Flavonoid 3′-hydroxylase of Camellia nitidissima Chi. promotes the synthesis of polyphenols better than flavonoids

Molecular Biology Reports - Camellia nitidissima Chi. is an ornamental plant of the genus Camellia L. Its flowers contain a lot of flavonoids and polyphenols. Flavonoid 3′-hydroxylase...     

凝胶电泳微流控芯片提取外泌体及对人血浆外泌体中miRNA-21的测定

为了开发一种用于人体血浆中外泌体的高效快速提取和分离的新型微流控芯片,文中收集健康人体外周血液样本,自主设计并制备基于纳米多孔薄膜和琼脂糖凝胶电泳的微流芯片。提取的外泌体使用透射电镜、Nanosight和Western blotting等技术进行表征,鉴定并分析其形态、浓度和粒径分布。同时将超速离心法和微流芯片所提取的外泌体进行粒径和浓度的分析比较,探讨两种方法各自的提取效率。最后,利用RT-PCR技术分析外泌体中miRNA-21的相对表达量。凝胶电泳微流芯片可在1 h内快速的从血浆中高效率地提取出纯度高、大小完整、尺寸分布在30–200 nm之间的外泌体,满足后续下游分析的要求。通过与现有最普遍的超速离心法进行对比分析,当血浆样本量小于100μL时,凝胶电泳微流芯片提取外泌体的效率为超速离心法的3.80倍。凝胶电泳微流芯片提取外泌体的优化参数是:电场电压:100 V;琼脂糖凝胶浓度:1.0%;注射泵流速:0.1 mL/h。凝胶电泳微流芯片可快速高效地提取出外泌体,对外泌体与癌症生物标记物的相关研究具有潜在的巨大优势,也为基于外泌体的即时诊断技术提供了可能。     

酿酒酵母酚类抑制物耐受性脂质组学研究

通过脂质组学分析方法从细胞膜磷脂分布方面探究适应进化酿酒酵母酚酸耐受性机制。主要利用高效液相色谱-质谱(LC-MS)对酚酸胁迫下适应进化菌株和原始菌株脂质成分检测并进行统计学比较分析。检测出565种脂质代谢物,包含细胞膜磷脂185种。相比初始菌株,适应进化菌株细胞膜中磷脂酰胆碱(PC)、磷脂酰乙醇胺(PE)和磷脂酰肌醇(PI)类磷脂分子相对含量增加,含有长链(C32-C36)和双不饱和脂酰链的磷脂分子含量增加。统计学分析表明显著性差异磷脂分子主要为含有长链不饱和脂酰链的PC和PE类磷脂分子。推测适应进化菌株通过膜磷脂重塑提高细胞膜完整性,对酚类抑制物起到选择性屏障作用,从而保持细胞活性。     

Blocking of the PD-1/PD-L1 interaction by a novel cyclic peptide inhibitor for cancer immunotherapy

The interaction of PD-1/PD-L1 allows tumor cells to escape from immune surveillance. Clinical success of the antibody drugs has proven that blockade of PD-1/PD-L1 pathway is a promising strategy for cancer immunotherapy. Here, we developed a cyclic peptide C8 by using Ph.D.-C7 C phage display technology. C8 showed high binding affinity with h PD-1 and could effectively interfere the interaction of PD-1/PD-L1. Furthermore, C8 could stimulate CD8+T cell activation in human peripheral blood mononuclear cells(PBMCs). We also observed that C8 could suppress tumor growth in CT26 and B16-OVA, as well as anti-PD-1 antibody resistant B16 mouse model. CD8+T cells infiltration significantly increased in tumor microenvironment, and IFN-γ secretion by CD8+T cells in draining lymph nodes also increased. Simultaneously, we exploited T cells depletion models and confirmed that C8 exerted anti-tumor effects via activating CD8+T cells dependent manner. The interaction model of C8 with h PD-1 was simulated and confirmed by alanine scanning. In conclusion, C8 shows anti-tumor capability by blockade of PD-1/PD-L1 interaction, and C8 may provide an alternative candidate for cancer immunotherapy.     

Interactions between commensal bacteria and viral infection: insights for viral disease control in farmed animals

Viral diseases cause serious economic loss in farmed animals industry. However, the efficacy of remedies for viral infection in farmed animals is limited, and treatment strategies are generally lacking for aquatic animals. Interactions of commensal microbiota and viral infection have been studied in recent years, demonstrating a third player in the interaction between hosts and viruses. Here, we discuss recent developments in the research of interactions between commensal bacteria and viral infection,including both promotion and inhibition effect of commensal bacteria on viral pathogenesis, as well as the impact of viral infection on commensal microbiota. The antiviral effect of commensal bacteria is mostly achieved through priming or regulation of the host immune responses, involving differential microbial components and host signaling pathways, and gives rise to various antiviral probiotics. Moreover, we summarize studies related to the interaction between commensal bacteria and viral infection in farmed animals, including pigs, chickens, fish and invertebrate species. Further studies in this area will deepen our understanding of antiviral immunity of farmed animals in the context of commensal microbiota, and promote the development of novel strategies for treatment of viral diseases in farmed animals.     

九州虫草-半枝莲发酵产物不同极性部位与其抗A549细胞增殖活性的相关性分析

建立九州虫草-半枝莲双向固体发酵产物不同极性部位的HPLC特征图谱,并考察与其抑制肺腺癌A549细胞增殖活性的相关性。采用双向固体发酵技术制备九州虫草-半枝莲发酵产物;溶剂萃取法获得发酵产物的不同极性部位,并运用HPLC法建立不同极性部位的特征图谱;MTT法考察不同极性部位对A549细胞的增殖抑制作用;偏最小二乘回归法分析不同极性部位HPLC色谱峰与其抗增殖作用的相关性。抗增殖试验结果表明,不同极性部位对A549细胞均具有增殖抑制作用并且呈浓度依赖性;标示的9个共有色谱峰与抗增殖活性均呈正相关,其中色谱峰8、4、1、2、9分别为木犀草素、黄芩苷、对香豆酸、野黄芩苷、黄芩素。本研究建立了不同极性部位的HPLC特征图谱,极性部位中以二氯甲烷部位对A549细胞的体外抗增殖作用最佳,并借助谱效相关初步探究了发酵产物抗A549细胞增殖的药效物质基础,为双向固体发酵技术应用于菌种与传统中药提供了参考。     

网隔栽培法对生姜姜瘟病防治及产量的影响

姜瘟病是由青枯雷尔氏菌(Ralstoniasolanacearum)引起的一种细菌性病害,被称为生姜种植产业的“癌症”.本试验设计了一种“网隔栽培法”,并探索其对土传姜瘟病发病率和生姜产量的影响.结果表明,经过连续3年的田间验证,相比传统栽培法,“网隔栽培法”种植可显著降低姜瘟病的发病率,平均减少了6.08个百分点,平均防治效果达到了48.33%;同时,生姜产量平均增加了13.21%.这种“短行播种、纵横开沟、深沟隔病”的“网隔栽培法”为姜瘟病的绿色防控提供了新方案,也为其他蔬菜、中药材等植物的土传病害防治提供了新的借鉴思路.