1.Putative Phosphorylation Sites On WCA Domain of HA2 Is Essential For Helicoverpa armigera Single Nucleopolyhedrovirus Replication
Yipin LV ; Qian WANG ; Chunchen WU ; Yuan ZHOU ; Yun WANG ; Xinwen CHEN
Virologica Sinica 2011;26(4):245-251
Protein phosphorylation is one of the most common post-translational modification processes that play an essential role in regulating protein functionality.The Helicoverpa armigera single nucleopolyhedrovirus (HearNPv) orf2-encoded nucleocapsid protein HA2 participates in orchestration of virus-induced actin polymerization through its WCA domain,in which phosphorylation status are supposed to be critical in respect to actin polymerization.In the present study,two putative phosphorylation sites (232Thr and 250Ser) and a highly conserved Serine (245Ser) on the WCA domain of HA2 were mutated,and their phenotypes were characterized by reintroducing the mutated HA2 into the HearNPV genome.Viral infectivity assays demonstrated that only the recombinant HearNPV bearing HA2 mutation at 245Ser can produce infectious virions,both 232Tbr and 250Ser mutations were lethal to the virus.However,actin polymerization assay demonstrated that all the three viruses bearing HA2 mutations were still capable of initiating actin polymerization in the host nucleus,which indicated the putative phosphorylation sites on HA2 may contribute to HearNPV replication through another unidentified pathway.
2.The Protamine-like DNA-binding Protein P6.9 Epigenetically Up-regulates Autographa californica Multiple Nucleopolyhedrovirus Gene Transcription in the Late Infection Phase
Ying PENG ; Kun LI ; Rongjuan PEI ; Chunchen WU ; Changyong LIANG ; Yun WANG ; Xinwen CHEN
Virologica Sinica 2012;27(1):57-68
Protamines are a group of highly basic proteins first discovered in spermatozoon that allow for denser packaging of DNA than histones and will result in down-regulation of gene transcription[1].It is well recognized that the Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) encodes P6.9,a protamine-like protein that forms the viral subnucleosome through binding to the viral genome[29].Previous research demonstrates that P6.9 is essential for viral nucleocapsid assembly,while it has no influence on viral genome replication[31].In the present study,the role of P6.9 in viral gene transcription regulation is characterized.In contrast to protamines or other protamine-like proteins that usually down-regulate gene transcription,P6.9 appears to up-regulate viral gene transcription at 12-24 hours post infection (hpi),whereas it is non-essential for the basal level of viral gene transcription.Fluorescence microscopy reveals the P6.9's co-localization with DNA is temporally and spatially synchronized with P6.9's impact on viral gene transcription,indicating the P6.9-DNA association contributes to transcription regulation.Chromatin fractionation assay further reveals an unexpected co-existence of P6.9 and host RNA polymerase Ⅱ in the same transcriptionally active chromatin fraction at 24 hpi,which may probably contribute to viral gene transcription up-regulation in the late infection phase.
3.Novel Evidence Suggests Hepatitis B Virus Surface Proteins Participate in Regulation of HBV Genome Replication
Jian QIU ; Bo QIN ; Simon RAYNER ; Chunchen WU ; Rangjuan PEI ; Song XU ; Yun WANG ; Xinwen CHEN
Virologica Sinica 2011;26(2):131-138
Naturally occurring mutations in surface proteins of Hepatitis B virus(HBV)usually result in altered hepatitis B surface antigen(HBsAg)secretion efficiency.In the present study,we reported two conserved residues,M75 and M103 with respect to HBsAg,mutations of which not only attenuated HBsAg secretion(M75 only),but also suppressed HBV genome replication without compromising the overlapping p-gene product.We also found M75 and M103 can initiate truncated surface protein(TSPs)synthesis upon over-expression of full-length surface proteins,which may possibly contribute to HBV genome replication.However,attempts to rescue replicationdefective HBV mutant by co-expression of TSPs initiated from M75 or M103 were unsuccessful,which indicated surface proteins rather than the putative TSPs were involved in regulation of HBV genome replication.
4.CCR7~+CD8~+CD45RO~+ T Cells induced Differentiation of CD4~+T Cells to Th2 Cells in Active Systemic Lupus Erythematosus
Lang CHEN ; Chunchen WU ; Yuling HE ; Luokun XIE ; Gang ZHOU ; Jinquan TAN
Chinese Journal of Dermatology 1994;0(06):-
Objective To determine the functions of CCR7+CD8+CD45RO+ T cells on CD4+T cells in systemic lupus erythematosu(SLE).Methods The expres sion of cytokines in CD4+T cells was measured by flow cytometry,real-time qua ntitative reverse transcription polymerase chain reaction and Northern blotting.A chemotaxis assay was used to detect their functions.Results In the case of active SLE,CCR7+CD8+CD45RO+T cells could induce CD4+T cells to express high le vels of Th2-cytokine (IL-4),and low levels of Tr1-cytokines (IL-10 and TGF-?),than those in normal controls and inactive SLE (P
5.Design of fuzzy PID control algorithm and simulink simulation for temperature control system of wave bioreactors
Liangzhe LI ; Feng CHEN ; Guang ZHANG ; Jianjun SUN ; Ming YU ; Chunchen WANG ; Zhengyang DONG ; Taihu WU
Military Medical Sciences 2016;40(10):824-828
Objective To design a temperature control strategy for wave bioreactors.Methods According to the requirements of temperature control precision and response speed of wave bioreactors,the traditional PID control method was combined with fuzzy control method which was used to adjust the parameters of the PID control in real time online in order to strengthen the ability of the temperature control strategy to regulate temperature.Results A fuzzy PID controller was completed and simulation results were compared with the traditional PID controller.Conclusion The fuzzy PID control method has a smaller overshoot and shorter stability than the traditional one, so it has a higher temperature control performance.
6.Design of BP neural network based on multi-parametes for VF detection
Ming YU ; Feng CHEN ; Guang ZHANG ; Biao GU ; Liangzhe LI ; Chunchen WANG ; Dan WANG ; Taihu WU
Military Medical Sciences 2016;40(10):829-832,838
Objective To develop a BP neural network to differentiate between ventricular fibrillation( VF) and non-VF rhythms.Methods Eighteen metrics were extracted from the ECG signals.Each of these metrics respectively characterized each aspect of the signals, such as morphology, gaussianity, spectra, variability, and complexity.These metrics were regarded as the input vector of the BP neural network.After training, a classifier used for VF and non-VF rhythm classification was obtained.Results and Conclusion The constructed BP neural network was tested with the databases of VFDB and CUDB, and the accuracy was 98.61%and 95.37%, respectively.
7.Improvement of proportion integration differentiation control strategy in temperature control of riptide bioreactor
Liangzhe LI ; Feng CHEN ; Guang ZHANG ; Jianjun SUN ; Ming YU ; Chunchen WANG ; Zhengyang DONG ; Taihu WU
Chinese Medical Equipment Journal 2017;38(4):17-21
Objective To design a temperature control strategy for riptide bioreactor to eliminate integral saturation by conventional proportion integration differentiation (PID) control.Methods According to the requirement of the riptide bioreactor for the temperature control,the temperature control system model determined by experiment was got,then the effectiveness of the integral limiter PID control method was verified,and finally the integral limiter PID control method wasimproved further using the integral separation combined with the actual experimental results and its effectiveness was tested.Results The simulation results showed that the control effects of the integral limiter PID was good.However,the actual tests proved that there was still deficiencies in large overshoot and long stable time,and good experimental results were obtainedafter improving the integral limiter PID by the integral separation method.Conclusion The improved integral limiter PID control method effectively avoids the overshoot of the system caused by the integral saturation,achieves high control precision,has a very good control performance for the temperature control of riptide bioreactor,and well meets the requirements of mammalian cell culture.
8.Research on algorithms for identifying the severity of acute respiratory distress syndrome patients based on noninvasive parameters.
Pengcheng YANG ; Feng CHEN ; Guang ZHANG ; Ming YU ; Meng LU ; Chunchen WANG ; Chunfei WANG ; Taihu WU
Journal of Biomedical Engineering 2019;36(3):435-443
Acute respiratory distress syndrome (ARDS) is a serious threat to human life and health disease, with acute onset and high mortality. The current diagnosis of the disease depends on blood gas analysis results, while calculating the oxygenation index. However, blood gas analysis is an invasive operation, and can't continuously monitor the development of the disease. In response to the above problems, in this study, we proposed a new algorithm for identifying the severity of ARDS disease. Based on a variety of non-invasive physiological parameters of patients, combined with feature selection techniques, this paper sorts the importance of various physiological parameters. The cross-validation technique was used to evaluate the identification performance. The classification results of four supervised learning algorithms using neural network, logistic regression, AdaBoost and Bagging were compared under different feature subsets. The optimal feature subset and classification algorithm are comprehensively selected by the sensitivity, specificity, accuracy and area under curve (AUC) of different algorithms under different feature subsets. We use four supervised learning algorithms to distinguish the severity of ARDS (P/F ≤ 300). The performance of the algorithm is evaluated according to AUC. When AdaBoost uses 20 features, AUC = 0.832 1, the accuracy is 74.82%, and the optimal AUC is obtained. The performance of the algorithm is evaluated according to the number of features. When using 2 features, Bagging has AUC = 0.819 4 and the accuracy is 73.01%. Compared with traditional methods, this method has the advantage of continuously monitoring the development of patients with ARDS and providing medical staff with auxiliary diagnosis suggestions.
Algorithms
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Area Under Curve
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Blood Gas Analysis
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Humans
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Machine Learning
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Monitoring, Physiologic
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methods
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ROC Curve
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Respiratory Distress Syndrome, Adult
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diagnosis
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Sensitivity and Specificity
10.RNA binding protein 24 regulates the translation and replication of hepatitis C virus.
Huang CAO ; Kaitao ZHAO ; Yongxuan YAO ; Jing GUO ; Xiaoxiao GAO ; Qi YANG ; Min GUO ; Wandi ZHU ; Yun WANG ; Chunchen WU ; Jizheng CHEN ; Yuan ZHOU ; Xue HU ; Mengji LU ; Xinwen CHEN ; Rongjuan PEI
Protein & Cell 2018;9(11):930-944
The secondary structures of hepatitis C virus (HCV) RNA and the cellular proteins that bind to them are important for modulating both translation and RNA replication. However, the sets of RNA-binding proteins involved in the regulation of HCV translation, replication and encapsidation remain unknown. Here, we identified RNA binding motif protein 24 (RBM24) as a host factor participated in HCV translation and replication. Knockdown of RBM24 reduced HCV propagation in Huh7.5.1 cells. An enhanced translation and delayed RNA synthesis during the early phase of infection was observed in RBM24 silencing cells. However, both overexpression of RBM24 and recombinant human RBM24 protein suppressed HCV IRES-mediated translation. Further analysis revealed that the assembly of the 80S ribosome on the HCV IRES was interrupted by RBM24 protein through binding to the 5'-UTR. RBM24 could also interact with HCV Core and enhance the interaction of Core and 5'-UTR, which suppresses the expression of HCV. Moreover, RBM24 enhanced the interaction between the 5'- and 3'-UTRs in the HCV genome, which probably explained its requirement in HCV genome replication. Therefore, RBM24 is a novel host factor involved in HCV replication and may function at the switch from translation to replication.
Cells, Cultured
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Hepacivirus
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genetics
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growth & development
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metabolism
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Humans
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Protein Biosynthesis
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RNA-Binding Proteins
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metabolism
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Virus Replication
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genetics