Changes in nanomechanical properties of single neuroblastoma cells as a model for oxygen and glucose deprivation (OGD).

Although complex, the biological processes underlying ischemic stroke are better known than those related to biomechanical alterations of single cells. Mechanisms of biomechanical changes and their relations to the molecular processes are crucial for understanding the function and dysfunction of the brain. In our study, we applied atomic force microscopy (AFM) to quantify the alterations in biomechanical properties in neuroblastoma SH-SY5Y cells subjected to oxygen and glucose deprivation (OGD) and reoxygenation (RO). Obtained results reveal several characteristics. Cell viability remained at the same level, regardless of the OGD and RO conditions, but, in parallel, the metabolic activity of cells decreased with OGD duration. 24 h RO did not recover the metabolic activity fully. Cells subjected to OGD appeared softer than control cells. Cell softening was strongly present in cells after 1 h of OGD and with longer OGD duration, and in RO conditions, cells recovered their mechanical properties. Changes in the nanomechanical properties of cells were attributed to the remodelling of actin filaments, which was related to cofilin-based regulation and impaired metabolic activity of cells. The presented study shows the importance of nanomechanics in research on ischemic-related pathological processes such as stroke.

Intracranial Aneurysm Classifier Using Phenotypic Factors: An International Pooled Analysis.

Intracranial aneurysms (IAs) are usually asymptomatic with a low risk of rupture, but consequences of aneurysmal subarachnoid hemorrhage (aSAH) are severe. Identifying IAs at risk of rupture has important clinical and socio-economic consequences. The goal of this study was to assess the effect of patient and IA characteristics on the likelihood of IA being diagnosed incidentally versus ruptured. Patients were recruited at 21 international centers. Seven phenotypic patient characteristics and three IA characteristics were recorded. The analyzed cohort included 7992 patients. Multivariate analysis demonstrated that: (1) IA location is the strongest factor associated with IA rupture status at diagnosis; (2) Risk factor awareness (hypertension, smoking) increases the likelihood of being diagnosed with unruptured IA; (3) Patients with ruptured IAs in high-risk locations tend to be older, and their IAs are smaller; (4) Smokers with ruptured IAs tend to be younger, and their IAs are larger; (5) Female patients with ruptured IAs tend to be older, and their IAs are smaller; (6) IA size and age at rupture correlate. The assessment of associations regarding patient and IA characteristics with IA rupture allows us to refine IA disease models and provide data to develop risk instruments for clinicians to support personalized decision-making.

Elevated plasma levels of galectin-3 binding protein are associated with post-stroke delirium - A pilot study.

To explore the role of systemic inflammation in post-stroke delirium, we investigated the level of two inflammatory mediators: high mobility group box 1 (HMGB1) and galectin-3 binding protein (Gal-3BP). Of 571 stroke patients, we compared plasma levels of HMGB1 and Gal-3BP in 79 delirious patients with 81 non-delirious patients matched for age and stroke severity. Delirious patients had higher Gal-3BP level (median: 1440 vs 1053 ng/mL, P < 0.01). An elevated level of Gal-3BP was associated with an increased risk of delirium. HMGB1 levels did not differ between groups. Our results suggest that pro-inflammatory monocytes and macrophages might be involved in delirium pathophysiology.

Opposite regulation of piRNAs, rRNAs and miRNAs in the blood after subarachnoid hemorrhage.

