热休克蛋白70在胚胎发育中的保护作用

热休克蛋白（heats hock proteins,HSPs）是生物体（或离体培养细胞）在受热、病原体、理化等不利因素刺激下,应激产生的一类在生物进化中高度保守的特殊蛋白质。现已证实,几乎生物界所有的细胞均能合成HSPs,而且多数HSPs是在不良应激（如高温、射线、氧化、重金属、有毒化合物、炎症及感染等作用下诱导产生,它能暂时快速地调整处于应激状态的细胞的存活机能,保护细胞免受损伤,     

Hsp70与胚胎发育

热休克蛋白70是生物体在各种应激条件下产生的蛋白之一,具有维持细胞自身稳定等多种生物学功能,与胚胎的生长发育有着密切的内在联系。目前及今后若干年热休克蛋白70与胚胎生长发育研究领域都将是世界各国生命科学研究的热点,同时也是极有希望的研究领域。文章就热休克蛋白70自身,热休克蛋白70与胚胎畸形发生的关系,以及热环境条件下热休克蛋白70与胚胎生长发育的关系作一综述。     

热休克蛋白70诱导剂及其应用

热休克蛋白70(HSP70)是生物体在应激原刺激下合成的一族进化上高度保守的蛋白质。HSP70家族的功能表现在多方面:作为分子伴侣,HSP70在应激状态下帮助需要折叠的蛋白质正确折叠,加快正常蛋白质合成的恢复;在细胞保护方面,HSP70表达的增加可以增强机体对应激的抵抗力,缓解细胞所受伤害。本文主要综述HSP70的生物学特性及其细胞保护作用,并讨论了HSP70诱导剂在畜牧业中潜在的应用意义。     

热休克蛋白70在抗感染与免疫中的作用

抗感染免疫是动物机体抵抗病原体感染的能力。热休克蛋白70通过激活天然免疫细胞活化等方式参与机体天然免疫．通过调节抗原递呈细胞对抗原的加工与递呈,增强免疫应答和参与免疫球蛋白组装等方式发挥对适应性免疫的影响．进而参与感染与免疫。根据国内外近年来对热休克蛋白70的研究概况．对热休克蛋白70在机体抗感染免疫中的作用进行了综述...     

热休克蛋白70的研究进展

热休克蛋白（HSP）是生物细胞在受热、生物应激、理化因素等应激原刺激后所产生的一类在生物进化中最保守的蛋白，其中HSP70是最受关注、研究最为深入的一种。随着研究的深入，在生物学的功能不断被发现的同时，HSP70的应用前景也变得越来越广泛。     

热休克蛋白70研究新进展

1962年,Ritassa在果蝇的研究中首次发现,短暂的热休克可以诱导唾液腺染色体出现3个膨突,提示这一区带转录加强,他将这一现象称为“热休克反应“(heat shock response,HSR).1974年,Tissieres发现热休克反应中转录合成的为一组特殊蛋白,而且伴随着这类蛋白的合成,细胞的其他蛋白合成却受到抑制,由于这类蛋白的合成与热休克反应有关,故命名为热休克蛋白(heat shock protein,HSP).除了高热之外,多种应激原如重金属、饥饿、缺氧、缺血等都可以诱导HSP的表达,但人们习惯上仍称为HSP或热应激蛋白(heat stress protein,HSP),有时也称为应激蛋白(stress protein,SP).……     

哺乳动物热休克蛋白70表达的基因调控与生物学功能

热休克蛋白70(HSP70)是热休克蛋白家族中的重要成员，作为一种细胞内源性保护蛋白，当机体或细胞遭受应激时，它可以通过一定的表达调控机制进行显著增量表达，并在一定范围内发挥其特有的生物学功能来抵御或减缓应激对细胞的损伤。     

