Schwann cells in peripheral nerves react to traumatic nerve injury by attempting to grow and regenerate.Howeve r,it is unclear what factors play a role in this process.In this study,we searched a GEO database and foun...Schwann cells in peripheral nerves react to traumatic nerve injury by attempting to grow and regenerate.Howeve r,it is unclear what factors play a role in this process.In this study,we searched a GEO database and found that expression of platelet factor 4 was markedly up-regulated after sciatic nerve injury.Platelet factor is an important molecule in cell apoptosis,diffe rentiation,survival,and proliferation.Further,polymerase chain reaction and immunohistochemical staining confirmed the change in platelet factor 4 in the sciatic nerve at different time points after injury.Enzyme-linked immunosorbent assay confirmed that platelet factor 4 was secreted by Schwann cells.We also found that silencing platelet factor 4 decreased the proliferation and migration of primary cultured Schwann cells,while exogenously applied platelet factor 4 stimulated Schwann cell prolife ration and migration and neuronal axon growth.Furthermore,knocking out platelet factor 4 inhibited the prolife ration of Schwann cells in injured rat sciatic nerve.These findings suggest that Schwann cell-secreted platelet factor 4 may facilitate peripheral nerve repair and regeneration by regulating Schwann cell activation and axon growth.Thus,platelet factor 4 may be a potential therapeutic target for traumatic peripheral nerve injury.展开更多
The infiltration of water contaminants into soil and groundwater systems can greatly affect the quality of groundwater. A laboratory-designed large soil tank with periodic and continuous infiltration models, respectiv...The infiltration of water contaminants into soil and groundwater systems can greatly affect the quality of groundwater. A laboratory-designed large soil tank with periodic and continuous infiltration models, respectively, was used to simulate the migration of the contaminants NH4 and NO3 in a soil and groundwater system, including unsaturated and saturated zones. The unsaturated soil zone had a significant effect on removing NH4 and NO3 infiltrated from the surface water. The patterns of breakthrough curves of NH4 and NO3 in the unsaturated zone were related to the infiltration time. A short infiltration time resulted in a single sharp peak in the breakthrough curve, while a long infiltration time led to a plateau curve. When NH4 and NO3 migrated from the unsaturated zone to the saturated zone, an interracial retardation was formed, resulting in an increased contaminant concentration on the interface. Under the influence of horizontal groundwater movement, the infiltrated contaminants formed a contamination-prone area downstream. As the contaminants migrated downstream, their concentrations were significantly reduced. Under the same infiltration concentration, the concentration of NO3 was greater than that of NH4 at every corresponding cross-section in the soil and groundwater tank, suggesting that the removal efficiency of NH4 was greater than that of NO3 in the soil and groundwater system.展开更多
BACKGROUND Esophageal squamous cell carcinoma(ESCC),the predominant type of esophageal cancer,has a 5-year survival rate less than 20%.Although the cause of poor prognosis is the high incidence and mortality of ESCC,t...BACKGROUND Esophageal squamous cell carcinoma(ESCC),the predominant type of esophageal cancer,has a 5-year survival rate less than 20%.Although the cause of poor prognosis is the high incidence and mortality of ESCC,the high rate of metastasis after esophageal cancer surgery is the main cause of death after the surgery.Bromodomain-containing protein 4(BRD4),an epigenetic reader of chromatinacetylated histones in tumorigenesis and development,plays an essential role in regulating oncogene expression.BRD4 inhibition and BRD4 inhibition-based treatment can potentially suppress ESCC growth.However,the effects and mechanisms of action of BRD4 on ESCC cell migration remain unclear.AIM To explore the effect of BRD4 on cell migration of ESCC in vitro and its possible molecular mechanism.METHODS Human ESCC cell