Project description:The diagnosis of cerebral vasospasm after Subarachnoid-Hemorrhage is currently very difficult, additional tools such as blood biomarkers are necessary. We tested the ability of gene expression profiles of blood cells to predict vasospasm. 32 patients suffering subarachnoid-hemorrhage were included in this prospective monocentre study. They were grouped according to have a complicated cerebral vasospasm (Vasospasm) or not (Control) and Paired according to age (+/- 10 years), sex, Fisher grade (+/- 1), location, smoking (at least 3 first parameters). Gene expression profiles of blood cells were determined using 25,000~gene microarray. Blood sample: 2.5 mL harvested in PAXgene® Blood RNA tubes (PreAnalytix) RNA extraction: PAXgene® Blood RNA kit (Qiagen). We used a Universel Reference RNA (Stratagene). RNA amplification and labelling: kit Amino Allyl MessageAmp II (Ambion). We hybridized 4 microarrays per patient using pangenomic microarrays from the "Réseau National des Génopôles" (Illkirch, France). 2 slides were hybridized with reference RNA labelled Cy3 and patient RNA labelled Cy5, and 2 slides were hybridized with reference RNA labelled Cy5 and patient RNA labelled Cy3. Hybridation : Agilent protocol with few modifications : 750 ng of each labelled RNA were hubriddized at 60°C during 17 hours in an Aglient hybridization oven. After washings, Slides were scanned with a GenePix 4000B scanner (Molecular Devices). Image intensity data were extracted with GenePix Pro 6.0 analysis software. Quantification of Cy3 and Cy5 and selection of good spots were performed using the MAIA software (Novikov E and Barillot E. Software package for automatic microarray image analysis (MAIA). The ACUITY software was then used to normalize log ratios Cy3/Cy5 with Lowess non linear normalization, to filter out genes not present in at least 3 slides out of 4, to evaluate the reproducibility of the 4 microarrays of each patient (hierarchical clustering, Self Organizing Maps). Statistical analyses to insure reproducibility was performed using Excel (correlation coefficients, ANOVA). Only slides that passed all reprocubility tests were validated.
Project description:The diagnosis of cerebral vasospasm after Subarachnoid-Hemorrhage is currently very difficult, additional tools such as blood biomarkers are necessary. We tested the ability of gene expression profiles of blood cells to predict vasospasm.
Project description:BackgroundCerebral vasospasm is a major contributor to disability and mortality after aneurysmal subarachnoid hemorrhage. Oxidation of cell-free hemoglobin plays an integral role in neuroinflammation and is a suggested source of tissue injury after aneurysm rupture. This study sought to determine whether patients with subarachnoid hemorrhage and cerebral vasospasm were more likely to have been exposed to early hyperoxemia than those without vasospasm.MethodsThis single-center retrospective cohort study included adult patients presenting with aneurysmal subarachnoid hemorrhage to Vanderbilt University Medical Center between January 2007 and December 2017. Patients with an ICD-9/10 diagnosis of aneurysmal subarachnoid hemorrhage were initially identified (N = 441) and subsequently excluded if they did not have intracranial imaging, arterial PaO2 values or died within 96 h post-rupture (N = 96). The final cohort was 345 subjects. The degree of hyperoxemia was defined by the highest PaO2 measured within 72 h after aneurysmal rupture. The primary outcome was development of cerebral vasospasm, which included asymptomatic vasospasm and delayed cerebral ischemia (DCI). Secondary outcomes were mortality and modified Rankin Scale.ResultsThree hundred and forty five patients met inclusion criteria; 218 patients (63%) developed vasospasm. Of those that developed vasospasm, 85 were diagnosed with delayed cerebral ischemia (DCI, 39%). The average patient age of the cohort was 55 ± 13 years, and 68% were female. Ninety percent presented with Fisher grade 3 or 4 hemorrhage (N = 310), while 42% presented as Hunt-Hess grade 4 or 5 (N = 146). In univariable analysis, patients exposed to higher levels of PaO2 by quintile of exposure had a higher mortality rate and were more likely to develop vasospasm in a dose-dependent fashion (P = 0.015 and P = 0.019, respectively). There were no statistically significant predictors that differentiated asymptomatic vasospasm from DCI and no significant difference in maximum PaO2 between these two groups. In multivariable analysis, early hyperoxemia was independently associated with vasospasm (OR = 1.15 per 50 mmHg increase in PaO2 [1.03, 1.28]; P = 0.013), but not mortality (OR = 1.10 [0.97, 1.25]; P = 0.147) following subarachnoid hemorrhage.ConclusionsHyperoxemia within 72 h post-aneurysmal rupture is an independent predictor of cerebral vasospasm, but not mortality in subarachnoid hemorrhage. Hyperoxemia is a variable that can be readily controlled by adjusting the delivered FiO2 and may represent a modifiable risk factor for vasospasm.
