Microvesicles-mediated communication between endothelial cells modulates,endothelial survival,and angiogenic function via transferring of miR-125a-5p

Endothelial cells (ECs) released microvesicles (EMVs) could modulate the functions of target cells by transferring their microRNAs (miRs). We have reported that miR-125a-5p protected EC function. In this study, we determined whether EMVs provided beneficial effects on ECs by transferring miR-125a-5p. Human brain microvessel ECs were transfected with miR-125a-5p mimic or miR-125a-5p short hairpin RNA to obtain miR-125a-5p overexpressing ECs and miR-125a-5p knockdown ECs, and their derived EMVs. For the functional study, ECs or hypoxia/reoxygenation injured ECs were coincubated with various EMVs. The survival and angiogenic function of ECs were measured. Western blot and quantitative real time polymerase chain reaction (qRT-PCR) were used for measuring the levels of phosphoinositide 3-kinase (PI3K), phosphorylation-Akt (p-Akt)/Akt, p-endothelial nitric oxide synthase (p-eNOS), cleaved caspase-3, and miR-125a-5p. PI3K inhibitor was used for pathway analysis. EMVs promoted the proliferation, migration, and tube formation ability of ECs, and alleviated the apoptotic rate of ECs. These effects were associated by an increase in p-Akt/Akt and p-eNOS, and a decrease in cleaved caspase-3 could be abolished by LY294002. Overexpression or downregulation of miR-125a-5p in EMVs promoted or inhibited those effects of EMVs. EMVs could enhance the survival and angiogenic function of ECs via delivering miR-125a-5p to modulate the expression of PI3K/Akt/eNOS pathway and caspase-3.     

CD38 inhibitor 78c increases mice lifespan and healthspan in a model of chronological aging

Nicotinamide adenine dinucleotide (NAD) levels decline during aging, contributing to physical and metabolic dysfunction. The NADase CD38 plays a key role in age‐related NAD decline. Whether the inhibition of CD38 increases lifespan is not known. Here, we show that the CD38 inhibitor 78c increases lifespan and healthspan of naturally aged mice. In addition to a 10% increase in median survival, 78c improved exercise performance, endurance, and metabolic function in mice. The effects of 78c were different between sexes. Our study is the first to investigate the effect of CD38 inhibition in naturally aged animals.     

小麦旗叶早衰性状的QTL定位

为小麦旗叶早衰性状的精细定位和基因克隆奠定基础,该试验以普通小麦(Triticum aestivum L.)‘宁春4号’和‘宁春27号’杂交得到的128个F10代RIL群体为研究材料,利用307对多态性SSR标记对小麦旗叶早衰性状进行了QTL定位,并通过构建整合图谱的方法进行了标记加密。结果表明,共检测到1个控制旗叶早衰性状的加性QTL,位于2A染色体长臂的gwm526和gwm382标记区间内,可解释49.88%的表型变异。经遗传图谱整合后发现,gwm526和gwm382标记之间存在124个SNP标记。     

水生态空间红线概念、划定方法及实证研究

我国面临着多方面、复杂的水生态问题:洪涝、干旱、水质污染、水生生境丧失以及人水关系日益疏远等等。解决这些问题,不能依赖单一目标的灰色工程方法,而必须从维护和保育水生态系统的完整性出发,来系统地解决问题。为此,如何定义一个相对完整的水生态系统的边界、划定维护其安全和健康的底线,即水生态空间红线,是用生态方法综合解决水问题的基础性的工作。研究提出了以保护水生态系统的综合生态服务为核心的水生态空间红线概念;提出了以水生态安全格局构建为基础的水生态空间红线划定方法和"水生态问题分析-水生态过程模拟和评价-水生态安全等级划分-水生态安全格局判定-水生态空间红线的划定"技术流程,分别划定水资源供给保护、水文调节保护、水生命支持和水文化保护四种类型的水生态保护空间红线,在此基础上,整合为综合的水生态空间红线,它呈现为对水生态过程具有关键意义的点、线、面和空间联系所构成的空间格局,并以雁栖湖流域为例进行了实证研究。     

城市湿地公园使用者评价的影响因素及其行为偏好——以宜昌运河公园为例

城市湿地公园是城市水环境保护和市民活动的共同载体。如何达到保护城市水环境和满足使用者社会需求的平衡是本研究的关键问题。以景观绩效评价为基础,对宜昌运河公园的社会绩效进行了详细量化,并在调查结果上分析研究了影响城市湿地公园使用者评价的原因,以及在城市湿地公园内使用者的行为偏好和季节变化下使用者满意度和行为模式的变化情况,并提出了设计建议。结果表明,城市湿地公园的水环境治理目标与城市居民的公园服务需求是统一的。但是在公园生态和社会效益之间还是存在着冲突关系,如湿地面积和活动空间面积的权衡,消减河流污染物和维持公园水景质量的权衡以及湿地生境冬季景观效果不佳降低使用者满意度的情况。     

不同年龄小鼠精原干细胞系的建立

精原干细胞（spennatogonial stem cells,SSCs）是雄性动物体内能进行终生自我更新并能将亲代基因遗传给予子代的一类细胞。不同年龄段的小鼠有不同的建系方法。6-7d幼鼠,可以用差异贴壁或直接贴壁法;5-6周成年鼠,一般采用差异贴壁法;31周老年鼠,最好种于饲养层细胞上。通过对精原干细胞系的甲基化和特异基因分析以及睾丸体内移植验证分析,成功建立了具有功能的不同年龄段的小鼠精原干细胞系。     

Field evidences for the positive effects of aerosols on tree growth

Theoretical and eddy covariance studies demonstrate that aerosol‐loading stimulates canopy photosynthesis, but field evidence for the aerosol effect on tree growth is limited. Here, we measured in situ daily stem growth rates of aspen trees under a wide range of aerosol‐loading in China. The results showed that daily stem growth rates were positively correlated with aerosol‐loading, even at exceptionally high aerosol levels. Using structural equation modeling analysis, we showed that variations in stem growth rates can be largely attributed to two environmental variables covarying with aerosol loading: diffuse fraction of radiation and vapor pressure deficit (VPD). Furthermore, we found that these two factors influence stem growth by influencing photosynthesis from different parts of canopy. Using field observations and a mechanistic photosynthesis model, we demonstrate that photosynthetic rates of both sun and shade leaves increased under high aerosol‐loading conditions but for different reasons. For sun leaves, the photosynthetic increase was primarily attributed to the concurrent lower VPD; for shade leaves, the positive aerosol effect was tightly connected with increased diffuse light. Overall, our study provides the first field evidence of increased tree growth under high aerosol loading. We highlight the importance of understanding biophysical mechanisms of aerosol‐meteorology interactions, and incorporating the different pathways of aerosol effects into earth system models to improve the prediction of large‐scale aerosol impacts, and the associated vegetation‐mediated climate feedbacks.     

水稻白叶枯病菌的RAPD分型

对植物病原菌的分型是生物技术应用的新领域,水稻白叶枯病菌(Xanthomonas oryzae pv． Oryzae)是亚洲地区水稻的主要病害。前人曾根据不同菌株在5个鉴别品种上的反应型将中国白叶枯病菌分为7个致病型⑴。近来,Leach等⑵已开始利用基因组特异的重复顺序对白叶枯病菌株进行DNA指纹分析,章琦等⑶也利用相同的探针对我国部分菌株进行了RELP分型,其结果与传统病理学的分类结果有相符之处．但又有相当的不同,说明传统分类结果尚有许多值得探索之处。与RFLP相比,RAPD(Random　Amplified Polymorphic DNA)具有简便和快速的优点,而且相当灵敏,在动植物基因组分型(gennome typing)上已得到较为广泛的应用〔4.5〕。我们利用RAPD标记对我国28个菌株进行分型,发现随机引物A－14可用以区分所研究的28个菌株。进而对扩增带型进行了相似百分率分析,并利用另一随机引物A一1 3作了进一步分析。本文是用RAPD方法尝试对部分水稻白叶枯病菌分型的首次报道。