腺病毒介导的人巨细胞病毒UL49基因小鼠模型的建立

建立表达HCMV UL49 基因的转基因小鼠,为抗病毒药物研究提供有效的实验动物模型。本实验将UL49-GFP基因插入腺病毒穿梭质粒pDC316中,构建重组质粒pDC316-UL49-GFP,与腺病毒骨架质粒pBHGloxΔE1,3Cre 通过脂质体介导共转染293 细胞,重组产生腺病毒Ad-UL49-GFP, 经PCR和Western Blot鉴定正确后,大量扩增、纯化,制备高滴度重组腺病毒。纯化腺病毒经尾静脉注射感染小鼠,通过荧光定量PCR 和Western blot 方法,检测UL49 基因在小鼠体内组织分布和表达时相。结果显示UL49基因在小鼠的心、肝、脾、肺、肾组织均有表达,并且表达量由高到低顺序依次是：肝、脾、肾、心、肺,在腺病毒感染第3天在各靶器官表达水平较高,此后逐渐下降,第14天时仅存在肝和脾中。表明表达UL49基因的小鼠模型构建成功。小鼠模型的成功建立为下一步筛选以UL49基因为靶的抗病毒药物奠定了基础。     

蛋白亚硝基化研究进展及其在植物抗病中的作用

蛋白亚硝基化（S-nitrosylation）是一种在一氧化氮作用下与蛋白半胱氨酸巯基共价结合,使巯基-SH转化为-SNO的反应。作为一种氧化还原依赖的翻译后调控形式,蛋白亚硝基化对多种蛋白的功能具有调节作用,越来越多的证据表明蛋白亚硝基化在植物抗病中发挥重要的作用。简要介绍了蛋白巯基亚硝基化的特点、检测方法、功能研究以及在植物抗病调节方面的最新进展。     

黑眶蟾蜍皮肤抗菌肽的制备及其性质

收集黑眶蟾蜍皮肤分泌物,经Sephadex G-25去除大分子蛋白后,利用微量测定法进行抗菌活性分析。结果发现:黑眶蟾蜍皮肤分泌物对革兰氏阳性菌——金黄色葡萄球菌、枯草芽孢杆菌的抑制作用较强,对革兰氏阴性菌中的嗜水气单细胞菌也表现出较强的抑制作用,对溶藻弧菌、副溶血弧菌、河流弧菌、大肠杆菌的抑制相对较弱。利用胰蛋白酶对黑眶蟾蜍皮肤抗菌肽水解后,其抗菌活性消失。将黑眶蟾蜍皮肤抗菌肽在37~95℃和pH 2.5~5.0下保温,发现其抗菌活性成分对热及酸耐受性较强。黑眶蟾蜍皮肤分泌物在低浓度无溶血活性。     

Beneficial effects of C-peptide on renal morphology in diabetic rats

The study was undertaken to examine the effects of C-peptide on glomerular volume (V(GLOM)), mesangial matrix synthesis, and degradation in streptozotocin (STZ)-diabetic rats with poor or moderate glycemic control. Series 1 (poor glycemic control) included groups of healthy rats, hyperglycemic rats, diabetic insulin-treated rats and diabetic C-peptide-treated rats. Series 2 (moderate glycemic control) included groups of healthy rats, diabetic insulin-treated rats, diabetic insulin- and C-peptide-treated rats. After 8 weeks, the left kidney was excised for evaluation of V(GLOM) and mesangial matrix area via light microscopy. Mesangial cells were cultured for 48 h and type IV collagen expression and matrix metalloproteinase (MMP)-2 expression were measured by ELISA and RT-PCR. The results indicated that in Series 1, C-peptide administration suppressed the diabetes-induced increase in the V(GLOM) and the mesangial matrix area. In Series 2, C-peptide administration resulted in a similar decrease in the V(GLOM) and a greater decrease in the mesangial matrix area when compared with insulin therapy alone. Moreover, C-peptide (300 nM) completely inhibited the glucose-induced increase of the collagen IV mRNA expression and protein concentration in mesangial cells cultured in 30 mM glucose medium. MMP-2 mRNA expression was not influenced by C-peptide. In conclusion, C-peptide administration to STZ-diabetic rats for 8 weeks results in the inhibition of diabetes-induced expansion of the mesangial matrix. This effect is independent of the level of glycemic control and results from the inhibition of diabetes-induced excessive formation of mesangial type IV collagen.     

