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1.
Int J Food Microbiol ; 312: 108362, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31669764

RESUMO

Stuck and sluggish fermentations are among the main problems in winemaking industry leading to important economic losses. Several factors have been described as causes of stuck and sluggish fermentations, being exposure to extreme temperatures barely studied. The objective of this study was to identify thermal conditions leading to stuck and sluggish fermentations, focusing on the impact of an abrupt and transient decrease/increase of temperature on fermentation performance and yeast viability/vitality. Different strains of Saccharomyces cerevisiae, SBB11, T73, and PDM were evaluated in synthetic grape must fermentations. Cold shocks (9 °C and 1.5 °C for 16 h) carried out on different days during the fermentation process were unable to alter fermentation performance. Conversely, shock temperatures higher than 32 °C, applied in early stages of the process, lead to sluggish fermentation showing a delay directly related to the temperature increase. Fermentation delay was associated with a decrease in cell vitality. The impact of the heat shock on fermentation performance was different depending on the strain evaluated and nitrogen supplementation (with or without diammonium phosphate addition). None of the conditions evaluated produced a stuck fermentation and importantly, in all cases must nutrition improved fermentation performance after a heat shock.


Assuntos
Temperatura Baixa , Fermentação/fisiologia , Temperatura Alta , Saccharomyces cerevisiae/metabolismo , Resposta ao Choque Frio/fisiologia , Resposta ao Choque Térmico/fisiologia , Fosfatos/farmacologia , Vitis/metabolismo , Vinho/análise
2.
Arq. bras. med. vet. zootec. (Online) ; 71(6): 1853-1860, Nov.-Dec. 2019. tab, ilus
Artigo em Português | LILACS, VETINDEX | ID: biblio-1055134

RESUMO

Avaliaram-se os efeitos do sistema de resfriamento evaporativo com pressão negativa (SRE) e aspersão de água sobre o telhado (AAT), as variáveis termofisiológicas, os hormônios tireoidianos e a relação neutrófilo:linfócito (N:L) em porcas. Utilizaram-se 61 fêmeas em lactação, que foram divididas nos dois ambientes térmicos, sendo 30 em SRE e 31 em AAT, no verão. A temperatura e a umidade do ar, a frequência respiratória (FR), as temperaturas de superfície (TS) e retal (TR), a concentração de tiroxina e de tri-iodotironina, o número de neutrófilos e linfócitos e a relação N:L foram determinados. A temperatura ambiente pela manhã foi menor em SRE que em AAT (22,1ºC vs. 23,5ºC) e pela tarde (24,8ºC vs. 28,0ºC). Em ambos os períodos, a FR, a TS e a TR foram menores em SRE (de manhã 49 resp.min-1, 31,1ºC e 38,5ºC, respectivamente, e à tarde 55 resp.min-1, 30,3ºC e 38,8ºC, respectivamente) que em AAT (de manhã 54 resp.min-1, 32,8ºC e 38,6ºC, respectivamente; e à tarde 65 resp.min-1, 31,4ºC e 39,1ºC, respectivamente). Animais sob galpão AAT apresentaram menores concentrações de T4 que animais sob SRE (37,84 vs. 42,22nmol.L-1). Em ambiente tropical, no verão, porcas lactantes de ambos os sistemas mantêm a homeotermia.(AU)


The effects of the evaporative cooling system with negative pressure (ECS) and water spray on the roof (WSR) on physiological variables, thyroid hormones and neutrophil/lymphocyte ratio (N:L) in lactating sows were evaluated. Sixty-one lactating females were divided in the two thermal environments, being 30 in SRE and 31 in the AAT shed in the summer. The air temperature and humidity, respiratory frequency (RF), surface temperatures (ST) and rectal (RT), serum thyroxine and triiodothyronine concentration, number of neutrophils and lymphocytes and the N/L ratio were determined. In the afternoon, the matrices in ECS (Tar: 25.0°C and THI: 74.7) and WSR (Tar: 27.6°C and THI: 77.3) were exposed to heat stress. In the morning, RF, ST and RT were lower in ECS (49 breaths.min -1 , 31.1°C and 38.5°C, respectively) than WSR (54 breaths.min -1 , 32.8°C and 38.6°C) and also in the afternoon ECS (55 breaths.min -1 , 30.3°C and 38.8°C, respectively) and WSR (65 breaths.min -1 , 31.4°C and 39.1°C, respectively). Animals under WSR shed presented lower concentrations of T4 than animals under ECS (37.84 vs 42.22nmol.L -1 ). In a tropical environment, in the summer, lactating sows of both systems maintain homeothermia.(AU)


