全氟辛酸对小鼠卵母细胞的毒性影响

【目的】研究全氟辛酸(Perfuorooctanoic aid,PFOA)对小鼠卵母细胞的毒性影响。【方法】选用6周龄体质量相近的昆明雌性小鼠160只,分为4组,每组5个重复,每个重复8只小鼠。在适应环境7 d后开始对小鼠灌服不同剂量的PFOA,其中,对照组、低剂量组、中剂量组和高剂量组的每日剂量分别为0、 5、 10和20 mg/kg,连续灌服14 d,然后利用孕马血清促性腺激素(Pregnant mare serum gonadotropin,PMSG)和人绒毛促性腺激素(Human chorionic gonadotropin,hCG)对各组小鼠进行超数排卵,获取卵母细胞进行检测。【结果】与对照组相比,PFOA中、高剂量组小鼠的卵母细胞成熟率分别下降了14.28%、28.17%;卵母细胞内活性氧含量分别升高了135%、177%;而且卵母细胞β-tubulin形态异常,染色体非整齐排列的比例分别升高了65.06%、75.60%。此外,低、中、高剂量组PFOA处理后小鼠的卵母细胞内磷酸化组蛋白H2AX(Phospho-histone H2A.X,P-H2A.X)比例分别比对照组升高了...     

Development of cell model of polymer/liquid crystal and effect of their elasticity on adhesion of rBM-MSCs

AIM: To develop the cell model of polymer/liquid crystal and to study the effect of their elasticity on the adhesion of rat bone marrow mesenchymal stem cells (rBM-MSCs). METHODS: Using the method of solvent evaporation induced phase separation, the cell model of polymer/liquid crystal was constructed. The surface morphology and phase separation structure were determined by polarized optical microscopy (POM), scanning electron microscopy (SEM) and small angle X-ray scattering (SAXS). rBM-MSCs were separated and expanded by adherent culture. The surface markers of rBM-MSCs were detected by flow cytometry. The cells were induced to osteogenic differentiation and adipogenic differentiation for 2 weeks. After 3 passages, the cells were divided into 4 groups, including total PU control group, 10% membrane group, 30% membrane group and 50% membrane group. The cells were then incubated with rhodamine phalloidin for cytoskeleton staining and were observed under the confocal laser scanning microscope after cultured for 24 h. RESULTS: The cell model of polymer/liquid crystal was constructed successfully using the method of solvent evaporation induced phase separation. Flow cytometry results showed that the rBM-MSCs positively expressed CD29, CD44 and CD90, and negatively expressed CD34 and CD45. After stained with alizarin red S and oil red O, the calcium nodule and lipid droplets in rBM-MSCs were observed obviously. The cytoskeleton staining result indicated that the area in total PU control group, 10% membrane group and 30% membrane group were greater, and the actin microfilaments were also clearer than that in 50% membrane group. CONCLUSION: The cell model with suitable content of liquid crystal made a contribution to the rBM-MSCs' adhesion, but too much liquid crystal inhibits cell adhesion.     

过表达沙门氏菌效应蛋白SopB对HeLa细胞骨架的影响

[目的]研究沙门氏菌感染宿州细胞过程中,沙门氏菌Ⅲ型分泌系统的效应蛋白SopB对宿主细胞细胞骨架的影响,同时寻找SopB蛋白调控细胞骨架变化的相关结构域。[方法]利用基因克隆的方法分别构建含鼠伤寒沙门氏菌LT2效应蛋白SopB的全长基因、SopBN末端基因片段及SopB肌醇磷脂酶活性中心氨基酸C460突变体的重组质粒,使其均在HeLa细胞中过量表达,对表达结果进行检测。[结果]SopB重组质粒在HeLa细胞中均能正常表达,其中SopB蛋白的过表达能显著改变HeLa细胞的细胞骨架,使细胞由正常的细胞形态转变为圆形。[结论]通过比较SopB各基因片段对细胞形态的影响,发现SopB过表达在改变HeLa细胞骨架方面与其N末端第46～112位氨基酸残基间的肽断直接相关,而与其肌醇磷脂酶活性关系不大。     

Alphaherpesvirus use and misuse of cellular actin and cholesterol

Two major structural elements of a cell are the cytoskeleton and the lipid membranes. Actin and cholesterol are key components of the cytoskeleton and membranes, respectively, and are involved in a plethora of different cellular processes. This review summarizes and discusses the interaction of alphaherpesviruses with actin and cholesterol during different stages of the replication cycle: virus entry, replication and assembly in the nucleus, and virus egress. Elucidating these interactions not only yields novel insights into the biology of these important pathogens, but may also shed new light on cell biological aspects of actin and cholesterol, and lead to novel avenues in the design of antiviral strategies.     

