Discovery and SAR analysis of phenylbenzo[d][1,3]dioxole-based proprotein convertase subtilisin/kexin type 9 inhibitors

Proprotein convertase subtilisin/kexin type 9 (PCSK9) has emerged as a novel therapeutic target for the development of cholesterol-lowering drugs. In the discovery of PCSK9/LDLR (low-density lipoprotein receptor) protein-protein interaction (PPI) impairing small molecules, a total of 47 phenylbenzo[d][1,3] dioxole-based compounds were designed and synthesised. The result revealed that the 4-chlorobenzyl substitution in the amino group is important for the PPI disrupting activity. In the hepatocyte-based functional tests, active compounds such as A12, B1, B3, B4 and B14, restored the LDLR levels on the surface of hepatic HepG2 cells and increased extracellular LDL uptake in the presence of PCSK9. It is notable that molecule B14 exhibited good performance in all the evaluations. Collectively, novel structures targeting PCSK9/LDLR PPI have been developed with hypolipidemic potential. Further structural modification of derived active compounds is promising in the discovery of lead compounds with improved activity for the treatment of hyperlipidaemia-related disorders.     

基于CRISPR/Cas9的基因编辑技术研究进展及其在植物中的应用

CRISPR/Cas9技术是利用RNA靶向引导Cas9核酸酶对基因组中的目标基因进行编辑的生物技术。近年来,该技术的多种新型基因编辑器更新迅猛,编辑效果愈加精细和高效,在作物定向分子设计育种中展现出巨大的应用前景。该文对CRISPR/Cas9及其相关编辑器的技术原理、编辑效果和应用情况进行综述,并探讨了该技术在应用中面临的问题、应对措施和发展前景,旨在为相关领域的科研工作者提供参考。     

水稻恢复系M630稻瘟病抗性改良及其代谢组研究

稻瘟病是水稻的主要病害之一,改良水稻稻瘟病抗性对水稻生产、推广具有重要意义.本研究以携带广谱抗稻瘟病基因Pi9材料9311-Pi9为供体,水稻优良恢复系M630为受体,将杂交、回交与分子标记辅助选择和背景筛选相结合,获得改良恢复系M630-Pi9.主要农艺性状和稻米品质分析显示改良后的M630-Pi9及其杂交组合徽两优...     

Putative therapeutic impacts of cardiac CTRP9 in ischaemia/reperfusion injury

Recently, cytokines belonging to C1q/tumour necrosis factor‐related proteins (CTRPs) superfamily have attracted increasing attention due to multiple metabolic functions and desirable anti‐inflammatory effects. These various molecular effectors exhibit key roles upon the onset of cardiovascular diseases, making them novel adipo/cardiokines. This review article aimed to highlight recent findings correlated with therapeutic effects and additional mechanisms specific to the CTRP9, particularly in cardiac ischaemia/reperfusion injury (IRI). Besides, the network of the CTPR9 signalling pathway and its possible relationship with IRI were discussed. Together, the discovery of all involved underlying mechanisms could shed light to alleviate the pathological sequelae after the occurrence of IRI.     

禽流感病毒H9N2血凝素基因和神经氨酸酶因在大肠杆菌中的表达

克隆、表达和鉴定禽流感病毒H9N2 HA,NA基因序列,为制备抗体和基因工程疫苗打下基础。在成功克隆禽流感病毒H9N2全长HA、NA基因并测序的基础上,将部分基因序列克隆到表达载体pET32a(+)上,全基因序列克隆到表达载体pGEX4T-1上,构建了重组表达质粒pET32a(+)/HA(截短)、pET32a(+)/NA(截短)、pGEX4T-1/HA、pGEX4T-1/NA,转化大肠杆菌BL21/rosetta,IPTG诱导表达,利用Ni2+亲和层析柱和GSTrap4B亲和层析柱对重组蛋白进行纯化,并用Western Blotting和ELISA方法检测其抗原性。结果重组蛋白在大肠杆菌中可以高效表达,SDS-PAGE显示其相对分子质量与预计大小一致。ELISA和Western Blotting实验证实,重组蛋白具有良好的抗原性。本研究成功克隆和表达了禽流感病毒H9N2 HA、NA基因序列。为禽流感病毒H9N2诊断试剂和疫苗的开发等进一步的研究奠定了基础。     

