Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Alzheimers Dement ; 17(9): 1509-1527, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33797837

RESUMO

INTRODUCTION: Genome-wide association studies have led to numerous genetic loci associated with Alzheimer's disease (AD). Whole-genome sequencing (WGS) now permits genome-wide analyses to identify rare variants contributing to AD risk. METHODS: We performed single-variant and spatial clustering-based testing on rare variants (minor allele frequency [MAF] ≤1%) in a family-based WGS-based association study of 2247 subjects from 605 multiplex AD families, followed by replication in 1669 unrelated individuals. RESULTS: We identified 13 new AD candidate loci that yielded consistent rare-variant signals in discovery and replication cohorts (4 from single-variant, 9 from spatial-clustering), implicating these genes: FNBP1L, SEL1L, LINC00298, PRKCH, C15ORF41, C2CD3, KIF2A, APC, LHX9, NALCN, CTNNA2, SYTL3, and CLSTN2. DISCUSSION: Downstream analyses of these novel loci highlight synaptic function, in contrast to common AD-associated variants, which implicate innate immunity and amyloid processing. These loci have not been associated previously with AD, emphasizing the ability of WGS to identify AD-associated rare variants, particularly outside of the exome.


Assuntos
Doença de Alzheimer/genética , Frequência do Gene/genética , Predisposição Genética para Doença , Sequenciamento Completo do Genoma , Estudo de Associação Genômica Ampla , Humanos , Canais Iônicos/genética , Cinesinas/genética , Proteínas de Membrana/genética , Proteínas Associadas aos Microtúbulos/genética , Proteínas/genética
2.
Ann Neurol ; 85(6): 835-851, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30990912

RESUMO

OBJECTIVE: MicroRNA (miRNA)-mediated (dys)regulation of gene expression has been implicated in Parkinson's disease (PD), although results of miRNA expression studies remain inconclusive. We aimed to identify miRNAs that show consistent differential expression across all published expression studies in PD. METHODS: We performed a systematic literature search on miRNA expression studies in PD and extracted data from eligible publications. After stratification for brain, blood, and cerebrospinal fluid (CSF)-derived specimen, we performed meta-analyses across miRNAs assessed in three or more independent data sets. Meta-analyses were performed using effect-size- and p-value-based methods, as applicable. RESULTS: After screening 599 publications, we identified 47 data sets eligible for meta-analysis. On these, we performed 160 meta-analyses on miRNAs quantified in brain (n = 125), blood (n = 31), or CSF (n = 4). Twenty-one meta-analyses were performed using effect sizes. We identified 13 significantly (Bonferroni-adjusted α = 3.13 × 10-4 ) differentially expressed miRNAs in brain (n = 3) and blood (n = 10) with consistent effect directions across studies. The most compelling findings were with hsa-miR-132-3p (p = 6.37 × 10-5 ), hsa-miR-497-5p (p = 1.35 × 10-4 ), and hsa-miR-133b (p = 1.90 × 10-4 ) in brain and with hsa-miR-221-3p (p = 4.49 × 10-35 ), hsa-miR-214-3p (p = 2.00 × 10-34 ), and hsa-miR-29c-3p (p = 3.00 × 10-12 ) in blood. No significant signals were found in CSF. Analyses of genome-wide association study data for target genes of brain miRNAs showed significant association (α = 9.40 × 10-5 ) of genetic variants in nine loci. INTERPRETATION: We identified several miRNAs that showed highly significant differential expression in PD. Future studies may assess the possible role of the identified brain miRNAs in pathogenesis and disease progression as well as the potential of the top blood miRNAs as biomarkers for diagnosis, progression, or prediction of PD. ANN NEUROL 2019;85:835-851.


