-
Ivan Marazzi,
Jessica S Y Ho,
Jaehoon Kim,
Balaji Manicassamy,
Scott Dewell,
Randy A Albrecht,
Chris W Seibert,
Uwe Schaefer,
Kate L Jeffrey, Rab K Prinjha,
Kevin Lee,
Adolfo García-Sastre,
Robert G Roeder,
Alexander Tarakhovsky
[show abstract]
[hide abstract]
ABSTRACT: Viral infection is commonly associated with virus-driven hijacking of host proteins. Here we describe a novel mechanism by which influenza virus affects host cells through the interaction of influenza non-structural protein 1 (NS1) with the infected cell epigenome. We show that the NS1 protein of influenza A H3N2 subtype possesses a histone-like sequence (histone mimic) that is used by the virus to target the human PAF1 transcription elongation complex (hPAF1C). We demonstrate that binding of NS1 to hPAF1C depends on the NS1 histone mimic and results in suppression of hPAF1C-mediated transcriptional elongation. Furthermore, human PAF1 has a crucial role in the antiviral response. Loss of hPAF1C binding by NS1 attenuates influenza infection, whereas hPAF1C deficiency reduces antiviral gene expression and renders cells more susceptible to viruses. We propose that the histone mimic in NS1 enables the influenza virus to affect inducible gene expression selectively, thus contributing to suppression of the antiviral response.
Nature 03/2012; 483(7390):428-33. · 36.28 Impact Factor
-
Terry C Fang,
Uwe Schaefer,
Ingrid Mecklenbrauker,
Astrid Stienen,
Scott Dewell,
Marie S Chen,
Inmaculada Rioja,
Valentino Parravicini, Rab K Prinjha,
Rohit Chandwani,
Margaret R MacDonald,
Kevin Lee,
Charles M Rice,
Alexander Tarakhovsky
[show abstract]
[hide abstract]
ABSTRACT: Effective antiviral immunity depends on the ability of infected cells or cells triggered with virus-derived nucleic acids to produce type I interferon (IFN), which activates transcription of numerous antiviral genes. However, disproportionately strong or chronic IFN expression is a common cause of inflammatory and autoimmune diseases. We describe an epigenetic mechanism that determines cell type-specific differences in IFN and IFN-stimulated gene (ISG) expression in response to exogenous signals. We identify di-methylation of histone H3 at lysine 9 (H3K9me2) as a suppressor of IFN and IFN-inducible antiviral gene expression. We show that levels of H3K9me2 at IFN and ISG correlate inversely with the scope and amplitude of IFN and ISG expression in fibroblasts and dendritic cells. Accordingly, genetic ablation or pharmacological inactivation of lysine methyltransferase G9a, which is essential for the generation of H3K9me2, resulted in phenotypic conversion of fibroblasts into highly potent IFN-producing cells and rendered these cells resistant to pathogenic RNA viruses. In summary, our studies implicate H3K9me2 and enzymes controlling its abundance as key regulators of innate antiviral immunity.
Journal of Experimental Medicine 03/2012; 209(4):661-9. · 13.85 Impact Factor
-
Jonathan Seal,
Yann Lamotte,
Frédéric Donche,
Anne Bouillot,
Olivier Mirguet,
Françoise Gellibert,
Edwige Nicodeme,
Gael Krysa,
Jorge Kirilovsky,
Soren Beinke, [......],
Chun-Wa Chung,
Laurie Gordon,
Toni Lewis,
Ann L Walker,
Leanne Cutler,
David Lugo,
David M Wilson,
Jason Witherington,
Kevin Lee, Rab K Prinjha
[show abstract]
[hide abstract]
ABSTRACT: A novel series of quinoline isoxazole BET family bromodomain inhibitors are discussed. Crystallography is used to illustrate binding modes and rationalize their SAR. One member, I-BET151 (GSK1210151A), shows good oral bioavailability in both the rat and minipig as well as demonstrating efficient suppression of bacterial induced inflammation and sepsis in a murine in vivo endotoxaemia model.
