高血压患者外周血CD4+T细胞Kv1.3钾通道的变化

Expression of Kv1.3 potassium channels in CD4^+T cells in peripheral blood of patients with hypertension

目的:探讨高血压患者外周血CD4+T淋巴细胞上的电压门控性钾通道(Kv1.3)电流的变化。方法:收集24例高血压患者和24例健康志愿者外周血,免疫磁珠法分选出CD4+T淋巴细胞,分别给予0、2nmol/L血管紧张素Ⅱ(AngⅡ)培养48h,采用全细胞膜片钳技术记录淋巴细胞Kv1.3钾通道电流,并用RT-PCR检测Kv1.3钾通道和血管紧张素受体(AT1)蛋白mRNA的表达,ELISA试剂盒检测培养上清IFN-γ浓度。结果:①高血压患者CD4+T细胞Kv1.3钾通道电流峰值(307±117)pA,明显高于正常人(233±95)pA(P<0.05)。②给予AngⅡ干预后,正常人CD4+T细胞Kv1.3钾通道电流峰值明显增高(325±99)pA(P<0.05);而高血压患者CD4+T细胞Kv1.3钾通道电流峰值增高不明显。正常加药组CD4+T细胞Kv1.3钾通道mRNA表达也增高。③淋巴细胞存在AT1受体,且高血压患者CD4+T细胞AT1受体mRNA表达明显高于正常人;AngⅡ干预后高血压患者CD4+T细胞培养上清IFN-γ浓度较正常人增加更明显。结论:高血压患者淋巴细胞Kv1.3钾通道表达增多,AngⅡ能增加Kv1.3钾通道表达,AngⅡ促进CD4+T细胞活化和IFN-γ分泌的效应可能由AT1受体介导。本研究提示炎症参与高血压的发病及其靶器官损害,而CD4+T细胞Kv1.3钾通道在高血压炎症的发生发展中发挥重要作用。

Objective：To explore the changes of voltage-gated potassium channels（Kv1.3）in CD4＋T lymphocytes in peripheral blood of patients with hypertension.Method：CD4＋T cells in 24hypertension patients and 24 healthy volunteers were isolated from peripheral blood with magnetic cell sorting,and trained respectively with 0, 2nmol/L angiotensin Ⅱ（AngⅡ）for 48h.The Kv1.3channel current for different groups were recorded by whole-cell patch-clamp technique.mRNA expression of Kv1.3potassium channels and angiotensin（AT1）receptor were detected by Real-time quantitative PCR,and the concentration of interferon gamma（IFN-γ）in culture supernatant were determined by ELISA kit.Result：①Peak Kv1.3channel current of CD4＋T cells in hypertension patients was significantly higher than that in healthy volunteers[（307±117）pA vs（233±95）pA,P〈0.05].② Both peak current and mRNA expression of CD4＋T cell Kv1.3potassium channels in healthy volunteers increased significantly after cultured with AngⅡ[（325±99）pA vs（233±95）pA,P〈0.05],while there was no obvious change in hypertension patients.③AT1receptors were expressed within T cells,and we found AT1receptor mRNA expression of CD4＋T cells in hypertension patients was apparently more than that in healthy volunteers.Moreover,compared with healthy volunteers,concentration of IFN-γin culture supernatant increased markedly in hypertension patients after interfered with AngⅡ.Conclusion：CD4＋T cells in hypertension patients expresse more Kv1.3potassium channels.AngⅡcan enhance the expression of Kv1.3potassium channels.Furthermore,AngⅡ can promote activation and IFN-γsecretion of CD4＋T cells,which may be mediated by AT1receptor.This study indicates that inflammation is involved in the pathogenesis of hypertension and its target organ damage,and Kv1.3 potassium channel plays an important role in the inflammation development of hypertension.