repeats (DR) terminal regions. Using these SNPs, deep sequencing analyses demonstrated superinfection with exogenous HHV-6A in two of the CiHHV-6A patients with recurrent cardiac disease. Characterisation of the integration sites in twelve patients identified the human chromosome 17p subtelomere as a prevalent site, which had specific repeat structures and phylogenetically related CiHHV-6A coding sequences indicating common ancestral origins. Overall CiHHV-6A genomes were similar, but distinct from known exogenous HHV-6A virus, and have the capacity to reactivate as emerging virus infections. PMID:26784220

1H NMR-metabolomics: can they be a useful tool in our understanding of cardiac arrest?

PubMed

Chalkias, Athanasios; Fanos, Vassilios; Noto, Antonio; Castrén, Maaret; Gulati, Anil; Svavarsdóttir, Hildigunnur; Iacovidou, Nicoletta; Xanthos, Theodoros

2014-05-01

This review focuses on the presentation of the emerging technology of metabolomics, a promising tool for the detection of identifying the unrevealed biological pathways that lead to cardiac arrest. The electronic bases of PubMed, Scopus, and EMBASE were searched. Research terms were identified using the MESH database and were combined thereafter. Initial search terms were "cardiac arrest", "cardiopulmonary resuscitation", "post-cardiac arrest syndrome" combined with "metabolomics". Metabolomics allow the monitoring of hundreds of metabolites from tissues or body fluids and already influence research in the field of cardiac metabolism. This approach has elucidated several pathophysiological mechanisms and identified profiles of metabolic changes that can be used to follow the disease processes occurring in the peri-arrest period. This can be achieved through leveraging the strengths of unbiased metabolome-wide scans, which include thousands of final downstream products of gene transcription, enzyme activity and metabolic products of extraneously administered substances, in order to identify a metabolomic fingerprint associated with an increased risk of cardiac arrest. Although this technology is still under development, metabolomics is a promising tool for elucidating biological pathways and discovering clinical biomarkers, strengthening the efforts for optimizing both the prevention and treatment of cardiac arrest. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Radio electric conveyed fields directly reprogram human dermal skin fibroblasts toward cardiac, neuronal, and skeletal muscle-like lineages.

PubMed

Maioli, Margherita; Rinaldi, Salvatore; Santaniello, Sara; Castagna, Alessandro; Pigliaru, Gianfranco; Gualini, Sara; Cavallini, Claudia; Fontani, Vania; Ventura, Carlo

2013-01-01

Somatic cells can be directly reprogrammed to alternative differentiated fates without first becoming stem/progenitor cells. Nevertheless, the initial need for viral-mediated gene delivery renders this strategy unsafe in humans. Here, we provide evidence that exposure of human skin fibroblasts to a Radio Electric Asymmetric Conveyer (REAC), an innovative device delivering radio electric conveyed fields at a radiofrequency of 2.4 GHz, afforded remarkable commitment toward cardiac, neuronal, and skeletal muscle lineages. REAC induced the transcription of tissue-restricted genes, including Mef2c, Tbx5, GATA4, Nkx2.5, and prodynorphin for cardiac reprogramming, as well as myoD, and neurogenin 1 for skeletal myogenesis and neurogenesis, respectively. Conversely, REAC treatment elicited a biphasic effect on a number of stemness-related genes, leading to early transcriptional increase of Oct4, Sox2, cMyc, Nanog, and Klf4 within 6-20 h, followed by a downregulation at later times. The REAC action bypassed a persistent reprogramming toward an induced pluripotent stem cell-like state and involved the transcriptional induction of the NADPH oxidase subunit Nox4. Our results show for the first time the feasibility of using a physical stimulus to afford the expression of pluripotentiality in human adult somatic cells up to the attainment of three major target lineages for regenerative medicine.

Research on the relativity between gene polymorphism and children cardiac insufficiency.

PubMed

He, X-H; Li, C-L; Ling, N; Wang, Q-W; Wang, Z-Z; An, X-J

2017-08-01

We analyzed the relationship between Mink-S27 gene polymorphism and children with cardiac insufficiency. From April 2013 to April 2015, we enrolled 73 cases of children with cardiac insufficiency for this study, and all 73 were placed in the observation group. 76 normal cases were selected for the control group. Restriction fragment length polymorphism (RFLP) was used to make polymorphism analysis of the Mink-S27. Our results showed no significant differences in Mink-S27 genotype and allele distribution in both observation and control groups (p>0.05). In lesion samples collected from children with cardiac insufficiency, we detected significant difference in AA, CC genotype frequency and allele frequency between the observation group and the control group (p< 0.05) (X2 = 15.43, p<0.05; X2  = 16.27, p<0.05). Further studies on samples obtained from both groups revealed certain differences of AA, CC, AC genotype frequency and allele frequency in the observation group. The proportion of homozygote (AA, CC) in children with severe cardiac insufficiency was relatively high. GNAS2 gene polymorphism was associated with the prevalence of cardiac insufficiency in children. And also the patients' condition was correlated to the frequency of different genotypes and alleles.

High burden of genetic conditions diagnosed in a cardiac neurodevelopmental clinic.

PubMed

Goldenberg, Paula C; Adler, Betsy J; Parrott, Ashley; Anixt, Julia; Mason, Karen; Phillips, Jannel; Cooper, David S; Ware, Stephanie M; Marino, Bradley S

2017-04-01

There is a known high prevalence of genetic and clinical syndrome diagnoses in the paediatric cardiac population. These disorders often have multisystem effects, which may have an important impact on neurodevelopmental outcomes. Taken together, these facts suggest that patients and families may benefit from consultation by genetic specialists in a cardiac neurodevelopmental clinic. This study assessed the burden of genetic disorders and utility of genetics evaluation in a cardiac neurodevelopmental clinic. A retrospective chart review was conducted of patients evaluated in a cardiac neurodevelopmental clinic from 6 December, 2011 to 16 April, 2013. All patients were seen by a cardiovascular geneticist with genetic counselling support. A total of 214 patients were included in this study; 64 of these patients had a pre-existing genetic or syndromic diagnosis. Following genetics evaluation, an additional 19 were given a new clinical or laboratory-confirmed genetic diagnosis including environmental such as teratogenic exposures, malformation associations, chromosomal disorders, and single-gene disorders. Genetic testing was recommended for 112 patients; radiological imaging to screen for congenital anomalies for 17 patients; subspecialist medical referrals for 73 patients; and non-genetic clinical laboratory testing for 14 patients. Syndrome-specific guidelines were available and followed for 25 patients with known diagnosis. American Academy of Pediatrics Red Book asplenia guideline recommendations were given for five heterotaxy patients, and family-based cardiac screening was recommended for 23 families affected by left ventricular outflow tract obstruction. Genetics involvement in a cardiac neurodevelopmental clinic is helpful in identifying new unifying diagnoses and providing syndrome-specific care, which may impact the patient's overall health status and neurodevelopmental outcome.

Estrogenic modulation of inflammation-related genes in male rats following volume overload

PubMed Central

McLarty, Jennifer L.; Meléndez, Giselle C.; Levick, Scott P.; Bennett, Shanté; Sabo-Attwood, Tara; Brower, Gregory L.

2012-01-01

Our laboratory has previously reported significant increases of the proinflammatory cytokine TNF-α in male hearts secondary to sustained volume overload. These elevated levels of TNF-α are accompanied by left ventricular (LV) dilatation and cardiac dysfunction. In contrast, estrogen has been shown to protect against this adverse cardiac remodeling in both female and male rats. The purpose of this study was to determine whether estrogen has an effect on inflammation-related genes that contribute to this estrogen-mediated cardioprotection. Myocardial volume overload was induced by aortocaval fistula in 8 wk old male Sprague-Dawley rats (n = 30), and genes of interest were identified using an inflammatory PCR array in Sham, Fistula, and Fistula + Estrogen-treated (0.02 mg/kg per day beginning 2 wk prior to fistula) groups. A total of 55 inflammatory genes were modified (≥2-fold change) at 3 days postfistula. The number of inflammatory gene was reduced to 21 genes by estrogen treatment, whereas 13 genes were comparably modulated in both fistula groups. The most notable were TNF-α, which was downregulated by estrogen, and the TNF-α receptors, which were differentially regulated by estrogen. Specific genes related to arachidonic acid metabolism were downregulated by estrogen, including cyclooxygenase-1 and -2. Finally, gene expression for the β1-integrin cell adhesion subunit was significantly upregulated in the LV of estrogen-treated animals. Protein levels reflected the changes observed at the gene level. These data suggest that estrogen provides its cardioprotective effects, at least in part, via genomic modulation of numerous inflammation-related genes. PMID:22274565

Metallothionein as a compensatory component prevents intermittent hypoxia-induced cardiomyopathy in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yin, Xia; Zhou, Shanshan; KCHRI at the Department of Pediatrics, School of Medicine, University of Louisville, Louisville, 40202

Obstructive sleep apnea (OSA) causes chronic intermittent hypoxia (IH) to induce cardiovascular disease, which may be related to oxidative damage. Metallothionein (MT) has been extensively proved to be an endogenous and highly inducible antioxidant protein expressed in the heart. Therefore, we tested the hypotheses that oxidative stress plays a critical role in OSA induced cardiac damage and MT protects the heart from OSA-induced cardiomyopathy. To mimic hypoxia/reoxygenation events that occur in adult OSA patients, mice were exposed to IH for 3 days to 8 weeks. The IH paradigm consisted of alternating cycles of 20.9% O{sub 2}/8% O{sub 2} F{sub I}O{submore » 2} (30 episodes per hour) with 20 s at the nadir F{sub I}O{sub 2} for 12 h a day during daylight. IH significantly increased the ratio of heart weight to tibia length at 4 weeks with a decrease in cardiac function from 4 to 8 weeks. Cardiac oxidative damage and fibrosis were observed after 4 and 8 weeks of IH exposures. Endogenous MT expression was up-regulated in response to 3-day IH, but significantly decreased at 4 and 8 weeks of IH. In support of MT as a major compensatory component, mice with cardiac overexpression of MT gene and mice with global MT gene deletion were completely resistant, and highly sensitive, respectively, to chronic IH induced cardiac effects. These findings suggest that chronic IH induces cardiomyopathy characterized by oxidative stress-mediated cardiac damage and the antioxidant MT protects the heart from such pathological and functional changes. - Highlights: • The effect of intermittent hypoxia (IH) on cardiac metallothionein (MT) • Cardiac MT expression was up-regulated in response to 3-day IH. • Exposure to 4- or 8-week IH downregulated cardiac MT expression. • Overexpression of cardiac MT protects from IH-induced cardiac damage. • Global deletion of MT gene made the heart more sensitive to IH damage.« less

Rapamycin Reverses Elevated mTORC1 Signaling in Lamin A/C–Deficient Mice, Rescues Cardiac and Skeletal Muscle Function, and Extends Survival

PubMed Central

Ramos, Fresnida J.; Chen, Steven C.; Garelick, Michael G.; Dai, Dao-Fu; Liao, Chen-Yu; Schreiber, Katherine H.; MacKay, Vivian L.; An, Elroy H.; Strong, Randy; Ladiges, Warren C.; Rabinovitch, Peter S.; Kaeberlein, Matt; Kennedy, Brian K.

2013-01-01

Mutations in LMNA, the gene that encodes A-type lamins, cause multiple diseases including dystrophies of the skeletal muscle and fat, dilated cardiomyopathy, and progeria-like syndromes (collectively termed laminopathies). Reduced A-type lamin function, however, is most commonly associated with skeletal muscle dystrophy and dilated cardiomyopathy rather than lipodystrophy or progeria. The mechanisms underlying these diseases are only beginning to be unraveled. We report that mice deficient in Lmna, which corresponds to the human gene LMNA, have enhanced mTORC1 (mammalian target of rapamycin complex 1) signaling specifically in tissues linked to pathology, namely, cardiac and skeletal muscle. Pharmacologic reversal of elevated mTORC1 signaling by rapamycin improves cardiac and skeletal muscle function and enhances survival in mice lacking A-type lamins. At the cellular level, rapamycin decreases the number of myocytes with abnormal desmin accumulation and decreases the amount of desmin in both muscle and cardiac tissue of Lmna–/– mice. In addition, inhibition of mTORC1 signaling with rapamycin improves defective autophagic-mediated degradation in Lmna–/– mice. Together, these findings point to aberrant mTORC1 signaling as a mechanistic component of laminopathies associated with reduced A-type lamin function and offer a potential therapeutic approach, namely, the use of rapamycin-related mTORC1 inhibitors. PMID:22837538

Natural history of left ventricular mechanics in transplanted hearts: relationships with clinical variables and genetic expression profiles of allograft rejection.

PubMed

Eleid, Mackram F; Caracciolo, Giuseppe; Cho, Eun Joo; Scott, Robert L; Steidley, D Eric; Wilansky, Susan; Arabia, Francisco A; Khandheria, Bijoy K; Sengupta, Partho P

2010-10-01

The aim of this study was to explore the temporal evolution of left ventricular (LV) mechanics in relation to clinical variables and genetic expression profiles implicated in cardiac allograft function. Considerable uncertainty exists regarding the range and determinants of variability in LV systolic performance in transplanted hearts (TXH). Fifty-one patients (mean age 53 ± 12 years; 37 men) underwent serial assessment of echocardiograms, cardiac catheterization, gene expression profiles, and endomyocardial biopsy data within 2 weeks and at 3, 6, 12, and 24 months after transplantation. Two-dimensional speckle-tracking data were compared between patients with TXH and 37 controls (including 12 post-coronary artery bypass patients). Post-transplantation mortality and hospitalizations were recorded with a median follow-up period of 944 days. Global longitudinal strain (LS) and radial strain remained attenuated in patients with TXH at all time points (p < 0.001 and p = 0.005), independent of clinical rejection episodes. Failure to improve global LS at 3 months (≥ 1 SD) was associated with higher incidence of death and cardiac events (hazard ratio: 5.92; 95% confidence interval: 1.96 to 17.91; p = 0.049). Multivariate analysis revealed gene expression score as the only independent predictor of global LS (R(2) = 0.53, p = 0.005), with SEMA7A gene expression having the highest correlation with global LS (r = -0.84, p < 0.001). Speckle tracking-derived LV strains are helpful in estimating the burden of LV dysfunction in patients with TXH that evolves independent of biopsy-detected cellular rejection. Failure to improve global LS at 3 months after transplantation is associated with a higher incidence of death and cardiac events. Serial changes in LV mechanics correlate with peripheral blood gene expression profiles and may affect the clinical assessment of long-term prognosis in patients with TXH. Copyright © 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Cardio-Metabolic Effects of HIV Protease Inhibitors (Lopinavir/Ritonavir)

PubMed Central

Reyskens, Kathleen M. S. E.; Fisher, Tarryn-Lee; Schisler, Jonathan C.; O'Connor, Wendi G.; Rogers, Arlin B.; Willis, Monte S.; Planesse, Cynthia; Boyer, Florence; Rondeau, Philippe; Bourdon, Emmanuel; Essop, M. Faadiel

2013-01-01

Although antiretroviral treatment decreases HIV-AIDS morbidity/mortality, long-term side effects may include the onset of insulin resistance and cardiovascular diseases. However, the underlying molecular mechanisms responsible for highly active antiretroviral therapy (HAART)-induced cardio-metabolic effects are poorly understood. In light of this, we hypothesized that HIV protease inhibitor (PI) treatment (Lopinavir/Ritonavir) elevates myocardial oxidative stress and concomitantly inhibits the ubiquitin proteasome system (UPS), thereby attenuating cardiac function. Lopinavir/Ritonavir was dissolved in 1% ethanol (vehicle) and injected into mini-osmotic pumps that were surgically implanted into Wistar rats for 8 weeks vs. vehicle and sham controls. We subsequently evaluated metabolic parameters, gene/protein markers and heart function (ex vivo Langendorff perfusions). PI-treated rats exhibited increased serum LDL-cholesterol, higher tissue triglycerides (heart, liver), but no evidence of insulin resistance. In parallel, there was upregulation of hepatic gene expression, i.e. acetyl-CoA carboxylase β and 3-hydroxy-3-methylglutaryl-CoA-reductase, key regulators of fatty acid oxidation and cholesterol synthesis, respectively. PI-treated hearts displayed impaired cardiac contractile function together with attenuated UPS activity. However, there was no significant remodeling of hearts exposed to PIs, i.e. lack of ultrastructural changes, fibrosis, cardiac hypertrophic response, and oxidative stress. Western blot analysis of PI-treated hearts revealed that perturbed calcium handling may contribute to the PI-mediated contractile dysfunction. Here chronic PI administration led to elevated myocardial calcineurin, nuclear factor of activated T-cells 3 (NFAT3), connexin 43, and phosphorylated phospholamban, together with decreased calmodulin expression levels. This study demonstrates that early changes triggered by PI treatment include increased serum LDL-cholesterol levels together with attenuated cardiac function. Furthermore, PI exposure inhibits the myocardial UPS and leads to elevated calcineurin and connexin 43 expression that may be associated with the future onset of cardiac contractile dysfunction. PMID:24098634

Transthyretin Cardiac Amyloidosis.

PubMed

Mankad, Anit K; Shah, Keyur B

2017-08-24

Transthyretin (TTR)-related cardiac amyloidosis is a progressive infiltrative cardiomyopathy that mimics hypertensive, hypertrophic heart disease and may go undiagnosed. Transthyretin-derived amyloidosis accounts for 18% of all cases of cardiac amyloidosis. Thus, the study's purpose is to provide a comprehensive review of transthyretin cardiac amyloidosis. Wild-type transthyretin (ATTRwt) protein causes cardiac amyloidosis sporadically, with 25 to 36% of the population older than 80 years of age are at risk to develop a slowly progressive, infiltrative amyloid cardiomyopathy secondary to ATTRwt. In contrast, hereditary amyloidosis (ATTRm) is an autosomal dominant inherited disease associated with more than 100 point mutations in the transthyretin gene and has a tendency to affect the heart and nervous system. Up to 4% of African-Americans carry the Val122Ile mutation in the transthyretin gene, the most prevalent cause of hereditary cardiac amyloidosis in the USA. Identifying transthyretin cardiac amyloidosis requires increased awareness of the prevalence, signs and symptoms, and diagnostic tools available for discrimination of this progressive form of cardiomyopathy associated with left ventricular hypertrophy. While there are no FDA-approved medical treatments, investigation is underway on agents to reduce circulating mutated transthyretin.

Dystrophic Cardiomyopathy: Complex Pathobiological Processes to Generate Clinical Phenotype

PubMed Central

Tsuda, Takeshi; Fitzgerald, Kristi K.

2017-01-01

Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), and X-linked dilated cardiomyopathy (XL-DCM) consist of a unique clinical entity, the dystrophinopathies, which are due to variable mutations in the dystrophin gene. Dilated cardiomyopathy (DCM) is a common complication of dystrophinopathies, but the onset, progression, and severity of heart disease differ among these subgroups. Extensive molecular genetic studies have been conducted to assess genotype-phenotype correlation in DMD, BMD, and XL-DCM to understand the underlying mechanisms of these diseases, but the results are not always conclusive, suggesting the involvement of complex multi-layers of pathological processes that generate the final clinical phenotype. Dystrophin protein is a part of dystrophin-glycoprotein complex (DGC) that is localized in skeletal muscles, myocardium, smooth muscles, and neuronal tissues. Diversity of cardiac phenotype in dystrophinopathies suggests multiple layers of pathogenetic mechanisms in forming dystrophic cardiomyopathy. In this review article, we review the complex molecular interactions involving the pathogenesis of dystrophic cardiomyopathy, including primary gene mutations and loss of structural integrity, secondary cellular responses, and certain epigenetic and other factors that modulate gene expressions. Involvement of epigenetic gene regulation appears to lead to specific cardiac phenotypes in dystrophic hearts. PMID:29367543

Control of early cardiac-specific transcription of Nkx2-5 by a GATA-dependent enhancer.

PubMed

Lien, C L; Wu, C; Mercer, B; Webb, R; Richardson, J A; Olson, E N

1999-01-01

The homeobox gene Nkx2-5 is the earliest known marker of the cardiac lineage in vertebrate embryos. Nkx2-5 expression is first detected in mesodermal cells specified to form heart at embryonic day 7.5 in the mouse and expression is maintained throughout the developing and adult heart. In addition to the heart, Nkx2-5 is transiently expressed in the developing pharynx, thyroid and stomach. To investigate the mechanisms that initiate cardiac transcription during embryogenesis, we analyzed the Nkx2-5 upstream region for regulatory elements sufficient to direct expression of a lacZ transgene in the developing heart of transgenic mice. We describe a cardiac enhancer, located about 9 kilobases upstream of the Nkx2-5 gene, that fully recapitulates the expression pattern of the endogenous gene in cardiogenic precursor cells from the onset of cardiac lineage specification and throughout the linear and looping heart tube. Thereafter, as the atrial and ventricular chambers become demarcated, enhancer activity becomes restricted to the developing right ventricle. Transcription of Nkx2-5 in pharynx, thyroid and stomach is controlled by regulatory elements separable from the cardiac enhancer. This distal cardiac enhancer contains a high-affinity binding site for the cardiac-restricted zinc finger transcription factor GATA4 that is essential for transcriptional activity. These results reveal a novel GATA-dependent mechanism for activation of Nkx2-5 transcription in the developing heart and indicate that regulation of Nkx2-5 is controlled in a modular manner, with multiple regulatory regions responding to distinct transcriptional networks in different compartments of the developing heart.

Interleukin-18 gene deletion protects against sepsis-induced cardiac dysfunction by inhibiting PP2A activity.

PubMed

Okuhara, Yoshitaka; Yokoe, Shunichi; Iwasaku, Toshihiro; Eguchi, Akiyo; Nishimura, Koichi; Li, Wen; Oboshi, Makiko; Naito, Yoshiro; Mano, Toshiaki; Asahi, Michio; Okamura, Haruki; Masuyama, Tohru; Hirotani, Shinichi

2017-09-15

Interleukin-18 (IL-18) neutralization protects against lipopolysaccharide (LPS)-induced injuries, including myocardial dysfunction. However, the mechanism is yet to be fully elucidated. The aim of the present study was to determine whether IL-18 gene deletion prevents sepsis-induced cardiac dysfunction and to elucidate the potential mechanisms underlying IL-18-mediated cardiotoxicity by LPS. Ten-week-old male wild-type (WT) and IL-18 knockout (IL-18 KO) mice were intraperitoneally administered LPS. Serial echocardiography showed better systolic pump function and less left ventricular (LV) dilatation in LPS-treated IL-18 KO mice compared with those in LPS-treated WT mice. LPS treatment significantly decreased the levels of phospholamban (PLN) and Akt phosphorylation in WT mice compared with those in saline-treated WT mice, while the LPS-induced decrease in the phosphorylation levels was attenuated in IL-18 KO mice compared with that in WT mice. IL-18 gene deletion also attenuated an LPS-induced increase of type 2 protein phosphatase 2A (PP2A) activity, a molecule that dephosphorylates PLN and Akt. There was no difference in type 1 protein phosphatase (PP1) activity. To address whether IL-18 affects PLN and Akt phosphorylation via PP2A activation in cardiomyocytes, rat neonatal cardiac myocytes were cultured and stimulated using 100ng/ml of recombinant rat IL-18. Exogenous IL-18 decreased the level of PLN and Akt phosphorylation in cardiomyocytes. PP2A activity but not PP1 activity was increased by IL-18 stimulation in cardiomyocytes. IL-18 plays a pivotal role in advancing sepsis-induced cardiac dysfunction, and the mechanisms underlying IL-18-mediated cardiotoxicity potentially involve the regulation of PLN and Akt phosphorylation through PP2A activity. Copyright © 2017 Elsevier B.V. All rights reserved.

A Novel Alpha Cardiac Actin (ACTC1) Mutation Mapping to a Domain in Close Contact with Myosin Heavy Chain Leads to a Variety of Congenital Heart Defects, Arrhythmia and Possibly Midline Defects.

PubMed

Augière, Céline; Mégy, Simon; El Malti, Rajae; Boland, Anne; El Zein, Loubna; Verrier, Bernard; Mégarbané, André; Deleuze, Jean-François; Bouvagnet, Patrice

2015-01-01

A Lebanese Maronite family presented with 13 relatives affected by various congenital heart defects (mainly atrial septal defects), conduction tissue anomalies and midline defects. No mutations were found in GATA4 and NKX2-5. A set of 399 poly(AC) markers was used to perform a linkage analysis which peaked at a 2.98 lod score on the long arm of chromosome 15. The haplotype analysis delineated a 7.7 meganucleotides genomic interval which included the alpha-cardiac actin gene (ACTC1) among 36 other protein coding genes. A heterozygous missense mutation was found (c.251T>C, p.(Met84Thr)) in the ACTC1 gene which changed a methionine residue conserved up to yeast. This mutation was absent from 1000 genomes and exome variant server database but segregated perfectly in this family with the affection status. This mutation and 2 other ACTC1 mutations (p.(Glu101Lys) and p.(Met125Val)) which result also in congenital heart defects are located in a region in close apposition to a myosin heavy chain head region by contrast to 3 other alpha-cardiac actin mutations (p.(Ala297Ser),p.(Asp313His) and p.(Arg314His)) which result in diverse cardiomyopathies and are located in a totally different interaction surface. Alpha-cardiac actin mutations lead to congenital heart defects, cardiomyopathies and eventually midline defects. The consequence of an ACTC1 mutation may in part be dependent on the interaction surface between actin and myosin.

Mitochondria-Targeted Antioxidant Prevents Cardiac Dysfunction Induced by Tafazzin Gene Knockdown in Cardiac Myocytes

PubMed Central

He, Quan; Harris, Nicole; Ren, Jun; Han, Xianlin

2014-01-01

Tafazzin, a mitochondrial acyltransferase, plays an important role in cardiolipin side chain remodeling. Previous studies have shown that dysfunction of tafazzin reduces cardiolipin content, impairs mitochondrial function, and causes dilated cardiomyopathy in Barth syndrome. Reactive oxygen species (ROS) have been implicated in the development of cardiomyopathy and are also the obligated byproducts of mitochondria. We hypothesized that tafazzin knockdown increases ROS production from mitochondria, and a mitochondria-targeted antioxidant prevents tafazzin knockdown induced mitochondrial and cardiac dysfunction. We employed cardiac myocytes transduced with an adenovirus containing tafazzin shRNA as a model to investigate the effects of the mitochondrial antioxidant, mito-Tempo. Knocking down tafazzin decreased steady state levels of cardiolipin and increased mitochondrial ROS. Treatment of cardiac myocytes with mito-Tempo normalized tafazzin knockdown enhanced mitochondrial ROS production and cellular ATP decline. Mito-Tempo also significantly abrogated tafazzin knockdown induced cardiac hypertrophy, contractile dysfunction, and cell death. We conclude that mitochondria-targeted antioxidant prevents cardiac dysfunction induced by tafazzin gene knockdown in cardiac myocytes and suggest mito-Tempo as a potential therapeutic for Barth syndrome and other dilated cardiomyopathies resulting from mitochondrial oxidative stress. PMID:25247053

Myocardin-related transcription factors are required for cardiac development and function

PubMed Central

Mokalled, Mayssa H.; Carroll, Kelli J.; Cenik, Bercin K.; Chen, Beibei; Liu, Ning; Olson, Eric N.; Bassel-Duby, Rhonda

2016-01-01

Myocardin-Related Transcription Factors A and B (MRTF-A and MRTF-B) are highly homologous proteins that function as powerful coactivators of serum response factor (SRF), a ubiquitously expressed transcription factor essential for cardiac development. The SRF/MRTF complex binds to CArG boxes found in the control regions of genes that regulate cytoskeletal dynamics and muscle contraction, among other processes. While SRF is required for heart development and function, the role of MRTFs in the developing or adult heart has not been explored. Through cardiac-specific deletion of MRTF alleles in mice, we show that either MRTF-A or MRTF-B is dispensable for cardiac development and function, whereas deletion of both MRTF-A and MRTF-B causes a spectrum of structural and functional cardiac abnormalities. Defects observed in MRTF-A/B null mice ranged from reduced cardiac contractility and adult onset heart failure to neonatal lethality accompanied by sarcomere disarray. RNA-seq analysis on neonatal hearts identified the most altered pathways in MRTF double knockout hearts as being involved in cytoskeletal organization. Together, these findings demonstrate redundant but essential roles of the MRTFs in maintenance of cardiac structure and function and as indispensible links in cardiac cytoskeletal gene regulatory networks. PMID:26386146

Decoding the complex genetic causes of heart diseases using systems biology.

PubMed

Djordjevic, Djordje; Deshpande, Vinita; Szczesnik, Tomasz; Yang, Andrian; Humphreys, David T; Giannoulatou, Eleni; Ho, Joshua W K

2015-03-01

The pace of disease gene discovery is still much slower than expected, even with the use of cost-effective DNA sequencing and genotyping technologies. It is increasingly clear that many inherited heart diseases have a more complex polygenic aetiology than previously thought. Understanding the role of gene-gene interactions, epigenetics, and non-coding regulatory regions is becoming increasingly critical in predicting the functional consequences of genetic mutations identified by genome-wide association studies and whole-genome or exome sequencing. A systems biology approach is now being widely employed to systematically discover genes that are involved in heart diseases in humans or relevant animal models through bioinformatics. The overarching premise is that the integration of high-quality causal gene regulatory networks (GRNs), genomics, epigenomics, transcriptomics and other genome-wide data will greatly accelerate the discovery of the complex genetic causes of congenital and complex heart diseases. This review summarises state-of-the-art genomic and bioinformatics techniques that are used in accelerating the pace of disease gene discovery in heart diseases. Accompanying this review, we provide an interactive web-resource for systems biology analysis of mammalian heart development and diseases, CardiacCode ( http://CardiacCode.victorchang.edu.au/ ). CardiacCode features a dataset of over 700 pieces of manually curated genetic or molecular perturbation data, which enables the inference of a cardiac-specific GRN of 280 regulatory relationships between 33 regulator genes and 129 target genes. We believe this growing resource will fill an urgent unmet need to fully realise the true potential of predictive and personalised genomic medicine in tackling human heart disease.

Cardiac mesenchymal stromal cells are a source of adipocytes in arrhythmogenic cardiomyopathy

PubMed Central

Sommariva, E.; Brambilla, S.; Carbucicchio, C.; Gambini, E.; Meraviglia, V.; Dello Russo, A.; Farina, F.M.; Casella, M.; Catto, V.; Pontone, G.; Chiesa, M.; Stadiotti, I.; Cogliati, E.; Paolin, A.; Ouali Alami, N.; Preziuso, C.; d'Amati, G.; Colombo, G.I.; Rossini, A.; Capogrossi, M.C.; Tondo, C.; Pompilio, G.

2016-01-01

Abstract Aim Arrhythmogenic cardiomyopathy (ACM) is a genetic disorder mainly due to mutations in desmosomal genes, characterized by progressive fibro-adipose replacement of the myocardium, arrhythmias, and sudden death. It is still unclear which cell type is responsible for fibro-adipose substitution and which molecular mechanisms lead to this structural change. Cardiac mesenchymal stromal cells (C-MSC) are the most abundant cells in the heart, with propensity to differentiate into several cell types, including adipocytes, and their role in ACM is unknown. The aim of the present study was to investigate whether C-MSC contributed to excess adipocytes in patients with ACM. Methods and results We found that, in ACM patients' explanted heart sections, cells actively differentiating into adipocytes are of mesenchymal origin. Therefore, we isolated C-MSC from endomyocardial biopsies of ACM and from not affected by arrhythmogenic cardiomyopathy (NON-ACM) (control) patients. We found that both ACM and control C-MSC express desmosomal genes, with ACM C-MSC showing lower expression of plakophilin (PKP2) protein vs. controls. Arrhythmogenic cardiomyopathy C-MSC cultured in adipogenic medium accumulated more lipid droplets than controls. Accordingly, the expression of adipogenic genes was higher in ACM vs. NON-ACM C-MSC, while expression of cell cycle and anti-adipogenic genes was lower. Both lipid accumulation and transcription reprogramming were dependent on PKP2 deficiency. Conclusions Cardiac mesenchymal stromal cells contribute to the adipogenic substitution observed in ACM patients' hearts. Moreover, C-MSC from ACM patients recapitulate the features of ACM adipogenesis, representing a novel, scalable, patient-specific in vitro tool for future mechanistic studies. PMID:26590176

Gene Therapy in Cardiac Surgery: Clinical Trials, Challenges, and Perspectives

PubMed Central

Katz, Michael G.; Fargnoli, Anthony S.; Kendle, Andrew P.; Hajjar, Roger J.; Bridges, Charles R.

2016-01-01

The concept of gene therapy was introduced in the 1970s after the development of recombinant DNA technology. Despite the initial great expectations, this field experienced early setbacks. Recent years have seen a revival of clinical programs of gene therapy in different fields of medicine. There are many promising targets for genetic therapy as an adjunct to cardiac surgery. The first positive long-term results were published for adenoviral administration of vascular endothelial growth factor with coronary artery bypass grafting. In this review we analyze the past, present, and future of gene therapy in cardiac surgery. The articles discussed were collected through PubMed and from author experience. The clinical trials referenced were found through the Wiley clinical trial database (http://www.wiley.com/legacy/wileychi/genmed/clinical/) as well as the National Institutes of Health clinical trial database (Clinicaltrials.gov). PMID:26801060

Cardiac transcriptional response to acute and chronic angiotensin II treatments.

PubMed

Larkin, Jennie E; Frank, Bryan C; Gaspard, Renee M; Duka, Irena; Gavras, Haralambos; Quackenbush, John

2004-07-08

Exposure of experimental animals to increased angiotensin II (ANG II) induces hypertension associated with cardiac hypertrophy, inflammation, and myocardial necrosis and fibrosis. Some of the most effective antihypertensive treatments are those that antagonize ANG II. We investigated cardiac gene expression in response to acute (24 h) and chronic (14 day) infusion of ANG II in mice; 24-h treatment induces hypertension, and 14-day treatment induces hypertension and extensive cardiac hypertrophy and necrosis. For genes differentially expressed in response to ANG II treatment, we tested for significant regulation of pathways, based on Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Microarray Pathway Profiler (GenMAPP) databases, as well as functional classes based on Gene Ontology (GO) terms. Both acute and chronic ANG II treatments resulted in decreased expression of mitochondrial metabolic genes, notably those for the electron transport chain and Krebs-TCA cycle; chronic ANG II treatment also resulted in decreased expression of genes involved in fatty acid metabolism. In contrast, genes involved in protein translation and ribosomal activity increased expression following both acute and chronic ANG II treatments. Some classes of genes showed differential response between acute and chronic ANG II treatments. Acute treatment increased expression of genes involved in oxidative stress and amino acid metabolism, whereas chronic treatments increased cytoskeletal and extracellular matrix genes, second messenger cascades responsive to ANG II, and amyloidosis genes. Although a functional linkage between Alzheimer disease, hypertension, and high cholesterol has been previously documented in studies of brain tissue, this is the first demonstration of induction of Alzheimer disease pathways by hypertension in heart tissue. This study provides the most comprehensive available survey of gene expression changes in response to acute and chronic ANG II treatment, verifying results from disparate studies, and suggests mechanisms that provide novel insight into the etiology of hypertensive heart disease and possible therapeutic interventions that may help to mitigate its effects.

Central leptin regulates heart lipid content by selectively increasing PPAR β/δ expression.

PubMed

Mora, Cristina; Pintado, Cristina; Rubio, Blanca; Mazuecos, Lorena; López, Virginia; Fernández, Alejandro; Salamanca, Aurora; Bárcena, Brenda; Fernández-Agulló, Teresa; Arribas, Carmen; Gallardo, Nilda; Andrés, Antonio

2018-01-01

The role of central leptin in regulating the heart from lipid accumulation in lean leptin-sensitive animals has not been fully elucidated. Herein, we investigated the effects of central leptin infusion on the expression of genes involved in cardiac metabolism and its role in the control of myocardial triacylglyceride (TAG) accumulation in adult Wistar rats. Intracerebroventricular (icv) leptin infusion (0.2 µg/day) for 7 days markedly decreased TAG levels in cardiac tissue. Remarkably, the cardiac anti-steatotic effects of central leptin were associated with the selective upregulation of gene and protein expression of peroxisome proliferator-activated receptor β/δ (PPARβ/δ, encoded by Pparb/d ) and their target genes, adipose triglyceride lipase (encoded by Pnpla2 , herefater referred to as Atgl ), hormone sensitive lipase (encoded by Lipe , herefater referred to as Hsl ), pyruvate dehydrogenase kinase 4 ( Pdk4 ) and acyl CoA oxidase 1 ( Acox1 ), involved in myocardial intracellular lipolysis and mitochondrial/peroxisomal fatty acid utilization. Besides, central leptin decreased the expression of stearoyl-CoA deaturase 1 ( Scd1 ) and diacylglycerol acyltransferase 1 ( Dgat1 ) involved in TAG synthesis and increased the CPT-1 independent palmitate oxidation, as an index of peroxisomal β-oxidation. Finally, the pharmacological inhibition of PPARβ/δ decreased the effects on gene expression and cardiac TAG content induced by leptin. These results indicate that leptin, acting at central level, regulates selectively the cardiac expression of PPARβ/δ, contributing in this way to regulate the cardiac TAG accumulation in rats, independently of its effects on body weight. © 2018 Society for Endocrinology.

Nppa and Nppb act redundantly during zebrafish cardiac development to confine AVC marker expression and reduce cardiac jelly volume.

PubMed

Grassini, Daniela R; Lagendijk, Anne K; De Angelis, Jessica E; Da Silva, Jason; Jeanes, Angela; Zettler, Nicole; Bower, Neil I; Hogan, Benjamin M; Smith, Kelly A

2018-05-11

Atrial natriuretic peptide ( nppa/anf ) and brain natriuretic peptide ( nppb/bnp ) form a gene cluster with expression in the chambers of the developing heart. Despite restricted expression, a function in cardiac development has not been demonstrated by mutant analysis. This is attributed to functional redundancy however their genomic location in cis has impeded formal analysis. Using genome-editing, we generated mutants for nppa and nppb and found single mutants indistinguishable from wildtype whereas nppa / nppb double mutants display heart morphogenesis defects and pericardial oedema. Analysis of atrioventricular canal (AVC) markers show expansion of bmp4 , tbx2b, has2 and versican expression into the atrium of double mutants. This expanded expression correlates with increased extracellular matrix in the atrium. Using a biosensor for Hyaluronic acid to measure the cardiac jelly (cardiac extracellular matrix), we confirm cardiac jelly expansion in nppa / nppb double mutants. Finally, bmp4 knockdown rescues the expansion of has2 expression and cardiac jelly in double mutants. This definitively shows that nppa and nppb function redundantly during cardiac development to restrict gene expression to the AVC, preventing excessive cardiac jelly synthesis in the atrial chamber. © 2018. Published by The Company of Biologists Ltd.

Advanced Echocardiography in Adult Zebrafish Reveals Delayed Recovery of Heart Function after Myocardial Cryoinjury

PubMed Central

Kossack, Mandy; Juergensen, Lonny; Fuchs, Dieter; Katus, Hugo A.; Hassel, David

2015-01-01

Translucent zebrafish larvae represent an established model to analyze genetics of cardiac development and human cardiac disease. More recently adult zebrafish are utilized to evaluate mechanisms of cardiac regeneration and by benefiting from recent genome editing technologies, including TALEN and CRISPR, adult zebrafish are emerging as a valuable in vivo model to evaluate novel disease genes and specifically validate disease causing mutations and their underlying pathomechanisms. However, methods to sensitively and non-invasively assess cardiac morphology and performance in adult zebrafish are still limited. We here present a standardized examination protocol to broadly assess cardiac performance in adult zebrafish by advancing conventional echocardiography with modern speckle-tracking analyses. This allows accurate detection of changes in cardiac performance and further enables highly sensitive assessment of regional myocardial motion and deformation in high spatio-temporal resolution. Combining conventional echocardiography measurements with radial and longitudinal velocity, displacement, strain, strain rate and myocardial wall delay rates after myocardial cryoinjury permitted to non-invasively determine injury dimensions and to longitudinally follow functional recovery during cardiac regeneration. We show that functional recovery of cryoinjured hearts occurs in three distinct phases. Importantly, the regeneration process after cryoinjury extends far beyond the proposed 45 days described for ventricular resection with reconstitution of myocardial performance up to 180 days post-injury (dpi). The imaging modalities evaluated here allow sensitive cardiac phenotyping and contribute to further establish adult zebrafish as valuable cardiac disease model beyond the larval developmental stage. PMID:25853735

Protective effects of puerarin against tetrabromobisphenol a-induced apoptosis and cardiac developmental toxicity in zebrafish embryo-larvae.

PubMed

Yang, Suwen; Wang, Shengrui; Sun, Fengchao; Zhang, Mengmeng; Wu, Fengchang; Xu, Fanfan; Ding, Zhishan

2015-09-01

Tetrabromobisphenol A (TBBPA), a brominated flame retardant, is detected commonly in aquatic environments, where it is thought to be highly toxic to the development of aquatic life. In this study, zebrafish embryos and larvae were used to investigate the protective effects of puerarin after exposure to TBBPA. Malformation, blood flow disorders, pericardial edema, and spawn coagulation rates increased, whereas survival decreased significantly after exposure to 0.5 and 1.0 mg L(-1) TBBPA. The measured indices of morphological toxicity improved after treatment with puerarin. TBBPA also induced reactive oxygen species (ROS) production in a dose-dependent manner. Acridine orange staining results revealed that TBBPA exposure caused cardiomyocyte apoptosis and induced the expression of three proapoptotic genes: P53, Bax, and Caspase9. In contrast, the expression of the antiapoptotic gene Bcl2 was down-regulated. When genes related to cardiac development were assessed, the expression of Tbx1, Raldh2, and Bmp2b changed after exposure to the combination of TBBPA and puerarin. These results suggest that TBBPA induces cardiomyocyte apoptosis and ROS production, resulting in cardiac developmental toxicity in zebrafish embryos or larvae. Therefore, puerarin regulates the expression of cardiac developmental genes, such as Tbx1, Bmp2b, and Raldh2 by inhibiting ROS production, and subsequently modulates cardiac development after the exposure of zebrafish larvae to TBBPA. © 2014 Wiley Periodicals, Inc.

Graphene induces spontaneous cardiac differentiation in embryoid bodies

NASA Astrophysics Data System (ADS)

Ahadian, Samad; Zhou, Yuanshu; Yamada, Shukuyo; Estili, Mehdi; Liang, Xiaobin; Nakajima, Ken; Shiku, Hitoshi; Matsue, Tomokazu

2016-03-01

Graphene was embedded into the structure of mouse embryoid bodies (EBs) using the hanging drop technique. The inclusion of 0.2 mg per mL graphene in the EBs did not affect the viability of the stem cells. However, the graphene decreased the stem cell proliferation, probably by accelerating cell differentiation. The graphene also enhanced the mechanical properties and electrical conductivity of the EBs. Interestingly, the cardiac differentiation of the EB-graphene was significantly greater than that of the EBs at day 5 of culture, as confirmed by high-throughput gene analysis. Electrical stimulation (voltage, 4 V; frequency, 1 Hz; and duration, 10 ms for 2 continuous days) further enhanced the cardiac differentiation of the EBs, as demonstrated by analyses of the cardiac protein and gene expression and the beating activity of the EBs. Taken together, the results demonstrated that graphene played a major role in directing the cardiac differentiation of EBs, which has potential cell therapy and tissue regeneration applications.Graphene was embedded into the structure of mouse embryoid bodies (EBs) using the hanging drop technique. The inclusion of 0.2 mg per mL graphene in the EBs did not affect the viability of the stem cells. However, the graphene decreased the stem cell proliferation, probably by accelerating cell differentiation. The graphene also enhanced the mechanical properties and electrical conductivity of the EBs. Interestingly, the cardiac differentiation of the EB-graphene was significantly greater than that of the EBs at day 5 of culture, as confirmed by high-throughput gene analysis. Electrical stimulation (voltage, 4 V; frequency, 1 Hz; and duration, 10 ms for 2 continuous days) further enhanced the cardiac differentiation of the EBs, as demonstrated by analyses of the cardiac protein and gene expression and the beating activity of the EBs. Taken together, the results demonstrated that graphene played a major role in directing the cardiac differentiation of EBs, which has potential cell therapy and tissue regeneration applications. Electronic supplementary information (ESI) available: Fig. S1-S3, Tables S1-S4, and Movies S1-S4. See DOI: 10.1039/c5nr07059g

A Murine Hypertrophic Cardiomyopathy Model: The DBA/2J Strain.

PubMed

Zhao, Wenyuan; Zhao, Tieqiang; Chen, Yuanjian; Zhao, Fengbo; Gu, Qingqing; Williams, Robert W; Bhattacharya, Syamal K; Lu, Lu; Sun, Yao

2015-01-01

Familial hypertrophic cardiomyopathy (HCM) is attributed to mutations in genes that encode for the sarcomere proteins, especially Mybpc3 and Myh7. Genotype-phenotype correlation studies show significant variability in HCM phenotypes among affected individuals with identical causal mutations. Morphological changes and clinical expression of HCM are the result of interactions with modifier genes. With the exceptions of angiotensin converting enzyme, these modifiers have not been identified. Although mouse models have been used to investigate the genetics of many complex diseases, natural murine models for HCM are still lacking. In this study we show that the DBA/2J (D2) strain of mouse has sequence variants in Mybpc3 and Myh7, relative to widely used C57BL/6J (B6) reference strain and the key features of human HCM. Four-month-old of male D2 mice exhibit hallmarks of HCM including increased heart weight and cardiomyocyte size relative to B6 mice, as well as elevated markers for cardiac hypertrophy including β-myosin heavy chain (MHC), atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and skeletal muscle alpha actin (α1-actin). Furthermore, cardiac interstitial fibrosis, another feature of HCM, is also evident in the D2 strain, and is accompanied by up-regulation of type I collagen and α-smooth muscle actin (SMA)-markers of fibrosis. Of great interest, blood pressure and cardiac function are within the normal range in the D2 strain, demonstrating that cardiac hypertrophy and fibrosis are not secondary to hypertension, myocardial infarction, or heart failure. Because D2 and B6 strains have been used to generate a large family of recombinant inbred strains, the BXD cohort, the D2 model can be effectively exploited for in-depth genetic analysis of HCM susceptibility and modifier screens.

Identification of differentially expressed lncRNAs involved in transient regeneration of the neonatal C57BL/6J mouse heart by next-generation high-throughput RNA sequencing.

PubMed

Chen, Yu-Mei; Li, Hua; Fan, Yi; Zhang, Qi-Jun; Li, Xing; Wu, Li-Jie; Chen, Zi-Jie; Zhu, Chun; Qian, Ling-Mei

2017-04-25

Previous studies have shown that mammalian cardiac tissue has a regenerative capacity. Remarkably, neonatal mice can regenerate their cardiac tissue for up to 6 days after birth, but this capacity is lost by day 7. In this study, we aimed to explore the expression pattern of long noncoding RNA (lncRNA) during this period and examine the mechanisms underlying this process. We found that 685 lncRNAs and 1833 mRNAs were differentially expressed at P1 and P7 by the next-generation high-throughput RNA sequencing. The coding genes associated with differentially expressed lncRNAs were mainly involved in metabolic processes and cell proliferation, and also were potentially associated with several key regeneration signalling pathways, including PI3K-Akt, MAPK, Hippo and Wnt. In addition, we identified some correlated targets of highly-dysregulated lncRNAs such as Igfbp3, Trnp1, Itgb6, and Pim3 by the coding-noncoding gene co-expression network. These data may offer a reference resource for further investigation about the mechanisms by which lncRNAs regulate cardiac regeneration.

Hypothyroidism and its rapid correction alter cardiac remodeling.

PubMed

Hajje, Georges; Saliba, Youakim; Itani, Tarek; Moubarak, Majed; Aftimos, Georges; Farès, Nassim

2014-01-01

The cardiovascular effects of mild and overt thyroid disease include a vast array of pathological changes. As well, thyroid replacement therapy has been suggested for preserving cardiac function. However, the influence of thyroid hormones on cardiac remodeling has not been thoroughly investigated at the molecular and cellular levels. The purpose of this paper is to study the effect of hypothyroidism and thyroid replacement therapy on cardiac alterations. Thirty Wistar rats were divided into 2 groups: a control (n = 10) group and a group treated with 6-propyl-2-thiouracil (PTU) (n = 20) to induce hypothyroidism. Ten of the 20 rats in the PTU group were then treated with L-thyroxine to quickly re-establish euthyroidism. The serum levels of inflammatory markers, such as C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL6) and pro-fibrotic transforming growth factor beta 1 (TGF-β1), were significantly increased in hypothyroid rats; elevations in cardiac stress markers, brain natriuretic peptide (BNP) and cardiac troponin T (cTnT) were also noted. The expressions of cardiac remodeling genes were induced in hypothyroid rats in parallel with the development of fibrosis, and a decline in cardiac function with chamber dilation was measured by echocardiography. Rapidly reversing the hypothyroidism and restoring the euthyroid state improved cardiac function with a decrease in the levels of cardiac remodeling markers. However, this change further increased the levels of inflammatory and fibrotic markers in the plasma and heart and led to myocardial cellular infiltration. In conclusion, we showed that hypothyroidism is related to cardiac function decline, fibrosis and inflammation; most importantly, the rapid correction of hypothyroidism led to cardiac injuries. Our results might offer new insights for the management of hypothyroidism-induced heart disease.

Hypothyroidism and Its Rapid Correction Alter Cardiac Remodeling

PubMed Central

Itani, Tarek; Moubarak, Majed; Aftimos, Georges; Farès, Nassim

2014-01-01

The cardiovascular effects of mild and overt thyroid disease include a vast array of pathological changes. As well, thyroid replacement therapy has been suggested for preserving cardiac function. However, the influence of thyroid hormones on cardiac remodeling has not been thoroughly investigated at the molecular and cellular levels. The purpose of this paper is to study the effect of hypothyroidism and thyroid replacement therapy on cardiac alterations. Thirty Wistar rats were divided into 2 groups: a control (n = 10) group and a group treated with 6-propyl-2-thiouracil (PTU) (n = 20) to induce hypothyroidism. Ten of the 20 rats in the PTU group were then treated with L-thyroxine to quickly re-establish euthyroidism. The serum levels of inflammatory markers, such as C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL6) and pro-fibrotic transforming growth factor beta 1 (TGF-β1), were significantly increased in hypothyroid rats; elevations in cardiac stress markers, brain natriuretic peptide (BNP) and cardiac troponin T (cTnT) were also noted. The expressions of cardiac remodeling genes were induced in hypothyroid rats in parallel with the development of fibrosis, and a decline in cardiac function with chamber dilation was measured by echocardiography. Rapidly reversing the hypothyroidism and restoring the euthyroid state improved cardiac function with a decrease in the levels of cardiac remodeling markers. However, this change further increased the levels of inflammatory and fibrotic markers in the plasma and heart and led to myocardial cellular infiltration. In conclusion, we showed that hypothyroidism is related to cardiac function decline, fibrosis and inflammation; most importantly, the rapid correction of hypothyroidism led to cardiac injuries. Our results might offer new insights for the management of hypothyroidism-induced heart disease. PMID:25333636

Identification of heart rate-associated loci and their effects on cardiac conduction and rhythm disorders.

PubMed

den Hoed, Marcel; Eijgelsheim, Mark; Esko, Tõnu; Brundel, Bianca J J M; Peal, David S; Evans, David M; Nolte, Ilja M; Segrè, Ayellet V; Holm, Hilma; Handsaker, Robert E; Westra, Harm-Jan; Johnson, Toby; Isaacs, Aaron; Yang, Jian; Lundby, Alicia; Zhao, Jing Hua; Kim, Young Jin; Go, Min Jin; Almgren, Peter; Bochud, Murielle; Boucher, Gabrielle; Cornelis, Marilyn C; Gudbjartsson, Daniel; Hadley, David; van der Harst, Pim; Hayward, Caroline; den Heijer, Martin; Igl, Wilmar; Jackson, Anne U; Kutalik, Zoltán; Luan, Jian'an; Kemp, John P; Kristiansson, Kati; Ladenvall, Claes; Lorentzon, Mattias; Montasser, May E; Njajou, Omer T; O'Reilly, Paul F; Padmanabhan, Sandosh; St Pourcain, Beate; Rankinen, Tuomo; Salo, Perttu; Tanaka, Toshiko; Timpson, Nicholas J; Vitart, Veronique; Waite, Lindsay; Wheeler, William; Zhang, Weihua; Draisma, Harmen H M; Feitosa, Mary F; Kerr, Kathleen F; Lind, Penelope A; Mihailov, Evelin; Onland-Moret, N Charlotte; Song, Ci; Weedon, Michael N; Xie, Weijia; Yengo, Loic; Absher, Devin; Albert, Christine M; Alonso, Alvaro; Arking, Dan E; de Bakker, Paul I W; Balkau, Beverley; Barlassina, Cristina; Benaglio, Paola; Bis, Joshua C; Bouatia-Naji, Nabila; Brage, Søren; Chanock, Stephen J; Chines, Peter S; Chung, Mina; Darbar, Dawood; Dina, Christian; Dörr, Marcus; Elliott, Paul; Felix, Stephan B; Fischer, Krista; Fuchsberger, Christian; de Geus, Eco J C; Goyette, Philippe; Gudnason, Vilmundur; Harris, Tamara B; Hartikainen, Anna-Liisa; Havulinna, Aki S; Heckbert, Susan R; Hicks, Andrew A; Hofman, Albert; Holewijn, Suzanne; Hoogstra-Berends, Femke; Hottenga, Jouke-Jan; Jensen, Majken K; Johansson, Asa; Junttila, Juhani; Kääb, Stefan; Kanon, Bart; Ketkar, Shamika; Khaw, Kay-Tee; Knowles, Joshua W; Kooner, Angrad S; Kors, Jan A; Kumari, Meena; Milani, Lili; Laiho, Päivi; Lakatta, Edward G; Langenberg, Claudia; Leusink, Maarten; Liu, Yongmei; Luben, Robert N; Lunetta, Kathryn L; Lynch, Stacey N; Markus, Marcello R P; Marques-Vidal, Pedro; Mateo Leach, Irene; McArdle, Wendy L; McCarroll, Steven A; Medland, Sarah E; Miller, Kathryn A; Montgomery, Grant W; Morrison, Alanna C; Müller-Nurasyid, Martina; Navarro, Pau; Nelis, Mari; O'Connell, Jeffrey R; O'Donnell, Christopher J; Ong, Ken K; Newman, Anne B; Peters, Annette; Polasek, Ozren; Pouta, Anneli; Pramstaller, Peter P; Psaty, Bruce M; Rao, Dabeeru C; Ring, Susan M; Rossin, Elizabeth J; Rudan, Diana; Sanna, Serena; Scott, Robert A; Sehmi, Jaban S; Sharp, Stephen; Shin, Jordan T; Singleton, Andrew B; Smith, Albert V; Soranzo, Nicole; Spector, Tim D; Stewart, Chip; Stringham, Heather M; Tarasov, Kirill V; Uitterlinden, André G; Vandenput, Liesbeth; Hwang, Shih-Jen; Whitfield, John B; Wijmenga, Cisca; Wild, Sarah H; Willemsen, Gonneke; Wilson, James F; Witteman, Jacqueline C M; Wong, Andrew; Wong, Quenna; Jamshidi, Yalda; Zitting, Paavo; Boer, Jolanda M A; Boomsma, Dorret I; Borecki, Ingrid B; van Duijn, Cornelia M; Ekelund, Ulf; Forouhi, Nita G; Froguel, Philippe; Hingorani, Aroon; Ingelsson, Erik; Kivimaki, Mika; Kronmal, Richard A; Kuh, Diana; Lind, Lars; Martin, Nicholas G; Oostra, Ben A; Pedersen, Nancy L; Quertermous, Thomas; Rotter, Jerome I; van der Schouw, Yvonne T; Verschuren, W M Monique; Walker, Mark; Albanes, Demetrius; Arnar, David O; Assimes, Themistocles L; Bandinelli, Stefania; Boehnke, Michael; de Boer, Rudolf A; Bouchard, Claude; Caulfield, W L Mark; Chambers, John C; Curhan, Gary; Cusi, Daniele; Eriksson, Johan; Ferrucci, Luigi; van Gilst, Wiek H; Glorioso, Nicola; de Graaf, Jacqueline; Groop, Leif; Gyllensten, Ulf; Hsueh, Wen-Chi; Hu, Frank B; Huikuri, Heikki V; Hunter, David J; Iribarren, Carlos; Isomaa, Bo; Jarvelin, Marjo-Riitta; Jula, Antti; Kähönen, Mika; Kiemeney, Lambertus A; van der Klauw, Melanie M; Kooner, Jaspal S; Kraft, Peter; Iacoviello, Licia; Lehtimäki, Terho; Lokki, Marja-Liisa L; Mitchell, Braxton D; Navis, Gerjan; Nieminen, Markku S; Ohlsson, Claes; Poulter, Neil R; Qi, Lu; Raitakari, Olli T; Rimm, Eric B; Rioux, John D; Rizzi, Federica; Rudan, Igor; Salomaa, Veikko; Sever, Peter S; Shields, Denis C; Shuldiner, Alan R; Sinisalo, Juha; Stanton, Alice V; Stolk, Ronald P; Strachan, David P; Tardif, Jean-Claude; Thorsteinsdottir, Unnur; Tuomilehto, Jaako; van Veldhuisen, Dirk J; Virtamo, Jarmo; Viikari, Jorma; Vollenweider, Peter; Waeber, Gérard; Widen, Elisabeth; Cho, Yoon Shin; Olsen, Jesper V; Visscher, Peter M; Willer, Cristen; Franke, Lude; Erdmann, Jeanette; Thompson, John R; Pfeufer, Arne; Sotoodehnia, Nona; Newton-Cheh, Christopher; Ellinor, Patrick T; Stricker, Bruno H Ch; Metspalu, Andres; Perola, Markus; Beckmann, Jacques S; Smith, George Davey; Stefansson, Kari; Wareham, Nicholas J; Munroe, Patricia B; Sibon, Ody C M; Milan, David J; Snieder, Harold; Samani, Nilesh J; Loos, Ruth J F

2013-06-01

Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously established loci. Experimental downregulation of gene expression in Drosophila melanogaster and Danio rerio identified 20 genes at 11 loci that are relevant for heart rate regulation and highlight a role for genes involved in signal transmission, embryonic cardiac development and the pathophysiology of dilated cardiomyopathy, congenital heart failure and/or sudden cardiac death. In addition, genetic susceptibility to increased heart rate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heart rate-increasing and heart rate-decreasing variants associate with risk of atrial fibrillation. Our findings provide fresh insights into the mechanisms regulating heart rate and identify new therapeutic targets.

