Alzheimer disease(AD) and typeⅡdiabetes mellitus(DM2) are the most common disease in aging people,with β-amyloid and amylin accumulation respectively.Studies have shown more and more correlations between these two d...Alzheimer disease(AD) and typeⅡdiabetes mellitus(DM2) are the most common disease in aging people,with β-amyloid and amylin accumulation respectively.Studies have shown more and more correlations between these two diseases,and amylin oligomerization in the brain provided a novel risk target for developing AD.Although cumulative studies reported that amylin aggregation induced cytotoxicity in pancreatic beta cells by altering Ca2+homeostasis,fewer studies investigated the effect of amylin on hippocampal neuron.To address this question,it was investigated the effect of amylin on primary cultured rat hippocampal neurons by calcium imaging and whole-cell patch clamp recording in this study,while the results revealed that human amylin(hAmylin) but not rat amylin or pramlintide(hAmylin analgue) produced a rapid increase in intracellular calcium in a dose dependent manner.This effect relied on extracellular calcium and not abolished by amylin receptor antagonist AC187.Additionally,the calcium increase induced by hAmylin was dependent onvoltage-gated Ca2+channels,especially L-type Ca2+channel activation.In whole-cell recording hAmylin could depolarize membrane potential and increase the cell exitability.Moreover,application of transient receptor potential vanilloid(TRPV) antagonist ruthenium red could abolish part of the intracellular calcium increase.Single cell RT-PCR revealed that TRPV4 mRNA expressed in most of the reactive neuron and selective TRPV4 antagonist HC067047 inhibited the intacellular calcium increasing.These results indicated that hAmylin aggregation precipitating on the neuron membrane activated TRPV4 channels and then triggered membrane voltage gated calcium channel opening followed by membrane depolarization,expressing that TRPV4 is a key molecular target for the cytotoxic effect of hAmylin on cultured neurons.展开更多
目的:观察人胰淀素和烟碱对大鼠脑乙酰胆碱能神经元膜上受体通道活动的影响。方法:在急性分离的大鼠基底前脑神经元上,采用细胞贴附式和全细胞膜片钳技术进行检测。结果:人胰淀素或烟碱单独应用可以分别诱导相同通道的激活。烟碱与人胰...目的:观察人胰淀素和烟碱对大鼠脑乙酰胆碱能神经元膜上受体通道活动的影响。方法:在急性分离的大鼠基底前脑神经元上,采用细胞贴附式和全细胞膜片钳技术进行检测。结果:人胰淀素或烟碱单独应用可以分别诱导相同通道的激活。烟碱与人胰淀素诱导的37 pS电导单通道电流幅度分别为(-3.6±0.4)和(-3.5±0.3)pA,65 p S电导单通道电流幅度分别为(-6.0±0.2)和(-6.1±0.3)pA,两电导水平的单通道电流比较,差异均无统计学意义(P均>0.05)。在电流钳记录模式,人胰淀素或烟碱单独应用可引起神经元膜电位去极化并诱发动作电位的产生。DHβE完全阻断烟碱和人胰淀素的作用,应用人胰淀素受体拮抗剂AC253也观察到类似的效果。结论:人胰淀素受体和烟碱受体在中枢神经元存在功能性协同作用。展开更多
文摘Alzheimer disease(AD) and typeⅡdiabetes mellitus(DM2) are the most common disease in aging people,with β-amyloid and amylin accumulation respectively.Studies have shown more and more correlations between these two diseases,and amylin oligomerization in the brain provided a novel risk target for developing AD.Although cumulative studies reported that amylin aggregation induced cytotoxicity in pancreatic beta cells by altering Ca2+homeostasis,fewer studies investigated the effect of amylin on hippocampal neuron.To address this question,it was investigated the effect of amylin on primary cultured rat hippocampal neurons by calcium imaging and whole-cell patch clamp recording in this study,while the results revealed that human amylin(hAmylin) but not rat amylin or pramlintide(hAmylin analgue) produced a rapid increase in intracellular calcium in a dose dependent manner.This effect relied on extracellular calcium and not abolished by amylin receptor antagonist AC187.Additionally,the calcium increase induced by hAmylin was dependent onvoltage-gated Ca2+channels,especially L-type Ca2+channel activation.In whole-cell recording hAmylin could depolarize membrane potential and increase the cell exitability.Moreover,application of transient receptor potential vanilloid(TRPV) antagonist ruthenium red could abolish part of the intracellular calcium increase.Single cell RT-PCR revealed that TRPV4 mRNA expressed in most of the reactive neuron and selective TRPV4 antagonist HC067047 inhibited the intacellular calcium increasing.These results indicated that hAmylin aggregation precipitating on the neuron membrane activated TRPV4 channels and then triggered membrane voltage gated calcium channel opening followed by membrane depolarization,expressing that TRPV4 is a key molecular target for the cytotoxic effect of hAmylin on cultured neurons.
文摘目的:观察人胰淀素和烟碱对大鼠脑乙酰胆碱能神经元膜上受体通道活动的影响。方法:在急性分离的大鼠基底前脑神经元上,采用细胞贴附式和全细胞膜片钳技术进行检测。结果:人胰淀素或烟碱单独应用可以分别诱导相同通道的激活。烟碱与人胰淀素诱导的37 pS电导单通道电流幅度分别为(-3.6±0.4)和(-3.5±0.3)pA,65 p S电导单通道电流幅度分别为(-6.0±0.2)和(-6.1±0.3)pA,两电导水平的单通道电流比较,差异均无统计学意义(P均>0.05)。在电流钳记录模式,人胰淀素或烟碱单独应用可引起神经元膜电位去极化并诱发动作电位的产生。DHβE完全阻断烟碱和人胰淀素的作用,应用人胰淀素受体拮抗剂AC253也观察到类似的效果。结论:人胰淀素受体和烟碱受体在中枢神经元存在功能性协同作用。
