Primary cilia of human endothelial cells disassemble under laminar shear stress.

We identified primary cilia and centrosomes in cultured human umbilical vein endothelial cells (HUVEC) by antibodies to acetyl-alpha-tubulin and capillary morphogenesis gene-1 product (CMG-1), a human homologue of the intraflagellar transport (IFT) protein IFT-71 in Chlamydomonas. CMG-1 was present in particles along primary cilia of HUVEC at interphase and around the oldest basal body/centriole at interphase and mitosis. To study the response of primary cilia and centrosomes to mechanical stimuli, we exposed cultured HUVEC to laminar shear stress (LSS). Under LSS, all primary cilia disassembled, and centrosomes were deprived of CMG-1. We conclude that the exposure to LSS ends the IFT in cultured endothelial cells.