Multiple classes of small RNAs (sRNAs) are expressed in the blood and are involved in the regulation of pivotal cellular processes. We aimed to elucidate the expression patterns and functional roles of sRNAs in the systemic response to intracranial aneurysm (IA) rupture. We used next-generation sequencing to analyze the expression of sRNAs in patients in the acute phase of IA rupture (first 72 h), in the chronic phase (3-15 months), and controls. The patterns of alterations in sRNA expression were analyzed in the context of clinically relevant information regarding the biological consequences of IA rupture. We identified 542 differentially expressed sRNAs (108 piRNAs, 99 rRNAs, 90 miRNAs, 43 scRNAs, 36 tRNAs, and 32 snoRNAs) among the studied groups with notable differences in upregulated and downregulated sRNAs between the groups and sRNAs categories. piRNAs and rRNAs showed a substantial decrease in RNA abundance that was sustained after IA rupture, whereas miRNAs were largely upregulated. Downregulated sRNA genes included piR-31080, piR-57947, 5S rRNA, LSU-rRNA, and SSU-rRNA s. Remarkable enrichment in the representation of transcription factor binding sites was revealed in genomic locations of the regulated sRNA. We found strong overrepresentation of glucocorticoid receptor, retinoid x receptor alpha, and estrogen receptor alpha binding sites at the locations of downregulated piRNAs, tRNAs, and rRNAs. This report, although preliminary and largely proof-of-concept, is the first to describe alterations in sRNAs abundance levels in response to IA rupture in humans. The obtained results indicate novel mechanisms that may constitute another level of control of the inflammatory response. KEY MESSAGES: A total of 542 sRNAs were differentially expressed after aneurysmal SAH comparing with controls piRNAs and rRNAs were upregulated and miRNAs were downregulated after IA rupture The regulated sRNA showed an enrichment in the representation of some transcription factor binding sites piRNAs, tRNAs, and rRNAs showed an overrepresentation for GR, RXRA, and ERALPHA binding sites.

Glucocorticoid Resistance is Associated with Poor Functional Outcome After Stroke.

Systemic inflammation is associated with poor outcome after stroke. Glucocorticoids (GCs) play a fundamental role in limiting inflammation. The aim of this study was to explore the associations between GC sensitivity, systemic inflammation, and outcome after ischemic stroke. The study population compised 246 ischemic stroke patients (median age: 69.0 years; 41.1% female). To assess GC sensitivity, we incubated venous blood samples that were obtained at day 3 after stroke with lipopolysaccharide (10 ng/mL) and dexamethasone (10-6 mol/L). We defined the GC sensitivity index as the ratio of tumor necrosis factor α (TNFα) released after blood stimulation with lipopolysaccharide and dexamethasone to the amount of TNFα released after blood stimulation with lipopolysaccharide alone. A higher index indicates higher GC resistance. The patients with poor functional outcome had a higher GC sensitivity index than those with good outcome (median: 16.1% vs. 13.5%, P < 0.01). In a logistic regression analysis adjusted for age, stroke severity, pneumonia, leukocyte count, plasma interleukin-6, and TNFα release ex vivo, a higher GC sensitivity index was associated with a higher risk of poor outcome after stroke (OR 2.32, 95% CI 1.21-4.45, P = 0.01). In conclusion, GC resistance is associated with poor functional outcome after stroke.

The Immunomodulary Effects of Systematic Exercise in Older Adults and People with Parkinson's Disease.

We sought to investigate whether regular balance training of moderate intensity (BT) has an effect on changes in selected cytokines, neurotrophic factors, CD200 and fractalkine in healthy older adults and participants with Parkinson's disease (PD). Sixty-two subjects were divided into groups depending on experimental intervention: (1) group of people with PD participating in BT (PDBT), (2) group of healthy older people participating in BT (HBT), (3,4) control groups including healthy individuals (HNT) and people with PD (PDNT). Blood samples were collected twice: before and after 12 weeks of balance exercise (PDBT, HBT), or 12 weeks apart (PDNT, HNT). The study revealed significant increase of interleukin10 (PDBT, p = 0.026; HBT, p = 0.011), ß-nerve growth factor (HBT, p = 0.002; PDBT, p = 0.016), transforming growth factor-ß1 (PDBT, p = 0.018; HBT, p < 0.004), brain-derived neurotrophic factor (PDBT, p = 0.011; HBT, p < 0.001) and fractalkine (PDBT, p = 0.045; HBT, p < 0.003) concentration only in training groups. In PDBT, we have found a significant decrease of tumor necrosis factor alpha. No training effect on concentration of interleukin6, insulin-like growth factor 1 and CD200 was observed in both training and control groups. Regular training can modulate level of inflammatory markers and induce neuroprotective mechanism to reduce the inflammatory response.

Posterior Subthalamic Area Deep Brain Stimulation for Treatment of Refractory Holmes Tremor.

