Gary M Fiskum

Publication Detail

The publication detail shows the title, authors (with indicators showing other profiled authors), information on the publishing organization, abstract and a link to the article in PubMed. This abstract is what is used to create the fingerprint of the publication. If any grants are referenced by the publication, they will be listed here as well.

Inhibition of Bax-induced cytochrome c release from neural cell and brain mitochondria by dibucaine and propranolol.

Brian M Polster; Gorka Basañez; Michael Young; Motoshi Suzuki; Gary Fiskum (Profiled Authors: Gary M Fiskum; Brian M Polster)

Department of Anesthesiology and Neuroscience Program, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
The Journal of neuroscience : the official journal of the Society for Neuroscience 2003;23(7):2735-43.

BH3 (Bcl-2 homology 3)-only proteins of the Bcl-2 family activate Bax or Bak during apoptosis to promote the release of pro-death factors sequestered in the mitochondrial intermembrane space. Previous results demonstrated that a synthetic BH3 peptide mimics the ability of the BH3-only protein Bid to promote Bax insertion and cytochrome c (cyt c) release from neural cell mitochondria. However, the BH3 peptide was deficient in promoting cyt c release from mitochondria without associated Bax, such as adult rat brain mitochondria. This study tested the hypothesis that the amphiphilic membrane-active cationic drugs dibucaine and propranolol block BH3 peptide-initiated cyt c efflux by preventing the integration of Bax into the mitochondrial outer membrane. BH3 peptide-initiated release of cyt c from GT1-7 neural cell mitochondria was inhibited by dibucaine and propranolol at concentrations of 100-300 microm. Recombinant Bax (100 nm) alone did not release cyt c from adult rat brain mitochondria; however, when BH3 peptide or caspase-8 cleaved Bid (cBid) was added, robust cyt c release was achieved that was inhibited completely by 200 microm dibucaine or propranolol. These drugs at similar concentrations also inhibited release of entrapped 10 kDa dextrans from protein-free liposomes treated with Bax and cBid. Contrary to the hypothesis that dibucaine and propranolol act by inhibiting the insertion of Bax into the mitochondrial outer membrane, membrane insertion of Bax was not inhibited in mitochondria or liposomes, indicating a mechanism of drug action downstream from this event. These results suggest that dibucaine and propranolol inhibit Bax-induced permeability changes through a direct interaction with the lipid membrane and present a novel target for the development of neuroprotective, antiapoptotic therapeutics.

1 Originating Grant

• 1.

  Fiskum, Gary

  Molecular Mechanisms of Ischemia Reperfusion Brain Injury

  1 May 1995 - 31 December 2008

  NATIONAL INSTITUTE OF NEUROLOGICAL DISORDERS AND STROKE

Scientific Context

This section shows information related to the publication - computed using the fingerprint of the publication - including related publications, related experts and related grants with fingerprints representing significant amounts of overlap between their fingerprint and this publication. The red dots indicate whether those experts or terms appear within the publication, thereby showing potential and actual connections.