Publications by authors named "Sarah Kummerfeld"

32 Publications

ClinSV: clinical grade structural and copy number variant detection from whole genome sequencing data.

Genome Med 2021 Feb 25;13(1):32. Epub 2021 Feb 25.

Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, 370 Victoria Street, Darlinghurst, NSW, Australia.

Whole genome sequencing (WGS) has the potential to outperform clinical microarrays for the detection of structural variants (SV) including copy number variants (CNVs), but has been challenged by high false positive rates. Here we present ClinSV, a WGS based SV integration, annotation, prioritization, and visualization framework, which identified 99.8% of simulated pathogenic ClinVar CNVs > 10 kb and 11/11 pathogenic variants from matched microarrays. The false positive rate was low (1.5-4.5%) and reproducibility high (95-99%). In clinical practice, ClinSV identified reportable variants in 22 of 485 patients (4.7%) of which 35-63% were not detectable by current clinical microarray designs. ClinSV is available at https://github.com/KCCG/ClinSV .
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http://dx.doi.org/10.1186/s13073-021-00841-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7908648PMC
February 2021

Diagnostic Yield of Whole Genome Sequencing After Nondiagnostic Exome Sequencing or Gene Panel in Developmental and Epileptic Encephalopathies.

Neurology 2021 03 10;96(13):e1770-e1782. Epub 2021 Feb 10.

From the School of Women's and Children's Health (E.E.P., R.S., S.R., T.K., H.S., P.I.A., J.L., M.C., D.M., M.J.C., A.B., E.K.), The School of Biotechnology and Biomolecular Sciences (M.E.D.), Childrens Cancer Institute (M.J.C.), and NeuRA (T.R.), University of New South Wales; Sydney Childrens Hospital Randwick (E.E.P., R.S., R.M., S.R., T.K., H.S., P.I.A., J.L., M.C., D.M., A.B., E.K.), Sydney Childrens Hospital Network; GOLD Service (E.E.P.), Hunter Genetics; Kinghorn Centre for Clinical Genomics (E.E.P., A.E.M., C.P., V.G., L.H., S.I., R.L.D., A.P.D., S.K., M.J.C.), Garvan Institute of Medical Research, Sydney, Australia; RG Development & Disease (U.S.M., S.M.), Max Planck Institute for Molecular Genetics; Institute for Medical Genetics and Human Genetics (U.S.M., S.M.), Charité-Universitätsmedizin, Berlin, Germany; Faculty of Medicine, Prince of Wales Clinical School (L.H.), and Faculty of Medicine, St Vincents Clinical School (S.K.), UNSW Sydney, Randwick; Adelaide Medical School (C.S., M.H.N.T.), University of Adelaide; Kolling Institute (R.L.D.), University of Sydney; SWSLHD Liverpool Hospital (A.C.), Liverpool; and New South Wales Health Pathology Randwick Genomics Laboratory (T.R., E.K.), Australia.

Objective: To assess the benefits and limitations of whole genome sequencing (WGS) compared to exome sequencing (ES) or multigene panel (MGP) in the molecular diagnosis of developmental and epileptic encephalopathies (DEE).

Methods: We performed WGS of 30 comprehensively phenotyped DEE patient trios that were undiagnosed after first-tier testing, including chromosomal microarray and either research ES (n = 15) or diagnostic MGP (n = 15).

Results: Eight diagnoses were made in the 15 individuals who received prior ES (53%): 3 individuals had complex structural variants; 5 had ES-detectable variants, which now had additional evidence for pathogenicity. Eleven diagnoses were made in the 15 MGP-negative individuals (68%); the majority (n = 10) involved genes not included in the panel, particularly in individuals with postneonatal onset of seizures and those with more complex presentations including movement disorders, dysmorphic features, or multiorgan involvement. A total of 42% of diagnoses were autosomal recessive or X-chromosome linked.

Conclusion: WGS was able to improve diagnostic yield over ES primarily through the detection of complex structural variants (n = 3). The higher diagnostic yield was otherwise better attributed to the power of re-analysis rather than inherent advantages of the WGS platform. Additional research is required to assist in the assessment of pathogenicity of novel noncoding and complex structural variants and further improve diagnostic yield for patients with DEE and other neurogenetic disorders.
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http://dx.doi.org/10.1212/WNL.0000000000011655DOI Listing
March 2021

Molecular patterns in salivary duct carcinoma identify prognostic subgroups.

Mod Pathol 2020 10 26;33(10):1896-1909. Epub 2020 May 26.

Kinghorn Cancer Centre and Garvan Institute of Medical Research, Sydney, NSW, Australia.

Salivary duct carcinoma (SDCa) is a rare cancer with high rate of metastases and poor survival despite aggressive multimodality treatment. This study analyzes the genetic changes in SDCa, their impact on cancer pathways, and evaluates whether molecular patterns can identify subgroups with distinct clinical characteristics and outcome. Clinicopathologic details and tissue samples from 66 patients (48 males, 18 females) treated between 1995 and 2018 were obtained from multiple institutions. Androgen receptor (AR) was assessed by immunohistochemistry, and the Illumina TruSight 170 gene panel was used for DNA sequencing. Male gender, lympho-vascular invasion, lymph node metastasis, and smoking were significant predictors of disease-free survival. AR was present in 79%. Frequently encountered alterations were mutations in TP53 (51%), PIK3CA (32%) and HRAS (22%), as well as amplifications of CDK4/6 (22%), ERBB2 (21%), MYC (16%), and deletions of CDKN2A (13%). TP53 mutation and MYC amplifications were associated with decreased disease-free survival. Analysis of cancer pathways revealed that the PI3K pathway was most commonly affected. Alterations in the cell cycle pathway were associated with impaired disease-free survival (HR 2.6, P = 0.038). Three subgroups based on AR and ERBB2 status were identified, which featured distinct molecular patterns and outcome. Among AR positive SDCa, HRAS mutations were restricted to AR positive tumors without ERBB2 amplification and HRAS mutations featured high co-occurrence with PIK3CA alterations, which seems specific to SDCa. AR negative SDCa were associated with poor disease-free survival in multivariate analysis (HR 4.5, P = 0.010) and none of these tumors exhibited ERBB2 amplification or HRAS mutations. AR and ERBB2 status in SDCa thus classifies tumors with distinct molecular profiles relevant to future targeted therapy. Furthermore, clinical factors such as smoking and molecular features such as MYC amplification may serve as markers of poor prognosis of SDCa.
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http://dx.doi.org/10.1038/s41379-020-0576-2DOI Listing
October 2020

