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31.
32.
Peiyu Liu Yan Liu Xiang Zhao Andrew P. Roberts Heng Zhang Yue Zheng Fuxian Wang Lushan Wang Nicolas Menguy Yongxin Pan Jinhua Li 《Environmental microbiology》2021,23(2):1115-1129
Magnetotactic bacteria (MTB) are diverse prokaryotes that produce magnetic nanocrystals within intracellular membranes (magnetosomes). Here, we present a large-scale analysis of diversity and magnetosome biomineralization in modern magnetotactic cocci, which are the most abundant MTB morphotypes in nature. Nineteen novel magnetotactic cocci species are identified phylogenetically and structurally at the single-cell level. Phylogenetic analysis demonstrates that the cocci cluster into an independent branch from other Alphaproteobacteria MTB, that is, within the Etaproteobacteria class in the Proteobacteria phylum. Statistical analysis reveals species-specific biomineralization of magnetosomal magnetite morphologies. This further confirms that magnetosome biomineralization is controlled strictly by the MTB cell and differs among species or strains. The post-mortem remains of MTB are often preserved as magnetofossils within sediments or sedimentary rocks, yet paleobiological and geological interpretation of their fossil record remains challenging. Our results indicate that magnetofossil morphology could be a promising proxy for retrieving paleobiological information about ancient MTB. 相似文献
33.
Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2 (NPFF), an endogenous mammalian antiopioid peptide, has been shown by other laboratories to attenuate the acute antinociceptive effects of morphine, the development of morphine tolerance, and naloxone-induced withdrawal in morphine-dependent rats. The present study determined the effect of chronic NPFF on mu opioid receptors and mRNA for the endogenous opioids dynorphin and enkephalin. Rats received ICV infusions of either saline or NPFF (5 μg/h) for 13 days via Alzet 2002 osmotic minipumps. Homogenate binding studies, which used whole brain membranes, demonstrated that NPFF decreased the Bmax of mu binding sites (labeled by [3H][
-Ala2-MePhe4,Gly-ol5]enkephalin) from 262 ± 12 to 192 ± 12 fmolmg protein, and increased the Kd from 1.1 to 2.3 nM. Quantitative receptor autoradiography and in situ hybridization experiments were conducted with sections collected at the level of the striatum. The density of mu opioid binding sites labeled by [3H][
-Ala2-MePhe4,Gly-ol5]enkephalin was decreased in all brain areas measured except the corpus callosum, and there was no change in dynorphin mRNA or enkephalin mRNA in the caudate, the nucleus accumbens, or the ventral pallidum. Rats chronically administered ICV morphine sulfate (20 μg/h) for 14 days developed tolerance to morphine and a low degree of dependence, as measured by naloxone-precipitated withdrawal. Chronic administration of NPFF concurrently with morphine sulfate did not significantly alter naloxone-induced withdrawal signs or the development of morphine tolerance. Viewed collectively with previous findings that chronic ICV infusion of anti-NPFF IgG upregulates mu receptors, these data provide additional evidence that the density of CNS mu receptors is tonically regulated by NPFF in the extracellular fluid. The action of NPFF to decrease mu receptors is consistent with an antiopioid role for this peptide; however, the fact that NPFF (administered into the lateral ventricle) did not appreciably alter expression of morphine tolerance and dependence contrasts with previous findings and reinforces the view that this effect is most reliably seen after third ventricle administration. 相似文献
34.
Yongliang Liu Xiangqin Qi Zhenan Zhao Daoliang Song Lianqing Wang Qiaoli Zhai Xiaoning Zhang Peiqing Zhao Xinxin Xiang 《Journal of cellular and molecular medicine》2020,24(16):9135-9144
Recent studies have shown that tumour necrosis factor‐α–induced protein 8 like‐1(TIPE1) plays distinct roles in different cancers. TIPE1 inhibits tumour proliferation and metastasis in a variety of tumours but acts as an oncogene in cervical cancer. The role of TIPE1 in nasopharyngeal carcinoma (NPC) remains unknown. Interestingly, TIPE1 expression was remarkably increased in NPC tissue samples compared to adjacent normal nasopharyngeal epithelial tissue samples in our study. TIPE1 expression was positively correlated with that of the proliferation marker Ki67 and negatively correlated with patient lifespan. In vitro, TIPE1 inhibited autophagy and induced cell proliferation in TIPE1‐overexpressing CNE‐1 and CNE‐2Z cells. In addition, knocking down TIPE1 expression promoted autophagy and decreased proliferation, whereas overexpressing TIPE1 increased the levels of pmTOR, pS6 and P62 and decreased the level of pAMPK and the LC3B. Furthermore, the decrease in autophagy was remarkably rescued in TIPE1‐overexpressing CNE‐1 and CNE‐2Z cells treated with the AMPK activator AICAR. In addition, TIPE1 promoted tumour growth in BALB/c nude mice. Taken together, results indicate that TIPE1 promotes NPC progression by inhibiting autophagy and inducing cell proliferation via the AMPK/mTOR signalling pathway. Thus, TIPE1 could potentially be used as a valuable diagnostic and prognostic biomarker for NPC. 相似文献
35.
