Docosahexaenoic fatty acid-containing phospholipids affect plasma membrane susceptibility to disruption by bacterial toxin-induced macroapertures

Metabolic studies and animal knockout models point to the critical role of polyunsaturated docosahexaenoic acid (22:6, DHA)-containing phospholipids (PLs) in physiology. Here, we study the impact of DHA-PLs on the dynamics of transendothelial cell macroapertures (TEMs) tunnels triggered by the RhoA GTPase inhibitory exotoxin C3 from Clostridium botulinum . Through lipidomic analyses, we show that primary human umbilical vein endothelial cells (HUVECs) subjected to DHA-diet undergo a 6-fold DHA-PLs enrichment in plasma membrane at the expense of monounsaturated OA-PLs. In contrast, OA-diet had almost no effect on PLs composition. Consequently, DHA treatment increases the nucleation rate of TEMs by 2-fold that we ascribe to a reduction of cell thickness. We reveal that the global transcellular area of cells remains conserved through a reduction of the width and lifetime of TEMs. Altogether, we reveal a homeostasis between plasma membrane DHA-PLs content and large-scale membrane dynamics.