Assuntos
Perfilação da Expressão Gênica/métodos , Estudo de Associação Genômica Ampla/métodos , MicroRNAs/genética , Doença de Parkinson/genética , Humanos , MicroRNAs/biossíntese , Doença de Parkinson/diagnóstico , Doença de Parkinson/epidemiologia
3.
Alzheimers Dement ; 15(11): 1468-1477, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31495604

RESUMO

INTRODUCTION: Several microRNAs (miRNAs) have been implicated in Alzheimer's disease pathogenesis, but the evidence from individual case-control studies remains inconclusive. METHODS: A systematic literature review was performed, followed by standardized multistage data extraction, quality control, and meta-analyses on eligible data for brain, blood, and cerebrospinal fluid specimens. Results were compared with miRNAs reported in the abstracts of eligible studies or recent qualitative reviews to assess novelty. RESULTS: Data from 147 independent data sets across 107 publications were quantitatively assessed in 461 meta-analyses. Twenty-five, five, and 32 miRNAs showed studywide significant differential expression (α < 1·08 × 10-4) in brain, cerebrospinal fluid, and blood-derived specimens, respectively, with 5 miRNAs showing differential expression in both brain and blood. Of these 57 miRNAs, 13 had not been reported in the abstracts of previous original or review articles. DISCUSSION: Our systematic assessment of differential miRNA expression is the first of its kind in Alzheimer's disease and highlights several miRNAs of potential relevance.


Assuntos
Doença de Alzheimer/genética , Doença de Alzheimer/fisiopatologia , Biomarcadores/líquido cefalorraquidiano , MicroRNAs/genética , Doença de Alzheimer/sangue , Doença de Alzheimer/líquido cefalorraquidiano , Encéfalo/patologia , Estudos de Casos e Controles , Epigenômica , Humanos
4.
J Autoimmun ; 94: 83-89, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30143393

RESUMO

Genome-wide association studies (GWAS) have identified a large number of genetic risk loci for autoimmune diseases. However, the functional variants underlying these disease associations remain largely unknown. There is evidence that microRNA-mediated regulation may play an important role in this context. Therefore, we assessed whether autoimmune disease loci unfold their effects via altering microRNA expression in relevant immune cells. To this end, we performed comprehensive data integration of many large and publicly available datasets to combine information on autoimmune disease risk loci with RNA-Seq-based microRNA expression data. Specifically, we carried out microRNA expression quantitative trait loci (eQTL) analyses across 115 GWAS regions associated with 12 autoimmune diseases using next-generation sequencing data of 345 lymphoblastoid cell lines. Statistical analyses included the application and extension of a recently proposed framework (joint likelihood mapping) to microRNA expression data and microRNA target gene enrichment analyses of relevant GWAS data. Overall, only a minority of autoimmune disease risk loci may exert their pathophysiologic effects by altering microRNA expression based on JLIM. However, detailed functional fine-mapping revealed two independent GWAS regions harboring autoimmune disease risk SNPs with significant effects on microRNA expression. These relate to SNPs associated with Crohn's disease (CD; rs102275) and rheumatoid arthritis (RA; rs968567), which affect the expression of miR-1908-5p (prs102275 = 1.44e-20, prs968567 = 2.54e-14). In addition, an independent CD risk SNP, rs3853824, was found to alter the expression of miR-3614-5p (p = 5.70e-7). To support these findings, we demonstrate that GWAS signals for RA and CD were enriched in genes predicted to be targeted by both microRNAs (all with p < 0.05). In summary, our study points towards a potential pathophysiological role of miR-1908-5p and miR-3614-5p in autoimmunity.


Assuntos
Artrite Reumatoide/genética , Doença de Crohn/genética , Linfócitos/imunologia , MicroRNAs/genética , Artrite Reumatoide/diagnóstico , Artrite Reumatoide/imunologia , Artrite Reumatoide/patologia , Linhagem Celular , Biologia Computacional/métodos , Doença de Crohn/diagnóstico , Doença de Crohn/imunologia , Doença de Crohn/patologia , Conjuntos de Dados como Assunto , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Estudo de Associação Genômica Ampla , Projeto HapMap , Humanos , Linfócitos/patologia , MicroRNAs/imunologia , Locos de Características Quantitativas , Risco
5.
Int J Cancer ; 138(1): 121-4, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26199174

