Literature Watch
The role of genetics in primary ventricular fibrillation, inherited channelopathies and cardiomyopathies.
The role of genetics in primary ventricular fibrillation, inherited channelopathies and cardiomyopathies.
Int J Cardiol. 2017 Jun 15;237:45-48
Authors: Crotti L, Kotta MC
Abstract
Sudden cardiac death (SCD) has a strong familial component; however, our understanding of its genetic basis varies significantly according to the underlying causes. When coronary artery disease is involved, the predisposing genetic background is complex and despite some interesting findings it remains largely unknown. Quite different is the case of monogenic structural and non-structural heart diseases, in which a number of disease-causing genes have been established and are being used in clinical practice. As SCD can be the first clinical manifestation of inherited syndromes, in order to ascertain the cause of death, it is extremely important to include molecular autopsy among the standard post-mortem examinations. Indeed, molecular screening of the major disease-causing genes in the deceased person is often the only way to achieve a post-mortem diagnosis in channelopathies, which may prove crucial for the identification and management of at risk family members. Overall, these data, together with the inclusion in current guidelines of molecular screening for diagnosis and/or risk stratification of specific inherited cardiac diseases, exemplify how research on the genetic basis of SCD may be deeply translational, while the transition of genetic testing from the research to the diagnostic setting is already improving every-day clinical practice.
PMID: 28532586 [PubMed - in process]
A pipeline combining multiple strategies for prioritizing heterozygous variants for the identification of candidate genes in exome datasets.
A pipeline combining multiple strategies for prioritizing heterozygous variants for the identification of candidate genes in exome datasets.
Hum Genomics. 2017 May 22;11(1):11
Authors: Requena T, Gallego-Martinez A, Lopez-Escamez JA
Abstract
BACKGROUND: The identification of disease-causing variants in autosomal dominant diseases using exome-sequencing data remains a difficult task in small pedigrees. We combined several strategies to improve filtering and prioritizing of heterozygous variants using exome-sequencing datasets in familial Meniere disease: an in-house Pathogenic Variant (PAVAR) score, the Variant Annotation Analysis and Search Tool (VAAST-Phevor), Exomiser-v2, CADD, and FATHMM. We also validated the method by a benchmarking procedure including causal mutations in synthetic exome datasets.
RESULTS: PAVAR and VAAST were able to select the same sets of candidate variants independently of the studied disease. In contrast, Exomiser V2 and VAAST-Phevor had a variable correlation depending on the phenotypic information available for the disease on each family. Nevertheless, all the selected diseases ranked a limited number of concordant variants in the top 10 ranking, using the three systems or other combined algorithm such as CADD or FATHMM. Benchmarking analyses confirmed that the combination of systems with different approaches improves the prediction of candidate variants compared with the use of a single method. The overall efficiency of combined tools ranges between 68 and 71% in the top 10 ranked variants.
CONCLUSIONS: Our pipeline prioritizes a short list of heterozygous variants in exome datasets based on the top 10 concordant variants combining multiple systems.
PMID: 28532469 [PubMed - in process]
Defects in myosin VB are associated with a spectrum of previously undiagnosed low γ-glutamyltransferase cholestasis.
Defects in myosin VB are associated with a spectrum of previously undiagnosed low γ-glutamyltransferase cholestasis.
Hepatology. 2017 May;65(5):1655-1669
Authors: Qiu YL, Gong JY, Feng JY, Wang RX, Han J, Liu T, Lu Y, Li LT, Zhang MH, Sheps JA, Wang NL, Yan YY, Li JQ, Chen L, Borchers CH, Sipos B, Knisely AS, Ling V, Xing QH, Wang JS
Abstract
Hereditary cholestasis in childhood and infancy with normal serum gamma-glutamyltransferase (GGT) activity is linked to several genes. Many patients, however, remain genetically undiagnosed. Defects in myosin VB (MYO5B; encoded by MYO5B) cause microvillus inclusion disease (MVID; MIM251850) with recurrent watery diarrhea. Cholestasis, reported as an atypical presentation in MVID, has been considered a side effect of parenteral alimentation. Here, however, we report on 10 patients who experienced cholestasis associated with biallelic, or suspected biallelic, mutations in MYO5B and who had neither recurrent diarrhea nor received parenteral alimentation. Seven of them are from two study cohorts, together comprising 31 undiagnosed low-GGT cholestasis patients; 3 are sporadic. Cholestasis in 2 patients was progressive, in 3 recurrent, in 2 transient, and in 3 uncategorized because of insufficient follow-up. Liver biopsy specimens revealed giant-cell change of hepatocytes and intralobular cholestasis with abnormal distribution of bile salt export pump (BSEP) at canaliculi, as well as coarse granular dislocation of MYO5B. Mass spectrometry of plasma demonstrated increased total bile acids, primary bile acids, and conjugated bile acids, with decreased free bile acids, similar to changes in BSEP-deficient patients. Literature review revealed that patients with biallelic mutations predicted to eliminate MYO5B expression were more frequent in typical MVID than in isolated-cholestasis patients (11 of 38 vs. 0 of 13).
