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2.
Transl Psychiatry ; 13(1): 121, 2023 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-37037832

RESUMO

Increasing lines of evidence suggest deviations from the normal early developmental trajectory could give rise to the onset of schizophrenia during adolescence and young adulthood, but few studies have investigated brain imaging changes associated with schizophrenia common variants in neonates. This study compared the brain volumes of both grey and white matter regions with schizophrenia polygenic risk scores (PRS) for 207 healthy term-born infants of European ancestry. Linear regression was used to estimate the relationship between PRS and brain volumes, with gestational age at birth, postmenstrual age at scan, ancestral principal components, sex and intracranial volumes as covariates. The schizophrenia PRS were negatively associated with the grey (ß = -0.08, p = 4.2 × 10-3) and white (ß = -0.13, p = 9.4 × 10-3) matter superior temporal gyrus volumes, white frontal lobe volume (ß = -0.09, p = 1.5 × 10-3) and the total white matter volume (ß = -0.062, p = 1.66 × 10-2). This result also remained robust when incorporating individuals of Asian ancestry. Explorative functional analysis of the schizophrenia risk variants associated with the right frontal lobe white matter volume found enrichment in neurodevelopmental pathways. This preliminary result suggests possible involvement of schizophrenia risk genes in early brain growth, and potential early life structural alterations long before the average age of onset of the disease.


Assuntos
Conectoma , Esquizofrenia , Recém-Nascido , Adolescente , Humanos , Lactente , Adulto Jovem , Adulto , Estudos Transversais , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/genética , Esquizofrenia/metabolismo , Imageamento por Ressonância Magnética/métodos , Encéfalo/metabolismo
3.
Transl Psychiatry ; 13(1): 108, 2023 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-37012252

RESUMO

Very preterm birth (VPT; ≤32 weeks' gestation) is associated with altered brain development and cognitive and behavioral difficulties across the lifespan. However, heterogeneity in outcomes among individuals born VPT makes it challenging to identify those most vulnerable to neurodevelopmental sequelae. Here, we aimed to stratify VPT children into distinct behavioral subgroups and explore between-subgroup differences in neonatal brain structure and function. 198 VPT children (98 females) previously enrolled in the Evaluation of Preterm Imaging Study (EudraCT 2009-011602-42) underwent Magnetic Resonance Imaging at term-equivalent age and neuropsychological assessments at 4-7 years. Using an integrative clustering approach, we combined neonatal socio-demographic, clinical factors and childhood socio-emotional and executive function outcomes, to identify distinct subgroups of children based on their similarity profiles in a multidimensional space. We characterized resultant subgroups using domain-specific outcomes (temperament, psychopathology, IQ and cognitively stimulating home environment) and explored between-subgroup differences in neonatal brain volumes (voxel-wise Tensor-Based-Morphometry), functional connectivity (voxel-wise degree centrality) and structural connectivity (Tract-Based-Spatial-Statistics). Results showed two- and three-cluster data-driven solutions. The two-cluster solution comprised a 'resilient' subgroup (lower psychopathology and higher IQ, executive function and socio-emotional scores) and an 'at-risk' subgroup (poorer behavioral and cognitive outcomes). No neuroimaging differences between the resilient and at-risk subgroups were found. The three-cluster solution showed an additional third 'intermediate' subgroup, displaying behavioral and cognitive outcomes intermediate between the resilient and at-risk subgroups. The resilient subgroup had the most cognitively stimulating home environment and the at-risk subgroup showed the highest neonatal clinical risk, while the intermediate subgroup showed the lowest clinical, but the highest socio-demographic risk. Compared to the intermediate subgroup, the resilient subgroup displayed larger neonatal insular and orbitofrontal volumes and stronger orbitofrontal functional connectivity, while the at-risk group showed widespread white matter microstructural alterations. These findings suggest that risk stratification following VPT birth is feasible and could be used translationally to guide personalized interventions aimed at promoting children's resilience.


