RESUMO
Fear of death is an emotional manifestation of the instinct for self-preservation. Any threat to our existence induces an anxiety response. Death anxiety can trigger obsessive-compulsive behaviours, such as an obsessive passion for work. Using a sample of 314 participants (68.2% female), with a mean age of 38.97 years (SD = 10.36), this study sought to observe the predictive effect of death anxiety on work passion, as well as the moderating effect of work-family centrality and connection on the relationship between anxiety and passion. The results revealed that death anxiety negatively affects harmonious passion, and positively affects obsessive passion. Work centrality did not moderate the influence of death anxiety on harmonious and obsessive passion. Nonetheless, work connection moderated the influence of death anxiety on harmonious passion. The negative influence of death anxiety on harmonious passion was greater in a group with high work connection than a group with low connection.
RESUMO
Chronic intermittent hypoxia (CIH) is a major contributor to the development of hypertension (HTN) in obstructive sleep apnea (OSA). OSA subjects frequently display a non-dipping pattern of blood pressure (BP) and resistant HTN. After discovering that AHR-CYP1A1 axis is a druggable target in CIH-HTN, we hypothesized that CH-223191 could control BP in both active and inactive periods of the animals, recovering the BP dipping profile in CIH conditions.We evaluated the chronopharmacology of the antihypertensive efficacy of the AhR blocker CH-223191 in CIH conditions (21% to 5% of O2, 5.6 cycles/h, 10.5 h/day, in inactive period of Wistar rats). BP was measured by radiotelemetry, at 8 am (active phase) and at 6 pm (inactive phase) of the animals. The circadian variation of AhR activation in the kidney in normoxia was also assessed, measuring the CYP1A1 (hallmark of AhR activation) protein levels.Despite drug administration before starting the inactive period of the animals, CH-223191 was not able to decrease BP during the inactive phase, in CIH conditions, therefore not reverting the non-dipping profile. These results suggest that a higher dose or different time of administration of CH-223191 might be needed for an antihypertensive effect throughout the 24-h cycle.
Assuntos
Hipertensão , Apneia Obstrutiva do Sono , Ratos , Animais , Anti-Hipertensivos/farmacologia , Anti-Hipertensivos/uso terapêutico , Citocromo P-450 CYP1A1/genética , Ratos Sprague-Dawley , Ratos Wistar , HipóxiaRESUMO
The chemical modification of natural compounds is a promising strategy to improve their frequently poor bioavailability and low potency. This study aimed at synthesizing chemical derivatives of carvone, a natural monoterpene with anti-inflammatory properties, which we recently identified, and evaluating their potential anti-inflammatory activity. Fourteen chemical derivatives of carvone were synthesized, purified and their chemical structures confirmed. Noncytotoxic concentrations of the test compounds were selected based on the resazurin reduction assay. Among the tested compounds, four significantly reduced the lipopolysaccharides-induced protein levels of the inducible isoform of the nitric oxide synthase and nitric oxide production and showed a dual effect on pro-IL-1 protein levels in the Raw 264.7 cell line. The Ligand Express drug discovery platform was used to predict the targets of the test compounds, and an enrichment analysis was performed to group the different biological processes and molecular and cellular functions of the tested compounds. Moreover, Ligand Express also predicted that all chemicals evaluated have intestinal and blood-brain barrier permeability, do not inhibit P-gp and do not interact with major receptors. Although presenting anti-inflammatory and some advantageous ADME properties, the tested compounds still have low potency and specificity but may provide novel structures the further chemical modification of which may yield more promising drugs.