Assuntos
Animais , Feminino , Suínos/fisiologia , Hormônios Tireóideos/análise , Bem-Estar do Animal , Resposta ao Choque Térmico/fisiologia
4.
Plant Sci ; 289: 110258, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31623797

RESUMO

High temperature stress (HTS) is one of the most crucial factors that limits plant growth and development, and reduces crop yields worldwide. Cool-season crops, particularly the legumes, are severely affected by increasing ambient temperature associated with global climate change. We characterized the HTS-induced modulations of morpho-physicochemical traits and gene expression of several chickpea genotypes and the metabolic profile of the tolerant cultivar. Higher water use efficiency and photosynthetic capacity, minimal membrane lipid peroxidation in conjunction with increased abundance of osmolytes and secondary metabolites depicted thermotolerance of ICC 1205. The adaptive responses were accompanied by high transcript abundance of heat shock proteins and antioxidant enzymes. To integrate stress-responsive signalling and metabolic networks, the HTS-induced physicochemical analysis was further extended to metabolite profiling of the thermotolerant cultivar. The screening of the metabolome landscape led to the identification of 49 HTS-responsive metabolites that include polycarboxylic acid, sugar acids, sugar alcohols and amino acids which might confer thermotolerance in chickpea. The present study, to our knowledge, is the most comprehensive of its kind in dissecting cultivar-specific differential adaptive responses to HTS in chickpea, which might potentiate the identification of genetic traits extendible to improvement of thermotolerance of crops.


Assuntos
Cicer/fisiologia , Regulação da Expressão Gênica de Plantas , Resposta ao Choque Térmico/fisiologia , Traços de História de Vida , Cicer/genética , Genótipo , Temperatura Alta/efeitos adversos , Metaboloma , Estresse Fisiológico/genética
5.
Int J Occup Environ Med ; 10(4): 194-202, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31586384

RESUMO

BACKGROUND: Heat stress is common among workers in hot-dry areas. To take preventive strategies for the protection of workers against heat stress, it is important to choose a suitable index that can accurately explain environmental parameters relative to physiological responses. OBJECTIVE: To evaluate heat stress and maximum acceptable work time (MAWT) based on physiological and environmental response in hot-dry climate among traditional bakers. METHODS: The current study was carried out on 30 traditional bakers of 3 different bread baking systems in Ahvaz, Iran. Environmental and physiological parameters were measured simultaneously for a work shift. The work-rest time was also determined based on the relative heart rate (RHR) and the wet-bulb globe temperature (WBGT) index. RESULTS: The average WBGT index was estimated to be higher than the standard limit for all baking stations. Despite the higher-than-the-recommended-limit WBGT index, there was no significant relationship between the WBGT index and physiological parameters. The results indicated a significant (p<0.05) difference between the percentages of work-rest time estimated using the WBGT and RHR index. CONCLUSION: Based on the results of environmental and physiological monitoring of this study as well as the limitations of the use of the WBGT index, it seems that using WBGT as a standard index would not suit heat stress management in hot-dry climates. A revision of this standard to adapt to hot climatic conditions should be in order.


Assuntos
Culinária , Indústria Alimentícia , Transtornos de Estresse por Calor , Temperatura Alta , Satisfação no Emprego , Exposição Ocupacional , Adulto , Pão , Doces , Clima , Culinária/métodos , Culinária/estatística & dados numéricos , Indústria Alimentícia/estatística & dados numéricos , Frequência Cardíaca/fisiologia , Transtornos de Estresse por Calor/epidemiologia , Transtornos de Estresse por Calor/fisiopatologia , Transtornos de Estresse por Calor/prevenção & controle , Resposta ao Choque Térmico/fisiologia , Humanos , Umidade , Irã (Geográfico)/epidemiologia , Pessoa de Meia-Idade , Exposição Ocupacional/prevenção & controle , Exposição Ocupacional/estatística & dados numéricos , Temperatura , Fatores de Tempo , Local de Trabalho/estatística & dados numéricos , Adulto Jovem
6.
Int J Mol Sci ; 20(19)2019 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-31547604