Assuntos
Lactente Extremamente Prematuro , Nascimento Prematuro , Feminino , Humanos , Recém-Nascido , Criança , Nascimento Prematuro/diagnóstico por imagem , Nascimento Prematuro/patologia , Encéfalo/patologia , Imageamento por Ressonância Magnética/métodos , Idade Gestacional
4.
Front Neurosci ; 16: 886772, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35677357

RESUMO

The Developing Human Connectome Project has created a large open science resource which provides researchers with data for investigating typical and atypical brain development across the perinatal period. It has collected 1228 multimodal magnetic resonance imaging (MRI) brain datasets from 1173 fetal and/or neonatal participants, together with collateral demographic, clinical, family, neurocognitive and genomic data from 1173 participants, together with collateral demographic, clinical, family, neurocognitive and genomic data. All subjects were studied in utero and/or soon after birth on a single MRI scanner using specially developed scanning sequences which included novel motion-tolerant imaging methods. Imaging data are complemented by rich demographic, clinical, neurodevelopmental, and genomic information. The project is now releasing a large set of neonatal data; fetal data will be described and released separately. This release includes scans from 783 infants of whom: 583 were healthy infants born at term; as well as preterm infants; and infants at high risk of atypical neurocognitive development. Many infants were imaged more than once to provide longitudinal data, and the total number of datasets being released is 887. We now describe the dHCP image acquisition and processing protocols, summarize the available imaging and collateral data, and provide information on how the data can be accessed.

6.
JCI Insight ; 6(16)2021 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-34255744

RESUMO

The syndrome of spontaneous preterm birth (sPTB) presents a challenge to mechanistic understanding, effective risk stratification, and clinical management. Individual associations between sPTB, self-reported ethnic ancestry, vaginal microbiota, metabolome, and innate immune response are known but not fully understood, and knowledge has yet to impact clinical practice. Here, we used multi-data type integration and composite statistical models to gain insight into sPTB risk by exploring the cervicovaginal environment of an ethnically heterogenous pregnant population (n = 346 women; n = 60 sPTB < 37 weeks' gestation, including n = 27 sPTB < 34 weeks). Analysis of cervicovaginal samples (10-15+6 weeks) identified potentially novel interactions between risk of sPTB and microbiota, metabolite, and maternal host defense molecules. Statistical modeling identified a composite of metabolites (leucine, tyrosine, aspartate, lactate, betaine, acetate, and Ca2+) associated with risk of sPTB < 37 weeks (AUC 0.752). A combination of glucose, aspartate, Ca2+, Lactobacillus crispatus, and L. acidophilus relative abundance identified risk of early sPTB < 34 weeks (AUC 0.758), improved by stratification by ethnicity (AUC 0.835). Increased relative abundance of L. acidophilus appeared protective against sPTB < 34 weeks. By using cervicovaginal fluid samples, we demonstrate the potential of multi-data type integration for developing composite models toward understanding the contribution of the vaginal environment to risk of sPTB.


Assuntos
Colo do Útero/microbiologia , Microbiota/imunologia , Nascimento Prematuro/epidemiologia , Vagina/microbiologia , Adulto , Ácido Aspártico/metabolismo , Cálcio/metabolismo , Estudos de Casos e Controles , Feminino , Glucose/metabolismo , Humanos , Recém-Nascido , Lactobacillus acidophilus/imunologia , Lactobacillus acidophilus/metabolismo , Lactobacillus crispatus/imunologia , Lactobacillus crispatus/metabolismo , Estudos Longitudinais , Idade Materna , Metabolômica , Gravidez , Nascimento Prematuro/imunologia , Nascimento Prematuro/microbiologia , Estudos Prospectivos , Medição de Risco/métodos , Medição de Risco/estatística & dados numéricos , Reino Unido/epidemiologia
7.
Nat Commun ; 12(1): 3406, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099652

RESUMO

Prognostic characteristics inform risk stratification in intensive care unit (ICU) patients with coronavirus disease 2019 (COVID-19). We obtained blood samples (n = 474) from hospitalized COVID-19 patients (n = 123), non-COVID-19 ICU sepsis patients (n = 25) and healthy controls (n = 30). Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA was detected in plasma or serum (RNAemia) of COVID-19 ICU patients when neutralizing antibody response was low. RNAemia is associated with higher 28-day ICU mortality (hazard ratio [HR], 1.84 [95% CI, 1.22-2.77] adjusted for age and sex). RNAemia is comparable in performance to the best protein predictors. Mannose binding lectin 2 and pentraxin-3 (PTX3), two activators of the complement pathway of the innate immune system, are positively associated with mortality. Machine learning identified 'Age, RNAemia' and 'Age, PTX3' as the best binary signatures associated with 28-day ICU mortality. In longitudinal comparisons, COVID-19 ICU patients have a distinct proteomic trajectory associated with mortality, with recovery of many liver-derived proteins indicating survival. Finally, proteins of the complement system and galectin-3-binding protein (LGALS3BP) are identified as interaction partners of SARS-CoV-2 spike glycoprotein. LGALS3BP overexpression inhibits spike-pseudoparticle uptake and spike-induced cell-cell fusion in vitro.


