RT Journal Article SR Electronic T1 Identification of a Survival-Promoting Peptide in Medium Conditioned by Oxidatively Stressed Cell Lines of Nervous System Origin JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 7047 OP 7060 DO 10.1523/JNEUROSCI.18-18-07047.1998 VO 18 IS 18 A1 Timothy J. Cunningham A1 Lisa Hodge A1 David Speicher A1 Dave Reim A1 Carla Tyler-Polsz A1 Pat Levitt A1 Kathie Eagleson A1 Sarah Kennedy A1 Ying Wang YR 1998 UL http://www.jneurosci.org/content/18/18/7047.abstract AB A survival-promoting peptide has been purified from medium conditioned by Y79 human retinoblastoma cells and a mouse hippocampal cell line (HN 33.1) exposed to H2O2. A 30 residue synthetic peptide was made on the basis of N-terminal sequences obtained during purification, and it was found to exhibit gel mobility and staining properties similar to the purified molecules. The peptide maintains cells and their processes in vitro for the HN 33.1 cell line treated with H2O2, andin vivo for cortical neurons after lesions of the cerebral cortex. It has weak homology with a fragment of a putative bacterial antigen and, like that molecule, binds IgG. The peptide also contains a motif reminiscent of a critical sequence in the catalytic region of calcineurin-type phosphatases; surprisingly, like several members of this family, the peptide catalyzes the hydrolysis ofpara-nitrophenylphosphate in the presence of Mn2+. Application of the peptide to one side of bilateral cerebral cortex lesions centered on area 2 in rats results in an increase in IgG immunoreactivity in the vicinity of the lesions 7 d after surgery. Microglia immunopositive for IgG and ED-1 are, however, dramatically reduced around the lesions in the treated hemisphere. Furthermore, pyramidal neurons that would normally shrink, die, or disintegrate were maintained, as determined by MAP2 immunocytochemistry and Nissl staining. These survival effects were often found in both hemispheres. The results suggest that this peptide operates by diffusion to regulate the immune response and thereby rescue neurons that would usually degenerate after cortical lesions. The phosphatase activity of this molecule also suggests the potential for direct neuron survival-promoting effects.