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1.
Environ Pollut ; 251: 555-563, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31108288

RESUMO

In the present study, the 16S-rRNA sequencing of heavy metal-resistant and susceptible bacterial strains isolated from the industrial and agriculture soil showed resemblance with Pseudomonas taiwanensis. Based on the growth rate, two bacterial strains SJPS_KUD54 and KUD-MBBT4 exhibited 10 ppm tolerance to Arsenic and Cadmium. These two heavy metals caused, a significant increase in stress enzymes like superoxide dismutase, catalase and glutathione S-transferase activities in SJPS_KUD54 when compared to KUD-MBBT4. Following heavy metal treatment, the atomic-force-microscopy observations showed no change in the cell-wall of SJPS_KUD54, whereas the cell-wall of KUD-MBBT4 got ruptured. Moreover, the protein-profile of SJPS_KUD54 treated with heavy metals exhibited varied patterns in comparison with untreated control. In addition, the accumulation of hydroxyl, thiol and amides were found in the SJPS_KUD54 relative to its control. Furthermore, the resistant SJPS_KUD54 strain showed a remarkable bioaccumulation properties to both Arsenic and Cadmium. Thus, it is inferred that the growth rate, stress enzymes and functional-groups play a significant role in the physiological-adaption of SJPS_KUD54 during stress conditions, which is positively involved in the prevention or repair mechanism for reducing the risks caused by heavy metal stress.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Arsênico/toxicidade , Cádmio/toxicidade , Pseudomonas/efeitos dos fármacos , Poluentes do Solo/toxicidade , Arsênico/metabolismo , Cádmio/metabolismo , Farmacorresistência Bacteriana/efeitos dos fármacos , Pseudomonas/enzimologia , Pseudomonas/fisiologia , Solo/química , Microbiologia do Solo , Poluentes do Solo/metabolismo
2.
Phys Rev E ; 99(2-1): 022404, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30934318

RESUMO

We use a three-component replicator system with healthy cells, sensitive cells, and resistant cells, with a prisoner's dilemma payoff matrix from evolutionary game theory, to model and control the nonlinear dynamical system governing the ecological mechanism of competitive release by which tumors develop chemotherapeutic resistance. The control method we describe is based on nonlinear trajectory design and energy transfer methods first introduced in the orbital mechanics literature for Hamiltonian systems. For continuous therapy, the basin boundaries of attraction associated with the chemo-sensitive population and the chemo-resistant population for increasing values of chemo-concentrations have an intertwined spiral structure with extreme sensitivity to changes in chemo-concentration level as well as sensitivity with respect to resistant mutations. For time-dependent therapies, we introduce an orbit transfer method to construct continuous families of periodic (closed) orbits by switching the chemo-dose at carefully chosen times and appropriate levels to design schedules that are superior to both maximum tolerated dose (MTD) schedules and low-dose metronomic (LDM) schedules, both of which ultimately lead to fixation of sensitive cells or resistant cells. By keeping the three subpopulations of cells in competition with each other indefinitely, we avoid fixation of the cancer cell population and regrowth of a resistant tumor. The method can be viewed as a way to dynamically shape the average population fitness landscape of a tumor to steer the chemotherapeutic response curve. We show that the method is remarkably insensitive to initial conditions and small changes in chemo-dosages, an important criterion for turning the method into an actionable strategy.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Neoplasias/tratamento farmacológico , Neoplasias/fisiopatologia , Dinâmica não Linear , Modelos Biológicos
3.
Aquat Toxicol ; 211: 57-65, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30952066

RESUMO

Three submerged macrophytes, Ceratophyllum demersum (CD), Myriophyllum spicatum (MS) and Myriophyllum aquaticum (MA), were treated with various concentrations of ammonia for different lengths of time. Ammonium ions (NH4+) in the medium severely inhibited plant growth and led to a reduction in total chlorophyll (chl a and b) in CD and MS. The addition of ammonia significantly decreased the soluble protein content and increased the free amino acid content of CD and MS in treatments with high concentrations of NH4+, but MA showed no significant physiological response. The antioxidant enzyme system of MA was activated, which in turn reduced the peroxidation level in the plant and maintained the plant's normal physiological activities when the ammonia nitrogen in the culture fluid increased. The study continued to use higher concentrations (25, 50, 100, 200 and 400 mg/L) of ammonium nitrogen to treat and observe the peroxidation level and corresponding enzyme production for this species of MA in vivo to explore its resistance mechanism. The experiments show that MA can normally live for a period of time in a high-ammonia environment of up to 100 mg/L. The results of the present study will assist in studies of the detoxification of high ammonium ion contents in submersed macrophytes and the selection of plants suitable for macrophyte recovery.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Compostos de Amônio/toxicidade , Magnoliopsida/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Antioxidantes/metabolismo , Clorofila/metabolismo , Relação Dose-Resposta a Droga , Magnoliopsida/metabolismo , Saxifragales/efeitos dos fármacos , Saxifragales/metabolismo , Especificidade da Espécie
4.
Ecotoxicol Environ Saf ; 178: 9-16, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-30980964