RESUMO

The pathogenesis of T-cell large granular lymphocytic leukemia (T-LGL) is poorly understood, as STAT3 mutations are the only known frequent genetic lesions. Here, we identified non-synonymous alterations in the TNFAIP3 tumor suppressor gene in 3 of 39 T-LGL. In two cases these were somatic mutations, in one case the somatic origin was likely. A further case harbored a SNP that is a known risk allele for autoimmune diseases and B cell lymphomas. Thus, TNFAIP3 mutations represent recurrent genetic lesions in T-LGL that affect about 8% of cases, likely contributing to deregulated NF-κB activity in this leukemia.


Assuntos
Proteínas de Ligação a DNA/genética , Variação Genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Leucemia Linfocítica Granular Grande/genética , Proteínas Nucleares/genética , Estudos de Coortes , Variações do Número de Cópias de DNA , Proteínas de Ligação a DNA/metabolismo , Éxons , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Leucemia Linfocítica Granular Grande/metabolismo , Leucemia Linfocítica Granular Grande/patologia , Mutação , Proteínas Nucleares/metabolismo , Polimorfismo de Nucleotídeo Único , Fator de Transcrição STAT3/genética , Análise de Sequência de DNA , Proteína 3 Induzida por Fator de Necrose Tumoral alfa
6.
J Med Genet ; 52(12): 848-55, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26475045

RESUMO

OBJECTIVE: A recent large-scale study in multiple sclerosis (MS) using the ImmunoChip platform reported on 11 loci that showed suggestive genetic association with MS. Additional data in sufficiently sized and independent data sets are needed to assess whether these loci represent genuine MS risk factors. METHODS: The lead SNPs of all 11 loci were genotyped in 10 796 MS cases and 10 793 controls from Germany, Spain, France, the Netherlands, Austria and Russia, that were independent from the previously reported cohorts. Association analyses were performed using logistic regression based on an additive model. Summary effect size estimates were calculated using fixed-effect meta-analysis. RESULTS: Seven of the 11 tested SNPs showed significant association with MS susceptibility in the 21 589 individuals analysed here. Meta-analysis across our and previously published MS case-control data (total sample size n=101 683) revealed novel genome-wide significant association with MS susceptibility (p<5×10(-8)) for all seven variants. This included SNPs in or near LOC100506457 (rs1534422, p=4.03×10(-12)), CD28 (rs6435203, p=1.35×10(-9)), LPP (rs4686953, p=3.35×10(-8)), ETS1 (rs3809006, p=7.74×10(-9)), DLEU1 (rs806349, p=8.14×10(-12)), LPIN3 (rs6072343, p=7.16×10(-12)) and IFNGR2 (rs9808753, p=4.40×10(-10)). Cis expression quantitative locus effects were observed in silico for rs6435203 on CD28 and for rs9808753 on several immunologically relevant genes in the IFNGR2 locus. CONCLUSIONS: This study adds seven loci to the list of genuine MS genetic risk factors and further extends the list of established loci shared across autoimmune diseases.


Assuntos
Esclerose Múltipla/genética , Estudos de Casos e Controles , Frequência do Gene , Loci Gênicos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Polimorfismo de Nucleotídeo Único , Fatores de Risco
8.
Nucleic Acids Res ; 40(Web Server issue): W303-9, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22553365

RESUMO

CSA is a web server for the computation, evaluation and comprehensive comparison of pairwise protein structure alignments. Its exact alignment engine computes either optimal, top-scoring alignments or heuristic alignments with quality guarantee for the inter-residue distance-based scorings of contact map overlap, PAUL, DALI and MATRAS. These and additional, uploaded alignments are compared using a number of quality measures and intuitive visualizations. CSA brings new insight into the structural relationship of the protein pairs under investigation and is a valuable tool for studying structural similarities. It is available at http://csa.project.cwi.nl.