Assuntos
COVID-19/prevenção & controle , Cuidados Críticos/estatística & dados numéricos , Proteômica/métodos , RNA Viral/genética , SARS-CoV-2/genética , Adulto , Animais , Anticorpos Neutralizantes/imunologia , Antígenos de Neoplasias/metabolismo , Biomarcadores Tumorais/metabolismo , Proteína C-Reativa/metabolismo , COVID-19/metabolismo , COVID-19/virologia , Feminino , Células HEK293 , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , RNA Viral/sangue , SARS-CoV-2/metabolismo , SARS-CoV-2/fisiologia , Componente Amiloide P Sérico/metabolismo , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Carga Viral/imunologia
8.
Sci Rep ; 11(1): 11443, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34075065

RESUMO

Preterm birth is an extreme environmental stress associated with an increased risk of later cognitive dysfunction and mental health problems. However, the extent to which preterm birth is modulated by genetic variation remains largely unclear. Here, we test for an interaction effect between psychiatric polygenic risk and gestational age at birth on cognition at age four. Our sample comprises 4934 unrelated individuals (2066 individuals born < 37 weeks, 918 born < = 34 weeks). Genome-wide polygenic scores (GPS's) were calculated for each individual for five different psychiatric pathologies: Schizophrenia, Bipolar Disorder, Major Depressive Disorder, Attention Deficit Hyperactivity Disorder and Autism Spectrum Disorder. Linear regression modelling was used to estimate the interaction effect between psychiatric GPS and gestational age at birth (GA) on cognitive outcome for the five psychiatric disorders. We found a significant interaction effect between Schizophrenia GPS and GA (ß = 0.038 ± 0.013, p = 6.85 × 10-3) and Bipolar Disorder GPS and GA (ß = 0.038 ± 0.014, p = 6.61 × 10-3) on cognitive outcome. Individuals with greater genetic risk for Schizophrenia or Bipolar Disorder are more vulnerable to the adverse effects of birth at early gestational age on brain development, as assessed by cognition at age four. Better understanding of gene-environment interactions will inform more effective risk-reducing interventions for this vulnerable population.


Assuntos
Idade Gestacional , Recém-Nascido Prematuro , Transtornos Mentais , Nascimento Prematuro , Gêmeos Dizigóticos , Gêmeos Monozigóticos , Adulto , Feminino , Estudo de Associação Genômica Ampla , Humanos , Masculino , Transtornos Mentais/epidemiologia , Transtornos Mentais/genética , Nascimento Prematuro/epidemiologia , Nascimento Prematuro/genética
9.
BMC Bioinformatics ; 19(1): 408, 2018 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-30404611

RESUMO

BACKGROUND: Towards discovering robust cancer biomarkers, it is imperative to unravel the cellular heterogeneity of patient samples and comprehend the interactions between cancer cells and the various cell types in the tumor microenvironment. The first generation of 'partial' computational deconvolution methods required prior information either on the cell/tissue type proportions or the cell/tissue type-specific expression signatures and the number of involved cell/tissue types. The second generation of 'complete' approaches allowed estimating both of the cell/tissue type proportions and cell/tissue type-specific expression profiles directly from the mixed gene expression data, based on known (or automatically identified) cell/tissue type-specific marker genes. RESULTS: We present Deblender, a flexible complete deconvolution tool operating in semi-/unsupervised mode based on the user's access to known marker gene lists and information about cell/tissue composition. In case of no prior knowledge, global gene expression variability is used in clustering the mixed data to substitute marker sets with cluster sets. In addition, we integrate a model selection criterion to predict the number of constituent cell/tissue types. Moreover, we provide a tailored algorithmic scheme to estimate mixture proportions for realistic experimental cases where the number of involved cell/tissue types exceeds the number of mixed samples. We assess the performance of Deblender and a set of state-of-the-art existing tools on a comprehensive set of benchmark and patient cancer mixture expression datasets (including TCGA). CONCLUSION: Our results corroborate that Deblender can be a valuable tool to improve understanding of gene expression datasets with implications for prediction and clinical utilization. Deblender is implemented in MATLAB and is available from ( https://github.com/kondim1983/Deblender/ ).