lines KYSE-450 and KYSE-150 were used.The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay was performed to examine cell proliferation,and the transwell migration assay was conducted to test ESCC cell migration.JQ1,a BRD4 inhibitor,was applied to cells,and BRD4 siRNA was transfected into ESCC cells to knockdown endogenous BRD4.GFP-RFP-LC3 adenovirus was infected into ESCC cells to evaluate the effect of JQ1 on autophagy.Western blotting was performed to determine the protein levels of BRD4,E-cadherin,vimentin,AMP-activated protein kinase(AMPK),and p-AMPK.RESULTS BRD4 was either downregulated by small interfering RNA or pretreated with JQ1 in ESCC cells,leading to increased tumor migration in ESCC cells in a dose-and time-dependent manner.Inhibition of BRD4 not only significantly suppressed cell proliferation but also strongly increased cell migration by inducing epithelial-mesenchymal transition(EMT).The protein expression of vimentin was increased and E-cadherin decreased in a dose-dependent manner,subsequently promoting autophagy in KYSE-450 and KYSE-150 cells.Pretreatment with JQ1,a BRD4 inhibitor,inhibited BRD4-induced LC3-II activation and upregulated AMPK phosphorylation in a dosedependent manner.Additionally,an increased number of autophagosomes and autolysosomes were observed in JQ1-treated ESCC cells.The autophagy inhibitor 3-methyladenine(3-MA)reversed the effects of BRD4 knockdown on ESCC cell migration and blocked JQ1-induced cell migration.3-MA also downregulated the expression of vimentin and upregulation E-cadherin.CONCLUSION BRD4 inhibition enhances cell migration by inducing EMT and autophagy in ESCC cells via the AMPK-modified pathway.Thus,the facilitating role on ESCC cell migration should be considered for BRD4 inhibitor clinical application to ESCC patients.展开更多
The present internet version which was established and consolidated over internet protocol version 4 (IPV4) in 1981, and whose amount of public addresses available is insufficient to meet the demands explosion and cur...The present internet version which was established and consolidated over internet protocol version 4 (IPV4) in 1981, and whose amount of public addresses available is insufficient to meet the demands explosion and current internet multimedia devices, services and application intensive environment has posed serious problems of incomplete web transactions. Stakeholders and communication industry in Nigeria are unwilling and feel reluctant to migrate to IPV6 because of inhibiting factors. This needs urgent redress to overcome the tractions that are responsible for apathy to migration from IPV4 to IPV6 launched in 1994 by the Internet Engineering Task Force (IETF). If nothing is done, sometime, internet may run out of space, ARIN [1]. Users may suffer disillusionment and frustration. The objective of this study therefore is to design a model for predicting migration from IPV4 to IPV6 in Nigeria by 2027 based on growth trend developed from statistical indices. The essence is to explore and analyze the factors that can encourage migration to IPV6 in the next 10 years and use those factors to forecast growth, so that IPV6 will receive boost in terms of growth and patronage. The study also aims at designing a predictive model that simulates the behaviour of the restrictive policies on migration to 1PV6 so as to ascertain the current impact on non-motivation and unwillingness to migrate to IPV6 in Nigeria. The motivation behind this study is to identify the inhibiting factors responsible for lack of motivation to migrate from IPV4 to IPV6 in Nigeria. The methodologies that were deployed in packaging the model include the statistical methodology, Structured Systems Analysis and Design Methodology (SSADM) and prototyping. The result is indeed functional software, programmed through Visual Basic. Net. (VB.Net) that can be used to simulate the behavioural impact of any government policy formulation for Telecommunication industry and stakeholders.展开更多
