A New Pathway for Senescence Regulation

<正>Research concerning senescence has become a hotspot since the conception of‘cellular senescence’was put forward by Drs.Hayflick and Moorhead over five decades ago[1].Recently,a paper published in Science by Kang and colleagues,which this article aims to comment on,provides evidence of a new pathway involved in senescence[2].Senescence is a physiological and pathological process induced by numerous factors,during which cell growth ceases     

气候变化下中国八种梧桐属树种潜在适生区模拟

中国梧桐属（Firmiana）在世界梧桐属中占比较大，且除梧桐外其余种均为中国特有且分布范围狭窄的植物种，灭绝风险大，研究气候变化对中国梧桐属树种的影响对于维护生物多样性具有重要的意义。结合多时期第六次国际气候耦合模式比较计划（CMIP6）气候变量数据和中国八种梧桐属树种的分布数据，基于R语言kuenm程序包优化的最大熵（Maxent）模型模拟分析中国八种梧桐属树种在多尺度下的潜在适生区，得出梧桐属最适宜的模拟尺度、潜在适生区的面积变化和迁移方向、梧桐属多样性保护关键区域及保护空缺。结果表明：（1）梧桐属最适宜的模拟尺度为亚洲；（2） Maxent模型的接收者操作特征曲线下面积（AUC）值均大于0.9，表明模型对梧桐属潜在适生区预测结果具有较高准确度；（3）气候变化影响下除云南梧桐（Firmiana major）外其它树种的潜在适生区都将在未来有所扩大；（4）中国八种梧桐属树种潜在适生区迁移方向主要为东西向，南北向大跨度迁移较少，纬度变化不大；（5）丹霞梧桐（Firmiana danxiaensis）的稳定潜在适生区最小；（6）中国梧桐属多样性保护关键区域主要分布于广西壮族自治区及云南、广东、海南等省区；（7）中国梧桐属多样性保护空缺区域主要分布于广西壮族自治区中部及海南省北部；（8）梧桐属多样性保护关键区域正在为人造地表所侵蚀。研究分析气候变化对中国八种梧桐属树种的影响及其潜在适生区变化、中国梧桐属多样性保护状态，可为中国梧桐属建立多样性保护廊道提供相关建议，为制定多样性保护规划及相应措施提供参考。     

High-speed broadband monitoring of cell viscoelasticity in real time shows myosin-dependent oscillations

Study of the dynamic evolutions of cell viscoelasticity is important as during cell activities such as cell metastasis and invasion, the rheological behaviors of the cells also change dynamically, reflecting the biophysical and biochemical connections between the outer cortex and the intracellular structures. Although the time variations of the static modulus of cells have been investigated, few studies have been reported on the dynamic variations of the frequency-dependent viscoelasticity of cells. Measuring and monitoring such dynamic evolutions of cells at nanoscale can be challenging as the measurement needs to meet two objectives inherently contradictory to each other—the measurement must be broadband (to cover a large frequency spectrum) but also rapid (to capture the time-elapsed changes). In this study, we exploited a recently developed control-based nanomechanical protocol of atomic force microscope to monitor in real time the dynamic evolutions of the viscoelasticity of live human prostate cancer cells (PC-3 cells) and study its dependence on myosin activities. We found that the viscoelasticity of PC-3 cells, followed the power law, and oscillated at a period of about 200 s. Both the amplitude and the frequency of the oscillation strongly depended on the intracellular calcium and blebbistatin-sensitive motor proteins.     