CONCLUSION: MYO5B deficiency may underlie 20% of previously undiagnosed low-GGT cholestasis. MYO5B deficiency appears to impair targeting of BSEP to the canalicular membrane with hampered bile acid excretion, resulting in a spectrum of cholestasis without diarrhea. (Hepatology 2017;65:1655-1669).
PMID: 28027573 [PubMed - indexed for MEDLINE]
Mutations in PROSC Disrupt Cellular Pyridoxal Phosphate Homeostasis and Cause Vitamin-B6-Dependent Epilepsy.
Mutations in PROSC Disrupt Cellular Pyridoxal Phosphate Homeostasis and Cause Vitamin-B6-Dependent Epilepsy.
Am J Hum Genet. 2016 Dec 01;99(6):1325-1337
Authors: Darin N, Reid E, Prunetti L, Samuelsson L, Husain RA, Wilson M, El Yacoubi B, Footitt E, Chong WK, Wilson LC, Prunty H, Pope S, Heales S, Lascelles K, Champion M, Wassmer E, Veggiotti P, de Crécy-Lagard V, Mills PB, Clayton PT
Abstract
Pyridoxal 5'-phosphate (PLP), the active form of vitamin B6, functions as a cofactor in humans for more than 140 enzymes, many of which are involved in neurotransmitter synthesis and degradation. A deficiency of PLP can present, therefore, as seizures and other symptoms that are treatable with PLP and/or pyridoxine. Deficiency of PLP in the brain can be caused by inborn errors affecting B6 vitamer metabolism or by inactivation of PLP, which can occur when compounds accumulate as a result of inborn errors of other pathways or when small molecules are ingested. Whole-exome sequencing of two children from a consanguineous family with pyridoxine-dependent epilepsy revealed a homozygous nonsense mutation in proline synthetase co-transcribed homolog (bacterial), PROSC, which encodes a PLP-binding protein of hitherto unknown function. Subsequent sequencing of 29 unrelated indivduals with pyridoxine-responsive epilepsy identified four additional children with biallelic PROSC mutations. Pre-treatment cerebrospinal fluid samples showed low PLP concentrations and evidence of reduced activity of PLP-dependent enzymes. However, cultured fibroblasts showed excessive PLP accumulation. An E.coli mutant lacking the PROSC homolog (ΔYggS) is pyridoxine sensitive; complementation with human PROSC restored growth whereas hPROSC encoding p.Leu175Pro, p.Arg241Gln, and p.Ser78Ter did not. PLP, a highly reactive aldehyde, poses a problem for cells, which is how to supply enough PLP for apoenzymes while maintaining free PLP concentrations low enough to avoid unwanted reactions with other important cellular nucleophiles. Although the mechanism involved is not fully understood, our studies suggest that PROSC is involved in intracellular homeostatic regulation of PLP, supplying this cofactor to apoenzymes while minimizing any toxic side reactions.
PMID: 27912044 [PubMed - indexed for MEDLINE]
Autosomal-Recessive Mutations in AP3B2, Adaptor-Related Protein Complex 3 Beta 2 Subunit, Cause an Early-Onset Epileptic Encephalopathy with Optic Atrophy.
Autosomal-Recessive Mutations in AP3B2, Adaptor-Related Protein Complex 3 Beta 2 Subunit, Cause an Early-Onset Epileptic Encephalopathy with Optic Atrophy.
