目的:观察不同频率电针对脑缺血再灌注恢复期大鼠血脑屏障(BBB)开放效应,探讨电针促血脑屏障开放调控机制。方法:频率研究:150只健康雄性SD大鼠建立大脑中动脉闭塞(MCAO)模型,饲养3周后,按随机原则分为模型组、假手术组及2、15、30、50...目的:观察不同频率电针对脑缺血再灌注恢复期大鼠血脑屏障(BBB)开放效应,探讨电针促血脑屏障开放调控机制。方法:频率研究:150只健康雄性SD大鼠建立大脑中动脉闭塞(MCAO)模型,饲养3周后,按随机原则分为模型组、假手术组及2、15、30、50、100Hz组。检测大鼠脑含水量以及伊文思蓝(EB)透过量。机制研究:180只SD大鼠建立MCAO模型,饲养3周后,随机分为模型组、假手术组、电针组、假电针组、电针+PKC抑制剂组;检测大鼠大脑皮层蛋白激酶C亚型β1(PKCβ1)的磷酸化水平、P-糖蛋白(P-gp)以及mdr1a、mdr1b m RNA的表达。结果:2Hz组、100Hz组大鼠脑组织EB含量明显升高(P<0.05);模型组与其余4组比较,大鼠脑组织含水量差异无统计学意义。与模型组比较,2Hz组大鼠大脑皮层的PKCβ1、p-PKCβ1/PKCβ1均显著提高(P<0.05),电针组P-gp的IHS评分显著降低(P<0.05),电针组mdr1、mdr1b m RNA的表达均明显降低(P<0.05);电针+PKC抑制剂组mdr1a m RNA表达高于电针组(P<0.05)。结论:2Hz、100Hz电针刺激对脑缺血再灌注恢复期大鼠BBB均具有一定开放效应,且无明显脑水肿出现;电针诱导大鼠BBB开放可能是通过促使PKCβ1磷酸化,下调药物外排系统P-gp、mdr1a m RNA,抑制P-gp在大脑皮层毛细血管内皮细胞的表达实现。展开更多
Background and Objective:Research has shown that 5-bromotetrandrine(BrTet) can effectively reverse multidrug resistance(MDR).Imatinib plays an important role in cell proliferation.This study explored the efficacy of t...Background and Objective:Research has shown that 5-bromotetrandrine(BrTet) can effectively reverse multidrug resistance(MDR).Imatinib plays an important role in cell proliferation.This study explored the efficacy of the combination of imatinib and BrTet on reversing MDR of tumor cells and its mechanism.Methods:Cytoxicity was assessed by MTT assay.Apoptosis of K562/A02 cells was analyzed by flow cytometry.The expressions of mdr1 mRNA and P-glycoprotein(P-gp) were detected using reverse transcription-polymerase chain reaction(RT-PCR) and Western blot analysis.Results:After 48 h of treatment with 0.0625 μmol/L imatinib,0.5 μmol/L BrTet,or both,the 50% inhibition concentration(IC50) of daunorubicin(DNR) for the K562/A02 cells were 5.69 mg/L,5.41 mg/L,and 2.19 mg/L,respectively.The gray-scale values of mdr1 mRNA expression in the K562/A02 cells were 0.65 ± 0.02,0.64 ± 0.01,and 0.25 ± 0.03,respectively.The expression levels of P-gp were 0.74 ± 0.02,0.52 ± 0.02,and 0.29 ± 0.02,respectively.All decreased significantly in the K562/A02 cells treated with both imatinib and BrTet compared to cells treated with imatinib and BrTet alone(P < 0.05).The apoptosis rates of the K562/A02 cells increased without a significant difference after treatment with DNR,imatinib,or BrTet(P > 0.05),while increased significantly after treatment with DNR combined with imatinib,BrTet,or both(P < 0.05).Conclusions:The MDR of K562/A02 cells may be partially reversed by imatinib or BrTet,and the mechanism may be related to the downregulation of mdr1 mRNA and P-gp expression and the upregulation of the rate of apoptosis in K562/A02 cells.Imatinib combined with BrTet showed a synergistic effect on K562/A02 cells.展开更多