BACKGROUND： Studies of several animal models of central nervous system diseases have shown that neural progenitor cells （NPCs） can migrate to injured tissues. Stromal cell-derived factor 1 alpha （SDF-la）, and its...BACKGROUND： Studies of several animal models of central nervous system diseases have shown that neural progenitor cells （NPCs） can migrate to injured tissues. Stromal cell-derived factor 1 alpha （SDF-la）, and its primary physiological receptor CXCR4, have been shown to contribute to this process. OBJECTIVE： To investigate migration efficacy of human NPCs toward a SDF-1α gradient, and the regulatory roles of tumor necrosis factor-α （TNF-α） and interleukin-8 （IL-8） in SDF-1α/CXCR4 axis-induced migration of NPCs. DESIGN, TIME AND SETTING： An in vitro, randomized, controlled, cellular and molecular biology study was performed at the Laboratory of Department of Cell Biology, Medical College of Soochow University between October 2005 and November 2007. MATERIALS： SDF-1α and mouse anti-human CXCR4 fusion antibody were purchased from R＆D Systems, USA. TNF-αwas purchased from Biomyx Technology, USA and IL-8 was kindly provided by the Biotechnology Research Institute of Soochow University. METHODS： NPCs isolated from forebrain tissue of 9 to 10-week-old human fetuses were cultured in vitro. The cells were incubated with 0, 20, and 40 ng/mL TNF-α, or 0, 20, and 40 ng/mL IL-8, for 48 hours prior to migration assay. For antibody-blocking experiments, cells were further pretreated with 0, 20, and 40 μg/mL mouse anti-human CXCR4 fusion antibody for 2 hours. Subsequently, the transwell assay and CXCR4 blockade experiments were performed to evaluate migration of human NPCs toward a SDF-1α gradient. Serum-free culture medium without SDF-1α served as the negative control. MAIN OUTCOME MEASURES： The transwell assay was performed to evaluate migration of human NPCs toward a SDF-1α gradient, which was blocked by fusion antibody against CXCR4. In addition, CXCR4 expression in human NPCs stimulated by TNF-α and IL-8 was measured by flow cytometry. RESULTS： Results from the transwell assay demonstrated that SDF-1α was a strong chemoattractant for human NPCs （P 〈 0.01）, and 20 ng/mL produced the highest levels of migration. Anti-human CXCR4 fusion antibody significantly blocked the chemotactic effect （P 〈 0.05）. Flow cytometry results showed that treatment with TNF-α and IL-8 resulted in increased CXCR4 expression and greater chemotaxis efficiency of NPCs towards SDF-1α（P 〈 0.01）. CONCLUSION： These results demonstrated that SDF-la significantly attracted NPCs in vitro, and neutralizing anti-CXCR4 antibody could block part of this chemotactic function. TNF-α and IL-8 increased chemotaxis efficiency of NPCs towards the SDF-1αgradient by upregulating CXCR4 expression in NPCs.展开更多
Objective: To study the correlation of KLF4 and UBE2C expression levels in neuroblastoma with cell adhesion and migration. Methods: A total of 56 children who were diagnosed with neuroblastoma in the Central Hospital ...Objective: To study the correlation of KLF4 and UBE2C expression levels in neuroblastoma with cell adhesion and migration. Methods: A total of 56 children who were diagnosed with neuroblastoma in the Central Hospital of Enshi Autonomous Prefecture between May 2014 and February 2017 were selected as the NB group of the study, and the lesion tissue was collected;38 children who were treated in the Central Hospital of Enshi Autonomous Prefecture due to serious hydronephrosis during the same period were selected as the control group of the study, and the normal adrenal gland tissue was collected. The mRNA expression and protein expression of KLF4 and UBE2C as well as the protein expression of cell adhesion molecules and migration molecules in clinical tissue samples were determined. Results: The mRNA expression and protein expression of KLF4 in neuroblastoma tissue of NB group were greatly lower than those of control group whereas the mRNA expression and protein expression of UBE2C were greatly higher than those of control group;PDLIM1, AMF, GPx1, L1CAM, Nrg1, RANK, RANKL, Inβ1, MTA1 and MMP9 protein expression in neuroblastoma tissue of NB group were greatly higher than those of control group, negatively correlated with the protein expression KLF4, and positively correlated with the protein expression of UBE2C. Conclusion: The low expression of KLF4 and the high expression of UBE2C in neuroblastoma can promote the adhesion and migration of tumor cells.展开更多