RESUMO

Recently, sulfur dioxide (SO2) has been considered to be a beneficial bio-regulator in animals. However, the positive roles of SO2 in plant adaptation to drought stress are still unclear. In this study, we investigated the physiological and molecular changes that are induced by SO2 fumigation to improve the drought tolerance of foxtail millet seedlings. The relative water content in the leaves of drought-stressed seedlings was significantly improved by pre-exposure to 30 mg/m3 SO2. These responses might be related to decreased stomatal apertures and a reduced leaf transpiration rate, which were induced by SO2 under drought conditions. In addition, the SO2 pretreatment markedly enhanced proline accumulation in the leaves of drought-stressed seedlings, which was supported by increased Δ1-pyrroline-5-carboxylate synthetase (P5CS) activity, decreased proline dehydrogenase (ProDH) activity, and the corresponding transcripts. Moreover, the SO2 application upregulated the enzyme activity of catalase (CAT) and peroxidase (POD) in the leaves of drought-stressed plants, as well as their transcripts, which contributed to the scavenging of hydrogen peroxide (H2O2) and alleviated drought-induced oxidative damage, as indicated by the decreased malondialdehyde (MDA) level in SO2-pretreated plants. Together, these results indicate that the application of SO2 might enhance drought tolerance by reducing stomatal apertures, increasing proline accumulation, and promoting antioxidant defence in foxtail millet seedlings. This study presents new insight into the beneficial roles of SO2 in plant responses to drought stress.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Secas , Fumigação , Setaria (Planta)/efeitos dos fármacos , Dióxido de Enxofre/farmacologia , Antioxidantes/metabolismo , Prolina/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Setaria (Planta)/crescimento & desenvolvimento , Setaria (Planta)/metabolismo , Estresse Fisiológico/efeitos dos fármacos
5.
Int J Mol Sci ; 20(6)2019 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-30893759

RESUMO

The role of nitric oxide (NO) signaling in the cold acclimation of forage legumes was investigated in this study. Medicago sativa subsp. falcata (L.) Arcang. (hereafter M. falcata) is a forage legume with a higher cold tolerance than Medicago truncatula, a model legume. Cold acclimation treatment resulted in increased cold tolerance in both M. falcata and M. truncatula, which was suppressed by pretreatment with tungstate, an inhibitor of nitrate reductase (NR), and 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO), a scavenger of NO. Likely, NITRATE REDUCTASE 1 (NIA1), but not NIA2 transcript, NR activity, and NO production were increased after cold treatment. Treatments with exogenous NO donors resulted in increased cold tolerance in both species. Superoxide dismutase (SOD), catalase (CAT), and ascorbate-peroxidase (APX) activities and Cu,Zn-SOD2, Cu,Zn-SOD3, cytosolic APX1 (cAPX1), cAPX3 and chloroplastic APX1 (cpAPX1) transcript levels were induced in both species after cold treatment, which was suppressed by tungstate and 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO). Treatment with exogenous NO resulted in enhanced activities of SOD, CAT, and APX. Moreover, higher levels of NIA1 transcript, NR activity, NO production, and antioxidant enzyme activities and transcripts were observed in M. falcata as compared with M. truncatula after cold treatment. The results suggest that NR-derived NO production and upregulated antioxidant defense are involved in cold acclimation in both species, while the higher levels of NO production and its derived antioxidant enzymes are associated with the higher cold tolerance in M. falcata as compared with M. truncatula.


Assuntos
Adaptação Fisiológica , Medicago sativa/fisiologia , Medicago truncatula/fisiologia , Óxido Nítrico/metabolismo , Oxirredutases/metabolismo , Adaptação Fisiológica/efeitos dos fármacos , Antioxidantes/metabolismo , Óxidos N-Cíclicos/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Imidazóis/farmacologia , Íons , Medicago sativa/efeitos dos fármacos , Medicago sativa/enzimologia , Medicago sativa/genética , Medicago truncatula/efeitos dos fármacos , Medicago truncatula/enzimologia , Medicago truncatula/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
6.
Prog Mol Subcell Biol ; 58: 37-59, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30911888

