Matricellular protein: a new player in cerebral vasospasm following subarachnoid hemorrhage.
BACKGROUND
Matricellular protein (MCP) is a class of nonstructural and secreted extracellular matrix proteins that exert diverse functions, but its role in vascular smooth muscle contraction has not been investigated.


METHODS
First, rat subarachnoid hemorrhage (SAH) models were produced by endovascular perforation and examined for tenascin-C (TNC) and osteopontin (OPN) induction (representatives of MCPs) in vasospastic cerebral arteries using immunostaining. Second, recombinant TNC (r-TNC), recombinant OPN (r-OPN), or both were injected into a cisterna magna in healthy rats, and the effects on the diameter of basilar arteries were determined using India ink angiography.


RESULTS
In SAH rats, TNC immunoreactivity was markedly induced in the smooth muscle cell layers of spastic cerebral arteries on day 1 but not in control animals. The TNC immunoreactivity decreased on day 3 as vasospasm improved: OPN immunoreactivity, on the other hand, was more induced in the arterial wall on day 3. r-TNC injections caused prolonged contractions of rat basilar arteries, which were reversed by r-OPN, although r-OPN itself had no effect on the vessel diameter.


CONCLUSIONS
MCPs, including TNC and OPN, may contribute to the pathophysiology of cerebral vasospasm and provide a novel therapeutic approach against it.
Department of Neurosurgery, Mie University Graduate School of Medicine, Mie, Japan. suzuki02@clin.medic.mie-u.ac.jp
Hidenori
H
Suzuki
Masato
M
Shiba
Masashi
M
Fujimoto
Kengo
K
Kawamura
Mai
M
Nanpei
Eriko
E
Tekeuchi
Satoshi
S
Matsushima
Kenji
K
Kanamaru
Kyoko
K
Imanaka-Yoshida
Toshimichi
T
Yoshida
Waro
W
Taki
D000818:Animals; D001488:Basilar Artery / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D002244:Carbon; D002533:Cerebral Angiography; D002946:Cisterna Magna / Q000187:drug effects / Q000503:physiopathology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects; D008297:Male; D009460:Neurologic Examination; D053495:Osteopontin / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018709:Statistics, Nonparametric; D013345:Subarachnoid Hemorrhage / Q000150:complications* / Q000209:etiology; D019063:Tenascin / Q000378:metabolism* / Q000494:pharmacology; D013997:Time Factors; D014661:Vasoconstriction / Q000187:drug effects; D020301:Vasospasm, Intracranial / Q000209:etiology* / Q000473:pathology
D019063:Tenascin; C028433:chinese ink; D053495:Osteopontin; D002244:Carbon