The Lifeact-EGFP mouse is a translationally controlled fluorescent reporter of T cell activation.

J Cell Sci 2020 03 5;133(5). Epub 2020 Mar 5.

EMBL Australia, Single Molecule Science Node, School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia

It has become increasingly evident that T cell functions are subject to translational control in addition to transcriptional regulation. Here, by using live imaging of CD8 T cells isolated from the Lifeact-EGFP mouse, we show that T cells exhibit a gain in fluorescence intensity following engagement of cognate tumour target cells. The GFP signal increase is governed by Erk1/2-dependent distal T cell receptor (TCR) signalling and its magnitude correlates with IFN-γ and TNF-α production, which are hallmarks of T cell activation. Enhanced fluorescence was due to increased translation of Lifeact-EGFP protein, without an associated increase in its mRNA. Activation-induced gains in fluorescence were also observed in naïve and CD4 T cells from the Lifeact-EGFP reporter, and were readily detected by both flow cytometry and live cell microscopy. This unique, translationally controlled reporter of effector T cell activation simultaneously enables tracking of cell morphology, F-actin dynamics and activation state in individual migrating T cells. It is a valuable addition to the limited number of reporters of T cell dynamics and activation, and opens the door to studies of translational activity and heterogeneities in functional T cell responses .
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http://dx.doi.org/10.1242/jcs.238014DOI Listing
March 2020

Whole genome sequencing for the genetic diagnosis of heterogenous dystonia phenotypes.

Parkinsonism Relat Disord 2019 12 7;69:111-118. Epub 2019 Nov 7.

Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia; Department of Neurogenetics, Kolling Institute, University of Sydney and Royal North Shore Hospital, St Leonards, New South Wales, 2065, Australia; Sydney Medical School, Faculty of Medicine and Health, University of Sydney, Camperdown, 2050, Australia; Department of Neurology, Royal North Shore Hospital, St Leonards, New South Wales, 2065, Australia. Electronic address:

Introduction: Dystonia is a clinically and genetically heterogeneous disorder and a genetic cause is often difficult to elucidate. This is the first study to use whole genome sequencing (WGS) to investigate dystonia in a large sample of affected individuals.

Methods: WGS was performed on 111 probands with heterogenous dystonia phenotypes. We performed analysis for coding and non-coding variants, copy number variants (CNVs), and structural variants (SVs). We assessed for an association between dystonia and 10 known dystonia risk variants.

Results: A genetic diagnosis was obtained for 11.7% (13/111) of individuals. We found that a genetic diagnosis was more likely in those with an earlier age at onset, younger age at testing, and a combined dystonia phenotype. We identified pathogenic/likely-pathogenic variants in ADCY5 (n = 1), ATM (n = 1), GNAL (n = 2), GLB1 (n = 1), KMT2B (n = 2), PRKN (n = 2), PRRT2 (n = 1), SGCE (n = 2), and THAP1 (n = 1). CNVs were detected in 3 individuals. We found an association between the known risk variant ARSG rs11655081 and dystonia (p = 0.003).

Conclusion: A genetic diagnosis was found in 11.7% of individuals with dystonia. The diagnostic yield was higher in those with an earlier age of onset, younger age at testing, and a combined dystonia phenotype. WGS may be particularly relevant for dystonia given that it allows for the detection of CNVs, which accounted for 23% of the genetically diagnosed cases.
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http://dx.doi.org/10.1016/j.parkreldis.2019.11.004DOI Listing
December 2019

Molecular Portraits of Early Rheumatoid Arthritis Identify Clinical and Treatment Response Phenotypes.

Cell Rep 2019 08;28(9):2455-2470.e5

Centre for Experimental Medicine and Rheumatology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK. Electronic address:

There is a current imperative to unravel the hierarchy of molecular pathways that drive the transition of early to established disease in rheumatoid arthritis (RA). Herein, we report a comprehensive RNA sequencing analysis of the molecular pathways that drive early RA progression in the disease tissue (synovium), comparing matched peripheral blood RNA-seq in a large cohort of early treatment-naive patients, namely, the Pathobiology of Early Arthritis Cohort (PEAC). We developed a data exploration website (https://peac.hpc.qmul.ac.uk/) to dissect gene signatures across synovial and blood compartments, integrated with deep phenotypic profiling. We identified transcriptional subgroups in synovium linked to three distinct pathotypes: fibroblastic pauci-immune pathotype, macrophage-rich diffuse-myeloid pathotype, and a lympho-myeloid pathotype characterized by infiltration of lymphocytes and myeloid cells. This is suggestive of divergent pathogenic pathways or activation disease states. Pro-myeloid inflammatory synovial gene signatures correlated with clinical response to initial drug therapy, whereas plasma cell genes identified a poor prognosis subgroup with progressive structural damage.
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http://dx.doi.org/10.1016/j.celrep.2019.07.091DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6718830PMC
August 2019

IRF2 transcriptionally induces expression for pyroptosis.

