热应激对肉仔鸡热应激蛋白转录的影响

试验选270只28日龄AA肉用公鸡,随机分为3组,每组6个重复,每重复15只鸡,分别饲养于3个环境控制舱中.采用配对试验设计,各组温度分别为,持续日变高温组为28℃～34℃～28℃,适温自由采食组和适温配对组都为22℃.高温组和适温组鸡自由采食,配对组鸡喂给高温组前1 d的饲料采食量.于试验第2、5、8、12、15和22天每重复取1只鸡屠宰,测定旰中HSP72mRNA含量.试验结果表明:高温和限饲均导致肝中HSP72 mRNA含量升高,第22天高温组与适温组差异显著.试验说明,HSPs可作为热应激的一个敏感指标.     

热应激对奶牛乳中活性蛋白的影响

试验随机选取23头泌乳中期荷斯坦奶牛,通过实时监控外界环境温湿度,计算温湿度指数,确定奶牛热应激状态,测定奶牛产奶量、乳成分和乳中活性蛋白,以研究热应激对中国荷斯坦泌乳奶牛乳中活性蛋白的影响。结果表明:与轻度热应激奶牛相比,中度热应激奶牛生产性能会极显著下降(P0.01),平均降低了20.06%;中度热应激奶牛乳脂率显著降低(P0.05),乳中尿素氮极显著升高(P0.01),体细胞数显著升高(P0.05);中度热应激奶牛乳中血清蛋白显著升高(P0.05),α-乳白蛋白极显著升高(P0.01),但乳中免疫球蛋白(IgG、IgA和IgM)含量并无显著差异。因此,不同程度的热应激影响泌乳中期奶牛生产性能、乳成分和乳中活性蛋白。     

热应激蛋白对畜禽抗应激机理的研究进展

热应激蛋白(heat shock proteins, HSPs)是机体在应激条件下所产生的一组特异性蛋白质,能使机体迅速适应环境变化。作者简要介绍了HSPs的来源及分类,阐述了HSP70 的基因结构和调控机制,综述了HSPs抗应激功能及在畜禽应激反应中的表达,以期为从分子水平探索HSPs 抗应激机理提供参考。     

急性热应激对鹅血清激素水平及肝脏HSP70基因表达的影响

为了探讨急性热应激对鹅血清激素以及肝脏热休克蛋白70 mRNA(HSP70 mRNA)水平的影响。以60只8周龄仔鹅为研究对象,随机分成6组,每组10只,对照组环境温度为(22±1)℃,试验组分别施与2 h、4 h、6 h、8 h和10 h(40±1)℃的高温处理,各组处理均在16:00结束。试验鹅全部屠宰取血清和肝脏,测定血清中胰岛素(INS)、皮质醇(COR)、三碘甲腺原氨酸(T3)、甲状腺素(T4)及肝脏HSP70 m RNA水平。结果表明,急性热应激处理下,INS、T3、T4的水平均随热应激时间的延长出现了显著性降低(P0.05),COR的水平显著升高(P0.05)。急性热应激处理可极显著提高仔鹅肝脏中HSP70 mRNA的表达水平(P0.01)。     

鸡热应激与热应激蛋白的作用机理研究

高温导致畜禽热应激问题的危害正日益突出并倍受关注。针对这些问题本刊推出“热应激专栏”,目的是为缓解夏季普遍存在的畜禽热应激提供理论和技术支持,使从业者能通过一些技术手段来规避热应激带来的损失。由于时间的仓促,本期组织的稿件内容覆盖面不是很全,但是以后会陆续推出有关内容,希望大家能继续关注。同时我们也希望专家、学者能踊跃地发表真知灼见与广大读者分享,把热应激理论、防制调控推到一个更高的阶段。     

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 ...     