RESUMO

Activation and enhancement of heat shock factor (HSF) pathways are important adaptive responses to heat stress in plants. The γ-aminobutyric acid (GABA) plays an important role in regulating heat tolerance, but it is unclear whether GABA-induced thermotolerance is associated with activation of HSF pathways in plants. In this study, the changes of endogenous GABA level affecting physiological responses and genes involved in HSF pathways were investigated in creeping bentgrass during heat stress. The increase in endogenous GABA content induced by exogenous application of GABA effectively alleviated heat damage, as reflected by higher leaf relative water content, cell membrane stability, photosynthesis, and lower oxidative damage. Contrarily, the inhibition of GABA accumulation by the application of GABA biosynthesis inhibitor further aggravated heat damage. Transcriptional analyses showed that exogenous GABA could significantly upregulate transcript levels of genes encoding heat shock factor HSFs (HSFA-6a, HSFA-2c, and HSFB-2b), heat shock proteins (HSP17.8, HSP26.7, HSP70, and HSP90.1-b1), and ascorbate peroxidase 3 (APX3), whereas the inhibition of GABA biosynthesis depressed these genes expression under heat stress. Our results indicate GABA regulates thermotolerance associated with activation and enhancement of HSF pathways in creeping bentgrass.


Assuntos
Agrostis/metabolismo , Proteínas de Choque Térmico/metabolismo , Resposta ao Choque Térmico/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Termotolerância/efeitos dos fármacos , Ácido gama-Aminobutírico/farmacologia , Agrostis/genética , Proteínas de Choque Térmico/genética , Resposta ao Choque Térmico/fisiologia , Proteínas de Plantas/genética , Termotolerância/fisiologia
7.
Int J Mol Sci ; 20(18)2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31505730

RESUMO

Heat stress (HS) is an important factor for the survival of the marine organism Apostichopus japonicus. Lysine acetylation is a pivotal post-translational modification that modulates diverse physiological processes including heat shock response (HSR). In this study, 4028 lysine acetylation sites in 1439 proteins were identified in A. japonicus by acetylproteome sequencing. A total of 13 motifs were characterized around the acetylated lysine sites. Gene Ontology analysis showed that major acetylated protein groups were involved in "oxidation-reduction process", "ribosome", and "protein binding" terms. Compared to the control group, the acetylation quantitation of 25 and 41 lysine sites changed after 6 and 48 h HS. Notably, lysine acetyltransferase CREB-binding protein (CBP) was identified to have differential acetylation quantitation at multiple lysine sites under HS. Various chaperones, such as caseinolytic peptidase B protein homolog (CLBP), T-complex protein 1 (TCP1), and cyclophilin A (CYP1), showed differential acetylation quantitation after 48 h HS. Additionally, many translation-associated proteins, such as ribosomal proteins, translation initiation factor (IF), and elongation factors (EFs), had differential acetylation quantitation under HS. These proteins represented specific interaction networks. Collectively, our results offer novel insight into the complex HSR in A. japonicus and provide a resource for further mechanistic studies examining the regulation of protein function by lysine acetylation.


Assuntos
Resposta ao Choque Térmico/fisiologia , Processamento de Proteína Pós-Traducional/fisiologia , Proteoma/metabolismo , Pepinos-do-Mar/metabolismo , Acetilação , Animais , Lisina/metabolismo
8.
Plant Physiol Biochem ; 143: 11-18, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31473401

RESUMO

Two chickpea genotypes viz. Bhakar-2011 (desi) and Noor-2013 (kabuli) were sown in soil filled pots supplied with low (0.3 mg kg-1) and high (3 mg kg-1 soil) zinc (Zn) under control (70% water holding capacity and 25/20 °C day/night temperature), drought (35% water holding capacity) and heat (35/30 °C day/night temperature) stresses. Drought and heat stresses reduced rate of photosynthesis, photosystem II efficiency, plant growth and Zn uptake in chickpea. Low Zn supply exacerbated adverse effects of drought and heat stresses in chickpea, and caused reduction in plant biomass, carbon assimilation, antioxidant activity, impeded Zn uptake and enhanced oxidative damage. However, adequate Zn supply ameliorated adverse effect of drought and heat stresses in both chickpea types. The improvements were more in desi than kabuli type. Adequate Zn nutrition is crucial to augment growth of chickpea plants under high temperature and arid climatic conditions.