Sci Signal 2019 05 21;12(582). Epub 2019 May 21.

Department of Physiological Chemistry, Genentech Inc., South San Francisco, CA 94080, USA.

Gasdermin-D (GSDMD) is cleaved by caspase-1, caspase-4, and caspase-11 in response to canonical and noncanonical inflammasome activation. Upon cleavage, GSDMD oligomerizes and forms plasma membrane pores, resulting in interleukin-1β (IL-1β) secretion, pyroptotic cell death, and inflammatory pathologies, including periodic fever syndromes and septic shock-a plague on modern medicine. Here, we showed that IRF2, a member of the interferon regulatory factor (IRF) family of transcription factors, was essential for the transcriptional activation of A forward genetic screen with -ethyl--nitrosourea (ENU)-mutagenized mice linked IRF2 to inflammasome signaling. expression was substantially attenuated in deficient macrophages, endothelial cells, and multiple tissues, which corresponded with reduced IL-1β secretion and inhibited pyroptosis. Mechanistically, IRF2 bound to a previously uncharacterized but unique site within the promoter to directly drive transcription for the execution of pyroptosis. Disruption of this single IRF2-binding site abolished signaling by both the canonical and noncanonical inflammasomes. Together, our data illuminate a key transcriptional mechanism for expression of the gene encoding GSDMD, a critical mediator of inflammatory pathologies.
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http://dx.doi.org/10.1126/scisignal.aax4917DOI Listing
May 2019

Intrinsic apoptosis shapes the tumor spectrum linked to inactivation of the deubiquitinase BAP1.

Science 2019 Apr 18;364(6437):283-285. Epub 2019 Apr 18.

Department of Physiological Chemistry, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA.

Malignancies arising from mutation of tumor suppressors have unexplained tissue proclivity. For example, encodes a widely expressed deubiquitinase for histone H2A, but germline mutations are predominantly associated with uveal melanomas and mesotheliomas. We show that BAP1 inactivation causes apoptosis in mouse embryonic stem cells, fibroblasts, liver, and pancreatic tissue but not in melanocytes and mesothelial cells. Ubiquitin ligase RNF2, which silences genes by monoubiquitinating H2A, promoted apoptosis in BAP1-deficient cells by suppressing expression of the prosurvival genes and In contrast, BAP1 loss in melanocytes had little impact on expression of prosurvival genes, instead inducing Thus, BAP1 appears to modulate gene expression by countering H2A ubiquitination, but its loss only promotes tumorigenesis in cells that do not engage an RNF2-dependent apoptotic program.
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http://dx.doi.org/10.1126/science.aav4902DOI Listing
April 2019

The Gag protein PEG10 binds to RNA and regulates trophoblast stem cell lineage specification.

PLoS One 2019 5;14(4):e0214110. Epub 2019 Apr 5.

Physiological Chemistry Department, Genentech, South San Francisco, California, United States of America.

Peg10 (paternally expressed gene 10) is an imprinted gene that is essential for placental development. It is thought to derive from a Ty3-gyspy LTR (long terminal repeat) retrotransposon and retains Gag and Pol-like domains. Here we show that the Gag domain of PEG10 can promote vesicle budding similar to the HIV p24 Gag protein. Expressed in a subset of mouse endocrine organs in addition to the placenta, PEG10 was identified as a substrate of the deubiquitinating enzyme USP9X. Consistent with PEG10 having a critical role in placental development, PEG10-deficient trophoblast stem cells (TSCs) exhibited impaired differentiation into placental lineages. PEG10 expressed in wild-type, differentiating TSCs was bound to many cellular RNAs including Hbegf (Heparin-binding EGF-like growth factor), which is known to play an important role in placentation. Expression of Hbegf was reduced in PEG10-deficient TSCs suggesting that PEG10 might bind to and stabilize RNAs that are critical for normal placental development.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0214110PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6450627PMC
December 2019

Ubiquitin ligase COP1 coordinates transcriptional programs that control cell type specification in the developing mouse brain.

Proc Natl Acad Sci U S A 2018 10 15;115(44):11244-11249. Epub 2018 Oct 15.

Department of Physiological Chemistry, Genentech, South San Francisco, CA 94080;

The E3 ubiquitin ligase CRL4 is active in the absence of ERK signaling, modifying the transcription factors ETV1, ETV4, ETV5, and c-JUN with polyubiquitin that targets them for proteasomal degradation. Here we show that this posttranslational regulatory mechanism is active in neurons, with ETV5 and c-JUN accumulating within minutes of ERK activation. Mice with () deleted in neural stem cells showed abnormally elevated expression of ETV1, ETV4, ETV5, and c-JUN in the developing brain and spinal cord. Expression of c-JUN target genes and was increased, whereas ETV5 and c-JUN both contributed to an expanded number of cells expressing genes associated with gliogenesis, including , , and The mice had subtle morphological abnormalities in the cerebral cortex, hippocampus, and cerebellum by embryonic day 18 and died soon after birth. Elevated c-JUN, ETV5, and ETV1 contributed to the perinatal lethality, as several -deficient mice also lacking and , or lacking and heterozygous for , were viable.
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http://dx.doi.org/10.1073/pnas.1805033115DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6217379PMC
October 2018

ASC- and caspase-8-dependent apoptotic pathway diverges from the NLRC4 inflammasome in macrophages.

Sci Rep 2018 02 28;8(1):3788. Epub 2018 Feb 28.