An environmental benign procedure for synthesis of 2-(N-formyl)-5-aryl/aryloxymethyl-1,3,4-thiadiazoles has been developed by reaction of 2-amino-5-aryl/aryloxymethyl-1,3,4-thiadiazoles with formic acid in PEG-400.The...An environmental benign procedure for synthesis of 2-(N-formyl)-5-aryl/aryloxymethyl-1,3,4-thiadiazoles has been developed by reaction of 2-amino-5-aryl/aryloxymethyl-1,3,4-thiadiazoles with formic acid in PEG-400.The key advantages of this protocol are the shorter reaction time,higher yields,lower cost,simple workup,and environment-friendly compared to conventional organic solvent reaction.The present method does not involve any hazardous organic solvent or catalyst.展开更多
基金supported by the National Natural Science Foundation of China,Nos.31730031,32130060the National Natural Science Foundation of China,No.31971276(to JH)+1 种基金the Natural Science Foundation of Jiangsu Province,No.BK20202013(to XG)the Natural Science Foundation of Jiangsu Higher Education Institutions of China(Major Program),No.19KJA320005(to JH)。
文摘Schwann cells in peripheral nerves react to traumatic nerve injury by attempting to grow and regenerate.Howeve r,it is unclear what factors play a role in this process.In this study,we searched a GEO database and found that expression of platelet factor 4 was markedly up-regulated after sciatic nerve injury.Platelet factor is an important molecule in cell apoptosis,diffe rentiation,survival,and proliferation.Further,polymerase chain reaction and immunohistochemical staining confirmed the change in platelet factor 4 in the sciatic nerve at different time points after injury.Enzyme-linked immunosorbent assay confirmed that platelet factor 4 was secreted by Schwann cells.We also found that silencing platelet factor 4 decreased the proliferation and migration of primary cultured Schwann cells,while exogenously applied platelet factor 4 stimulated Schwann cell prolife ration and migration and neuronal axon growth.Furthermore,knocking out platelet factor 4 inhibited the prolife ration of Schwann cells in injured rat sciatic nerve.These findings suggest that Schwann cell-secreted platelet factor 4 may facilitate peripheral nerve repair and regeneration by regulating Schwann cell activation and axon growth.Thus,platelet factor 4 may be a potential therapeutic target for traumatic peripheral nerve injury.
基金the National Key Basic Research Program (973 Program) of China (No.2002CB412303)the National Natural Science Foundation of China (No.50709009)the Key Project of Chinese Ministry of Education (No.106088).
文摘The infiltration of water contaminants into soil and groundwater systems can greatly affect the quality of groundwater. A laboratory-designed large soil tank with periodic and continuous infiltration models, respectively, was used to simulate the migration of the contaminants NH4 and NO3 in a soil and groundwater system, including unsaturated and saturated zones. The unsaturated soil zone had a significant effect on removing NH4 and NO3 infiltrated from the surface water. The patterns of breakthrough curves of NH4 and NO3 in the unsaturated zone were related to the infiltration time. A short infiltration time resulted in a single sharp peak in the breakthrough curve, while a long infiltration time led to a plateau curve. When NH4 and NO3 migrated from the unsaturated zone to the saturated zone, an interracial retardation was formed, resulting in an increased contaminant concentration on the interface. Under the influence of horizontal groundwater movement, the infiltrated contaminants formed a contamination-prone area downstream. As the contaminants migrated downstream, their concentrations were significantly reduced. Under the same infiltration concentration, the concentration of NO3 was greater than that of NH4 at every corresponding cross-section in the soil and groundwater tank, suggesting that the removal efficiency of NH4 was greater than that of NO3 in the soil and groundwater system.
基金the Key Project of Science and Technology of Xinxiang,No.GG2020027the Health Commission of Henan Province of China,No.SBGJ202102188.
