Modulation of nuclear T-tubules in endocardial endothelium by ET-1. Modulation des tubules-T nucléaires par l'ET-1 au niveau de l'endothelium endocardique

导语：最近，在Hela细胞、人肝癌SKHep1细胞和小鼠成肌细胞C2C12细胞等几种细胞系中发现了核内结构。最近，我们的研究小组首次在正常人心内膜内皮细胞（EECs）中发现了类似的核内结构。这些管状内陷被我们的实验室称为核t管（ntt），因为它们与质膜t管相似。我们和其他人认为它们的存在可能取决于细胞的代谢和活动，如增殖。然而，这些结构是否有效地延伸了核包膜，并可能像人类EECs的核包膜一样，具有ET-1受体（ET-1Rs）和核孔，目前还没有相关信息。此外，还没有关于ntt是否会影响ET-1对人心内膜内皮细胞核Ca2+稳态和细胞周期的调节的信息。此外，ET-1是否调节ntt的存在或不存在，特别是在人类EECs中，仍有待发现。

INTRODUCTION: Recently, intranuclear structures were identified in several cell lines such as Hela cells, human hepatoma SKHep1 cells, and mouse myoblast C2C12 cells. Very recently, our group identified, for the first time, similar intranuclear structures in normal human endocardial endothelial cells (EECs). These tubular-like invaginations were called by our laboratory nuclear T-tubules (NTTs) because of their resemblance to the plasma membrane T-tubules. We and others suggested that their presence may depend on the metabolism and activities of the cells such as proliferation. However, there are no information on whether these structures are effectively an extension of the nuclear envelope membranes and may possess, as the nuclear envelope membranes of human EECs, ET-1 receptors (ET-1Rs) and nuclear pores. Furthermore, there is no information on whether NTTs would affect ET-1 modulation of nuclear Ca2+ homeostasis and cell cycle of human endocardial endothelial cells. In addition, whether or not ET-1 modulates the presence or absence of NTTs and more particularly in human EECs, remains to be discovered.