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1.
N Engl J Med ; 382(5): 437-445, 2020 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-31995689

RESUMO

BACKGROUND: Cytomegalovirus (CMV) can cause severe disease in children and adults with a variety of inherited or acquired T-cell immunodeficiencies, who are prone to multiple infections. It can also rarely cause disease in otherwise healthy persons. The pathogenesis of idiopathic CMV disease is unknown. Inbred mice that lack the gene encoding nitric oxide synthase 2 (Nos2) are susceptible to the related murine CMV infection. METHODS: We studied a previously healthy 51-year-old man from Iran who after acute CMV infection had an onset of progressive CMV disease that led to his death 29 months later. We hypothesized that the patient may have had a novel type of inborn error of immunity. Thus, we performed whole-exome sequencing and tested candidate mutant alleles experimentally. RESULTS: We found a homozygous frameshift mutation in NOS2 encoding a truncated NOS2 protein that did not produce nitric oxide, which determined that the patient had autosomal recessive NOS2 deficiency. Moreover, all NOS2 variants that we found in homozygosity in public databases encoded functional proteins, as did all other variants with an allele frequency greater than 0.001. CONCLUSIONS: These findings suggest that inherited NOS2 deficiency was clinically silent in this patient until lethal infection with CMV. Moreover, NOS2 appeared to be redundant for control of other pathogens in this patient. (Funded by the National Center for Advancing Translational Sciences and others.).


Assuntos
Infecções por Citomegalovirus , Mutação da Fase de Leitura , Óxido Nítrico Sintase Tipo II/deficiência , Evolução Fatal , Feminino , Genótipo , Homozigoto , Humanos , Mutação com Perda de Função , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Linhagem , Sequenciamento Completo do Exoma
2.
Sci Immunol ; 4(41)2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31784499

RESUMO

Genetic etiologies of chronic mucocutaneous candidiasis (CMC) disrupt human IL-17A/F-dependent immunity at mucosal surfaces, whereas those of connective tissue disorders (CTDs) often impair the TGF-ß-dependent homeostasis of connective tissues. The signaling pathways involved are incompletely understood. We report a three-generation family with an autosomal dominant (AD) combination of CMC and a previously undescribed form of CTD that clinically overlaps with Ehlers-Danlos syndrome (EDS). The patients are heterozygous for a private splice-site variant of MAPK8, the gene encoding c-Jun N-terminal kinase 1 (JNK1), a component of the MAPK signaling pathway. This variant is loss-of-expression and loss-of-function in the patients' fibroblasts, which display AD JNK1 deficiency by haploinsufficiency. These cells have impaired, but not abolished, responses to IL-17A and IL-17F. Moreover, the development of the patients' TH17 cells was impaired ex vivo and in vitro, probably due to the involvement of JNK1 in the TGF-ß-responsive pathway and further accounting for the patients' CMC. Consistently, the patients' fibroblasts displayed impaired JNK1- and c-Jun/ATF-2-dependent induction of key extracellular matrix (ECM) components and regulators, but not of EDS-causing gene products, in response to TGF-ß. Furthermore, they displayed a transcriptional pattern in response to TGF-ß different from that of fibroblasts from patients with Loeys-Dietz syndrome caused by mutations of TGFBR2 or SMAD3, further accounting for the patients' complex and unusual CTD phenotype. This experiment of nature indicates that the integrity of the human JNK1-dependent MAPK signaling pathway is essential for IL-17A- and IL-17F-dependent mucocutaneous immunity to Candida and for the TGF-ß-dependent homeostasis of connective tissues.

3.
Nat Med ; 25(12): 1873-1884, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31806906

RESUMO

Herpes simplex virus-1 (HSV-1) encephalitis (HSE) is typically sporadic. Inborn errors of TLR3- and DBR1-mediated central nervous system cell-intrinsic immunity can account for forebrain and brainstem HSE, respectively. We report five unrelated patients with forebrain HSE, each heterozygous for one of four rare variants of SNORA31, encoding a small nucleolar RNA of the H/ACA class that are predicted to direct the isomerization of uridine residues to pseudouridine in small nuclear RNA and ribosomal RNA. We show that CRISPR/Cas9-introduced bi- and monoallelic SNORA31 deletions render human pluripotent stem cell (hPSC)-derived cortical neurons susceptible to HSV-1. Accordingly, SNORA31-mutated patient hPSC-derived cortical neurons are susceptible to HSV-1, like those from TLR3- or STAT1-deficient patients. Exogenous interferon (IFN)-ß renders SNORA31- and TLR3- but not STAT1-mutated neurons resistant to HSV-1. Finally, transcriptome analysis of SNORA31-mutated neurons revealed normal responses to TLR3 and IFN-α/ß stimulation but abnormal responses to HSV-1. Human SNORA31 thus controls central nervous system neuron-intrinsic immunity to HSV-1 by a distinctive mechanism.