文摘目的:观察不同频率电针对脑缺血再灌注恢复期大鼠血脑屏障(BBB)开放效应,探讨电针促血脑屏障开放调控机制。方法:频率研究:150只健康雄性SD大鼠建立大脑中动脉闭塞(MCAO)模型,饲养3周后,按随机原则分为模型组、假手术组及2、15、30、50、100Hz组。检测大鼠脑含水量以及伊文思蓝(EB)透过量。机制研究:180只SD大鼠建立MCAO模型,饲养3周后,随机分为模型组、假手术组、电针组、假电针组、电针+PKC抑制剂组;检测大鼠大脑皮层蛋白激酶C亚型β1(PKCβ1)的磷酸化水平、P-糖蛋白(P-gp)以及mdr1a、mdr1b m RNA的表达。结果:2Hz组、100Hz组大鼠脑组织EB含量明显升高(P<0.05);模型组与其余4组比较,大鼠脑组织含水量差异无统计学意义。与模型组比较,2Hz组大鼠大脑皮层的PKCβ1、p-PKCβ1/PKCβ1均显著提高(P<0.05),电针组P-gp的IHS评分显著降低(P<0.05),电针组mdr1、mdr1b m RNA的表达均明显降低(P<0.05);电针+PKC抑制剂组mdr1a m RNA表达高于电针组(P<0.05)。结论:2Hz、100Hz电针刺激对脑缺血再灌注恢复期大鼠BBB均具有一定开放效应,且无明显脑水肿出现;电针诱导大鼠BBB开放可能是通过促使PKCβ1磷酸化,下调药物外排系统P-gp、mdr1a m RNA,抑制P-gp在大脑皮层毛细血管内皮细胞的表达实现。
文摘目的探讨小干扰RNA(small interfering RNA,si RNA)对口腔鳞癌多药耐药基因mdr1(MDRI)及其表达产物P-糖蛋白(permeability-glyco-protein,P-gp)的干扰作用。方法体外构建针对MDR1的小干扰RNA,将其转染至人舌癌耐药细胞系Tca8113/DDP,采用RT-PCR法检测转染前后MDR1 m RNA的表达;采用免疫细胞化学技术比较转染前后P-gp的表达;采用MTT法检测转染前后肿瘤耐药细胞对顺铂的敏感性。结果 Tca8113/DDP细胞经MDR1-si RNA转染后48 h的转染率达最高,为71.3%;转染后mdr1 m RNA表达较对照组显著降低,降低率为68.32%,转染48 h后P-gp的表达较对照组明显降低;si RNA可显著提高Tca8113/DDP细胞对DDP的敏感性,逆转其耐药性,耐药倍数为2.05。结论 si RNA可以明显干扰口腔鳞癌MDR1及相应蛋白P-gp的表达。
基金National Natural Science Foundation of China (No. 30740062)
文摘Background and Objective:Research has shown that 5-bromotetrandrine(BrTet) can effectively reverse multidrug resistance(MDR).Imatinib plays an important role in cell proliferation.This study explored the efficacy of the combination of imatinib and BrTet on reversing MDR of tumor cells and its mechanism.Methods:Cytoxicity was assessed by MTT assay.Apoptosis of K562/A02 cells was analyzed by flow cytometry.The expressions of mdr1 mRNA and P-glycoprotein(P-gp) were detected using reverse transcription-polymerase chain reaction(RT-PCR) and Western blot analysis.Results:After 48 h of treatment with 0.0625 μmol/L imatinib,0.5 μmol/L BrTet,or both,the 50% inhibition concentration(IC50) of daunorubicin(DNR) for the K562/A02 cells were 5.69 mg/L,5.41 mg/L,and 2.19 mg/L,respectively.The gray-scale values of mdr1 mRNA expression in the K562/A02 cells were 0.65 ± 0.02,0.64 ± 0.01,and 0.25 ± 0.03,respectively.The expression levels of P-gp were 0.74 ± 0.02,0.52 ± 0.02,and 0.29 ± 0.02,respectively.All decreased significantly in the K562/A02 cells treated with both imatinib and BrTet compared to cells treated with imatinib and BrTet alone(P < 0.05).The apoptosis rates of the K562/A02 cells increased without a significant difference after treatment with DNR,imatinib,or BrTet(P > 0.05),while increased significantly after treatment with DNR combined with imatinib,BrTet,or both(P < 0.05).Conclusions:The MDR of K562/A02 cells may be partially reversed by imatinib or BrTet,and the mechanism may be related to the downregulation of mdr1 mRNA and P-gp expression and the upregulation of the rate of apoptosis in K562/A02 cells.Imatinib combined with BrTet showed a synergistic effect on K562/A02 cells.