RESUMO

Cells face genetic and/or environmental changes in order to outlast and proliferate. Characterization of changes after stress at different "omics" levels is crucial to understand the adaptation of yeast to changing conditions. Wine fermentation is a stressful situation which yeast cells have to cope with. Genome-wide analyses extend our cellular physiology knowledge by pointing out the mechanisms that contribute to sense the stress caused by these perturbations (temperature, ethanol, sulfites, nitrogen, etc.) and related signaling pathways. The model organism, Saccharomyces cerevisiae, was studied in response to industrial stresses and changes at different cellular levels (transcriptomic, proteomic, and metabolomics), which were followed statically and/or dynamically in the short and long terms. This chapter focuses on the response of yeast cells to the diverse stress situations that occur during wine fermentations, which induce perturbations, including nutritional changes, ethanol stress, temperature stress, oxidative stress, etc.


Assuntos
Adaptação Fisiológica , Fermentação , Saccharomyces cerevisiae/metabolismo , Vinho/microbiologia , Adaptação Fisiológica/efeitos dos fármacos , Adaptação Fisiológica/genética , Etanol/metabolismo , Etanol/farmacologia , Fermentação/genética , Estudo de Associação Genômica Ampla , Metabolômica , Estresse Oxidativo/efeitos dos fármacos , Proteômica , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Temperatura Ambiente
7.
Int J Mol Sci ; 20(5)2019 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-30818835

RESUMO

Melatonin is a multifunctional signaling molecule, ubiquitously distributed in different parts of plants and responsible for stimulating several physiological responses to adverse environmental conditions. In the current review, we showed that the biosynthesis of melatonin occurred in plants by themselves, and accumulation of melatonin fluctuated sharply by modulating its biosynthesis and metabolic pathways under stress conditions. Melatonin, with its precursors and derivatives, acted as a powerful growth regulator, bio-stimulator, and antioxidant, which delayed leaf senescence, lessened photosynthesis inhibition, and improved redox homeostasis and the antioxidant system through a direct scavenging of reactive oxygen species (ROS) and reactive nitrogen species (RNS) under abiotic and biotic stress conditions. In addition, exogenous melatonin boosted the growth, photosynthetic, and antioxidant activities in plants, confirming their tolerances against drought, unfavorable temperatures, salinity, heavy metals, acid rain, and pathogens. However, future research, together with recent advancements, would support emerging new approaches to adopt strategies in overcoming the effect of hazardous environments on crops and may have potential implications in expanding crop cultivation against harsh conditions. Thus, farming communities and consumers will benefit from elucidating food safety concerns.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Melatonina/farmacologia , Fenômenos Fisiológicos Vegetais/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , Antioxidantes/farmacologia , Melatonina/biossíntese , Melatonina/química , Reguladores de Crescimento de Planta/farmacologia
8.
Aquat Toxicol ; 210: 30-43, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30822701

RESUMO

Sentinel species such as the Atlantic killifish (Fundulus heteroclitus) living in urban waterways can be used as toxicological models to understand impacts of environmental metabolism disrupting compound (MDC) exposure on both wildlife and humans. Exposure to MDCs is associated with increased risk of metabolic syndrome, including impaired lipid and glucose homeostasis, adipogenesis, appetite control, and basal metabolism. MDCs are ubiquitous in the environment, including in aquatic environments. New Bedford Harbor (NBH), Massachusetts is polluted with polychlorinated biphenyls (PCBs), and, as we show for the first time, tin (Sn). PCBs and organotins are ligands for two receptor systems known to regulate lipid homeostasis, the aryl hydrocarbon receptor (AHR) and the peroxisome proliferator-activated receptors (PPARs), respectively. In the current study, we compared lipid homeostasis in laboratory-reared killifish from NBH (F2) and a reference location (Scorton Creek, Massachusetts; F1 and F2) to evaluate how adaptation to local conditions may influence responses to MDCs. Adult killifish from each population were exposed to 3,3',4,4',5-pentachlorobiphenyl (PCB126, dioxin-like), 2,2',4,4',5,5'-hexachlorobiphenyl (PCB153, non-dioxin-like), or tributyltin (TBT, a PPARγ ligand) by a single intraperitoneal injection and analyzed after 3 days. AHR activation was assessed by measuring cyp1a mRNA expression. Lipid homeostasis was evaluated phenotypically by measuring liver triglycerides and organosomatic indices, and at the molecular level by measuring the mRNA expression of pparg and ppara and a target gene for each receptor. Acute MDC exposure did not affect phenotypic outcomes. However, overall NBH killifish had higher liver triglycerides and adiposomatic indices than SC killifish. Both season and population were significant predictors of the lipid phenotype. Acute MDC exposure altered hepatic gene expression only in male killifish from SC. PCB126 exposure induced cyp1a and pparg, whereas PCB153 exposure induced ppara. TBT exposure did not induce ppar-dependent pathways. Comparison of lipid homeostasis in two killifish populations extends our understanding of how MDCs act on fish and provides a basis to infer adaptive benefits of these differences in the wild.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Fundulidae/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Bifenilos Policlorados/toxicidade , Receptores de Hidrocarboneto Arílico/metabolismo , Poluentes Químicos da Água/toxicidade , Animais , Exposição Ambiental/efeitos adversos , Regulação da Expressão Gênica/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Homeostase/genética , Metabolismo dos Lipídeos/genética , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Massachusetts , Receptores de Hidrocarboneto Arílico/genética
9.
Int J Mol Sci ; 20(5)2019 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-30813508