Statures in Han populations of China

<正>Dear Editor,Shortly after initiating the"Physical Anthropological Research on Han Chinese"research project,we applied uniform sampling methods as well as methods and instruments of measurement to obtain a complete set of measurements of physical anthropological indicators among Han populations across China.Among these measurements,body stature was a key indicator.Currently,there should be reliable     

miR‐124a inhibits the proliferation and inflammation in rheumatoid arthritis fibroblast‐like synoviocytes via targeting PIK3/NF‐κB pathway

Abnormal hyperplasia of fibroblast‐like synoviocytes (FLS) leads to the progression of rheumatoid arthritis (RA). This study aimed to investigate the role of miR‐124a in the pathogenesis of RA. The viability and cell cycle of FLS in rheumatoid arthritis (RAFLS) were evaluated by Cell Counting Kit 8 and flow cytometry assay. The expression of PIK3CA, Akt, and NF‐κB in RAFLS was examined by real‐time PCR and Western blot analysis. The production of tumour necrosis factor (TNF)‐α and interleukin (IL)‐6 was detected by ELISA. The joint swelling and inflammation in collagen‐induced arthritis (CIA) mice were examined by histological and immunohistochemical analysis. We found that miR‐124a suppressed the viability and proliferation of RAFLS and increased the percentage of cells in the G1 phase. miR‐124a suppressed PIK3CA 3'UTR luciferase reporter activity and decreased the expression of PIK3CA at mRNA and protein levels. Furthermore, miR‐124a inhibited the expression of the key components of the PIK3/Akt/NF‐κB signal pathway and inhibited the expression of pro‐inflammatory factors TNF‐α and IL‐6. Local overexpression of miR‐124a in the joints of CIA mice inhibited inflammation and promoted apoptosis in FLS by decreasing PIK3CA expression. In conclusion, miR‐124a inhibits the proliferation and inflammation in RAFLS via targeting PIK3/NF‐κB pathway. miR‐124a is a promising therapeutic target for RA.     

Functional analysis of a miRNA‐like small RNA derived from Bombyx mori cytoplasmic polyhedrosis virus

Bombyx mori cytoplasmic polyhedrosis virus (BmCPV) is a major pathogen of the economic insect silkworm, Bombyx mori. Virus‐encoded microRNAs (miRNAs) have been proven to play important roles in host–pathogen interactions. In this study we identified a BmCPV‐derived miRNA‐like 21 nt small RNA, BmCPV‐miR‐1, from the small RNA deep sequencing of BmCPV‐infected silkworm larvae by stem‐loop quantitative real‐time PCR (qPCR) and investigated its functions with qPCR and lentiviral expression systems. Bombyx mori inhibitor of apoptosis protein (BmIAP) gene was predicted by both target prediction software miRanda and Targetscan to be one of its target genes with a binding site for BmCPV‐miR‐1 at the 5′ untranslated region. It was found that the expression of BmCPV‐miR‐1 and its target gene BmIAP were both up‐regulated in BmCPV‐infected larvae. At the same time, it was confirmed that BmCPV‐miR‐1 could up‐regulate the expression of BmIAP gene in HEK293T cells with lentiviral expression systems and in BmN cells by transfecting mimics. Furthermore, BmCPV‐miR‐1 mimics could up‐regulate the expression level of BmIAP gene in midgut and fat body in the silkworm. In the midgut of BmCPV‐infected larvae, BmCPV‐miR‐1 mimics could be further up‐regulated and inhibitors could lower the virus‐mediated expression of BmIAP gene. With the viral genomic RNA segments S1 and S10 as indicators, BmCPV‐miR‐1 mimics could up‐regulate and inhibitors down‐regulate their replication in the infected silkworm. These results implied that BmCPV‐miR‐1 could inhibit cell apoptosis in the infected silkworm through up‐regulating BmIAP expression, providing the virus with a better cell circumstance for its replication.     

纳米孔测序技术在病毒性传染病检测及研究中的应用

快速、准确鉴定出病原体是临床感染性疾病诊断和传染病预防控制的基础。高通量测序基因检测技术突破了传统检测手段的时效性、灵敏度等的局限，为病原体检测和研究提供了便捷、高效的途径。本综述以高通量测序技术发展过程为基础，回顾纳米孔三代测序技术，及其在病毒性传染病检测鉴定及研究中的应用，并对该技术的应用前景及可能存在的问题进行阐述，期望它能在病毒性传染病的防控方面发挥更大的作用。