Percorrer por autor "Valente, Ana"
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- Aleitamento materno e peso à nascença – fatores protetores ou de risco para a obesidade infantil? - Estudo COSI Portugal 2010 .Publication . Baleia, Joana; Valente, Ana; Rito, AnaIntrodução: A obesidade continua a ser uma doenças mais prevalentes na infância e um sério desafio de saúde pública a nível mundial. Devido ao seu carácter preditivo de obesidade na idade adulta e co-morbilidades, fatores inerentes ao início da vida têm vindo a ser estudados pelo seu potencial papel determinante no risco de desenvolver obesidade na infância. Objetivos: O presente trabalho pretende estudar o aleitamento materno e o peso à nascença, como possíveis fatores protetores ou de risco para a obesidade infantil. Métodos: O estudo compreende 3637 crianças dos 6-8 anos avaliadas na 2ª fase do COSI Portugal 2010. Os dados do peso à nascença e da amamentação foram obtidos por um questionário familiar. A prevalência de obesidade e excesso de peso foi determinada aplicando o critério da Organização Mundial de Saúde. Resultados: Segundo os critérios estabelecidos pela Organização Mundial de Saúde, no ano de 2010 o excesso de peso afetava 39% das crianças portuguesas, das quais 16,4% eram obesas. No que concerne ao peso à nascença, os resultados mostraram que 8,3% das crianças nasceram com baixo peso (<2500g) e 5,4% apresentaram macrossomia (>4000g) no momento do nascimento. Cerca de 52% das crianças foram amamentadas por um período inferior a 6 meses. Nesta amostra o baixo peso à nascença não constituiu um risco do excesso de peso nas crianças portuguesas (OR = 0,74; IC95% 0,57-0,98) no entanto, as crianças com macrossomia apresentaram uma maior probabilidade de ter excesso de peso (OR = 1,41; IC95% 1,05 1,90) e as crianças com alimentação artificial exclusiva desde o nascimento, maior risco de obesidade (OR = 1,39; IC95% 1,09-1,77). Conclusões: Maior peso à nascença e a ausência de amamentação revelaram ser factores de risco para a prevalência de excesso de peso e de obesidade infantil.
- Avaliação da ingestão de micronutrientes em diabéticos tipo 2Publication . Valente, Ana; Bicho, Manuel; Duarte, Rui; Raposo, João F.; Costa, H.S.
- Comparative analysis of hybrid‑SNP microarray and nanopore sequencing for detection of large‑sized copy number variants in the human genomePublication . Silva, Catarina; Ferrão, José; Marques, Bárbara; Pedro, Sónia; Correia, Hildeberto; Valente, Ana; Rodrigues, António Sebastião; Vieira, LuísBackground: Nanopore sequencing is a technology that holds great promise for identifying all types of human genome variations, particularly structural variations. In this work, we used nanopore sequencing technology to sequence 2 human cell lines at low depth of coverage to call copy number variations (CNV), and compared the results variant by variant with chromosomal microarray (CMA) results. Results: We analysed sequencing data using CuteSV and Sniffles2 variant callers, compared breakpoints based on hybrid-SNP microarray, nanopore sequencing and Sanger sequencing, and analysed CNV coverage. From a total of 48 high confidence variants (truth set), variant calling detected 79% of the truth set variants, increasing to 86% for interstitial CNV. Simultaneous use of the 2 callers slightly increased variant calling. Both callers performed better when calling CNV losses than gains. Variant sizes from CMA and nanopore sequencing showed an excellent correlation, with breakpoints determined by nanopore sequencing differing by only 20 base pairs on average from Sanger sequencing. Nanopore sequencing also revealed that four variants concealed genomic inversions undetectable by CMA. In the 10 CNV not called in nanopore sequencing, 8 showed coverage evidence of genomic loss or gain, highlighting the need to improve SV calling algorithms performance. Conclusions: Nanopore sequencing offers advantages over CMA for structural variant detection, including the identification of multiple variant types and their breakpoints with increased precision. However, further improvements in variant calling algorithms are still needed for nanopore sequencing to become a highly robust and standardized approach for a comprehensive analysis of genomic structural variation.