RESUMO

Nanotechnology was well developed during past decades and implemented in a broad range of industrial applications, which led to an inevitable release of nanomaterials into the environment and ecosystem. Silver nanoparticles (AgNPs) are one of the most commonly used nanomaterials in various fields, especially in the agricultural sector. Plants are the basic component of the ecosystem and the most important source of food for mankind; therefore, understanding the impacts of AgNPs on plant growth and development is crucial for the evaluation of potential environmental risks on food safety and human health imposed by AgNPs. The present review summarizes uptake, translocation, and accumulation of AgNPs in plants, and exemplifies the phytotoxicity of AgNPs on plants at morphological, physiological, cellular, and molecular levels. It also focuses on the current understanding of phytotoxicity mechanisms via which AgNPs exert their toxicity on plants. In addition, the tolerance mechanisms underlying survival strategy that plants adopt to cope with adverse effects of AgNPs are discussed.


Assuntos
Nanopartículas Metálicas/toxicidade , Plantas/efeitos dos fármacos , Prata/toxicidade , Adaptação Fisiológica/efeitos dos fármacos , Saúde , Humanos , Fatores de Risco
10.
Ecotoxicol Environ Saf ; 173: 77-85, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-30769206

RESUMO

To better evaluate chemical damage in chronically contaminated habitats, a nine-generational exposure to Lead (Pb) was done with two monophyletic Daphnia species, from temperate (Daphnia magna) and tropical (Daphnia similis) environments. The multi-generational test consisted generally of a continuous Pb exposed set of organisms, plus an extra control set running simultaneously. To assess daphnids recovery after Pb exposure, some organisms from the sixth generation were transferred to clean media for three extra generations (recovery period; F6 to F9), while others were keep Pb exposed. All setups (control, Pb exposure and recovery period) were submitted to two different dietary regimes, the standard (3 × 105 cells/mL) and restricted food (1.5 × 105 cells/mL) regimes. To evaluate the effects of generational Pb exposure and food regimes, individual, functional and population related endpoints were assessed (number of offspring, body length and rate of population increase (r) and feeding rate (FR)). The tests were conducted on the first (F0) and last generations (F9). No differences were shown on number of offspring and feeding among F9 control and continuous Pb exposed D. magna, although a higher r was shown for F9 Pb exposed organisms. F9 Pb exposed D. similis also presented a higher r than F9 control, however, lethality was induced at high Pb exposure levels. At food restriction the patterns were opposite and D. magna died at high Pb exposure while Pb exposed D. similis was the only setup (compared to control and recovery period) to survive at high Pb exposure levels. Regarding the recovery period, D. magna (standard food) did not cope well with the Pb re-exposure and lethality was induced, while D. similis indicate a decreased Pb sensitivity (only setup that survived high Pb exposure levels). Under food restriction, both species presented a decreased Pb sensitivity and consequent failed recovery (possibly due to epigenetic changes). Both species presented similar patterns regarding generations. Organisms from F0 presented enhanced reproductive outputs in comparison to F9 and the contrary occurred to the FR (even in control organisms). Data show an acclimation under a generational Pb exposure, which could increase the population of adapted organisms in natural habitats. And, since there was not a full recovery after three generations in clean media, an indication of epigenetic changes for both species may also be considered.


