IJPPP Copyright © 2009-All rights reserved. Published by e-Century Publishing Corporation, Madison, WI 53711
Int J Physiol Pathophysiol Pharmacol 2013;5(4):216-227

Original Article
Investigating the role of the actin regulating complex ARP2/3 in rapid ischemic
tolerance induced neuro-protection

Veronica J Jessick, Mian Xie, Andrea N Pearson, Dan J Torrey, Michelle D Ashley, Simon Thompson, Robert Meller

Neuroscience Institute, Morehouse School of Medicine, 720 Westview Drive SW, Atlanta, GA, 30310, USA; Robert S. Dow Neurobiology
Laboratories, Legacy Research, Portland, Oregon, USA

Received August 31, 2013; Accepted October 27, 2013; Epub December 15, 2013; Published December 30, 2013

Abstract: Neuronal morphology is highly sensitive to ischemia, although some re-organization may promote neuroprotection. In this
study we investigate the role of actin regulating proteins (ARP2, ARP3 and WAVE-1) and their role in rapid ischemic tolerance. Using an
established in vitro model of rapid ischemic tolerance, we show that WAVE-1 protein levels are stabilized following brief tolerance
inducing ischemia (preconditioning). The stabilization appears to be due to a reduction in the ubiquitination of WAVE-1. Levels of ARP2,
ARP3 and N-WASP were not affected by ischemic preconditioning. Immunocytochemical studies show a relocalization of ARP2 and
ARP3 proteins in neurons following preconditioning ischemia, as well as a re-organization of actin. Blocking the protein kinase CK2
using emodin blocks ischemic tolerance, and our data suggests CK2 binds to WAVE-1 in neurons. We observe an increase in binding
of the ARP2 subunit with WAVE-1. The neuroprotection observed following preconditioning is inhibited when cells are transduced with
an N-WASP CA domain that blocks the activation of ARP2/3. Together these data show that ischemia affects actin regulating enzymes,
and that the ARP2/3 pathway plays a role in rapid ischemic tolerance induced neuroprotection. (IJPPP1308004).

Keywords: Actin, WAVE-1, ischemic tolerance, neurons, Arp2/3

Address correspondence to: Robert Meller, Neuroscience Institute, Morehouse School of Medicine, 720 Westview Drive SW, Atlanta,
GA 30310, USA. Tel: 404-756-5789; E-mail: rmeller@msm.edu