Department of Physiological Chemistry, Genentech Inc., South San Francisco, California, USA.

The NLRC4 inflammasome recognizes bacterial flagellin and components of the type III secretion apparatus. NLRC4 stimulation leads to caspase-1 activation followed by a rapid lytic cell death known as pyroptosis. NLRC4 is linked to pathogen-free auto-inflammatory diseases, suggesting a role for NLRC4 in sterile inflammation. Here, we show that NLRC4 activates an alternative cell death program morphologically similar to apoptosis in caspase-1-deficient BMDMs. By performing an unbiased genome-wide CRISPR/Cas9 screen with subsequent validation studies in gene-targeted mice, we highlight a critical role for caspase-8 and ASC adaptor in an alternative apoptotic pathway downstream of NLRC4. Furthermore, caspase-1 catalytically dead knock-in (Casp1 C284A KI) BMDMs genetically segregate pyroptosis and apoptosis, and confirm that caspase-1 does not functionally compete with ASC for NLRC4 interactions. We show that NLRC4/caspase-8-mediated apoptotic cells eventually undergo plasma cell membrane damage in vitro, suggesting that this pathway can lead to secondary necrosis. Unexpectedly, we found that DFNA5/GSDME, a member of the pore-forming gasdermin family, is dispensable for the secondary necrosis that follows NLRC4-mediated apoptosis in macrophages. Together, our data confirm the existence of an alternative caspase-8 activation pathway diverging from the NLRC4 inflammasome in primary macrophages.
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http://dx.doi.org/10.1038/s41598-018-21998-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5830643PMC
February 2018

Non-canonical reader modules of BAZ1A promote recovery from DNA damage.

Nat Commun 2017 10 11;8(1):862. Epub 2017 Oct 11.

Department of Early Discovery Biochemistry, Genentech, Inc., 1 DNA Way, South San Francisco, CA, 94080, USA.

Members of the ISWI family of chromatin remodelers mobilize nucleosomes to control DNA accessibility and, in some cases, are required for recovery from DNA damage. However, it remains poorly understood how the non-catalytic ISWI subunits BAZ1A and BAZ1B might contact chromatin to direct the ATPase SMARCA5. Here, we find that the plant homeodomain of BAZ1A, but not that of BAZ1B, has the unusual function of binding DNA. Furthermore, the BAZ1A bromodomain has a non-canonical gatekeeper residue and binds relatively weakly to acetylated histone peptides. Using CRISPR-Cas9-mediated genome editing we find that BAZ1A and BAZ1B each recruit SMARCA5 to sites of damaged chromatin and promote survival. Genetic engineering of structure-designed bromodomain and plant homeodomain mutants reveals that reader modules of BAZ1A and BAZ1B, even when non-standard, are critical for DNA damage recovery in part by regulating ISWI factors loading at DNA lesions and supporting transcriptional programs required for survival.ISWI chromatin remodelers regulate DNA accessibility and have been implicated in DNA damage repair. Here, the authors uncover functions, in response to DNA damage, for the bromodomain of the ISWI subunit BAZ1B and for the non-canonical PHD and bromodomain modules of the paralog BAZ1A.
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http://dx.doi.org/10.1038/s41467-017-00866-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5636791PMC
October 2017

Transcription factor Etv5 is essential for the maintenance of alveolar type II cells.

Proc Natl Acad Sci U S A 2017 04 28;114(15):3903-3908. Epub 2017 Mar 28.

Department of Physiological Chemistry, Genentech, South San Francisco, CA 94080;

Alveolar type II (AT2) cell dysfunction contributes to a number of significant human pathologies including respiratory distress syndrome, lung adenocarcinoma, and debilitating fibrotic diseases, but the critical transcription factors that maintain AT2 cell identity are unknown. Here we show that the E26 transformation-specific (ETS) family transcription factor Etv5 is essential to maintain AT2 cell identity. Deletion of from AT2 cells produced gene and protein signatures characteristic of differentiated alveolar type I (AT1) cells. Consistent with a defect in the AT2 stem cell population, deficiency markedly reduced recovery following bleomycin-induced lung injury. Lung tumorigenesis driven by mutant KrasG12D was also compromised by Etv5 deficiency. ERK activation downstream of Ras was found to stabilize Etv5 through inactivation of the cullin-RING ubiquitin ligase CRL4 that targets Etv5 for proteasomal degradation. These findings identify Etv5 as a critical output of Ras signaling in AT2 cells, contributing to both lung homeostasis and tumor initiation.
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http://dx.doi.org/10.1073/pnas.1621177114DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5393225PMC
April 2017

β-Cell Insulin Secretion Requires the Ubiquitin Ligase COP1.

Cell 2015 Dec 25;163(6):1457-67. Epub 2015 Nov 25.

Department of Physiological Chemistry, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA. Electronic address:

A variety of signals finely tune insulin secretion by pancreatic β cells to prevent both hyper-and hypoglycemic states. Here, we show that post-translational regulation of the transcription factors ETV1, ETV4, and ETV5 by the ubiquitin ligase COP1 (also called RFWD2) in β cells is critical for insulin secretion. Mice lacking COP1 in β cells developed diabetes due to insulin granule docking defects that were fully rescued by genetic deletion of Etv1, Etv4, and Etv5. Genes regulated by ETV1, ETV4, or ETV5 in the absence of mouse COP1 were enriched in human diabetes-associated genes, suggesting that they also influence human β-cell pathophysiology. In normal β cells, ETV4 was stabilized upon membrane depolarization and limited insulin secretion under hyperglycemic conditions. Collectively, our data reveal that ETVs negatively regulate insulin secretion for the maintenance of normoglycemia.
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http://dx.doi.org/10.1016/j.cell.2015.10.076DOI Listing
December 2015

Caspase-11 cleaves gasdermin D for non-canonical inflammasome signalling.