急性热应激对山羊血液生化指标及血淋巴细胞热休克蛋白70家族基因表达的影响

旨在研究急性热应激对山羊抗氧化能力、免疫功能和血淋巴细胞热休克蛋白70(HSP70)家族基因表达的影响。本试验选取5只健康、体况接近的(12±0.5)月龄波尔山羊×关中奶山羊杂交F1母羊,饲养于环控舱内(温度维持20℃,相对湿度60%),适应5d。第6天利用环控舱对5只试验羊进行38℃急性热应激处理12h,采集热应激前(0h,20℃)和热应激后2、4、8和12h试验羊血样。分别利用比色法测定血清抗氧化指标(总抗氧化能力、超氧化物歧化酶、谷胱甘肽过氧化物酶活性和丙二醛含量),ELISA法测定血清免疫指标(免疫球蛋白和细胞因子含量),实时荧光定量PCR法测定血淋巴细胞HSP70家族基因(HSPA1A、HSPA6和HSPA8)mRNA的表达量。结果显示:1)热应激时间对血清抗氧化指标有显著影响。与热应激前0h相比,血清T-AOC(P<0.05)、SOD(P<0.05)和GSH-Px(P<0.01)活性均在热应激8h后显著下降,MDA含量在热应激4h后显著增加(P<0.05)。2)热应激时间对血清免疫指标有显著影响。与热应激前0h相比,血清TNF-α、IL-1β、IFN-γ和IL-2含量分别在热应激4、8、8和4h后显著增加(P<0.05);IL-4(P<0.01)、IgG(P<0.01)、IgM(P<0.01)和IgA(P<0.05)含量分别在热应激12、4、4和4h后显著下降。3)热应激时间显著提高血淋巴细胞中HSP70家族基因(HSPA1A、HSPA6和HSPA8)的表达量。HSPA1AmRNA表达量呈先升高后下降的趋势,在热应激4h时达到峰值,各检测时间点均显著高于应激前水平(P<0.01);HSPA6mRNA表达量在热应激2h时显著升高(P<0.01),4h后恢复到应激前水平(P>0.05);HSPA8mRNA表达量在热应激4(P<0.05)、8(P<0.01)、12h(P<0.01)时显著高于应激前水平。在本试验条件下,38℃急性热应激能够抑制山羊的免疫和抗氧化功能;提高血淋巴细胞HSPA1A、HSPA6和HSPA8基因的表达量,其中HSPA1A对热应激温度和时间更敏感,可作为山羊热应激早期的分子标志物。     

谷氨酰胺对热应激肉鸡S-IgA、血液内毒素和细胞因子的影响

选用1日龄科宝-500肉鸡240只,随机分为6个处理,每处理4个重复,每重复10只,Ⅰ组饲喂玉米-豆粕型基础日粮,Ⅱ、Ⅲ、Ⅳ、Ⅴ和Ⅵ组分别在基础日粮中添加0.4%、0.8%、1.2%、1.6%和2.0%的谷氨酰胺,试验时间15～42日龄,共28d。试验期间从每天09：00-17：00温度维持在（35±1）℃8h,17：00至次日09：00温度维持在（30±1）℃,鸡舍相对湿度控制在70%～80%。试验测定了热应激条件下21、28、35、42日龄肉鸡小肠黏膜分泌型免疫球蛋白含量A,血浆中血液内毒素含量和白介素-1、肿瘤细胞坏死因子含量。结果表明,日粮中添加谷氨酰胺显著提高了21、28、35、42日龄热应激肉鸡小肠黏膜分泌型免疫球蛋白含量（P〈0.05）,降低血浆中血液内毒素、白介素-1、肿瘤细胞坏死因子的含量（P〈0.05）。因此,在基础日粮中添加一定水平的谷氨酰胺可改善热应激肉鸡的肠道免疫性能。     

二氢吡啶对热应激小鼠的影响

将小鼠随机分为常规饲料喂养组和掺有不同量二氢吡啶组,测量各组小鼠的胸腺指数、脾指数及各种血液指标。结果表明,服用二氢吡啶组的小鼠体重明显比不服用组大,饲喂200mg／kg时效果最明显;热应激后小鼠脾指数、胸腺指数有所下降．服用二氢吡啶后的热应激小鼠胸腺指数、脾指数高于对照组;热应激使小鼠的一些生理生化指标异常,二氢吡啶在一定程度上可缓解这些异常。     

动物热应激蛋白研究进展

热应激蛋白(HSPs)是生物细胞受应激作用而合成的一组高度保守的蛋白质.热应激蛋白主要作为分子伴侣参与蛋白质的折叠、转运及组装等过程,并能恢复或加速清除细胞内已变性的蛋白质而稳定细胞结构.     