Identification of heart rate–associated loci and their effects on cardiac conduction and rhythm disorders

PubMed Central

den Hoed, Marcel; Eijgelsheim, Mark; Esko, Tõnu; Brundel, Bianca J J M; Peal, David S; Evans, David M; Nolte, Ilja M; Segrè, Ayellet V; Holm, Hilma; Handsaker, Robert E; Westra, Harm-Jan; Johnson, Toby; Isaacs, Aaron; Yang, Jian; Lundby, Alicia; Zhao, Jing Hua; Kim, Young Jin; Go, Min Jin; Almgren, Peter; Bochud, Murielle; Boucher, Gabrielle; Cornelis, Marilyn C; Gudbjartsson, Daniel; Hadley, David; Van Der Harst, Pim; Hayward, Caroline; Heijer, Martin Den; Igl, Wilmar; Jackson, Anne U; Kutalik, Zoltán; Luan, Jian’an; Kemp, John P; Kristiansson, Kati; Ladenvall, Claes; Lorentzon, Mattias; Montasser, May E; Njajou, Omer T; O’Reilly, Paul F; Padmanabhan, Sandosh; Pourcain, Beate St.; Rankinen, Tuomo; Salo, Perttu; Tanaka, Toshiko; Timpson, Nicholas J; Vitart, Veronique; Waite, Lindsay; Wheeler, William; Zhang, Weihua; Draisma, Harmen H M; Feitosa, Mary F; Kerr, Kathleen F; Lind, Penelope A; Mihailov, Evelin; Onland-Moret, N Charlotte; Song, Ci; Weedon, Michael N; Xie, Weijia; Yengo, Loic; Absher, Devin; Albert, Christine M; Alonso, Alvaro; Arking, Dan E; de Bakker, Paul I W; Balkau, Beverley; Barlassina, Cristina; Benaglio, Paola; Bis, Joshua C; Bouatia-Naji, Nabila; Brage, Søren; Chanock, Stephen J; Chines, Peter S; Chung, Mina; Darbar, Dawood; Dina, Christian; Dörr, Marcus; Elliott, Paul; Felix, Stephan B; Fischer, Krista; Fuchsberger, Christian; de Geus, Eco J C; Goyette, Philippe; Gudnason, Vilmundur; Harris, Tamara B; Hartikainen, Anna-liisa; Havulinna, Aki S; Heckbert, Susan R; Hicks, Andrew A; Hofman, Albert; Holewijn, Suzanne; Hoogstra-Berends, Femke; Hottenga, Jouke-Jan; Jensen, Majken K; Johansson, Åsa; Junttila, Juhani; Kääb, Stefan; Kanon, Bart; Ketkar, Shamika; Khaw, Kay-Tee; Knowles, Joshua W; Kooner, Angrad S; Kors, Jan A; Kumari, Meena; Milani, Lili; Laiho, Päivi; Lakatta, Edward G; Langenberg, Claudia; Leusink, Maarten; Liu, Yongmei; Luben, Robert N; Lunetta, Kathryn L; Lynch, Stacey N; Markus, Marcello R P; Marques-Vidal, Pedro; Leach, Irene Mateo; McArdle, Wendy L; McCarroll, Steven A; Medland, Sarah E; Miller, Kathryn A; Montgomery, Grant W; Morrison, Alanna C; Müller-Nurasyid, Martina; Navarro, Pau; Nelis, Mari; O’Connell, Jeffrey R; O’Donnell, Christopher J; Ong, Ken K; Newman, Anne B; Peters, Annette; Polasek, Ozren; Pouta, Anneli; Pramstaller, Peter P; Psaty, Bruce M; Rao, Dabeeru C; Ring, Susan M; Rossin, Elizabeth J; Rudan, Diana; Sanna, Serena; Scott, Robert A; Sehmi, Jaban S; Sharp, Stephen; Shin, Jordan T; Singleton, Andrew B; Smith, Albert V; Soranzo, Nicole; Spector, Tim D; Stewart, Chip; Stringham, Heather M; Tarasov, Kirill V; Uitterlinden, André G; Vandenput, Liesbeth; Hwang, Shih-Jen; Whitfield, John B; Wijmenga, Cisca; Wild, Sarah H; Willemsen, Gonneke; Wilson, James F; Witteman, Jacqueline C M; Wong, Andrew; Wong, Quenna; Jamshidi, Yalda; Zitting, Paavo; Boer, Jolanda M A; Boomsma, Dorret I; Borecki, Ingrid B; Van Duijn, Cornelia M; Ekelund, Ulf; Forouhi, Nita G; Froguel, Philippe; Hingorani, Aroon; Ingelsson, Erik; Kivimaki, Mika; Kronmal, Richard A; Kuh, Diana; Lind, Lars; Martin, Nicholas G; Oostra, Ben A; Pedersen, Nancy L; Quertermous, Thomas; Rotter, Jerome I; van der Schouw, Yvonne T; Verschuren, W M Monique; Walker, Mark; Albanes, Demetrius; Arnar, David O; Assimes, Themistocles L; Bandinelli, Stefania; Boehnke, Michael; de Boer, Rudolf A; Bouchard, Claude; Caulfield, W L Mark; Chambers, John C; Curhan, Gary; Cusi, Daniele; Eriksson, Johan; Ferrucci, Luigi; van Gilst, Wiek H; Glorioso, Nicola; de Graaf, Jacqueline; Groop, Leif; Gyllensten, Ulf; Hsueh, Wen-Chi; Hu, Frank B; Huikuri, Heikki V; Hunter, David J; Iribarren, Carlos; Isomaa, Bo; Jarvelin, Marjo-Riitta; Jula, Antti; Kähönen, Mika; Kiemeney, Lambertus A; van der Klauw, Melanie M; Kooner, Jaspal S; Kraft, Peter; Iacoviello, Licia; Lehtimäki, Terho; Lokki, Marja-Liisa L; Mitchell, Braxton D; Navis, Gerjan; Nieminen, Markku S; Ohlsson, Claes; Poulter, Neil R; Qi, Lu; Raitakari, Olli T; Rimm, Eric B; Rioux, John D; Rizzi, Federica; Rudan, Igor; Salomaa, Veikko; Sever, Peter S; Shields, Denis C; Shuldiner, Alan R; Sinisalo, Juha; Stanton, Alice V; Stolk, Ronald P; Strachan, David P; Tardif, Jean-Claude; Thorsteinsdottir, Unnur; Tuomilehto, Jaako; van Veldhuisen, Dirk J; Virtamo, Jarmo; Viikari, Jorma; Vollenweider, Peter; Waeber, Gérard; Widen, Elisabeth; Cho, Yoon Shin; Olsen, Jesper V; Visscher, Peter M; Willer, Cristen; Franke, Lude; Erdmann, Jeanette; Thompson, John R; Pfeufer, Arne; Sotoodehnia, Nona; Newton-Cheh, Christopher; Ellinor, Patrick T; Stricker, Bruno H Ch; Metspalu, Andres; Perola, Markus; Beckmann, Jacques S; Smith, George Davey; Stefansson, Kari; Wareham, Nicholas J; Munroe, Patricia B; Sibon, Ody C M; Milan, David J; Snieder, Harold; Samani, Nilesh J; Loos, Ruth J F

2013-01-01

Elevated resting heart rate is associated with greater risk of cardiovascular disease and mortality. In a 2-stage meta-analysis of genome-wide association studies in up to 181,171 individuals, we identified 14 new loci associated with heart rate and confirmed associations with all 7 previously established loci. Experimental downregulation of gene expression in Drosophila melanogaster and Danio rerio identified 20 genes at 11 loci that are relevant for heart rate regulation and highlight a role for genes involved in signal transmission, embryonic cardiac development and the pathophysiology of dilated cardiomyopathy, congenital heart failure and/or sudden cardiac death. In addition, genetic susceptibility to increased heart rate is associated with altered cardiac conduction and reduced risk of sick sinus syndrome, and both heart rate–increasing and heart rate–decreasing variants associate with risk of atrial fibrillation. Our findings provide fresh insights into the mechanisms regulating heart rate and identify new therapeutic targets. PMID:23583979

SYSTEMIC IMBALANCE OF ESSENTIAL METALS AND CARDIAC GENE EXPRESSION IN RATS FOLLOWING ACUTE PULMONARY ZINC EXPOSURE

EPA Science Inventory

We have recently demonstrated that PM containing water-soluble zinc may cause cardiac injury following pulmonary exposure. To investigate if pulmonary zinc exposure causes systemic metal imbalance and direct cardiac effects, we intratracheally (IT) instilled male Wistar Kyoto (WK...

Diet and sex modify exercise and cardiac adaptation in the mouse

PubMed Central

Chen, Hao; Luczak, Elizabeth; McKee, Laurel A.; Regan, Jessica; Watson, Peter A.; Stauffer, Brian L.; Khalpey, Zain I; Mckinsey, Timothy A.; Horn, Todd; LaFleur, Bonnie; Leinwand, Leslie A.

2014-01-01

The heart adapts to exercise stimuli in a sex-dimorphic manner when mice are fed the traditional soy-based chow. Females undergo more voluntary exercise (4 wk) than males and exhibit more cardiac hypertrophy per kilometer run (18, 32). We have found that diet plays a critical role in cage wheel exercise and cardiac adaptation to the exercise stimulus in this sex dimorphism. Specifically, feeding male mice a casein-based, soy-free diet increases daily running distance over soy-fed counterparts to equal that of females. Moreover, casein-fed males have a greater capacity to increase their cardiac mass in response to exercise compared with soy-fed males. To further explore the biochemical mechanisms for these differences, we performed a candidate-based RT-PCR screen on genes previously implicated in diet- or exercise-based cardiac hypertrophy. Of the genes screened, many exhibit significant exercise, diet, or sex effects but only transforming growth factor-β1 shows a significant three-way interaction with no genes showing a two-way interaction. Finally, we show that the expression and activity of adenosine monophosphate-activated kinase-α2 and acetyl-CoA carboxylase is dependent on exercise, diet, and sex. PMID:25398983

Diet and sex modify exercise and cardiac adaptation in the mouse.

PubMed

Konhilas, John P; Chen, Hao; Luczak, Elizabeth; McKee, Laurel A; Regan, Jessica; Watson, Peter A; Stauffer, Brian L; Khalpey, Zain I; Mckinsey, Timothy A; Horn, Todd; LaFleur, Bonnie; Leinwand, Leslie A

2015-01-15

The heart adapts to exercise stimuli in a sex-dimorphic manner when mice are fed the traditional soy-based chow. Females undergo more voluntary exercise (4 wk) than males and exhibit more cardiac hypertrophy per kilometer run (18, 32). We have found that diet plays a critical role in cage wheel exercise and cardiac adaptation to the exercise stimulus in this sex dimorphism. Specifically, feeding male mice a casein-based, soy-free diet increases daily running distance over soy-fed counterparts to equal that of females. Moreover, casein-fed males have a greater capacity to increase their cardiac mass in response to exercise compared with soy-fed males. To further explore the biochemical mechanisms for these differences, we performed a candidate-based RT-PCR screen on genes previously implicated in diet- or exercise-based cardiac hypertrophy. Of the genes screened, many exhibit significant exercise, diet, or sex effects but only transforming growth factor-β1 shows a significant three-way interaction with no genes showing a two-way interaction. Finally, we show that the expression and activity of adenosine monophosphate-activated kinase-α2 and acetyl-CoA carboxylase is dependent on exercise, diet, and sex.

Cardiac DPP-4 inhibition by saxagliptin ameliorates isoproterenol-induced myocardial remodeling and cardiac diastolic dysfunction in rats.

PubMed

Ikeda, Junichi; Kimoto, Naoya; Kitayama, Tetsuya; Kunori, Shunji

2016-09-01

Saxagliptin, a potent and selective DPP-4 inhibitor, is characterized by its slow dissociation from DPP-4 and its long half-life and is expected to have a potent tissue membrane-bound DPP-4-inhibitory effect in various tissues. In the present study, we examined the effects of saxagliptin on in situ cardiac DPP-4 activity. We also examined the effects of saxagliptin on isoproterenol-induced the changes in the early stage such as, myocardial remodeling and cardiac diastolic dysfunction. Male SD rats treated with isoproterenol (1 mg/kg/day via osmotic pump) received vehicle or saxagliptin (17.5 mg/kg via drinking water) for 2 weeks. In situ cardiac DPP-4 activity was measured by a colorimetric assay. Cardiac gene expressions were examined and an echocardiographic analysis was performed. Saxagliptin treatment significantly inhibited in situ cardiac DPP-4 activity and suppressed isoproterenol-induced myocardial remodeling and the expression of related genes without altering the blood glucose levels. Saxagliptin also significantly ameliorated cardiac diastolic dysfunction in isoproterenol-treated rats. In conclusion, the inhibition of DPP-4 activity in cardiac tissue by saxagliptin was associated with suppression of myocardial remodeling and cardiac diastolic dysfunction independently of its glucose-lowering action in isoproterenol-treated rats. Cardiac DPP-4 activity may contribute to myocardial remodeling in the development of heart failure. Copyright © 2016 Kyowa Hakko Kirin Co.,Ltd. Production and hosting by Elsevier B.V. All rights reserved.

Methamphetamine and HIV-Tat alter murine cardiac DNA methylation and gene expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koczor, Christopher A., E-mail: ckoczor@emory.edu; Fields, Earl; Jedrzejczak, Mark J.

This study addresses the individual and combined effects of HIV-1 and methamphetamine (N-methyl-1-phenylpropan-2-amine, METH) on cardiac dysfunction in a transgenic mouse model of HIV/AIDS. METH is abused epidemically and is frequently associated with acquisition of HIV-1 infection or AIDS. We employed microarrays to identify mRNA differences in cardiac left ventricle (LV) gene expression following METH administration (10 d, 3 mg/kg/d, subcutaneously) in C57Bl/6 wild-type littermates (WT) and Tat-expressing transgenic (TG) mice. Arrays identified 880 differentially expressed genes (expression fold change > 1.5, p < 0.05) following METH exposure, Tat expression, or both. Using pathway enrichment analysis, mRNAs encoding polypeptides formore » calcium signaling and contractility were altered in the LV samples. Correlative DNA methylation analysis revealed significant LV DNA methylation changes following METH exposure and Tat expression. By combining these data sets, 38 gene promoters (27 related to METH, 11 related to Tat) exhibited differences by both methods of analysis. Among those, only the promoter for CACNA1C that encodes L-type calcium channel Cav1.2 displayed DNA methylation changes concordant with its gene expression change. Quantitative PCR verified that Cav1.2 LV mRNA abundance doubled following METH. Correlative immunoblots specific for Cav1.2 revealed a 3.5-fold increase in protein abundance in METH LVs. Data implicate Cav1.2 in calcium dysregulation and hypercontractility in the murine LV exposed to METH. They suggest a pathogenetic role for METH exposure to promote LV dysfunction that outweighs Tat-induced effects. - Highlights: • HIV-1 Tat and methamphetamine (METH) alter cardiac gene expression and epigenetics. • METH impacts gene expression or epigenetics more significantly than Tat expression. • METH alters cardiac mitochondrial function and calcium signaling independent of Tat. • METH alters DNA methylation, expression, and protein abundance of CACNA1C (Cav1.2).« less

Extracellular high-mobility group box 1 mediates pressure overload-induced cardiac hypertrophy and heart failure.

PubMed

Zhang, Lei; Liu, Ming; Jiang, Hong; Yu, Ying; Yu, Peng; Tong, Rui; Wu, Jian; Zhang, Shuning; Yao, Kang; Zou, Yunzeng; Ge, Junbo

2016-03-01

Inflammation plays a key role in pressure overload-induced cardiac hypertrophy and heart failure, but the mechanisms have not been fully elucidated. High-mobility group box 1 (HMGB1), which is increased in myocardium under pressure overload, may be involved in pressure overload-induced cardiac injury. The objectives of this study are to determine the role of HMGB1 in cardiac hypertrophy and cardiac dysfunction under pressure overload. Pressure overload was imposed on the heart of male wild-type mice by transverse aortic constriction (TAC), while recombinant HMGB1, HMGB1 box A (a competitive antagonist of HMGB1) or PBS was injected into the LV wall. Moreover, cardiac myocytes were cultured and given sustained mechanical stress. Transthoracic echocardiography was performed after the operation and sections for histological analyses were generated from paraffin-embedded hearts. Relevant proteins and genes were detected. Cardiac HMGB1 expression was increased after TAC, which was accompanied by its translocation from nucleus to both cytoplasm and intercellular space. Exogenous HMGB1 aggravated TAC-induced cardiac hypertrophy and cardiac dysfunction, as demonstrated by echocardiographic analyses, histological analyses and foetal cardiac genes detection. Nevertheless, the aforementioned pathological change induced by TAC could partially be reversed by HMGB1 inhibition. Consistent with the in vivo observations, mechanical stress evoked the release and synthesis of HMGB1 in cultured cardiac myocytes. This study indicates that the activated and up-regulated HMGB1 in myocardium, which might partially be derived from cardiac myocytes under pressure overload, may be of crucial importance in pressure overload-induced cardiac hypertrophy and cardiac dysfunction. © 2015 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Cardiac troponin T is necessary for normal development in the embryonic chick heart.

PubMed

England, Jennifer; Pang, Kar Lai; Parnall, Matthew; Haig, Maria Isabel; Loughna, Siobhan

2016-09-01

The heart is the first functioning organ to develop during embryogenesis. The formation of the heart is a tightly regulated and complex process, and alterations to its development can result in congenital heart defects. Mutations in sarcomeric proteins, such as alpha myosin heavy chain and cardiac alpha actin, have now been associated with congenital heart defects in humans, often with atrial septal defects. However, cardiac troponin T (cTNT encoded by gene TNNT2) has not. Using gene-specific antisense oligonucleotides, we have investigated the role of cTNT in chick cardiogenesis. TNNT2 is expressed throughout heart development and in the postnatal heart. TNNT2-morpholino treatment resulted in abnormal atrial septal growth and a reduction in the number of trabeculae in the developing primitive ventricular chamber. External analysis revealed the development of diverticula from the ventricular myocardial wall which showed no evidence of fibrosis and still retained a myocardial phenotype. Sarcomeric assembly appeared normal in these treated hearts. In humans, congenital ventricular diverticulum is a rare condition, which has not yet been genetically associated. However, abnormal haemodynamics is known to cause structural defects in the heart. Further, structural defects, including atrial septal defects and congenital diverticula, have previously been associated with conduction anomalies. Therefore, to provide mechanistic insights into the effect that cTNT knockdown has on the developing heart, quantitative PCR was performed to determine the expression of the shear stress responsive gene NOS3 and the conduction gene TBX3. Both genes were differentially expressed compared to controls. Therefore, a reduction in cTNT in the developing heart results in abnormal atrial septal formation and aberrant ventricular morphogenesis. We hypothesize that alterations to the haemodynamics, indicated by differential NOS3 expression, causes these abnormalities in growth in cTNT knockdown hearts. In addition, the muscular diverticula reported here suggest a novel role for mutations of structural sarcomeric proteins in the pathogenesis of congenital cardiac diverticula. From these studies, we suggest TNNT2 is a gene worthy of screening for those with a congenital heart defect, particularly atrial septal defects and ventricular diverticula. © 2016 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.

Gene silencing of myofibrillogenesis regulator-1 by adenovirus-delivered small interfering RNA suppresses cardiac hypertrophy induced by angiotensin II in mice.

PubMed

Dai, Wenjian; He, Weiqing; Shang, Guangdong; Jiang, Jiandong; Wang, Yiguang; Kong, Weijia

2010-11-01

Our previous studies proved that myofibrillogenesis regulator (MR)-1 has a close relationship with cardiac hypertrophy induced by ANG II. In the present study, we developed a recombinant adenoviral vector (AdSiR-MR-1) driving small interfering (si)RNA against MR-1 to evaluate its effect on cardiac hypertrophy in vivo. Cardiac hypertrophy was induced by chronic ANG II infusion in mice; AdSiR-MR-1 was administered via the jugular vein through one bolus injection. Thirteen days after the injection, viral DNA was still detectable in the heart, validating the efficiency of gene transfer. Expression levels of MR-1 mRNA and protein were increased by 2.5-fold in the heart after ANG II infusion; AdSiR-control, which contained a scrambled siRNA sequence, had no effect on them. AdSiR-MR-1 treatment abolished the upregulation of MR-1 induced by ANG II. The silencing effect of AdSiR-MR-1 was observed in many other tissues, such as the liver, lung, and kidney, except skeletal muscle. ANG II-induced cardiac hypertrophy was suppressed in mice treated with AdSiR-MR-1, as determined by echocardiography. Morphological and immnohistochemical examinations revealed that interstitial cardiac fibrosis as well as infiltrating inflammatory cells were increased after ANG II infusion; AdSiR-MR-1 greatly ameliorated these disorders. In ANG II-infused mice, MR-1 silencing also blocked the upregulation of other genes related to cardiac hypertrophy or metabolism of the extracellular matrix. In summary, our results demonstrate the feasibility of MR-1 silencing in vivo and suggest that MR-1 could be a potential new target to treat cardiac hypertrophy induced by ANG II.

Evaluation of 10 genes encoding cardiac proteins in Doberman Pinschers with dilated cardiomyopathy.

PubMed

O'Sullivan, M Lynne; O'Grady, Michael R; Pyle, W Glen; Dawson, John F

2011-07-01

To identify a causative mutation for dilated cardiomyopathy (DCM) in Doberman Pinschers by sequencing the coding regions of 10 cardiac genes known to be associated with familial DCM in humans. 5 Doberman Pinschers with DCM and congestive heart failure and 5 control mixed-breed dogs that were euthanized or died. RNA was extracted from frozen ventricular myocardial samples from each dog, and first-strand cDNA was synthesized via reverse transcription, followed by PCR amplification with gene-specific primers. Ten cardiac genes were analyzed: cardiac actin, α-actinin, α-tropomyosin, β-myosin heavy chain, metavinculin, muscle LIM protein, myosinbinding protein C, tafazzin, titin-cap (telethonin), and troponin T. Sequences for DCM-affected and control dogs and the published canine genome were compared. None of the coding sequences yielded a common causative mutation among all Doberman Pinscher samples. However, 3 variants were identified in the α-actinin gene in the DCM-affected Doberman Pinschers. One of these variants, identified in 2 of the 5 Doberman Pinschers, resulted in an amino acid change in the rod-forming triple coiled-coil domain. Mutations in the coding regions of several genes associated with DCM in humans did not appear to consistently account for DCM in Doberman Pinschers. However, an α-actinin variant was detected in some Doberman Pinschers that may contribute to the development of DCM given its potential effect on the structure of this protein. Investigation of additional candidate gene coding and noncoding regions and further evaluation of the role of α-actinin in development of DCM in Doberman Pinschers are warranted.

OCT4 expression mediates partial cardiomyocyte reprogramming of mesenchymal stromal cells.

PubMed

Yannarelli, Gustavo; Pacienza, Natalia; Montanari, Sonia; Santa-Cruz, Diego; Viswanathan, Sowmya; Keating, Armand

2017-01-01

Mesenchymal stem/stromal cells (MSCs) are in numerous cell therapy clinical trials, including for injured myocardium. Acquisition of cardiomyocyte characteristics by MSCs may improve cardiac regeneration but the mechanisms regulating this process are unclear. Here, we investigated whether the pluripotency transcription factor OCT4 is involved in the activation of cardiac lineage genetic programs in MSCs. We employed our established co-culture model of MSCs with rat embryonic cardiomyocytes showing co-expression of cardiac markers on MSCs independent of cell fusion. Bone marrow-derived MSCs were isolated from transgenic mice expressing GFP under the control of the cardiac-specific α-myosin heavy chain promoter. After 5 days of co-culture, MSCs expressed cardiac specific genes, including Nkx2.5, atrial natriuretic factor and α-cardiac actin. The frequency of GFP+ cells was 7.6±1.9%, however, these cells retained the stromal cell phenotype, indicating, as expected, only partial differentiation. Global OCT4 expression increased 2.6±0.7-fold in co-cultured MSCs and of interest, 87±5% vs 79±4% of MSCs expressed OCT4 by flow cytometry in controls and after co-culture, respectively. Consistent with the latter observation, the GFP+ cells did not express nuclear OCT4 and showed a significant increase in OCT4 promoter methylation compared with undifferentiated MSCs (92% vs 45%), inferring that OCT4 is regulated by an epigenetic mechanism. We further showed that siRNA silencing of OCT4 in MSCs resulted in a reduced frequency of GFP+ cells in co-culture to less than 1%. Our data infer that OCT4 expression may have a direct effect on partial cardiomyocyte reprogramming of MSCs and suggest a new mechanism(s) associated with MSC multipotency and a requirement for crosstalk with the cardiac microenvironment.

OCT4 expression mediates partial cardiomyocyte reprogramming of mesenchymal stromal cells

PubMed Central

Montanari, Sonia; Santa-Cruz, Diego; Viswanathan, Sowmya; Keating, Armand

2017-01-01

Mesenchymal stem/stromal cells (MSCs) are in numerous cell therapy clinical trials, including for injured myocardium. Acquisition of cardiomyocyte characteristics by MSCs may improve cardiac regeneration but the mechanisms regulating this process are unclear. Here, we investigated whether the pluripotency transcription factor OCT4 is involved in the activation of cardiac lineage genetic programs in MSCs. We employed our established co-culture model of MSCs with rat embryonic cardiomyocytes showing co-expression of cardiac markers on MSCs independent of cell fusion. Bone marrow-derived MSCs were isolated from transgenic mice expressing GFP under the control of the cardiac-specific α-myosin heavy chain promoter. After 5 days of co-culture, MSCs expressed cardiac specific genes, including Nkx2.5, atrial natriuretic factor and α-cardiac actin. The frequency of GFP+ cells was 7.6±1.9%, however, these cells retained the stromal cell phenotype, indicating, as expected, only partial differentiation. Global OCT4 expression increased 2.6±0.7-fold in co-cultured MSCs and of interest, 87±5% vs 79±4% of MSCs expressed OCT4 by flow cytometry in controls and after co-culture, respectively. Consistent with the latter observation, the GFP+ cells did not express nuclear OCT4 and showed a significant increase in OCT4 promoter methylation compared with undifferentiated MSCs (92% vs 45%), inferring that OCT4 is regulated by an epigenetic mechanism. We further showed that siRNA silencing of OCT4 in MSCs resulted in a reduced frequency of GFP+ cells in co-culture to less than 1%. Our data infer that OCT4 expression may have a direct effect on partial cardiomyocyte reprogramming of MSCs and suggest a new mechanism(s) associated with MSC multipotency and a requirement for crosstalk with the cardiac microenvironment. PMID:29216265

Genotype-phenotype correlation between the cardiac myosin binding protein C mutation A31P and hypertrophic cardiomyopathy in a cohort of Maine Coon cats: a longitudinal study.

PubMed

Granström, S; Godiksen, M T N; Christiansen, M; Pipper, C B; Martinussen, T; Møgelvang, R; Søgaard, P; Willesen, J L; Koch, J

2015-12-01

A missense mutation (A31P) in the cardiac myosin binding protein C gene has been associated with hypertrophic cardiomyopathy (HCM) in Maine Coon cats. The aim of this study was to investigate the effect of A31P on development of HCM, myocardial diastolic dysfunction detected by color tissue Doppler imaging and occurrence of cardiac death during longitudinal follow-up in a cohort of Maine Coon cats. The original cohort comprised 282 cats (158 of wild-type genotype, 99 heterozygous for A31P and 25 homozygous for A31P). Prospective longitudinal study including echocardiography and registration of survival. The median age at the initial examination was 1.7 years (range, 0.8-9.2 years) and 6.4% (18/282) of the cats were diagnosed with HCM. One hundred sixty-five cats were eligible for echocardiographic re-examination, and during an average follow-up period of 2.7 years an additional 6.7% (11/165) of the cats developed HCM. Survival data could be obtained for 262 of the cats originally included, and among these 9.2% (24/262) died of causes that met the study criteria for cardiac death. In the homozygous group 80% (20/25) of cats included were diagnosed with HCM and 48% (12/25) suffered cardiac death during follow-up. These results corresponded to a significantly higher risk for cats homozygous for A31P to develop HCM (p<0.001) and die from cardiac-related causes compared with both other genotypes (p<0.001). Homozygosity for A31P was associated with a high penetrance of HCM and a substantial risk for cardiac death in the study population. Copyright © 2015 Elsevier B.V. All rights reserved.

Molecular consequences of the R453C hypertrophic cardiomyopathy mutation on human β-cardiac myosin motor function.

PubMed

Sommese, Ruth F; Sung, Jongmin; Nag, Suman; Sutton, Shirley; Deacon, John C; Choe, Elizabeth; Leinwand, Leslie A; Ruppel, Kathleen; Spudich, James A

2013-07-30

Cardiovascular disorders are the leading cause of morbidity and mortality in the developed world, and hypertrophic cardiomyopathy (HCM) is among the most frequently occurring inherited cardiac disorders. HCM is caused by mutations in the genes encoding the fundamental force-generating machinery of the cardiac muscle, including β-cardiac myosin. Here, we present a biomechanical analysis of the HCM-causing mutation, R453C, in the context of human β-cardiac myosin. We found that this mutation causes a ∼30% decrease in the maximum ATPase of the human β-cardiac subfragment 1, the motor domain of myosin, and a similar percent decrease in the in vitro velocity. The major change in the R453C human β-cardiac subfragment 1 is a 50% increase in the intrinsic force of the motor compared with wild type, with no appreciable change in the stroke size, as observed with a dual-beam optical trap. These results predict that the overall force of the ensemble of myosin molecules in the muscle should be higher in the R453C mutant compared with wild type. Loaded in vitro motility assay confirms that the net force in the ensemble is indeed increased. Overall, this study suggests that the R453C mutation should result in a hypercontractile state in the heart muscle.

The p21-activated kinase 1 (Pak1) signalling pathway in cardiac disease: from mechanistic study to therapeutic exploration.

PubMed

Wang, Yanwen; Wang, Shunyao; Lei, Ming; Boyett, Mark; Tsui, Hoyee; Liu, Wei; Wang, Xin

2018-04-01

p21-activated kinase 1 (Pak1) is a member of the highly conserved family of serine/threonine protein kinases regulated by Ras-related small G-proteins, Cdc42/Rac1. It has been previously demonstrated to be involved in cardiac protection. Based on recent studies, this review provides an overview of the role of Pak1 in cardiac diseases including disrupted Ca 2+ homoeostasis-related cardiac arrhythmias, adrenergic stress- and pressure overload-induced hypertrophy, and ischaemia/reperfusion injury. These findings demonstrate the important role of Pak1 mediated through the phosphorylation and transcriptional modification of hypertrophy and/or arrhythmia-related genes. This review also discusses the anti-arrhythmic and anti-hypertrophic, protective function of Pak1 and the beneficial effects of fingolimod (an FDA-approved sphingolipid drug), a Pak1 activator, and its ability to prevent arrhythmias and cardiac hypertrophy. These findings also highlight the therapeutic potential of Pak1 signalling in the treatment and prevention of cardiac diseases. This article is part of a themed section on Spotlight on Small Molecules in Cardiovascular Diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.8/issuetoc. © 2017 The British Pharmacological Society.

Genetically engineered SCN5A mutant pig hearts exhibit conduction defects and arrhythmias

PubMed Central

Park, David S.; Cerrone, Marina; Morley, Gregory; Vasquez, Carolina; Fowler, Steven; Liu, Nian; Bernstein, Scott A.; Liu, Fang-Yu; Zhang, Jie; Rogers, Christopher S.; Priori, Silvia G.; Chinitz, Larry A.; Fishman, Glenn I.

2014-01-01

SCN5A encodes the α subunit of the major cardiac sodium channel NaV1.5. Mutations in SCN5A are associated with conduction disease and ventricular fibrillation (VF); however, the mechanisms that link loss of sodium channel function to arrhythmic instability remain unresolved. Here, we generated a large-animal model of a human cardiac sodium channelopathy in pigs, which have cardiac structure and function similar to humans, to better define the arrhythmic substrate. We introduced a nonsense mutation originally identified in a child with Brugada syndrome into the orthologous position (E558X) in the pig SCN5A gene. SCN5AE558X/+ pigs exhibited conduction abnormalities in the absence of cardiac structural defects. Sudden cardiac death was not observed in young pigs; however, Langendorff-perfused SCN5AE558X/+ hearts had an increased propensity for pacing-induced or spontaneous VF initiated by short-coupled ventricular premature beats. Optical mapping during VF showed that activity often began as an organized focal source or broad wavefront on the right ventricular (RV) free wall. Together, the results from this study demonstrate that the SCN5AE558X/+ pig model accurately phenocopies many aspects of human cardiac sodium channelopathy, including conduction slowing and increased susceptibility to ventricular arrhythmias. PMID:25500882

Abnormal cardiac autonomic regulation in mice lacking ASIC3.

PubMed

Cheng, Ching-Feng; Kuo, Terry B J; Chen, Wei-Nan; Lin, Chao-Chieh; Chen, Chih-Cheng

2014-01-01

Integration of sympathetic and parasympathetic outflow is essential in maintaining normal cardiac autonomic function. Recent studies demonstrate that acid-sensing ion channel 3 (ASIC3) is a sensitive acid sensor for cardiac ischemia and prolonged mild acidification can open ASIC3 and evoke a sustained inward current that fires action potentials in cardiac sensory neurons. However, the physiological role of ASIC3 in cardiac autonomic regulation is not known. In this study, we elucidate the role of ASIC3 in cardiac autonomic function using Asic3(-/-) mice. Asic3(-/-) mice showed normal baseline heart rate and lower blood pressure as compared with their wild-type littermates. Heart rate variability analyses revealed imbalanced autonomic regulation, with decreased sympathetic function. Furthermore, Asic3(-/-) mice demonstrated a blunted response to isoproterenol-induced cardiac tachycardia and prolonged duration to recover to baseline heart rate. Moreover, quantitative RT-PCR analysis of gene expression in sensory ganglia and heart revealed that no gene compensation for muscarinic acetylcholines receptors and beta-adrenalin receptors were found in Asic3(-/-) mice. In summary, we unraveled an important role of ASIC3 in regulating cardiac autonomic function, whereby loss of ASIC3 alters the normal physiological response to ischemic stimuli, which reveals new implications for therapy in autonomic nervous system-related cardiovascular diseases.

Inflammatory gene polymorphisms and risk of postoperative myocardial infarction after cardiac surgery.

PubMed

Podgoreanu, M V; White, W D; Morris, R W; Mathew, J P; Stafford-Smith, M; Welsby, I J; Grocott, H P; Milano, C A; Newman, M F; Schwinn, D A

2006-07-04

The inflammatory response triggered by cardiac surgery with cardiopulmonary bypass (CPB) is a primary mechanism in the pathogenesis of postoperative myocardial infarction (PMI), a multifactorial disorder with significant inter-patient variability poorly predicted by clinical and procedural factors. We tested the hypothesis that candidate gene polymorphisms in inflammatory pathways contribute to risk of PMI after cardiac surgery. We genotyped 48 polymorphisms from 23 candidate genes in a prospective cohort of 434 patients undergoing elective cardiac surgery with CPB. PMI was defined as creatine kinase-MB isoenzyme level > or = 10x upper limit of normal at 24 hours postoperatively. A 2-step analysis strategy was used: marker selection, followed by model building. To minimize false-positive associations, we adjusted for multiple testing by permutation analysis, Bonferroni correction, and controlling the false discovery rate; 52 patients (12%) experienced PMI. After adjusting for multiple comparisons and clinical risk factors, 3 polymorphisms were found to be independent predictors of PMI (adjusted P<0.05; false discovery rate <10%). These gene variants encode the proinflammatory cytokine interleukin 6 (IL6 -572G>C; odds ratio [OR], 2.47), and 2 adhesion molecules: intercellular adhesion molecule-1 (ICAM1 Lys469Glu; OR, 1.88), and E-selectin (SELE 98G>T; OR, 0.16). The inclusion of genotypic information from these polymorphisms improved prediction models for PMI based on traditional risk factors alone (C-statistic 0.764 versus 0.703). Functional genetic variants in cytokine and leukocyte-endothelial interaction pathways are independently associated with severity of myonecrosis after cardiac surgery. This may aid in preoperative identification of high-risk cardiac surgical patients and development of novel cardioprotective strategies.

Gene network analysis: from heart development to cardiac therapy.

PubMed

Ferrazzi, Fulvia; Bellazzi, Riccardo; Engel, Felix B

2015-03-01

Networks offer a flexible framework to represent and analyse the complex interactions between components of cellular systems. In particular gene networks inferred from expression data can support the identification of novel hypotheses on regulatory processes. In this review we focus on the use of gene network analysis in the study of heart development. Understanding heart development will promote the elucidation of the aetiology of congenital heart disease and thus possibly improve diagnostics. Moreover, it will help to establish cardiac therapies. For example, understanding cardiac differentiation during development will help to guide stem cell differentiation required for cardiac tissue engineering or to enhance endogenous repair mechanisms. We introduce different methodological frameworks to infer networks from expression data such as Boolean and Bayesian networks. Then we present currently available temporal expression data in heart development and discuss the use of network-based approaches in published studies. Collectively, our literature-based analysis indicates that gene network analysis constitutes a promising opportunity to infer therapy-relevant regulatory processes in heart development. However, the use of network-based approaches has so far been limited by the small amount of samples in available datasets. Thus, we propose to acquire high-resolution temporal expression data to improve the mathematical descriptions of regulatory processes obtained with gene network inference methodologies. Especially probabilistic methods that accommodate the intrinsic variability of biological systems have the potential to contribute to a deeper understanding of heart development.

Nerve Growth Factor Gene Therapy Using Adeno-Associated Viral Vectors Prevents Cardiomyopathy in Type 1 Diabetic Mice

PubMed Central

Meloni, Marco; Descamps, Betty; Caporali, Andrea; Zentilin, Lorena; Floris, Ilaria; Giacca, Mauro; Emanueli, Costanza

2012-01-01

Diabetes is a cause of cardiac dysfunction, reduced myocardial perfusion, and ultimately heart failure. Nerve growth factor (NGF) exerts protective effects on the cardiovascular system. This study investigated whether NGF gene transfer can prevent diabetic cardiomyopathy in mice. We worked with mice with streptozotocin-induced type 1 diabetes and with nondiabetic control mice. After having established that diabetes reduces cardiac NGF mRNA expression, we tested NGF gene therapies with adeno-associated viral vectors (AAVs) for the capacity to protect the diabetic mouse heart. To this aim, after 2 weeks of diabetes, cardiac expression of human NGF or β-Gal (control) genes was induced by either intramyocardial injection of AAV serotype 2 (AAV2) or systemic delivery of AAV serotype 9 (AAV9). Nondiabetic mice were given AAV2–β-Gal or AAV9–β-Gal. We found that the diabetic mice receiving NGF gene transfer via either AAV2 or AAV9 were spared the progressive deterioration of cardiac function and left ventricular chamber dilatation observed in β-Gal–injected diabetic mice. Moreover, they were additionally protected from myocardial microvascular rarefaction, hypoperfusion, increased deposition of interstitial fibrosis, and increased apoptosis of endothelial cells and cardiomyocytes, which afflicted the β-Gal–injected diabetic control mice. Our data suggest therapeutic potential of NGF for the prevention of cardiomyopathy in diabetic subjects. PMID:22187379

Sarcomere protein gene mutations and inherited heart disease: a beta-cardiac myosin heavy chain mutation causing endocardial fibroelastosis and heart failure.

PubMed

Kamisago, Mitsuhiro; Schmitt, Joachim P; McNamara, Dennis; Seidman, Christine; Seidman, J G

2006-01-01

Inherited human cardiomyopathies often lead to heart failure. A common feature of these conditions is that affected individuals can express the disease causing mutations for many years without showing clinical signs of the disease. Previous studies have demonstrated that sarcomere protein gene mutations can cause either dilated cardiomyopathy or hypertrophic cardiomyopathy. Here we demonstrate that the Arg442His missense mutation in beta-cardiac myosin heavy chain (betaMHC) causes dilated cardiomyopathy, endocardial fibroelastosis and heart failure at a very early age. Using standard genetic engineering tools we and others have made murine models by introducing human disease causing mutations into mice. The central hypothesis of these studies has been that by identifying the pathophysiological pathways activated by these mutations we can define enzymatic activities that are modified during the disease process and which may be involved in pathways that involve more common forms of cardiac disease. Murine models bearing different mutant myosins are being used to address whether each disease causing mutant betaMHC activates the same or different cellular pathways. Dissecting the molecular pathways modulated by mutations in sarcomere protein genes as well as other genes has already demonstrated that there are multiple pathways leading to cardiac remodelling and heart failure. Defining the mechanisms by which mutations in the same genes activate different cellular pathways remains an important question.

Gene Therapy With Angiotensin-(1-9) Preserves Left Ventricular Systolic Function After Myocardial Infarction.

PubMed

Fattah, Caroline; Nather, Katrin; McCarroll, Charlotte S; Hortigon-Vinagre, Maria P; Zamora, Victor; Flores-Munoz, Monica; McArthur, Lisa; Zentilin, Lorena; Giacca, Mauro; Touyz, Rhian M; Smith, Godfrey L; Loughrey, Christopher M; Nicklin, Stuart A

2016-12-20

Angiotensin-(1-9) [Ang-(1-9)] is a novel peptide of the counter-regulatory axis of the renin-angiotensin-aldosterone system previously demonstrated to have therapeutic potential in hypertensive cardiomyopathy when administered via osmotic mini-pump. Here, we investigate whether gene transfer of Ang-(1-9) is cardioprotective in a murine model of myocardial infarction (MI). The authors evaluated effects of Ang-(1-9) gene therapy on myocardial structural and functional remodeling post-infarction. C57BL/6 mice underwent permanent left anterior descending coronary artery ligation and cardiac function was assessed using echocardiography for 8 weeks followed by a terminal measurement of left ventricular pressure volume loops. Ang-(1-9) was delivered by adeno-associated viral vector via single tail vein injection immediately following induction of MI. Direct effects of Ang-(1-9) on cardiomyocyte excitation/contraction coupling and cardiac contraction were evaluated in isolated mouse and human cardiomyocytes and in an ex vivo Langendorff-perfused whole-heart model. Gene delivery of Ang-(1-9) reduced sudden cardiac death post-MI. Pressure volume measurements revealed complete restoration of end-systolic pressure, ejection fraction, end-systolic volume, and the end-diastolic pressure volume relationship by Ang-(1-9) treatment. Stroke volume and cardiac output were significantly increased versus sham. Histological analysis revealed only mild effects on cardiac hypertrophy and fibrosis, but a significant increase in scar thickness. Direct assessment of Ang-(1-9) on isolated cardiomyocytes demonstrated a positive inotropic effect via increasing calcium transient amplitude and contractility. Ang-(1-9) increased contraction in the Langendorff model through a protein kinase A-dependent mechanism. Our novel findings showed that Ang-(1-9) gene therapy preserved left ventricular systolic function post-MI, restoring cardiac function. Furthermore, Ang-(1-9) directly affected cardiomyocyte calcium handling through a protein kinase A-dependent mechanism. These data emphasized Ang-(1-9) gene therapy as a potential new strategy in the context of MI. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Sarcospan Regulates Cardiac Isoproterenol Response and Prevents Duchenne Muscular Dystrophy-Associated Cardiomyopathy.

PubMed

Parvatiyar, Michelle S; Marshall, Jamie L; Nguyen, Reginald T; Jordan, Maria C; Richardson, Vanitra A; Roos, Kenneth P; Crosbie-Watson, Rachelle H

2015-12-23

Duchenne muscular dystrophy is a fatal cardiac and skeletal muscle disease resulting from mutations in the dystrophin gene. We have previously demonstrated that a dystrophin-associated protein, sarcospan (SSPN), ameliorated Duchenne muscular dystrophy skeletal muscle degeneration by activating compensatory pathways that regulate muscle cell adhesion (laminin-binding) to the extracellular matrix. Conversely, loss of SSPN destabilized skeletal muscle adhesion, hampered muscle regeneration, and reduced force properties. Given the importance of SSPN to skeletal muscle, we investigated the consequences of SSPN ablation in cardiac muscle and determined whether overexpression of SSPN into mdx mice ameliorates cardiac disease symptoms associated with Duchenne muscular dystrophy cardiomyopathy. SSPN-null mice exhibited cardiac enlargement, exacerbated cardiomyocyte hypertrophy, and increased fibrosis in response to β-adrenergic challenge (isoproterenol; 0.8 mg/day per 2 weeks). Biochemical analysis of SSPN-null cardiac muscle revealed reduced sarcolemma localization of many proteins with a known role in cardiomyopathy pathogenesis: dystrophin, the sarcoglycans (α-, δ-, and γ-subunits), and β1D integrin. Transgenic overexpression of SSPN in Duchenne muscular dystrophy mice (mdx(TG)) improved cardiomyofiber cell adhesion, sarcolemma integrity, cardiac functional parameters, as well as increased expression of compensatory transmembrane proteins that mediate attachment to the extracellular matrix. SSPN regulates sarcolemmal expression of laminin-binding complexes that are critical to cardiac muscle function and protects against transient and chronic injury, including inherited cardiomyopathy. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

CIP, a cardiac Isl1-interacting protein, represses cardiomyocyte hypertrophy.

PubMed

Huang, Zhan-Peng; Young Seok, Hee; Zhou, Bin; Chen, Jinghai; Chen, Jian-Fu; Tao, Yazhong; Pu, William T; Wang, Da-Zhi

2012-03-16

Mammalian heart has minimal regenerative capacity. In response to mechanical or pathological stress, the heart undergoes cardiac remodeling. Pressure and volume overload in the heart cause increased size (hypertrophic growth) of cardiomyocytes. Whereas the regulatory pathways that activate cardiac hypertrophy have been well-established, the molecular events that inhibit or repress cardiac hypertrophy are less known. To identify and investigate novel regulators that modulate cardiac hypertrophy. Here, we report the identification, characterization, and functional examination of a novel cardiac Isl1-interacting protein (CIP). CIP was identified from a bioinformatic search for novel cardiac-expressed genes in mouse embryonic hearts. CIP encodes a nuclear protein without recognizable motifs. Northern blotting, in situ hybridization, and reporter gene tracing demonstrated that CIP is highly expressed in cardiomyocytes of developing and adult hearts. Yeast two-hybrid screening identified Isl1, a LIM/homeodomain transcription factor essential for the specification of cardiac progenitor cells in the second heart field, as a cofactor of CIP. CIP directly interacted with Isl1, and we mapped the domains of these two proteins, which mediate their interaction. We show that CIP represses the transcriptional activity of Isl1 in the activation of the myocyte enhancer factor 2C. The expression of CIP was dramatically reduced in hypertrophic cardiomyocytes. Most importantly, overexpression of CIP repressed agonist-induced cardiomyocyte hypertrophy. Our studies therefore identify CIP as a novel regulator of cardiac hypertrophy.

Rbm20-deficient cardiogenesis reveals early disruption of RNA processing and sarcomere remodeling establishing a developmental etiology for dilated cardiomyopathy.

PubMed

Beraldi, Rosanna; Li, Xing; Martinez Fernandez, Almudena; Reyes, Santiago; Secreto, Frank; Terzic, Andre; Olson, Timothy M; Nelson, Timothy J

2014-07-15

Dilated cardiomyopathy (DCM) due to mutations in RBM20, a gene encoding an RNA-binding protein, is associated with high familial penetrance, risk of progressive heart failure and sudden death. Although genetic investigations and physiological models have established the linkage of RBM20 with early-onset DCM, the underlying basis of cellular and molecular dysfunction is undetermined. Modeling human genetics using a high-throughput pluripotent stem cell platform was herein designed to pinpoint the initial transcriptome dysfunction and mechanistic corruption in disease pathogenesis. Tnnt2-pGreenZeo pluripotent stem cells were engineered to knockdown Rbm20 (shRbm20) to determine the cardiac-pathogenic phenotype during cardiac differentiation. Intracellular Ca(2+) transients revealed Rbm20-dependent alteration in Ca(2+) handling, coinciding with known pathological splice variants of Titin and Camk2d genes by Day 24 of cardiogenesis. Ultrastructural analysis demonstrated elongated and thinner sarcomeres in the absence of Rbm20 that is consistent with human cardiac biopsy samples. Furthermore, Rbm20-depleted transcriptional profiling at Day 12 identified Rbm20-dependent dysregulation with 76% of differentially expressed genes linked to known cardiac pathology ranging from primordial Nkx2.5 to mature cardiac Tnnt2 as the initial molecular aberrations. Notably, downstream consequences of Rbm20-depletion at Day 24 of differentiation demonstrated significant dysregulation of extracellular matrix components such as the anomalous overexpression of the Vtn gene. By using the pluripotent stem cell platform to model human cardiac disease according to a stage-specific cardiogenic roadmap, we established a new paradigm of familial DCM pathogenesis as a developmental disorder that is patterned during early cardiogenesis and propagated with cellular mechanisms of pathological cardiac remodeling. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Inhibition of histone acetylation by curcumin reduces alcohol-induced fetal cardiac apoptosis.

PubMed

Yan, Xiaochen; Pan, Bo; Lv, Tiewei; Liu, Lingjuan; Zhu, Jing; Shen, Wen; Huang, Xupei; Tian, Jie

2017-01-05

Prenatal alcohol exposure may cause cardiac development defects, however, the underlying mechanisms are not yet clear. In the present study we have investigated the roles of histone modification by curcumin on alcohol induced fetal cardiac abnormalities during the development. Q-PCR and Western blot results showed that alcohol exposure increased gene and active forms of caspase-3 and caspase-8, while decreased gene and protein of bcl-2. ChIP assay results showed that, alcohol exposure increased the acetylation of histone H3K9 near the promoter region of caspase-3 and caspase-8, and decreased the acetylation of histone H3K9 near the promoter region of bcl-2. TUNEL assay data revealed that alcohol exposure increased the apoptosis levels in the embryonic hearts. In vitro experiments demonstrated that curcumin treatment could reverse the up-regulation of active forms of caspase-3 and caspase-8, and down-regulation of bcl-2 induced by alcohol treatment. In addition, curcumin also corrected the high level of histone H3K9 acetylation induced by alcohol. Moreover, the high apoptosis level induced by alcohol was reversed after curcumin treatment in cardiac cells. These findings indicate that histone modification may play an important role in mediating alcohol induced fetal cardiac apoptosis, possibly through the up-regulation of H3K9 acetylation near the promoter regions of apoptotic genes. Curcumin treatment may correct alcohol-mediated fetal cardiac apoptosis, suggesting that curcumin may play a protective role against alcohol abuse caused cardiac damage during pregnancy.

CALCIUM-DRIVEN TRANSCRIPTION OF CARDIAC SPECIFYING GENE PROGRAM IN LIVER STEM CELLS

EPA Science Inventory

We have previously shown that a cloned liver stem cell line (WB F344) acquires a cardiac phenotype when seeded in a cardiac microenvironment in vivo and ex vivo. Here we investigated the mechanisms of this transdifferentiation in early (<72 hr) WB F344 cell, rat neonatal ventricu...

Molecular and immunohistochemical analyses of cardiac troponin T during cardiac development in the Mexican axolotl, Ambystoma mexicanum.

