Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 93
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Immunol ; 211(5): 804-815, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37436030

RESUMO

Because of the growing numbers of immunocompromised patients, the incidence of life-threatening fungal infections caused by Candida albicans and Aspergillus fumigatus is increasing. We have recently identified enolase 1 (Eno1) from A. fumigatus as an immune evasion protein. Eno1 is a fungal moonlighting protein that mediates adhesion and invasion of human cells and also immune evasion through complement inactivation. We now show that soluble Eno1 has immunostimulatory activity. We observed that Eno1 from both C. albicans and A. fumigatus directly binds to the surface of lymphocytes, preferentially human and mouse B cells. Functionally, Eno1 upregulated CD86 expression on B cells and induced proliferation. Although the receptor for fungal Eno1 on B lymphocytes is still unknown, the comparison of B cells from wild-type and MyD88-deficient mice showed that B cell activation by Eno1 required MyD88 signaling. With respect to infection biology, we noted that mouse B cells stimulated by Eno1 secreted IgM and IgG2b. These Igs bound C. albicans hyphae in vitro, suggesting that Eno1-induced Ab secretion might contribute to protection from invasive fungal disease in vivo. Eno1 also triggered the release of proinflammatory cytokines from monocytes, particularly IL-6, which is a potent activator of B cells. Together, our data shed new light on the role of secreted Eno1 in infections with C. albicans and A. fumigatus. Eno1 secretion by these pathogenic microbes appears to be a double-edged sword by supporting fungal pathogenicity while triggering (antifungal) immunity.


Assuntos
Aspergillus fumigatus , Candida albicans , Fosfopiruvato Hidratase , Animais , Humanos , Camundongos , Aspergillus fumigatus/enzimologia , Aspergillus fumigatus/metabolismo , Candida albicans/enzimologia , Candida albicans/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Monócitos/metabolismo , Monócitos/microbiologia , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Fosfopiruvato Hidratase/metabolismo , Linfócitos B/metabolismo , Linfócitos B/microbiologia
2.
Am J Hum Genet ; 108(1): 115-133, 2021 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-33308444

RESUMO

Signal peptide-CUB-EGF domain-containing protein 3 (SCUBE3) is a member of a small family of multifunctional cell surface-anchored glycoproteins functioning as co-receptors for a variety of growth factors. Here we report that bi-allelic inactivating variants in SCUBE3 have pleiotropic consequences on development and cause a previously unrecognized syndromic disorder. Eighteen affected individuals from nine unrelated families showed a consistent phenotype characterized by reduced growth, skeletal features, distinctive craniofacial appearance, and dental anomalies. In vitro functional validation studies demonstrated a variable impact of disease-causing variants on transcript processing, protein secretion and function, and their dysregulating effect on bone morphogenetic protein (BMP) signaling. We show that SCUBE3 acts as a BMP2/BMP4 co-receptor, recruits the BMP receptor complexes into raft microdomains, and positively modulates signaling possibly by augmenting the specific interactions between BMPs and BMP type I receptors. Scube3-/- mice showed craniofacial and dental defects, reduced body size, and defective endochondral bone growth due to impaired BMP-mediated chondrogenesis and osteogenesis, recapitulating the human disorder. Our findings identify a human disease caused by defective function of a member of the SCUBE family, and link SCUBE3 to processes controlling growth, morphogenesis, and bone and teeth development through modulation of BMP signaling.


Assuntos
Osso e Ossos/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Deficiências do Desenvolvimento/metabolismo , Osteogênese/fisiologia , Transdução de Sinais/fisiologia , Animais , Proteína Morfogenética Óssea 2/metabolismo , Proteína Morfogenética Óssea 4/metabolismo , Proteínas Morfogenéticas Ósseas/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Feminino , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Células HEK293 , Células Hep G2 , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Células MCF-7 , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL
3.
Eur J Immunol ; 53(11): e2250284, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37503840

RESUMO

To obtain a better understanding of the biology behind life-threatening fungal infections caused by Candida albicans, we recently conducted an in silico screening for fungal and host protein interaction partners. We report here that the extracellular domain of human CD4 binds to the moonlighting protein enolase 1 (Eno1) of C. albicans as predicted bioinformatically. By using different anti-CD4 monoclonal antibodies, we determined that C. albicans Eno1 (CaEno1) primarily binds to the extracellular domain 3 of CD4. Functionally, we observed that CaEno1 binding to CD4 activated lymphocyte-specific protein tyrosine kinase (LCK), which was also the case for anti-CD4 monoclonal antibodies tested in parallel. CaEno1 binding to naïve human CD4+ T cells skewed cytokine secretion toward a Th2 profile indicative of poor fungal control. Moreover, CaEno1 inhibited human memory CD4+ T-cell recall responses. Therapeutically, CD4+ T cells transduced with a p41/Crf1-specific T-cell receptor developed for adoptive T-cell therapy were not inhibited by CaEno1 in vitro. Together, the interaction of human CD4+ T cells with CaEno1 modulated host CD4+ T-cell responses in favor of the fungus. Thus, CaEno1 mediates not only immune evasion through its interference with complement regulators but also through the direct modulation of CD4+ T-cell responses.