Orally administered rutin inhibits the gene expression of Th2 cytokines in the gut and lung in aged mice

Rutin is one of the flavonoids derived from plants such as buckwheat and is well known as a powerful antioxidant. To determine whether dietary rutin could modulate mucosal immunity, we examined the gene expression of Th1/Th2 cytokines and the receptors in the gut and lung. Aged (18 months old, 18 M) C3H/HeN female mice were orally administered rutin for 10 days. The small intestine and lung were taken and analyzed by real-time PCR for gene expression. Interleukin (IL)-13 and IL-13Rα2 gene expression was significantly low (P<0.05 respectively) in the small intestine of aged rutin-fed mice. Meanwhile, there was no change in interferon γ gene expression between control and rutin-fed mice. IL-13 gene expression was also downregulated in the lung. To examine the mechanism of the inhibitory effect of rutin on Th2 cytokines in aged mice, intestinal nitric oxide synthase (NOS) expression was evaluated. Rutin inhibited inducible NOS (NOS2) gene expression, but not neuronal NOS and endothelial NOS. Gene analysis of cells collected from the small intestine by laser capture dissection revealed that NOS2 expression was significantly inhibited in crypt regions. Thus, rutin might be effective against a Th2-dominant profile through NOS2 inhibition in aged mice.     

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.     

谷氨酰胺对急性肺损伤小鼠MUC5AC的调节及其对肺脏的保护作用

旨在探讨谷氨酰胺(GLN)对脂多糖(LPS)诱导急性肺损伤小鼠黏蛋白MUC5AC表达的调节作用及其对肺损伤的保护作用。选用雌性ICR小鼠32只随机分成4组:正常对照组(PBS组)、谷氨酰胺组(GLN)、内毒素组(LPS)、谷氨酰胺+内毒素组(GLN+LPS)。采用气管滴注LPS的方法刺激小鼠建立急性肺损伤(ALI)模型,在滴注LPS12 h后采集肺组织进行湿干重比值,IL-6、TNF-α、IL-1β、IL-8、HSP70、MUC5AC的mRNA水平,IL-6、TNF-α含量以及HSP70、MUC5AC蛋白含量的测定,通过HE染色观察肺组织形态学变化。结果显示:与对照组相比,LPS组MUC5AC、IL-6、TNF-α、IL-1β、IL-8 mRNA表达量极显著升高,HSP70 mRNA表达量极显著降低;MUC5AC蛋白的表达量极显著增加,HSP70蛋白的表达量极显著降低;IL-6、TNF-α含量极显著升高,肺组织湿干比值极显著增加;肺泡破裂较严重,细支气管黏液分泌增加且可见杯状细胞部分脱落;与LPS组相比,GLN+LPS组IL-6、TNF-α、IL-1βmRNA表达量极显著降低,MUC5AC、IL-8 mRNA表达量显著降低,HSP70 mRNA表达量显著升高;MUC5AC蛋白的表达量显著减少,HSP70蛋白的表达量显著升高,IL-6、TNF-α含量极显著降低;肺组织湿干比值显著减少;部分肺泡破裂,杯状细胞排列整齐,细支气管黏液分泌量减少。结果表明:静脉注射谷氨酰胺能减少LPS诱导的小鼠肺组织中MUC5AC、IL-6、TNF-α、IL-1β、IL-8 mRNA和MUC5AC蛋白的表达,减少IL-6、TNF-α的含量,增加HSP70 mRNA和HSP70蛋白的表达,减轻肺组织损伤;谷氨酰胺可能通过增加HSP70的表达来对LPS诱导的急性肺损伤小鼠起到保护作用。     

橄榄苦苷对脂多糖诱导的急性肺损伤小鼠的保护作用

为了探讨橄榄苦苷对脂多糖(LPS)诱导的急性肺损伤小鼠的保护作用,选用80只健康昆明系小鼠分成正常对照组、模型组、地塞米松组和橄榄苦苷组。结果显示,橄榄苦苷能减少炎症细胞浸润,使肺泡壁增厚减轻;能降低血清中肿瘤坏死因子α(TNF-α)、细胞间粘附分子-1(ICAM-1)、白细胞介素6(IL-6)的含量(P0.05,P0.01);能提高肺组织超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽还原酶(GR)活性,降低丙二醛(MDA)的含量(P0.01);能提高肺组织闭锁蛋白表达水平(P0.01)。说明橄榄苦苷对LPS诱导的急性肺损伤具有明显的保护作用,其机制可能与减少自由基损伤、抑制炎症因子水平及提高肺组织细胞连接蛋白的表达有关。     

