ORCID Profile
0000-0002-8954-4930
Current Organisation
Walter and Eliza Hall Institute of Medical Research
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Bentham Science Publishers Ltd.
Date: 06-04-2017
Publisher: Wiley
Date: 27-12-2011
DOI: 10.1111/J.1463-1326.2011.01538.X
Abstract: Obesity levels have increased significantly in the past five decades and are predicted to continue rising, resulting in important health implications. In particular, this has translated to an increase in the occurrence of type II diabetes mellitus (T2D). To alleviate associated problems, certain nutraceuticals have been considered as potential adjuncts or alternatives to conventional prescription drugs. Cinnamon, a commonly consumed spice originating from South East Asia, is currently being investigated as a potential preventative supplement and treatment for insulin resistance, metabolic syndrome and T2D. Extensive in vitro evidence has shown that cinnamon may improve insulin resistance by preventing and reversing impairments in insulin signalling in skeletal muscle. In adipose tissue, it has been shown that cinnamon increases the expression of peroxisome proliferator-activated receptors including, PPARγ. This is comparable to the action of commonly used thiazolinediones, which are PPAR agonists. Studies have also shown that cinnamon has potent anti-inflammatory properties. However, numerous human clinical trials with cinnamon have been conducted with varying findings. While some studies have showed no beneficial effect, others have indicated improvements in cholesterol levels, systolic blood pressure, insulin sensitivity and postprandial glucose levels with cinnamon. However, the only measurement consistently improved by cinnamon consumption is fasting glucose levels. While it is still premature to suggest the use of cinnamon supplementation based on the evidence, further investigation into mechanisms of action is warranted. Apart from further characterization of genetic and epigenetic changes in model systems, systematic large-scale clinical trials are required. In this study, we discuss the mechanisms of action of cinnamon in the context of T2D and we highlight some of the associated controversies.
Publisher: Oxford University Press (OUP)
Date: 17-11-2021
Abstract: In 2003, an Australian woman was convicted by a jury of smothering and killing her four children over a 10-year period. Each child died suddenly and unexpectedly during a sleep period, at ages ranging from 19 days to 18 months. In 2019 we were asked to investigate if a genetic cause could explain the children’s deaths as part of an inquiry into the mother’s convictions. Whole genomes or exomes of the mother and her four children were sequenced. Functional analysis of a novel CALM2 variant was performed by measuring Ca2+-binding affinity, interaction with calcium channels and channel function. We found two children had a novel calmodulin variant (CALM2 G114R) that was inherited maternally. Three genes (CALM1-3) encode identical calmodulin proteins. A variant in the corresponding residue of CALM3 (G114W) was recently reported in a child who died suddenly at age 4 and a sibling who suffered a cardiac arrest at age 5. We show that CALM2 G114R impairs calmodulin's ability to bind calcium and regulate two pivotal calcium channels (CaV1.2 and RyR2) involved in cardiac excitation contraction coupling. The deleterious effects of G114R are similar to those produced by G114W and N98S, which are considered arrhythmogenic and cause sudden cardiac death in children. A novel functional calmodulin variant (G114R) predicted to cause idiopathic ventricular fibrillation, catecholaminergic polymorphic ventricular tachycardia, or mild long QT syndrome was present in two children. A fatal arrhythmic event may have been triggered by their intercurrent infections. Thus, calmodulinopathy emerges as a reasonable explanation for a natural cause of their deaths.