Assuntos
Cicer/metabolismo , Zinco/metabolismo , Ascorbato Peroxidases/genética , Ascorbato Peroxidases/metabolismo , Biomassa , Cicer/genética , Secas , Resposta ao Choque Térmico/fisiologia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
9.
Biomed Res Int ; 2019: 6534745, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31396532

RESUMO

Chloroplasts are intracellular semiautonomous organelles central to photosynthesis and are essential for plant growth and yield. The significance of the function of chloroplast-related genes in response to climate change has not been well studied in crops. In the present study, the initial focus was on genes that were predicted to be located in the chloroplast genome in rice, a model crop plant, with genes either preferentially expressed in the leaf or ubiquitously expressed in all organs. The characteristics were analyzed by Gene Ontology (GO) enrichment and MapMan functional classification tools. It was then identified that 110 GO terms (45 for leaf expression and 65 for ubiquitous expression) and 1,695 genes mapped to MapMan overviews were strongly associated with chloroplasts. In particular, the MapMan cellular response overview revealed a close association between heat stress response and chloroplast-related genes in rice. Moreover, features of these genes in response to abiotic stress were analyzed using a large-scale publicly available transcript dataset. Consequently, the expression of 215 genes was found to be upregulated in response to high temperature stress. Conversely, genes that responded to other stresses were extremely limited. In other words, chloroplast-related genes were found to affect abiotic stress response mainly through high temperature response, with little effect on response to drought and salinity stress. These results suggest that genes involved in diurnal rhythm in the leaves participate in the reaction to recognize temperature changes in the environment. Furthermore, the predicted protein-protein interaction network analysis associated with high temperature stress is expected to provide a very important basis for the study of molecular mechanisms by which chloroplasts will respond to future climate changes.


Assuntos
Cloroplastos/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Resposta ao Choque Térmico/fisiologia , Oryza/metabolismo , Estresse Salino/fisiologia , Cloroplastos/genética , Desidratação/genética , Desidratação/metabolismo , Oryza/genética
10.
Nat Commun ; 10(1): 3626, 2019 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-31399574

RESUMO

The molecular chaperone Hsp90 is an important regulator of proteostasis. It has remained unclear why S. cerevisiae possesses two Hsp90 isoforms, the constitutively expressed Hsc82 and the stress-inducible Hsp82. Here, we report distinct differences despite a sequence identity of 97%. Consistent with its function under stress conditions, Hsp82 is more stable and refolds more efficiently than Hsc82. The two isoforms also differ in their ATPases and conformational cycles. Hsc82 is more processive and populates closed states to a greater extent. Variations in the N-terminal ATP-binding domain modulate its dynamics and conformational cycle. Despite these differences, the client interactomes are largely identical, but isoform-specific interactors exist both under physiological and heat shock conditions. Taken together, changes mainly in the N-domain create a stress-specific, more resilient protein with a shifted activity profile. Thus, the precise tuning of the Hsp90 isoforms preserves the basic mechanism but adapts it to specific needs.


Assuntos
Proteínas de Choque Térmico HSP90/química , Chaperonas Moleculares/química , Isoformas de Proteínas/química , Proteínas de Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/metabolismo , Adenosina Trifosfatases/metabolismo , Sequência de Aminoácidos , Proteínas de Choque Térmico HSP90/genética , Proteínas de Choque Térmico HSP90/metabolismo , Proteínas de Choque Térmico HSP90/fisiologia , Resposta ao Choque Térmico/fisiologia , Ligantes , Modelos Moleculares , Chaperonas Moleculares/metabolismo , Ligação Proteica , Conformação Proteica , Dobramento de Proteína , Isoformas de Proteínas/metabolismo , Estabilidade Proteica , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Alinhamento de Sequência , Estresse Fisiológico
12.
J Therm Biol ; 84: 1-7, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31466741

RESUMO

Heat can trigger testicular damage and impair fertility. Leydig cells produce testosterone in response to stimulation by luteinizing hormone (LH), which induces Ca2+ entry and K+ efflux through ion channels in their plasma membrane. Considering that mechanisms coordinating the Leydig cell responses to hyperthermic stress remain unclear; the present study analyzed the effects of heat stress (HS, 43°C, 15 min) and inhibition of Hsp90 on T-type calcium currents and voltage-dependent potassium currents (VKC) in mice Leydig cells. Results show that HS reduced the VKC steady state currents at +80 mV (45.3%) and maximum conductance (71.5%), as well as increased the activation time constant (31.7%) and the voltage for which half the channels are open (30%). Hsp90 inhibition did not change the VKC currents. T-type calcium currents were not affected by HS or Hsp90 inhibition. In conclusion, HS can slow the activation, reduce the currents and voltage dependence of the VKC, suggesting a possible role of these currents in the response to hyperthermic stress in Leydig cells.