Assuntos
Anti-Inflamatórios , Macrófagos , Camundongos , Animais , Ligantes , Óxido Nítrico Sintase Tipo II/metabolismo , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/metabolismo , Macrófagos/metabolismo , Células RAW 264.7 , Óxido Nítrico/metabolismo , Lipopolissacarídeos/farmacologia , Lipopolissacarídeos/metabolismoRESUMO
Peritoneal membrane status, clinical data and aging-related molecules were investigated as predictors of long-term peritoneal dialysis (PD) outcomes. A 5-year prospective study was conducted with the following endpoints: (a) PD failure and time until PD failure, (b) major cardiovascular event (MACE) and time until MACE. A total of 58 incident patients with peritoneal biopsy at study baseline were included. Peritoneal membrane histomorphology and aging-related indicators were assessed before the start of PD and investigated as predictors of study endpoints. Fibrosis of the peritoneal membrane was associated with MACE occurrence and earlier MACE, but not with the patient or membrane survival. Serum α-Klotho bellow 742 pg/mL was related to the submesothelial thickness of the peritoneal membrane. This cutoff stratified the patients according to the risk of MACE and time until MACE. Uremic levels of galectin-3 were associated with PD failure and time until PD failure. This work unveils peritoneal membrane fibrosis as a window to the vulnerability of the cardiovascular system, whose mechanisms and links to biological aging need to be better investigated. Galectin-3 and α-Klotho are putative tools to tailor patient management in this home-based renal replacement therapy.
Assuntos
Fragilidade , Falência Renal Crônica , Diálise Peritoneal , Fibrose Peritoneal , Humanos , Estudos Prospectivos , Galectina 3 , Fibrose Peritoneal/patologia , Envelhecimento , Falência Renal Crônica/terapiaRESUMO
Biallelic mismatch repair deficiency (BMMRD) is a rare autosomal recessive disorder characterized by numerous early-onset cancers, especially gastrointestinal tumors. Biallelic germline mutations in one of four mismatch repair (MMR) genes (MLH1, MSH2, MSH6, or PMS2) cause this devastating disease. Given the rarity of the syndrome, often-asymptomatic tumors, diagnosis is frequently unrecognized or delayed. A high degree of clinical awareness is needed to identify new cases. Immunohistochemical assessment of MMR protein expression and analysis of microsatellite instability are the first tools with which to initiate the study of this syndrome in solid malignancies. MMR immunohistochemical shows a hallmark pattern with absence of staining in both neoplastic and non-neoplastic cells for the biallelic mutated gene. We present a unique case of a young boy diagnosed with invasive colon adenocarcinoma and brain tumor, with classical BMMRD features, found to have biallelic pathogenic PMS2 mutations.
Assuntos
Adenocarcinoma , Neoplasias Encefálicas , Neoplasias do Colo , Neoplasias Colorretais , Masculino , Humanos , Neoplasias do Colo/patologia , Endonuclease PMS2 de Reparo de Erro de Pareamento/genética , Endonuclease PMS2 de Reparo de Erro de Pareamento/metabolismo , Adenocarcinoma/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Neoplasias Colorretais/genética , Reparo de Erro de Pareamento de DNA , Instabilidade de MicrossatélitesRESUMO
Osteoarthritis (OA) and Obstructive Sleep Apnea (OSA) are two highly prevalent chronic diseases for which effective therapies are urgently needed. Recent epidemiologic studies, although scarce, suggest that the concomitant occurrence of OA and OSA is associated with more severe manifestations of both diseases. Moreover, OA and OSA share risk factors, such as aging and metabolic disturbances, and co-morbidities, including cardiovascular and metabolic diseases, sleep deprivation and depression. Whether this coincidental occurrence is fortuitous or involves cause-effect relationships is unknown. This review aims at collating and integrating present knowledge on both diseases by providing a brief overview of their epidemiology and pathophysiology, analyzing current evidences relating OA and OSA and discussing potential common mechanisms by which they can aggravate each other. Such mechanisms constitute potential therapeutic targets whose pharmacological modulation may provide more efficient ways of reducing the consequences of OA and OSA and, thus, lessen the huge individual and social burden that they impose.
Assuntos
Osteoartrite/epidemiologia , Apneia Obstrutiva do Sono/epidemiologia , Envelhecimento , Animais , Comorbidade , Humanos , Osteoartrite/tratamento farmacológico , Fatores de Risco , Apneia Obstrutiva do Sono/tratamento farmacológicoRESUMO
Estrogen hormones are important for cartilage homeostasis, but nothing is known regarding the expression and role of the membrane G protein-coupled estrogen receptor (GPER), G protein-coupled receptor 30 (GPR30), in adult articular chondrocytes. Using immunohistochemistry of cartilage sections, quantitative real-time polymerase chain reaction and Western blot of chondrocyte extracts, we found that these cells express GPR30. Nonetheless, the pattern of bands detected by two distinct antibodies does not overlap, suggesting that the proteins detected represent partially degraded forms of the receptor. Treatment with GPR30 agonists did not induce Akt or ERK1/2 phosphorylation, two known GPR30-activated signaling pathways, suggesting that GPR30 is not functional in human chondrocytes. Therefore, the protective anti-osteoarthritic role of estrogen hormones in cartilage homeostasis is likely independent of GPR30. This study was performed using human cartilage collected from the distal femoral condyles of multiorgan donors at the Bone and Tissue Bank of the University and Hospital Center of Coimbra.