Assuntos
Daphnia/efeitos dos fármacos , Chumbo/toxicidade , Poluentes Químicos da Água/toxicidade , Adaptação Fisiológica/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Animais , Daphnia/fisiologia , Epigênese Genética/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Especificidade da Espécie
11.
J Food Sci ; 84(3): 599-605, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30730584

RESUMO

Acid adaptation in Salmonella Enteritidis was characterized by phenotypic and gene-expression analyses. S. Enteritidis cells at log-phase and stationary-phase were kept at pH 4.5 to 6.0 for 1 to 4 hours. All treatments induced various levels of acid tolerance response that were dependent on pH, exposure time and growth phase. This acid adaptation resulted in tolerance to 50 °C and 8% NaCl regardless of the growth phase. However, the tolerance of log-phase and stationary-phase cells to low temperatures (4 and -20 °C) was increased and decreased, respectively. RT-qPCR analysis revealed that genes involved in tolerance to acid (SEN1564A and cfa), heat (rpoH, uspB, and htrA), salt (proP, proV, and osmW), and cold (cspA, cspC, and csdA) stress were generally upregulated after acid adaptation. These results provide an initial insight into mechanisms of acid adaptation and induced cross protection in S. Enteritidis. PRACTICAL APPLICATION: Stress tolerance acquisition resulting from acid adaptation in foodborne pathogens poses a great threat to food safety. The current work showed that acid adaptation induced direct tolerance and cross-tolerance to high temperature, low temperature, and salt in Salmonella Enteritidis, possibly due to the upregulation of stress tolerance-related genes. These results provide key insights into acid adaptation mechanisms and efficient control of S. Enteritidis.


Assuntos
Ácidos/farmacologia , Adaptação Fisiológica/efeitos dos fármacos , Salmonella enteritidis/efeitos dos fármacos , Temperatura Baixa , Temperatura Alta , Concentração de Íons de Hidrogênio , Cloreto de Sódio
12.
Mol Genet Genomics ; 294(3): 597-605, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30710177

RESUMO

Antimicrobial resistance makes pathogenic bacteria hard to control, but little is known about the general processes of resistance gain or loss. Here, we compared distinct S. typhimurium DT104 strains resistant to zero, two, five, or more of the tested antimicrobials. We found that common resistance phenotypes could be encoded by distinct genes, on SGI-1 or plasmid. We also demonstrated close clonality among all the tested non-resistant and differently resistant DT104 strains, demonstrating dynamic acquisition or loss (by total deletion or gradual decaying of multi-drug resistance gene clusters) of the genetic traits. These findings reflect convergent processes to make the bacteria resistant to multiple antimicrobials by acquiring the needed traits from stochastically available origins. When the antimicrobial stress is absent, the resistance genes may be dropped off quickly, so the bacteria can save the cost for maintaining unneeded genes. Therefore, this work reiterates the importance of strictly controlled use of antimicrobials.


Assuntos
Adaptação Fisiológica/genética , Farmacorresistência Bacteriana Múltipla/genética , Evolução Molecular , Salmonella typhimurium/genética , Estresse Fisiológico , Adaptação Fisiológica/efeitos dos fármacos , Antibacterianos/farmacologia , Sequência de Bases , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Genes Bacterianos/genética , Genoma Bacteriano/genética , Filogenia , Plasmídeos/classificação , Plasmídeos/genética , Salmonella typhimurium/classificação , Salmonella typhimurium/efeitos dos fármacos , Homologia de Sequência do Ácido Nucleico
13.
Mol Brain ; 12(1): 10, 2019 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-30736837

RESUMO

Chronic opiate exposure induces neuroadaptations in the mesocorticolimbic system including ventral tegmental area (VTA) dopamine (DA) neurons, whose soma size is decreased following opiate exposure. Yet it is now well documented that VTA DA neurons are heterogeneous, with notable differences between VTA DA neurons based on their projection target. Therefore, we sought to determine whether chronic morphine induced similar changes in the morphology of VTA DA neurons that project to the nucleus accumbens (NAc) and prefrontal cortex (PFC). We utilized Cre-dependent retrograde viral vectors in DA Cre driver lines to label VTA DA neurons that projected to NAc and PFC and assessed neuronal soma size. Consistent with previous data, the soma size of VTA DA neurons that projected to the NAc medial shell was decreased following morphine exposure. However, soma size of VTA DA neurons that projected to the NAc core was unaltered by morphine. Interestingly, morphology of PFC-projecting VTA DA neurons was also altered by morphine, but in this case soma size was increased compared to sham controls. Differences in basal soma size were also noted, suggesting stable differences in projection-specific morphology in addition to drug-induced changes. Together, these data suggest morphine-induced changes in VTA DA morphology occur within distinct VTA DA populations and that study of opiate-induced structural plasticity of individual VTA DA subcircuits may be critical for understanding addiction-related behavior.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Neurônios Dopaminérgicos/patologia , Morfina/farmacologia , Rede Nervosa/patologia , Área Tegmentar Ventral/patologia , Animais , Biomarcadores/metabolismo , Neurônios Dopaminérgicos/efeitos dos fármacos , Feminino , Masculino , Camundongos , Proteínas do Tecido Nervoso/metabolismo
14.
Aquat Toxicol ; 209: 91-98, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30753974