Nature 2015 Oct 16;526(7575):666-71. Epub 2015 Sep 16.

Department of Physiological Chemistry, Genentech Inc., South San Francisco, California 94080, USA.

Intracellular lipopolysaccharide from Gram-negative bacteria including Escherichia coli, Salmonella typhimurium, Shigella flexneri, and Burkholderia thailandensis activates mouse caspase-11, causing pyroptotic cell death, interleukin-1β processing, and lethal septic shock. How caspase-11 executes these downstream signalling events is largely unknown. Here we show that gasdermin D is essential for caspase-11-dependent pyroptosis and interleukin-1β maturation. A forward genetic screen with ethyl-N-nitrosourea-mutagenized mice links Gsdmd to the intracellular lipopolysaccharide response. Macrophages from Gsdmd(-/-) mice generated by gene targeting also exhibit defective pyroptosis and interleukin-1β secretion induced by cytoplasmic lipopolysaccharide or Gram-negative bacteria. In addition, Gsdmd(-/-) mice are protected from a lethal dose of lipopolysaccharide. Mechanistically, caspase-11 cleaves gasdermin D, and the resulting amino-terminal fragment promotes both pyroptosis and NLRP3-dependent activation of caspase-1 in a cell-intrinsic manner. Our data identify gasdermin D as a critical target of caspase-11 and a key mediator of the host response against Gram-negative bacteria.
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http://dx.doi.org/10.1038/nature15541DOI Listing
October 2015

Synovial phenotypes in rheumatoid arthritis correlate with response to biologic therapeutics.

Arthritis Res Ther 2014 30;16(2):R90. Epub 2014 Apr 30.

Introduction: Rheumatoid arthritis (RA) is a complex and clinically heterogeneous autoimmune disease. Currently, the relationship between pathogenic molecular drivers of disease in RA and therapeutic response is poorly understood.

Methods: We analyzed synovial tissue samples from two RA cohorts of 49 and 20 patients using a combination of global gene expression, histologic and cellular analyses, and analysis of gene expression data from two further publicly available RA cohorts. To identify candidate serum biomarkers that correspond to differential synovial biology and clinical response to targeted therapies, we performed pre-treatment biomarker analysis compared with therapeutic outcome at week 24 in serum samples from 198 patients from the ADACTA (ADalimumab ACTemrA) phase 4 trial of tocilizumab (anti-IL-6R) monotherapy versus adalimumab (anti-TNFα) monotherapy.

Results: We documented evidence for four major phenotypes of RA synovium - lymphoid, myeloid, low inflammatory, and fibroid - each with distinct underlying gene expression signatures. We observed that baseline synovial myeloid, but not lymphoid, gene signature expression was higher in patients with good compared with poor European league against rheumatism (EULAR) clinical response to anti-TNFα therapy at week 16 (P =0.011). We observed that high baseline serum soluble intercellular adhesion molecule 1 (sICAM1), associated with the myeloid phenotype, and high serum C-X-C motif chemokine 13 (CXCL13), associated with the lymphoid phenotype, had differential relationships with clinical response to anti-TNFα compared with anti-IL6R treatment. sICAM1-high/CXCL13-low patients showed the highest week 24 American College of Rheumatology (ACR) 50 response rate to anti-TNFα treatment as compared with sICAM1-low/CXCL13-high patients (42% versus 13%, respectively, P =0.05) while anti-IL-6R patients showed the opposite relationship with these biomarker subgroups (ACR50 20% versus 69%, P =0.004).

Conclusions: These data demonstrate that underlying molecular and cellular heterogeneity in RA impacts clinical outcome to therapies targeting different biological pathways, with patients with the myeloid phenotype exhibiting the most robust response to anti-TNFα. These data suggest a path to identify and validate serum biomarkers that predict response to targeted therapies in rheumatoid arthritis and possibly other autoimmune diseases.

Trial Registration: ClinicalTrials.gov NCT01119859
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http://dx.doi.org/10.1186/ar4555DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4060385PMC
September 2015

PILRα negatively regulates mouse inflammatory arthritis.

J Immunol 2014 Jul 16;193(2):860-70. Epub 2014 Jun 16.

Department of Immunology, Genentech, South San Francisco, CA 94080;

Paired Ig-like type 2 receptor (PILR)α inhibitory receptor and its counterpart PILRβ activating receptor are coexpressed on myeloid cells. In this article, we report that PILRα, but not PILRβ, is elevated in human rheumatoid arthritis synovial tissue and correlates with inflammatory cell infiltration. Pilrα(-/-) mice produce more pathogenic cytokines during inflammation and are prone to enhanced autoimmune arthritis. Correspondingly, engaging PILRα with anti-PILRα mAb ameliorates inflammation in mouse arthritis models and suppresses the production of proinflammatory cytokines. Our studies suggest that PILRα mediates an important inhibitory pathway that can dampen inflammatory responses.
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http://dx.doi.org/10.4049/jimmunol.1400045DOI Listing
July 2014

gCMAP: user-friendly connectivity mapping with R.

Bioinformatics 2014 Jan 15;30(1):127-8. Epub 2013 Oct 15.

Department of Bioinformatics and Computational Biology, Genentech Inc., South San Francisco, CA 94080, USA.