Assuntos
Cartilagem/metabolismo , Condrócitos/metabolismo , Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptor alfa de Estrogênio/metabolismo , Estrogênios/metabolismo , Humanos , Proteína Quinase 3 Ativada por Mitógeno , Transdução de Sinais/efeitos dos fármacosRESUMO
Acute lymphoblastic leukemia maintenance chemotherapy includes mercaptopurine, a purine analog with uncommon side effects, that can be life-threatening. We describe a 7-year-old female patient with ALL that presented with altered state of consciousness after maintenance chemotherapy with methotrexate and 6-mercaptopurine, due to severe hypoglycemia with metabolic acidosis. She initiated metabolic corrections with rapid resolution of symptoms. Hypoglycemia secondary to 6-mercaptopurine is a rare and transient side effect. The cause effect relation is difficult to establish, leading to underdiagnosis. Hypoglycemia is preventable without compromising maintenance therapy efficacy.
Assuntos
Acidose , Hipoglicemia , Mercaptopurina , Leucemia-Linfoma Linfoblástico de Células Precursoras , Acidose/sangue , Acidose/induzido quimicamente , Acidose/diagnóstico , Criança , Feminino , Humanos , Hipoglicemia/sangue , Hipoglicemia/induzido quimicamente , Hipoglicemia/diagnóstico , Mercaptopurina/administração & dosagem , Mercaptopurina/efeitos adversos , Leucemia-Linfoma Linfoblástico de Células Precursoras/sangue , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Índice de Gravidade de DoençaRESUMO
The protocadherins Fat4 and Dchs1 act as a receptor-ligand pair to regulate many developmental processes in mice and humans, including development of the vertebrae. Based on conservation of function between Drosophila and mammals, Fat4-Dchs1 signalling has been proposed to regulate planar cell polarity (PCP) and activity of the Hippo effectors Yap and Taz, which regulate cell proliferation, survival and differentiation. There is strong evidence for Fat regulation of PCP in mammals but the link with the Hippo pathway is unclear. In Fat4(-/-) and Dchs1(-/-) mice, many vertebrae are split along the midline and fused across the anterior-posterior axis, suggesting that these defects might arise due to altered cell polarity and/or changes in cell proliferation/differentiation. We show that the somite and sclerotome are specified appropriately, the transcriptional network that drives early chondrogenesis is intact, and that cell polarity within the sclerotome is unperturbed. We find that the key defect in Fat4 and Dchs1 mutant mice is decreased proliferation in the early sclerotome. This results in fewer chondrogenic cells within the developing vertebral body, which fail to condense appropriately along the midline. Analysis of Fat4;Yap and Fat4;Taz double mutants, and expression of their transcriptional target Ctgf, indicates that Fat4-Dchs1 regulates vertebral development independently of Yap and Taz. Thus, we have identified a new pathway crucial for the development of the vertebrae and our data indicate that novel mechanisms of Fat4-Dchs1 signalling have evolved to control cell proliferation within the developing vertebrae.
