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91.
Li Jiang Yanguo Qiao Zhenghui Wang Xiuzhu Ma Haichao Wang Jian Li 《Journal of cellular physiology》2020,235(1):380-393
Atherosclerosis (AS), a chronic disorder of large arteries, is the underlying pathological process of heart disease and stroke. Former researchers have found that microRNAs (miRs) are involved in the several key processes of AS. Apolipoprotein E knockout (ApoE−/−) mice fed a high-fat-diet (HFD) to establish AS model. The expression of miR-103 was characterized in the mice model. The effects of miR-103 on inflammation and endoplasmic reticulum stress (ERS) were analyzed when the expression of miR-103 was inhibited in ApoE −/− mice fed an HFD and human aortic endothelial cells (HAECs) exposed to oxidized low-density lipoprotein (ox-LDL). The relationship between miR-103 and phosphatase and tensin homolog (PTEN) was identified by luciferase activity detection and real-time quantitative polymerase chain reaction (RT-qPCR). Gain- and loss-function approaches were further applied for investigating the regulatory effects of miR-103 and PTEN on ERS. Role of MAPK signaling was then analyzed using PD98059 to block this pathway. miR-103 was highly expressed in the ApoEApoE −/− mice fed an HFD. Downregulation of miR-103 suppressed inflammation and ERS in endothelial cells isolated from ApoE −/− mice fed a HFD and ox-LDL-exposed HAECs. In addition, miR-103 can target PTEN and downregulate its expression. Overexpression of PTEN reversed the miR-103-induced activation of MAPK signaling. Moreover, PTEN upregulation or MAPK signaling inhibition ease miR-103-induced inflammation and ERS in vivo and in vitro. Thus, miR-103 depletion restrains the progression of AS through blocking PTEN-mediated MAPK signaling. 相似文献
92.
甲基化修饰是蛋白翻译后修饰的主要方式之一。真菌中,多种赖氨酸甲基转移酶能够执行组蛋白特定位点上赖氨酸的甲基化。组蛋白上赖氨酸的甲基化与真菌DNA的复制、转录以及异染色质的形成相关。甲基化参与了多种生物学过程,如真菌发育、昼夜节律调节、次级代谢基因簇表达、水解酶合成、致病真菌毒力形成。本文结合笔者工作,对目前真菌中已经发现的组蛋白赖氨酸甲基转移酶的命名、分类、结构域特征、催化域的三维结构以及它们所执行的甲基化在各种真菌中的作用进行了总结,提出了目前研究的不足并对未来的研究方向和内容进行了展望。 相似文献
93.
Starting in 1991, the advance of Tyr-recombinases Flp and Cre enabled superior strategies for the predictable insertion of transgenes into compatible target sites of mammalian cells. Early approaches suffered from the reversibility of integration routes and the fact that co-introduction of prokaryotic vector parts triggered uncontrolled heterochromatization. Shortcomings of this kind were overcome when Flp-Recombinase Mediated Cassette Exchange entered the field in 1994. RMCE enables enhanced tag-and-exchange strategies by precisely replacing a genomic target cassette by a compatible donor construct. After “gene swapping” the donor cassette is safely locked in, but can nevertheless be re-mobilized in case other compatible donor cassettes are provided (“serial RMCE”). These features considerably expand the options for systematic, stepwise genome modifications. The first decade was dominated by the systematic generation of cell lines for biotechnological purposes. Based on the reproducible expression capacity of the resulting strains, a comprehensive toolbox emerged to serve a multitude of purposes, which constitute the first part of this review. The concept per se did not, however, provide access to high-producer strains able to outcompete industrial multiple-copy cell lines. This fact gave rise to systematic improvements, among these certain accumulative site-specific integration pathways. The exceptional value of RMCE emerged after its entry into the stem cell field, where it started to contribute to the generation of induced pluripotent stem (iPS-) cells and their subsequent differentiation yielding a variety of cell types for diagnostic and therapeutic purposes. This topic firmly relies on the strategies developed in the first decade and can be seen as the major ambition of the present article. In this context an unanticipated, potent property of serial Flp-RMCE setups concerns the potential to re-open loci that have served to establish the iPS status before the site underwent the obligatory silencing process. Other relevant options relate to the introduction of composite Flp-recognition target sites (“heterospecific FRT-doublets”), into the LTRs of lentiviral vectors. These “twin sites” enhance the safety of iPS re-programming and -differentiation as they enable the subsequent quantitative excision of a transgene, leaving behind a single “FRT-twin”. Such a strategy combines the established expression potential of the common retro- and lentiviral systems with options to terminate the process at will. The remaining genomic tag serves to identify and characterize the insertion site with the goal to identify genomic “safe harbors” (GOIs) for re-use. This is enabled by the capacity of “FRT-twins” to accommodate any incoming RMCE-donor cassette with a compatible design. 相似文献
94.
