Transient receptor potential canonical channels are required for in vitro endothelial tube formation.
In endothelial cells Ca(2+) entry is an essential component of the Ca(2+) signal that takes place during processes such as cell proliferation or angiogenesis. Ca(2+) influx occurs via the store-operated Ca(2+) entry pathway, involving stromal interaction molecule-1 (STIM1) and Orai1, but also through channels gated by second messengers like the transient receptor potential canonical (TRPC) channels. The human umbilical vein-derived endothelial cell line EA.hy926 expressed STIM1 and Orai1 as well as several TRPC channels. By invalidating each of these molecules, we showed that TRPC3, TRPC4, and TRPC5 are essential for the formation of tubular structures observed after EA.hy926 cells were plated on Matrigel. On the contrary, the silencing of STIM1 or Orai1 did not prevent tubulogenesis. Soon after being plated on Matrigel, the cells displayed spontaneous Ca(2+) oscillations that were strongly reduced by treatment with siRNA against TRPC3, TRPC4, or TRPC5, but not siRNA against STIM1 or Orai1. Furthermore, we showed that cell proliferation was reduced upon siRNA treatment against TRPC3, TRPC5, and Orai1 channels, whereas the knockdown of STIM1 had no effect. On primary human umbilical vein endothelial cells, TRPC1, TRPC4, and STIM1 are involved in tube formation, whereas Orai1 has no effect. These data showed that TRPC channels are essential for in vitro tubulogenesis, both on endothelial cell line and on primary endothelial cells.
Department of Cell Physiology and Metabolism, Geneva Medical Center, 1 rue Michel Servet, 1211 Geneva 4, Switzerland.
Fabrice
F
Antigny
Nathalie
N
Girardin
Maud
M
Frieden
D002118:Calcium / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D006632:Histamine / Q000494:pharmacology; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D008567:Membranes, Artificial; D018919:Neovascularization, Physiologic / Q000187:drug effects; D020033:Protein Isoforms / Q000378:metabolism; D050052:TRPC Cation Channels / Q000378:metabolism*
D008567:Membranes, Artificial; D020033:Protein Isoforms; D050052:TRPC Cation Channels; D006632:Histamine; D002118:Calcium