PubMed

Zhang, C; Pietras, K M; Sferrazza, G F; Jia, P; Athauda, G; Rueda-de-Leon, E; Rveda-de-Leon, E; Maier, J A; Dube, D K; Lemanski, S L; Lemanski, L F

2007-01-01

The Mexican axolotl, Ambystoma mexicanum, is an excellent animal model for studying heart development because it carries a naturally occurring recessive genetic mutation, designated gene c, for cardiac nonfunction. The double recessive mutants (c/c) fail to form organized myofibrils in the cardiac myoblasts resulting in hearts that fail to beat. Tropomyosin expression patterns have been studied in detail and show dramatically decreased expression in the hearts of homozygous mutant embryos. Because of the direct interaction between tropomyosin and troponin T (TnT), and the crucial functions of TnT in the regulation of striated muscle contraction, we have expanded our studies on this animal model to characterize the expression of the TnT gene in cardiac muscle throughout normal axolotl development as well as in mutant axolotls. In addition, we have succeeded in cloning the full-length cardiac troponin T (cTnT) cDNA from axolotl hearts. Confocal microscopy has shown a substantial, but reduced, expression of TnT protein in the mutant hearts when compared to normal during embryonic development. 2006 Wiley-Liss, Inc.

Direct In Vivo Reprogramming with Sendai Virus Vectors Improves Cardiac Function after Myocardial Infarction.

PubMed

Miyamoto, Kazutaka; Akiyama, Mizuha; Tamura, Fumiya; Isomi, Mari; Yamakawa, Hiroyuki; Sadahiro, Taketaro; Muraoka, Naoto; Kojima, Hidenori; Haginiwa, Sho; Kurotsu, Shota; Tani, Hidenori; Wang, Li; Qian, Li; Inoue, Makoto; Ide, Yoshinori; Kurokawa, Junko; Yamamoto, Tsunehisa; Seki, Tomohisa; Aeba, Ryo; Yamagishi, Hiroyuki; Fukuda, Keiichi; Ieda, Masaki

2018-01-04

Direct cardiac reprogramming holds great promise for regenerative medicine. We previously generated directly reprogrammed induced cardiomyocyte-like cells (iCMs) by overexpression of Gata4, Mef2c, and Tbx5 (GMT) using retrovirus vectors. However, integrating vectors pose risks associated with insertional mutagenesis and disruption of gene expression and are inefficient. Here, we show that Sendai virus (SeV) vectors expressing cardiac reprogramming factors efficiently and rapidly reprogram both mouse and human fibroblasts into integration-free iCMs via robust transgene expression. SeV-GMT generated 100-fold more beating iCMs than retroviral-GMT and shortened the duration to induce beating cells from 30 to 10 days in mouse fibroblasts. In vivo lineage tracing revealed that the gene transfer of SeV-GMT was more efficient than retroviral-GMT in reprogramming resident cardiac fibroblasts into iCMs in mouse infarct hearts. Moreover, SeV-GMT improved cardiac function and reduced fibrosis after myocardial infarction. Thus, efficient, non-integrating SeV vectors may serve as a powerful system for cardiac regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

Peptide-enhanced mRNA transfection in cultured mouse cardiac fibroblasts and direct reprogramming towards cardiomyocyte-like cells

PubMed Central

Lee, Kunwoo; Yu, Pengzhi; Lingampalli, Nithya; Kim, Hyun Jin; Tang, Richard; Murthy, Niren

2015-01-01

The treatment of myocardial infarction is a major challenge in medicine due to the inability of heart tissue to regenerate. Direct reprogramming of endogenous cardiac fibroblasts into functional cardiomyocytes via the delivery of transcription factor mRNAs has the potential to regenerate cardiac tissue and to treat heart failure. Even though mRNA delivery to cardiac fibroblasts has the therapeutic potential, mRNA transfection in cardiac fibroblasts has been challenging. Herein, we develop an efficient mRNA transfection in cultured mouse cardiac fibroblasts via a polyarginine-fused heart-targeting peptide and lipofectamine complex, termed C-Lipo and demonstrate the partial direct reprogramming of cardiac fibroblasts towards cardiomyocyte cells. C-Lipo enabled the mRNA-induced direct cardiac reprogramming due to its efficient transfection with low toxicity, which allowed for multiple transfections of Gata4, Mef2c, and Tbx5 (GMT) mRNAs for a period of 2 weeks. The induced cardiomyocyte-like cells had α-MHC promoter-driven GFP expression and striated cardiac muscle structure from α-actinin immunohistochemistry. GMT mRNA transfection of cultured mouse cardiac fibroblasts via C-Lipo significantly increased expression of the cardiomyocyte marker genes, Actc1, Actn2, Gja1, Hand2, and Tnnt2, after 2 weeks of transfection. Moreover, this study provides the first direct evidence that the stoichiometry of the GMT reprogramming factors influence the expression of cardiomyocyte marker genes. Our results demonstrate that mRNA delivery is a potential approach for cardiomyocyte generation. PMID:25834424

KLF5/BTEB2, a Krüppel-like zinc-finger type transcription factor, mediates both smooth muscle cell activation and cardiac hypertrophy.

PubMed

Nagai, Ryozo; Shindo, Takayuki; Manabe, Ichiro; Suzuki, Toru; Kurabayashi, Masahiko

2003-01-01

Cardiac and vascular biology need to be approached interactively because they share many common biological features as seen in activation of the local renin-angiotensin system, angiogenesis, and extracellular matrix production. We previously reported KLF5/BTEB2, a Krüppel-like zinc-finger type transcription factor, to activate various gene promoters that are activated in phenotypically modulated smooth muscle cells, such as a nonmuscle type myosin heavy chain gene SMemb, plasminogen activator inhibitor-1 (PAI-1), iNOS, PDGF-A, Egr-1 and VEGF receptors at least in vitro. KLF5/BTEB2 mRNA levels are downregulated with vascular development but upregulated in neointima that is produced in response to vascular injury. Mitogenic stimulation activates KLF5/BTEB2 gene expression through MEK1 and Egr-1. Chromatin immunoprecipitation assay showed KLF5/BTEB2 to be induced and to bind the promoter of the PDGF-A gene in response to angiotensin II stimulation. In order to define the role of KLF5/BTEB2 in cardiovascular remodeling, we targeted the KLF5/BTEB2 gene in mice. Homozygous mice resulted in early embryonic lethality whereas heterozygous mice were apparently normal. However, in response to external stress, arteries of heterozygotes exhibited diminished levels of smooth muscle and adventitial cell activation. Furthermore, cardiac fibrosis and hypertrophy induced by continuous angiotensin II infusion. We also found that RARa binds KLF5/BTEB2, and that Am80, a potent synthetic RAR agonist, inhibits angiotensin II-induced cardiac hypertrophy. These results indicate that KLF5/BTEB2 is an essential transcription factor that causes not only smooth muscle phenotypic modulation but also cardiac hypertrophy and fibrosis.

A vigilant, hypoxia-regulated heme oxygenase-1 gene vector in the heart limits cardiac injury after ischemia-reperfusion in vivo.

PubMed

Tang, Yao Liang; Qian, Keping; Zhang, Y Clare; Shen, Leping; Phillips, M Ian

2005-12-01

The effect of a cardiac specific, hypoxia-regulated, human heme oxygenase-1 (hHO-1) vector to provide cardioprotection from ischemia-reperfusion injury was assessed. When myocardial ischemia and reperfusion is asymptomatic, the damaging effects are cumulative and patients miss timely treatment. A gene therapy approach that expresses therapeutic genes only when ischemia is experienced is a desirable strategy. We have developed a cardiac-specific, hypoxia-regulated gene therapy "vigilant vector'' system that amplifies cardioprotective gene expression. Vigilant hHO-1 plasmids, LacZ plasmids, or saline (n = 40 per group) were injected into mouse heart 2 days in advance of ischemia-reperfusion injury. Animals were exposed to 60 minutes of ischemia followed by 24 hours of reperfusion. For that term (24 hours) effects, the protein levels of HO-1, inflammatory responses, apoptosis, and infarct size were determined. For long-term (3 week) effects, the left ventricular remodeling and recovery of cardiac function were assessed. Ischemia-reperfusion resulted in a timely overexpression of HO-1 protein. Infarct size at 24 hours after ischemia-reperfusion was significantly reduced in the HO-1-treated animals compared with the LacZ-treated group or saline-treated group (P < .001). The reduction of infarct size was accompanied by a decrease in lipid peroxidant activity, inflammatory cell infiltration, and proapoptotic protein level in ischemia-reperfusion-injured myocardium. The long-term study demonstrated that timely, hypoxia-induced HO-1 overexpression is beneficial in conserving cardiac function and attenuating left ventricle remodelling. The vigilant HO-1 vector provides a protective therapy in the heart for reducing cellular damage during ischemia-reperfusion injury and preserving heart function.

Common Variants in Cardiac Ion Channel Genes are Associated with Sudden Cardiac Death

PubMed Central

Albert, Christine M.; MacRae, Calum A.; Chasman, Daniel I.; VanDenburgh, Martin; Buring, Julie E; Manson, JoAnn E; Cook, Nancy R; Newton-Cheh, Christopher

2010-01-01

Background Rare variants in cardiac ion channel genes are associated with sudden cardiac death (SCD) in rare primary arrhythmic syndromes; however, it is unknown whether common variation in these same genes may contribute to SCD risk at the population level. Methods and Results We examined the association between 147 single nucleotide polymorphisms (SNPs) (137 tag, 5 non-coding SNPs associated with QT interval duration and 5 nonsynonymous SNPs) in 5 cardiac ion channel genes, KCNQ1, KCNH2, SCN5A, KCNE1 and KCNE2 and sudden and/or arrhythmic death in a combined nested case-control analysis among 516 cases and 1522 matched controls of European ancestry enrolled in six prospective cohort studies. After accounting for multiple testing, two SNPs (rs2283222 located in intron 11 in KCNQ1 and rs11720524 located in intron 1 in SCN5A) remained significantly associated with sudden/arrhythmic death (FDR = 0.01 and 0.03 respectively). Each increasing copy of the major T allele of rs2283222 or the major C allele of rs1172052 was associated with an OR = 1.36 (95% CI 1.16-1.60, P=0.0002) and 1.30 (95% CI 1.12-1.51, P=0.0005) respectively. Control for cardiovascular risk factors and/or limiting the analysis to definite SCDs did not significantly alter these relationships. Conclusion In this combined analysis of 6 prospective cohort studies, two common intronic variants in KCNQ1 and SCN5A were associated with SCD in individuals of European ancestry. Further study in other populations and investigation into the functional abnormalities associated with non-coding variation in these genes may lead to important insights into predisposition to lethal arrhythmias. PMID:20400777

Cardiac mesenchymal stromal cells are a source of adipocytes in arrhythmogenic cardiomyopathy.

PubMed

Sommariva, E; Brambilla, S; Carbucicchio, C; Gambini, E; Meraviglia, V; Dello Russo, A; Farina, F M; Casella, M; Catto, V; Pontone, G; Chiesa, M; Stadiotti, I; Cogliati, E; Paolin, A; Ouali Alami, N; Preziuso, C; d'Amati, G; Colombo, G I; Rossini, A; Capogrossi, M C; Tondo, C; Pompilio, G

2016-06-14

Arrhythmogenic cardiomyopathy (ACM) is a genetic disorder mainly due to mutations in desmosomal genes, characterized by progressive fibro-adipose replacement of the myocardium, arrhythmias, and sudden death. It is still unclear which cell type is responsible for fibro-adipose substitution and which molecular mechanisms lead to this structural change. Cardiac mesenchymal stromal cells (C-MSC) are the most abundant cells in the heart, with propensity to differentiate into several cell types, including adipocytes, and their role in ACM is unknown. The aim of the present study was to investigate whether C-MSC contributed to excess adipocytes in patients with ACM. We found that, in ACM patients' explanted heart sections, cells actively differentiating into adipocytes are of mesenchymal origin. Therefore, we isolated C-MSC from endomyocardial biopsies of ACM and from not affected by arrhythmogenic cardiomyopathy (NON-ACM) (control) patients. We found that both ACM and control C-MSC express desmosomal genes, with ACM C-MSC showing lower expression of plakophilin (PKP2) protein vs. Arrhythmogenic cardiomyopathy C-MSC cultured in adipogenic medium accumulated more lipid droplets than controls. Accordingly, the expression of adipogenic genes was higher in ACM vs. NON-ACM C-MSC, while expression of cell cycle and anti-adipogenic genes was lower. Both lipid accumulation and transcription reprogramming were dependent on PKP2 deficiency. Cardiac mesenchymal stromal cells contribute to the adipogenic substitution observed in ACM patients' hearts. Moreover, C-MSC from ACM patients recapitulate the features of ACM adipogenesis, representing a novel, scalable, patient-specific in vitro tool for future mechanistic studies. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.

MiRNAs with Apoptosis Regulating Potential Are Differentially Expressed in Chronic Exercise-Induced Physiologically Hypertrophied Hearts

PubMed Central

Ramprasath, Tharmarajan; Kalpana, Krishnan

2015-01-01

Physiological cardiac hypertrophy is an adaptive mechanism, induced during chronic exercise. As it is reversible and not associated with cardiomyocyte death, it is considered as a natural tactic to prevent cardiac dysfunction and failure. Though, different studies revealed the importance of microRNAs (miRNAs) in pathological hypertrophy, their role during physiological hypertrophy is largely unexplored. Hence, this study is aimed at revealing the global expression profile of miRNAs during physiological cardiac hypertrophy. Chronic swimming protocol continuously for eight weeks resulted in induction of physiological hypertrophy in rats and histopathology revealed the absence of tissue damage, apoptosis or fibrosis. Subsequently, the total RNA was isolated and small RNA sequencing was executed. Analysis of small RNA reads revealed the differential expression of a large set of miRNAs during physiological hypertrophy. The expression profile of the significantly differentially expressed miRNAs was validated by qPCR. In silico prediction of target genes by miRanda, miRdB and TargetScan and subsequent qPCR analysis unraveled that miRNAs including miR-99b, miR-100, miR-19b, miR-10, miR-208a, miR-133, miR-191a, miR-22, miR-30e and miR-181a are targeting the genes that primarily regulate cell proliferation and cell death. Gene ontology and pathway mapping showed that the differentially expressed miRNAs and their target genes were mapped to apoptosis and cell death pathways principally via PI3K/Akt/mTOR and MAPK signaling. In summary, our data indicates that regulation of these miRNAs with apoptosis regulating potential can be one of the major key factors in determining pathological or physiological hypertrophy by controlling fibrosis, apoptosis and cell death mechanisms. PMID:25793527

Contribution of rare inherited and de novo variants in 2,871 congenital heart disease probands.

PubMed

Jin, Sheng Chih; Homsy, Jason; Zaidi, Samir; Lu, Qiongshi; Morton, Sarah; DePalma, Steven R; Zeng, Xue; Qi, Hongjian; Chang, Weni; Sierant, Michael C; Hung, Wei-Chien; Haider, Shozeb; Zhang, Junhui; Knight, James; Bjornson, Robert D; Castaldi, Christopher; Tikhonoa, Irina R; Bilguvar, Kaya; Mane, Shrikant M; Sanders, Stephan J; Mital, Seema; Russell, Mark W; Gaynor, J William; Deanfield, John; Giardini, Alessandro; Porter, George A; Srivastava, Deepak; Lo, Cecelia W; Shen, Yufeng; Watkins, W Scott; Yandell, Mark; Yost, H Joseph; Tristani-Firouzi, Martin; Newburger, Jane W; Roberts, Amy E; Kim, Richard; Zhao, Hongyu; Kaltman, Jonathan R; Goldmuntz, Elizabeth; Chung, Wendy K; Seidman, Jonathan G; Gelb, Bruce D; Seidman, Christine E; Lifton, Richard P; Brueckner, Martina

2017-11-01

Congenital heart disease (CHD) is the leading cause of mortality from birth defects. Here, exome sequencing of a single cohort of 2,871 CHD probands, including 2,645 parent-offspring trios, implicated rare inherited mutations in 1.8%, including a recessive founder mutation in GDF1 accounting for ∼5% of severe CHD in Ashkenazim, recessive genotypes in MYH6 accounting for ∼11% of Shone complex, and dominant FLT4 mutations accounting for 2.3% of Tetralogy of Fallot. De novo mutations (DNMs) accounted for 8% of cases, including ∼3% of isolated CHD patients and ∼28% with both neurodevelopmental and extra-cardiac congenital anomalies. Seven genes surpassed thresholds for genome-wide significance, and 12 genes not previously implicated in CHD had >70% probability of being disease related. DNMs in ∼440 genes were inferred to contribute to CHD. Striking overlap between genes with damaging DNMs in probands with CHD and autism was also found.

Activation of cardiac renin-angiotensin system and plasminogen activator inhibitor-1 gene expressions in oral contraceptive-induced cardiometabolic disorder.

PubMed

Olatunji, Lawrence A; Usman, Taofeek O; Seok, Young-Mi; Kim, In-Kyeom

2017-02-01

Clinical studies have shown that combined oral contraceptive (COC) use is associated with cardiometabolic disturbances. Elevated renin-angiotensin system (RAS) and plasminogen activator inhibitor-1 (PAI-1) have also been implicated in the development of cardiometabolic events. To determine the effect of COC treatment on cardiac RAS and PAI-1 gene expressions, and whether the effect is circulating aldosterone or corticosterone dependent. Female rats were treated (p.o.) with olive oil (vehicle) or COC (1.0 µg ethinylestradiol and 10.0 µg norgestrel) daily for six weeks. COC treatment led to increases in blood pressure, HOMA-IR, Ace1 mRNA, Atr1 mRNA, Pai1 mRNA, cardiac PAI-1, plasma PAI-1, C-reactive protein, uric acid, insulin and corticosterone. COC treatment also led to dyslipidemia, decreased glucose tolerance and plasma 17β-estradiol. These results demonstrates that hypertension and insulin resistance induced by COC is associated with increased cardiac RAS and PAI-1 gene expression, which is likely to be through corticosterone-dependent but not aldosterone-dependent mechanism.

Gene therapy delivery systems for enhancing viral and nonviral vectors for cardiac diseases: current concepts and future applications.

PubMed

Katz, Michael G; Fargnoli, Anthony S; Williams, Richard D; Bridges, Charles R

2013-11-01

Gene therapy is one of the most promising fields for developing new treatments for the advanced stages of ischemic and monogenetic, particularly autosomal or X-linked recessive, cardiomyopathies. The remarkable ongoing efforts in advancing various targets have largely been inspired by the results that have been achieved in several notable gene therapy trials, such as the hemophilia B and Leber's congenital amaurosis. Rate-limiting problems preventing successful clinical application in the cardiac disease area, however, are primarily attributable to inefficient gene transfer, host responses, and the lack of sustainable therapeutic transgene expression. It is arguable that these problems are directly correlated with the choice of vector, dose level, and associated cardiac delivery approach as a whole treatment system. Essentially, a delicate balance exists in maximizing gene transfer required for efficacy while remaining within safety limits. Therefore, the development of safe, effective, and clinically applicable gene delivery techniques for selected nonviral and viral vectors will certainly be invaluable in obtaining future regulatory approvals. The choice of gene transfer vector, dose level, and the delivery system are likely to be critical determinants of therapeutic efficacy. It is here that the interactions between vector uptake and trafficking, delivery route means, and the host's physical limits must be considered synergistically for a successful treatment course.

Estrogen-Related Receptor α (ERRα) and ERRγ Are Essential Coordinators of Cardiac Metabolism and Function

PubMed Central

Wang, Ting; McDonald, Caitlin; Petrenko, Nataliya B.; Leblanc, Mathias; Wang, Tao; Giguere, Vincent; Evans, Ronald M.; Patel, Vickas V.

2015-01-01

Almost all cellular functions are powered by a continuous energy supply derived from cellular metabolism. However, it is little understood how cellular energy production is coordinated with diverse energy-consuming cellular functions. Here, using the cardiac muscle system, we demonstrate that nuclear receptors estrogen-related receptor α (ERRα) and ERRγ are essential transcriptional coordinators of cardiac energy production and consumption. On the one hand, ERRα and ERRγ together are vital for intact cardiomyocyte metabolism by directly controlling expression of genes important for mitochondrial functions and dynamics. On the other hand, ERRα and ERRγ influence major cardiomyocyte energy consumption functions through direct transcriptional regulation of key contraction, calcium homeostasis, and conduction genes. Mice lacking both ERRα and cardiac ERRγ develop severe bradycardia, lethal cardiomyopathy, and heart failure featuring metabolic, contractile, and conduction dysfunctions. These results illustrate that the ERR transcriptional pathway is essential to couple cellular energy metabolism with energy consumption processes in order to maintain normal cardiac function. PMID:25624346

Rescue of neonatal cardiac dysfunction in mice by administration of cardiac progenitor cells in utero

PubMed Central

Liu, Xiaoli; Hall, Sean R. R.; Wang, Zhihong; Huang, He; Ghanta, Sailaja; Di Sante, Moises; Leri, Annarosa; Anversa, Piero; Perrella, Mark A.

2015-01-01

Striated preferentially expressed gene (Speg) is a member of the myosin light chain kinase family. We previously showed that disruption of the Speg gene locus in mice leads to a dilated cardiomyopathy with immature-appearing cardiomyocytes. Here we show that cardiomyopathy of Speg−/− mice arises as a consequence of defects in cardiac progenitor cell (CPC) function, and that neonatal cardiac dysfunction can be rescued by in utero injections of wild-type CPCs into Speg−/− foetal hearts. CPCs harvested from Speg−/− mice display defects in clone formation, growth and differentiation into cardiomyocytes in vitro, which are associated with cardiac dysfunction in vivo. In utero administration of wild-type CPCs into the hearts of Speg−/− mice results in CPC engraftment, differentiation and myocardial maturation, which rescues Speg−/− mice from neonatal heart failure and increases the number of live births by fivefold. We propose that in utero administration of CPCs may have future implications for treatment of neonatal heart diseases. PMID:26593099

microRNA expression profiling in fetal single ventricle malformation identified by deep sequencing.

PubMed

Yu, Zhang-Bin; Han, Shu-Ping; Bai, Yun-Fei; Zhu, Chun; Pan, Ya; Guo, Xi-Rong

2012-01-01

microRNAs (miRNAs) have emerged as key regulators in many biological processes, particularly cardiac growth and development, although the specific miRNA expression profile associated with this process remains to be elucidated. This study aimed to characterize the cellular microRNA profile involved in the development of congenital heart malformation, through the investigation of single ventricle (SV) defects. Comprehensive miRNA profiling in human fetal SV cardiac tissue was performed by deep sequencing. Differential expression of 48 miRNAs was revealed by sequencing by oligonucleotide ligation and detection (SOLiD) analysis. Of these, 38 were down-regulated and 10 were up-regulated in differentiated SV cardiac tissue, compared to control cardiac tissue. This was confirmed by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis. Predicted target genes of the 48 differentially expressed miRNAs were analyzed by gene ontology and categorized according to cellular process, regulation of biological process and metabolic process. Pathway-Express analysis identified the WNT and mTOR signaling pathways as the most significant processes putatively affected by the differential expression of these miRNAs. The candidate genes involved in cardiac development were identified as potential targets for these differentially expressed microRNAs and the collaborative network of microRNAs and cardiac development related-mRNAs was constructed. These data provide the basis for future investigation of the mechanism of the occurrence and development of fetal SV malformations.

Transcriptional Regulation Patterns Revealed by High Resolution Chromatin Immunoprecipitation during Cardiac Hypertrophy*

PubMed Central

Sayed, Danish; He, Minzhen; Yang, Zhi; Lin, Lin; Abdellatif, Maha

2013-01-01

Cardiac hypertrophy is characterized by a generalized increase in gene expression that is commensurate with the increase in myocyte size and mass, on which is superimposed more robust changes in the expression of specialized genes. Both transcriptional and posttranscriptional mechanisms play fundamental roles in these processes; however, genome-wide characterization of the transcriptional changes has not been investigated. Our goal was to identify the extent and modes, RNA polymerase II (pol II) pausing versus recruitment, of transcriptional regulation underlying cardiac hypertrophy. We used anti-pol II and anti-histone H3K9-acetyl (H3K9ac) chromatin immunoprecipitation-deep sequencing to determine the extent of pol II recruitment and pausing, and the underlying epigenetic modifications, respectively, during cardiac growth. The data uniquely reveal two mutually exclusive modes of transcriptional regulation. One involves an incremental increase (30–50%) in the elongational activity of preassembled, promoter-paused, pol II, and encompasses ∼25% of expressed genes that are essential/housekeeping genes (e.g. RNA synthesis and splicing). Another involves a more robust activation via de novo pol II recruitment, encompassing ∼5% of specialized genes (e.g. contractile and extracellular matrix). Moreover, the latter subset has relatively shorter 3′-UTRs with fewer predicted targeting miRNA, whereas most miRNA targets fall in the former category, underscoring the significance of posttranscriptional regulation by miRNA. The results, for the first time, demonstrate that promoter-paused pol II plays a role in incrementally increasing housekeeping genes, proportionate to the increase in heart size. Additionally, the data distinguish between the roles of posttranscriptional versus transcriptional regulation of specific genes. PMID:23229551

Exploring Regulatory Mechanisms of Atrial Myocyte Hypertrophy of Mitral Regurgitation through Gene Expression Profiling Analysis: Role of NFAT in Cardiac Hypertrophy

PubMed Central

Chang, Tzu-Hao; Chen, Mien-Cheng; Chang, Jen-Ping; Huang, Hsien-Da; Ho, Wan-Chun; Lin, Yu-Sheng; Pan, Kuo-Li; Huang, Yao-Kuang; Liu, Wen-Hao; Wu, Chia-Chen

2016-01-01

Background Left atrial enlargement in mitral regurgitation (MR) predicts a poor prognosis. The regulatory mechanisms of atrial myocyte hypertrophy of MR patients remain unknown. Methods and Results This study comprised 14 patients with MR, 7 patients with aortic valve disease (AVD), and 6 purchased samples from normal subjects (NC). We used microarrays, enrichment analysis and quantitative RT-PCR to study the gene expression profiles in the left atria. Microarray results showed that 112 genes were differentially up-regulated and 132 genes were differentially down-regulated in the left atria between MR patients and NC. Enrichment analysis of differentially expressed genes demonstrated that “NFAT in cardiac hypertrophy” pathway was not only one of the significant associated canonical pathways, but also the only one predicted with a non-zero score of 1.34 (i.e. activated) through Ingenuity Pathway Analysis molecule activity predictor. Ingenuity Pathway Analysis Global Molecular Network analysis exhibited that the highest score network also showed high association with cardiac related pathways and functions. Therefore, 5 NFAT associated genes (PPP3R1, PPP3CB, CAMK1, MEF2C, PLCE1) were studies for validation. The mRNA expressions of PPP3CB and MEF2C were significantly up-regulated, and CAMK1 and PPP3R1 were significantly down-regulated in MR patients compared to NC. Moreover, MR patients had significantly increased mRNA levels of PPP3CB, MEF2C and PLCE1 compared to AVD patients. The atrial myocyte size of MR patients significantly exceeded that of the AVD patients and NC. Conclusions Differentially expressed genes in the “NFAT in cardiac hypertrophy” pathway may play a critical role in the atrial myocyte hypertrophy of MR patients. PMID:27907007

Global Gene Expression Profiling in PAI-1 Knockout Murine Heart and Kidney: Molecular Basis of Cardiac-Selective Fibrosis

PubMed Central

Ghosh, Asish K.; Murphy, Sheila B.; Kishore, Raj; Vaughan, Douglas E.

2013-01-01

Fibrosis is defined as an abnormal matrix remodeling due to excessive synthesis and accumulation of extracellular matrix proteins in tissues during wound healing or in response to chemical, mechanical and immunological stresses. At present, there is no effective therapy for organ fibrosis. Previous studies demonstrated that aged plasminogen activator inhibitor-1(PAI-1) knockout mice develop spontaneously cardiac-selective fibrosis without affecting any other organs. We hypothesized that differential expressions of profibrotic and antifibrotic genes in PAI-1 knockout hearts and unaffected organs lead to cardiac selective fibrosis. In order to address this prediction, we have used a genome-wide gene expression profiling of transcripts derived from aged PAI-1 knockout hearts and kidneys. The variations of global gene expression profiling were compared within four groups: wildtype heart vs. knockout heart; wildtype kidney vs. knockout kidney; knockout heart vs. knockout kidney and wildtype heart vs. wildtype kidney. Analysis of illumina-based microarray data revealed that several genes involved in different biological processes such as immune system processing, response to stress, cytokine signaling, cell proliferation, adhesion, migration, matrix organization and transcriptional regulation were affected in hearts and kidneys by the absence of PAI-1, a potent inhibitor of urokinase and tissue-type plasminogen activator. Importantly, the expressions of a number of genes, involved in profibrotic pathways including Ankrd1, Pi16, Egr1, Scx, Timp1, Timp2, Klf6, Loxl1 and Klotho, were deregulated in PAI-1 knockout hearts compared to wildtype hearts and PAI-1 knockout kidneys. While the levels of Ankrd1, Pi16 and Timp1 proteins were elevated during EndMT, the level of Timp4 protein was decreased. To our knowledge, this is the first comprehensive report on the influence of PAI-1 on global gene expression profiling in the heart and kidney and its implication in fibrogenesis and several other biological processes. The significance of these observations in the light of heart-specific profibrotic signaling and fibrogenesis are discussed. PMID:23724005

Quantitative determination of adenovirus-mediated gene delivery to rat cardiac myocytes in vitro and in vivo.

PubMed Central

Kass-Eisler, A; Falck-Pedersen, E; Alvira, M; Rivera, J; Buttrick, P M; Wittenberg, B A; Cipriani, L; Leinwand, L A

1993-01-01

To optimize the use of modified adenoviruses as vectors for gene delivery to the myocardium, we have characterized infection of cultured fetal and adult rat cardiac myocytes in vitro and of adult cardiac myocytes in vivo by using a replication-defective adenovirus carrying the chloramphenicol acetyltransferase (CAT) reporter gene driven by the cytomegalovirus promoter (AdCMVCATgD). In vitro, virtually all fetal or adult cardiocytes express the CAT gene when infected with 1 plaque-forming unit of virus per cell. CAT enzymatic activity can be detected in these cells as early as 4 hr after infection, reaching near-maximal levels at 48 hr. In fetal cells, CAT expression was maintained without a loss in activity for at least 1 week. Using in vitro studies as a guide, we introduced the AdCMVCATgD virus directly into adult rat myocardium and compared the expression results obtained from virus injection with those obtained by direct injection of pAdCMVCATgD plasmid DNA. The amount of CAT activity resulting from adenovirus infection of the myocardium was orders of magnitude higher than that seen from DNA injection and was proportional to the amount of input virus. Immunostaining for CAT protein in cardiac tissue sections following adenovirus injection demonstrated large numbers of positive cells, reaching nearly 100% of the myocytes in many regions of the heart. Expression of genes introduced by adenovirus peaked at 5 days but was still detectable 55 days following infection. Adenoviruses are therefore a very useful tool for high-efficiency gene transfer into the cardiovascular system. Images Fig. 1 Fig. 5 PMID:8265580

Transcriptomic alterations in the heart of non-obese type 2 diabetic Goto-Kakizaki rats.

PubMed

Sárközy, Márta; Szűcs, Gergő; Fekete, Veronika; Pipicz, Márton; Éder, Katalin; Gáspár, Renáta; Sója, Andrea; Pipis, Judit; Ferdinandy, Péter; Csonka, Csaba; Csont, Tamás

2016-08-05

There is a spectacular rise in the global prevalence of type 2 diabetes mellitus (T2DM) due to the worldwide obesity epidemic. However, a significant proportion of T2DM patients are non-obese and they also have an increased risk of cardiovascular diseases. As the Goto-Kakizaki (GK) rat is a well-known model of non-obese T2DM, the goal of this study was to investigate the effect of non-obese T2DM on cardiac alterations of the transcriptome in GK rats. Fasting blood glucose, serum insulin and cholesterol levels were measured at 7, 11, and 15 weeks of age in male GK and control rats. Oral glucose tolerance test and pancreatic insulin level measurements were performed at 11 weeks of age. At week 15, total RNA was isolated from the myocardium and assayed by rat oligonucleotide microarray for 41,012 genes, and then expression of selected genes was confirmed by qRT-PCR. Gene ontology and protein-protein network analyses were performed to demonstrate potentially characteristic gene alterations and key genes in non-obese T2DM. Fasting blood glucose, serum insulin and cholesterol levels were significantly increased, glucose tolerance and insulin sensitivity were significantly impaired in GK rats as compared to controls. In hearts of GK rats, 204 genes showed significant up-regulation and 303 genes showed down-regulation as compared to controls according to microarray analysis. Genes with significantly altered expression in the heart due to non-obese T2DM includes functional clusters of metabolism (e.g. Cyp2e1, Akr1b10), signal transduction (e.g. Dpp4, Stat3), receptors and ion channels (e.g. Sln, Chrng), membrane and structural proteins (e.g. Tnni1, Mylk2, Col8a1, Adam33), cell growth and differentiation (e.g. Gpc3, Jund), immune response (e.g. C3, C4a), and others (e.g. Lrp8, Msln, Klkc1, Epn3). Gene ontology analysis revealed several significantly enriched functional inter-relationships between genes influenced by non-obese T2DM. Protein-protein interaction analysis demonstrated that Stat is a potential key gene influenced by non-obese T2DM. Non-obese T2DM alters cardiac gene expression profile. The altered genes may be involved in the development of cardiac pathologies and could be potential therapeutic targets in non-obese T2DM.

Down-regulation of fibroblast growth factor 2 and its co-receptors heparan sulfate proteoglycans by resveratrol underlies the improvement of cardiac dysfunction in experimental diabetes.

PubMed

Strunz, Célia Maria Cássaro; Roggerio, Alessandra; Cruz, Paula Lázara; Pacanaro, Ana Paula; Salemi, Vera Maria Cury; Benvenuti, Luiz Alberto; Mansur, Antonio de Pádua; Irigoyen, Maria Cláudia

2017-02-01

Cardiac remodeling in diabetes involves cardiac hypertrophy and fibrosis, and fibroblast growth factor 2 (FGF2) is an important mediator of this process. Resveratrol, a polyphenolic antioxidant, reportedly promotes the improvement of cardiac dysfunction in diabetic rats. However, little information exists linking the amelioration of the cardiac function promoted by resveratrol and the expression of FGF2 and its co-receptors, heparan sulfate proteoglycans (HSPGs: Glypican-1 and Syndecan-4), in cardiac muscle of Type 2 diabetic rats. Diabetes was induced experimentally by the injection of streptozotocin and nicotinamide, and the rats were treated with resveratrol for 6 weeks. According to our results, there is an up-regulation of the expression of genes and/or proteins of Glypican-1, Syndecan-4, FGF2, peroxisome proliferator-activated receptor gamma and AMP-activated protein kinase in diabetic rats. On the other hand, resveratrol treatment promoted the attenuation of left ventricular diastolic dysfunction and the down-regulation of the expression of all proteins under study. The trigger for the changes in gene expression and protein synthesis promoted by resveratrol was the presence of diabetes. The negative modulation conducted by resveratrol on FGF2 and HSPGs expression, which are involved in cardiac remodeling, underlies the amelioration of cardiac function. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

The Potential Role of Aerobic Exercise to Modulate Cardiotoxicity of Molecularly Targeted Cancer Therapeutics

PubMed Central

Lakoski, Susan; Mackey, John R.; Douglas, Pamela S.; Haykowsky, Mark J.; Jones, Lee W.

2013-01-01

Molecularly targeted therapeutics (MTT) are the future of cancer systemic therapy. They have already moved from palliative therapy for advanced solid malignancies into the setting of curative-intent treatment for early-stage disease. Cardiotoxicity is a frequent and potentially serious adverse complication of some targeted therapies, leading to a broad range of potentially life-threatening complications, therapy discontinuation, and poor quality of life. Low-cost pleiotropic interventions are therefore urgently required to effectively prevent and/or treat MTT-induced cardiotoxicity. Aerobic exercise therapy has the unique capacity to modulate, without toxicity, multiple gene expression pathways in several organ systems, including a plethora of cardiac-specific molecular and cell-signaling pathways implicated in MTT-induced cardiac toxicity. In this review, we examine the molecular signaling of antiangiogenic and HER2-directed therapies that may underpin cardiac toxicity and the hypothesized molecular mechanisms underlying the cardioprotective properties of aerobic exercise. It is hoped that this knowledge can be used to maximize the benefits of small molecule inhibitors, while minimizing cardiac damage in patients with solid malignancies. PMID:23335619

CIP, a cardiac Isl1-interacting protein, represses cardiomyocyte hypertrophy

PubMed Central

Huang, Zhan-Peng; Seok, Hee Young; Zhou, Bin; Chen, Jinghai; Chen, Jian-Fu; Tao, Yazhong; Pu, William T.; Wang, Da-Zhi

2012-01-01

Rationale Mammalian heart has minimal regenerative capacity. In response to mechanical or pathological stress, the heart undergoes cardiac remodeling. Pressure and volume overload in the heart cause increased size (hypertrophic growth) of cardiomyocytes. Whereas the regulatory pathways that activate cardiac hypertrophy have been well established, the molecular events that inhibit or repress cardiac hypertrophy are less known. Objective To identify and investigate novel regulators that modulate cardiac hypertrophy. Methods and Results Here, we report the identification, characterization and functional examination of CIP, a novel cardiac Isl1-interacting protein. CIP was identified from a bioinformatic search for novel cardiac-expressed genes in mouse embryonic hearts. CIP encodes a nuclear protein without recognizable motifs. Northern blotting, in situ hybridization and reporter gene tracing demonstrated that CIP is highly expressed in cardiomyocytes of developing and adult hearts. Yeast-two-hybrid screening identified Isl1, a LIM/homeodomain transcription factor essential for the specification of cardiac progenitor cells in the second heart field, as a co-factor of CIP. CIP directly interacted with Isl1 and we mapped the domains of these two proteins which mediate their interaction. We show that CIP represses the transcriptional activity of Isl1 in the activation of the MEF2C enhancer. The expression of CIP was dramatically reduced in hypertrophic cardiomyocytes. Most importantly, overexpression of CIP repressed agonist-induced cardiomyocyte hypertrophy. Conclusions Our studies therefore identify CIP a novel regulator of cardiac hypertrophy. PMID:22343712

The NF-κB Subunit c-Rel Stimulates Cardiac Hypertrophy and Fibrosis

PubMed Central

Gaspar-Pereira, Silvia; Fullard, Nicola; Townsend, Paul A.; Banks, Paul S.; Ellis, Elizabeth L.; Fox, Christopher; Maxwell, Aidan G.; Murphy, Lindsay B.; Kirk, Adam; Bauer, Ralf; Caamaño, Jorge H.; Figg, Nichola; Foo, Roger S.; Mann, Jelena; Mann, Derek A.; Oakley, Fiona

2012-01-01

Cardiac remodeling and hypertrophy are the pathological consequences of cardiovascular disease and are correlated with its associated mortality. Activity of the transcription factor NF-κB is increased in the diseased heart; however, our present understanding of how the individual subunits contribute to cardiovascular disease is limited. We assign a new role for the c-Rel subunit as a stimulator of cardiac hypertrophy and fibrosis. We discovered that c-Rel-deficient mice have smaller hearts at birth, as well as during adulthood, and are protected from developing cardiac hypertrophy and fibrosis after chronic angiotensin infusion. Results of both gene expression and cross-linked chromatin immunoprecipitation assay analyses identified transcriptional activators of hypertrophy, myocyte enhancer family, Gata4, and Tbx proteins as Rel gene targets. We suggest that the p50 subunit could limit the prohypertrophic actions of c-Rel in the normal heart, because p50 overexpression in H9c2 cells repressed c-Rel levels and the absence of cardiac p50 was associated with increases in both c-Rel levels and cardiac hypertrophy. We report for the first time that c-Rel is highly expressed and confined to the nuclei of diseased adult human hearts but is restricted to the cytoplasm of normal cardiac tissues. We conclude that c-Rel-dependent signaling is critical for both cardiac remodeling and hypertrophy. Targeting its activities could offer a novel therapeutic strategy to limit the effects of cardiac disease. PMID:22210479

A data analysis framework for biomedical big data: Application on mesoderm differentiation of human pluripotent stem cells

PubMed Central

Karlsson, Alexander; Riveiro, Maria; Améen, Caroline; Åkesson, Karolina; Andersson, Christian X.; Sartipy, Peter; Synnergren, Jane

2017-01-01

The development of high-throughput biomolecular technologies has resulted in generation of vast omics data at an unprecedented rate. This is transforming biomedical research into a big data discipline, where the main challenges relate to the analysis and interpretation of data into new biological knowledge. The aim of this study was to develop a framework for biomedical big data analytics, and apply it for analyzing transcriptomics time series data from early differentiation of human pluripotent stem cells towards the mesoderm and cardiac lineages. To this end, transcriptome profiling by microarray was performed on differentiating human pluripotent stem cells sampled at eleven consecutive days. The gene expression data was analyzed using the five-stage analysis framework proposed in this study, including data preparation, exploratory data analysis, confirmatory analysis, biological knowledge discovery, and visualization of the results. Clustering analysis revealed several distinct expression profiles during differentiation. Genes with an early transient response were strongly related to embryonic- and mesendoderm development, for example CER1 and NODAL. Pluripotency genes, such as NANOG and SOX2, exhibited substantial downregulation shortly after onset of differentiation. Rapid induction of genes related to metal ion response, cardiac tissue development, and muscle contraction were observed around day five and six. Several transcription factors were identified as potential regulators of these processes, e.g. POU1F1, TCF4 and TBP for muscle contraction genes. Pathway analysis revealed temporal activity of several signaling pathways, for example the inhibition of WNT signaling on day 2 and its reactivation on day 4. This study provides a comprehensive characterization of biological events and key regulators of the early differentiation of human pluripotent stem cells towards the mesoderm and cardiac lineages. The proposed analysis framework can be used to structure data analysis in future research, both in stem cell differentiation, and more generally, in biomedical big data analytics. PMID:28654683

A data analysis framework for biomedical big data: Application on mesoderm differentiation of human pluripotent stem cells.

PubMed

Ulfenborg, Benjamin; Karlsson, Alexander; Riveiro, Maria; Améen, Caroline; Åkesson, Karolina; Andersson, Christian X; Sartipy, Peter; Synnergren, Jane

2017-01-01

The development of high-throughput biomolecular technologies has resulted in generation of vast omics data at an unprecedented rate. This is transforming biomedical research into a big data discipline, where the main challenges relate to the analysis and interpretation of data into new biological knowledge. The aim of this study was to develop a framework for biomedical big data analytics, and apply it for analyzing transcriptomics time series data from early differentiation of human pluripotent stem cells towards the mesoderm and cardiac lineages. To this end, transcriptome profiling by microarray was performed on differentiating human pluripotent stem cells sampled at eleven consecutive days. The gene expression data was analyzed using the five-stage analysis framework proposed in this study, including data preparation, exploratory data analysis, confirmatory analysis, biological knowledge discovery, and visualization of the results. Clustering analysis revealed several distinct expression profiles during differentiation. Genes with an early transient response were strongly related to embryonic- and mesendoderm development, for example CER1 and NODAL. Pluripotency genes, such as NANOG and SOX2, exhibited substantial downregulation shortly after onset of differentiation. Rapid induction of genes related to metal ion response, cardiac tissue development, and muscle contraction were observed around day five and six. Several transcription factors were identified as potential regulators of these processes, e.g. POU1F1, TCF4 and TBP for muscle contraction genes. Pathway analysis revealed temporal activity of several signaling pathways, for example the inhibition of WNT signaling on day 2 and its reactivation on day 4. This study provides a comprehensive characterization of biological events and key regulators of the early differentiation of human pluripotent stem cells towards the mesoderm and cardiac lineages. The proposed analysis framework can be used to structure data analysis in future research, both in stem cell differentiation, and more generally, in biomedical big data analytics.

Identification of a Novel GLA Gene Mutation, p.Ile239Met, in Fabry Disease With a Predominant Cardiac Phenotype.

PubMed

Csányi, Beáta; Hategan, Lidia; Nagy, Viktória; Obál, Izabella; Varga, Edina T; Borbás, János; Tringer, Annamária; Eichler, Sabrina; Forster, Tamás; Rolfs, Arndt; Sepp, Róbert

2017-05-31

Fabry disease (FD) is an X-linked inherited lysosomal storage disorder caused by mutations in the GLA gene, encoding for the enzyme α-galactosidase A. Although hundreds of mutations in the GLA gene have been described, many of them are variants of unknown significance. Here we report a novel GLA mutation, p.Ile239Met, identified in a large Hungarian three-generation family with FD. A 69 year-old female index patient with a clinical history of renal failure, hypertrophic cardiomyopathy, and 2nd degree AV block was screened for mutation in the GLA gene. Genetic screening identified a previously unreported heterozygous mutation in exon 5 of the GLA gene (c.717A>G; p.Ile239Met). Family screening indicated that altogether 6 family members carried the mutation (5 females, 1 male, average age: 55 ± 16 years). Three family members, including the index patient, manifested the cardiac phenotype of hypertrophic cardiomyopathy, while two other family members were diagnosed with left ventricular hypertrophy. Taking affection status as the presence of hypertrophic cardiomyopathy, left ventricular hypertrophy or elevated lyso-Gb3 levels, all affected family members carried the mutation. Linkage analysis of the family gave a two-point LOD score of 2.01 between the affection status and the p.Ile239Met GLA mutation. Lyso-Gb3 levels were elevated in all carrier family members (range: 2.4-13.8 ng/mL; upper limit of normal +2STD: ≤ 1.8 ng/mL). The GLA enzyme level was markedly reduced in the affected male family member (< 0.2 µmol/L/hour; upper limit of normal ± 2STD: ≥ 2.6 µmol/L/hour). We conclude that the p. Ile239Met GLA mutation is a pathogenic mutation for FD associated with predominant cardiac phenotype.

The Popeye domain containing 2 (popdc2) gene in zebrafish is required for heart and skeletal muscle development

PubMed Central

Kirchmaier, Bettina C.; Poon, Kar Lai; Schwerte, Thorsten; Huisken, Jan; Winkler, Christoph; Jungblut, Benno; Stainier, Didier Y.; Brand, Thomas

2013-01-01

The Popeye domain containing (Popdc) genes encode a family of transmembrane proteins with an evolutionary conserved Popeye domain. These genes are abundantly expressed in striated muscle tissue, however their function is not well understood. In this study we have investigated the role of the popdc2 gene in zebrafish. Popdc2 transcripts were detected in the embryonic myocardium and transiently in the craniofacial and tail musculature. Morpholino oligonucleotide-mediated knockdown of popdc2 resulted in aberrant development of skeletal muscle and heart. Muscle segments in the trunk were irregularly shaped and craniofacial muscles were severely reduced or even missing. In the heart, pericardial edema was prevalent in the morphants and heart chambers were elongated and looping was abnormal. These pathologies in muscle and heart were alleviated after reducing the morpholino concentration. However the heart still was abnormal displaying cardiac arrhythmia at later stages of development. Optical recordings of cardiac contractility revealed irregular ventricular contractions with a 2:1, or 3:1 atrial/ventricular conduction ratio, which caused a significant reduction in heart frequency. Recordings of calcium transients with high spatiotemporal resolution using a transgenic calcium indicator line (Tg(cmlc2:gCaMP)s878) and SPIM microscopy confirmed the presence of a severe arrhythmia phenotype. Our results identify popdc2 as a gene important for striated muscle differentiation and cardiac morphogenesis. In addition it is required for the development of the cardiac conduction system. PMID:22290329

Translating golden retriever muscular dystrophy microarray findings to novel biomarkers for cardiac/skeletal muscle function in Duchenne muscular dystrophy.

PubMed

Galindo, Cristi L; Soslow, Jonathan H; Brinkmeyer-Langford, Candice L; Gupte, Manisha; Smith, Holly M; Sengsayadeth, Seng; Sawyer, Douglas B; Benson, D Woodrow; Kornegay, Joe N; Markham, Larry W

2016-04-01

In Duchenne muscular dystrophy (DMD), abnormal cardiac function is typically preceded by a decade of skeletal muscle disease. Molecular reasons for differences in onset and progression of these muscle groups are unknown. Human biomarkers are lacking. We analyzed cardiac and skeletal muscle microarrays from normal and golden retriever muscular dystrophy (GRMD) dogs (ages 6, 12, or 47+ mo) to gain insight into muscle dysfunction and to identify putative DMD biomarkers. These biomarkers were then measured using human DMD blood samples. We identified GRMD candidate genes that might contribute to the disparity between cardiac and skeletal muscle disease, focusing on brain-derived neurotropic factor (BDNF) and osteopontin (OPN/SPP1, hereafter indicated as SPP1). BDNF was elevated in cardiac muscle of younger GRMD but was unaltered in skeletal muscle, while SPP1 was increased only in GRMD skeletal muscle. In human DMD, circulating levels of BDNF were inversely correlated with ventricular function and fibrosis, while SPP1 levels correlated with skeletal muscle function. These results highlight gene expression patterns that could account for differences in cardiac and skeletal disease in GRMD. Most notably, animal model-derived data were translated to DMD and support use of BDNF and SPP1 as biomarkers for cardiac and skeletal muscle involvement, respectively.

MiR-133 promotes cardiac reprogramming by directly repressing Snai1 and silencing fibroblast signatures.

PubMed

Muraoka, Naoto; Yamakawa, Hiroyuki; Miyamoto, Kazutaka; Sadahiro, Taketaro; Umei, Tomohiko; Isomi, Mari; Nakashima, Hanae; Akiyama, Mizuha; Wada, Rie; Inagawa, Kohei; Nishiyama, Takahiko; Kaneda, Ruri; Fukuda, Toru; Takeda, Shu; Tohyama, Shugo; Hashimoto, Hisayuki; Kawamura, Yoshifumi; Goshima, Naoki; Aeba, Ryo; Yamagishi, Hiroyuki; Fukuda, Keiichi; Ieda, Masaki

2014-07-17

Fibroblasts can be directly reprogrammed into cardiomyocyte-like cells (iCMs) by overexpression of cardiac transcription factors or microRNAs. However, induction of functional cardiomyocytes is inefficient, and molecular mechanisms of direct reprogramming remain undefined. Here, we demonstrate that addition of miR-133a (miR-133) to Gata4, Mef2c, and Tbx5 (GMT) or GMT plus Mesp1 and Myocd improved cardiac reprogramming from mouse or human fibroblasts by directly repressing Snai1, a master regulator of epithelial-to-mesenchymal transition. MiR-133 overexpression with GMT generated sevenfold more beating iCMs from mouse embryonic fibroblasts and shortened the duration to induce beating cells from 30 to 10 days, compared to GMT alone. Snai1 knockdown suppressed fibroblast genes, upregulated cardiac gene expression, and induced more contracting iCMs with GMT transduction, recapitulating the effects of miR-133 overexpression. In contrast, overexpression of Snai1 in GMT/miR-133-transduced cells maintained fibroblast signatures and inhibited generation of beating iCMs. MiR-133-mediated Snai1 repression was also critical for cardiac reprogramming in adult mouse and human cardiac fibroblasts. Thus, silencing fibroblast signatures, mediated by miR-133/Snai1, is a key molecular roadblock during cardiac reprogramming. © 2014 The Authors.

MiR-133 promotes cardiac reprogramming by directly repressing Snai1 and silencing fibroblast signatures

PubMed Central

Muraoka, Naoto; Yamakawa, Hiroyuki; Miyamoto, Kazutaka; Sadahiro, Taketaro; Umei, Tomohiko; Isomi, Mari; Nakashima, Hanae; Akiyama, Mizuha; Wada, Rie; Inagawa, Kohei; Nishiyama, Takahiko; Kaneda, Ruri; Fukuda, Toru; Takeda, Shu; Tohyama, Shugo; Hashimoto, Hisayuki; Kawamura, Yoshifumi; Goshima, Naoki; Aeba, Ryo; Yamagishi, Hiroyuki; Fukuda, Keiichi; Ieda, Masaki

2014-01-01

Fibroblasts can be directly reprogrammed into cardiomyocyte-like cells (iCMs) by overexpression of cardiac transcription factors or microRNAs. However, induction of functional cardiomyocytes is inefficient, and molecular mechanisms of direct reprogramming remain undefined. Here, we demonstrate that addition of miR-133a (miR-133) to Gata4, Mef2c, and Tbx5 (GMT) or GMT plus Mesp1 and Myocd improved cardiac reprogramming from mouse or human fibroblasts by directly repressing Snai1, a master regulator of epithelial-to-mesenchymal transition. MiR-133 overexpression with GMT generated sevenfold more beating iCMs from mouse embryonic fibroblasts and shortened the duration to induce beating cells from 30 to 10 days, compared to GMT alone. Snai1 knockdown suppressed fibroblast genes, upregulated cardiac gene expression, and induced more contracting iCMs with GMT transduction, recapitulating the effects of miR-133 overexpression. In contrast, overexpression of Snai1 in GMT/miR-133-transduced cells maintained fibroblast signatures and inhibited generation of beating iCMs. MiR-133-mediated Snai1 repression was also critical for cardiac reprogramming in adult mouse and human cardiac fibroblasts. Thus, silencing fibroblast signatures, mediated by miR-133/Snai1, is a key molecular roadblock during cardiac reprogramming. PMID:24920580

Single-Construct Polycistronic Doxycycline-Inducible Vectors Improve Direct Cardiac Reprogramming and Can Be Used to Identify the Critical Timing of Transgene Expression.

PubMed

Umei, Tomohiko C; Yamakawa, Hiroyuki; Muraoka, Naoto; Sadahiro, Taketaro; Isomi, Mari; Haginiwa, Sho; Kojima, Hidenori; Kurotsu, Shota; Tamura, Fumiya; Osakabe, Rina; Tani, Hidenori; Nara, Kaori; Miyoshi, Hiroyuki; Fukuda, Keiichi; Ieda, Masaki

2017-08-19

Direct reprogramming is a promising approach in regenerative medicine. Overexpression of the cardiac transcription factors Gata4, Mef2c, and Tbx5 (GMT) or GMT plus Hand2 (GHMT) directly reprogram fibroblasts into cardiomyocyte-like cells (iCMs). However, the critical timing of transgene expression and the molecular mechanisms for cardiac reprogramming remain unclear. The conventional doxycycline (Dox)-inducible temporal transgene expression systems require simultaneous transduction of two vectors (pLVX-rtTA/pLVX-cDNA) harboring the reverse tetracycline transactivator (rtTA) and the tetracycline response element (TRE)-controlled transgene, respectively, leading to inefficient cardiac reprogramming. Herein, we developed a single-construct-based polycistronic Dox-inducible vector (pDox-cDNA) expressing both the rtTA and TRE-controlled transgenes. Fluorescence activated cell sorting (FACS) analyses, quantitative RT-PCR, and immunostaining revealed that pDox-GMT increased cardiac reprogramming three-fold compared to the conventional pLVX-rtTA/pLVX-GMT. After four weeks, pDox-GMT-induced iCMs expressed multiple cardiac genes, produced sarcomeric structures, and beat spontaneously. Co-transduction of pDox-Hand2 with retroviral pMX-GMT increased cardiac reprogramming three-fold compared to pMX-GMT alone. Temporal Dox administration revealed that Hand2 transgene expression is critical during the first two weeks of cardiac reprogramming. Microarray analyses demonstrated that Hand2 represses cell cycle-promoting genes and enhances cardiac reprogramming. Thus, we have developed an efficient temporal transgene expression system, which could be invaluable in the study of cardiac reprogramming.

