Molecular signature and colony morphology affect in vitro pluripotency of porcine induced pluripotent stem cells

Overall efficiency of cell reprogramming for porcine fibroblasts into induced pluripotent stem cells (iPSCs) is currently poor, and few cell lines have been established. This study examined gene expression during early phase of cellular reprogramming in the relationship to the iPSC colony morphology and in vitro pluripotent characteristics. Fibroblasts were reprogrammed with OCT4, SOX2, KLF4 and c-MYC. Two different colony morphologies referred to either compact (n = 10) or loose (n = 10) colonies were further examined for proliferative activity, gene expression and in vitro pluripotency. A total of 1,697 iPSC-like colonies (2.34%) were observed after gene transduction. The compact colonies contained with tightly packed cells with a distinct-clear border between the colony and feeder cells, while loose colonies demonstrated irregular colony boundary. For quantitative expression of genes responsible for early phase cell reprogramming, the Dppa2 and EpCAM were significantly upregulated while NR0B1 was downregulated in compact colonies compared with loose phenotype (p < .05). Higher proportion of compact iPSC phenotype (5 of 10, 50%) could be maintained in undifferentiated state for more than 50 passages compared unfavourably with loose morphology (3 of 10, 30%). All iPS cell lines obtained from these two types of colony morphologies expressed pluripotent genes and proteins (OCT4, NANOG and E-cadherin). In addition, they could aggregate and form three-dimensional structure of embryoid bodies. However, only compact iPSC colonies differentiated into three germ layers. Molecular signature of early phase of cell reprogramming coupled with primary colony morphology reflected the in vitro pluripotency of porcine iPSCs. These findings can be simply applied for pre-screening selection of the porcine iPSC cell line.     

白藜芦醇对脂多糖诱导草鱼肾脏细胞炎症的抑制作用

为评价白藜芦醇(resveratrol)对脂多糖诱导损伤草鱼(Ctenopharyngodon idella)肾脏细胞(CIK)的保护作用,本研究通过脂多糖(LPS)诱导细胞炎症损伤,测定和分析白藜芦醇对CIK细胞抗氧化因子活性和抗氧化、炎症相关基因表达变化的影响。结果表明,与对照组相比,LPS处理导致CIK细胞活力降低(P<0.05),乳酸脱氢酶(LDH)活性升高(P<0.05),降低了细胞内过氧化氢酶(CAT)和超氧化物歧化酶(SOD)的活性,并导致还原型谷胱甘肽(GSH)浓度降低(P<0.05)和丙二醛(MDA)含量升高(P<0.05)。此外,LPS处理能引起CIK细胞的CAT、TNF-α、IFN-γ、IL-1基因表达显著上调(P<0.05),而对IL-10和SOD基因的转录表达无显著影响(P>0.05)。通过向培养基中添加白藜芦醇(4μg/mL)可以显著减弱LPS对CIK细胞造成的损伤,维系细胞抗氧化能力,抑制TNF-α等炎症相关基因的表达(P<0.05),促进CAT基因的表达(P<0.05)。研究认为白藜芦醇对LPS造成的CIK细胞损伤有明显的干预作用,主要原因可能是由于白藜芦醇对CIK细胞的抗氧化能力的改善以及对促炎因子表达的抑制。本研究可为白藜芦醇应用于鱼类炎症、氧化损伤相关疾病的防治提供理论依据。     

二甲双胍对牛骨骼肌卫星细胞增殖与分化的影响

为探究二甲双胍对牛骨骼肌卫星细胞增殖和分化的影响，本研究将体外培养的牛骨骼肌卫星细胞分别用0（对照组）、1、2、4 mmol/L二甲双胍进行处理，采用CCK-8法筛选出二甲双胍作用于牛骨骼肌卫星细胞的最适浓度，接着通过EdU染色法检测二甲双胍处理牛骨骼肌卫星细胞后对其增殖的影响，然后对二甲双胍处理的牛骨骼肌卫星细胞进行体外成肌诱导分化，通过显微镜观察牛骨骼肌卫星细胞分化时期的细胞状态，然后利用Western blotting技术检测牛骨骼肌卫星细胞的分化标志因子肌球蛋白重链（MyHC）、肌细胞生成素（MyoG）在分化24、48和72 h的表达情况。结果表明，二甲双胍作用于牛骨骼肌卫星细胞的最适浓度为2 mmol/L。2 mmol/L二甲双胍处理牛骨骼肌卫星细胞后，其细胞增殖率显著降低（P<0.05），说明二甲双胍可以抑制牛骨骼肌卫星细胞的增殖；牛骨骼肌卫星细胞诱导分化后形成的肌管数量和直径均呈现减少趋势，牛骨骼肌卫星细胞成肌分化标志因子MyHC、MyoG在分化24、48和72 h的表达均显著低于0 mmol/L （对照）组（P<0.05），说明2 mmol/L二甲双胍能够抑制牛骨骼肌卫星细胞的成肌分化过程。研究结果表明，二甲双胍可以显著抑制牛骨骼肌卫星细胞的增殖及成肌分化过程。该研究为二甲双胍在肌肉发育调控及肌损伤修复方面的应用提供一定的理论依据。     

