Research Progress and Countermeasures of Porcine Endogenous Retrovirus in Chinese Miniature

The paper is a brief introduction of porcine endogenous retrovirus (PERV) innovative research results in the world and also expounds the passing PERV existence situation on different varieties of miniature pig, analyzes the PERV-virus gene cloning and sequence, appraises method on cell level, create the platform of infection HEK293 cells research, study on pigs A3F inhibition of PERV, and reveal the innovative research results on the specific molecular genetics in the different strain of PERV, analyzes the advantages of Wuzhishan miniature pig inbred line such as low gene copy of PERV,and there is no passing PERV-C specificity and as well as looking forward to cultivate the methods for new strain of PERV negative pigs. It will provide a scientific counter measure and new perspective to solve the spread of disease risk of miniature pig PERV and product safety for human xenotransplantation and biomedical materials of research and development.     

豚鼠至大鼠原位肝移植肝下下腔静脉套管方法的改进

目的探讨豚鼠至大鼠异种原位肝移植中肝下下腔静脉套管的改进方法。方法豚鼠和SD大鼠各40只分别作为供、受体,随机分为实验组和对照组并随机配对。实验组采用改进的肝下下静脉套管方法进行肝下下腔静脉袖套管的安装及吻合,对照组采用常规方法进行肝下下腔静脉袖套管的安装及吻合。比较两组肝下下腔静脉袖套管安装时间、安装成功率、吻合时间、吻合成功率和手术成功率。结果实验组较对照组肝下下腔静脉袖套管安装时间、吻合时间和无肝期明显缩短,袖套安装成功率、吻合成功率和手术成功率明显提高,差异有统计学意义(P<0.05)。结论应用改进的肝下下腔静脉套管方法进行豚鼠至大鼠原位肝移植,手术成功率高,可用于豚鼠至大鼠原位肝移植实验研究模型。     

人血栓调节蛋白基因的表达及转基因小鼠的建立

用PCR方法从人的基因组DNA中扩增了人血栓调节蛋白（hTM)基因，将其克隆到带有人EF－1α启动子的pEF-neo哺乳动物表达载体上，得到表达质粒pEF-TM。在转染pEF-TM的COS－1细胞中，hTM得到了瞬时表达，并且正确地定位到细胞膜上。用pEF-TM转染猪内皮细胞（PEC），经G418筛先得到稳定转染的克隆。凝血活性测定结果显示，表达hTM的PEC凝血时间明显延长，表明其抗凝血能力增强。通过显微注射方法，得到了1只F0代hTM转基因小鼠。Southern杂交结果表明，该转基因小鼠整合了9个拷贝的pEF-TM DNA,并能将外源DNA遗传给后代。     

牛羊水间充质干细胞对小鼠酒精性肝病的影响

试验旨在分离培养牛羊水间充质干细胞（AF-MSCs），并研究其对酒精性肝病（ALD）小鼠治疗效果以及对肝组织中缺氧诱导因子-1α（HIF-1α）、血管内皮生长因子（VEGF）及Toll样受体4（TLR4）mRNA表达的影响。从4~5月龄雌性胎牛羊水中获取AF-MSCs，进行RT-PCR、免疫荧光及诱导成脂鉴定。将48只ICR小鼠（雄性）随机分为4组：空白对照组（BC组）、模型对照组（MC组）、AF-MSCs组（MC+AF-MSCs组）和水飞蓟宾胶囊（SC）组（MC+SC组），每组12只。除BC组灌胃0.2 mL生理盐水，其余各组均灌胃56度红星二锅头（5 g· kg ^-1，2次· d ^-1），连续4周；第29天MC+AF-MSCs组进行肝外注射Dil标记的AF-MSCs（5×10⁶个·mL ^-1），MC+SC组分2次灌胃SC 2.4 mg（溶于56度红星二锅头）；试验结束后，测定小鼠血清谷丙转氨酶（ALT）、谷草转氨酶（AST）和甘油三酯（TG）活性。HE染色、免疫组化法观察造模情况，Dil示踪AF-MSCs在肝内定植分布；qRT-PCR法检测HIF-1α、VEGF及TLR4基因表达情况。RT-PCR、免疫荧光结果表明，分离得到牛AF-MSCs，且有诱导成脂分化能力。血清学结果显示，MC组ALT、AST和TG活性极显著高于BC组（P<0.01）。组织病理切片显示，MC组肝组织中出现脂肪性变、炎性细胞浸润及肝血窦充血等病理性变化，说明56度红星二锅头成功复制ALD小鼠模型；与MC+SC组相比，MC+AF-MSCs组ALT、AST活性显著降低（P<0.01），肝组织中脂肪性变减轻，肝血窦未见充血，说明AF-MSCs对肝功能的改善比SC效果显著；qRT-PCR结果显示，MC+AF-MSCs组下调HIF-1α、VEGF、TLR4基因的表达量较MC+SC组显著（P<0.01），说明AF-MSCs参与HIF-1α/VEGF信号通路的调控，抑制TLR4表达的效果优于SC；细胞示踪术证明，AF-MSCs定植在病变部位并趋化更多AF-MSCs向炎症部位迁移参与肝组织的修复。综上，本研究成功分离得到牛AF-MSCs，其能够参与调节氧化应激、血管生成及抑制炎性因子的释放，且改善ALD的效果优于SC。     