Assuntos
Encefalite por Herpes Simples/genética , Herpesvirus Humano 1/genética , Neurônios/imunologia , RNA Nucleolar Pequeno/genética , Adulto , Sistema Nervoso Central/imunologia , Sistema Nervoso Central/virologia , Pré-Escolar , Encefalite por Herpes Simples/imunologia , Encefalite por Herpes Simples/patologia , Encefalite por Herpes Simples/virologia , Feminino , Predisposição Genética para Doença , Herpesvirus Humano 1/imunologia , Herpesvirus Humano 1/patogenicidade , Humanos , Imunidade/genética , Lactente , Masculino , Metagenoma/genética , Metagenoma/imunologia , Pessoa de Meia-Idade , Neurônios/virologia , RNA Nucleolar Pequeno/imunologia
4.
Proc Natl Acad Sci U S A ; 116(38): 19055-19063, 2019 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-31484767

RESUMO

Juvenile-onset recurrent respiratory papillomatosis (JRRP) is a rare and debilitating childhood disease that presents with recurrent growth of papillomas in the upper airway. Two common human papillomaviruses (HPVs), HPV-6 and -11, are implicated in most cases, but it is still not understood why only a small proportion of children develop JRRP following exposure to these common viruses. We report 2 siblings with a syndromic form of JRRP associated with mild dermatologic abnormalities. Whole-exome sequencing of the patients revealed a private homozygous mutation in NLRP1, encoding Nucleotide-Binding Domain Leucine-Rich Repeat Family Pyrin Domain-Containing 1. We find the NLRP1 mutant allele to be gain of function (GOF) for inflammasome activation, as demonstrated by the induction of inflammasome complex oligomerization and IL-1ß secretion in an overexpression system. Moreover, patient-derived keratinocytes secrete elevated levels of IL-1ß at baseline. Finally, both patients displayed elevated levels of inflammasome-induced cytokines in the serum. Six NLRP1 GOF mutations have previously been described to underlie 3 allelic Mendelian diseases with differing phenotypes and modes of inheritance. Our results demonstrate that an autosomal recessive, syndromic form of JRRP can be associated with an NLRP1 GOF mutation.

6.
Biol Blood Marrow Transplant ; 25(6): 1142-1151, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30625392

RESUMO

Mutational profiling has demonstrated utility in predicting the likelihood of disease progression in patients with myelofibrosis (MF). However, there is limited data regarding the prognostic utility of genetic profiling in MF patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HCT). We performed high-throughput sequencing of 585 genes on pre-transplant samples from 101 patients with MF who underwent allo-HCT and evaluated the association of mutations and clinical variables with transplantation outcomes. Overall survival (OS) at 5 years post-transplantation was 52%, and relapse-free survival (RFS) was 51.1 % for this cohort. Nonrelapse mortality (NRM) accounted for most deaths. Patient's age, donor's age, donor type, and Dynamic International Prognostic Scoring System score at diagnosis did not predict for outcomes. Mutations known to be associated with increased risk of disease progression, such as ASXL1, SRSF2, IDH1/2, EZH2, and TP53, did not impact OS or RFS. The presence of U2AF1 (P = .007) or DNMT3A (P = .034) mutations was associated with worse OS. A Mutation-Enhanced International Prognostic Scoring System 70 score was available for 80 patients (79%), and there were no differences in outcomes between patients with high risk scores and those with intermediate and low risk scores. Collectively, these data identify mutational predictors of outcome in MF patients undergoing allo-HCT. These genetic biomarkers in conjunction with clinical variables may have important utility in guiding transplantation decision making.

