Low-dose effects of Bisphenol A on human primary vascular endothelial cells and colon cancer cells

Doutoramento em Biologia - Instituto Superior de AgronomiaBisphenol A (BPA) is an extensively utilized endocrine disruptor for which human exposure is considered generalized through ingestion. Information regarding BPA effects on vascular and digestive tract tissues is scarce. Therefore, in this work primary Human Umbilical Vein Endothelial Cells (HUVEC) and human colon adenocarcinona cell line HT29 were used to evaluate BPA effects at two distinct low-dose concentrations relevant in terms of human health risk assessment. BPA differentially affects the cell types studied, with more pronounced aneugenic effects, nucleolar disruption and transcriptional deregulation observed in HUVEC. Prolonged BPA exposure affects aging processes in senescent HUVEC. Interaction experiments involving expression of key cancer related genes shows that BPA antagonizes transcriptional effects of the chemotherapeutic agent doxorubicin in HT29. Additionally BPA aneugenic effects are enhanced by co-exposure with Eupatorium cannabinum L. ethanolic extract, a medicinal plant, for which a potent cytotoxic activity against HT29 cells is also demonstrated here. Altogether these results support increasing concerns regarding harmful effects of BPA at low-dose on human health and draw attention to the importance of a deeper understanding of BPA potential interactions with other chemicals

Bisphenol A alters transcript levels of biomarker genes for major depressive disorder

Major depressive disorder is a moderately heritable disorder characterized by one or more major depressive episodes. Laboratory tests to suport MDD diagnosis are not available. Diagnosis and treatment are based on various signs and symptoms not always fitting into strict diagnostic categories. Research for biological markers of neuropsychiatric disorders has been a challenge

The efficiency of urine dipsticks for the diagnosis of urinary tract infection

Urinary tract infection (UTI) is one of the most prevalent pathologies in developed countries, particularly in women, characterized by the presence of bacterial growth in any part of the urinary system. Currently, urine culture is considered the gold standard method for the diagnosis of UTI. However, this method has several disadvantages including the time necessary for obtaining the results and the associated high costs. Therefore, it is important to evaluate new efficient and valuable methods for the diagnosis of these infections. Objectives: Presently, dipsticks are considered a possible valuable alternative to urine culture. This method has very low costs associated and the results can be obtained in few minutes. Here we aim to compare the sensibility, specificity, predictive value of a positive test and a negative test of both methods in order to determine the efficiency of the test strips method and also to characterize the microorganism more frequently isolated

DNA methylation in diabetic macular edema: first report

Projeto IPL/2021/DiffMeDiME_ESTeSLEnvelhecimento humano e estilos de vida tem contribuído para aumento da DM. Edema macular diabético (EMD), uma das manifestações oculares da RD, é a principal causa de perda de visão em pessoas diabéticas. 30-40% casos EMD não respondem da melhor forma aos AVEGF (loading phase). Resistência pode persistir após 12 meses tratamento (+/50%). Objetivo do estudo: Desenvolver uma caracterização multimodal não invasiva (SD OCT e OCT A) combinada com a avaliação da metilação de DNA de forma a pode esclarecer alguns mecanismos importantes da doença mas também para novas abordagens terapêuticas que contribuem para a medicina de precisão.info:eu-repo/semantics/publishedVersio

DNA methyltransferase expression (DNMT1, DNMT3a and DNMT3b) as a potential biomarker for anti-VEGF diabetic macular edema response

Funding Information: This project was partially supported by an IDI&CA grant IPL/2021/DiffMeDiME_ESTeSL by H&TRC- Health & Technology Research Center, ESTeSL- Escola Superior de Tecnologia da Saúde, Instituto Politécnico de Lisboa and by Retina Institute of Lisbon (IRL).Purpose: DNA methylation is involved in Diabetic Retinopathy progression showing a metabolic memory mechanism. However, the association of DNA methyltransferase with diabetic macular edema is still unknown. We aimed to describe the differences in DNA methyltransferase gene expression in patients with different diabetic macular edema responses. Methods: A total of 27 diabetic patients, aged 59–90 years, were prospectively enrolled in this cross-sectional study. The participants were classified into control group (CG, n = 11), diabetic macular edema responders (rDME, n = 9) and non-responder diabetic macular edema (nrDME, n = 7) after anti-vascular endothelial growth factor (anti-VEGF) treatment. Only cases with a complete ophthalmological examination, digital 133° color fundus, and SD-OCT assessments were used. After RNA extraction and first-strand cDNA synthesis, quantitative real-time PCR was performed with specific primers on the CFX Connect™ Real-Time PCR Detection System to assess differential transcriptional expression patterns. Results: The DNMT1 gene showed a positive correlation (r = 0.617; p = 0.043) with Best Corrected Visual Acuity (BCVA) in CG, a positive correlation (r = 0.917; p = 0.010) with HbA1c in nrDME and a negative correlation (r = −0.659; p = 0.049) with GCL-IPL thickness in rDME. DNMT3A gene showed a positive correlation (r = −0.890; p = 0.001) with Sub-foveal Choroidal thickness in rDME whereas DNMT3b gene showed a negative correlation (r = −0.815; p = 0.007) with HbA1c and RNFL (r = −0.664; p = 0.026) in CG. Conclusions: Patients with similar metabolic profile risk factors showed associated DNA methyltransferase transcriptional expression patterns differences fitting with the anti-VEGF diabetic macular edema response. Further studies are needed to clarify if these results (1) reflect disease evolution, (2) translate the therapeutic impact, (3) or can help to predict the therapeutic resistance profile.publishersversionepub_ahead_of_prin