Assuntos
Software , Homologia Estrutural de Proteína , Algoritmos , Calmodulina/química , Internet
9.
BMC Bioinformatics ; 14 Suppl 15: S18, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24564758

RESUMO

BACKGROUND: We study the problem of mapping proteins between two protein families in the presence of paralogs. This problem occurs as a difficult subproblem in coevolution-based computational approaches for protein-protein interaction prediction. RESULTS: Similar to prior approaches, our method is based on the idea that coevolution implies equal rates of sequence evolution among the interacting proteins, and we provide a first attempt to quantify this notion in a formal statistical manner. We call the units that are central to this quantification scheme the units of coevolution. A unit consists of two mapped protein pairs and its score quantifies the coevolution of the pairs. This quantification allows us to provide a maximum likelihood formulation of the paralog mapping problem and to cast it into a binary quadratic programming formulation. CONCLUSION: CUPID, our software tool based on a Lagrangian relaxation of this formulation, makes it, for the first time, possible to compute state-of-the-art quality pairings in a few minutes of runtime. In summary, we suggest a novel alternative to the earlier available approaches, which is statistically sound and computationally feasible.


Assuntos
Proteínas/análise , Software , Sequência de Aminoácidos , Dados de Sequência Molecular , Proteínas/química , Alinhamento de Sequência , Análise de Sequência de Proteína
11.
Sci Rep ; 13(1): 20517, 2023 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-37993469

RESUMO

Diabetes mellitus (DM) represents a major health problem in Egypt and worldwide, with increasing numbers of patients with prediabetes every year. Numerous factors, such as obesity, hyperlipidemia, and hypertension, which have recently become serious concerns, affect the complex pathophysiology of diabetes. These metabolic syndrome diseases are highly linked to genetic variability that drives certain populations, such as Egypt, to be more susceptible to developing DM. Here we conduct a comprehensive analysis to pinpoint the similarities and uniqueness among the Egyptian genome reference and the 1000-genome subpopulations (Europeans, Ad-Mixed Americans, South Asians, East Asians, and Africans), aiming at defining the potential genetic risk of metabolic syndromes. Selected approaches incorporated the analysis of the allele frequency of the different populations' variations, supported by genotypes' principal component analysis. Results show that the Egyptian's reference metabolic genes were clustered together with the Europeans', Ad-Mixed Americans', and South-Asians'. Additionally, 8563 variants were uniquely identified in the Egyptian cohort, from those, two were predicted to cause structural damage, namely, CDKAL1: 6_21065070 (A > T) and PPARG: 3_12351660 (C > T) utilizing the Missense3D database. The former is a protein coding gene associated with Type 2 DM while the latter is a key regulator of adipocyte differentiation and glucose homeostasis. Both variants were detected heterozygous in two different Egyptian individuals from overall 110 sample. This analysis sheds light on the unique genetic traits of the Egyptian population that play a role in the DM high prevalence in Egypt. The proposed analysis pipeline -available through GitHub- could be used to conduct similar analysis for other diseases across populations.


Assuntos
Síndrome Metabólica , Humanos , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/genética , Egito/epidemiologia , Frequência do Gene , Fatores de Risco , Genótipo , Polimorfismo de Nucleotídeo Único
12.
J Adv Res ; 54: 59-76, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-36736695

RESUMO

INTRODUCTION: Mitochondria are maternally inherited cell organelles with their own genome, and perform various functions in eukaryotic cells such as energy production and cellular homeostasis. Due to their inheritance and manifold biological roles in health and disease, mitochondrial genetics serves a dual purpose of tracing the history as well as disease susceptibility of human populations across the globe. This work requires a comprehensive catalogue of commonly observed genetic variations in the mitochondrial DNAs for all regions throughout the world. So far, however, certain regions, such as North and East Africa have been understudied. OBJECTIVES: To address this shortcoming, we have created the most comprehensive quality-controlled North and East African mitochondrial data set to date and use it for characterizing mitochondrial genetic variation in this region. METHODS: We compiled 11 published cohorts with novel data for mitochondrial genomes from 159 Sudanese individuals. We combined these 641 mitochondrial sequences with sequences from the 1000 Genomes (n = 2504) and the Human Genome Diversity Project (n = 828) and used the tool haplocheck for extensive quality control and detection of in-sample contamination, as well as Nanopore long read sequencing for haplogroup validation of 18 samples. RESULTS: Using a subset of high-coverage mitochondrial sequences, we predict 15 potentially novel haplogroups in North and East African subjects and observe likely phylogenetic deviations from the established PhyloTree reference for haplogroups L0a1 and L2a1. CONCLUSION: Our findings demonstrate common hitherto unexplored variants in mitochondrial genomes of North and East Africa that lead to novel phylogenetic relationships between haplogroups present in these regions. These observations call for further in-depth population genetic studies in that region to enable the prospective use of mitochondrial genetic variation for precision medicine.