Nanomaterials with superior physiochemical properties have been rapidly developed and integrated in every aspect of cell engineering and therapy for translating their great promise to clinical success. Here we demonstrate the multifaceted roles played by innovatively-designed nanomaterials in addressing key challenges in cell engineering and therapy such as cell isolation from heterogeneous cell population, cell instruction in vitro to enable desired functionalities, and targeted cell delivery to therapeutic sites for prompting tissue repair. The emerging trends in this interdisciplinary and dynamic field are also highlighted, where the nanomaterial-engineered cells constitute the basis for establishing in vitro disease model; and nanomaterial-based in situ cell engineering are accomplished directly within the native tissue in vivo. We will witness the increasing importance of nanomaterials in revolutionizing the concept and toolset of cell engineering and therapy which will enrich our scientific understanding of diseases and ultimately fulfill the therapeutic demand in clinical medicine. 相似文献
95.
Xing Pan Xiao-Jun Li Xi-Juan Liu Hui Yuan Jia-Fu Li Ying-Liang Duan Han-Qing Ye Ya-Ru Fu Guan-Hua Qiao Cong-Cong Wu Bo Yang Xiao-Hui Tian Kang-Hong Hu Ling-Feng Miao Xiao-Ling Chen Jun Zheng Simon Rayner Philip H. Schwartz William J. Britt Jiang Xu Min-Hua Luo 《Journal of virology》2013,87(20):10968-10979
Congenital human cytomegalovirus (HCMV) infection is the most frequent infectious cause of birth defects, primarily neurological disorders. Neural progenitor/stem cells (NPCs) are the major cell type in the subventricular zone and are susceptible to HCMV infection. In culture, the differentiation status of NPCs may change with passage, which in turn may alter susceptibility to virus infection. Previously, only early-passage (i.e., prior to passage 9) NPCs were studied and shown to be permissive to HCMV infection. In this study, NPC cultures derived at different gestational ages were evaluated after short (passages 3 to 6) and extended (passages 11 to 20) in vitro passages for biological and virological parameters (i.e., cell morphology, expression of NPC markers and HCMV receptors, viral entry efficiency, viral gene expression, virus-induced cytopathic effect, and release of infectious progeny). These parameters were not significantly influenced by the gestational age of the source tissues. However, extended-passage cultures showed evidence of initiation of differentiation, increased viral entry, and more efficient production of infectious progeny. These results confirm that NPCs are fully permissive for HCMV infection and that extended-passage NPCs initiate differentiation and are more permissive for HCMV infection. Later-passage NPCs being differentiated and more permissive for HCMV infection suggest that HCMV infection in fetal brain may cause more neural cell loss and give rise to severe neurological disabilities with advancing brain development. 相似文献
96.
Canwei Xia Jiayu Liu Per Alström Qiao Wu Yanyun Zhang 《Ethology : formerly Zeitschrift fur Tierpsychologie》2013,119(8):653-661
Soft songs have been detected in many songbirds, but in most species, research on soft songs has lagged behind studies of broadcast songs. In this study, we describe the acoustic features of a soft song in the brownish‐flanked bush warbler Cettia fortipes. Compared with the broadcast song, the warbler's soft song was characterized by a lower minimum frequency and longer duration, and it had a higher proportion of rapid frequency modulation notes. Using playback experiments, some in combination with mounted specimens, we found different responses to soft and broadcast songs, and we found that soft song can predict aggressive escalation (attack). We conclude that the soft song is an aggressive signal in this species. 相似文献
97.
Can-Jie Guo Qin Pan Hua Xiong Yu-Qi Qiao Zhao-Lian Bian Wei Zhong Li Sheng Hai Li Lei Shen Jing Hua Xiong Ma Jing-Yuan Fang 《FEBS letters》2013
In our previous study, miR-126 was identified as one of the leading miRNAs that is downregulated during activation of hepatic stellate cells (HSCs). However, the roles and related mechanisms of miR-126 in HSCs are not understood. In this study, we compared expression of miR-126 during HSC activation both in vitro and in vivo. We also applied RNA interference to analyze the role and mechanism of miR-126∗ in the activation of HSCs. Restoring HSCs with Lv-miR-126∗ resulted in decreased proliferation, accumulation of extracellular matrix components, and cell contraction, while also negatively regulating the vascular endothelial growth factor (VEGF) signal transduction pathways by partially targeted VEGF-A. Thus, we postulate that miR-126 may be a biological marker for the activation of HSCs, and useful for reducing intrahepatic vascular resistance and improving the sinusoidal microcirculation in chronic liver diseases. 相似文献
98.
不同成熟度煤样产甲烷潜力 总被引:4,自引:2,他引:2
摘要:【目的】评估不同类型煤炭生物降解转化为甲烷的潜力,研究原位煤层的微生物群落结构特征。【方法】分别在原位模拟、补加烃降解产甲烷菌系和补加碳源下厌氧培养煤样,利用气相色谱监测甲烷产生趋势,及高通量测序技术研究原位煤层的细菌和古菌群落。【结果】10个样品中有3个高成熟度煤样可以被厌氧降解转化为甲烷。通过生物强化和添加外源底物可以促进HF煤样的产甲烷潜力。其中SL 煤样中的古菌类群主要是氢营养型产甲烷菌Methanoculleus和乙酸营养型产甲烷菌Methanosaeta为主,细菌类群主要
属于Firmicutes(54.4%)、Proteobacteria(30.9%)、未培养微生物(10.8%)、Caldiserica(1.5%)及Thermotogae(1.3%)。【结论】不同成熟度煤样降解产气潜力不同,在部分原位煤层中可能存在参与烃降解与甲烷产生的功能菌。 相似文献
99.
Yi Chen Zilian Zhang Yingnan Fu Yanan Wang Yu Wang Nianzhi Jiao 《Antonie van Leeuwenhoek》2013,104(6):1151-1157
A novel chemoheterotrophic, aerobic, Gram-negative, rod-shaped, yellow-pigmented, bacterial strain JLT2010T was isolated from deep seawater of the South China Sea. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that strain JLT2010T belongs to the family Flavobacteriaceae and is most closely related to Ulvibacter antarcticus IMCC3101T with 95.7 % similarity. Some phenotypic characteristics such as the absence of flexirubin-type pigments, growth at 37 °C, hydrolysis of casein differentiated strain JLT2010T from the genus Ulvibacter as well as other genera in the family Flavobacteriaceae. The DNA G+C content of the strain JLT2010T was found to be 35.7 mol% and the major respiratory quinone was found to be MK-6. On the basis of phenotypic and phylogenetic features, JLT2010T is classified as a novel genus and species within the family Flavobacteriaceae, for which the name Altuibacter lentus gen. nov., sp. nov. is proposed. The type strain is JLT2010T (=JCM 18884T = CGMCC 1.12167T). 相似文献
100.
Zheng Liu Ning Sun Shangjun Yang Yanhong Zhao Xiaoqin Wang Xingyu Hao Zhijun Qiao 《Biologia》2013,68(4):577-586
Compared with C3 plants, C4 plants possess a mechanism to concentrate CO2 around the ribulose-1,5-bisphosphate carboxylase/oxygenase in chloroplasts of bundle sheath cells so that the carboxylation reaction work at a much more efficient rate, thereby substantially eliminate the oxygenation reaction and the resulting photorespiration. It is observed that C4 photosynthesis is more efficient than C3 photosynthesis under conditions of low atmospheric CO2, heat, drought and salinity, suggesting that these factors are the important drivers to promote C4 evolution. Although C4 evolution took over 66 times independently, it is hypothesized that it shared the following evolutionary trajectory: 1) gene duplication followed by neofunctionalization; 2) anatomical and ultrastructral changes of leaf architecture to improve the hydraulic systems; 3) establishment of two-celled photorespiratory pump; 4) addition of transport system; 5) co-option of the duplicated genes into C4 pathway and adaptive changes of C4 enzymes. Based on our current understanding on C4 evolution, several strategies for engineering C4 rice have been proposed to increase both photosynthetic efficiency and yield significantly in order to avoid international food crisis in the future, especially in the developing countries. Here we summarize the latest progresses on the studies of C4 evolution and discuss the strategies to introduce two-celled C4 pathway into rice. 相似文献