Quantitative structure–activity relationship study using artificial neural network (ANN) methodology were conducted to predict the inhibition constants of 127 symmetrical and unsymmetrical cyclic urea and cyclic cyan...Quantitative structure–activity relationship study using artificial neural network (ANN) methodology were conducted to predict the inhibition constants of 127 symmetrical and unsymmetrical cyclic urea and cyclic cyanoguanidine derivatives containing different substituent groups such as: benzyl, isopropyl, 4-hydroxybenzyl, ketone, oxime, pyrazole, imidazole, triazole and having anti-HIV-1 protease activities. The results obtained by artificial neural network give advanced regression models with good prediction ability. The two optimal artificial neural network models obtained have coefficients of determination of 0.746 and 0.756. The lowest prediction’s root mean square error obtained is 0.607. Artificial neural networks provide improved models for heterogeneous data sets without splitting them into families. Both the external and cross-validation methods are used to validate the performances of the resulting models. Randomization test is employed to check the suitability of the models.展开更多
The influence of mild hypothermia on neural cell apoptosis remains poorly understood. Therefore, the present study established rat models of diffuse axonal injury （DAI） at 33℃. Morris water maze results demonstrate...The influence of mild hypothermia on neural cell apoptosis remains poorly understood. Therefore, the present study established rat models of diffuse axonal injury （DAI） at 33℃. Morris water maze results demonstrated significantly better learning and memory functions in DAI rats with hypothermia compared with DAI rats with normothermia. Expression of apoptotic protease activating factor-1 in the hippocampal CA1 region was significantly lower in the DAI hypothermia group compared with the DAI normothermia group. Expression of apoptotic protease activating factor-1 positively correlated with latency, but negatively correlated with platform location times and time of swimming in the quadrant area. Results suggested that post-traumatic mild hypothermia in a rat model of DAI could provide cerebral protection by attenuating expression of apoptotic protease activating factor-1.展开更多
Cerebral ischemia/reperfusion injury is partially mediated by thrombin, which causes brain damage through protease-activated receptor 1（PAR1）. However, the role and mechanisms underlying the effects of PAR1 activati...Cerebral ischemia/reperfusion injury is partially mediated by thrombin, which causes brain damage through protease-activated receptor 1（PAR1）. However, the role and mechanisms underlying the effects of PAR1 activation require further elucidation. Therefore, the present study investigated the effects of the PAR1 antagonist SCH79797 in a rabbit model of global cerebral ischemia induced by cardiac arrest. SCH79797 was intravenously administered 10 minutes after the model was established. Forty-eight hours later, compared with those administered saline, rabbits receiving SCH79797 showed markedly decreased neuronal damage as assessed by serum neuron specific enolase levels and less neurological dysfunction as determined using cerebral performance category scores. Additionally, in the hippocampus, cell apoptosis, polymorphonuclear cell infiltration, and c-Jun levels were decreased, whereas extracellular signal-regulated kinase phosphorylation levels were increased. All of these changes were inhibited by the intravenous administration of the phosphoinositide 3-kinase/Akt pathway inhibitor LY29004（3 mg/kg） 10 minutes before the SCH79797 intervention. These findings suggest that SCH79797 mitigates brain injury via anti-inflammatory and anti-apoptotic effects, possibly by modulating the extracellular signal-regulated kinase, c-Jun N-terminal kinase/c-Jun and phosphoinositide 3-kinase/Akt pathways.展开更多
Objective:To investigate the in vitro anti-HIV-1 activities and its associated mechanism of action of an extract isolated from Phyllanthus urinaria (P.urinaria) and to develop an HPLC test method for detecting gallic ...Objective:To investigate the in vitro anti-HIV-1 activities and its associated mechanism of action of an extract isolated from Phyllanthus urinaria (P.urinaria) and to develop an HPLC test method for detecting gallic acid (GA) in plasma and tissues to study its pharmacokinetics and tissue distribution in rats.Methods:An extract of P.urinaria was isolated and purified by phytochemistry and chromatography techniques.The anti-HIV-1 activities and toxicities of the extract and its component GA were determined in human T lymph cells (MT-4) by theMTTr method.The mechanism of its anti-HIV-1 action was studied to examine the in vitro binding of its components with HIV-1 target proteins by Biacore technique.The pharmacokinetics and tissue distribution of GA were investigated after oral administration of polyphenol extract (PE) and pure GA in rats.The concentrations of GA in plasma and tissues were determined by HPLC.Results:The PE and GA isolated from P.urinaria had anti-HIV-1 activities with IC50s of 0.61 μg/mL and 0.76 μg/mL,respectively.The Biacore study indicated that PE and GA interacted with HIV-1 RT,gp120,and P24.The pharmacokinetic parameters Tmax,Cm ax,AUC0-t,and T1/2 for GA were (60.0 ± 3.0) minutes,(2.87 ± 0.50) μg·mL-1,(343.5 ± 11.2) mg·min·L-1,and (113.3 ± 9.3) minutes while the parameters for GA in the PE were (10.0 ± 1.3) minutes,(3.89 ± 0.90) μg·mL-1,(394.7 ± 14.0) mg· min· L-1,and (81.7 ± 4.1) minutes,respectively.GA was detected in rat lungs,liver,kidneys,heart and spleen.Conclusion:APE isolated from P.urinaria containing GA has anti-HIV-1 activities.GA is quickly absorbed and slowly eliminated in rats after oral administration.The pharmacokinetics of GA administered as a PE is desirable,and it is widely distributed in the main tissues of lung and liver.Both its properties and anti-HIV-1 activities make it of interest for further studies.展开更多
Site-directed spin-labeling with continuous wave electron paramagnetic resonance spectroscopy was used to monitor autoproteolysis of HIV-1 protease, an enzyme essential for viral maturation. Two protein constructs wer...Site-directed spin-labeling with continuous wave electron paramagnetic resonance spectroscopy was used to monitor autoproteolysis of HIV-1 protease, an enzyme essential for viral maturation. Two protein constructs were examined, namely subtype F and the circulating recombinant form CRF01_A/E. As the protease undergoes self-cleavage, protein unfolds and small peptide fragments containing the spin label are generated, which collectively give rise to a sharp spectral component that is easily discernable in the high-field resonance line in the EPR spectrum. By monitoring the intensity of this spectral component over time, the autoproteolytic stability of each construct was characterized under various conditions. Data were collected for samples stored at 4 °C, 25 °C, and 37 °C, and on a subtype F HIV-1 protease sample stored at 25 °C and containing the FDA-approved protease inhibitor Tipranavir. As expected, the rate of autoproteolysis decreased as the storage temperature was lowered. Minimal autoproteolysis was seen for the sample that contained Tipranavir, providing direction for future spectroscopic studies of active protease samples. When compared to standard methods of monitoring protein degradation such as gel electrophoresis or chromatographic analyses, spin-labeling with CW EPR offers a facile, real-time, non-consuming way to monitor autoproteolysis or protein degradation. Additionally, mass spectrometry studies revealed that the N-termini of both constructs are sensitive to degradation and that the sites of specific autoproteolysis vary.展开更多
Understanding interactions between viruses and their hosts is conducive to enabling better application of viruses as biocontrol agents.Certain viruses carried by parasitic wasps enhance the parasitic efficiency of was...Understanding interactions between viruses and their hosts is conducive to enabling better application of viruses as biocontrol agents.Certain viruses carried by parasitic wasps enhance the parasitic efficiency of wasp-larvae by protecting them against the immune system of their Lepidopteran host.However,the relationship between prey pests and viruses found in predatory natural enemies remains unclear.Herein,we report the interaction between Arma chinensis virus-1(AcV-1),originally isolated from a predatory natural enemy,Arma chinensis(Hemiptera:Pentatomidae),and one of its prey species,Spodoptera frugiperda(Lepidoptera:Noctuidae).The results showed that the AcV-1 virus appeared harmful to the novel host S.frugiperda by inhibiting larval diet consumption and increasing pupal mortality.Meanwhile,sequencing data indicated that the virus altered the gene expression profiles of S.frugiperda.KEGG analysis showed that the proteasome and phagosome pathways related to protein degradation and immune response were significantly enriched.Although the expression levels of digestive enzyme genes did not change significantly,the total protease activity of AcV-1 virus-positive individuals was significantly decreased,suggesting that the virus inhibited diet consumption of S.frugiperda via the down-regulation of digestive enzyme activities.These results indicate that a virus initially isolated in a predatory natural enemy can decrease the fitness of its prey species.The virus was found to impact the host proteasome and phagosome pathways related to protein degradation and immunity,providing a potential mechanism to enhance controlling efficiency.展开更多
Objective To investigate the inhibitory effect of the mycelium extract from a Chinese fungus （MI） on HIV-I and its mode of action. Methods Several in vitro methods including time of action, time of addition and PCR ...Objective To investigate the inhibitory effect of the mycelium extract from a Chinese fungus （MI） on HIV-I and its mode of action. Methods Several in vitro methods including time of action, time of addition and PCR were used to test the mode of action of M 1. Results M 1 inhibited acute HIV infection in vitro and was effective when it was added 12 h after infection. PCR analysis of infected cells demonstrated that MI delayed the appearance of late product of reverse transcription and HIV was blocked before its RNA expression. Conclusion The target of M 1 is post-integration of proviral DNA.展开更多
文摘Quantitative structure–activity relationship study using artificial neural network (ANN) methodology were conducted to predict the inhibition constants of 127 symmetrical and unsymmetrical cyclic urea and cyclic cyanoguanidine derivatives containing different substituent groups such as: benzyl, isopropyl, 4-hydroxybenzyl, ketone, oxime, pyrazole, imidazole, triazole and having anti-HIV-1 protease activities. The results obtained by artificial neural network give advanced regression models with good prediction ability. The two optimal artificial neural network models obtained have coefficients of determination of 0.746 and 0.756. The lowest prediction’s root mean square error obtained is 0.607. Artificial neural networks provide improved models for heterogeneous data sets without splitting them into families. Both the external and cross-validation methods are used to validate the performances of the resulting models. Randomization test is employed to check the suitability of the models.
基金a grant from Department of Public Health of Heibei Province, No. 20100134
文摘The influence of mild hypothermia on neural cell apoptosis remains poorly understood. Therefore, the present study established rat models of diffuse axonal injury （DAI） at 33℃. Morris water maze results demonstrated significantly better learning and memory functions in DAI rats with hypothermia compared with DAI rats with normothermia. Expression of apoptotic protease activating factor-1 in the hippocampal CA1 region was significantly lower in the DAI hypothermia group compared with the DAI normothermia group. Expression of apoptotic protease activating factor-1 positively correlated with latency, but negatively correlated with platform location times and time of swimming in the quadrant area. Results suggested that post-traumatic mild hypothermia in a rat model of DAI could provide cerebral protection by attenuating expression of apoptotic protease activating factor-1.
基金supported by the Natural Science Foundation of Hubei Province of China,No.2010CDB09101
文摘Cerebral ischemia/reperfusion injury is partially mediated by thrombin, which causes brain damage through protease-activated receptor 1（PAR1）. However, the role and mechanisms underlying the effects of PAR1 activation require further elucidation. Therefore, the present study investigated the effects of the PAR1 antagonist SCH79797 in a rabbit model of global cerebral ischemia induced by cardiac arrest. SCH79797 was intravenously administered 10 minutes after the model was established. Forty-eight hours later, compared with those administered saline, rabbits receiving SCH79797 showed markedly decreased neuronal damage as assessed by serum neuron specific enolase levels and less neurological dysfunction as determined using cerebral performance category scores. Additionally, in the hippocampus, cell apoptosis, polymorphonuclear cell infiltration, and c-Jun levels were decreased, whereas extracellular signal-regulated kinase phosphorylation levels were increased. All of these changes were inhibited by the intravenous administration of the phosphoinositide 3-kinase/Akt pathway inhibitor LY29004（3 mg/kg） 10 minutes before the SCH79797 intervention. These findings suggest that SCH79797 mitigates brain injury via anti-inflammatory and anti-apoptotic effects, possibly by modulating the extracellular signal-regulated kinase, c-Jun N-terminal kinase/c-Jun and phosphoinositide 3-kinase/Akt pathways.
基金The experiment was supported by the National Natural Science Foundation of China(30171197)Natural Science Foundation of Beijing(7073093).
文摘Objective:To investigate the in vitro anti-HIV-1 activities and its associated mechanism of action of an extract isolated from Phyllanthus urinaria (P.urinaria) and to develop an HPLC test method for detecting gallic acid (GA) in plasma and tissues to study its pharmacokinetics and tissue distribution in rats.Methods:An extract of P.urinaria was isolated and purified by phytochemistry and chromatography techniques.The anti-HIV-1 activities and toxicities of the extract and its component GA were determined in human T lymph cells (MT-4) by theMTTr method.The mechanism of its anti-HIV-1 action was studied to examine the in vitro binding of its components with HIV-1 target proteins by Biacore technique.The pharmacokinetics and tissue distribution of GA were investigated after oral administration of polyphenol extract (PE) and pure GA in rats.The concentrations of GA in plasma and tissues were determined by HPLC.Results:The PE and GA isolated from P.urinaria had anti-HIV-1 activities with IC50s of 0.61 μg/mL and 0.76 μg/mL,respectively.The Biacore study indicated that PE and GA interacted with HIV-1 RT,gp120,and P24.The pharmacokinetic parameters Tmax,Cm ax,AUC0-t,and T1/2 for GA were (60.0 ± 3.0) minutes,(2.87 ± 0.50) μg·mL-1,(343.5 ± 11.2) mg·min·L-1,and (113.3 ± 9.3) minutes while the parameters for GA in the PE were (10.0 ± 1.3) minutes,(3.89 ± 0.90) μg·mL-1,(394.7 ± 14.0) mg· min· L-1,and (81.7 ± 4.1) minutes,respectively.GA was detected in rat lungs,liver,kidneys,heart and spleen.Conclusion:APE isolated from P.urinaria containing GA has anti-HIV-1 activities.GA is quickly absorbed and slowly eliminated in rats after oral administration.The pharmacokinetics of GA administered as a PE is desirable,and it is widely distributed in the main tissues of lung and liver.Both its properties and anti-HIV-1 activities make it of interest for further studies.
文摘Site-directed spin-labeling with continuous wave electron paramagnetic resonance spectroscopy was used to monitor autoproteolysis of HIV-1 protease, an enzyme essential for viral maturation. Two protein constructs were examined, namely subtype F and the circulating recombinant form CRF01_A/E. As the protease undergoes self-cleavage, protein unfolds and small peptide fragments containing the spin label are generated, which collectively give rise to a sharp spectral component that is easily discernable in the high-field resonance line in the EPR spectrum. By monitoring the intensity of this spectral component over time, the autoproteolytic stability of each construct was characterized under various conditions. Data were collected for samples stored at 4 °C, 25 °C, and 37 °C, and on a subtype F HIV-1 protease sample stored at 25 °C and containing the FDA-approved protease inhibitor Tipranavir. As expected, the rate of autoproteolysis decreased as the storage temperature was lowered. Minimal autoproteolysis was seen for the sample that contained Tipranavir, providing direction for future spectroscopic studies of active protease samples. When compared to standard methods of monitoring protein degradation such as gel electrophoresis or chromatographic analyses, spin-labeling with CW EPR offers a facile, real-time, non-consuming way to monitor autoproteolysis or protein degradation. Additionally, mass spectrometry studies revealed that the N-termini of both constructs are sensitive to degradation and that the sites of specific autoproteolysis vary.
基金supported by the Major Special Projects for Green Pest Control,China(110202101028(LS-03),201938,110202201017(LS-01)and 110202001035(LS04))the National Natural Science Foundation of China(31901893)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(ASTIP-TRIC04)。
文摘Understanding interactions between viruses and their hosts is conducive to enabling better application of viruses as biocontrol agents.Certain viruses carried by parasitic wasps enhance the parasitic efficiency of wasp-larvae by protecting them against the immune system of their Lepidopteran host.However,the relationship between prey pests and viruses found in predatory natural enemies remains unclear.Herein,we report the interaction between Arma chinensis virus-1(AcV-1),originally isolated from a predatory natural enemy,Arma chinensis(Hemiptera:Pentatomidae),and one of its prey species,Spodoptera frugiperda(Lepidoptera:Noctuidae).The results showed that the AcV-1 virus appeared harmful to the novel host S.frugiperda by inhibiting larval diet consumption and increasing pupal mortality.Meanwhile,sequencing data indicated that the virus altered the gene expression profiles of S.frugiperda.KEGG analysis showed that the proteasome and phagosome pathways related to protein degradation and immune response were significantly enriched.Although the expression levels of digestive enzyme genes did not change significantly,the total protease activity of AcV-1 virus-positive individuals was significantly decreased,suggesting that the virus inhibited diet consumption of S.frugiperda via the down-regulation of digestive enzyme activities.These results indicate that a virus initially isolated in a predatory natural enemy can decrease the fitness of its prey species.The virus was found to impact the host proteasome and phagosome pathways related to protein degradation and immunity,providing a potential mechanism to enhance controlling efficiency.
基金This project was supported by National Medicine Science Foundation during the 10th-five year plan period (2001BA705B01) and Chinese National Science Fund for Outstanding Youths (30325047).
文摘Objective To investigate the inhibitory effect of the mycelium extract from a Chinese fungus （MI） on HIV-I and its mode of action. Methods Several in vitro methods including time of action, time of addition and PCR were used to test the mode of action of M 1. Results M 1 inhibited acute HIV infection in vitro and was effective when it was added 12 h after infection. PCR analysis of infected cells demonstrated that MI delayed the appearance of late product of reverse transcription and HIV was blocked before its RNA expression. Conclusion The target of M 1 is post-integration of proviral DNA.
