Inhibition of c-Jun N-terminal kinase pathway attenuates cerebral vasospasm after experimental subarachnoid hemorrhage through the suppression of apoptosis.

BACKGROUND: Recent studies have demonstrated that apoptosis in cerebral arteries could play an essential role in cerebral vasospasm after subarachnoid hemorrhage (SAH) and that SP600125, an inhibitor of c-Jun N-terminal kinase (JNK) could suppress apoptosis. The present study examined whether SP600125 could reduce cerebral vasospasm through the suppression of apoptosis.
METHOD: Fifteen dogs were assigned to 3 groups: control, SAH, and SAH + SP600125 (30 micromol/l). SAH was induced by the injection of autologous blood into the cisterna magna on day 0 and day 2. Angiograms were evaluated on day 0 and day 7. The activation of the JNK pathway and caspase-3 were also evaluated using Western blot. To determine the distribution, TUNEL staining and immunohistochemistry for phosphorylated c-jun and cleaved caspase-3 were performed.
FINDINGS: Severe vasospasm was observed in the basilar artery of the SAH dogs. SP600125 reduced angiographic and morphological vasospasm and reduced the expression of cleaved caspase-3, thereby suppressing apoptosis.
CONCLUSIONS: These results demonstrate that SP600125 attenuates cerebral vasospasm through the suppression of apoptosis, which may provide a novel therapeutic target for cerebral vasospasm.