蓝莓果渣提取物总酚含量及抗氧化活性研究

研究了蓝莓果渣提取物总酚含量及其抗氧化活性。分别采用水、40%乙醇及纤维素酶辅助乙醇超声提取蓝莓果渣,并用Folin-Ciocalteu试剂对3种提取物的总酚含量进行评估;并采用DPPH清除实验及O2—.清除实验对3种提取物的抗氧化活性进行研究。实验结果表明,纤维素酶辅助超声提取蓝莓果渣的总酚含量最高,可达425.36±15.21 mg GAE.100 g-1DW,远远高于水提物(169.46±9.75 mg GAE.100 g-1DW)及醇提物(218.39±12.54mg GAE.100 g-1DW)中的总酚含量。且纤维素酶辅助乙醇超声提取物对DPPH的清除能力为2.67±0.13 gVc.100 g-1DW,对O—.2的清除能力2.48±0.14 g Vc.100 g-1DW,明显好于醇提物及水提物抗氧化活性。     

The alternative pathway in cucumber seedlings under low temperature stress was enhanced by salicylic acid

The alternative pathway is a cyanide-resistant and non-phosphorylatory electron transport pathway in mitochondria of higher plants. Alternative oxidase (AOX) is the terminal oxidase of this pathway. Our present study investigated the effect of exogenous salicylic acid (SA) on alternative pathway in cucumber (Cucumis sativus L.) seedlings under low temperature stress. Results showed that during the process of low temperature stress, the alternative pathway capacity was enhanced as AOX expression increased in SA pretreated seedlings. Compared with seedlings without SA pretreatment, slower decrease of relative water content and lower levels of electrolyte leakage, H₂O₂ and malonyldialdehyde content were detected in SA pretreated seedlings. These results indicated that SA could alleviate the injury caused by low temperature on cucumber seedlings. Since the special protective functions of alternative pathway and AOX in plants, we suggested that the alternative pathway was related to SA-mediated plant resistance to environmental stresses such as low temperature.     

A phosphoinositide 3-kinase-γ inhibitor, AS605240 prevents bleomycin-induced pulmonary fibrosis in rats

Phosphoinositide 3-kinase-γ (PI3Kγ) has been identified to play the critical roles in inflammatory cells activation and recruitment in multiply inflammatory diseases and it promised to be a prospective target for relevant inflammatory diseases therapy. AS605240, a selective PI3Kγ inhibitor, has been proved effective on several inflammatory diseases. In this study, we investigated the protective effect of AS605240 on bleomycin-induced pulmonary fibrosis in rats. Our results showed that orally administration of AS605240 significantly prevented lung inflammation and reduced collagen deposition. AS605240 also inhibited augmented expression of TNF-α and IL-1β induced by bleomycin instillation. Moreover, the mRNA levels of TNF-α and IL-1β in lung were remarkably suppressed. Histological assessment found that AS605240 reduced the expression of TGF-β₁ and prevented T lymphocytes infiltration to lung. Phospho-Akt level in inflammatory cells by blocking PI3Kγ was down-regulated and the inhibition of Akt phosphorylation was further confirmed by Western blot. Our findings illustrated that AS605240 was effective for preventing pulmonary fibrosis by suppressing inflammatory cells recruitment and production of inflammatory cytokines. These findings also suggest that PI3Kγ may be a useful target in treating inflammation diseases and AS605240 may represent a promising novel agent for the future therapy of pulmonary fibrosis.     

Calcium signal-initiated early activation of NF-κB in neurons is a neuroprotective event in response to kainic acid-induced excitotoxicity

We demonstrate that activation of nuclear factor κB (NF-κB) in neurons is neuroprotective in response to kainic acid (KA)-induced excitotoxicity. Combination of Western blotting, immunocytochemistry, and electrophoresis mobility shift assay showed that KA exposure induced a fast but transient nuclear translocation of the NF-κB p65 subunit and increased DNA-binding activity of NF-κB in primary cultured cortical neurons. The transient NF-κB activity was associated with upregulation of antiapoptotic Bcl-xL and XIAP gene products revealed by real-time PCR. Knockdown of p65 decreased neuronal viability and antiapoptotic gene expression. In addition, we showed that KA-stimulated DNA-binding activity of NF-κB was associated with reactive oxygen species and calcium signals, using AMPA/KA receptor antagonist, calcium chelator, and antioxidant. These results suggest that the fast and transient activation of NF-κB initiated by calcium signals is one of the important proximal events in response to KA-induced excitotoxicity, which has neuroprotective effect against KA-induced apoptosis.