Assuntos
DNA Mitocondrial , População da África Oriental , População do Norte da África , Humanos , DNA Mitocondrial/genética , População da África Oriental/genética , Variação Genética/genética , Haplótipos , Filogenia , Medicina de Precisão , Análise de Sequência de DNA , População do Norte da África/genética
13.
Microbiome ; 11(1): 232, 2023 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-37864204

RESUMO

BACKGROUND: Like its human counterpart, canine atopic dermatitis (cAD) is a chronic relapsing condition; thus, most cAD-affected dogs will require lifelong treatment to maintain an acceptable quality of life. A potential intervention is modulation of the composition of gut microbiota, and in fact, probiotic treatment has been proposed and tried in human atopic dermatitis (AD) patients. Since dogs are currently receiving intensive medical care, this will be the same option for dogs, while evidence of gut dysbiosis in cAD is still missing, although skin microbial profiling in cAD has been conducted in several studies. Therefore, we conducted a comprehensive analysis of both gut and skin microbiota in cAD in one specific cAD-predisposed breed, Shiba Inu. Additionally, we evaluated the impact of commonly used medical management on cAD (Janus kinase; JAK inhibitor, oclacitinib) on the gut and skin microbiota. Furthermore, we genotyped the Shiba Inu dogs according to the mitochondrial DNA haplogroup and assessed its association with the composition of the gut microbiota. RESULTS: Staphylococcus was the most predominant bacterial genus observed in the skin; Escherichia/Shigella and Clostridium sensu stricto were highly abundant in the gut of cAD-affected dogs. In the gut microbiota, Fusobacteria and Megamonas were highly abundant in healthy dogs but significantly reduced in cAD-affected dogs. The abundance of these bacterial taxa was positively correlated with the effect of the treatment and state of the disease. Oclacitinib treatment on cAD-affected dogs shifted the composition of microbiota towards that in healthy dogs, and the latter brought it much closer to healthy microbiota, particularly in the gut. Additionally, even within the same dog breed, the mtDNA haplogroup varied, and there was an association between the mtDNA haplogroup and microbial composition in the gut and skin. CONCLUSIONS: Dysbiosis of both the skin and the gut was observed in cAD in Shiba Inu dogs. Our findings provide a basis for the potential treatment of cAD by manipulating the gut microbiota as well as the skin microbiota. Video Abstract.


Assuntos
Dermatite Atópica , Microbiota , Cães , Humanos , Animais , Dermatite Atópica/veterinária , Dermatite Atópica/microbiologia , Disbiose , Qualidade de Vida , Bactérias , DNA Mitocondrial
14.
Front Immunol ; 13: 972107, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35990650