Am J Hum Genet. 2016 Dec 01;99(6):1368-1376
Authors: Assoum M, Philippe C, Isidor B, Perrin L, Makrythanasis P, Sondheimer N, Paris C, Douglas J, Lesca G, Antonarakis S, Hamamy H, Jouan T, Duffourd Y, Auvin S, Saunier A, Begtrup A, Nowak C, Chatron N, Ville D, Mireskandari K, Milani P, Jonveaux P, Lemeur G, Milh M, Amamoto M, Kato M, Nakashima M, Miyake N, Matsumoto N, Masri A, Thauvin-Robinet C, Rivière JB, Faivre L, Thevenon J
Abstract
Early-onset epileptic encephalopathy (EOEE) represents a heterogeneous group of severe disorders characterized by seizures, interictal epileptiform activity with a disorganized electroencephalography background, developmental regression or retardation, and onset before 1 year of age. Among a cohort of 57 individuals with epileptic encephalopathy, we ascertained two unrelated affected individuals with EOEE associated with developmental impairment and autosomal-recessive variants in AP3B2 by means of whole-exome sequencing. The targeted sequencing of AP3B2 in 86 unrelated individuals with EOEE led to the identification of an additional family. We gathered five additional families with eight affected individuals through the Matchmaker Exchange initiative by matching autosomal-recessive mutations in AP3B2. Reverse phenotyping of 12 affected individuals from eight families revealed a homogeneous EOEE phenotype characterized by severe developmental delay, poor visual contact with optic atrophy, and postnatal microcephaly. No spasticity, albinism, or hematological symptoms were reported. AP3B2 encodes the neuron-specific subunit of the AP-3 complex. Autosomal-recessive variations of AP3B1, the ubiquitous isoform, cause Hermansky-Pudlak syndrome type 2. The only isoform for the δ subunit of the AP-3 complex is encoded by AP3D1. Autosomal-recessive mutations in AP3D1 cause a severe disorder cumulating the symptoms of the AP3B1 and AP3B2 defects.
PMID: 27889060 [PubMed - indexed for MEDLINE]
Mechanistic Insight into NMDA Receptor Dysregulation by Rare Variants in the GluN2A and GluN2B Agonist Binding Domains.
Mechanistic Insight into NMDA Receptor Dysregulation by Rare Variants in the GluN2A and GluN2B Agonist Binding Domains.
Am J Hum Genet. 2016 Dec 01;99(6):1261-1280
Authors: Swanger SA, Chen W, Wells G, Burger PB, Tankovic A, Bhattacharya S, Strong KL, Hu C, Kusumoto H, Zhang J, Adams DR, Millichap JJ, Petrovski S, Traynelis SF, Yuan H
Abstract
Epilepsy and intellectual disability are associated with rare variants in the GluN2A and GluN2B (encoded by GRIN2A and GRIN2B) subunits of the N-methyl-D-aspartate receptor (NMDAR), a ligand-gated ion channel with essential roles in brain development and function. By assessing genetic variation across GluN2 domains, we determined that the agonist binding domain, transmembrane domain, and the linker regions between these domains were particularly intolerant to functional variation. Notably, the agonist binding domain of GluN2B exhibited significantly more variation intolerance than that of GluN2A. To understand the ramifications of missense variation in the agonist binding domain, we investigated the mechanisms by which 25 rare variants in the GluN2A and GluN2B agonist binding domains dysregulated NMDAR activity. When introduced into recombinant human NMDARs, these rare variants identified in individuals with neurologic disease had complex, and sometimes opposing, consequences on agonist binding, channel gating, receptor biogenesis, and forward trafficking. Our approach combined quantitative assessments of these effects to estimate the overall impact on synaptic and non-synaptic NMDAR function. Interestingly, similar neurologic diseases were associated with both gain- and loss-of-function variants in the same gene. Most rare variants in GluN2A were associated with epilepsy, whereas GluN2B variants were associated with intellectual disability with or without seizures. Finally, discerning the mechanisms underlying NMDAR dysregulation by these rare variants allowed investigations of pharmacologic strategies to correct NMDAR function.
PMID: 27839871 [PubMed - indexed for MEDLINE]
The Contribution of Mosaic Variants to Autism Spectrum Disorder.
The Contribution of Mosaic Variants to Autism Spectrum Disorder.