Single-Construct Polycistronic Doxycycline-Inducible Vectors Improve Direct Cardiac Reprogramming and Can Be Used to Identify the Critical Timing of Transgene Expression

PubMed Central

Umei, Tomohiko C.; Yamakawa, Hiroyuki; Muraoka, Naoto; Sadahiro, Taketaro; Isomi, Mari; Haginiwa, Sho; Kojima, Hidenori; Kurotsu, Shota; Tamura, Fumiya; Osakabe, Rina; Tani, Hidenori; Nara, Kaori; Miyoshi, Hiroyuki; Fukuda, Keiichi; Ieda, Masaki

2017-01-01

Direct reprogramming is a promising approach in regenerative medicine. Overexpression of the cardiac transcription factors Gata4, Mef2c, and Tbx5 (GMT) or GMT plus Hand2 (GHMT) directly reprogram fibroblasts into cardiomyocyte-like cells (iCMs). However, the critical timing of transgene expression and the molecular mechanisms for cardiac reprogramming remain unclear. The conventional doxycycline (Dox)-inducible temporal transgene expression systems require simultaneous transduction of two vectors (pLVX-rtTA/pLVX-cDNA) harboring the reverse tetracycline transactivator (rtTA) and the tetracycline response element (TRE)-controlled transgene, respectively, leading to inefficient cardiac reprogramming. Herein, we developed a single-construct-based polycistronic Dox-inducible vector (pDox-cDNA) expressing both the rtTA and TRE-controlled transgenes. Fluorescence activated cell sorting (FACS) analyses, quantitative RT-PCR, and immunostaining revealed that pDox-GMT increased cardiac reprogramming three-fold compared to the conventional pLVX-rtTA/pLVX-GMT. After four weeks, pDox-GMT-induced iCMs expressed multiple cardiac genes, produced sarcomeric structures, and beat spontaneously. Co-transduction of pDox-Hand2 with retroviral pMX-GMT increased cardiac reprogramming three-fold compared to pMX-GMT alone. Temporal Dox administration revealed that Hand2 transgene expression is critical during the first two weeks of cardiac reprogramming. Microarray analyses demonstrated that Hand2 represses cell cycle-promoting genes and enhances cardiac reprogramming. Thus, we have developed an efficient temporal transgene expression system, which could be invaluable in the study of cardiac reprogramming. PMID:28825623

Single allele Lmbrd1 knockout results in cardiac hypertrophy.

PubMed

Tseng, Linda Tzu-Ling; Lin, Chieh-Liang; Pan, Kuei-Hsiang; Tzen, Kai-Yuan; Su, Ming-Jai; Tsai, Chia-Ti; Li, Yi-Han; Li, Pai-Chi; Chiang, Fu-Tien; Chang, Shin C; Chang, Ming-Fu

2018-06-01

LMBD1 protein, a type IV-B plasma membrane protein possessing nine putative trans-membrane domains, was previously demonstrated at cellular level to play a critical part in the signaling cascade of insulin receptor through its involvement in regulating clathrin-mediated endocytosis. However, at physiological level, the significance of LMBD1 protein in cardiac development remains unclear. To understand the role of Lmbrd1 gene involved in the cardiac function, heterozygous knockout mice were used as an animal model system. The pathological outcomes were analyzed by micro-positron emission tomography, ECG acquisition, cardiac ultrasound, and immunohistochemistry. By studying the heterozygous knockout of Lmbrd1 (Lmbrd1 +/- ), we discovered that lack of Lmbrd1 not only resulted in the increase of cardiac-glucose uptake, pathological consequences were also observed. Here, we have distinguished that Lmbrd1 +/- is sufficient in causing cardiac diseases through a pathway independent of the recessive vitamin B 12 cblF cobalamin transport defect. Lmbrd1 +/- mice exhibited an increase in myocardial glucose uptake and insulin receptor signaling that is insensitive to the administration of additional insulin. Pathological symptoms such as cardiac hypertrophy, ventricular tissue fibrosis, along with the increase of heart rate and cardiac muscle contractility were observed. As Lmbrd1 +/- mice aged, the decrease in ejection fraction and fraction shortening showed signs of ventricular function deterioration. The results suggested that Lmbrd1 gene not only plays a significant role in mediating the energy homeostasis in cardiac tissue, it may also be a key factor in the regulation of cardiac function in mice. Copyright © 2017. Published by Elsevier B.V.

Mediator complex dependent regulation of cardiac development and disease.

PubMed

Grueter, Chad E

2013-06-01

Cardiovascular disease (CVD) is a leading cause of morbidity and mortality. The risk factors for CVD include environmental and genetic components. Human mutations in genes involved in most aspects of cardiovascular function have been identified, many of which are involved in transcriptional regulation. The Mediator complex serves as a pivotal transcriptional regulator that functions to integrate diverse cellular signals by multiple mechanisms including recruiting RNA polymerase II, chromatin modifying proteins and non-coding RNAs to promoters in a context dependent manner. This review discusses components of the Mediator complex and the contribution of the Mediator complex to normal and pathological cardiac development and function. Enhanced understanding of the role of this core transcriptional regulatory complex in the heart will help us gain further insights into CVD. Copyright © 2013. Production and hosting by Elsevier Ltd.

Tauroursodeoxycholic acid (TUDCA) attenuates pressure overload-induced cardiac remodeling by reducing endoplasmic reticulum stress

PubMed Central

Rani, Shilpa; Sreenivasaiah, Pradeep Kumar; Kim, Jin Ock; Lee, Mi Young; Kang, Wan Seok; Kim, Yong Sook; Ahn, Youngkeun; Park, Woo Jin; Cho, Chunghee

2017-01-01

Pressure overload in the heart induces pathological hypertrophy and is associated with cardiac dysfunction. Apoptosis and fibrosis signaling initiated by the endoplasmic reticulum stress (ERS) is known to contribute to these maladaptive effects. The aim of this study was to investigate whether reduction of ERS by a known chemical chaperone, tauroursodeoxycholic acid (TUDCA) can attenuate pressure overload-induced cardiac remodeling in a mouse model of transverse aortic constriction (TAC). Oral administration of TUDCA at a dose of 300 mg/kg body weight (BW) in the TUDCA-TAC group reduced ERS markers (GRP78, p-PERK, and p-eIf2α), compared to the Vehicle (Veh)-TAC group. TUDCA administration, for 4 weeks after TAC significantly reduced cardiac hypertrophy as shown by the reduced heart weight (HW) to BW ratio, and expression of hypertrophic marker genes (ANF, BNP, and α-SKA). Masson's trichrome staining showed that myocardial fibrosis and collagen deposition were also significantly reduced in the TUDCA-TAC group. We also found that TUDCA significantly decreased expression of TGF-β signaling proteins and collagen isoforms. TUDCA administration also reduced cardiac apoptosis and the related proteins in the TUDCA-TAC group. Microarray analysis followed by gene ontology (GO) and pathway analysis demonstrated that extracellular matrix genes responsible for hypertrophy and fibrosis, and mitochondrial genes responsible for apoptosis and fatty acid metabolism were significantly altered in the Veh-TAC group, but the alterations were normalized in the TUDCA-TAC group, suggesting potential of TUDCA in treatment of heart diseases related to pressure-overload. PMID:28426781

[Lead compound optimization strategy(5) – reducing the hERG cardiac toxicity in drug development].

PubMed

Zhou, Sheng-bin; Wang, Jiang; Liu, Hong

2016-10-01

The potassium channel encoded by the human ether-a-go-go related gene(hERG) plays a very important role in the physiological and pathological processes in human. hERG potassium channel determines the outward currents which facilitate the repolarization of the myocardial cells. Some drugs were withdrawn from the market for the serious side effect of long QT interval and arrhythmia due to blockade of hERG channel. The strategies for lead compound optimization are to reduce inhibitory activity of hERG potassium channel and decrease cardiac toxicity. These methods include reduction of lipophilicity and basicity of amines, introduction of hydroxyl and acidic groups, and restricting conformation.

The UNC-45 Chaperone Is Critical for Establishing Myosin-Based Myofibrillar Organization and Cardiac Contractility in the Drosophila Heart Model

PubMed Central

Melkani, Girish C.; Bodmer, Rolf; Ocorr, Karen; Bernstein, Sanford I.

2011-01-01

UNC-45 is a UCS (UNC-45/CRO1/She4P) class chaperone necessary for myosin folding and/or accumulation, but its requirement for maintaining cardiac contractility has not been explored. Given the prevalence of myosin mutations in eliciting cardiomyopathy, chaperones like UNC-45 are likely to be equally critical in provoking or modulating myosin-associated cardiomyopathy. Here, we used the Drosophila heart model to examine its role in cardiac physiology, in conjunction with RNAi-mediated gene silencing specifically in the heart in vivo. Analysis of cardiac physiology was carried out using high-speed video recording in conjunction with movement analysis algorithms. unc-45 knockdown resulted in severely compromised cardiac function in adults as evidenced by prolonged diastolic and systolic intervals, and increased incidence of arrhythmias and extreme dilation; the latter was accompanied by a significant reduction in muscle contractility. Structural analysis showed reduced myofibrils, myofibrillar disarray, and greatly decreased cardiac myosin accumulation. Cardiac unc-45 silencing also dramatically reduced life-span. In contrast, third instar larval and young pupal hearts showed mild cardiac abnormalities, as severe cardiac defects only developed during metamorphosis. Furthermore, cardiac unc-45 silencing in the adult heart (after metamorphosis) led to less severe phenotypes. This suggests that UNC-45 is mostly required for myosin accumulation/folding during remodeling of the forming adult heart. The cardiac defects, myosin deficit and decreased life-span in flies upon heart-specific unc-45 knockdown were significantly rescued by UNC-45 over-expression. Our results are the first to demonstrate a cardiac-specific requirement of a chaperone in Drosophila, suggestive of a critical role of UNC-45 in cardiomyopathies, including those associated with unfolded proteins in the failing human heart. The dilated cardiomyopathy phenotype associated with UNC-45 deficiency is mimicked by myosin knockdown suggesting that UNC-45 plays a crucial role in stabilizing myosin and possibly preventing human cardiomyopathies associated with functional deficiencies of myosin. PMID:21799905

An abundant tissue macrophage population in the adult murine heart with a distinct alternatively-activated macrophage profile.

PubMed

Pinto, Alexander R; Paolicelli, Rosa; Salimova, Ekaterina; Gospocic, Janko; Slonimsky, Esfir; Bilbao-Cortes, Daniel; Godwin, James W; Rosenthal, Nadia A

2012-01-01

Cardiac tissue macrophages (cTMs) are a previously uncharacterised cell type that we have identified and characterise here as an abundant GFP(+) population within the adult Cx(3)cr1(GFP/+) knock-in mouse heart. They comprise the predominant myeloid cell population in the myocardium, and are found throughout myocardial interstitial spaces interacting directly with capillary endothelial cells and cardiomyocytes. Flow cytometry-based immunophenotyping shows that cTMs exhibit canonical macrophage markers. Gene expression analysis shows that cTMs (CD45(+)CD11b(+)GFP(+)) are distinct from mononuclear CD45(+)CD11b(+)GFP(+) cells sorted from the spleen and brain of adult Cx(3)cr1(GFP/+) mice. Gene expression profiling reveals that cTMs closely resemble alternatively-activated anti-inflammatory M2 macrophages, expressing a number of M2 markers, including Mrc1, CD163, and Lyve-1. While cTMs perform normal tissue macrophage homeostatic functions, they also exhibit a distinct phenotype, involving secretion of salutary factors (including IGF-1) and immune modulation. In summary, the characterisation of cTMs at the cellular and molecular level defines a potentially important role for these cells in cardiac homeostasis.

Chronic sustained inflammation links to left ventricular hypertrophy and aortic valve sclerosis: a new link between S100/RAGE and FGF23.

PubMed

Yan, Ling; Bowman, Marion A Hofmann

Cardiovascular disease including left ventricular hypertrophy, diastolic dysfunction and ectopic valvular calcification are common in patients with chronic kidney disease (CKD). Both S100A12 and fibroblast growth factor 23 (FGF23) have been identified as biomarkers of cardiovascular morbidity and mortality in patients with CKD. We tested the hypothesis that human S100/calgranulin would accelerate cardiovascular disease in mice subjected to CKD. This review paper focuses on S100 proteins and their receptor for advanced glycation end products (RAGE) and summarizes recent findings obtained in novel developed transgenic hBAC-S100 mice that express S100A12 and S100A8/9 proteins. A bacterial artificial chromosome of the human S100/calgranulin gene cluster containing the genes and regulatory elements for S100A8, S100A9 and S100A12 was expressed in C57BL/6J mice (hBAC-S100). CKD was induced by ureteral ligation, and hBAC-S100 mice and WT mice were studied after 10 weeks of chronic uremia. hBAC-S100 mice with CKD showed increased FGF23 in the heart, left ventricular hypertrophy (LVH), diastolic dysfunction, focal cartilaginous metaplasia and calcification of the mitral and aortic valve annulus together with aortic valve sclerosis. This phenotype was not observed in WT mice with CKD or in hBAC-S100 mice lacking RAGE with CKD, suggesting that the inflammatory milieu mediated by S100/RAGE promotes pathological cardiac hypertrophy in CKD. In vitro, inflammatory stimuli including IL-6, TNFα, LPS, or serum from hBAC-S100 mice up regulated FGF23 mRNA and protein in primary murine neonatal and adult cardiac fibroblasts. Taken together, our study shows that myeloid-derived human S100/calgranulin is associated with the development of cardiac hypertrophy and ectopic cardiac calcification in a RAGE dependent manner in a mouse model of CKD. We speculate that FGF23 produced by cardiac fibroblasts in response to cytokines may act in a paracrine manner to accelerate LVH and diastolic dysfunction in hBAC-S100 mice with CKD. We suggest that S100/RAGE-mediated chronic sustained systemic inflammation is linked to pathological cardiac remodeling via direct up regulation of FGF23 in cardiac fibroblasts, thereby providing a new mechanistic understanding for the common association between CKD, diabetes, metabolic syndrome, or hypertension with left ventricular hypertrophy with diastolic dysfunction.

TGF-β Polymorphisms Are a Risk Factor for Chagas Disease

PubMed Central

Ferreira, Roberto Rodrigues; Madeira, Fabiana da Silva; Alves, Gabriel Farias; Chambela, Mayara da Costa; Curvo, Eduardo de Oliveira Vaz; Moreira, Aline dos Santos; Almeida de Sá, Renata; Cabello, Pedro Hernan; Bailly, Sabine; Araujo-Jorge, Tania Cremonini; Saraiva, Roberto Magalhães

2018-01-01

Transforming growth factor β1 (TGF-β1) is an important mediator in Chagas disease. Furthermore, patients with higher TGF-β1 serum levels show a worse clinical outcome. Gene polymorphism may account for differences in cytokine production during infectious diseases. We tested whether TGFB1 polymorphisms could be associated with Chagas disease susceptibility and severity in a Brazilian population. We investigated five single-nucleotide polymorphisms (−800 G>A, −509 C>T, +10 T>C, +25 G>C, and +263 C>T). 152 patients with Chagas disease (53 with the indeterminate form and 99 with the cardiac form) and 48 noninfected subjects were included. Genotypes CT and TT at position −509 of the TGFB1 gene were more frequent in Chagas disease patients than in noninfected subjects. Genotypes TC and CC at codon +10 of the TGFB1 gene were also more frequent in Chagas disease patients than in noninfected subjects. We found no significant differences in the distribution of the studied TGFB1 polymorphisms between patients with the indeterminate or cardiac form of Chagas disease. Therefore, −509 C>T and +10 T>C TGFB1 polymorphisms are associated with Chagas disease susceptibility in a Brazilian population. PMID:29670670

TGF-β Polymorphisms Are a Risk Factor for Chagas Disease.

PubMed

Ferreira, Roberto Rodrigues; Madeira, Fabiana da Silva; Alves, Gabriel Farias; Chambela, Mayara da Costa; Curvo, Eduardo de Oliveira Vaz; Moreira, Aline Dos Santos; Almeida de Sá, Renata; Mendonça-Lima, Leila; Cabello, Pedro Hernan; Bailly, Sabine; Feige, Jean-Jacques; Araujo-Jorge, Tania Cremonini; Saraiva, Roberto Magalhães; Waghabi, Mariana Caldas

2018-01-01

Transforming growth factor β 1 (TGF- β 1) is an important mediator in Chagas disease. Furthermore, patients with higher TGF- β 1 serum levels show a worse clinical outcome. Gene polymorphism may account for differences in cytokine production during infectious diseases. We tested whether TGFB1 polymorphisms could be associated with Chagas disease susceptibility and severity in a Brazilian population. We investigated five single-nucleotide polymorphisms (-800 G>A, -509 C>T, +10 T>C, +25 G>C, and +263 C>T). 152 patients with Chagas disease (53 with the indeterminate form and 99 with the cardiac form) and 48 noninfected subjects were included. Genotypes CT and TT at position -509 of the TGFB1 gene were more frequent in Chagas disease patients than in noninfected subjects. Genotypes TC and CC at codon +10 of the TGFB1 gene were also more frequent in Chagas disease patients than in noninfected subjects. We found no significant differences in the distribution of the studied TGFB1 polymorphisms between patients with the indeterminate or cardiac form of Chagas disease. Therefore, -509 C>T and +10 T>C TGFB1 polymorphisms are associated with Chagas disease susceptibility in a Brazilian population.

Development of the cardiac pacemaker

PubMed Central

Liang, Xingqun; Evans, Sylvia M.

2017-01-01

The sinoatrial node (SAN) is the dominant pacemaker of the heart. Abnormalities in SAN formation and function can cause sinus arrhythmia, including sick sinus syndrome and sudden death. A better understanding of genes and signaling pathways that regulate SAN development and function is essential to develop more effective treatment to sinus arrhythmia, including biological pacemakers. In this review, we briefly summarize the key processes of SAN morphogenesis during development, and focus on the transcriptional network that drives SAN development. PMID:27770149

The transcriptional activator ZNF143 is essential for normal development in zebrafish

PubMed Central

2012-01-01

Background ZNF143 is a sequence-specific DNA-binding protein that stimulates transcription of both small RNA genes by RNA polymerase II or III, or protein-coding genes by RNA polymerase II, using separable activating domains. We describe phenotypic effects following knockdown of this protein in developing Danio rerio (zebrafish) embryos by injection of morpholino antisense oligonucleotides that target znf143 mRNA. Results The loss of function phenotype is pleiotropic and includes a broad array of abnormalities including defects in heart, blood, ear and midbrain hindbrain boundary. Defects are rescued by coinjection of synthetic mRNA encoding full-length ZNF143 protein, but not by protein lacking the amino-terminal activation domains. Accordingly, expression of several marker genes is affected following knockdown, including GATA-binding protein 1 (gata1), cardiac myosin light chain 2 (cmlc2) and paired box gene 2a (pax2a). The zebrafish pax2a gene proximal promoter contains two binding sites for ZNF143, and reporter gene transcription driven by this promoter in transfected cells is activated by this protein. Conclusions Normal development of zebrafish embryos requires ZNF143. Furthermore, the pax2a gene is probably one example of many protein-coding gene targets of ZNF143 during zebrafish development. PMID:22268977

The transcriptional activator ZNF143 is essential for normal development in zebrafish.

PubMed

Halbig, Kari M; Lekven, Arne C; Kunkel, Gary R

2012-01-23

ZNF143 is a sequence-specific DNA-binding protein that stimulates transcription of both small RNA genes by RNA polymerase II or III, or protein-coding genes by RNA polymerase II, using separable activating domains. We describe phenotypic effects following knockdown of this protein in developing Danio rerio (zebrafish) embryos by injection of morpholino antisense oligonucleotides that target znf143 mRNA. The loss of function phenotype is pleiotropic and includes a broad array of abnormalities including defects in heart, blood, ear and midbrain hindbrain boundary. Defects are rescued by coinjection of synthetic mRNA encoding full-length ZNF143 protein, but not by protein lacking the amino-terminal activation domains. Accordingly, expression of several marker genes is affected following knockdown, including GATA-binding protein 1 (gata1), cardiac myosin light chain 2 (cmlc2) and paired box gene 2a (pax2a). The zebrafish pax2a gene proximal promoter contains two binding sites for ZNF143, and reporter gene transcription driven by this promoter in transfected cells is activated by this protein. Normal development of zebrafish embryos requires ZNF143. Furthermore, the pax2a gene is probably one example of many protein-coding gene targets of ZNF143 during zebrafish development.

Large-scale genome-wide analysis identifies genetic variants associated with cardiac structure and function

PubMed Central

Wild, Philipp S.; Felix, Janine F.; Schillert, Arne; Chen, Ming-Huei; Leening, Maarten J.G.; Völker, Uwe; Großmann, Vera; Brody, Jennifer A.; Irvin, Marguerite R.; Shah, Sanjiv J.; Pramana, Setia; Lieb, Wolfgang; Schmidt, Reinhold; Stanton, Alice V.; Malzahn, Dörthe; Lyytikäinen, Leo-Pekka; Tiller, Daniel; Smith, J. Gustav; Di Tullio, Marco R.; Musani, Solomon K.; Morrison, Alanna C.; Pers, Tune H.; Morley, Michael; Kleber, Marcus E.; Aragam, Jayashri; Bis, Joshua C.; Bisping, Egbert; Broeckel, Ulrich; Cheng, Susan; Deckers, Jaap W.; Del Greco M, Fabiola; Edelmann, Frank; Fornage, Myriam; Franke, Lude; Friedrich, Nele; Harris, Tamara B.; Hofer, Edith; Hofman, Albert; Huang, Jie; Hughes, Alun D.; Kähönen, Mika; investigators, KNHI; Kruppa, Jochen; Lackner, Karl J.; Lannfelt, Lars; Laskowski, Rafael; Launer, Lenore J.; Lindgren, Cecilia M.; Loley, Christina; Mayet, Jamil; Medenwald, Daniel; Morris, Andrew P.; Müller, Christian; Müller-Nurasyid, Martina; Nappo, Stefania; Nilsson, Peter M.; Nuding, Sebastian; Nutile, Teresa; Peters, Annette; Pfeufer, Arne; Pietzner, Diana; Pramstaller, Peter P.; Raitakari, Olli T.; Rice, Kenneth M.; Rotter, Jerome I.; Ruohonen, Saku T.; Sacco, Ralph L.; Samdarshi, Tandaw E.; Sharp, Andrew S.P.; Shields, Denis C.; Sorice, Rossella; Sotoodehnia, Nona; Stricker, Bruno H.; Surendran, Praveen; Töglhofer, Anna M.; Uitterlinden, André G.; Völzke, Henry; Ziegler, Andreas; Münzel, Thomas; März, Winfried; Cappola, Thomas P.; Hirschhorn, Joel N.; Mitchell, Gary F.; Smith, Nicholas L.; Fox, Ervin R.; Dueker, Nicole D.; Jaddoe, Vincent W.V.; Melander, Olle; Lehtimäki, Terho; Ciullo, Marina; Hicks, Andrew A.; Lind, Lars; Gudnason, Vilmundur; Pieske, Burkert; Barron, Anthony J.; Zweiker, Robert; Schunkert, Heribert; Ingelsson, Erik; Liu, Kiang; Arnett, Donna K.; Psaty, Bruce M.; Blankenberg, Stefan; Larson, Martin G.; Felix, Stephan B.; Franco, Oscar H.; Zeller, Tanja; Vasan, Ramachandran S.; Dörr, Marcus

2017-01-01

BACKGROUND. Understanding the genetic architecture of cardiac structure and function may help to prevent and treat heart disease. This investigation sought to identify common genetic variations associated with inter-individual variability in cardiac structure and function. METHODS. A GWAS meta-analysis of echocardiographic traits was performed, including 46,533 individuals from 30 studies (EchoGen consortium). The analysis included 16 traits of left ventricular (LV) structure, and systolic and diastolic function. RESULTS. The discovery analysis included 21 cohorts for structural and systolic function traits (n = 32,212) and 17 cohorts for diastolic function traits (n = 21,852). Replication was performed in 5 cohorts (n = 14,321) and 6 cohorts (n = 16,308), respectively. Besides 5 previously reported loci, the combined meta-analysis identified 10 additional genome-wide significant SNPs: rs12541595 near MTSS1 and rs10774625 in ATXN2 for LV end-diastolic internal dimension; rs806322 near KCNRG, rs4765663 in CACNA1C, rs6702619 near PALMD, rs7127129 in TMEM16A, rs11207426 near FGGY, rs17608766 in GOSR2, and rs17696696 in CFDP1 for aortic root diameter; and rs12440869 in IQCH for Doppler transmitral A-wave peak velocity. Findings were in part validated in other cohorts and in GWAS of related disease traits. The genetic loci showed associations with putative signaling pathways, and with gene expression in whole blood, monocytes, and myocardial tissue. CONCLUSION. The additional genetic loci identified in this large meta-analysis of cardiac structure and function provide insights into the underlying genetic architecture of cardiac structure and warrant follow-up in future functional studies. FUNDING. For detailed information per study, see Acknowledgments. PMID:28394258

BET Acetyl-Lysine Binding Proteins Control Pathological Cardiac Hypertrophy

PubMed Central

Spiltoir, Jessica I.; Stratton, Matthew S.; Cavasin, Maria A.; Demos-Davies, Kim; Reid, Brian G.; Qi, Jun; Bradner, James E.; McKinsey, Timothy A.

2014-01-01

Cardiac hypertrophy is an independent predictor of adverse outcomes in patients with heart failure, and thus represents an attractive target for novel therapeutic intervention. JQ1, a small molecule inhibitor of bromodomain and extraterminal (BET) acetyl-lysine reader proteins, was identified in a high throughput screen designed to discover novel small molecule regulators of cardiomyocyte hypertrophy. JQ1 dose-dependently blocked agonist-dependent hypertrophy of cultured neonatal rat ventricular myocytes (NRVMs) and reversed the prototypical gene program associated with pathological cardiac hypertrophy. JQ1 also blocked left ventricular hypertrophy (LVH) and improved cardiac function in adult mice subjected to transverse aortic constriction (TAC). The BET family consists of BRD2, BRD3, BRD4 and BRDT. BRD4 protein expression was increased during cardiac hypertrophy, and hypertrophic stimuli promoted recruitment of BRD4 to the transcriptional start site (TSS) of the gene encoding atrial natriuretic factor (ANF). Binding of BRD4 to the ANF TSS was associated with increased phosphorylation of local RNA polymerase II. These findings define a novel function for BET proteins as signal-responsive regulators of cardiac hypertrophy, and suggest that small molecule inhibitors of these epigenetic reader proteins have potential as therapeutics for heart failure. PMID:23939492

Signal-dependent repression of DUSP5 by class I HDACs controls nuclear ERK activity and cardiomyocyte hypertrophy.

PubMed

Ferguson, Bradley S; Harrison, Brooke C; Jeong, Mark Y; Reid, Brian G; Wempe, Michael F; Wagner, Florence F; Holson, Edward B; McKinsey, Timothy A

2013-06-11

Cardiac hypertrophy is a strong predictor of morbidity and mortality in patients with heart failure. Small molecule histone deacetylase (HDAC) inhibitors have been shown to suppress cardiac hypertrophy through mechanisms that remain poorly understood. We report that class I HDACs function as signal-dependent repressors of cardiac hypertrophy via inhibition of the gene encoding dual-specificity phosphatase 5 (DUSP5) DUSP5, a nuclear phosphatase that negatively regulates prohypertrophic signaling by ERK1/2. Inhibition of DUSP5 by class I HDACs requires activity of the ERK kinase, mitogen-activated protein kinase kinase (MEK), revealing a self-reinforcing mechanism for promotion of cardiac ERK signaling. In cardiac myocytes treated with highly selective class I HDAC inhibitors, nuclear ERK1/2 signaling is suppressed in a manner that is absolutely dependent on DUSP5. In contrast, cytosolic ERK1/2 activation is maintained under these same conditions. Ectopic expression of DUSP5 in cardiomyocytes results in potent inhibition of agonist-dependent hypertrophy through a mechanism involving suppression of the gene program for hypertrophic growth. These findings define unique roles for class I HDACs and DUSP5 as integral components of a regulatory signaling circuit that controls cardiac hypertrophy.

8-Oxoguanine DNA glycosylase 1 (ogg1) maintains the function of cardiac progenitor cells during heart formation in zebrafish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Lifeng; Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 210029; Zhou, Yong

Genomic damage may devastate the potential of progenitor cells and consequently impair early organogenesis. We found that ogg1, a key enzyme initiating the base-excision repair, was enriched in the embryonic heart in zebrafish. So far, little is known about DNA repair in cardiogenesis. Here, we addressed the critical role of ogg1 in cardiogenesis for the first time. ogg1 mainly expressed in the anterior lateral plate mesoderm (ALPM), the primary heart tube, and subsequently the embryonic myocardium by in situ hybridisation. Loss of ogg1 resulted in severe cardiac morphogenesis and functional abnormalities, including the short heart length, arrhythmia, decreased cardiomyocytes andmore » nkx2.5{sup +} cardiac progenitor cells. Moreover, the increased apoptosis and repressed proliferation of progenitor cells caused by ogg1 deficiency might contribute to the heart phenotype. The microarray analysis showed that the expression of genes involved in embryonic heart tube morphogenesis and heart structure were significantly changed due to the lack of ogg1. Among those, foxh1 is an important partner of ogg1 in the cardiac development in response to DNA damage. Our work demonstrates the requirement of ogg1 in cardiac progenitors and heart development in zebrafish. These findings may be helpful for understanding the aetiology of congenital cardiac deficits. - Highlights: • A key DNA repair enzyme ogg1 is expressed in the embryonic heart in zebrafish. • We found that ogg1 is essential for normal cardiac morphogenesis in zebrafish. • The production of embryonic cardiomyocytes requires appropriate ogg1 expression. • Ogg1 critically regulated proliferation of cardiac progenitor cells in zebrafish. • foxh1 is a partner of ogg1 in the cardiac development in response to DNA damage.« less

Disruption of cardiogenesis in human embryonic stem cells exposed to trichloroethylene.

PubMed

Jiang, Yan; Wang, Dan; Zhang, Guoxing; Wang, Guoqing; Tong, Jian; Chen, Tao

2016-11-01

Trichloroethylene (TCE) is ubiquitous in our living environment, and prenatal exposure to TCE is reported to cause congenital heart disease in humans. Although multiple studies have been performed using animal models, they have limited value in predicting effects on humans due to the unknown species-specific toxicological effects. To test whether exposure to low doses of TCE induces developmental toxicity in humans, we investigated the effect of TCE on human embryonic stem cells (hESCs) and cardiomyocytes (derived from the hESCs). In the current study, hESCs cardiac differentiation was achieved by using differentiation medium consisting of StemPro-34. We examined the effects of TCE on cell viability by cell growth assay and cardiac inhibition by analysis of spontaneously beating cluster. The expression levels of genes associated with cardiac differentiation and Ca 2+ channel pathways were measured by immunofluorescence and qPCR. The overall data indicated the following: (1) significant cardiac inhibition, which was characterized by decreased beating clusters and beating rates, following treatment with low doses of TCE; (2) significant up-regulation of the Nkx2.5/Hand1 gene in cardiac progenitors and down regulation of the Mhc-7/cTnT gene in cardiac cells; and (3) significant interference with Ca 2+ channel pathways in cardiomyocytes, which contributes to the adverse effect of TCE on cardiac differentiation during early embryo development. Our results confirmed the involvement of Ca 2+ turnover network in TCE cardiotoxicity as reported in animal models, while the inhibition effect of TCE on the transition of cardiac progenitors to cardiomyocytes is unique to hESCs, indicating a species-specific effect of TCE on heart development. This study provides new insight into TCE biology in humans, which may help explain the development of congenital heart defects after TCE exposure. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1372-1380, 2016. © 2015 Wiley Periodicals, Inc.

Genome-Wide Screens for In Vivo Tinman Binding Sites Identify Cardiac Enhancers with Diverse Functional Architectures

PubMed Central

Jin, Hong; Stojnic, Robert; Adryan, Boris; Ozdemir, Anil; Stathopoulos, Angelike; Frasch, Manfred

2013-01-01

The NK homeodomain factor Tinman is a crucial regulator of early mesoderm patterning and, together with the GATA factor Pannier and the Dorsocross T-box factors, serves as one of the key cardiogenic factors during specification and differentiation of heart cells. Although the basic framework of regulatory interactions driving heart development has been worked out, only about a dozen genes involved in heart development have been designated as direct Tinman target genes to date, and detailed information about the functional architectures of their cardiac enhancers is lacking. We have used immunoprecipitation of chromatin (ChIP) from embryos at two different stages of early cardiogenesis to obtain a global overview of the sequences bound by Tinman in vivo and their linked genes. Our data from the analysis of ∼50 sequences with high Tinman occupancy show that the majority of such sequences act as enhancers in various mesodermal tissues in which Tinman is active. All of the dorsal mesodermal and cardiac enhancers, but not some of the others, require tinman function. The cardiac enhancers feature diverse arrangements of binding motifs for Tinman, Pannier, and Dorsocross. By employing these cardiac and non-cardiac enhancers in machine learning approaches, we identify a novel motif, termed CEE, as a classifier for cardiac enhancers. In vivo assays for the requirement of the binding motifs of Tinman, Pannier, and Dorsocross, as well as the CEE motifs in a set of cardiac enhancers, show that the Tinman sites are essential in all but one of the tested enhancers; although on occasion they can be functionally redundant with Dorsocross sites. The enhancers differ widely with respect to their requirement for Pannier, Dorsocross, and CEE sites, which we ascribe to their different position in the regulatory circuitry, their distinct temporal and spatial activities during cardiogenesis, and functional redundancies among different factor binding sites. PMID:23326246

Expression of genes of the cardiac and renal renin-angiotensin systems in preterm piglets: is this system a suitable target for therapeutic intervention?

PubMed

Kim, Eleanor; Eiby, Yvonne; Lumbers, Eugenie; Boyce, Amanda; Gibson, Karen; Lingwood, Barbara

2015-10-01

The newborn circulating, cardiac and renal renin-angiotensin systems (RASs) are essential for blood pressure control, and for cardiac and renal development. If cardiac and renal RASs are immature this may contribute to cardiovascular compromise in preterm infants. This study measured mRNA expression of cardiac and renal RAS components in preterm, glucocorticoid (GC) exposed preterm, and term piglets. Renal and cardiac RAS mRNA levels were measured using real-time polymerase chain reaction (PCR). Genes studied were: (pro)renin receptor, renin, angiotensinogen, angiotensin converting enzyme (ACE), ACE2, angiotensin type 1 receptor (AT1R) and angiotensin type 2 receptor (AT2R). All the genes studied were expressed in the kidney; neither renin nor AT2R mRNA were detected in the heart. There were no gestational changes in (pro)renin receptor, renin, ACE or AT1R mRNA levels. Right ventricular angiotensinogen mRNA levels in females were lower in preterm animals than at term, and GC exposure increased levels in male piglets. Renal angiotensinogen mRNA levels in female term piglets were lower than females from both preterm groups, and lower than male term piglets. Left ventricular ACE2 mRNA expression was lower in GC treated preterm piglets. Renal AT2R mRNA abundance was highest in GC treated preterm piglets, and the AT1R/AT2R ratio was increased at term. Preterm cardiac and renal RAS mRNA levels were similar to term piglets, suggesting that immaturity of these RASs does not contribute to preterm cardiovascular compromise. Since preterm expression of both renal and cardiac angiotensin II-AT1R is similar to term animals, cardiovascular dysfunction in the sick preterm human neonate might be effectively treated by agents acting on their RASs. © The Author(s), 2015.

Haploinsufficiency of TAB2 Causes Congenital Heart Defects in Humans

PubMed Central

Thienpont, Bernard; Zhang, Litu; Postma, Alex V.; Breckpot, Jeroen; Tranchevent, Léon-Charles; Van Loo, Peter; Møllgård, Kjeld; Tommerup, Niels; Bache, Iben; Tümer, Zeynep; van Engelen, Klaartje; Menten, Björn; Mortier, Geert; Waggoner, Darrel; Gewillig, Marc; Moreau, Yves; Devriendt, Koen; Larsen, Lars Allan

2010-01-01

Congenital heart defects (CHDs) are the most common major developmental anomalies and the most frequent cause for perinatal mortality, but their etiology remains often obscure. We identified a locus for CHDs on 6q24-q25. Genotype-phenotype correlations in 12 patients carrying a chromosomal deletion on 6q delineated a critical 850 kb region on 6q25.1 harboring five genes. Bioinformatics prioritization of candidate genes in this locus for a role in CHDs identified the TGF-β-activated kinase 1/MAP3K7 binding protein 2 gene (TAB2) as the top-ranking candidate gene. A role for this candidate gene in cardiac development was further supported by its conserved expression in the developing human and zebrafish heart. Moreover, a critical, dosage-sensitive role during development was demonstrated by the cardiac defects observed upon titrated knockdown of tab2 expression in zebrafish embryos. To definitively confirm the role of this candidate gene in CHDs, we performed mutation analysis of TAB2 in 402 patients with a CHD, which revealed two evolutionarily conserved missense mutations. Finally, a balanced translocation was identified, cosegregating with familial CHD. Mapping of the breakpoints demonstrated that this translocation disrupts TAB2. Taken together, these data clearly demonstrate a role for TAB2 in human cardiac development. PMID:20493459

MicroRNA-133 mediates cardiac diseases: Mechanisms and clinical implications.

PubMed

Liu, Yi; Liang, Yan; Zhang, Jin-Fang; Fu, Wei-Ming

2017-05-15

MicroRNAs (miRNAs) belong to the family of small non-coding RNAs that mediate gene expression by post-transcriptional regulation. Increasing evidence have demonstrated that miR-133 is enriched in muscle tissues and myogenic cells, and its aberrant expression could induce the occurrence and development of cardiac disorders, such as cardiac hypertrophy, heart failure, etc. In this review, we summarized the regulatory roles of miR-133 in cardiac disorders and the underlying mechanisms, which suggest that miR-133 may be a potential diagnostic and therapeutic tool for cardiac disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

Polymer microfiber meshes facilitate cardiac differentiation of c-kit{sup +} human cardiac stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kan, Lijuan; Thayer, Patrick; Fan, Huimin

Electrospun microfiber meshes have been shown to support the proliferation and differentiation of many types of stem cells, but the phenotypic fate of c-kit{sup +} human cardiac stem cells (hCSCs) have not been explored. To this end, we utilized thin (~5 µm) elastomeric meshes consisting of aligned 1.7 µm diameter poly (ester-urethane urea) microfibers as substrates to examine their effect on hCSC viability, morphology, proliferation, and differentiation relative to cells cultured on tissue culture polystyrene (TCPS). The results showed that cells on microfiber meshes displayed an elongated morphology aligned in the direction of fiber orientation, lower proliferation rates, but increasedmore » expressions of genes and proteins majorly associated with cardiomyocyte phenotype. The early (NK2 homeobox 5, Nkx2.5) and late (cardiac troponin I, cTnI) cardiomyocyte genes were significantly increased on meshes (Nkx=2.5 56.2±13.0, cTnl=2.9±0.56,) over TCPS (Nkx2.5=4.2±0.9, cTnl=1.6±0.5, n=9, p<0.05 for both groups) after differentiation. In contrast, expressions of smooth muscle markers, Gata6 and myosin heavy chain (SM-MHC), were decreased on meshes. Immunocytochemical analysis with cardiac antibody exhibited the similar pattern of above cardiac differentiation. We conclude that aligned microfiber meshes are suitable for guiding cardiac differentiation of hCSCs and may facilitate stem cell-based therapies for treatment of cardiac diseases. - Highlights: • First study to characterize c-kit{sup +} human cardiac stem cells on microfiber meshes. • Microfiber meshes seem reducing cell proliferation, but no effect on cell viability. • Microfiber meshes facilitate the elongation of human cardiac stem cells in culture. • Cardiac but not smooth muscle differentiation were enhanced on microfiber meshes. • Microfiber meshes may be used as cardiac patches in cell-based cardiac therapy.« less

Trichloroethylene perturbs HNF4a expression and activity in the developing chick heart.

PubMed

Harris, Alondra P; Ismail, Kareem A; Nunez, Martha; Martopullo, Ira; Lencinas, Alejandro; Selmin, Ornella I; Runyan, Raymond B

2018-03-15

Exposure to trichloroethylene (TCE) is linked to formation of congenital heart defects in humans and animals. Prior interactome analysis identified the transcription factor, Hepatocyte Nuclear Factor 4 alpha (HNF4a), as a potential target of TCE exposure. As a role for HNF4a is unknown in the heart, we examined developing avian hearts for HNF4a expression and for sensitivity to TCE and the HNF4a agonist, Benfluorex. In vitro analysis using a HNF4a reporter construct showed both TCE and HFN4a to be antagonists of HNF4a-mediated transcription at the concentrations tested. HNF4a mRNA is expressed transiently in the embryonic heart during valve formation and cardiac development. Embryos were examined for altered gene expression in the presence of TCE or Benfluorex. TCE altered expression of selected mRNAs including HNF4a, TRAF6 and CYP2C45. There was a transition between inhibition and induction of marker gene expression in embryos as TCE concentration increased. Benfluorex was largely inhibitory to selected markers. Echocardiography of exposed embryos showed reduced cardiac function with both TCE and Benfluorex. Cardiac contraction was reduced by 29% and 23%, respectively at 10 ppb. The effects of TCE and Benfluorex on autocrine regulation of HNF4a, selected markers and cardiac function argue for a functional interaction of TCE and HNF4a. Further, the dose-sensitive shift between inhibition and induction of marker expression may explain the nonmonotonic-like dose response observed with TCE exposure in the heart. Copyright © 2018 Elsevier B.V. All rights reserved.

Gene Therapy Delivery Systems for Enhancing Viral and Nonviral Vectors for Cardiac Diseases: Current Concepts and Future Applications

PubMed Central

Katz, Michael G.; Fargnoli, Anthony S.; Williams, Richard D.

2013-01-01

Abstract Gene therapy is one of the most promising fields for developing new treatments for the advanced stages of ischemic and monogenetic, particularly autosomal or X-linked recessive, cardiomyopathies. The remarkable ongoing efforts in advancing various targets have largely been inspired by the results that have been achieved in several notable gene therapy trials, such as the hemophilia B and Leber's congenital amaurosis. Rate-limiting problems preventing successful clinical application in the cardiac disease area, however, are primarily attributable to inefficient gene transfer, host responses, and the lack of sustainable therapeutic transgene expression. It is arguable that these problems are directly correlated with the choice of vector, dose level, and associated cardiac delivery approach as a whole treatment system. Essentially, a delicate balance exists in maximizing gene transfer required for efficacy while remaining within safety limits. Therefore, the development of safe, effective, and clinically applicable gene delivery techniques for selected nonviral and viral vectors will certainly be invaluable in obtaining future regulatory approvals. The choice of gene transfer vector, dose level, and the delivery system are likely to be critical determinants of therapeutic efficacy. It is here that the interactions between vector uptake and trafficking, delivery route means, and the host's physical limits must be considered synergistically for a successful treatment course. PMID:24164239

Sequencing of mRNA identifies re-expression of fetal splice variants in cardiac hypertrophy

PubMed Central

Ames, EG; Lawson, MJ; Mackey, AJ; Holmes, JW

2013-01-01

Cardiac hypertrophy has been well-characterized at the level of transcription. During cardiac hypertrophy, genes normally expressed primarily during fetal heart development are reexpressed, and this fetal gene program is believed to be a critical component of the hypertrophic process. Recently, alternative splicing of mRNA transcripts has been shown to be temporally regulated during heart development, leading us to consider whether fetal patterns of splicing also reappear during hypertrophy. We hypothesized that patterns of alternative splicing occurring during heart development are recapitulated during cardiac hypertrophy. Here we present a study of isoform expression during pressure-overload cardiac hypertrophy induced by 10 days of transverse aortic constriction (TAC) in rats and in developing fetal rat hearts compared to sham-operated adult rat hearts, using high-throughput sequencing of poly(A) tail mRNA. We find a striking degree of overlap between the isoforms expressed differentially in fetal and pressure-overloaded hearts compared to control: forty-four percent of the isoforms with significantly altered expression in TAC hearts are also expressed at significantly different levels in fetal hearts compared to control (P < 0.001). The isoforms that are shared between hypertrophy and fetal heart development are significantly enriched for genes involved in cytoskeletal organization, RNA processing, developmental processes, and metabolic enzymes. Our data strongly support the concept that mRNA splicing patterns normally associated with heart development recur as part of the hypertrophic response to pressure overload. These findings suggest that cardiac hypertrophy shares post-transcriptional as well as transcriptional regulatory mechanisms with fetal heart development. PMID:23688780

Percutaneous transendocardial delivery of self-complementary adeno-associated virus 6 achieves global cardiac gene transfer in canines

PubMed Central

Bish, Lawrence T.; Sleeper, Meg M.; Brainard, Benjamin; Cole, Stephen; Russell, Nicholas; Withnall, Elanor; Arndt, Jason; Reynolds, Caryn; Davison, Ellen; Sanmiguel, Julio; Wu, Di; Gao, Guangping; Wilson, James M.; Sweeney, H. Lee

2011-01-01

Achieving efficient cardiac gene transfer in a large animal model has proven to be technically challenging. Prior strategies have employed cardio-pulmonary bypass or dual catheterization with the aid of vasodilators to deliver vectors, such as adenovirus, adeno-associated virus or plasmid DNA. While single stranded adeno-associated virus vectors have shown the greatest promise, they suffer from delayed expression, which might be circumvented by using self-complementary vectors. We sought to optimize cardiac gene transfer using a percutaneous transendocardial injection catheter to deliver adeno-associated virus vectors to the canine myocardium. Four vectors were evaluated—single stranded adeno-associated virus 9, self-complementary adeno-associated virus 9, self-complementary adeno-associated virus 8, self-complementary adeno-associated virus 6—so that comparison could be made between single stranded and self complementary vectors as well as among serotypes 9, 8, and 6. We demonstrate that self-complementary adeno-associated virus is superior to single stranded adeno-associated virus and that adeno-associated virus 6 is superior to other serotypes evaluated. Biodistribution studies revealed that vector genome copies were 15 to 4000 times more abundant in the heart than in any other organ for self-complementary adeno-associated virus 6. Percutaneous transendocardial injection of self-complementary adeno-associated virus 6 is a safe, effective method for achieving efficient cardiac gene transfer. PMID:18813281

Disruption of Canonical TGFβ-signaling in Murine Coronary Progenitor Cells by Low Level Arsenic

PubMed Central

Allison, Patrick; Huang, Tianfang; Broka, Derrick; Parker, Patti; Barnett, Joey V.; Camenisch, Todd D.

2013-01-01

Exposure to arsenic results in several types of cancers as well as heart disease. A major contributor to ischemic heart pathologies is coronary artery disease, however the influences by environmental arsenic in this disease process are not known. Similarly, the impact of toxicants on blood vessel formation and function during development has not been studied. During embryogenesis, the epicardium undergoes proliferation, migration, and differentiation into several cardiac cell types including smooth muscle cells which contribute to the coronary vessels. The TGFβ family of ligands and receptors are essential for developmental cardiac epithelial to mesenchymal transition (EMT) and differentiation into coronary smooth muscle cells. In this in vitrostudy, 18 hour exposure to 1.34 μMarsenite disrupted developmental EMT programming in murine epicardial cells causing a deficit in cardiac mesenchyme. The expression of EMT genes including TGFβ2, TGFβ receptor-3, Snail, and Has-2 are decreased in a dose-dependent manner following exposure to arsenite. TGFβ2 cell signaling is abrogated as detected by decreases in phosphorylated Smad2/3 when cells are exposed to 1.34 μMarsenite. There is also loss of nuclear accumulation pSmad due to arsenite exposure. These observations coincide with a decrease invimentinpositive mesenchymal cells invading three-dimensional collagen gels. However, arsenite does not block TGFβ2 mediated smooth muscle cell differentiation by epicardial cells. Overall these results show that arsenic exposure blocks developmental EMT gene programming in murine coronary progenitor cells by disrupting TGFβ2 signals and Smad activation, and that smooth muscle cell differentiation is refractory to this arsenic toxicity. PMID:23732083

Mechanisms of action of sacubitril/valsartan on cardiac remodeling: a systems biology approach.

PubMed

Iborra-Egea, Oriol; Gálvez-Montón, Carolina; Roura, Santiago; Perea-Gil, Isaac; Prat-Vidal, Cristina; Soler-Botija, Carolina; Bayes-Genis, Antoni

2017-01-01

Sacubitril/Valsartan, proved superiority over other conventional heart failure management treatments, but its mechanisms of action remains obscure. In this study, we sought to explore the mechanistic details for Sacubitril/Valsartan in heart failure and post-myocardial infarction remodeling, using an in silico, systems biology approach. Myocardial transcriptome obtained in response to myocardial infarction in swine was analyzed to address post-infarction ventricular remodeling. Swine transcriptome hits were mapped to their human equivalents using Reciprocal Best (blast) Hits, Gene Name Correspondence, and InParanoid database. Heart failure remodeling was studied using public data available in gene expression omnibus (accession GSE57345, subseries GSE57338), processed using the GEO2R tool. Using the Therapeutic Performance Mapping System technology, dedicated mathematical models trained to fit a set of molecular criteria, defining both pathologies and including all the information available on Sacubitril/Valsartan, were generated. All relationships incorporated into the biological network were drawn from public resources (including KEGG, REACTOME, INTACT, BIOGRID, and MINT). An artificial neural network analysis revealed that Sacubitril/Valsartan acts synergistically against cardiomyocyte cell death and left ventricular extracellular matrix remodeling via eight principal synergistic nodes. When studying each pathway independently, Valsartan was found to improve cardiac remodeling by inhibiting members of the guanine nucleotide-binding protein family, while Sacubitril attenuated cardiomyocyte cell death, hypertrophy, and impaired myocyte contractility by inhibiting PTEN. The complex molecular mechanisms of action of Sacubitril/Valsartan upon post-myocardial infarction and heart failure cardiac remodeling were delineated using a systems biology approach. Further, this dataset provides pathophysiological rationale for the use of Sacubitril/Valsartan to prevent post-infarct remodeling.

A novel needleless liquid jet injection methodology for improving direct cardiac gene delivery: An optimization of parameters, AAV mediated therapy and investigation of host responses in ischemic heart failure

NASA Astrophysics Data System (ADS)

Fargnoli, Anthony Samuel

Heart disease remains the leading cause of mortality and morbidity worldwide, with 22 million new patients diagnosed annually. Essentially, all present therapies have significant cost burden to the healthcare system, yet fail to increase survival rates. One key employed strategy is the genetic reprogramming of cells to increase contractility via gene therapy, which has advanced to Phase IIb Clinical Trials for advanced heart failure patients. It has been argued that the most significant barrier preventing FDA approval are resolving problems with safe, efficient myocardial delivery, whereby direct injection in the infarct and remote tissue areas is not clinically feasible. Here, we aim to: (1) Improve direct cardiac gene delivery through the development of a novel liquid jet device approach (2) Compare the new method against traditional IM injection with two different vector constructions and evaluate outcome (3) Evaluate the host response resulting from both modes of direct cardiac injection, then advance a drug/gene combination with controlled release nanoparticle formulations.

Whole transcriptome analysis of the fasting and fed Burmese python heart: insights into extreme physiological cardiac adaptation.

PubMed

Wall, Christopher E; Cozza, Steven; Riquelme, Cecilia A; McCombie, W Richard; Heimiller, Joseph K; Marr, Thomas G; Leinwand, Leslie A

2011-01-01

The infrequently feeding Burmese python (Python molurus) experiences significant and rapid postprandial cardiac hypertrophy followed by regression as digestion is completed. To begin to explore the molecular mechanisms of this response, we have sequenced and assembled the fasted and postfed Burmese python heart transcriptomes with Illumina technology using the chicken (Gallus gallus) genome as a reference. In addition, we have used RNA-seq analysis to identify differences in the expression of biological processes and signaling pathways between fasted, 1 day postfed (DPF), and 3 DPF hearts. Out of a combined transcriptome of ∼2,800 mRNAs, 464 genes were differentially expressed. Genes showing differential expression at 1 DPF compared with fasted were enriched for biological processes involved in metabolism and energetics, while genes showing differential expression at 3 DPF compared with fasted were enriched for processes involved in biogenesis, structural remodeling, and organization. Moreover, we present evidence for the activation of physiological and not pathological signaling pathways in this rapid, novel model of cardiac growth in pythons. Together, our data provide the first comprehensive gene expression profile for a reptile heart.

Gene expression related to oxidative stress in the heart of mice after intestinal ischemia

PubMed Central

Somaio Neto, Frederico; Ikejiri, Adauto Tsutomu; Bertoletto, Paulo Roberto; Chaves, José Carlos Bertoletto; Teruya, Roberto; Fagundes, Djalma José; Taha, Murched Omar

2014-01-01

Background Intestinal ischemia-reperfusion is a frequent clinical event associated to injury in distant organs, especially the heart. Objective To investigate the gene expression of oxidative stress and antioxidant defense in the heart of inbred mice subjected to intestinal ischemia and reperfusion (IR). Methods Twelve mice (C57BL / 6) were assigned to: IR Group (GIR) with 60 minutes of superior mesenteric artery occlusion followed by 60 minutes of reperfusion; Control Group (CG) which underwent anesthesia and laparotomy without IR procedure and was observed for 120 minutes. Intestine and heart samples were processed using the RT-qPCR / Reverse transcriptase-quantitative Polymerase Chain Reaction method for the gene expression of 84 genes related to oxidative stress and oxidative defense (Student's "t" test, p < 0.05). Results The intestinal tissue (GIR) was noted to have an up-regulation of 65 genes (74.71%) in comparison to normal tissue (CG), and 37 genes (44.04%) were hyper-expressed (greater than three times the threshold allowed by the algorithm). Regarding the remote effects of intestinal I/R in cardiac tissue an up-regulation of 28 genes (33.33%) was seen, but only eight genes (9.52%) were hyper-expressed three times above threshold. Four (7.14%) of these eight genes were expressed in both intestinal and cardiac tissues. Cardiomyocytes with smaller and pyknotic nuclei, rich in heterochromatin with rare nucleoli, indicating cardiac distress, were observed in the GIR. Conclusion Intestinal I/R caused a statistically significant over expression of 8 genes associated with oxidative stress in remote myocardial tissue. PMID:24346830

Loss of Prox1 in striated muscle causes slow to fast skeletal muscle fiber conversion and dilated cardiomyopathy.

PubMed

Petchey, Louisa K; Risebro, Catherine A; Vieira, Joaquim M; Roberts, Tom; Bryson, John B; Greensmith, Linda; Lythgoe, Mark F; Riley, Paul R

2014-07-01

Correct regulation of troponin and myosin contractile protein gene isoforms is a critical determinant of cardiac and skeletal striated muscle development and function, with misexpression frequently associated with impaired contractility or disease. Here we reveal a novel requirement for Prospero-related homeobox factor 1 (Prox1) during mouse heart development in the direct transcriptional repression of the fast-twitch skeletal muscle genes troponin T3, troponin I2, and myosin light chain 1. A proportion of cardiac-specific Prox1 knockout mice survive beyond birth with hearts characterized by marked overexpression of fast-twitch genes and postnatal development of a fatal dilated cardiomyopathy. Through conditional knockout of Prox1 from skeletal muscle, we demonstrate a conserved requirement for Prox1 in the repression of troponin T3, troponin I2, and myosin light chain 1 between cardiac and slow-twitch skeletal muscle and establish Prox1 ablation as sufficient to cause a switch from a slow- to fast-twitch muscle phenotype. Our study identifies conserved roles for Prox1 between cardiac and skeletal muscle, specifically implicated in slow-twitch fiber-type specification, function, and cardiomyopathic disease.