Assuntos
Canais de Cálcio Tipo T/fisiologia , Proteínas de Choque Térmico HSP90/fisiologia , Resposta ao Choque Térmico/fisiologia , Células Intersticiais do Testículo/fisiologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana/fisiologia , Animais , Benzoquinonas/farmacologia , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Temperatura Alta , Lactamas Macrocíclicas/farmacologia , Células Intersticiais do Testículo/efeitos dos fármacos , Masculino , Camundongos
13.
J Therm Biol ; 84: 154-163, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31466748

RESUMO

L-proline (L-PROL) is an essential amino acid, a constituent of many proteins and the osmoprotective molecule produced and accumulated in higher plants and some freshwater microalgae in response to various environmental stressors. Knowledge on thermoprotective effects of this amino acid on freshwater invertebrates is very scarce. Therefore the aim of our study was to determine the effect of L-PROL at concentrations: 10 mg/L, 20 mg/L and 50 mg/L on swimming behavior (immobilization, swimming track density, swimming speed, turning ability) of Daphnia magna subjected to temperatures: 22 °C, 35 °C and 38 °C. We found that L-PROL elevated all the measured swimming parameters at 22 °C when compared to the untreated crustaceans. Furthermore, L-PROL alleviated heat-induced inhibition of these parameters in the experimental animals subjected to 35 °C. The results suggest that L-PROL stimulates swimming performance and alleviates alterations of swimming parameters induced by heat stress in D. magna. Moreover, these findings may support the hypothesis that in natural conditions, L-PROL may protect crustaceans against thermal stress.


Assuntos
Daphnia/efeitos dos fármacos , Resposta ao Choque Térmico/efeitos dos fármacos , Prolina/farmacologia , Natação , Animais , Comportamento Animal/efeitos dos fármacos , Daphnia/fisiologia , Feminino , Resposta ao Choque Térmico/fisiologia
14.
J Therm Biol ; 84: 451-459, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31466786

RESUMO

We aimed to determine whether the use of injectable vitamins and minerals improves growth performance and immune and antioxidant responses in dairy calves during pre- and post-weaning period in summer. Twenty dairy calves (45 days of age) were randomized to two groups (10 each): control group (CON) and treated group [TREAT; injection providing 0.20, 0.80, 0.20, 0.10, 35 and 1 mg/kg of copper, zinc, manganese selenium, and vitamins A and E, during two periods (15 days pre- and 15 days post-weaning)]. The animals were weighed and blood samples were collected on days 1, 15, 30 and 45 of the study. Levels of serum copper, selenium, zinc, and manganese were measured on day 1; and the results showed that calves were not deficient in these minerals. The TREAT group had greater BW gain during the final third of the experiment. There was an increase in total leukocyte numbers as a result of elevation in neutrophil counts (day 45) and monocytes (days 30 and 45) in the TREAT group. This group also had lower reactive oxygen species (ROS) content (days 15, 30 and 45) and lipid peroxidation (LPO; days 15 and 45). Furthermore, the TREAT group had greater antioxidant capacity against peroxyl radicals (ACAP; days 15 and 30), activities of the enzymes glutathione peroxidase (GPx; days 15, 30 and 45) and superoxide dismutase (SOD; day 15), concentrations of total serum proteins (day 30), serum globulin (days 15 and 30), ceruloplasmin (day 15), tumor necrosis factor-alpha (TNF-α), interleukin-1, (IL-1; days 30 and 45) and interferon gamma (IFNγ; day 45), compared to CON group. High respiratory rates during hot times of the day in all study calves was suggestive of heat stress. Taken together, the data suggest that mineral and vitamins injections increased the growth performance and boosted the antioxidant and immunological systems of dairy calves during the diet transition period in summer.