- Effects of TiO2 Nanoparticles on the Genome-Wide Methylation of Human Epithelial Intestinal CellsPublication . Valente, Ana; Vieira, Luís; Silva, Catarina; Louro, Henriqueta; Silva, Maria João; Ventura, CéliaIntroduction: Titanium dioxide nanoparticles (TiO2NP) have multiple applications in industry (e.g., engineering, cosmetics, food additives), and biomedicine (e.g., targeted drug delivery and biosensing). Food-grade TiO2 (E171) is applied as a food additive to whiten and improve the opacity of food products, while also having the ability to enhance its flavour. In 2021, EU member states banned E171 from all food products, since there is doubts about its genotoxicity. Nevertheless, the ingestion of TiO2NPs may still occur through to other sources, such as contaminated food or water, consumer products (e.g., toothpaste and lipstick) or pharmaceutics. To date, there is some in vitro evidence that TiO2NP may induce changes in DNA methylation. However, very few studies were performed, and none used genome-wide approaches to identify possible differentially methylated genes induced by TiO2NP exposure, and its impact on molecular pathways. Methodology: Caco-2 epithelial intestinal cells were exposed to 14 μg/ml of anatase, rutile or brookite phase TiO2NP for 24h. Genomic DNA was extracted from exposed and non-exposed cells. DNA libraries were generated using the Premium Reduced Representative Bisulfite Sequencing (RRBS) kit (Diagenode) and sequenced on the NextSeq 550 system (Illumina) using 100 bp paired reads. The Galaxy platform was used for read treatment and mapping, methylation calling and assessing of differentially methylated regions between exposed and non-exposed cells. Pathway analysis was performed using Reactome, and gene ontology analysis with the ClueGO plugin in Cytoscape. Results: Significant differential methylation (p ≤ 0.05) of 92 genes (21 hyper- and 71 hypo-methylated), 70 genes (12 hyper- and 58 hypo-methylated) and 88 genes (21 hyper- and 67 hypo-methylated) was observed for the anatase, rutile and brookite phase TiO2NP, respectively. Functional pathway analysis of these methylation changes identified several relevant cellular pathways that may be altered by exposure, such as G alpha signalling events, being some associated to colon cancer. Conclusions: All types of TiO2NP induce changes in genome methylation of intestinal cells, which may affect cell proliferation, differentiation and survival. Moreover, although some dysfunctional pathways are shared between the three TiO2NP, many are type-specific, suggesting different molecular mechanisms of action for each TiO2NP.
- Epigenomics as a novel approach to explore the toxic effects of nanomaterialsPublication . Ventura, Célia; Vieira, Luís; Valente, Ana; Fernandes, Camila; Silva, Catarina; Louro, Henriqueta; Ferreira, Paulo J.T.; Silva, Maria JoãoIn recent years, there has been a huge development of innovative engineered nanomaterials with potential use in industrial and biomedical applications. This increased widespread use raised concerns that nanomaterials may elicit human adverse health effects through occupational, environmental or consumer exposure. Many toxicity studies, mainly in vitro, have showed that some nanomaterials, such as carbon nanotubes or titanium dioxide nanoparticles (TiO 2 NP), may cause genotoxicity, inflammation, and associated adverse health effects. Nevertheless, few studies have focused on the nanomaterials effect s on the epigenome, namely, modifications of histone tails, microRNA expression or DNA methylation. Here we wil l present two “omics” studies based on next generation sequencing , one focusing on the effect of three nanocellulose s derived from Eucaliptus globulus kraft pulp on the microRNA expression of BEAS 2B, and an other one focusing on the effect of three types of TiO 2 NP on the DNA methylation of Caco 2 cells. Regarding the former 24h exposure to fibrillar micro/nanocellulose s did not induced significant (FDR ≤ 0.05) differentially expressed microRNAs, as compared to non exposed cells. By contrast, the crystalline nanocelul l ose induced the over and under expression of 22 and 30 microRNAs, respectively. These microRNAs can be f urther explored as potential biomarkers for human biomonitoring and co ntribute to elucidate the mechanisms of action of crystalline nanocellulose. As to the genome wide methylation study Reduced Representative Bisulfite Sequencing allowed the identification of significant ( p ≤ 0.05) differential methylation of 92, 70, and 88 gene sequences for the anatase, rutile and brookite phase TiO 2 NP exposures, respectively. Functional pathway analysis of these methylation changes showed that all TiO 2 NP may affect cell proliferation, differentiation, and survival, and suggested different molecular mechanisms of action for each type of TiO 2 NP. In conclusion, epigenomics revealed to be a powerful tool to understand the key molecular events underlying nanomaterials effects.