哺乳动物热休克蛋白70表达的基因调控与生物学功能

热休克蛋白70(HSP70)是热休克蛋白家族中的重要成员,作为一种细胞内源性保护蛋白,当机体或细胞遭受应激时,它可以通过一定的表达调控机制进行显著增量表达,并在一定范围内发挥其特有的生物学功能来抵御或减缓应激对细胞的损伤。     

中药对急性热应激小白鼠肺、肾脏的热休克蛋白70及热休克因子1表达量的影响

文章旨在研究中药对急性热应激小白鼠肺、肾脏的热休克蛋白70及热休克因子1表达量的影响。试验选用体质健康,体重基本一致的6～7周龄健康SPF级昆明小白鼠90只,将其随机分为7组,分别为复方一组、复方二组和复方三组、紫锥菊组、王老吉组、阳性空白对照组、阴性空白对照组,每组10只。在试验第1、3小时每组取5只小白鼠,采用ELISA法测定小白鼠肺、肾脏组织热休克蛋白70(HSP70)和热休克因子1(HSF1)表达量。结果显示,中药复方组能有效提高热应激小白鼠肺脏和肾脏HSP70表达量,复方一,复方二和紫锥菊能提高热应激小鼠肺脏HSP70的含量,复方三和王老吉组能缓解其下降幅度。高热应激过程中小白鼠肺脏HSF1表达量呈上升趋势,复方二能显著提高肺脏HSF1的表达量;但肾脏HSF1的表达量却呈下降趋势,这与肾脏HSP70高表达有关。结果表明,在此试验中,通过HSP70的表达量变化阐明了中药对急性热应激的预防保护能力。     

水通道蛋白7和8在牛早期胚胎发育过程中的表达规律

以牛卵母细胞为研究对象,体外成熟后孤雌激活,收集各个时期的卵母细胞和不同发育阶段的早期胚胎,提取总RNA。根据GenBank公布的mRNA序列设计引物,进行RT-qPCR,检测不同阶段AQP7与AQP8的时空表达规律,结果表明:AQP7与AQP8在不同时期卵母细胞和早期胚胎中具有相似的表达规律,在8Cell达到峰值,而到16Cell期表达量均有显著下降。在牛早期胚胎发育阻滞期(8-16Cell期),胚胎发育由母源基因主导调控转向依赖合子自身遗传物质,这期间AQP7与AQP8表达变化说明其在转变过程中具有重要作用,本试验为AQP7与AQP8在牛早期胚胎发育过程中的功能研究奠定基础。     

Structural remodelling of the heart valves extracellular matrix during embryo development

Alterations in heart valve development represent more than 20% of congenital cardiovascular malformations. Most of the functional properties of heart valves depend on extracellular matrix. Despite its relevance, little is known about fibrillar components on developing stages. Our objective is to define histological changes on valves fibrillar components in late embryonic development of Mus musculus. We found type III collagen as the predominant fibre type in the ECM in prenatal stages followed by a switch to a type I predominance for postnatal ages. The change in fibrillar components is necessary to support the normal mechanical function of adult heart valves.     

Antioxidant systems of the avian embryo: tissue-specific accumulation and distribution of vitamin E in the turkey embryo during development

Tissue-specific accumulation of tocopherols and tocotrienols in turkey tissues during embryonic development and their susceptibility to lipid peroxidation were investigated. Fertile turkey eggs were incubated using standard commercial conditions. Embryonic tissues were collected at 16, 22, 25 d of incubation and from day-old poults (referred to as day 29) and alpha-; beta- + gamma- and delta-tocopherols and respective tocotrienols were analysed by HPLC. A turkey diet provided to the parent hens contained the complete range of tocopherols and tocotrienols. Between days 16 and 22 of embryo development, the alpha-tocopherol concentration in the liver remained constant and then increased significantly (P<0.01) reaching a maximum just after hatching. Similar changes were observed for the other tocopherols and tocotrienols. The accumulation of alpha-tocopherol in the yolk sac membrane (YSM) started after day 20 of development and at hatching the alpha-tocopherol concentration in the YSM was twice that of beta- + gamma-tocopherols and 15 times greater than that of alpha-tocotrienol. In the kidney, heart, lung, muscle and adipose tissues a gradual increase in tocopherol and tocotrienol concentrations took place between days 20 and 25 of development with a sharp increase in particular of alpha-tocopherol between days 25 and 29. There was a discrimination between tocopherols and tocotrienols during their assimilation from the diet by the parent hen and during metabolism by the developing turkey embryo. Tissue-specific features in the susceptibility to lipid peroxidation were found with the brain being the most susceptible to lipid peroxidation at day 25 and in day-old poults.     