Loss of Prox1 in striated muscle causes slow to fast skeletal muscle fiber conversion and dilated cardiomyopathy

PubMed Central

Petchey, Louisa K.; Risebro, Catherine A.; Vieira, Joaquim M.; Roberts, Tom; Bryson, John B.; Greensmith, Linda; Lythgoe, Mark F.; Riley, Paul R.

2014-01-01

Correct regulation of troponin and myosin contractile protein gene isoforms is a critical determinant of cardiac and skeletal striated muscle development and function, with misexpression frequently associated with impaired contractility or disease. Here we reveal a novel requirement for Prospero-related homeobox factor 1 (Prox1) during mouse heart development in the direct transcriptional repression of the fast-twitch skeletal muscle genes troponin T3, troponin I2, and myosin light chain 1. A proportion of cardiac-specific Prox1 knockout mice survive beyond birth with hearts characterized by marked overexpression of fast-twitch genes and postnatal development of a fatal dilated cardiomyopathy. Through conditional knockout of Prox1 from skeletal muscle, we demonstrate a conserved requirement for Prox1 in the repression of troponin T3, troponin I2, and myosin light chain 1 between cardiac and slow-twitch skeletal muscle and establish Prox1 ablation as sufficient to cause a switch from a slow- to fast-twitch muscle phenotype. Our study identifies conserved roles for Prox1 between cardiac and skeletal muscle, specifically implicated in slow-twitch fiber-type specification, function, and cardiomyopathic disease. PMID:24938781

[Genetics of congenital heart diseases].

PubMed

Bonnet, Damien

2017-06-01

Developmental genetics of congenital heart diseases has evolved from analysis of serial slices in embryos towards molecular genetics of cardiac morphogenesis with a dynamic view of cardiac development. Genetics of congenital heart diseases has also changed from formal genetic analysis of familial recurrences or population-based analysis to screening for mutations in candidates genes identified in animal models. Close cooperation between molecular embryologists, pathologists involved in heart development and pediatric cardiologists is crucial for further increase of knowledge in the field of cardiac morphogenesis and genetics of cardiac defects. The genetic model for congenital heart disease has to be revised to favor a polygenic origin rather than a monogenic one. The main mechanism is altered genic dosage that can account for heart diseases in chromosomal anomalies as well as in point mutations in syndromic and isolated congenital heart diseases. The use of big data grouping information from cardiac development, interactions between genes and proteins, epigenetic factors such as chromatin remodeling or DNA methylation is the current source for improving our knowledge in the field and to give clues for future therapies. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Gene expression profiles of peripheral blood mononuclear cells reveal transcriptional signatures as novel biomarkers of cardiac remodeling in rats with aldosteronism and hypertensive heart disease.

PubMed

Gerling, Ivan C; Ahokas, Robert A; Kamalov, German; Zhao, Wenyuan; Bhattacharya, Syamal K; Sun, Yao; Weber, Karl T

2013-12-01

In searching for a noninvasive surrogate tissue mimicking the pro-oxidant/proinflammatory hypertensive heart disease (HHD) phenotype, we turned to peripheral blood mononuclear cells (PBMCs). We tested whether iterations in [Ca2+]i, [Zn2+]i, and oxidative stress in cardiomyocytes and PBMCs would complement each other, eliciting similar shifts in gene expression profiles in these tissues demonstrable during the preclinical (week 1) and pathological (week 4) stages of aldosterone/salt treatment (ALDOST). Inappropriate neurohormonal activation contributes to pathological remodeling of myocardium in HHD associated with aldosteronism. In rats receiving long-term ALDOST, evidence of reparative fibrosis replacing necrotic cardiomyocytes and coronary vasculopathy appears at week 4 associated with the induction of oxidative stress by mitochondria that overwhelms endogenous, largely Zn2+-based, antioxidant defenses. Biomarker-guided prediction of risk before the appearance of cardiac pathology would prove invaluable. In PBMCs and cardiomyocytes, quantitation of cytoplasmic free Ca2+ and Zn2+, H2O2, and 8-iosprostane levels and isolation of ribonucleic acid (RNA) and gene expression together with statistical and clustering analyses and confirmation of genes by in situ hybridization and reverse-transcription polymerase chain reaction were performed. Compared with controls, at weeks 1 and 4 of ALDOST, we found comparable increments in [Ca2+]i, [Zn2+]i, and 8-isoprotane coupled with increased H2O2 production in cardiac mitochondria and PBMCs, together with the common networks of expression profiles dominated by genes involved in oxidative stress, inflammation, and repair. These included 3 central Ingenuity pathway-linked genes: p38 mitogen-activated protein kinase, a stress-responsive protein; nuclear factor-κB, a redox-sensitive transcription factor and a proinflammatory cascade that it regulates; and transforming growth factor-β1, a fibrogenic cytokine involved in tissue repair. Significant overlapping demonstrated in the molecular mimicry of PBMCs and cardiomyocytes during preclinical and pathological stages of ALDOST implies that transcriptional signatures of PBMCs may serve as early noninvasive and novel sentinels predictive of impending pathological remodeling in HHD.

Silencing of the Drosophila ortholog of SOX5 in heart leads to cardiac dysfunction as detected by optical coherence tomography

PubMed Central

Li, Airong; Ahsen, Osman O.; Liu, Jonathan J.; Du, Chuang; McKee, Mary L.; Yang, Yan; Wasco, Wilma; Newton-Cheh, Christopher H.; O'Donnell, Christopher J.; Fujimoto, James G.; Zhou, Chao; Tanzi, Rudolph E.

2013-01-01

The SRY-related HMG-box 5 (SOX5) gene encodes a member of the SOX family of transcription factors. Recently, genome-wide association studies have implicated SOX5 as a candidate gene for susceptibility to four cardiac-related endophenotypes: higher resting heart rate (HR), the electrocardiographic PR interval, atrial fibrillation and left ventricular mass. We have determined that human SOX5 has a highly conserved Drosophila ortholog, Sox102F, and have employed transgenic Drosophila models to quantitatively measure cardiac function in adult flies. For this purpose, we have developed a high-speed and ultrahigh-resolution optical coherence tomography imaging system, which enables rapid cross-sectional imaging of the heart tube over various cardiac cycles for the measurement of cardiac structural and dynamical parameters such as HR, dimensions and areas of heart chambers, cardiac wall thickness and wall velocities. We have found that the silencing of Sox102F resulted in a significant decrease in HR, heart chamber size and cardiac wall velocities, and a significant increase in cardiac wall thickness that was accompanied by disrupted myofibril structure in adult flies. In addition, the silencing of Sox102F in the wing led to increased L2, L3 and wing marginal veins and increased and disorganized expression of wingless, the central component of the Wnt signaling pathway. Collectively, the silencing of Sox102F resulted in severe cardiac dysfunction and structural defects with disrupted Wnt signaling transduction in flies. This implicates an important functional role for SOX5 in heart and suggests that the alterations in SOX5 levels may contribute to the pathogenesis of multiple cardiac diseases or traits. PMID:23696452

Silencing of the Drosophila ortholog of SOX5 in heart leads to cardiac dysfunction as detected by optical coherence tomography.

PubMed

Li, Airong; Ahsen, Osman O; Liu, Jonathan J; Du, Chuang; McKee, Mary L; Yang, Yan; Wasco, Wilma; Newton-Cheh, Christopher H; O'Donnell, Christopher J; Fujimoto, James G; Zhou, Chao; Tanzi, Rudolph E

2013-09-15

The SRY-related HMG-box 5 (SOX5) gene encodes a member of the SOX family of transcription factors. Recently, genome-wide association studies have implicated SOX5 as a candidate gene for susceptibility to four cardiac-related endophenotypes: higher resting heart rate (HR), the electrocardiographic PR interval, atrial fibrillation and left ventricular mass. We have determined that human SOX5 has a highly conserved Drosophila ortholog, Sox102F, and have employed transgenic Drosophila models to quantitatively measure cardiac function in adult flies. For this purpose, we have developed a high-speed and ultrahigh-resolution optical coherence tomography imaging system, which enables rapid cross-sectional imaging of the heart tube over various cardiac cycles for the measurement of cardiac structural and dynamical parameters such as HR, dimensions and areas of heart chambers, cardiac wall thickness and wall velocities. We have found that the silencing of Sox102F resulted in a significant decrease in HR, heart chamber size and cardiac wall velocities, and a significant increase in cardiac wall thickness that was accompanied by disrupted myofibril structure in adult flies. In addition, the silencing of Sox102F in the wing led to increased L2, L3 and wing marginal veins and increased and disorganized expression of wingless, the central component of the Wnt signaling pathway. Collectively, the silencing of Sox102F resulted in severe cardiac dysfunction and structural defects with disrupted Wnt signaling transduction in flies. This implicates an important functional role for SOX5 in heart and suggests that the alterations in SOX5 levels may contribute to the pathogenesis of multiple cardiac diseases or traits.

Mutation-Specific Phenotypes in hiPSC-Derived Cardiomyocytes Carrying Either Myosin-Binding Protein C Or α-Tropomyosin Mutation for Hypertrophic Cardiomyopathy

PubMed Central

Prajapati, Chandra; Pölönen, Risto-Pekka; Rajala, Kristiina; Pekkanen-Mattila, Mari; Rasku, Jyrki; Larsson, Kim; Aalto-Setälä, Katriina

2016-01-01

Hypertrophic cardiomyopathy (HCM) is a genetic cardiac disease, which affects the structure of heart muscle tissue. The clinical symptoms include arrhythmias, progressive heart failure, and even sudden cardiac death but the mutation carrier can also be totally asymptomatic. To date, over 1400 mutations have been linked to HCM, mostly in genes encoding for sarcomeric proteins. However, the pathophysiological mechanisms of the disease are still largely unknown. Two founder mutations for HCM in Finland are located in myosin-binding protein C (MYBPC3-Gln1061X) and α-tropomyosin (TPM1-Asp175Asn) genes. We studied the properties of HCM cardiomyocytes (CMs) derived from patient-specific human induced pluripotent stem cells (hiPSCs) carrying either MYBPC3-Gln1061X or TPM1-Asp175Asn mutation. Both types of HCM-CMs displayed pathological phenotype of HCM but, more importantly, we found differences between CMs carrying either MYBPC3-Gln1061X or TPM1-Asp175Asn gene mutation in their cellular size, Ca2+ handling, and electrophysiological properties, as well as their gene expression profiles. These findings suggest that even though the clinical phenotypes of the patients carrying either MYBPC3-Gln1061X or TPM1-Asp175Asn gene mutation are similar, the genetic background as well as the functional properties on the cellular level might be different, indicating that the pathophysiological mechanisms behind the two mutations would be divergent as well. PMID:27057166

A Nonsynonymous Polymorphism in Semaphorin 3A as a Risk Factor for Human Unexplained Cardiac Arrest with Documented Ventricular Fibrillation

PubMed Central

Nakano, Yukiko; Chayama, Kazuaki; Ochi, Hidenori; Toshishige, Masaaki; Hayashida, Yasufumi; Miki, Daiki; Hayes, C. Nelson; Suzuki, Hidekazu; Tokuyama, Takehito; Oda, Noboru; Suenari, Kazuyoshi; Uchimura-Makita, Yuko; Kajihara, Kenta; Sairaku, Akinori; Motoda, Chikaaki; Fujiwara, Mai; Watanabe, Yoshikazu; Yoshida, Yukihiko; Ohkubo, Kimie; Watanabe, Ichiro; Nogami, Akihiko; Hasegawa, Kanae; Watanabe, Hiroshi; Endo, Naoto; Aiba, Takeshi; Shimizu, Wataru; Ohno, Seiko; Horie, Minoru; Arihiro, Koji; Tashiro, Satoshi; Makita, Naomasa; Kihara, Yasuki

2013-01-01

Unexplained cardiac arrest (UCA) with documented ventricular fibrillation (VF) is a major cause of sudden cardiac death. Abnormal sympathetic innervations have been shown to be a trigger of ventricular fibrillation. Further, adequate expression of SEMA3A was reported to be critical for normal patterning of cardiac sympathetic innervation. We investigated the relevance of the semaphorin 3A (SEMA3A) gene located at chromosome 5 in the etiology of UCA. Eighty-three Japanese patients diagnosed with UCA and 2,958 healthy controls from two different geographic regions in Japan were enrolled. A nonsynonymous polymorphism (I334V, rs138694505A>G) in exon 10 of the SEMA3A gene identified through resequencing was significantly associated with UCA (combined P = 0.0004, OR 3.08, 95%CI 1.67–5.7). Overall, 15.7% of UCA patients carried the risk genotype G, whereas only 5.6% did in controls. In patients with SEMA3A I334V, VF predominantly occurred at rest during the night. They showed sinus bradycardia, and their RR intervals on the 12-lead electrocardiography tended to be longer than those in patients without SEMA3A I334V (1031±111 ms versus 932±182 ms, P = 0.039). Immunofluorescence staining of cardiac biopsy specimens revealed that sympathetic nerves, which are absent in the subendocardial layer in normal hearts, extended to the subendocardial layer only in patients with SEMA3A I334V. Functional analyses revealed that the axon-repelling and axon-collapsing activities of mutant SEMA3A I334V genes were significantly weaker than those of wild-type SEMA3A genes. A high incidence of SEMA3A I334V in UCA patients and inappropriate innervation patterning in their hearts implicate involvement of the SEMA3A gene in the pathogenesis of UCA. PMID:23593010

Characterization of human septic sera induced gene expression modulation in human myocytes

PubMed Central

Hussein, Shaimaa; Michael, Paul; Brabant, Danielle; Omri, Abdelwahab; Narain, Ravin; Passi, Kalpdrum; Ramana, Chilakamarti V.; Parrillo, Joseph E.; Kumar, Anand; Parissenti, Amadeo; Kumar, Aseem

2009-01-01

To gain a better understanding of the gene expression changes that occurs during sepsis, we have performed a cDNA microarray study utilizing a tissue culture model that mimics human sepsis. This study utilized an in vitro model of cultured human fetal cardiac myocytes treated with 10% sera from septic patients or 10% sera from healthy volunteers. A 1700 cDNA expression microarray was used to compare the transcription profile from human cardiac myocytes treated with septic sera vs normal sera. Septic sera treatment of myocytes resulted in the down-regulation of 178 genes and the up-regulation of 4 genes. Our data indicate that septic sera induced cell cycle, metabolic, transcription factor and apoptotic gene expression changes in human myocytes. Identification and characterization of gene expression changes that occur during sepsis may lead to the development of novel therapeutics and diagnostics. PMID:19684886

Myocardial regeneration in adriamycin cardiomyopathy by nuclear expression of GLP1 using ultrasound targeted microbubble destruction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Shuyuan; Chen, Jiaxi; Huang, Pintong

Recently GLP-1 was found to have cardioprotective effects independent of those attributable to tight glycemic control. Methods and results: We employed ultrasound targeted microbubble destruction (UTMD) to deliver piggybac transposon plasmids encoding the GLP-1 gene with a nuclear localizing signal to rat hearts with adriamycin cardiomyopathy. After a single UTMD treatment, overexpression of transgenic GLP-1 was found in nuclei of rat heart cells with evidence that transfected cardiac cells had undergone proliferation. UTMD-GLP-1 gene therapy restored LV mass, fractional shortening index, and LV posterior wall diameter to nearly normal. Nuclear overexpression of GLP-1 by inducing phosphorylation of FoxO1-S256 and translocationmore » of FoxO1 from the nucleus to the cytoplasm significantly inactivated FoxO1 and activated the expression of cyclin D1 in nuclei of cardiac muscle cells. Reversal of adriamycin cardiomyopathy appeared to be mediated by dedifferentiation and proliferation of nuclear FoxO1-positive cardiac muscle cells with evidence of embryonic stem cell markers (OCT4, Nanog, SOX2 and c-kit), cardiac early differentiation markers (NKX2.5 and ISL-1) and cellular proliferation markers (BrdU and PHH3) after UTMD with GLP-1 gene therapy. Conclusions: Intranuclear myocardial delivery of the GLP-1gene can reverse established adriamycin cardiomyopathy by stimulating myocardial regeneration. - Highlights: • The activation of nuclear FoxO1 in cardiac muscle cells associated with adriamycin cardiomyopathy. • Myocardial nuclear GLP-1 stimulates myocardial regeneration and reverses adriamycin cardiomyopathy. • The process of myocardial regeneration associated with dedifferentiation and proliferation.« less

Endothelin receptor B, a candidate gene from human studies at high altitude, improves cardiac tolerance to hypoxia in genetically engineered heterozygote mice

PubMed Central

Stobdan, Tsering; Zhou, Dan; Ao-Ieong, Eilleen; Ortiz, Daniel; Ronen, Roy; Hartley, Iain; Gan, Zhuohui; McCulloch, Andrew D.; Bafna, Vineet; Cabrales, Pedro; Haddad, Gabriel G.

2015-01-01

To better understand human adaptation to stress, and in particular to hypoxia, we took advantage of one of nature’s experiments at high altitude (HA) and studied Ethiopians, a population that is well-adapted to HA hypoxic stress. Using whole-genome sequencing, we discovered that EDNRB (Endothelin receptor type B) is a candidate gene involved in HA adaptation. To test whether EDNRB plays a critical role in hypoxia tolerance and adaptation, we generated EdnrB knockout mice and found that when EdnrB−/+ heterozygote mice are treated with lower levels of oxygen (O2), they tolerate various levels of hypoxia (even extreme hypoxia, e.g., 5% O2) very well. For example, they maintain ejection fraction, cardiac contractility, and cardiac output in severe hypoxia. Furthermore, O2 delivery to vital organs was significantly higher and blood lactate was lower in EdnrB−/+ compared with wild type in hypoxia. Tissue hypoxia in brain, heart, and kidney was lower in EdnrB−/+ mice as well. These data demonstrate that a lower level of EDNRB significantly improves cardiac performance and tissue perfusion under various levels of hypoxia. Transcriptomic profiling of left ventricles revealed three specific genes [natriuretic peptide type A (Nppa), sarcolipin (Sln), and myosin light polypeptide 4 (Myl4)] that were oppositely expressed (q < 0.05) between EdnrB−/+ and wild type. Functions related to these gene networks were consistent with a better cardiac contractility and performance. We conclude that EDNRB plays a key role in hypoxia tolerance and that a lower level of EDNRB contributes, at least in part, to HA adaptation in humans. PMID:26240367

Prevention of Hypovolemic Circulatory Collapse by IL-6 Activated Stat3

PubMed Central

Tsimelzon, Anna I.; Mastrangelo, Mary-Ann A.; Hilsenbeck, Susan G.; Poli, Valeria; Tweardy, David J.

2008-01-01

Half of trauma deaths are attributable to hypovolemic circulatory collapse (HCC). We established a model of HCC in rats involving minor trauma plus severe hemorrhagic shock (HS). HCC in this model was accompanied by a 50% reduction in peak acceleration of aortic blood flow and cardiomyocyte apoptosis. HCC and apoptosis increased with increasing duration of hypotension. Apoptosis required resuscitation, which provided an opportunity to intervene therapeutically. Administration of IL-6 completely reversed HCC, prevented cardiac dysfunction and cardiomyocyte apoptosis, reduced mortality 5-fold and activated intracardiac signal transducer and activator of transcription (STAT) 3. Pre-treatment of rats with a selective inhibitor of Stat3, T40214, reduced the IL-6-mediated increase in cardiac Stat3 activity, blocked successful resuscitation by IL-6 and reversed IL-6-mediated protection from cardiac apoptosis. The hearts of mice deficient in the naturally occurring dominant negative isoform of Stat3, Stat3β, were completely resistant to HS-induced apoptosis. Microarray analysis of hearts focusing on apoptosis related genes revealed that expression of 29% of apoptosis related genes was altered in HS vs. sham rats. IL-6 treatment normalized the expression of these genes, while T40214 pretreatment prevented IL-6-mediated normalization. Thus, cardiac dysfunction, cardiomyocyte apoptosis and induction of apoptosis pathway genes are important components of HCC; IL-6 administration prevented HCC by blocking cardiomyocyte apoptosis and induction of apoptosis pathway genes via Stat3 and warrants further study as a resuscitation adjuvant for prevention of HCC and death in trauma patients. PMID:18270592

Impaired redox environment modulates cardiogenic and ion-channel gene expression in cardiac-resident and non-resident mesenchymal stem cells.

PubMed

Subramani, Baskar; Subbannagounder, Sellamuthu; Ramanathanpullai, Chithra; Palanivel, Sekar; Ramasamy, Rajesh

2017-03-01

Redox homeostasis plays a crucial role in the regulation of self-renewal and differentiation of stem cells. However, the behavioral actions of mesenchymal stem cells in redox imbalance state remain elusive. In the present study, the effect of redox imbalance that was induced by either hydrogen peroxide (H 2 O 2 ) or ascorbic acid on human cardiac-resident (hC-MSCs) and non-resident (umbilical cord) mesenchymal stem cells (hUC-MSCs) was evaluated. Both cells were sensitive and responsive when exposed to either H 2 O 2 or ascorbic acid at a concentration of 400 µmol/L. Ascorbic acid pre-treated cells remarkably ameliorated the reactive oxygen species level when treated with H 2 O 2 . The endogenous antioxidative enzyme gene (Sod1, Sod2, TRXR1 and Gpx1) expressions were escalated in both MSCs in response to reactive oxygen species elevation. In contrast, ascorbic acid pre-treated hUC-MSCs attenuated considerable anti-oxidative gene (TRXR1 and Gpx1) expressions, but not the hC-MSCs. Similarly, the cardiogenic gene (Nkx 2.5, Gata4, Mlc2a and β-MHC) and ion-channel gene ( I KDR , I KCa , I to and I Na.TTX ) expressions were significantly increased in both MSCs on the oxidative state. On the contrary, reduced environment could not alter the ion-channel gene expression and negatively regulated the cardiogenic gene expressions except for troponin-1 in both cells. In conclusion, redox imbalance potently alters the cardiac-resident and non-resident MSCs stemness, cardiogenic, and ion-channel gene expressions. In comparison with cardiac-resident MSC, non-resident umbilical cord-MSC has great potential to tolerate the redox imbalance and positively respond to cardiac regeneration. Impact statement Human mesenchymal stem cells (h-MSCs) are highly promising candidates for tissue repair in cardiovascular diseases. However, the retention of cells in the infarcted area has been a major challenge due to its poor viability and/or low survival rate after transplantation. The regenerative potential of mesenchymal stem cells (MSCs) repudiate and enter into premature senescence via oxidative stress. Thus, various strategies have been attempted to improve the MSC survival in 'toxic' conditions. Similarly, we investigated the response of cardiac resident MSC (hC-MSCs) and non-resident MSCs against the oxidative stress induced by H 2 O 2 . Supplementation of ascorbic acid (AA) into MSCs culture profoundly rescued the stem cells from oxidative stress induced by H 2 O 2 . Our data showed that the pre-treatment of AA is able to inhibit the cell death and thus preserving the viability and differentiation potential of MSCs.

TRPC6 fulfills a calcineurin signaling circuit during pathologic cardiac remodeling

PubMed Central

Kuwahara, Koichiro; Wang, Yanggan; McAnally, John; Richardson, James A.; Bassel-Duby, Rhonda; Hill, Joseph A.; Olson, Eric N.

2006-01-01

The heart responds to injury and chronic pressure overload by pathologic growth and remodeling, which frequently result in heart failure and sudden death. Calcium-dependent signaling pathways promote cardiac growth and associated changes in gene expression in response to stress. The calcium/calmodulin-dependent phosphatase calcineurin, which signals to nuclear factor of activated T cells (NFAT) transcription factors, serves as a transducer of calcium signals and is sufficient and necessary for pathologic cardiac hypertrophy and remodeling. Transient receptor potential (TRP) proteins regulate cation entry into cells in response to a variety of signals, and in skeletal muscle, expression of TRP cation channel, subfamily C, member 3 (TRPC3) is increased in response to neurostimulation and calcineurin signaling. Here we show that TRPC6 was upregulated in mouse hearts in response to activated calcineurin and pressure overload, as well as in failing human hearts. Two conserved NFAT consensus sites in the promoter of the TRPC6 gene conferred responsiveness to cardiac stress. Cardiac-specific overexpression of TRPC6 in transgenic mice resulted in heightened sensitivity to stress, a propensity for lethal cardiac growth and heart failure, and an increase in NFAT-dependent expression of β–myosin heavy chain, a sensitive marker for pathologic hypertrophy. These findings implicate TRPC6 as a positive regulator of calcineurin-NFAT signaling and a key component of a calcium-dependent regulatory loop that drives pathologic cardiac remodeling. PMID:17099778

International Society for Heart and Lung Transplantation working formulation of a standardized nomenclature for cardiac allograft vasculopathy-2010.

PubMed

Mehra, Mandeep R; Crespo-Leiro, Maria G; Dipchand, Anne; Ensminger, Stephan M; Hiemann, Nicola E; Kobashigawa, Jon A; Madsen, Joren; Parameshwar, Jayan; Starling, Randall C; Uber, Patricia A

2010-07-01

The development of cardiac allograft vasculopathy remains the Achilles heel of cardiac transplantation. Unfortunately, the definitions of cardiac allograft vasculopathy are diverse, and there are no uniform international standards for the nomenclature of this entity. This consensus document, commissioned by the International Society of Heart and Lung Transplantation Board, is based on best evidence and clinical consensus derived from critical analysis of available information pertaining to angiography, intravascular ultrasound imaging, microvascular function, cardiac allograft histology, circulating immune markers, non-invasive imaging tests, and gene-based and protein-based biomarkers. This document represents a working formulation for an international nomenclature of cardiac allograft vasculopathy, similar to the development of the system for adjudication of cardiac allograft rejection by histology.

Role of the epidermal growth factor receptor in signaling strain-dependent activation of the brain natriuretic peptide gene.

PubMed

Anderson, Hope D I; Wang, Feng; Gardner, David G

2004-03-05

The epidermal growth factor receptor (EGFR) and ectoshedding of heparin-binding epidermal growth factor (HBEGF), an EGFR ligand, have been linked to the development of cardiac myocyte hypertrophy. However, the precise role that the liganded EGFR plays in the transcriptional activation of the gene program that accompanies hypertrophy remains undefined. Utilizing the human (h) BNP gene as a model of hypertrophy-dependent gene activation, we show that activation of the EGFR plays an important role in mediating mechanical strain-dependent stimulation of the hBNP promoter. Strain promotes endothelin (ET) generation through NAD(P)H oxidase-dependent production of reactive oxygen species. ET in turn induces metalloproteinase-mediated cleavage of pro-HBEGF and ectoshedding of HBEGF, which activates the EGFR and stimulates hBNP promoter activity. HBEGF also stimulates other phenotypic markers of hypertrophy including protein synthesis and sarcomeric assembly. The antioxidant N-acetylcysteine or the NAD(P)H oxidase inhibitor, apocynin, inhibited strain-dependent activation of the ET-1 promoter, HBEGF shedding, and hBNP promoter activation. The metalloproteinase inhibitor, GM-6001, prevented the induction of HBEGF ectoshedding and the hBNP promoter response to strain, suggesting a critical role for the metalloproteinase-dependent cleavage event in signaling the strain response. These findings suggest that metalloproteinase activity as an essential step in this pathway may prove to be a relevant therapeutic target in the management of cardiac hypertrophy.

MicroRNA expression, target genes, and signaling pathways in infants with a ventricular septal defect.

PubMed

Chai, Hui; Yan, Zhaoyuan; Huang, Ke; Jiang, Yuanqing; Zhang, Lin

2018-02-01

This study aimed to systematically investigate the relationship between miRNA expression and the occurrence of ventricular septal defect (VSD), and characterize the miRNA target genes and pathways that can lead to VSD. The miRNAs that were differentially expressed in blood samples from VSD and normal infants were screened and validated by implementing miRNA microarrays and qRT-PCR. The target genes regulated by differentially expressed miRNAs were predicted using three target gene databases. The functions and signaling pathways of the target genes were enriched using the GO database and KEGG database, respectively. The transcription and protein expression of specific target genes in critical pathways were compared in the VSD and normal control groups using qRT-PCR and western blotting, respectively. Compared with the normal control group, the VSD group had 22 differentially expressed miRNAs; 19 were downregulated and three were upregulated. The 10,677 predicted target genes participated in many biological functions related to cardiac development and morphogenesis. Four target genes (mGLUR, Gq, PLC, and PKC) were involved in the PKC pathway and four (ECM, FAK, PI3 K, and PDK1) were involved in the PI3 K-Akt pathway. The transcription and protein expression of these eight target genes were significantly upregulated in the VSD group. The 22 miRNAs that were dysregulated in the VSD group were mainly downregulated, which may result in the dysregulation of several key genes and biological functions related to cardiac development. These effects could also be exerted via the upregulation of eight specific target genes, the subsequent over-activation of the PKC and PI3 K-Akt pathways, and the eventual abnormal cardiac development and VSD.

Effect of transverse aortic constriction on cardiac structure, function and gene expression in pregnant rats.

PubMed

Songstad, Nils Thomas; Johansen, David; How, Ole-Jacob; Kaaresen, Per Ivar; Ytrehus, Kirsti; Acharya, Ganesh

2014-01-01

There is an increased risk of heart failure and pulmonary edema in pregnancies complicated by hypertensive disorders. However, in a previous study we found that pregnancy protects against fibrosis and preserves angiogenesis in a rat model of angiotensin II induced cardiac hypertrophy. In this study we test the hypothesis that pregnancy protects against negative effects of increased afterload. Pregnant (gestational day 5.5-8.5) and non-pregnant Wistar rats were randomized to transverse aortic constriction (TAC) or sham surgery. After 14.2 ± 0.14 days echocardiography was performed. Aortic blood pressure and left ventricular (LV) pressure-volume loops were obtained using a conductance catheter. LV collagen content and cardiomyocyte circumference were measured. Myocardial gene expression was assessed by real-time polymerase chain reaction. Heart weight was increased by TAC (p<0.001) but not by pregnancy. Cardiac myocyte circumference was larger in pregnant compared to non-pregnant rats independent of TAC (p = 0.01), however TAC per se did not affect this parameter. Collagen content in LV myocardium was not affected by pregnancy or TAC. TAC increased stroke work more in pregnant rats (34.1 ± 2.4 vs 17.5 ± 2.4 mmHg/mL, p<0.001) than in non-pregnant (28.2 ± 1.7 vs 20.9 ± 1.5 mmHg/mL, p = 0.06). However, it did not lead to overt heart failure in any group. In pregnant rats, α-MHC gene expression was reduced by TAC. Increased in the expression of β-MHC gene was higher in pregnant (5-fold) compared to non-pregnant rats (2-fold) after TAC (p = 0.001). Nine out of the 19 genes related to cardiac remodeling were affected by pregnancy independent of TAC. This study did not support the hypothesis that pregnancy is cardioprotective against the negative effects of increased afterload. Some differences in cardiac structure, function and gene expression between pregnant and non-pregnant rats following TAC indicated that afterload increase is less tolerated in pregnancy.

Comparison of transcriptomic responses to pancreas disease (PD) and heart and skeletal muscle inflammation (HSMI) in heart of Atlantic salmon (Salmo salar L).

PubMed

Johansen, Lill-Heidi; Thim, Hanna L; Jørgensen, Sven Martin; Afanasyev, Sergey; Strandskog, Guro; Taksdal, Torunn; Fremmerlid, Kjersti; McLoughlin, Marion; Jørgensen, Jorunn B; Krasnov, Aleksei

2015-10-01

Pancreas disease (PD) and heart and skeletal muscle inflammation (HSMI) are viral diseases associated with SAV (salmonid alphavirus) and PRV (piscine reovirus), which induce systemic infections and pathologies in cardiac and skeletal muscle tissue of farmed Atlantic salmon (Salmo salar L), resulting in severe morbidity and mortality. While general features of the clinical symptoms and pathogenesis of salmonid viral diseases are relatively well studied, much less is known about molecular mechanisms associated with immunity and disease-specific changes. In this study, transcriptomic analyses of heart tissue from PD and HSMI challenged Atlantic salmon were done, focusing on the mature phases of both diseases at respectively 28-35 and 42-77 days post infection. A large number of immune genes was activated in both trials with prevalence of genes associated with early innate antiviral responses, their expression levels being slightly higher in PD challenged fish. Activation of the IFN axis was in parallel with inflammatory changes that involved diverse humoral and cellular factors. Adaptive immune response genes were more pronounced in fish with HSMI, as suggested by increased expression of a large number of genes associated with differentiation and maturation of B lymphocytes and cytotoxic T cells. A similar down-regulation of non-immune genes such as myofiber and mitochondrial proteins between diseases was most likely reflecting myocardial pathology. A suite of genes important for cardiac function including B-type natriuretic peptide and four neuropeptides displayed differential expression between PD and HSMI. Comparison of results revealed common and distinct features and added to the understanding of both diseases at their mature phases with typical clinical pictures. A number of genes that showed disease-specific changes can be of interest for diagnostics. Copyright © 2015 Elsevier Ltd. All rights reserved.

Signal-dependent repression of DUSP5 by class I HDACs controls nuclear ERK activity and cardiomyocyte hypertrophy

PubMed Central

Ferguson, Bradley S.; Harrison, Brooke C.; Jeong, Mark Y.; Reid, Brian G.; Wempe, Michael F.; Wagner, Florence F.; Holson, Edward B.; McKinsey, Timothy A.

2013-01-01

Cardiac hypertrophy is a strong predictor of morbidity and mortality in patients with heart failure. Small molecule histone deacetylase (HDAC) inhibitors have been shown to suppress cardiac hypertrophy through mechanisms that remain poorly understood. We report that class I HDACs function as signal-dependent repressors of cardiac hypertrophy via inhibition of the gene encoding dual-specificity phosphatase 5 (DUSP5) DUSP5, a nuclear phosphatase that negatively regulates prohypertrophic signaling by ERK1/2. Inhibition of DUSP5 by class I HDACs requires activity of the ERK kinase, mitogen-activated protein kinase kinase (MEK), revealing a self-reinforcing mechanism for promotion of cardiac ERK signaling. In cardiac myocytes treated with highly selective class I HDAC inhibitors, nuclear ERK1/2 signaling is suppressed in a manner that is absolutely dependent on DUSP5. In contrast, cytosolic ERK1/2 activation is maintained under these same conditions. Ectopic expression of DUSP5 in cardiomyocytes results in potent inhibition of agonist-dependent hypertrophy through a mechanism involving suppression of the gene program for hypertrophic growth. These findings define unique roles for class I HDACs and DUSP5 as integral components of a regulatory signaling circuit that controls cardiac hypertrophy. PMID:23720316

Crude oil exposures reveal roles for intracellular calcium cycling in haddock craniofacial and cardiac development

PubMed Central

Sørhus, Elin; Incardona, John P.; Karlsen, Ørjan; Linbo, Tiffany; Sørensen, Lisbet; Nordtug, Trond; van der Meeren, Terje; Thorsen, Anders; Thorbjørnsen, Maja; Jentoft, Sissel; Edvardsen, Rolf B.; Meier, Sonnich

2016-01-01

Recent studies have shown that crude oil exposure affects cardiac development in fish by disrupting excitation-contraction (EC) coupling. We previously found that eggs of Atlantic haddock (Melanogrammus aeglefinus) bind dispersed oil droplets, potentially leading to more profound toxic effects from uptake of polycyclic aromatic hydrocarbons (PAHs). Using lower concentrations of dispersed crude oil (0.7–7 μg/L ∑PAH), here we exposed a broader range of developmental stages over both short and prolonged durations. We quantified effects on cardiac function and morphogenesis, characterized novel craniofacial defects, and examined the expression of genes encoding potential targets underlying cardiac and craniofacial defects. Because of oil droplet binding, a 24-hr exposure was sufficient to create severe cardiac and craniofacial abnormalities. The specific nature of the craniofacial abnormalities suggests that crude oil may target common craniofacial and cardiac precursor cells either directly or indirectly by affecting ion channels and intracellular calcium in particular. Furthermore, down-regulation of genes encoding specific components of the EC coupling machinery suggests that crude oil disrupts excitation-transcription coupling or normal feedback regulation of ion channels blocked by PAHs. These data support a unifying hypothesis whereby depletion of intracellular calcium pools by crude oil-derived PAHs disrupts several pathways critical for organogenesis in fish. PMID:27506155

Gene-expression profiling for rejection surveillance after cardiac transplantation.

PubMed

Pham, Michael X; Teuteberg, Jeffrey J; Kfoury, Abdallah G; Starling, Randall C; Deng, Mario C; Cappola, Thomas P; Kao, Andrew; Anderson, Allen S; Cotts, William G; Ewald, Gregory A; Baran, David A; Bogaev, Roberta C; Elashoff, Barbara; Baron, Helen; Yee, James; Valantine, Hannah A

2010-05-20

Endomyocardial biopsy is the standard method of monitoring for rejection in recipients of a cardiac transplant. However, this procedure is uncomfortable, and there are risks associated with it. Gene-expression profiling of peripheral-blood specimens has been shown to correlate with the results of an endomyocardial biopsy. We randomly assigned 602 patients who had undergone cardiac transplantation 6 months to 5 years previously to be monitored for rejection with the use of gene-expression profiling or with the use of routine endomyocardial biopsies, in addition to clinical and echocardiographic assessment of graft function. We performed a noninferiority comparison of the two approaches with respect to the composite primary outcome of rejection with hemodynamic compromise, graft dysfunction due to other causes, death, or retransplantation. During a median follow-up period of 19 months, patients who were monitored with gene-expression profiling and those who underwent routine biopsies had similar 2-year cumulative rates of the composite primary outcome (14.5% and 15.3%, respectively; hazard ratio with gene-expression profiling, 1.04; 95% confidence interval, 0.67 to 1.68). The 2-year rates of death from any cause were also similar in the two groups (6.3% and 5.5%, respectively; P=0.82). Patients who were monitored with the use of gene-expression profiling underwent fewer biopsies per person-year of follow-up than did patients who were monitored with the use of endomyocardial biopsies (0.5 vs. 3.0, P<0.001). Among selected patients who had received a cardiac transplant more than 6 months previously and who were at a low risk for rejection, a strategy of monitoring for rejection that involved gene-expression profiling, as compared with routine biopsies, was not associated with an increased risk of serious adverse outcomes and resulted in the performance of significantly fewer biopsies. (ClinicalTrials.gov number, NCT00351559.) 2010 Massachusetts Medical Society

Identification of the functional domain in the transcription factor RTEF-1 that mediates alpha 1-adrenergic signaling in hypertrophied cardiac myocytes.

PubMed

Ueyama, T; Zhu, C; Valenzuela, Y M; Suzow, J G; Stewart, A F

2000-06-09

Cardiac myocytes respond to alpha(1)-adrenergic receptor stimulation by a progressive hypertrophy accompanied by the activation of many fetal genes, including skeletal muscle alpha-actin. The skeletal muscle alpha-actin gene is activated by signaling through an MCAT element, the binding site of the transcription enhancer factor-1 (TEF-1) family of transcription factors. Previously, we showed that overexpression of the TEF-1-related factor (RTEF-1) increased the alpha(1)-adrenergic response of the skeletal muscle alpha-actin promoter, whereas TEF-1 overexpression did not. Here, we identified the functional domains and specific sequences in RTEF-1 that mediate the alpha(1)-adrenergic response. Chimeric TEF-1 and RTEF-1 expression constructs localized the region responsible for the alpha(1)-adrenergic response to the carboxyl-terminal domain of RTEF-1. Site-directed mutagenesis was used to inactivate eight serine residues of RTEF-1, not present in TEF-1, that are putative targets of alpha(1)-adrenergic-dependent kinases. Mutation of a single serine residue, Ser-322, reduced the alpha(1)-adrenergic activation of RTEF-1 by 70% without affecting protein stability, suggesting that phosphorylation at this serine residue accounts for most of the alpha(1)-adrenergic response. Thus, these results demonstrate that RTEF-1 is a direct target of alpha(1)-adrenergic signaling in hypertrophied cardiac myocytes.

RhoA Regulation of Cardiomyocyte Differentiation

PubMed Central

Kaarbø, Mari; Crane, Denis I.; Murrell, Wayne G.

2013-01-01

Earlier findings from our laboratory implicated RhoA in heart developmental processes. To investigate factors that potentially regulate RhoA expression, RhoA gene organisation and promoter activity were analysed. Comparative analysis indicated strict conservation of both gene organisation and coding sequence of the chick, mouse, and human RhoA genes. Bioinformatics analysis of the derived promoter region of mouse RhoA identified putative consensus sequence binding sites for several transcription factors involved in heart formation and organogenesis generally. Using luciferase reporter assays, RhoA promoter activity was shown to increase in mouse-derived P19CL6 cells that were induced to differentiate into cardiomyocytes. Overexpression of a dominant negative mutant of mouse RhoA (mRhoAN19) blocked this cardiomyocyte differentiation of P19CL6 cells and led to the accumulation of the cardiac transcription factors SRF and GATA4 and the early cardiac marker cardiac α-actin. Taken together, these findings indicate a fundamental role for RhoA in the differentiation of cardiomyocytes. PMID:23935420

KCNE4 and KCNE5: K+ channel regulation and cardiac arrhythmogenesis

PubMed Central

Abbott, Geoffrey W.

2016-01-01

KCNE proteins are single transmembrane-segment voltage-gated potassium (Kv) channel ancillary subunits that exhibit a diverse range of physiological functions. Human KCNE gene mutations are associated with various pathophysiological states, most notably cardiac arrhythmias. Of the five isoforms in the human KCNE gene family, KCNE4 and the X-linked KCNE5 are, to date, the least-studied. Recently, however, interest in these neglected genes has been stoked by their putative association with debilitating or lethal cardiac arrhythmias. The sometimes-overlapping functional effects of KCNE4 and KCNE5 vary depending on both their Kv α subunit partner and on other ancillary subunits within the channel complex, but mostly fall into two contrasting categories either inhibition, or fine-tuning of gating kinetics. This review covers current knowledge regarding the molecular mechanisms of KCNE4 and KCNE5 function, human disease associations, and findings from very recent studies of cardiovascular pathophysiology in Kcne4−/− mice. PMID:27484720

KCNE4 and KCNE5: K(+) channel regulation and cardiac arrhythmogenesis.

PubMed

Abbott, Geoffrey W

2016-11-30

KCNE proteins are single transmembrane-segment voltage-gated potassium (Kv) channel ancillary subunits that exhibit a diverse range of physiological functions. Human KCNE gene mutations are associated with various pathophysiological states, most notably cardiac arrhythmias. Of the five isoforms in the human KCNE gene family, KCNE4 and the X-linked KCNE5 are, to date, the least-studied. Recently, however, interest in these neglected genes has been stoked by their putative association with debilitating or lethal cardiac arrhythmias. The sometimes-overlapping functional effects of KCNE4 and KCNE5 vary depending on both their Kv α subunit partner and on other ancillary subunits within the channel complex, but mostly fall into two contrasting categories - either inhibition, or fine-tuning of gating kinetics. This review covers current knowledge regarding the molecular mechanisms of KCNE4 and KCNE5 function, human disease associations, and findings from very recent studies of cardiovascular pathophysiology in Kcne4(-/-) mice. Copyright © 2016 Elsevier B.V. All rights reserved.

The C-terminus of the long AKAP13 isoform (AKAP-Lbc) is critical for development of compensatory cardiac hypertrophy

PubMed Central

Taglieri, Domenico M.; Johnson, Keven R.; Burmeister, Brian T.; Monasky, Michelle M.; Spindler, Matthew J.; DeSantiago, Jaime; Banach, Kathrin; Conklin, Bruce R.; Carnegie, Graeme K.

2014-01-01

The objective of this study was to determine the role of A-Kinase Anchoring Protein (AKAP)-Lbc in the development of heart failure, by investigating AKAP-Lbc-protein kinase D1 (PKD1) signaling in vivo in cardiac hypertrophy. Using a gene-trap mouse expressing a truncated version of AKAP-Lbc (due to disruption of the endogenous AKAP-Lbc gene), that abolishes PKD1 interaction with AKAP-Lbc (AKAPLbc-ΔPKD), we studied two mouse models of pathological hypertrophy: i) angiotensin (AT-II) and phenylephrine (PE) infusion and ii) transverse aortic constriction (TAC)-induced pressure overload. Our results indicate that AKAP-Lbc-ΔPKD mice exhibit an accelerated progression to cardiac dysfunction in response to AT-II/PE treatment and TAC. AKAP-Lbc-ΔPKD mice display attenuated compensatory cardiac hypertrophy, increased collagen deposition and apoptosis, compared to wild-type (WT) control littermates. Mechanistically, reduced levels of PKD1 activation are observed in AKAP-Lbc-ΔPKD mice compared to WT mice, resulting in diminished phosphorylation of histone deacetylase 5 (HDAC5) and decreased hypertrophic gene expression. This is consistent with a reduced compensatory hypertrophy phenotype leading to progression of heart failure in AKAP-Lbc-ΔPKD mice. Overall, our data demonstrates a critical in vivo role for AKAP-Lbc-PKD1 signaling in the development of compensatory hypertrophy to enhance cardiac performance in response to TAC-induced pressure overload and neurohumoral stimulation by AT-II/PE treatment. PMID:24161911

The C-terminus of the long AKAP13 isoform (AKAP-Lbc) is critical for development of compensatory cardiac hypertrophy.

PubMed

Taglieri, Domenico M; Johnson, Keven R; Burmeister, Brian T; Monasky, Michelle M; Spindler, Matthew J; DeSantiago, Jaime; Banach, Kathrin; Conklin, Bruce R; Carnegie, Graeme K

2014-01-01

The objective of this study was to determine the role of A-Kinase Anchoring Protein (AKAP)-Lbc in the development of heart failure, by investigating AKAP-Lbc-protein kinase D1 (PKD1) signaling in vivo in cardiac hypertrophy. Using a gene-trap mouse expressing a truncated version of AKAP-Lbc (due to disruption of the endogenous AKAP-Lbc gene), that abolishes PKD1 interaction with AKAP-Lbc (AKAP-Lbc-ΔPKD), we studied two mouse models of pathological hypertrophy: i) angiotensin (AT-II) and phenylephrine (PE) infusion and ii) transverse aortic constriction (TAC)-induced pressure overload. Our results indicate that AKAP-Lbc-ΔPKD mice exhibit an accelerated progression to cardiac dysfunction in response to AT-II/PE treatment and TAC. AKAP-Lbc-ΔPKD mice display attenuated compensatory cardiac hypertrophy, increased collagen deposition and apoptosis, compared to wild-type (WT) control littermates. Mechanistically, reduced levels of PKD1 activation are observed in AKAP-Lbc-ΔPKD mice compared to WT mice, resulting in diminished phosphorylation of histone deacetylase 5 (HDAC5) and decreased hypertrophic gene expression. This is consistent with a reduced compensatory hypertrophy phenotype leading to progression of heart failure in AKAP-Lbc-ΔPKD mice. Overall, our data demonstrates a critical in vivo role for AKAP-Lbc-PKD1 signaling in the development of compensatory hypertrophy to enhance cardiac performance in response to TAC-induced pressure overload and neurohumoral stimulation by AT-II/PE treatment. © 2013.

Sustained viral gene delivery from a micro-fibrous, elastomeric cardiac patch to the ischemic rat heart.

PubMed

Gu, Xinzhu; Matsumura, Yasumoto; Tang, Ying; Roy, Souvik; Hoff, Richard; Wang, Bing; Wagner, William R

2017-07-01

Biodegradable and elastomeric patches have been applied to the surface of infarcted hearts as temporary mechanical supports to effectively alter adverse left ventricular remodeling processes. In this report, recombinant adeno-associated virus (AAV), known for its persistent transgene expression and low pathogenicity, was incorporated into elastomeric polyester urethane urea (PEUU) and polyester ether urethane urea (PEEUU) and processed by electrospinning into two formats (solid fibers and core-sheath fibers) designed to influence the controlled release behavior. The extended release of AAV encoding green fluorescent protein (GFP) was assessed in vitro. Sustained and localized viral particle delivery was achieved over 2 months in vitro. The biodegradable cardiac patches with or without AAV-GFP were implanted over rat left ventricular lesions three days following myocardial infarction to evaluate the transduction effect of released viral vectors. AAV particles were directly injected into the infarcted hearts as a control. Cardiac function and remodeling were significantly improved for 12 weeks after patch implantation compared to AAV injection. More GFP genes was expressed in the AAV patch group than AAV injection group, with both α-SMA positive cells and cardiac troponin T positive cells transduced in the patch group. Overall, the extended release behavior, prolonged transgene expression, and elastomeric mechanical properties make the AAV-loaded scaffold an attractive option for cardiac tissue engineering where both gene delivery and appropriate mechanical support are desired. Copyright © 2017. Published by Elsevier Ltd.

Essential and Unexpected Role of YY1 to Promote Mesodermal Cardiac Differentiation

PubMed Central

Gregoire, Serge; Karra, Ravi; Passer, Derek; Deutsch, Marcus-Andre; Krane, Markus; Feistritzer, Rebecca; Sturzu, Anthony; Domian, Ibrahim; Saga, Yumiko; Wu, Sean M.

2013-01-01

Rational Cardiogenesis is regulated by a complex interplay between transcription factors. However, little is known about how these interactions regulate the transition from mesodermal precursors to cardiac progenitor cells (CPCs). Objective To identify novel regulators of mesodermal cardiac lineage commitment. Methods and Results We performed a bioinformatic-based transcription factor binding site analysis on upstream promoter regions of genes that are enriched in embryonic stem cell (ESC)-derived CPCs. From 32 candidate transcription factors screened, we found that YY1, a repressor of sarcomeric gene expression, is present in CPCs in vivo. Interestingly, we uncovered the ability of YY1 to transcriptionally activate Nkx2.5, a key marker of early cardiogenic commitment. YY1 regulates Nkx2.5 expression via a 2.1 kb cardiac-specific enhancer as demonstrated by in vitro luciferase-based assays and in vivo chromatin immunoprecipitation (ChIP) and genome-wide sequencing analysis. Furthermore, the ability of YY1 to activate Nkx2.5 expression depends on its cooperative interaction with Gata4 at a nearby chromatin. Cardiac mesoderm-specific loss-of-function of YY1 resulted in early embryonic lethality. This was corroborated in vitro by ESC-based assays where we show that the overexpression of YY1 enhanced the cardiogenic differentiation of ESCs into CPCs. Conclusion These results demonstrate an essential and unexpected role for YY1 to promote cardiogenesis as a transcriptional activator of Nkx2.5 and other CPC-enriched genes. PMID:23307821

Cardiac mesenchymal progenitors from postmortem cardiac tissues retained cellular characterization.

PubMed

Kami, D; Kitani, T; Nakata, M; Gojo, S

2014-05-01

Currently, cells for transplantation in regenerative medicine are derived from either autologous or allogeneic tissue. The former has the drawbacks that the quality of donor cells may depend on the condition of the patient, while the quantity of the cells may also be limited. To solve these problems, we investigated the potential of allogeneic cardiac mesenchymal progenitors (CMPs) derived from postmortem hearts, which may be immunologically privileged similar to bone marrow-derived mesenchymal progenitors. We examined whether viable CMPs could be isolated from C57/B6 murine cardiac tissues harvested at 24 hours postmortem. After 2- to 3-week propagation with a high dose of basic fibroblast growth factor, we performed cellular characteristics analyses, which included proliferation and differentiation property flow cytometry and microarray analyses. Postmortem CMPs had a longer lag phase after seeding than CMPs obtained from living tissues, but otherwise had similar characteristics in all the analyses. In addition, global gene expression analysis by microarray showed that cells derived from postmortem and living tissues had similar characteristics. These results indicate that allogeneic postmortem CMPs have potential for cell transplantation because they circumvent the issue of both the quality and quantity of donor cells. Copyright © 2014 Elsevier Inc. All rights reserved.

Estrogen regulates histone deacetylases to prevent cardiac hypertrophy

PubMed Central

Pedram, Ali; Razandi, Mahnaz; Narayanan, Ramesh; Dalton, James T.; McKinsey, Timothy A.; Levin, Ellis R.

2013-01-01

The development and progression of cardiac hypertrophy often leads to heart failure and death, and important modulators of hypertrophy include the histone deacetylase proteins (HDACs). Estrogen inhibits cardiac hypertrophy and progression in animal models and humans. We therefore investigated the influence of 17-β-estradiol on the production, localization, and functions of prohypertrophic (class I) and antihypertrophic (class II) HDACs in cultured neonatal rat cardiomyocytes. 17-β-Estradiol or estrogen receptor β agonists dipropylnitrile and β-LGND2 comparably suppressed angiotensin II–induced HDAC2 (class I) production, HDAC-activating phosphorylation, and the resulting prohypertrophic mRNA expression. In contrast, estrogenic compounds derepressed the opposite effects of angiotensin II on the same parameters for HDAC4 and 5 (class II), resulting in retention of these deacetylases in the nucleus to inhibit hypertrophic gene expression. Key aspects were confirmed in vivo from the hearts of wild-type but not estrogen receptor β (ERβ) gene–deleted mice administered angiotensin II and estrogenic compounds. Our results identify a novel dual regulation of cardiomyocyte HDACs, shown here for the antihypertrophic sex steroid acting at ERβ. This mechanism potentially supports using ERβ agonists as HDAC modulators to treat cardiac disease. PMID:24152730

Coding Sequence Mutations Identified in MYH7, TNNT2, SCN5A, CSRP3, LBD3, and TCAP from 313 Patients with Familial or Idiopathic Dilated Cardiomyopathy

PubMed Central

Hershberger, Ray E.; Parks, Sharie B.; Kushner, Jessica D.; Li, Duanxiang; Ludwigsen, Susan; Jakobs, Petra; Nauman, Deirdre; Burgess, Donna; Partain, Julie; Litt, Michael

2008-01-01

Abstract Background: More than 20 genes have been reported to cause idiopathic and familial dilated cardiomyopathy (IDC/FDC), but the frequency of genetic causation remains poorly understood. Methods and Results: Blood samples were collected and DNA prepared from 313 patients, 183 with FDC and 130 with IDC. Genomic DNA underwent bidirectional sequencing of six genes, and mutation carriers were followed up by evaluation of additional family members. We identified in 36 probands, 31 unique protein‐altering variants (11.5% overall) that were not identified in 253 control subjects (506 chromosomes). These included 13 probands (4.2%) with 12 β‐myosin heavy chain (MYH7) mutations, nine probands (2.9%) with six different cardiac troponin T (TNNT2) mutations, eight probands (2.6%) carrying seven different cardiac sodium channel (SCN5A) mutations, three probands (1.0%) with three titin‐cap or telethonin (TCAP) mutations, three probands (1.0%) with two LIM domain binding 3 (LDB3) mutations, and one proband (0.3%) with a muscle LIM protein (CSRP3) mutation. Four nucleotide changes did not segregate with phentoype and/or did not alter a conserved amino acid and were therefore considered unlikely to be disease‐causing. Mutations in 11 probands were assessed as likely disease‐causing, and in 21 probands were considered possibly disease‐causing. These 32 probands included 14 of the 130 with IDC (10.8%) and 18 of the 183 with FDC (9.8%) Conclusions: Mutations of these six genes each account for a small fraction of the genetic cause of FDC/IDC. The frequency of possible or likely disease‐causing mutations in these genes is similar for IDC and FDC. PMID:19412328

Cardiac-Specific IGF-1 Receptor Transgenic Expression Protects Against Cardiac Fibrosis and Diastolic Dysfunction in a Mouse Model of Diabetic Cardiomyopathy

PubMed Central

Huynh, Karina; McMullen, Julie R.; Julius, Tracey L.; Tan, Joon Win; Love, Jane E.; Cemerlang, Nelly; Kiriazis, Helen; Du, Xiao-Jun; Ritchie, Rebecca H.

