Extended therapeutic window and functional recovery after intraarterial administration of neuregulin-1 after focal ischemic stroke.
We have previously shown that neuregulin-1 (NRG-1) protects neurons from ischemic brain injury if administered before focal stroke. Here, we examined the therapeutic window and functional recovery after NRG-1 treatment in rats subjected to 90 mins of middle cerebral artery occlusion (MCAO) and 24 h of reperfusion. Neuregulin-1 (2.5 microg/kg [corrected] bolus, 1.25 microg/kg/min [corrected] infusion) reduced infarct volume by 89.2%+/-41.9% (mean+/-s.d.; n=8; P<0.01) if administered immediately after the onset of reperfusion. Neuroprotection was also evident if NRG-1 was administered 4 h (66.4%+/-52.6%; n=7; P<0.01) and 12 h (57.0%+/-20.8%; n=8; P<0.01) after reperfusion. Neuregulin-1 administration also resulted in a significant improvement of functional neurologic outcome compared with vehicle-treated animals (32.1%+/-5.7%; n=9; P<0.01). The neuroprotective effect of the single administration of NRG-1 was seen as long as 2 weeks after treatment. Neurons labeled with the neurodegeneration marker dye Fluoro-JadeB were observed after MCAO in the cortex, but the numbers were significantly reduced after NRG-1 treatment. These results indicate that NRG-1 is a potent neuroprotective compound with an extended therapeutic window that has practical therapeutic potential in treating individuals after ischemic brain injury.
Xu
Zhenfeng
Z
Department of Anatomy and Neurobiology, Neuroscience Institute, Morehouse School of Medicine, Atlanta, Georgia 30310, USA.
Croslan
Dajoie R
DR
Harris
Adalynn E
AE
Ford
Gregory D
GD
Ford
Byron D
BD
D000818:Animals; D002545:Brain Ischemia / Q000188:drug therapy*; D020244:Infarction, Middle Cerebral Artery / Q000188:drug therapy; D020890:Neuregulin-1 / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D009474:Neurons / Q000187:drug effects / Q000473:pathology; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000517:prevention & control; D020521:Stroke / Q000188:drug therapy*; D013997:Time Factors
D020890:Neuregulin-1; D018696:Neuroprotective Agents