PLoS Genet. 2016 Sep;12(9):e1006245
Authors: Freed D, Pevsner J
Abstract
De novo mutation is highly implicated in autism spectrum disorder (ASD). However, the contribution of post-zygotic mutation to ASD is poorly characterized. We performed both exome sequencing of paired samples and analysis of de novo variants from whole-exome sequencing of 2,388 families. While we find little evidence for tissue-specific mosaic mutation, multi-tissue post-zygotic mutation (i.e. mosaicism) is frequent, with detectable mosaic variation comprising 5.4% of all de novo mutations. We identify three mosaic missense and likely-gene disrupting mutations in genes previously implicated in ASD (KMT2C, NCKAP1, and MYH10) in probands but none in siblings. We find a strong ascertainment bias for mosaic mutations in probands relative to their unaffected siblings (p = 0.003). We build a model of de novo variation incorporating mosaic variants and errors in classification of mosaic status and from this model we estimate that 33% of mosaic mutations in probands contribute to 5.1% of simplex ASD diagnoses (95% credible interval 1.3% to 8.9%). Our results indicate a contributory role for multi-tissue mosaic mutation in some individuals with an ASD diagnosis.
PMID: 27632392 [PubMed - indexed for MEDLINE]
Whole Exome Sequencing in Atrial Fibrillation.
Whole Exome Sequencing in Atrial Fibrillation.
PLoS Genet. 2016 Sep;12(9):e1006284
Authors: Lubitz SA, Brody JA, Bihlmeyer NA, Roselli C, Weng LC, Christophersen IE, Alonso A, Boerwinkle E, Gibbs RA, Bis JC, NHLBI GO Exome Sequencing Project, Cupples LA, Mohler PJ, Nickerson DA, Muzny D, Perez MV, Psaty BM, Soliman EZ, Sotoodehnia N, Lunetta KL, Benjamin EJ, Heckbert SR, Arking DE, Ellinor PT, Lin H
Abstract
Atrial fibrillation (AF) is a morbid and heritable arrhythmia. Over 35 genes have been reported to underlie AF, most of which were described in small candidate gene association studies. Replication remains lacking for most, and therefore the contribution of coding variation to AF susceptibility remains poorly understood. We examined whole exome sequencing data in a large community-based sample of 1,734 individuals with and 9,423 without AF from the Framingham Heart Study, Cardiovascular Health Study, Atherosclerosis Risk in Communities Study, and NHLBI-GO Exome Sequencing Project and meta-analyzed the results. We also examined whether genetic variation was enriched in suspected AF genes (N = 37) in AF cases versus controls. The mean age ranged from 59 to 73 years; 8,656 (78%) were of European ancestry. None of the 99,404 common variants evaluated was significantly associated after adjusting for multiple testing. Among the most significantly associated variants was a common (allele frequency = 86%) missense variant in SYNPO2L (rs3812629, p.Pro707Leu, [odds ratio 1.27, 95% confidence interval 1.13-1.43, P = 6.6x10-5]) which lies at a known AF susceptibility locus and is in linkage disequilibrium with a top marker from prior analyses at the locus. We did not observe significant associations between rare variants and AF in gene-based tests. Individuals with AF did not display any statistically significant enrichment for common or rare coding variation in previously implicated AF genes. In conclusion, we did not observe associations between coding genetic variants and AF, suggesting that large-effect coding variation is not the predominant mechanism underlying AF. A coding variant in SYNPO2L requires further evaluation to determine whether it is causally related to AF. Efforts to identify biologically meaningful coding variation underlying AF may require large sample sizes or populations enriched for large genetic effects.
PMID: 27589061 [PubMed - indexed for MEDLINE]
Olanzapine-Induced Neuroleptic Malignant Syndrome.
Olanzapine-Induced Neuroleptic Malignant Syndrome.
Iran J Med Sci. 2017 May;42(3):306-309
Authors: Hosseini S, Elyasi F
Abstract
Neuroleptic malignant syndrome (NMS) is a rare but life-threatening idiosyncratic side effect resulting from neuroleptic drugs. NMS mainly occurs in patients treated with high-potency typical antipsychotics, but rarely caused by atypical antipsychotics. Although NMS is less common with atypical antipsychotic, but it seems that its incidence is rising due to increased administration of such drugs. We present the case of a 27-year-old man with a history of paranoid schizophrenia that showed signs consistent with NMS that occurred after treatment with olanzapine. The patient was adherent to treatment. He had decreased level of consciousness, muscle rigidity, diaphoresis, fever, drooling, urinary incontinence, and high blood pressure. This patient illustrates that NMS can occur due to treatment with atypical antipsychotic drugs like olanzapine, particularly in the presence of risk factors. This phenomenon is often unrecognized, underdiagnosed, or not treated properly. Physicians should be aware that NMS with extrapyramidal syndrome could occur with olanzapine at steady state doses without recent dosage adjustments or titration. It is essential that adequate and safe dose of medication is chosen and the patient is monitored by the signs and symptoms of this lethal syndrome.