Assuntos
Candida albicans , Linfócitos T , Humanos , Linfócitos T/metabolismo , Linfócitos T CD4-Positivos , Fosfopiruvato Hidratase/metabolismo , Anticorpos Monoclonais/metabolismo
4.
J Exp Bot ; 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38628155

RESUMO

Optimal stomatal regulation is important for plant adaptation to changing environmental conditions and for maintaining crop yield. The guard-cell signal GABA is produced from glutamate by Glutamate Decarboxylase (GAD) during a reaction that generates carbon dioxide (CO2) as a by-product. Here, we investigated a putative connection between GABA signalling and the more clearly defined CO2 signalling pathway in guard cells. The GABA-deficient mutant lines gad2-1, gad2-2 and gad1/2/4/5 were examined for stomatal sensitivity to various CO2 concentrations. Our findings show a phenotypical discrepancy between the allelic mutant lines gad2-1 and gad2-2 - a weakened CO2 response in gad2-1 (GABI_474_E05) in contrast to a wild-type response in gad2-2 (SALK_028819) and gad1/2/4/5. Through transcriptomic and genomic investigation, we traced the response of gad2-1 to a deletion of full-length Mitogen-activated protein kinase 12 (MPK12) in the GABI-KAT line, thereafter as renamed gad2-1*. Guard cell-specific complementation of MPK12 restored the gad2-1* CO2 phenotype, which confirms the proposed importance of MPK12 to CO2 sensitivity. Additionally, we found that stomatal opening under low atmospheric CO2 occurs independently of the GABA-modulated opening-channel ALMT9. Our results confirm that GABA has a role in modulating the rate of stomatal opening and closing - but not in response to CO2  per se.

5.
Platelets ; 34(1): 2184183, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36883692

RESUMO

Platelets play a critical role in immune response. Coronavirus disease 2019 (COVID-19) patients with a severe course often show pathological coagulation parameters including thrombocytopenia, and at the same time the proportion of immature platelets increases. In this study, the platelet count and the immature platelet fraction (IPF) of hospitalized patients with different oxygenation requirements was investigated daily over a course of 40 days. In addition, the platelet function of COVID-19 patients was analyzed. It was found that the number of platelets in patients with the most severe course (intubation and extracorporeal membrane oxygenation (ECMO)) was significantly lower (111.5 ∙ 106 /mL) than in the other groups (mild (no intubation, no ECMO): 203.5 ∙ 106 /mL, p < .0001, moderate (intubation, no ECMO): 208.0 ∙ 106 /mL, p < .0001). IPF tended to be elevated (10.9%). Platelet function was reduced. Differentiation by outcome revealed that the deceased patients had a highly significant lower platelet count and higher IPF (97.3 ∙ 106 /mL, p < .0001, 12.2%, p = .0003).


What is the context? Pathological coagulation is a feature of severe cases of COVID-19, with both bleeding complications and thrombosis. Patients with severe COVID-19 are frequently treated with extracorporeal membrane oxygenation (ECMO), which is often associated with bleeding complications. Platelets play an important role in blood clotting. The proportion of immature platelets has been characterized as hyperreactive and associated with high prothrombotic activity. In addition, they are discussed as predictors of COVID-19 disease severity.What is new? In grading the severity of disease in our patient cohort, we consider the required oxygenation measures. Thus, the focus is on severe cases requiring intubation and ECMO compared to moderate (intubation, no ECMO) and mild (no intubation, no ECMO) cases.What is the impact? This study focuses on severely ill patients who require ECMO treatment. Therefore, this study provides further evidence to use immature platelet fraction to predict the outcome of severe COVID-19 courses.


