严重急性呼吸综合征冠状病毒2膜蛋白对宿主细胞pre-mRNA 3"UTR加工的影响

目的 研究严重急性呼吸综合征冠状病毒2（SARS-CoV-2）膜蛋白对宿主细胞mRNA前体（pre-mRNA）3"非翻译区（UTR）加工的影响。方法 本研究以人肺上皮细胞系A549为模型，利用瞬时转染在细胞内过表达SARS-CoV-2膜蛋白；利用RNA-Seq测序技术及生物信息学分析方法，系统性描绘宿主细胞选择性多聚腺苷酸化（alternative polyadenylation，APA）事件；Metascape数据库对发生显著APA变化的基因进行功能富集分析；RT-qPCR验证靶基因3"UTR长度变化；蛋白质免疫印迹（Western blot）检测目的蛋白表达水平。结果 SARS-CoV-2膜蛋白外源表达后宿主细胞内共813个基因发生显著APA变化。GO和KEGG分析显示，差异APA基因广泛参与有丝分裂细胞周期、调节细胞应激等生物过程，涉及病毒感染和蛋白质加工等。从中进一步筛选出AKT1基因，在IGV软件中显示3"UTR延长；RT-qPCR验证AKT1基因的3"UTR长度变化趋势；Western blot结果显示AKT1蛋白磷酸化水平增加。结论 SARS-CoV-2膜蛋白潜在影响宿主pre-mRNA的3"UTR加工，其中参与多种病毒性生物过程的AKT1基因 3"UTR延长，且其编码的蛋白质功能在细胞内被激活。     

Contrasting patterns in elevational diversity between microorganisms and macroorganisms

Aim Data and analyses of elevational gradients in diversity have been central to the development and evaluation of a range of general theories of biodiversity. Elevational diversity patterns have, however, been severely understudied for microbes, which often represent decomposer subsystems. Consequently, generalities in the patterns of elevational diversity across different trophic levels remain poorly understood. Our aim was to examine elevational gradients in the diversity of macroinvertebrates, diatoms and bacteria along a stony stream that covered a large elevational gradient. Location Laojun Mountain, Yunnan province, China. Methods The sampling scheme included 26 sites spaced at elevational intervals of 89 m from 1820 to 4050 m elevation along a stony stream. Macroinvertebrate and diatom richness were determined based on the morphology of the specimens. Taxonomic richness for bacteria was quantified using a molecular fingerprinting method. Over 50 environmental variables were measured at each site to quantify environmental variables that could correlate with the patterns of diversity. We used eigenvector‐based spatial filters with multiple regressions to account for spatial autocorrelation. Results The bacterial richness followed an unexpected monotonic increase with elevation. Diatoms decreased monotonically, and macroinvertebrate richness showed a clear unimodal pattern with elevation. The unimodal richness pattern for macroinvertebrates was best explained by the mid‐domain effect (r² = 0.72). The diatom richness was best explained by the variation in nutrient supply, and the increase in bacterial richness with elevation may be related to an increased carbon supply. Main conclusions We found contrasting patterns in elevational diversity among the three studied multi‐trophic groups comprising unicellular and multicellular aquatic taxa. We also found that there may be fundamental differences in the mechanisms underlying these species diversity patterns.     

A tailed primers protocol to identify the association of eNOS gene variable number of tandem repeats polymorphism with ischemic stroke in Chinese Han population by capillary electrophoresis

Endothelial nitric oxide synthase (eNOS) plays an important role in mediating endothelium-dependent vasodilatation and antithrombotic action and is thus involved in the development of ischemic stroke (IS). Controversial results regarding the association of eNOS gene variable number of tandem repeats (VNTR) polymorphism with IS have been reported by conventional PCR-polyacrylamide gel electrophoresis methods. We aimed to identify any common association of eNOS gene VNTR polymorphism with IS in Chinese Han population by capillary electrophoresis (CE). The VNTR polymorphism of 27 bp within the eNOS intron-4 was determined by CE with specially designed tailed primers in Chinese Han patients with IS (n = 457) and matched elderly controls without IS (n = 457). Significant differences in BMI, WHR, hypertension, diabetes, smoking, TG, HDL, LDL, LDL, and FBG were observed between cases and controls. The distributions of eNOS VNTR polymorphism were not significantly associated with IS after adjustment for cardiovascular risk factors (OR = 1.18, 95% CI: 0.82–1.69). This finding was consistent with the further meta-analysis in Asians. The meta-analysis in Americans demonstrated that 4a/4b + 4a/4a genotype was significantly associated with IS risk with an OR of 1.54 (95% CI, 1.09–2.17) compared with the 4b/4b genotype. Our data suggests that BMI, WHR, hypertension, diabetes, smoking, TG, LDL, and FBG may increase the risk of IS. However, eNOS VNTR polymorphism may be not an independent major contributor for IS in Chinese Han population. The VNTR polymorphism might be associated with IS in Americans based on meta-analysis.     

树轮木质素甲氧基稳定氢同位素比率测定方法研究进展

在森林树木合成的有机化合物中,氢元素(H)主要源于大汽水,经植物光合与生理代谢参与生物地球化学循环。近年来,树轮木质素甲氧基稳定氢同位素比率(δ²H_LM)作为新的古气候和古环境研究的代用指标,重建了多个地区的降水稳定同位素比率及气候变化信息,展现了其特有的优势。本文综述了现有树轮δ²H_LM测定的详细分析方法和基本原理,从树轮木质素含量、单体组成等方面对树轮δ²H_LM测定方法的稳定性和有效性进行评价,阐述了树轮木质素甲氧基稳定同位素指标现有研究成果。中纬度地区森林树轮δ²H_LM在记录气温变化和降水稳定同位素变化等方面有着巨大的潜力。但是树轮δ²H_LM的研究尚处于起步阶段,主要表现为: 1) 研究区局限于北半球中纬度地区,研究对象局限于针叶树种;2) 高分辨率树轮δ²H_LM研究有待开展,以弥补硝化纤维稳定氢同位素记录的局限;3) 树轮δ²H_LM在植物生理和森林生态研究方面的潜力有待开发。     

R-2-hydroxyglutarate attenuates aerobic glycolysis in leukemia by targeting the FTO/m6A/PFKP/LDHB axis

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基于低相干光干涉的眼睛光学生物参数测量研究

目的 眼睛的光学生物参数中的眼轴长度（AL）和角膜曲率半径（CR）可以作为预防和监测眼球近视的两个重要参数。为了提高测量眼轴长度的速度与精度和同步实现角膜曲率高精度动态测量，本文提出一种基于低相干光干涉技术眼睛光学生物参数测量的系统。方法 该系统使用旋转光学延迟线快速改变参考光的光程，利用曲率半径为8 mm的标准件标定人眼角膜顶点到靶环之间的距离，利用角膜的干涉信号对相机和数据采集卡进行触发实现同步采集，从而实现眼轴长度的快速测量和精准定位靶环到角膜顶点之间的距离，同时保证成像系统的放大倍率恒定和数据的实时采集。结果 实验结果表明，这种低相干光干涉测量系统，可以实时测量眼轴长度和角膜曲率半径，眼轴长度误差低于40 μm，人眼角膜曲率半径方差为2.082 36×10^-2 μm。结论 该系统能够快速、精准地测量AL和CR，可在近视的预防和监测中发挥重要作用。     

5例前列腺癌T细胞受体β链CDR3的多样性分析

T淋巴细胞受体(TCRs)在抗原识别免疫应答中作用重要,其多样性与宿主免疫反应及肿瘤预后判断密切相关。目的:采用高通量测序技术研究前列腺癌组织和癌旁组织中T细胞受体(TCR)克隆多样性及其克隆序列。方法:收集5例PC患者的癌组织和癌旁组织,提取DNA后经多重PCR技术对TCRβ链CDR3区进行扩增。用Illumina MiSeq进行测序,经过数据处理和比对分析,比较前列腺癌组织TCR CDR3组库的组成特征。结果:前列腺癌组织具有更高程度的克隆百分比和较高的高度扩增克隆比HEC(HEC:频率样本总读数的0. 5%的TCR克隆),并获得了24对在癌组织样本中差异表达的V-J基因组合、16对在癌旁组织样本中差异表达的V-J基因组合。结论:前列腺癌组织与癌旁组织均存在差异性的V-J基因组合以及高克隆表达的HEC,其中癌组织样品具有更高的HEC。PC发生发展对免疫学研究提供了新的数据,对PC免疫监视、T细胞受体变异标志等研究提供了参考,对以后继续研究打下了基础。