Recombinant erythropoietin is neuroprotective in a novel mouse oxidative injury model.
To identify neuroprotective changes in gene expression, we developed a neonatal mouse model of moderate to severe oxidative brain injury and hypothesized that recombinant erythropoietin (rEpo) would decrease the expression of proapoptotic and proinflammatory genes 24 and 48 h, respectively, after injury and increase the expression of neurogenic and angiogenic genes 168 h after injury. Postnatal day 10 BALB-c mice underwent sham surgery or right common carotid artery occlusion followed by alternating hypoxia and hyperoxia and were then treated with rEpo (5,000 U/kg s.c.) or saline (vehicle) daily for up to three doses. At death, gross brain injury was assessed, then hippocampus, cortex, and thalamus were isolated for RNA or protein extraction. Microarray analysis, real-time polymerase chain reaction, and Bio-Plex suspension array system validation were performed. rEpo decreased both incidence and severity of brain injury (median injury score 3 vs. 0, p < 0.0001) and reduced the injury-induced increases in interleukin-1alpha and interleukin-6 gene expression (p < 0.001), with corresponding effects on protein translation. Similarly, the expression of caspase-1, caspase-4, and caspase-6 and of p53 was increased by brain injury at 24 h, but mitigated by rEpo (p < 0.01). The interleukin-10 expression was higher in the rEpo-treated animals. Apoptotic and proinflammatory gene expression persisted for 168 h. There was no increase in angiogenic gene expression at the time points studied.
Juul
Sandra E
SE
Department of Pediatrics, University of Washington, Seattle, WA 98195-6320, USA. sjuul@u.washington.edu
McPherson
Ronald J
RJ
Bammler
Theodor K
TK
Wilkerson
Jasmine
J
Beyer
Richard P
RP
Farin
Federico M
FM
D000818:Animals; D020170:Caspase 1 / Q000235:genetics; D053178:Caspase 6 / Q000235:genetics; D020169:Caspases / Q000235:genetics; D053471:Caspases, Initiator; D004195:Disease Models, Animal; D004921:Erythropoietin / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D002534:Hypoxia, Brain / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D016753:Interleukin-10 / Q000378:metabolism; D053582:Interleukin-1alpha / Q000235:genetics / Q000378:metabolism; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D018696:Neuroprotective Agents / Q000494:pharmacology*; D020411:Oligonucleotide Array Sequence Analysis; D018384:Oxidative Stress / Q000187:drug effects; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000235:genetics
D053582:Interleukin-1alpha; D015850:Interleukin-6; D018696:Neuroprotective Agents; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D016159:Tumor Suppressor Protein p53; D004921:Erythropoietin; D016753:Interleukin-10; C101136:Casp4 protein, mouse; C505516:Casp6 protein, mouse; D053178:Caspase 6; D020169:Caspases; D053471:Caspases, Initiator; D020170:Caspase 1