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1.
PLoS One ; 18(11): e0293879, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37943810

RESUMO

Science, technology, engineering, mathematics, and medicine (STEMM) fields change rapidly and are increasingly interdisciplinary. Commonly, STEMM practitioners use short-format training (SFT) such as workshops and short courses for upskilling and reskilling, but unaddressed challenges limit SFT's effectiveness and inclusiveness. Education researchers, students in SFT courses, and organizations have called for research and strategies that can strengthen SFT in terms of effectiveness, inclusiveness, and accessibility across multiple dimensions. This paper describes the project that resulted in a consensus set of 14 actionable recommendations to systematically strengthen SFT. A diverse international group of 30 experts in education, accessibility, and life sciences came together from 10 countries to develop recommendations that can help strengthen SFT globally. Participants, including representation from some of the largest life science training programs globally, assembled findings in the educational sciences and encompassed the experiences of several of the largest life science SFT programs. The 14 recommendations were derived through a Delphi method, where consensus was achieved in real time as the group completed a series of meetings and tasks designed to elicit specific recommendations. Recommendations cover the breadth of SFT contexts and stakeholder groups and include actions for instructors (e.g., make equity and inclusion an ethical obligation), programs (e.g., centralize infrastructure for assessment and evaluation), as well as organizations and funders (e.g., professionalize training SFT instructors; deploy SFT to counter inequity). Recommendations are aligned with a purpose-built framework-"The Bicycle Principles"-that prioritizes evidenced-based teaching, inclusiveness, and equity, as well as the ability to scale, share, and sustain SFT. We also describe how the Bicycle Principles and recommendations are consistent with educational change theories and can overcome systemic barriers to delivering consistently effective, inclusive, and career-spanning SFT.


Assuntos
Estudantes , Tecnologia , Humanos , Consenso , Engenharia
2.
bioRxiv ; 2022 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-35794887

RESUMO

The clinical presentation overlap between malaria and COVID-19 poses special challenges for rapid diagnosis in febrile children. In this study, we collected RNA-seq data of children with malaria and COVID-19 infection from the public databases as raw data in fastq format paired end files. A group of six, five and two biological replicates of malaria, COVID-19 and healthy donors respectively were used for the study. We conducted differential gene expression analysis to visualize differences in the expression profiles. Using edgeR, we explored particularly gene expression levels in different phenotype groups and found that 1084 genes and 2495 genes were differentially expressed in the malaria samples and COVID-19 samples respectively when compared to healthy controls. The highly expressed gene in the COVID-19 group we found CD151 gene which is facilitates in T cell proliferation, while in the malaria group, among the highly expressed gene we identified GBP5 gene which involved in inflammatory response and response to bacterium. By comparing both malaria and COVID-19 infections, the overlap of 62 differentially expressed genes patterns were identified. Among them, three genes (ENSG00000234998, H2AC19 and TXNDC5) were highly upregulated in both infections. Strikingly, we observed 13 genes such as HBQ1, HBM, SLC7A5, SERINC2, ATP6V0C, ST6GALNAC4, RAD23A, PNPLA2, GAS2L1, TMEM86B, SLC6A8, UBALD1, RNF187 were downregulated in children with malaria and uniquely upregulated in children with COVID-19, thus may be further validated as potential biomarkers to delineate COVID-19 from malaria-related febrile infection. The hemoglobin complexes and lipid metabolism biological pathways are highly expressed in both infections. Our study provided new insights for further investigation of the biological pattern in hosts with malaria and COVID-19 coinfection.

3.
F1000Res ; 9: 376, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32864105

RESUMO

The Sequence Read Archive (SRA) is a large public repository that stores raw next-generation sequencing data from thousands of diverse scientific investigations.  Despite its promise, reuse and re-analysis of SRA data has been challenged by the heterogeneity and poor quality of the metadata that describe its biological samples. Recently, the MetaSRA project standardized these metadata by annotating each sample with terms from biomedical ontologies. In this work, we present a pair of Jupyter notebook-based tools that utilize the MetaSRA for building structured datasets from the SRA in order to facilitate secondary analyses of the SRA's human RNA-seq data. The first tool, called the Case-Control Finder, finds suitable case and control samples for a given disease or condition where the cases and controls are matched by tissue or cell type.  The second tool, called the Series Finder, finds ordered sets of samples for the purpose of addressing biological questions pertaining to changes over a numerical property such as time. These tools were the result of a three-day-long NCBI Codeathon in March 2019 held at the University of North Carolina at Chapel Hill.