7.
Proc Natl Acad Sci U S A ; 116(3): 950-959, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30591557

RESUMO

Computational analyses of human patient exomes aim to filter out as many nonpathogenic genetic variants (NPVs) as possible, without removing the true disease-causing mutations. This involves comparing the patient's exome with public databases to remove reported variants inconsistent with disease prevalence, mode of inheritance, or clinical penetrance. However, variants frequent in a given exome cohort, but absent or rare in public databases, have also been reported and treated as NPVs, without rigorous exploration. We report the generation of a blacklist of variants frequent within an in-house cohort of 3,104 exomes. This blacklist did not remove known pathogenic mutations from the exomes of 129 patients and decreased the number of NPVs remaining in the 3,104 individual exomes by a median of 62%. We validated this approach by testing three other independent cohorts of 400, 902, and 3,869 exomes. The blacklist generated from any given cohort removed a substantial proportion of NPVs (11-65%). We analyzed the blacklisted variants computationally and experimentally. Most of the blacklisted variants corresponded to false signals generated by incomplete reference genome assembly, location in low-complexity regions, bioinformatic misprocessing, or limitations inherent to cohort-specific private alleles (e.g., due to sequencing kits, and genetic ancestries). Finally, we provide our precalculated blacklists, together with ReFiNE, a program for generating customized blacklists from any medium-sized or large in-house cohort of exome (or other next-generation sequencing) data via a user-friendly public web server. This work demonstrates the power of extracting variant blacklists from private databases as a specific in-house but broadly applicable tool for optimizing exome analysis.


Assuntos
Bases de Dados de Ácidos Nucleicos , Exoma , Variação Genética , Genoma Humano , Análise de Sequência de DNA , Software , Estudos de Coortes , Feminino , Humanos , Masculino
8.
Sci Immunol ; 3(30)2018 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-30578351

RESUMO

Hundreds of patients with autosomal recessive, complete IL-12p40 or IL-12Rß1 deficiency have been diagnosed over the last 20 years. They typically suffer from invasive mycobacteriosis and, occasionally, from mucocutaneous candidiasis. Susceptibility to these infections is thought to be due to impairments of IL-12-dependent IFN-γ immunity and IL-23-dependent IL-17A/IL-17F immunity, respectively. We report here patients with autosomal recessive, complete IL-12Rß2 or IL-23R deficiency, lacking responses to IL-12 or IL-23 only, all of whom, unexpectedly, display mycobacteriosis without candidiasis. We show that αß T, γδ T, B, NK, ILC1, and ILC2 cells from healthy donors preferentially produce IFN-γ in response to IL-12, whereas NKT cells and MAIT cells preferentially produce IFN-γ in response to IL-23. We also show that the development of IFN-γ-producing CD4+ T cells, including, in particular, mycobacterium-specific TH1* cells (CD45RA-CCR6+), is dependent on both IL-12 and IL-23. Last, we show that IL12RB1, IL12RB2, and IL23R have similar frequencies of deleterious variants in the general population. The comparative rarity of symptomatic patients with IL-12Rß2 or IL-23R deficiency, relative to IL-12Rß1 deficiency, is, therefore, due to lower clinical penetrance. There are fewer symptomatic IL-23R- and IL-12Rß2-deficient than IL-12Rß1-deficient patients, not because these genetic disorders are rarer, but because the isolated absence of IL-12 or IL-23 is, in part, compensated by the other cytokine for the production of IFN-γ, thereby providing some protection against mycobacteria. These experiments of nature show that human IL-12 and IL-23 are both required for optimal IFN-γ-dependent immunity to mycobacteria, both individually and much more so cooperatively.


Assuntos
Imunidade Inata/imunologia , Interferon gama/imunologia , Interleucina-12/imunologia , Interleucina-23/imunologia , Infecções por Micobactéria não Tuberculosa/imunologia , Mycobacterium/imunologia , Humanos , Interleucina-12/deficiência , Interleucina-12/genética , Interleucina-23/deficiência , Interleucina-23/genética , Linhagem
9.
Bioinformatics ; 34(24): 4307-4309, 2018 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-30535305

RESUMO

Summary: Next-generation sequencing (NGS) generates large amounts of genomic data and reveals about 20 000 genetic coding variants per individual studied. Several mutation damage prediction scores are available to prioritize variants, but there is currently no application to help investigators to determine the relevance of the candidate genes and variants quickly and visually from population genetics data and deleteriousness scores. Here, we present PopViz, a user-friendly, rapid, interactive, mobile-compatible webserver providing a gene-centric visualization of the variants of any human gene, with (i) population-specific minor allele frequencies from the gnomAD population genetic database; (ii) mutation damage prediction scores from CADD, EIGEN and LINSIGHT and (iii) amino-acid positions and protein domains. This application will be particularly useful in investigations of NGS data for new disease-causing genes and variants, by reinforcing or rejecting the plausibility of the candidate genes, and by selecting and prioritizing, the candidate variants for experimental testing. Availability and implementation: PopViz webserver is freely accessible from http://shiva.rockefeller.edu/PopViz/. Supplementary information: Supplementary data are available at Bioinformatics online.


