Manipulation of antioxidant pathways in neonatal murine brain

Sheldon, RA; Jiang, X; Francisco, C; Christen, S; Vexler, ZS; Täuber, MG; Ferriero, DM (2004). Manipulation of antioxidant pathways in neonatal murine brain. Pediatric research, 56(4), pp. 656-62. New York, N.Y.: Nature Publishing Group 10.1203/01.PDR.0000139413.27864.50

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To assess the role of brain antioxidant capacity in the pathogenesis of neonatal hypoxic-ischemic brain injury, we measured the activity of glutathione peroxidase (GPX) in both human-superoxide dismutase-1 (hSOD1) and human-GPX1 overexpressing transgenic (Tg) mice after neonatal hypoxia-ischemia (HI). We have previously shown that mice that overexpress the hSOD1 gene are more injured than their wild-type (WT) littermates after HI, and that H(2)O(2) accumulates in HI hSOD1-Tg hippocampus. We hypothesized that lower GPX activity is responsible for the accumulation of H(2)O(2). Therefore, increasing the activity of this enzyme through gene manipulation should be protective. We show that brains of hGPX1-Tg mice, in contrast to those of hSOD-Tg, have less injury after HI than WT littermates: hGPX1-Tg, median injury score = 8 (range, 0-24) versus WT, median injury score = 17 (range, 2-24), p < 0.01. GPX activity in hSOD1-Tg mice, 2 h and 24 h after HI, showed a delayed and bilateral decline in the cortex 24 h after HI (36.0 +/- 1.2 U/mg in naive hSOD1-Tg versus 29.1 +/- 1.7 U/mg in HI cortex and 29.2 +/- 2.0 for hypoxic cortex, p < 0.006). On the other hand, GPX activity in hGPX1-Tg after HI showed a significant increase by 24 h in the cortex ipsilateral to the injury (48.5 +/- 5.2 U/mg, compared with 37.2 +/- 1.5 U/mg in naive hGPX1-Tg cortex, p < 0.008). These findings support the hypothesis that the immature brain has limited GPX activity and is more susceptible to oxidative damage and may explain the paradoxical effect seen in ischemic neonatal brain when SOD1 is overexpressed.

Item Type:	Journal Article (Original Article)
Division/Institute:	04 Faculty of Medicine > Service Sector > Institute for Infectious Diseases
UniBE Contributor:	Christen, Stephan, Täuber, Martin G.
ISSN:	0031-3998
ISBN:	15295091
Publisher:	Nature Publishing Group
Language:	English
Submitter:	Factscience Import
Date Deposited:	04 Oct 2013 14:55
Last Modified:	05 Dec 2022 14:17
Publisher DOI:	10.1203/01.PDR.0000139413.27864.50
PubMed ID:	15295091
Web of Science ID:	000224005000021
URI:	https://boris.unibe.ch/id/eprint/23682 (FactScience: 43468)