Jules Farah, Avedanian Levon, Al-Khoury Johny, Keita Ramatoulaye, Normand Alexandre, Bkaily Ghassan, Jacques Danielle
Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
J Cardiovasc Pharmacol. 2015 Jul;66(1):50-7. doi: 10.1097/FJC.0000000000000242.
In fetal human left ventricular endocardial endothelial cells (EECLs), both plasma membrane (PM) ET(A)R and ET(B)R were reported to mediate ET-1-induced increase of intracellular calcium Ca; however, this effect was mediated by ET(A)R in right EECs (EECRs). In this study, we verified whether, as for the PM, nuclear membranes (NMs) ET-1 receptors activation in EECLs and EECRs induce an increase of nuclear calcium (Ca) and if this effect is mediated through the same receptor type as in PM. Using a plasmalemma-perforated technique and 3D confocal microscopy, our results showed that, as in PM intact cells, superfusion of nuclei of both cell types with cytosolic ET-1 induced a concentration-dependent sustained increase of Ca. In EECRs, the ET(A)R antagonist prevented the effect of ET-1 on Ca without affecting EECLs. However, in both cell types, the effect of cytosolic ET-1 on Ca was prevented by the ETBR antagonist. In conclusion, both NMs' ET(A)R and ET(B)R mediated the effect of cytosolic ET-1 on Ca in EECRs. In contrast, only NMs' ET(B)R activation mediated the effect of cytosolic ET-1 in EECLs. Hence, the type of NMs' receptors mediating the effect of ET-1 on Ca are different from those of PM mediating the increase in Ca.
在人类胎儿左心室心内膜内皮细胞(EECLs)中,据报道质膜(PM)ET(A)R和ET(B)R均可介导ET-1诱导的细胞内钙Ca增加;然而,在右心内膜内皮细胞(EECRs)中,这种效应是由ET(A)R介导的。在本研究中,我们验证了对于质膜而言,EECLs和EECRs中核膜(NMs)ET-1受体的激活是否会诱导核钙(Ca)增加,以及这种效应是否通过与质膜中相同的受体类型介导。使用质膜穿孔技术和三维共聚焦显微镜,我们的结果表明,与完整质膜细胞一样,用细胞溶质ET-1灌注两种细胞类型的细胞核均会诱导Ca浓度依赖性持续增加。在EECRs中,ET(A)R拮抗剂可阻止ET-1对Ca的作用,而不影响EECLs。然而,在两种细胞类型中,细胞溶质ET-1对Ca的作用均被ETBR拮抗剂阻止。总之,核膜的ET(A)R和ET(B)R均介导了细胞溶质ET-1对EECRs中Ca的作用。相比之下,只有核膜ET(B)R的激活介导了细胞溶质ET-1在EECLs中的作用。因此,介导ET-1对Ca作用的核膜受体类型与介导Ca增加的质膜受体类型不同。