Effects of p21-activated kinase 6 on invasion and migration of human non-small-cell lung cancer A549 cells

AIM：To investigate the effects of p21-activated kinase 6 (PAK6) on the invasive and migratory abilities of human non-small-cell lung cancer A549 cells. METHODS：The expression of PAK6 mRNA in A549 cells, human bronchial epithelial (HBE) cells, non-small-cell lung cancer tissues and paired adjacent non-tumor tissues was measured by real-time PCR. After A549 cells were transfected with siRNA-PAK6 (siPAK6) or negative control (NC) for 48 h, the expression of PAK6 at mRNA and protein levels was measured by real-time PCR and Western blotting, respectively. The invasion and migration of A549 cells were detected by Matrigel invasion assay and Transwell migration assay. The cytoskeletal changes were observed with FITC-phalloidin staining under confocal microscope. RESULTS：The level of PAK6 mRNA in A549 cells was higher than that in HBE cells (3.50±1.16 vs 1.12±0.42, P<0.05). The level of PAK6 mRNA in non-small-cell lung cancer tissues was higher than that in paired adjacent non-tumor tissues (5.13±1.33 vs 1.08±0.37, P<0.05). The expression of PAK6 protein decreased by 72% in A549 cells transfected with siPAK6 (P<0.05), and the level of PAK6 mRNA significantly decreased in A549 cells transfected with siPAK6 (3.72±0.75 vs 0.69±0.21, P<0.05). Matrigel invasion assay and Transwell migration assay demonstrated that knockdown of PAK6 markedly attenuated the invasion and migration of A549 cells (P<0.05). The cytoskeletal actin remodeling and reduction of stress fibers in A549 cells transfected with siPAK6 were observed under confocal microscope. CONCLUSION：PAK6 may affect the invasive and migratory abilities of non-small-cell lung cancer cells by cytoskeletal actin remodeling.     

The sensation and transduction of mechanical stimulus in cells

Mechanical stresses modulate almost all aspects of cell function, including growth, differentiation, migration, gene expression, protein synthesis and apoptosis. Thus, uncovering the mechanisms by which living cells sense and transduce mechanical stress lies at the core of understanding how they respond and adapt to their physical environments. In this review, the possible mechanism about cell response to mechanical stimulus was discussed from outer cell membrane to inner nucleus.     

Cytoskeletal changes in <Emphasis Type="Italic">Eimeria bovis</Emphasis>-infected host endothelial cells during first merogony

The first merogony of Eimeria bovis takes place in lymphatic endothelial cells of the ileum, resulting in the formation of macromeronts up to 250 mum. In this study, we investigated the host cell cytoskeleton (actin filaments, microtubules, spectrin, vimentin intermediate filaments) associated with parasitic development in vitro by confocal laser scanning microscopy (CLSM) using primary bovine umbilical vein endothelial cells (BUVEC) and bovine spleen lymphatic endothelial cells (BSLEC) as host cells. No prominent changes in the host cell cytoskeleton were detected 1-3 days after E. bovis sporozoite invasion. With ongoing meront maturation a significant increase in microtubules and actin filaments close to the parasitophorous vacuole (PV) was found. Mature macromeronts within the PV were completely enclosed by these cytoskeletal elements. Our findings suggest, that in order to guarantee the survival of the host cell on the enlargement of macromeronts, E. bovis needs not only to augment but also to rearrange its cytoskeletal system.     

卵丘细胞和细胞骨架稳定剂对绵羊成熟卵母细胞玻璃化冷冻的影响

[目的]为了提高绵羊成熟卵母细胞玻璃化冷冻的效果。[方法]以未冷冻的卵母细胞为对照,研究卵丘细胞存在与否以及不同浓度的细胞骨架稳定剂对绵羊成熟卵母细胞冷冻保存的影响。[结果]卵丘细胞存在与否对绵羊成熟卵母细胞玻璃化冷冻没有影响。在所有细胞松弛素B处理组中,用7.5、10.0μg/ml细胞松弛素B处理的绵羊成熟卵母细胞玻璃化冷冻后获得较高的囊胚率(P<0.05),分别为8.1%、7.8%;在所有紫杉醇处理组中,用0.5μmol/L紫杉醇处理的绵羊成熟卵母细胞玻璃化冷冻后获得的囊胚率最高为10.1%(P<0.05)。[结论]细胞骨架稳定剂细胞松弛素B或紫杉醇可以提高绵羊成熟卵母细胞的玻璃化冷冻效果。     

细胞骨架的显微镜观察实验方法改进研究

显微观察细胞骨架是细胞生物学教学的重要内容之一,为了达到有效的实验观察效果,采取对比法比较观察效果,确定了材料的前处理、1%Triton X-100处理细胞膜蛋白30 min、考马斯亮蓝R250染色30 min、甲醇-冰醋酸和戊二醛固定剂选用和二甲苯透明剂的使用作为改进内容。结果表明,改进后使得细胞骨架的观察效果和实验重复性提高,经过一轮学生课程实验操作应用,该方法已达到基本稳定。     

植物耐低温的分子机理

冷害是世界范围内普遍存在的问题.从膜伤害、酶系统和细胞骨架破坏等方面概述植物低温下受害的生理表现,从细胞骨架、质膜、抗氧化酶等方面分析了植物耐低温遗传的分子机理,并对植物低温遗传研究的未来进行了展望.