Saccharomyces cerevisiae as a model to study synthetic cannabinoids : the impact of using different carbon sources

Abstract in proceedings of the Fourth International Congress of CiiEM: Health, Well-Being and Ageing in the 21st Century, held at Egas Moniz’ University Campus in Monte de Caparica, Almada, from 3–5 June 2019.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.info:eu-repo/semantics/publishedVersio

Stepwise functional evolution in a fungal sugar transporter family

This is a pre-copyedited, author-produced version of an article accepted for publication in Molecular Biology and Evolution following peer review. The version of record Mol Biol Evol (2016) 33 (2): 352-366 is available online at: http://mbe.oxfordjournals.org/content/33/2/352 DOI 10.1093/molbev/msv220."Sugar transport is of the utmost importance for most cells and is important to a wide range of applied fields. However, despite the straightforward in silico assignment of many novel transporters, including sugar porters, to existing families, their exact biological role and evolutionary trajectory often remain unclear, mainly because biochemical characterization of membrane proteins is inherently challenging, but also owing to their uncommonly turbulent evolutionary histories. In addition, many important shifts in membrane carrier function are apparently ancient, which further limits our ability to reconstruct evolutionary trajectories in a reliable manner.Here we circumvented some of these obstacles by examining the relatively recent emergence of a unique family of fungal sugar facilitators, related to drug antiporters. The former transporters, named Ffz, were previously shown to be required for fructophilic metabolism in yeasts. We first exploited the wealth of fungal genomic data available to define a comprehensive but well-delimited family of Ffz-like transporters, showing that they are only present in Dikarya. Subsequently, a combination of phylogenetic analyses and in vivo functional characterization was used to retrace important changes in function, while highlighting the evolutionary events that are most likely to have determined extant distribution of the gene, such as horizontal gene transfers (HGTs). One such HGT event is proposed to have set the stage for the onset of fructophilic metabolism in yeasts, a trait that according to our results may be the metabolic hallmark of approximately one hundred yeast species that thrive in sugar rich environments."info:eu-repo/semantics/publishedVersio

Adaptation of yeasts to fructose rich environments: a role for horizontal gene transfer of a fructose transporter

Abstract of the poster presented 33rd Small Meeting on Yeast Transport and Energetics, 21-24 July 2015, Lisbon, Portugal

Influence of intensive training on salivary flow, on salivary pH and on salivary lactate concentration: consequences for oral health

Abstract of the poster presented at the First international Congress of CiiEM “From Basic Sciences to Clinical Research”, 27-28 November 2015, Egas Moniz, Caparica, Portugal

Comparison of in-office and at-home tooth-whitening products cytotoxicity

Abstract in proceedings of the Fourth International Congress of CiiEM: Health, Well-Being and Ageing in the 21st Century, held at Egas Moniz’ University Campus in Monte de Caparica, Almada, from 3–5 June 2019.Abstract in proceedings of the Fourth International Congress of CiiEM: Health, Well-Being and Ageing in the 21st Century, held at Egas Moniz’ University Campus in Monte de Caparica, Almada, from 3–5 June 2019.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.info:eu-repo/semantics/publishedVersio

Drug-Loaded Hydrogels for Intraocular Lenses with Prophylactic Action against Pseudophakic Cystoid Macular Edema

Pseudophakic cystoid macular edema (PCME), caused by chronic inflammation, is the most common cause of visual impairment in the medium-term after cataract surgery. Therefore, the prophylactic topical administration of combined steroidal and non-steroidal anti-inflammatory drugs is commonly done. Drug-eluting intraocular lenses (IOLs) gained interest as an efficient way to overcome the compliance issues related to the use of ocular drops without the need for additional surgical steps. The incorporation of functional monomers and molecular imprinting were herein applied to design hydrogels suitable as IOLs and able to co-deliver steroidal (dexamethasone sodium phosphate) and non-steroidal (bromfenac sodium) drugs. The incorporation of N-(2-aminopropyl) methacrylamide (APMA) increased the drug uptake and improved the in vitro release kinetics. Imprinting with bromfenac resulted in a decreased drug release due to permanent drug bonding, while imprinting with dexamethasone increased the amount of dexamethasone released after dual-drug loading. The application of a mathematical model to predict the in vivo drug release behavior suggests the feasibility of achieving therapeutic drug concentrations of bromfenac and dexamethasone in the aqueous humor for about 2 and 8 weeks, respectively, which is compatible with the current topical prophylaxis after cataract surgeryThis project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement N° 813440 (OR-BITAL—Ocular Research by Integrated Training and Learning) and is also supported by Fundação para a Ciência e Tecnologia (FCT) [UID/QUI/00100/2019, UIDB/00100/2020, and UID/BIM/04585/2020].S

