Bax基因及其产物对细胞凋亡的调节

Bax蛋白是Bcl-2家族中的一员,Bax基因由六个外显子组成,其过表达可促进细胞的凋亡。现已运用Bax体外转染、基因重组等方法治疗人类的多种肿瘤疾病。本文就Bax对细胞凋亡作用的研究进展进行阐述。     

CTSD对黔北麻羊卵泡颗粒细胞的调控机制及功能分析

旨在分析组织蛋白酶D（cathepsin D, CTSD）对黔北麻羊卵泡颗粒细胞的调控机制并初步探究其对产羔性状的影响机理。本研究以36周龄、健康、多胎黔北麻羊母羊（n=5）为研究对象,屠宰后采集卵巢组织分离培养卵泡颗粒细胞,构建真核表达载体pEGFP-N3-CTSD,将其导入细胞后在转录与翻译水平验证真核表达效率;通过CCK-8法检测在不同时间段内重组质粒对颗粒细胞增殖的影响;通过流式细胞仪检测重组质粒对颗粒细胞凋亡及周期的影响;随后使用RT-qPCR法在细胞水平检测重组质粒对细胞凋亡相关基因Bcl-2、Bax、Caspase-3,细胞周期相关因子Cyclin A1、Cyclin D2、Cyclin E mRNA表达水平的影响,最后,以多胎性状候选基因BMPR-IB、FSHR、INHA为功能基因,在转录与翻译水平上验证重组质粒对其mRNA与蛋白表达的影响。双酶切及测序结果证实,黔北麻羊CTSD基因真核表达载体pEGFP-N3-CTSD构建成功,且在转录与翻译水平极显著上调CTSD在颗粒细胞中的表达（P<0.01）;细胞增殖检测结果表明,颗粒细胞中上调CTSD后能够抑制细胞的增殖,其中在12、24、48、72 h对细胞增殖的抑制效率达到极显著（P<0.01）;细胞凋亡检测结果表明,CTSD的过表达能够极显著促进颗粒细胞的凋亡（P<0.01）,且能够显著下调细胞抗凋亡基因Bcl-2的表达（P<0.05）,极显著上调细胞促凋亡相关基因Bax、Caspase-3的表达（P<0.01）;此外,细胞周期检测发现,pEGFP-N3-CTSD在转染后能够极显著上调G0/G1期与G2/M期的细胞数量（P<0.01）,极显著下调S期细胞数量（P<0.01）,同时能够极显著提高细胞周期相关因子Cyclin A1的表达（P<0.01）,极显著降低Cyclin D2的表达（P<0.01）。RT-qPCR及Western blot检测结果表明,在颗粒细胞中上调CTSD后,能够极显著的下调多胎性状候选基因与蛋白BMPR-IB、FSHR、INHA在转录和翻译水平中的表达（P<0.01）。本研究发现,CTSD的高表达能抑制细胞的增殖,促进细胞凋亡,改变颗粒细胞的周期进程;还能改变细胞凋亡相关因子Bcl-2、Bax、Caspase-3与细胞周期相关因子Cyclin A1、Cyclin D2、Cyclin E的表达;同时也能够极显著降低颗粒细胞中多胎性状候选基因与蛋白BMPR-IB、FSHR、INHA的表达量（P<0.01）。这提示,CTSD可能通过改变细胞水平相关因子的表达量来调控颗粒细胞的生物学行为以及影响山羊多胎性状候选基因的表达进而间接的成为影响山羊产羔性状的重要因子,本研究为进一步探明CTSD对山羊产羔性状调控机理及对颗粒细胞的影响机制奠定基础。     