Publisher: Springer Science and Business Media LLC
Date: 16-03-2202
Publisher: Cold Spring Harbor Laboratory
Date: 14-04-2014
Abstract: HDAC inhibitors can regulate gene expression by post-translational modification of histone as well as nonhistone proteins. Often studied at single loci, increased histone acetylation is the paradigmatic mechanism of action. However, little is known of the extent of genome-wide changes in cells stimulated by the hydroxamic acids, TSA and SAHA. In this article, we map vascular chromatin modifications including histone H3 acetylation of lysine 9 and 14 (H3K9/14ac) using chromatin immunoprecipitation (ChIP) coupled with massive parallel sequencing (ChIP-seq). Since acetylation-mediated gene expression is often associated with modification of other lysine residues, we also examined H3K4me3 and H3K9me3 as well as changes in CpG methylation (CpG-seq). RNA sequencing indicates the differential expression of ∼30% of genes, with almost equal numbers being up- and down-regulated. We observed broad deacetylation and gene expression changes conferred by TSA and SAHA mediated by the loss of EP300/CREBBP binding at multiple gene promoters. This study provides an important framework for HDAC inhibitor function in vascular biology and a comprehensive description of genome-wide deacetylation by pharmacological HDAC inhibition.
Publisher: Portland Press Ltd.
Date: 21-09-2023
DOI: 10.1042/ETLS20230018
Publisher: Elsevier BV
Date: 2017
Publisher: Wiley
Date: 16-12-2011
Publisher: Elsevier BV
Date: 07-2015
Publisher: Wiley
Date: 23-09-2022
DOI: 10.1002/MDS.29221
Abstract: Coding and noncoding repeat expansions are an important cause of neurodegenerative diseases. This study determined the clinical and genetic features of a large German family that has been followed for almost 2 decades with an autosomal dominantly inherited spinocerebellar ataxia (SCA) and independent co‐occurrence of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). We carried out clinical examinations and telephone interviews, reviewed medical records, and performed magnetic resonance imaging and positron emission tomography scans of all available family members. Comprehensive genetic investigations included linkage analysis, short‐read genome sequencing, long‐read sequencing, repeat‐primed polymerase chain reaction, and Southern blotting. The family comprises 118 members across seven generations, 30 of whom were definitely and five possibly affected. In this family, two different pathogenic mutations were found, a heterozygous repeat expansion in C9ORF72 in four patients with ALS/FTD and a heterozygous repeat expansion in DAB1 in at least nine patients with SCA, leading to a diagnosis of DAB1 ‐related ataxia (ATX‐DAB1 SCA37). One patient was affected by ALS and SCA and carried both repeat expansions. The repeat in DAB1 had the same configuration but was larger than those previously described ([ATTTT] ≈75 [ATTTC] ≈40‐100 [ATTTT] ≈415 ). Clinical features in patients with SCA included spinocerebellar symptoms, sometimes accompanied by additional ophthalmoplegia, vertical nystagmus, tremor, sensory deficits, and dystonia. After several decades, some of these patients suffered from cognitive decline and one from additional nonprogressive lower motor neuron affection. We demonstrate genetic and clinical findings during an 18‐year period in a unique family carrying two different pathogenic repeat expansions, providing novel insights into their genotypic and phenotypic spectrums. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Publisher: Cold Spring Harbor Laboratory
Date: 25-11-2019
DOI: 10.1101/851675
Abstract: Spinocerebellar ataxias (SCA) are often caused by expansions of short tandem repeats (STRs). Recent methodological advances have made repeat expansion (RE) detection with whole genome sequencing (WGS) feasible. To determine the genetic basis of ataxia in a multigenerational Australian pedigree, with autosomal dominant inheritance. WGS was performed on three affected relatives. The sequence data was screened for known pathogenic REs using two repeat expansion detection tools: exSTRa and ExpansionHunter. This screen provided a clear and rapid diagnosis ( five days from receiving the sequencing data) of SCA36, a rare form of ataxia caused by an intronic GGCCTG RE in NOP56 . the that diagnosis of rare ataxias caused by REs is highly feasible and cost effective with WGS. We propose that WGS be implemented as the frontline, cost effective methodology for molecular testing of in iduals with a clinical diagnosis of ataxia.