文摘BACKGROUND Esophageal squamous cell carcinoma(ESCC),the predominant type of esophageal cancer,has a 5-year survival rate less than 20%.Although the cause of poor prognosis is the high incidence and mortality of ESCC,the high rate of metastasis after esophageal cancer surgery is the main cause of death after the surgery.Bromodomain-containing protein 4(BRD4),an epigenetic reader of chromatinacetylated histones in tumorigenesis and development,plays an essential role in regulating oncogene expression.BRD4 inhibition and BRD4 inhibition-based treatment can potentially suppress ESCC growth.However,the effects and mechanisms of action of BRD4 on ESCC cell migration remain unclear.AIM To explore the effect of BRD4 on cell migration of ESCC in vitro and its possible molecular mechanism.METHODS Human ESCC cell lines KYSE-450 and KYSE-150 were used.The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay was performed to examine cell proliferation,and the transwell migration assay was conducted to test ESCC cell migration.JQ1,a BRD4 inhibitor,was applied to cells,and BRD4 siRNA was transfected into ESCC cells to knockdown endogenous BRD4.GFP-RFP-LC3 adenovirus was infected into ESCC cells to evaluate the effect of JQ1 on autophagy.Western blotting was performed to determine the protein levels of BRD4,E-cadherin,vimentin,AMP-activated protein kinase(AMPK),and p-AMPK.RESULTS BRD4 was either downregulated by small interfering RNA or pretreated with JQ1 in ESCC cells,leading to increased tumor migration in ESCC cells in a dose-and time-dependent manner.Inhibition of BRD4 not only significantly suppressed cell proliferation but also strongly increased cell migration by inducing epithelial-mesenchymal transition(EMT).The protein expression of vimentin was increased and E-cadherin decreased in a dose-dependent manner,subsequently promoting autophagy in KYSE-450 and KYSE-150 cells.Pretreatment with JQ1,a BRD4 inhibitor,inhibited BRD4-induced LC3-II activation and upregulated AMPK phosphorylation in a dosedependent manner.Additionally,an increased number of autophagosomes and autolysosomes were observed in JQ1-treated ESCC cells.The autophagy inhibitor 3-methyladenine(3-MA)reversed the effects of BRD4 knockdown on ESCC cell migration and blocked JQ1-induced cell migration.3-MA also downregulated the expression of vimentin and upregulation E-cadherin.CONCLUSION BRD4 inhibition enhances cell migration by inducing EMT and autophagy in ESCC cells via the AMPK-modified pathway.Thus,the facilitating role on ESCC cell migration should be considered for BRD4 inhibitor clinical application to ESCC patients.
文摘The present internet version which was established and consolidated over internet protocol version 4 (IPV4) in 1981, and whose amount of public addresses available is insufficient to meet the demands explosion and current internet multimedia devices, services and application intensive environment has posed serious problems of incomplete web transactions. Stakeholders and communication industry in Nigeria are unwilling and feel reluctant to migrate to IPV6 because of inhibiting factors. This needs urgent redress to overcome the tractions that are responsible for apathy to migration from IPV4 to IPV6 launched in 1994 by the Internet Engineering Task Force (IETF). If nothing is done, sometime, internet may run out of space, ARIN [1]. Users may suffer disillusionment and frustration. The objective of this study therefore is to design a model for predicting migration from IPV4 to IPV6 in Nigeria by 2027 based on growth trend developed from statistical indices. The essence is to explore and analyze the factors that can encourage migration to IPV6 in the next 10 years and use those factors to forecast growth, so that IPV6 will receive boost in terms of growth and patronage. The study also aims at designing a predictive model that simulates the behaviour of the restrictive policies on migration to 1PV6 so as to ascertain the current impact on non-motivation and unwillingness to migrate to IPV6 in Nigeria. The motivation behind this study is to identify the inhibiting factors responsible for lack of motivation to migrate from IPV4 to IPV6 in Nigeria. The methodologies that were deployed in packaging the model include the statistical methodology, Structured Systems Analysis and Design Methodology (SSADM) and prototyping. The result is indeed functional software, programmed through Visual Basic. Net. (VB.Net) that can be used to simulate the behavioural impact of any government policy formulation for Telecommunication industry and stakeholders.
