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1.
Int J Mol Sci ; 22(5)2021 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-33800127

RESUMO

Heat stress causes huge losses in the yield of cereal crops. Temperature influences the rate of plant metabolic and developmental processes that ultimately determine the production of grains, with high temperatures causing a reduction in grain yield and quality. To ensure continued food security, the tolerance of high temperature is rapidly becoming necessary. Brassinosteroids (BR) are a class of plant hormones that impact tolerance to various biotic and abiotic stresses and regulate cereal growth and fertility. Fine-tuning the action of BR has the potential to increase cereals' tolerance and acclimation to heat stress and maintain yields. Mechanistically, exogenous applications of BR protect yields through amplifying responses to heat stress and rescuing the expression of growth promoters. Varied BR compounds and differential signaling mechanisms across cereals point to a diversity of mechanisms that can be leveraged to mitigate heat stress. Further, hormone transport and BR interaction with other molecules in plants may be critical to utilizing BR as protective agrochemicals against heat stress. Understanding the interplay between heat stress responses, growth processes and hormone signaling may lead us to a comprehensive dogma of how to tune BR application for optimizing cereal growth under challenging environments in the field.


Assuntos
Brassinosteroides/metabolismo , Grão Comestível/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Resposta ao Choque Térmico/fisiologia , Transdução de Sinais/fisiologia , Temperatura Alta
2.
Plant Sci ; 306: 110850, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33775357

RESUMO

Autophagy is a major degradation pathway in plants for maintaining cellular homeostasis in response to various environmental stressors. ATG8 is one of a series of autophagy-related (ATG) proteins and plays a central role in both bulk and selective autophagy. Previously, we characterized MdATG8i in apple and demonstrated that it has a positive role in apple stress resistance. Although many ATG8-interacting proteins have been found in Arabidopsis, no protein has been reported to interact with MdATG8 in apple. Here, we identified MdHARBI1 as a MdATG8i-interacting protein in apple, however, the functions of HARBI1-like proteins have not been explored in plants. Expression analysis of MdHARBI1 and pro-MdHARBI1-GUS staining of transgenic Arabidopsis exposed to high temperature demonstrated that MdHARBI1 was significantly induced by heat stress. Moreover, heat-treated MdHARBI1-trangenic tomato plants maintained higher autophagic activity, accumulated fewer ROS, and displayed stronger chlorophyll fluorescence than wild-type plants. Because these phenotypes were consistent with those displayed by MdATG8i-overexpressing apple plants under high temperature, we concluded that the MdATG8i-interacting protein MdHARBI1 plays a critical role in the basal thermotolerance of plants, mainly by influencing autophagy pathways.


Assuntos
Proteínas Relacionadas à Autofagia/fisiologia , Autofagia/genética , Resposta ao Choque Térmico/genética , Malus/genética , Malus/fisiologia , Termotolerância/genética , Termotolerância/fisiologia , Autofagia/fisiologia , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Resposta ao Choque Térmico/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/fisiologia
3.
Life Sci ; 275: 119352, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33771521

RESUMO

AIMS: The autophagy-lysosomal system plays a crucial role in maintaining muscle proteostasis. Excessive stimulation of the autophagic machinery is a major contributor to muscle atrophy induced by tendon transection. Hyperthermia is known to attenuate muscle protein loss during disuse conditions; however, little is known regarding the response of the autophagy pathway to heat stress following tenotomy-induced muscle atrophy. The purpose of this study was to evaluate whether heat stress would have a beneficial impact on the activation of autophagy in tenotomized soleus and plantaris muscles. MAIN METHODS: Male Wistar rats were divided into control, control plus heat stress, tenotomy, and tenotomy plus heat stress groups. The effects of tenotomy were evaluated at 8 and 14 days with heat treatment applied using thermal blankets (30 min. day-1, at 40.5-41.5 °C, for 7 days). KEY FINDINGS: Heat stress could normalize tenotomy-induced muscle loss and over-activation of autophagy-lysosomal signaling; this effect was evidently observed in soleus muscle tenotomized for 14 days. The autophagy-related proteins LC3B-II and LC3B-II/I tended to decrease, and lysosomal cathepsin L protein expression was significantly suppressed. While p62/SQSTM1 was not altered in response to intermittent heat exposure in tenotomized soleus muscle at day 14. Phosphorylation of the 4E-BP1 protein was significantly increased in tenotomized plantaris muscle; whereas heat stress had no impact on phosphorylation of Akt and FoxO3a proteins in both tenotomized muscles examined. SIGNIFICANCE: Our results provide evidence that heat stress associated attenuation of tenotomy-induced muscle atrophy is mediated through limiting over-activation of the autophagy-lysosomal pathway in oxidative and glycolytic muscles.