2010-01-01

OBJECTIVE Compelling epidemiological and clinical evidence has identified a specific cardiomyopathy in diabetes, characterized by early diastolic dysfunction and adverse structural remodeling. Activation of the insulin-like growth factor 1 (IGF-1) receptor (IGF-1R) promotes physiological cardiac growth and enhances contractile function. The aim of the present study was to examine whether cardiac-specific overexpression of IGF-1R prevents diabetes-induced myocardial remodeling and dysfunction associated with a murine model of diabetes. RESEARCH DESIGN AND METHODS Type 1 diabetes was induced in 7-week-old male IGF-1R transgenic mice using streptozotocin and followed for 8 weeks. Diastolic and systolic function was assessed using Doppler and M-mode echocardiography, respectively, in addition to cardiac catheterization. Cardiac fibrosis and cardiomyocyte width, heart weight index, gene expression, Akt activity, and IGF-1R protein content were also assessed. RESULTS Nontransgenic (Ntg) diabetic mice had reduced initial (E)-to-second (A) blood flow velocity ratio (E:A ratio) and prolonged deceleration times on Doppler echocardiography compared with nondiabetic counterparts, indicative markers of diastolic dysfunction. Diabetes also increased cardiomyocyte width, collagen deposition, and prohypertrophic and profibrotic gene expression compared with Ntg nondiabetic littermates. Overexpression of the IGF-1R transgene markedly reduced collagen deposition, accompanied by a reduction in the incidence of diastolic dysfunction. Akt phosphorylation was elevated ∼15-fold in IGF-1R nondiabetic mice compared with Ntg, and this was maintained in a setting of diabetes. CONCLUSIONS The current study suggests that cardiac overexpression of IGF-1R prevented diabetes-induced cardiac fibrosis and diastolic dysfunction. Targeting IGF-1R–Akt signaling may represent a therapeutic target for the treatment of diabetic cardiac disease. PMID:20215428

β-Arrestin2 Improves Post-Myocardial Infarction Heart Failure via Sarco(endo)plasmic Reticulum Ca2+-ATPase-Dependent Positive Inotropy in Cardiomyocytes.

PubMed

McCrink, Katie A; Maning, Jennifer; Vu, Angela; Jafferjee, Malika; Marrero, Christine; Brill, Ava; Bathgate-Siryk, Ashley; Dabul, Samalia; Koch, Walter J; Lymperopoulos, Anastasios

2017-11-01

Heart failure is the leading cause of death in the Western world, and new and innovative treatments are needed. The GPCR (G protein-coupled receptor) adapter proteins βarr (β-arrestin)-1 and βarr-2 are functionally distinct in the heart. βarr1 is cardiotoxic, decreasing contractility by opposing β 1 AR (adrenergic receptor) signaling and promoting apoptosis/inflammation post-myocardial infarction (MI). Conversely, βarr2 inhibits apoptosis/inflammation post-MI but its effects on cardiac function are not well understood. Herein, we sought to investigate whether βarr2 actually increases cardiac contractility. Via proteomic investigations in transgenic mouse hearts and in H9c2 rat cardiomyocytes, we have uncovered that βarr2 directly interacts with SERCA2a (sarco[endo]plasmic reticulum Ca 2+ -ATPase) in vivo and in vitro in a β 1 AR-dependent manner. This interaction causes acute SERCA2a SUMO (small ubiquitin-like modifier)-ylation, increasing SERCA2a activity and thus, cardiac contractility. βarr1 lacks this effect. Moreover, βarr2 does not desensitize β 1 AR cAMP-dependent procontractile signaling in cardiomyocytes, again contrary to βarr1. In vivo, post-MI heart failure mice overexpressing cardiac βarr2 have markedly improved cardiac function, apoptosis, inflammation, and adverse remodeling markers, as well as increased SERCA2a SUMOylation, levels, and activity, compared with control animals. Notably, βarr2 is capable of ameliorating cardiac function and remodeling post-MI despite not increasing cardiac βAR number or cAMP levels in vivo. In conclusion, enhancement of cardiac βarr2 levels/signaling via cardiac-specific gene transfer augments cardiac function safely, that is, while attenuating post-MI remodeling. Thus, cardiac βarr2 gene transfer might be a novel, safe positive inotropic therapy for both acute and chronic post-MI heart failure. © 2017 American Heart Association, Inc.

Trastuzumab Alters the Expression of Genes Essential for Cardiac Function and Induces Ultrastructural Changes of Cardiomyocytes in Mice

PubMed Central

ElZarrad, M. Khair; Mukhopadhyay, Partha; Mohan, Nishant; Hao, Enkui; Dokmanovic, Milos; Hirsch, Dianne S.; Shen, Yi; Pacher, Pal; Wu, Wen Jin

2013-01-01

Treatment with trastuzumab, a humanized monoclonal antibody directed against the extracellular domain of Human Epidermal Growth Factor Receptor 2 (HER2), very successfully improves outcomes for women with HER2-positive breast cancer. However, trastuzumab treatment was recently linked to potentially irreversible serious cardiotoxicity, the mechanisms of which are largely elusive. This study reports that trastuzumab significantly alters the expression of myocardial genes essential for DNA repair, cardiac and mitochondrial functions, which is associated with impaired left ventricular performance in mice coupled with significant ultrastructural alterations in cardiomyocytes revealed by electron microscopy. Furthermore, trastuzumab treatment also promotes oxidative stress and apoptosis in myocardium of mice, and elevates serum levels of cardiac troponin-I (cTnI) and cardiac myosin light chain-1 (cMLC1). The elevated serum levels of cMLC1 in mice treated with trastuzumab highlights the potential that cMLC1 could be a useful biomarker for trastuzumab-induced cardiotoxicity. PMID:24255707

Cardiac Gene Expression Knockdown Using Small Inhibitory RNA-Loaded Microbubbles and Ultrasound.

PubMed

Kopechek, Jonathan A; Carson, Andrew R; McTiernan, Charles F; Chen, Xucai; Klein, Edwin C; Villanueva, Flordeliza S

2016-01-01

RNA interference has potential therapeutic value for cardiac disease, but targeted delivery of interfering RNA is a challenge. Custom designed microbubbles, in conjunction with ultrasound, can deliver small inhibitory RNA to target tissues in vivo. The efficacy of cardiac RNA interference using a microbubble-ultrasound theranostic platform has not been demonstrated in vivo. Therefore, our objective was to test the hypothesis that custom designed microbubbles and ultrasound can mediate effective delivery of small inhibitory RNA to the heart. Microbubble and ultrasound mediated cardiac RNA interference was tested in transgenic mice displaying cardiac-restricted luciferase expression. Luciferase expression was assayed in select tissues of untreated mice (n = 14). Mice received intravenous infusion of cationic microbubbles bearing small inhibitory RNA directed against luciferase (n = 9) or control RNA (n = 8) during intermittent cardiac-directed ultrasound at mechanical index of 1.6. Simultaneous echocardiography in a separate group of mice (n = 3) confirmed microbubble destruction and replenishment during treatment. Three days post treatment, cardiac luciferase messenger RNA and protein levels were significantly lower in ultrasound-treated mice receiving microbubbles loaded with small inhibitory RNA directed against luciferase compared to mice receiving microbubbles bearing control RNA (23±7% and 33±7% of control mice, p<0.01 and p = 0.03, respectively). Passive cavitation detection focused on the heart confirmed that insonification resulted in inertial cavitation. In conclusion, small inhibitory RNA-loaded microbubbles and ultrasound directed at the heart significantly reduced the expression of a reporter gene. Ultrasound-targeted destruction of RNA-loaded microbubbles may be an effective image-guided strategy for therapeutic RNA interference in cardiac disease.

Cardiac-specific expression and hypertrophic upregulation of the feline Na(+)-Ca(2+) exchanger gene H1-promoter in a transgenic mouse model.

PubMed

Müller, Joachim G; Isomatsu, Yukihisa; Koushik, Srinagesh V; O'Quinn, Michael; Xu, Lin; Kappler, Christiana S; Hapke, Elizabeth; Zile, Michael R; Conway, Simon J; Menick, Donald R

2002-02-08

The NCX1 gene contains three promoters (H1, K1, and Br1), and as a result of alternative promoter usage and alternative splicing, there are multiple tissue-specific variants of the Na(+)-Ca(2+) exchanger. We have proposed that for NCX1, the H1 promoter regulates expression in the heart, the K1 promoter regulates expression in the kidney, and the Br1 promoter regulates expression in the brain as well as low-level ubiquitous expression. Here, using a transgenic mouse model, we test the role of the DNA region including -1831 to 67 bp of intron 1, encompassing exon H1 of the feline NCX1 gene (NCX1H1). The NCX1H1 promoter was sufficient for driving the normal spatiotemporal pattern of NCX1 expression in cardiac development. The luciferase reporter gene was expressed in a heart-restricted pattern both in early embryos (embryonic days 8 to 14) and in later embryos (after embryonic day 14), when NCX1 is also expressed in other tissues. In the adult, no luciferase activity was detected in the kidney, liver, spleen, uterus, or skeletal muscle; minimal activity was detected in the brain; and very high levels of luciferase expression were detected in the heart. Transverse aortic constriction-operated mice showed significantly increased left ventricular mass after 7 days. In addition, there was a 2-fold upregulation of NCX1H1 promoter activity in the left ventricle in animals after 7 days of pressure overload compared with both control and sham-operated animals. This work demonstrates that the NCX1H1 promoter directs cardiac-specific expression of the exchanger in both the embryo and adult and is also sufficient for the upregulation of NCX1 in response to pressure overload.

Bradykinin activates a cross-signaling pathway between sensory and adrenergic nerve endings in the heart: a novel mechanism of ischemic norepinephrine release?

PubMed

Seyedi, N; Maruyama, R; Levi, R

1999-08-01

We had shown that bradykinin (BK) generated by cardiac sympathetic nerve endings (i.e., synaptosomes) promotes exocytotic norepinephrine (NE) release in an autocrine mode. Because the synaptosomal preparation may include sensory C-fiber endings, which BK is known to stimulate, sensory nerves could contribute to the proadrenergic effects of BK in the heart. We report that BK is a potent releaser of NE from guinea pig heart synaptosomes (EC(50) approximately 20 nM), an effect mediated by B(2) receptors, and almost completely abolished by prior C-fiber destruction or blockade of calcitonin gene-related peptide and neurokinin-1 receptors. C-fiber destruction also greatly decreased BK-induced NE release from the intact heart, whereas tyramine-induced NE release was unaffected. Furthermore, C-fiber stimulation with capsaicin and activation of calcitonin gene-related peptide and neurokinin-1 receptors initiated NE release from cardiac synaptosomes, indicating that stimulation of sensory neurons in turn activates sympathetic nerve terminals. Thus, BK is likely to release NE in the heart in part by first liberating calcitonin gene-related peptide and Substance P from sensory nerve endings; these neuropeptides then stimulate specific receptors on sympathetic terminals. This action of BK is positively modulated by cyclooxygenase products, attenuated by activation of histamine H(3) receptors, and potentiated at a lower pH. The NE-releasing action of BK is likely to be enhanced in myocardial ischemia, when protons accumulate, C fibers become activated, and the production of prostaglandins and BK increases. Because NE is a major arrhythmogenic agent, the activation of this interneuronal signaling system between sensory and adrenergic neurons may contribute to ischemic dysrhythmias and sudden cardiac death.

Mucopolysaccharidosis-like phenotype in feline Sandhoff disease and partial correction after AAV gene therapy.

PubMed

Gray-Edwards, Heather L; Brunson, Brandon L; Holland, Merrilee; Hespel, Adrien-Maxence; Bradbury, Allison M; McCurdy, Victoria J; Beadlescomb, Patricia M; Randle, Ashley N; Salibi, Nouha; Denney, Thomas S; Beyers, Ronald J; Johnson, Aime K; Voyles, Meredith L; Montgomery, Ronald D; Wilson, Diane U; Hudson, Judith A; Cox, Nancy R; Baker, Henry J; Sena-Esteves, Miguel; Martin, Douglas R

2015-01-01

Sandhoff disease (SD) is a fatal neurodegenerative disease caused by a mutation in the enzyme β-N-acetylhexosaminidase. Children with infantile onset SD develop seizures, loss of motor tone and swallowing problems, eventually reaching a vegetative state with death typically by 4years of age. Other symptoms include vertebral gibbus and cardiac abnormalities strikingly similar to those of the mucopolysaccharidoses. Isolated fibroblasts from SD patients have impaired catabolism of glycosaminoglycans (GAGs). To evaluate mucopolysaccharidosis-like features of the feline SD model, we utilized radiography, MRI, echocardiography, histopathology and GAG quantification of both central nervous system and peripheral tissues/fluids. The feline SD model exhibits cardiac valvular and structural abnormalities, skeletal changes and spinal cord compression that are consistent with accumulation of GAGs, but are much less prominent than the severe neurologic disease that defines the humane endpoint (4.5±0.5months). Sixteen weeks after intracranial AAV gene therapy, GAG storage was cleared in the SD cat cerebral cortex and liver, but not in the heart, lung, skeletal muscle, kidney, spleen, pancreas, small intestine, skin, or urine. GAG storage worsens with time and therefore may become a significant source of pathology in humans whose lives are substantially lengthened by gene therapy or other novel treatments for the primary, neurologic disease. Published by Elsevier Inc.

An Observational Cohort Feasibility Study to Identify Microvesicle and Micro-RNA Biomarkers of Acute Kidney Injury Following Pediatric Cardiac Surgery.

PubMed

Sullo, Nikol; Mariani, Silvia; JnTala, Maria; Kumar, Tracy; Woźniak, Marcin J; Smallwood, Dawn; Pais, Paolo; Westrope, Claire; Lotto, Attilio; Murphy, Gavin J

2018-06-15

Micro-RNA, small noncoding RNA fragments involved in gene regulation, and microvesicles, membrane-bound particles less than 1 μm known to regulate cellular processes including responses to injury, may serve as disease-specific biomarkers of acute kidney injury. We evaluated the feasibility of measuring these signals as well as other known acute kidney injury biomarkers in a mixed pediatric cardiac surgery population. Single center prospective cohort feasibility study. PICU. Twenty-four children (≤ 17 yr) undergoing cardiac surgery with cardiopulmonary bypass without preexisting inflammatory state, acute kidney injury, or extracorporeal life support. None. Acute kidney injury was defined according to modified Kidney Diseases Improving Global Outcomes criteria. Blood and urine samples were collected preoperatively and at 6-12 and 24 hours. Microvesicles derivation was assessed using flow cytometry and NanoSight analysis. Micro-RNAs were isolated from plasma and analyzed by microarray and quantitative real-time polymerase chain reaction. Data completeness for the primary outcomes was 100%. Patients with acute kidney injury (n = 14/24) were younger, underwent longer cardiopulmonary bypass, and required greater inotrope support. Acute kidney injury subjects had different fractional content of platelets and endothelial-derived microvesicles before surgery. Platelets and endothelial microvesicles levels were higher in acute kidney injury patients. A number of micro-RNA species were differentially expressed in acute kidney injury patients. Pathway analysis of candidate target genes in the kidney suggested that the most often affected pathways were phosphatase and tensin homolog and signal transducer and activator of transcription 3 signaling. Microvesicles and micro-RNAs expression patterns in pediatric cardiac surgery patients can be measured in children and potentially serve as tools for stratification of patients at risk of acute kidney injury.

Phosphoinositide 3-kinase (PI3K(p110alpha)) directly regulates key components of the Z-disc and cardiac structure.

PubMed

Waardenberg, Ashley J; Bernardo, Bianca C; Ng, Dominic C H; Shepherd, Peter R; Cemerlang, Nelly; Sbroggiò, Mauro; Wells, Christine A; Dalrymple, Brian P; Brancaccio, Mara; Lin, Ruby C Y; McMullen, Julie R

2011-09-02

Maintenance of cardiac structure and Z-disc signaling are key factors responsible for protecting the heart in a setting of stress, but how these processes are regulated is not well defined. We recently demonstrated that PI3K(p110α) protects the heart against myocardial infarction. The aim of this study was to determine whether PI3K(p110α) directly regulates components of the Z-disc and cardiac structure. To address this question, a unique three-dimensional virtual muscle model was applied to gene expression data from transgenic mice with increased or decreased PI3K(p110α) activity under basal conditions (sham) and in a setting of myocardial infarction to display the location of structural proteins. Key findings from this analysis were then validated experimentally. The three-dimensional virtual muscle model visually highlighted reciprocally regulated transcripts associated with PI3K activation that encoded key components of the Z-disc and costamere, including melusin. Studies were performed to assess whether PI3K and melusin interact in the heart. Here, we identify a novel melusin-PI3K interaction that generates lipid kinase activity. The direct impact of PI3K(p110α) on myocyte structure was assessed by treating neonatal rat ventricular myocytes with PI3K(p110α) inhibitors and examining the myofiber morphology of hearts from PI3K transgenic mice. Results demonstrate that PI3K is critical for myofiber maturation and Z-disc alignment. In summary, PI3K regulates the expression of genes essential for cardiac structure and Z-disc signaling, interacts with melusin, and is critical for Z-disc alignment.

Phosphoinositide 3-Kinase (PI3K(p110α)) Directly Regulates Key Components of the Z-disc and Cardiac Structure*

PubMed Central

Waardenberg, Ashley J.; Bernardo, Bianca C.; Ng, Dominic C. H.; Shepherd, Peter R.; Cemerlang, Nelly; Sbroggiò, Mauro; Wells, Christine A.; Dalrymple, Brian P.; Brancaccio, Mara; Lin, Ruby C. Y.; McMullen, Julie R.

2011-01-01

Maintenance of cardiac structure and Z-disc signaling are key factors responsible for protecting the heart in a setting of stress, but how these processes are regulated is not well defined. We recently demonstrated that PI3K(p110α) protects the heart against myocardial infarction. The aim of this study was to determine whether PI3K(p110α) directly regulates components of the Z-disc and cardiac structure. To address this question, a unique three-dimensional virtual muscle model was applied to gene expression data from transgenic mice with increased or decreased PI3K(p110α) activity under basal conditions (sham) and in a setting of myocardial infarction to display the location of structural proteins. Key findings from this analysis were then validated experimentally. The three-dimensional virtual muscle model visually highlighted reciprocally regulated transcripts associated with PI3K activation that encoded key components of the Z-disc and costamere, including melusin. Studies were performed to assess whether PI3K and melusin interact in the heart. Here, we identify a novel melusin-PI3K interaction that generates lipid kinase activity. The direct impact of PI3K(p110α) on myocyte structure was assessed by treating neonatal rat ventricular myocytes with PI3K(p110α) inhibitors and examining the myofiber morphology of hearts from PI3K transgenic mice. Results demonstrate that PI3K is critical for myofiber maturation and Z-disc alignment. In summary, PI3K regulates the expression of genes essential for cardiac structure and Z-disc signaling, interacts with melusin, and is critical for Z-disc alignment. PMID:21757757

Distinct subsets of Eve-positive pericardial cells stabilise cardiac outflow and contribute to Hox gene-triggered heart morphogenesis in Drosophila.

PubMed

Zmojdzian, Monika; de Joussineau, Svetlana; Da Ponte, Jean Philippe; Jagla, Krzysztof

2018-01-17

The Drosophila heart, composed of discrete subsets of cardioblasts and pericardial cells, undergoes Hox-triggered anterior-posterior morphogenesis, leading to a functional subdivision into heart proper and aorta, with its most anterior part forming a funnel-shaped cardiac outflow. Cardioblasts differentiate into Tin-positive 'working myocytes' and Svp-expressing ostial cells. However, developmental fates and functions of heart-associated pericardial cells remain elusive. Here, we show that the pericardial cells that express the transcription factor Even Skipped adopt distinct fates along the anterior-posterior axis. Among them, the most anterior Antp-Ubx-AbdA - negative cells form a novel cardiac outflow component we call the outflow hanging structure, whereas the Antp-expressing cells differentiate into wing heart precursors. Interestingly, Hox gene expression in the Even Skipped-positive cells not only underlies their antero-posterior diversification, but also influences heart morphogenesis in a non-cell-autonomous way. In brief, we identify a new cardiac outflow component derived from a subset of Even Skipped-expressing cells that stabilises the anterior heart tip, and demonstrate non-cell-autonomous effects of Hox gene expression in the Even Skipped-positive cells on heart morphogenesis. © 2018. Published by The Company of Biologists Ltd.

Partial IGF-1 deficiency is sufficient to reduce heart contractibility, angiotensin II sensibility, and alter gene expression of structural and functional cardiac proteins.

PubMed

González-Guerra, José Luis; Castilla-Cortazar, Inma; Aguirre, Gabriel A; Muñoz, Úrsula; Martín-Estal, Irene; Ávila-Gallego, Elena; Granado, Miriam; Puche, Juan E; García-Villalón, Ángel Luis

2017-01-01

Circulating levels of IGF-1 may decrease under several circumstances like ageing, metabolic syndrome, and advanced cirrhosis. This reduction is associated with insulin resistance, dyslipidemia, progression to type 2 diabetes, and increased risk for cardiovascular diseases. However, underlying mechanisms between IGF-1 deficiency and cardiovascular disease remain elusive. The specific aim of the present work was to study whether the partial IGF-1 deficiency influences heart and/or coronary circulation, comparing vasoactive factors before and after of ischemia-reperfusion (I/R). In addition, histology of the heart was performed together with cardiac gene expression for proteins involved in structure and function (extracellular matrix, contractile proteins, active peptides); carried out using microarrays, followed by RT-qPCR confirmation of the three experimental groups. IGF-1 partial deficiency is associated to a reduction in contractility and angiotensin II sensitivity, interstitial fibrosis as well as altered expression pattern of genes involved in extracellular matrix proteins, calcium dynamics, and cardiac structure and function. Although this work is descriptive, it provides a clear insight of the impact that partial IGF-1 deficiency on the heart and establishes this experimental model as suitable for studying cardiac disease mechanisms and exploring therapeutic options for patients under IGF-1 deficiency conditions.

Partial IGF-1 deficiency is sufficient to reduce heart contractibility, angiotensin II sensibility, and alter gene expression of structural and functional cardiac proteins

PubMed Central

Aguirre, Gabriel A.; Muñoz, Úrsula; Martín-Estal, Irene; Ávila-Gallego, Elena; Granado, Miriam; Puche, Juan E.; García-Villalón, Ángel Luis

2017-01-01

Circulating levels of IGF-1 may decrease under several circumstances like ageing, metabolic syndrome, and advanced cirrhosis. This reduction is associated with insulin resistance, dyslipidemia, progression to type 2 diabetes, and increased risk for cardiovascular diseases. However, underlying mechanisms between IGF-1 deficiency and cardiovascular disease remain elusive. The specific aim of the present work was to study whether the partial IGF-1 deficiency influences heart and/or coronary circulation, comparing vasoactive factors before and after of ischemia-reperfusion (I/R). In addition, histology of the heart was performed together with cardiac gene expression for proteins involved in structure and function (extracellular matrix, contractile proteins, active peptides); carried out using microarrays, followed by RT-qPCR confirmation of the three experimental groups. IGF-1 partial deficiency is associated to a reduction in contractility and angiotensin II sensitivity, interstitial fibrosis as well as altered expression pattern of genes involved in extracellular matrix proteins, calcium dynamics, and cardiac structure and function. Although this work is descriptive, it provides a clear insight of the impact that partial IGF-1 deficiency on the heart and establishes this experimental model as suitable for studying cardiac disease mechanisms and exploring therapeutic options for patients under IGF-1 deficiency conditions. PMID:28806738

Maturation of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) in 3D collagen matrix: Effects of niche cell supplementation and mechanical stimulation.

PubMed

Zhang, W; Kong, C W; Tong, M H; Chooi, W H; Huang, N; Li, R A; Chan, B P

2017-02-01

Cardiomyocytes derived from human embryonic stem cells (hESC-CMs) are regarded as a promising source for regenerative medicine, drug testing and disease modeling. Nevertheless, cardiomyocytes are immature in terms of their contractile structure, metabolism and electrophysiological properties. Here, we fabricate cardiac muscle strips by encapsulating hESC-CMs in collagen-based biomaterials. Supplementation of niche cells at 3% to the number of hESC-CMs enhance the maturation of the hESC-CMs in 3D tissue matrix. The benefits of adding mesenchymal stem cells (MSCs) are comparable to that of adding fibroblasts. These two cell types demonstrate similar effects in promoting the compaction and cell spreading, as well as expression of maturation markers at both gene and protein levels. Mechanical loading, particularly cyclic stretch, produces engineered cardiac tissues with higher maturity in terms of twitch force, elastic modulus, sarcomere length and molecular signature, when comparing to static stretch or non-stretched controls. The current study demonstrates that the application of niche cells and mechanical stretch both stimulate the maturation of hESC-CMs in 3D architecture. Our results therefore suggest that this 3D model can be used for in vitro cardiac maturation study. Cardiomyocytes derived from human embryonic stem cells (hESC-CMs) are regarded as being a promising source of cells for regenerative medicine, drug testing and disease modeling. Nevertheless, cardiomyocytes are immature in terms of their contractile structure, metabolism and electrophysiological properties. In the current study, we have fabricated cardiac muscle strips by encapsulating hESC-CMs in collagen-based biomaterials and demonstrated that supplementation of mesenchymal niche cells as well as provision of mechanical loading particularly stretching have significantly promoted the maturation of the cardiomyocytes and hence improved the mechanical functional characteristics of the tissue strips. Specifically, with 3% niche cells including both fibroblasts and mesenchymal stem cells, a more mature hESC-CMs derived cardiac strip was resulted, in terms of compaction and spreading of cells, and upregulation of molecular signature in both gene and protein expression of maturation. Mechanical loading, particularly cyclic stretch, produces engineered cardiac tissues with higher maturity in terms of molecular signature markers and functional parameters including twitch force, elastic modulus and sarcomere length, when comparing with static stretch or non-stretched controls. The current study demonstrates that the application of niche cells and mechanical stretch both stimulate the maturation of hESC-CMs in 3D architecture, resulting in more mature cardiac strips. Our results contribute to bioengineering of functional heart tissue strips for drug screening and disease modeling. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

The transcription factor MEF2C mediates cardiomyocyte hypertrophy induced by IGF-1 signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Munoz, Juan Pablo; Collao, Andres; Chiong, Mario

2009-10-09

Myocyte enhancer factor 2C (MEF2C) plays an important role in cardiovascular development and is a key transcription factor for cardiac hypertrophy. Here, we describe MEF2C regulation by insulin-like growth factor-1 (IGF-1) and its role in IGF-1-induced cardiac hypertrophy. We found that IGF-1 addition to cultured rat cardiomyocytes activated MEF2C, as evidenced by its increased nuclear localization and DNA binding activity. IGF-1 stimulated MEF2 dependent-gene transcription in a time-dependent manner, as indicated by increased MEF2 promoter-driven reporter gene activity; IGF-1 also induced p38-MAPK phosphorylation, while an inhibitor of p38-MAPK decreased both effects. Additionally, inhibitors of phosphatidylinositol 3-kinase and calcineurin prevented IGF-1-inducedmore » MEF2 transcriptional activity. Via MEF2C-dependent signaling, IGF-1 also stimulated transcription of atrial natriuretic factor and skeletal {alpha}-actin but not of fos-lux reporter genes. These novel data suggest that MEF2C activation by IGF-1 mediates the pro-hypertrophic effects of IGF-1 on cardiac gene expression.« less

Concise Review: Mending a Broken Heart: The Evolution of Biological Therapeutics.

PubMed

Chen, Caressa; Termglinchan, Vittavat; Karakikes, Ioannis

2017-05-01

Heart failure (HF), a common sequela of cardiovascular diseases, remains a staggering clinical problem, associated with high rates of morbidity and mortality worldwide. Advances in pharmacological, interventional, and operative management have improved patient care, but these interventions are insufficient to halt the progression of HF, particularly the end-stage irreversible loss of functional cardiomyocytes. Innovative therapies that could prevent HF progression and improve the function of the failing heart are urgently needed. Following successful preclinical studies, two main strategies have emerged as potential solutions: cardiac gene therapy and cardiac regeneration through stem and precursor cell transplantation. Many potential gene- and cell-based therapies have entered into clinical studies, intending to ameliorate cardiac dysfunction in patients with advanced HF. In this review, we focus on the recent advances in cell- and gene-based therapies in the context of cardiovascular disease, emphasizing the most advanced therapies. The principles and mechanisms of action of gene and cell therapies for HF are discussed along with the limitations of current approaches. Finally, we highlight the emerging technologies that hold promise to revolutionize the biological therapies for cardiovascular diseases. Stem Cells 2017;35:1131-1140. © 2017 AlphaMed Press.

Gut microbiome composition is associated with cardiac disease in zoo-housed western lowland gorillas (Gorilla gorilla gorilla).

PubMed

Krynak, Katherine L; Burke, David J; Martin, Ryan A; Dennis, Patricia M

2017-08-15

Cardiac disease is a leading cause of mortality in zoo-housed western lowland gorillas (Gorilla gorilla gorilla). The gut microbiome is associated with cardiac disease in humans and similarly the gut microbiome may be associated with cardiac diseases in close relatives of humans, such as gorillas. We assessed the relationship between cardiac disease and gut bacterial composition in eight zoo-housed male western lowland gorillas (N = 4 with and N = 4 without cardiac disease) utilizing 16S rRNA gene analysis on the Illumina MiSeq sequencing platform. We found bacterial composition differences between gorillas with and without cardiac disease. Bacterial operational taxonomic units from phyla Bacteroidetes, Spirochaetes, Proteobacteria and Firmicutes were significant indicators of cardiac disease. Our results suggest that further investigations between diet and cardiac disease could improve the management and health of zoo-housed populations of this endangered species. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Patterns of gene expression associated with recovery and injury in heat-stressed rats.

PubMed

Stallings, Jonathan D; Ippolito, Danielle L; Rakesh, Vineet; Baer, Christine E; Dennis, William E; Helwig, Bryan G; Jackson, David A; Leon, Lisa R; Lewis, John A; Reifman, Jaques

2014-12-03

The in vivo gene response associated with hyperthermia is poorly understood. Here, we perform a global, multiorgan characterization of the gene response to heat stress using an in vivo conscious rat model. We heated rats until implanted thermal probes indicated a maximal core temperature of 41.8°C (Tc,Max). We then compared transcriptomic profiles of liver, lung, kidney, and heart tissues harvested from groups of experimental animals at Tc,Max, 24 hours, and 48 hours after heat stress to time-matched controls kept at an ambient temperature. Cardiac histopathology at 48 hours supported persistent cardiac injury in three out of six animals. Microarray analysis identified 78 differentially expressed genes common to all four organs at Tc,Max. Self-organizing maps identified gene-specific signatures corresponding to protein-folding disorders in heat-stressed rats with histopathological evidence of cardiac injury at 48 hours. Quantitative proteomics analysis by iTRAQ (isobaric tag for relative and absolute quantitation) demonstrated that differential protein expression most closely matched the transcriptomic profile in heat-injured animals at 48 hours. Calculation of protein supersaturation scores supported an increased propensity of proteins to aggregate for proteins that were found to be changing in abundance at 24 hours and in animals with cardiac injury at 48 hours, suggesting a mechanistic association between protein misfolding and the heat-stress response. Pathway analyses at both the transcript and protein levels supported catastrophic deficits in energetics and cellular metabolism and activation of the unfolded protein response in heat-stressed rats with histopathological evidence of persistent heat injury, providing the basis for a systems-level physiological model of heat illness and recovery.

Exome Sequencing Identified a Splice Site Mutation in FHL1 that Causes Uruguay Syndrome, an X-Linked Disorder With Skeletal Muscle Hypertrophy and Premature Cardiac Death.

PubMed

Xue, Yuan; Schoser, Benedikt; Rao, Aliz R; Quadrelli, Roberto; Vaglio, Alicia; Rupp, Verena; Beichler, Christine; Nelson, Stanley F; Schapacher-Tilp, Gudrun; Windpassinger, Christian; Wilcox, William R

2016-04-01

Previously, we reported a rare X-linked disorder, Uruguay syndrome in a single family. The main features are pugilistic facies, skeletal deformities, and muscular hypertrophy despite a lack of exercise and cardiac ventricular hypertrophy leading to premature death. An ≈19 Mb critical region on X chromosome was identified through identity-by-descent analysis of 3 affected males. Exome sequencing was conducted on one affected male to identify the disease-causing gene and variant. A splice site variant (c.502-2A>G) in the FHL1 gene was highly suspicious among other candidate genes and variants. FHL1A is the predominant isoform of FHL1 in cardiac and skeletal muscle. Sequencing cDNA showed the splice site variant led to skipping of exons 6 of the FHL1A isoform, equivalent to the FHL1C isoform. Targeted analysis showed that this splice site variant cosegregated with disease in the family. Western blot and immunohistochemical analysis of muscle from the proband showed a significant decrease in protein expression of FHL1A. Real-time polymerase chain reaction analysis of different isoforms of FHL1 demonstrated that the FHL1C is markedly increased. Mutations in the FHL1 gene have been reported in disorders with skeletal and cardiac myopathy but none has the skeletal or facial phenotype seen in patients with Uruguay syndrome. Our data suggest that a novel FHL1 splice site variant results in the absence of FHL1A and the abundance of FHL1C, which may contribute to the complex and severe phenotype. Mutation screening of the FHL1 gene should be considered for patients with uncharacterized myopathies and cardiomyopathies. © 2016 American Heart Association, Inc.

Gallic acid attenuates pulmonary fibrosis in a mouse model of transverse aortic contraction-induced heart failure.

PubMed

Jin, Li; Piao, Zhe Hao; Sun, Simei; Liu, Bin; Ryu, Yuhee; Choi, Sin Young; Kim, Gwi Ran; Kim, Hyung-Seok; Kee, Hae Jin; Jeong, Myung Ho

2017-12-01

Gallic acid, a trihydroxybenzoic acid found in tea and other plants, attenuates cardiac hypertrophy, fibrosis, and hypertension in animal models. However, the role of gallic acid in heart failure remains unknown. In this study, we show that gallic acid administration prevents heart failure-induced pulmonary fibrosis. Heart failure induced in mice, 8weeks after transverse aortic constriction (TAC) surgery, was confirmed by echocardiography. Treatment for 2weeks with gallic acid but not furosemide prevented cardiac dysfunction in mice. Gallic acid significantly inhibited TAC-induced pathological changes in the lungs, such as increased lung mass, pulmonary fibrosis, and damaged alveolar morphology. It also decreased the expression of fibrosis-related genes, including collagen types I and III, fibronectin, connective tissue growth factor (CTGF), and phosphorylated Smad3. Further, it inhibited the expression of epithelial-mesenchymal transition (EMT)-related genes, such as N-cadherin, vimentin, E-cadherin, SNAI1, and TWIST1. We suggest that gallic acid has therapeutic potential for the treatment of heart failure-induced pulmonary fibrosis. Copyright © 2017 Elsevier Inc. All rights reserved.

The Role of Nrf2-Mediated Pathway in Cardiac Remodeling and Heart Failure

PubMed Central

Sun, Wanqing; Zhang, Zhiguo; Zheng, Yang

2014-01-01

Heart failure (HF) is frequently the consequence of sustained, abnormal neurohormonal, and mechanical stress and remains a leading cause of death worldwide. The key pathophysiological process leading to HF is cardiac remodeling, a term referring to maladaptation to cardiac stress at the molecular, cellular, tissue, and organ levels. HF and many of the conditions that predispose one to HF are associated with oxidative stress. Increased generation of reactive oxygen species (ROS) in the heart can directly lead to increased necrosis and apoptosis of cardiomyocytes which subsequently induce cardiac remodeling and dysfunction. Nuclear factor-erythroid-2- (NF-E2-) related factor 2 (Nrf2) is a transcription factor that controls the basal and inducible expression of a battery of antioxidant genes and other cytoprotective phase II detoxifying enzymes that are ubiquitously expressed in the cardiovascular system. Emerging evidence has revealed that Nrf2 and its target genes are critical regulators of cardiovascular homeostasis via the suppression of oxidative stress, which is the key player in the development and progression of HF. The purpose of this review is to summarize evidence that activation of Nrf2 enhances endogenous antioxidant defenses and counteracts oxidative stress-associated cardiac remodeling and HF. PMID:25101151

Telmisartan regresses left ventricular hypertrophy in caveolin-1 deficient mice

PubMed Central

Kreiger, Marta H; Di Lorenzo, Annarita; Teutsch, Christine; Kauser, Katalin; Sessa, William C.

2011-01-01

The role of angiotensin II (Ang II) in promoting cardiac hypertrophy is well known, however the role of the Ang II in a spontaneous model of hypertrophy in mice lacking the protein caveolin-1 (Cav- KO) has not been explored. In this study, WT and Cav-1 KO mice were treated with angiotensin receptor blocker (ARB), telmisartan, and cardiac function assessed by echocardiography. Treatment of Cav-1 KO mice with telmisartan significantly improved cardiac function compared to age-matched, vehicle treated Cav-1 KO mice, while telmisartan did not affected cardiac function in WT mice. Both left ventricular (LV) weight to body weight ratios and LV to tibial length ratios were also reverted by telmisartan in Cav-1 KO but not WT mice. LV hypertrophy was associated with increased expression of natriuretic peptides-A and –B, β-myosin heavy chain and TGF-β and telmisartan treatment normalized the expression of these genes. Telmisartan reduced the expression of collagen genes (Col1A and Col3A) and associated perivascular fibrosis in intramyocardial vessels in Cav-1 KO mice. In conclusion, telmisartan treatment reduces indexes of cardiac hypertrophy in this unique genetic model of spontaneous LV hypertrophy. PMID:20585312

Increased temperature, not cardiac load, activates heat shock transcription factor 1 and heat shock protein 72 expression in the heart.

PubMed

Staib, Jessica L; Quindry, John C; French, Joel P; Criswell, David S; Powers, Scott K

2007-01-01

The expression of myocardial heat shock protein 72 (HSP72) postexercise is initiated by the activation of heat shock transcription factor 1 (HSF1). However, it remains unknown which physiological stimuli govern myocardial HSF1 activation during exercise. These experiments tested the hypothesis that thermal stress and mechanical load, concomitant with simulated exercise, provide independent stimuli for HSF1 activation and ensuing cardiac HSP72 gene expression. To elucidate the independent roles of increased temperature and cardiac workload in the exercise-mediated upregulation of left-ventricular HSP72, hearts from adult male Sprague-Dawley rats were randomly assigned to one of five simulated exercise conditions. Upon reaching a surgical plane of anesthesia, each experimental heart was isolated and perfused using an in vitro working heart model, while independently varying temperatures (i.e., 37 degrees C vs. 40 degrees C) and cardiac workloads (i.e., low preload and afterload vs. high preload and afterload) to mimic exercise responses. Results indicate that hyperthermia, independent of cardiac workload, promoted an increase in nuclear translocation and phosphorylation of HSF1 compared with normothermic left ventricles. Similarly, hyperthermia, independent of workload, resulted in significant increases in cardiac levels of HSP72 mRNA. Collectively, these data suggest that HSF1 activation and HSP72 gene transcriptional competence during simulated exercise are linked to elevated heart temperature and are not a direct function of increased cardiac workload.

Improving cardiac conduction with a skeletal muscle sodium channel by gene and cell therapy

PubMed Central

Lu, Jia; Wang, Hong-Zhan; Jia, Zhiheng; Zuckerman, Joan; Lu, Zhongju; Guo, Yuanjian; Boink, Gerard J.J.; Brink, Peter R.; Robinson, Richard B.; Entcheva, Emilia; Cohen, Ira S.

2012-01-01

The voltage-gated Na+ channel is a critical determinant of the action potential upstroke. Increasing Na+ conductance may speed action potential propagation. Here we propose use of the skeletal muscle Na+ channel SkM1 as a more favorable gene than the cardiac isoform SCN5A to enhance conduction velocity in depolarized cardiac tissue. We used cells which electrically coupled with cardiac myocytes as a delivery platform to introduce the Na+ channels. HEK293 cells were stably transfected with SkM1 or SCN5A. SkM1 had a more depolarized (18mV shift) inactivation curve than SCN5A. We also found that SkM1 recovered faster from inactivation than SCN5A. When coupled with SkM1 expressing cells, cultured myocytes showed an increase in the dV/dtmax of the action potential. Expression of SCN5A had no such effect. In an in vitro cardiac syncytium, coculture of neonatal cardiac myocytes with SkM1 expressing but not SCN5A expressing cells significantly increased the conduction velocity under both normal and depolarized conditions. In an in vitro re-entry model induced by high frequency stimulation, expression of SkM1 also enhanced angular velocity of the induced re-entry. These results suggest that cells carrying a Na+ channel with a more depolarized inactivation curve can improve cardiac excitability and conduction in depolarized tissues. PMID:22526298

The heart and cardiac pacing in Steinert disease.

PubMed

Nigro, Gerardo; Papa, Andrea Antonio; Politano, Luisa

2012-10-01

Myotonic dystrophy (Dystrophia Myotonica, DM) is the most frequently inherited neuromuscular disease of adult life. It is a multisystemic disease with major cardiac involvement. Core features of myotonic dystrophy are myotonia, muscle weakness, cataract, respiratory failure and cardiac conduction abnormalities. Classical DM, first described by Steinert and called Steinert's disease or DM1 (Dystrophia Myotonica type 1) has been identified as an autosomal dominant disorder associated with the presence of an abnormal expansion of a CTG trinucleotide repeat in the 3' untranslated region of DMPK gene on chromosome 19. This review will mainly focus on the various aspects of cardiac involvement in DM1 patients and the current role of cardiac pacing in their treatment.

PULMONARY AND CARDIAC GENE EXPRESSION FOLLOWING ACUTE ULTRAFINE CARBON PARTICLE INHALATION IN HYPERTENSIVE RATS

EPA Science Inventory

Inhalation of ultrafine carbon particles (ufCP) causes cardiac physiological changes without marked pulmonary injury or inflammation. We hypothesized that acute ufCP exposure of 13 months old Spontaneously Hypertensive (SH) rats will cause differential effects on the lung and hea...

Large scale cardiac modeling on the Blue Gene supercomputer.

PubMed

Reumann, Matthias; Fitch, Blake G; Rayshubskiy, Aleksandr; Keller, David U; Weiss, Daniel L; Seemann, Gunnar; Dössel, Olaf; Pitman, Michael C; Rice, John J

2008-01-01

Multi-scale, multi-physical heart models have not yet been able to include a high degree of accuracy and resolution with respect to model detail and spatial resolution due to computational limitations of current systems. We propose a framework to compute large scale cardiac models. Decomposition of anatomical data in segments to be distributed on a parallel computer is carried out by optimal recursive bisection (ORB). The algorithm takes into account a computational load parameter which has to be adjusted according to the cell models used. The diffusion term is realized by the monodomain equations. The anatomical data-set was given by both ventricles of the Visible Female data-set in a 0.2 mm resolution. Heterogeneous anisotropy was included in the computation. Model weights as input for the decomposition and load balancing were set to (a) 1 for tissue and 0 for non-tissue elements; (b) 10 for tissue and 1 for non-tissue elements. Scaling results for 512, 1024, 2048, 4096 and 8192 computational nodes were obtained for 10 ms simulation time. The simulations were carried out on an IBM Blue Gene/L parallel computer. A 1 s simulation was then carried out on 2048 nodes for the optimal model load. Load balances did not differ significantly across computational nodes even if the number of data elements distributed to each node differed greatly. Since the ORB algorithm did not take into account computational load due to communication cycles, the speedup is close to optimal for the computation time but not optimal overall due to the communication overhead. However, the simulation times were reduced form 87 minutes on 512 to 11 minutes on 8192 nodes. This work demonstrates that it is possible to run simulations of the presented detailed cardiac model within hours for the simulation of a heart beat.

Prevalence and Spectrum of Large Deletions or Duplications in the Major Long QT Syndrome-Susceptibility Genes and Implications for Long QT Syndrome Genetic Testing

PubMed Central

Tester, David J.; Benton, Amber J.; Train, Laura; Deal, Barbara; Baudhuin, Linnea M.; Ackerman, Michael J.

2010-01-01

Long QT Syndrome (LQTS) is a cardiac channelopathy associated with syncope, seizures, and sudden death. Approximately 75% of LQTS is due to mutations in genes encoding for three cardiac ion channel alpha-subunits (LQT1-3). However, traditional mutational analyses have limited detection capabilities for atypical mutations such as large gene rearrangements. Here, we set out to determine the prevalence and spectrum of large deletions/duplications in the major LQTS-susceptibility genes among unrelated patients who were mutation-negative following point mutation analysis of LQT1-12-susceptibility genes. Forty-two unrelated clinically strong LQTS patients were analyzed using multiplex ligation-dependent probe amplification (MLPA), a quantitative fluorescent technique for detecting multiple exon deletions and duplications. The SALSA-MLPA LQTS Kit from MRC-Holland was used to analyze the three major LQTS-associated genes: KCNQ1, KCNH2, and SCN5A and the two minor genes: KCNE1 and KCNE2. Overall, 2 gene rearrangements were found in 2/42 (4.8%, CI, 1.7–11%) unrelated patients. A deletion of KCNQ1 exon 3 was identified in a 10 year-old Caucasian boy with a QTc of 660 milliseconds (ms), a personal history of exercise-induced syncope, and a family history of syncope. A deletion of KCNQ1 exon 7 was identified in a 17 year-old Caucasian girl with a QTc of 480 ms, a personal history of exercise-induced syncope, and a family history of sudden cardiac death. In conclusion, since nearly 5% of patients with genetically elusive LQTS had large genomic rearrangements involving the canonical LQTS-susceptibility genes, reflex genetic testing to investigate genomic rearrangements may be of clinical value. PMID:20920651

Transcriptome analysis reveals potential mechanisms underlying differential heart development in fast- and slow-growing broilers under heat stress.

PubMed

Zhang, Jibin; Schmidt, Carl J; Lamont, Susan J

2017-04-13

Modern fast-growing broilers are susceptible to heart failure under heat stress because their relatively small hearts cannot meet increased need of blood pumping. To improve the cardiac tolerance to heat stress in modern broilers through breeding, we need to find the important genes and pathways that contribute to imbalanced cardiac development and frequent occurrence of heat-related heart dysfunction. Two broiler lines - Ross 708 and Illinois - were included in this study as a fast-growing model and a slow-growing model respectively. Each broiler line was separated to two groups at 21 days posthatch. One group was subjected to heat stress treatment in the range of 35-37 °C for 8 h per day, and the other was kept in thermoneutral condition. Body and heart weights were measured at 42 days posthatch, and gene expression in left ventricles were compared between treatments and broiler lines through RNA-seq analysis. Body weight and normalized heart weight were significantly reduced by heat stress only in Ross broilers. RNA-seq results of 44 genes were validated using Biomark assay. A total of 325 differentially expressed (DE) genes were detected between heat stress and thermoneutral in Ross 708 birds, but only 3 in Illinois broilers. Ingenuity pathway analysis (IPA) predicted dramatic changes in multiple cellular activities especially downregulation of cell cycle. Comparison between two lines showed that cell cycle activity is higher in Ross than Illinois in thermoneutral condition but is decreased under heat stress. Among the significant pathways (P < 0.01) listed for different comparisons, "Mitotic Roles of Polo-like Kinases" is always ranked first. The increased susceptibility of modern broilers to cardiac dysfunction under heat stress compared to slow-growing broilers could be due to diminished heart capacity related to reduction in relative heart size. The smaller relative heart size in Ross heat stress group than in Ross thermoneutral group is suggested by the transcriptome analysis to be caused by decreased cell cycle activity and increased apoptosis. The DE genes in RNA-seq analysis and significant pathways in IPA provides potential targets for breeding of heat-tolerant broilers with optimized heart function.

Complex Roads from Genotype to Phenotype in Dilated Cardiomyopathy: Scientific update from the Working Group of Myocardial Function of the European Society of Cardiology

PubMed

Bondue, Antoine; Arbustini, Eloisa; Bianco, Anna M; Ciccarelli, Michele; Dawson, Dana; De Rosa, Matteo; Hamdani, Nazha; Hilfiker-Kleiner, Denise; Meder, Benjamin; Leite Moreira, Adelino; Thum, Thomas; Gabriele Tocchetti, Carlo; Varricchi, Gilda; Van der Velden, Jolanda; Walsh, Roddy; Heymans, Stephane

2018-05-23

Dilated cardiomyopathy (DCM) frequently affects relatively young, economically and socially active adults, and is an important cause of heart failure and transplantation. DCM is a complex disease and its pathological architecture encounters many genetic determinants interacting with environmental factors. The old perspective that every pathogenic gene mutation would lead to a diseased heart, is now being replaced by the novel observation that the phenotype depends not only on the penetrance -malignancy of the mutated gene- but also on epigenetics, age, toxic factors, pregnancy and a diversity of acquired diseases. This review discusses how gene mutations will result in mutation-specific molecular alterations in the heart including increased mitochondrial oxidation (sarcomeric gene e.g. TTN), decreased calcium sensitivity (sarcomeric genes), fibrosis (e.g. LMNA and TTN) or inflammation. Therefore, getting a complete picture of the DCM patient will include genomic data, molecular assessment by preference from cardiac samples, stratification according to co-morbidities, and phenotypic description. Those data will help to better guide the heart failure and anti-arrhythmic treatment, predict response to therapy, develop novel siRNA-based gene silencing for malignant gene mutations, or intervene with mutation-specific altered gene pathways in the heart.

Congenital diaphragmatic hernias: from genes to mechanisms to therapies

PubMed Central

McCulley, David J.; Shen, Yufeng; Wynn, Julia; Shang, Linshan; Bogenschutz, Eric; Sun, Xin

2017-01-01

ABSTRACT Congenital diaphragmatic hernias (CDHs) and structural anomalies of the diaphragm are a common class of congenital birth defects that are associated with significant morbidity and mortality due to associated pulmonary hypoplasia, pulmonary hypertension and heart failure. In ∼30% of CDH patients, genomic analyses have identified a range of genetic defects, including chromosomal anomalies, copy number variants and sequence variants. The affected genes identified in CDH patients include transcription factors, such as GATA4, ZFPM2, NR2F2 and WT1, and signaling pathway components, including members of the retinoic acid pathway. Mutations in these genes affect diaphragm development and can have pleiotropic effects on pulmonary and cardiac development. New therapies, including fetal endoscopic tracheal occlusion and prenatal transplacental fetal treatments, aim to normalize lung development and pulmonary vascular tone to prevent and treat lung hypoplasia and pulmonary hypertension, respectively. Studies of the association between particular genetic mutations and clinical outcomes should allow us to better understand the origin of this birth defect and to improve our ability to predict and identify patients most likely to benefit from specialized treatment strategies. PMID:28768736

Histone Deacetylase Inhibitors Prolong Cardiac Repolarization through Transcriptional Mechanisms.

PubMed

Spence, Stan; Deurinck, Mark; Ju, Haisong; Traebert, Martin; McLean, LeeAnne; Marlowe, Jennifer; Emotte, Corinne; Tritto, Elaine; Tseng, Min; Shultz, Michael; Friedrichs, Gregory S

2016-09-01

Histone deacetylase (HDAC) inhibitors are an emerging class of anticancer agents that modify gene expression by altering the acetylation status of lysine residues of histone proteins, thereby inducing transcription, cell cycle arrest, differentiation, and cell death or apoptosis of cancer cells. In the clinical setting, treatment with HDAC inhibitors has been associated with delayed cardiac repolarization and in rare instances a lethal ventricular tachyarrhythmia known as torsades de pointes. The mechanism(s) of HDAC inhibitor-induced effects on cardiac repolarization is unknown. We demonstrate that administration of structurally diverse HDAC inhibitors to dogs causes delayed but persistent increases in the heart rate corrected QT interval (QTc), an in vivo measure of cardiac repolarization, at timepoints far removed from the Tmax for parent drug and metabolites. Transcriptional profiling of ventricular myocardium from dogs treated with various HDAC inhibitors demonstrated effects on genes involved in protein trafficking, scaffolding and insertion of various ion channels into the cell membrane as well as genes for specific ion channel subunits involved in cardiac repolarization. Extensive in vitro ion channel profiling of various structural classes of HDAC inhibitors (and their major metabolites) by binding and acute patch clamp assays failed to show any consistent correlations with direct ion channel blockade. Drug-induced rescue of an intracellular trafficking-deficient mutant potassium ion channel, hERG (G601S), and decreased maturation (glycosylation) of wild-type hERG expressed by CHO cells in vitro correlated with prolongation of QTc intervals observed in vivo The results suggest that HDAC inhibitor-induced prolongation of cardiac repolarization may be mediated in part by transcriptional changes of genes required for ion channel trafficking and localization to the sarcolemma. These data have broad implications for the development of these drug classes and suggest that the optimal time to assess potentially transcriptionally mediated physiologic effects will be delayed relative to an epigenetic drug's Tmax/Cmax. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

α-cardiac actin is a novel disease gene in familial hypertrophic cardiomyopathy

PubMed Central

Mogensen, Jens; Klausen, Ib C.; Pedersen, Anders K.; Egeblad, Henrik; Bross, Peter; Kruse, Torben A.; Gregersen, Niels; Hansen, Peter S.; Baandrup, Ulrik; Børglum, Anders D.

1999-01-01

We identified the α-cardiac actin gene (ACTC) as a novel disease gene in a pedigree suffering from familial hypertrophic cardiomyopathy (FHC). Linkage analyses excluded all the previously reported FHC loci as possible disease loci in the family studied, with lod scores varying between –2.5 and –6.0. Further linkage analyses of plausible candidate genes highly expressed in the adult human heart identified ACTC as the most likely disease gene, showing a maximal lod score of 3.6. Mutation analysis of ACTC revealed an Ala295Ser mutation in exon 5 close to 2 missense mutations recently described to cause the inherited form of idiopathic dilated cardiomyopathy (IDC). ACTC is the first sarcomeric gene described in which mutations are responsible for 2 different cardiomyopathies. We hypothesize that ACTC mutations affecting sarcomere contraction lead to FHC and that mutations affecting force transmission from the sarcomere to the surrounding syncytium lead to IDC. PMID:10330430

The detection and differentiation of methicillin-resistant and methicillin-susceptible Staphylococcus aureus endocarditis by using the BD GeneOhm StaphSR Assay.