RESUMO

While the phenomenon of increased population tolerance to environmental contaminants has been widely reported for aquatic animal species living in contaminated ecosystems, the question of the nature of the tolerance, i.e., genetic adaptation or phenotypic plasticity, has not yet been studied to the same degree and remains under debate when explaining the variability of toxicological sensitivity among field populations. The occurrence of both processes challenges the ecological risk assessment (ERA) of chemicals, questioning the relevance of toxicity assessment procedures based on bioassays employing organisms from naive reference populations. Nonetheless, given that genetic adaptation and phenotypic acclimation are based on different mechanisms, with different persistence periods over time when exposure is stopped, gaining insight into the mechanism of tolerance to contaminants of field populations is a major concern for ERA. In this context, this study aimed to test whether genetic adaptation underlies the tolerance to cadmium (Cd) in a field Gammarus fossarum population identified in a previous study. Breeding and exposure experiments conducted in laboratory conditions revealed that: (1) first and second cohorts of neonates produced from field-collected parents present an increased Cd tolerance, which is explained by a reduction of between-brood variability of Cd sensitivity with an absence of sensitive broods compared to two reference populations rather than by the existence of more tolerant individuals; and (2) Cd tolerance was no longer evident for broods of the third cohort produced by these breeders when maintained under Cd-free conditions in the laboratory. Hence, this study drew the striking conclusion that the observation of Cd tolerance inheritance within the field population studied does not demonstrate genetic adaptation, but it results from an effect of parental exposure inducing transgenerational plasticity, which deeply influences the variability of population sensitivity. To our knowledge, this study is only the second report of increased tolerance to contaminants in a field population explicitly attributed to the phenomenon of transgenerational acclimation.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Anfípodes/efeitos dos fármacos , Cádmio/toxicidade , Exposição Ambiental , Padrões de Herança , Animais , Análise de Sobrevida , Poluentes Químicos da Água
15.
Artigo em Inglês | MEDLINE | ID: mdl-30781732

RESUMO

Titanium dioxide nanoparticles (TiO2 NPs) have become a widely used nanomaterial due to the photocatalytic activity and absorption of ultraviolet light of specific wavelengths. This study investigated the toxic effects of rutile TiO2 NPs on zebrafish by examining its embryos and adults. In the embryo acute toxicity test, exposure to 100 mg/L TiO2 NPs didn't affect the hatching rate of zebrafish embryos, and there was no sign of deformity. In the adult toxicity test, the effects of TiO2 NPs on oxidative damage in liver, intestine and gill tissue were studied. Enzyme linked immunosorbent assay (ELISA) and fluorescence-based quantitative real-time reverse transcription PCR (qRT-PCR) were used to detect the three antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT) and glutathione S transferase (GSTs) in the above mentioned zebrafish organs at protein and gene levels. The results showed that long-term exposure to TiO2 NPs can cause oxidative damage to organisms; and compared with the control group, the activity of the three kinds of enzyme declined somewhat at the protein level. In addition, long-term exposure to TiO2 NPs could cause high expression of CAT, SOD and GSTs in three organs of adult zebrafish in order to counter the adverse reaction. The effects of long-term exposure to TiO2 NPs to adult zebrafish were more obvious in the liver and gill.


Assuntos
Nanopartículas/toxicidade , Titânio/toxicidade , Peixe-Zebra/fisiologia , Adaptação Fisiológica/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Nanopartículas/química , Estresse Oxidativo/efeitos dos fármacos , Titânio/química , Testes de Toxicidade Aguda , Peixe-Zebra/crescimento & desenvolvimento , Peixe-Zebra/metabolismo
16.
Curr Genet ; 65(3): 735-745, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30603874

