Objective:To study the effects of Transient receptor potential cation channel,subfamily V,member 1(TRPV1) combined with lidocaine on status and apoptosis of U87-MG glioma cell line,and explore whether local anesthetic...Objective:To study the effects of Transient receptor potential cation channel,subfamily V,member 1(TRPV1) combined with lidocaine on status and apoptosis of U87-MG glioma cell line,and explore whether local anesthetic produces neurotoxicity by TRPVI.Methods:U87-MG cells were divided into control group,gene silencing group,empty vector group and TRPV gene up-rcgulation group.For cells in each group,flow cytometry was employed to detect the intracellular calcium ion concentration and mitochondrial membrane potential at different lime point from cellular perspective.Cell apoptosis of U87-MG was assayed by flow cytometry and MTT from a holistic perspective.Results:Calcium ion concentration increased along with time.The concentration in TRPV1 gene up-regulation group was significantly higher than those in other groups at each time point(P<0.05).After adding lidocaine.mitochondrial membrane potential in U87-MG significantly increased(P<0.05).This increasing trend in TRPV1 gene up-regulation group was more significant than other groups(P<0.05).while in TRPV1 gene silencing group,the trend significantly decreased(P<0.05).Flow cytometry result and MTT result both showed that cell apoptosis in each group significantly increased after lidocaine was added(P<0.05).This increasing trend in TRPV1 gene up-regulation group was more significant than other groups(P<0.05),while in TRPV1 gene silencing group,the trend significandy decreased(P<0.05).Moreover,apoptosis was more severe along with the increasing concentration of lidocaine(P<0.05).Conclusions:In this study,it was proved that lidocaine could dose-dependently induce the increase of intracellular calcium ion concentration,mitochondrial membrane potential and apoptosis in U87-MG glioma cell line.The up-regulation of TRPV1 enhanced cytotoxicity of lidocaine,which revealed the correlations between mem.Lidocaine might have increased intracellular calcium ion concentration by activating TRPVI gene and induced apoptosis of U87-GM glioma cell line by up-regulating mitochondrial membrane potential.展开更多
The present study aimed to investigate the targeting effect of H7K（R2）2-modified pH -sensitive liposomes on U87-MG cells. Using coumarin-6 as a fluorescence probe, we prepared H7K（R2）2-modified p H-sensitive lipos...The present study aimed to investigate the targeting effect of H7K（R2）2-modified pH -sensitive liposomes on U87-MG cells. Using coumarin-6 as a fluorescence probe, we prepared H7K（R2）2-modified p H-sensitive liposomes（designated as coumarin-6-PSL-H7K（R2）2）. The flow cytometry assay was used to evaluate the effect of H7K（R2）2 proportions on the cellular uptake and endocytosis pathways of coumarin--6--PSL--H7K（R2）2 on U87-MG cells. The circular dichroism（CD） spectroscopy assay was used to investigate the secondary structures of H7K（R2）2 peptide at pH 7.4 and H 6.8, respectively. Our results indicated that the 2.5% proportion of H7K（R2）2 in the coumarin-6--PSL-H7K（R2）2 was superior to those of 1% and 3.5% of H7K（R2）2. The uptake of coumarin--6-PSL--H7K（R2）2 on U87--MG cells was not inhibited by filipin, M-β--CD or chlorpromazine. The secondary structure of H7K（R2）2 at pH 6.8 was mostly presented as β--turn. In conclusion, we suggested that the appropriate proportion of H7K（R2）2 in the H7K（R2）2--modified pH--sensitive liposomes could be set at 2.5%. The cellular uptake pathway for H7K（R2）2-modified pH--sensitive liposomes was via the cell penetrating capacity of H7K（R2）2 which responded to acidic condition. The secondary structure of H7K（R2）2 at pH 6.8, which was presented as the shape of hairpin, might be mainly responsible for its targeting and cell penetrating effect.展开更多
基金supported by the National Natural Science Foundation(NO.81260176)
文摘Objective:To study the effects of Transient receptor potential cation channel,subfamily V,member 1(TRPV1) combined with lidocaine on status and apoptosis of U87-MG glioma cell line,and explore whether local anesthetic produces neurotoxicity by TRPVI.Methods:U87-MG cells were divided into control group,gene silencing group,empty vector group and TRPV gene up-rcgulation group.For cells in each group,flow cytometry was employed to detect the intracellular calcium ion concentration and mitochondrial membrane potential at different lime point from cellular perspective.Cell apoptosis of U87-MG was assayed by flow cytometry and MTT from a holistic perspective.Results:Calcium ion concentration increased along with time.The concentration in TRPV1 gene up-regulation group was significantly higher than those in other groups at each time point(P<0.05).After adding lidocaine.mitochondrial membrane potential in U87-MG significantly increased(P<0.05).This increasing trend in TRPV1 gene up-regulation group was more significant than other groups(P<0.05).while in TRPV1 gene silencing group,the trend significantly decreased(P<0.05).Flow cytometry result and MTT result both showed that cell apoptosis in each group significantly increased after lidocaine was added(P<0.05).This increasing trend in TRPV1 gene up-regulation group was more significant than other groups(P<0.05),while in TRPV1 gene silencing group,the trend significandy decreased(P<0.05).Moreover,apoptosis was more severe along with the increasing concentration of lidocaine(P<0.05).Conclusions:In this study,it was proved that lidocaine could dose-dependently induce the increase of intracellular calcium ion concentration,mitochondrial membrane potential and apoptosis in U87-MG glioma cell line.The up-regulation of TRPV1 enhanced cytotoxicity of lidocaine,which revealed the correlations between mem.Lidocaine might have increased intracellular calcium ion concentration by activating TRPVI gene and induced apoptosis of U87-GM glioma cell line by up-regulating mitochondrial membrane potential.
基金Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20120001110012)the National Basic Research Program of China(973 Program,Grant No.2013CB932501)National Natural Science Foundation of China(Grant No.81172992)
文摘The present study aimed to investigate the targeting effect of H7K（R2）2-modified pH -sensitive liposomes on U87-MG cells. Using coumarin-6 as a fluorescence probe, we prepared H7K（R2）2-modified p H-sensitive liposomes（designated as coumarin-6-PSL-H7K（R2）2）. The flow cytometry assay was used to evaluate the effect of H7K（R2）2 proportions on the cellular uptake and endocytosis pathways of coumarin--6--PSL--H7K（R2）2 on U87-MG cells. The circular dichroism（CD） spectroscopy assay was used to investigate the secondary structures of H7K（R2）2 peptide at pH 7.4 and H 6.8, respectively. Our results indicated that the 2.5% proportion of H7K（R2）2 in the coumarin-6--PSL-H7K（R2）2 was superior to those of 1% and 3.5% of H7K（R2）2. The uptake of coumarin--6-PSL--H7K（R2）2 on U87--MG cells was not inhibited by filipin, M-β--CD or chlorpromazine. The secondary structure of H7K（R2）2 at pH 6.8 was mostly presented as β--turn. In conclusion, we suggested that the appropriate proportion of H7K（R2）2 in the H7K（R2）2--modified pH--sensitive liposomes could be set at 2.5%. The cellular uptake pathway for H7K（R2）2-modified pH--sensitive liposomes was via the cell penetrating capacity of H7K（R2）2 which responded to acidic condition. The secondary structure of H7K（R2）2 at pH 6.8, which was presented as the shape of hairpin, might be mainly responsible for its targeting and cell penetrating effect.
