Browsing by Author "Correia, Sara"
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- Chemical signature and antimicrobial activity of Central Portuguese Natural Mineral Waters against selected skin pathogensPublication . Oliveira, AS; Vaz, CV; Silva, Ana; Ferreira, Sandra S.; Correia, Sara; Ferreira, Raquel; Granadeiro, Luiza Breitenfeld ; Oliveira, J. Martinez de; Oliveira, Rita Palmeira de; Pereira, C; Cruz, MT; Oliveira, Ana Palmeira deThe common therapeutic indications of Portuguese Natural Mineral Waters (NMWs) are primarily for respiratory, rheumatic and muscu- loskeletal systems. However, these NMWs have been increasingly sought for dermatologic purposes. Opposing to what is observed in the major European Thermal Centres, there are few scientific evidences supporting the use of Portuguese NMWs for clinical applications. The aim of this study was to characterize the antimicrobial profile of individual NMWs from the central region of Portugal and correlate the results with their physicochemical characterization. An extensive multivariate analysis (principal component analysis) was also performed to further investigate this possible correlation. Six collection strains representing skin microbiota, namely Staphylococcus aureus, Escher- ichia coli, Corynebacterium amycolatum, Candida albicans, Staphylococcus epidermidis and Cutibac- terium acnes, were analysed, and their antimicrobial profile was determined using Clinical and Laboratory Standards Institute M07-A10, M45-A2, M11-A6 and M27-A3 microdilution methods. Different NMWs presented different antimicrobial profiles against the strains used; the physicochemical composition of NMWs seemed to be correlated with the different susceptibility profiles. Cutibacterium acnes showed a particularly high susceptibility to all NMWs belong- ing sulphurous/bicarbonated/sodic ionic profile, exhibiting microbial reductions up to 65%. However, due to the complex physicochemical composition of each water an overall conclusion regarding the effect of a specific ion on the growth of different microor- ganisms is yet to be known.
- Effects of the endocrine disruptor vinclozolin in male reproduction: a systematic review and meta-analysisPublication . Feijó, Mariana; Martins, Roberta VL; Socorro, Sílvia; Pereira, L.; Correia, SaraEndocrine-disrupting chemicals have become an issue of scientific and public discussion. Vinclozolin (VNZ) is a fungicide that competitively antagonizes the binding of natural androgens to their receptor, disturbing the function of tissues that are sensitive to these hormones, as is the case of the male reproductive organs. A systematic review with meta-analyses of rodent studies was conducted to answer the following question: Does exposure to VNZ affect sperm parameters and testicular/epididymal weight? The methodology was prespecified according to the Cochrane Handbook for Systematic Reviews and PRISMA recommendations. Sixteen articles met the inclusion criteria, comprising a total of 1189 animals. The risk of publication bias was assessed using the Trim and Fill adjustment, funnel plot, and Egger regression test. Heterogeneity and inconsistency across the findings were tested using the Q-statistic and I2 of Higgins, respectively. Sensitivitywas also analyzed. Statistical analysiswas performed on Comprehensive Meta-Analysis software (Version 2.0), using random models and weighted mean differences along with a 95% confidence interval. Sperm motility, counts, daily sperm production (evidence of publication bias), and epididymis weight were decreased in VNZ-treated animals. Exposure length and dose, as well as the time point of exposure, influenced the obtained results. Despite the moderate/high heterogeneity observed, the sensitivity analysis overall demonstrated the robustness of the findings. The quality scores of the included studies were superior to 4 in a total of 9, then classified as good. The obtained data corroborate the capability of VNZ exposure to disrupt spermatogenic output and compromise male fertility.
- Estrogenic regulation of testicular expression of stem cell factor and c-kit: implications in germ cell survival and male fertilityPublication . Correia, Sara; Alves, Mário Rui Castanheira; Cavaco, José E.; Oliveira, P.F.; Socorro, SílviaObjective: To study the effect of estrogens regulating the testicular expression of stem cell factor (SCF) and c-kit. Design: Experimental study. Setting: University research center. Animal(s): Male Wistar rats. Intervention(s): Rat seminiferous tubules (SeT) cultured in the presence or absence of 17β-estradiol (E2). Main outcome measure(s): Expression of SCF and c-kit as well as apoptotic factors, FasL, FasR, Bcl-2, and Bax analyzed via quantitative reverse transcription-polymerase and Western blot; enzymatic activity of apoptosis effector caspase-3 assessed by colorimetric assay; proliferation index in SeT epithelium determined via fluorescent immunohistochemistry of nuclear proliferation marker Ki67. Result(s): E2 (100 nM) induced a decrease in c-kit expression while increasing expression of SCF. Altered expression of the SCF/c-kit system relied on apoptosis of germ cells, as evidenced by the up-regulated expression of FasL/FasR, the increased ratio of proapoptotic/antiapoptotic proteins (Bax/Bcl-2), and the augmented activity of caspase-3. Decreased proliferation was also found in SeT in response to E2. Conclusion(s): A 100 nM dose of E2 unbalance the SCF/c-kit system, with a crucial impact on germ cell survival and thus male fertility. These findings contribute to our knowledge of the mechanisms underlying male idiopathic infertility associated with hyperestrogenism and open new perspectives on treatment targeting estrogen-signaling mechanisms.
