Browsing by Author "Couto, Francisco"
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- Associação entre variantes genéticas e perfil clínico multidimensional de doentes com perturbação do espetro do autismo: uma abordagem integrativaPublication . Asif, Muhammad; Couto, Francisco; Vicente, Astrid M.A complexidade genética e clínica que caracterizam a per turbação do espetro do autismo (PEA) têm limitado o desenvolvimento de biomarcadores que permitam um diagnóstico precoce e um prognóstico fiável, assim como uma abordagem personalizada para a inter venção terapêutica. Neste estudo pretendeu-se desenvolver uma abordagem integrativa para predição da apresentação clínica baseada em informação de variantes genéticas (Copy Number Variants, CNVs), com aplicação clínica no diagnóstico e prognóstico na PEA. Para tal, técnicas de aprendizagem automática (machine learning) foram aplicadas a dados clínicos e genéticos de 2446 doentes com PEA, recrutados no âmbito do consórcio Autism Genome Project. Análise de clustering de dados clínicos multidimensionais definiu, nesta população, dois subgrupos de pacientes com per fis clínicos diferindo significativamente em termos de capacidade verbal, nível cognitivo, gravidade da doença e compor tamento adaptativo. A análise dos CNVs que afetam especificamente genes do cérebro, nos mesmos indivíduos, identificou 15 processos biológicos enriquecidos em genes alterados. A aplicação de um algoritmo de machine learning para classificação dos doentes com apresentação clínica mais disfuncional, com base nos processos biológicos alterados, mostrou que correlações entre fenótipo clínico e biologia subjacente são possíveis na PEA e que, para grupos populacionais com dados informativos, existe um poder preditivo razoável. Para implementação deste conceito na prática clínica serão necessários estudos mais alargados com dados clínicos e genómicos mais completos.
- Maternal CNV transmission to sons with autism correlates with phenotypic traits in the Broad Autism PhenotypePublication . Vicente, A.M.; Asif, Muhammad; Conceição, Inês; Kwiatkowska, Katarzyna; Rasga, Celia; Oliveira, Guiomar; Sousa, Lisete; Couto, FranciscoAutism Spectrum Disorder (ASD): Common neurodevelopmental disorder, global prevalence ~1 %; Persistent deficits in social communication and social interaction; restricted and repetitive behavior, interests, or activities – highly heterogeneous clinical presentation; Male to female ratio ~4:1.
- Molecular profiling of the human nasal epithelium: a proteomics approachPublication . Simoes, Tania; Charro, Nuno; Blonder, Josip; Faria, Daniel; Couto, Francisco; Chan, King C.; Waybright, Timothy; Isaaq, Haleem J.; Veenstra, Timothy D.; Penque, DeborahA comprehensive proteomic profiling of nasal epithelium (NE) is described. This study relies on simple subcellular fractionation used to obtain soluble- and membrane-enriched fractions followed by 2-dimensional liquid chromatography (2D-LC) separation and tandem mass spectrometry (MS/MS). The cells were collected using a brushing technique applied on NE of clinically evaluated volunteers. Subsequently, the soluble- and the membrane-protein enriched fractions were prepared and analyzed in parallel using 2D-LC-MS/MS. In a set of 1482 identified proteins, 947 (63.9%) proteins were found to be associated to membrane fraction. Grand average hydropathy value index (GRAVY) analysis, the transmembrane protein mapping and annotations of primary location deposited in the Human Protein Reference Database (HPRD) confirmed an enrichment of hydrophobic proteins on this dataset. Ingenuity Pathway Analysis (IPA) of soluble fraction revealed an enrichment of molecular and cellular functions associated with cell death, protein folding and drug metabolism while in membrane fraction showed an enrichment of functions associated with molecular transport, protein trafficking and cell-to-cell signaling and interaction. The IPA showed similar enrichment of functions associated with cellular growth and proliferation in both soluble and membrane subproteomes. This finding was in agreement with protein content analysis using exponentially modified protein abundance index (emPAI). A comparison of our data with previously published studies focusing on respiratory tract epithelium revealed similarities related to identification of proteins associated with physical barrier function and immunological defence. In summary, we extended the NE molecular profile by identifying and characterizing proteins associated to pivotal functions of a respiratory epithelium, including the control of fluid volume and ionic composition at the airways' surface, physical barrier maintenance, detoxification and immunological defence. The extent of similarities supports the applicability of a less invasive analysis of NE to assess prognosis and treatment response of lung diseases such as asthma, cystic fibrosis and chronic obstructive pulmonary disease.
- Rescue of F508del-CFTR by RXR motif inactivation triggers proteome modulation associated with the unfolded protein responsePublication . Gomes-Alves, Patrícia; Couto, Francisco; Pesquita, Cátia; Coelho, Ana V.; Penque, DeborahF508del-CFTR, the most common mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) protein, disrupts intracellular trafficking leading to cystic fibrosis (CF). The trafficking defect of F508del-CFTR can be rescued by simultaneous inactivation of its four RXR motifs (4RK). Proteins involved in the F508del-CFTR trafficking defect and/or rescue are therefore potential CF therapeutic targets. We sought to identify these proteins by investigating differential proteome modulation in BHK cells over-expressing wt-CFTR, F508del-CFTR or the revertant F508del/4RK-CFTR. By 2-dimensional electrophoresis-based proteomics and western blot approaches we demonstrated that over-expression of F508del/4RK-CFTR modulates the expression of a large number of proteins, many of which are reported interactors of CFTR and/ or 14-3-3 with potential roles in CFTR trafficking. GRP78/BiP, a marker of ER stress and unfolded protein response (UPR), is up-regulated in cells over-expressing either F508del-CFTR or F598del/4RK-CFTR. However, over-expression of F508del/4RK-CFTR induces the up-regulation of many other UPR-associated proteins (e.g. GRP94, PDI, GRP75/mortalin) and, interestingly, the down-regulation of proteasome components associated with CFTR degradation, such as the proteasome activator PA28 (PSME2) and COP9 signalosome (COPS5/CSN5). Moreover, the F508del-CFTR-induced proteostasis imbalance, which involves some heat shock chaperones (e.g. HSP72/Hpa2), ER-EF-hand Ca2+-binding proteins (calumenin) and the proteasome activator PA28 (PSME2), tends to be ‘restored’, i.e., in BHK cells over-expressing F508del/4RK-CFTR those proteins tend to have expression levels similar to the wild-type ones. These findings indicate that a particular cellular environment orchestrated by the UPR contributes to and/or is compatible with F508del/4RK-CFTR rescue.