Assuntos
Autofagia/fisiologia , Resposta ao Choque Térmico/fisiologia , Lisossomos/fisiologia , Atrofia Muscular/fisiopatologia , Tendão do Calcâneo/cirurgia , Animais , Eletroforese em Gel de Poliacrilamida , Humanos , Lisossomos/metabolismo , Masculino , Atrofia Muscular/metabolismo , Cadeias Pesadas de Miosina/metabolismo , Ratos , Ratos Wistar , Transdução de Sinais , Tenotomia/efeitos adversos
4.
Poult Sci ; 100(2): 957-963, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33518149

RESUMO

Broiler chickens reared under heat stress (HS) conditions have decreased growth performance and show metabolic and immunologic alterations. This study aimed to evaluate the effect of supplementation with a standardized blend of plant-derived isoquinoline alkaloids (IQ) on the growth performance, protein catabolism, intestinal barrier function, and inflammatory status of HS-treated chickens. Three hundred sixty 0-day-old Ross 308 male broiler chickens were randomly distributed into 2 treatment groups: control diet (no additives) or diet supplemented with 100 ppm IQ. At day 14, the chicks in each diet group were further divided into 2 groups, each of which was reared under thermoneutral (TN) (22.4°C) or constant HS (33.0°C) conditions until day 42. Each group consisted of 6 replicates with 15 birds per replicate, and chickens were provided ad libitum access to water and feed. During days 15-21, the body weight gain (BWG) and feed intake (FI) were significantly lower in the HS treatment group than in the TN group, and feed conversion ratio was higher (P < 0.05); these factors were not alleviated by IQ supplementation. During days 22-42, the final BW, BWG, and FI of the HS birds were better among those administered IQ than those that were not (P < 0.05). HS treatment increased plasma lipid peroxide, corticosterone, and uric acid concentrations as well as serum fluorescein isothiocyanate-dextran, a marker of intestinal barrier function, and decreased plasma total protein content (P < 0.05). These changes were not observed in the IQ group, suggesting that IQ supplementation improved oxidative damage, protein catabolism, and intestinal barrier function of chickens under HS. Isoquinoline alkaloid supplementation inhibited the expression of intestinal inflammatory factors, IL-6, tumor necrosis factor-like factor 1A, and inducible nitric oxide synthase under HS treatment (P < 0.05). These results suggest that IQ supplementation can improve the growth performance of broiler chickens under HS conditions, which may be associated with amelioration of oxidative damage, protein catabolism, intestinal barrier function, and inflammation.


Assuntos
Alcaloides/farmacologia , Galinhas/fisiologia , Resposta ao Choque Térmico/fisiologia , Intestinos/efeitos dos fármacos , Isoquinolinas/administração & dosagem , Alcaloides/administração & dosagem , Ração Animal/análise , Animais , Galinhas/crescimento & desenvolvimento , Dieta/veterinária , Suplementos Nutricionais , Temperatura Alta , Intestinos/fisiologia , Isoquinolinas/química , Masculino
5.
Poult Sci ; 100(2): 1213-1220, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33518079

RESUMO

This experiment aimed to evaluate the impact of continuous and intermittent thermal stress during early embryogenesis on hatchability, physiological body reaction, ovary weight, and follicle development of quails. A total of 540 eggs were divided into 3 equal groups (3 groups × 6 replicates × 30 eggs). In the first group (control), eggs were incubated at normal incubation conditions (37.5°C and 50-55% relative humidity) from day 0 till hatching. In the second group (continuous thermal stress [CTS]), eggs were daily exposed to 39.5°C and 50 to 55% during the early embryogenesis for 3 successive days (E4-E6) for 3 h (12:00-15:00). In the third group (intermittent thermal stress [ITS]), eggs were daily exposed to 39.5°C and 50 to 55% during the early embryogenesis for 90 min (12:00-13:30) then temperature was returned to 37.5°C for 60 min (13:30-14:30) after that the temperature was raised again for 39.5°C for 90 min (14:30-16:00) daily for 3 successive days (E4-E6). The findings showed that the highest relative water loss form egg (RWL/%) at 6 d of incubation was obtained in the CTS group (P ≤ 0.05). The hatchability rate was significantly (P ≤ 0.05) decreased in the thermal-treated groups compared with the control group. The body surface temperature and cloacal temperature in the CTS and ITS groups significantly (P ≤ 0.001) increased compared with the control group. Chick weight (g) at 5 wk old, total weight gain, daily weight gain were significantly lower (P ≤ 0.05) in the CTS group compared with the control group. Triiodothyronine (T3) hormone concentration and globulin level were significantly (P ≤ 0.05) lower in the CTS and ITS groups compared with the control. The ovarian follicle weights (first, second, third, fourth, and fifth) and the diameter of the large follicle (fifth follicle) were significantly (P ≤ 0.01) decreased by increasing incubation temperature. From these findings, it could be concluded that the hatchability and body weight at sexual maturity for quails produced from eggs exposed to CTS and IST were significantly decreased by 8 and 2.1% as well as 2.98 and 2.1%, respectively, compared with the control group.


