Document Type

Article

Publication Date

2014

Publication Title

Cell Biochemistry and Biophysics

Volume

69

Issue

3

Pages

555-566

DOI

10.1007/s12013-014-9831-9

Abstract

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

Comments

NOTE: This is the author's post-print version of a work that was published in Cell Biochemistry and Biophysics. The final version was published as:

Rassokhin, M. A., & Pakhomov, A. G. (2014). Cellular regulation of extension and retraction of pseudopod-like blebs produced by nanosecond pulsed electric field (nsPEF). Cell Biochemistry and Biophysics, 69(3), 555-566. doi:10.1007/s12013-014-9831-9

Available at: http://dx.doi.org/10.1007/s12013-014-9831-9

Original Publication Citation

Rassokhin, M. A., & Pakhomov, A. G. (2014). Cellular regulation of extension and retraction of pseudopod-like blebs produced by nanosecond pulsed electric field (nsPEF). Cell Biochemistry and Biophysics, 69(3), 555-566. doi:10.1007/s12013-014-9831-9

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