Unlabelled: Connections between disease phenotypes and drug effects can be made by identifying commonalities in the associated patterns of differential gene expression. Searchable databases that record the impacts of chemical or genetic perturbations on the transcriptome--here referred to as 'connectivity maps'--permit discovery of such commonalities. We describe two R packages, gCMAP and gCMAPWeb, which provide a complete framework to construct and query connectivity maps assembled from user-defined collections of differential gene expression data. Microarray or RNAseq data are processed in a standardized way, and results can be interrogated using various well-established gene set enrichment methods. The packages also feature an easy-to-deploy web application that facilitates reproducible research through automatic generation of graphical and tabular reports.

Availability And Implementation: The gCMAP and gCMAPWeb R packages are freely available for UNIX, Windows and Mac OS X operating systems at Bioconductor (http://www.bioconductor.org).
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http://dx.doi.org/10.1093/bioinformatics/btt592DOI Listing
January 2014

Pretreatment synovial transcriptional profile is associated with early and late clinical response in rheumatoid arthritis patients treated with rituximab.

Ann Rheum Dis 2012 Nov 26;71(11):1888-94. Epub 2012 Jun 26.

Musculoskeletal Research Group, Institute of Cellular Medicine, Newcastle University, UK.

Objective: Personalised healthcare is contingent on the identification of biomarkers that represent disease relevant pathways and predict drug response. The authors aimed to develop a gene expression signature in synovial tissue that could enrich clinical response of rheumatoid arthritis (RA) patients to rituximab.

Methods: The authors studied synovial gene expression using high-throughput quantitative real-time-PCR in 20 RA patients who underwent arthroscopy before and after treatment with rituximab. Several objective approaches were used to explore patterns in the data and to find genes associated with changes in disease activity due to treatment.

Results: This analysis revealed two patient populations associated with distinct clinical, laboratory and histological features and, importantly, showed enrichment for response (60% non-responders vs 90% responders). A composite baseline gene score (GS) correlated with change in disease activity score (ΔDAS) between baseline and month 3 (r=0.74, p=0.0002), but also with ΔDAS at later time-points (month 9, r=0.54, p=0.016; month 15, r=0.45, p=0.06; month 21, r=0.72, p=0.003). Notably, the GS significantly correlated with baseline erythrocyte sedimentation rate (r=0.69, p=0.0008), but not with other DAS components. The GS genes represented T cell, macrophage, remodelling and interferon-α biology. Responders demonstrated higher expression of macrophage and T cell genes, while non-responders showed higher expression of interferon-α and remodelling genes.

Conclusions: This study reveals a baseline synovial GS that correlates with early and late clinical responses to rituximab. The GS biology suggests that T cells and macrophages are important for response to B cell depleting therapy, while expression of remodelling and interferon-α genes correlates with poor response.
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http://dx.doi.org/10.1136/annrheumdis-2011-201115DOI Listing
November 2012

Gene expression patterns of Th2 inflammation and intercellular communication in asthmatic airways.

J Immunol 2011 Feb 27;186(3):1861-9. Epub 2010 Dec 27.

Immunology, Tissue Growth, and Repair Biomarker Discovery, Genentech, South San Francisco, CA 94080, USA.

Asthma is canonically thought of as a disorder of excessive Th2-driven inflammation in the airway, although recent studies have described heterogeneity with respect to asthma pathophysiology. We have previously described distinct phenotypes of asthma based on the presence or absence of a three-gene "Th2 signature" in bronchial epithelium, which differ in terms of eosinophilic inflammation, mucin composition, subepithelial fibrosis, and corticosteroid responsiveness. In the present analysis, we sought to describe Th2 inflammation in human asthmatic airways quantitatively with respect to known mediators of inflammation and intercellular communication. Using whole-genome microarray and quantitative real-time PCR analysis of endobronchial biopsies from 27 mild-to-moderate asthmatics and 13 healthy controls with associated clinical and demographic data, we found that asthmatic Th2 inflammation is expressed over a variable continuum, correlating significantly with local and systemic measures of allergy and eosinophilia. We evaluated a composite metric describing 79 coexpressed genes associated with Th2 inflammation against the biological space comprising cytokines, chemokines, and growth factors, identifying distinctive patterns of inflammatory mediators as well as Wnt, TGF-β, and platelet-derived growth factor family members. This integrated description of the factors regulating inflammation, cell migration, and tissue remodeling in asthmatic airways has important consequences for the pathophysiological and clinical impacts of emerging asthma therapeutics targeting Th2 inflammation.
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http://dx.doi.org/10.4049/jimmunol.1002568DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3981556PMC
February 2011

A census of human transcription factors: function, expression and evolution.

Nat Rev Genet 2009 04;10(4):252-63

EMBL-European Bioinformatics Institute, Wellcome Trust Genome Campus, Cambridge, UK.

Transcription factors are key cellular components that control gene expression: their activities determine how cells function and respond to the environment. Currently, there is great interest in research into human transcriptional regulation. However, surprisingly little is known about these regulators themselves. For example, how many transcription factors does the human genome contain? How are they expressed in different tissues? Are they evolutionarily conserved? Here, we present an analysis of 1,391 manually curated sequence-specific DNA-binding transcription factors, their functions, genomic organization and evolutionary conservation. Much remains to be explored, but this study provides a solid foundation for future investigations to elucidate regulatory mechanisms underlying diverse mammalian biological processes.
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http://dx.doi.org/10.1038/nrg2538DOI Listing
April 2009

Protein domain organisation: adding order.

BMC Bioinformatics 2009 Jan 29;10:39. Epub 2009 Jan 29.

Department of Developmental Biology, 279 Campus Dr, Stanford, 94305, CA, USA.