Assuntos
Resposta ao Choque Térmico/fisiologia , Folículo Ovariano/crescimento & desenvolvimento , Codorniz/fisiologia , Animais , Ovos/normas , Feminino , Codorniz/embriologia , Codorniz/crescimento & desenvolvimento
6.
Ecotoxicol Environ Saf ; 212: 111962, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33550082

RESUMO

The production of cucumber under combined salinity and heat stress is a crucial challenge facing many countries particularly in arid environments. This challenge could be controlled through exogenous foliar application of some bio-stimulants or anti-stressors. This study was carried out to investigate the management and improving cucumber production under combined salinity and heat stress. Nano-selenium (nano-Se, 25 mg L-1), silicon (Si, 200 mg L-1) and hydrogen peroxide (H2O2, 20 mmol L-1) were foliar applied on cucumber plants as anti-stress compounds. The results revealed that studied anti-stressors improved growth and productivity of cucumber grown in saline soil regardless the kind of anti-stressor under heat stress. The foliar application of nano-Se (25 mg L-1) clearly improved cucumber growth parameters (plant height and leaf area) compared to other anti-stressor and control. Foliar Si application showed the greatest impact on enzymatic antioxidant capacities among the other anti-stressor treatments. This applied rate of Si also showed the greatest increase in marketable fruit yield and yield quality (fruit firmness and total soluble solids) compared to untreated plants. These increases could be due to increasing nutrient uptake particularly N, P, K, and Mg, as well as Se (by 40.2% and 43%) in leaves and Si (by 11.2% and 22.1% in fruits) in both seasons, respectively. The potential role of Si in mitigating soil salinity under heat stress could be referred to high Si content found in leaf which regulates water losses via transpiration as well as high nutrient uptake of other nutrients (N, P, K, Mg and Se). The distinguished high K+ content found in cucumber leaves might help stressed plants to tolerate studied stresses by regulating the osmotic balance and controlling stomatal opening, which support cultivated plants to adapt to soil salinity under heat stress. Further studies are needed to be carried out concerning the different response of cultivated plants to combined stresses.


Assuntos
Selênio , Silício , Antioxidantes , Cucumis sativus/crescimento & desenvolvimento , Frutas , Resposta ao Choque Térmico/fisiologia , Peróxido de Hidrogênio , Folhas de Planta , Salinidade , Solo
7.
Trop Anim Health Prod ; 53(1): 97, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33415455

RESUMO

Induction of heat stress as an experimental procedure in animals is commonly used to examine heat-related impacts on sperm quality. This study aimed to develop potential heat stress models that could be used at any time of the year, to advance the study of seasonal infertility in the pig under controlled conditions. Heat stress was induced by either housing boars (n = 6) at 30 °C inside a hot room for 42 days (55-65% humidity; LD 12:12 h; in vivo), or by heating boar semen (n = 7) for 30 min at various temperatures (35.5, 38.8, 40, 42, 46, 50, 54 and 60 °C; in vitro). Sperm motility was then characterized by computer-assisted sperm analysis (CASA; IVOS version 10: Hamilton Thorne, USA), and DNA integrity was evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) and flow cytometry. Our in vivo hot room model induced biologically meaningful levels of DNA damage in boar spermatozoa (10.1 ± 1.9 hot room vs. 6.7 ± 1.7% control; P > 0.05), although not statistically significant from controls. Moreover, sperm concentration and motility parameters did not differ between treatments (P > 0.05). Compared to the 38.8 °C control, our in vitro heat shock model significantly increased sperm DNA damage after incubation at 54 and 60 °C (3.0 ± 1.0, 2.9 ± 1.0, 1.2 ± 0.3, 2.5 ± 0.7, 9.0 ± 3.7, 16.2 ± 7.1, 14.2 ± 5.8 and 41.8 ± 18.6% respectively; P ≤ 0.05). However, these temperatures rendered sperm completely immotile or dead, with most motility parameters declining rapidly to zero above 40 or 42 °C. In conclusion, our results suggest that temperature combined with individual factors may contribute to a boar's overall susceptibility to heat stress. Refinement of these models particularly of the in vitro heat shock model could be further pursued to overcome environmental variability, reduce whole animal experiments and provide a putative diagnostic fertility screening tool to evaluate heat tolerance in the boar.


