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- Distúrbios alimentares – anorexia: da auto-imagem às atitudes e comportamentosPublication . Fernandes, Rúben; Reis, AC.; Esteves-Pinto, A.; Fonte, R.; Coelho, Pedro; Prudêncio, CristinaSão ainda escassos os estudos sobre distúrbios alimentares em alunos do ensino universitário em Portugal. Estudos mais recentes indicam que poderá existir uma predisposição genética para a anorexia, no entanto, os fatores ambientais são os que apresentam um papel determinante, em particular factores sócio-económicos, psicológicos, biológicos entre outros. Entre esses diversos factores, sabe-se que a auto-imagem pode relacionar-se como múltiplos distúrbios alimentares como a anorexia e bulimia.
- Potentional radiosensitizer effect of TUDCA in a obesity model of brain tumor cellsPublication . Silva, Liliana; Almeida, Joana; Coelho, Pedro; Faria, Isabel; Monteiro, Armanda; Soares, Raquel; Vieira, Mónica; Prudêncio, Cristina; Fernandes, RúbenObesity may play an important role in the biology of seve ral types of cancer, but the correlation with glioma Is still not very well defined. Former studies indicated that obesity may be related with an decreased resistance to radiation and increased redox status in brain tumors. Since radiothetapy is the most commonly treatment modality used in this type of tumor, we creale a new model of experiments to determinate the influence of obesity in glioma cells [n the presence of radiation with an imbalance of redox status, BC3H1 glioma cells were treated with t-BOOH (150~M), TUDCA (25~M) and a mix of t-BOOH and TUOCA{150~M and 25~M respectively) in serum-free OMEM or conditioned media (CM) from differentiated 3T3-L 1 adj pocytes. Afterwards the cells were irradiated with a total dose of 2 Gy. Subsequently BC3H1 viability was evaluated, by MTT assay, after 4 and 12 hours. We observed an increase in viability In all cells treated solely with 3T3-L 1 eM. Interestingly, in the presence of CM plus TUDCA or t-BOOH, the viability of 6C3H1 was inferior of TUOCA or t~BOOH treatments alone, this effect was independent of irradia tion. After 12 hours the I/iability of the glioma cells was significantly higher on irradiated ceUs treated only with eM, this effect was not yet observed at the 4 hours time point But, in the presence of mix of t~BOOH and TUDCA, with eM and irradiation the cells viability decrea se significanUy. The 3T3-L 1 Me increase (he cell viabrlity in the presence of radiation or not, after 12 hours expose" But in the presence of oxidatIve inducer and, In specially, with the antioxidant TUDCA, the BC3Hi viability significantly decrease. So, we observed a potential radiosensitfzer effect of TUDCA in BC3H1 in the presence of 3T3-L1 adipocytes.
- Evaluation of the probiotic potential of a strain of Saccharomyces cerevisiaePublication . Areal-Hermida, Lara; Pichardo-Gallardo, Ángeles; Coelho, Pedro; Prudêncio, Cristina; Sieiro, CarmenAccording to the World Health Organization (WHO) and the Food and Agriculture Organization of the United Nations (FAO), probiotics are living microorganisms that, when administered in appropriate quantities, can confer a beneficial effect on the health of the host. Probiotic potential has been demonstrated especially for many strains of different species of bacteria. However, there are fewer strains of yeast for which their probiotic properties have been studied, despite their advantages, which include the fact that they are not affected by antibacterial antibiotics or their inability to disperse antibiotic resistance genes. As a result, there is a growing interest in characterizing new yeasts as probiotics. The aim of this study was to evaluate in our laboratories the probiotic potential of a strain of Saccharomyces cerevisiae var. boulardii (the main species marketed as a probiotic so far), to compare it with that of other yeasts. Strain identification was carried out by analyzing the ITS and D1/D2 regions of the rDNA. Regarding the ability of the strain to survive at 37ºC and resist gastrointestinal conditions, the strain showed 100 % viability at 37ºC and between 95-100 % in synthetic gastric and duodenal juices (pH 2-7.5, 0.3-10 % bile salts, 0.3 % pepsin and 0.1 % pancreatin). In addition, the selfaggregation and hydrophobicity properties shown by the strain allowed inferring the ability to adhere to the intestine, which was confirmed in Caco-2 cells. Additionally, the strain presented other properties of interest for probiotics, including a high anti-oxidant capacity and pathogen coaggregation, as well as a variable cytotoxic activity against different tumor cell lines.
