目标?鄄诱饵库搜索策略在蛋白质组质谱鉴定和质控中的应用及研究进展

基于串联质谱的蛋白质组研究会产生海量的质谱数据,这些数据通常使用数据库搜索引擎进行鉴定分析,并根据肽段谱图匹配(PSM)反推真实的样品蛋白质．对于高通量蛋白质组数据的处理,其鉴定结果的可信是后续分析应用的前提,因此对鉴定结果的质量控制尤为重要,而基于目标-诱饵库(target-decoy)搜索策略的质量控制是目前应用最为广泛的方法．本文首先介绍了基于目标-诱饵库搜索策略搜库和质量控制的实施流程,然后综述了基于目标-诱饵库搜索策略的质量控制工具,并提出了目标-诱饵库搜索策略的不足及改善方法,最后对目标-诱饵库搜索策略进行了总结与展望．     

绣球菌多糖表征及其抗氧化和免疫活性

提取纯化绣球菌多糖(Sparassis latifolia polysaccharides,SCPs),研究其表征和功能活性,探索绣球菌多糖表征与其抗氧化及免疫活性之间的关系。以绣球菌子实体为原料,采用聚能超声波辅助水提醇沉法提取绣球菌多糖,经DEAE-52、SephadexG-100纯化,用高效凝胶渗透色谱法、离子色谱法、傅里叶红外色谱法、扫描电镜、原子力显微镜对绣球菌多糖进行初步表征,检测绣球菌多糖清除DPPH、·OH、O2^-·自由基能力以及总还原力,用MTT法检测绣球菌多糖对巨噬细胞RAW264.7增殖的影响。结果表明,SCPs分子量范围为215Da–393kDa,由葡萄糖、甘露糖、半乳糖、木糖、果糖构成,摩尔比13:4:1:2:3,其表观形貌为簇状堆积,交织,结构规律性不强,表面光滑,呈一定的网络状结构,分子呈现链状构象,具有高度的分支结构,链间形成小环且伴随一定的球形颗粒。SCPs具有一定的还原能力和清除DPPH、·OH、O2^-·自由基的能力,且能够促进巨噬细胞RAW264.7的增殖。绣球菌多糖的抗氧化及免疫活性可能与其分子量、单糖组成、糖链分支及分子构象有关。     

月季F1代群体表型性状变异分析

以月季（Rosa spp.）品种‘云蒸霞蔚’和‘太阳城’正交获得的184株F₁代群体为研究对象,采用方差分析、变异系数、遗传分析、相关性分析对花部形态性状以及叶片形态性状进行测定分析。结果表明：该杂交群体表型变异丰富,变异系数在7.33%~68.08%,其中花瓣数量在群体中的变异程度最高;杂交后代各个性状上均发生分离变异,出现不同于亲本的表现型,且离散程度较高。表型性状的遗传特点与关联分析,为挖掘控制表型性状的优良基因及辅助选择育种提供参考。     

MicroRNA-21在卵巢癌病灶转移过程中的作用及机制研究

目的:探讨micro RNA-21在卵巢癌病灶转移过程中的作用及其机制。方法:选取本院2016年6月-2018年5月收治的138例卵巢癌患者,其中63例出现结直肠转移,75例未发现有转移。q RT-PCR分别检测两组患者肿瘤组织、癌旁组织和正常组织中micro RNA-21的表达;Western blot检测两组患者肿瘤组织中PGDH、PGE2、Twist表达。通过转染过表达载has-micro RNA-21上调A2780细胞中micro RNA-21的表达,采用平板克隆实验检测细胞克隆形成能力,Trans-well细胞迁移实验和侵袭实验分别检测细胞迁移和侵袭能力。Western blot检测PGDH、PGE2、Twist蛋白表达。结果:卵巢癌转移组肿瘤组织中micro RNA-21表达高于未转移组、癌旁组织和正常卵巢组织(P0.05),卵巢癌转移组肿瘤组织中PGDH表达低于未转移组,而PGE2、Twist表达高于未转移组(P0.05)。micro RNA-21过表达的A2780细胞平板克隆形成能力、迁移和侵袭能力及上皮间质转化相关蛋白PGE2和Twist表达均明显高于阴性对照组(P0.05),而PGDH表达的表达明显降低(P0.05)。结论:micro RNA-21可能通过抑制PGDH的表达增加PGE2的表达,进而激活上皮间质转化,促进卵巢癌转移。     