Bioorganic & medicinal chemistry letters 02/2012; 22(8):2968-72. · 2.65 Impact Factor
-
Mark A Dawson, Rab K Prinjha,
Antje Dittmann,
George Giotopoulos,
Marcus Bantscheff,
Wai-In Chan,
Samuel C Robson,
Chun-wa Chung,
Carsten Hopf,
Mikhail M Savitski, [......],
Kurt R Auger,
Olivier Mirguet,
Konstanze Doehner,
Ruud Delwel,
Alan K Burnett,
Phillip Jeffrey,
Gerard Drewes,
Kevin Lee,
Brian J P Huntly,
Tony Kouzarides
[show abstract]
[hide abstract]
ABSTRACT: Recurrent chromosomal translocations involving the mixed lineage leukaemia (MLL) gene initiate aggressive forms of leukaemia, which are often refractory to conventional therapies. Many MLL-fusion partners are members of the super elongation complex (SEC), a critical regulator of transcriptional elongation, suggesting that aberrant control of this process has an important role in leukaemia induction. Here we use a global proteomic strategy to demonstrate that MLL fusions, as part of SEC and the polymerase-associated factor complex (PAFc), are associated with the BET family of acetyl-lysine recognizing, chromatin 'adaptor' proteins. These data provided the basis for therapeutic intervention in MLL-fusion leukaemia, via the displacement of the BET family of proteins from chromatin. We show that a novel small molecule inhibitor of the BET family, GSK1210151A (I-BET151), has profound efficacy against human and murine MLL-fusion leukaemic cell lines, through the induction of early cell cycle arrest and apoptosis. I-BET151 treatment in two human leukaemia cell lines with different MLL fusions alters the expression of a common set of genes whose function may account for these phenotypic changes. The mode of action of I-BET151 is, at least in part, due to the inhibition of transcription at key genes (BCL2, C-MYC and CDK6) through the displacement of BRD3/4, PAFc and SEC components from chromatin. In vivo studies indicate that I-BET151 has significant therapeutic value, providing survival benefit in two distinct mouse models of murine MLL-AF9 and human MLL-AF4 leukaemia. Finally, the efficacy of I-BET151 against human leukaemia stem cells is demonstrated, providing further evidence of its potent therapeutic potential. These findings establish the displacement of BET proteins from chromatin as a promising epigenetic therapy for these aggressive leukaemias.
Nature 10/2011; 478(7370):529-33. · 36.28 Impact Factor
-
Chun-Wa Chung,
Herve Coste,
Julia H White,
Olivier Mirguet,
Jonathan Wilde,
Romain L Gosmini,
Chris Delves,
Sylvie M Magny,
Robert Woodward,
Stephen A Hughes, [......],
Iain J Uings,
Jerome Toum,
Catherine A Clement,
Anne-Benedicte Boullay,
Rachel L Grimley,
Florence M Blandel, Rab K Prinjha,
Kevin Lee,
Jorge Kirilovsky,
Edwige Nicodeme
[show abstract]
[hide abstract]
ABSTRACT: Epigenetic mechanisms of gene regulation have a profound role in normal development and disease processes. An integral part of this mechanism occurs through lysine acetylation of histone tails which are recognized by bromodomains. While the biological and structural characterization of many bromodomain containing proteins has advanced considerably, the therapeutic tractability of this protein family is only now becoming understood. This paper describes the discovery and molecular characterization of potent (nM) small molecule inhibitors that disrupt the function of the BET family of bromodomains (Brd2, Brd3, and Brd4). By using a combination of phenotypic screening, chemoproteomics, and biophysical studies, we have discovered that the protein-protein interactions between bromodomains and acetylated histones can be antagonized by selective small molecules that bind at the acetylated lysine recognition pocket. X-ray crystal structures of compounds bound into bromodomains of Brd2 and Brd4 elucidate the molecular interactions of binding and explain the precisely defined stereochemistry required for activity.
Journal of Medicinal Chemistry 06/2011; 54(11):3827-38. · 4.80 Impact Factor
-
Dan Levy,
Alex J Kuo,
Yanqi Chang,
Uwe Schaefer,
Christopher Kitson,
Peggie Cheung,
Alexsandra Espejo,
Barry M Zee,
Chih Long Liu,
Stephanie Tangsombatvisit, [......],
Katrin F Chua,
Paul J Utz,
Xiaobing Shi, Rab K Prinjha,
Kevin Lee,
Benjamin A Garcia,
Mark T Bedford,
Alexander Tarakhovsky,
Xiaodong Cheng,
Or Gozani
[show abstract]
[hide abstract]
ABSTRACT: Signaling via the methylation of lysine residues in proteins has been linked to diverse biological and disease processes, yet the catalytic activity and substrate specificity of many human protein lysine methyltransferases (PKMTs) are unknown. We screened over 40 candidate PKMTs and identified SETD6 as a methyltransferase that monomethylated chromatin-associated transcription factor NF-κB subunit RelA at Lys310 (RelAK310me1). SETD6-mediated methylation rendered RelA inert and attenuated RelA-driven transcriptional programs, including inflammatory responses in primary immune cells. RelAK310me1 was recognized by the ankryin repeat of the histone methyltransferase GLP, which under basal conditions promoted a repressed chromatin state at RelA target genes through GLP-mediated methylation of histone H3 Lys9 (H3K9). NF-κB-activation-linked phosphorylation of RelA at Ser311 by protein kinase C-ζ (PKC-ζ) blocked the binding of GLP to RelAK310me1 and relieved repression of the target gene. Our findings establish a previously uncharacterized mechanism by which chromatin signaling regulates inflammation programs.