Background: Domains are the building blocks of proteins. During evolution, they have been duplicated, fused and recombined, to produce proteins with novel structures and functions. Structural and genome-scale studies have shown that pairs or groups of domains observed together in a protein are almost always found in only one N to C terminal order and are the result of a single recombination event that has been propagated by duplication of the multi-domain unit. Previous studies of domain organisation have used graph theory to represent the co-occurrence of domains within proteins. We build on this approach by adding directionality to the graphs and connecting nodes based on their relative order in the protein. Most of the time, the linear order of domains is conserved. However, using the directed graph representation we have identified non-linear features of domain organization that are over-represented in genomes. Recognising these patterns and unravelling how they have arisen may allow us to understand the functional relationships between domains and understand how the protein repertoire has evolved.

Results: We identify groups of domains that are not linearly conserved, but instead have been shuffled during evolution so that they occur in multiple different orders. We consider 192 genomes across all three kingdoms of life and use domain and protein annotation to understand their functional significance. To identify these features and assess their statistical significance, we represent the linear order of domains in proteins as a directed graph and apply graph theoretical methods. We describe two higher-order patterns of domain organisation: clusters and bi-directionally associated domain pairs and explore their functional importance and phylogenetic conservation.

Conclusion: Taking into account the order of domains, we have derived a novel picture of global protein organization. We found that all genomes have a higher than expected degree of clustering and more domain pairs in forward and reverse orientation in different proteins relative to random graphs with identical degree distributions. While these features were statistically over-represented, they are still fairly rare. Looking in detail at the proteins involved, we found strong functional relationships within each cluster. In addition, the domains tended to be involved in protein-protein interaction and are able to function as independent structural units. A particularly striking example was the human Jak-STAT signalling pathway which makes use of a set of domains in a range of orders and orientations to provide nuanced signaling functionality. This illustrated the importance of functional and structural constraints (or lack thereof) on domain organisation.
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http://dx.doi.org/10.1186/1471-2105-10-39DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2657131PMC
January 2009

Sticking together? Falling apart? Exploring the dynamics of the interactome.

Trends Biochem Sci 2008 May 20;33(5):195-200. Epub 2008 Apr 20.

School of Biotechnology and Biomolecular Sciences, University of New South Wales, NSW 2052, Australia.

Advances in techniques for the study of protein-protein interactions have dramatically improved our understanding of the interactome. However, we know little about the dynamics of this complex system. To better understand the dynamics of the interactome, it is important to consider what happens when single proteins are perturbed. Changes in protein abundance and post-translational modification can function as switches in the interactome, affecting protein-complex assembly and function. Changes in protein sequence or a dramatic increase in abundance might cause a promiscuous gain of interactions. These effects are not identical for all proteins and will differ depending on the number and type of interaction partners that a protein has.
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http://dx.doi.org/10.1016/j.tibs.2008.03.001DOI Listing
May 2008

AGEMAP: a gene expression database for aging in mice.

PLoS Genet 2007 Nov 2;3(11):e201. Epub 2007 Oct 2.

Department of Developmental Biology, Stanford University Medical Center, Stanford, California, United States of America.

We present the AGEMAP (Atlas of Gene Expression in Mouse Aging Project) gene expression database, which is a resource that catalogs changes in gene expression as a function of age in mice. The AGEMAP database includes expression changes for 8,932 genes in 16 tissues as a function of age. We found great heterogeneity in the amount of transcriptional changes with age in different tissues. Some tissues displayed large transcriptional differences in old mice, suggesting that these tissues may contribute strongly to organismal decline. Other tissues showed few or no changes in expression with age, indicating strong levels of homeostasis throughout life. Based on the pattern of age-related transcriptional changes, we found that tissues could be classified into one of three aging processes: (1) a pattern common to neural tissues, (2) a pattern for vascular tissues, and (3) a pattern for steroid-responsive tissues. We observed that different tissues age in a coordinated fashion in individual mice, such that certain mice exhibit rapid aging, whereas others exhibit slow aging for multiple tissues. Finally, we compared the transcriptional profiles for aging in mice to those from humans, flies, and worms. We found that genes involved in the electron transport chain show common age regulation in all four species, indicating that these genes may be exceptionally good markers of aging. However, we saw no overall correlation of age regulation between mice and humans, suggesting that aging processes in mice and humans may be fundamentally different.
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http://dx.doi.org/10.1371/journal.pgen.0030201DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2098796PMC
November 2007

DBD--taxonomically broad transcription factor predictions: new content and functionality.

Nucleic Acids Res 2008 Jan 11;36(Database issue):D88-92. Epub 2007 Dec 11.

MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 0QH, UK.

DNA-binding domain (DBD) is a database of predicted sequence-specific DNA-binding transcription factors (TFs) for all publicly available proteomes. The proteomes have increased from 150 in the initial version of DBD to over 700 in the current version. All predicted TFs must contain a significant match to a hidden Markov model representing a sequence-specific DNA-binding domain family. Access to TF predictions is provided through http://transcriptionfactor.org, where new search options are now provided such as searching by gene names in model organisms, searching for all proteins in a particular DBD family and specific organism. We illustrate the application of this type of search facility by contrasting trends of DBD family occurrence throughout the tree of life, highlighting the clear partition between eukaryotic and prokaryotic DBD expansions. The website content has been expanded to include dedicated pages for each TF containing domain assignment details, gene names, links to external databases and links to TFs with similar domain arrangements. We compare the increase in number of predicted TFs with proteome size in eukaryotes and prokaryotes. Eukaryotes follow a slower rate of increase in TFs than prokaryotes, which could be due to the presence of splice variants or an increase in combinatorial control.
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http://dx.doi.org/10.1093/nar/gkm964DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2238844PMC
January 2008

Discrimination of non-protein-coding transcripts from protein-coding mRNA.