基金the National Natural Science Foundation of China,No.30671041the National Basic Research Program of China(973 Program),No. 2005CB623902
文摘BACKGROUND： Studies of several animal models of central nervous system diseases have shown that neural progenitor cells （NPCs） can migrate to injured tissues. Stromal cell-derived factor 1 alpha （SDF-la）, and its primary physiological receptor CXCR4, have been shown to contribute to this process. OBJECTIVE： To investigate migration efficacy of human NPCs toward a SDF-1α gradient, and the regulatory roles of tumor necrosis factor-α （TNF-α） and interleukin-8 （IL-8） in SDF-1α/CXCR4 axis-induced migration of NPCs. DESIGN, TIME AND SETTING： An in vitro, randomized, controlled, cellular and molecular biology study was performed at the Laboratory of Department of Cell Biology, Medical College of Soochow University between October 2005 and November 2007. MATERIALS： SDF-1α and mouse anti-human CXCR4 fusion antibody were purchased from R＆D Systems, USA. TNF-αwas purchased from Biomyx Technology, USA and IL-8 was kindly provided by the Biotechnology Research Institute of Soochow University. METHODS： NPCs isolated from forebrain tissue of 9 to 10-week-old human fetuses were cultured in vitro. The cells were incubated with 0, 20, and 40 ng/mL TNF-α, or 0, 20, and 40 ng/mL IL-8, for 48 hours prior to migration assay. For antibody-blocking experiments, cells were further pretreated with 0, 20, and 40 μg/mL mouse anti-human CXCR4 fusion antibody for 2 hours. Subsequently, the transwell assay and CXCR4 blockade experiments were performed to evaluate migration of human NPCs toward a SDF-1α gradient. Serum-free culture medium without SDF-1α served as the negative control. MAIN OUTCOME MEASURES： The transwell assay was performed to evaluate migration of human NPCs toward a SDF-1α gradient, which was blocked by fusion antibody against CXCR4. In addition, CXCR4 expression in human NPCs stimulated by TNF-α and IL-8 was measured by flow cytometry. RESULTS： Results from the transwell assay demonstrated that SDF-1α was a strong chemoattractant for human NPCs （P 〈 0.01）, and 20 ng/mL produced the highest levels of migration. Anti-human CXCR4 fusion antibody significantly blocked the chemotactic effect （P 〈 0.05）. Flow cytometry results showed that treatment with TNF-α and IL-8 resulted in increased CXCR4 expression and greater chemotaxis efficiency of NPCs towards SDF-1α（P 〈 0.01）. CONCLUSION： These results demonstrated that SDF-la significantly attracted NPCs in vitro, and neutralizing anti-CXCR4 antibody could block part of this chemotactic function. TNF-α and IL-8 increased chemotaxis efficiency of NPCs towards the SDF-1αgradient by upregulating CXCR4 expression in NPCs.
文摘Objective: To study the correlation of KLF4 and UBE2C expression levels in neuroblastoma with cell adhesion and migration. Methods: A total of 56 children who were diagnosed with neuroblastoma in the Central Hospital of Enshi Autonomous Prefecture between May 2014 and February 2017 were selected as the NB group of the study, and the lesion tissue was collected;38 children who were treated in the Central Hospital of Enshi Autonomous Prefecture due to serious hydronephrosis during the same period were selected as the control group of the study, and the normal adrenal gland tissue was collected. The mRNA expression and protein expression of KLF4 and UBE2C as well as the protein expression of cell adhesion molecules and migration molecules in clinical tissue samples were determined. Results: The mRNA expression and protein expression of KLF4 in neuroblastoma tissue of NB group were greatly lower than those of control group whereas the mRNA expression and protein expression of UBE2C were greatly higher than those of control group;PDLIM1, AMF, GPx1, L1CAM, Nrg1, RANK, RANKL, Inβ1, MTA1 and MMP9 protein expression in neuroblastoma tissue of NB group were greatly higher than those of control group, negatively correlated with the protein expression KLF4, and positively correlated with the protein expression of UBE2C. Conclusion: The low expression of KLF4 and the high expression of UBE2C in neuroblastoma can promote the adhesion and migration of tumor cells.
基金support from the Natural Science Foundation of Gansu Province(No.3ZS061- A25-019)the Scientific Research fund of Gansu Provincial Education Department(No.0601-25)
文摘An environmental benign procedure for synthesis of 2-(N-formyl)-5-aryl/aryloxymethyl-1,3,4-thiadiazoles has been developed by reaction of 2-amino-5-aryl/aryloxymethyl-1,3,4-thiadiazoles with formic acid in PEG-400.The key advantages of this protocol are the shorter reaction time,higher yields,lower cost,simple workup,and environment-friendly compared to conventional organic solvent reaction.The present method does not involve any hazardous organic solvent or catalyst.