Nature Immunology 01/2011; 12(1):29-36. · 26.01 Impact Factor
-
Edwige Nicodeme,
Kate L Jeffrey,
Uwe Schaefer,
Soren Beinke,
Scott Dewell,
Chun-Wa Chung,
Rohit Chandwani,
Ivan Marazzi,
Paul Wilson,
Hervé Coste,
Julia White,
Jorge Kirilovsky,
Charles M Rice,
Jose M Lora, Rab K Prinjha,
Kevin Lee,
Alexander Tarakhovsky
[show abstract]
[hide abstract]
ABSTRACT: Interaction of pathogens with cells of the immune system results in activation of inflammatory gene expression. This response, although vital for immune defence, is frequently deleterious to the host due to the exaggerated production of inflammatory proteins. The scope of inflammatory responses reflects the activation state of signalling proteins upstream of inflammatory genes as well as signal-induced assembly of nuclear chromatin complexes that support mRNA expression. Recognition of post-translationally modified histones by nuclear proteins that initiate mRNA transcription and support mRNA elongation is a critical step in the regulation of gene expression. Here we present a novel pharmacological approach that targets inflammatory gene expression by interfering with the recognition of acetylated histones by the bromodomain and extra terminal domain (BET) family of proteins. We describe a synthetic compound (I-BET) that by 'mimicking' acetylated histones disrupts chromatin complexes responsible for the expression of key inflammatory genes in activated macrophages, and confers protection against lipopolysaccharide-induced endotoxic shock and bacteria-induced sepsis. Our findings suggest that synthetic compounds specifically targeting proteins that recognize post-translationally modified histones can serve as a new generation of immunomodulatory drugs.
Nature 11/2010; 468(7327):1119-23. · 36.28 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Synaptic loss represents one of the earliest signs of neuronal damage and is observed within both Alzheimer's disease patients and transgenic mouse models of the disease. We have developed a novel in vitro assay using high content screening technology to measure changes in a number of cell physiological parameters simultaneously within a neuronal population. Using Hoechst-33342 to label nuclei, betaIII-tubulin as a neuron-specific marker, and synapsin-I as an indicator of pre-synaptic sites, we have designed software to interrogate triple-labelled images, counting only those synaptic puncta associated with tubulin-positive structures. Here we demonstrate that addition of amyloid beta peptide (Abeta(1-42)), to either primary hippocampal or cortical neurons for 4 days in vitro has deleterious effects upon synapse formation, neurite outgrowth and arborisation in a concentration-dependent manner. Control reverse peptide showed no effect over the same concentration range. The effects of Abeta(1-42) were inhibited by D-KLVFFA, which contains residues 16-20 of Abeta that function as a self-recognition element during Abeta assembly and bind to the homologous region of Abeta and block its oligomerisation. These effects of Abeta(1-42) on synapse number and neurite outgrowth are similar to those described within AD patient pathology and transgenic mouse models.
Journal of Neuroscience Methods 09/2008; 175(1):96-103. · 1.98 Impact Factor
-
Mary M Hulihan,
Lianna Ishihara-Paul,
Jennifer Kachergus,
Liling Warren,
Rim Amouri,
Ramu Elango, Rab K Prinjha,
Ruchi Upmanyu,
Mounir Kefi,
Mourad Zouari,
Samia Ben Sassi,
Samia Ben Yahmed,
Ghada El Euch-Fayeche,
Paul M Matthews,
Lefkos T Middleton,
Rachel A Gibson,
Fayçal Hentati,
Matthew J Farrer
[show abstract]
[hide abstract]
ABSTRACT: Several genes have been implicated in the pathogenesis of Parkinson's disease (PD). The aim of this study was to define the clinical symptoms and age-associated cumulative incidence of the most frequent mutation associated with PD, LRRK2 Gly2019Ser.
