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《动物医学进展》2020,(4)
在卵母细胞成熟过程中以及胚胎着床前,具备特定功能的各类蛋白质必须在内质网(endoplasmic reticulum,ER)中完成折叠与修饰,这对于维持卵母细胞成熟和胚胎发育是至关重要的。然而,外界不良因素的刺激会破坏内质网功能,阻碍蛋白质合成,诱发ER应激和未折叠蛋白反应(unfolded protein response,UPR),适当的应激反应有利于细胞恢复功能。卵母细胞和早期胚胎对各类外源刺激高度敏感,多项研究表明ER应激和UPR信号影响卵母细胞成熟和胚胎着床前发育。论文总结了ER应激、UPR信号通路及其在哺乳动物卵母细胞成熟和胚胎着床前发育中的作用和机制的现状,以期为卵母细胞体外发育成熟及人类生殖临床提供借鉴。 相似文献
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《中国兽医学报》2020,(3)
体外培养奶牛乳腺上皮细胞,并用0.1 mg/L重组蛋白Chemerin处理细胞。Western blot检测炎症相关蛋白IL-1β和IL-6、自噬标志蛋白LC3和p62以及内质网应激关键蛋白GRP78和CHOP的表达;细胞免疫荧光染色分析细胞内活性氧(ROS)含量及p62蛋白表达定位情况。结果显示,Chemerin处理奶牛乳腺上皮细胞后,细胞内炎症因子IL-1β和IL-6、内质网应激蛋白GRP78和CHOP相对表达量及细胞ROS含量均显著上调(P0.05)。同时,自噬标志蛋白LC3-Ⅱ的表达明显上升(P0.01),而自噬底物p62呈显著性降低趋势(P0.01)。结果表明,细胞因子Chemerin可以通过调控相关基因的表达诱导奶牛乳腺上皮细胞炎症的发生,同时激活内质网应激和自噬反应,其具体机制有待进一步阐明。 相似文献
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《中国兽医学报》2019,(5):962-966
为探究NFκB-Orai1是否参与游离脂肪酸(NEFA)诱导的内质网应激,首先通过体外添加一定浓度的非酯化脂肪酸(nonestesterifiedfatty acid,NEFAs)(1.2 mmol/L)处理大鼠肝细胞不同时间,运用Western blot和实时荧光定量PCR(qRT-PCR)方法,测定NEFAs对内质网应激(ER stress)标志分子GRP78表达量以及钙通道相关蛋白Orai1表达水平的影响。结果显示NEFAs处理12 h时GRP78、Orai1表达量极显著高于对照组(P0.01),证明12 h NEFAs刺激诱导产生内质网应激效果最佳。而后又通过分别添加NFκB抑制剂wogonin与Orai1抑制剂2APB,结果显示抑制NFκB和Orai1后NEFAs刺激可明显降低GRP78、NFκB p65、Orai1的表达水平。结果表明NFκB-Orai1参与NEFA诱导的内质网应激。 相似文献
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《黑龙江畜牧兽医》2020,(7)
为了探究β-羟丁酸(β-hydroxybu-tyric acid,BHBA)是否参与诱导内质网应激导致牛乳腺上皮细胞脂质沉积,试验首先向牛乳腺上皮细胞中添加BHBA,运用实时荧光定量PCR和Western-blot方法检测BHBA对内质网应激标志分子GRP78基因及其蛋白以及脂肪从头合成SREBP1、FASN基因及其蛋白表达水平的影响;然后应用毒胡萝卜素(thapsigargin,TG)刺激牛乳腺上皮细胞,推断脂质沉积和内质网应激顺序,以此确定是否为内质网应激导致了细胞脂质沉积。结果表明:向细胞中添加BHBA后,内质网应激标志分子GRP78及脂肪从头合成SREBP1、FASN的基因及其蛋白表达水平均升高,在细胞中添加毒胡萝卜素后这几种基因的表达水平也升高。说明BHBA可诱导牛乳腺上皮细胞发生内质网应激,导致脂质沉积。 相似文献
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C/EBP同源蛋白CHOP是一种29K的细胞蛋白,主要参与调控细胞增殖、分化以及能量代谢等。CHOP作为转录因子在内质网应激(ER Stress,ERS)介导的细胞凋亡中起重要作用。ERS通常是指ER中错误折叠或未折叠蛋白质增加引起的应激反应。发生ERS时,细胞会通过未折叠蛋白反应(UPR)维持细胞内稳态。长期或过度的应激会导致ER功能障碍和凋亡发生。ER通过3个主要途径诱导细胞凋亡,包括IRE1/ASK1/JNK途径、Caspase-12 激酶途径和CHOP途径。 相似文献
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《畜牧与兽医》2020,(2):67-72
为了探究蓝刺头多糖B(ETPB)对棕榈酸(PA)诱导的胰岛素抵抗L6骨骼肌细胞耗糖量及腺苷酸活化蛋白激酶(AMPK)表达的影响,体外培养大鼠L6成肌细胞,诱导分化为骨骼肌细胞并进行分化鉴定;采用CCK8法检测细胞存活率,筛选PA和ETPB的安全浓度;葡萄糖氧化酶法检测各组细胞耗糖量;实时荧光定量PCR法检测AMPK mRNA基因表达水平,Western blot法检测AMPK蛋白表达量。结果显示:PA诱导L6骨骼肌细胞发生胰岛素抵抗的最适造模浓度为0.4 mmol/L,ETPB的最大安全浓度为200 mg/mL;ETPB可显著提高胰岛素抵抗L6骨骼肌细胞耗糖量(P<0.05),上调AMPK mRNA表达水平,增加AMPK蛋白表达量。提示:ETPB可以通过提高AMPK基因及蛋白表达而促进胰岛素抵抗L6骨骼肌细胞耗糖,这可能是ETPB改善骨骼肌胰岛素抵抗的作用机制之一。 相似文献
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《动物营养学报》2021,33(6)
内质网是蛋白质在哺乳动物细胞内修饰、折叠和加工的场所。内质网的功能发生障碍时,未折叠蛋白或错误折叠蛋白在内质网腔中大量蓄积并激活内质网应激信号,细胞通过减少新蛋白质的合成或促进已合成蛋白质的折叠,恢复内质网稳态。因此,内质网应激信号是机体应对不利外界环境的适应性反应。严重的内质网应激可引发细胞凋亡,清除受损细胞。最近的研究发现,断奶仔猪肠道屏障功能障碍的发病过程伴随未折叠蛋白反应和内质网应激,合理的氨基酸营养可以通过调节内质网应激信号相关蛋白,恢复肠上皮屏障功能。本文对内质网应激影响猪肠道屏障功能的研究进展进行总结和综述,为通过营养物质调节内质网应激信号通路改善仔猪肠道健康提供参考。 相似文献
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利用MTT方法和免疫共沉淀技术研究α-甘露糖苷酶样内质网降解增强蛋白2（ER degradation enhancing α-mannosidase-like protein 2,EDEM2）对于蓖麻毒素从内质网（Endoplasmic reticulum,ER）向胞浆逆向转运过程的影响。结果显示,过量表达EDEM2的细胞能够抵抗蓖麻毒素。然而,当用Kifunensine抑制EDEM2与错误折叠蛋白间的作用后,EDEM2反而促进了蓖麻毒素从内质网向胞浆的逆向转运。此外,嘌呤霉素（Puromycin）也能够促进蓖麻毒素的逆向转运。免疫共沉淀试验发现蓖麻毒素与EDEM2及Sec61α可以相互作用,Kifunensine和嘌呤霉素能够提高这种相互作用。结果表明,EDEM2与蓖麻毒素从内质网向胞浆的逆向转运有关。关键词：EDEM2;蓖麻毒素;逆向转运;细胞毒性;免疫共沉淀;293T细胞 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献