Three right-handed patients diagnosed with Holmes tremor (HT), who suffered from pharmacotherapy-refractory tremor, were eligible for unilateral posterior subthalamic area deep brain stimulation (PSA-DBS). All patients were evaluated with the Fahn-Tolosa-Marin Tremor Rating Scale (FTMTRS) and Clinical Global Impression scale (CGI) before DBS, 6, and 12 months after the PSA-DBS as well as at the last follow-up. In all patients, we observed a significant improvement of tremor control as demonstrated by changes in the FTMTRS and the CGI scales. Mean improvement of tremor in all patients was 56% for the FTMRTS with a corresponding change in the CGI scale. Our study demonstrates that PSA-DBS is efficacious in the treatment of HT. Indeed, PSA is a promising target for DBS for intractable proximal and distal tremor, even in cases of previous, suboptimal functional neurosurgery. The beneficial effect lasts over a long-term follow-up. PSA-DBS may be considered as an alternative target of DBS in tremor treatment.

Reduced ex vivo release of pro-inflammatory cytokines and elevated plasma interleukin-6 are inflammatory signatures of post-stroke delirium.

BACKGROUND: Experimental studies suggest that systemic inflammation contributes to the pathophysiology of delirium. The aim of our study was to determine blood-derived inflammatory signatures of post-stroke delirium. METHODS: We included 144 ischemic stroke patients. We assessed delirium on a daily basis during the first 7 days of hospitalization. Venous blood was collected at day 3 after the onset of stroke and stimulated ex vivo with lipopolysaccharide (LPS). We measured LPS-induced cytokine concentration (TNFα, IP-10, IL-1ß, IL-6, IL-8, IL-10, and IL-12p70) as well as plasma levels of IL-6 and TNFα. RESULTS: Delirium was diagnosed in 21.5% of patients. After correction for monocyte count, patients with delirium had reduced LPS-induced TNFα, IP-10, IL-1ß, IL-6, and IL-12 release. The plasma IL-6 level was higher in delirious patients compared to patients without delirium. After adjusting for stroke severity and infections, higher ex vivo TNFα (OR 0.29, 95%CI 0.11-0.72, P = 0.01), IP-10 (OR 0.25, 95%CI 0.08-0.73, P = 0.01), IL-1ß (OR 0.42, 95%CI 0.20-0.89, P = 0.02), and IL-12 (OR 0.07, 95%CI 0.01-0.70, P = 0.02) release was associated with the reduced risk of delirium. In multivariate analysis, the higher plasma IL-6 was associated with the increased risk of delirium (OR 1.61, 95%CI 1.00-2.58, P = 0.04). CONCLUSIONS: Reduced ex vivo release of pro-inflammatory cytokines after LPS stimulation and the elevated plasma IL-6 are signatures of post-stroke delirium.

Reduced release of TNFα and IP-10 after ex vivo blood stimulation with endotoxin is associated with poor outcome after stroke.

BACKGROUND AND AIMS: The immune response to acute cerebral ischemia plays an important role in the pathophysiology of stroke and could be a therapeutic target. Toll-like receptor 4 (TLR4) is a master regulator of innate immunity. The aim of our study was to determine the association between selected cytokine release after TLR4 activation in blood cells and the outcome after ischemic stroke. METHODS: We included 156 ischemic stroke patients (median age: 69; 40.4% female). Venous blood was collected at day 3 after the onset of stroke and stimulated ex vivo with lipopolysaccharide (LPS). The LPS-induced level of tumor necrosis factor alpha (TNFα) was used as a proxy of the MyD88-dependent pathway, and interferon-gamma-inducible protein 10 (IP-10) was used as a proxy of the MyD88-independent pathway. The functional outcome was assessed at 3 months after stroke onset. RESULTS: TNFα (median: 2.2 vs. 3.5 pg/103 monocytes, p < .01) and IP-10 release (median: 0.3 vs. 0. 6 pg/103 monocytes, p < .01) was reduced in patients with a poor outcome. In a multivariate logistic regression analysis adjusted for age, stroke severity, and pneumonia, low TNFα release was associated with a poor outcome (OR: 4.23, 95%CI: 1.64-10.90, p = .03). Similarly, low IP-10 release was related to an unfavorable prognosis (adjusted OR: 3.42, 95%CI: 1.49-8.21, p < .01). CONCLUSIONS: The reduced release of TNFα and IP-10 after ex vivo blood stimulation with endotoxin is independently associated with poor outcome after stroke. Our results suggest that the inhibition of both the MyD88-dependent pathway and MyD88-independent pathway of TLR4 signaling in blood cells correlates with an unfavorable prognosis in stroke patients.