Assuntos
Ontologias Biológicas , Conjuntos de Dados como Assunto , Sequenciamento de Nucleotídeos em Larga Escala , Metadados , Software , Estudos de Casos e Controles , Humanos , RNA-Seq
4.
Sci Rep ; 10(1): 4277, 2020 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-32152337

RESUMO

The ε4 allele of apolipoprotein E (APOE) is the dominant genetic risk factor for late-onset Alzheimer's disease (AD). However, the reason for the association between APOE4 and AD remains unclear. While much of the research has focused on the ability of the apoE4 protein to increase the aggregation and decrease the clearance of Aß, there is also an abundance of data showing that APOE4 negatively impacts many additional processes in the brain, including bioenergetics. In order to gain a more comprehensive understanding of APOE4's role in AD pathogenesis, we performed a transcriptomics analysis of APOE4 vs. APOE3 expression in the entorhinal cortex (EC) and primary visual cortex (PVC) of aged APOE mice. This study revealed EC-specific upregulation of genes related to oxidative phosphorylation (OxPhos). Follow-up analysis utilizing the Seahorse platform showed decreased mitochondrial respiration with age in the hippocampus and cortex of APOE4 vs. APOE3 mice, but not in the EC of these mice. Additional studies, as well as the original transcriptomics data, suggest that multiple bioenergetic pathways are differentially regulated by APOE4 expression in the EC of aged APOE mice in order to increase the mitochondrial coupling efficiency in this region. Given the importance of the EC as one of the first regions to be affected by AD pathology in humans, the observation that the EC is susceptible to differential bioenergetic regulation in response to a metabolic stressor such as APOE4 may point to a causative factor in the pathogenesis of AD.


Assuntos
Apolipoproteína E4/genética , Encéfalo/metabolismo , Metabolismo Energético/genética , Metaboloma , Mitocôndrias/patologia , Transcriptoma , Animais , Masculino , Camundongos , Mitocôndrias/genética , Mitocôndrias/metabolismo
5.
Oncotarget ; 11(4): 362-377, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-32064040

RESUMO

Prostate cancer is a disease with heterogeneity of multiple gene transcriptomes and biological signaling pathways involved in tumor development. The prostate transmembrane protein, androgen induced 1 (PMEPA1), a multifunctional protein played critical roles in prostate tumorigenesis. The pleiotropic nature of PMEPA1 in modulating androgen and TGF-ß signaling as well as splice variants mechanisms for functional regulations of cancer-associated genes prompted us to investigate the biological roles of PMEPA1 isoforms in prostate cancer. In addition to 4 reported PMEPA1 isoforms (a, b, c and d), one novel isoform PMEPA1-e was identified with RNA Seq analysis of hormone responsive VCaP, LNCaP cells and human prostate cancer samples from The Cancer Genome Atlas (TCGA) dataset. We analyzed the structures, expressions, biological functions and clinical relevance of PMEPA1-e isoform and less characterized isoforms c and d in the context of prostate cancer and AR/TGF-ß signaling. The expression of PMEPA1-e was induced by androgen and AR. In contrast, PMEPA1-d was responsive to TGF-ß and inhibited TGF-ß signaling. Both PMEPA1-d and PMPEA1-e promoted the growth of androgen independent prostate cancer cells. Although PMEPA1-c was responsive to TGF-ß, it was found to have no impacts on cell growth and androgen/TGF-ß signaling. The TCGA data analysis from 499 patients showed higher expression ratios of PMEAP1-b versus -d or -e strongly associated with enhanced Gleason score. Taken together, our findings first time defined the prostate tumorigenesis mediated by PMEPA1-d and -e isoforms, providing novel insights into the new strategies for prognostic evaluation and therapeutics of prostate tumor.