Assuntos
COVID-19 , Trombocitopenia , Humanos , Plaquetas , Trombocitopenia/etiologia , Contagem de Plaquetas , Coagulação Sanguínea
6.
Cell Immunol ; 371: 104459, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34847408

RESUMO

Invasive candidiasis is a healthcare-associated fungal infection with a high mortality rate. Neutrophils, the first line of defense during fungal infections, express the immunoregulatory Candida albicans receptors CEACAM1, CEACAM3, and CEACAM6. We analyzed the effects of specific antibodies on C. albicans-induced neutrophil responses. CEACAM6 ligation by 1H7-4B and to some extent CEACAM1 ligation by B3-17, but not CEACAM3 ligation by 308/3-3, resulted in the immediate release of stored CXCL8 and altered transcriptional responses of the C. albicans-stimulated neutrophils. Integrated network analyses and dynamic simulations of signaling cascades predicted alterations in apoptosis and cytokine secretion. We verified that CEACAM6 ligation enhanced Candida-induced neutrophil apoptosis and increased long-term IL-1ß/IL-6 release in responses to C. albicans. CEACAM3 ligation, but not CEACAM1 ligation, increased the long-term release of pro-inflammatory IL-1ß/IL-6. Taken together, we demonstrated for the first time that ligation of CEACAM receptors differentially affects the regulation of C. albicans-induced immune functions in human neutrophils.


Assuntos
Antígenos CD/imunologia , Candida albicans/imunologia , Antígeno Carcinoembrionário/imunologia , Moléculas de Adesão Celular/imunologia , Neutrófilos/imunologia , Anticorpos Monoclonais/imunologia , Apoptose/imunologia , Candidíase Invasiva/mortalidade , Candidíase Invasiva/patologia , Citocinas/imunologia , Feminino , Proteínas Ligadas por GPI/imunologia , Humanos , Imunomodulação/imunologia , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Masculino
7.
J Theor Biol ; 550: 111222, 2022 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-35843440

RESUMO

BACKGROUND: The cyclic nucleotides cAMP and cGMP inhibit platelet activation. Different platelet signaling modules work together. We develop here a modelling framework to integrate different signaling modules and apply it to platelets. RESULTS: We introduce a novel standardized bilinear coupling mechanism allowing sub model debugging and standardization of coupling with optimal data driven modelling by methods from optimization. Besides cAMP signaling our model considers specific cGMP effects including external stimuli by drugs. Moreover, the output of the cGMP module serves as input for a modular model of VASP phosphorylation and for the activity of cAMP and cGMP pathways in platelets. Experimental data driven modeling allows us to design models with quantitative output. We use the condensed information about involved regulation and system responses for modeling drug effects and obtaining optimal experimental settings. Stepwise further validation of our model is given by direct experimental data. CONCLUSIONS: We present a general framework for model integration using modules and their stimulus responses. We demonstrate it by a multi-modular model for platelet signaling focusing on cGMP and VASP phosphorylation. Moreover, this allows to estimate drug action on any of the inhibitory cyclic nucleotide pathways (cGMP, cAMP) and is supported by experimental data.


Assuntos
Plaquetas , AMP Cíclico , GMP Cíclico , Nucleotídeos Cíclicos , Fosfoproteínas , Fosforilação
8.
Pediatr Crit Care Med ; 23(10): 812-821, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-35834676

RESUMO

OBJECTIVES: In children with congenital heart disease (CHD), excessive perioperative bleeding is associated with increased morbidity and mortality, thus making adequate perioperative hemostasis crucial. We investigate the prevalence of acquired von Willebrand syndrome type 2A (aVWS) in CHD and develop a treatment algorithm for patients with aVWS and CHD (TAPAC) to reduce perioperative blood loss. DESIGN: Retrospective cohort study. SETTING: Single-center study. PATIENTS: A total of 627 patients with CHD, undergoing corrective cardiac surgery between January 2008 and May 2017. INTERVENTIONS: The evaluation of perioperative bleeding risk was based on the laboratory parameters von Willebrand factor (VWF) antigen, ristocetin cofactor activity, platelet function analyzer (PFA) closure time adenosine diphosphate, and PFA epinephrine. According to the bleeding risk, treatment was performed with desmopressin or VWF. MEASUREMENTS AND MAIN RESULTS: aVWS was confirmed in 63.3 %, with a prevalence of 45.5% in the moderate and 66.3 % in the high-risk group. In addition, prevalence increased with ascending peak velocity above the stenosis (v max ) from 40.0% at less than or equal to 3 m/s to 83.3% at greater than 5 m/s. TAPAC reduced mean blood loss by 36.3% in comparison with a historical control cohort ( p < 0.001), without increasing the number of thrombotic or thromboembolic events during the hospital stay. With ascending v max , there was an increase in perioperative blood loss in the historical cohort ( p < 0.001), which was not evident in the TAPAC cohort ( p = 0.230). CONCLUSIONS: The prevalence of aVWS in CHD seems to be higher than assumed and leads to significantly higher perioperative blood loss, especially at high v max . Identifying these patients through appropriate laboratory analytics and adequate treatment could reduce blood loss effectively.