Challenges in matrix metalloproteinases inhibition

SAICT-POL/24288/2016 UIDB/50006/2020 UID/Multi/04378/2019Matrix metalloproteinases are enzymes that degrade the extracellular matrix. They have different substrates but similar structural organization. Matrix metalloproteinases are involved in many physiological and pathological processes and there is a need to develop inhibitors for these enzymes in order to modulate the degradation of the extracellular matrix (ECM). There exist two classes of inhibitors: endogenous and synthetics. The development of synthetic inhibitors remains a great challenge due to the low selectivity and specificity, side effects in clinical trials, and instability. An extensive review of currently reported synthetic inhibitors and description of their properties is presented.publishersversionpublishe

A new pathway for Mannitol metabolism in yeasts suggests a link to the evolution of alcoholic fermentation

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.The yeasts belonging to the Wickerhamiella and Starmerella genera (W/S clade) share a distinctive evolutionary history marked by loss and subsequent reinstatement of alcoholic fermentation mediated by horizontal gene transfer events. Species in this clade also share unusual features of metabolism, namely the preference for fructose over glucose as carbon source, a rare trait known as fructophily. Here we show that fructose may be the preferred sugar in W/S-clade species because, unlike glucose, it can be converted directly to mannitol in a reaction with impact on redox balance. According to our results, mannitol is excreted to the growth medium in appreciable amounts along with other fermentation products such as glycerol and ethanol but unlike the latter metabolites mannitol production increases with temperature. We used comparative genomics to find genes involved in mannitol metabolism and established the mannitol biosynthesis pathway in W/S-clade species Starmerella bombicola using molecular genetics tools. Surprisingly, mannitol production seems to be so important that St. bombicola (and other W/S-clade species) deploys a novel pathway to mediate the conversion of glucose to fructose, thereby allowing cells to produce mannitol even when glucose is the sole carbon source. Using targeted mutations and 13C-labeled glucose followed by NMR analysis of end-products, we showed that the novel mannitol biosynthesis pathway involves fructose-6-phosphate as an intermediate, implying a key role for a yet unknown fructose-6-P phosphatase. We hypothesize that mannitol production contributed to mitigate the negative effects on redox balance of the ancient loss of alcoholic fermentation in the W/S clade. Presently, mannitol also seems to play a role in stress protection.info:eu-repo/semantics/publishedVersio

Polymerizable matrix metalloproteinases’ inhibitors with potential application for dental restorations

Funding Information: This research was funded by A Molecular View of Dental Restoration, grant number PTDC/SAU-BMA/122444/2010 and by Molecular Design for Dental Restauration, grant number SAICT-POL/24288/2016. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Collagen cleavage by matrix metalloproteinase (MMP) is considered a major cause of dental resins long term failure. Most MMP inhibitors display significant toxicity and are unsuitable for dental resins’ applications. Here we report a study of a new class of inhibitors that display the unique property of being co-polymerizable with other vinyl compounds present in commercial dental resins, limiting their release and potential toxicity. Computational affinity towards the active site of different MMP-1;-2;-8;-9 and-13 of several compounds showed interesting properties and were synthesized. These free compounds were tested concerning their toxicity upon contact with two different cell types, with no substantial decrease in cell viability at high concentrations. Even so, compound’s safety can be further improved upon copolymerization with commercial dental resins, limiting their release.publishersversionpublishe

Fsy1, the sole hexose-proton transporter characterized in Saccharomyces yeasts, exhibits a variable fructose:H+ stoichiometry

AbstractIn the model yeast Saccharomyces cerevisiae, hexose uptake is mediated exclusively by a family of facilitators (Hxt, hexose transporters). Some other Saccharomyces species (e.g. Saccharomyces bayanus and Saccharomyces pastorianus) possess, in addition, a specific fructose transporter (Fsy1, fructose symporter) that has been previously described to function as a proton symporter. In the present work, we compared growth of a yeast strain in which FSY1 occurs naturally in anaerobic, fructose- and glucose-limited chemostat cultures. Especially at low specific growth rates, fructose-proton symport was shown to have a strong impact on the biomass yield on sugar. We subsequently employed energized hybrid plasma membrane vesicles to confirm previous observations concerning the mode of operation and specificity of Fsy1 mediated transport. Surprisingly, these experiments suggested that the carrier exhibits an unusual fructose:H+ stoichiometry of 1:2. This energetically expensive mode of operation was also found consistently in vivo, in shake flask and in chemostat cultures, and both when Fsy1 is the sole transporter and when the Hxt carriers are present. However, it is observed only when Fsy1 is operating at higher glycolytic fluxes, a situation that is normally prevented by downregulation of the gene. Taken together, our results suggest the possibility that fructose symport with more than one proton may constitute an energetically unfavorable mode of operation of the Fsy1 transporter that, in growing cultures, is prevented by transcriptional regulation