PMID: 28533580 [PubMed - in process]
[Medication administration practices in elderly residential facilities in Ile de France Region in 2014: findings and room for improvement].
[Medication administration practices in elderly residential facilities in Ile de France Region in 2014: findings and room for improvement].
Sante Publique. 2016 Nov 25;28(5):623-632
Authors: de Saunière A, Bonneau L, Donio V, Godinot V, Flouzat JP, Bensasson G, Code C, Galay G, Pige D
Abstract
The institutions expressed great interest in medication administration systems and tools designed to monitor all stages of medication administration. A dozen simple and pragmatic improvement actions were identified and listed in the Ile-de-France Regional Health Agency action plan to improve medication administration management of in EHPAD.</ce:para>.
PMID: 28155738 [PubMed - indexed for MEDLINE]
Therapeutic monitoring of the immuno-modulating drugs in systemic lupus erythematosus.
Therapeutic monitoring of the immuno-modulating drugs in systemic lupus erythematosus.
Expert Rev Clin Immunol. 2017 Jan;13(1):35-41
Authors: Mok CC
Abstract
INTRODUCTION: Despite the emergence of newer immunomodulating agents for systemic lupus erythematosus (SLE), a substantial proportion of patients still do not respond optimally. While the mechanisms for the differential responses to drug therapy are unclear, variation in drug exposure with the same dosing protocol related to pharmacogenetic and pharmacokinetic factors may contribute. This article discusses the use of therapeutic drug monitoring (TDM) to optimize therapies in SLE patients. Areas covered: Evidence on the relationship between blood levels and efficacy/toxicity of immuno-modulating drugs such as hydroxychloroquine (HCQ), mycophenolate mofetil (MMF) and the calcineurin inhibitors that are often used in SLE. Expert commentary: Current data suggest a correlation between exposure and efficacy of HCQ and MMF in SLE. The relationship between HCQ or MMF blood concentrations and their adverse effects requires further elucidation. The serum trough level of tacrolimus does not appear to correlate with clinical response in lupus nephritis but is associated with toxic effects. Owing to the paucity of data, the 'optimal' blood levels of these agents in SLE have yet to be determined by large population pharmacokinetic studies. Nevertheless, TDM enables early identification of non-adherence and over-exposure to these SLE medications so that dosing adjustment can be performed to minimize toxicities and wastage.
PMID: 27417340 [PubMed - indexed for MEDLINE]
Prophylactic immunoglobulin therapy in secondary immune deficiency - an expert opinion.
Prophylactic immunoglobulin therapy in secondary immune deficiency - an expert opinion.
Expert Rev Clin Immunol. 2016 Sep;12(9):921-6
Authors: Agostini C, Blau IW, Kimby E, Plesner T
Abstract
INTRODUCTION: In primary immunodeficiency (PID), immunoglobulin replacement therapy (IgRT) for infection prevention is well-established and supported by a wealth of clinical data. On the contrary, very little evidence-based data is available on the challenges surrounding the use of IgRT in secondary immune deficiencies (SID), and most published guidelines are mere extrapolations from the experience in PID.
AREAS COVERED: In this article, four European experts provide their consolidated opinion on open questions surrounding the prophylactic use of IgRT in SID, based on their clinical experience. The main topics are IgRT initiation, route of administration, dose optimization, and therapy discontinuation. The authors hope this discussion will be of assistance to practicing physicians in their daily decision-making. Expert commentary: Although growing experience indicates that IgRT could play an important role in the management of SID, very little robust evidence is available to guide clinical practice. The authors stress the urgent need for new studies in the field and discuss points they find of importance to design them adequately.
PMID: 27415820 [PubMed - indexed for MEDLINE]
Defining conditions where long-term glucocorticoid treatment has an acceptably low level of harm to facilitate implementation of existing recommendations: viewpoints from an EULAR task force.