- Frequência de polimorfismos genéticos de enzimas envolvidas no metabolismo da homocisteína em diabéticos tipo 2Publication . Valente, Ana; Bicho, Manuel; Duarte, Rui; Raposo, João F.; Costa, H.S.INTRODUÇÃO: A hiperhomocisteinémia tem vindo a ser associada com polimorfismos genéticos das enzimas 5,10-metilenotetrahidrofolato (MTHF), cistationina β-sintetase (CBS) e dihidrofolato redutase (DHFR). São escassos os dados epidemiológicos de distribuição dos polimorfismos C677T da MTHFR, 844ins68 da CBS e deleção de 19 pares de bases do gene da DHFR em diabéticos tipo 2. Conhecer a variação polimórfica destas enzimas e sua relação com outros factores de risco cardiovascular pode ajudar a definir medidas de prevenção e contribuir de forma relevante para uma nutrição clínica personalizada. OBJECTIVO: Avaliar a distribuição dos polimorfismos C677T da MTHFR, 844ins68 da CBS e deleção de 19 pares de bases do gene da DHFR em diabéticos tipo 2, bem como a frequência da presença simultânea de dois ou mais destes polimorfismos. MÉTODOS: Estudo epidemiológico observacional tipo caso-controlo em 134 adultos caucasianos com idades entre 40-75 anos. Foram constituídos dois grupos: GI - 69 diabéticos tipo 2 com angiopatia; GII - 65 diabéticos tipo 2 sem angiopatia. Os polimorfismos genéticos foram identificados por PCR e/ou RFLP. A análise estatística foi realizada em SPSS®, versão 20.0 (SPSS Inc, Chicago). RESULTADOS: A frequência do polimorfismo da CBS, em heterozigotia foi no GI: 28,4% e no GII: 18,5%. No polimorfismo da MTHFR, os genótipos CT e TT foram mais frequentes no GI (46,4%; 7,2%) do que no GII (41,5%; 6,2%). A prevalência de homozigóticos no polimorfismo da DHFR foi 19,7% (GI) e 16,9% (GII). O genótipo da heterozigotia foi o mais prevalente (GI: 53%; GII: 73,9%). Os diabéticos do GI com o polimorfismo da MTHFR apresentaram com maior frequência hiperhomocisteinémia (OR = 5,37; P = 0,040) em comparação com o GII. O mesmo se verificou para a CBS (OR = 6,71; P = 0,018). A presença simultânea dos polimorfismos da MTHFR e da DHFR foi a mais frequente (GI: 41% vs. GII: 43%). A frequência conjunta dos 3 polimorfismos foi superior no GI (9,1%) em relação ao GII (4,6%). CONCLUSÃO: A elevada frequência isolada do polimorfismo de delecção de 19 pares de bases do gene da DHFR e combinada com o polimorfismo C677T da MTHFR, são condições que têm vindo a ser associadas com uma maior susceptibilidade à ocorrência de eventos cérebro-cardiovasculares. Os polimorfismos C677T da MTHFR e 844ins68 da CBS estão associados com a hiperhomocisteinémia e a sua identificação poderá ser muito relevante em nutrição clínica.