PubMed

Frey, Amy B; Wilson, Deborah A; LaSalvia, Margaret M; Tan, Carmela D; Rodriguez, E Rene; Shrestha, Nabin K; Hall, Gerri S; Procop, Gary W

2011-11-01

We use the BD GeneOhm StaphSR Assay (BD Diagnostics, Oakville, Canada) to screen for Staphylococcus aureus nasal colonization and sought to evaluate this assay for the assessment of valve specimens from patients with endocarditis. We examined 23 paired fresh and formalin-fixed, paraffin-embedded cardiac valve tissue samples, 12 of which had S aureus endocarditis, using the BD GeneOhm StaphSR Assay for the detection and differentiation of methicillin-susceptible and methicillin-resistant S aureus. This assay appropriately characterized all specimens with respect to the presence or absence of S aureus. There was an 87.5% correlation between the presence or absence of the mecA gene and the oxacillin susceptibility results for the S aureus isolates studied. The GeneOhm StaphSR assay accurately detected S aureus in cardiac valve tissue samples. Rare discordances were observed between oxacillin susceptibility status and mecA gene detection by this assay.

Augmented sphingosine 1 phosphate receptor-1 signaling in cardiac fibroblasts induces cardiac hypertrophy and fibrosis through angiotensin II and interleukin-6

PubMed Central

Ohkura, Sei-ichiro; Takashima, Shin-ichiro; Yoshioka, Kazuaki; Okamoto, Yasuo; Inagaki, Yutaka; Sugimoto, Naotoshi; Kitano, Teppei; Takamura, Masayuki; Wada, Takashi; Kaneko, Shuichi; Takuwa, Yoh

2017-01-01

Background: Cardiac fibroblasts, together with cardiomyocytes, occupy the majority of cells in the myocardium and are involved in myocardial remodeling. The lysophospholipid mediator sphigosine-1-phosphate (S1P) regulates functions of cardiovascular cells through multiple receptors including S1PR1–S1PR3. S1PR1 but not other S1P receptors was upregulated in angiotensin II-induced hypertrophic hearts. Therefore, we investigated a role of S1PR1 in fibroblasts for cardiac remodeling by employing transgenic mice that overexpressed S1PR1 under the control of α-smooth muscle actin promoter. In S1PR1-transgenic mouse heart, fibroblasts and/or myofibroblasts were hyperplastic, and those cells as well as vascular smooth muscle cells overexpressed S1PR1. Transgenic mice developed bi-ventricular hypertrophy by 12-week-old and diffuse interstitial fibrosis by 24-week-old without hemodynamic stress. Cardiac remodeling in transgenic mice was associated with greater ERK phosphorylation, upregulation of fetal genes, and systolic dysfunction. Transgenic mouse heart showed increased mRNA expression of angiotensin-converting enzyme and interleukin-6 (IL-6). Isolated fibroblasts from transgenic mice exhibited enhanced generation of angiotensin II, which in turn stimulated IL-6 release. Either an AT1 blocker or angiotensin-converting enzyme inhibitor prevented development of cardiac hypertrophy and fibrosis, systolic dysfunction and increased IL-6 expression in transgenic mice. Finally, administration of anti-IL-6 antibody abolished an increase in tyrosine phosphorylation of STAT3, a major signaling molecule downstream of IL-6, in the transgenic mouse heart and prevented development of cardiac hypertrophy in transgenic mice. These results demonstrate a promoting role of S1PR1 in cardiac fibroblasts for cardiac remodeling, in which angiotensin II—AT1 and IL-6 are involved. PMID:28771545

A landscape of circular RNA expression in the human heart.

PubMed

Tan, Wilson L W; Lim, Benson T S; Anene-Nzelu, Chukwuemeka G O; Ackers-Johnson, Matthew; Dashi, Albert; See, Kelvin; Tiang, Zenia; Lee, Dominic Paul; Chua, Wee Woon; Luu, Tuan D A; Li, Peter Y Q; Richards, Arthur Mark; Foo, Roger S Y

2017-03-01

Circular RNA (circRNA) is a newly validated class of single-stranded RNA, ubiquitously expressed in mammalian tissues and possessing key functions including acting as microRNA sponges and as transcriptional regulators by binding to RNA-binding proteins. While independent studies confirm the expression of circRNA in various tissue types, genome-wide circRNA expression in the heart has yet to be described in detail. We performed deep RNA-sequencing on ribosomal-depleted RNA isolated from 12 human hearts, 25 mouse hearts and across a 28-day differentiation time-course of human embryonic stem cell-derived cardiomyocytes. Using purpose-designed bioinformatics tools, we uncovered a total of 15 318 and 3017 cardiac circRNA within human and mouse, respectively. Their abundance generally correlates with the abundance of their cognate linear RNA, but selected circRNAs exist at disproportionately higher abundance. Top highly expressed circRNA corresponded to key cardiac genes including Titin (TTN), RYR2, and DMD. The most abundant cardiac-expressed circRNA is a cytoplasmic localized single-exon circSLC8A1-1. The longest human transcript TTN alone generates up to 415 different exonic circRNA isoforms, the majority (83%) of which originates from the I-band domain. Finally, we confirmed the expression of selected cardiac circRNA by RT-PCR, Sanger sequencing and single molecule RNA-fluorescence in situ hybridization. Our data provide a detailed circRNA expression landscape in hearts. There is a high-abundance of specific cardiac-expressed circRNA. These findings open up a new avenue for future investigation into this emerging class of RNA. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For Permissions, please email: journals.permissions@oup.com.

Deletion of CXCR4 in cardiomyocytes exacerbates cardiac dysfunction following isoproterenol administration

PubMed Central

Wang, ER; Jarrah, AA; Benard, L; Chen, J; Schwarzkopf, M; Hadri, L; Tarzami, ST

2014-01-01

Altered alpha- and beta-adrenergic receptor signaling is associated with cardiac hypertrophy and failure. Stromal cell-derived factor-1α (SDF-1α) and its cognate receptor CXCR4 have been reported to mediate cardioprotection after injury through the mobilization of stem cells into injured tissue. However, little is known regarding whether SDF-1/CXCR4 induces acute protection following pathological hypertrophy and if so, by what molecular mechanism. We have previously reported that CXCR4 physically interacts with the beta-2 adrenergic receptor and modulates its down stream signaling. Here we have shown that CXCR4 expression prevents beta-adrenergic receptor induced hypertrophy. Cardiac beta-adrenergic receptors were stimulated with the implantation of a subcutaneous osmotic pump administrating isoproterenol and CXCR4 expression was selectively abrogated in cardiomyocytes using Cre-loxP-mediated gene recombination. CXCR4 knockout mice showed worsened fractional shortening and ejection fraction. CXCR4 ablation increased susceptibility to isoproterenol-induced heart failure, by upregulating apoptotic markers and reducing mitochondrial function; cardiac function decreases while fibrosis increases. Additionally, CXCR4 expression was rescued with the use of cardiotropic Adeno-associated viral-9 (AAV9) vectors. CXCR4 gene transfer reduced cardiac apoptotic signaling, improved mitochondrial function and resulted in a recovered cardiac function. Our results represent the first evidence that SDF-1/CXCR4 signaling mediates acute cardioprotection through modulating beta-adrenergic receptor signaling in vivo. PMID:24646609

Cardiac-Specific Disruption of GH Receptor Alters Glucose Homeostasis While Maintaining Normal Cardiac Performance in Adult Male Mice.

PubMed

Jara, Adam; Liu, Xingbo; Sim, Don; Benner, Chance M; Duran-Ortiz, Silvana; Qian, Yanrong; List, Edward O; Berryman, Darlene E; Kim, Jason K; Kopchick, John J

2016-05-01

GH is considered necessary for the proper development and maintenance of several tissues, including the heart. Studies conducted in both GH receptor null and bovine GH transgenic mice have demonstrated specific cardiac structural and functional changes. In each of these mouse lines, however, GH-induced signaling is altered systemically, being decreased in GH receptor null mice and increased in bovine GH transgenic mice. Therefore, to clarify the direct effects GH has on cardiac tissue, we developed a tamoxifen-inducible, cardiac-specific GHR disrupted (iC-GHRKO) mouse line. Cardiac GH receptor was disrupted in 4-month-old iC-GHRKO mice to avoid developmental effects due to perinatal GHR gene disruption. Surprisingly, iC-GHRKO mice showed no difference vs controls in baseline or postdobutamine stress test echocardiography measurements, nor did iC-GHRKO mice show differences in longitudinal systolic blood pressure measurements. Interestingly, iC-GHRKO mice had decreased fat mass and improved insulin sensitivity at 6.5 months of age. By 12.5 months of age, however, iC-GHRKO mice no longer had significant decreases in fat mass and had developed glucose intolerance and insulin resistance. Furthermore, investigation via immunoblot analysis demonstrated that iC-GHRKO mice had appreciably decreased insulin stimulated Akt phosphorylation, specifically in heart and liver, but not in epididymal white adipose tissue. These changes were accompanied by a decrease in circulating IGF-1 levels in 12.5-month-old iC-GHRKO mice. These data indicate that whereas the disruption of cardiomyocyte GH-induced signaling in adult mice does not affect cardiac function, it does play a role in systemic glucose homeostasis, in part through modulation of circulating IGF-1.

Chemical Endoplasmic Reticulum Chaperone Alleviates Doxorubicin-Induced Cardiac Dysfunction.

PubMed

Fu, Hai Ying; Sanada, Shoji; Matsuzaki, Takashi; Liao, Yulin; Okuda, Keiji; Yamato, Masaki; Tsuchida, Shota; Araki, Ryo; Asano, Yoshihiro; Asanuma, Hiroshi; Asakura, Masanori; French, Brent A; Sakata, Yasushi; Kitakaze, Masafumi; Minamino, Tetsuo

2016-03-04

Doxorubicin is an effective chemotherapeutic agent for cancer, but its use is often limited by cardiotoxicity. Doxorubicin causes endoplasmic reticulum (ER) dilation in cardiomyocytes, and we have demonstrated that ER stress plays important roles in the pathophysiology of heart failure. We evaluated the role of ER stress in doxorubicin-induced cardiotoxicity and examined whether the chemical ER chaperone could prevent doxorubicin-induced cardiac dysfunction. We confirmed that doxorubicin caused ER dilation in mouse hearts, indicating that doxorubicin may affect ER function. Doxorubicin activated an ER transmembrane stress sensor, activating transcription factor 6, in cultured cardiomyocytes and mouse hearts. However, doxorubicin suppressed the expression of genes downstream of activating transcription factor 6, including X-box binding protein 1. The decreased levels of X-box binding protein 1 resulted in a failure to induce the expression of the ER chaperone glucose-regulated protein 78 which plays a major role in adaptive responses to ER stress. In addition, doxorubicin activated caspase-12, an ER membrane-resident apoptotic molecule, which can lead to cardiomyocyte apoptosis and cardiac dysfunction. Cardiac-specific overexpression of glucose-regulated protein 78 by adeno-associated virus 9 or the administration of the chemical ER chaperone 4-phenylbutyrate attenuated caspase-12 cleavage, and alleviated cardiac apoptosis and dysfunction induced by doxorubicin. Doxorubicin activated the ER stress-initiated apoptotic response without inducing the ER chaperone glucose-regulated protein 78, further augmenting ER stress in mouse hearts. Cardiac-specific overexpression of glucose-regulated protein 78 or the administration of the chemical ER chaperone alleviated the cardiac dysfunction induced by doxorubicin and may facilitate the safe use of doxorubicin for cancer treatment. © 2016 American Heart Association, Inc.

Integrative Analyses of De Novo Mutations Provide Deeper Biological Insights into Autism Spectrum Disorder.

PubMed

Takata, Atsushi; Miyake, Noriko; Tsurusaki, Yoshinori; Fukai, Ryoko; Miyatake, Satoko; Koshimizu, Eriko; Kushima, Itaru; Okada, Takashi; Morikawa, Mako; Uno, Yota; Ishizuka, Kanako; Nakamura, Kazuhiko; Tsujii, Masatsugu; Yoshikawa, Takeo; Toyota, Tomoko; Okamoto, Nobuhiko; Hiraki, Yoko; Hashimoto, Ryota; Yasuda, Yuka; Saitoh, Shinji; Ohashi, Kei; Sakai, Yasunari; Ohga, Shouichi; Hara, Toshiro; Kato, Mitsuhiro; Nakamura, Kazuyuki; Ito, Aiko; Seiwa, Chizuru; Shirahata, Emi; Osaka, Hitoshi; Matsumoto, Ayumi; Takeshita, Saoko; Tohyama, Jun; Saikusa, Tomoko; Matsuishi, Toyojiro; Nakamura, Takumi; Tsuboi, Takashi; Kato, Tadafumi; Suzuki, Toshifumi; Saitsu, Hirotomo; Nakashima, Mitsuko; Mizuguchi, Takeshi; Tanaka, Fumiaki; Mori, Norio; Ozaki, Norio; Matsumoto, Naomichi

2018-01-16

Recent studies have established important roles of de novo mutations (DNMs) in autism spectrum disorders (ASDs). Here, we analyze DNMs in 262 ASD probands of Japanese origin and confirm the "de novo paradigm" of ASDs across ethnicities. Based on this consistency, we combine the lists of damaging DNMs in our and published ASD cohorts (total number of trios, 4,244) and perform integrative bioinformatics analyses. Besides replicating the findings of previous studies, our analyses highlight ATP-binding genes and fetal cerebellar/striatal circuits. Analysis of individual genes identified 61 genes enriched for damaging DNMs, including ten genes for which our dataset now contributes to statistical significance. Screening of compounds altering the expression of genes hit by damaging DNMs reveals a global downregulating effect of valproic acid, a known risk factor for ASDs, whereas cardiac glycosides upregulate these genes. Collectively, our integrative approach provides deeper biological and potential medical insights into ASDs. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Myocardial Gene Transfer: Routes and Devices for Regulation of Transgene Expression by Modulation of Cellular Permeability

PubMed Central

Katz, Michael G.; Bridges, Charles R.

2013-01-01

Abstract Heart diseases are major causes of morbidity and mortality in Western society. Gene therapy approaches are becoming promising therapeutic modalities to improve underlying molecular processes affecting failing cardiomyocytes. Numerous cardiac clinical gene therapy trials have yet to demonstrate strong positive results and advantages over current pharmacotherapy. The success of gene therapy depends largely on the creation of a reliable and efficient delivery method. The establishment of such a system is determined by its ability to overcome the existing biological barriers, including cellular uptake and intracellular trafficking as well as modulation of cellular permeability. In this article, we describe a variety of physical and mechanical methods, based on the transient disruption of the cell membrane, which are applied in nonviral gene transfer. In addition, we focus on the use of different physiological techniques and devices and pharmacological agents to enhance endothelial permeability. Development of these methods will undoubtedly help solve major problems facing gene therapy. PMID:23427834

Elastin overexpression by cell-based gene therapy preserves matrix and prevents cardiac dilation

PubMed Central

Li, Shu-Hong; Sun, Zhuo; Guo, Lily; Han, Mihan; Wood, Michael F G; Ghosh, Nirmalya; Alex Vitkin, I; Weisel, Richard D; Li, Ren-Ke

2012-01-01

After a myocardial infarction, thinning and expansion of the fibrotic scar contribute to progressive heart failure. The loss of elastin is a major contributor to adverse extracellular matrix remodelling of the infarcted heart, and restoration of the elastic properties of the infarct region can prevent ventricular dysfunction. We implanted cells genetically modified to overexpress elastin to re-establish the elastic properties of the infarcted myocardium and prevent cardiac failure. A full-length human elastin cDNA was cloned, subcloned into an adenoviral vector and then transduced into rat bone marrow stromal cells (BMSCs). In vitro studies showed that BMSCs expressed the elastin protein, which was deposited into the extracellular matrix. Transduced BMSCs were injected into the infarcted myocardium of adult rats. Control groups received either BMSCs transduced with the green fluorescent protein gene or medium alone. Elastin deposition in the infarcted myocardium was associated with preservation of myocardial tissue structural integrity (by birefringence of polarized light; P < 0.05 versus controls). As a result, infarct scar thickness and diastolic compliance were maintained and infarct expansion was prevented (P < 0.05 versus controls). Over a 9-week period, rats implanted with BMSCs demonstrated better cardiac function than medium controls; however, rats receiving BMSCs overexpressing elastin showed the greatest functional improvement (P < 0.01). Overexpression of elastin in the infarcted heart preserved the elastic structure of the extracellular matrix, which, in turn, preserved diastolic function, prevented ventricular dilation and preserved cardiac function. This cell-based gene therapy provides a new approach to cardiac regeneration. PMID:22435995

Overlapping and Divergent Actions of Structurally Distinct Histone Deacetylase Inhibitors in Cardiac Fibroblasts

PubMed Central

Schuetze, Katherine B.; Stratton, Matthew S.; Blakeslee, Weston W.; Wempe, Michael F.; Wagner, Florence F.; Holson, Edward B.; Kuo, Yin-Ming; Andrews, Andrew J.; Gilbert, Tonya M.; Hooker, Jacob M.

2017-01-01

Inhibitors of zinc-dependent histone deacetylases (HDACs) profoundly affect cellular function by altering gene expression via changes in nucleosomal histone tail acetylation. Historically, investigators have employed pan-HDAC inhibitors, such as the hydroxamate trichostatin A (TSA), which simultaneously targets members of each of the three zinc-dependent HDAC classes (classes I, II, and IV). More recently, class- and isoform-selective HDAC inhibitors have been developed, providing invaluable chemical biology probes for dissecting the roles of distinct HDACs in the control of various physiologic and pathophysiological processes. For example, the benzamide class I HDAC-selective inhibitor, MGCD0103 [N-(2-aminophenyl)-4-[[(4-pyridin-3-ylpyrimidin-2-yl)amino]methyl] benzamide], was shown to block cardiac fibrosis, a process involving excess extracellular matrix deposition, which often results in heart dysfunction. Here, we compare the mechanisms of action of structurally distinct HDAC inhibitors in isolated primary cardiac fibroblasts, which are the major extracellular matrix–producing cells of the heart. TSA, MGCD0103, and the cyclic peptide class I HDAC inhibitor, apicidin, exhibited a common ability to enhance histone acetylation, and all potently blocked cardiac fibroblast cell cycle progression. In contrast, MGCD0103, but not TSA or apicidin, paradoxically increased expression of a subset of fibrosis-associated genes. Using the cellular thermal shift assay, we provide evidence that the divergent effects of HDAC inhibitors on cardiac fibroblast gene expression relate to differential engagement of HDAC1- and HDAC2-containing complexes. These findings illustrate the importance of employing multiple compounds when pharmacologically assessing HDAC function in a cellular context and during HDAC inhibitor drug development. PMID:28174211

Transcription Factors MYOCD, SRF, Mesp1 and SMARCD3 Enhance the Cardio-Inducing Effect of GATA4, TBX5, and MEF2C during Direct Cellular Reprogramming

PubMed Central

Christoforou, Nicolas; Chellappan, Malathi; Adler, Andrew F.; Kirkton, Robert D.; Wu, Tianyi; Addis, Russell C.; Bursac, Nenad; Leong, Kam W.

2013-01-01

Transient overexpression of defined combinations of master regulator genes can effectively induce cellular reprogramming: the acquisition of an alternative predicted phenotype from a differentiated cell lineage. This can be of particular importance in cardiac regenerative medicine wherein the heart lacks the capacity to heal itself, but simultaneously contains a large pool of fibroblasts. In this study we determined the cardio-inducing capacity of ten transcription factors to actuate cellular reprogramming of mouse embryonic fibroblasts into cardiomyocyte-like cells. Overexpression of transcription factors MYOCD and SRF alone or in conjunction with Mesp1 and SMARCD3 enhanced the basal but necessary cardio-inducing effect of the previously reported GATA4, TBX5, and MEF2C. In particular, combinations of five or seven transcription factors enhanced the activation of cardiac reporter vectors, and induced an upregulation of cardiac-specific genes. Global gene expression analysis also demonstrated a significantly greater cardio-inducing effect when the transcription factors MYOCD and SRF were used. Detection of cross-striated cells was highly dependent on the cell culture conditions and was enhanced by the addition of valproic acid and JAK inhibitor. Although we detected Ca2+ transient oscillations in the reprogrammed cells, we did not detect significant changes in resting membrane potential or spontaneously contracting cells. This study further elucidates the cardio-inducing effect of the transcriptional networks involved in cardiac cellular reprogramming, contributing to the ongoing rational design of a robust protocol required for cardiac regenerative therapies. PMID:23704920

THE INVOLVEMENT OF HUMAN MONOGENIC CARDIOMYOPATHY GENES IN EXPERIMENTAL POLYGENIC CARDIAC HYPERTROPHY.

PubMed

Prestes, Priscilla R; Marques, Francine Z; Lopez-Campos, Guillermo; Lewandowski, Paul; Delbridge, Lea M D; Charchar, Fadi J; Harrap, Stephen B

2018-05-18

Hypertrophic cardiomyopathy thickens heart muscles reducing functionality and increasing risk of cardiac disease and morbidity. Genetic factors are involved, but their contribution is poorly understood. We used the hypertrophic heart rat (HHR), a unique normotensive polygenic model of cardiac hypertrophy and heart failure to investigate the role of genes associated with monogenic human cardiomyopathy. We selected 42 genes involved in monogenic human cardiomyopathies to study: 1) DNA variants, by sequencing the whole-genome of 13-week old HHR and age-matched normal heart rat (NHR), its genetic control strain; 2) mRNA expression, by targeted RNA-sequencing in left ventricles of HHR and NHR at five ages (2-days old, 4-, 13-, 33- and 50-weeks old) compared to human idiopathic dilated data; and 3) microRNA expression, with rat microRNA microarrays in left ventricles of 2-days old HHR and age-matched NHR. We also investigated experimentally validated microRNA-mRNA interactions. Whole-genome sequencing revealed unique variants mostly located in non-coding regions of HHR and NHR. We found 29 genes differentially expressed in at least one age. Genes encoding desmoglein 2 (Dsg2) and transthyretin (Ttr) were significantly differentially expressed at all ages in the HHR, but only Ttr was also differentially expressed in human idiopathic cardiomyopathy. Lastly, only two microRNAs differentially expressed in the HHR were present in our comparison of validated microRNA-mRNA interactions. These two microRNAs interact with five of the genes studied. Our study shows that genes involved in monogenic forms of human cardiomyopathies may also influence polygenic forms of the disease.

Cardiac Gene Expression Knockdown Using Small Inhibitory RNA-Loaded Microbubbles and Ultrasound

PubMed Central

McTiernan, Charles F.; Chen, Xucai; Klein, Edwin C.; Villanueva, Flordeliza S.

2016-01-01

RNA interference has potential therapeutic value for cardiac disease, but targeted delivery of interfering RNA is a challenge. Custom designed microbubbles, in conjunction with ultrasound, can deliver small inhibitory RNA to target tissues in vivo. The efficacy of cardiac RNA interference using a microbubble-ultrasound theranostic platform has not been demonstrated in vivo. Therefore, our objective was to test the hypothesis that custom designed microbubbles and ultrasound can mediate effective delivery of small inhibitory RNA to the heart. Microbubble and ultrasound mediated cardiac RNA interference was tested in transgenic mice displaying cardiac-restricted luciferase expression. Luciferase expression was assayed in select tissues of untreated mice (n = 14). Mice received intravenous infusion of cationic microbubbles bearing small inhibitory RNA directed against luciferase (n = 9) or control RNA (n = 8) during intermittent cardiac-directed ultrasound at mechanical index of 1.6. Simultaneous echocardiography in a separate group of mice (n = 3) confirmed microbubble destruction and replenishment during treatment. Three days post treatment, cardiac luciferase messenger RNA and protein levels were significantly lower in ultrasound-treated mice receiving microbubbles loaded with small inhibitory RNA directed against luciferase compared to mice receiving microbubbles bearing control RNA (23±7% and 33±7% of control mice, p<0.01 and p = 0.03, respectively). Passive cavitation detection focused on the heart confirmed that insonification resulted in inertial cavitation. In conclusion, small inhibitory RNA-loaded microbubbles and ultrasound directed at the heart significantly reduced the expression of a reporter gene. Ultrasound-targeted destruction of RNA-loaded microbubbles may be an effective image-guided strategy for therapeutic RNA interference in cardiac disease. PMID:27471848

Cardiac-Specific Deletion of Pyruvate Dehydrogenase Impairs Glucose Oxidation Rates and Induces Diastolic Dysfunction.

PubMed

Gopal, Keshav; Almutairi, Malak; Al Batran, Rami; Eaton, Farah; Gandhi, Manoj; Ussher, John Reyes

2018-01-01

Obesity and type 2 diabetes (T2D) increase the risk for cardiomyopathy, which is the presence of ventricular dysfunction in the absence of underlying coronary artery disease and/or hypertension. As myocardial energy metabolism is altered during obesity/T2D (increased fatty acid oxidation and decreased glucose oxidation), we hypothesized that restricting myocardial glucose oxidation in lean mice devoid of the perturbed metabolic milieu observed in obesity/T2D would produce a cardiomyopathy phenotype, characterized via diastolic dysfunction. We tested our hypothesis via producing mice with a cardiac-specific gene knockout for pyruvate dehydrogenase (PDH, gene name Pdha1 ), the rate-limiting enzyme for glucose oxidation. Cardiac-specific Pdha1 deficient ( Pdha1 Cardiac-/- ) mice were generated via crossing a tamoxifen-inducible Cre expressing mouse under the control of the alpha-myosin heavy chain (αMHC-MerCreMer) promoter with a floxed Pdha1 mouse. Energy metabolism and cardiac function were assessed via isolated working heart perfusions and ultrasound echocardiography, respectively. Tamoxifen administration produced an ~85% reduction in PDH protein expression in Pdha1 Cardiac-/- mice versus their control littermates, which resulted in a marked reduction in myocardial glucose oxidation and a corresponding increase in palmitate oxidation. This myocardial metabolism profile did not impair systolic function in Pdha1 Cardiac-/- mice, which had comparable left ventricular ejection fractions and fractional shortenings as their αMHC-MerCreMer control littermates, but did produce diastolic dysfunction as seen via the reduced mitral E/A ratio. Therefore, it does appear that forced restriction of glucose oxidation in the hearts of Pdha1 Cardiac-/- mice is sufficient to produce a cardiomyopathy-like phenotype, independent of the perturbed metabolic milieu observed in obesity and/or T2D.

BMP type I receptor ALK2 is required for angiotensin II-induced cardiac hypertrophy

PubMed Central

Spagnolli, Ester; Ernande, Laura; Thoonen, Robrecht; Kolodziej, Starsha A.; Leyton, Patricio A.; Cheng, Juan; Tainsh, Robert E. T.; Mayeur, Claire; Rhee, David K.; Wu, Mei. X.; Scherrer-Crosbie, Marielle; Buys, Emmanuel S.; Zapol, Warren M.; Bloch, Kenneth D.; Bloch, Donald B.

2016-01-01

Bone morphogenetic protein (BMP) signaling contributes to the development of cardiac hypertrophy. However, the identity of the BMP type I receptor involved in cardiac hypertrophy and the underlying molecular mechanisms are poorly understood. By using quantitative PCR and immunoblotting, we demonstrated that BMP signaling increased during phenylephrine-induced hypertrophy in cultured neonatal rat cardiomyocytes (NRCs), as evidenced by increased phosphorylation of Smads 1 and 5 and induction of Id1 gene expression. Inhibition of BMP signaling with LDN193189 or noggin, and silencing of Smad 1 or 4 using small interfering RNA diminished the ability of phenylephrine to induce hypertrophy in NRCs. Conversely, activation of BMP signaling with BMP2 or BMP4 induced hypertrophy in NRCs. Luciferase reporter assay further showed that BMP2 or BMP4 treatment of NRCs repressed atrogin-1 gene expression concomitant with an increase in calcineurin protein levels and enhanced activity of nuclear factor of activated T cells, providing a mechanism by which BMP signaling contributes to cardiac hypertrophy. In a model of cardiac hypertrophy, C57BL/6 mice treated with angiotensin II (A2) had increased BMP signaling in the left ventricle. Treatment with LDN193189 attenuated A2-induced cardiac hypertrophy and collagen deposition in left ventricles. Cardiomyocyte-specific deletion of BMP type I receptor ALK2 (activin-like kinase 2), but not ALK1 or ALK3, inhibited BMP signaling and mitigated A2-induced cardiac hypertrophy and left ventricular fibrosis in mice. The results suggest that BMP signaling upregulates the calcineurin/nuclear factor of activated T cell pathway via BMP type I receptor ALK2, contributing to cardiac hypertrophy and fibrosis. PMID:26873969

Ott1 (Rbm15) is essential for placental vascular branching morphogenesis and embryonic development of the heart and spleen.

PubMed

Raffel, Glen D; Chu, Gerald C; Jesneck, Jonathan L; Cullen, Dana E; Bronson, Roderick T; Bernard, Olivier A; Gilliland, D Gary

2009-01-01

The infant leukemia-associated gene Ott1 (Rbm15) has broad regulatory effects within murine hematopoiesis. However, germ line Ott1 deletion results in fetal demise prior to embryonic day 10.5, indicating additional developmental requirements for Ott1. The spen gene family, to which Ott1 belongs, has a transcriptional activation/repression domain and RNA recognition motifs and has a significant role in the development of the head and thorax in Drosophila melanogaster. Early Ott1-deficient embryos show growth retardation and incomplete closure of the notochord. Further analysis demonstrated placental defects in the spongiotrophoblast and syncytiotrophoblast layers, resulting in an arrest of vascular branching morphogenesis. The rescue of the placental defect using a conditional allele with a trophoblast-sparing cre transgene allowed embryos to form a normal placenta and survive gestation. This outcome showed that the process of vascular branching morphogenesis in Ott1-deficient animals was regulated by the trophoblast compartment rather than the fetal vasculature. Mice surviving to term manifested hyposplenia and abnormal cardiac development. Analysis of global gene expression of Ott1-deficient embryonic hearts showed an enrichment of hypoxia-related genes and a significant alteration of several candidate genes critical for cardiac development. Thus, Ott1-dependent pathways, in addition to being implicated in leukemogenesis, may also be important for the pathogenesis of placental insufficiency and cardiac malformations.

A Role for the p38 Mitogen-activated Protein Kinase Pathway in Myocardial Cell Growth, Sarcomeric Organization, and Cardiac-specific Gene Expression

PubMed Central

Zechner, Dietmar; Thuerauf, Donna J.; Hanford, Deanna S.; McDonough, Patrick M.; Glembotski, Christopher C.

1997-01-01

Three hallmark features of the cardiac hypertrophic growth program are increases in cell size, sarcomeric organization, and the induction of certain cardiac-specific genes. All three features of hypertrophy are induced in cultured myocardial cells by α1- adrenergic receptor agonists, such as phenylephrine (PE) and other growth factors that activate mitogen- activated protein kinases (MAPKs). In this study the MAPK family members extracellular signal–regulated kinase (ERK), c-jun NH2-terminal kinase (JNK), and p38 were activated by transfecting cultured cardiac myocytes with constructs encoding the appropriate kinases possessing gain-of-function mutations. Transfected cells were then analyzed for changes in cell size, sarcomeric organization, and induction of the genes for the A- and B-type natriuretic peptides (NPs), as well as the α-skeletal actin (α-SkA) gene. While activation of JNK and/or ERK with MEKK1COOH or Raf-1 BXB, respectively, augmented cell size and effected relatively modest increases in NP and α-SkA promoter activities, neither upstream kinase conferred sarcomeric organization. However, transfection with MKK6 (Glu), which specifically activated p38, augmented cell size, induced NP and α-Ska promoter activities by up to 130-fold, and elicited sarcomeric organization in a manner similar to PE. Moreover, all three growth features induced by MKK6 (Glu) or PE were blocked with the p38-specific inhibitor, SB 203580. These results demonstrate novel and potentially central roles for MKK6 and p38 in the regulation of myocardial cell hypertrophy. PMID:9314533

The H3K9 dimethyltransferases EHMT1/2 protect against pathological cardiac hypertrophy

PubMed Central

Aronsen, Jan Magnus; Ferrini, Arianna; Brien, Patrick; Alkass, Kanar; Tomasso, Antonio; Agrawal, Asmita; Bergmann, Olaf; Reik, Wolf; Roderick, Hywel Llewelyn

2016-01-01

Cardiac hypertrophic growth in response to pathological cues is associated with reexpression of fetal genes and decreased cardiac function and is often a precursor to heart failure. In contrast, physiologically induced hypertrophy is adaptive, resulting in improved cardiac function. The processes that selectively induce these hypertrophic states are poorly understood. Here, we have profiled 2 repressive epigenetic marks, H3K9me2 and H3K27me3, which are involved in stable cellular differentiation, specifically in cardiomyocytes from physiologically and pathologically hypertrophied rat hearts, and correlated these marks with their associated transcriptomes. This analysis revealed the pervasive loss of euchromatic H3K9me2 as a conserved feature of pathological hypertrophy that was associated with reexpression of fetal genes. In hypertrophy, H3K9me2 was reduced following a miR-217–mediated decrease in expression of the H3K9 dimethyltransferases EHMT1 and EHMT2 (EHMT1/2). miR-217–mediated, genetic, or pharmacological inactivation of EHMT1/2 was sufficient to promote pathological hypertrophy and fetal gene reexpression, while suppression of this pathway protected against pathological hypertrophy both in vitro and in mice. Thus, we have established a conserved mechanism involving a departure of the cardiomyocyte epigenome from its adult cellular identity to a reprogrammed state that is accompanied by reexpression of fetal genes and pathological hypertrophy. These results suggest that targeting miR-217 and EHMT1/2 to prevent H3K9 methylation loss is a viable therapeutic approach for the treatment of heart disease. PMID:27893464

Impaired Transcriptional Response of the Murine Heart to Cigarette Smoke in the Setting of High Fat Diet and Obesity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tilton, Susan C.; Karin, Norman J.; Webb-Robertson, Bobbie-Jo M.

Smoking and obesity are each well-established risk factors for cardiovascular heart disease, which together impose earlier onset and greater severity of disease. To identify early signaling events in the response of the heart to cigarette smoke exposure within the setting of obesity, we exposed normal weight and high fat diet-induced obese (DIO) C57BL/6 mice to repeated inhaled doses of mainstream (MS) or sidestream (SS) cigarette smoke administered over a two week period, monitoring effects on both cardiac and pulmonary transcriptomes. MS smoke (250 μg wet total particulate matter (WTPM)/L, 5 h/day) exposures elicited robust cellular and molecular inflammatory responses inmore » the lung with 1466 differentially expressed pulmonary genes (p < 0.01) in normal weight animals and a much-attenuated response (463 genes) in the hearts of the same animals. In contrast, exposures to SS smoke (85 μg WTPM/L) with a CO concentration equivalent to that of MS smoke (250 CO ppm) induced a weak pulmonary response (328 genes) but an extensive cardiac response (1590 genes). SS smoke and to a lesser extent MS smoke preferentially elicited hypoxia- and stress-responsive genes as well as genes predicting early changes of vascular smooth muscle and endothelium, precursors of cardiovascular disease. The most sensitive smoke-induced cardiac transcriptional changes of normal weight mice were largely absent in DIO mice after smoke exposure, while genes involved in fatty acid utilization were unaffected. At the same time, smoke exposure suppressed multiple proteome maintenance genes induced in the hearts of DIO mice. Together, these results underscore the sensitivity of the heart to SS smoke and reveal adaptive responses in healthy individuals that are absent in the setting of high fat diet and obesity.« less

Impaired transcriptional response of the murine heart to cigarette smoke in the setting of high fat diet and obesity.

PubMed

Tilton, Susan C; Karin, Norman J; Webb-Robertson, Bobbie-Jo M; Waters, Katrina M; Mikheev, Vladimir; Lee, K Monica; Corley, Richard A; Pounds, Joel G; Bigelow, Diana J

2013-07-15

Smoking and obesity are each well-established risk factors for cardiovascular heart disease, which together impose earlier onset and greater severity of disease. To identify early signaling events in the response of the heart to cigarette smoke exposure within the setting of obesity, we exposed normal weight and high fat diet-induced obese (DIO) C57BL/6 mice to repeated inhaled doses of mainstream (MS) or sidestream (SS) cigarette smoke administered over a two week period, monitoring effects on both cardiac and pulmonary transcriptomes. MS smoke (250 μg wet total particulate matter (WTPM)/L, 5 h/day) exposures elicited robust cellular and molecular inflammatory responses in the lung with 1466 differentially expressed pulmonary genes (p < 0.01) in normal weight animals and a much-attenuated response (463 genes) in the hearts of the same animals. In contrast, exposures to SS smoke (85 μg WTPM/L) with a CO concentration equivalent to that of MS smoke (~250 CO ppm) induced a weak pulmonary response (328 genes) but an extensive cardiac response (1590 genes). SS smoke and to a lesser extent MS smoke preferentially elicited hypoxia- and stress-responsive genes as well as genes predicting early changes of vascular smooth muscle and endothelium, precursors of cardiovascular disease. The most sensitive smoke-induced cardiac transcriptional changes of normal weight mice were largely absent in DIO mice after smoke exposure, while genes involved in fatty acid utilization were unaffected. At the same time, smoke exposure suppressed multiple proteome maintenance genes induced in the hearts of DIO mice. Together, these results underscore the sensitivity of the heart to SS smoke and reveal adaptive responses in healthy individuals that are absent in the setting of high fat diet and obesity.

Differential effects of saturated and unsaturated fatty acid diets on cardiomyocyte apoptosis, adipose distribution, and serum leptin.

PubMed

Okere, Isidore C; Chandler, Margaret P; McElfresh, Tracy A; Rennison, Julie H; Sharov, Victor; Sabbah, Hani N; Tserng, Kou-Yi; Hoit, Brian D; Ernsberger, Paul; Young, Martin E; Stanley, William C

2006-07-01

Fatty acids are the primary fuel for the heart and are ligands for peroxisome proliferator-activated receptors (PPARs), which regulate the expression of genes encoding proteins involved in fatty acid metabolism. Saturated fatty acids, particularly palmitate, can be converted to the proapoptotic lipid intermediate ceramide. This study assessed cardiac function, expression of PPAR-regulated genes, and cardiomyocyte apoptosis in rats after 8 wk on either a low-fat diet [normal chow control (NC); 10% fat calories] or high-fat diets composed mainly of either saturated (Sat) or unsaturated fatty acids (Unsat) (60% fat calories) (n = 10/group). The Sat group had lower plasma insulin and leptin concentrations compared with the NC or Unsat groups. Cardiac function and mass and body mass were not different. Cardiac triglyceride content was increased in the Sat and Unsat groups compared with NC (P < 0.05); however, ceramide content was higher in the Sat group compared with the Unsat group (2.9 +/- 0.2 vs. 1.4 +/- 0.2 nmol/g; P < 0.05), whereas the NC group was intermediate (2.3 +/- 0.3 nmol/g). The number of apoptotic myocytes, assessed by terminal deoxynucleotide transferase-mediated dUTP nick-end labeling staining, was higher in the Sat group compared with the Unsat group (0.28 +/- 0.05 vs. 0.17 +/- 0.04 apoptotic cells/1,000 nuclei; P < 0.04) and was positively correlated to ceramide content (P < 0.02). Both high-fat diets increased the myocardial mRNA expression of the PPAR-regulated genes encoding uncoupling protein-3 and pyruvate dehydrogenase kinase-4, but only the Sat diet upregulated medium-chain acyl-CoA dehydrogenase. In conclusion, dietary fatty acid composition affects cardiac ceramide accumulation, cardiomyocyte apoptosis, and expression of PPAR-regulated genes independent of cardiac mass or function.

Liganded Peroxisome Proliferator-Activated Receptors (PPARs) Preserve Nuclear Histone Deacetylase 5 Levels in Endothelin-Treated Sprague-Dawley Rat Cardiac Myocytes

PubMed Central

Zhang, Haining; Shao, Zongjun; Alibin, Caroline P.; Acosta, Crystal; Anderson, Hope D.

2014-01-01

Ligand activation of peroxisome proliferator-activated receptors (PPARs) prevents cardiac myocyte hypertrophy, and we previously reported that diacylglycerol kinase zeta (DGKζ) is critically involved. DGKζ is an intracellular lipid kinase that catalyzes phosphorylation of diacylglycerol; by attenuating DAG signaling, DGKζ suppresses protein kinase C (PKC) and G-protein signaling. Here, we investigated how PPAR-DGKζ signaling blocks activation of the hypertrophic gene program. We focused on export of histone deacetylase 5 (HDAC5) from the nucleus, a key event during hypertrophy, since crosstalk occurs between PPARs and other members of the HDAC family. Using cardiac myocytes isolated from Sprague-Dawley rats, we determined that liganded PPARs disrupt endothelin-1 (ET1)-induced nuclear export of HDAC5 in a manner that is dependent on DGKζ. When DGKζ-mediated PKC inhibition was circumvented using a constitutively-active PKCε mutant, PPARs failed to block ET1-induced nuclear retention of HDAC5. Liganded PPARs also prevented (i) activation of protein kinase D (the downstream effector of PKC), (ii) HDAC5 phosphorylation at 14-3-3 protein chaperone binding sites (serines 259 and 498), and (iii) physical interaction between HDAC5 and 14-3-3, all of which are consistent with blockade of nucleo-cytoplasmic shuttling of HDAC5. Finally, the ability of PPARs to prevent neutralization of HDAC5 activity was associated with transcriptional repression of hypertrophic genes. This occurred by first, reduced MEF2 transcriptional activity and second, augmented deacetylation of histone H3 associated with hypertrophic genes expressing brain natriuretic peptide, β-myosin heavy chain, skeletal muscle α-actin, and cardiac muscle α-actin. Our findings identify spatial regulation of HDAC5 as a target for liganded PPARs, and to our knowledge, are the first to describe a mechanistic role for nuclear DGKζ in cardiac myocytes. In conclusion, these results implicate modulation of HDAC5 as a mechanism by which liganded PPARs suppress the hypertrophic gene program. PMID:25514029

Association of the genetic markers for myocardial infarction with sudden cardiac death.

PubMed

Ivanova, Anastasiya A; Maksimov, Vladimir N; Orlov, Pavel S; Ivanoshchuk, Dinara E; Savchenko, Sergei V; Voevoda, Mikhail I

2017-04-01

Investigate the association of rs17465637 gene MIAF3 (1q41), rs1376251 gene TAS2R50 (12p13), rs4804611 gene ZNF627 (19p13), rs619203 gene ROS1 (6q22), rs1333049 (9p21), rs10757278 (9p21), rs2549513 (16q23), rs499818 (6p24) associated with myocardial infarction available from the international genome-wide studies with sudden cardiac death (SCD) in a case-control study. A sample of SCD cases (n=285) was formed using the WHO criteria; the control sample (n=421) was selected according to sex and age. DNA was isolated by phenol-chloroform extraction from the myocardial tissue of SCD cases and blood of control cases. The groups were genotyped for the selected SNPs by real-time PCR using TaqMan probes (Applied Biosystems, United States). No statistically significant differences in the genotype and allelic frequencies of studied single nucleotide polymorphisms between sudden cardiac death cases and control were detectable in general group. By separating the groups of sex and age differences in the genotype frequencies of rs1333049, rs10757278 and rs499818 are statistical significance. Genotypes CC of rs1333049 and GG of rs10757278 are associated with an increased sudden cardiac death risk in men (p=0.019, OR=1.7, 95% CI 1.1-2.8; p=0.011, OR=1.8, 95% CI 1.2-2.8, respectively). Genotype AG of rs499818 is associated with an increased sudden cardiac death risk in the women over 50 years old (p=0.009, OR=2.4, 95% CI 1.3-4.6). Polymorphisms rs1333049 and rs10757278 are associated with SCD in men and rs499818 in the women aged over 50 years. Copyright © 2016. Published by Elsevier B.V.

HSP70: therapeutic potential in acute and chronic cardiac disease settings.

PubMed

Bernardo, Bianca C; Weeks, Kate L; Patterson, Natalie L; McMullen, Julie R

2016-12-01

Heat shock proteins are a family of proteins that are produced by cells in response to exposure to stressful conditions. The best studied heat shock protein is HSP70, which is known to act as a molecular chaperone to maintain cellular homeostasis and inhibit protein aggregation in response to stress. While early animal studies suggested that increasing HSP70 in the heart (using a transgenic, gene transfer or pharmacological approach) provided cardiac protection against acute cardiac stress, recent studies have found no benefit of increasing HSP70 in mouse models of chronic cardiac stress. As HSP70 has been considered a potential therapeutic target, it is important to comprehensively assess HSP70 therapies in preclinical models of acute and chronic cardiac disease.

Canine candidate genes for dilated cardiomyopathy: annotation of and polymorphic markers for 14 genes

PubMed Central

Wiersma, Anje C; Leegwater, Peter AJ; van Oost, Bernard A; Ollier, William E; Dukes-McEwan, Joanna

2007-01-01

Background Dilated cardiomyopathy is a myocardial disease occurring in humans and domestic animals and is characterized by dilatation of the left ventricle, reduced systolic function and increased sphericity of the left ventricle. Dilated cardiomyopathy has been observed in several, mostly large and giant, dog breeds, such as the Dobermann and the Great Dane. A number of genes have been identified, which are associated with dilated cardiomyopathy in the human, mouse and hamster. These genes mainly encode structural proteins of the cardiac myocyte. Results We present the annotation of, and marker development for, 14 of these genes of the dog genome, i.e. α-cardiac actin, caveolin 1, cysteine-rich protein 3, desmin, lamin A/C, LIM-domain binding factor 3, myosin heavy polypeptide 7, phospholamban, sarcoglycan δ, titin cap, α-tropomyosin, troponin I, troponin T and vinculin. A total of 33 Single Nucleotide Polymorphisms were identified for these canine genes and 11 polymorphic microsatellite repeats were developed. Conclusion The presented polymorphisms provide a tool to investigate the role of the corresponding genes in canine Dilated Cardiomyopathy by linkage analysis or association studies. PMID:17949487

Canine candidate genes for dilated cardiomyopathy: annotation of and polymorphic markers for 14 genes.

PubMed

Wiersma, Anje C; Leegwater, Peter Aj; van Oost, Bernard A; Ollier, William E; Dukes-McEwan, Joanna

2007-10-19

Dilated cardiomyopathy is a myocardial disease occurring in humans and domestic animals and is characterized by dilatation of the left ventricle, reduced systolic function and increased sphericity of the left ventricle. Dilated cardiomyopathy has been observed in several, mostly large and giant, dog breeds, such as the Dobermann and the Great Dane. A number of genes have been identified, which are associated with dilated cardiomyopathy in the human, mouse and hamster. These genes mainly encode structural proteins of the cardiac myocyte. We present the annotation of, and marker development for, 14 of these genes of the dog genome, i.e. alpha-cardiac actin, caveolin 1, cysteine-rich protein 3, desmin, lamin A/C, LIM-domain binding factor 3, myosin heavy polypeptide 7, phospholamban, sarcoglycan delta, titin cap, alpha-tropomyosin, troponin I, troponin T and vinculin. A total of 33 Single Nucleotide Polymorphisms were identified for these canine genes and 11 polymorphic microsatellite repeats were developed. The presented polymorphisms provide a tool to investigate the role of the corresponding genes in canine Dilated Cardiomyopathy by linkage analysis or association studies.

Functional Analyses of a Novel CITED2 Nonsynonymous Mutation in Chinese Tibetan Patients with Congenital Heart Disease.

PubMed

Liu, Shiming; Su, Zhaobing; Tan, Sainan; Ni, Bin; Pan, Hong; Liu, Beihong; Wang, Jing; Xiao, Jianmin; Chen, Qiuhong

2017-08-01

CITED2 gene is an important cardiac transcription factor that plays a fundamental role in the formation and development of embryonic cardiovascular. Previous studies have showed that knock-out of CITED2 in mice might result in various cardiac malformations. However, the mechanisms of CITED2 mutation on congenital heart disease (CHD) in Chinese Tibetan population are still poorly understood. In the present study, 187 unrelated Tibetan patients with CHD and 200 unrelated Tibetan healthy controls were screened for variants in the CITED2 gene; we subsequently identified one potential disease-causing mutation p.G143A in a 6-year-old girl with PDA and functional analyses of the mutation were carried out. Our study showed that the novel mutation of CITED2 significantly enhanced the expression activity of vascular endothelial growth factor (VEGF) under the role of co-receptor hypoxia inducible factor 1-aipha (HIF-1A), which is closely related with embryonic cardiac development. As a result, CITED2 gene mutation may play a significant role in the development of pediatric congenital heart disease.

Developmental pattern of ANF gene expression reveals a strict localization of cardiac chamber formation in chicken.

PubMed

Houweling, Arjan C; Somi, Semir; Van Den Hoff, Maurice J B; Moorman, Antoon F M; Christoffels, Vincent M

2002-02-01

In mouse, atrial natriuretic factor (ANF) gene expression was shown to be a marker for chamber formation within the embryonic heart. To gain insight into the process of chamber formation in the chicken embryonic heart, we analyzed the expression pattern of cANF during development. We found cANF to be specifically expressed in the myocardium of the morphologically distinguishable atrial and ventricular chambers, similar to ANF in mouse. cANF expression was never detected in the myocardium of the atrioventricular canal (AVC), inner curvature, and outflow tract (OFT), which is lined by endocardial cushions. Expression was strictly excluded from the interventricular myocardium and most proximal part of the bundle branches, as identified by the expression of Msx-2, whereas the rest of the bundle branches, trabeculae, and surrounding working myocardium did express cANF. The myocardium that forms de novo within the cushions after looping did not express cANF. At HH9 cANF expression was first observed in a subset of cardiomyocytes, which was localized ventrally in the fused heart tube and laterally in the unfused cardiac sheets. Together, these results show that cANF expression can be used to distinguish differentiated chamber (working) myocardium, including the peripheral ventricular conduction system, from embryonic myocardium. We conclude that differentiation of chamber myocardium takes place already at HH9 at the ventral side of the linear heart tube, possibly preceded by latero-medial signals in the unfused cardiac sheets. Copyright 2002 Wiley-Liss, Inc.

Adipose tissue-derived stem cell response to the differently processed 316L stainless steel substrates.

PubMed

Faghihi, Shahab; Zia, Sonia; Taha, Masoumeh Fakhr

2012-12-01

Stainless steel (SS) is one of the most applicable materials in fabrication of cardiac implants. The aim of this study is to investigate the effect of atomic structure of polycrystalline stainless steel on the response of adipose tissue-derived stem cells (ADSCs). Samples are prepared from differently processed extruded rod and rolled sheet of 316L SS having different crystallographic structure. X-ray diffraction analysis indicated (200) and (111) orientations with distinct volume fractions in the specimens. Morphology and ADSCs behavior including adhesion, proliferation and differentiation are assessed. The expression of cardiac specific protein (cardiac troponin I) and genes of differentiating cardiomyocytes is analyzed by immunofluorescence and RT-PCR. The number of attached and grown cells on the rod sample is higher than the sheet sample also the scanning electron microscopy (SEM) analysis of ADSCs grown on the samples demonstrates higher cell density and spreading pattern on the surface of rod sample. In differentiated ADSCs on the rod sample the expression of all genes except ANF are detectable, while on the sheet sample only the MEF2C and β-MHC are expressed. This study shows that the cellular response is influenced by the crystal structure of the substrate therefore; the skill to alter the structure of substrate may lend itself to engineer a biomaterial which could be suitable for differentiation of stem cells into a definite lineage. Copyright © 2012 Elsevier Ltd. All rights reserved.

Cardiac Gab1 deletion leads to dilated cardiomyopathy associated with mitochondrial damage and cardiomyocyte apoptosis

PubMed Central

Zhao, J; Yin, M; Deng, H; Jin, F Q; Xu, S; Lu, Y; Mastrangelo, M A; Luo, H; Jin, Z G

2016-01-01

A vital step in the development of heart failure is the transition from compensatory cardiac hypertrophy to decompensated dilated cardiomyopathy (DCM) during cardiac remodeling under mechanical or pathological stress. However, the molecular mechanisms underlying the development of DCM and heart failure remain incompletely understood. In the present study, we investigate whether Gab1, a scaffolding adaptor protein, protects against hemodynamic stress-induced DCM and heat failure. We first observed that the protein levels of Gab1 were markedly reduced in hearts from human patients with DCM and from mice with experimental viral myocarditis in which DCM developed. Next, we generated cardiac-specific Gab1 knockout mice (Gab1-cKO) and found that Gab-cKO mice developed DCM in hemodynamic stress-dependent and age-dependent manners. Under transverse aorta constriction (TAC), Gab1-cKO mice rapidly developed decompensated DCM and heart failure, whereas Gab1 wild-type littermates exhibited adaptive left ventricular hypertrophy without changes in cardiac function. Mechanistically, we showed that Gab1-cKO mouse hearts displayed severe mitochondrial damages and increased cardiomyocyte apoptosis. Loss of cardiac Gab1 in mice impaired Gab1 downstream MAPK signaling pathways in the heart under TAC. Gene profiles further revealed that ablation of Gab1 in heart disrupts the balance of anti- and pro-apoptotic genes in cardiomyocytes. These results demonstrate that cardiomyocyte Gab1 is a critical regulator of the compensatory cardiac response to aging and hemodynamic stress. These findings may provide new mechanistic insights and potential therapeutic target for DCM and heart failure. PMID:26517531

Functional properties of cells obtained from human cord blood CD34+ stem cells and mouse cardiac myocytes in coculture.

PubMed

Orlandi, Alessia; Pagani, Francesca; Avitabile, Daniele; Bonanno, Giuseppina; Scambia, Giovanni; Vigna, Elisa; Grassi, Francesca; Eusebi, Fabrizio; Fucile, Sergio; Pesce, Maurizio; Capogrossi, Maurizio C

2008-04-01

Prior in vitro studies suggested that different types of hematopoietic stem cells may differentiate into cardiomyocytes. The present work examined whether human CD34(+) cells from the human umbilical cord blood (hUCB), cocultured with neonatal mouse cardiomyocytes, acquire the functional properties of myocardial cells and express human cardiac genes. hUCB CD34(+) cells were cocultured onto cardiomyocytes following an infection with a lentivirus-encoding enhanced green fluorescent protein (EGFP). After 7 days, mononucleated EGFP(+) cells were tested for their electrophysiological features by patch clamp and for cytosolic [Ca(2+)] ([Ca(2+)](i)) homeostasis by [Ca(2+)](i) imaging of X-rhod1-loaded cells. Human Nkx2.5 and GATA-4 expression was examined in cocultured cell populations by real-time RT-PCR. EGFP(+) cells were connected to surrounding cells by gap junctions, acquired electrophysiological properties similar to those of cardiomyocytes, and showed action potential-associated [Ca(2+)](i) transients. These cells also exhibited spontaneous sarcoplasmic reticulum [Ca(2+)](i) oscillations and the associated membrane potential depolarization. However, RT-PCR of both cell populations showed no upregulation of human-specific cardiac genes. In conclusion, under our experimental conditions, hUCB CD34(+) cells cocultured with murine cardiomyocytes formed cells that exhibited excitation-contraction coupling features similar to those of cardiomyocytes. However, the expression of human-specific cardiac genes was undetectable by RT-PCR.