Identification of duck HSP70 gene,polymorphism analysis and tissue expression under control and heat stress conditions

1. This study was designed to characterise the duck heat shock protein 70 gene (HSP70) and identify sequence variation.

2. Chicken HSP70 sequence (GenBank: AY143693) was used as a template to design a primer pair to amplify partial duck HSP70 gene. Primers were subsequently designed with the duck HSP70 gene as a template to amplify the complete duck HSP70 sequence.

3. Twelve commercial Sanshui White ducklings were subjected to a heat stress experiment. Tissue samples were collected for RNA extraction and real-time PCR to analyse the expression mechanism of duck HSP70.

4. A DNA pool was constructed from three different species for single nucleotide polymorphism (SNP) screening. The genotypes of the identified SNPs were detected in 145 Sanshui White ducklings.

5. Duck HSP70 gene was identified and characterised (GenBank: EU678246) and shown to contain no introns. Fifteen variations were identified within the open reading frame. Quantitative real-time PCR results showed that the expression of duck HSP70 gene was tissue specific and the highest expression level was seen in pectoral muscle.     

Effect of acute heat stress on heat shock protein 70 messenger RNA and on heat shock protein expression in the liver of broilers

1. The synthesis of heat shock protein 70 (Hsp70) mRNA and the expression of Hsp70 in the liver of broiler chickens submitted to acute heat stress (35°C for 5 h) was investigated.

2. Hsp70 expression was detected by SDS‐PAGE and Western blot analysis using a polyclonal antiserum against Hsp70 of Blastocladiella emersonii. The specific signal of Hsp70 mRNA was analysed by Northern blot using as probe a Hsp70 cDNA of B. emersonii.

3. An increase in the amount of Hsp70 was detected from the first up to the fifth hour of acute heat exposure. This increase in the amount of Hsp70 was accompanied by an increase in Hsp70 mRNA which peaked at 3 h.

4. This study shows that the heat induced increase in Hsp70 mRNA and protein in broiler liver, in vivo, are time dependent, similar to that in mammals.     

SB203580对猪流感病毒诱导小鼠急性肺损伤中炎症因子的影响

为探讨SB203580对猪流感病毒(SIV)诱导小鼠急性肺损伤(ALI)中炎症因子的影响,将180只6⁸周龄SPF级BALB/c雌性小鼠,随机平均分成SIV感染组(感染组)、SIV感染+SB203580组(SB组)和对照组,于感染后2、4、6、8和14d,分别进行临床症状、肺脏病理组织学观察和肺组织中炎症因子测定。结果显示,感染组和SB组小鼠均表现明显的ALI症状,但SB组小鼠症状较轻,肺损伤程度明显低于感染组;感染组和SB组中炎症因子水平均高于对照组,SB组小鼠肺脏炎症因子水平较感染组降低。说明p38MAPK特异性抑制剂SB203580可以下调磷酸化p38MAPK的表达水平,降低炎症因子的表达,减轻ALI中肺组织的病理损伤。     

A note on the effects of heat stress on carcass composition and adipose tissue cellularity of ducklings

1. The effects of heat exposure (36 °C) from 14 or 18 to 28 d of age on ducklings were assessed by comparison with pair‐fed or ad libitum‐fed controls at 22 °C. From 28 d all groups were fed ad libitum at normal temperature until samples were killed at 41 or 54 d.

2. At 28 d performance was similar in heat‐exposed and respective pair‐fed controls, but poorer than in ad libitum‐fed controls. Food intake and gain were less for heat‐exposed than for pair‐fed birds at 41 and 54 d (data combined).

3. Proportional fat pad size, adipose cell volume and number were less for all groups than for ad libitum‐fed controls at 41 d, but these differences largely disappeared by 54 d. Carcass fat varied little between groups.

4. Carcass moisture was less in heat‐exposed than in pair‐fed birds at 54 d and carcass protein greater at 41 d.