Cellular Regulation of Extension and Retraction of Pseudopod-Like Blebs Produced by Nanosecond Pulsed Electric Field (nsPEF)

摘要: Recently we described a new phenomenon of anodotropic pseudopod-like blebbing in U937 cells exposed to nanosecond pulsed electric field (nsPEF). In Ca2+-free buffer such exposure initiates formation blebs (PLBs), protrusive cylindrical cell extensions that are distinct from apoptotic and necrotic blebs. PLBs nucleate predominantly on anode-facing pole extend toward anode during nsPEF exposure. Bleb extension depends actin polymerization availability monomers. Inhibition intracellular Ca2+, contractility, RhoA produced no effect PLB initiation. Meanwhile, inhibition WASP by wiskostatin causes dose-dependent suppression growth. Soon after the end lose directionality growth then retract. Microtubule toxins nocodazole paclitaxel did not show immediate PLBs; however, increased mobility components retraction. Retraction is myosin activation corresponding increase cortex contractility. blebbistatin reduces retraction while RhoA–ROCK pathway Y-27632 completely prevents Contraction can produce translocation resembling active movement. Overall, formation, properties, life cycle share common features with protrusions associated ameboid migration. may be controlled through its upstream effectors as Cdc42 PIP2, main ROCK activator—RhoA. Parallels between motility provide insights into their underlying mechanisms.