MLKL mediates apoptosis via a mutual regulation with PERK/eIF2α pathway in response to reactive oxygen species generation

The pseudokinase mixed lineage kinase domain-like protein (MLKL) is a core effector of necroptosis, and its function in necroptosis is widely studied. However, the function of MLKL in apoptosis remains unclear. In the present study, the role of MLKL in chelerythrine (CHE)-promoted apoptosis was studied. A special band of MLKL (i.e., *MLKL) was observed after treatment with CHE. MLKL and *MLKL were accumulated in the nucleus upon treatment with CHE and MLKL silencing reversed the CHE-induced apoptosis. Blockade of CHE-triggered reactive oxygen species (ROS) generation or inhibition of CHE-activated protein kinase-like endoplasmic reticulum kinase (PERK)-eukaryotic initiation factor 2 α subunit (eIF2α) pathway reversed the apoptosis. A decreased ROS level inhibited CHE-mediated nuclear translocation of MLKL and *MLKL and the activation of eIF2α, whereas MLKL or eIF2α silencing did not affect the CHE-triggered ROS generation. Furthermore, MLKL silencing prevented the CHE-activated eIF2α signal, and eIF2α silencing blocked the CHE-induced nuclear translocation of MLKL and *MLKL. Our studies suggested that CHE possibly induces apoptosis through the nuclear translocation of MLKL and *MLKL, which is promoted by a mutual regulation between MLKL and PERK–eIF2α pathway in response to ROS formation. The present study clarified the new function of MLKL in apoptosis.     

Activity dynamics and propagation of synchronous spiking in locally connected random networks

Random network models have been a popular tool for investigating cortical network dynamics. On the scale of roughly a cubic millimeter of cortex, containing about 100,000 neurons, cortical anatomy suggests a more realistic architecture. In this locally connected random network, the connection probability decreases in a Gaussian fashion with the distance between neurons. Here we present three main results from a simulation study of the activity dynamics in such networks. First, for a broad range of parameters these dynamics exhibit a stationary state of asynchronous network activity with irregular single-neuron spiking. This state can be used as a realistic model of ongoing network activity. Parametric dependence of this state and the nature of the network dynamics in other regimes are described. Second, a synchronous excitatory stimulus to a fraction of the neurons results in a strong activity response that easily dominates the network dynamics. And third, due to that activity response an embedding of a divergent-convergent feed-forward subnetwork (as in synfire chains) does not naturally lead to a stable propagation of synchronous activity in the subnetwork; this is in contrast to our earlier findings in isolated subnetworks of that type. Possible mechanisms for stabilizing the interplay of volleys of synchronous spikes and network dynamics by specific learning rules or generalizations of the subnetworks are discussed.     

华南植物区系的评论（三） Ⅳ．旋花科一些种类的修订

作者编写《广东植物志》旋花科时,对据本科的花粉形态特征划分族和属的意义予肯定并采用之;现将其中４个属、６个分类单位的分类或其分布等予于报道．对华南和北越的心萼薯属植物作修订;论证本地区不产ＡｎｉｓｅｉａＣｈｏｉｓｙ．被认为该属的狭花心萼薯Ａ．ｓｔｅｎａｎｔｈｏ和大花心萼薯Ａ．ｓｔｅｎａｎｔｈａｖａｒ．ｍａｃｒｏｓｒｅｐｈａｎａ均是龙骨萼牵牛Ｉｐｏｍｏｅａａｔｅｎａｎｔｈａ;心萼薯Ａｎｉｓｅｉａｂｉｆｌｏｒａ是毛牵牛Ａｎｉｓｅｉａｓｉｎｅｎｓｉｓ;云南土丁桂Ｅｖｏｌｖｕｌｕｓｙｕｎｎａｎｅｎｓｉｓ作新异名处理．应为我国新纪录的归化种（美洲土丁桂Ｅ．ｎｕｍｍｕｌａｒｉｕｓ）;裂叶鳞蕊藤Ｌｅｐｉｓｔｅｍｏｎｌｏｂａｔｕｍ为越南新纪录．也分布于我国江西、海南;海滩牵牛Ｉｐｏｍｏｅｏｓｔｏｌｏｎｉｆｅｒａ这个开白花的海滩植物是一种中草药;虎脚牵牛Ｉｐｏｍｏｅａｐｅｓ－ｔｉｇｒｉｄｉｓ是亚洲和非洲东部热带的广布种,广东大陆西部也有;它是ＩｐｏｍｏｅａＬｉｎｎ．选模式种;这属的中名,本文恢复《广州植物志》（１９５６）等采用的牵牛属,会比较确切用“番薯属”为这个属的中名。     

靶向M细胞的抗原递送¾¾增强黏膜免疫应答的关键策略

黏膜是阻止病原入侵的第一道防线,黏膜免疫系统在抵抗感染方面起着至关重要的作用。通过黏膜途径接种疫苗可以同时诱导黏膜和全身免疫反应,因此,理论上针对黏膜的免疫策略是最合理和有效的。但黏膜免疫系统的复杂性和屏障作用造成抗原诱导的免疫应答水平低下,制约了黏膜疫苗的发展。M细胞(Microfoldcells)是黏膜免疫系统所独有的,其具有捕获腔内抗原和启动抗原特异性免疫应答的功能。M细胞摄取抗原的多少直接关系到黏膜疫苗的免疫效力,而利用M细胞配体可将抗原靶向递呈给M细胞,从而实现高效的黏膜免疫应答。靶向M细胞的抗原递送策略及其应用可以提高黏膜免疫应答水平,促进黏膜疫苗的研制。尽管如此,要成功研制安全高效的黏膜疫苗,今后依然有漫长的路要走,这可能有赖于进一步探究M细胞的特性和功能及黏膜免疫机制。     

EBV编码miRNAs在病毒感染和肿瘤发生中的功能和意义

EB病毒(Epstein-Barr virus,EBV)是一种172 kb大小的线性双链DNA病毒,与鼻咽癌、淋巴瘤、胃癌等恶性肿瘤的发生密切相关. EBV编码的微小RNAs (miRNAs)可以调节病毒和宿主细胞基因的表达,并且在癌症发生发展中起着多种作用.本文综述了EBV编码的miRNAs (EBV-encoded miRNA,EBV miRNAs)在病毒感染和肿瘤发生、侵袭转移、抗凋亡、信号通路等方面的生物学功能,以及对于EBV相关肿瘤诊断标志物的潜在意义. EB病毒编码的miRNAs也可能成为进一步研究EBV相关肿瘤治疗的一个候选靶点.     

冻融条件下生物结皮覆盖对土壤饱和导水率的影响

生物结皮(BSC)是广泛分布的地被物,每逢冬春季节,受冻融交替作用影响,结皮土壤的理化性质和水文学特征明显改变且与裸土差异显著,从而影响该地区土壤可蚀性评估和土壤侵蚀防治。采用室内模拟实验,以蓝藻结皮土壤为对象,研究不同冻融交替次数和初始含水量下,土壤三相对温度变化的响应特征并定量分析结皮覆盖土壤在此条件下饱和导水率(Ks)的变化趋势和突变点。结果表明:初始含水量对Ks无显著影响(P>0.05),冻融交替次数对Ks有极显著影响(P<0.01),冻融条件下裸土的平均Ks为1.941 mm/min,结皮覆盖土壤平均Ks为0.325 mm/min,两者具有极显著差异(P<0.01),且随交替次数增加,Ks差异逐渐增大,并在10次时达到最大值为10.13倍。不同冻融含水量下的结皮土壤的Ks在冻融10—20次时趋近,平均值为0.219mm/min。冻融作用显著改变土壤结构,且在冻融7次时土壤结构变化较明显,冻融过程中<0.1 mm的土壤颗粒显著变化。试验条件下,Ks受因子影响程度大小为:冻融交替次数>土壤结构>结皮厚度>结皮容重>下层土壤容重>...     

鸡源暹罗芽孢杆菌CML548的益生特性及全基因组分析

【背景】芽孢杆菌是用于动物微生态制剂的重要菌株之一。暹罗芽孢杆菌因具有较强的抑菌活性,近年来受到广泛关注。【目的】对实验室前期分离的鸡源暹罗芽孢杆菌CML548的益生特性进行评价,通过全基因组测序及生物信息学分析,探究其抑菌及潜在的益生机制。【方法】通过牛津杯法、稀释涂布平板法分别对菌株CML548的抑菌和产酶特性、酸和胆盐的耐受性进行研究。使用IlluminaHiSeq2500测序平台进行全基因组测序,并通过多种生物信息学工具和数据库对基因组进行注释和分析。【结果】体外实验表明该菌株具有优良的益生性状：能够有效抑制致病性大肠杆菌、鼠伤寒沙门氏菌、产气荚膜梭菌的生长;能够同时产生蛋白酶、淀粉酶和纤维素酶;具有较高的酸和胆盐耐受性。全基因组测序分析表明菌株CML548的基因组大小为4061741bp,GC含量为46.07%,预测到3 961个编码基因。分别有1 693、2 704、3 413、186、67、1、5个基因被GO、KEGG、COG、CAZy、DBAASP、CARD、VFDB数据库注释;通过antiSMASH预测到16个与次级代谢产物合成相关的基因簇。此外,还发现其含有抗菌活性...     

基于成果导向教育理念的“发酵工程实验”课程内容设计及实践

"发酵工程实验"是生物工程专业的工程类重要主干课之一,是培养学生工程设计、工程实践和创新思维的重要课程。基于构思—设计—实现—运行(conceive—design—implement—operate,CDIO)理念,"发酵工程实验"通过构建模块化课程内容,以构思、设计、实现、运作的项目导向模块开展课程设计,进行目标导向的教学模式改革。以"发酵工程实验"课程为载体,将工程基础知识、发酵工程系统实践能力、团队合作能力、创新能力培养等融为一体。建立基于成果导向教育(outcome-based education,OBE)理念的学生学习效果评价体系,完成"发酵工程实验"课程教学任务。学生对改革后的"发酵工程实验"课程满意度明显提高,教学效果显著。