The association of Hsp90 expression induced by aspirin with anti-stress damage in chicken myocardial cells

The protective effect of aspirin during exposure to heat stress in broiler chickens was investigated. We assayed pathological damage, expression and distribution of Hsp90 protein and hsp90 mRNA expression in chicken heart tissues after oral administration of aspirin following exposure to high temperature for varying times. Heat stress induced increases in plasma aspartate aminotransferase, creatine kinase and lactate dehydrogenase activities while causing severe heart damage, which was characterized by granular and vacuolar degeneration, nuclear shrinkage and even myocardium fragmentation in cardiac muscle fibers. After aspirin administration, myocardial cells showed fewer pathological lesions than broilers treated with heat alone. A high positive Hsp90 signal was always detected in the nuclei of myocardial cells from broilers treated with aspirin, while in myocardial cells treated with heat alone, Hsp90 in the nuclei decreased, as did that in the cytoplasm. Aspirin induced rapid and significant synthesis of Hsp90 before and at the initial phase of heat stress, and significant expression of hsp90 mRNA was stimulated throughout the experiment when compared with cells exposed to heat stress alone. Thus, specific pre-induction of Hsp90 in cardiovascular tissue was useful for resisting heat stress damage because it produced stable damage-related enzymes and fewer pathologic changes.     

Inhibition of heat stress-related apoptosis of chicken myocardial cells through inducing Hsp90 expression by aspirin administration in vivo

1. This experiment investigated the anti-apoptosis effects and the mechanism of aspirin action in the heat shock response of chicken myocardial cells in vivo, via changes in the heat stress (HS) protein Hsp90 and the rate of apoptosis. Broiler chickens were administered aspirin (1 mg/kg body weight) 2 h before exposure to HS, and then exposed to 40 ± 1°C for 0, 1, 2, 3, 5, 7, 10, 15 and 24 h.

2. The induction and consumption of the HS factor heat shock factor (HSF)-1, and reductions of HSF-2 and HSF-3 induced by HS led to a delay in Hsp90 expression. HSF-1, 2 and 3 regulation of hsp90 expression in turn inhibited the synthesis and activation of protein kinase β (Akt), which resulted in a significant increase in caspase-3 at 2 and 10 h, caspase-9 from 1 to 7 h (except at 5 h), and the heat-stressed apoptosis of the myocardial cells.

3. Administration of aspirin changed the expression patterns of HSF-1, 2 and 3 such that the expression of Hsp90 protein was significantly upregulated (by 2.3–4.1 times compared with that of the non-treated cells). The resultant increase in Akt expression and activation, compared with the HS group, inhibited caspase-3 and caspase-9 activities and reduced the myocardial cells apoptosis rate (by 2.14–2.56 times).

4. Aspirin administration could inhibit heat-stressed apoptosis of myocardial cells in vivo and may be closely associated with its promotion of HS response of chicken hearts, especially Hsp90 expression.     

急性热应激对鸡呼吸系统损伤及肺脏热休克蛋白表达的影响

为探讨热应激对鸡肺脏组织损伤的影响,将60只35日龄SPF鸡随机分为对照组,热应激1、2、3、5、10 h组,每组10只,试验开始后环境温度迅速从25℃升高到35 ℃,观察热应激组鸡临床症状,热应激结束迅速剖杀、取病料,检测血清pH值、乳酸脱氢酶(LDH)、钾离子和钙离子浓度,石蜡切片检测肺脏组织结构,Western ...     

Polymorphisms in the bovine HSP90AB1 gene are associated with heat tolerance in Thai indigenous cattle

Heat shock proteins act as molecular chaperones that have preferentially been transcribed in response to severe perturbations of the cellular homeostasis such as heat stress. Here the traits respiration rate (RR), rectal temperature (RT), pack cell volume (PCV) and the individual heat tolerance coefficient (HTC) were recorded as physiological responses on heat stress (environmental temperatures) in Bos taurus (crossbred Holstein Friesian; HF) and B. indicus (Thai native cattle: White Lamphun; WL and Mountain cattle; MT) animals (n = 47) in Thailand. Polymorphisms of the heat shock protein 90-kDa beta gene (HSP90AB1) were evaluated by comparative sequencing. Nine single nucleotide polymorphisms (SNP) were identified, i.e. three in exons 10 and 11, five in introns 8, 9, 10 and 11, and one in the 3′UTR. The exon 11 SNP g.5082C>T led to a missense mutation (alanine to valine). During the period of extreme heat (in the afternoon) RR and RT were elevated in each of the three breeds, whereas the PCV decreased. Mountain cattle and White Lamphun heifers recorded significantly better physiologic parameters (p < 0.05) in all traits considered, including or particularly HTC than Holstein Friesian heifers. The association analysis revealed that the T allele at SNP g.4338T>C within intron 3 improved the heat tolerance (p < 0.05). Allele T was exclusively found in White Lamphun animals and to 84% in Mountain cattle. Holstein Friesian heifers revealed an allele frequency of only 18%. Polymorphisms within HSP90AB1 were not causative for the physiological responses; however, we propose that they should at least be used as genetic markers to select appropriate breeds for hot climates.     