Assuntos
Cardiopatias Congênitas , Doenças de von Willebrand , Difosfato de Adenosina , Algoritmos , Perda Sanguínea Cirúrgica/prevenção & controle , Criança , Desamino Arginina Vasopressina/uso terapêutico , Epinefrina , Cardiopatias Congênitas/complicações , Cardiopatias Congênitas/cirurgia , Humanos , Estudos Retrospectivos , Síndrome , Doenças de von Willebrand/complicações , Doenças de von Willebrand/terapia , Fator de von Willebrand
9.
New Phytol ; 231(3): 1040-1055, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33774818

RESUMO

Soil salinity is an increasingly global problem which hampers plant growth and crop yield. Plant productivity depends on optimal water-use efficiency and photosynthetic capacity balanced by stomatal conductance. Whether and how stomatal behavior contributes to salt sensitivity or tolerance is currently unknown. This work identifies guard cell-specific signaling networks exerted by a salt-sensitive and salt-tolerant plant under ionic and osmotic stress conditions accompanied by increasing NaCl loads. We challenged soil-grown Arabidopsis thaliana and Thellungiella salsuginea plants with short- and long-term salinity stress and monitored genome-wide gene expression and signals of guard cells that determine their function. Arabidopsis plants suffered from both salt regimes and showed reduced stomatal conductance while Thellungiella displayed no obvious stress symptoms. The salt-dependent gene expression changes of guard cells supported the ability of the halophyte to maintain high potassium to sodium ratios and to attenuate the abscisic acid (ABA) signaling pathway which the glycophyte kept activated despite fading ABA concentrations. Our study shows that salinity stress and even the different tolerances are manifested on a single cell level. Halophytic guard cells are less sensitive than glycophytic guard cells, providing opportunities to manipulate stomatal behavior and improve plant productivity.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Ácido Abscísico , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Transporte de Íons , Estômatos de Plantas/metabolismo , Estresse Salino , Plantas Tolerantes a Sal/metabolismo
10.
BMC Genomics ; 21(1): 897, 2020 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-33353544

RESUMO

BACKGROUND: Understanding the molecular mechanisms of platelet activation and aggregation is of high interest for basic and clinical hemostasis and thrombosis research. The central platelet protein interaction network is involved in major responses to exogenous factors. This is defined by systemsbiological pathway analysis as the central regulating signaling cascade of platelets (CC). RESULTS: The CC is systematically compared here between mouse and human and major differences were found. Genetic differences were analysed comparing orthologous human and mouse genes. We next analyzed different expression levels of mRNAs. Considering 4 mouse and 7 human high-quality proteome data sets, we identified then those major mRNA expression differences (81%) which were supported by proteome data. CC is conserved regarding genetic completeness, but we observed major differences in mRNA and protein levels between both species. Looking at central interactors, human PLCB2, MMP9, BDNF, ITPR3 and SLC25A6 (always Entrez notation) show absence in all murine datasets. CC interactors GNG12, PRKCE and ADCY9 occur only in mice. Looking at the common proteins, TLN1, CALM3, PRKCB, APP, SOD2 and TIMP1 are higher abundant in human, whereas RASGRP2, ITGB2, MYL9, EIF4EBP1, ADAM17, ARRB2, CD9 and ZYX are higher abundant in mouse. Pivotal kinase SRC shows different regulation on mRNA and protein level as well as ADP receptor P2RY12. CONCLUSIONS: Our results highlight species-specific differences in platelet signaling and points of specific fine-tuning in human platelets as well as murine-specific signaling differences.


Assuntos
Ativação Plaquetária , Trombose , Animais , Plaquetas , Fatores de Troca do Nucleotídeo Guanina , Humanos , Camundongos , Proteoma , Transdução de Sinais
11.
Int J Mol Sci ; 21(1)2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31906439

RESUMO

CDC14A encodes the Cell Division Cycle 14A protein and has been associated with autosomal recessive non-syndromic hearing loss (DFNB32), as well as hearing impairment and infertile male syndrome (HIIMS) since 2016. To date, only nine variants have been associated in patients whose initial symptoms included moderate-to-profound hearing impairment. Exome analysis of Iranian and Pakistani probands who both showed bilateral, sensorineural hearing loss revealed a novel splice site variant (c.1421+2T>C, p.?) that disrupts the splice donor site and a novel frameshift variant (c.1041dup, p.Ser348Glnfs*2) in the gene CDC14A, respectively. To evaluate the pathogenicity of both loss-of-function variants, we analyzed the effects of both variants on the RNA-level. The splice variant was characterized using a minigene assay. Altered expression levels due to the c.1041dup variant were assessed using RT-qPCR. In summary, cDNA analysis confirmed that the c.1421+2T>C variant activates a cryptic splice site, resulting in a truncated transcript (c.1414_1421del, p.Val472Leufs*20) and the c.1041dup variant results in a defective transcript that is likely degraded by nonsense-mediated mRNA decay. The present study functionally characterizes two variants and provides further confirmatory evidence that CDC14A is associated with a rare form of hereditary hearing loss.


