title: Investigating the role of the actin regulating complex ARP2/3 in rapid ischemic tolerance induced neuro-protection.
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.
authors.affiliation: Neuroscience Institute, Morehouse School of Medicine 720 Westview Drive SW, Atlanta, GA, 30310, USA.
authors.forename: Veronica J
authors.initials: VJ
authors.lastname: Jessick
authors.affiliation: Neuroscience Institute, Morehouse School of Medicine 720 Westview Drive SW, Atlanta, GA, 30310, USA.
authors.forename: Mian
authors.initials: M
authors.lastname: Xie
authors.affiliation: Neuroscience Institute, Morehouse School of Medicine 720 Westview Drive SW, Atlanta, GA, 30310, USA ; Robert S. Dow Neurobiology Laboratories, Legacy Research Portland, Oregon, USA.
authors.forename: Andrea N
authors.initials: AN
authors.lastname: Pearson
authors.affiliation: Neuroscience Institute, Morehouse School of Medicine 720 Westview Drive SW, Atlanta, GA, 30310, USA.
authors.forename: Dan J
authors.initials: DJ
authors.lastname: Torrey
authors.affiliation: Neuroscience Institute, Morehouse School of Medicine 720 Westview Drive SW, Atlanta, GA, 30310, USA.
authors.forename: Michelle D
authors.initials: MD
authors.lastname: Ashley
authors.affiliation: Neuroscience Institute, Morehouse School of Medicine 720 Westview Drive SW, Atlanta, GA, 30310, USA.
authors.forename: Simon
authors.initials: S
authors.lastname: Thompson
authors.affiliation: Neuroscience Institute, Morehouse School of Medicine 720 Westview Drive SW, Atlanta, GA, 30310, USA ; Robert S. Dow Neurobiology Laboratories, Legacy Research Portland, Oregon, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Meller
keywords: Actin; Arp2/3; WAVE-1; ischemic tolerance; neurons