- A hiperglicemia e o secretoma de adipócitos alteram o padrão de crescimento de micobactérias in vitroPublication . Fernandes, Rúben; Bronze, M.; Pereira, C.; Coelho, Pedro; Prudêncio, Cristina
- Adipocyte secretome increases radioresistance of malignant melanocytes by improving cell survival and decreasing oxidative statusPublication . Coelho, Pedro; Silva, Liliana; Faria, Isabel; Vieira, Mónica; Monteiro, Armanda; Pinto, Gabriela; Prudêncio, Cristina; Fernandes, Rúben; Soares, RaquelRadiotherapy is a treatment option for the majority of malignancies. However, because melanoma is known to be radioresistant, the use of ionizing radiation as an adjuvant therapy in cutaneous melanoma patients is ineffective. Obesity has now been recognized as a risk factor for melanoma. High adiposity is generally associated with a more pro-oxidative status. Oxidative stress is a major player in radiation therapy and also a common link between obesity and cancer. Several adipocyte-released proteins are known to have a role in controlling cellular growth and pro-survival signaling. For that reason, we investigated the influence of 3T3-L1 mature adipocyte secretome in B16-F10 malignant melanocyte radiosensitivity. We evaluated B16-F10 cell survival and redox homeostasis when exposed to four daily doses of ionizing radiation (2 Gy per day) up to a total of 8 Gy in a medical linear accelerator. B16-F10 melanocytes exhibited slight alterations in survival, catalase activity, nitrative stress and total oxidant concentration after the first 2 Gy irradiation. The motility of the melanocytes was also delayed by ionizing radiation. Subsequent irradiations of the malignant melanocytes led to more prominent reductions in overall survival. Remarkably, 3T3-L1 adipocyte-secreted molecules were able to increase the viability and migration of melanocytes, as well as lessen the pro-oxidant burden induced by both the single and cumulative X-ray doses. In vitro adipocyte-released factors protected B16-F10 malignant melanocytes from both oxidative stress and loss of viability triggered by radiation, enhancing the radioresistant phenoyype of these cells with a concomitant activation of the AKT signaling pathway These results both help to elucidate how obesity influences melanoma radioresistance and support the usage of conventional medical linear accelerators as a valid model for the in vitro radiobiological study of tumor cell lines.
- Adipocyte-released factors enhance melanocyte’s proliferation and motilityPublication . Fernandes, Rúben; Coelho, Pedro; Almeida, Joana; Prudêncio, Cristina; Soares, RaquelObesity, favored by the modern lifestyle, acquired epidemic proportions nowadays. Obesity has been associated with various major causes of death and morbidity including malignant neoplasms. Cutaneous melanoma incidence rates have also been increasing uring the last four decades in several countries. Obesity involvement in melanoma etiology has been recognized, but the implicated mechanisms remain unclear. We propose to address the above relationship and investigate the mechanism interplaying between obesity and an increased risk of melanoma onset.
- Book of abstracts 4th Meeting on Medicinal Biotechnology (4EBtM)Publication . Costa, Ana Rita; Dias, Ana Rita; Prudêncio, Cristina; Borges, Cristina; Teixeira, Dulce; Almeida, Joana; Vieira, Mónica; Coelho, Pedro; Ferraz, Ricardo; Cunha, SofiaThese meetings have been held once a year since 2015 and have played an important role as a point of contact among several professionals and students in Medicinal Biotechnology. Like the Medicinal Biotechnology field itself, these meetings have also been expanding, not only in the number of participants, but also in their geographical origin. Therefore, it is our goal to act as an interface between students and biotechnology companies/researchers, as well as to increasingly promote networking, projects and collaborations within this field for the upcoming years.
- Development of a chromatographic method for simultaneous analysis of glutathione formsPublication . Teixeira, Dulce; Coelho, Pedro; Prudêncio, Cristina; Azenha, Manuel; Vieira, MónicaReduced glutathione (GSH)is the most abundant low molecular weight thiol-containing tripeptide (glycine, cysteine, and glutamate) which is synthesized in the cells. GSHplays critical roles in protecting cells from oxidative damage and the toxicity of xenobiotics. Besides, it is also involved in the regulation of intracellular redox homeostasis, which leads to its oxidation into oxidized glutathione (GSSG). Determining the ratio of GSH/GSSG in different biological samples is a major procedure for the evaluation of an individual’s oxidative status and can be a potential biomarker of oxidative stress.
- Quinoxaline-1, 4-dioxide derivatives inhibitory action in melanoma and brain tumor cellsPublication . Silva, Liliana; Coelho, Pedro; Soares, Raquel; Prudêncio, Cristina; Vieira, MónicaQuinoxaline-1,4-dioxide derivatives are synthetic heterocyclic compounds with multiple biological and pharmacological effects. In this study, we investigated the bioactivity of five quinoxaline-1,4-di-N-oxides derivatives in different animal cell lines.
- Differential imune response to vitamin A in B16-F10 malignant melanocytesPublication . Oliveira, S.; Coelho, Pedro; Costa, J.; Prudêncio, Cristina; Soares, R.; Guerreiro, S. G.; Fernandes, RúbenMelanoma is an aggressive form of skin cancer with a poor prognosis, due to its refractory behavior to radiation and chemotherapy. Although the diagnosis is straightforward, there are many disagreements regarding its treatment and surveillance. In order to surpass some of the limitations addressed to the treatment, preventive methods like antioxidant vitamins are nowadays a relevant field of research, as well as immunostimulation by external agents. Despite the knowledge about melanoma biology, pathogenesis and developed therapies, is important to understand the effect of vitamin A in order to suggest alternatives to conventional therapies, which are known to be ineffective against melanoma.
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