Assuntos
Perda Auditiva Neurossensorial/genética , Proteínas Tirosina Fosfatases/genética , Adulto , Exoma/genética , Feminino , Estudos de Associação Genética , Humanos , Irã (Geográfico) , Mutação com Perda de Função , Masculino , Paquistão , Linhagem , Proteínas Tirosina Fosfatases/metabolismo , Sítios de Splice de RNA/genética , Splicing de RNA
12.
Semin Cell Dev Biol ; 69: 172-182, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28694114

RESUMO

Protocadherins (Pcdhs) are a group of cell-cell adhesion molecules that are highly expressed in the nervous system and have a major function in dendrite development and neural circuit formation. However, the role protocadherins play in human health and disease remains unclear. Several recent studies have associated epigenetic dysregulation of protocadherins with possible implications for disease pathogenesis. In this review, we briefly recap the various epigenetic mechanisms regulating protocadherin genes, particularly the clustered Pcdhs. We further outline research describing altered epigenetic regulation of protocadherins in neurological and psychiatric disorders, as well as in cancer and during aging. We additionally present preliminary data on DNA methylation dynamics of clustered protocadherins during fetal brain development, as well as the epigenetic differences distinguishing adult neuronal and glial cells. A deeper understanding of the role of protocadherins in disease is crucial for designing novel diagnostic tools and therapies targeting brain disorders.


Assuntos
Caderinas/genética , Doença/genética , Epigênese Genética , Animais , Encefalopatias/genética , Encefalopatias/patologia , Caderinas/metabolismo , Variações do Número de Cópias de DNA/genética , Metilação de DNA/genética , Humanos
13.
Exp Cell Res ; 370(2): 322-332, 2018 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-29964050

RESUMO

To study delayed genetic and epigenetic radiation effects, which may trigger radiation-induced carcinogenesis, we have established single-cell clones from irradiated and non-irradiated primary human fibroblasts. Stable clones were endowed with the same karyotype in all analyzed metaphases after 20 population doublings (PDs), whereas unstable clones displayed mosaics of normal and abnormal karyotypes. To account for variation in radiation sensitivity, all experiments were performed with two different fibroblast strains. After a single X-ray dose of 2 Gy more than half of the irradiated clones exhibited radiation-induced genome instability (RIGI). Irradiated clones displayed an increased rate of loss of chromosome Y (LOY) and copy number variations (CNVs), compared to controls. CNV breakpoints clustered in specific chromosome regions, in particular 3p14.2 and 7q11.21, coinciding with common fragile sites. CNVs affecting the FHIT gene in FRA3B were observed in independent unstable clones and may drive RIGI. Bisulfite pyrosequencing of control clones and the respective primary culture revealed global hypomethylation of ALU, LINE-1, and alpha-satellite repeats as well as rDNA hypermethylation during in vitro ageing. Irradiated clones showed further reduced ALU and alpha-satellite methylation and increased rDNA methylation, compared to controls. Methylation arrays identified several hundred differentially methylated genes and several enriched pathways associated with in vitro ageing. Methylation changes in 259 genes and the MAP kinase signaling pathway were associated with delayed radiation effects (after 20 PDs). Collectively, our results suggest that both genetic (LOY and CNVs) and epigenetic changes occur in the progeny of exposed cells that were not damaged directly by irradiation, likely contributing to radiation-induced carcinogenesis. We did not observe epigenetic differences between stable and unstable irradiated clones. The fact that the DNA methylation (DNAm) age of clones derived from the same primary culture varied greatly suggests that DNAm age of a single cell (represented by a clone) can be quite different from the DNAm age of a tissue. We propose that DNAm age reflects the emergent property of a large number of individual cells whose respective DNAm ages can be highly variable.


Assuntos
Variações do Número de Cópias de DNA/genética , Dano ao DNA/genética , Epigênese Genética/genética , Fibroblastos/citologia , Tolerância a Radiação/genética , Sobrevivência Celular/genética , Células Cultivadas , Metilação de DNA/genética , Fibroblastos/efeitos da radiação , Instabilidade Genômica/genética , Humanos
14.
Cereb Cortex ; 28(10): 3724-3739, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30085031

RESUMO

Epigenetic changes have likely contributed to the large size and enhanced cognitive abilities of the human brain which evolved within the last 2 million years after the human-chimpanzee split. Using reduced representation bisulfite sequencing, we have compared the methylomes of neuronal and non-neuronal cells from 3 human and 3 chimpanzee cortices. Differentially methylated regions (DMRs) with genome-wide significance were enriched in specific genomic regions. Intraspecific methylation differences between neuronal and non-neuronal cells were approximately 3 times more abundant than interspecific methylation differences between human and chimpanzee cell types. The vast majority (>90%) of human intraspecific DMRs (including DMRs in retrotransposons) were hypomethylated in neurons, compared with glia. Intraspecific DMRs were enriched in genes associated with different neuropsychiatric disorders. Interspecific DMRs were enriched in genes showing human-specific brain histone modifications. Human-chimpanzee methylation differences were much more frequent in non-neuronal cells (n. DMRs = 666) than in neurons (n. DMRs = 96). More than 95% of interspecific DMRs in glia were hypermethylated in humans. Although without an outgroup we cannot assign whether a change in methylation occurred in the human or chimpanzee lineage, our results are consistent with a wave of methylation affecting several hundred non-neuronal genes during human brain evolution.