Assuntos
Frequência do Gene , Variação Genética , Software , Biologia Computacional , Genômica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos
10.
Neurol Neuroimmunol Neuroinflamm ; 5(6): e500, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30211253

RESUMO

Objective: Deficiency in the cytosolic DNA sensor RNA Polymerase III (POL III) was recently described in children with severe varicella-zoster virus (VZV) infection in the CNS or lungs. Here, we describe a pair of monozygotic female twins, who both experienced severe recurrent CNS vasculitis caused by VZV reactivation. The clinical presentation and findings included recurrent episodes of headache, dizziness, and neurologic deficits, CSF with pleocytosis and intrathecal VZV antibody production, and MRI of the brain showing ischemic lesions. Methods: We performed whole-exome sequencing and identified a rare mutation in the POL III subunit POLR3F. Subsequently, antiviral responses in patient peripheral blood mononuclear cells (PBMCs) were examined and compared with healthy controls. Results: The identified R50W POLR3F mutation is predicted by bioinformatics to be damaging, and when tested in functional assays, patient PBMCs exhibited impaired antiviral and inflammatory responses to the POL III agonist poly(dA:dT) and increased viral replication compared with controls. Conclusions: Altogether, these cases add genetic and immunologic evidence to the novel association between defects in sensing of AT-rich DNA present in the VZV genome and increased susceptibility to severe manifestations of VZV infection in the CNS in humans.

14.
J Clin Invest ; 128(2): 789-804, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29355841

RESUMO

Patients with myeloproliferative neoplasms (MPNs) frequently progress to bone marrow failure or acute myeloid leukemia (AML), and mutations in epigenetic regulators such as the metabolic enzyme isocitrate dehydrogenase (IDH) are associated with poor outcomes. Here, we showed that combined expression of Jak2V617F and mutant IDH1R132H or Idh2R140Q induces MPN progression, alters stem/progenitor cell function, and impairs differentiation in mice. Jak2V617F Idh2R140Q-mutant MPNs were sensitive to small-molecule inhibition of IDH. Combined inhibition of JAK2 and IDH2 normalized the stem and progenitor cell compartments in the murine model and reduced disease burden to a greater extent than was seen with JAK inhibition alone. In addition, combined JAK2 and IDH2 inhibitor treatment also reversed aberrant gene expression in MPN stem cells and reversed the metabolite perturbations induced by concurrent JAK2 and IDH2 mutations. Combined JAK2 and IDH2 inhibitor therapy also showed cooperative efficacy in cells from MPN patients with both JAK2mut and IDH2mut mutations. Taken together, these data suggest that combined JAK and IDH inhibition may offer a therapeutic advantage in this high-risk MPN subtype.


Assuntos
Antineoplásicos/farmacologia , Regulação Neoplásica da Expressão Gênica , Isocitrato Desidrogenase/genética , Janus Quinase 2/genética , Transtornos Mieloproliferativos/tratamento farmacológico , Transtornos Mieloproliferativos/genética , Idoso , Animais , Progressão da Doença , Epigênese Genética , Feminino , Perfilação da Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Mutantes , Camundongos Transgênicos , Pessoa de Meia-Idade , Mutação , Fenótipo , Células-Tronco
15.
Cancer Cell ; 33(1): 29-43.e7, 2018 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-29249691

RESUMO

Genetic and functional studies underscore the central role of JAK/STAT signaling in myeloproliferative neoplasms (MPNs). However, the mechanisms that mediate transformation in MPNs are not fully delineated, and clinically utilized JAK inhibitors have limited ability to reduce disease burden or reverse myelofibrosis. Here we show that MPN progenitor cells are characterized by marked alterations in gene regulation through differential enhancer utilization, and identify nuclear factor κB (NF-κB) signaling as a key pathway activated in malignant and non-malignant cells in MPN. Inhibition of BET bromodomain proteins attenuated NF-κB signaling and reduced cytokine production in vivo. Most importantly, combined JAK/BET inhibition resulted in a marked reduction in the serum levels of inflammatory cytokines, reduced disease burden, and reversed bone marrow fibrosis in vivo.