Project description:ObjectiveOsteopontin (OPN), a pleiotropic extracellular matrix glycoprotein, has been reported to be protective against ischemic lesions, but effects of OPN on vascular functions have not been investigated. The aim of this study was to assess whether recombinant OPN (r-OPN) could prevent cerebral vasospasm after subarachnoid hemorrhage (SAH) in rats.Methodsr-OPN was administered intraventricularly to rats undergoing SAH by endovascular perforation, and its protective effects were evaluated by measuring the diameter of cerebral arteries and neurobehavioral testing. Western blotting and immunofluorescence were performed to explore the underlying mechanisms. An integrin receptor antagonist GRGDSP or mitogen-activated protein kinase (MAPK) phosphatase (MKP)-1 small interfering RNA (siRNA) was also administered to r-OPN-treated SAH rats, and those effects were evaluated.ResultsPre-SAH administration of r-OPN prevented vasospasm and neurological impairments at 24-72 hours post-SAH. r-OPN enhanced an endogenous MAPK inhibitor, MKP-1, and suppressed the phosphorylation of MAPKs, caldesmon, and heat shock protein 27 in the spastic cerebral arteries at 24 hours post-SAH. Immunofluorescence revealed that MKP-1 was induced in the arterial smooth muscle layer. GRGDSP prevented r-OPN-induced MKP-1 upregulation, and MKP-1 siRNA abolished both MAPK inactivation and anti-vasospastic effects by r-OPN. Post-SAH r-OPN treatment also prevented vasospasm.Interpretationr-OPN induced MKP-1 in the spastic cerebral arteries via binding to L-arginyl-glycyl-L-aspartate-dependent integrin receptors and prevented vasospasm after SAH. Therapeutic induction of MKP-1 may be a novel approach for the prevention and treatment of cerebral vasospasm.
Project description:Cerebral vasospasm occurs frequently after aneurysmal subarachnoid and contributes to delayed cerebral ischemia. In this article we address systematic problems with the literature on vasospasm and then review both established and experimental treatment options.
Project description:IntroductionThe causal association between the gut microbiome and the risk of intracranial aneurysm (IA), subarachnoid hemorrhage (SAH), and unruptured aneurysm (uIA) is unclear.MethodsThe single nucleotide polymorphisms concerning gut microbiome were retrieved from the gene-wide association study (GWAS) of the MiBioGen consortium. The summary-level datasets of IA and SAH were obtained from the GWAS meta-analysis of the International Stroke Genetics Consortium (ISGC). Inverse variance weighting (IVW) was utilized as the primary method, complemented with sensitivity analyses for pleiotropy and increasing robustness.ResultsFive, seven, and six bacterial traits were found to have a causal effect on IA, SAH, and uIA, respectively (IVW, all P < 0.05). Family.Porphyromonadaceae and genus.Bilophila were common protective bacterial features for both SAH and uIA. The heterogeneity and pleiotropy analyses confirmed the robustness of IVW results.ConclusionOur study demonstrates that gut microbiomes may exert therapeutic effects on IA, uIA, and SAH, providing clinical implications for the development of novel biomarkers and therapeutic targets.