Assuntos
Córtex Cerebral/citologia , Córtex Cerebral/metabolismo , Metilação de DNA/genética , Neurônios/metabolismo , Pan troglodytes/fisiologia , Idoso , Animais , Evolução Molecular , Feminino , Estudo de Associação Genômica Ampla , Humanos , Transtornos Mentais/genética , Transtornos Mentais/patologia , Metaboloma , Neuroglia/metabolismo , Especificidade da Espécie
15.
Proc Natl Acad Sci U S A ; 113(22): E3101-10, 2016 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-27185949

RESUMO

Staphylococcus aureus is a major bacterial pathogen, which causes severe blood and tissue infections that frequently emerge by autoinfection with asymptomatically carried nose and skin populations. However, recent studies report that bloodstream isolates differ systematically from those found in the nose and skin, exhibiting reduced toxicity toward leukocytes. In two patients, an attenuated toxicity bloodstream infection evolved from an asymptomatically carried high-toxicity nasal strain by loss-of-function mutations in the gene encoding the transcription factor repressor of surface proteins (rsp). Here, we report that rsp knockout mutants lead to global transcriptional and proteomic reprofiling, and they exhibit the greatest signal in a genome-wide screen for genes influencing S. aureus survival in human cells. This effect is likely to be mediated in part via SSR42, a long-noncoding RNA. We show that rsp controls SSR42 expression, is induced by hydrogen peroxide, and is required for normal cytotoxicity and hemolytic activity. Rsp inactivation in laboratory- and bacteremia-derived mutants attenuates toxin production, but up-regulates other immune subversion proteins and reduces lethality during experimental infection. Crucially, inactivation of rsp preserves bacterial dissemination, because it affects neither formation of deep abscesses in mice nor survival in human blood. Thus, we have identified a spontaneously evolving, attenuated-cytotoxicity, nonhemolytic S. aureus phenotype, controlled by a pleiotropic transcriptional regulator/noncoding RNA virulence regulatory system, capable of causing S. aureus bloodstream infections. Such a phenotype could promote deep infection with limited early clinical manifestations, raising concerns that bacterial evolution within the human body may contribute to severe infection.


Assuntos
Abscesso/etiologia , Apoptose , Bacteriemia/etiologia , Proteínas de Bactérias/genética , Mutação/genética , RNA não Traduzido/genética , Infecções Estafilocócicas/complicações , Fatores de Virulência/genética , Abscesso/patologia , Animais , Bacteriemia/patologia , Feminino , Regulação Bacteriana da Expressão Gênica , Células HeLa , Hemólise , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Proteômica , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/patologia , Staphylococcus aureus/patogenicidade , Virulência
16.
Hum Mol Genet ; 25(22): 4996-5005, 2016 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-28171595

RESUMO

Children of older fathers carry an increased risk for developing autism and other disorders. To elucidate the underlying mechanisms, we investigated the correlation of sperm DNA methylation with paternal age and its impact on the epigenome of the offspring. Methylation levels of nine candidate genes and LINE-1 repeats were quantified by bisulfite pyrosequencing in sperm DNA of 162 donors and 191 cord blood samples of resulting children (conceived by IVF/ICSI with the same sperm samples). Four genes showed a significant negative correlation between sperm methylation and paternal age. For FOXK1 and KCNA7, the age effect on the sperm epigenome was replicated in an independent cohort of 188 sperm samples. For FOXK1, paternal age also significantly correlated with foetal cord blood (FCB) methylation. Deep bisulfite sequencing and allele-specific pyrosequencing allowed us to distinguish between maternal and paternal alleles in FCB samples with an informative SNP. FCB methylation of the paternal FOXK1 allele was negatively correlated with paternal age, whereas maternal allele was unaffected by maternal age. Since FOXK1 duplication has been associated with autism, we studied blood FOXK1 methylation in 74 children with autism and 41 age-matched controls. The FOXK1 promoter showed a trend for accelerated demethylation in the autism group. Dual luciferase reporter assay revealed that FOXK1 methylation influences gene expression. Collectively, our study demonstrates that age-related DNA methylation changes in sperm can be transmitted to the next generation and may contribute to the increased disease risk in offspring of older fathers.