Assuntos
Citocinas/metabolismo , Inflamação/tratamento farmacológico , Transtornos Mieloproliferativos/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Animais , Regulação da Expressão Gênica/efeitos dos fármacos , Janus Quinase 2/genética , Camundongos Transgênicos , Mutação/efeitos dos fármacos , NF-kappa B/metabolismo , Neoplasias/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos
16.
Cancer Cell ; 33(1): 44-59.e8, 2018 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-29275866

RESUMO

Mutations in epigenetic modifiers and signaling factors often co-occur in myeloid malignancies, including TET2 and NRAS mutations. Concurrent Tet2 loss and NrasG12D expression in hematopoietic cells induced myeloid transformation, with a fully penetrant, lethal chronic myelomonocytic leukemia (CMML), which was serially transplantable. Tet2 loss and Nras mutation cooperatively led to decrease in negative regulators of mitogen-activated protein kinase (MAPK) activation, including Spry2, thereby causing synergistic activation of MAPK signaling by epigenetic silencing. Tet2/Nras double-mutant leukemia showed preferential sensitivity to MAPK kinase (MEK) inhibition in both mouse model and patient samples. These data provide insights into how epigenetic and signaling mutations cooperate in myeloid transformation and provide a rationale for mechanism-based therapy in CMML patients with these high-risk genetic lesions.


Assuntos
Proteínas de Ligação a DNA/genética , GTP Fosfo-Hidrolases/genética , Leucemia Mielomonocítica Crônica/genética , Proteínas de Membrana/genética , Proteínas Monoméricas de Ligação ao GTP/genética , Mutação/genética , Proteínas Proto-Oncogênicas/genética , Animais , Transformação Celular Neoplásica/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Camundongos Transgênicos , Transtornos Mieloproliferativos/genética , Proteínas Serina-Treonina Quinases , Transdução de Sinais/genética
17.
Cell Stem Cell ; 21(4): 489-501.e7, 2017 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-28965767

RESUMO

JAK1 is a critical effector of pro-inflammatory cytokine signaling and plays important roles in immune function, while abnormal JAK1 activity has been linked to immunological and neoplastic diseases. Specific functions of JAK1 in the context of hematopoiesis, and specifically within hematopoietic stem cells (HSCs), have not clearly been delineated. Here, we show that conditional Jak1 loss in HSCs reduces their self-renewal and markedly alters lymphoid/myeloid differentiation in vivo. Jak1-deficient HSCs exhibit decreased competitiveness in vivo and are unable to rescue hematopoiesis in the setting of myelosuppression. They exhibit increased quiescence, an inability to enter the cell cycle in response to hematopoietic stress, and a marked reduction in cytokine sensing, including in response to type I interferons and IL-3. Moreover, Jak1 loss is not fully rescued by expression of a constitutively active Jak2 allele. Together, these data highlight an essential role for Jak1 in HSC homeostasis and stress responses.


Assuntos
Hematopoese , Células-Tronco Hematopoéticas/metabolismo , Interleucina-3/metabolismo , Janus Quinase 1/metabolismo , Estresse Fisiológico , Alelos , Animais , Transplante de Medula Óssea , Ciclo Celular , Diferenciação Celular , Ativação Enzimática , Regulação da Expressão Gênica , Células-Tronco Hematopoéticas/citologia , Imunossupressão , Interferon Tipo I/metabolismo , Camundongos Knockout , Células Mieloides/metabolismo , Transdução de Sinais
18.
JCI Insight ; 2(7): e90932, 2017 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-28405618