238 patients with sporadic PD and 371 unrelated control participants from the Arab-Berber population were screened at the Institut National de Neurologie, Tunis. Symptoms of PD were assessed using the Hoehn and Yahr scale, the unified Parkinson's disease rating scale, and the Epworth scale. Genotyping for LRRK2 6055G-->A, which causes the Gly2019Ser mutation, was done in all participants, and the age-specific cumulative incidence of PD was calculated by Kaplan-Meier analysis.
30% of patients with PD in this case-control sample were carriers of LRRK2 Gly2019Ser. The age of onset of symptoms and the clinical presentation of patients with LRRK2 Gly2019Ser were similar to those of patients with idiopathic PD. Carriers of LRRK2 Gly2019Ser were 22.6 times (95% CI 10.2-50.1) more likely to be affected by PD than non-carriers. Tremor was the predominant symptom in LRRK2 Gly2019Ser carriers (92% [homozygotes] vs 75% [heterozygotes] vs 69% [non-carriers]; Cochran-Armitage trend test p=0.0587). Disease severity, response to treatment, and disease duration were similar among LRRK2 Gly2019Ser homozygotes, heterozygotes, and non-carriers (p=0.85). Disease penetrance in LRRK2 Gly2019Ser carriers ranged from less than 20% in those younger than 50 years to greater than 80% at 70 years.
The LRRK2 Gly2019Ser mutation in patients with PD is a useful aid to diagnosis. LRRK2 Gly2019Ser penetrance can vary but in most carriers PD seems an inevitable consequence of ageing. LRRK2 Gly2019Ser considerably increases susceptibility to neuronal degeneration, although the process might be mediated by many triggers. By contrast, idiopathic PD is rare before 50 years and the prevalence only increases to 4% in the oldest members of the population.
GlaxoSmithKline; National Institutes of Health; and Mayo Foundation.
The Lancet Neurology 08/2008; 7(7):591-4. · 23.46 Impact Factor
-
John P Cogswell,
James Ward,
Ian A Taylor,
Michelle Waters,
Yunling Shi,
Brian Cannon,
Kevin Kelnar,
Jon Kemppainen,
David Brown,
Caifu Chen, Rab K Prinjha,
Jill C Richardson,
Ann M Saunders,
Allen D Roses,
Cynthia A Richards
[show abstract]
[hide abstract]
ABSTRACT: MicroRNAs have essential functional roles in brain development and neuronal specification but their roles in neurodegenerative diseases such as Alzheimer's disease (AD) is unknown. Using a sensitive qRT-PCR platform we identified regional and stage-specific deregulation of miRNA expression in AD patient brains. We used experimental validation in addition to literature to reveal how the deregulated brain microRNAs are biomarkers for known and novel pathways in AD pathogenesis related to amyloid processing, neurogenesis, insulin resistance, and innate immunity. We additionally recovered miRNAs from cerebrospinal fluid and discovered AD-specific miRNA changes consistent with their role as potential biomarkers of disease.
Journal of Alzheimer's disease: JAD 05/2008; 14(1):27-41. · 3.74 Impact Factor
-
Hao Li,
Sally Wetten,
Li Li,
Pamela L St Jean,
Ruchi Upmanyu,
Linda Surh,
David Hosford,
Michael R Barnes,
James David Briley,
Michael Borrie, [......],
Sandra W Stinnett,
Jina E Swartz,
Rachel L Taylor,
John Wherrett,
Julie Williams,
David P Yarnall,
Rachel A Gibson,
Michael C Irizarry,
Lefkos T Middleton,
Allen D Roses
[show abstract]
[hide abstract]
ABSTRACT: To identify single-nucleotide polymorphisms (SNPs) associated with risk and age at onset of Alzheimer disease (AD) in a genomewide association study of 469 438 SNPs.
Case-control study with replication.
Memory referral clinics in Canada and the United Kingdom.
