Protective effects of recombinant osteopontin on early brain injury after subarachnoid hemorrhage in rats.
OBJECTIVE
Accumulated evidence suggests that the primary cause of poor outcome after subarachnoid hemorrhage is not only cerebral arterial narrowing but also early brain injury. Our objective was to determine the effect of recombinant osteopontin, a pleiotropic extracellular matrix glycoprotein, on early brain injury after subarachnoid hemorrhage in rats.


METHODS
Controlled in vivo laboratory study.


METHODS
Animal research laboratory.


METHODS
One hundred seventy-seven male adult Sprague-Dawley rats weighing 300 to 370 g.


METHODS
The endovascular perforation model of subarachnoid hemorrhage was produced. Subarachnoid hemorrhage or sham-operated rats were treated with an equal volume (1 microL) of pre-subarachnoid hemorrhage intracerebroventricular administration of two dosages (0.02 and 0.1 microg) of recombinant osteopontin, albumin, or vehicle. Body weight, neurologic scores, brain edema, and blood-brain barrier disruption were evaluated, and Western blot analyses were performed to determine the effect of recombinant osteopontin on matrix metalloproteinase-9, substrates of matrix metalloproteinase-9 (zona occludens-1, laminin), tissue inhibitor of matrix metalloproteinase-1, inflammation (interleukin-1beta), and nuclear factor-kappaB signaling pathways.


RESULTS
Treatment with recombinant osteopontin prevented a significant loss in body weight, neurologic impairment, brain edema, and blood-brain barrier disruption after subarachnoid hemorrhage. These effects were associated with the deactivation of nuclear factor-kappaB activity, inhibition of matrix metalloproteinase-9 induction, the maintenance of tissue inhibitor of matrix metalloproteinase-1, the consequent preservation of the cerebral microvessel basal lamina protein laminin, and the tight junction protein zona occludens-1.


CONCLUSIONS
These results demonstrate that recombinant osteopontin treatment is effective for early brain injury after subarachnoid hemorrhage.
Department of Physiology, Loma Linda University of Medicine, Loma Linda, CA, USA.
Hidenori
H
Suzuki
Robert
R
Ayer
Takashi
T
Sugawara
Wanqiu
W
Chen
Takumi
T
Sozen
Yu
Y
Hasegawa
Kenji
K
Kanamaru
John H
JH
Zhang
D000818:Animals; D001812:Blood-Brain Barrier / Q000378:metabolism; D015153:Blotting, Western; D001930:Brain Injuries / Q000188:drug therapy* / Q000378:metabolism; D004195:Disease Models, Animal; D007276:Injections, Intraventricular; D007375:Interleukin-1 / Q000096:biosynthesis; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000096:biosynthesis; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis; D016328:NF-kappa B / Q000096:biosynthesis; D018696:Neuroprotective Agents / Q000627:therapeutic use; D053495:Osteopontin / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000627:therapeutic use; D013345:Subarachnoid Hemorrhage / Q000188:drug therapy* / Q000378:metabolism
D007375:Interleukin-1; D016328:NF-kappa B; D018696:Neuroprotective Agents; D011994:Recombinant Proteins; D053495:Osteopontin; D020780:Matrix Metalloproteinase 9; D020781:Matrix Metalloproteinase 1