Efeitos do ácido acético e do etanol na respiração e na fermentação da glucose em Zygosaccharomyces bailii

AnexoZygosaccharomyces bailiié uma levedura de contaminação tipicamente considerada como das mais perigosas na indústria alimentar dada a sua aptidão para se desenvolver em condições de ambientes extremos muito particulares e presentes no processo final de estabilização e engarrafamento de vinhos

Selective activation of protein kinase C-δ and -ɛ by 6,11,12,14-tetrahydroxy-abieta-5,8,11,13-tetraene-7-one (coleon U)

6,11,12,14-tetrahydroxy-abieta-5,8,11,13-tetraene-7-one (coleon U) is a diterpene compound isolated from Plectranthus grandidentatus with an antiproliferative effect on several human cancer cell lines. Herein, we studied the modulatory activity of coleon U on individual isoforms of the three protein kinase C (PKC) subfamilies, classical (cPKC-α and -βI), novel (nPKC-δ and -ɛ) and atypical (aPKC-ζ), using a yeast PKC assay. The results showed that, whereas the PKC activator phorbol-12-myristate-13-acetate (PMA) activated every PKC tested except aPKC, coleon U had no effect on aPKC and cPKCs. Besides, the effect of coleon U on nPKCs was higher than that of PMA. This revealed that coleon U was a potent and selective activator of nPKCs. The isoform-selectivity of coleon U for nPKC-δ and -ɛ was confirmed using an in vitro PKC assay. Most importantly, while PMA activated nPKCs inducing an isoform translocation from the cytosol to the plasma membrane and a G2/M cell cycle arrest, coleon U induced nPKCs translocation to the nucleus and a metacaspase- and mitochondrial-dependent apoptosis. This work therefore reconstitutes in yeast distinct subcellular translocations of a PKC isoform and the subsequent distinct cellular responses reported for mammalian cells. Together, our study identifies a new isoform-selective PKC activator with promising pharmacological applications. Indeed, since coleon U has no effect on cPKCs and aPKC, recognised as anti-apoptotic proteins, and selectively induces an apoptotic pathway dependent on nPKC-δ and -ɛ activation, it represents a promising compound for evaluation as an anti-cancer drug.We are grateful to Dr. Nigel Goode for providing YEplac181-PKC-α, PKC-βI, PKC-δ, -PKC-ɛ and -PKC-ζ; to Dr. Heimo Riedel for providing YEp52-PKC-α and Yep51-PKC-βI; to Dr. Charles Rudin for providing pOW4-Bcl-xL; to Dr. Stéphen Manon for providing pCLbGFP-mt-GFP; to Joana Tavares for her help and technical advice in some experiments; to Cristina G-Marques for the previous isolation of coleon U; to Helena Vasconcelos for critical reading of the manuscript. We thank REQUIMTE/CEQUP and FCT (I&D No 8/94), POCTI (QCA III) and FEDER for financial support. I. Coutinho is recipient of a PhD fellowship from FCT (SFRH/BD/36066/2007).info:eu-repo/semantics/publishedVersio

Mitochondrial DNA variability in populations from East Timor (Timor Leste)

In this study we continue the genetic characterization of human populations from East Timor, as previously started for autosomal STRs and Y STRs, with a preliminary report on mitochondrial DNA (mtDNA) diversity. Individual samples (n = 133) collected from all the districts of East Timor and representing different linguistic groups were studied for the hypervariable region 1 (HVS1) sequence and the 9-bp deletion (intergenic region COII-tRNA lys).http://www.sciencedirect.com/science/article/B7581-4JSBXBX-1J/1/f4cc71eebbd2186e586bae7a77c79cc

Biological activity and cellular uptake of [Ru(eta(5)-C5H5)(PPh3)(Me(2)bpy)][CF3SO3] complex

Anticancer activity of the new [Ru(eta(5)-C5H5)(PPh3)(Me(2)bpy)][CF3SO3] (Me(2)bpy = 4,4'-dimethyl-2,2'-bipyridine) complex was evaluated in vitro against several human cancer cell lines, namely A2780, A2780CisR, HT29, MCF7, MDAMB231 and PC3. Remarkably, the IC50 values, placed in the nanomolar and sub-micromolar range, largely exceeded the activity of cisplatin. Binding to human serum albumin, either HSA (human serum albumin) or HSA(faf) (fatty acid-free human serum albumin) does not affect the complex activity. Fluorescence studies revealed that the present ruthenium complex strongly quench the intrinsic fluorescence of albumin. Cell death by the [Ru(eta(5)-C5H5)(PPh3)(Me(2)bpy)][CF3SO3] complex was reduced in the presence of endocytosis modulators and at low temperature, suggesting an energy-dependent mechanism consistent with endocytosis. On the whole, the biological activity evaluated herein suggests that the complex could be a promising anticancer agent. (C) 2013 Elsevier Inc. All rights reserved