RESUMO

Autoimmune diseases share a general mechanism of auto-antigens harming tissues. Still. they are phenotypically diverse, with genetic as well as environmental factors contributing to their etiology at varying degrees. Associated genomic loci and variants have been identified in numerous genome-wide association studies (GWAS), whose results are increasingly used for polygenic scores (PGS) that are used to predict disease risk. At the same time, a technological shift from genotyping arrays to next generation sequencing (NGS) is ongoing. NGS allows the identification of virtually all - including rare - genetic variants, which in combination with methodological developments promises to improve the prediction of disease risk and elucidate molecular mechanisms underlying disease. Here we review current, publicly available autoimmune disease GWAS and PGS data based on information from the GWAS and PGS catalog, respectively. We summarize autoimmune diseases investigated, respective studies conducted and their results. Further, we review genetic data and autoimmune disease patients in the UK Biobank (UKB), the largest resource for genetic and phenotypic data available for academic research. We find that only comparably prevalent autoimmune diseases are covered by the UKB and at the same time assessed by both GWAS and PGS catalogs. These are systemic (systemic lupus erythematosus) as well as organ-specific, affecting the gastrointestinal tract (inflammatory bowel disease as well as specifically Crohn's disease and ulcerative colitis), joints (juvenile ideopathic arthritis, psoriatic arthritis, rheumatoid arthritis, ankylosing spondylitis), glands (Sjögren syndrome), the nervous system (multiple sclerosis), and the skin (vitiligo).


Assuntos
Doenças Autoimunes , Estudo de Associação Genômica Ampla , Doenças Autoimunes/genética , Bancos de Espécimes Biológicos , Predisposição Genética para Doença , Humanos , Reino Unido
15.
Front Immunol ; 13: 960068, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36211394

RESUMO

Glomerulonephritis (GN) is a complex disease with intricate underlying pathogenic mechanisms. The possible role of underlying complement dysregulation is not fully elucidated in some GN subsets, especially in the setting of autoimmunity or infection. In the current study, diagnosed cases of lupus nephritis (LN) and post-infectious GN (PIGN) were recruited for molecular genetic analysis and targeted next-generation DNA sequencing was performed for two main complement regulating genes: in the fluid phase; CFH, and on tissue surfaces; MCP. Three heterozygous pathogenic variants in CFH (Q172*, W701*, and W1096*) and one likely pathogenic heterozygous variant in MCP (C223R) have been identified in four of the studied LN cases. Additionally, among the several detected variants of uncertain significance, one novel variant (CFH:F614S) was identified in 74% of the studied LN cases and in 65% of the studied PIGN cases. This variant was detected for the first time in the Egyptian population. These findings suggest that subtle mutations may be present in complement regulating genes in patients with immune-complex mediated category of GN that may add to the disease pathogenesis. These findings also call for further studies to delineate the impact of these gene variants on the protein function, the disease course, and outcome.


Assuntos
Glomerulonefrite , Nefrite Lúpica , Fator H do Complemento , Proteínas do Sistema Complemento/genética , Proteínas do Sistema Complemento/metabolismo , Egito , Heterozigoto , Humanos , Nefrite Lúpica/genética , Proteína Cofatora de Membrana
16.
Genes (Basel) ; 13(1)2022 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-35052466

RESUMO

BACKGROUND: X-linked dystonia-parkinsonism (XDP) is an adult-onset neurodegenerative disorder characterized by progressive dystonia and parkinsonism. It is caused by a SINE-VNTR-Alu (SVA) retrotransposon insertion in the TAF1 gene with a polymorphic (CCCTCT)n domain that acts as a genetic modifier of disease onset and expressivity. METHODS: Herein, we used Nanopore sequencing to investigate SVA genetic variability and methylation. We used blood-derived DNA from 96 XDP patients for amplicon-based deep Nanopore sequencing and validated it with fragment analysis which was performed using fluorescence-based PCR. To detect methylation from blood- and brain-derived DNA, we used a Cas9-targeted approach. RESULTS: High concordance was observed for hexanucleotide repeat numbers detected with Nanopore sequencing and fragment analysis. Within the SVA locus, there was no difference in genetic variability other than variations of the repeat motif between patients. We detected high CpG methylation frequency (MF) of the SVA and flanking regions (mean MF = 0.94, SD = ±0.12). Our preliminary results suggest only subtle differences between the XDP patient and the control in predicted enhancer sites directly flanking the SVA locus. CONCLUSIONS: Nanopore sequencing can reliably detect SVA hexanucleotide repeat numbers, methylation and, lastly, variation in the repeat motif.