Assuntos
Caderinas/metabolismo , Transdução de Sinais , Coluna Vertebral/citologia , Coluna Vertebral/embriologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proteínas de Ciclo Celular , Polaridade Celular , Proliferação de Células , Camundongos Mutantes , Morfogênese , Mutação/genética , Fosfoproteínas/metabolismo , Coluna Vertebral/metabolismo , Transativadores , Proteínas de Sinalização YAPRESUMO
The expansion of the industrial use of nickel oxide (NiO) nanoparticles (NPs) raises concerns about their potential adverse effects. Our work aimed to investigate the mechanisms of toxicity induced by NiO NPs, using the yeast Saccharomyces cerevisiae as a cell model. Yeast cells exposed to NiO NPs exhibited typical hallmarks of regulated cell death (RCD) by apoptosis [loss of cell proliferation capacity (cell viability), exposure of phosphatidylserine at the outer cytoplasmic membrane leaflet, nuclear chromatin condensation, and DNA damage] in a process that required de novo protein synthesis. The execution of yeast cell death induced by NiO NPs is Yca1p metacaspase-dependent. NiO NPs also induced a decrease in the mitochondrial membrane potential and an increase in the frequency of respiratory-deficient mutants, which supports the involvement of mitochondria in the cell death process. Cells deficient in the apoptosis-inducing factor ( aif1Δ) displayed higher tolerance to NiO NPs, which reinforces the involvement of mitochondria in RCD by apoptosis. In summary, this study shows that NiO NPs induce caspase- and mitochondria-dependent apoptosis in yeast. Our results warn about the possible harmful effects associated with the use of NiO NPs.
Assuntos
Apoptose/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Nanopartículas/toxicidade , Níquel/química , Saccharomyces cerevisiae/metabolismo , Caspases/metabolismo , Dano ao DNA/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/metabolismo , NADH NADPH Oxirredutases/metabolismo , Nanopartículas/química , Saccharomyces cerevisiae/efeitos dos fármacos , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMO
In this work, the physicochemical characterization of five (Al2O3, In2O3, Mn3O4, SiO2 and SnO2) nanoparticles (NPs) was carried out. In addition, the evaluation of the possible toxic impacts of these NPs and the respective modes of action were performed using the yeast Saccharomyces cerevisiae. In general, in aqueous suspension, metal(loid) oxide (MOx) NPs displayed an overall negative charge and agglomerated; these NPs were practically insoluble (dissolution < 8%) and did not generate detectable amounts of reactive oxygen species (ROS) under abiotic conditions. Except In2O3 NPs, which did not induce an obvious toxic effect on yeast cells (up to 100 mg/L), the other NPs induced a loss of cell viability in a dose-dependent manner. The comparative analysis of the loss of cell viability induced by the NPs with the ions released by NPs (NPs supernatant) suggested that SiO2 toxicity was mainly caused by the NPs themselves, Al2O3 and SnO2 toxic effects could be attributed to both the NPs and the respective released ions and Mn3O4 harmfulness could be mainly due to the released ions. Al2O3, Mn3O4, SiO2 and SnO2 NPs induced the loss of metabolic activity and the generation of intracellular ROS without permeabilization of plasma membrane. The co-incubation of yeast cells with MOx NPs and a free radical scavenger (ascorbic acid) quenched intracellular ROS and significantly restored cell viability and metabolic activity. These results evidenced that the intracellular generation of ROS constituted the main cause of the cytotoxicity exhibited by yeasts treated with the MOx NPs. This study highlights the importance of a ROS-mediated mechanism in the toxicity induced by MOx NPs.
Assuntos
Nanopartículas Metálicas/toxicidade , Metaloides/toxicidade , Viabilidade Microbiana/efeitos dos fármacos , Óxidos/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Fenômenos Químicos , Relação Dose-Resposta a Droga , Metabolismo/efeitos dos fármacos , Nanopartículas Metálicas/química , Metaloides/química , Óxidos/química , SolubilidadeRESUMO
The present work aimed to elucidate whether the toxic effects of nickel oxide (NiO) nanoparticles (NPs) on the yeast Saccharomyces cerevisiae were associated with oxidative stress (OS) and what mechanisms may have contributed to this OS. Cells exposed to NiO NPs accumulated superoxide anions and hydrogen peroxide, which were intracellularly generated. Yeast cells coexposed to NiO NPs and antioxidants (l-ascorbic acid and N- tert-butyl-α-phenylnitrone) showed quenching of reactive oxygen species (ROS) and increased resistance to NiO NPs, indicating that the loss of cell viability was associated with ROS accumulation. Mutants lacking mitochondrial DNA (ρ0) displayed reduced levels of ROS and increased resistance to NiO NPs, which suggested the involvement of the mitochondrial respiratory chain in ROS production. Yeast cells exposed to NiO NPs presented decreased levels of reduced glutathione (GSH). Mutants deficient in GSH1 ( gsh1Δ) or GSH2 ( gsh2Δ) genes displayed increased levels of ROS and increased sensitivity to NiO NPs, which underline the central role of GSH against NiO NPs-induced OS. This work suggests that the increased levels of intracellular ROS (probably due to the perturbation of the electron transfer chain in mitochondria) combined with the depletion of GSH pool constitute important mechanisms of NiO NPs-induced loss of cell viability in the yeast S. cerevisiae.
