Development of functional antibodies against influenza B virus by activation-induced cytidine deaminase in hybridoma cells

Highlights
1. Class-switch recombination was mimicked in hybridomas through a controllable expression system of activation-induced cytidine deaminase.
2. IgG antibodies were generated through this system in an anti-Flu B IgM hybridoma 7G1.
3. IgG1 and IgG2a subtypes of 7G1 present improved antiviral activity in vitro and in vivo.     

Genome-wide CRISPR activation screen identifies candidate receptors for SARS-CoV-2 entry

Science China Life Sciences - The outbreak of coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 has created a global health crisis. SARS-CoV-2 infects varieties of tissues where the known...     

不同耐性水稻幼苗根系对镉胁迫的形态及生理响应

采用水培试验,以两个耐镉性不同的水稻品种为材料,研究了不同浓度镉胁迫对水稻幼苗根系形态、根系活力、游离脯氨酸含量及抗氧化酶活性的影响。结果表明:低于5 μmol/L Cd胁迫对2个水稻品种总根长、根表面积、根体积、根干重、根系活力无明显影响,在1 μmol/L Cd时,甚至起促进作用。随Cd浓度增加表现出一定的抑制效应,秀水63在10 μmol/L Cd胁迫下根系形态、根系活力明显受到抑制,而秀水09在25 μmol/L Cd胁迫下明显受抑。随Cd胁迫浓度的增加,游离脯氨酸含量、丙二醛(MDA)含量、超氧化物歧化酶(SOD)、过氧化物酶(POD)活性均呈上升趋势,两品种相比,秀水09的游离脯氨酸含量、SOD和POD增幅大于秀水63,而MDA含量增幅小于秀水63;过氧化氢酶(CAT)活性变化表现为先上升后下降,10-100 μmol/L Cd胁迫下秀水63根系中CAT活性明显低于秀水09。总之,水稻对Cd毒害响应存在明显的品种差异,且Cd胁迫下根系生理响应的差异是品种间耐性差异的重要原因之一。     

LINC00668 Modulates SOCS5 Expression Through Competitively Sponging miR-518c-3p to Facilitate Glioma Cell Proliferation

Neurochemical Research - Glioma is a common invasive cancer with unfavorable prognosis in patients. Long non-coding RNAs (lncRNAs) exert significant functions in carcinogenesis of various cancers...     

Structural Basis of Ist1 Function and Ist1–Did2 Interaction in the Multivesicular Body Pathway and Cytokinesis

The ESCRT machinery functions in several important eukaryotic cellular processes. The AAA-ATPase Vps4 catalyzes disassembly of the ESCRT-III complex and may regulate membrane deformation and vesicle scission as well. Ist1 was proposed to be a regulator of Vps4, but its mechanism of action was unclear. The crystal structure of the N-terminal domain of Ist1 (Ist1NTD) reveals an ESCRT-III subunit-like fold, implicating Ist1 as a divergent ESCRT-III family member. Ist1NTD specifically binds to the ESCRT-III subunit Did2, and cocrystallization of Ist1NTD with a Did2 fragment shows that Ist1 interacts with the Did2 C-terminal MIM1 (MIT-interacting motif 1) via a novel MIM-binding structural motif. This arrangement indicates a mechanism for intermolecular ESCRT-III subunit association and may also suggest one form of ESCRT-III subunit autoinhibition via intramolecular interaction.     

Gualou Xiebai Banxia decoction ameliorates Poloxamer 407-induced hyperlipidemia

Ethnopharmacological relevance: Gualou Xiebai Banxia (GLXBBX) decoction is a well-known traditional Chinese herbal formula that was first discussed in the Synopsis of the Golden Chamber by Zhang Zhongjing in the Eastern Han Dynasty. In traditional Chinese medicine, GLXBBX is commonly prescribed to treat cardiovascular diseases, such as coronary heart disease and atherosclerosis.Objective: The present study aimed to examine GLXBBX’s preventative capacity and elucidate the potential molecular mechanism of Poloxamer 407 (P407)-induced hyperlipidemia in rats.Materials and methods: Both the control and model groups received pure water, and the test group also received a GLXBBX decoction. For each administration, 3 ml of the solution was administered orally. To establish hyperlipidemia, a solution mixed with 0.25 g/kg P407 dissolved in 0.9% normal saline was injected slowly into the abdominal cavity. At the end of the study, the rats’ plasma lipid levels were calculated using an automatic biochemical analyzer to evaluate the preventative capability of the GLXBBX decoction, and the serum and liver of the rats were collected.Results: The GLXBBX decoction significantly improved P407-induced hyperlipidemia, including increased plasma triglycerides (TGs), aspartate aminotransferase (AST) elevation, and lipid accumulation. Moreover, GLXBBX decoction treatment increased lipoprotein lipase (LPL) activity and mRNA expression of LPL. Furthermore, GLXBBX significantly suppressed the mRNA expression of stearoyl-CoA desaturase (SCD1).Conclusion: GLXBBX significantly improved P407-induced hyperlipidemia, which may have been related to enhanced LPL activity, increased LPL mRNA expression, and decreased mRNA expression of SCD1.     

Root-Associated Endophytic Bacterial Community Composition of Asparagus officinalis of Three Different Varieties

Asparagus (Asparagus officinalis L) is an economically important crop, rich in nutrients, and is also conducive to solving ecological and environmental problems. Plants may acquire benefits from root-associated endophytic bacteria. However, the composition of the endophytic bacterial community associated with the roots of asparagus is poorly elucidated. In this study, the nine root samples of asparagus from three different varieties including Asparagus officinalis var. Grande (GLD), A. officinalis var. Jinglvlu3 (JL3) and A. officinalis var. Jingzilu2 (JZL) were investigated by high-throughput sequencing technology of the 16S rDNA V5-V7 hypervariable region of endophytic bacteria. A total of 16 phyla, 29 classes, 90 orders, 171 families, and 312 genera were identified. Endophytic bacteria diversity and bacteria structure was different among the three varieties and was influenced by rhizosphere soil properties and varieties. In the GLD variety, the main phyla were Proteobacteria, Actinobacteria, and Firmicutes. The main phylum in JL3 and JZL varieties was Proteobacteria. The observations showed that GLD had the highest diversity of endophytes as indicated by the Shannon index (GLD > JZL > JL3). The order of the endophytes richness was GLD > JL3 > JZL. The PCA and PCoA analysis revealed the microbial communities were different between three different asparagus varieties, and the microbial composition of GLD and JZL was more similar. This report provides an important reference for the study of endophytic microorganisms of asparagus. Supplementary informationThe online version contains supplementary material available at (10.1007/s12088-021-00926-6) contains supplementary material, which is available to authorized users.     

DPSN：扩增子测序引物标准化命名数据库

扩增子测序是目前用来衡量微生物多样性时使用最广泛的测序手段。因为其扩增的需要,所以选择合适的特定引物是必需的,且其对结果影响甚大。probeBase是目前最常用的记录了人工校正后的rRNA探针和引物的数据库。然而,我们发现probeBase中63.58%的引物存在不同程度的注释错误,包括命名重复、命名无规律以及匹配位置错误等。更严重的是,目前主流的短命名方式不具有唯一性,导致对应关系模糊不清。因此,我们定义了更简单可行的短命名标准并开发了新的引物科学命名数据库（DPSN）,并对probeBase里的所有173个引物进行了校正,并新加入了4个新的改良引物以及38个针对大亚基的新引物。新的短命名规则包含3个基本要素：在正链5''端的位置、版本号和方向。此外在前面加入了识别大/小亚基以及主要针对的菌界的标志。使用DPSN,可以快速查找感兴趣区域对应的引物并比较不同版本的差异选择合适的引物。同时还能建立命名与序列的明确一一对应关系,避免歧义。