Regulation of cell death induced by acetic acid in yeasts

Acetic acid has long been considered a molecule of great interest in the yeast research field. It is mostly recognized as a by-product of alcoholic fermentation or as a product of the metabolism of acetic and lactic acid bacteria, as well as of lignocellulosic biomass pretreatment. High acetic acid levels are commonly associated with arrested fermentations or with utilization as vinegar in the food industry. Due to its obvious interest to industrial processes, research on the mechanisms underlying the impact of acetic acid in yeast cells has been increasing. In the past twenty years, a plethora of studies have addressed the intricate cascade of molecular events involved in cell death induced by acetic acid, which is now considered a model in the yeast regulated cell death field. As such, understanding how acetic acid modulates cellular functions brought about important knowledge on modulable targets not only in biotechnology but also in biomedicine. Here, we performed a comprehensive literature review to compile information from published studies performed with lethal concentrations of acetic acid, which shed light on regulated cell death mechanisms. We present an historical retrospective of research on this topic, first providing an overview of the cell death process induced by acetic acid, including functional and structural alterations, followed by an in-depth description of its pharmacological and genetic regulation. As the mechanistic understanding of regulated cell death is crucial both to design improved biomedical strategies and to develop more robust and resilient yeast strains for industrial applications, acetic acid-induced cell death remains a fruitful and open field of study. © 2021 Chaves, Rego, Martins, Santos-Pereira, Sousa and Côrte-Real.This work was supported by the "Contrato-Programa" UIDB/04050/2020 funded by national funds through the FCT I.P.info:eu-repo/semantics/publishedVersio

A new family of iron(II)-cyclopentadienyl compounds shows strong activity against colorectal and triple negative breast cancer cells

The following is available online, Figure S1—1H NMR spectrum of complexes 6, in acetone-d6, Table S1. Bond lengths [Å] and angles [°] for [Fe(η5-Cp)(CO)(PhCN)(PPh3)][CF3SO3] 1, [Fe(η5-Cp)(CO)(p-NCPhNH2)(PPh3)][CF3SO3] 4 and [Fe(η5-Cp)(CO)(p-NCPhBr)(PPh3)][CF3SO3] 5, Table S2. Relevant TD-DFT (PBE0) excitation energies (λ), oscillator strengths (f) and compositions (only those > 5% are shown), for complexes 1–6, compared with experimental data (λexp). Both calculated and experimental values were obtained in dichloromethane, Figure S2—UV-Vis spectra of complexes 1–6 in DMSO along the 24 h study, Figure S3—UV-Vis spectra of complexes 1–6 in DMSO/DMEM mixture along the 24 h study and its variation plot (%) (bottom), Figure S4. ‘FeCp’ compounds affect the colony formation ability of SW480 cell line. Analysis of the colony formation ability, after 48 h of incubation with 1/4 IC50 and IC50, in SW480 cell line. Representative images of colony formation assay in SW480 cell line, Figure S5. ‘FeCp’ compounds induce apoptosis colorectal cancer-derived cell line. Apoptotic cell death was analyzed by Annexin V fluorescein isothiocyanate (AV-FITC) and propidium iodide (PI) assay in SW480 cells, after incubation with IC50 and 2×IC50 concentrations for 48 h. Representative histograms of SW480 cell line double stained with AV and PI, Table S4. Crystal data and structure refinement for [Fe(η5-Cp)(CO)(PhCN)(PPh3)][CF3SO3] 1, [Fe(η5-Cp)(CO)(p-NCPhNH2)(PPh3)][CF3SO3] 4 and [Fe(η5-Cp)(CO)(p-NCPhBr)(PPh3)][CF3SO3] 5.A family of compounds with the general formula [Fe(η5-C5H5)(CO)(PPh3)(NCR)]+ has been synthesized (NCR = benzonitrile (1); 4-hydroxybenzonitrile (2); 4-hydroxymethylbenzonitrile (3); 4-aminobenzonitrile (4); 4-bromobenzonitrile (5); and, 4-chlorocinnamonitrile (6)). All of the compounds were obtained in good yields and were completely characterized by standard spectroscopic and analytical techniques. Compounds 1, 4, and 5 crystallize in the monoclinc P21/c space group and packing is determined by short contacts between the phosphane phenyl rings and cyclopentadienyl (compounds 1 and 4) or π-π lateral interactions between the benzonitrile molecules (complex 5). DFT and TD-DFT calculations were performed to help in the interpretation of the experimental UV-Vis. data and assign the electronic transitions. Cytotoxicity studies in MDA-MB-231 breast and SW480 colorectal cancer-derived cell lines showed IC50 values at a low micromolar range for all of the compounds in both cell lines. The determination of the selectivity index for colorectal cells (SW480 vs. NCM460, a normal colon-derived cell line) indicates that the compounds have some inherent selectivity. Further studies on the SW480 cell line demonstrated that the compounds induce cell death by apoptosis, inhibit proliferation by inhibiting the formation of colonies, and affect the actin-cytoskeleton of the cells. These results are not observed for the hydroxylated compounds 2 and 3, where an alternative mode of action might be present. Overall, the results indicate that the substituent at the nitrile-based ligand is associated to the biological activity of the compounds.Centro de Química Estrutural acknowledges Fundação para a Ciência e Tecnologia (FCT) for the Project UIDB/00100/2020. This work was also funded in the scope of the project PTDC/QUI-QIN/28662/2017 (FCT) and by the strategic program UID/BIA/04050/2019 (FCT). A. Pilon and Ana Rita Brás thank FCT for their Ph.D. Grants (SFRH/BD/139412/2018 and SFRH/BD/139271/2018, respectively). A. Valente acknowledges the CEECIND 2017 Initiative (CEECIND/01974/2017). P. J Costa thank FCT for Investigador FCT Program IF/00069/2014, exploratory project IF/00069/2014/CP1216/CT0006, and strategic project UID/MULTI/04046/2019. P. J. Costa also acknowledges FCT, Programa Operacional Regional de Lisboa (Lisboa 2020), Portugal 2020, FEDER/FN, and the European Union for project LISBOA-01-0145-FEDER-028455 / PTDC/QUI-QFI/28455/2017

