Tol2转座子系统在转基因动物中的应用

Tol2是在青鳉鱼基因组中发现的一种具有自主性的转座子元件.它编码转座酶,催化Tol2转座子结构中5’端200 bp和3’端150 bp序列发生转座反应.Tol2的多种特性,如可携带大片段外源DNA、单拷贝整合效率高、转座子活性强等,使得以Tol2特座子系统为载体的转基因技术在多种生物中得到应用.综述了Tol2转座子系统的结构、特性以及近年来在多种动物转基因中的应用.     

Overlapping functions of different dynamin isoforms in clathrin-dependent and -independent endocytosis in pancreatic beta cells

Previously, we identified a clathrin-dependent slow endocytosis and a clathrin-independent fast endocytosis in pancreatic β cells, both triggered by elevated cytoplasmic Ca²⁺ concentration. In the current study, we attempted to explore the roles of different dynamin isoforms in these endocytotic processes. We first confirmed the existence of both neuron-specific dynamin 1 and ubiquitous dynamin 2 in INS-1 cells using both quantitative RT-PCR and Western blot experiments. By specifically knocking down the endogenous level of either dynamin isoform from INS-1 cells, we showed that dynamin 1 and dynamin 2 simultaneously participate in the clathrin-independent and -dependent membrane retrieval in pancreatic β cells. Transferrin internalization was also inhibited in cells with knock down of both dynamin 1 and dynamin 2. Based on these results, we argue that different dynamin isoforms play overlapping roles in different types of endocytosis.     

Rhynchophylline attenuates migraine in trigeminal nucleus caudalis in nitroglycerin-induced rat model by inhibiting MAPK/NF-кB signaling

Cis-diamminedichloroplatinum(II) (cisplatin) (CP) is an important chemotherapeutic agent used in the treatment of several cancers. However, it has several side effects including nephrotoxicity gonadotoxicity, hepatotoxicity, and ototoxicity. In in vitro experiments, antioxidants or reactive oxygen species scavengers have a cytoprotective effect on cells exposed to cisplatin (CP). Ellagic acid (EA) is one such bioactive polyphenol that is abundant in some fruits, nuts, and seeds. Various authors have reported that EA has strong antioxidant and antitumor potential. The present study was, therefore, carried out to explore the protective potential of EA on CP-induced gonadotoxicity and nephrotoxicity in colon tumor-bearing mice. Animals were divided into five groups: Group I: normal control, Group II: DMH treated. After 20 weeks of DMH treatment, the animals were divided into four subgroups, viz., Group III: no treatment, Group IV: EA, Group V: CP, and Group VI: CP?+?EA. Administration of EA significantly ameliorated the toxicity caused by CP as indicated by improved kidney function tests and reproductive function tests. EA treatment to CP-abused mice also led to a marked reduction in the extent of peroxidative damage to tissue as was evident from the improvement in the histopathological changes in kidney and testis. Blood counts were also improved on administration of EA to CP-treated mice. This article provides the evidence that antioxidant efficacy of EA has beneficial effects on CP-induced nephrotoxicity and gonadotoxicity and contributes to understanding the role of oxidative stress, and suggests several points as part of the mechanism of CP toxicity.

     

带卫星RNA黄瓜花叶病毒保护接种的植物中病毒积累与基因组RNA合成及病状表达

本文报道了三生烟在接种带卫星RNA的黄瓜花叶病毒(CMV-S52)后,或接种后用强毒CMV攻击,其病状表现、组织中病毒含量,病毒基因组RNA合成与卫星RNA合成的关系.植物在接种CMV-S52后7～10天,所有接种植物都表现出不同程度的轻度花叶症状,此期正是组织内病毒含量最高,而卫星dsRNA占总dsRNA百分比较低时期.接种后不同时间的测定证明,组织内病毒基因组dsRNAl和dsRNA2的合成水平均较低,而卫星dsRNA则始终保持较高的合成水平;到接种后15天病状消失时,卫星dsRNA占总dsRNA合成百分比的84.79％之多. 用CMV-S52保护接种后再用强病毒攻击,植物中的病毒含量、病毒ssRNA合成不增加或稍有增加;而基因组dsRNA和卫星dsRNA合成都有增加,但卫星dsRNA合成仍占绝对优势.保护作用的效果,取决于攻强病毒时已存在于组织内的卫星RNA与基因组RNA合成量的相对比例。讨论了卫星RNA的保护机理。     

