Richard P Harvey

Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia

Are you Richard P Harvey?

Claim your profile

Publications (161)1261.72 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: To model cardiac gene regulatory networks in health and disease we used DamID to establish robust target gene sets for the cardiac homeodomain factor NKX2-5 and two congenital heart disease-associated mutants carrying a crippled homeodomain, which normally functions as DNA- and protein-binding interface. Despite compromised direct DNA-binding, NKX2-5 mutants retained partial functionality and bound hundreds of targets, including NKX2-5 wild type targets and unique sets of 'off-targets'. NKX2-5∆HD, which lacks the entire homeodomain, could still dimerise with wild type NKX2-5 and its cofactors, including newly-discovered cofactors of the ETS family, through the conserved tyrosine-rich domain (YRD). NKX2-5∆HD off-targets showed overrepresentation of many binding motifs, including ETS motifs, the majority co-occupied by ETS proteins as determined by DamID. Off-targets of an NKX2-5 YRD mutant were not enriched in ETS targets. Our study reveals off-target binding and transcriptional activity for NKX2-5 mutations driven in part by cofactor interactions, suggesting a novel type of gain-of-function in congenital heart disease.
    eLife Sciences 07/2015; 4. DOI:10.7554/eLife.06942 · 8.52 Impact Factor
  • Source
    04/2015; 4(4):768-781. DOI:10.3390/jcm4040768
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Frameshift mutations in the TTN gene encoding titin are a major cause for inherited forms of dilated cardiomyopathy (DCM), a heart disease characterized by ventricular dilatation, systolic dysfunction, and progressive heart failure. To date, there are no specific treatment options for DCM patients but heart transplantation. Here, we show the beneficial potential of reframing titin transcripts by antisense oligonucleotide (AON)-mediated exon skipping in human and murine models of DCM carrying a previously identified autosomal-dominant frameshift mutation in titin exon 326. Correction of TTN reading frame in patient-specific cardiomyocytes derived from induced pluripotent stem cells rescued defective myofibril assembly and stability and normalized the sarcomeric protein expression. AON treatment in Ttn knock-in mice improved sarcomere formation and contractile performance in homozygous embryos and prevented the development of the DCM phenotype in heterozygous animals. These results demonstrate that disruption of the titin reading frame due to a truncating DCM mutation can be restored by exon skipping in both patient cardiomyocytes in vitro and mouse heart in vivo, indicating RNA-based strategies as a potential treatment option for DCM. © 2015 The Authors. Published under the terms of the CC BY 4.0 license.
    EMBO Molecular Medicine 03/2015; DOI:10.15252/emmm.201505047 · 8.25 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Hypertrophic cardiomyopathy (HCM) is caused by mutations in sarcomere protein genes, and left ventricular hypertrophy (LVH) develops as an adaptive response to sarcomere dysfunction. It remains unclear whether persistent expression of the mutant gene is required for LVH or whether early gene expression acts as an immutable inductive trigger. The aim of this study was to use a regulatable murine model of HCM to study the reversibility of pathological LVH. The authors generated a double-transgenic mouse model, tTA x αMHC(R403Q), in which expression of the HCM-causing Arg403Gln mutation in the α-myosin heavy chain (MHC) gene is inhibited by doxycycline administration. Cardiac structure and function were evaluated in groups of mice that received doxycycline for varying periods from 0 to 40 weeks of age. Untreated tTA x αMHC(R403Q) mice showed increased left ventricular (LV) mass, contractile dysfunction, myofibrillar disarray, and fibrosis. In contrast, mice treated with doxycycline from conception to 6 weeks had markedly less LVH and fibrosis at 40 weeks. Transgene inhibition from 6 weeks reduced fibrosis but did not prevent LVH or functional changes. There were no differences in LV parameters at 40 weeks between mice with transgene inhibition from 20 weeks and mice with continuous transgene expression. These findings highlight the critical role of the early postnatal period in HCM pathogenesis and suggest that mutant sarcomeres manifest irreversible cardiomyocyte defects that induce LVH. In HCM, mutation-silencing therapies are likely to be ineffective for hypertrophy regression and would have to be administered very early in life to prevent hypertrophy development. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
    Journal of the American College of Cardiology 02/2015; 65(6):560-569. DOI:10.1016/j.jacc.2014.10.069 · 15.34 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The shortage of donors in cardiac transplantation may be alleviated by the use of allografts from donation after circulatory death (DCD) donors. We have previously shown that hearts exposed to 30 min warm ischemic time and then flushed with Celsior supplemented with agents that activate ischemic postconditioning pathways, show complete recovery on a blood-perfused ex vivo working heart apparatus. In this study, these findings were assessed in a porcine orthotopic heart transplant model. DCD hearts were preserved with either normothermic ex vivo perfusion (NEVP) using a clinically approved device, or with standard cold storage (CS) for 4 h. Orthotopic transplantation into recipient animals was subsequently undertaken. Five of six hearts preserved with NEVP demonstrated favorable lactate profiles during NEVP and all five could be weaned off cardiopulmonary bypass posttransplant, compared with 0 of 3 hearts preserved with CS (p < 0.05, Fisher's exact test). In conclusion, DCD hearts flushed with supplemented Celsior solution and preserved with NEVP display viability before and after transplantation. Viability studies of human DCD hearts using NEVP are warranted. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.