Project description:Background and purposeCerebral autoregulation may be impaired in the early days after subarachnoid hemorrhage (SAH). The purpose of this study was to examine the relationship between cerebral autoregulation and angiographic vasospasm (aVSP) and radiographic delayed cerebral ischemia (DCI) in patients with SAH.MethodsSixty-eight patients (54±13 years) with a diagnosis of nontraumatic SAH were studied. Dynamic cerebral autoregulation was assessed using transfer function analysis (phase and gain) of the spontaneous blood pressure and blood flow velocity oscillations on days 2 to 4 post-SAH. aVSP was diagnosed using a 4-vessel conventional angiogram. DCI was diagnosed from CT. Decision tree models were used to identify optimal cut-off points for clinical and physiological predictors of aVSP and DCI. Multivariate logistic regression models were used to develop and validate a risk scoring tool for each outcome.ResultsSixty-two percent of patients developed aVSP, and 19% developed DCI. Patients with aVSP had higher transfer function gain (1.06±0.33 versus 0.89±0.30; P=0.04) and patients with DCI had lower transfer function phase (17.5±39.6 versus 38.3±18.2; P=0.03) compared with those who did not develop either. Multivariable scoring tools using transfer function gain>0.98 and phase<12.5 were strongly predictive of aVSP (92% positive predictive value; 77% negative predictive value; area under the receiver operating characteristic curve, 0.92) and DCI (80% positive predictive value; 91% negative predictive value; area under the curve, 0.94), respectively.ConclusionsDynamic cerebral autoregulation is impaired in the early days after SAH. Including autoregulation as part of the initial clinical and radiographic assessment may enhance our ability to identify patients at a high risk for developing secondary complications after SAH.
Project description:Background: Subarachnoid hemorrhage is a serious condition caused by ruptured intracranial aneurysms, resulting in severe disability mainly in young adults. Cerebral vasospasm is one of the most common complication of subarachnoid hemorrhage; thus, active prevention is key to improve the prognosis. The glycosylation of proteins is a critical quality attribute which is reportedly altered in patients diagnosed with acute ischemic stroke. In this study, we examined the N-glycosylation profile of serum glycoproteins in patients with subarachnoid hemorrhage without vasospasm compared to patients with vasospasm. Methods: The serum N-glycans were released by PNGase F (Peptide: N-glycosidase F) digestion and subsequently labeled by procainamide via reductive amination. The samples were analyzed by hydrophilic-interaction liquid chromatography after solid-phase extraction-based sample purification. Results: Besides the glycosylation pattern, we also investigated the biomarkers following subarachnoid hemorrhage. Multiple statistical analyses were performed in order to find significant differences and identify potential prediction factors of cerebral vasospasm. Significant differences were identified such as higher sialylation on bi-, tri-, and tetra-antennary structures in patients with subarachnoid hemorrhage and cerebral vasospasm. Conclusions: Our results suggest that glycosylation analysis can improve the identification of patients with cerebral vasospasm in combination with laboratory parameters.
Project description:BACKGROUND:Gap junctions are involved in the development of cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH). However, the specific roles and regulatory functions of related connexin isoforms remain unknown. The aim of this study was to investigate the importance of connexin 43 (Cx43) in CVS and determine whether Cx43 alterations are modulated via the protein kinase C (PKC) signaling transduction pathway. METHODS:Oxyhemoglobin (OxyHb)-induced smooth muscle cells of basilar arterial and second-injection model in rat were used as CVS models in vitro and in vivo. In addition, dye transfer assays were used for gap junction-mediated intercellular communication (GJIC) observation in vitro and delayed cerebral ischemia (DCI) was observed in vivo by perfusion-weighted imaging (PWI) and intravital fluorescence microscopy. RESULTS:Increase in Cx43 mediated the development of SAH-induced CVS was found in both in vitro and in vivo CVS models. Enhanced GJIC was observed in vitro CVS model, this effect and increased Cx43 were reversed by preincubation with specific PKC inhibitors (chelerythrine or GF 109203X). DCI was observed in vivo on day 7 after SAH. However, DCI was attenuated by pretreatment with Cx43 siRNA or PKC inhibitors, and the increased Cx43 expression in vivo was also reversed by Cx43 siRNA or PKC inhibitors. CONCLUSIONS:These data provide strong evidence that Cx43 plays an important role in CVS and indicate that changes in Cx43 expression may be mediated by the PKC pathway. The current findings suggest that Cx43 and the PKC pathway are novel targets for developing treatments for SAH-induced CVS.