Regulation of mitochondrial NAD pool via NAD+ transporter 2 is essential for matrix NADH homeostasis and ROS production in Arabidopsis

Reactive oxygen species(ROS) play a crucial role in numerous biological processes in plants, including development, responses to environmental stimuli, and programmed cell death(PCD). Deficiency in MOSAIC DEATH 1(MOD1), a plastid-localized enoyl-ACP reductase essential for de novo fatty acid biosynthesis in Arabidopsis thaliana, leads to the increased malate export from chloroplasts to mitochondria, and the subsequent accumulation of mitochondria-generated ROS and PCD. In this study, we report the identification and characterization of a mod1 suppressor, som592. SOM592 encodes mitochondrion-localized NAD~+ transporter 2(NDT2). We show that the mitochondrial NAD pool is elevated in the mod1 mutant. The som592 mutation fully suppressed mitochondrial NADH hyper-accumulation, ROS production, and PCD in the mod1 mutant, indicating a causal relationship between mitochondrial NAD accumulation and ROS/PCD phenotypes. We also show that in wild-type plants, the mitochondrial NAD+uptake is involved in the regulation of ROS production in response to continuous photoperiod. Elevation of the alternative respiration pathway can suppress ROS accumulation and PCD in mod1, but leads to growth restriction. These findings uncover a regulatory mechanism for mitochondrial ROS production via NADH homeostasis in Arabidopsis thaliana that is likely important for growth regulation in response to altered photoperiod.     

Picroside II attenuates hyperhomocysteinemia‐induced endothelial injury by reducing inflammation,oxidative stress and cell apoptosis

Picroside II (P‐II), one of the main active components of scrophularia extract, which have anti‐oxidative, anti‐inflammatory effects, but its effect on hyperhomocysteinemia (HHcy) induced endothelial injury remains to be determined. Here, we test whether P‐II protects HHcy‐induced endothelial dysfunction against oxidative stress, inflammation and cell apoptosis. In vitro study using HUVECs, and in hyperhomocysteinemia mouse models, we found that HHcy decreased endothelial SIRT1 expression and increased LOX‐1 expression, subsequently causing reactive oxygen species generation, up‐regulation of NADPH oxidase activity and NF‐κB activation, thereby promoting pro‐inflammatory response and cell apoptosis. Blockade of Sirt1 with Ex527 or siRNASIRT1 increased LOX‐1 expression, whereas overexpression of SIRT1 decreased LOX‐1 expression markedly. P‐II treatment significantly increased SIRT1 expression and reduced LOX‐1 expression, and protected against endothelial cells from Hcy‐induced oxidative injury, inflammation and apoptosis. However, blockade of SIRT1 or overexpression of LOX‐1 attenuated the therapeutic effects of P‐II. In conclusion, our results suggest that P‐II prevents the Hcy induced endothelial damage probably through regulating the SIRT1/LOX‐1 signaling pathway.     

Circulating serum vitamin D levels and total body bone mineral density: A Mendelian randomization study

Until recently, randomized controlled trials have not demonstrated convincing evidence that vitamin D, or vitamin D in combination with calcium supplementation could improve bone mineral density (BMD), osteoporosis and fracture. It remains unclear whether vitamin D levels are causally associated with total body BMD. Here, we performed a Mendelian randomization study to investigate the association of vitamin D levels with total body BMD using a large‐scale vitamin D genome‐wide association study (GWAS) dataset (including 79 366 individuals) and a large‐scale total body BMD GWAS dataset (including 66,628 individuals). We selected three Mendelian randomization methods including inverse‐variance weighted meta‐analysis (IVW), weighted median regression and MR‐Egger regression. All these three methods did not show statistically significant association of genetically increased vitamin D levels with total body BMD. Importantly, our findings are consistent with recent randomized clinical trials and Mendelian randomization study. In summary, we provide genetic evidence that increased vitamin D levels could not improve BMD in the general population. Hence, vitamin D supplementation alone may not be associated with reduced fracture incidence among community‐dwelling adults without known vitamin D deficiency, osteoporosis, or prior fracture.     

A single nucleotide mutation in GID1c disrupts its interaction with DELLA1 and causes a GA‐insensitive dwarf phenotype in peach

Plant stature is one important factor that affects the productivity of peach orchards. However, little is known about the molecular mechanism(s) underlying the dwarf phenotype of peach tree. Here, we report a dwarfing mechanism in the peach cv. FenHuaShouXingTao (FHSXT). The dwarf phenotype of ‘FHSXT’ was caused by shorter cell length compared to the standard cv. QiuMiHong (QMH). ‘FHSXT’ contained higher endogenous GA levels than did ‘QMH’ and did not response to exogenous GA treatment (internode elongation). These results indicated that ‘FHSXT’ is a GA‐insensitive dwarf mutant. A dwarf phenotype‐related single nucleotide mutation in the gibberellic acid receptor GID1 was identified in ‘FHSXT’ (GID1c^S191F), which was also cosegregated with dwarf phenotype in 30 tested cultivars. GID1c^S191F was unable to interact with the growth‐repressor DELLA1 even in the presence of GA. ‘FHSXT’ accumulated a higher level of DELLA1, the degradation of which is normally induced by its interaction with GID1. The DELLA1 protein level was almost undetectable in ‘QMH’, but not reduced in ‘FHSXT’ after GA₃ treatment. Our results suggested that a nonsynonymous single nucleotide mutation in GID1c disrupts its interaction with DELLA1 resulting in a GA‐insensitive dwarf phenotype in peach.     

LncRNA FENDRR represses proliferation,migration and invasion through suppression of survivin in cholangiocarcinoma cells

This study was to investigate the biological function and underlying mechanisms of FENDRR in cholangiocarcinoma (CCA) cell proliferation, migration and invasion. FENDRR and survivin expression in CCA tissues or cell lines were measured by qRT-PCR. In QBC939 and HuCCTl cells, cell proliferation was detected by CCK-8, cell migration and invasion were using transwell assay. RNA pull-down and RIP assay were performed to determine whether FENDRR can combine with SETDB1 in CCA cell. The effect of SETDB1 on survivin and H3K9me1 expression in CCA cells were determined by western blotting. ChIP analysis was performed to analyze the combination of SETDB1 with survivin promoter in CCA cell. The effect of SETDB1 knockdown on survivin and H3K9me1 expression in CCA cells after transfection with FENDRR were determined by western blotting. The results showed that lncRNA FENDRR was downregulated in CCA tissues and cells, and was negatively correlated with survivin expression. Further investigation demonstrated that FENDRR represses CCA cell proliferation, migration and invasion through regulating survivin expression. FENDRR associated with SETDB1 and H3K9 to epigenetically silence survivin and then regulated cell proliferation, migration and invasion. These findings indicate an important role for FENDRR–survivin axis in CCA cell proliferation, migration and invasion, and reveal a novel epigenetic mechanism for survivin silencing. Our data indicated that FENDRR silences survivin via SETDB1-mediated H3K9 methylation, thereby represses CCA cell proliferation, migration and invasion.     

Design,synthesis and biological evaluation of novel human monoamine oxidase B inhibitors based on a fragment in an X-ray crystal structure

Herein we report our efforts of developing reversible selective hMAO-B inhibitors based on isatin, a fragment in an X-ray crystal structure. Five different scaffolds were designed and many compounds were synthesized. Among them, compound A3 demonstrated very high potency and isoform selectivity against hMAO-B, 11 and 13 times more potent (IC₅₀?=?3?nM) and 23.64 and 6.8 times more selective than the marked drugs, selegiline and safinamide. However, the endeavors to modify the polar 3-one group of isatin, that is in a hydrophobic environment in the binding site of hMAO-B, to small nonpolar hydrophobic groups did not bring about improved hMAO-B inhibitors, which may challenge our understanding of molecular interactions and molecular recognition in biological systems.