Assuntos
Resposta ao Choque Térmico/fisiologia , Espermatozoides/fisiologia , Sus scrofa/fisiologia , Animais , Masculino , Modelos Animais
8.
Int J Mol Sci ; 22(1)2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33466228

RESUMO

Atrial fibrillation (AF) is the most common age-related cardiac arrhythmia worldwide and is associated with ischemic stroke, heart failure, and substantial morbidity and mortality. Unfortunately, current AF therapy is only moderately effective and does not prevent AF progression from recurrent intermittent episodes (paroxysmal) to persistent and finally permanent AF. It has been recognized that AF persistence is related to the presence of electropathology. Electropathology is defined as structural damage, including degradation of sarcomere structures, in the atrial tissue which, in turn, impairs electrical conduction and subsequently the contractile function of atrial cardiomyocytes. Recent research findings indicate that derailed proteostasis underlies structural damage and, consequently, electrical conduction impairment. A healthy proteostasis is of vital importance for proper function of cells, including cardiomyocytes. Cells respond to a loss of proteostatic control by inducing a heat shock response (HSR), which results in heat shock protein (HSP) expression. Emerging clinical evidence indicates that AF-induced proteostasis derailment is rooted in exhaustion of HSPs. Cardiomyocytes lose defense against structural damage-inducing pathways, which drives progression of AF and induction of HSP expression. In particular, small HSPB1 conserves sarcomere structures by preventing their degradation by proteases, and overexpression of HSPB1 accelerates recovery from structural damage in experimental AF model systems. In this review, we provide an overview of the mechanisms of action of HSPs in preventing AF and discuss the therapeutic potential of HSP-inducing compounds in clinical AF, as well as the potential of HSPs as biomarkers to discriminate between the various stages of AF and recurrence of AF after treatment.


Assuntos
Fibrilação Atrial/metabolismo , Proteínas de Choque Térmico/metabolismo , Animais , Átrios do Coração/metabolismo , Resposta ao Choque Térmico/fisiologia , Humanos , Contração Miocárdica/fisiologia , Miócitos Cardíacos/metabolismo , Proteostase/fisiologia
9.
Int J Mol Sci ; 22(2)2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33477941

RESUMO

High temperatures causing heat stress disturb cellular homeostasis and impede growth and development in plants. Extensive agricultural losses are attributed to heat stress, often in combination with other stresses. Plants have evolved a variety of responses to heat stress to minimize damage and to protect themselves from further stress. A narrow temperature window separates growth from heat stress, and the range of temperatures conferring optimal growth often overlap with those producing heat stress. Heat stress induces a cytoplasmic heat stress response (HSR) in which heat shock transcription factors (HSFs) activate a constellation of genes encoding heat shock proteins (HSPs). Heat stress also induces the endoplasmic reticulum (ER)-localized unfolded protein response (UPR), which activates transcription factors that upregulate a different family of stress response genes. Heat stress also activates hormone responses and alternative RNA splicing, all of which may contribute to thermotolerance. Heat stress is often studied by subjecting plants to step increases in temperatures; however, more recent studies have demonstrated that heat shock responses occur under simulated field conditions in which temperatures are slowly ramped up to more moderate temperatures. Heat stress responses, assessed at a molecular level, could be used as traits for plant breeders to select for thermotolerance.


Assuntos
Resposta ao Choque Térmico/genética , Termotolerância/genética , Ativação Transcricional/genética , Zea mays/genética , Regulação da Expressão Gênica de Plantas/genética , Fatores de Transcrição de Choque Térmico/genética , Resposta ao Choque Térmico/fisiologia , Temperatura Alta , Resposta a Proteínas não Dobradas/genética , Zea mays/fisiologia
10.
Exp Parasitol ; 222: 108077, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33465379

RESUMO

Protein arginine methylation regulates several cellular events, including epigenetics, splicing, translation, and stress response, among others. This posttranslational modification is catalyzed by protein arginine methyltransferases (PRMTs), which according to their products are classified from type I to type IV. The type I produces monomethyl arginine and asymmetric dimethyl arginine; in mammalian there are six families of this PRMT type (PRMT1, 2, 3, 4, 6, and 8). The protozoa parasite Entamoeba histolytica has four PRMTs related to type I; three of them are similar to PRMT1, but the other one does not show significant homology to be grouped in any known PRMT family, thus we called it as atypical PRMT (EhPRMTA). Here, we showed that EhPRMTA does not contain several of the canonical amino acid residues of type I PRMTs, confirming that it is an atypical PRMT. A specific antibody against EhPRMTA localized this protein in cytoplasm. The recombinant EhPRMTA displayed catalytic activity on commercial histones and the native enzyme modified its expression level during heat shock and erythrophagocytosis. Besides, the knockdown of EhPRMTA produced an increment in cell growth, and phagocytosis, but decreases cell migration and the survival of trophozoites submitted to heat shock, suggesting that this protein is involved in regulate negatively or positively these events, respectively. Thus, results suggest that this methyltransferase regulates some cellular functions related to virulence and cell surviving.


