Pifithrin-alpha reduces cerebral vasospasm by attenuating apoptosis of endothelial cells in a subarachnoid haemorrhage model of rat.
BACKGROUND
The mechanism of cerebral vasospasm following subarachnoid haemorrhage (SAH) is not understood. Here, we hypothesized that apoptosis of endothelial cells induced by p53 and its target gene em dash p53 upregulated modulator of apoptosis (PUMA) played an important role in development of cerebral vasospasm. We also observed the effects of a p53 inhibitor, pifithrin-alpha (PFT-alpha), on reducing the expression of p53 and PUMA, consequently decreasing the apoptosis of endothelial cells and alleviating cerebral vasospasm.


METHODS
Male Sprague-Dawley rats weighing 300-350 g were randomly divided into five groups: a control group (sham surgery), a SAH group, a SAH+dimethyl sulfoxide (DMSO) group, a SAH + PFT-alpha (0.2 mg/kg) group and a SAH + PFT-alpha (2.0 mg/kg) group. PFT-alpha was injected intraperitoneally immediately after SAH. Rats were sacrificed 24 hours after SAH. Western blot and immunohistochemical staining were used to detect the levels of p53, PUMA and caspase-3 protein. In addition, mortality and neurological scores were assessed for each group. Statistical significance was assured by analysis of variance performed in one way ANOVA followed by the Tukey test. The neurological and mortality scores were analyzed by Dunn's method and Fisher exact test, respectively.


RESULTS
After SAH, Western blot and immunohistochemical staining showed the levels of p53, PUMA and caspase-3 in the endothelial cells and the numbers of TdT mediated dUTP nick end labelling (TUNEL) positive endothelial cells were all significantly increased in the basilar arteries (P<0.05), but significantly reduced by PFT-alpha (P<0.05). These changes were accompanied by increasing diameters and declining wall thickness of basilar arteries (P<0.05), as well as reduced mortality and neurological deficits of the rats (P<0.05).


CONCLUSIONS
PFT-alpha could protect cerebral vessels from development of vasospasm and improve neurological outcome as well as reduce the mortality via suppressing apoptosis induced by p53 in the endothelial cells of cerebral vessels.
Yan
Jun-hao
JH
Department of Anatomy and Embryology, Peking University Health Science Centre, Beijing 100083, China.
Yang
Xiao-mei
XM
Chen
Chun-hua
CH
Hu
Qin
Q
Zhao
Jing
J
Shi
Xian-zhong
XZ
Luan
Li-ju
LJ
Yang
Lei
L
Qin
Li-hua
LH
Zhou
Chang-man
CM
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D052160:Benzothiazoles / Q000494:pharmacology / Q000627:therapeutic use*; D015153:Blotting, Western; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000187:drug effects* / Q000473:pathology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D014050:Toluene / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D016159:Tumor Suppressor Protein p53 / Q000502:physiology; D020301:Vasospasm, Intracranial / Q000517:prevention & control*
D052160:Benzothiazoles; D016159:Tumor Suppressor Protein p53; D014050:Toluene; C121565:pifithrin