Benextramine逆转神经肽Y下调人血管平滑肌细胞LDL-R的表达

目的:探讨benextramine对神经肽Y(NPY)人血管平滑肌细胞(hVSMC)低密度脂蛋白受体(LDL-R)表达影响的逆转作用。方法:应用荧光免疫组化和激光扫描共聚焦显微技术,定量检测hVSMC的LDL-R表达的变化。Benextramine(B组)浓度设为10^-5mol/L,NPY设10^-8mol/L(N1组)、10^-7mol/L(N2组)、10^-6mol/L(N3组)和10^-5mol/L(N4组)4个浓度,培养时间分别为6、12、24和48h。结果:对照组LDL-R表达的平均荧光值较高,介于2564-2649之间,且各时段间均无显著差异(P>0.05)。各NPY组LDL-R表达的平均荧光值均明显低于对照组和各benextramine组(P<0.05),介于1639-2512之间,其荧光值随NPY浓度增加而下降,N1-N4组分别平均下降15.64%、20.31%、22.58%和27.42%,呈现一定的剂量依赖效应;同时其荧光值也随NPY作用时间的延长而下降,在6、12、24和48h时间段分别平均下降11.24%、21.29%、23.04%和30.38%,亦呈现一定的时间依赖效应。各benextramine组(包括B组、B+N1组、B+N2组、B+N3组及B+N4组)的LDL-R表达荧光值介于2554-2631之间,与对照组间差异无显著(P>0.05),且与NPY作用浓度及时间无关(P>0.05)。结论:NPY能导致hVSMC的LDL-R表达下降,benextramine可逆转该作用。

Influence of benextramine on the expression of low density lipoprotein receptor in human vascular smooth muscle cells induced by neuropeptide Y

AIM: To explore the influence of benextramine on the expression of low density lipoprotein receptor (LDL-R) in human vascular smooth muscle cells (hVSMCs) treated with neuropeptide Y (NPY). METHODS: The quantitative fluorescent immunocytochemistry was applied to examine the expression of LDL-R in hVSMCs through laser scanning confocal micropscope system. The concentration of benextramine was 10^-5 mol/L (B group) and the concentrations of NPY were 10^-8 mol/L (N1 group), 10^-7 mol/L (N2 group), 10^-6 mol/L (N3 group) and 10^-5 mol/L (N4 group). The culture time was 6, 12, 24 and 48 h, respectively. RESULTS: The average fluorescent value of the LDL-R expression in control group was high (from 2 564 to 2 649) and there was no significant difference among the different culture time (P>0.05). The average fluorescent value in NPY group was lower than that in control and benextramine groups(form 1 639 to 2 512)(P<0.05), decreasing by 15.64%, 20.31%, 22.58% and 27.42%, respectively in N1-N4 groups in a dose-dependent manner. Besides, the average fluorescent value in N1-N4 groups decreased by 11.24%, 21.29%, 23.04% and 30.38%, respectively at 6, 12, 24 and 48 h in a time-dependent manner. The average fluorescent value of the LDL-R expression in benextramine groups (including B+N1 group, B+N2 group, B+N3 group and B+N4 group) was also high (from 2 554 to 2 631) and there was no significant difference between benextramine groups and control (P>0.05). The average fluorescent value of benextramine groups were not affected by the action time and the concentrations of NPY(P>0.05). CONCLUSION: NPY could downregulate the expression of LDL-R in hVSMCs and the downregulation was blocked by benextramine.