Assuntos
Nanopartículas Metálicas/toxicidade , Níquel/toxicidade , Estresse Oxidativo , Saccharomyces cerevisiae/efeitos dos fármacos , Antioxidantes/farmacologia , DNA Mitocondrial/metabolismo , Transporte de Elétrons , Glutationa/metabolismo , Mutação , Espécies Reativas de Oxigênio/metabolismo , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/metabolismoRESUMO
The increasing use of nanoparticles (NPs) has spurred concerns about their toxic effects. This work aimed to assess the potential hazards of nickel oxide (NiO) NPs using the yeast Saccharomyces cerevisiae as a cell model. Yeast cells exposed for 6 h to 100 mg/L NiO NPs presented reduced metabolic activity (esterase activity and FUN-1 dye processing) and enhanced accumulation of reactive oxygen species. NiO NPs induced the loss of cell viability in a dose-dependent manner. Study of the dissolution of NiO NPs in aqueous media, together with the toxicological data, suggests that the nickel released by the NPs cannot explain all the toxic effects observed in S. cerevisiae caused by the NPs. Transmission electron microscopy observations revealed that NiO NPs were adsorbed onto cell surface but did not enter into yeast cells. Isogenic mutants (cwp1∆ and cwp2∆) with increased cell wall porosity did not display enhanced susceptibility to NiO NPs compared to the wild type strain. Our results suggest that NiO NPs exert their toxic effect by an indirect mechanism. This work contributes to knowledge of the potential hazards of NiO NPs and to the elucidation of their mechanisms of toxic action.
Assuntos
Viabilidade Microbiana/efeitos dos fármacos , Nanopartículas/toxicidade , Níquel/toxicidade , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/fisiologia , Adsorção , Microscopia Eletrônica de Transmissão , Nanopartículas/ultraestrutura , Espécies Reativas de Oxigênio/análise , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/ultraestrutura , Propriedades de SuperfícieRESUMO
CONTEXT/OBJECTIVE: Cell lines used to study the role of the G protein-coupled receptor 30 (GPR30) or G protein-coupled estrogen receptor (GPER) as a mediator of estrogen responses have yielded conflicting results. This work identified a simple assay to predict cell line competence for pharmacological studies of GPR30. MATERIALS AND METHODS: The phosphorylation or expression levels of ERK1/2, Akt, c-Fos and eNOS were evaluated to assess GPR30 activation in response to known agonists (17ß-estradiol and G-1) in MCF-7 and T-47D breast cancer cell lines and in bovine aortic endothelial cells. GPR30 expression was analyzed by qRT-PCR and Western blot with two distinct antibodies directed at its carboxy and amino terminals. RESULTS: None of the agonists, at any of the concentrations tested, activated any of those target proteins. Additional experiments excluded the disruption of the signaling pathway, interference of phenol red in the culture medium and constitutive proteasome degradation of GPR30 as possible causes for the lack of response of the three cell lines. Analysis of receptor expression showed the absence of clearly detectable GPR30 species of 44 and 50-55 kDa previously identified in cell lines that respond to 17ß-estradiol and G-1. DISCUSSION AND CONCLUSION: Cells that do not express the 44 and 50-55 kDa species do not respond to GPR30 agonists. Thus, the presence or absence of these GPR30 species is a simple and rapid manner to determine whether a given cell line is suitable for pharmacological or molecular studies of GPR30 modulation.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Receptor alfa de Estrogênio/metabolismo , Estrogênios/metabolismo , Receptores de Estrogênio/biossíntese , Receptores Acoplados a Proteínas G/biossíntese , Animais , Aorta/citologia , Aorta/efeitos dos fármacos , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Bovinos , Ciclopentanos/administração & dosagem , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Estradiol/administração & dosagem , Receptor alfa de Estrogênio/genética , Estrogênios/agonistas , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Células MCF-7 , Proteína Oncogênica v-akt/biossíntese , Fosforilação , Proteínas Proto-Oncogênicas c-fos/biossíntese , Quinolinas/administração & dosagem , Receptores de Estrogênio/genética , Receptores Acoplados a Proteínas G/genética , Transdução de Sinais/efeitos dos fármacosRESUMO