Publisher: MDPI AG
Date: 25-05-2016
DOI: 10.3390/NCRNA2020004
Publisher: Elsevier BV
Date: 11-2012
DOI: 10.1016/J.BIOCHI.2012.06.002
Abstract: The advent of massive parallel sequencing of immunopurified chromatin and its determinants has provided new avenues for researchers to map epigenome-wide changes and there is tremendous interest to uncover regulatory signatures to understand fundamental questions associated with chromatin structure and function. Indeed, the rapid development of large genome annotation projects has seen a resurgence in chromatin immunoprecipitation (ChIP) based protocols which are used to distinguish protein interactions coupled with large scale sequencing (Seq) to precisely map epigenome-wide interactions. Despite some of the great advances in our understanding of chromatin modifying complexes and their determinants, the development of ChIP-Seq technologies also pose specific demands on the integration of data for visualization, manipulation and analysis. In this article we discuss some of the considerations for experimental design planning, quality control, and bioinformatic analysis. The key aspects of post sequencing analysis are the identification of regions of interest, differentiation between biological conditions and the characterization of sequence differences for chromatin modifications. We provide an overview of best-practise approaches with background information and considerations of integrative analysis from ChIP-Seq experiments.
Publisher: American Society for Clinical Investigation
Date: 23-03-2017
Publisher: Elsevier BV
Date: 07-2019
Publisher: Springer Science and Business Media LLC
Date: 09-08-2023
DOI: 10.1038/S41431-022-01166-Y
Abstract: Several neurological disorders, such as myotonic dystrophy are caused by expansions of short tandem repeats (STRs) which can be difficult to detect by molecular tools. Methodological advances have made repeat expansion (RE) detection with whole genome sequencing (WGS) feasible. We recruited a multi-generational family (family A) ascertained for genetic studies of autism spectrum disorder. WGS was performed on seven children from four nuclear families from family A and analyzed for REs of STRs known to cause neurological disorders. We detected an expansion of a heterozygous intronic CCTG STR in CNBP in two siblings. This STR causes myotonic dystrophy type 2 (DM2). The expansion did not segregate with the ASD phenotype. Repeat-primed PCR showed that the DM2 CCTG motif was expanded above the pathogenic threshold in both children and their mother. On subsequent examination, the mother had mild features of DM2. We show that screening of STRs in WGS datasets has diagnostic utility, both in the clinical and research domain, with potential management and genetic counseling implications.
Publisher: Hindawi Limited
Date: 21-10-2022
DOI: 10.1002/HUMU.24289
Publisher: American Physiological Society
Date: 2019
DOI: 10.1152/AJPHEART.00609.2018
Abstract: Dilated cardiomyopathy (DCM) is a major cause of heart failure without effective therapy. Fibrogenesis plays a key role in the development of DCM, but little is known of the expression of the profibrotic factor galectin-3 (Gal-3) and its role in DCM pathophysiology. In a mouse DCM model with transgenic (TG) overexpression of mammalian sterile 20-like kinase 1 (Mst1), we studied Gal-3 expression and effects of the Gal-3 inhibitor modified citrus pectin (MCP) or Gal-3 gene knockout (KO). Gal-3 deletion in TG mice (TG/KO) was achieved by crossbreeding Mst1-TG mice with Gal-3 KO mice. The DCM phenotype was assessed by echocardiography and micromanometry. Cardiac expression of Gal-3 and fibrosis were determined. The cardiac transcriptome was profiled by RNA sequencing. Mst1-TG mice at 3−8 mo of age exhibited upregulated expression of Gal-3 by ~40-fold. TG mice had dilatation of cardiac chambers, suppressed left ventricular (LV) ejection fraction, poor LV contractility and relaxation, a threefold increase in LV collagen content, and upregulated fibrotic genes. Four-month treatment with MCP showed no beneficial effects. Gal-3 deletion in Mst1-TG mice attenuated chamber dilatation, organ congestion, and fibrogenesis. RNA sequencing identified profound disturbances by Mst1 overexpression in the cardiac transcriptome, which largely remained in TG/KO hearts. Gal-3 deletion in Mst1-TG mice, however, partially reversed the dysregulated transcriptional signaling involving extracellular matrix remodeling and collagen formation. We conclude that cardiac Mst1 activation leads to marked Gal-3 upregulation and transcriptome disturbances in the heart. Gal-3 deficiency attenuated cardiac remodeling and fibrotic signaling. NEW & NOTEWORTHY We found in a transgenic mouse dilated cardiomyopathy (DCM) model a pronounced upregulation of galectin-3 in cardiomyocytes. Galectin-3 gene deletion reduced cardiac fibrosis and fibrotic gene profiles and ameliorated cardiac remodeling and dysfunction. These benefits of galectin-3 deletion were in contrast to the lack of effect of treatment with the galectin-3 inhibitor modified citrus pectin. Our study suggests that suppression of galectin-3 mRNA expression could be used to treat DCM with high cardiac galectin-3 content.