- Genome-wide methylation changes upon Caco-2 cells exposure to undigested and digested titanium dioxide nanoparticlesPublication . Ventura, Célia; Valente, Ana; Vieira, Luís; Silva, Catarina; Rolo, Dora; Silva, Maria Joao; Louro, HenriquetaIntroduction: Titanium dioxide nanoparticles (TiO2NPs) are relevant nanomaterials (NMs) for biomedicine and industry, which raise concerns about its effects on human health, particularly through ingestion. Several studies found that exposure to NMs can lead to DNA methylation changes. DNA methylation regulates gene expression, playing a vital role in development and disease, with aberrant methylation linked to cancer and other health conditions. Aim: We aimed at identifying DNA methylation changes in intestinal cells exposed to three TiO2NPs (NM-102, NM-103, NM-105), either digested or undigested. Their cellular effects were investigated by functional pathway and gene ontology (GO) analysis. Results: 48, 41, 55 differentially methylated genes (DMG) were identified after exposure to undigested NM-102, NM-103, NM-105; 71, 65, 55 DMG in the digested counterparts. Undigested TiO2NPs affected many G-proteins/adenylate cyclase-related pathways (PKA, glucagon, GPER1, CREB1, ADORA2B); the digested had lower impact. Cancer-related pathways were shared. Enriched molecular functions were mainly transcription-related; different biological processes were enriched if TiO2NPs were digested or not. Conclusions: TiO2NPs exposure causes DNA methylation changes that have a functional impact on intestinal cells, which differs with its physicochemical properties and digestion. NM-105 caused hypermethylation, unlike the other TiO2NPs. This study highlights DNA methylation relevance in assessing NMs’ toxicity.
- Impact of nanocelluloses on genome-wide DNA methylation pattern of human pulmonary and intestinal cellsPublication . Ventura, Célia; Vital, Nádia; Valente, Ana; Vieira, Luís; Louro, Henriqueta; Silva, Maria JoãoObjective: Nanocellulose is an innovative nanomaterial with interesting physicochemical properties for several industrial and biomedical applications and its safety for human health must be ensured. This study aimed to identify DNA methylation changes in human pulmonary and intestinal cells after exposure to two fibrillar celluloses with different physicochemical properties, both derived from Eucaliptus globulus. Their cellular effects were investigated in silico by functional pathway and gene ontology (GO) analysis. Methods: We applied Reduced Representation Bisulfite Sequencing to analyze the methylation differences in DNA CpG-rich regions from human bronchial (BEAS-2B) and intestinal (Caco-2) cells exposed for 24h to 14.3 µg/mL of cellulose nanofibrils (CNF) or microfibrils (CMF) versus non-exposed ones. A bioinformatics pipeline was implemented for identifying differentially methylated genes (DMGs), functional pathways, and GO associations. Results: CNF and CMF exposure resulted in 11 and 14 DMGs, respectively, in BEAS-2B cells, 6 being common to both nanocelluloses. In Caco-2 cells, 36 and 31 DMGs were identified, sharing 12 DMGs. No DMGs were shared between these cell lines. Hypomethylation predominated in BEAS-2B cells, and hypermethylation in Caco-2 cells. In BEAS-2B cells, both nanocelluloses affected similar pathways and GO terms (e.g., regulation of DNA replication, damage repair and senescence, telomere maintenance, and D-glucose transport). In Caco-2 cells, both CNF and CMF enriched, for instance, signal transduction, glycosylation, and cytoskeletal dynamics. Each nanocellulose type also affected other different pathways and terms. Conclusions: Nanocellulose may have a wide impact on the metabolism and survival of pulmonary and intestinal cells through several regulatory pathways, which depend on nanocellulose physicochemical properties. Cell type also influences the outcome, suggesting tissue-specific effects. These findings highlight the relevance of DNA methylation in nanotoxicology, providing insights into underlying molecular mechanisms of action. Keywords: gene ontology; nanomaterial; pathway analysis; RRBS