    American Journal of Transplantation 02/2015; 15(2):371-80. DOI:10.1111/ajt.12994 · 6.19 Impact Factor
  • Heart, Lung and Circulation 12/2014; 23S2:e12. DOI:10.1016/j.hlc.2014.07.031 · 1.17 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Many genes have been implicated in the development of congenital heart disease (CHD). Next-generation sequencing offers opportunities for genetic testing but is often complicated by logistic and interpretative hurdles. This study sought to apply next-generation sequencing technology to CHD families with multiple affected members using a purpose-designed gene panel to assess diagnostic potential for future clinical applications. We designed a targeted next-generation sequencing gene panel for 57 genes previously implicated in CHD. Probands were screened in 16 families with strong CHD histories and in 15 control subjects. Variants affecting protein-coding regions were classified in silico using prediction programs and filtered according to predicted mode of inheritance, minor allele frequencies, and presence in databases such as dbSNP (Single Nucleotide Polymorphism Database) and ESP (Exome Sequencing Project). Disease segregation studies were conducted in variants identified in CHD cases predicted to be deleterious and with minor allele frequencies <0.1%. Thirteen potential disease-causing variants were identified in 9 families. Of these, 5 variants segregated with disease phenotype, revealing a likely molecular diagnosis in 31% of this cohort. Significant increases in the number of "indels, nonsense, and splice" variants, as well as variants classified as "probably damaging" were identified in CHD cases but not in control subjects. Also, there was a significant increase in the total number of "rare" and "low" frequency variants (minor allele frequencies <0.05) in the CHD cases. When multiple relatives are affected by CHD, a gene panel-based approach may identify its cause in up to 31% of families. Identifying causal variants has implications for clinical care and future family planning. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
    Journal of the American College of Cardiology 12/2014; 64(23):2498-506. DOI:10.1016/j.jacc.2014.09.048 · 15.34 Impact Factor
  • Source
    Richard P. Harvey, Robert M. Graham, William T. Pu
    [Show abstract] [Hide abstract]
    ABSTRACT: Despite therapeutic advances that slow its progression, heart disease remains the world's leading cause of death. Until recently, the "Holy Grail" of cardiac biology, to regenerate the damaged heart, appeared to be a fantastical and quixotic quest. However, recent studies showing that the mammalian heart possesses an innate, albeit limited, regenerative capacity offer hope that effective cardiac regeneration may be an attainable goal. This Special Issue of Stem Cell Research reviews the remarkable progress that has been made in this field in the last few years. Copyright © 2014. Published by Elsevier B.V.
    Stem Cell Research 10/2014; 13(3). DOI:10.1016/j.scr.2014.10.003 · 3.91 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Animal genomes contain a code for construction of the body plan from a fertilized egg. Understanding how genome information is deciphered to create the complex multilayered regulatory systems that drive organismal development, and which become altered in disease, is one of the greatest challenges in the biological sciences. The development of methods that effectively represent and communicate the complexity inherent in gene regulatory networks remains a major barrier. This review introduces the philosophy of systems biology and discusses recent progress in understanding the development of the heart at a systems biology level.