类猪圆环病毒 P1诱导 PK15细胞自噬的研究

旨在探讨类猪圆环病毒P1感染对PK15细胞自噬的影响。将同一批PK15细胞分成对照组和感染组，感染组在类猪圆环病毒P1感染PK15细胞后14，24，48 h分别收集细胞，对照组也在同样时间收获，用透射电镜观察自噬现象的发生。结果表明，与对照组相比，感染组PK15细胞内出现典型自噬形态学变化。揭示类猪圆环病毒P1能诱导PK15细胞发生自噬，但细胞发生自噬的相关信号传导通路还有待进一步研究。     

禽脑脊髓炎免疫细胞类别和数量变化的分析

本研究用ＡＥＶ－ＮＨ９３７株分别给１日龄雏鸡口服感染和脑内接种，并在感染后的不同阶段采血、剖检，进行琼扩试验和病理组织学观察（Ｈ．Ｅ．染色、胶质细胞染色、ＲＮＡ显色、ＡＮＡＥ显色），结果表明：ＡＥＶ经不同途径感染均引起了典型的非化脓性脑脊髓炎，血清琼扩反应阳性，各免疫器官和中枢神经小血管周围均见ＲＮＡ阳性细胞（主要是前浆细胞和浆细胞）明显增多。感染后机体出现了活跃而持续的体液免疫应答；同时也见ＡＮＡＥ阳性细胞（主要是巨噬细胞）增多。     

水貂病毒性肠炎弱毒疫苗株的选育及实验免疫研究

从自然发病死亡貂体内分离到１株水貂病毒性肠炎（ＭＶＦ）强毒株－ＭＥＶ，将该株病毒在犊牛睾丸（ＣＴ）细胞和猫肾传代细胞（ＣＲＦＫ）上混合培养进行适应。当传至５６代时，在ＣＴ细胞上出现细胞病变（ＣＰＥ），而后单独在ＣＴ细胞上传至７０代，经终点稀释克隆和鉴定获得一弱毒株。以其制备的ＣＴ细胞弱毒疫苗，给每只貂注射或口服１～５ｍＬ均未见任何不良反应。注苗后１２、６０、７２、１８０ｄ攻毒，保护率均为１００％。     

体外培养牛腔前卵泡颗粒细胞的超微结构研究

透射电镜下，简易机械法分离得到的腔前卵泡有1～3层颗粒细胞，相邻颗粒细胞间存在明显而广泛的间隙连接，卵泡基膜完整，外无卵泡膜。培养过程中超微结构的变化与体内发育腔前卵泡类似。培养6d时观察到颗粒细胞增殖现象，培养15d时，个别卵泡的内膜细胞开始形成。超微结构研究结果表明，本培养体系适于小腔前卵泡的体外培养。     

应用聚合酶链反应检测山羊关节炎—脑炎病毒

应用聚合酶链反应（ＰＣＲ）检测了山羊关节炎－脑炎病毒（ＣＡＥＶ）人工感染山羊后其前病毒的动态学变化，从而阐明了ＣＡＥＶ与实验动物外周血单核细胞整合机制问题。     

Development of High-speed Rectangle Burner Used in Baked Aluminum Reduction Cells

Bake out of Aluminum reduction cells will affect the normal production and the ultimate life of reduction cell directly. The method of thermal bake out is a key of novel technology which possesses such advantages as well distributed temperature, easy control for the speed of heating up, fully baking for the joint and ramming paste of the edge. The design of the burner is a key technology of thermal bake out. A new high speed rectangle burner has been developed based on the experiment, and the structure of this burner has also been optimized. The new burner an fire easily, burn stably and fully, and has high ratio of load adjustment, and low noise, etc.. It can meet the needs of thermal bake out reduction cells. Its development can provide the technological guarantee for the use of thermal bake out Aluminum reduction cells.     

Bactericidal activity of cecropin B and cecropin P1 expressed in fish cells (CHSE-214): application in controlling fish bacterial pathogens

Cecropins are a group of antimicrobial peptides which have bactericidal activity against a broad range of bacteria. To date, the cecropins used in a variety of studies were either purified from their natural source or obtained by chemical synthesis. The present study was conducted to test whether bactericidally active cecropins could be expressed in a fish cell line. For this purpose, Chinook salmon embryo cells (CHSE-214) were transfected with cecropin transgene constructs: Hyalophora cecropia preprocecropin B, procecropin B, cecropin B, and porcine P₁ cecropin. From the transfected cells, single cell clones were selected and screened for the presence of cecropin gene constructs by PCR amplification. The expression of the cecropin transgene in the PCR positive clones was determined by RT-PCR reaction. Southern blot hybridization results showed that the cecropin gene constructs were integrated into the genome in a multiple integration pattern. Bactericidal activity of the cecropins, synthesized from transgene constructs, was detected using inhibition zone assay for fish pathogenic bacteria: Aeromonas hydrophila, Pseudomonas fluorescens, and Vibrio anguillarum. Cecropin antimicrobial peptides produced in CHSE-214 cells possess bactericidal activity against these three fish pathogenic bacteria.