Assuntos
Biologia Computacional/métodos , Expressão Gênica/genética , Algoritmos , Humanos
10.
Sci Rep ; 7(1): 1089, 2017 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-28439082

RESUMO

We here examined whether Nestin, by protein and mRNA levels, could be a predictor of BRCA1 related breast cancer, a basal-like phenotype, and aggressive tumours. Immunohistochemical staining of Nestin was done in independent breast cancer hospital cohorts (Series I-V, total 1257 cases). Also, TCGA proteomic data (n = 103), mRNA microarray data from TCGA (n = 520), METABRIC (n = 1992), and 6 open access breast cancer datasets (n = 1908) were analysed. Patients with Nestin protein expression in tumour cells more often had BRCA1 germline mutations (OR 8.7, p < 0.0005, Series III), especially among younger patients (<40 years at diagnosis) (OR 16.5, p = 0.003). Nestin protein positivity, observed in 9-28% of our hospital cases (Series I-IV), was independently associated with reduced breast cancer specific survival (HR = 2.0, p = 0.035) and was consistently related to basal-like differentiation (by Cytokeratin 5, OR 8.7-13.8, p < 0.0005; P-cadherin OR 7.0-8.9, p < 0.0005; EGFR staining, OR 3.7-8.2, p ≤ 0.05). Nestin mRNA correlated significantly with Nestin protein expression (ρ = 0.6, p < 0.0005), and high levels were seen in the basal-like intrinsic subtype. Gene expression signalling pathways linked to high Nestin were explored, and revealed associations with stem-like tumour features. In summary, Nestin was strongly associated with germline BRCA1 related breast cancer, a basal-like phenotype, reduced survival, and stemness characteristics.


Assuntos
Proteína BRCA1/genética , Neoplasias da Mama/patologia , Expressão Gênica , Mutação , Nestina/biossíntese , RNA Mensageiro/biossíntese , Idoso , Feminino , Humanos , Imuno-Histoquímica , Análise em Microsséries , Pessoa de Meia-Idade , Nestina/genética , Fenótipo , Proteoma/análise , RNA Mensageiro/genética
11.
Bioinformatics ; 32(6): 884-92, 2016 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-26568631

RESUMO

MOTIVATION: In the era of network medicine and the rapid growth of paired time series mRNA/microRNA expression experiments, there is an urgent need for pathway enrichment analysis methods able to capture the time- and condition-specific 'active parts' of the biological circuitry as well as the microRNA impact. Current methods ignore the multiple dynamical 'themes'-in the form of enriched biologically relevant microRNA-mediated subpathways-that determine the functionality of signaling networks across time. RESULTS: To address these challenges, we developed time-vaRying enriCHment integrOmics Subpathway aNalysis tOol (CHRONOS) by integrating time series mRNA/microRNA expression data with KEGG pathway maps and microRNA-target interactions. Specifically, microRNA-mediated subpathway topologies are extracted and evaluated based on the temporal transition and the fold change activity of the linked genes/microRNAs. Further, we provide measures that capture the structural and functional features of subpathways in relation to the complete organism pathway atlas. Our application to synthetic and real data shows that CHRONOS outperforms current subpathway-based methods into unraveling the inherent dynamic properties of pathways. AVAILABILITY AND IMPLEMENTATION: CHRONOS is freely available at http://biosignal.med.upatras.gr/chronos/ CONTACT: tassos.bezerianos@nus.edu.sg SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
MicroRNAs/genética , Transdução de Sinais
12.
BMC Genomics ; 16: 147, 2015 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-25887273