Assuntos
Bovinos , Suplementos Nutricionais , Metais/farmacologia , Selênio/farmacologia , Vitamina A/farmacologia , Vitamina E/farmacologia , Vitaminas/farmacologia , Animais , Bovinos/sangue , Bovinos/crescimento & desenvolvimento , Bovinos/imunologia , Bovinos/metabolismo , Citocinas/sangue , Dieta/veterinária , Feminino , Glutationa Peroxidase/sangue , Resposta ao Choque Térmico/fisiologia , Metais/sangue , Espécies Reativas de Oxigênio/sangue , Taxa Respiratória , Estações do Ano , Selênio/sangue , Superóxido Dismutase/sangue
15.
J Therm Biol ; 84: 92-98, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31466795

RESUMO

The aim of this study was to identify whether more and less adapted Angus and Simmental cattle differed in physiological responses and expression of the heat shock factor 1 (HSF1) and the heat shock 70 kDa protein 6 (HSPA6), when subjected to heat stress. Thirty bulls (n = 15 ANG; n = 15 SIM), extremes "more adapted" and "less adapted" within each breed were selected to the heat tolerance test. They were selected according to an index based on the average of the respiratory rate obtained on two hot summer days from one hundred bulls. Before the heat tolerance test day, animals were taken to a paddock with water, grass and shade until 7 a.m. of the following day for morning measurements. They were kept in the barn without access to water and shade until 1 p.m. for the afternoon measurements. Respiratory rate in the morning (MRR) and afternoon (ARR), hair coat surface temperature in the morning (MST) and afternoon (AST), rectal temperature in the morning (MRT) and afternoon (ART) were measured and blood samples were collected for expression analysis of the HSF1 and HSPA6 genes. The MIXED procedure of SAS was used for all statistical analysis. The more adapted Simmental group had lesser values of MRR (P = 0.023) and MRT (P = 0.095), but there was no difference within Angus breed. The ARR was greater (P = 0.004) in less adapted animals for both breeds. The ART was lower in the Simmental breed (P < 0.001). Less adapted had greater levels of mRNA of HSF1 (P = 0.06) and HSPA6 (P = 0.09). In conclusion, respiratory rate, rectal temperature and expression of the HSF1 and HSPA6 genes can be indicators of thermotolerance in taurine cattle. Both breeds show physiologically similar responses under heat stress conditions.


Assuntos
Bovinos/fisiologia , Proteínas de Choque Térmico HSP70/fisiologia , Fatores de Transcrição de Choque Térmico/fisiologia , Termotolerância/fisiologia , Animais , Temperatura Corporal , Bovinos/genética , Regulação da Expressão Gênica , Proteínas de Choque Térmico HSP70/genética , Fatores de Transcrição de Choque Térmico/genética , Resposta ao Choque Térmico/genética , Resposta ao Choque Térmico/fisiologia , Umidade , Masculino , Taxa Respiratória , Temperatura , Termotolerância/genética
16.
Res Vet Sci ; 126: 94-102, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31445399

RESUMO

Heat stress is well documented to have a negative influence on livestock productivity and these impacts may be exacerbated by climate change. Dairy cattle can be more vulnerable to the negative effects of heat stress as these adverse impacts may be more profound during pregnancy and lactation. New emerging diseases are usually linked to a positive relationship with climate change and the survival of microrganisms and/or their vectors. These diseases may exaggerate the immune suppression associated with the immune suppressive effect of heat stress that is mediated by the hypothalamic-pituitary-adrenal (HPA) and the sympathetic-adrenal-medullary (SAM) axes. It has been established that heat stress has a negative impact on the immune system via cell mediated and humoral immune responses. Heat stress activates the HPA axis and increases peripheral levels of glucocorticoids subsequently suppressing the synthesis and release of cytokines. Heat stress has been reported to induce increased blood cortisol concentrations which have been shown to inhibit the production of cytokines such as interleukin-4 (IL-4), IL-5, IL-6, IL-12, interferon γ (IFNγ), and tumor necrosis factor-α (TNF- α). The impact of heat stress on the immune responses of dairy cows could be mediated by developing appropriate amelioration strategies through nutritional interventions and cooling management. In addition, improving current animal selection methods and the development of climate resilient breeds may support the sustainability of livestock production systems into the future.


