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1.
TRAF family member-associated NF-κB activator (TANK) is a negative regulator of canonical NF-κB signaling in the Toll-like receptor- and B-cell receptor-mediated signaling pathways. However, functions of TANK in viral infection-mediated NF-κB activation remain unclear. Here, we reported that TANK was cleaved by encephalomyocarditis virus 3C at the 197 and 291 glutamine residues, which depends on its cysteine protease activity. In addition, encephalomyocarditis virus 3C impaired the ability of TANK to inhibit TRAF6-mediated NF-κB signaling. Interestingly, we found that several viral proteases encoded by the foot and mouth disease virus, porcine reproductive and respiratory syndrome virus, and equine arteritis virus also cleaved TANK. Our results suggest that TANK is a novel target of some viral proteases, indicating that some positive RNA viruses have evolved to utilize their major proteases to regulate NF-κB activation.  相似文献   
2.
檀菲菲  陆兆华 《生态学报》2016,36(8):2403-2412
区域可持续发展水平、发展的持续性和系统的协调性是区域可持续发展定量评价研究的三角构架,而在传统上基于各子系统主成分分析结果直接进行形色各异的加权计算对可持续发展评价而言是有待商榷的。提出了非线性主成分分析和施密特正交化(NLPCA-GSO)相耦合的方法评价区域的可持续发展水平来弥补传统方法的不足,并由此建立区域发展持续性模型和可持续发展系统协调度模型,再以环渤海区域为实证分析其2001—2010年的可持续发展状况。结果表明:基于NLPCA-GSO的可持续发展水平模型可以很好地弥补传统主成分分析及对各子系统结果的综合评价的不足;区域发展持续性模型、协调性模型和区域可持续系统变化的滤波分析形象地揭示区域可持续发展的实质和内涵;实证研究表明环渤海区域在研究时段内可持续发展水平有所上升,而环境子系统持续性的下降是引起区域发展持续性和系统协调度的变化的主要原因。研究结果可丰富区域可持续发展评价的方法学,也可为环渤海区域的可持续发展研究奠定基础。  相似文献   
3.
The aim of the study was to explore the mechanism of mesenchymal stem cell‐derived exosomes (MSC‐EXO) to protect against experimentally induced pulmonary hypertension (PH). Monocrotaline (MCT)‐induced rat model of PH was successfully established by a single intraperitoneal injection of 50 mg/kg MCT, 3 weeks later the animals were treated with MSC‐EXO via tail vein injection. Post‐operation, our results showed that MSC‐EXO could significantly reduce right ventricular systolic pressure (RVSP) and the right ventricular hypertrophy index, attenuate pulmonary vascular remodelling and lung fibrosis in vivo. In vitro experiment, the hypoxia models of pulmonary artery endothelial cell (PAEC) and pulmonary vascular smooth muscle cell (PASMC) were used. We found that the expression levels of Wnt5a, Wnt11, BMPR2, BMP4 and BMP9 were increased, but β‐catenin, cyclin D1 and TGF‐β1 were decreased in MSC‐EXO group as compared with MCT or hypoxia group in vivo or vitro. However, these increased could be blocked when cells were transfected with Wnt5a siRNA in vitro. Taken together, these results suggested that the mechanism of MSC‐EXO to prevent PH vascular remodelling may be via regulation of Wnt5a/BMP signalling pathway.  相似文献   
4.

Purpose

To introduce a model for the time evolution of active caspase-3 protein expression in albino rat lens up to 24 hours after in vivo exposure to low dose UVR in the 300 nm wavelength region (UVR-300 nm).

Methods

Forty Sprague-Dawley rats were unilaterally exposed in vivo to 1 kJ/m2 UVR-300 nm for 15 minutes. At 0.5, 8, 16, and 24 hours after the UVR exposure, the exposed and contralateral not-exposed lenses were removed and processed for immunohistochemistry. The differences in the probability of active caspase-3 expression at four different time points after exposure were used to determine the time evolution of active caspase-3 expression. A logistic model was introduced for the expression of active caspase-3. The parameters for the exposed and the not exposed lenses were estimated for the observation time points.

Results

The exposure to UVR-300 nm impacted on the parameters of the logistic model. Further, the parameters of the model varied with time after exposure to UVR-300 nm.