RESUMO

BACKGROUND: The avalanche of integromics and panomics approaches shifted the deciphering of aging mechanisms from single molecular entities to communities of them. In this orientation, we explore the cardiac aging mechanisms - risk factor for multiple cardiovascular diseases - by capturing the micronome synergism and detecting longevity signatures in the form of communities (modules). For this, we developed a meta-analysis scheme that integrates transcriptome expression data from multiple cardiac-specific independent studies in mouse and human along with proteome and micronome interaction data in the form of multiple independent weighted networks. Modularization of each weighted network produced modules, which in turn were further analyzed so as to define consensus modules across datasets that change substantially during lifespan. Also, we established a metric that determines - from the modular perspective - the synergism of microRNA-microRNA interactions as defined by significantly functionally associated targets. RESULTS: The meta-analysis provided 40 consensus integromics modules across mouse datasets and revealed microRNA relations with substantial collective action during aging. Three modules were reproducible, based on homology, when mapped against human-derived modules. The respective homologs mainly represent NADH dehydrogenases, ATP synthases, cytochrome oxidases, Ras GTPases and ribosomal proteins. Among various observations, we corroborate to the involvement of miR-34a (included in consensus modules) as proposed recently; yet we report that has no synergistic effect. Moving forward, we determined its age-related neighborhood in which HCN3, a known heart pacemaker channel, was included. Also, miR-125a-5p/-351, miR-200c/-429, miR-106b/-17, miR-363/-92b, miR-181b/-181d, miR-19a/-19b, let-7d/-7f, miR-18a/-18b, miR-128/-27b and miR-106a/-291a-3p pairs exhibited significant synergy and their association to aging and/or cardiovascular diseases is supported in many cases by a disease database and previous studies. On the contrary, we suggest that miR-22 has not substantial impact on heart longevity as proposed recently. CONCLUSIONS: We revised several proteins and microRNAs recently implicated in cardiac aging and proposed for the first time modules as signatures. The integromics meta-analysis approach can serve as an efficient subvening signature tool for more-oriented better-designed experiments. It can also promote the combinational multi-target microRNA therapy of age-related cardiovascular diseases along the continuum from prevention to detection, diagnosis, treatment and outcome.


Assuntos
Envelhecimento/genética , Doenças Cardiovasculares/genética , MicroRNAs/genética , Transcriptoma/genética , Envelhecimento/patologia , Animais , Doenças Cardiovasculares/patologia , Redes Reguladoras de Genes , Coração/fisiopatologia , Humanos , Camundongos
13.
OMICS ; 18(3): 167-83, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24512282

RESUMO

Towards unraveling the influenza A (H1N1) immunome, this work aims at constructing the murine host response pathway interactome. To accomplish that, an ensemble of dynamic and time-varying Gene Regulatory Network Inference methodologies was recruited to set a confident interactome based on mouse time series transcriptome data (day 1-day 60). The proposed H1N1 interactome demonstrated significant transformations among activated and suppressed pathways in time. Enhanced interplay was observed at day 1, while the maximal network complexity was reached at day 8 (correlated with viral clearance and iBALT tissue formation) and one interaction was present at day 40. Next, we searched for common interactivity features between the murine-adapted PR8 strain and other influenza A subtypes/strains. For this, two other interactomes, describing the murine host response against H5N1 and H1N1pdm, were constructed, which in turn validated many of the observed interactions (in the period day 1-day 7). The H1N1 interactome revealed the role of cell cycle both in innate and adaptive immunity (day 1-day 14). Also, pathogen sensory pathways (e.g., RIG-I) displayed long-lasting association with cytokine/chemokine signaling (until day 8). Interestingly, the above observations were also supported by the H5N1 and H1N1pdm models. It also elucidated the enhanced coupling of the activated innate pathways with the suppressed PPAR signaling to keep low inflammation until viral clearance (until day 14). Further, it showed that interactions reflecting phagocytosis processes continued long after the viral clearance and the establishment of adaptive immunity (day 8-day 40). Additionally, interactions involving B cell receptor pathway were evident since day 1. These results collectively inform the emerging field of public health omics and future clinical studies aimed at deciphering dynamic host responses to infectious agents.


Assuntos
Genômica , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Vírus da Influenza A Subtipo H1N1/imunologia , Infecções por Orthomyxoviridae/genética , Infecções por Orthomyxoviridae/imunologia , Animais , Análise por Conglomerados , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Virus da Influenza A Subtipo H5N1/imunologia , Camundongos , Infecções por Orthomyxoviridae/metabolismo , Transdução de Sinais , Fatores de Tempo , Transcriptoma
14.
OMICS ; 18(1): 15-33, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24299457