6.
iScience ; 19: 326-339, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31404833

RESUMO

The mechanisms supporting dynamic regulation of CTCF-binding sites remain poorly understood. Here we describe the TET-catalyzed 5-methylcytosine derivative, 5-carboxylcytosine (5caC), as a factor driving new CTCF binding within genomic DNA. Through a combination of in vivo and in vitro approaches, we reveal that 5caC generally strengthens CTCF association with DNA and facilitates binding to suboptimal sequences. Dramatically, profiling of CTCF binding in a cellular model that accumulates genomic 5caC identified ~13,000 new CTCF sites. The new sites were enriched for overlapping 5caC and were marked by an overall reduction in CTCF motif strength. As CTCF has multiple roles in gene expression, these findings have wide-reaching implications and point to induced 5caC as a potential mechanism to achieve differential CTCF binding in cells.

7.
BMC Genomics ; 20(1): 591, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31319791

RESUMO

BACKGROUND: During the last decade, plant biotechnological laboratories have sparked a monumental revolution with the rapid development of next sequencing technologies at affordable prices. Soon, these sequencing technologies and assembling of whole genomes will extend beyond the plant computational biologists and become commonplace within the plant biology disciplines. The current availability of large-scale genomic resources for non-traditional plant model systems (the so-called 'orphan crops') is enabling the construction of high-density integrated physical and genetic linkage maps with potential applications in plant breeding. The newly available fully sequenced plant genomes represent an incredible opportunity for comparative analyses that may reveal new aspects of genome biology and evolution. The analysis of the expansion and evolution of gene families across species is a common approach to infer biological functions. To date, the extent and role of gene families in plants has only been partially addressed and many gene families remain to be investigated. Manual identification of gene families is highly time-consuming and laborious, requiring an iterative process of manual and computational analysis to identify members of a given family, typically combining numerous BLAST searches and manually cleaning data. Due to the increasing abundance of genome sequences and the agronomical interest in plant gene families, the field needs a clear, automated annotation tool. RESULTS: Here, we present the geneHummus package, an R-based pipeline for the identification and characterization of plant gene families. The impact of this pipeline comes from a reduction in hands-on annotation time combined with high specificity and sensitivity in extracting only proteins from the RefSeq database and providing the conserved domain architectures based on SPARCLE. As a case study we focused on the auxin receptor factors gene (ARF) family in Cicer arietinum (chickpea) and other legumes. CONCLUSION: We anticipate that our pipeline should be suitable for any taxonomic plant family, and likely other gene families, vastly improving the speed and ease of genomic data processing.


Assuntos
Fabaceae/genética , Genes de Plantas , Família Multigênica , Software , Cicer/genética , Filogenia , Proteínas de Plantas/genética , Receptores de Superfície Celular/genética , Transcriptoma
8.
Neurochem Res ; 44(6): 1446-1459, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30291536

RESUMO

Mutations in the Leucine-rich repeat kinase 2 (LRRK2) gene have been implicated in the pathogenesis of Parkinson's disease (PD). Identification of PD-associated LRRK2 mutations has led to the development of novel animal models, primarily in mice. However, the characteristics of human LRRK2 and mouse Lrrk2 protein have not previously been directly compared. Here we show that proteins from different species have different biochemical properties, with the mouse protein being more stable but having significantly lower kinase activity compared to the human orthologue. In examining the effects of PD-associated mutations and risk factors on protein function, we found that conserved substitutions such as G2019S affect human and mouse LRRK2 proteins similarly, but variation around position 2385, which is not fully conserved between humans and mice, induces divergent in vitro behavior. Overall our results indicate that structural differences between human and mouse LRRK2 are likely responsible for the different properties we have observed for these two species of LRRK2 protein. These results have implications for disease modelling of LRRK2 mutations in mice and on the testing of pharmacological therapies in animals.