The yeast Saccharomyces cerevisiae is a useful model organism for studying lead (Pb) toxicity. Yeast cells of a laboratory S. cerevisiae strain (WT strain) were incubated with Pb concentrations up to 1,000 µmol/l for 3 h. Cells exposed to Pb lost proliferation capacity without damage to the cell membrane, and they accumulated intracellular superoxide anion (O2 (.-)) and hydrogen peroxide (H2O2). The involvement of the mitochondrial electron transport chain (ETC) in the generation of reactive oxygen species (ROS) induced by Pb was evaluated. For this purpose, an isogenic derivative ρ(0) strain, lacking mitochondrial DNA, was used. The ρ(0) strain, without respiratory competence, displayed a lower intracellular ROS accumulation and a higher resistance to Pb compared to the WT strain. The kinetic study of ROS generation in yeast cells exposed to Pb showed that the production of O2 (.-) precedes the accumulation of H2O2, which is compatible with the leakage of electrons from the mitochondrial ETC. Yeast cells exposed to Pb displayed mutations at the mitochondrial DNA level. This is most likely a consequence of oxidative stress. In conclusion, mitochondria are an important source of Pb-induced ROS and, simultaneously, one of the targets of its toxicity.
Assuntos
Chumbo/toxicidade , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Estresse Oxidativo , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/fisiologia , Citosol/química , Peróxido de Hidrogênio/análise , Saccharomyces cerevisiae/crescimento & desenvolvimento , Superóxidos/análiseRESUMO
Lead is an important environmental pollutant. The role of vacuole, in Pb detoxification, was studied using a vacuolar protein sorting mutant strain (vps16Δ), belonging to class C mutants. Cells disrupted in VPS16 gene, did not display a detectable vacuolar-like structure. Based on the loss of cell proliferation capacity, it was found that cells from vps16Δ mutant exhibited a hypersensitivity to Pb-induced toxicity, compared to wild type (WT) strain. The function of vacuolar H(+)-ATPase (V-ATPase), in Pb detoxification, was evaluated using mutants with structurally normal vacuoles but defective in subunits of catalytic (vma1Δ or vma2Δ) or membrane domain (vph1Δ or vma3Δ) of V-ATPase. All mutants tested, lacking a functional V-ATPase, displayed an increased susceptibility to Pb, comparatively to cells from WT strain. Modification of vacuolar morphology, in Pb-exposed cells, was visualized using a Vma2p-GFP strain. The treatment of yeast cells with Pb originated the fusion of the medium size vacuolar lobes into one enlarged vacuole. In conclusion, it was found that vacuole plays an important role in the detoxification of Pb in Saccharomyces cerevisiae; in addition, a functional V-ATPase was required for Pb compartmentalization.
Assuntos
Chumbo/farmacologia , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , ATPases Vacuolares Próton-Translocadoras/genética , Chumbo/toxicidade , Viabilidade Microbiana/efeitos dos fármacos , Reprodutibilidade dos Testes , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Vacúolos/metabolismo , Proteínas de Transporte Vesicular/genéticaRESUMO
Ageing is a natural process characterized by a time-dependent decline of physiological integrity that compromises functionality and inevitably leads to death. This decline is also quite relevant in major human pathologies, being a primary risk factor in neurodegenerative diseases, metabolic disorders, cardiovascular diseases and musculoskeletal disorders. Bearing this in mind, it is not surprising that research aiming at improving human health during this process has burst in the last decades. Importantly, major hallmarks of the ageing process and phenotype have been identified, this knowledge being quite relevant for future studies towards the identification of putative pharmaceutical targets, enabling the development of preventive/therapeutic strategies to improve health and longevity. In this context, aromatic plants have emerged as a source of potential bioactive volatile molecules, mainly monoterpenes, with many studies referring to their anti-ageing potential. Nevertheless, an integrated review on the current knowledge is lacking, with several research approaches studying isolated ageing hallmarks or referring to an overall anti-ageing effect, without depicting possible mechanisms of action. Herein, we aim to provide an updated systematization of the bioactive potential of volatile monoterpenes on recently proposed ageing hallmarks, and highlight the main mechanisms of action already identified, as well as possible chemical entity-activity relations. By gathering and categorizing the available scattered information, we also aim to identify important research gaps that could help pave the way for future research in the field.