Ceftriaxone- and N-acetylcysteine-induced brain tolerance to ischemia: Influence on glutamate levels in focal cerebral ischemia.

One of the major players in the pathophysiology of cerebral ischemia is disrupted homeostasis of glutamatergic neurotransmission, resulting in elevated extracellular glutamate (Glu) concentrations and excitotoxicity-related cell death. In the brain, Glu concentrations are regulated by Glu transporters, including Glu transporter-1 (GLT-1) and cystine/Glu antiporter (system xc-). Modulation of these transporters by administration of ceftriaxone (CEF, 200 mg/kg, i.p.) or N-acetylcysteine (NAC, 150 mg/kg, i.p.) for 5 days before focal cerebral ischemia may induce brain tolerance to ischemia by significantly limiting stroke-related damage and normalizing Glu concentrations. In the present study, focal cerebral ischemia was induced by 90-minute middle cerebral artery occlusion (MCAO). We compared the effects of CEF and NAC pretreatment on Glu concentrations in extracellular fluid and cellular-specific expression of GLT-1 and xCT with the effects of two reference preconditioning methods, namely, ischemic preconditioning and chemical preconditioning in rats. Both CEF and NAC significantly reduced Glu levels in the frontal cortex and hippocampus during focal cerebral ischemia, and this decrease was comparable with the Glu level achieved with the reference preconditioning strategies. The results of immunofluorescence staining of GLT-1 and xCT on astrocytes, neurons and microglia accounted for the observed changes in extracellular Glu levels to a certain extent. Briefly, after MCAO, the expression of GLT-1 on astrocytes decreased, but pretreatment with CEF seemed to prevent this downregulation. In addition, every intervention used in this study seemed to reduce xCT expression on astrocytes and neurons. The results of this study indicate that modulation of Glu transporter expression may restore Glu homeostasis. Moreover, our results suggest that CEF and NAC may induce brain tolerance to ischemia by influencing GLT-1 and system xc- expression levels. These transporters are presumably good targets for the development of novel therapies for brain ischemia.

PPM1A Methylation Is Associated With Vascular Recurrence in Aspirin-Treated Patients.

BACKGROUND AND PURPOSE: Despite great efforts by pharmacogenetic studies, the causes of aspirin failure to prevent the recurrence of ischemic events remain unclear. Our aim was to study whether epigenetics could be associated with the risk of vascular recurrence in aspirin-treated stroke patients. METHODS: We performed an epigenetic joint analysis study in 327 patients treated with aspirin. In the discovery stage, we performed a nested case-control study in 38 matched ischemic stroke patients in whom 450 000 methylation sites were analyzed. Nineteen patients presented vascular recurrence after stroke, and 19 matched patients did not present vascular recurrence during the first year of follow-up. In a second stage, 289 new patients were analyzed by EpiTYPER. RESULTS: The following 3 differentially methylated candidate CpG sites, were identified in the discovery stage and analyzed in the second stage: cg26039762 (P=9.69×10(-06), RAF1), cg04985020 (P=3.47×10(-03), PPM1A), and cg08419850 (P=3.47×10(-03), KCNQ1). Joint analysis identified an epigenome-wide association for cg04985020 (PPM1A; P=1.78×10(-07)), with vascular recurrence in patients treated with aspirin. CONCLUSIONS: The pattern of differential methylation in PPM1A is associated with vascular recurrence in aspirin-treated stroke patients.

N-Acetylcysteine and Ceftriaxone as Preconditioning Strategies in Focal Brain Ischemia: Influence on Glutamate Transporters Expression.