Assuntos
Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/metabolismo , Animais , Técnicas de Introdução de Genes , Células HEK293 , Proteínas de Choque Térmico HSC70/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/química , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Camundongos , Mutação , Fosforilação/fisiologia , Estabilidade Proteica , Proteínas rab de Ligação ao GTP , Proteínas rab1 de Ligação ao GTP/metabolismo
9.
Cell ; 175(7): 1872-1886.e24, 2018 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-30449621

RESUMO

Generation of the "epitranscriptome" through post-transcriptional ribonucleoside modification embeds a layer of regulatory complexity into RNA structure and function. Here, we describe N4-acetylcytidine (ac4C) as an mRNA modification that is catalyzed by the acetyltransferase NAT10. Transcriptome-wide mapping of ac4C revealed discretely acetylated regions that were enriched within coding sequences. Ablation of NAT10 reduced ac4C detection at the mapped mRNA sites and was globally associated with target mRNA downregulation. Analysis of mRNA half-lives revealed a NAT10-dependent increase in stability in the cohort of acetylated mRNAs. mRNA acetylation was further demonstrated to enhance substrate translation in vitro and in vivo. Codon content analysis within ac4C peaks uncovered a biased representation of cytidine within wobble sites that was empirically determined to influence mRNA decoding efficiency. These findings expand the repertoire of mRNA modifications to include an acetylated residue and establish a role for ac4C in the regulation of mRNA translation.


Assuntos
Citidina/análogos & derivados , Acetiltransferase N-Terminal E/metabolismo , Biossíntese de Proteínas , RNA Mensageiro/metabolismo , Acetilação , Citidina/genética , Citidina/metabolismo , Células HeLa , Humanos , Acetiltransferase N-Terminal E/genética , Acetiltransferases N-Terminal , RNA Mensageiro/genética
10.
Sci Rep ; 7(1): 16890, 2017 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-29203886

RESUMO

Aging is a biologically universal event, and yet the key events that drive aging are still poorly understood. One approach to generate new hypotheses about aging is to use unbiased methods to look at change across lifespan. Here, we have examined gene expression in the human dorsolateral frontal cortex using RNA- Seq to populate a whole gene co-expression network analysis. We show that modules of co-expressed genes enriched for those encoding synaptic proteins are liable to change with age. We extensively validate these age-dependent changes in gene expression across several datasets including the publically available GTEx resource which demonstrated that gene expression associations with aging vary between brain regions. We also estimated the extent to which changes in cellular composition account for age associations and find that there are independent signals for cellularity and aging. Overall, these results demonstrate that there are robust age-related alterations in gene expression in the human brain and that genes encoding for neuronal synaptic function may be particularly sensitive to the aging process.


Assuntos
Envelhecimento , Regulação da Expressão Gênica , Córtex Pré-Frontal/metabolismo , Sinapses/metabolismo , Perfilação da Expressão Gênica , Humanos , Longevidade/genética , RNA/química , RNA/isolamento & purificação , RNA/metabolismo , Análise de Sequência de RNA
11.
Mol Neurodegener ; 12(1): 70, 2017 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-28962651

RESUMO

BACKGROUND: Early onset Parkinson's disease is caused by variants in PINK1, parkin, and DJ-1. PINK1 and parkin operate in pathways that preserve mitochondrial integrity, but the function of DJ-1 and how it relates to PINK1 and parkin is poorly understood. METHODS: A series of unbiased high-content screens were used to analyze changes at the protein, RNA, and metabolite level in rodent brains lacking DJ-1. Results were validated using targeted approaches, and cellular assays were performed to probe the mechanisms involved. RESULTS: We find that in both rat and mouse brains, DJ-1 knockout results in an age-dependent accumulation of hexokinase 1 in the cytosol, away from its usual location at the mitochondria, with subsequent activation of the polyol pathway of glucose metabolism in vivo. Both in the brain and in cultured cells, DJ-1 deficiency is associated with accumulation of the phosphatase PTEN that antagonizes the kinase AKT. In cells, addition of an inhibitor of AKT (MK2206) or addition of a peptide to dissociate association of hexokinases from mitochondria both inhibit the PINK1/parkin pathway, which works to maintain mitochondrial integrity. CONCLUSION: Hexokinases are an important link between three major genetic causes of early onset Parkinson's disease. Because aging is associated with deregulated nutrient sensing, these results help explain why DJ-1 is associated with age-dependent disease.