Leon Wong Yu‐An Huang Zhu‐Hong You Zhan‐Heng Chen Mei‐Yuan Cao 《Journal of cellular and molecular medicine》2020,24(1):79-87
LncRNA and miRNA are key molecules in mechanism of competing endogenous RNAs(ceRNA), and their interactions have been discovered with important roles in gene regulation. As supplementary to the identification of lncRNA‐miRNA interactions from CLIP‐seq experiments, in silico prediction can select the most potential candidates for experimental validation. Although developing computational tool for predicting lncRNA‐miRNA interaction is of great importance for deciphering the ceRNA mechanism, little effort has been made towards this direction. In this paper, we propose an approach based on linear neighbour representation to predict lncRNA‐miRNA interactions (LNRLMI). Specifically, we first constructed a bipartite network by combining the known interaction network and similarities based on expression profiles of lncRNAs and miRNAs. Based on such a data integration, linear neighbour representation method was introduced to construct a prediction model. To evaluate the prediction performance of the proposed model, k‐fold cross validations were implemented. As a result, LNRLMI yielded the average AUCs of 0.8475 ± 0.0032, 0.8960 ± 0.0015 and 0.9069 ± 0.0014 on 2‐fold, 5‐fold and 10‐fold cross validation, respectively. A series of comparison experiments with other methods were also conducted, and the results showed that our method was feasible and effective to predict lncRNA‐miRNA interactions via a combination of different types of useful side information. It is anticipated that LNRLMI could be a useful tool for predicting non‐coding RNA regulation network that lncRNA and miRNA are involved in. 相似文献
36.
The unique physicochemical properties of (2D) nanomaterials make them well‐suited for use in sustainable energy applications. Many of these materials can be further improved with vacancy engineering. This review details recent progress in the vacancy engineering of ultrathin 2D nanomaterials. For clarity, it mainly focuses on various ultrathin 2D materials in three categories: Xa&XaYb‐, MaXb‐, or MaXbYc‐structured materials. Recently developed vacancies in different types of ultrathin 2D materials, as well as their preparation and characterization, are described. Emphasis is placed on the potential electrochemical energy storage and conversion applications of these materials. This review considers the relationship between vacancy properties and material categories of various ultrathin 2D materials in terms of application requirements, preparation, and characterization techniques. The challenges and future outlook of this promising field are summarized. 相似文献
37.
Yunzhen Wu Shuyan Cao Jungang Hou Zhuwei Li Bo Zhang Panlong Zhai Yanting Zhang Licheng Sun 《Liver Transplantation》2020,10(29)
Converting CO2 to valuable carbonaceous fuels and chemicals via electrochemical CO2 reduction by using renewable energy sources is considered to be a scalable strategy with substantial environmental and economic benefits. One of the challenges in this field is to develop nanocatalysts with superior electrocatalytic activity and selectivity for targeted products. Nonmetal species modification of nanocatalysts is of great significance for the construction of distinctive active sites to overcome the kinetic limitations of CO2 reduction. These types of modification enable the efficient control of the selectivity and significantly decrease the reaction overpotential. Herein, a comprehensive review of the recent progress of nonmetal species modification of nanocatalysts for electrochemical CO2 reduction is presented. After discussing some fundamental parameters and the basic principles of CO2 reduction, including possible reaction pathways in light of theoretical modeling and experiments, the identification of active sites and elucidation of reaction mechanisms are emphasized for unraveling the role of nonmetal species modification, such as heteroatom incorporation, organic molecule decoration, electrolyte engineering, and single‐atom engineering. In the final section, future challenges and constructive perspectives are provided, facilitating the accelerated advancement of mechanism research and practical applications of green carbon cycling. 相似文献
38.
Luo Dan Xia Zhi Li Heng Tu Danna Wang Ting Zhang Wei Peng Lu Yi Wenfu Zhang Sai Shu Junhua Xu Hui Li Yong Shi Buyun Huang Chengjiao Tang Wen Xiao Shuna Shu Xiaolan Liu Yan Zhang Yuan Guo Shan Yu Zhi Wang Baoxiang Gao Yuan Hu Qinxue Wang Hanzhong Song Xiaohui Mei Hong Zhou Xiaoqin Zheng Zhenhua 《中国病毒学》2020,35(6):861-867
In December 2019, SARS-CoV-2 was first detected in the samples obtained from three adult patients who suffered from an unknown viral pneumonia in Wuhan (Li et al. 2020). This unknown viral pneumonia is further named as coronavirus disease 2019 (COVID-19) by the World Health Organization. To date, the number of new COVID-19 cases has continued to skyrocket and the impact of SARS-CoV-2 on humans is far greater than any pathogen of this century in both breadth and depth. Previous studies have shown that adults with COVID-19 have symptoms of fever, dry cough, dyspnea, fatigue and lymphocytopenia. Moreover, COVID-19 is more likely to cause death in the elderly, especially those with chronic comorbidities (Huang et al. 2020). In Wuhan, more than 50, 000 COVID-19 cases have been confirmed, including over 780 pediatric patients, and only one child death case (Lu et al. 2020). Although the number of children cases was far fewer than that of adults, COVID-19 might endanger children's health and the information on children remains limited, especially in serological study. In the retrospective study, the investigators analyzed the epidemiological, clinical and serological characteristics of children with COVID-19 in Wuhan in the early stages of the outbreak, which might provide theoretical and practical help in controlling COVID-19 and similar emerging infectious diseases in the future. 相似文献
39.
Yingfan Cai Xiaoyan Cai Qinglian Wang Ping Wang Yu Zhang Chaowei Cai Yanchao Xu Kunbo Wang Zhongli Zhou Chenxiao Wang Shuaipeng Geng Bo Li Qi Dong Yuqing Hou Heng Wang Peng Ai Zhen Liu Feifei Yi Minshan Sun Guoyong An Jieru Cheng Yuanyuan Zhang Qian Shi Yuanhui Xie Xinying Shi Ying Chang Feifei Huang Yun Chen Shimiao Hong Lingyu Mi Quan Sun Lin Zhang Baoliang Zhou Renhai Peng Xiao Zhang Fang Liu 《Plant biotechnology journal》2020,18(3):814-828
40.
Fanli Zeng Yanan Meng Zhimin Hao Pan Li Weibo Zhai Shen shen Zhiyan Cao Jingao Dong 《Molecular Plant Pathology》2020,21(3):401-414
Eukaryotic organisms activate conserved signalling networks to maintain genomic stability in response to DNA genotoxic stresses. However, the coordination of this response pathway in fungal pathogens remains largely unknown. In the present study, we investigated the mechanism by which the northern corn leaf blight pathogen Setosphaeria turcica controls maize infection and activates self-protection pathways in response to DNA genotoxic insults. Appressorium-mediated maize infection by S. turcica was blocked by the S-phase checkpoint. This repression was dependent on the checkpoint central kinase Ataxia Telangiectasia and Rad3 related (ATR), as inhibition of ATR activity or knockdown of the ATR gene recovered appressorium formation in the presence of genotoxic reagents. ATR promoted melanin biosynthesis in S. turcica as a defence response to stress. The melanin biosynthesis genes StPKS and StLac2 were induced by the ATR-mediated S-phase checkpoint. The responses to DNA genotoxic stress were conserved in a wide range of phytopathogenic fungi, including Cochliobolus heterostrophus, Cochliobolus carbonum, Alternaria solani, and Alternaria kikuchiana, which are known causal agents for plant diseases. We propose that in response to genotoxic stress, phytopathogenic fungi including S. turcica activate an ATR-dependent pathway to suppress appressorium-mediated infection and induce melanin-related self-protection in addition to conserved responses in eukaryotes. 相似文献