Oxidative Stress after Subarachnoid Hemorrhage in gp91^phox Knockout Mice

Abstract

356Spontaneous subarachnoid hemorrhage (SAH) represents 5-7% of all strokes, 1,2 and SAH-related mortality reaches 50%. [3][4][5] Acute cerebral ischemia and subsequent injury are major causes of morbidity after SAH. 3,6 Several studies, including investigations in superoxide dismutase (SOD) transgenic mice, showed that superoxide and other reactive oxygen species (ROS) largely contribute to the early brain injury after SAH. [7][8][9][10][11] NADPH oxidase has been primarily described as responsible for superoxide production in phagocytes.12 Superoxide is generated on the membrane component gp91 phox , [13][14][15] which is expressed in all regions of the brain, with prominent localizations in the hippocampus, cortex, amygdale, striatum, and thalamus. 16ABSTRACT: Background: Oxidative stress largely contributes to early brain injury after subarachnoid hemorrhage (SAH). One of the major sources of reactive oxygen species is NADPH oxidase, upregulated after SAH. We hypothesized that NADPH oxidase-induced oxidative stress plays a major causative role in early brain injury after SAH. Methods: Using gp91 phox knockout (ko) and wild-type (wt) mice, we studied early brain injury in the endovascular perforation model of SAH. Mortality rate, cerebral edema, oxidative stress, and superoxide production were measured at 24 h after SAH. Neurological evaluation was done at 23 h after SAH surgery. Results: Genotyping confirmed the existence of a nonfunctional gp91 phox gene in the ko mice. CBF measurements did not show differences in SAH-induced acute ischemia between ko and wt mice. SAH caused a significant increase of water content in the ipsilateral hemisphere as well as an increase of Malondialdehyde (MDA) levels and superoxide production. There were no significant differences in post-SAH mortality rate, brain water content and the intensity of the oxidative stress between knockout and wild type groups of mice. Conclusions: Our results suggest that gp91 phox is not critically important to the early brain injury after SAH. An adaptive compensatory mechanism for free radical production in knockout mice is discussed.RÉSUMÉ: Le stress oxydatif après une hémorragie sous-arachnoïdienne chez les souris knock-out gp91-phox. Contexte : Le stress oxydatif contribue de façon importante aux lésions précoces dues à une hémorragie sous-arachnoïdienne (HSA). La NADPH oxydase est une des sources majeures de dérivés réactifs de l'oxygène qui est régulée à la hausse après une HSA. Nous avons émis l'hypothèse que le stress oxydatif induit par la NADPH oxydase est une cause majeure de dommage cérébral après une HSA. Méthodes : Nous avons étudié les dommages cérébraux précoces chez le modèle de HSA par perforation endovasculaire chez des souris de phénotype sauvage (ps) et des souris knock-out (ko) gp91-phox. Le taux de mortalité, l'?dème cérébral, le stress oxydatif et la production de superoxyde ont été mesurés 24 heures après l'HSA. L'évaluation neurologique était faite 23 heures après la chirurgie. Résultats : Le génotypage a confirmé l'ex...

Mouse Model of Subarachnoid Hemorrhage: Technical Note on the Filament Perforation Model

“…At this point, the impossibility of controlling the degree of SAH has to be mentioned again as the most crucial disadvantage of the cWp model, as already discussed in the literature [4,9]. Advantages and disadvantages of the cWp model com-pared with other models have been discussed in detail else-where [1,4,10,19]. In brief, the cWp model is technically (surgically) the most challenging model.…”

Standardized induction of subarachnoid hemorrhage in mice by intracranial pressure monitoring

“…availability, size, or available standardized models, these species have, in contrast to mice, the inherent disadvantage of not being amenable to genetic manipulation. Therefore several groups developed murine SAH models by directly injecting blood into the cisterna magna (Lin et al, 2003), dissecting an intracisternal vein (Altay et al, 2009), or perforating an artery at the skull base by introducing a filament into the cerebral circulation through an extra-cranial approach (Kamii et al, 1999;Sozen et al, 2009;Ishikawa et al, 2009;Liu et al, 2007;McGirt et al, 2002a,b;Parra et al, 2002;Saito et al, 2001;Gao et al, 2006). The cisterna magna injection model and the venous dissection model can be performed quickly, are highly reproducible due to the controlled application of the blood, result in an acute increase of ICP and subsequent decrease of CBF, and lead the development of brain edema and intracranial hypertension as also observed in man (Broderick et al, 1994;Claassen et al, 2002).…”

“…So far several research groups studied SAH in mice either by perforating the Circle of Willis at the skull base using an intraluminal filament inserted through the external carotid artery (Kamii et al, 1999;Sozen et al, 2009;Ishikawa et al, 2009;Liu et al, 2007;McGirt et al, 2002a;Parra et al, 2002;Saito et al, 2001;Gao et McGirt et al, 2002b), by directly injecting blood into the cisterna magna (Lin et al, 2003), or by perforating an intracisternal vein (Altay et al, 2009). Since perforation of an intracerebral vessel by a filament resembles aneurysmal hemorrhage closer than intraventricular injection of blood, Circulus of Willis perforation (CWp) became the most widely used SAH model in mice.…”

“…Since perforation of an intracerebral vessel by a filament resembles aneurysmal hemorrhage closer than intraventricular injection of blood, Circulus of Willis perforation (CWp) became the most widely used SAH model in mice. Pioneering studies using CWp demonstrated delayed cerebral vasospasm (Gao et al, 2006;Kamii et al, 1999;McGirt et al, 2002a,b;Parra et al, 2002;Saito et al, 2001), neurological dysfunction (Gao et al, 2006;McGirt et al, 2002a,b;Parra et al, 2002;Liu et al, 2007;Sozen et al, 2009), brain edema formation (Liu et al, 2007;Sozen et al, 2009), and a clinically relevant mortality of ∼30% (Gao et al, 2006;Liu et al, 2007;Sozen et al, 2009). So far, however, it remains unclear how the initial bleeding is linked to these rather late and severe pathophysiological findings since it is not known if experimental SAH in mice causes intracranial hypertension, reduces cerebral perfusion pressure, and causes subsequent ischemic brain damage.…”

Hemolysate-induced Expression of Intercellular Adhesion Molecule-1 and Monocyte Chemoattractant Protein-1 Expression in Cultured Brain Microvascular Endothelial Cells via Through ROS-dependent NF-κB Pathways

“…Involvement of oxidative stress in the development of SAH was suggested by demonstrating the presence of increased protein and lipid peroxidation in the brain and cerebrospinal fluid (Liu et al 2007;Clark et al 2008). Previous results demonstrated that hemolysate has been shown to induce oxidative stress directly and indirectly (Yoshida et al 1994;Matz et al 2000).…”