Assuntos
Hexoquinase/metabolismo , Doença de Parkinson/metabolismo , Proteína Desglicase DJ-1/metabolismo , Proteínas Quinases/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Técnicas de Inativação de Genes , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Ratos Long-Evans , Transdução de Sinais/fisiologia
12.
Biochem J ; 474(9): 1547-1558, 2017 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-28320779

RESUMO

Autosomal dominant mutations in leucine-rich repeat kinase 2 (LRRK2) are associated with Parkinson's disease (PD). Most pathogenic LRRK2 mutations result in amino acid substitutions in the central ROC (Ras of complex proteins)-C-terminus of ROC-kinase triple domain and affect enzymatic functions of the protein. However, there are several variants in LRRK2, including the risk factor G2385R, that affect PD pathogenesis by unknown mechanisms. Previously, we have shown that G2385R LRRK2 has decreased kinase activity in vitro and altered affinity to LRRK2 interactors. Specifically, we found an increased binding to the chaperone Hsp90 (heat shock protein 90 kDa) that is known to stabilize LRRK2, suggesting that G2385R may have structural effects on LRRK2. In the present study, we further explored the effects of G2385R on LRRK2 in cells. We found that G2385R LRRK2 has lower steady-state intracellular protein levels compared with wild-type LRRK2 due to increased protein turnover of the mutant protein. Mechanistically, this is a consequence of a higher affinity of G2385R compared with the wild-type protein for two proteins involved in proteasomal degradation, Hsc70 and carboxyl-terminus of Hsc70-interacting protein (CHIP). Overexpression of CHIP decreased intracellular protein levels of both G2385R mutant and wild-type LRRK2, while short interfering RNA CHIP knockdown had the opposite effect. We suggest that the G2385R substitution tilts the equilibrium between refolding and proteasomal degradation toward intracellular degradation. The observation of lower steady-state protein levels may explain why G2385R is a risk factor rather than a penetrant variant for inherited PD.


Assuntos
Predisposição Genética para Doença , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Mutação , Doença de Parkinson/genética , Ubiquitina-Proteína Ligases/metabolismo , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Fatores de Risco , Ubiquitina-Proteína Ligases/genética
13.
Front Neurosci ; 11: 702, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29311783

RESUMO

Possession of the ε4 allele of apolipoprotein E (APOE) is the major genetic risk factor for late-onset Alzheimer's disease (AD). Although numerous hypotheses have been proposed, the precise cause of this increased AD risk is not yet known. In order to gain a more comprehensive understanding of APOE4's role in AD, we performed RNA-sequencing on an AD-vulnerable vs. an AD-resistant brain region from aged APOE targeted replacement mice. This transcriptomics analysis revealed a significant enrichment of genes involved in endosomal-lysosomal processing, suggesting an APOE4-specific endosomal-lysosomal pathway dysregulation in the brains of APOE4 mice. Further analysis revealed clear differences in the morphology of endosomal-lysosomal compartments, including an age-dependent increase in the number and size of early endosomes in APOE4 mice. These findings directly link the APOE4 genotype to endosomal-lysosomal dysregulation in an in vivo, AD pathology-free setting, which may play a causative role in the increased incidence of AD among APOE4 carriers.

14.
Genome Med ; 8(1): 65, 2016 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-27287230

RESUMO

BACKGROUND: Expression quantitative trait loci (eQTL) analysis is a powerful method to detect correlations between gene expression and genomic variants and is widely used to interpret the biological mechanism underlying identified genome wide association studies (GWAS) risk loci. Numerous eQTL studies have been performed on different cell types and tissues of which the majority has been based on microarray technology. METHODS: We present here an eQTL analysis based on cap analysis gene expression sequencing (CAGEseq) data created from human postmortem frontal lobe tissue combined with genotypes obtained through genotyping arrays, exome sequencing, and CAGEseq. Using CAGEseq as an expression profiling technique combined with these different genotyping techniques allows measurement of the molecular effect of variants on individual transcription start sites and increases the resolution of eQTL analysis by also including the non-annotated parts of the genome. RESULTS: We identified 2410 eQTLs and show that non-coding transcripts are more likely to contain an eQTL than coding transcripts, in particular antisense transcripts. We provide evidence for how previously identified GWAS loci for schizophrenia (NRGN), Parkinson's disease, and Alzheimer's disease (PARK16 and MAPT loci) could increase the risk for disease at a molecular level. Furthermore, we demonstrate that CAGEseq improves eQTL analysis because variants obtained from CAGEseq are highly enriched for having a functional effect and thus are an efficient method towards the identification of causal variants. CONCLUSION: Our data contain both coding and non-coding transcripts and has the added value that we have identified eQTLs for variants directly adjacent to TSS. Future eQTL studies would benefit from combining CAGEseq with RNA sequencing for a more complete interpretation of the transcriptome and increased understanding of eQTL signals.