Assuntos
Entamoeba histolytica/enzimologia , Entamoeba histolytica/patogenicidade , Proteína-Arginina N-Metiltransferases/metabolismo , Sequência de Aminoácidos , Movimento Celular , Proliferação de Células/fisiologia , Sequência Conservada , Entamoeba histolytica/citologia , Entamoeba histolytica/metabolismo , Eritrócitos/metabolismo , Regulação Enzimológica da Expressão Gênica , Técnicas de Silenciamento de Genes , Resposta ao Choque Térmico/fisiologia , Fagocitose , Processamento de Proteína Pós-Traducional/fisiologia , Proteína-Arginina N-Metiltransferases/classificação , Proteína-Arginina N-Metiltransferases/genética , Virulência
11.
Trop Anim Health Prod ; 53(1): 66, 2021 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-33392887

RESUMO

The decline of milk production in crossbred cattle during the onset of summer was evaluated using lactation records of the cows (n = 48) maintained at the Livestock Research Station, Thiruvazhamkunnu, for the period between January 2019 and March 2019. Climate data were obtained from an automatic weather station maintained on the campus. The temperature-humidity index (THI) was used to assess the thermal stress on animals. Values varied between 70.78 and 83.93 during the study period, indicating that the cows were exposed to mild and moderate stress. Highly significant negative correlations (p < 0.01) were observed between the average temperature, THI, and milk production. Linear, logarithmic, power, and polynomial models linking milk production and THI were used to fit the data. The coefficient of determination (R2) in general exceeded 0.85 and these equations could be used to model the drop in milk production or predict production loss due to thermal stress. The rate of decline in daily milk production observed in the study was 2.13% per unit increase in THI. A general linear model that included THI, parity, and the stage of lactation as independent variables, and milk production as a response variable, was also tested. Parity and stages of lactation were observed to influence forenoon and afternoon milk production significantly (p < 0.01). The temperature-humidity index also had a significant effect on forenoon milk production (p < 0.05) and afternoon milk production (p < 0.01).


Assuntos
Indústria de Laticínios/estatística & dados numéricos , Resposta ao Choque Térmico/fisiologia , Lactação , Clima Tropical , Animais , Bovinos , Doenças dos Bovinos , Feminino , Temperatura Alta , Umidade , Modelos Lineares , Leite , Modelos Estatísticos , Dinâmica não Linear , Paridade , Gravidez , Estações do Ano , Temperatura , Tempo (Meteorologia)
12.
J Plant Physiol ; 256: 153326, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33310528

RESUMO

Internal browning (IB) of Japanese radish, in which the entire central part of the root changes from light tan to dark brown, is a physiological disorder caused by heat stress at the root maturation stage and represents significant economic losses to farmers. In this study, we cultivated three cultivars with different tolerance to IB disorder under high-temperature conditions, and examined the physiological factors involved in IB disorder differences among cultivars. There was a close correlation between the severity of IB disorder among cultivars and the size of root parenchymal cells. Significantly smaller cells were observed in the IB-resistant cultivars compared to the IB-susceptible one. Glucose concentration and invertase gene expression level tended to be higher in the normal roots of the IB-susceptible cultivar than in those of the resistant cultivars. Results of immunohistochemical analysis revealed that hexanoyl-lysine and acrolein, which are indicators of oxidative stress, in parenchymal cells were significantly elevated in the normal roots of the IB-susceptible cultivar than in those of the resistant ones. Similarly, the normal roots of the IB-susceptible cultivar showed elevated levels of Nε-(carboxymethyl)lysine, which is an indicator of the Maillard reaction, compared with those of the resistant cultivars. In addition, the immunohistochemistry of these indicators of oxidative stress and the Maillard reaction were more strongly observed in the damaged roots of the IB-susceptible cultivar. These results indicate that the occurrence of IB in Japanese radish is closely related to the increase in cell size, enhancement of the Maillard reaction by elevation in reducing sugar concentration, and increase in intracellular oxidative stress.


Assuntos
Resposta ao Choque Térmico/genética , Reação de Maillard , Estresse Oxidativo/genética , Estresse Oxidativo/fisiologia , Raízes de Plantas/química , Raphanus/química , Raphanus/genética , Variação Genética , Genótipo , Resposta ao Choque Térmico/fisiologia , Japão , Raízes de Plantas/genética
13.
J Dairy Sci ; 104(2): 1744-1758, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33309378

RESUMO

The objective of this study was to differentiate the effects of acute heat stress (HS) from those of decreased dry matter intake (DMI) during the prepartum period on metabolism, colostrum, and subsequent production of dairy cows. Holstein dairy cows (n = 30) with similar parity and body weight were randomly assigned to 1 of 3 treatments on 45 d before calving: (1) cooled (CL, n = 10) conditions with ad libitum feed intake, (2) HS conditions with ad libitum feed intake (n = 10), and (3) pair-fed cooled (CLPF, n = 10) with reduced DMI similar to the HS group while housed under cooled conditions. The reduction in the amount of feed offered to the CLPF cows was calculated daily as the percentage decrease from the average DMI of HS cows relative to the CL cows. For CLPF and CL cows, barns provided shade, sprinklers, and fans, whereas the HS cows were provided only with shade. Cows in all groups received individually the same total mixed ration. Cows were dried off 60 d before the expected calving. Cows in the HS group and, by design, the CLPF cows had reduced DMI (~20%) during the experiment. Heat stress decreased gestation length, first colostrum yield, and calf birth weight compared with CL and CLPF cows. Milk yield decreased 21% (5 kg) in the HS and 8% (2 kg) in CLPF cows, indicating that reduced feed intake during late gestation accounted for 60% of the total reduced milk yield. The CLPF cows exhibited an elevated NEFA concentration compared with the CL and HS cows. The HS cows had a greater mRNA abundance of HSP70 in the peripheral blood leukocytes at 21 d prepartum compared with the other groups. At calving, the mRNA abundance of HSP70 was greater in HS cows, followed by CLPF, compared with the CL cows. In conclusion, HS during the late gestation period caused metabolism and production differences, which were only partially attributed to reduced feed intake in dairy cows.