RESUMO

Azoles are the most widely used antifungals for controlling fungal infections in clinic and agriculture. Fungi can adapt to azole stress by rapidly activating the transcription of a number of genes, and some of these genes can elevate resistance to azoles. We had reported the transcription factor CCG-8 as a new regulator in the adaptation to antifungal azole stress in Neurospora crassa and Fusarium verticillioides. In this study, we further investigate the mechanisms by which CCG-8 promotes fungal adaptation to azole stress using N. crassa as a model. While deletion of ccg-8 made N. crassa hypersensitive to azoles, ccg-8 overexpression strain was more resistant to azoles than wild type, which further confirmed the positive role of ccg-8 in the adaptation to antifungal azoles. Liquid chromatography-mass spectrometry analysis showed that deletion of ccg-8 resulted in decrease of ergosterol biosynthesis, and high accumulation of toxic sterol 14α-methyl-3,6-diol and ketoconazole (KTC) in the cells, whereas intracellular accumulation of ketoconazole was decreased in the ccg-8 overexpression strain as compared to wild type. For analyzing the effect of CCG-8 on azole export, we tested the contribution of predicted multidrug transporters to azole resistance and found that CDR4 is the major contributor for azole efflux in N. crassa. Interestingly, overexpression of cdr4 or erg11 in the ccg-8 deletion mutant restored its hypersensitive phenotype and overexpression of cdr4 can reduce the level of intracellular KTC. However, the double mutant of ccg-8 and cdr4 was more sensitive than each single mutant, suggesting that drug efflux pump CDR4 plays less contribution for intracellular azole accumulation in the ccg-8 deletion mutant, and CCG-8 may regulate drug uptake. Together, our results revealed that CCG-8 plays a pivotal role in azole adaptive responses of N. crassa by regulating the drug accumulation in the cells.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Azóis/farmacologia , Farmacorresistência Fúngica , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Neurospora crassa/efeitos dos fármacos , Fatores de Transcrição/metabolismo , Antifúngicos/farmacologia , Proteínas Fúngicas/genética , Testes de Sensibilidade Microbiana , Fatores de Transcrição/genética
17.
Plant Mol Biol ; 99(3): 265-281, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30604324

RESUMO

KEY MESSAGE: PsLecRLK overexpression in rice provides tolerance against salinity stress and cause upregulation of SOS1 pathway genes, which are responsible for extrusion of excess Na+ ion under stress condition. Soil salinity is one of the most devastating factors threatening cultivable land. Rice is a major staple crop and immensely affected by soil salinity. The small genome size of rice relative to wheat and barley, together with its salt sensitivity, makes it an ideal candidate for studies on salt stress response caused by a particular gene. Under stress conditions crosstalk between organelles and cell to cell response is imperative. LecRLK is an important family, which plays a key role under stress conditions and regulates the physiology of the plant. Here we have functionally validated the PsLecRLK gene in rice for salinity stress tolerance and hypothesized the model for its working. Salt stress sensitive rice variety IR64 was used for developing marker-free transgenic with modified binary vector pCAMBIA1300 overexpressing PsLecRLK gene. Comparison of transgenic and wild-type (WT) plants showed better physiological and biochemical results in transgenic lines with a low level of ROS, MDA and ion accumulation and a higher level of proline, relative water content, root/shoot ration, enzymatic activities of ROS scavengers and upregulation of stress-responsive genes. Based on the relative expression of stress-responsive genes and ionic content, the working model highlights the role of PsLecRLK in the extrusion of Na+ ion from the cell. This extrusion of Na+ ion is facilitated by higher expression of SOS1 (Na+/K+ channel) in transgenic plants as compared to WT plants. Altered expression of stress-responsive genes and change in biochemical and physiological properties of the cell suggests an extensive reprogramming of the stress-responsive metabolic pathways by PsLecRLK under stress condition, which could be responsible for the salt tolerance capability.


Assuntos
Oryza/metabolismo , Ervilhas/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Tolerância ao Sal/fisiologia , Sódio/metabolismo , Adaptação Fisiológica/efeitos dos fármacos , Adaptação Fisiológica/genética , Cálcio/metabolismo , Morte Celular , Membrana Celular/efeitos dos fármacos , Clonagem Molecular , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Genes de Plantas , Germinação , Homozigoto , Íons , Oryza/genética , Ervilhas/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Transporte Proteico/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Receptores Mitogênicos/genética , Receptores Mitogênicos/metabolismo , Proteína SOS1/genética , Proteína SOS1/metabolismo , Salinidade , Tolerância ao Sal/genética , Cloreto de Sódio/metabolismo , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Regulação para Cima
18.
Cell Stress Chaperones ; 24(1): 247-257, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30632065

RESUMO

Herbaceous peony (Paeonia lactiflora Pall.) is an excellent ornamental plant, which is usually stressed by summer high temperatures, but little is known about its relevant measures. In this study, the effects of trehalose on alleviating high temperature-induced damage in P. lactiflora were examined. High temperature stress in P. lactiflora increased production of reactive oxygen species (ROS), including superoxide anion free radical (O2·-) and hydrogen peroxide (H2O2), enhanced both malondialdehyde (MDA) content and relative electrical conductivity (REC), decreased superoxide dismutase (SOD) activity, increased catalase (CAT) activity, inhibited photosynthesis, and destroyed cell structure. However, exogenous trehalose effectively alleviated its high temperature-induced damage. Trehalose decreased O2·- and H2O2 accumulation, MDA content, and REC, increased the activities of antioxidant enzymes, enhanced photosynthesis, improved cell structure, and made chloroplasts rounder. Additionally, trehalose induced high temperature-tolerant-related gene expressions to different degrees. These results indicated that trehalose decreased the deleterious effect of high temperature stress on P. lactiflora growth by enhancing antioxidant systems, activating photosynthesis, and protecting cell structure. These findings indicate the potential application of trehalose for managing high temperatures in P. lactiflora cultivation.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Antioxidantes/metabolismo , Citoproteção/efeitos dos fármacos , Temperatura Alta , Paeonia/fisiologia , Fotossíntese/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , Trealose/farmacologia , Adaptação Fisiológica/genética , Clorofila/metabolismo , Fluorescência , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Modelos Biológicos , Estresse Oxidativo/efeitos dos fármacos , Paeonia/efeitos dos fármacos , Paeonia/genética , Estômatos de Plantas/efeitos dos fármacos , Estômatos de Plantas/fisiologia , Estresse Fisiológico/genética
19.
Aquat Toxicol ; 207: 163-169, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30572176

RESUMO

Human activities have radically shaped the global landscape, affecting the structure and function of ecosystems. Habitat loss is one of the most visible changes to the landscape and a primary driver of species declines; however, anthropogenic environmental contamination also threatens population persistence, but is not as readily observed. Aquatic organisms are especially susceptible to chemical perturbations, which can negatively impact survival and fitness related traits. Some populations have evolved tolerance to chemical stressors, which could mitigate the consequences associated with contamination. Amphibians are experiencing global declines due to multiple stressors and are particularly at risk to aquatic chemical stressors due to their permeable skin and reliance on wetlands for reproduction and larval development. However, amphibians also have substantial plasticity in response to environmental variation. We designed our study to examine whether tolerance to heavy metals is greater in Southern toad (Anaxyrus terrestris) larvae from wetlands with a history of contamination. Considering many of the most common trace elements elicit acute toxicity by disrupting osmotic- and ionic-regulation, we hypothesized that alterations to these aspects of physiology resulting from multigenerational exposure to trace element mixtures would be the most likely routes by which tolerance would evolve. We used copper (Cu) as a proxy for heavy metal exposure because it is a widely distributed aquatic stressor known to cause osmotic stress that can also cause mortality at levels commonly encountered in the environment. We found considerable within and among population variation in Cu tolerance, as measured by time to death. Larvae from populations living in sites contaminated with mixtures of heavy metals associated with coal fly ash were no more tolerant to Cu than those from reference sites. However, larvae from a population inhabiting a constructed wetland complex with high Cu levels were significantly more tolerant; having half the risk of mortality as reference animals. This wetland complex was created < 20 years ago, thus if elevated Cu tolerance in this population is due to selection in the aquatic habitat, such adaptation may occur rapidly (i.e. ∼10 generation). Our results provide evidence that amphibians may be able to evolve tolerance in response to trace element contamination, though such tolerance may be specific to the combination of contaminants present.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Bufonidae/fisiologia , Exposição Ambiental , Metais Pesados/toxicidade , Animais , Monitoramento Ambiental , Geografia , Larva/efeitos dos fármacos , Óvulo/metabolismo , Análise de Sobrevida , Oligoelementos/análise , Poluentes Químicos da Água/toxicidade
20.
J Physiol Sci ; 69(2): 327-333, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30536041

RESUMO

Statins and exercise reduce cardiovascular disease incidence. We investigated whether endurance exercise in mice induces mitochondrial adaptation in skeletal muscle and muscle injury during administration of atorvastatin, a member of the statin medication class. Male C57BL mice were assigned to one of three groups: control (Con), statin (Statin), or statin and exercise (Statin + Ex). Atorvastatin was administered, and exercise performed on a treadmill for 8 weeks. The levels of mitochondria-associated proteins, PGC-1α, and respiratory chain complex, (COX) I-V, in the quadriceps femoris, and serum creatine kinase, a muscle injury marker, were measured. PGC-1α and COX I-V were upregulated in the Statin + Ex group compared to those in the Statin and Con groups; serum creatine kinase levels were similar. Endurance training in mice induced mitochondrial adaptation in skeletal muscle without causing muscle injury, during atorvastatin administration.


Assuntos
Atorvastatina/farmacologia , Transporte de Elétrons/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Condicionamento Físico Animal/fisiologia , Adaptação Fisiológica/efeitos dos fármacos , Animais , Creatina Quinase/sangue , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias Musculares/efeitos dos fármacos , Mitocôndrias Musculares/metabolismo , Músculo Quadríceps/efeitos dos fármacos , Músculo Quadríceps/metabolismo
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