- Ingested titanium dioxide nanomaterials: new approach to investigate intestinal genotoxicity and key cellular/molecular effectsPublication . Ventura, Célia; Rolo, Dora; Gramacho, Ana C.; Vieira, Adriana; Roque, Rossana; Valente, Ana; Vital, Nádia; Pinto, Fátima; Alvito, Paula; Assunção, Ricardo; Martins, Carla; Bettencourt, Ana; Gonçalves, Lídia; Pereira, Joana; Matos, Paulo; Jordan, Peter; Vieira, Luís; Silva, Catarina; Silva, Maria Joao; Louro, HenriquetaOral exposure to titanium dioxide nanomaterials (TiO2NMs) is due to their presence in food, food contact materials, medicines and cosmetics. The gastrointestinal tract(GIT) represents primary site of contact, that may result in systemic exposure, if biological barriers are surpassed. The INGESTnano project aimed to investigate nano-bio interactions at the cellular/molecular levels within the context of the intestinal tract and digestion processes, for understanding potential effects on human health. A group of three TiO₂NMs(NM-102, NM-103, NM-105) was selected as case study using a new approach methodology(NAM), incorporating the in vitro human digestion simulation prior to biological assays in Caco-2 and HT29-MTX-E12 intestinal cells. The endpoints included cyto- and genotoxicity, cell uptake, intestinal permeability, GIT transport and epigenomic modifications. The results showed a more pronounced cytotoxicity in HT29-MTX-E12 cells for digested NM-105, as compared to undigested, concomitantly with subtle changes in hydrodynamic-size. DNA-damage induction was more relevant for NM-105, and the micronucleus assay showed chromosomal damage in HT29-MTX-E12 cells for all TiO2NMs, especially after in vitro digestion.All NMs, digested or not, were internalized by intestinal cells, but did not affect transepithelial resistance, nor the epithelial markers in polarized enterocytes. NM-102 was retained in lysosomes, while NM-103 and NM-105 showed transcytosis, a potential gateway for systemic distribution. Using Reduced Representation Bisulfite Sequencing, several differentially methylated genes were identified for the TiO₂NMs, either digested or not. Pathway and Gene Ontology analyses showed that each TiO2NMs has a different functional impact on intestinal cells, probably linked to specific physicochemical properties, and digestion seems to reduce this impact. A trend towards CpG hypermethylation was observed upon NM-105 exposure, unlike for the other TiO2NMs. This integrated approach enabled the identification of key events and molecular pathways elicited by TiO2NMs, highlighting the importance of considering the digestion on the induction of adverse outcomes.
- Perspetiva do consumidor relativa aos efeitos na saúde associados ao consumo de sumos detoxPublication . Santos, Inês Carvalho; Costa, H.S.; Silva, Mafalda A.; Valente, Ana; Albuquerque, T.G.Os sumos detox são uma nova tendência alimentar associada à perda de peso e a um estilo de vida saudável. São constituídos por frutas e hortícolas, alimentos naturalmente ricos em antioxidantes, compostos bioativos e vitaminas, cujo consumo está associado à redução de fatores de risco de doenças crónicas. O objetivo deste trabalho foi avaliar a perceção dos consumidores relativamente aos efeitos na saúde associados ao consumo de sumos detox. Foi desenvolvido e aplicado um questionário online a 285 indivíduos com idades compreendidas entre os 18 e os 84 anos. Os resultados obtidos indicaram que a maioria da população inquirida já ouviu falar em sumos detox e considera que estes não constituem uma boa opção para substituir refeições, embora lhes associe diversos benefícios. Relativamente aos benefícios nutricionais dos sumos detox, os inquiridos destacaram a sua riqueza vitamínica (80,7%), o seu poder de hidratação (61,4%), a sua riqueza mineral (57,9%) e seu teor de fibra (52,6%).