Assuntos
Bovinos/fisiologia , Colostro/fisiologia , Ingestão de Alimentos/fisiologia , Resposta ao Choque Térmico/fisiologia , Lactação/fisiologia , Parto/fisiologia , Ar Condicionado , Animais , Peso ao Nascer , Feminino , Idade Gestacional , Abrigo para Animais , Leite/metabolismo , Gravidez , Temperatura
14.
PLoS One ; 15(12): e0242381, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33315917

RESUMO

Cryptococcus neoformans is a pathogenic basidiomycetous yeast that primarily infects immunocompromised individuals. C. neoformans can thrive during infections due to its three main virulence-related characteristics: the ability to grow at host temperature (37°C), formation of carbohydrate capsule, and its ability to produce melanin. C. neoformans strains lacking septin proteins Cdc3 or Cdc12 are viable at 25°C; however, they fail to proliferate at 37°C and are avirulent in the murine model of infection. The basis of septin contribution to growth at host temperature remains unknown. Septins are a family of conserved filament-forming GTPases with roles in cytokinesis and morphogenesis. In the model organism Saccharomyces cerevisiae septins are essential. S. cerevisiae septins form a higher order complex at the mother-bud neck to scaffold over 80 proteins, including those involved in cell wall organization, cell polarity, and cell cycle control. In C. neoformans, septins also form a complex at the mother-bud neck but the septin interacting proteome in this species remains largely unknown. Moreover, it remains possible that septins play other roles important for high temperature stress that are independent of their established role in cytokinesis. Therefore, we propose to perform a global analysis of septin Cdc10 binding partners in C. neoformans, including those that are specific to high temperature stress. This analysis will shed light on the underlying mechanism of survival of this pathogenic yeast during infection and can potentially lead to the discovery of novel drug targets.


Assuntos
Cryptococcus neoformans/fisiologia , Proteínas Fúngicas/metabolismo , Mapeamento de Interação de Proteínas/métodos , Proteômica/métodos , Septinas/metabolismo , Criptococose/tratamento farmacológico , Criptococose/microbiologia , Cryptococcus neoformans/efeitos dos fármacos , Descoberta de Drogas/métodos , Proteínas Fúngicas/análise , Resposta ao Choque Térmico/fisiologia , Humanos , Ligação Proteica , Proteoma/análise , Proteoma/metabolismo , Septinas/análise
15.
Anim Sci J ; 91(1): e13486, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33222328

RESUMO

Pyruvate and creatine, energetics and antioxidant substances, can promote rumen fermentation and metabolism. This study aimed to evaluate the stress resistance and rumen fermentation effects of the compound creatine pyruvate (CrPyr) in diets for beef cattle under heat stress. Four Jinjiang steers fitted with permanent rumen cannulas were used in a 4 × 4 Latin square design and fed a diet supplemented with CrPyr at 0, 20, 40, or 60 g/d. Heat stress was employed for 62 of 64 days. Supplementing with CrPyr elevated their levels of free triiodothyronine and triiodothyronine, superoxide dismutase activity, ruminal pH value, microbial crude protein concentration, crude fat digestibility, nitrogen intake, and levels of urine allantoin and total purine derivatives. It also reduced their levels of cortisol and corticosterone, malondialdehyde concentration, lactate dehydrogenase activity, and urine nitrogen excretion. In conclusion, CrPyr relieves the heat stress of beef cattle by improving antioxidant activity and rumen microbial protein synthesis.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Antioxidantes/metabolismo , Creatina , Dieta/veterinária , Suplementos Nutricionais , Fermentação , Resposta ao Choque Térmico/fisiologia , Ácido Pirúvico , Rúmen/metabolismo , Animais , Bovinos , Creatina/farmacologia , Fermentação/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Masculino , Ácido Pirúvico/farmacologia , Superóxido Dismutase/metabolismo , Tri-Iodotironina/metabolismo
16.
PLoS One ; 15(10): e0239605, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33006971