Role of DNA methylation in persistent diabetic macular edema

Projeto ID&CA 2021_IPL/2021/DiffMeDiME_ESTeSLBackground: a) Disease duration and metabolic control are insufficient to understand Diabetic Macular Edema (DME), the leading cause of vision loss in people with diabetes; b) 30-40% of cases of DME do not respond optimally to AVEGF (loading phase); c) poor genetic association in DR development (<25% RD) and PDR progression (25-50%). Purpose: To study the role of DNA methyltransferase expression (DNMT1,DNMT3a, DNMT3b) in persistent diabetic macular edema.info:eu-repo/semantics/publishedVersio

O paradigmático Bisfenol A: exposição humana ambiental e ocupacional e efeitos associados

Os desreguladores endócrinos (EDCs) são uma importante preocupação para a saúde humana devido aos seus potenciais efeitos negativos. Por definição, os EDCs têm a capacidade de interferir com a sinalização hormonal através da sua capacidade de ligação aos recetores hormonais e, deste modo, afetar o normal funcionamento do sistema endócrino. O sistema endócrino regula a transcrição génica através de moléculas sinalizadoras, hormonas, que atuam em baixas concentrações. Assim, a exposição a EDCs, mesmo em baixas doses, pode ter efeitos biológicos adversos. Entre os EDCs, o 4,4'-isopropylidene diphenol (Bisphenol A:BPA) destaca-se como um caso paradigmático de um xenoestrógeneo sintético, utilizado na produção de plásticos e das resinas de cola Epoxy, encontrando-se presente numa grande variedade de produtos para consumo humano. Estudos epidemiológicos têm revelado correlações positivas entre a presença de BPA em amostras biológicas humanas e a ocorrência de várias patologias, como infertilidade e desregulação do sistema reprodutivo, diabetes Mellitus tipo II e obesidade

Low-dose effects of Bisphenol A on human primary and cancer cells

Bisphenol A (BPA), 2,2-bis(4-hydroxyphenyl) propane is an organic compound and one of the greatest volume industrial chemicals produced worldwide. Human exposure to BPA, in the range of the called “low-doses”, is considered a generalized phenomenon particularly through oral intake. Biomonitoring studies reveal the presence of BPA in the majority of the individuals from developed countries. BPA is a well characterized endocrine disruptor which can endorse very distinct cellular responses through several estrogen receptor signalling pathways frequently associated to cell type specificities. Extensive research in human cell lines from sex hormone responsive tissues have demonstrated the potential harmful effects of BPA exposure including carcinogenesis. However, although BPA is absorbed in the gut and enters blood circulation, its effects on cells from digestive or vascular systems are largely unknown. There is an urgent need to address increasing concerns regarding the potential adverse effects of BPA low-dose exposures and to evaluate potential interactions in the context of human health risk assessment.info:eu-repo/semantics/publishedVersio

Bisphenol A at the reference level counteracts doxorubicin transcriptional effects on cancer related genes in HT29 cells

Human exposure to Bisphenol A (BPA) results mainly from ingestion of food and beverages. Information regarding BPA effects on colon cancer, one of the major causes of death in developed countries, is still scarce. Likewise, little is known about BPA drug interactions although its potential role in doxorubicin (DOX) chemoresistance has been suggested. This study aims to assess potential interactions between BPA and DOX on HT29 colon cancer cells. HT29 cell response was evaluated after exposure to BPA, DOX, or co-exposure to both chemicals. Transcriptional analysis of several cancer-associated genes (c-fos, AURKA, p21, bcl-xl and CLU) shows that BPA exposure induces slight up-regulation exclusively of bcl-xl without affecting cell viability. On the other hand, a sub-therapeutic DOX concentration (40 nM) results in highly altered c-fos, bcl-xl, and CLU transcript levels, and this is not affected by co-exposure with BPA. Conversely, DOX at a therapeutic concentration (4 μM) results in distinct and very severe transcriptional alterations of c-fos, AURKA, p21 and CLU that are counteracted by co-exposure with BPA resulting in transcript levels similar to those of control. Co-exposure with BPA slightly decreases apoptosis in relation to DOX 4 μM alone without affecting DOX-induced loss of cell viability. These results suggest that BPA exposure can influence chemotherapy outcomes and therefore emphasize the necessity of a better understanding of BPA interactions with chemotherapeutic agents in the context of risk assessment

Endocrine disruptors mixtures: the real scenario of human exposure

Endocrine disrupting chemicals (EDCs) are exogenous agents that have the ability to interfere with/or mimic estrogenic hormones and, therefore can simultaneously and differentially trigger specific signaling pathways responsible for the nature and magnitude of biological responses in diverse cell types. Human exposure to EDCs, particularly at low-doses, is ubiquitous, persistent and occurs in complex mixtures. These compounds can bioaccumulate in lipid compartments of tissues forming a mixed “body burden” of contaminants of different origins. Although the independent action of chemicals has been considered the main principle in EDCs mixture toxicity, several effects cannot be predicted when analyzing single compounds individually. Based in a revision of the literature, focused in studies that evaluated EDCs mixtures, we hypothesize the scenario of a pregnant woman environmentally exposed to three different EDCs as a potential real scenario of human exposure supported by data describing where exposure to these compounds occur