RESUMO

Myelofibrosis (MF) is a bone marrow disorder characterized by clonal myeloproliferation, aberrant cytokine production, extramedullary hematopoiesis, and bone marrow fibrosis. Although somatic mutations in JAK2, MPL, and CALR have been identified in the pathogenesis of these diseases, inhibitors of the Jak2 pathway have not demonstrated efficacy in ameliorating MF in patients. TGF-ß family members are profibrotic cytokines and we observed significant TGF-ß1 isoform overexpression in a large cohort of primary MF patient samples. Significant overexpression of TGF-ß1 was also observed in murine clonal MPLW515L megakaryocytic cells. TGF-ß1 stimulated the deposition of excessive collagen by mesenchymal stromal cells (MSCs) by activating the TGF-ß receptor I kinase (ALK5)/Smad3 pathway. MSCs derived from MPLW515L mice demonstrated sustained overproduction of both collagen I and collagen III, effects that were abrogated by ALK5 inhibition in vitro and in vivo. Importantly, use of galunisertib, a clinically active ALK5 inhibitor, significantly improved MF in both MPLW515L and JAK2V617F mouse models. These data demonstrate the role of malignant hematopoietic stem cell (HSC)/TGF-ß/MSC axis in the pathogenesis of MF, and provide a preclinical rationale for ALK5 blockade as a therapeutic strategy in MF.


Assuntos
Janus Quinase 2/metabolismo , Mielofibrose Primária/tratamento farmacológico , Pirazóis/farmacologia , Quinolinas/farmacologia , Receptor do Fator de Crescimento Transformador beta Tipo I/antagonistas & inibidores , Receptores de Trombopoetina/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Animais , Medula Óssea/patologia , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Colágeno/metabolismo , Células HEK293 , Células-Tronco Hematopoéticas/metabolismo , Humanos , Masculino , Megacariócitos/metabolismo , Megacariócitos/patologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mielofibrose Primária/metabolismo , Transdução de Sinais , Proteína Smad3/metabolismo
19.
Blood ; 129(13): 1779-1790, 2017 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-28077417

RESUMO

Recent studies have reported that activation-induced cytidine deaminase (AID) and ten-eleven-translocation (TET) family members regulate active DNA demethylation. Genetic alterations of TET2 occur in myeloid malignancies, and hematopoietic-specific loss of Tet2 induces aberrant hematopoietic stem cell (HSC) self-renewal/differentiation, implicating TET2 as a master regulator of normal and malignant hematopoiesis. Despite the functional link between AID and TET in epigenetic gene regulation, the role of AID loss in hematopoiesis and myeloid transformation remains to be investigated. Here, we show that Aid loss in mice leads to expansion of myeloid cells and reduced erythroid progenitors resulting in anemia, with dysregulated expression of Cebpa and Gata1, myeloid/erythroid lineage-specific transcription factors. Consistent with data in the murine context, silencing of AID in human bone marrow cells skews differentiation toward myelomonocytic lineage. However, in contrast to Tet2 loss, Aid loss does not contribute to enhanced HSC self-renewal or cooperate with Flt3-ITD to induce myeloid transformation. Genome-wide transcription and differential methylation analysis uncover the critical role of Aid as a key epigenetic regulator. These results indicate that AID and TET2 share common effects on myeloid and erythroid lineage differentiation, however, their role is nonredundant in regulating HSC self-renewal and in myeloid transformation.


Assuntos
Diferenciação Celular , Citidina Desaminase/fisiologia , Metilação de DNA , Células-Tronco Hematopoéticas/metabolismo , Animais , Linhagem da Célula , Autorrenovação Celular , Transformação Celular Neoplásica , Citidina Desaminase/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/fisiologia , Células Eritroides/citologia , Inativação Gênica , Células-Tronco Hematopoéticas/citologia , Humanos , Camundongos , Células Mieloides/citologia , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/fisiologia
20.
Leuk Res ; 49: 62-5, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27568819

RESUMO

We examined the genetic implications and clinical impact of telomere length (TL) in 67 patients with acute myeloid leukemia (AML). There was a trend toward improved survival at 6 months in patients with longer TL. We found that patients with activating mutations, such as FLT3-ITD, had shorter TL, while those with mutations in epigenetic modifying enzymes, particularly IDH1 and IDH2, had longer TL. These are intriguing findings that warrant further investigation in larger cohorts. Our data show the potential of TL as a predictive biomarker in AML and identify genetic subsets that may be particularly vulnerable to telomere-targeted therapies.


Assuntos
Leucemia Mieloide Aguda/genética , Mutação , Telômero/ultraestrutura , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais , Feminino , Humanos , Isocitrato Desidrogenase/genética , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Análise de Sobrevida , Resultado do Tratamento , Tirosina Quinase 3 Semelhante a fms/genética
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