YY1 Protects Cardiac Myocytes from Pathologic Hypertrophy by Interacting with HDAC5

PubMed Central

Dockstader, Karen; McKinsey, Timothy A.

2008-01-01

YY1 is a transcription factor that can repress or activate the transcription of a variety of genes. Here, we show that the function of YY1 as a repressor in cardiac myocytes is tightly dependent on its ability to interact with histone deacetylase 5 (HDAC5). YY1 interacts with HDAC5, and overexpression of YY1 prevents HDAC5 nuclear export in response to hypertrophic stimuli and the increase in cell size and re-expression of fetal genes that accompany pathological cardiac hypertrophy. Knockdown of YY1 results in up-regulation of all genes present during fetal development and increases the cell size of neonatal cardiac myocytes. Moreover, overexpression of a YY1 deletion construct that does not interact with HDAC5 results in transcription activation, suggesting that HDAC5 is necessary for YY1 function as a transcription repressor. In support of this relationship, we show that knockdown of HDAC5 results in transcription activation by YY1. Finally, we show that YY1 interaction with HDAC5 is dependent on the HDAC5 phosphorylation domain and that overexpression of YY1 reduces HDAC5 phosphorylation in response to hypertrophic stimuli. Our results strongly suggest that YY1 functions as an antihypertrophic factor by preventing HDAC5 nuclear export and that up-regulation of YY1 in human heart failure may be a protective mechanism against pathological hypertrophy. PMID:18632988

MicroRNA-327 regulates cardiac hypertrophy and fibrosis induced by pressure overload.

PubMed

Ji, Yue; Qiu, Ming; Shen, Yejiao; Gao, Li; Wang, Yaqing; Sun, Wei; Li, Xinli; Lu, Yan; Kong, Xiangqing

2018-04-01

MicroRNA (miRNA/miR) dysregulation has been reported to be fundamental in the development and progression of cardiac hypertrophy and fibrosis. In the present study, miR-327 levels in fibroblasts were increased in response to cardiac hypertrophy induced by transverse aortic constriction with prominent cardiac fibrosis, particularly when compared with the levels in unstressed cardiomyocytes. In neonatal rat cardiac fibroblasts, induced expression of miR-327 upregulated fibrosis-associated gene expression and activated angiotensin II-induced differentiation into myofibroblasts, as assessed via α-smooth muscle actin staining. By contrast, miR-327 knockdown mitigated angiotensin II-induced differentiation. Cardiac fibroblast proliferation was not affected under either condition. In a mouse model subjected to transverse aortic constriction, miR-327 knockdown through tail-vein injection reduced the development of cardiac fibrosis and ventricular dysfunction. miR-327 was demonstrated to target integrin β3 and diminish the activation of cardiac fibroblasts. Thus, the present study supports the use of miR-327 as a therapeutic target in the reduction of cardiac fibrosis.

Plants and their bioactive compounds with the potential to enhance mechanisms of inherited cardiac regeneration.

PubMed

Zhou, Zhen; Li, Dianbin; Zhou, Hua; Lin, Xiaoli; Li, Censing; Tang, Mingfeng; Feng, Zhou; Li, Ming

2015-06-01

This article reviews the current progress and research indications in the application of natural plant compounds with the potential for the treatment of cardiovascular diseases. Our understanding of how to apply natural plant compounds to enhance mechanisms of inherited cardiac regeneration, which is physiologically pertinent to myocyte turnover or minor cardiac repair, for substantial cardiac regeneration to repair pathological heart injuries is discussed. Although significant progress has been made in the application of natural plant compounds for therapy of heart diseases, the understanding or the application of these compounds specifically for enhancing mechanisms of inherited cardiac regeneration for the treatment of cardiovascular diseases is little. Recent recognition of some natural plant compounds that can repair damaged myocardial tissues through enhancing mechanisms of inherited cardiac regeneration has offered an alternative for clinical translation. Application of natural plant compounds, which show the activity of manipulating gene expressions in such a way to enhance mechanisms of inherited cardiac regeneration for cardiac repair, may provide a promising strategy for the reconstruction of damaged cardiac tissues due to cardiovascular diseases. Georg Thieme Verlag KG Stuttgart · New York.

Sex-dependent alteration of cardiac cytochrome P450 gene expression by doxorubicin in C57Bl/6 mice.

PubMed

Grant, Marianne K O; Seelig, Davis M; Sharkey, Leslie C; Zordoky, Beshay N

2017-01-01

There is inconclusive evidence about the role of sex as a risk factor for doxorubicin (DOX)-induced cardiotoxicity. Recent experimental studies have shown that adult female rats are protected against DOX-induced cardiotoxicity. However, the mechanisms of this sexual dimorphism are not fully elucidated. We have previously demonstrated that DOX alters the expression of several cytochrome P450 (CYP) enzymes in the hearts of male rats. Nevertheless, the sex-dependent effect of DOX on the expression of CYP enzymes is still not known. Therefore, in the present study, we determined the effect of acute DOX exposure on the expression of CYP genes in the hearts of both male and female C57Bl/6 mice. Acute DOX cardiotoxicity was induced by a single intraperitoneal injection of 20 mg/kg DOX in male and female adult C57Bl/6 mice. Cardiac function was assessed 5 days after DOX exposure by trans-thoracic echocardiography. Mice were euthanized 1 day or 6 days after DOX or saline injection. Thereafter, the hearts were harvested and weighed. Heart sections were evaluated for pathological lesions. Total RNA was extracted and expression of natriuretic peptides, inflammatory and apoptotic markers, and CYP genes was measured by real-time PCR. Adult female C57Bl/6 mice were protected from acute DOX-induced cardiotoxicity as they show milder pathological lesions, less inflammation, and faster recovery from DOX-induced apoptosis and DOX-mediated inhibition of beta-type natriuretic peptide. Acute DOX exposure altered the gene expression of multiple CYP genes in a sex-dependent manner. In 24 h, DOX exposure caused male-specific induction of Cyp1b1 and female-specific induction of Cyp2c29 and Cyp2e1. Acute DOX exposure causes sex-dependent alteration of cardiac CYP gene expression. Since cardiac CYP enzymes metabolize several endogenous compounds to biologically active metabolites, sex-dependent alteration of CYP genes may play a role in the sexual dimorphism of acute DOX-induced cardiotoxicity.

Cardiac and renal function in patients with type 2 diabetes who have chronic kidney disease: potential effects of bardoxolone methyl.

PubMed

McCullough, Peter A; Ali, Sajid

2012-01-01

The intracellular and tissue balance of oxidant and antioxidant forces is a potential therapeutic target for a variety of agents in the treatment of complications due to chronic disease including diabetes mellitus and hypertension. There are a myriad of processes controlled at the level of genes, transcription factors, and protein messages that work to control the normal use of oxidative reactions within cells. Loss of control of these processes may lead to reversible dysfunction in many cell lines including the podocyte, renal tubular cells, and cardiac myocytes. Bardoxolone methyl is a novel nuclear regulator factor (Nrf-2) activator which works to tip the balance of effects towards antioxidation and as an observation made serendipitously, improves renal filtration function in humans after approximately 12 weeks of therapy. The improvement in estimated glomerular filtration can be up to 30% in those with stage 3 and 4 chronic kidney disease. However, experimental evidence suggests there may be a consequence of relative hyperfiltration in diseased kidneys as well as potential adverse effects on skeletal and cardiac myocytes. Only large, prospective randomized trials with carefully collected and adjudicated clinical outcomes will inform the research community on the therapeutic risks and benefits of this important new agent.

Cardiac and renal function in patients with type 2 diabetes who have chronic kidney disease: potential effects of bardoxolone methyl

PubMed Central

McCullough, Peter A; Ali, Sajid

2012-01-01

The intracellular and tissue balance of oxidant and antioxidant forces is a potential therapeutic target for a variety of agents in the treatment of complications due to chronic disease including diabetes mellitus and hypertension. There are a myriad of processes controlled at the level of genes, transcription factors, and protein messages that work to control the normal use of oxidative reactions within cells. Loss of control of these processes may lead to reversible dysfunction in many cell lines including the podocyte, renal tubular cells, and cardiac myocytes. Bardoxolone methyl is a novel nuclear regulator factor (Nrf-2) activator which works to tip the balance of effects towards antioxidation and as an observation made serendipitously, improves renal filtration function in humans after approximately 12 weeks of therapy. The improvement in estimated glomerular filtration can be up to 30% in those with stage 3 and 4 chronic kidney disease. However, experimental evidence suggests there may be a consequence of relative hyperfiltration in diseased kidneys as well as potential adverse effects on skeletal and cardiac myocytes. Only large, prospective randomized trials with carefully collected and adjudicated clinical outcomes will inform the research community on the therapeutic risks and benefits of this important new agent. PMID:22787387

MicroRNAs 33, 122, and 208: a potential novel targets in the treatment of obesity, diabetes, and heart-related diseases.

PubMed

Alrob, Osama Abo; Khatib, Said; Naser, Saleh A

2017-05-01

Despite decades of research, obesity and diabetes remain major health problems in the USA and worldwide. Among the many complications associated with diabetes is an increased risk of cardiovascular diseases, including myocardial infarction and heart failure. Recently, microRNAs have emerged as important players in heart disease and energy regulation. However, little work has investigated the role of microRNAs in cardiac energy regulation. Both human and animal studies have reported a significant increase in circulating free fatty acids and triacylglycerol, increased cardiac reliance on fatty acid oxidation, and subsequent decrease in glucose oxidation which all contributes to insulin resistance and lipotoxicity seen in obesity and diabetes. Importantly, MED13 was initially identified as a negative regulator of lipid accumulation in Drosophilia. Various metabolic genes were downregulated in MED13 transgenic heart, including sterol regulatory element-binding protein. Moreover, miR-33 and miR-122 have recently revealed as key regulators of lipid metabolism. In this review, we will focus on the role of microRNAs in regulation of cardiac and total body energy metabolism. We will also discuss the pharmacological and non-pharmacological interventions that target microRNAs for the treatment of obesity and diabetes.

Data on cardiac defects, morbidity and mortality in patients affected by RASopathies. CARNET study results.

PubMed

Calcagni, Giulio; Limongelli, Giuseppe; D'Ambrosio, Angelo; Gesualdo, Francesco; Digilio, Maria Cristina; Baban, Anwar; Albanese, Sonia B; Versacci, Paolo; De Luca, Enrica; Ferrero, Giovanni B; Baldassarre, Giuseppina; Agnoletti, Gabriella; Banaudi, Elena; Marek, Jan; Kaski, Juan P; Tuo, Giulia; Russo, Maria Giovanna; Pacileo, Giuseppe; Milanesi, Ornella; Messina, Daniela; Marasini, Maurizio; Cairello, Francesca; Formigari, Roberto; Brighenti, Maurizio; Dallapiccola, Bruno; Tartaglia, Marco; Marino, Bruno

2018-02-01

A comprehensive description of morbidity and mortality in patients affected by mutations in genes encoding for signal transducers of the RAS-MAPK cascade (RASopathies) was performed in our study recently published in the International Journal of Cardiology. Seven European cardiac centres participating to the CArdiac Rasopathy NETwork (CARNET), collaborated in this multicentric, observational, retrospective data analysis and collection. In this study, clinical records of 371 patients with confirmed molecular diagnosis of RASopathy were reviewed. Cardiac defects, crude mortality, survival rate of patients with 1) hypertrophic cardiomyopathy (HCM) and age <2 years or young adults; 2) individuals with Noonan syndrome and pulmonary stenosis carrying PTPN11 mutations; 3) biventricular obstruction and PTPN11 mutations; 4) Costello syndrome or cardiofaciocutaneous syndrome were analysed. Mortality was described as crude mortality, cumulative survival and restricted estimated mean survival. In particular, with this Data In Brief (DIB) paper, the authors aim to report specific statistic highlights of the multivariable regression analysis that was used to assess the impact of mutated genes on number of interventions and overall prognosis.

Tmem88a mediates GATA-dependent specification of cardiomyocyte progenitors by restricting WNT signaling

PubMed Central

Novikov, Natasha; Evans, Todd

2013-01-01

Biphasic control of WNT signaling is essential during cardiogenesis, but how the pathway switches from promoting cardiac mesoderm to restricting cardiomyocyte progenitor fate is unknown. We identified genes expressed in lateral mesoderm that are dysregulated in zebrafish when both gata5 and gata6 are depleted, causing a block to cardiomyocyte specification. This screen identified tmem88a, which is expressed in the early cardiac progenitor field and was previously implicated in WNT modulation by overexpression studies. Depletion of tmem88a results in a profound cardiomyopathy, secondary to impaired cardiomyocyte specification. In tmem88a morphants, activation of the WNT pathway exacerbates the cardiomyocyte deficiency, whereas WNT inhibition rescues progenitor cells and cardiogenesis. We conclude that specification of cardiac fate downstream of gata5/6 involves activation of the tmem88a gene to constrain WNT signaling and expand the number of cardiac progenitors. Tmem88a is a novel component of the regulatory mechanism controlling the second phase of biphasic WNT activity essential for embryonic cardiogenesis. PMID:23903195

Novel Genetic Variants in BAG3 and TNNT2 in a Swedish Family with a History of Dilated Cardiomyopathy and Sudden Cardiac Death.

PubMed

Fernlund, Eva; Österberg, A Wålinder; Kuchinskaya, E; Gustafsson, M; Jansson, K; Gunnarsson, C

2017-08-01

Familial dilated cardiomyopathy is a rare cause of dilated cardiomyopathy (DCM), especially in childhood. Our aim was to describe the clinical course and the genetic variants in a family where the proband was a four-month-old infant presenting with respiratory problems due to DCM. In the family, there was a strong family history of DCM and sudden cardiac death in four generations. DNA was analyzed initially from the deceased girl using next-generation sequencing including 50 genes involved in cardiomyopathy. A cascade family screening was performed in the family after identification of the TNNT2 and the BAG3 variants in the proband. The first-degree relatives underwent clinical examination including biochemistry panel, cardiac ultrasound, Holter ECG, exercise stress test, and targeted genetic testing. The index patient presented with advanced DCM. After a severe clinical course, the baby had external left ventricular assist as a bridge to heart transplantation. 1.5 months after transplantation, the baby suffered sudden cardiac death (SCD) despite maximal treatment in the pediatric intensive care unit. The patient was shown to carry two heterozygous genetic variants in the TNNT2 gene [TNNT2 c.518G>A(p.Arg173Gln)] and BAG3 [BAG3 c.785C>T(p.Ala262Val)]. Two of the screened individuals (two females) appeared to carry both the familial variants. All the individuals carrying the TNNT2 variant presented with DCM, the two adult patients had mild or moderate symptoms of heart failure and reported palpitations but no syncope or presyncopal attacks prior to the genetic diagnosis. The female carriers of TNNT2 and BAG3 variants had more advanced DCM. In the family history, there were three additional cases of SCD due to DCM, diagnosed by autopsy, but no genetic analysis was possible in these cases. Our findings suggest that the variants in TNNT2 and BAG3 are associated with a high propensity to life-threatening cardiomyopathy presenting from childhood and young adulthood.

PubMed Central

NIGRO, GERARDO; PAPA, ANDREA ANTONIO; POLITANO, LUISA

2012-01-01

Myotonic dystrophy (Dystrophia Myotonica, DM) is the most frequently inherited neuromuscular disease of adult life. It is a multisystemic disease with major cardiac involvement. Core features of myotonic dystrophy are myotonia, muscle weakness, cataract, respiratory failure and cardiac conduction abnormalities. Classical DM, first described by Steinert and called Steinert's disease or DM1 (Dystrophia Myotonica type 1) has been identified as an autosomal dominant disorder associated with the presence of an abnormal expansion of a CTG trinucleotide repeat in the 3' untranslated region of DMPK gene on chromosome 19. This review will mainly focus on the various aspects of cardiac involvement in DM1 patients and the current role of cardiac pacing in their treatment. PMID:23097601

OCT imaging of craniofacial anatomy in xenopus embryos (Conference Presentation)

NASA Astrophysics Data System (ADS)

Deniz, Engin; Jonas, Stephan M.; Griffin, John; Hooper, Michael C.; Choma, Michael A.; Khokha, Mustafa K.

2016-03-01

The etiology of craniofacial defects is incompletely understood. The ability to obtain large amounts of gene sequence data from families affected by craniofacial defects is opening up new ways to understand molecular genetic etiological factors. One important link between gene sequence data and clinical relevance is biological research into candidate genes and molecular pathways. We present our recent research using OCT as a nondestructive phenotyping modality of craniofacial morphology in Xenopus embryos, an important animal model for biological research in gene and pathway discovery. We define 2D and 3D scanning protocols for a standardized approach to craniofacial imaging in Xenopus embryos. We define standard views and planar reconstructions for visualizing normal anatomy and landmarks. We compare these views and reconstructions to traditional histopathology using alcian blue staining. In addition to being 3D, nondestructive, and having much faster throughout, OCT can identify craniofacial features that are lost during traditional histopathological preparation. We also identify quantitative morphometric parameters to define normative craniofacial anatomy. We also note that craniofacial and cardiac defects are not infrequently present in the same patient (e.g velocardiofacial syndrome). Given that OCT excels at certain aspects of cardiac imaging in Xenopus embryos, our work highlights the potential of using OCT and Xenopus to study molecular genetic factors that impact both cardiac and craniofacial development.

Cerebellar Ataxia, Seizures, Premature Death, and Cardiac Abnormalities in Mice with Targeted Disruption of the Cacna2d2 Gene

PubMed Central

Ivanov, Sergey V.; Ward, Jerrold M.; Tessarollo, Lino; McAreavey, Dorothea; Sachdev, Vandana; Fananapazir, Lameh; Banks, Melissa K.; Morris, Nicole; Djurickovic, Draginja; Devor-Henneman, Deborah E.; Wei, Ming-Hui; Alvord, Gregory W.; Gao, Boning; Richardson, James A.; Minna, John D.; Rogawski, Michael A.; Lerman, Michael I.

2004-01-01

CACNA2D2 is a putative tumor suppressor gene located in the human chromosome 3p21.3 region that shows frequent allelic imbalances in lung, breast, and other cancers. The α2δ-2 protein encoded by the gene is a regulatory subunit of voltage-dependent calcium channels and is expressed in brain, heart, and other tissues. Here we report that mice homozygous for targeted disruption of the Cacna2d2 gene exhibit growth retardation, reduced life span, ataxic gait with apoptosis of cerebellar granule cells followed by Purkinje cell depletion, enhanced susceptibility to seizures, and cardiac abnormalities. The Cacna2d2tm1NCIF null phenotype has much in common with that of Cacna1a mutants, such as cerebellar neuro-degeneration associated with ataxia, seizures, and premature death. A tendency to bradycardia and limited response of null mutants to isoflurane implicate α2δ-2 in sympathetic regulation of cardiac function. In summary, our findings provide genetic evidence that the α2δ-2 subunit serves in vivo as a component of P/Q-type calcium channels, is indispensable for the central nervous system function, and may be involved in hereditary cerebellar ataxias and epileptic disorders in humans. PMID:15331424

The DEAD-box RNA helicase Ddx39ab is essential for myocyte and lens development in zebrafish.

PubMed

Zhang, Linlin; Yang, Yuxi; Li, Beibei; Scott, Ian C; Lou, Xin

2018-04-23

RNA helicases from the DEAD-box family are found in almost all organisms and have important roles in RNA metabolism, including RNA synthesis, processing and degradation. The function and mechanism of action of most of these helicases in animal development and human disease remain largely unexplored. In a zebrafish mutagenesis screen to identify genes essential for heart development we identified a mutant that disrupts the gene encoding the RNA helicase DEAD-box 39ab ( ddx39ab ). Homozygous ddx39ab mutant embryos exhibit profound cardiac and trunk muscle dystrophy, along with lens abnormalities, caused by abrupt terminal differentiation of cardiomyocyte, myoblast and lens fiber cells. Loss of ddx39ab hindered splicing of mRNAs encoding epigenetic regulatory factors, including members of the KMT2 gene family, leading to misregulation of structural gene expression in cardiomyocyte, myoblast and lens fiber cells. Taken together, these results show that Ddx39ab plays an essential role in establishment of the proper epigenetic status during differentiation of multiple cell lineages. © 2018. Published by The Company of Biologists Ltd.

The transcription factor GATA4 promotes myocardial regeneration in neonatal mice.

PubMed

Malek Mohammadi, Mona; Kattih, Badder; Grund, Andrea; Froese, Natali; Korf-Klingebiel, Mortimer; Gigina, Anna; Schrameck, Ulrike; Rudat, Carsten; Liang, Qiangrong; Kispert, Andreas; Wollert, Kai C; Bauersachs, Johann; Heineke, Joerg

2017-02-01

Heart failure is often the consequence of insufficient cardiac regeneration. Neonatal mice retain a certain capability of myocardial regeneration until postnatal day (P)7, although the underlying transcriptional mechanisms remain largely unknown. We demonstrate here that cardiac abundance of the transcription factor GATA4 was high at P1, but became strongly reduced at P7 in parallel with loss of regenerative capacity. Reconstitution of cardiac GATA4 levels by adenoviral gene transfer markedly improved cardiac regeneration after cryoinjury at P7. In contrast, the myocardial scar was larger in cardiomyocyte-specific Gata4 knockout (CM-G4-KO) mice after cryoinjury at P0, indicative of impaired regeneration, which was accompanied by reduced cardiomyocyte proliferation and reduced myocardial angiogenesis in CM-G4-KO mice. Cardiomyocyte proliferation was also diminished in cardiac explants from CM-G4-KO mice and in isolated cardiomyocytes with reduced GATA4 expression. Mechanistically, decreased GATA4 levels caused the downregulation of several pro-regenerative genes (among them interleukin-13, Il13) in the myocardium. Interestingly, systemic administration of IL-13 rescued defective heart regeneration in CM-G4-KO mice and could be evaluated as therapeutic strategy in the future. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

TBX1 Represses Vegfr2 Gene Expression and Enhances the Cardiac Fate of VEGFR2+ Cells

PubMed Central

Lania, Gabriella; Ferrentino, Rosa; Baldini, Antonio

2015-01-01

The T-box transcription factor TBX1 has critical roles in maintaining proliferation and inhibiting differentiation of cardiac progenitor cells of the second heart field (SHF). Haploinsufficiency of the gene that encodes it is a cause of congenital heart disease. Here, we developed an embryonic stem (ES) cell-based model in which Tbx1 expression can be modulated by tetracycline. Using this model, we found that TBX1 down regulates the expression of VEGFR2, and we confirmed this finding in vivo during embryonic development. In addition, we found a Vegfr2 domain of expression, not previously described, in the posterior SHF and this expression is extended by loss of Tbx1. VEGFR2 has been previously described as a marker of a subpopulation of cardiac progenitors. Clonal analysis of ES-derived VEGFR2+ cells indicated that 12.5% of clones expressed three markers of cardiac lineage (cardiomyocyte, smooth muscle and endothelium). However, a pulse of Tbx1 expression was sufficient to increase the percentage to 20.8%. In addition, the percentage of clones expressing markers of multiple cardiac lineages increased from 41.6% to 79.1% after Tbx1 pulse. These results suggest that TBX1 plays a role in maintaining a progenitor state in VEGFR2+ cells. PMID:26382615

MyoR Modulates Cardiac Conduction by Repressing Gata4

PubMed Central

Harris, John P.; Bhakta, Minoti; Bezprozvannaya, Svetlana; Wang, Lin; Lubczyk, Christina; Olson, Eric N.

2014-01-01

The cardiac conduction system coordinates electrical activation through a series of interconnected structures, including the atrioventricular node (AVN), the central connection point that delays impulse propagation to optimize cardiac performance. Although recent studies have uncovered important molecular details of AVN formation, relatively little is known about the transcriptional mechanisms that regulate AV delay, the primary function of the mature AVN. We identify here MyoR as a novel transcription factor expressed in Cx30.2+ cells of the AVN. We show that MyoR specifically inhibits a Cx30.2 enhancer required for AVN-specific gene expression. Furthermore, we demonstrate that MyoR interacts directly with Gata4 to mediate transcriptional repression. Our studies reveal that MyoR contains two nonequivalent repression domains. While the MyoR C-terminal repression domain inhibits transcription in a context-dependent manner, the N-terminal repression domain can function in a heterologous context to convert the Hand2 activator into a repressor. In addition, we show that genetic deletion of MyoR in mice increases Cx30.2 expression by 50% and prolongs AV delay by 13%. Taken together, we conclude that MyoR modulates a Gata4-dependent regulatory circuit that establishes proper AV delay, and these findings may have wider implications for the variability of cardiac rhythm observed in the general population. PMID:25487574

Advances in the Study of Heart Development and Disease Using Zebrafish

PubMed Central

Brown, Daniel R.; Samsa, Leigh Ann; Qian, Li; Liu, Jiandong

2016-01-01

Animal models of cardiovascular disease are key players in the translational medicine pipeline used to define the conserved genetic and molecular basis of disease. Congenital heart diseases (CHDs) are the most common type of human birth defect and feature structural abnormalities that arise during cardiac development and maturation. The zebrafish, Danio rerio, is a valuable vertebrate model organism, offering advantages over traditional mammalian models. These advantages include the rapid, stereotyped and external development of transparent embryos produced in large numbers from inexpensively housed adults, vast capacity for genetic manipulation, and amenability to high-throughput screening. With the help of modern genetics and a sequenced genome, zebrafish have led to insights in cardiovascular diseases ranging from CHDs to arrhythmia and cardiomyopathy. Here, we discuss the utility of zebrafish as a model system and summarize zebrafish cardiac morphogenesis with emphasis on parallels to human heart diseases. Additionally, we discuss the specific tools and experimental platforms utilized in the zebrafish model including forward screens, functional characterization of candidate genes, and high throughput applications. PMID:27335817

RAGE-dependent activation of gene expression of superoxide dismutase and vanins by AGE-rich extracts in mice cardiac tissue and murine cardiac fibroblasts.

PubMed

Leuner, Beatrice; Ruhs, Stefanie; Brömme, Hans-Jürgen; Bierhaus, Angelika; Sel, Saadettin; Silber, Rolf-Edgar; Somoza, Veronika; Simm, Andreas; Nass, Norbert

2012-10-01

Advanced glycation end products (AGEs) are stable compounds formed from initial Maillard reaction products. They are considered as markers for ageing and often associated with age-related, degenerative diseases. Bread crust represents an established model for nutritional compounds rich in AGEs and is able to induce antioxidative defense genes such as superoxide dismutases and vanins in cardiac cells. The aim of this study was to investigate to what extend the receptor for AGEs (RAGE) contributes to this response. Signal transduction in response to bread crust extract was analysed in cardiac fibroblasts derived from C57/B6-NCrl (RAGE +/+) and the corresponding RAGE-knock out C57/B6-NCrl mouse strain (RAGE -/-). Activation of superoxide dismutases in animals was then analysed upon bread crust feeding in these two mice strains. Cardiac fibroblasts from RAGE -/- mice did not express RAGE, but the expression of AGER-1 and AGER-3 was up-regulated, whereas the expression of SR-B1 was down-regulated. RAGE -/- cells were less sensitive to BCE in terms of MAP-kinase phosphorylation and NF-κB reporter gene activation. Bread crust extract induced mRNA levels of MnSOD and Vnn-1 were also reduced in RAGE -/- cells, whereas Vnn-3 mRNA accumulation seemed to be RAGE receptor independent. In bread crust feeding experiments, RAGE -/- mice did not exhibit an activation of MnSOD-mRNA and -protein accumulation as observed for the RAGE +/+ animals. In conclusion, RAGE was clearly a major factor for the induction of antioxidant defense signals derived from bread crust in cardiac fibroblast and mice. Nevertheless higher doses of bread crust extract could overcome the RAGE dependency in cell cultures, indicating that additional mechanisms are involved in BCE-mediated activation of SOD and vanin expression.

Mechanisms of epigenetic and cell-type specific regulation of Hey target genes in ES cells and cardiomyocytes.

PubMed

Weber, David; Heisig, Julia; Kneitz, Susanne; Wolf, Elmar; Eilers, Martin; Gessler, Manfred

2015-02-01

Hey bHLH transcription factors are critical effectors of Notch signaling. During mammalian heart development they are expressed in atrial and ventricular cardiomyocytes and in the developing endocardium. Hey knockout mice suffer from lethal cardiac defects, such as ventricular septum defects, valve defects and cardiomyopathy. Despite this functional relevance, little is known about the regulation of downstream targets in relevant cell types. The objective of this study was to elucidate the regulatory mechanisms by which Hey proteins affect gene expression in a cell type specific manner. We used an in vitro cardiomyocyte differentiation system with inducible Hey1 or Hey2 expression to study target gene regulation in cardiomyocytes (CM) generated from murine embryonic stem cells (ESC). The effects of Hey1 and Hey2 are largely redundant, but cell type specific. The number of regulated genes is comparable between ESC and CM, but the total number of binding sites is much higher, especially in ESC, targeting mainly genes involved in transcriptional regulation and developmental processes. Repression by Hey proteins generally correlates with the extent of Hey-binding to target promoters, Hdac recruitment and lower histone acetylation. Functionally, treatment with the Hdac inhibitor TSA abolished Hey target gene regulation. However, in CM the repressive effect of Hey-binding is lost for a subset of genes. These also lack Hey-dependent histone deacetylation in CM and are enriched for binding sites of cardiac specific activators like Srf, Nkx2-5, and Gata4. Ectopic Nkx2-5 overexpression in ESC blocks Hey-mediated repression of these genes. Thus, Hey proteins mechanistically repress target genes via Hdac recruitment and histone deacetylation. In CM Hey-repression is counteracted by cardiac activators, which recruit histone acetylases and prevent Hey mediated deacetylation and subsequent repression for a subset of genes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Accumulation of 5-oxoproline in myocardial dysfunction and the protective effects of OPLAH.

PubMed

van der Pol, Atze; Gil, Andres; Silljé, Herman H W; Tromp, Jasper; Ovchinnikova, Ekaterina S; Vreeswijk-Baudoin, Inge; Hoes, Martijn; Domian, Ibrahim J; van de Sluis, Bart; van Deursen, Jan M; Voors, Adriaan A; van Veldhuisen, Dirk J; van Gilst, Wiek H; Berezikov, Eugene; van der Harst, Pim; de Boer, Rudolf A; Bischoff, Rainer; van der Meer, Peter

2017-11-08

In response to heart failure (HF), the heart reacts by repressing adult genes and expressing fetal genes, thereby returning to a more fetal-like gene profile. To identify genes involved in this process, we carried out transcriptional analysis on murine hearts at different stages of development and on hearts from adult mice with HF. Our screen identified Oplah , encoding for 5-oxoprolinase, a member of the γ-glutamyl cycle that functions by scavenging 5-oxoproline. OPLAH depletion occurred as a result of cardiac injury, leading to elevated 5-oxoproline and oxidative stress, whereas OPLAH overexpression improved cardiac function after ischemic injury. In HF patients, we observed elevated plasma 5-oxoproline, which was associated with a worse clinical outcome. Understanding and modulating fetal-like genes in the failing heart may lead to potential diagnostic, prognostic, and therapeutic options in HF. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Histone Deacetylases 5 and 9 Govern Responsiveness of the Heart to a Subset of Stress Signals and Play Redundant Roles in Heart Development

PubMed Central

Chang, Shurong; McKinsey, Timothy A.; Zhang, Chun Li; Richardson, James A.; Hill, Joseph A.; Olson, Eric N.

2004-01-01

The adult heart responds to stress signals by hypertrophic growth, which is often accompanied by activation of a fetal cardiac gene program and eventual cardiac demise. We showed previously that histone deacetylase 9 (HDAC9) acts as a suppressor of cardiac hypertrophy and that mice lacking HDAC9 are sensitized to cardiac stress signals. Here we report that mice lacking HDAC5 display a similar cardiac phenotype and develop profoundly enlarged hearts in response to pressure overload resulting from aortic constriction or constitutive cardiac activation of calcineurin, a transducer of cardiac stress signals. In contrast, mice lacking either HDAC5 or HDAC9 show a hypertrophic response to chronic β-adrenergic stimulation identical to that of wild-type littermates, suggesting that these HDACs modulate a specific subset of cardiac stress response pathways. We also show that compound mutant mice lacking both HDAC5 and HDAC9 show a propensity for lethal ventricular septal defects and thin-walled myocardium. These findings reveal central roles for HDACs 5 and 9 in the suppression of a subset of cardiac stress signals as well as redundant functions in the control of cardiac development. PMID:15367668

Histone deacetylases 5 and 9 govern responsiveness of the heart to a subset of stress signals and play redundant roles in heart development.

PubMed

Chang, Shurong; McKinsey, Timothy A; Zhang, Chun Li; Richardson, James A; Hill, Joseph A; Olson, Eric N

2004-10-01

The adult heart responds to stress signals by hypertrophic growth, which is often accompanied by activation of a fetal cardiac gene program and eventual cardiac demise. We showed previously that histone deacetylase 9 (HDAC9) acts as a suppressor of cardiac hypertrophy and that mice lacking HDAC9 are sensitized to cardiac stress signals. Here we report that mice lacking HDAC5 display a similar cardiac phenotype and develop profoundly enlarged hearts in response to pressure overload resulting from aortic constriction or constitutive cardiac activation of calcineurin, a transducer of cardiac stress signals. In contrast, mice lacking either HDAC5 or HDAC9 show a hypertrophic response to chronic beta-adrenergic stimulation identical to that of wild-type littermates, suggesting that these HDACs modulate a specific subset of cardiac stress response pathways. We also show that compound mutant mice lacking both HDAC5 and HDAC9 show a propensity for lethal ventricular septal defects and thin-walled myocardium. These findings reveal central roles for HDACs 5 and 9 in the suppression of a subset of cardiac stress signals as well as redundant functions in the control of cardiac development.

Sulforaphane prevents the development of cardiomyopathy in type 2 diabetic mice probably by reversing oxidative stress-induced inhibition of LKB1/AMPK pathway.

PubMed

Zhang, Zhiguo; Wang, Shudong; Zhou, Shanshan; Yan, Xiaoqing; Wang, Yonggang; Chen, Jing; Mellen, Nicholas; Kong, Maiying; Gu, Junlian; Tan, Yi; Zheng, Yang; Cai, Lu

2014-12-01

Type 2 diabetes mellitus (T2DM)-induced cardiomyopathy is associated with cardiac oxidative stress, inflammation, and remodeling. Sulforaphane (SFN), an isothiocyanate naturally presenting in widely consumed vegetables, particularly broccoli, plays an important role in cardiac protection from diabetes. We investigated the effect of SFN on T2DM-induced cardiac lipid accumulation and subsequent cardiomyopathy. Male C57BL/6J mice were fed a high-fat diet for 3months to induce insulin resistance, followed by a treatment with 100mg/kg body-weight streptozotocin to induce hyperglycemia; we referred to it as the T2DM mouse model. Other age-matched mice were fed a normal diet as control. T2DM and control mice were treated with or without 4-month SFN at 0.5mg/kg daily five days a week. At the study's end, cardiac function was assessed. SFN treatment significantly attenuated cardiac remodeling and dysfunction induced by T2DM. SFN treatment also significantly inhibited cardiac lipid accumulation, measured by Oil Red O staining, and improved cardiac inflammation oxidative stress and fibrosis, shown by down-regulating diabetes-induced PAI-1, TNF-α, CTGF, TGF-β, 3-NT, and 4-HNE expression. Elevated 4-HNE resulted in the increase of 4-HNE-LKB1 adducts that should inhibit LKB1 and subsequent AMPK activity. SFN upregulated the expression of Nrf2 and its downstream genes, NQO1 and HO-1, decreased 4-HNE-LKB1 adducts and then reversed diabetes-induced inhibition of LKB1/AMPK and its downstream targets, including sirtuin 1, PGC-1α, phosphorylated acetyl-CoA carboxylase, carnitine palmitoyl transferase-1, ULK1, and light chain-3 II. These results suggest that SFN treatment to T2DM mice may attenuate the cardiac oxidative stress-induced inhibition of LKB1/AMPK signaling pathway, thereby preventing T2DM-induced lipotoxicity and cardiomyopathy. Copyright © 2014 Elsevier Ltd. All rights reserved.

Mutation analysis of the STRA6 gene in isolated and non-isolated anophthalmia/microphthalmia.

PubMed

Chassaing, N; Ragge, N; Kariminejad, A; Buffet, A; Ghaderi-Sohi, S; Martinovic, J; Calvas, P

2013-03-01

PDAC syndrome [Pulmonary hypoplasia/agenesis, Diaphragmatic hernia/eventration, Anophthalmia/microphthalmia (A/M) and Cardiac Defect] is a condition associated with recessive mutations in the STRA6 gene in some of these patients. Recently, cases with isolated anophthalmia have been associated with STRA6 mutations. To determine the minimal findings associated with STRA6 mutations, we performed mutation analysis of the STRA6 gene in 28 cases with anophthalmia. In 7 of the cases the anophthalmia was isolated, in 14 cases it was associated with one of the major features included in PDAC and 7 had other abnormalities. Mutations were identified in two individuals: one with bilateral anophthalmia and some features included in PDAC, who was a compound heterozygote for a missense mutation and a large intragenic deletion, and the second case with all the major features of PDAC and who had a homozygous splicing mutation. This study suggests that STRA6 mutations are more likely to be identified in individuals with A/M and other abnormalities included in the PDAC spectrum, rather than in isolated A/M cases. © 2012 John Wiley & Sons A/S.

Phosphorylation of the chromatin remodeling factor DPF3a induces cardiac hypertrophy through releasing HEY repressors from DNA.

PubMed

Cui, Huanhuan; Schlesinger, Jenny; Schoenhals, Sophia; Tönjes, Martje; Dunkel, Ilona; Meierhofer, David; Cano, Elena; Schulz, Kerstin; Berger, Michael F; Haack, Timm; Abdelilah-Seyfried, Salim; Bulyk, Martha L; Sauer, Sascha; Sperling, Silke R

2016-04-07

DPF3 (BAF45c) is a member of the BAF chromatin remodeling complex. Two isoforms have been described, namely DPF3a and DPF3b. The latter binds to acetylated and methylated lysine residues of histones. Here, we elaborate on the role of DPF3a and describe a novel pathway of cardiac gene transcription leading to pathological cardiac hypertrophy. Upon hypertrophic stimuli, casein kinase 2 phosphorylates DPF3a at serine 348. This initiates the interaction of DPF3a with the transcriptional repressors HEY, followed by the release of HEY from the DNA. Moreover, BRG1 is bound by DPF3a, and is thus recruited to HEY genomic targets upon interaction of the two components. Consequently, the transcription of downstream targets such as NPPA and GATA4 is initiated and pathological cardiac hypertrophy is established. In human, DPF3a is significantly up-regulated in hypertrophic hearts of patients with hypertrophic cardiomyopathy or aortic stenosis. Taken together, we show that activation of DPF3a upon hypertrophic stimuli switches cardiac fetal gene expression from being silenced by HEY to being activated by BRG1. Thus, we present a novel pathway for pathological cardiac hypertrophy, whose inhibition is a long-term therapeutic goal for the treatment of the course of heart failure. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

NKX2-5 regulates human cardiomyogenesis via a HEY2 dependent transcriptional network.

PubMed

Anderson, David J; Kaplan, David I; Bell, Katrina M; Koutsis, Katerina; Haynes, John M; Mills, Richard J; Phelan, Dean G; Qian, Elizabeth L; Leitoguinho, Ana Rita; Arasaratnam, Deevina; Labonne, Tanya; Ng, Elizabeth S; Davis, Richard P; Casini, Simona; Passier, Robert; Hudson, James E; Porrello, Enzo R; Costa, Mauro W; Rafii, Arash; Curl, Clare L; Delbridge, Lea M; Harvey, Richard P; Oshlack, Alicia; Cheung, Michael M; Mummery, Christine L; Petrou, Stephen; Elefanty, Andrew G; Stanley, Edouard G; Elliott, David A

2018-04-10

Congenital heart defects can be caused by mutations in genes that guide cardiac lineage formation. Here, we show deletion of NKX2-5, a critical component of the cardiac gene regulatory network, in human embryonic stem cells (hESCs), results in impaired cardiomyogenesis, failure to activate VCAM1 and to downregulate the progenitor marker PDGFRα. Furthermore, NKX2-5 null cardiomyocytes have abnormal physiology, with asynchronous contractions and altered action potentials. Molecular profiling and genetic rescue experiments demonstrate that the bHLH protein HEY2 is a key mediator of NKX2-5 function during human cardiomyogenesis. These findings identify HEY2 as a novel component of the NKX2-5 cardiac transcriptional network, providing tangible evidence that hESC models can decipher the complex pathways that regulate early stage human heart development. These data provide a human context for the evaluation of pathogenic mutations in congenital heart disease.

Functional hypervariability and gene diversity of cardioactive neuropeptides.

PubMed

Möller, Carolina; Melaun, Christian; Castillo, Cecilia; Díaz, Mary E; Renzelman, Chad M; Estrada, Omar; Kuch, Ulrich; Lokey, Scott; Marí, Frank

2010-12-24

Crustacean cardioactive peptide (CCAP) and related peptides are multifunctional regulatory neurohormones found in invertebrates. We isolated a CCAP-related peptide (conoCAP-a, for cone snail CardioActive Peptide) and cloned the cDNA of its precursor from venom of Conus villepinii. The precursor of conoCAP-a encodes for two additional CCAP-like peptides: conoCAP-b and conoCAP-c. This multi-peptide precursor organization is analogous to recently predicted molluscan CCAP-like preprohormones, and suggests a mechanism for the generation of biological diversification without gene amplification. While arthropod CCAP is a cardio-accelerator, we found that conoCAP-a decreases the heart frequency in Drosophila larvae, demonstrating that conoCAP-a and CCAP have opposite effects. Intravenous injection of conoCAP-a in rats caused decreased heart frequency and blood pressure in contrast to the injection of CCAP, which did not elicit any cardiac effect. Perfusion of rat ventricular cardiac myocytes with conoCAP-a decreased systolic calcium, indicating that conoCAP-a cardiac negative inotropic effects might be mediated via impairment of intracellular calcium trafficking. The contrasting cardiac effects of conoCAP-a and CCAP indicate that molluscan CCAP-like peptides have functions that differ from those of their arthropod counterparts. Molluscan CCAP-like peptides sequences, while homologous, differ between taxa and have unique sequences within a species. This relates to the functional hypervariability of these peptides as structure activity relationship studies demonstrate that single amino acids variations strongly affect cardiac activity. The discovery of conoCAPs in cone snail venom emphasizes the significance of their gene plasticity to have mutations as an adaptive evolution in terms of structure, cellular site of expression, and physiological functions.

Mouse genome-wide association study identifies polymorphisms on chromosomes 4, 11, and 15 for age-related cardiac fibrosis.

PubMed

Li, Qiaoli; Berndt, Annerose; Sundberg, Beth A; Silva, Kathleen A; Kennedy, Victoria E; Cario, Clinton L; Richardson, Matthew A; Chase, Thomas H; Schofield, Paul N; Uitto, Jouni; Sundberg, John P

2016-06-01

Dystrophic cardiac calcinosis (DCC), also called epicardial and myocardial fibrosis and mineralization, has been detected in mice of a number of laboratory inbred strains, most commonly C3H/HeJ and DBA/2J. In previous mouse breeding studies between these DCC susceptible and the DCC-resistant strain C57BL/6J, 4 genetic loci harboring genes involved in DCC inheritance were identified and subsequently termed Dyscalc loci 1 through 4. Here, we report susceptibility to cardiac fibrosis, a sub-phenotype of DCC, at 12 and 20 months of age and close to natural death in a survey of 28 inbred mouse strains. Eight strains showed cardiac fibrosis with highest frequency and severity in the moribund mice. Using genotype and phenotype information of the 28 investigated strains, we performed genome-wide association studies (GWAS) and identified the most significant associations on chromosome (Chr) 15 at 72 million base pairs (Mb) (P < 10(-13)) and Chr 4 at 122 Mb (P < 10(-11)) and 134 Mb (P < 10(-7)). At the Chr 15 locus, Col22a1 and Kcnk9 were identified. Both have been reported to be morphologically and functionally important in the heart muscle. The strongest Chr 4 associations were located approximately 6 Mb away from the Dyscalc 2 quantitative trait locus peak within the boundaries of the Extl1 gene and in close proximity to the Trim63 and Cap1 genes. In addition, a single-nucleotide polymorphism association was found on chromosome 11. This study provides evidence for more than the previously reported 4 genetic loci determining cardiac fibrosis and DCC. The study also highlights the power of GWAS in the mouse for dissecting complex genetic traits.

Mouse genome-wide association study identifies polymorphisms on chromosomes 4, 11 and 15 for age-related cardiac fibrosis

PubMed Central

Li, Qiaoli; Berndt, Annerose; Sundberg, Beth A.; Silva, Kathleen A.; Kennedy, Victoria E.; Cario, Clinton L; Richardson, Matthew A.; Chase, Thomas H.; Schofield, Paul N.; Uitto, Jouni; Sundberg, John P.

2017-01-01

Dystrophic cardiac calcinosis (DCC), also called epicardial and myocardial fibrosis and mineralization, has been detected in mice of a number of laboratory inbred strains, most commonly C3H/HeJ and DBA/2J. In previous mouse breeding studies between these DCC susceptible and the DCC resistant strain C57BL/6J, 4 genetic loci harboring genes involved in DCC inheritance were identified and subsequently termed Dyscal loci 1 through 4. Here we report susceptibility to cardiac fibrosis, a sub-phenotype of DCC, at 12 and 20 months of age and close to natural death in a survey of 28 inbred mouse strains. Eight strains showed cardiac fibrosis with highest frequency and severity in the moribund mice. Using genotype and phenotype information of the 28 investigated strains we performed genome-wide association studies (GWAS) and identified the most significant associations on chromosome (Chr) 15 at 72 million base pairs (Mb) (P < 10−13) and Chr 4 at 122 Mb (P < 10−11) and 134 Mb (P < 10−7). At the Chr 15 locus Col22a1 and Kcnk9 were identified. Both have been reported to be morphologically and functionally important in the heart muscle. The strongest Chr 4 associations were located approximate 6 Mb away from the Dyscal 2 quantitative trait locus peak within the boundaries of the Extl1 gene and in close proximity to the Trim63 and Cap1 genes. In addition, a single nucleotide polymorphism association was found on chromosome 11. This study provides evidence for more than the previously reported 4 genetic loci determining cardiac fibrosis and DCC. The study also highlights the power of GWAS in the mouse for dissecting complex genetic traits. PMID:27126641

Cardiomyocyte Circadian Oscillations Are Cell-Autonomous, Amplified by β-Adrenergic Signaling, and Synchronized in Cardiac Ventricle Tissue

PubMed Central

Welsh, David K.

2016-01-01

Circadian clocks impact vital cardiac parameters such as blood pressure and heart rate, and adverse cardiac events such as myocardial infarction and sudden cardiac death. In mammals, the central circadian pacemaker, located in the suprachiasmatic nucleus of the hypothalamus, synchronizes cellular circadian clocks in the heart and many other tissues throughout the body. Cardiac ventricle explants maintain autonomous contractions and robust circadian oscillations of clock gene expression in culture. In the present study, we examined the relationship between intrinsic myocardial function and circadian rhythms in cultures from mouse heart. We cultured ventricular explants or dispersed cardiomyocytes from neonatal mice expressing a PER2::LUC bioluminescent reporter of circadian clock gene expression. We found that isoproterenol, a β-adrenoceptor agonist known to increase heart rate and contractility, also amplifies PER2 circadian rhythms in ventricular explants. We found robust, cell-autonomous PER2 circadian rhythms in dispersed cardiomyocytes. Single-cell rhythms were initially synchronized in ventricular explants but desynchronized in dispersed cells. In addition, we developed a method for long-term, simultaneous monitoring of clock gene expression, contraction rate, and basal intracellular Ca2+ level in cardiomyocytes using PER2::LUC in combination with GCaMP3, a genetically encoded fluorescent Ca2+ reporter. In contrast to robust PER2 circadian rhythms in cardiomyocytes, we detected no rhythms in contraction rate and only weak rhythms in basal Ca2+ level. In summary, we found that PER2 circadian rhythms of cardiomyocytes are cell-autonomous, amplified by adrenergic signaling, and synchronized by intercellular communication in ventricle explants, but we detected no robust circadian rhythms in contraction rate or basal Ca2+. PMID:27459195

Association of the 98T ELAM-1 polymorphism with increased bleeding after cardiac surgery.

PubMed

Welsby, Ian J; Podgoreanu, Mihai V; Phillips-Bute, Barbara; Morris, Richard; Mathew, Joseph P; Smith, Peter K; Newman, Mark F; Schwinn, Debra A; Stafford-Smith, Mark

2010-06-01

Hemorrhage continues to be a major problem after cardiac surgery despite the routine use of antifibrinolytic drugs, with striking inter-patient variability poorly explained by already known risk factors. The authors tested the hypothesis that genetic polymorphisms of inflammatory mediators and cellular adhesion molecules are associated with bleeding after cardiac surgery. Prospective, observational study. Single, tertiary referral university heart center. Adult patients undergoing aortocoronary surgery with cardiopulmonary bypass. Patients (n = 759) had 10 mL of blood drawn preoperatively and genomic DNA isolated then genotyped for 17 polymorphisms in 7 candidate genes: tumor necrosis factor, interleukins 1beta and 6, interleukin 1 receptor antagonist, intercellular adhesion molecule-1 (ICAM-1), P-selectin and endothelial leucocyte adhesion molecule-1 (E-selectin). Multivariate analyses were used to relate clinical and genetic factors to bleeding and transfusion. The 98G/T polymorphism of the E-selectin gene was independently associated with bleeding after cardiac surgery (p = 0.002), after adjusting for significant clinical predictors (patient size and baseline hemoglobin concentration). There was a gene dose effect according to the number of minor alleles in the genotype; carriers of the minor allele bled 17% (GT) and 54% (TT) more than wild type (GG) genotypes, respectively (p = 0.01). Carriers of the minor allele also had longer activated partial thromboplastin times (p = 0.0023) and increased fresh frozen plasma transfusion (p = 0.03) compared with wild type. The authors found a dose-related association between the 98T E-selectin polymorphism and bleeding after cardiac surgery, independent of and additive to standard clinical risk factors. Copyright 2010 Elsevier Inc. All rights reserved.

Functional Hypervariability and Gene Diversity of Cardioactive Neuropeptides*

PubMed Central

Möller, Carolina; Melaun, Christian; Castillo, Cecilia; Díaz, Mary E.; Renzelman, Chad M.; Estrada, Omar; Kuch, Ulrich; Lokey, Scott; Marí, Frank

2010-01-01

Crustacean cardioactive peptide (CCAP) and related peptides are multifunctional regulatory neurohormones found in invertebrates. We isolated a CCAP-related peptide (conoCAP-a, for cone snail CardioActive Peptide) and cloned the cDNA of its precursor from venom of Conus villepinii. The precursor of conoCAP-a encodes for two additional CCAP-like peptides: conoCAP-b and conoCAP-c. This multi-peptide precursor organization is analogous to recently predicted molluscan CCAP-like preprohormones, and suggests a mechanism for the generation of biological diversification without gene amplification. While arthropod CCAP is a cardio-accelerator, we found that conoCAP-a decreases the heart frequency in Drosophila larvae, demonstrating that conoCAP-a and CCAP have opposite effects. Intravenous injection of conoCAP-a in rats caused decreased heart frequency and blood pressure in contrast to the injection of CCAP, which did not elicit any cardiac effect. Perfusion of rat ventricular cardiac myocytes with conoCAP-a decreased systolic calcium, indicating that conoCAP-a cardiac negative inotropic effects might be mediated via impairment of intracellular calcium trafficking. The contrasting cardiac effects of conoCAP-a and CCAP indicate that molluscan CCAP-like peptides have functions that differ from those of their arthropod counterparts. Molluscan CCAP-like peptides sequences, while homologous, differ between taxa and have unique sequences within a species. This relates to the functional hypervariability of these peptides as structure activity relationship studies demonstrate that single amino acids variations strongly affect cardiac activity. The discovery of conoCAPs in cone snail venom emphasizes the significance of their gene plasticity to have mutations as an adaptive evolution in terms of structure, cellular site of expression, and physiological functions. PMID:20923766

Overlapping and Divergent Actions of Structurally Distinct Histone Deacetylase Inhibitors in Cardiac Fibroblasts.

PubMed

Schuetze, Katherine B; Stratton, Matthew S; Blakeslee, Weston W; Wempe, Michael F; Wagner, Florence F; Holson, Edward B; Kuo, Yin-Ming; Andrews, Andrew J; Gilbert, Tonya M; Hooker, Jacob M; McKinsey, Timothy A

2017-04-01

Inhibitors of zinc-dependent histone deacetylases (HDACs) profoundly affect cellular function by altering gene expression via changes in nucleosomal histone tail acetylation. Historically, investigators have employed pan-HDAC inhibitors, such as the hydroxamate trichostatin A (TSA), which simultaneously targets members of each of the three zinc-dependent HDAC classes (classes I, II, and IV). More recently, class- and isoform-selective HDAC inhibitors have been developed, providing invaluable chemical biology probes for dissecting the roles of distinct HDACs in the control of various physiologic and pathophysiological processes. For example, the benzamide class I HDAC-selective inhibitor, MGCD0103 [ N -(2-aminophenyl)-4-[[(4-pyridin-3-ylpyrimidin-2-yl)amino]methyl] benzamide], was shown to block cardiac fibrosis, a process involving excess extracellular matrix deposition, which often results in heart dysfunction. Here, we compare the mechanisms of action of structurally distinct HDAC inhibitors in isolated primary cardiac fibroblasts, which are the major extracellular matrix-producing cells of the heart. TSA, MGCD0103, and the cyclic peptide class I HDAC inhibitor, apicidin, exhibited a common ability to enhance histone acetylation, and all potently blocked cardiac fibroblast cell cycle progression. In contrast, MGCD0103, but not TSA or apicidin, paradoxically increased expression of a subset of fibrosis-associated genes. Using the cellular thermal shift assay, we provide evidence that the divergent effects of HDAC inhibitors on cardiac fibroblast gene expression relate to differential engagement of HDAC1- and HDAC2-containing complexes. These findings illustrate the importance of employing multiple compounds when pharmacologically assessing HDAC function in a cellular context and during HDAC inhibitor drug development. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Characterization of the Pathological and Biochemical Markers that Correlate to the Clinical Features of Autism

DTIC Science & Technology

2009-10-01

Specified (PDD-NOS), Asperger disorder, Childhood Disintegrative Disorder (CDD) and Rett syndrome . According to the Centers for Disease Control (CDC), 1 in...induced epilepsy (Fernandes et al., 1996; Reime et al., 2007), and in Crush syndrome (Desai and Desai, 2007). In chronic fatigue syndrome , the...the gene encoding the L-type voltage-gated Ca2+channel CaV1.2 (CACNA1C) cause Timothy syndrome , a multisystem disorder that includes cardiac