Glutamate (Glu) plays a key role in excitotoxicity-related injury in cerebral ischemia. In the brain, Glu homeostasis depends on Glu transporters, including the excitatory amino acid transporters and the cysteine/Glu antiporter (xc-). We hypothesized that drugs acting on Glu transporters, such as ceftriaxone (CEF, 200 mg/kg, i.p.) and N-acetylcysteine (NAC, 150 mg/kg, i.p.), administered repeatedly for 5 days before focal cerebral ischemia in rats and induced by a 90-min middle cerebral artery occlusion (MCAO), may induce brain tolerance to ischemia. We compared the effects of these drugs on brain infarct volume, neurological deficits and the mRNA and protein expression of the Glu transporter-1 (GLT-1) and xc- with the effects of ischemic preconditioning and chemical preconditioning using 3-nitropropionic acid. Administration of CEF and NAC significantly reduced infarct size and neurological deficits caused by a 90-min MCAO. These beneficial effects were accompanied by changes in GLT-1 expression caused by a 90-min MCAO at both the mRNA and protein levels in the frontal cortex, hippocampus, and dorsal striatum. Thus, the results of this study suggest that the regulation of GLT-1 and xc- plays a role in the development of cerebral tolerance to ischemia and that this regulation may be a novel approach in the therapy of brain ischemia.

Hyperfibrinogenemia predicts long-term risk of death after ischemic stroke.

In stroke patients higher levels of plasma fibrinogen are associated with increased risk of unfavourable functional outcome and short-term mortality. The aim of our study was to determine the relationship between plasma fibrinogen level and long-term risk of death in ischemic stroke patients. Seven hundred thirty six patients (median age 71; 47.1% men) admitted to the stroke unit within 24 h after stroke were included. Plasma fibrinogen level was measured on day 1 of hospitalisation. Hyperfibrinogenemia was defined as plasma fibrinogen concentration >3.5 g/L. The maximal follow-up period was 84 months. Hyperfibrinogenemia was found in 25.0% of patients. On multivariate logistic regression analysis, after adjustment for age, stroke severity, atrial fibrillation, smoking, white blood cell count, fever, in-hospital pneumonia and hyperglycemia, hyperfibrinogenemia was associated with increased case fatality (HR 1.71, 95% CI 1.29-2.26, P < 0.01). Hyperfibrinogenemia predicts the long-term risk of death in ischemic stroke patients.

Glutamate transporters in brain ischemia: to modulate or not?

In this review, we briefly describe glutamate (Glu) metabolism and its specific transports and receptors in the central nervous system (CNS). Thereafter, we focus on excitatory amino acid transporters, cystine/glutamate antiporters (system xc-) and vesicular glutamate transporters, specifically addressing their location and roles in CNS and the molecular mechanisms underlying the regulation of Glu transporters. We provide evidence from in vitro or in vivo studies concerning alterations in Glu transporter expression in response to hypoxia or ischemia, including limited human data that supports the role of Glu transporters in stroke patients. Moreover, the potential to induce brain tolerance to ischemia through modulation of the expression and/or activities of Glu transporters is also discussed. Finally we present strategies involving the application of ischemic preconditioning and pharmacological agents, eg ß-lactam antibiotics, amitriptyline, riluzole and N-acetylcysteine, which result in the significant protection of nervous tissues against ischemia.

Gene expression profiling of blood in ruptured intracranial aneurysms: in search of biomarkers.

The molecular mechanisms underlying the systemic response to subarachnoid hemorrhage (SAH) from ruptured intracranial aneurysms (RAs) are not fully understood. We investigated whether the analysis of gene expression in peripheral blood could provide clinically relevant information regarding the biologic consequences of SAH. Transcriptomics were performed using Illumina HumanHT-12v4 microarrays for 43 RA patients and 18 controls (C). Differentially expressed transcripts were analyzed for overrepresented functional groups and blood cell type-specific gene expression. The set of differentially expressed transcripts was validated using quantitative polymerase chain reaction in an independent group of subjects (15 RA patients and 14 C). There were 135 differentially expressed genes (false discovery rate 1%, absolute fold change 1.7): the abundant levels of 78 mRNAs increased and 57 mRNAs decreased. Among RA patients, transcripts specific to T lymphocyte subpopulations were downregulated, whereas those related to monocytes and neutrophils were upregulated. Expression profiles of a set of 16 genes and lymphocyte-to-monocyte-and-neutrophil gene expression ratios distinguished RA patients from C. These results indicate that SAH from RAs strongly influences the transcription profiles of blood cells. A specific pattern of these changes suggests suppression in lymphocyte response and enhancements in monocyte and neutrophil activities. This is probably related to the immunodepression observed in SAH.

[Vascular abnormalities in patients with primary intracerebral hemorrhage]. / Malformacje naczyn mózgowych u chorych z pierwotnym krwotokiem sródmózgowym.