肿瘤转移抑制因子(Kisspeptin)对牛卵巢颗粒细胞凋亡的影响

肿瘤转移抑制因子(Kisspeptin)在颗粒细胞上有表达,但其对颗粒细胞凋亡的作用尚不清楚,本试验旨在利用流式细胞术和荧光定量PCR的技术研究Kisspeptin对牛卵巢颗粒细胞凋亡的影响。向DMEM-F12培养液中分别添加0、100 nmol/L的Kp-10培养牛颗粒细胞,24 h后收集细胞,用流式细胞技术检测细胞凋亡和细胞周期,用荧光定量PCR技术检测Caspase-3、Bcl-2、Fas和Fasl的m RNA表达。结果表明:Kisspeptin可显著促进牛颗粒细胞凋亡,且伴随着Caspase-3、Fas和Fasl m RNA表达上调及Bcl-2 m RNA表达下调(P0.01);流式细胞分析表明,Kisspeptin可使牛颗粒细胞在G1期增加、S期下降(P0.05)。研究结果说明,Kisspeptin可促进牛颗粒细胞凋亡,这一作用可能通过上调促凋亡基因Caspase-3、Fas、Fasl和下调抗凋亡基因Bcl-2的m RNA表达实现。     

2型猪圆环病毒感染对小鼠组织中Caspase3、Bak及Bcl-2基因表达的影响

Caspase3、Bcl-2、Bak是细胞凋亡过程中3种重要的调节蛋白,为研究感染猪圆环2型病毒(PCV2)后体内细胞的凋亡情况,本实验以BALB/c小鼠为实验模型,建立了SYBR Green Ⅰ实时定量PCR检测细胞凋亡的方法.结果表明实验组Caspase3的表达在各时间段里与对照组相比均呈上升趋势,提示了PCV2感染可以上调Caspase3水平,从而增加被病毒感染组织的细胞凋亡,而小鼠心、脑、脾等组织Bak基因表达明显上调,Bcl-2基因表达水平也伴随Bak基因而升高.这些结果揭示了PCV2感染BALB/c小鼠后,相关细胞凋亡基因在体内的作用与机制,同时为今后细胞凋亡的检测提供了新的方法.     

去甲斑蝥素对U937细胞凋亡相关基因蛋白表达的影响

为了观察去甲斑蝥素(NCTD)对人白血病U937细胞凋亡相关基因蛋白表达的影响,试验将5,10,20 nmol/L去甲斑蝥素与U937细胞共同培养48 h,采用MTT法测定细胞活性,应用免疫组织化学法检测细胞中细胞型FLICE抑制蛋白(cFLIP)、存活蛋白(survivin)以及胱天蛋白酶-3(caspase-3)的表达。结果表明:与阴性对照组比较,5,10,20 nmol/L去甲斑蝥素组细胞活性下降(P<0.05或0.01);去甲斑蝥素显著抑制cFLIP和存活蛋白的阳性表达,促进胱天蛋白酶-3的阳性表达(P<0.05或0.01)。推测去甲斑蝥素可能通过下调cFLIP和存活蛋白的表达,上调胱天蛋白酶-3的表达诱导U937细胞凋亡。     

干扰B-Raf基因对绵羊毛囊干细胞增殖和凋亡的影响

本研究旨在探讨编码丝氨酸/苏氨酸蛋白激酶（Serine/Threonine-Protein Kinase）的B-Raf基因对绵羊毛囊干细胞（HFSCs）增殖和凋亡的影响。将si-B-Raf转染至HFSCs，通过RT-qPCR实验技术检测B-Raf基因、Erk1/2基因和STAT3基因的表达水平，通过Western Blot实验技术检测B-Raf蛋白、Erk1/2蛋白、p-Erk1/2蛋白和STAT3蛋白的表达水平，通过EdU细胞增殖法和CCK-8细胞增殖检测法检测HFSCs的增殖情况，通过流式细胞仪检测HFSCs的凋亡情况。结果表明，si-B-Raf转染细胞后，B-Raf基因的表达量显著降低，Erk1/2基因和STAT3基因的表达量也显著降低；Western Blot实验结果表明，B-Raf蛋白、Erk1/2蛋白、p-Erk1/2蛋白和STAT3蛋白的表达水平显著降低；EdU和CCK-8结果发现细胞增殖受到抑制，细胞增殖水平显著下降；流式细胞仪检测到细胞凋亡水平显著上升。综上，干扰B-Raf基因表达显著抑制HFSCs增殖并促进其凋亡，可能是通过MAPK/Erk1/2通路进行的，研究可为...     

TDRKH基因对NIH3T3细胞凋亡的影响

使用NIH3T3细胞进行试验,利用RNAi方法抑制TDRKH的mRNA的表达水平。通过流式细胞术、RTqPCR等方法分别检测细胞凋亡情况及凋亡相关基因Bcl-2、Bax等的表达变化。结果显示:敲减TDRKH表达并不会明显导致NIH3T3细胞的凋亡,凋亡相关基因Bax、P53mRNA表达量无显著性变化,但Bcl-2、Survivin mRNA表达量显著下降,Bcl-2/Bax值显著降低。结果表明:TDRKH虽然不能直接诱导细胞凋亡,但可通过其他潜在基因调控通路影响细胞功能。     

SMAD6对猪未成熟支持细胞增殖和凋亡的影响

睾丸未成熟支持细胞的增殖活性对种公畜繁殖性能有重要影响，睾丸基因组DNA甲基化(5mC)不同发育阶段特异性引起的基因差异表达可以调控支持细胞的增殖活性。在课题组前期研究中，SMAD6被鉴定出是睾丸发育过程中受3′UTR甲基化水平调控的枢纽基因之一，但其生物学功能尚未被发掘。本研究旨在探究SMAD6对猪未成熟支持细胞增殖和凋亡的作用。在体外培养的猪未成熟支持细胞中过表达SMAD6或干扰SMAD6表达后，检测细胞周期和增殖相关基因的相对表达量、细胞增殖情况、细胞ATP水平、细胞凋亡率及凋亡相关蛋白的表达情况。结果显示：过表达SMAD6后细胞周期及增殖相关基因的相对表达量上升(P<0.05或P<0.01)、细胞增殖增加(P<0.05或P<0.01)、细胞ATP水平升高(P<0.01)、细胞的凋亡率下降(P<0.05)、促凋亡相关蛋白BAX和Caspase3的表达降低(P<0.05);干扰SMAD6表达结果则与之相反。研究结果提示，SMAD6促进猪未成熟支持细胞的增殖且抑制其凋亡。     

家蚕核型多角体病毒对寄主细胞凋亡抑制蛋白BmAPI5表达的影响

API5是一种新的细胞凋亡抑制蛋白因子,能有效抑制细胞凋亡。API5在结构与功能上高度保守,并已在包括家蚕在内的多种昆虫中发现存在同源基因。本文检测了家蚕幼虫BmAPI5基因在BmNPV和大肠杆菌侵染后的转录与表达变化。结果表明,微生物侵染能快速显著诱导BmAPI5基因的转录与表达,其中以BmNPV的诱导作用较为明显。这表明BmAPI5可能参与BmNPV-宿主的互作机制。     

水牛BMP1基因对颗粒细胞增殖与凋亡的功能研究

本研究旨在探讨BMP1基因对体外培养水牛颗粒细胞增殖与凋亡的影响,采用qRT-PCR检测体外培养0、24、48、72和96h水牛颗粒细胞中BMP1基因的表达规律,通过在水牛颗粒细胞培养液中添加BMP1基因重组蛋白和抗BMP1抗体,观察其对体外培养水牛颗粒细胞增殖变化的影响,并应用qRT-PCR和Western blotting方法检测与细胞增殖和细胞凋亡相关因子表达的变化规律。结果显示,随着颗粒细胞体外培养时间的延长,BMP1基因的相对表达量显著上调(P0.05),96h培养组BMP1表达最高。添加BMP1重组蛋白可显著促进水牛颗粒细胞的体外增殖(P0.05),并能够显著上调细胞周期关键蛋白Cyclin D1、Cyclin D2和PCNA mRNA表达水平(P0.05),同时显著抑制了细胞凋亡信号通路中促凋亡相关因子(Fas、FasL、TNFR1、TNF-α、Cytochrome C、Apaf1、Chop、Caspase-3、Caspase-8和Caspase-9)mRNA表达(P0.05)。Western blotting检测结果表明,BMP1重组蛋白能够抑制Fas、Bax和Caspase-9蛋白表达,蛋白与mRNA表达一致。而添加抗BMP1抗体的试验则得出相反的结果。综上表明,BMP1基因能通过调控相关基因的表达促进体外培养水牛颗粒细胞的增殖并抑制其凋亡,在水牛卵泡发生过程中具有重要的调控功能,为阐明BMP1基因参与家畜卵泡发生的分子机制奠定基础。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -