Objective To study the regulatory roles of SIRT1 on EZH2 expression and the further ef-fects on EZH2's repression of target gene expression. Methods The stable SIRT1 RNAi and Control RNAi HeLa cells were establish...Objective To study the regulatory roles of SIRT1 on EZH2 expression and the further ef-fects on EZH2's repression of target gene expression. Methods The stable SIRT1 RNAi and Control RNAi HeLa cells were established by in-fection with retroviruses expressing shSIRT1 and shLuc respectively followed by puromycin selection. EZH2 protein level was detected by Western blot in either whole cell lysate or the fractional cell extract. Reverse transcription-polymerase chain reaction was performed to detect the mRNA level of EZH2. Cycloheximide was used to treat SIRT1 RNAi and Control RNAi cells for protein stability assay. Chromatin immunoprecipitation (ChIP) assay was applied to measure enrichment of SIRT1, EZH2, and trimethylated H3K27 (H3K27me3) at SATB1 promoter in SIRT1 RNAi and Control RNAi cells. Results Western blot results showed that EZH2 protein level increased upon SIRT1 de-pletion. Fractional extraction results showed unchanged cytoplasmic fraction and increased chromatin fraction of EZH2 protein in SIRT1 RNAi cells. The mRNA level of EZH2 was not affected by knockdown of SIRT1. SIRT1 recruitment was not detected at the promoter region of EZH2 gene locus. The protein stability assay showed that the protein stability of EZH2 increases upon SIRT1 knockdown. Upon SIRT1 depletion, EZH2 and H3K27me3 recruitment at SATB1 promoter increases and the mRNA level of SATB1 decreases. Conclusions Depletion of SIRT1 increases the protein stability of EZH2. The regulation of EZH2 protein level by SIRT1 affects the repressive effects of EZH2 on the target gene expres-sion.展开更多
Objective To discover the pharmacological mechanisms of monotropein in colorectal cancer by network pharmacology methods.Methods The main-candidate-target network was constructed by the prediction of targets of monotr...Objective To discover the pharmacological mechanisms of monotropein in colorectal cancer by network pharmacology methods.Methods The main-candidate-target network was constructed by the prediction of targets of monotropein, collection of therapeutic targets of colorectal cancer drugs, and construction of the target network and layers of screening. The data were interpreted by pathway enrichment and target score calculation.Results This study:(1) Demonstrated the potential of monotropein to be a multi-target drug against colorectal cancer using a computational approach;(2) Discovered 10 candidate targets of monotropein, among which protein kinase B(AKT1)exhibited the highest relevance and importance to colorectal cancer and proto-oncogene tyrosine-protein kinase Src(SRC),Bruton’s tyrosine kinase(BTK), and heat shock protein HSP 90-alpha(HSP90 AA1) also exhibited high relevance;(3) Observed 32 possible pathways related to the effects of monotropein on colorectal cancer, which might explain the mechanism of its action;and(4) Established a method to assess the importance of targets in the network.Conclusions This study offered clues for the mechanism of the bioactivities of monotropein against colorectal cancer by network analysis. Monotropein has the potential to be a multi-target drug against colorectal cancer, which lays the foundation for its clinical applications and further study.展开更多
The underwater target recognition is a key technology in acoustic confrontation and underwater defence. In this article, a recognition system based on fuzzy logic inference (FLI) is set up. This system is mainly compo...The underwater target recognition is a key technology in acoustic confrontation and underwater defence. In this article, a recognition system based on fuzzy logic inference (FLI) is set up. This system is mainly composed of three parts: the fuzzy input module, the fuzzy logic inference module with a set of inference rules and the de-fuzzy output module. The inference result shows the recognition system is effective in most conditions.展开更多
Brain edema leading to an expansion of brain volume has a crucial impact on morbidity and mortality following traumatic brain injury as it increases intracranial pressure, impairs cerebral perfusion and oxygenation, a...Brain edema leading to an expansion of brain volume has a crucial impact on morbidity and mortality following traumatic brain injury as it increases intracranial pressure, impairs cerebral perfusion and oxygenation, and contributes to additional ischemic injuries. Classically, two major types of traumatic brain edema exist： ＂vasogenic＂ and ＂cytotoxic/cellular＂. However, the cellular and molecular mechanisms contributing to the development/resolution of traumatic brain edema are poorly understood and no effective drugs can be used now. Aquaporin-4 （AQP4） is a water-channel protein expressed strongly in the brain, predominantly in astrocyte foot processes at the borders between the brain parenchyma and major fluid compartments,including cerebrospinal fluid and blood. This distribution suggests that AQP4 controls water fluxes into and out of the brain parenchyma. In cytotoxic edema, AQP4 deletion slows the rate of water entry into brain, whereas in vasogenic edema, AQP4 deletion reduces the rate of water outflow from brain parenchyma. AQP4 has been proposed as a novel drug target in brain edema. These findings suggest that modulation of AQP4 expression or function may be beneficial in traumatic brain edema.展开更多