Assuntos
Metilação de DNA , Distúrbios Distônicos/genética , Distúrbios Distônicos/patologia , Epigênese Genética , Doenças Genéticas Ligadas ao Cromossomo X/genética , Doenças Genéticas Ligadas ao Cromossomo X/patologia , Sequenciamento por Nanoporos/métodos , Retroelementos , Fatores Associados à Proteína de Ligação a TATA/genética , Adulto , Elementos Alu , Humanos , Masculino , Pessoa de Meia-Idade , Repetições Minissatélites , Elementos Nucleotídeos Curtos e Dispersos
17.
Bioinformatics ; 26(18): 2273-80, 2010 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-20639543

RESUMO

MOTIVATION: Structural alignments of proteins are important for identification of structural similarities, homology detection and functional annotation. The structural alignment problem is well studied and computationally difficult. Many different scoring schemes for structural similarity as well as many algorithms for finding high-scoring alignments have been proposed. Algorithms using contact map overlap (CMO) as scoring function are currently the only practical algorithms able to compute provably optimal alignments. RESULTS: We propose a new mathematical model for the alignment of inter-residue distance matrices, building upon previous work on maximum CMO. Our model includes all elements needed to emulate various scoring schemes for the alignment of protein distance matrices. The algorithm that we use to compute alignments is practical only for sparse distance matrices. Therefore, we propose a more effective scoring function, which uses a distance threshold and only positive structural scores. We show that even under these restrictions our approach is in terms of alignment accuracy competitive with state-of-the-art structural alignment algorithms, whereas it additionally either proves the optimality of an alignment or returns bounds on the optimal score. Our novel method is freely available and constitutes an important promising step towards truly provably optimal structural alignments of proteins. AVAILABILITY: An executable of our program PAUL is available at http://planet-lisa.net/.


Assuntos
Algoritmos , Modelos Químicos , Proteínas/química , Alinhamento de Sequência/métodos , Software , Humanos , Conformação Proteica
18.
PeerJ ; 9: e11017, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33763305

RESUMO

Mice are the most widely used animal model to study genotype to phenotype relationships. Inbred mice are genetically identical, which eliminates genetic heterogeneity and makes them particularly useful for genetic studies. Many different strains have been bred over decades and a vast amount of phenotypic data has been generated. In addition, recently whole genome sequencing-based genome-wide genotype data for many widely used inbred strains has been released. Here, we present an approach for in silico fine-mapping that uses genotypic data of 37 inbred mouse strains together with phenotypic data provided by the user to propose candidate variants and genes for the phenotype under study. Public genome-wide genotype data covering more than 74 million variant sites is queried efficiently in real-time to provide those variants that are compatible with the observed phenotype differences between strains. Variants can be filtered by molecular consequences and by corresponding molecular impact. Candidate gene lists can be generated from variant lists on the fly. Fine-mapping together with annotation or filtering of results is provided in a Bioconductor package called MouseFM. In order to characterize candidate variant lists under various settings, MouseFM was applied to two expression data sets across 20 inbred mouse strains, one from neutrophils and one from CD4+ T cells. Fine-mapping was assessed for about 10,000 genes, respectively, and identified candidate variants and haplotypes for many expression quantitative trait loci (eQTLs) reported previously based on these data. For albinism, MouseFM reports only one variant allele of moderate or high molecular impact that only albino mice share: a missense variant in the Tyr gene, reported previously to be causal for this phenotype. Performing in silico fine-mapping for interfrontal bone formation in mice using four strains with and five strains without interfrontal bone results in 12 genes. Of these, three are related to skull shaping abnormality. Finally performing fine-mapping for dystrophic cardiac calcification by comparing 9 strains showing the phenotype with eight strains lacking it, we identify only one moderate impact variant in the known causal gene Abcc6. In summary, this illustrates the benefit of using MouseFM for candidate variant and gene identification.

