Trapping endoplasmic reticulum with amphiphilic AIE-active sensor via specific interaction of ATP-sensitive potassium (KATP)

The current aggregation-induced emission luminogens (AIEgens) sometimes suffer from poor targeting selectivity due to undesirable aggregation in the hydrophilic biosystem with ‘always-on’ fluorescence or unspecific aggregation in the lipophilic organelle with prematurely activated fluorescence. Herein, we report an unprecedented ‘amphiphilic AIEgen’ sensor QM-SO₃-ER based on the AIE building block of quinoline-malononitrile (QM). The introduced hydrophilic sulfonate group can well control the specific solubility in a hydrophilic system with desirable initial ‘fluorescence-off’ state. Moreover, the incorporated p-toluenesulfonamide group plays two roles: enhancing the lipophilic dispersity, and behaving as binding receptor to the adenosine triphosphate (ATP)-sensitive potassium (K_ATP) on the endoplasmic reticulum (ER) membrane to generate the docking assay confinement effect with targetable AIE signal. The amphiphilic AIEgen has for the first time settled down the predicament of unexpected ‘always-on’ fluorescence in the aqueous system and the untargetable aggregation signal in the lipophilic organelle before binding to ER, thus successfully overcoming the bottleneck of AIEgens'' targetability.     

Relationships between endothelial nitric oxide synthase gene polymorphisms and osteoporosis in postmenopausal women

Objective: To investigate the relationships between endothelial nitric oxide synthases (eNOS) G894T and 27 bp-variable number tandem repeat (VNTR) gene polymorphisms and osteoporosis in the postmenopausal women of Chinese Han nationality. Methods: In the present study, 281 postmenopausal women from Xi'an urban area in West China were recruited, and divided into osteoporosis, osteopenia, and normal groups according to the diagnostic criteria of osteoporosis proposed by World Health Organization (WHO). The bone mineral density (BMD) values of lumbar vertebrae and left hips were determined by QDR-2000 dual energy X-ray absorptiometry. Blood samples were tested for plasma biochemical indicators including testosterone, estradiol, calcitonin, osteocalcin, and procollagen type I amino-terminal propeptide by enzyme-linked immunosorbent assay (ELISA), tartrate-resistant acid phosphatase by spectrophotometric method, and the content of nitric oxide by Griess method. Genome DNA was extracted from whole blood, and G894T polymorphism of eNOS gene was analyzed by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and 27 bp-VNTR polymorphism of eNOS gene was genotyped by PCR method. Then the relationships between genotypes and biochemical indicators, genotypes and osteoporosis, and haplotypes and osteoporosis were analyzed. Results: The average BMD values of the femoral neck, ward's triangle and lumbar vertebrae 1～4 (L1～L4) in the subjects with T/T genotype in eNOS G894T locus were significantly higher than those in the subjects with G/T and G/G genotypes (P<0.05). The average BMD of the femoral neck in the subjects with a/a genotype of eNOS 27 bp-VNTR locus was evidently higher than that in the subjects with b/b genotype (P<0.05). The plasma testosterone and osteocalcin concentrations in the subjects of eNOS G894T G/T genotype were evidently higher than those in the subjects of other genotypes (P<0.05); the plasma estradiol concentration in the subjects of eNOS 27 bp-VNTR a/a genotype was obviously higher than that in the subjects of b/b genotype (P<0.01). eNOS G/G homozygous frequencies in osteoporosis women, osteopenia women, and normal women were 85.37%, 76.38%, and 83.87%, respectively (P＞0.05). 0% osteoporosis woman, 0.79% osteopenia women, and 3.23% normal women were eNOS a/a homozygous (P<0.05). The frequencies of eNOS 27 bp-VNTR a allele were 5.33% in the osteoporosis group, 10.24% in the osteopenia group, and 16.13% in the normal group (P<0.05, odds ratio (OR)=0.29, 95% confidence interval (CI)=0.11～0.77), suggesting that a/a genotype and a allele might have protective effects on osteoporosis. The haplotype analysis showed that G-b was 87.7% (214/244) in the osteoporosis group (P<0.05, OR=2AS, 95% CI=1.18～5.18). G-a was 5.3% (13/244) in the osteoporosis group (P<0.05, OR=0.29, 95% CI=0.11～0.77). G-b was a risk factor for osteoporosis, and G-a a protective factor. Conclusion: eNOS G894T G/T genotype influenced the plasma testosterone and osteocalcin concentrations, and T/T genotype influenced BMD. eNOS 27 bp-VNTR a/a genotype increased plasma estradiol concentration to have a protective effect on osteoporosis.     

Osteogenic differentiation of mesenchymal stem cells promoted by overexpression of connective tissue growth factor

Objective: Large segmental bone defect repair remains a clinical and scientific challenge with increasing interest focusing on combining gene transfection with tissue engineering techniques. The aim of this study is to investigate the effect of connective tissue growth factor (CTGF) on the proliferation and osteogenic differentiation of the bone marrow mesenchymal stem cells (MSCs). Methods: A CTGF-expressing plasmid (pCTGF) was constructed and transfected into MSCs. Then expressions of bone morphogenesis-related genes, proliferation rate, alkaline phosphatase activity, and mineralization were examined to evaluate the osteogenic potential of the CTGF gene-modified MSCs. Results: Overexpression of CTGF was confirmed in pCTGF-MSCs. pCTGF transfection significantly enhanced the proliferation rates of pCTGF-MSCs (P<0.05). CTGF induced a 7.5-fold increase in cell migration over control (P<0.05). pCTGF transfection enhanced the expression of bone matrix proteins, such as bone sialo-protein, osteocalcin, and collagen type I in MSCs. The levels of alkaline phosphatase (ALP) activities of pCTGF-MSCs at the 1st and 2nd weeks were 4.0- and 3.0-fold higher than those of MSCs cultured in OS-medium, significantly higher than those of mock-MSCs and normal control MSCs (P<0.05). Overexpression of CTGF in MSCs enhanced the capability to form mineralized nodules. Conclusion: Overexpression of CTGF could improve the osteogenic differentiation ability of MSCs, and the CTGF gene-modified MSCs are potential as novel cell resources of bone tissue engineering.     