Assuntos
Lobo Frontal/química , Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Locos de Características Quantitativas , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Bases de Dados Genéticas , Feminino , Variação Genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Regiões Promotoras Genéticas , Adulto Jovem
15.
RNA Biol ; 13(1): 15-24, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26669816

RESUMO

Adenosine deaminases bind double stranded RNA and convert adenosine to inosine. Editing creates multiple isoforms of neurotransmitter receptors, such as with Gria2. Adar2 KO mice die of seizures shortly after birth, but if the Gria2 Q/R editing site is mutated to mimic the edited version then the animals are viable. We performed RNA-Seq on frontal cortices of Adar2(-/-) Gria2(R/R) mice and littermates. We found 56 editing sites with significantly diminished editing levels in Adar2 deficient animals with the majority in coding regions. Only two genes and 3 exons showed statistically significant differences in expression levels. This work illustrates that ADAR2 is important in site-specific changes of protein coding sequences but has relatively modest effects on gene expression and splicing in the adult mouse frontal cortex.


Assuntos
Adenosina Desaminase/metabolismo , Expressão Gênica , Splicing de RNA , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/metabolismo , Análise de Sequência de RNA/métodos , Adenosina Desaminase/genética , Animais , Lobo Frontal/metabolismo , Técnicas de Inativação de Genes , Camundongos , Mutação , Edição de RNA , Proteínas de Ligação a RNA/genética
16.
Int Rev Neurobiol ; 116: 233-50, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25172477

RESUMO

The transcriptome changes hugely during development of the brain. Whole genes, alternate exons, and single base pair changes related to RNA editing all show differences between embryonic and mature brain. Collectively, these changes control proteomic diversity as the brain develops. Additionally, there are many changes in noncoding RNAs (miRNA and lncRNA) that interact with mRNA to influence the overall transcriptional landscape. Here, we will discuss what is known about such changes in brain development, particularly focusing on high-throughput approaches and how those can be used to infer mechanisms by which gene expression is controlled in the brain as it matures.


Assuntos
Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Transcriptoma/fisiologia , Animais , Sequência de Bases , Expressão Gênica/fisiologia , Humanos , Splicing de RNA
17.
PLoS One ; 9(4): e94646, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24722488

RESUMO

Mitochondrial DNA damage is thought to be a causal contributor to aging as mice with inactivating mutations in polymerase gamma (Polg) develop a progeroid phenotype. To further understand the molecular mechanisms underlying this phenotype, we used iTRAQ and RNA-Seq to determine differences in protein and mRNA abundance respectively in the brains of one year old Polg mutator mice compared to control animals. We found that mitochondrial respiratory chain proteins are specifically decreased in abundance in the brains of the mutator mice, including several nuclear encoded mitochondrial components. However, we found no evidence that the changes we observed in protein levels were the result of decreases in mRNA expression. These results show that there are post-translational effects associated with mutations in Polg.


Assuntos
Encéfalo/metabolismo , DNA Polimerase Dirigida por DNA/genética , Transporte de Elétrons/genética , Biossíntese de Proteínas/fisiologia , Animais , DNA Polimerase gama , DNA Mitocondrial/genética , DNA Polimerase Dirigida por DNA/metabolismo , Camundongos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Mutação , Fenótipo
18.
Mult Scler Relat Disord ; 3(2): 211-219, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25568836