- Estrogens down-regulate the stem cell factor (SCF)/c-KIT system in prostate cells: Evidence of antiproliferative and proapoptotic effectsPublication . Figueira, Marília I; Correia, Sara; Vaz, Cátia; Cardoso, HJ; Gomes, Inês; Marques, Ricardo; Baptista, Cláudio; Socorro, SílviaThe development of prostate cancer (PCa) is intimately associated with the hormonal environment, and the sex steroids estrogens have been implicated in prostate malignancy. However, if some studies identified estrogens as causative agents of PCa, others indicated that these steroids have a protective role counteracting prostate overgrowth. The tyrosine kinase receptor c-KIT and its ligand, the stem cell factor (SCF), have been associated with the control of cell proliferation/apoptosis and prostate carcinogenesis, and studies show that estrogens regulate their expression in different tissues, though, in the case of prostate this remains unknown. The present study aims to evaluate the role of 17β-estradiol (E2) in regulating the expression of SCF/c-KIT in human prostate cell lines and rat prostate, and to investigate the consequent effects on prostate cell proliferation and apoptosis. qPCR, Western Blot, and immuno(cito)histochemistry analysis showed that E2-treatment decreased the expression of SCF and c-KIT both in human prostate cells and rat prostate. Furthermore, the diminished expression of SCF/c-KIT was underpinned by the diminished prostate weight and reduced proliferation index. On the other hand, the results of TUNEL labelling, the increased activity of caspase-3, and the augmented expression of caspase-8 and Fas system in the prostate of E2-treated animals indicated augmented apoptosis in response to E2. The obtained results demonstrated that E2 down-regulated the expression of SCF/c-KIT system in prostate cells, which was associated with antiproliferative and proapoptotic effects. Moreover, these findings support the protective role of estrogens in PCa and open new perspectives on the application of estrogen-based therapies.
- Glucose and glutamine handling in the Sertoli cells of transgenic rats overexpressing regucalcin: plasticity towards lactate productionPublication . Mateus, Inês; Feijó, Mariana; Espínola, Luís M; Vaz, CV; Correia, Sara; Socorro, SílviaSertoli cells (SCs) possess the unparalleled ability to provide the germ line with growth factors and nutrients. Although SCs can oxidize amino acids, e.g., glutamine, they mostly metabolize glucose, producing high amounts of lactate, the germ cells preferential substrate. Regucalcin (RGN) is a calcium-binding protein that has been indicated as a regulator of cell metabolism. In this study, we investigated glucose and glutamine handling in the SCs of transgenic rats overexpressing RGN (Tg-RGN) comparatively with wild-type (Wt) littermates. Primary SCs isolated from adult Tg-RGN animals and maintained in culture for 24 hours, produced and exported more lactate, despite consuming less glucose. These observations were underpinned by increased expression of alanine transaminase, and augmented glutamine consumption, suggesting that alternative routes are contributing to the enhanced lactate production in the SCs of Tg-RGN rats. Moreover, lactate seems to be used by germ cells, with diminished apoptosis being detected in the seminiferous tubules of Tg-RGN animals cultured ex vivo. The obtained results showed a distinct metabolism in the SCs of Wt and Tg-RGN rats widening the roles assigned to RGN in spermatogenesis. These findings also highlighted the plasticity of SCs metabolism, a feature that would be exploited in the context of male infertility.
- Hormonal regulation of c-KIT receptor and its ligand: implications for human infertility?Publication . Figueira, Marília I; Cardoso, HJ; Correia, Sara; Baptista, Cláudio; Socorro, SílviaThe c-KIT, a tyrosine kinase receptor, and its ligand the stem cell factor (SCF) play an important role in the production of male and female gametes. The interaction of SCF with c-KIT is required for germ cell survival and growth, and abnormalities in the activity of the SCF/c-KIT system have been associated with human infertility. Recently, it was demonstrated that gonadotropic and sex steroid hormones, among others, regulate the expression of SCF and c-KIT in testicular and ovarian cells. Therefore, the hormonal (de)regulation of SCF/c-KIT system in the testis and ovary may be a cause underpinning infertility. In the present review, we will discuss the effects of hormones modulating the expression levels of SCF and c-KIT in the human gonads. In addition, the implications of hormonal regulation of SCF/c-KIT system for germ cell development and fertility will be highlighted.