The hypothesis-generating data set consisted of 753 individuals with AD by National Institute of Neurological and Communicative Diseases and Stroke/Alzheimer's Disease and Related Disorders Association criteria recruited from 9 memory referral clinics in Canada and 736 ethnically matched control subjects; control subjects were recruited from nonbiological relatives, friends, or spouses of the patients and did not exhibit cognitive impairment by history or cognitive testing. The follow-up data set consisted of 418 AD cases and 249 nondemented control cases from the United Kingdom Medical Research Council Genetic Resource for Late-Onset AD recruited from clinics at Cardiff University, Cardiff, Wales, and King's College London, London, England.
Odds ratios and 95% confidence intervals for association of SNPs with AD by logistic regression adjusted for age, sex, education, study site, and French Canadian ancestry (for the Canadian data set). Hazard ratios and 95% confidence intervals from Cox proportional hazards regression for age at onset with similar covariate adjustments.
Unadjusted, SNP RS4420638 within APOC1 was strongly associated with AD due entirely to linkage disequilibrium with APOE. In the multivariable adjusted analyses, 3 SNPs within the top 120 by P value in the logistic analysis and 1 in the Cox analysis of the Canadian data set provided additional evidence for association at P< .05 within the United Kingdom Medical Research Council data set: RS7019241 (GOLPH2), RS10868366 (GOLPH2), RS9886784 (chromosome 9), and RS10519262 (intergenic between ATP8B4 and SLC27A2).
Our genomewide association analysis again identified the APOE linkage disequilibrium region as the strongest genetic risk factor for AD. This could be a consequence of the coevolution of more than 1 susceptibility allele, such as APOC1, in this region. We also provide new evidence for additional candidate genetic risk factors for AD that can be tested in further studies.
Archives of Neurology 01/2008; 65(1):45-53. · 7.58 Impact Factor
-
Mary Vinson,
Oliver Rausch,
Peter R Maycox, Rab K Prinjha,
Debra Chapman,
Rachel Morrow,
Alex J Harper,
Colin Dingwall,
Frank S Walsh,
Stephen A Burbidge,
David R Riddell
[show abstract]
[hide abstract]
ABSTRACT: The interaction between myelin-associated glycoprotein (MAG), expressed at the periaxonal membrane of myelin, and receptors on neurons initiates a bidirectional signalling system that results in inhibition of neurite outgrowth and maintenance of myelin integrity. We show that this involves a lipid-raft to lipid-raft interaction on opposing cell membranes. MAG is exclusively located in low buoyancy Lubrol WX-insoluble membrane fractions isolated from whole brain, primary oligodendrocytes, or MAG-expressing CHO cells. Localisation within these domains is dependent on cellular cholesterol and occurs following terminal glycosylation in the trans-Golgi network, characteristics of association with lipid rafts. Furthermore, a recombinant form of MAG interacts specifically with lipid-raft fractions from whole brain and cultured cerebellar granule cells, containing functional MAG receptors GT1b and Nogo-66 receptor and molecules required for transduction of signal from MAG into neurons. The localisation of both MAG and MAG receptors within lipid rafts on the surface of opposing cells may create discrete areas of high avidity multivalent interaction, known to be critical for signalling into both cell types. Localisation within lipid rafts may provide a molecular environment that facilitates the interaction between MAG and multiple receptors and also between MAG ligands and molecules involved in signal transduction.
Molecular and Cellular Neuroscience 04/2003; 22(3):344-52. · 3.66 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Synaptic loss represents one of the earliest signs of neuronal damage and is observed within both Alzheimer's disease patients and transgenic mouse models of the disease. We have developed a novel in vitro assay using high content screening technology to measure changes in a number of cell physiological parameters simultaneously within a neuronal population. Using Hoechst-33342 to label nuclei, βIII-tubulin as a neuron-specific marker, and synapsin-I as an indicator of pre-synaptic sites, we have designed software to interrogate triple-labelled images, counting only those synaptic puncta associated with tubulin-positive structures. Here we demonstrate that addition of amyloid beta peptide (Aβ1–42), to either primary hippocampal or cortical neurons for 4 days in vitro has deleterious effects upon synapse formation, neurite outgrowth and arborisation in a concentration-dependent manner. Control reverse peptide showed no effect over the same concentration range. The effects of Aβ1–42 were inhibited by D-KLVFFA, which contains residues 16–20 of Aβ that function as a self-recognition element during Aβ assembly and bind to the homologous region of Aβ and block its oligomerisation. These effects of Aβ1–42 on synapse number and neurite outgrowth are similar to those described within AD patient pathology and transgenic mouse models.
Journal of Neuroscience Methods.