Extracellular ATP stimulates exocytosis via localized Ca(2+) release from acidic stores in rat pancreatic beta cells

Three different methods, membrane capacitance (C(m)) measurement, amperometry and FM dye labeling were used to investigate the role of extracellular ATP in insulin secretion from rat pancreatic beta cells. We found that extracellular application of ATP mobilized intracellular Ca(2+) stores and synchronously triggered vigorous exocytosis. No influence of ATP on the readily releasable pool of vesicles was observed, which argues against a direct modulation of the secretory machinery at a level downstream of Ca(2+) elevation. The stimulatory effects of ATP were greatly reduced by intracellular perfusion of BAPTA but not EGTA, suggesting a close spatial association of fusion sites with intracellular Ca(2+) releasing sites. ATP-induced Ca(2+) transients and exocytosis were not blocked by thapsigargin (TG), by a ryanodine receptor antagonist or by dissipation of pH in acidic stores by monensin alone, but they were greatly attenuated by IP(3) receptor inhibition as well as ionomycin plus monensin, suggesting involvement of IP(3)-sensitive acidic Ca(2+) stores. Taken together, our data suggest that extracellular ATP triggers exocytosis by mobilizing spatially limited acidic Ca(2+) stores through IP(3) receptors. This mechanism may explain how insulin secretion from the pancreas is coordinated through diffusible ATP that is co-released with insulin.     

大黄鱼肝细胞肿瘤相关抗原-127基因克隆及分子特征分析

在构建大黄鱼肌肉组织cDNA文库的基础上,克隆了肝细胞肿瘤相关抗原-127基因.克隆到的基因全长l439bp,其中5′-UTR 124 bp,3′-UTR 640 bp,编码序列675 bp,编码224个氨基酸.生物信息学分析显示,大黄鱼HCA127基因存在多个功能位点,即N端糖基化位点、蛋白激酶C磷酸化位点、酪蛋白激酶Ⅱ磷酸化位点和亮氨酸拉链结构位点.大黄鱼HCA127氨基酸序列具有较高的保守性,与斑马鱼、胡瓜鱼、大西洋鲑等多种鱼类的相似性在80％以上.在检测的9种组织中,肝细胞肿瘤相关抗原-127基因在肝、肾、肠、鳃、眼、脑组织中表达,其中在脑组织中表达最强,肝和鳃组织中次之,肾和眼组织中表达较微弱.     

核酸酶BN及SN基因的克隆和序列分析

分别从解淀粉芽孢杆菌(Bacillus amyloliquefaciens)和金黄色葡萄球菌(Staphylococcus aurcus)中提取染色体DNA,经HindⅢ酶解后PCR扩增获得Barnase(核酸酶BN)基因和Staphylococcal Nuclease(核酸酶SN)基因,并克隆到质粒pGEMTZ-f(+)上。序列分析表明,核酸酶BN的核苷酸序列与已发表的序列有99.3%的同源性,而与据此推测的氨基酸序列完全一致。核酸酶SN基因的核苷酸序列与已发表     

Antigen-specific Immunotherapy Regulates B Cell Activities in the Intestine

Mature B cells (BCs) express CD23 and B cell receptors. Whether activation of CD23 and B cell receptors has different effects on BC activities is unclear. This study aims to investigate the mechanism by which the specific antigen immunotherapy regulates the activation of BCs in the skewed Th2 responses. Mice were sensitized to ovalbumin. The specific antigen vaccination (SAV) at graded doses was employed to modulate the activities of BCs in which the expression of IL-10, IgE, matrix metalloproteinase-9 (MMP9), CD23, and serum soluble CD23 by BCs was evaluated. The immune regulatory effect of BCs primed by lower or higher SAV doses was observed with an adoptive transfer mouse experiment. SAV activated CD23 to produce IL-10 in BCs at lower doses. The higher doses of SAV increased the expression of MMP9 in BCs that reduced the amounts of CD23 in BCs and increased the serum levels of soluble CD23, which was abrogated by the pretreatment with MMP9 inhibitor. Adoptively transfer with BCs primed by lower doses of SAV inhibited the ongoing antigen-specific Th2 responses whereas the BCs primed by higher doses of SAV exacerbated the ongoing Th2 responses. Exposure to specific antigens at optimal doses can activate BCs to produce IL-10 to suppress the skewed antigen-specific Th2 responses. The antigen doses of SAV higher than the optimal doses may promote the production of soluble CD23 to exacerbate the ongoing immune responses.