Synthesis and cytotoxicity assessment of citrate-coated calcium and manganese ferrite nanoparticles for magnetic hyperthermia

Calcium-doped manganese ferrite nanoparticles (NPs) are gaining special interest in the biomedical field due to their lower cytotoxicity compared with other ferrites, and the fact that they have improved magnetic properties. Magnetic hyperthermia (MH) is an alternative cancer treatment, in which magnetic nanoparticles promote local heating that can lead to the apoptosis of cancer cells. In this work, manganese/calcium ferrite NPs coated with citrate (CaxMn1−xFe2O4 (x=0, 0.2, 1), were synthesized by the sol-gel method, followed by calcination, and then characterized regarding their crystalline structure (by X-ray diffraction, XRD), size and shape (by Transmission Electron Microscopy, TEM), hydrodynamic size and zeta potential (by Dynamic Light Scattering, DLS), and heating efficiency (measuring the Specific Absorption Rate, SAR, and Intrinsic Loss Power, ILP) under an alternating magnetic field. The obtained NPs showed a particle size within the range of 10 nm to 20 nm (by TEM) with a spherical or cubic shape. Ca0.2Mn0.8Fe2O4 NPs exhibited the highest SAR value of 36.3 W/g at the lowest field frequency tested, and achieved a temperature variation of ~7 °C in 120 s, meaning that these NPs are suitable magnetic hyperthermia agents. In vitro cellular internalization and cytotoxicity experiments, performed using the human cell line HEK 293T, confirmed cytocompatibility over 0–250 µg/mL range and successful internalization after 24 h. Based on these studies, our data suggest that these manganese-calcium ferrite NPs have potential for MH application and further use in in vivo systems.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of CEB (UIDB/04469/2020), CBMA (UIDB/04050/2020) and CF-UM-UP (UIDB/04650/2020) units. R.G.D. Andrade and S.R.S. Veloso acknowledge FCT for the PhD grants 2020.05781.BD and SFRH/BD/144017/2019, respectively.info:eu-repo/semantics/publishedVersio

Isolation of an acetyl-CoA synthetase gene (ZbACS2) from Zygosaccharomyces bailii

A gene homologous to Saccharomyces cerevisiae ACS genes, coding for acetyl-CoA synthetase, has been cloned from the yeast Zygosaccharomyces bailii ISA 1307, by using reverse genetic approaches. A probe obtained by PCR amplification from Z. bailii DNA, using primers derived from two conserved regions of yeast ACS proteins, RIGAIHSVVF (ScAcs1p; 210–219) and RVDDVVNVSG (ScAcs1p; 574–583), was used for screening a Z. bailii genomic library. Nine clones with partially overlapping inserts were isolated. The sequenced DNA fragment contains a complete ORF of 2027 bp (ZbACS2) and the deduced polypeptide shares significant homologies with the products of ACS2 genes from S. cerevisiae and Kluyveromyces lactis (81% and 82% identity and 84% and 89% similarity, respectively). Phylogenetic analysis shows that the sequence of Zbacs2 is more closely related to the sequences from Acs2 than to those from Acs1 proteins. Moreover, this analysis revealed that the gene duplication producing Acs1 and Acs2 proteins has occurred in the common ancestor of S. cerevisiae, K. lactis, Candida albicans, C. glabrata and Debaryomyces hansenii lineages. Additionally, the cloned gene allowed growth of S. cerevisiae Scacs2 null mutant, in medium containing glucose as the only carbon and energy source, indicating that it encodes a functional acetyl-CoA synthetase. Also, S. cerevisiae cells expressing ZbACS2 have a shorter lag time, in medium containing glucose (2%, w/v) plus acetic acid (0.1–0.35%, v/v). No differences in cell response to acetic acid stress were detected both by specific growth and death rates. The mode of regulation of ZbACS2 appears to be different from ScACS2 and KlACS2, being subject to repression by a glucose pulse in acetic acid-grown cells. The nucleotide sequence of a common 5269 bp fragment has been deposited in the EMBL Data Library under Accession No. AJ314837.Fundação para a Ciência e a Tecnologia (FCT) - PRAXIS XXI P/AGR/11135/9