Publisher: Informa UK Limited
Date: 2012
Publisher: Elsevier BV
Date: 04-2017
DOI: 10.1016/J.MAM.2016.09.004
Abstract: The regulation of gene expression in response to environmental and behavioural cues is critical for many biological processes. Histone tail modifications are dynamic and, as such, can regulate gene expression in response to extracellular conditions. Many of the enzymes involved in adding and removing these modifications require cofactors that are products of intermediary metabolism pathways, thus linking cellular metabolism to the regulation of gene expression. Furthermore, the expression and activity of such enzymes are influenced by the cellular concentrations of metabolic products. Under- and over-nutrition can induce epigenetic changes that influence chromatin structure and define a metabolic program. Importantly, recent studies have demonstrated that such changes during the pre- and peri-natal periods can be long-lasting, influencing the disease risk later in life and could be transmitted to subsequent generations. Moreover, damaging gene expression patterns observed in metabolic diseases such as diabetes are driven by persistent changes in chromatin structure, raising the possibility of targeting epigenetic pathways for the treatment of disease.
Publisher: Informa UK Limited
Date: 04-05-2015
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 20-04-2021
DOI: 10.1161/CIRCULATIONAHA.120.051921
Abstract: Despite in-depth knowledge of the molecular mechanisms controlling embryonic heart development, little is known about the signals governing postnatal maturation of the human heart. Single-nucleus RNA sequencing of 54 140 nuclei from 9 human donors was used to profile transcriptional changes in erse cardiac cell types during maturation from fetal stages to adulthood. Bulk RNA sequencing and the Assay for Transposase-Accessible Chromatin using sequencing were used to further validate transcriptional changes and to profile alterations in the chromatin accessibility landscape in purified cardiomyocyte nuclei from 21 human donors. Functional validation studies of sex steroids implicated in cardiac maturation were performed in human pluripotent stem cell–derived cardiac organoids and mice. Our data identify the progesterone receptor as a key mediator of sex-dependent transcriptional programs during cardiomyocyte maturation. Functional validation studies in human cardiac organoids and mice demonstrate that the progesterone receptor drives sex-specific metabolic programs and maturation of cardiac contractile properties. These data provide a blueprint for understanding human heart maturation in both sexes and reveal an important role for the progesterone receptor in human heart development.
Publisher: Informa UK Limited
Date: 17-05-2012
DOI: 10.3109/19390211.2012.682644
Abstract: Olive oil, an oil rich in monounsaturated fatty acids (MUFCs) and minor constituents including phenolic compounds, is a major component of the Mediterranean diet. The potential health benefits of the Mediterranean diet were highlighted by the seminal Seven Countries Study, and more contemporary research has identified olive oil as a major element responsible for these effects. It is emerging that the phenolic compounds are the most likely candidates accounting for the cardioprotective and cancer preventative effects of extra virgin olive oil (EVOO). In particular, the phenolic compound, hydroxytyrosol has been identified as one of the most potent antioxidants found in olive oil. This review will briefly consider historical aspects of olive oil research and the biological properties of phenolic compounds in olive oil will be discussed. The focus of the discussion will be related to the mechanisms of action of hydroxytyrosol. Studies have demonstrated that hydroxytyrosol induces apoptosis and cell cycle arrest in cancer cells. Further, research has shown that hydroxytyrosol can prevent cardiovascular disease by reducing the expression of adhesion molecules on endothelial cells and preventing the oxidation of low-density lipoprotein (LDL). The molecular mechanisms accounting for these effects are reviewed.