基金Supported by National Natural Science Foundation of China (30721063)National Basic Research Program of China (973 Program) (2005CB522402, 2006CB910403)+1 种基金National Laboratory of Medical Molecular Biology grant (2060204)Beijing municipal government grant (YB20081002301)
文摘Objective To study the regulatory roles of SIRT1 on EZH2 expression and the further ef-fects on EZH2's repression of target gene expression. Methods The stable SIRT1 RNAi and Control RNAi HeLa cells were established by in-fection with retroviruses expressing shSIRT1 and shLuc respectively followed by puromycin selection. EZH2 protein level was detected by Western blot in either whole cell lysate or the fractional cell extract. Reverse transcription-polymerase chain reaction was performed to detect the mRNA level of EZH2. Cycloheximide was used to treat SIRT1 RNAi and Control RNAi cells for protein stability assay. Chromatin immunoprecipitation (ChIP) assay was applied to measure enrichment of SIRT1, EZH2, and trimethylated H3K27 (H3K27me3) at SATB1 promoter in SIRT1 RNAi and Control RNAi cells. Results Western blot results showed that EZH2 protein level increased upon SIRT1 de-pletion. Fractional extraction results showed unchanged cytoplasmic fraction and increased chromatin fraction of EZH2 protein in SIRT1 RNAi cells. The mRNA level of EZH2 was not affected by knockdown of SIRT1. SIRT1 recruitment was not detected at the promoter region of EZH2 gene locus. The protein stability assay showed that the protein stability of EZH2 increases upon SIRT1 knockdown. Upon SIRT1 depletion, EZH2 and H3K27me3 recruitment at SATB1 promoter increases and the mRNA level of SATB1 decreases. Conclusions Depletion of SIRT1 increases the protein stability of EZH2. The regulation of EZH2 protein level by SIRT1 affects the repressive effects of EZH2 on the target gene expres-sion.
基金the funding support from the Joint Research Fund for Overseas Chinese,Hong Kong and Macao Young Scholars of National Science Foundation of China(No.81929003)the Science and Technology Development Fund,Macao SAR(No.0027/2017/AMJ)the National Key Research and Development Program of China(No.2017YFE0119900).
文摘Objective To discover the pharmacological mechanisms of monotropein in colorectal cancer by network pharmacology methods.Methods The main-candidate-target network was constructed by the prediction of targets of monotropein, collection of therapeutic targets of colorectal cancer drugs, and construction of the target network and layers of screening. The data were interpreted by pathway enrichment and target score calculation.Results This study:(1) Demonstrated the potential of monotropein to be a multi-target drug against colorectal cancer using a computational approach;(2) Discovered 10 candidate targets of monotropein, among which protein kinase B(AKT1)exhibited the highest relevance and importance to colorectal cancer and proto-oncogene tyrosine-protein kinase Src(SRC),Bruton’s tyrosine kinase(BTK), and heat shock protein HSP 90-alpha(HSP90 AA1) also exhibited high relevance;(3) Observed 32 possible pathways related to the effects of monotropein on colorectal cancer, which might explain the mechanism of its action;and(4) Established a method to assess the importance of targets in the network.Conclusions This study offered clues for the mechanism of the bioactivities of monotropein against colorectal cancer by network analysis. Monotropein has the potential to be a multi-target drug against colorectal cancer, which lays the foundation for its clinical applications and further study.
文摘The underwater target recognition is a key technology in acoustic confrontation and underwater defence. In this article, a recognition system based on fuzzy logic inference (FLI) is set up. This system is mainly composed of three parts: the fuzzy input module, the fuzzy logic inference module with a set of inference rules and the de-fuzzy output module. The inference result shows the recognition system is effective in most conditions.
文摘Brain edema leading to an expansion of brain volume has a crucial impact on morbidity and mortality following traumatic brain injury as it increases intracranial pressure, impairs cerebral perfusion and oxygenation, and contributes to additional ischemic injuries. Classically, two major types of traumatic brain edema exist： ＂vasogenic＂ and ＂cytotoxic/cellular＂. However, the cellular and molecular mechanisms contributing to the development/resolution of traumatic brain edema are poorly understood and no effective drugs can be used now. Aquaporin-4 （AQP4） is a water-channel protein expressed strongly in the brain, predominantly in astrocyte foot processes at the borders between the brain parenchyma and major fluid compartments,including cerebrospinal fluid and blood. This distribution suggests that AQP4 controls water fluxes into and out of the brain parenchyma. In cytotoxic edema, AQP4 deletion slows the rate of water entry into brain, whereas in vasogenic edema, AQP4 deletion reduces the rate of water outflow from brain parenchyma. AQP4 has been proposed as a novel drug target in brain edema. These findings suggest that modulation of AQP4 expression or function may be beneficial in traumatic brain edema.