    Cold Spring Harbor Perspectives in Medicine 10/2014; DOI:10.1101/cshperspect.a013839 · 7.56 Impact Factor
  • Source
    James J.H. Chong, Elvira Forte, Richard P. Harvey
    [Show abstract] [Hide abstract]
    ABSTRACT: Mammalian hearts carry a number of primitive stem cell-like populations, although the magnitude of their contribution to tissue homeostasis and repair remains controversial. Recent CRE recombinase-based lineage tracing experiments suggest only a minor contribution to the formation of new cardiomyocytes from such cells, albeit one that might be augmented therapeutically. As the field explores clinical translation of cardiac stem cells, it will be important to understand the biology of these cells in great detail. In this review we document the various reported stem and progenitor cell populations in mammalian hearts and discuss the current state of knowledge on their origins and lineage capabilities.
    Stem Cell Research 10/2014; 13(3). DOI:10.1016/j.scr.2014.09.008 · 3.91 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Donation after circulatory death (DCD) offers a potential additional source of cardiac allografts. We used a porcine asphyxia model to evaluate viability of DCD hearts subjected to warm ischemic times (WIT) of 20–40 min prior to flushing with Celsior (C) solution. We then assessed potential benefits of supplementing C with erythropoietin, glyceryl trinitrate and zoniporide (Cs), a combination that we have shown previously to activate ischemic postconditioning pathways. Hearts flushed with C/Cs were assessed for functional, biochemical and metabolic recovery on an ex vivo working heart apparatus. Hearts exposed to 20-min WIT showed full recovery of functional and metabolic profiles compared with control hearts (no WIT). Hearts subjected to 30- or 40-min WIT prior to C solution showed partial and no recovery, respectively. Hearts exposed to 30-min WIT and Cs solution displayed complete recovery, while hearts exposed to 40-min WIT and Cs solution demonstrated partial recovery. We conclude that DCD hearts flushed with C solution demonstrate complete recovery up to 20-min WIT after which there is rapid loss of viability. Cs extends the limit of WIT tolerability to 30 min. DCD hearts with ≤30-min WIT may be suitable for transplantation and warrant assessment in a transplant model.
    American Journal of Transplantation 07/2014; 14(8). DOI:10.1111/ajt.12782 · 6.19 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Risk for schizophrenia is likely to involve gene × environment interactions. Neuregulin 1 (NRG1) is a schizophrenia risk gene, hence any interaction with environmental adversity, such as maternal infection, may provide further insights into the basis of the disease. This study examined the individual and combined effects of prenatal immune activation with Poly I:C and disruption of the schizophrenia risk gene NRG1 on the expression of behavioural phenotypes related to schizophrenia. NRG1 heterozygous (NRG1 HET) mutant breeding pairs were time-mated. Pregnant dams received a single injection (5 mg/kg i.p.) of Poly I:C or vehicle on gestation day 9 (GD9). Offspring were then cross-fostered to vehicle-treated or PolyI:C-treated dams. Expression of schizophrenia-related behavioural endophenotypes was assessed at adolescence and in adulthood. Combining NRG1 disruption and prenatal environmental insult (Poly I:C) caused developmental stage-specific deficits in social behaviour, spatial working memory and PPI. However, combining Poly I:C and cross-fostering produced a number of behavioural deficits in the open field, social behaviour and PPI. This became more complex by combining NRG1 deletion with both Poly I:C exposure and cross-fostering, which had a robust effect on PPI. These findings suggest that concepts of gene × environment interaction in risk for schizophrenia should be elaborated to multiple interactions that involve individual genes interacting with diverse biological and psychosocial environmental factors over early life, to differentially influence particular domains of psychopathology, sometimes over specific stages of development.