Publisher: Springer Science and Business Media LLC
Date: 28-09-2012
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 19-09-2017
DOI: 10.1161/CIRCULATIONAHA.117.028252
Abstract: The inability of the adult mammalian heart to regenerate following injury represents a major barrier in cardiovascular medicine. In contrast, the neonatal mammalian heart retains a transient capacity for regeneration, which is lost shortly after birth. Defining the molecular mechanisms that govern regenerative capacity in the neonatal period remains a central goal in cardiac biology. Here, we assemble a transcriptomic framework of multiple cardiac cell populations during postnatal development and following injury, which enables comparative analyses of the regenerative (neonatal) versus nonregenerative (adult) state for the first time. Cardiomyocytes, fibroblasts, leukocytes, and endothelial cells from infarcted and noninfarcted neonatal (P1) and adult (P56) mouse hearts were isolated by enzymatic dissociation and fluorescence-activated cell sorting at day 3 following surgery. RNA sequencing was performed on these cell populations to generate the transcriptome of the major cardiac cell populations during cardiac development, repair, and regeneration. To complement our transcriptomic data, we also surveyed the epigenetic landscape of cardiomyocytes during postnatal maturation by performing deep sequencing of accessible chromatin regions by using the Assay for Transposase-Accessible Chromatin from purified mouse cardiomyocyte nuclei (P1, P14, and P56). Profiling of cardiomyocyte and nonmyocyte transcriptional programs uncovered several injury-responsive genes across regenerative and nonregenerative time points. However, the majority of transcriptional changes in all cardiac cell types resulted from developmental maturation from neonatal stages to adulthood rather than activation of a distinct regeneration-specific gene program. Furthermore, adult leukocytes and fibroblasts were characterized by the expression of a proliferative gene expression network following infarction, which mirrored the neonatal state. In contrast, cardiomyocytes failed to reactivate the neonatal proliferative network following infarction, which was associated with loss of chromatin accessibility around cell cycle genes during postnatal maturation. This work provides a comprehensive framework and transcriptional resource of multiple cardiac cell populations during cardiac development, repair, and regeneration. Our findings define a regulatory program underpinning the neonatal regenerative state and identify alterations in the chromatin landscape that could limit reinduction of the regenerative program in adult cardiomyocytes.
Publisher: Informa UK Limited
Date: 17-03-2016
DOI: 10.1586/14789450.2016.1159960
Abstract: Many epigenetic-based therapeutics, including drugs such as histone deacetylase inhibitors, are now used in the clinic or are undergoing advanced clinical trials. The study of chromatin-modifying proteins has benefited from the rapid advances in high-throughput sequencing methods, the organized efforts of major consortiums and by in idual groups to profile human epigenomes in erse tissues and cell types. However, while such initiatives have carefully characterized healthy human tissue, disease epigenomes and drug-epigenome interactions remain very poorly understood. Reviewed here is how high-throughput sequencing improves our understanding of chromatin regulator proteins and the potential implications for the study of human disease and drug development and discovery.