Conclusion

The logistic model predicts the impact of exposure to UVR-300 nm on the spatial distribution of probability of active caspase-3 protein expression, depending on time.  相似文献   
5.
Rapid environmental fluctuations are ubiquitous in the wild, yet majority of experimental studies mostly consider effects of slow fluctuations on organism. To test the evolutionary consequences of fast fluctuations, we conducted nine independent experimental evolution experiments with bacteria. Experimental conditions were same for all species, and we allowed them to evolve either in fluctuating temperature alternating rapidly between 20°C and 40°C or at constant 30°C temperature. After experimental evolution, we tested the performance of the clones in both rapid fluctuation and in constant environments (20°C, 30°C and 40°C). Results from experiments on these nine species were combined meta‐analytically. We found that overall the clones evolved in the fluctuating environment had evolved better efficiency in tolerating fluctuations (i.e., they had higher yield in fluctuating conditions) than the clones evolved in the constant environment. However, we did not find any evidence that fluctuation‐adapted clones would have evolved better tolerance to any measured constant environments (20°C, 30°C, and 40°C). Our results back up recent empirical findings reporting that it is hard to predict adaptations to fast fluctuations using tolerance curves.  相似文献   
6.
柯萨奇病毒B组(Coxsackievirus B,CVB)感染细胞时其基因组RNA存在不稳定现象,但产生机制尚不清楚。本研究将柯萨奇病毒B组3型(CVB3)感染细胞后,利用5′ cDNA末端快速扩增技术(5′ rapid amplification of cDNA ends,5′ RACE)扩增并克隆细胞内CVB3基因组片段,并对每条序列及其5′端的二级结构进行分析。结果获得的20条CVB3基因组片段,长度为 2 067~5 547 bp,片段断端主要分布于2Apro和2C编码区。RNAfold分析显示,这些片段多数在5′断点端形成二级茎-环结构。本研究显示,CVB在宿主细胞感染时可形成大量不完整基因组RNA片段,这些片段可在5′断点端形成局部双链结构,提示片段不是随机产生,可能是RNA酶剪切产物。此发现有助于理解CVB基因组不稳定的机制。  相似文献   
7.
8.
TRPML3 and TRPV5 are members of the mucolipin (TRPML) and TRPV subfamilies of transient receptor potential (TRP) cation channels. Based on sequence similarities of the pore forming regions and on structure-function evidence, we hypothesized that the pore forming domains of TRPML and TRPV5/TRPV6 channels have similarities that indicate possible functional interactions between these TRP channel subfamilies. Here we show that TRPML3 and TRPV5 associate to form a novel heteromeric ion channel. This novel conductance is detectable under conditions that do not activate either TRPML3 or TRPV5. It has pharmacological similarity with TRPML3 and requires functional TRPML3 as well as functional TRPV5. Single channel analyses revealed that TRPML3 and TRPV5 heteromers have different features than the respective homomers, and furthermore, that they occur in potentially distinct stoichiometric configurations. Based on overlapping expression of TRPML3 and TRPV5 in the kidney and the inner ear, we propose that TRPML3 and TRPV5 heteromers could have a biological function in these organs.  相似文献   
9.
Resting state functional magnetic resonance imaging (fMRI) has been commonly used to measure functional connectivity between cortical regions, while diffusion tensor imaging (DTI) can be used to characterize structural connectivity of white matter tracts. In principle combining resting state fMRI and DTI data could allow characterization of structure-function relations of distributed neural networks. However, due to differences in the biophysical origins of their signals and in the tissues to which they apply, there has been no direct integration of these techniques to date. We demonstrate that MRI signal variations and power spectra in a resting state are largely comparable between gray matter and white matter, that there are temporal correlations of fMRI signals that persist over long distances within distinct white matter structures, and that neighboring intervoxel correlations of low frequency resting state signals showed distinct anisotropy in many regions. These observations suggest that MRI signal variations from within white matter in a resting state may convey similar information as their corresponding fluctuations of MRI signals in gray matter. We thus derive a local spatio-temporal correlation tensor which captures directional variations of resting-state correlations and which reveals distinct structures in both white and gray matter. This novel concept is illustrated with in vivo experiments in a resting state, which demonstrate the potential of the technique for mapping the functional structure of neural networks and for direct integration of structure-function relations in the human brain.  相似文献   
10.
N‐acetylglucosaminyltransferase V (GnT‐V) has been reported to be positively associated with tumor progression, but its mechanism still remains unknown. In the present study, we found that GnT‐V overexpression not only changed the glycosylation of receptor protein tyrosine phosphatase kappa (RPTPκ) but also decreased its protein level. Moreover, GnT‐V overexpression decreased cell calcium‐independent adhesion and increased the tyrosine phosphorylation level of β‐catenin, in which RPTPκ played an important role. Since RPTPκ has an RXKR motif, which is a favored cleavage site for furin, we used furin inhibitor to further explore the effect of RPTPκ on the change of cell adhesion and β‐catenin signaling induced by GnT‐V. Our results showed that preventing RPTPκ cleavage rescued the above effects of GnT‐V, suggesting that furin cleavage could be one of the factors for RPTPκ to regulate cell adhesion and β‐catenin signaling in GnT‐V overexpression cell lines. In addition, the increased tyrosine phosphorylation level of β‐catenin was associated with the increased nuclear level of β‐catenin and downstream signaling molecules such as c‐myc and cyclin D1 that were associated with cell proliferation. Our results suggest that GnT‐V could decrease human hepatoma SMMC‐7721 cell adhesion and promote cell proliferation partially through RPTPκ. J. Cell. Biochem. 109: 113–123, 2010. © 2009 Wiley‐Liss, Inc.  相似文献   
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