线性遗传程序设计比较分析

遗传程序设计是近几年各专家学者研究的热点之一。主要论述了6种线性遗传程序设计的原理,比较分析了各线性遗传程序设计的共同点和差异性,简单介绍了各遗传程序设计的应用领域,总结了针对不同的问题采用相应的遗传程序设计的方法。     

基因重组对企业发展的影响

随着市场经济的发展,企业的目标已不仅仅是获得满意的利润,还在追求企业的长寿、持续发展。而市场环境的不确定性及高度复杂性等特点又加大了企业持续发展的困难,本文针对这样一种状况,将企业看作生命体,借鉴了生物基因重组的思想,从企业基因重组理论的视角,探讨了企业基因重组对企业发展的影响,并认为企业可以通过基因重组产生企业的差异性和多样性,进而形成了企业难以复制的竞争优势,达到企业的持续发展的目的。     

亲密因子对科研合作网的影响

参照人际关系网络中的亲密因子构造一个科研合作网络演化模型,分别从网络的度分布、点强度分布、平均路径长度以及聚集系数对亲密因子进行分析,发现演化后的科研合作网具有较短的平均路径长度和较大的聚集系数。最后对一个科研合作的实证网络和仿真网络进行比较,发现两者社团结构具有相同的特征。     

新一轮退耕还林工程多元目标瞄准研究——基于农户决策自主权视角

退耕还林工程进入政策调整的新阶段,新一轮退耕还林工程能否瞄准多元政策目标是这一时期的关键问题。本文基于一手调查的农户及地块数据,考察新一轮退耕还林工程对生态效益、成本有效性、益贫性等多元目标的瞄准成效,并进一步探究农户决策自主权在退耕瞄准过程中的作用。结果表明,新一轮退耕还林工程基本能够瞄准生态效益较高、成本较低的地块,但并未瞄准贫困户的地块,尤其是在农户没有瞄准自主权的情况下,家庭经济贫困对参与新一轮退耕还林有显著负向影响。农户决策自主权对新一轮退耕还林工程瞄准多元目标有积极作用,由农户自主瞄准的地块更具成本有效性和益贫性。因此,为提升退耕还林工程的瞄准效率,实现成本有效性、益贫性等多元目标及成果的可持续性,应在政策实施过程中赋予农户更多决策自主权;改进新一轮退耕还林工程的瞄准方案与指标体系;完善退耕补偿方案,建立动态的、差异化的生态补偿机制等。     

用于输送siRNA的聚乙烯亚胺-聚乙二醇二丙烯酸酯纳米凝胶

阐述了一种新的用于输送小干扰核糖核酸(siRNA)的聚乙烯亚胺-聚乙二醇二丙烯酸酯纳米凝胶的合成及其表征.在反相微乳液体系中,聚乙烯亚胺(PEI)和聚乙二醇二丙烯酸酯(PEG-DA)通过麦克尔加成交联得到纳米凝胶.1H-NMR和FTIR的结果充分证明纳米凝胶的化学结构,而动态光散射则表明纳米凝胶的颗粒粒径均匀,约为180 nm,zeta电位为37.9 mV.同时,MTT结果表明纳米凝胶在高达1 mg/mL的浓度下对MCF-7细胞也基本没有毒性.凝胶阻滞实验证明纳米凝胶在体外可以通过静电相互作用稳定结合siRNA.转染实验结果表明纳米凝胶与GFP siRNA的复合物能降低MCF-7 KMRV细胞(一种能稳定表达GFP蛋白的MCF-7细胞系)GFP蛋白的表达.以上结果证明这种生物相容性的纳米凝胶可以结合并输送siRNA进入细胞,沉默相关基因的表达.     

Magnaporthe oryzae MTP1 gene encodes a type III transmembrane protein involved in conidiation and conidial germination

In this study the MTP1 gene, encoding a type III integral transmembrane protein, was isolated from the rice blast fungus Magnaporthe oryzae. The Mtp1 protein is 520 amino acids long and is comparable to the Ytp1 protein of Saccharomyces cerevisiae with 46% sequence similarity. Prediction programs and MTP1-GFP (green fluorescent protein) fusion expression results indicate that Mtp1 is a protein located at several membranes in the cytoplasm. The functions of the MTP1 gene in the growth and development of the fungus were studied using an MTP1 gene knockout mutant. The MTP1 gene was primarily expressed at the hyphal and conidial stages and is necessary for conidiation and conidial germination, but is not required for pathogenicity. The Deltamtp1 mutant grew more efficiently than the wild type strain on non-fermentable carbon sources, implying that the MTP1 gene has a unique role in respiratory growth and carbon source use.