RESUMO

Recent advances in pharmacogenomics technologies allow bold steps to be taken towards personalized medicine, more accurate health planning, and personalized drug development. In this framework, systems pharmacology network-based approaches offer an appealing way for integrating multi-omics data and set the basis for defining systems-level drug response biomarkers. On the road to individualized tamoxifen treatment in estrogen receptor-positive breast cancer patients, we examine the dynamics of the attendant pharmacological response mechanisms. By means of an "integromics" network approach, we assessed the tamoxifen effect through the way the high-order organization of interactome (i.e., the modules) is perturbed. To accomplish that, first we integrated the time series transcriptome data with the human protein interaction data, and second, an efficient module-detecting algorithm was applied onto the composite graphs. Our findings show that tamoxifen induces severe modular transformations on specific areas of the interactome. Our modular biomarkers in response to tamoxifen attest to the immunomodulatory role of tamoxifen, and further reveal that it deregulates cell cycle and apoptosis pathways, while coordinating the proteasome and basal transcription factors. To the best of our knowledge, this is the first report that informs the fields of personalized medicine and clinical pharmacology about the actual dynamic interactome response to tamoxifen administration.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/genética , Farmacogenética , Medicina de Precisão , Tamoxifeno/uso terapêutico , Transcriptoma , Algoritmos , Apoptose/genética , Biomarcadores Farmacológicos/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Ciclo Celular/genética , Feminino , Redes Reguladoras de Genes/efeitos dos fármacos , Humanos , Complexo de Endopeptidases do Proteassoma/metabolismo , Mapeamento de Interação de Proteínas , Fatores de Transcrição/genética
15.
Artigo em Inglês | MEDLINE | ID: mdl-25569961

RESUMO

MicroRNAs play an important role in regulation of gene expression, but still detection of their targets remains a challenge. In this work we present a supervised regulatory network inference method with aim to identify potential target genes (mRNAs) of microRNAs. Briefly, the proposed method exploiting mRNA and microRNA expression trains Random Forests on known interactions and subsequently it is able to predict novel ones. In parallel, we incorporate different available data sources, such as Gene Ontology and ProteinProtein Interactions, to deliver biologically consistent results. Application in both benchmark data and an experiment studying aging showed robust performance.


Assuntos
Envelhecimento , Coração/fisiologia , MicroRNAs/fisiologia , RNA Mensageiro/metabolismo , Algoritmos , Área Sob a Curva , Biologia Computacional , Perfilação da Expressão Gênica/métodos , Ontologia Genética , Humanos , Modelos Biológicos , Mapeamento de Interação de Proteínas , Interferência de RNA , RNA Mensageiro/genética
16.
Comput Methods Programs Biomed ; 111(3): 650-61, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23796450

RESUMO

The increasing flow of short time series microarray experiments for the study of dynamic cellular processes poses the need for efficient clustering tools. These tools must deal with three primary issues: first, to consider the multi-functionality of genes; second, to evaluate the similarity of the relative change of amplitude in the time domain rather than the absolute values; third, to cope with the constraints of conventional clustering algorithms such as the assignment of the appropriate cluster number. To address these, we propose OLYMPUS, a novel unsupervised clustering algorithm that integrates Differential Evolution (DE) method into Fuzzy Short Time Series (FSTS) algorithm with the scope to utilize efficiently the information of population of the first and enhance the performance of the latter. Our hybrid approach provides sets of genes that enable the deciphering of distinct phases in dynamic cellular processes. We proved the efficiency of OLYMPUS on synthetic as well as on experimental data. The discriminative power of OLYMPUS provided clusters, which refined the so far perspective of the dynamics of host response mechanisms to Influenza A (H1N1). Our kinetic model sets a timeline for several pathways and cell populations, implicated to participate in host response; yet no timeline was assigned to them (e.g. cell cycle, homeostasis). Regarding the activity of B cells, our approach revealed that some antibody-related mechanisms remain activated until day 60 post infection. The Matlab codes for implementing OLYMPUS, as well as example datasets, are freely accessible via the Web (http://biosignal.med.upatras.gr/wordpress/biosignal/).


Assuntos
Automação , Regulação Viral da Expressão Gênica , Interações Hospedeiro-Patógeno , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/virologia , Algoritmos , Ciclo Celular , Lógica Fuzzy , Homeostase , Humanos , Imunidade Inata , Influenza Humana/imunologia
17.
Artigo em Inglês | MEDLINE | ID: mdl-23366123

RESUMO

Regulome is the dynamic network representation of the regulatory interplay among genes, proteins and other cellular components that control cellular processes. Reconstruction of gene regulatory networks (GRN) delineates one of the main objectives of Systems Biology towards understanding the organization of regulome. Significant progress has been reported the last years regarding GRN reconstruction methods, but the majority of them either consider information originating solely from gene expression data or/and are applied on a small fraction of the experimental dataset. In this paper, we will describe an integrative method, utilizing both temporal information arriving from time-series gene expression profiles, as well as topological properties of protein networks. The proposed methodology detects relations among either groups of genes or specific genes depending on the level of abstraction or resolution requested. Application on real data proved the ability of the method to extract relations in accordance with current biological knowledge as well as discriminate between different experimental conditions.