RESUMO

BACKGROUND: Multiple sclerosis (MS) is a common disease of the central nervous system and a major cause of disability amongst young adults. Genome-wide association studies have identified many novel susceptibility loci including rs2248359. We hypothesized that genotypes of this locus could increase the risk of MS by regulating expression of neighboring gene, CYP24A1 which encodes the enzyme responsible for initiating degradation of 1,25-dihydroxyvitamin D3. METHODS: We investigated this hypothesis using paired gene expression and genotyping data from three independent datasets of neurologically healthy adults of European descent. The UK Brain Expression Consortium (UKBEC) consists of post-mortem samples across 10 brain regions originating from 134 individuals (1231 samples total). The North American Brain Expression Consortium (NABEC) consists of cerebellum and frontal cortex samples from 304 individuals (605 samples total). The brain dataset from Heinzen and colleagues consists of prefrontal cortex samples from 93 individuals. Additionally, we used gene network analysis to analyze UKBEC expression data to understand CYP24A1 function in human brain. FINDINGS: The risk allele, rs2248359-C, is strongly associated with increased expression of CYP24A1 in frontal cortex (p-value=1.45×10-13), but not white matter. This association was replicated using data from NABEC (p-value=7.2×10-6) and Heinzen and colleagues (p-value=1.2×10-4). Network analysis shows a significant enrichment of terms related to immune response in eight out of the 10 brain regions. INTERPRETATION: The known MS risk allele rs2248359-C increases CYP24A1 expression in human brain providing a genetic link between MS and vitamin D metabolism, and predicting that the physiologically active form of vitamin D3 is protective. Vitamin D3's involvement in MS may relate to its immunomodulatory functions in human brain. FUNDING: Medical Research Council UK; King Faisal Specialist Hospital and Research Centre, Saudi Arabia; Intramural Research Program of the National Institute on Aging, National Institutes of Health, USA.

19.
Nucleic Acids Res ; 41(7): e88, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23435227

RESUMO

Polymorphisms in the target mRNA sequence can greatly affect the binding affinity of microarray probe sequences, leading to false-positive and false-negative expression quantitative trait locus (QTL) signals with any other polymorphisms in linkage disequilibrium. We provide the most complete solution to this problem, by using the latest genome and exome sequence reference data to identify almost all common polymorphisms (frequency >1% in Europeans) in probe sequences for two commonly used microarray panels (the gene-based Illumina Human HT12 array, which uses 50-mer probes, and exon-based Affymetrix Human Exon 1.0 ST array, which uses 25-mer probes). We demonstrate the impact of this problem using cerebellum and frontal cortex tissues from 438 neuropathologically normal individuals. We find that although only a small proportion of the probes contain polymorphisms, they account for a large proportion of apparent expression QTL signals, and therefore result in many false signals being declared as real. We find that the polymorphism-in-probe problem is insufficiently controlled by previous protocols, and illustrate this using some notable false-positive and false-negative examples in MAPT and PRICKLE1 that can be found in many eQTL databases. We recommend that both new and existing eQTL data sets should be carefully checked in order to adequately address this issue.


Assuntos
Perfilação da Expressão Gênica , Sondas de Oligonucleotídeos/química , Polimorfismo Genético , Locos de Características Quantitativas , Expressão Gênica , Humanos , Desequilíbrio de Ligação , Análise de Sequência com Séries de Oligonucleotídeos
20.
Nat Neurosci ; 16(4): 499-506, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23416452

RESUMO

The complexity of the adult brain is a result of both developmental processes and experience-dependent circuit formation. One way to look at the differences between embryonic and adult brain is to examine gene expression. Previous studies have used microarrays to address this in a global manner. However, the transcriptome is more complex than gene expression levels alone, as alternative splicing and RNA editing generate a diverse set of mature transcripts. Here we report a high-resolution transcriptome data set of mouse cerebral cortex at embryonic and adult stages using RNA sequencing (RNA-Seq). We found many differences in gene expression, splicing and RNA editing between embryonic and adult cerebral cortex. Each data set was validated technically and biologically, and in each case we found our RNA-Seq observations to have predictive validity. We provide this data set and analysis as a resource for understanding gene expression in the embryonic and adult cerebral cortex.


Assuntos
Córtex Cerebral/embriologia , Córtex Cerebral/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Edição de RNA/fisiologia , Splicing de RNA/fisiologia , RNA Mensageiro/biossíntese , Fatores Etários , Animais , Córtex Cerebral/fisiologia , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Gravidez , RNA Mensageiro/genética , Análise de Sequência de RNA/métodos
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