RNA Biol 2006 Jan-Mar;3(1):40-8. Epub 2006 Apr 3.

Genome Exploration Research Group (Genome Network Project Core Group), RIKEN Genomic Sciences Center (GSC), RIKEN Yokohama Institute, Kanagawa, Japan.

Several recent studies indicate that mammals and other organisms produce large numbers of RNA transcripts that do not correspond to known genes. It has been suggested that these transcripts do not encode proteins, but may instead function as RNAs. However, discrimination of coding and non-coding transcripts is not straightforward, and different laboratories have used different methods, whose ability to perform this discrimination is unclear. In this study, we examine ten bioinformatic methods that assess protein-coding potential and compare their ability and congruency in the discrimination of non-coding from coding sequences, based on four underlying principles: open reading frame size, sequence similarity to known proteins or protein domains, statistical models of protein-coding sequence, and synonymous versus non-synonymous substitution rates. Despite these different approaches, the methods show broad concordance, suggesting that coding and non-coding transcripts can, in general, be reliably discriminated, and that many of the recently discovered extra-genic transcripts are indeed non-coding. Comparison of the methods indicates reasons for unreliable predictions, and approaches to increase confidence further. Conversely and surprisingly, our analyses also provide evidence that as much as approximately 10% of entries in the manually curated protein database Swiss-Prot are erroneous translations of actually non-coding transcripts.
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http://dx.doi.org/10.4161/rna.3.1.2789DOI Listing
September 2007

DBD: a transcription factor prediction database.

Nucleic Acids Res 2006 Jan;34(Database issue):D74-81

MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK.

Regulation of gene expression influences almost all biological processes in an organism; sequence-specific DNA-binding transcription factors are critical to this control. For most genomes, the repertoire of transcription factors is only partially known. Hitherto transcription factor identification has been largely based on genome annotation pipelines that use pairwise sequence comparisons, which detect only those factors similar to known genes, or on functional classification schemes that amalgamate many types of proteins into the category of 'transcription factor'. Using a novel transcription factor identification method, the DBD transcription factor database fills this void, providing genome-wide transcription factor predictions for organisms from across the tree of life. The prediction method behind DBD identifies sequence-specific DNA-binding transcription factors through homology using profile hidden Markov models (HMMs) of domains. Thus, it is limited to factors that are homologus to those HMMs. The collection of HMMs is taken from two existing databases (Pfam and SUPERFAMILY), and is limited to models that exclusively detect transcription factors that specifically recognize DNA sequences. It does not include basal transcription factors or chromatin-associated proteins, for instance. Based on comparison with experimentally verified annotation, the prediction procedure is between 95% and 99% accurate. Between one quarter and one-half of our genome-wide predicted transcription factors represent previously uncharacterized proteins. The DBD (www.transcriptionfactor.org) consists of predicted transcription factor repertoires for 150 completely sequenced genomes, their domain assignments and the hand curated list of DNA-binding domain HMMs. Users can browse, search or download the predictions by genome, domain family or sequence identifier, view families of transcription factors based on domain architecture and receive predictions for a protein sequence.
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http://dx.doi.org/10.1093/nar/gkj131DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1347493PMC
January 2006

Comparative genomics of trypanosomatid parasitic protozoa.

Science 2005 Jul;309(5733):404-9

Institute for Genomic Research, 9712 Medical Center Drive, Rockville, MD 20850, USA.

A comparison of gene content and genome architecture of Trypanosoma brucei, Trypanosoma cruzi, and Leishmania major, three related pathogens with different life cycles and disease pathology, revealed a conserved core proteome of about 6200 genes in large syntenic polycistronic gene clusters. Many species-specific genes, especially large surface antigen families, occur at nonsyntenic chromosome-internal and subtelomeric regions. Retroelements, structural RNAs, and gene family expansion are often associated with syntenic discontinuities that-along with gene divergence, acquisition and loss, and rearrangement within the syntenic regions-have shaped the genomes of each parasite. Contrary to recent reports, our analyses reveal no evidence that these species are descended from an ancestor that contained a photosynthetic endosymbiont.
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http://dx.doi.org/10.1126/science.1112181DOI Listing
July 2005

Relative rates of gene fusion and fission in multi-domain proteins.

Trends Genet 2005 Jan;21(1):25-30

MRC Laboratory of Molecular Biology, Hills Road, Cambridge, UK, CB2 2QH.

During evolution genes can produce more complex proteins by gene fusion or less complex proteins by gene fission. Considering proteins from 131 completely sequenced genomes from all three kingdoms of life, we identified 2869 groups of multi-domain proteins as a single protein in certain organisms and as two or more smaller proteins with equivalent domain architectures in other organisms. We found that fusion events are approximately four times more common than fission events, and we established that, in most cases, any particular fusion or fission event only occurred once during the course of evolution.
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http://dx.doi.org/10.1016/j.tig.2004.11.007DOI Listing
January 2005

AMID: autonomous modeler of intragenic duplication.

Appl Bioinformatics 2003 ;2(3):169-76

School of Molecular and Microbiological Biosciences, University of Sydney, Sydney, NSW, Australia.

Intragenic duplication is an evolutionary process where segments of a gene become duplicated. While there has been much research into whole-gene or domain duplication, there have been very few studies of non-tandem intragenic duplication. The identification of intragenically replicated sequences may provide insight into the evolution of proteins, helping to link sequence data with structure and function. This paper describes a tool for autonomously modelling intragenic duplication. AMID provides: identification of modularly repetitive genes; an algorithm for identifying repeated modules; and a scoring system for evaluating the modules' similarity. An evaluation of the algorithms and use cases are presented.
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June 2004