Assuntos
Metilação de DNA , Fatores de Transcrição Forkhead/genética , Idade Paterna , Superfamília Shaker de Canais de Potássio/genética , Espermatozoides/fisiologia , Adulto , Idoso , Alelos , Transtorno Autístico/sangue , Transtorno Autístico/genética , Criança , Pré-Escolar , Cordocentese , DNA/sangue , DNA/genética , Epigênese Genética , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Regiões Promotoras Genéticas , Espermatozoides/metabolismo
17.
PLoS Pathog ; 12(9): e1005857, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27632173

RESUMO

Community-acquired (CA) Staphylococcus aureus cause various diseases even in healthy individuals. Enhanced virulence of CA-strains is partly attributed to increased production of toxins such as phenol-soluble modulins (PSM). The pathogen is internalized efficiently by mammalian host cells and intracellular S. aureus has recently been shown to contribute to disease. Upon internalization, cytotoxic S. aureus strains can disrupt phagosomal membranes and kill host cells in a PSM-dependent manner. However, PSM are not sufficient for these processes. Here we screened for factors required for intracellular S. aureus virulence. We infected escape reporter host cells with strains from an established transposon mutant library and detected phagosomal escape rates using automated microscopy. We thereby, among other factors, identified a non-ribosomal peptide synthetase (NRPS) to be required for efficient phagosomal escape and intracellular survival of S. aureus as well as induction of host cell death. By genetic complementation as well as supplementation with the synthetic NRPS product, the cyclic dipeptide phevalin, wild-type phenotypes were restored. We further demonstrate that the NRPS is contributing to virulence in a mouse pneumonia model. Together, our data illustrate a hitherto unrecognized function of the S. aureus NRPS and its dipeptide product during S. aureus infection.


Assuntos
Dipeptídeos/biossíntese , Células Epiteliais/metabolismo , Viabilidade Microbiana , Biossíntese de Peptídeos Independentes de Ácido Nucleico/fisiologia , Peptídeos Cíclicos/biossíntese , Fagócitos/metabolismo , Staphylococcus aureus/metabolismo , Animais , Células Epiteliais/citologia , Células Epiteliais/microbiologia , Células HeLa , Humanos , Camundongos , Fagócitos/citologia , Fagócitos/microbiologia
18.
Int J Med Microbiol ; 308(8): 1018-1026, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30201279

RESUMO

Mold specific T-cells have been described as a supportive biomarker to monitor invasive mycoses and mold exposure. This study comparatively evaluated frequencies and cytokine profiles of Aspergillus fumigatus and Mucorales reactive T-cells depending on environmental mold exposure. Peripheral blood mononuclear cells (PBMCs) obtained from 35 healthy donors were stimulated with mycelial lysates of A. fumigatus and three human pathogenic Mucorales species. CD154+ specific T-cells were quantified by flow cytometry. In a second cohort of 20 additional donors, flow cytometry was complemented by 13-plex cytokine assays. Mold exposure of the subjects was determined using a previously established questionnaire. Highly exposed subjects exhibited significantly greater CD154+A. fumigatus and Mucorales specific naïve and memory T-helper cell frequencies. Significant correlation (r = 0.48 - 0.79) was found between A. fumigatus and Mucorales specific T-cell numbers. Logistic regression analyses revealed that combined analysis of mold specific T-cell frequencies and selected cytokine markers (A. fumigatus: IL-5 and TNF-α, R. arrhizus: IL-17A and IL-13) significantly improves classification performance, resulting in 75-90 % predictive power using 10-fold cross-validation. In conclusion, mold specific T-cell frequencies and their cytokine signatures offer promising potential in the assessment of environmental mold exposure. The cytokines identified in this pilot study should be validated in the clinical setting, e. g. in patients with hypersensitivity pneumonitis.


Assuntos
Aspergilose/imunologia , Aspergillus fumigatus/imunologia , Exposição Ambiental , Leucócitos Mononucleares/imunologia , Rhizomucor/imunologia , Rhizopus/imunologia , Células Th1/imunologia , Adulto , Aspergilose/microbiologia , Aspergillus fumigatus/crescimento & desenvolvimento , Biomarcadores/metabolismo , Estudos de Coortes , Citocinas/metabolismo , Feminino , Humanos , Leucócitos Mononucleares/microbiologia , Masculino , Mucormicose/microbiologia , Rhizomucor/crescimento & desenvolvimento , Rhizopus/crescimento & desenvolvimento , Células Th1/microbiologia
19.
BMC Med Genet ; 19(1): 81, 2018 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-29776397