    Neuroscience 06/2014; 277. DOI:10.1016/j.neuroscience.2014.06.028 · 3.33 Impact Factor
  • Source
    Naisana S Asli, Munira Xaymardan, Richard P. Harvey
    06/2014; 2:117-137. DOI:10.3390/jdb2020117
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: eLife digest Human embryos contain cells called ‘cardiac progenitor cells’ that serve as the building blocks to make the heart. Cardiac progenitor cells, or CPCs for short, initially move into areas of the embryo called the first and second heart fields, and then undergo a change to become specific types of heart cells: such as cardiac muscle cells. However, it is not known if CPCs are maintained during the development of the heart. Now, Shenje, Andersen et al. have shown that Numb and Numblike—two proteins that are needed for the development of nerve cells—are also involved in the development of the heart. Mouse embryos without the genes for Numb and Numblike failed to develop hearts normally; and these mutants also had fewer CPCs in the ‘second pharyngeal arch’: a part of the embryo that becomes the sides and front of the neck. Experiments on wild-type mice showed that the CPCs multiplied within this arch, and then changed into specific heart cells as they left this structure. Furthermore, mixing CPCs in a petri dish with cells taken from this arch encouraged the CPCs to multiply without changing into specific cell types. To investigate the importance of these two proteins further, Shenje, Andersen et al. engineered ‘chimeric’ mice in which some CPCs contained the Numb and Numblike genes and other CPCs did not. In most of these chimeric mice, the hearts developed normally, but the CPCs without the Numb or Numblike genes failed to multiply in the second pharyngeal arch. This shows that these genes must be present within an individual CPC to regulate the multiplication of that cell within this arch. By uncovering how problems with the maintenance of CPCs can lead to heart defects—a very common birth defect in humans—this work may lead to new ways to prevent or treat congenital heart disease. Furthermore, identifying the other factors or mechanisms that can allow the long-term maintenance of CPCs in the laboratory will be crucial for research into heart regeneration, and for CPC-based treatments to repair the heart. DOI: http://dx.doi.org/10.7554/eLife.02164.002
    eLife Sciences 04/2014; 3:e02164. DOI:10.7554/eLife.02164 · 8.52 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: 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. 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. 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. 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.
    Circulation Research 03/2014; 114(9). DOI:10.1161/CIRCRESAHA.114.302530 · 11.09 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Mammalian embryos develop in a low oxygen environment. The transcription factor hypoxia inducible factor 1a (HIF1α) is a key element in the cellular response to hypoxia. Complete deletion of Hif1α from the mouse conceptus causes extensive placental, vascular and heart defects, resulting in embryonic lethality. However the precise role of Hif1α in each of these organ systems remains unknown. To further investigate, we conditionally-deleted Hif1α from mesoderm, vasculature and heart individually. Surprisingly, deletion from these tissues did not recapitulate the same severe heart phenotype or embryonic lethality. Placental insufficiency, such as occurs in the complete Hif1α null, results in elevated cellular hypoxia in mouse embryos. We hypothesized that subjecting the Hif1α conditional null embryos to increased hypoxic stress might exacerbate the effects of tissue-specific Hif1α deletion. We tested this hypothesis using a model system mimicking placental insufficiency. We found that the majority of embryos lacking Hif1α in the heart died when exposed to non-physiological hypoxia. This was a heart-specific phenomenon, as HIF1α protein accumulated predominantly in the myocardium of hypoxia-stressed embryos. Our study demonstrates the vulnerability of the heart to lowered oxygen levels, and that under such conditions of non-physiological hypoxia the embryo absolutely requires Hif1α to continue normal development. Importantly, these findings extend our understanding of the roles of Hif1α in cardiovascular development.