RESUMO
This study investigates the impact of three key variables on the performance of nanoporous AM-3 and layered AM-4 titanosilicates in removing nine REEs (Y, La, Ce, Pr, Nd, Eu, Gd, Tb, and Dy) from natural mineral water and identifies optimal operational conditions using Response Surface Methodology (RSM). The experimental conditions were determined by a Box-Behnken Design of 3 factors-3 levels (pH 4, 6, and 8; sorbent dose 20, 100, and 180 mg/L; and element concentration 1, 3, and 5 µmol/L). Three-dimensional response surfaces were used to assess the linear, quadratic, and interaction influences of each factor on the REEs' removal percentage. The pH was the most significant factor in the removal process using AM-3, while the sorbent dose was more important for AM-4. The results highlighted the sorbents' strong capacity for REE removal. The optimal operating conditions obtained by RSM were applied to aqueous solutions with salinity 10 (common in coastal and transitional systems) and 30 (average seawater salinity). The results showed that AM-3 has a strong potential for removing REEs in solutions with salinity 10 and 30, while AM-4 was less efficient due to competition between REEs and other ions present in the solution.
Assuntos
Metais Terras Raras , Poluentes Químicos da Água , Metais Terras Raras/química , Poluentes Químicos da Água/química , Adsorção , Purificação da Água/métodosRESUMO
The effect of intracellular reduced glutathione (GSH) in the lead stress response of Saccharomyces cerevisiae was investigated. Yeast cells exposed to Pb, for 3 h, lost the cell proliferation capacity (viability) and decreased intracellular GSH level. The Pb-induced loss of cell viability was compared among yeast cells deficient in GSH1 (∆gsh1) or GSH2 (∆gsh2) genes and wild-type (WT) cells. When exposed to Pb, ∆gsh1 and ∆gsh2 cells did not display an increased loss of viability, compared with WT cells. However, the depletion of cellular thiols, including GSH, by treatment of WT cells with iodoacetamide (an alkylating agent, which binds covalently to thiol group), increased the loss of viability in Pb-treated cells. In contrast, GSH enrichment, due to the incubation of WT cells with amino acids mixture constituting GSH (L-glutamic acid, L-cysteine and glycine), reduced the Pb-induced loss of proliferation capacity. The obtained results suggest that intracellular GSH is involved in the defence against the Pb-induced toxicity; however, at physiological concentration, GSH seems not to be sufficient to prevent the Pb-induced loss of cell viability.
Assuntos
Glutationa/metabolismo , Chumbo/toxicidade , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , Viabilidade Microbiana/efeitos dos fármacos , Saccharomyces cerevisiae/crescimento & desenvolvimento , Estresse FisiológicoRESUMO
Supported by the Intergroup Threat Theory (ITT), this study analyzes the effect of multicultural ideology on attitudes towards immigrants mediated by realistic, symbolic, and zero-sum threats. With a sample of Portuguese participants (N = 404)), polynomial regression analysis with response surface methodology was used to test the effects of multicultural attitude (MA) and perceived intergroup threat (PIT) on attitudes towards immigrants (ATI). This study also tested a model in which positive MA leads to a lower PIT, and consequently to more favorable ATI. Four hypotheses were proposed; all of which were confirmed. The results further showed that the direction of discrepancy between MA and PIT can provide a more comprehensive understanding of the complex role of multicultural ideology in predicting ATI. Findings, limitations, and directions for future research are discussed.