热应激 脂多糖 谷氨酰胺 诱导牛睾丸支持细胞HSP72时效表达

为了探讨温和热应激、脂多糖(LPS)和谷氨酰胺(Gln)诱导牛睾丸支持细胞(b SCs)HSP72的时效表达规律,本试验将传至第3代b SCs分成热应激、LPS和Gln处理组,用CCK-8试剂盒检测细胞活性,用RT-PCR和Western-Blot方法分别检测处理后0、2、4、6、8、12、14h和16 h时细胞内HSP72 mRNA和蛋白表达。结果显示,3种方式均能诱导HSP72表达,且HSP72蛋白分别在热应激、Gln和LPS预处理后2、4h和12 h时表达量最高。结果表明,热应激或Gln均比LPS诱导牛睾丸支持细胞HSP72表达的时间早,提示可考虑用Gln减少由LPS诱导的细胞损伤。     

Single nucleotide polymorphisms associated with thermoregulation in lactating dairy cows exposed to heat stress

Dairy cows with increased rectal temperature experience lower milk yield and fertility. Rectal temperature during heat stress is heritable, so genetic selection for body temperature regulation could reduce effects of heat stress on production. One aim of the study was to validate the relationship between genotype and heat tolerance for single nucleotide polymorphisms (SNPs) previously associated with resistance to heat stress. A second aim was to identify new SNPs associated with heat stress resistance. Thermotolerance was assessed in lactating Holsteins during the summer by measuring rectal temperature (a direct measurement of body temperature regulation; n = 435), respiration rate (an indirect measurement of body temperature regulation, n = 450) and sweating rate (the major evaporative cooling mechanism in cattle, n = 455). The association between genotype and thermotolerance was evaluated for 19 SNPs previously associated with rectal temperature from a genomewide analysis study (GWAS), four SNPs previously associated with change in milk yield during heat stress from GWAS, 2 candidate gene SNPs previously associated with rectal temperature and respiration rate during heat stress (ATPA1A and HSP70A) and 66 SNPs in genes previously shown to be associated with reproduction, production or health traits in Holsteins. For SNPs previously associated with heat tolerance, regions of BTA4, BTA6 and BTA24 were associated with rectal temperature; regions of BTA6 and BTA24 were associated with respiration rate; and regions of BTA5, BTA26 and BTA29 were associated with sweating rate. New SNPs were identified for rectal temperature (n = 12), respiration rate (n = 8) and sweating rate (n = 3) from among those previously associated with production, reproduction or health traits. The SNP that explained the most variation were PGR and ASL for rectal temperature, ACAT2 and HSD17B7 for respiration rate, and ARL6IP1 and SERPINE2 for sweating rate. ARL6IP1 was associated with all three thermotolerance traits. In conclusion, specific genetic markers responsible for genetic variation in thermoregulation during heat stress in Holsteins were identified. These markers may prove useful in genetic selection for heat tolerance in Holstein cattle.     

Regulation of gene expression in chickens by heat stress

High ambient temperatures are a critical chal enge in the poultry industry which is a key producer of the animal-based food. To evaluate heat stress levels, various parameters have been used, including growth rates, blood metabolites, and hormones. The most recent advances have explored expression profiling of genes that may play vital roles under stress. A high ambient temperature adversely affects nutrient uptake and is known to modulate the expression of genes encoding for sodium-dependent glucose transporters, glucose transporters, excitatory amino acid transporters, and fatty acidbinding proteins which are responsible for the absorption of macronutrients in the intestine. Various defensive activities are stimulated to protect the cel of different tissues from the heat-generated stress, including expression of early stress response genes coding for heat shock protein(HSP), c-FOS like protein, brain-derived neurotrophic factor(BDNF), and neuronal nitric oxide synthase(n NOS); antioxidant enzyme genes such as superoxide dismutase(SOD), catalase(CAT), and nicotinamide adenine dinucleotide phosphate oxidase(NOX4); and immune-related genes such as cytokines and tol-like receptors(TLRs). The potential role of HSPs in protecting the cel from stress and their presence in several tissues make them suitable markers to be evaluated under heat stress. BDNF and c-FOS genes expressed in the hypothalamus help cel s to adapt to an adverse environment. Heat causes damage to the cel by generating reactive oxygen species(ROS).The NOX4 gene is the inducer of ROS under heat stress, which is in turns control ed by antioxidant enzymes such as SOD and CAT. TLRs are responsible for protecting against pathogenic attacks arising from enhanced membrane permeability,and cytokines help in control ing the pathogen and maintaining homeostasis. Thus, the evaluation of nutrient transporters and defense mechanisms using the latest molecular biology tools has made it possible to shed light on the complex cel ular mechanism of heat-stressed chickens. As the impacts of heat stress on the above-mentioned aspects are beyond the extent to which the reduced growth performance could be explained, heat stress has more specific effects on the regulation of these genes than previously thought.     