RESUMO

The lily, a famous bulbous flower, is seriously affected by high temperatures, which affect their growth and production. To date, the signalling pathways and the molecular mechanisms related to heat response in Lilium have not been elucidated. In this study, a comparative transcriptome analysis was performed in an important thermo-tolerant flower, L. longiflorum, and a thermo-sensitive flower, L. distichum. Lily seedlings were first exposed to heat stress at 42°C for different lengths of time, and the optimal time-points (2 h and 24 h) were selected for RNA sequencing (RNA-seq). Approximately 66.51, 66.21, and 65.36 Mb clean reads were identified from three libraries of L. longiflorum (LL_CK, LL_T2h and LL_T24h, respectively) and 66.18, 66.03, and 65.16 Mb clean reads were obtained from three libraries of L. distichum (LD_CK, LD_T2h and LD_T24h, respectively) after rRNA removing. A total of 34,301 unigenes showed similarity to known proteins in the database NCBI non-redundant protein (NR), Swiss-Prot proteins, InterPro proteins, Clusters of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG). In addition, 1,621 genes were differentially expressed in the overlapping libraries between LL_DEGs and LD_DEGs; of these genes, 352 DEGs were obviously upregulated in L. longiflorum and downregulated in L. distichum during heat stress, including 4-coumarate, CoA ligase (4CL), caffeoyl-CoA O-methyltransferase (CCoAOMT), peroxidase, pathogenesis-related protein 10 family genes (PR10s), 14-3-3 protein, leucine-rich repeat receptor-like protein kinase, and glycine-rich cell wall structural protein-like. These genes were mainly involved in metabolic pathways, phenylpropanoid biosynthesis, plant-pathogen interactions, plant hormone signal transduction, and kinase signalling pathways. Quantitative RT-PCR was performed to validate the expression profiling of these DEGs in RNA-seq data. Taken together, the results obtained in the present study provide a comprehensive sequence resource for the discovery of heat-resistance genes and reveal potential key components that are responsive to heat stress in lilies, which may help to elucidate the heat signal transcription networks and facilitate heat-resistance breeding in lily.


Assuntos
Lilium/genética , Lilium/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Fatores de Transcrição de Choque Térmico/genética , Fatores de Transcrição de Choque Térmico/fisiologia , Resposta ao Choque Térmico/genética , Resposta ao Choque Térmico/fisiologia , Lilium/crescimento & desenvolvimento , Redes e Vias Metabólicas/genética , Anotação de Sequência Molecular , Família Multigênica , Proteínas de Plantas/genética , Proteínas de Plantas/fisiologia , RNA-Seq , Transdução de Sinais/genética , Especificidade da Espécie , Termotolerância/genética , Termotolerância/fisiologia
17.
PLoS One ; 15(10): e0239558, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33002025

RESUMO

Climate change is a serious threat to biodiversity; it is therefore important to understand how animals will react to this stress. Ectotherms, such as ants, are especially sensitive to the climate as the environmental temperature influences myriad aspects of their biology, from optimal foraging time to developmental rate. In this study, we conducted an RNA-seq analysis to identify stress-induced genes in the winter ant (Prenolepis imparis). We quantified gene expression during heat and cold stress relative to a control temperature. From each of our conditions, we sequenced the transcriptome of three individuals. Our de novo assembly included 13,324 contigs that were annotated against the nr and SwissProt databases. We performed gene ontology and enrichment analyses to gain insight into the physiological processes involved in the stress response. We identified a total of 643 differentially expressed genes across both treatments. Of these, only seven genes were differentially expressed in the cold-stressed ants, which could indicate that the temperature we chose for trials did not induce a strong stress response, perhaps due to the cold adaptations of this species. Conversely, we found a strong response to heat: 426 upregulated genes and 210 downregulated genes. Of these, ten were expressed at a greater than ten-fold change relative to the control. The transcripts we could identify included those encoding for protein folding genes, heat shock proteins, histones, and Ca2+ ion transport. One of these transcripts, hsc70-4L was found to be under positive selection. We also characterized the functional categories of differentially expressed genes. These candidate genes may be functionally conserved and relevant for related species that will deal with rapid climate change.


Assuntos
Adaptação Fisiológica/genética , Formigas/genética , Formigas/fisiologia , Temperatura Baixa , Perfilação da Expressão Gênica , Resposta ao Choque Térmico/fisiologia , Animais , Mudança Climática , Evolução Molecular , Ontologia Genética , Resposta ao Choque Térmico/genética , Anotação de Sequência Molecular , Seleção Genética
18.
Nat Commun ; 11(1): 5099, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-33037202

RESUMO

Mutations in the skeletal muscle Ca2+ release channel, the type 1 ryanodine receptor (RYR1), cause malignant hyperthermia susceptibility (MHS) and a life-threatening sensitivity to heat, which is most severe in children. Mice with an MHS-associated mutation in Ryr1 (Y524S, YS) display lethal muscle contractures in response to heat. Here we show that the heat response in the YS mice is exacerbated by brown fat adaptive thermogenesis. In addition, the YS mice have more brown adipose tissue thermogenic capacity than their littermate controls. Blood lactate levels are elevated in both heat-sensitive MHS patients with RYR1 mutations and YS mice due to Ca2+ driven increases in muscle metabolism. Lactate increases brown adipogenesis in both mouse and human brown preadipocytes. This study suggests that simple lifestyle modifications such as avoiding extreme temperatures and maintaining thermoneutrality could decrease the risk of life-threatening responses to heat and exercise in individuals with RYR1 pathogenic variants.


