双效表达载体的构建及其U6启动子的功能效率鉴定

利用pBudcE4.1双表达载体构建shRNA与蛋白共表达载体,为双效疫苗的研制提供新的研究思路.以含U6启动子的载体为模板,PCR扩增得到U6启动子,用其置换载体pBudcE4.1内的CMV启动子的核心部分构建shRNA与蛋白共表达载体.用干扰绿色荧光蛋白表达的方法鉴定重组载体中的U6启动子能否启动shRNA的表达.经PCR扩增、双酶切鉴定及DNA测序证明成功构建了载体pBudcE4.1-U6.用干扰载体pBudcE4.1-U6-eGFPshRNA与含eGFP的载体共转染293T细胞后,荧光显微镜观察显示eGFP的表达量下降;流式细胞仪检测细胞的转染效率降低.研究结果证明U6启动子正常发挥作用. 成功构建RNAi与蛋白共表达载体,为利用该载体研制动物双效疫苗奠定了基础.     

细胞凋亡的研究进展

细胞凋亡（apoptosis)是一种主动的细胞死亡,是机体维持自身稳定的一种基本生理机制,参与许多疾病的病理过程,具有重要的生理病理意义,近年来倍受关注,本文概括介绍有关细胞凋亡的研究进展。     

Effects of Cystamine on antioxidant activities and regulatory T cells in lupus‐prone mice

Attenuated antioxidant activities, irregular cytokines expressions and reduced regulatory T cells, are strongly associated with the pathogenesis of systemic lupus erythematosus (SLE). Despite the well‐established beneficial effects of cystamine on lupus‐prone mice, the extent to which cystamine contributes to antioxidant activity and the reduction of regulatory T cells has seldom been investigated. Therefore, this study elucidates how cystamine affects anti‐oxidant activities in NZB/W F1 mice by performing assays of Glutathione (GSH), 1,1‐diphenyl‐2‐ picryl‐hydrazyl (DPPH) and malondialdehyde thiobarbituric acid (MDA). In addition, investigations of the effects of cystamine on CD4⁺/CD25⁺ regulatory T cells and interleukin‐6 (IL6)/STAT‐3 signalling were performed with flow cytometry and immunoblots. Experimental results reveal more significantly reduced MDA and increased GSH and DPPH in NZB/W F1 mice receiving cystamine than in those mice receiving PBS. Meanwhile, CD4⁺/CD25⁺ regulatory T cells more significantly increase in NZB/W F1 mice receiving cystamine than in those mice receiving PBS, accompanied by significantly reduced IL‐6/phosphorylated STAT‐3 expression. The above findings suggest the beneficial effects of cystamine in terms of increasing antioxidant activities and CD4⁺/CD25⁺ regulatory T cells in lupus‐prone mice by suppressing IL‐6/STAT3 signalling.     

spindlin1基因的原核表达及多克隆抗体制备

目的:明确人新基因spindlin1的组织表达谱、相互作用蛋白。方法与结果:应用PCR技术获得spindlin1的开放读框,并将其插入原核表达载体pGEX-2T,转化大肠杆菌BL21(DE3),经IPTG诱导后,融合蛋白GST-Spindlin1获得了可溶性表达。用SDS-PAGE胶上的目的条带做抗原制备了多克隆抗体,进行了抗体纯化。结论:spindlin1在OVCar3细胞中可能以二聚体形式存在,这一现象还有待于进一步研究。     

弄岗北热带喀斯特季节性雨林15hm2动态监测样地树木死亡特征分析

以广西弄岗北热带喀斯特季节性雨林15 hm²森林动态监测样地为对象,结合2011年和2016年两次调查数据,分析5年间样地树木死亡个体的数量、径级结构和空间格局特征等。结果显示:2011年至2016年,样地有86.5%的树种出现了个体死亡的现象,死亡个体占个体总数的14.4%;死亡个体的聚集程度随空间尺度的增大而逐渐减弱;小径级个体死亡与周边邻体和环境的关联性较大;竞争是影响弄岗北热带喀斯特季节性云林树木死亡的主要因素。综合来看,北热带喀斯特季节性雨林内树木死亡并非是一个完全随机的过程,而是树木本身特征和生物与非生物环境共同作用的结果。     

Ageing related thyroid deficiency increases brain-targeted transport of liver-derived ApoE4-laden exosomes leading to cognitive impairment

Alzheimer’s disease (AD) is the prevalent cause of dementia in the ageing world population. Apolipoprotein E4 (ApoE4) allele is the key genetic risk factor for AD, although the mechanisms linking ApoE4 with neurocognitive impairments and aberrant metabolism remains to be fully characterised. We discovered a significant increase in the ApoE4 content of serum exosomes in old healthy subjects and AD patients carrying ApoE4 allele as compared with healthy adults. Elevated exosomal ApoE4 demonstrated significant inverse correlation with serum level of thyroid hormones and cognitive function. We analysed effects of ApoE4-containing peripheral exosomes on neural cells and neurological outputs in aged or thyroidectomised young mice. Ageing-associated hypothyroidism as well as acute thyroidectomy augmented transport of liver-derived ApoE4 reach exosomes into the brain, where ApoE4 activated nucleotide-binding oligomerisation domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome by increasing cholesterol level in neural cells. This, in turn, affected cognition, locomotion and mood. Our study reveals pathological potential of exosomes-mediated relocation of ApoE4 from the periphery to the brain, this process can represent potential therapeutic target.Subject terms: Cognitive neuroscience, Alzheimer''s disease, Cellular neuroscience     

TNFα‐induced abnormal activation of TNFR/NF‐κB/FTH1 in endometrium is involved in the pathogenesis of early spontaneous abortion

Early spontaneous abortion (ESA) is one of the most common complications during pregnancy and the inflammation condition in uterine environment such as long‐term exposure to high TNFα plays an essential role in the aetiology. Ferritin heavy chain (FTH1) is considered to be closely associated with inflammation and very important in normal pregnancy, yet the underlying mechanism of how TNFα induced abortion and its relationship with FTH1 remain elusive. In this study, we found that TNFα and FTH1 were positively expressed in decidual stromal cells and increased significantly in the ESA group compared with the normal pregnancy group (NP group). Besides, TNFα expression was positively correlated with FTH1 expression. Furthermore, in vitro cell model demonstrated that high TNFα could induce the abnormal signals of TNFR/NF‐κB/FTH1 and activate apoptosis both in human endometrium stromal cells (hESCs) and in local decidual tissues. Taken together, the present findings suggest that the excessive apoptosis in response to TNFα‐induced upregulation of FTH1 may be responsible for the occurrence of ESA, and thus provide a possible therapeutic target for the treatment of ESA.