利用反向遗传技术研究H9N2亚型AIV传播途径的分子机制

利用反向遗传技术,通过基因重排方法,产生两个表面基因来自A/Chicken/Guangdong/SS/94(H9N2)禽流感病毒(avian influenza virus,AIV)株和其余基因来自A/Chicken/Shanghai/F/98(H9N2)AIV株的3株H9N2亚型重排AIV,动物传播性试验发现A/Chicken/Shanghai/F/98(H9N2)株、A/Chicken/Guangdong/SS/94(H9N2)AIV株和3株H9N2亚型重排AIV都可以经直接接触途径传播;在粪便接触途径下,3株重排AIV都不经粪便接触传播;只有A/Chicken/Shanghai/F/98(H9N2)株和重排AIV RF7/SSHA能经过气溶胶途径传播。HI试验结果进一步证明了以上的结果。实验结果表明H9N2亚型AIV的NA基因与H9N2亚型AIV气溶胶传播途径有重要的关系,即1998年中国大陆H9N2亚型AIV大流行可能是因为病毒获得气溶胶传播途径的特性,推测病毒的NA基因发挥了重要作用。     

人骨髓间充质干细胞分化为运动神经元过程中Nestin与Hb9表达的研究

目的探讨全反式维甲酸(RA)与音猬因子(Shh)诱导人骨髓间充质干细胞向神经干细胞乃至运动神经元方向分化过程中Nestin与Hb9的表达变化情况。方法采用传至第3代的人骨髓间充质干细胞,经含有RA与Shh的诱导液处理后,应用免疫细胞化学及荧光定量PCR方法分析Nestin与Hb9表达的变化情况。结果人骨髓间充质干细胞经过RA与Shh诱导后Nestin与Hb9的表达明显高于未加RA与Shh的对照组及空白组。结论 hBMSC具有向神经干细胞乃至运动神经元方向分化的潜能,RA与Shh可以在体外诱导hBMSC定向向该方向分化。     

Downregulation of p‐COUMAROYL ESTER 3‐HYDROXYLASE in rice leads to altered cell wall structures and improves biomass saccharification

p‐Coumaroyl ester 3‐hydroxylase (C3′H) is a key enzyme involved in the biosynthesis of lignin, a phenylpropanoid polymer that is the major constituent of secondary cell walls in vascular plants. Although the crucial role of C3′H in lignification and its manipulation to upgrade lignocellulose have been investigated in eudicots, limited information is available in monocotyledonous grass species, despite their potential as biomass feedstocks. Here we address the pronounced impacts of C3′H deficiency on the structure and properties of grass cell walls. C3′H‐knockdown lines generated via RNA interference (RNAi)‐mediated gene silencing, with about 0.5% of the residual expression levels, reached maturity and set seeds. In contrast, C3′H‐knockout rice mutants generated via CRISPR/Cas9‐mediated mutagenesis were severely dwarfed and sterile. Cell wall analysis of the mature C3′H‐knockdown RNAi lines revealed that their lignins were largely enriched in p‐hydroxyphenyl (H) units while being substantially reduced in the normally dominant guaiacyl (G) and syringyl (S) units. Interestingly, however, the enrichment of H units was limited to within the non‐acylated lignin units, with grass‐specific γ‐p‐coumaroylated lignin units remaining apparently unchanged. Suppression of C3′H also resulted in relative augmentation in tricin residues in lignin as well as a substantial reduction in wall cross‐linking ferulates. Collectively, our data demonstrate that C3′H expression is an important determinant not only of lignin content and composition but also of the degree of cell wall cross‐linking. We also demonstrated that C3′H‐suppressed rice displays enhanced biomass saccharification.     

枸杞脱落酸生物合成关键酶基因NCED的克隆及表达分析

脱落酸(abscisic acid,ABA)对植物的生长发育具有独特的调控功能,并在植物适应逆境环境中发挥重要作用。9-顺式环氧类胡萝卜素双加氧酶(NCED)是高等植物中ABA生物合成途径的一个关键酶。根据GenBank中的植物NCED基因的同源序列设计简并引物,通过RT-PCR及RACE技术从枸杞叶片中克隆到1个编码NCED的基因,命名为LbNCED。其cDNA全长为2316 bp,含有1个1824 bp的开放阅读框,编码1个含607氨基酸残基,分子量为67.38 kDa、等电点(pI)为6.43的假定蛋白,其氨基酸序列与番茄(Lycopersicon esculentum)和马铃薯(Solanum tuberosum)的同源性达90%,在N-末端具有1个含15个氨基酸的叶绿体转运肽。Southern杂交结果表明,该基因在枸杞基因组中以低拷贝形式存在。盐处理和脱水处理的枸杞叶片中LbNCED基因的表达与内源ABA的积累同步变化。