Differences in body temperature, cell viability, and HSP-70 concentrations between Pelibuey and Suffolk sheep under heat stress

Pelibuey and Suffolk sheep were compared as to their capacity to regulate body temperature under environmental hyperthermia by measuring their differences in cellular response to heat stress (HS). In a first experiment, seven Pelibuey and seven Suffolk ewes were kept in a climatic chamber for 6 h daily during 10 days (temperatures within the 18 to 39.5 °C range). As chamber temperature rose, sheep rectal temperature increased in both groups, but to a lesser extent in Pelibuey (0.3 °C) than in Suffolk sheep (0.7 °C) (P?<?0.05). In a second experiment, cellular viability was assessed using cultured blood mononuclear cells from 15 Pelibuey and 15 Suffolk sheep. They were incubated at 37 °C for 24 h (control) or 43 °C for 6 h followed by 18 h at 37 °C (HS). In a third experiment, another blood mononuclear cells culture from eight Pelibuey and eight Suffolk sheep was kept at 37 °C for 15 h; these were subsequently cultured for 6 h at 37 °C (controls) or 43 °C (HS). Next, HSP-70 concentration was determined. HS reduced the percentage of viable cells to a greater extent in Suffolk [37 °C (73.7 %) vs. 43 °C (61.9 %); P?<?0.05] than in Pelibuey sheep [37 °C (74.9 %) vs. 43 °C (66.7 %); P?>?0.05]. HS significantly increased HSP-70 average concentrations for both breeds at 43 °C. A significant effect was observed for the breed by temperature interaction (P?<?0.05) caused by a greater difference between Pelibuey and Suffolk at 43 °C (2.85 vs. 0.53 ng/mL, respectively; P?<?0.05) than at 37 °C (0.05 vs. 0.03 ng/mL, respectively; P?>?0.05). In conclusion, Pelibuey sheep show more effective body temperature regulation under conditions of environmental hyperthermia. Also, cell viability after HS was higher in Pelibuey than in Suffolk, an effect that could be mediated by an HSP-70-related mechanism.     

Expression of cytokeratin 18 during pre- and post-natal porcine lung development

The expression pattern of the intermediate filament protein cytokeratin 18 (CK 18) is described during pre- and post-natal development of the porcine lung using a monoclonal antibody against human CK 18. Lungs from 16 foetuses in pseudoglandular, canalicular, saccular and alveolar stages of lung development and lungs from 12 pigs ranging in age from birth to 49 days after birth were studied by immunohistochemistry.In the early pseudoglandular stage of development (day 70 of gestation) all the columnar epithelial cells lining the tubular endbuds strongly expressed CK 18 predominantly in the apical cell compartment. A modest staining was found in the more cuboidal cells of the canalicular stage (day 80 of gestation) where the labelling occurred as a distinct positive rim at the apical cell membrane in most of the cells lining the canaliculi. In 96- and 100-day-old foetuses, parts of the gas exchanging area were formed as terminal sacs by extreme attenuation of the epithelium. In this stage, CK 18 was clearly detectable in the flat type I as well as in the cuboidal type II alveolar epithelial cells. A marked change of the CK 18 expression pattern occurred during formation of the alveoli by septal outgrowth and maturation of the epithelium in 105- and 111-day-old foetuses. Differentiated type I cells no longer expressed CK 18, whereas type II cells were still labelled. Moreover, a specific change in the subcellular distribution pattern from the luminal periphery in immature porcine type II cells to a cytoplasmic localization in differentiated type II cells could be observed. Our investigation additionally demonstrated that the epithelium of bronchi, bronchioli and terminal bronchioli expressed CK 18 in all pre- and post-natal developmental stages. From the 96 days of gestation onwards the epithelial cells of developing bronchial glands were also labelled. Our results clearly show that during porcine lung development profound changes in the cellular expression pattern of CK 18 occur and that CK 18 can be regarded as a selective marker for differentiated porcine alveolar type II cells from the 105th day of gestation onwards. We also assume that the intermediate filament CK 18 could be of significance in the maturation process of the type II alveolar cells.     