- Paradoxical and contradictory effects of imatinib in two cell line models of hormone-refractory prostate cancerPublication . Cardoso, HJ; Vaz, CV; Correia, Sara; Figueira, Marília I; Marques, Ricardo; Baptista, Cláudio; Socorro, SílviaImatinib mesylate is a chemotherapeutic drug that inhibits the tyrosine kinase activity of c-KIT and has been successfully used to treat leukemias and some solid tumors. However, its application for treatment of hormone-refractory prostate cancer (HRPC) has shown modest effectiveness and did not follow the outcomes in cultured cells or animal models. Moreover, the molecular pathways by which imatinib induces cytotoxicity in prostate cancer cells are poorly characterized.
- Propolis Protects GC-1spg Spermatogonial Cells against Tert-Butyl Hydroperoxide-Induced Oxidative DamagePublication . Duarte, Filipa Maia; Feijó, Mariana; Luís, Ângelo; Socorro, Sílvia; Maia, Cláudio J.; Correia, SaraPropolis is a natural resin produced by honeybees with plenty of pharmacologic properties, including antioxidant activity. Oxidative stress disrupts germ cell development and sperm function, with demonstrated harmful effects on male reproduction. Several natural antioxidants have been shown to reduce oxidative damage and increase sperm fertility potential; however, little is known about the effects of propolis. This work evaluated the role of propolis in protecting spermatogonial cells from oxidative damage. Propolis’ phytochemical composition and antioxidant potential were determined, and mouse GC-1spg spermatogonial cells were treated with 0.1–500 µg/mL propolis (12–48 h) in the presence or absence of an oxidant stimulus (tert-butyl hydroperoxide, TBHP, 0.005–3.6 µg/mL, 12 h). Cytotoxicity was assessed by MTT assays and proliferation by Ki-67 immunocytochemistry. Apoptosis, reactive oxygen species (ROS), and antioxidant defenses were evaluated colorimetrically. Propolis presented high phenolic and flavonoid content and moderate antioxidant activity, increasing the viability of GC-1spg cells and counteracting TBHP’s effects on viability and proliferation. Additionally, propolis reduced ROS levels in GC-1spg, regardless of the presence of TBHP. Propolis decreased caspase-3 and increased glutathione peroxidase activity in TBHP-treated GC-1spg cells. The present study shows the protective action of propolis against oxidative damage in spermatogonia, opening the possibility of exploiting its benefits to male fertility.
- Regucalcin is an androgen-target gene in the rat prostate modulating cell-cycle and apoptotic pathwaysPublication . Vaz, C V; Baptista, Cláudio; Marques, Ricardo; Gomes, Inês; Correia, Sara; Alves, Marco G; Cavaco, JE; Oliveira, Pedro F.; Socorro, SílviaRegucalcin (RGN) is a calcium (Ca(2+) )-binding protein underexpressed in prostate adenocarcinoma comparatively to non-neoplastic prostate or benign prostate hyperplasia cases. Moreover, RGN expression is negatively associated with the cellular differentiation of prostate adenocarcinoma, suggesting that loss of RGN may be associated with tumor onset and progression. However, the RGN actions over the control of prostate cell growth have not been investigated.
- Sweet Cherries as Anti-Cancer Agents: From Bioactive Compounds to FunctionPublication . Fonseca, Lara R. S.; Silva, Gonçalo R.; Luís, Ângelo; Cardoso, Henrique J.; Correia, Sara; Vaz, CV; Duarte, Ana Paula; Socorro, SílviaSweet cherries (Prunus avium L.) are among the most appreciated fruits worldwide because of their organoleptic properties and nutritional value. The accurate phytochemical composition and nutritional value of sweet cherries depends on the climatic region, cultivar, and bioaccessibility and bioavailability of specific compounds. Nevertheless, sweet cherry extracts are highly enriched in several phenolic compounds with relevant bioactivity. Over the years, technological advances in chemical analysis and fields as varied as proteomics, genomics and bioinformatics, have allowed the detailed characterization of the sweet cherry bioactive phytonutrients and their biological function. In this context, the effect of sweet cherries on suppressing important events in the carcinogenic process, such as oxidative stress and inflammation, was widely documented. Interestingly, results from our research group and others have widened the action of sweet cherries to many hallmarks of cancer, namely metabolic reprogramming. The present review discusses the anticarcinogenic potential of sweet cherries by addressing their phytochemical composition, the bioaccessibility and bioavailability of specific bioactive compounds, and the existing knowledge concerning the effects against oxidative stress, chronic inflammation, deregulated cell proliferation and apoptosis, invasion and metastization, and metabolic alterations. Globally, this review highlights the prospective use of sweet cherries as a dietary supplement or in cancer treatment.