Defining conditions where long-term glucocorticoid treatment has an acceptably low level of harm to facilitate implementation of existing recommendations: viewpoints from an EULAR task force.
Ann Rheum Dis. 2016 Jun;75(6):952-7
Authors: Strehl C, Bijlsma JW, de Wit M, Boers M, Caeyers N, Cutolo M, Dasgupta B, Dixon WG, Geenen R, Huizinga TW, Kent A, de Thurah AL, Listing J, Mariette X, Ray DW, Scherer HU, Seror R, Spies CM, Tarp S, Wiek D, Winthrop KL, Buttgereit F
Abstract
There is convincing evidence for the known and unambiguously accepted beneficial effects of glucocorticoids at low dosages. However, the implementation of existing recommendations and guidelines on the management of glucocorticoid therapy in rheumatic diseases is lagging behind. As a first step to improve implementation, we aimed at defining conditions under which long-term glucocorticoid therapy may have an acceptably low level of harm. A multidisciplinary European League Against Rheumatism task force group of experts including patients with rheumatic diseases was assembled. After a systematic literature search, breakout groups critically reviewed the evidence on the four most worrisome adverse effects of glucocorticoid therapy (osteoporosis, hyperglycaemia/diabetes mellitus, cardiovascular diseases and infections) and presented their results to the other group members following a structured questionnaire for final discussion and consensus finding. Robust evidence on the risk of harm of long-term glucocorticoid therapy was often lacking since relevant study results were often either missing, contradictory or carried a high risk of bias. The group agreed that the risk of harm is low for the majority of patients at long-term dosages of ≤5 mg prednisone equivalent per day, whereas at dosages of >10 mg/day the risk of harm is elevated. At dosages between >5 and ≤10 mg/day, patient-specific characteristics (protective and risk factors) determine the risk of harm. The level of harm of glucocorticoids depends on both dose and patient-specific parameters. General and glucocorticoid-associated risk factors and protective factors such as a healthy lifestyle should be taken into account when evaluating the actual and future risk.
PMID: 26933146 [PubMed - indexed for MEDLINE]
Efficacy and safety of tofacitinib following inadequate response to conventional synthetic or biological disease-modifying antirheumatic drugs.
Efficacy and safety of tofacitinib following inadequate response to conventional synthetic or biological disease-modifying antirheumatic drugs.
Ann Rheum Dis. 2016 Jul;75(7):1293-301
Authors: Charles-Schoeman C, Burmester G, Nash P, Zerbini CA, Soma K, Kwok K, Hendrikx T, Bananis E, Fleischmann R
Abstract
OBJECTIVES: Biological disease-modifying antirheumatic drugs (bDMARDs) have shown diminished clinical response following an inadequate response (IR) to ≥1 previous bDMARD. Here, tofacitinib was compared with placebo in patients with an IR to conventional synthetic DMARDs (csDMARDs; bDMARD-naive) and in patients with an IR to bDMARDs (bDMARD-IR).
METHODS: Data were taken from phase II and phase III studies of tofacitinib in patients with rheumatoid arthritis (RA). Patients received tofacitinib 5 or 10 mg twice daily, or placebo, as monotherapy or with background methotrexate or other csDMARDs. Efficacy endpoints and incidence rates of adverse events (AEs) of special interest were assessed.
RESULTS: 2812 bDMARD-naive and 705 bDMARD-IR patients were analysed. Baseline demographics and disease characteristics were generally similar between treatment groups within subpopulations. Across subpopulations, improvements in efficacy parameters at month 3 were generally significantly greater for both tofacitinib doses versus placebo. Clinical response was numerically greater with bDMARD-naive versus bDMARD-IR patients (overlapping 95% CIs). Rates of safety events of special interest were generally similar between tofacitinib doses and subpopulations; however, patients receiving glucocorticoids had more serious AEs, discontinuations due to AEs, serious infection events and herpes zoster. Numerically greater clinical responses and incidence rates of AEs of special interest were generally reported for tofacitinib 10 mg twice daily versus tofacitinib 5 mg twice daily (overlapping 95% CIs).
CONCLUSIONS: Tofacitinib demonstrated efficacy in both bDMARD-naive and bDMARD-IR patients with RA. Clinical response to tofacitinib was generally numerically greater in bDMARD-naive than bDMARD-IR patients. The safety profile appeared similar between subpopulations.