Assuntos
Bases de Dados Genéticas , Redes Reguladoras de Genes , Modelos Genéticos , Biologia de Sistemas/métodos , Algoritmos , Células Sanguíneas/fisiologia , Fibrose Cística/sangue , Fibrose Cística/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Interferon beta/genética , Mapas de Interação de Proteínas
18.
Artigo em Inglês | MEDLINE | ID: mdl-23367158

RESUMO

A major challenge in modern breast cancer treatment is to unravel the effect of drug activity through the systematic rewiring of cellular networks over time. Here, we illustrate the efficacy and discriminative power of our integrative approach in detecting modules that represent the regulatory effect of tamoxifen, widely used in anti-estrogen treatment, on transcriptome and proteome and serve as dynamic sub-network signatures. Initially, composite networks, after integrating protein interaction and time series gene expression data between two conditions (estradiol and estradiol plus tamoxifen), were constructed. Further, the Detect Module from Seed Protein (DMSP) algorithm elaborated on the graphs and constructed modules, with specific 'seed' proteins used as starting points. Our findings provide evidence about the way drugs perturb and rewire the high-order organization of interactome in time.


Assuntos
Neoplasias da Mama/patologia , Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Feminino , Humanos , Proteoma , Tamoxifeno/uso terapêutico , Transcriptoma
19.
J Clin Bioinforma ; 1: 27, 2011 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-22017961

RESUMO

BACKGROUND: The immune response to viral infection is a temporal process, represented by a dynamic and complex network of gene and protein interactions. Here, we present a reverse engineering strategy aimed at capturing the temporal evolution of the underlying Gene Regulatory Networks (GRN). The proposed approach will be an enabling step towards comprehending the dynamic behavior of gene regulation circuitry and mapping the network structure transitions in response to pathogen stimuli. RESULTS: We applied the Time Varying Dynamic Bayesian Network (TV-DBN) method for reconstructing the gene regulatory interactions based on time series gene expression data for the mouse C57BL/6J inbred strain after infection with influenza A H1N1 (PR8) virus. Initially, 3500 differentially expressed genes were clustered with the use of k-means algorithm. Next, the successive in time GRNs were built over the expression profiles of cluster centroids. Finally, the identified GRNs were examined with several topological metrics and available protein-protein and protein-DNA interaction data, transcription factor and KEGG pathway data. CONCLUSIONS: Our results elucidate the potential of TV-DBN approach in providing valuable insights into the temporal rewiring of the lung transcriptome in response to H1N1 virus.

20.
BMC Syst Biol ; 2: 93, 2008 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-18976494

RESUMO

BACKGROUND: The ever-increasing flow of gene expression and protein-protein interaction (PPI) data has assisted in understanding the dynamics of the cell. The detection of functional modules is the first step in deciphering the apparent modularity of biological networks. However, most network-partitioning algorithms consider only the topological aspects and ignore the underlying functional relationships. RESULTS: In the current study we integrate proteomics and microarray data of yeast, in the form of a weighted PPI graph. We partition the enriched PPI network with the novel DetMod algorithm and we identify 335 modules. One of the main advantages of DetMod is that it manages to capture the inter-module cross-talk by allowing a controlled degree of overlap among the detected modules. The obtained modules are densely connected in terms of protein interactions, while their members share up to a high degree similar biological process GO terms.Moreover, known protein complexes are largely incorporated in the assessed modules. Finally, we display the prevalence of our method against modules resulting from other computational approaches. CONCLUSION: The successful integration of heterogeneous data and the concept of the proposed algorithm provide confident functional modules. We also proved that our approach is superior to methods restricted to PPI data only.


Assuntos
Biologia Computacional , Análise de Sequência com Séries de Oligonucleotídeos , Proteômica , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Algoritmos , Perfilação da Expressão Gênica , Ligação Proteica , Reprodutibilidade dos Testes
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