19.
Front Immunol ; 12: 632512, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33815385

RESUMO

Visceral leishmaniasis (VL) is a fatal parasitic disease if untreated. Treatment options of VL diminish due to emerging drug resistance. Although the principal host cells for the multiplication of Leishmania are macrophages, neutrophils are the first cells infected with the parasites rapidly after parasite inoculation. Leishmania can survive in neutrophils despite the potent antimicrobial effector functions of neutrophils that can eliminate the parasites. Recently, the growing field of immunometabolism provided strong evidence for the therapeutic potential in targeting metabolic processes as a means of controlling immune effector functions. Therefore, the understanding of the immunometabolic profile of neutrophils during Leishmania infection could provide new promising targets for host-directed therapies against VL. To our knowledge, this is the first study addressing the bioenergetics profile of L. donovani-infected primary human neutrophils. Transcriptome analysis of L. donovani-infected neutrophils revealed an early significant upregulation of several glycolytic enzymes. Extracellular flux analysis showed that glycolysis and glycolytic capacity were upregulated in L. donovani-infected neutrophils at 6 h post infection. An increased glucose uptake and accumulation of glycolytic end products were further signs for an elevated glycolytic metabolism in L. donovani-infected neutrophils. At the same time point, oxidative phosphorylation provided NADPH for the oxidative burst but did not contribute to ATP production. Inhibition of glycolysis with 2-DG significantly reduced the survival of L. donovani promastigotes in neutrophils and in culture. However, this reduction was due to a direct antileishmanial effect of 2-DG and not a consequence of enhanced antileishmanial activity of neutrophils. To further address the impact of glucose metabolism during the first days of infection in vivo, we treated C57BL/6 mice with 2-DG prior to infection with L. donovani and assessed the parasite load one day and seven days post infection. Our results show, that seven days post-infection the parasite load of 2-DG treated animals was significantly higher than in mock treated animals. This data indicates that glycolysis serves as major energy source for antimicrobial effector functions against L. donovani. Inhibition of glycolysis abrogates important neutrophil effector functions that are necessary the initial control of Leishmania infection.


Assuntos
Glucose/metabolismo , Leishmania donovani/fisiologia , Leishmaniose Visceral/imunologia , Neutrófilos/imunologia , Animais , Células Cultivadas , Desoxiglucose/efeitos adversos , Desoxiglucose/farmacologia , Glicólise/efeitos dos fármacos , Humanos , Leishmania donovani/efeitos dos fármacos , Leishmaniose Visceral/parasitologia , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Neutrófilos/parasitologia , Fosforilação Oxidativa , Carga Parasitária , Espécies Reativas de Oxigênio/metabolismo , Explosão Respiratória
20.
Neurobiol Aging ; 86: 202.e1-202.e3, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31685236

RESUMO

The role of microRNAs (miRNAs) in the pathogenesis of Alzheimer's disease (AD) is currently extensively investigated. In this study, we assessed the potential impact of AD genetic risk variants on miRNA expression by performing large-scale bioinformatic data integration. Our analysis was based on genetic variants from 3 AD genome-wide association studies (GWASs). Association with miRNA expression was tested by expression quantitative trait locus analysis using next-generation miRNA sequencing data generated in lymphoblastoid cell lines. Although, overall, we did not identify a strong effect of AD GWAS variants on miRNA expression in this cell type, we highlight 2 notable outliers, that is, miR-29c-5p and miR-6840-5p. MiR-29c-5p was recently reported to be involved in the regulation of BACE1 and SORL1 expression. In conclusion, despite 2 exceptions, our large-scale assessment provides only limited support for the hypothesis that AD GWAS variants act as miRNA expression quantitative trait loci.


Assuntos
Doença de Alzheimer/genética , Expressão Gênica , Linfócitos/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Polimorfismo de Nucleotídeo Único , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/genética , Ácido Aspártico Endopeptidases/metabolismo , Linhagem Celular , Estudo de Associação Genômica Ampla , Humanos , Proteínas Relacionadas a Receptor de LDL/genética , Proteínas Relacionadas a Receptor de LDL/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Resultados Negativos , Locos de Características Quantitativas/genética , Risco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA