Enhancement of Drug Resistance by Lysophosphatidic Acid Receptor-3 in Mouse Mammary Tumor FM3A Cells

Lysophosphatidic acid (LPA) acts as a simple phospholipid that interacts with G protein-coupled transmembrane LPA receptors. Recently, it has been reported that each LPA receptor plays different biological roles in acquisition of the malignant property of tumor cells. In this study, to assess the involvement of LPA receptor-3 (LPA₃) in cell survival after treatment with anticancer drugs, we generated Lpar3-expressing FM3A-a3A9 cells from mouse mammary tumor FM3A cells and examined the cell survival rate after treatment with anticancer drugs compared with Lpar3-unexpressing cells. Cells were treated with 0.005 to 10 μM of cisplatin (CDDP) or doxorubicin (DOX) for 3 days. For the CDDP and DOX treatments, the cell survival rate of FM3A-a3A9 cells was significantly higher than that of Lpar3-unexpressing cells. The expression level of the Mdr1a gene in FM3A-a3A9 cells was higher than that of Lpar3-unexpressing cells, whereas no significant difference in multidrug resistance 1b (Mdr1b) and glutathione S-transferase mu1 (Gstm1) expressions was found. These results suggest that LPA₃ may enhance the cell survival rate after treatment with anticancer drugs in mouse mammary tumor cells, correlating with increased expression of the Mdr1 gene.     

利用随机肽库鉴定猪瘟病毒E2蛋白抗原表位

利用噬菌体随机12肽库对抗猪瘟病毒（classical swine fever virus CSFV）糖蛋白E2特异的单抗A11进行表位鉴定，经过4轮筛选后，随机挑取10个噬菌体克隆作竞争ELISA检测。结果表明，10个克隆中除4号克隆外，其余9个均能抑制原核表达的E2蛋白和A1l单抗之间的抗原抗体反应，抑制率在35％～64％；DNA测序表明，所有产生竞争抑制作用的8个噬菌体克隆的12肽序列均舍有XXWRXXXL核心序列，而没有抑制作用的克隆则不含该核心序列；Western-blot试验证明，所挑阳性克隆均能被单抗A11识别。多序列比较发现，该核心序列与猪瘟病毒E蛋白的28～35位氨基酸TTWKEYSH有一定的同源性，人工合成的含有部分核心序列氨基酸的多肽可以与单抗A11反应，表明单抗A11所针对的抗原表位位于CSFVE2蛋白的28～35位氨基酸。     

人Bcl-2乳腺定位表达转基因小鼠的建立

以 p CAT、p WB和 p WC为原始质粒 ,构建 WAP启动子调控的 Bcl- 2乳腺组织特异性表达载体 p WBS。载体用Bgl +Sal +Pvu 酶切 ,回收 3.0 kb的基因片段 WAP- Bcl- 2 - SV40 Poly A,通过显微注射方法导入 C5 7BL / 6 J×DBA/ 2 JF1代小鼠受精卵的雄原核内。共注射 10 0 0枚卵 ,将存活的约 6 0 0枚卵分别移植至 2 9只假孕母鼠输卵管内 ,获得仔鼠 5 5只。PCR检测 ,阳性鼠 12只。Southern blot检测 ,阳性鼠 4只 ,其中公、母鼠各 2只 ,在饲养过程中 ,2只公鼠均意外死亡。Western blot证实 ,1只母鼠 Bcl- 2表达阳性 ,其 F1代的 40只小鼠中 ,有 18只呈 PCR阳性 ,其中母鼠8只 ,在 5个月的反复怀孕过程中 ,未观察到乳房有任何肿瘤或肿块的出现 ,证实 Bcl- 2单独在转基因鼠乳腺中表达不会引起转基因鼠乳腺癌的发生。     

信号肽对猪瘟病毒E2蛋白在杆状病毒表达系统中分泌表达的影响

旨在通过引入信号肽序列实现猪瘟病毒E2蛋白在杆状病毒表达系统中的高效表达。首先将内源信号肽（简称endo）、蜂素信号肽（简称mel）及gp67信号肽（简称gp67）分别引入pFastBac1载体,随后插入E2基因,构建重组质粒。随后将重组质粒转化至DH10Bac感受态细胞,经蓝白斑筛选得到重组黏粒,将重组黏粒转染sf21细胞以得到杆状病毒。经扩增后大量感染细胞,检测E2蛋白表达情况,利用镍填料纯化得到E2蛋白,并进行蛋白糖基化水平鉴定及蛋白免疫原性分析。PCR鉴定结果显示成功构建了重组质粒。挑选白斑进行PCR鉴定,证实得到重组黏粒。Western blot检测结果表明,E2蛋白实现了分泌表达,进一步比较细胞培养上清中E2蛋白的表达水平,确定gp67信号肽介导的E2蛋白分泌表达量最高。经镍填料纯化得到E2蛋白,SDS-PAGE结果显示其纯度较高,产率为25 mg·L^-1。通过ELISA分析其抗原性,结果表明纯化所得E2蛋白能特异性识别猪瘟阳性血清中的抗体,其抗原性良好。将纯化后的E2蛋白添加ISA201佐剂乳化后免疫BALB/c小鼠,阻断ELISA结果显示,免疫后14 d即产生较高水平的猪瘟特异性抗体,表明E2蛋白免疫原性良好。本研究为E2亚单位疫苗的研制奠定了基础。     

The therapeutic effects of SET/I2PP2A inhibitors on canine melanoma

Canine melanoma is one of the most important diseases in small animal medicine. Protein phosphatase 2A (PP2A), a well conserved serine/threonine phosphatase, plays a critical role as a tumor suppressor. SET/I2PP2A is an endogenous inhibitor for PP2A, which directly binds to PP2A and suppresses its phosphatase activity. Elevated SET protein levels have been reported to exacerbate human tumor progression. The role of SET in canine melanoma, however, has not been understood. Here, we investigated the potential therapeutic role for SET inhibitors in canine melanoma. The expression of SET protein was observed in 6 canine melanoma cell lines. We used CMeC-1 cells (primary origin) and CMeC-2 cells (metastatic origin) to generate cell lines stably expressing SET-targeting shRNAs. Knockdown of SET expression in CMeC-2, but not in CMeC-1, leads to decreased cell proliferation, invasion and colony formation. Phosphorylation level of p70 S6 kinase was decreased by SET knockdown in CMeC-2, suggesting the involvement of mTOR (mammalian target of rapamycin)/p70 S6 kinase signaling. The SET inhibitors, OP449 and FTY720, more effectively killed CMeC-2 than CMeC-1. We observed PP2A activation in CMeC-2 treated with OP449 and FTY720. These results demonstrated the potential therapeutic application of SET inhibitors for canine melanoma.     

A3启动子缺陷piggyBac转座子在家蚕中的转基因研究

构建了A3启动子缺陷piggyBac转座质粒,以增强型绿色荧光蛋白基因EGFP为标记基因对家蚕品种N is-tari进行转基因实验,发现其具有较高的表达EGFP的转化效率,G0代中EGFP阳性蛾区检出占总注射蚕卵的比率达0.618%,且EGFP的表达呈组织特异性。PCR实验分析也证实了标记基因的成功导入。该实验中标记基因及转基因阳性个体均易于检出,为启动子缺陷转基因方法在家蚕组织特异性启动子筛选研究上的应用奠定了基础。     

降钙素基因相关肽及其在免疫系统的功能

降钙素基因相关肽(CGRP)是迄今发现的人体内舒血管活性最强的多肽。CGRP与免疫系统关系密切,能够促进细胞表面分子表达;抑制B淋巴细胞早期发育;调节T淋巴细胞成熟与增殖;增强中性粒细胞的富集并与炎症反应相关。CGRP在免疫系统功能的研究为CGRP运用于抗感染免疫、免疫系统疾病的治疗提供可能性,也为“神经内分泌-免疫调节”的研究提供实例。     

苷肽注射液诱导犬产生IL-2的试验

为了探讨新型免疫增强剂——苷肽注射液对犬免疫功能的影响,以20只健康犬为研究对象,随机分为四组,每组5只,分别注射苷肽注射液、苷肽注射液和犬五联疫苗、犬五联疫苗、生理盐水,各组犬于注射后0、2、7、15、21 d采血,检测不同组间的IL-2分泌情况。结果表明:苷肽注射液单独应用及其与疫苗联合应用,在注射后2 d就可以显著提高IL-2水平,并且可以维持15 d;注射苷肽注射液联合犬五联疫苗组和单独注射苷肽注射液组IL-2水平显著高于单独注射犬五联疫苗组(P<0.05),说明苷肽注射液可以提高犬IL-2的水平,具有提高细胞免疫的作用。     

Development and application of a real-time RT-PCR assay to rapidly detect H2 subtype avian influenza A viruses

The H2 subtypes of avian influenza A viruses (avian IAVs) have been circulating in poultry, and they have the potential to infect humans. Therefore, establishing a method to quickly detect this subtype is pivotal. We developed a TaqMan minor groove binder real-time RT-PCR assay that involved probes and primers based on conserved sequences of the matrix and hemagglutinin genes. The detection limit of this assay was as low as one 50% egg infectious dose (EID₅₀)/mL per reaction. This assay is specific, sensitive, and rapid for detecting avian IAV H2 subtypes.     

牛IL-2重组质粒对口蹄疫病毒G-H环多肽免疫小鼠的佐剂效应

本试验目的是研究牛IL-2重组质粒对口蹄疫病毒(Foot-and-mouth disease virus,FMDV)G-H环多肽免疫小鼠的佐剂效应.作者构建了含有信号肽序列的牛IL-2真核表达质粒pcDNA3.1-pBoIL-2,并体外鉴定其表达,同时原核表达并纯化了Asial型FMDV G-H环多肽.采用不同组合的pcDNA3.1-pBoIL-2、FMDV G-H环多肽分组免疫小鼠,并设阴、阳性对照,通过间接ELISA试验、微量血清中和试验、淋巴细胞增殖试验和实时定量PCR试验对各免疫组小鼠体液和细胞免疫水平进行综合评价.结果表明,与G-H+pcDNA3.1免疫组比较,G-H+pcD-NA3.1-pBoIL-2免疫组特异性抗体水平、中和抗体滴度、淋巴细胞增殖水平和细胞因子相对表达水平显著提高(P<0.05).结果提示,牛IL-2真核表达质粒可以显著提高G-H环多肽的免疫效果.     

传染性法氏囊病毒VP2蛋白抗原表位多肽P22的免疫原性及生物学功能鉴定

为鉴定lBDV VP2蛋白线性B细胞抗原表位肽P22的免疫原性及生物学功能,作者采用固相多肽合成方法合成多肽P22,经纯化后用SMCC法分别与牛血清白蛋白(BSA)和细胞穿膜肽(PNT)进行偶联,得到免疫抗原P22-BSA和检测抗原P22-PNT;用P22-BSA免疫BALB/c小鼠3只,经3次免疫后得到多抗血清3份.应用ELISA检测了抗P22抗体的特异性,并通过抗P22多肽抗体作为特异性抗体检测了P22多肽结合CEF细胞的特性.结果经鉴定3份多抗血清均与P22多肽特异性反应,效价均达到1:105,且能特异性检测P22多肽与CEF细胞的特异性结合.本试验成功制备了P22免疫原,获得了效价高、特异性较好的鼠源抗P22多抗血清,并证明P22多肽与CEF细胞能够特异性结合,为进一步研究多肽疫苗的设计或试纸条的研制及表位单抗的制备提供了新的思路和基础.     

酵母双杂交随机肽库的设计及构建

构建一个含16个氨基酸的酵母双杂交随机肽库,设计合成编码16肽的随机DNA片段,PCR扩增随机DNA片段,经限制性内切酶BamHI和EcoRI酶切后克隆入酵母表达质粒pGADT7GH,构建酵母双杂交随机肽库质粒pGADT7GH-RP并检验其库容。结果表明,扩增获得编码16肽的随机DNA片段,并成功将随机DNA片段克隆入酵母表达质粒pGADT7GH,与GAL4AD形成融合蛋白,其库容为1.28×107。从而成功地构建了酵母双杂交随机肽库。     

抗菌肽对育成期母貂免疫功能及肠组织形态的影响

【目的】天蚕素抗菌肽是一种商品化的阳离子抗菌肽,在水貂体内的研究较少。试验旨在探究抗菌肽对育成期母貂脏器系数、血清及空肠免疫指标、肠组织形态的影响。【方法】选取65日龄体重相近的短毛黑母貂60只,随机分为6组,每组10个重复,每个重复1只,单笼饲养。各组饲粮中分别添加0(对照组)、100、200、300、400和500 mg/kg抗菌肽,预试期1周,正试期8周。饲养试验结束后,每组取6只水貂进行心脏采血,采集内脏器官、十二指肠及空肠样品,并测定血清及空肠免疫指标、肠道组织形态。【结果】与对照组相比,100、300和400 mg/kg抗菌肽组脾脏指数显著升高(P<0.05);各试验组补体C3(C3)、补体C4(C4)和免疫球蛋白M(IgM)含量均显著升高,除200 mg/kg抗菌肽组外的所有试验组免疫球蛋白A(IgA)和免疫球蛋白G(IgG)含量均显著升高(P<0.05);各试验组肿瘤坏死因子(TNF-α)含量均显著降低,100、200、300 mg/kg抗菌肽组分泌型免疫球蛋白(sIgA)、γ干扰素(IFN-γ)及白细胞介素-10(IL-10)含量均显著升高(P<0....     

Expression Analysis of C-type Natriuretic Peptide and Its Receptor in Buffalo Follicles

In order to investigate the expression pattern of C-type natriuretic peptide（CNP）and its receptors（NPR）in buffalo follicles,firstly,the mRNA expression level of ANP,BNP,CNP,NPR1 and NPR2 in ovary were assayed by Real-time quantitative PCR;Secondly,the protein expression of CNP and NPR2 in buffalo follicles were detected by immunohistochemical stainning method;Lastly,the mRNA expression level of CNP and NPR2 in granule cells and cumulus cells were assayed by Real-time quantitative PCR.The results showed that CNP gene and its receptor NPR2 mainly expressed in buffalo ovary,the protein of CNP and NPR2 expressed in all stages of follicles,CNP mainly expressed in mural granulosa cells and NPR2 primarily presented in cumulus cells,the mRNA expression of CNP gene in granule cells was significantly higher than cumulus cells（P<0.05),whereas the mRNA expression of NPR2 gene in cumulus cells was significantly higher than granule cells（P<0.05).In conclusion,among the main members of natriuretic peptides and its receptors,CNP and NPR2 presented strong expression in buffalo ovary.CNP mainly expressed in mural granulosa cells,but NPR2 primarily presented in cumulus cells which arounding oocytes.     

C型利钠肽及其受体在水牛卵泡中的表达分析

为了探明C型利钠肽（C-type natriuretic peptide,CNP）及其受体（natriuretic peptide receptor,NPR）在水牛卵泡中的表达模式,本研究首先采用实时荧光定量PCR技术检测水牛卵巢中利钠肽家族主要成员A型、B型、C型利钠肽（ANP、BNP、CNP）及其Ⅰ型、Ⅱ型受体（NPR1、NPR2）的mRNA表达情况,然后利用免疫组化技术对水牛卵泡中CNP及NPR2蛋白进行定位,最后利用实时荧光定量PCR技术检测颗粒细胞和卵丘细胞中CNP及NPR2的mRNA表达规律。结果显示,水牛卵巢主要表达CNP及NPR2,且在各级卵泡中均有表达,其中,CNP主要在壁层颗粒细胞中表达,NPR2主要在卵丘细胞中表达;颗粒细胞上CNP mRNA表达水平显著高于卵母细胞周围的卵丘细胞（P<0.05）,而卵丘细胞上NPR2 mRNA表达水平显著高于颗粒细胞（P<0.05）。综上所述,在利钠肽主要家族成员和受体中,CNP和NPR2在水牛卵巢中呈现强表达,CNP主要在壁层颗粒细胞中表达,而NPR2主要在卵母细胞周围的卵丘细胞中表达。     

Production of Diabetic Offspring Using Cryopreserved Epididymal Sperm by In Vitro Fertilization and Intrafallopian Insemination Techniques in Transgenic Pigs

Somatic cell nuclear transfer (SCNT) is a useful technique for creating pig strains that model human diseases. However, production of numerous cloned disease model pigs by SCNT for large-scale experiments is impractical due to its complexity and inefficiency. In the present study, we aimed to establish an efficient procedure for proliferating the diabetes model pig carrying the mutant human hepatocyte nuclear factor-1α gene. A founder diabetes transgenic cloned pig was generated by SCNT and treated with insulin to allow for normal growth to maturity, at which point epididymal sperm could be collected for cryopreservation. In vitro fertilization and intrafallopian insemination using the cryopreserved epididymal sperm resulted in diabetes model transgenic offspring. These results suggest that artificial reproductive technology using cryopreserved epididymal sperm could be a practical option for proliferation of genetically modified disease model pigs.     

Spontaneous Mammary Adenocarcinoma in a Twelve-week-old Female Sprague-Dawley Rat

Spontaneous mammary adenocarcinoma was observed in a 12-week-old female SD rat. A movable mass in the right cervical region was found at 11 weeks of age, and the rat was sacrificed the following week. The mass was located in the vicinity of the right salivary gland and measured 38 mm × 26 mm × 16 mm in gross size. It was a firm whitish mass, with a cut surface that was also whitish in appearance. Histopathologically, neoplastic cells formed glandular structures that contained secreted eosinophilic material. Ultrastructurally, similar secreted material and lipid droplets were in the cytoplasm of the neoplastic cells. Immunohistochemically, the neoplastic cells were positive for cytokeratin 8, cytokeratin 18 and estrogen receptor α. Based on these findings, the tumor was diagnosed as a mammary gland adenocarcinoma, and we therefore conclude that this tumor type can occur spontaneously in female SD rats as young as 12 weeks of age.