Kisspeptin-10对热应激引起大鼠心肌损伤的影响

试验旨在探究kisspeptin-10对热应激造成的大鼠心肌损伤的影响及其分子机制。将24只SD雄性大鼠随机分为3组(对照组、热应激组和热应激后kisspeptin-10皮下注射组),每组8只。诱导发生热应激后采用透射电镜、HE染色和masson染色来观察心脏组织病理变化情况;并采用RT-PCR技术检测与心肌损伤通路相关基因ITGA4、ITGB8、BNP、MYL7、HIF-1α和ITGB7的mRNA在心肌中的变化;用Western-Blot验证其关键蛋白ITGB8和BNP表达的变化。与对照组相比,热应激组(H)出现心肌损伤现象;热应激后kisspeptin-10皮下注射组(KH)与热应激组(H)相比,心肌纤维排列较整齐,细胞核染色较均匀,纤维增生减少,线粒体空泡和线粒体嵴断裂现象明显减少;另外,心脏组织中ITGB8和BNP在热应激组(H)发生上调,而热应激后kisspeptin-10皮下注射组(KH)与热应激组(H)相比显著下调。本研究从形态学和分子机制方面探究kisspeptin-10缓解SD大鼠由热应激所致心肌损伤的途径。一方面ITGB8作为心肌细胞膜的异二聚体在热应激后表达发生变化,另一方面热应激后心肌组织形态学上的改变。这些由热应激引起紊乱的在kisspeptin-10干预后有趋于正常表现,为进一步研究kisspeptin-10在热应激导致心肌损伤中的缓解作用机制提供了理论基础。     

Genetic polymorphisms in part of intron 7 and exon 8 of HSP90AA1 gene and its association with heat tolerance traits in two exotic layer chicken strains

Tropical Animal Health and Production - Chickens, like other vertebrates, react to stress conditions through their cultured cells by expressing heat shock proteins (HSPs). Genetic association of...     

小鼠卵巢HSP70诱导表达的免疫荧光组织化学研究

试验采用免疫荧光组织化学法,检验了经历不同温度热应激后,在不同恢复期内小鼠卵巢组织HSP70的诱导表达,确立了HSP70诱导表达模式。结果表明：随着热应激温度的升高,卵巢组织HSP70的表达量增加,表达持续期延长,特别是经历了预应激小鼠的HSP70表达更显著。这说明在一定的热应激条件下。小鼠卵巢组织可发生HSP70的诱导表达,其表达量和表达持续期与热应激强度相关,而且热应激可显著促进HSP70的表达。     

Immunological and gene expression responses to a Salmonella infection in the chicken intestine

Besides infection in humans, Salmonella enteritidis can also cause serious illness in young chickens. However, the genetic and immunological parameters important for the disease in chickens are not well characterized. In this study, processes in the chicken intestine in response to a Salmonella infection were investigated in two different chicken lines. One-day-old chickens were orally infected with Salmonella. T-cell subpopulations, phagocytic properties of intestinal mononuclear cells and RNA expression levels of the jejunum were investigated. The two chicken lines differed in the amount of cfu in the liver and growth retardation after the infection. Differences in phagocytic activity of intestinal mononuclear cells were found between control and Salmonella infected chickens. The number of CD4+ T-cells of the intestine decreased after the Salmonella infection in one chicken line, while the number of CD8+ T-cells increased in both chicken lines, but the time post infection of this increase differed between the lines. In one chicken line the expression levels of the genes carboxypeptidase M and similar to ORF2 decreased after the Salmonella infection, which might be related to a decrease in the amount of macrophages. With the microarray, ten genes were found that were regulated in only one of the chicken lines, while we found six genes regulated in response to the infection in both chicken lines. So differences in genetic background of the chickens influence the intestinal host response of the Salmonella infection as observed by phagocytic activity, gene expression and changes in the number of T-cell subpopulations and macrophages.     

Whole-blood concentrations of glutathione in cattle exposed to heat stress or a combination of heat stress and endophyte-infected tall fescue toxins in controlled environmental conditions

OBJECTIVE: To determine whether cattle exposed to heat stress alone or heat stress while consuming endophyte-infected fescue (EIF) have lower whole-blood (WB) concentrations of glutathione (GSH). ANIMALS: 10 Simmental cows. PROCEDURE: Cows were sequentially exposed to thermoneutral (TN; 2 weeks; 18 C, 50% relative humidity [RH]), heat stress (HS; 2 weeks; alternating 4-hour intervals at 26 and 33 C; 50% RH), and heat stress while consuming EIF (10 microg of ergovaline/kg/d; 2 weeks, HS + EIF). Blood samples were collected after each period and tested for GSH and oxidized glutathione (GSSG) concentrations. RESULTS: Feed consumption was similar when data were analyzed for time points at which WB concentrations of GSH or GSSG were determined. However, significant effects of treatment, cow, days exposed to heat, cow-by-treatment interaction, and treatment-by-days exposed to heat interaction were detected when data were considered simultaneously. Mean +/- SD hematocrit for TN, HS, and HS + EIF were 35.3+/-3, 33.3+/-2, and 37.1+/-3%, respectively. Mean WBGSH concentrations for TN, HS, and HS + EIF were 3.2+/-0.65, 2.7+/-0.62, and 2.4+/-0.56 mmol/L of RBC, respectively. Reduced WBGSH concentrations were associated with reduced feed intake during the later part of each heat period. CONCLUSIONS AND CLINICAL RELEVANCE: Decreased GSH and increased GSSG concentrations were evident during heat stress, especially when cattle consumed EIF These were associated with reduced feed intake during heat stress. Heat stress, reductions in feed intake, and thermoregulatory effects of EIF may induce oxidative stress in cattle.     

Electrolysed reduced water decreases reactive oxygen species-induced oxidative damage to skeletal muscle and improves performance in broiler chickens exposed to medium-term chronic heat stress

1. The present study was designed to achieve a reduction of reactive oxygen species (ROS)-induced oxidative damage to skeletal muscle and to improve the performance of broiler chickens exposed to chronic heat stress.

2. Chickens were given a control diet with normal drinking water, or diets supplemented with cashew nut shell liquid (CNSL) or grape seed extract (GSE), or a control diet with electrolysed reduced water (ERW) for 19 d after hatch. Thereafter, chickens were exposed to a temperature of either 34°C continuously for a period of 5 d, or maintained at 24°C, on the same diets.

3. The control broilers exposed to 34°C showed decreased weight gain and feed consumption and slightly increased ROS production and malondialdehyde (MDA) concentrations in skeletal muscle. The chickens exposed to 34°C and supplemented with ERW showed significantly improved growth performance and lower ROS production and MDA contents in tissues than control broilers exposed to 34°C. Following heat exposure, CNSL chickens performed better with respect to weight gain and feed consumption, but still showed elevated ROS production and skeletal muscle oxidative damage. GSE chickens did not exhibit improved performance or reduced skeletal muscle oxidative damage.

4. In conclusion, this study suggests that ERW could partially inhibit ROS-induced oxidative damage to skeletal muscle and improve growth performance in broiler chickens under medium-term chronic heat treatment.     

乙酰半胱氨酸对大鼠饮水镉暴露所致肾功能损伤的保护效应

采用饮水对大鼠进行镉染毒(CdCl2,50mg/L)和NAC保护(CdCl250mg/L+NAC1g/L)试验,为期8周,通过检测尿液中碱性磷酸酶(UALP)、N-乙酰-β-D-氨基葡萄糖苷酶(UNAG)、γ-谷氨酰基转移酶(UGGT)活性的动态变化及观察肾小管上皮刷状缘超微结构,探讨镉对大鼠肾脏功能损伤以及NAC的保护作用。结果显示,镉染毒2周后UNAG,UGGT,UALP活性即显著或极显著高于对照组(P0.05或P0.01),且升高幅度与染毒时间呈正相关;与染毒组比较,保护组尿液中酶活性从试验后4周开始显著或极显著下降(P0.05或P0.01)。超微结构观察发现,镉染毒使大鼠肾小管上皮刷状缘不同程度的断裂和脱落,保护组刷状缘基本完整。结果表明,50mg/LCdCl2饮水暴露对肾功能和结构造成了明显损伤,NAC对这种损伤有显著的保护作用。