RESUMO

BACKGROUND: Genetic heterogeneity and consanguineous marriages make recessive inherited hearing loss in Iran the second most common genetic disorder. Only two reported pathogenic variants (c.323G>C, p.Arg108Pro and c.419A>G, p.Tyr140Cys) in the S1PR2 gene have previously been linked to autosomal recessive hearing loss (DFNB68) in two Pakistani families. We describe a segregating novel homozygous c.323G>A, p.Arg108Gln pathogenic variant in S1PR2 that was identified in four affected individuals from a consanguineous five generation Iranian family. METHODS: Whole exome sequencing and bioinformatics analysis of 116 hearing loss-associated genes was performed in an affected individual from a five generation Iranian family. Segregation analysis and 3D protein modeling of the p.Arg108 exchange was performed. RESULTS: The two Pakistani families previously identified with S1PR2 pathogenic variants presented profound hearing loss that is also observed in the affected Iranian individuals described in the current study. Interestingly, we confirmed mixed hearing loss in one affected individual. 3D protein modeling suggests that the p.Arg108 position plays a key role in ligand receptor interaction, which is disturbed by the p.Arg108Gln change. CONCLUSION: In summary, we report the third overall mutation in S1PR2 and the first report outside the Pakistani population. Furthermore, we describe a novel variant that causes an amino acid exchange (p.Arg108Gln) in the same amino acid residue as one of the previously reported Pakistani families (p.Arg108Pro). This finding emphasizes the importance of the p.Arg108 amino acid in normal hearing and confirms and consolidates the role of S1PR2 in autosomal recessive hearing loss.


Assuntos
Substituição de Aminoácidos , Arginina/genética , Perda Auditiva/genética , Receptores de Lisoesfingolipídeo/genética , Adolescente , Consanguinidade , Feminino , Humanos , Irã (Geográfico) , Masculino , Modelos Moleculares , Linhagem , Ligação Proteica , Receptores de Lisoesfingolipídeo/química , Receptores de Lisoesfingolipídeo/metabolismo , Receptores de Esfingosina-1-Fosfato , Sequenciamento do Exoma/métodos
20.
Eur Heart J ; 38(29): 2279-2286, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28498942

RESUMO

AIMS: Circulating 25-hydroxyvitamin D (25OHD) levels <75 nmol/L are associated with a nonlinear increase in mortality risk. Such 25OHD levels are common in heart failure (HF). We therefore examined whether oral vitamin D supplementation reduces mortality in patients with advanced HF. METHODS AND RESULTS: Four hundred HF patients with 25OHD levels <75 nmol/L were randomized to receive 4000 IU vitamin D daily or matching placebo for 3 years. Primary endpoint was all-cause mortality. Key secondary outcome measures included hospitalization, resuscitation, mechanical circulatory support (MCS) implant, high urgent listing for heart transplantation, heart transplantation, and hypercalcaemia. Initial 25OHD levels were on average <40 nmol/L, remained around 40 nmol/L in patients assigned to placebo and plateaued around 100 nmol/L in patients assigned to vitamin D. Mortality was not different in patients receiving vitamin D (19.6%; n = 39) or placebo (17.9%; n = 36) with a hazard ratio (HR) of 1.09 [95% confidence interval (CI): 0.69-1.71; P = 0.726]. The need for MCS implant was however greater in patients assigned to vitamin D (15.4%, n = 28) vs. placebo [9.0%, n = 15; HR: 1.96 (95% CI: 1.04-3.66); P = 0.031]. Other secondary clinical endpoints were similar between groups. The incidence of hypercalcaemia was 6.2% (n = 10) and 3.1% (n = 5) in patients receiving vitamin D or placebo (P = 0.192). CONCLUSION: A daily vitamin D dose of 4000 IU did not reduce mortality in patients with advanced HF but was associated with a greater need for MCS implants. Data indicate caution regarding long-term supplementation with moderately high vitamin D doses. TRIAL REGISTRATION INFORMATION: clinicaltrials.gov Idenitfier: NCT01326650.


Assuntos
Insuficiência Cardíaca/dietoterapia , Vitamina D/administração & dosagem , Vitaminas/administração & dosagem , Cardiomiopatia Dilatada/complicações , Cardiomiopatia Dilatada/mortalidade , Causas de Morte , Suplementos Nutricionais , Feminino , Insuficiência Cardíaca/mortalidade , Transplante de Coração/mortalidade , Transplante de Coração/estatística & dados numéricos , Coração Auxiliar/estatística & dados numéricos , Hospitalização/estatística & dados numéricos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/complicações , Isquemia Miocárdica/mortalidade , Estudos Prospectivos , Fatores de Risco , Resultado do Tratamento , Vitamina D/análogos & derivados , Vitamina D/metabolismo , Deficiência de Vitamina D/dietoterapia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA