蹄蝠科的核型进化:比较染色体涂色、G带和C带分析(英文)

与其姐妹科(菊头蝠科)相比,蹄蝠科的细胞遗传学研究较少。迄今为止,仅少数蹄蝠科几个物种有高分辨率的G带核型报道,且有关该科核型进化的大多数结论都是基于常规Giemsa染色研究而得。该研究利用三叶小蹄蝠的染色体特异探针,通过比较染色体涂色、G和C显带,建立了5种蹄蝠的染色体同源性图谱,并探讨了它们同源染色体间的G和C带异同。结果表明:罗伯逊易位、臂内倒位以及异染色质的扩增可能是蹄蝠科物种核型进化的主要机制。通过对这5种蹄蝠物种及其外群物种之间的同源染色体片段的比较分析,作者推测蹄蝠科的祖先核型并不像先前认为的全由端着丝粒染色体组成,而应该含有中着丝粒染色体。     

Adaptive T cell immunotherapy in cancer

Impaired tumor-specific effector T cells contribute to tumor progression and unfavorable clinical outcomes. As a compensatory T cell-dependent cancer immunoediting strategy, adoptive T cell therapy(ACT) has achieved encouraging therapeutic results,and this strategy is now on the center stage of cancer treatment and research. ACT involves the ex vivo stimulation and expansion of tumor-infiltrating lymphocytes(TILs) with inherent tumor reactivity or T cells that have been genetically modified to express the cognate chimeric antigen receptor or T cell receptor(CAR/TCR), followed by the passive transfer of these cells into a lymphodepleted host. Primed T cells must provide highly efficient and long-lasting immune defense against transformed cells during ACT. Anin-depth understanding of the basic mechanisms of these living drugs can help us improve upon current strategies and design better next-generation T cell-based immunotherapies. From this perspective, we provide an overview of current developments in different ACT strategies, with a focus on frontier clinical trials that offer a proof of principle. Meanwhile, insights into the determinants of ACT are discussed, which will lead to more rational, potent and widespread applications in the future.     

hPNAS-4 inhibits proliferation through S phase arrest and apoptosis: underlying action mechanism in ovarian cancer cells

PNAS-4, a novel pro-apoptotic gene, was activated during the early response to DNA damage. Previous studies have shown that hPNAS-4 can inhibit tumor growth when over-expressed in ovarian cancer cells. However, the underlying action mechanism remains elusive. In this work, we found that hPNAS-4 expression was significantly increased in SKOV3 cells when exposed to cisplatin, methyl methanesulfonate or mitomycin C, and that its overexpression could induce proliferation inhibition, S phase arrest and apoptosis in A2780s and SKOV3 ovarian cancer cells. The S phase arrest caused by hPNAS-4 was associated with up-regulation of p21. p21 is p53-dispensable and correlates with activation of ERK, and activation of the Cdc25A-Cdk2-Cyclin E/Cyclin A pathway, while the pro-apoptotic effects of hPNAS-4 were mediated by activation of caspase-9 and -3 other than caspase-8, and accompanied by release of AIF, Smac and cytochrome c into the cytosol. Taken together, these data suggest a new mechanism by which hPNAS-4 inhibits proliferation of ovarian cancer cells by inducing S phase arrest and apoptosis via activation of Cdc25A-Cdk2-Cyclin E/Cyclin A axis and mitochondrial dysfunction-mediated caspase-dependent and -independent apoptotic pathways. To our knowledge, we provide the first molecular evidence for the potential application of hPNAS-4 as a novel target in ovarian cancer gene therapy.     

Activation of JNK/c-Jun is required for the proliferation, survival, and angiogenesis induced by EET in pulmonary artery endothelial cells

Pulmonary artery endothelial plexiform lesion is responsible for pulmonary vascular remodeling (PVR), a basic pathological change of pulmonary arterial hypertension (PAH). Recent evidence suggests that epoxyeicosatrienoic acid (EET), which is derived from arachidonic acid by cytochrome p450 (CYP) epoxygenase, has an essential role in PAH. However, until now, most research has focused on pulmonary vasoconstriction; it is unclear whether EET produces mitogenic and angiogenic effects in pulmonary artery endothelial cells (PAEC). Here we found that 500 nM/l 8,9-EET, 11,12-EET, and 14,15-EET markedly augmented JNK and c-Jun activation in PAECs and that the activation of c-Jun was mediated by JNK, but not the ERK or p38 MPAK pathway. Moreover, treatment with 8,9-EET, 11,12-EET, and 14,15-EET promoted cell proliferation and cell-cycle transition from the G0/G1 phase to S phase and stimulated tube formation in vitro. All these effects were reversed after blocking JNK with Sp600125 (a JNK inhibitor) or JNK1/2 siRNA. In addition, the apoptotic process was alleviated by three EET region isomers through the JNK/c-Jun pathway. These observations suggest that 8,9-EET, 11,12-EET, and 14,15-EET stimulate PAEC proliferation and angiogenesis, as well as protect the cells from apoptosis, via the JNK/c-Jun pathway, an important underlying mechanism that may promote PAEC growth and angiogenesis during PAH.     

Roseomonas alkaliterrae sp. nov., isolated from an alkali geothermal soil sample in Tengchong,Yunnan, south-west China

An alkalitolerant, thermotolerant and Gram-stain negative bacterium, designated strain YIM 78007^T, was isolated from an alkaline geothermal soil sample from Hehua hot spring, Tengchong, Yunnan province, south-west China. Cells of strain YIM 78007^T were observed to be aerobic and short rod-shaped. The colonies were observed to be orange-red, convex and circular. 16S rRNA gene sequence-based phylogenetic analysis showed that strain YIM 78007^T clustered with members of the genus Roseomonas (with similarities from 97.2 to 92.2 %). Optimal growth of strain YIM 78007 occurs at 40–50 °C and pH 8.0–10.0. The predominant ubiquinone was identified as Q-10 and the major fatty acids were identified as C_18:1 ω7c and C_16:0. The polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, two unidentified aminolipids and one unknown phospholipid. The G + C content of the genomic DNA was determined to be 63 mol %. The levels of DNA–DNA hybridization relatedness between strain YIM 78007^T and its closet neighbours (Roseomonas lacus JCM 13283^T and Roseomonas terrae JCM 14592^T) were well below the threshold required for the proposal of a novel species. The results of physiological and biochemical characteristics, the phylogenetic analysis, as well as low DNA–DNA hybridization values, allowed the phenotypic and genotypic differentiation of strain YIM 78007^T from its closest phylogenetic neighbours. Therefore, strain YIM 78007^T is considered to represent a novel species of the genus Roseomonas, for which the name Roseomonas alkaliterrae sp. nov. is proposed. The type strain is YIM 78007^T (=BCRC 80644^T = JCM 19656^T).     

资源型城市土地利用转型及其对生境质量的影响——以乌海市为例

资源型城市前期发展导致了生境丧失或退化,实现高质量转型需要深入理解城市转型与生态环境质量之间的关系,土地利用转型特征及其对生境质量的影响规律研究为此提供依据与支撑。以资源型城市--乌海市为研究区,通过地学信息图谱和InVEST模型探究2005-2018年乌海市土地利用转型特征、生境质量时空变化及土地利用转型对生境质量的影响。结果表明：（1）2005-2018年乌海市土地利用变化趋势发生改变,土地利用转型明显,土地利用变化图谱单元数量逐渐增加78.14%,分布范围逐渐广泛。主要表现为草地与建设用地、采矿用地之间的相互转化,第一阶段（2005-2015年）草地大面积减少,建设用地和采矿用地大面积增加,第二阶段（2015-2018年）趋势相反。（2）乌海市生境质量变化呈现先强退化后弱提升趋势。2005-2015年乌海市18.75%的区域生境质量退化,提升面积较小;2015-2018年生境质量提升面积略大于退化面积。（3）2005-2015年草地向采矿用地、建设用地转化是区域生境质量降低的主要原因,2015-2018年区域生境质量提升的主导因素是采矿用地和建设用地向草地转化。研究结果揭示了资源型城市土地利用转型过程中生境质量的响应规律,可为资源型城市土地利用转型决策提供参考。     

黄河口岸线变迁对潮滩盐沼景观格局变化的影响

基于2001、2005和2010年3期TM遥感影像,运用GIS技术,分析了黄河三角洲不同区士或(Ⅰ区,刁口段;Ⅱ区,东营港及临近岸段;Ⅲ区,河口段;Ⅳ区,南部莱州湾岸段)潮滩盐沼的景观演变与海岸线变迁的动因关系。结果表明,岸线变迁直接决定了潮滩盐沼面积的增长或缩减,但其在不同区域的影响程度差异较大。2001-2010年,Ⅰ区由于1976年以后刁口流路废弃、水沙输入量锐减导致其岸线持续蚀退,潮滩面积锐减明显(减少57.64 km~2,减少率25.94%);Ⅲ区由于1976年以后黄河由清水沟或清8汉入海,河口区域的持续淤积状态使得岸线持续增长,潮滩面积增加显著(增加66.17 km~2,增长率17.39%);而Ⅱ区由于海堤修建及港口建设等人类活动影响,岸线基本处于稳定状态,潮滩面积变化不大,Ⅳ区潮滩面积持续增加。不同区域潮滩盐沼景观格局随距海远近均呈明显带状分布,依次为芦苇盐沼、碱蓬-柽柳-芦苇盐沼、碱蓬盐沼和光滩。2001-2010年,不同景观类型之间存在明显转移,光滩、碱蓬盐沼和芦苇盐沼的面积持续减少(分别减少6.02、18.39和99.20 km~2,减少率为4.61%、12.86%和50.11%),碱蓬-柽柳-芦苇盐沼的面积整体呈增加趋势(增加35.50 km~2,增长率为24.99%)。研究发现,不同区域的景观类型均随岸线的淤积或蚀退而发生向海或向陆的演替,岸线变迁是影响不同区域潮滩盐沼景观格局的决定因素,而黄河调水调沙工程的长期实施对于近年来河口段岸线的变迁以及盐沼植被景观类型的演变具有深刻影响。