    Developmental Biology 01/2014; DOI:10.1016/j.ydbio.2014.03.005 · 3.64 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Congenital heart defects represent the most common human birth defects and are often life-threatening. Frequently, they are caused by abnormalities of the outflow tract whose formation results from coordinated development of cells from mesodermal and neural crest origin and depends on the activity of many different transcription factors. However, place, time, and mode of action have only been analyzed for a few of them. Here we assess the contribution of the closely related high-mobility-group transcription factors Sox4 and Sox11 to outflow tract development and determine their function. Using cell-type-specific deletion in the mouse, we show that Sox11 is required for proper development in both mesodermal cells and neural crest cells. Deletion in either mesoderm or neural crest, or both, leads to outflow tract defects ranging from double outlet right ventricle to common arterial trunk. Sox4 supports Sox11 in its function, but has additional roles with relevance for outflow tract formation in other cell types. The two Sox proteins are dispensable during early phases of cardiac neural crest development including neural tube emigration, proliferation, and migration through the pharyngeal arches. They become essential after arrival of the neural crest cells in the outflow tract for their proper differentiation and interaction with each other as well as with the environment through regulation of cytoskeletal, cell adhesion, and extracellular matrix molecules. Our results demonstrate that Sox4 and Sox11 have multiple functions in several cell types during outflow tract formation and may thus help to understand the basis of congenital heart defects in humans.
    Cellular and Molecular Life Sciences CMLS 12/2013; 71(15). DOI:10.1007/s00018-013-1523-x · 5.86 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The pharyngeal arch arteries (PAAs) are transient embryonic blood vessels that make indispensable contributions to the carotid arteries and great vessels of the heart, including the aorta and pulmonary arteries. During embryogenesis, the PAAs appear in a craniocaudal sequence to connect pre-existing segments of the primitive circulation after de novo vasculogenic assembly from angioblast precursors. Despite the unique spatiotemporal characteristics of PAA development, the embryonic origins of PAA angioblasts and the genetic factors regulating their emergence remain unknown. Here, we identify the embryonic source of PAA endothelium as nkx2.5(+) progenitors in lateral plate mesoderm long considered to adopt cell fates within the heart exclusively. Further, we report that PAA endothelial differentiation relies on Nkx2.5, a canonical cardiac transcription factor not previously implicated in blood vessel formation. Together, these studies reveal the heart field origin of PAA endothelium and attribute a new vasculogenic function to the cardiac transcription factor Nkx2.5 during great vessel precursor development.
    Nature Cell Biology 10/2013; 15(11). DOI:10.1038/ncb2862 · 20.06 Impact Factor
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Members of the T-box family of transcription factors are important regulators orchestrating the complex regionalization of the developing mammalian heart. Individual mutations in Tbx20 and Tbx3 cause distinct congenital heart abnormalities in the mouse: Tbx20 mutations result in failure of heart looping, developmental arrest and lack of chamber differentiation, while hearts of Tbx3 mutants progress further, loop normally but show atrioventricular convergence and outflow tract defects. The two genes have overlapping areas of expression in the atrioventricular canal and outflow tract of the heart but their potential genetic interaction has not been previously investigated. In this study we produced compound mutants to investigate potential genetic interactions at the earliest stages of heart development. We find that Tbx20; Tbx3 double heterozygous mice are viable and fertile with no apparent abnormalities, while double homozygous mutants are embryonic lethal by midgestation. Double homozygous mutant embryos display abnormal cardiac morphogenesis, lack of heart looping, expression patterns of cardiac genes and time of death that are indistinguishable from Tbx20 homozygous mutants. Prior to death, the double homozygotes show an overall developmental delay similar to Tbx3 homozygous mutants. Thus the effects of Tbx20 are epistatic to Tbx3 in the heart but Tbx3 is epistatic to Tbx20 with respect to developmental delay.
    PLoS ONE 07/2013; 8(7):e70149. DOI:10.1371/journal.pone.0070149 · 3.53 Impact Factor

Publication Stats

10k Citations
1,261.72 Total Impact Points

Institutions

  • 1998–2015
    • Victor Chang Cardiac Research Institute
      • Developmental and Stem Cell Biology Division
      Darlinghurst, New South Wales, Australia
  • 2010
    • Children's Hospital at Westmead
      • Heart Centre for Children
      Sydney, New South Wales, Australia
  • 2006
    • Royal College of Surgeons in Ireland
      • Department of Clinical Pharmacology
      Dublin, Leinster, Ireland
  • 2002
    • University of New South Wales
      Kensington, New South Wales, Australia
  • 1993–1999
    • Royal Melbourne Hospital
      Melbourne, Victoria, Australia
  • 1994–1998
    • The Walter and Eliza Hall Institute of Medical Research
      Melbourne, Victoria, Australia