TRIAL REGISTRATION NUMBERS: (NCT00413660, NCT0050446, NCT00603512, NCT00687193, NCT00960440, NCT00847613, NCT00814307, NCT00856544, NCT00853385).
PMID: 26275429 [PubMed - indexed for MEDLINE]
pharmacogenomics; +16 new citations
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"systems biology"; +40 new citations
40 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:
These pubmed results were generated on 2017/05/24
PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Claude D. Pepper Older Americans Independence Centers (P30)
Histone demethylases UTX and JMJD3 are required for NKT cell development in mice.
Histone demethylases UTX and JMJD3 are required for NKT cell development in mice.
Cell Biosci. 2017;7:25
Authors: Northrup D, Yagi R, Cui K, Proctor WR, Wang C, Placek K, Pohl LR, Wang R, Ge K, Zhu J, Zhao K
Abstract
BACKGROUND: Natural killer (NK)T cells and conventional T cells share phenotypic characteristic however they differ in transcription factor requirements and functional properties. The role of histone modifying enzymes in conventional T cell development has been extensively studied, little is known about the function of enzymes regulating histone methylation in NKT cells.
RESULTS: We show that conditional deletion of histone demethylases UTX and JMJD3 by CD4-Cre leads to near complete loss of liver NKT cells, while conventional T cells are less affected. Loss of NKT cells is cell intrinsic and not due to an insufficient selection environment. The absence of NKT cells in UTX/JMJD3-deficient mice protects mice from concanavalin A-induced liver injury, a model of NKT-mediated hepatitis. GO-analysis of RNA-seq data indicates that cell cycle genes are downregulated in UTX/JMJD3-deleted NKT progenitors, and suggest that failed expansion may account for some of the cellular deficiency. The phenotype appears to be demethylase-dependent, because UTY, a homolog of UTX that lacks catalytic function, is not sufficient to restore their development and removal of H3K27me3 by deletion of EZH2 partially rescues the defect.
CONCLUSIONS: NKT cell development and gene expression is sensitive to proper regulation of H3K27 methylation. The H3K27me3 demethylase enzymes, in particular UTX, promote NKT cell development, and are required for effective NKT function.
PMID: 28529687 [PubMed]
Perspectives on Gene Regulatory Network Evolution.
Perspectives on Gene Regulatory Network Evolution.
Trends Genet. 2017 May 18;:
Authors: Halfon MS
Abstract
Animal development proceeds through the activity of genes and their cis-regulatory modules (CRMs) working together in sets of gene regulatory networks (GRNs). The emergence of species-specific traits and novel structures results from evolutionary changes in GRNs. Recent work in a wide variety of animal models, and particularly in insects, has started to reveal the modes and mechanisms of GRN evolution. I discuss here various aspects of GRN evolution and argue that developmental system drift (DSD), in which conserved phenotype is nevertheless a result of changed genetic interactions, should regularly be viewed from the perspective of GRN evolution. Advances in methods to discover related CRMs in diverse insect species, a critical requirement for detailed GRN characterization, are also described.
PMID: 28528721 [PubMed - as supplied by publisher]
Finding Rare, Disease-Associated Variants in Isolated Groups: Potential Advantages of Mennonite Populations.
Finding Rare, Disease-Associated Variants in Isolated Groups: Potential Advantages of Mennonite Populations.
Hum Biol. 2016 Apr;88(2):109-120
Authors: Lopes FL, Hou L, Boldt AB, Kassem L, Alves VM, Nardi AE, McMahon FJ
Abstract
Large-scale genotyping and next-generation sequencing techniques have allowed great advances in the field of molecular genetics. Numerous common variants of low impact have been associated with many complex human traits and diseases, such as bipolar disorder and schizophrenia. Although they may exert a greater impact on risk, few rare disease variants have been found, owing to the greatly increased sample sizes that are typically necessary to demonstrate association with rarer variants. One alternative strategy is to study isolated populations, where historical bottlenecks reduce genetic diversity and some otherwise rare variants may drift to higher frequencies. Here we describe the Mennonite population settlements, considering their history of multiple bottlenecks followed by demographic expansion and a currently widespread geographical distribution. We argue that Mennonite populations are valuable partners for studies seeking genetic variants that exert a high impact on risk for a variety of common disorders, including mental illnesses.
PMID: 28162000 [PubMed - indexed for MEDLINE]
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