Reactive oxygen and nitrogen species regulate porcine embryo development during pre-implantation period: A mini-review

Significant porcine embryonic loss occurs during conceptus morphological elongation and attachment from d 10 to 20 of pregnancy, which directly decreases the reproductive efficiency of sows. A successful establishment of pregnancy mainly depends on the endometrium receptivity, embryo quality, and utero-placental microenvironment, which requires complex cross-talk between the conceptus and uterus. The understanding of the molecular mechanism regulating the uterine-conceptus communication during porcine conceptus elongation and attachment has developed in the past decades. Reactive oxygen and nitrogen species, which are intracellular reactive metabolites that regulate cell fate decisions and alter their biological functions, have recently reportedly been involved in porcine conceptus elongation and attachment. This mini-review will mainly focus on the recent researches about the role of reactive oxygen and nitrogen species in regulating porcine embryo development during the pre-implantation period.     

Exogenous paraoxonase‐1 during oocyte maturation improves bovine embryo development in vitro

Paraoxonase‐1 (PON1) is an enzyme found in serum and follicular fluid that protects cell membrane and circulating lipids against oxidative damage. The aims of this study were to measure the direct effects of recombinant PON1 (rPON1) on bovine oocyte maturation at the molecular level (gene expression) and to measure the carry‐over effects of PON1 on pre‐implantation embryo development in vitro. COCs were submitted to IVM with the addition of 0.0, 0.02, 0.04 and 0.08 mg ml^?1 of rPON1, corresponding to an average PON1 arylesterase enzyme activity of 2.2 ± 0.4, 15.5 ± 1.5, 30.2 ± 3.0 and 57.9 ± 5.0 U ml^?1, respectively. The results indicated that addition of rPON1 during IVM improved embryo development in a dose‐dependent manner as D7 embryo development was 22.2%, 29.4%, 32.2% and 37.0% for the treatment groups, respectively (p = 0.02). In conclusion, addition of PON1 enzyme during IVM exerted dose‐related positive effects on embryo development rates to blastocysts.     

Effect of folic acid and glycine supplementation on embryo development and folate metabolism during early pregnancy in pigs

The present work aimed to determine if different levels of prolificacy either by parity or by genetic origin are linked to folate metabolism. Nulliparous Yorkshire-Landrace (YL) and multiparous YL, and multiparous Meishan-Landrace (ML) sows were randomly assigned to two treatments: 0 ppm or 15 ppm folic acid+0.6% glycine. Supplements were given from the estrus before mating until slaughter on d 25 of gestation. At slaughter, embryo and endometrial tissues were collected to determine concentrations of DNA, protein, and homocysteine. Allantoic fluid samples were also collected to determine concentrations of folates, vitamin B12 and amino acids. Blood samples were taken at first estrus, at mating, and on d 8, 16, and 25 of gestation to determine serum concentrations of folates, vitamin B12, and relative total folate binding capacity (TFBC). Over the entire experiment, multiparous YL sows had higher average serum concentrations of folates than nulliparous YL sows (P < 0.05) but had similar serum concentrations of relative TFBC. Concentrations of folates and relative TFBC averaged higher in ML measured over the entire experiment than in multiparous YL sows (P < 0.05). Concentrations of serum vitamin B12 were higher in multiparous YL than in ML sows or YL nulliparous sows (P < 0.05) over the entire experiment. In allantoic fluid, folates, vitamin B12, and essential amino acids contents were significantly lower in ML than in YL multiparous sows (P < 0.05). The folic acid+glycine supplement increased concentrations of serum folates, but the increase was more marked in nulliparous YL sows (nulliparous x folic acid+glycine, P < 0.05). The folic acid+glycine supplement had no effect on litter size and embryo survival, but it tended to increase embryo DNA in multiparous YL sows (P = 0.06) but not in ML and nulliparous YL sows. Homocysteine was decreased by folic acid+glycine supplement in embryos from all sows, but in endometrium, the folic acid+glycine effect was dependent on parity (nulliparous x folic acid+glycine, P < 0.05). The effects of folic acid+glycine on litter size and embryo development and survival and some aspects of folate metabolism suggest that the basal dietary content of folic acid+glycine was adequate for ML and nulliparous YL sows but not to optimize embryo development in YL multiparous sows.     

Tissue-specific changes in the activities of antioxidant enzymes during the development of the chicken embryo.

1. Tissue-specific profiles of the expression of the antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) and the concentrations of reduced glutathione (GSH) during the development of the chick embryo were investigated. 2. The liver, brain, yolk sac membrane (YSM), kidney, lung, heart and skeletal muscles were collected at the following days of embryo development: 10, 11, 13, 15, 17, 19, 21 and 22 (day-old chicks). 3. The different tissues of the embryo displayed distinct development strategies with regard to the acquisition of antioxidant capacity. In the liver the specific activity of SOD increased between days 10 and 11 of development, then significantly decreased up to day 15 and remained at the same value during the rest of the developmental period. GSH-Px specific activity increased through the time of development. CAT had 2 peaks of specific activity at day 10 of the development and in day-old chicks. 4. The brain was characterised by comparatively high SOD-specific activity especially during the last days of incubation. The specific activities of GSH-Px and CAT were low throughout development. 5. In the YSM maximal GSH-Px and CAT-specific activities were found on day 15 of incubation. In the kidney and heart GSH-Px-specific activity increased at hatching time. CAT-specific activity in the kidney increased just after hatching. 6. It is concluded that each tissue studied expressed a profile of antioxidant defence mechanisms to deal with oxidative stress at hatching time.     

Functional role of type VI collagen during early feather development of the chicken embryo in vitro

The regulatory function of type VI collagen during early feather development in embryonic chickens was investigated at the cellular and organ levels. Immunohistochemical studies of embryonic chicken skin showed that type VI collagen was distributed in spatial‐specific and temporal‐specific manners related to early feather development. To clarify the role of type VI collagen, we studied the feather development in intact, reconstituted and reconstituted gel skin cultures. When ethyl‐3,4‐dihydroxybenzoate (EDHB) was added to the medium of intact skin as an inhibitor of type VI collagen synthesis, the feather buds did not elongate and the number of neural cell adhesion molecule (NCAM)‐positive cells was reduced. However, the magnitudes of both suppressive effects of EDHB were reduced by the addition of liquid type VI collagen. Similar improvement was also observed in the reconstituted skin with liquid type VI collagen and in the reconstituted gel skin with solid type VI collagen at a low concentration. Moreover, type VI collagen promoted feather bud development in the absence of EDHB. However, a high concentration of solid type VI collagen in the reconstituted gel skin arrested the feather bud elongation, and antitype VI collagen antibodies caused feather buds to become longer and smaller in the reconstituted skin. At the cellular level, type VI collagen affected the proliferation, migration and NCAM expression of mesenchymal cells. These results suggest that type VI collagen regulates early feather development by controlling mesenchymal cell behavior.