卵巢异种移植在生殖生物学和动物保存中的研究进展

随着关于卵巢组织较有效的冷冻保存方法的发展,生殖系的保存和繁殖已变成了现实的目标。本文就卵巢冷冻保存和卵巢移植上的发展进步,异种移植在保存稀有和濒危物种及一些女性卵巢功能上的潜在价值,以及即将出现的异种移植技术进行综述。     

Histological differences in full-thickness vs. lamellar corneal pig-to-rabbit xenotransplantation

To evaluate the differences in graft survival and histopathological characteristics between full-thickness and lamellar orthotopic corneal xenotransplantation in a pig-to-rabbit model, we orthotopically transplanted a full-thickness or the anterior half of a pig's cornea onto the OD of 16 rabbits. As a result, the median survival were 16.83 and 29.07 days for the full-thickness and lamellar xenografts, respectively ( P  = 0.0005). Histologically, the full-thickness corneal xenografts had massive infiltration by eosinophils, whereas the lamellar xenografts showed predominantly mononuclear infiltrates ( P  < 0.05). Given these preliminary findings, lamellar corneal xenografts in rabbits survived longer than the full-thickness xenografts and each type of graft demonstrated different rejection mechanisms.     

广西巴马小型猪SLA-DQB 基因 的克隆及序列分析

利用RT-PCR 的方法从广西巴马小型猪肝脏组织中扩增SLA-DQB 基因的编码区序列,旨在为下一步构 建SLA-DQB 转基因广西巴马小型猪奠定基础。结果表明,克隆的广西巴马小型猪SLA-DQB 基因编码区长687 bp,与 GenBank 参考序列（NM_001113694）相比,共有15 个氨基酸发生突变（位点为10、14、19、27、29、38、39、48、58、61、68、 72、76、78、183）。与普通猪、其他小型猪、奶牛、人类及小鼠的同源性分别为95.8%、95.8%、88.1%、86.2%和80.0%。     

Porcine endogenous retrovirus copy number in different pig breeds is not related to genetic diversity

The risk of zoonoses is a major obstacle to xenotransplantation. Porcine endogenous retrovirus (PERV) poses a potential risk of zoonotic infection, and its control is a prerequisite for the development of clinical xenotransplantation. The copy number of PERV varies among different breeds, and it has been suggested that the PERV integrations number is increased by inbreeding. The purpose of this study was (i) to examine the copy number of PERV in different Spanish pig breeds, Spanish wild boar and commercial cross-bred pigs from five different farms and genetic background (CCP1-CCP5) and (ii) to investigate the correlation between PERV copy number and the genetic background of the pigs in order to improve the selection of pigs for xenotransplantation. PERV copy number was determined by quantitative, real-time polymerase chain reactions. Thirty-four microsatellite markers were genotyped to describe the genetic diversity within populations (observed and expected heterozygosities, Ho and He, respectively) and the inbreeding coefficient (F). Pearson's correlation coefficient was used to determine the relationship between PERV copy number and Ho, He and F. The copy number of PERV among different pig breeds was estimated to range between three (CCP1) and 43 copies (Iberian Pig). Statistical differences were found among the studied populations concerning PERV copy number. No correlation was found between the PERV copy number and the heterozygosity (calculated at an individual level or at a population level) or the inbreeding coefficient of each population. Our data suggest that pigs inbreeding does not increase PERV copy number and support the idea that careful selection of pigs for organ donation with reduced PERV copy number will minimize the risk of retrovirus transmission to the human receptor.     

Multidetector computed tomographic angiography evaluation of micropig major systemic vessels for xenotransplantation

Due primarily to the increasing shortage of allogeneic donor organs, xenotransplantation has become the focus of a growing field of research. Currently, micropigs are the most suitable donor animal for humans. However, no standard method has been developed to evaluate the systemic vascular anatomy of micropigs and standard reference values to aid in the selection of normal healthy animals as potential organ donors are lacking. Using 64-channel multidetector row computed tomographic angiography (MDCTA), we evaluated morphological features of the major systemic vessels in micropigs and compared our results to published human data. The main vasculature of the animals was similar to that of humans, except for the iliac arterial system. However, diameters of the major systemic vessels were significantly different between micropigs and humans. Specifically, the diameter of the aortic arch, abdominal aorta, external iliac artery, and femoral artery, were measured as 1.50 ± 0.07 cm, 0.85 ± 0.06 cm, 0.52 ± 0.05 cm, and 0.48 ± 0.05 cm, respectively, in the micropigs. This MDCTA data for micropig major systemic vessels can be used as standard reference values for xenotransplantation studies. The use of 64-channel MDCTA enables accurate evaluation of the major systemic vasculature in micropigs.     

上海梅山猪封闭群内源性逆转录病毒的检测及亚型分析

为检测分析上海梅山猪携带猪内源性逆转录病毒(porcine endogenous retrovirus,PERV)的情况,为该猪种作为器官移植供体的生物安全性提供现实依据,笔者从上海嘉定区梅山猪育种中心的梅山猪封闭群内随机采集45头猪的耳组织,并构建耳成纤维细胞系,利用PCR检测PERV前病毒核心蛋白基因(gag)、多聚酶基因(pol)以及囊膜基因(env)的基因组DNA,利用RT-PCR的方法检测m RNA表达状况。结果发现被检测的45份样品均携带完整的3种亚型的PERV前病毒DNA;RT-PCR结果显示,45份样品中有40份同时有PERV-A和PERV-B两种亚型的表达,还有5份样品仅检测到PERV-B亚型的表达,未检测到PERV-C亚型的表达。鉴于生物安全性方面的考虑,该猪种能否作为人异种移植的供体仍有待进一步商榷。