Assuntos
Doenças dos Bovinos/etiologia , Transtornos de Estresse por Calor/veterinária , Resposta ao Choque Térmico/fisiologia , Animais , Bovinos , Doenças dos Bovinos/imunologia , Citocinas/metabolismo , Transtornos de Estresse por Calor/etiologia , Transtornos de Estresse por Calor/imunologia , Resposta ao Choque Térmico/imunologia , Sistema Hipotálamo-Hipofisário , Sistema Hipófise-Suprarrenal/fisiologia
17.
Eur J Appl Physiol ; 119(9): 2105-2118, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31377851

RESUMO

PURPOSE: To determine the impact of altering dietary sodium intake for 3 days preceding exercise on sweat sodium concentration [Na+], and cardiovascular and thermoregulatory variables. METHODS: Fifteen male endurance athletes (runners n = 8, cyclists n = 7) consumed a low (LNa, 15 mg kg-1 day-1) or high (HNa, 100 mg kg-1 day-1) sodium diet, or their usual free-living diet [UDiet, 46 (37-56) mg kg-1 day-1] for 3 days in a double-blind, randomized cross-over design, collecting excreted urine (UNa) and refraining from exercise. On day 4, they completed 2 h running at 55% [Formula: see text]O2max or cycling at 55% maximum aerobic power in Tamb 35 °C. Pre- and post-exercise blood samples were collected, and sweat from five sites using absorbent patches along the exercise protocol. RESULTS: UNa on days 2-3 pre-exercise [mean (95% CI) LNa 16 (12-19) mg kg-1 day-1, UDiet 46 (37-56) mg kg-1 day-1, HNa 79 (72-85) mg kg-1 day-1; p < 0.001] and pre-exercise aldosterone [LNa 240 (193-286) mg kg-1 day-1, UDiet 170 (116-224) mg kg-1 day-1, HNa 141 (111-171) mg kg-1 day-1; p = 0.001] reflected sodium intake as expected. Pre-exercise total body water was greater following HNa compared to LNa (p < 0.05), but not UDiet. Estimated whole-body sweat [Na+] following UDiet was 10-11% higher than LNa and 10-12% lower than HNa (p < 0.001), and correlated with pre-exercise aldosterone (1st h r = - 0.568, 2nd h r = - 0.675; p < 0.01). Rectal temperature rose more quickly in LNa vs HNa (40-70 min; p < 0.05), but was similar at the conclusion of exercise, and no significant differences in heart rate or perceived exertion were observed. CONCLUSIONS: Three day altered sodium intake influenced urinary sodium excretion and sweat [Na+], and the rise in rectal temperature, but had no effect on perceived exertion during moderate-intensity exercise in hot ambient conditions.


Assuntos
Transtornos de Estresse por Calor/metabolismo , Transtornos de Estresse por Calor/fisiopatologia , Resposta ao Choque Térmico/fisiologia , Sódio na Dieta/administração & dosagem , Sódio/metabolismo , Sudorese/fisiologia , Adulto , Estudos Cross-Over , Método Duplo-Cego , Ingestão de Líquidos/fisiologia , Exercício Físico/fisiologia , Frequência Cardíaca/fisiologia , Temperatura Alta , Humanos , Masculino , Resistência Física/fisiologia , Corrida/fisiologia , Suor/metabolismo , Equilíbrio Hidroeletrolítico/fisiologia
18.
Workplace Health Saf ; 67(9): 470-480, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31315538

RESUMO

With expected increases in extreme weather, there may be a greater risk of injury from extreme heat in outdoor worker populations. To plan for future adaptation measures, studies are needed that can characterize workers' physiologic responses to heat in outdoor settings such as agriculture. The objective of this study was to characterize occupational heat exposure, key vulnerability factors (e.g., gender, energy expenditure), and physiologic heat stress response in a sample of fernery workers. Forty-three fernery workers over 86 workdays were examined regarding heat-related illness (HRI) during the summer months of 2012 and 2013. The key outcome measure was whether a participant's body core temperature (Tc) reached or exceeded 38.0°C (100.4ºF; Tc38). Participants' Tc exceeded 38.0°C on 49 (57%) of the workdays, with 30 of 40 participants reaching or exceeding Tc38 on at least one workday. Adjusting for sex, there was a 12% increase in the odds of Tc38 for every 100 kilocalories of energy expended (OR: 1.12; 95% Confidence Interval [CI]: [1.03, 1.21]). Adjusting for energy expenditure, females had 5 times greater odds of Tc38 compared with males (OR: 5.38; 95% CI: [1.03, 18.30]). These findings provide evidence of elevated Tc in Florida fernery workers, indicating an increased risk of occupational HRI, and the need for policy and interventions to address this health risk.


Assuntos
Temperatura Corporal , Fazendeiros , Resposta ao Choque Térmico/fisiologia , Exposição Ocupacional/efeitos adversos , Actigrafia , Adulto , Agricultura , Exercício Físico , Feminino , Gleiquênias , Florida/epidemiologia , Temperatura Alta , Humanos , Masculino , Projetos Piloto , Fatores de Risco
19.
BMC Biol ; 17(1): 56, 2019 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-31311534

RESUMO

BACKGROUND: Adaptive responses to stress are essential for cell and organismal survival. In metazoans, little is known about the impact of environmental stress on RNA homeostasis. RESULTS: By studying the regulation of a cadmium-induced gene named numr-1 in Caenorhabditis elegans, we discovered that disruption of RNA processing acts as a signal for environmental stress. We find that NUMR-1 contains motifs common to RNA splicing factors and influences RNA splicing in vivo. A genome-wide screen reveals that numr-1 is strongly and specifically induced by silencing of genes that function in basal RNA metabolism including subunits of the metazoan integrator complex. Human integrator processes snRNAs for functioning with splicing factors, and we find that silencing of C. elegans integrator subunits disrupts snRNA processing, causes aberrant pre-mRNA splicing, and induces the heat shock response. Cadmium, which also strongly induces numr-1, has similar effects on RNA and the heat shock response. Lastly, we find that heat shock factor-1 is required for full numr-1 induction by cadmium. CONCLUSION: Our results are consistent with a model in which disruption of integrator processing of RNA acts as a molecular damage signal initiating an adaptive stress response mediated by heat shock factor-1. When numr-1 is induced via this pathway in C. elegans, its function in RNA metabolism may allow it to mitigate further damage and thereby promote tolerance to cadmium.


Assuntos
Cádmio/toxicidade , Caenorhabditis elegans/fisiologia , Regulação da Expressão Gênica , Resposta ao Choque Térmico/fisiologia , Processamento Pós-Transcricional do RNA/fisiologia , Processamento de RNA , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Resposta ao Choque Térmico/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fatores de Processamento de RNA/genética , Fatores de Processamento de RNA/metabolismo , RNA Nuclear Pequeno/genética , RNA Nuclear Pequeno/metabolismo , Estresse Fisiológico
20.
Microb Pathog ; 135: 103610, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31288065

RESUMO

The WRKY transcription factors (TFs) family constitutes a major group of TFs in spermatophytes. Different studies have endorsed the considerable biological roles performed by WRKY TFs in plant growth, biotic and abiotic stress responses. Genomic and transcriptomic profiling facilitate us in understanding the WRKY genes in various plants and reveal how WRKY TFs perform their action in response to different plant stresses. WRKY TFs actively take part in metabolism including carbohydrate synthesis, senescence, and secondary metabolites production. Molecular organization of WRKY TFs in plants highlight most predicted outcome of multiple responses simultaneously. Repression and activation related to W-box and other such elements is controlled at transcriptional, translational and domain level. WRKY TFs are becoming more important in crop improvement because of their binding with downstream elements. Additionally, WRKY proteins intermingle with various other TFs for modulating plant immunity. However, WRKY TFs self-regulation and crosstalk between different signaling pathways using WRKY TFs still need extensive investigations. In this review, we focused characteristics of WRKY TFs in Capsicum annum and related research advancement on their functional involvement in plant responses to the challenges of high temperature stress and pathogens infection. We summarized information about Capsicum annum WRKY TFs on the basis of their functions, their target genes and signaling pathways. Moreover, the mechanisms for synergistic responses to various biotic and abiotic stresses, WRKY target genes and other TFs as well will be of more interest with increments in existing information.


Assuntos
Capsicum/genética , Capsicum/imunologia , Imunidade Inata , Imunidade Vegetal/genética , Imunidade Vegetal/imunologia , Estresse Fisiológico/genética , Estresse Fisiológico/imunologia , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/imunologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Resposta ao Choque Térmico/fisiologia , Interações entre Hospedeiro e Microrganismos/fisiologia , Umidade , Estágios do Ciclo de Vida/fisiologia , Doenças das Plantas/imunologia , Proteínas de Plantas/genética , Metabolismo Secundário , Transdução de Sinais , Temperatura , Fatores de Transcrição
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