Alterations of caveolin-1 expression in a mouse model of delayed cerebral vasospasm following subarachnoid hemorrhage

Abstract

The aim of the present study was to evaluate the expression levels of caveolin-1 in the basilar artery following delayed cerebral vasospasm (DCVS) in a rat model of subarachnoid hemorrhage (SAH), in order to investigate the association between caveolin-1 and DCVS, and its potential as a treatment for DCVS of SAH. A total of 150 Sprague Dawley rats were randomly allocated into blank, saline and SAH groups. The SAH and saline groups were subdivided into days 3, 5, 7 and 14 following the establishment of the model. The murine model of SAH was established by double injection of autologous arterial blood into the cisterna magana and DCVS was detected using Bederson neurological severity scores. Hematoxylin and eosin (HE) staining was used to observe the inner perimeter of the basilar artery pipe and variations in the thickness of the basilar artery wall. Alterations in the levels of caveolin-1 protein in the basilar artery were measured using immunofluorescence and western blot analysis; whereas alterations in the mRNA expression levels of caveolin-1 were detected by reverse transcription-quantitative polymerase chain reaction. In the present study, 15 mice succumbed to SAH-induced DCVS in the day 3 (n=3), 5 (n=5) and 7 (n=2) groups. No mortality was observed in the blank control and saline groups during the process of observation in the SAH group, All mice in the SAH groups exhibited Bederson neurological severity scores ≥1; whereas no neurological impairment was detected in the blank and normal saline groups, demonstrating the success of the model. HE staining was used to assess vasospasm and the results demonstrated that the inner perimeter of the basal artery pipe decreased at day 3 in the SAH group; whereas values peaked in the day 7 group. The thickness of the basal artery wall significantly increased (P<0.05), as compared with the blank and saline groups, in which no significant alterations in the wall thickness and the inner perimeter of the basal artery pipe were detected. As detected by immunofluorescence and western blot analysis, the expression levels of caveolin-1 protein significantly decreased in the day 7 of SAH group, as compared with the blank and saline groups (P<0.01), in which no significant alterations were detected. Caveolin-1 mRNA expression levels significantly increased at the day 7 in the SAH group, as compared with the blank and the saline groups (P<0.01), as detected by RT-qPCR. Furthermore, significant differences were detected at day 14 in the SAH group, as compared with the blank and the saline groups (P>0.05), in which no significant alterations were detected. Therefore, the results of the present study demonstrated that caveolin-1 protein was downregulated in the basilar artery of a rat modeling SAH, which may be associated with DCVS. This suggested that caveolin-1 may be a potential target for the treatment of DCVS.