Assuntos
Hipertermia Maligna/genética , Mutação , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Termogênese/fisiologia , Tecido Adiposo Marrom/metabolismo , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Feminino , Resposta ao Choque Térmico/genética , Resposta ao Choque Térmico/fisiologia , Humanos , Lactente , Lactatos/sangue , Masculino , Hipertermia Maligna/etiologia , Hipertermia Maligna/mortalidade , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Estudos Retrospectivos , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Termogênese/genética , Proteína Desacopladora 1/genética , Adulto Jovem
19.
Anim Sci J ; 91(1): e13461, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33020974

RESUMO

The effects of heat stress on lipid oxidation and volatile compounds in duck meat were investigated. To simulate heat stress on ducks, room-temperature was controlled at 25°C, except that a raised temperature of 32°C for 8 hr each day was conducted. After stress for 1 and 3 weeks, respectively, the birds were euthanized and the breast meat was separated to evaluate the changes of lipid oxidation and volatile flavor compounds. Results showed that heat stress significantly increased the lipoxygenase activity and thiobarbituric acid reactive substances, and reduced the contents of free unsaturated fatty acids in duck meat. A total of 85 volatile flavor compounds were detected by gas chromatography-mass spectrometry. Interestingly, when exposed to heat stress, the volatiles generation in raw duck meat was promoted, which was then inhibited after cooking. These data reveal meat oxidative changes and flavor loss caused by heat stress and provide useful information for potential labels and meat flavor preservation against the negative effects of heat stress.


Assuntos
Patos/metabolismo , Análise de Alimentos , Qualidade dos Alimentos , Resposta ao Choque Térmico/fisiologia , Peroxidação de Lipídeos , Carne/análise , Odorantes/análise , Animais , Culinária , Ácidos Graxos não Esterificados/análise , Ácidos Graxos Insaturados/análise , Cromatografia Gasosa-Espectrometria de Massas/veterinária , Lipoxigenase/análise , Substâncias Reativas com Ácido Tiobarbitúrico/análise
20.
Exp Parasitol ; 218: 108003, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32980317

RESUMO

Dermatophagoides farinae, an important pathogen, has multiple allergens. However, their expression under physiological conditions are not understood. Our previous RNA-seq showed that allergens of D. farinae were up-regulated under temperature stress, implying that they may be involved in stress response. Here, we performed a comprehensive study. qRT-PCR detection indicated that 26 of the 34 allergens showed differential expression. Der f1 had the most abundant basic expression quantity. Der f 28.0201 (HSP70) and Der f3 had the same regulation pattern in 9 highly expressed transcripts, which only up-regulated at 41 °C and 43 °C, but Der f 28.0201 showed stronger regulation than Der f 3 (19.88-fold vs 6.02-fold). Whereas Der f 1, 2, 7, 21, 22, 27, and 30 were up-regulated under both heat and cold stress, and Der f 27 showed the strongest regulation ability among them. Der f 27 showed more significant up-regulation than Der f 28.0201 under heat stress (23.59-fold vs 19.88-fold), and Der f27 had more obvious up-regulation under cold than heat stress (30.70-fold vs 23.59-fold). The expression of Der f 27, 28.0201 and 1, and D. farinae survival rates significantly decreased following RNAi, indicating the upregulation of these allergens under temperature stress conferred thermo-tolerance or cold-tolerance to D. farinae. In this study, we described for the first time that these allergens have temperature-stress response functions. This new scientific discovery has important clinical value for revealing the more frequent and serious allergic diseases caused by D. farinae during the change of seasons.


Assuntos
Antígenos de Dermatophagoides/fisiologia , Resposta ao Choque Frio/fisiologia , Dermatophagoides farinae/fisiologia , Resposta ao Choque Térmico/fisiologia , Estresse Fisiológico/fisiologia , Animais , Antígenos de Dermatophagoides/genética , Antígenos de Dermatophagoides/metabolismo , Antígenos de Dermatophagoides/farmacologia , Sequência de Bases , Dermatophagoides farinae/genética , Feminino , Inativação Gênica , Anotação de Sequência Molecular , RNA/química , RNA/isolamento & purificação , Interferência de RNA/fisiologia , RNA de Cadeia Dupla/química , Reação em Cadeia da Polimerase em Tempo Real , Estações do Ano , Estresse Fisiológico/genética , Regulação para Cima
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