Publisher: American Society for Clinical Investigation
Date: 15-02-2023
DOI: 10.1172/JCI160959
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.PARKRELDIS.2019.03.013
Abstract: Bi-allelic mutations in PARK7 are a rare cause of autosomal recessive early onset Parkinson's disease (EO-PD). To date, 30 in iduals harbouring 20 unique causative variants have been described. Understanding of the spectrum of clinical features and natural history of PARK7 mediated EO-PD remain limited. We studied a family with three offspring, two of whom were affected with EO-PD. Family members underwent detailed clinical examination and DNA s les from both affected in iduals and parents were analysed by exome sequencing. Two brothers of Iranian descent presented at age 29 years with Parkinsonism associated with high-pitched voice and hypomimia. The brothers were followed over a six and fifteen-year period and displayed typical levodopa responsive slowly-progressive Parkinsonism. A novel homozygous frameshift mutation in PARK7 [NM_007262.4:c.90dupG, p(Ile31Aspfs*2)] was identified. Here we report the clinical presentation and progression of EO-PD in brothers with a novel pathogenic PARK7 variant. We expand the clinical phenotype and provide an update of clinical and pathological features of the disorder.
Publisher: Informa UK Limited
Date: 02-12-2017
Publisher: Wiley
Date: 14-05-2020
DOI: 10.1002/MDS.28105
Publisher: Wiley
Date: 07-05-2022
DOI: 10.1002/ANA.26366
Abstract: Dominant spinocerebellar ataxias (SCA) are characterized by genetic heterogeneity. Some mapped and named loci remain without a causal gene identified. Here we applied next generation sequencing (NGS) to uncover the genetic etiology of the SCA25 locus . Whole‐exome and whole‐genome sequencing were performed in families linked to SCA25 , including the French family in which the SCA25 locus was originally mapped. Whole exome sequence data were interrogated in a cohort of 796 ataxia patients of unknown etiology. The SCA25 phenotype spans a slowly evolving sensory and cerebellar ataxia, in most cases attributed to ganglionopathy. A pathogenic variant causing exon skipping was identified in the gene encoding Polyribonucleotide Nucleotidyltransferase PNPase 1 ( PNPT1) located in the SCA25 linkage interval. A second splice variant in PNPT1 was detected in a large Australian family with a dominant ataxia also mapping to SCA25 . An additional nonsense variant was detected in an unrelated in idual with ataxia. Both nonsense and splice heterozygous variants result in premature stop codons, all located in the S1‐domain of PNPase. In addition, an elevated type I interferon response was observed in blood from all affected heterozygous carriers tested. PNPase notably prevents the abnormal accumulation of double‐stranded mtRNAs in the mitochondria and leakage into the cytoplasm, associated with triggering a type I interferon response. This study identifies PNPT1 as a new SCA gene, responsible for SCA25, and highlights biological links between alterations of mtRNA trafficking, interferonopathies and ataxia. ANN NEUROL 2022 :122–137
Publisher: Elsevier BV
Date: 2221
Publisher: Elsevier BV
Date: 2021
Publisher: Informa UK Limited
Date: 02-11-2017
Publisher: Elsevier BV
Date: 11-2012
Publisher: Springer Science and Business Media LLC
Date: 29-10-2019
DOI: 10.1038/S41467-019-12763-9
Abstract: Familial Adult Myoclonic Epilepsy (FAME) is a genetically heterogeneous disorder characterized by cortical tremor and seizures. Intronic TTTTA/TTTCA repeat expansions in SAMD12 (FAME1) are the main cause of FAME in Asia. Using genome sequencing and repeat-primed PCR, we identify another site of this repeat expansion, in MARCH6 (FAME3) in four European families. Analysis of single DNA molecules with nanopore sequencing and molecular combing show that expansions range from 3.3 to 14 kb on average. However, we observe considerable variability in expansion length and structure, supporting the existence of multiple expansion configurations in blood cells and fibroblasts of the same in idual. Moreover, the largest expansions are associated with micro-rearrangements occurring near the expansion in 20% of cells. This study provides further evidence that FAME is caused by intronic TTTTA/TTTCA expansions in distinct genes and reveals that expansions exhibit an unexpectedly high somatic instability that can ultimately result in genomic rearrangements.
Location: Australia
No related grants have been discovered for Haloom Rafehi.