BACKGROUND: To prevent the recurrence of primary intracerebral hemorrhage (PIH) it is important to identify patients with underlying structural vascular abnormalities (VA). According to previous study data-- the site of hemorrhage, the patient's age and pre-existing hypertension affect the likelihood of finding VA. However, the indications for angiography, the gold standard for the diagnosis of VA, still remain controversial. PURPOSE: To assess the frequency of VA and to determine features that might increase the probability of finding VA in patients with PIH. MATERIAL AND METHODS: 100 patients with PIH, without a history of trauma, coagulopathy, or known pre-existing brain abnormality, who were admitted to the Stroke Unit of the Department of Neurology, Jagiellonian University, between January 1999 and November 2000 entered this prospectively designed study. In the group of 96 patients, 53 persons underwent conventional angiography within 14 days of stroke onset (in 4 cases we found bleeding into the tumor and these patients were not included in further analysis). RESULTS: Vascular abnormalities were found in 14 of 53 patients (26.4%); ruptured aneurysms in 9 patients (17.0%), arteriovenous malformations (AVM) in 3 patients (5.7%), venous angioma in 1 patient (1.8%) and cavernous angioma in 1 patient (1.9%). Vascular malformations were found in 12 of 25 patients with lobar hemorrhage, in 1 of 8 patients with hemorrhage originating in the thalamus and in 1 of 2 patients with hemorrhage originating in the pons. Angiographic findings were negative in 8 patients with hemorrhage in the periventricular white matter, in 8 with hemorrhage originating in the basal ganglia and in 2 patients with hemorrhage in the cerebellum. Patients with VA were significantly younger than patients without VA (49.9 +/- 11.7 years and 58.7 +/- 13.3 years respectively, p = 0.03) and they had a history of hypertension significantly less often (50.0% and 89.7%, p = 0.001). Intraventricular hemorrhage and subarachnoid bleeding occurred in a similar percentage of patients with ICH, independent of whether or not they had VA (28.6% and 38.5%; 21.4% and 10.3% respectively, p = n.s.). CONCLUSIONS: (1) A vascular abnormality is the cause of about 26% of ICH, with a higher likelihood in younger patients and with lobar hemorrhage. (2) A history of hypertension does not exclude the presence of VA. (3) Intraventricular hemorrhage or subarachnoid bleeding does not predict the presence of VA.

Alpha1-antichymotrypsin gene (SERPINA3) A/T polymorphism as a risk factor for aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: The member 3 of clade A of serine proteinase inhibitors (SERPINA3), known previously as the alpha1-antichymotrypsin, is an acute phase protein, the levels of which increase in acute and chronic inflammation. The A/T polymorphism of the SERPINA3 gene influences expression of SERPINA3 protein. SERPINA3 can be related to aneurysmal subarachnoid hemorrhage (SAH) by influencing inflammation or by regulating cathepsin G activity. We studied the significance of SERPINA3 A/T polymorphism in patients with aneurysmal SAH compared with healthy controls. METHODS: A total of 180 patients with aneurysmal SAH and 263 healthy controls were genotyped for the SERPINA3 A/T polymorphism. Aneurysmal SAH was diagnosed by cranial computed tomography or lumbar puncture and digital subtraction angiography. SERPINA3 polymorphism was detected by polymerase chain reaction amplification and restriction enzyme digestion. RESULTS: The SERPINA3 genotype distribution in patients with aneurysmal SAH (AA-29 16.1%; AT-108 60.0%; TT-43 23.9%) differed significantly from controls (AA-70 26.6%; AT-123 46.8%; TT-70 26.6%; P=0.009). A logistic regression model showed that the presence of genotype with T allele (AT+TT; odds ratio [OR], 2.01; 95% CI, 1.19 to 3.38; P=0.009) or AA genotype (OR, 0.49; 95% CI, 0.30 to 0.84; P=0.009) of the SERPINA3 influences the risk for aneurysmal SAH independently from smoking, excessive alcohol consumption, and hypertension. CONCLUSIONS: The A/T polymorphism of SERPINA3 gene is associated with the risk factor for aneurysmal SAH.

Influence of chemical and ischemic preconditioning on cytokine expression after focal brain ischemia.

Inflammation, upregulation of cytokines, proapoptotic molecules, and apoptosis are accepted widely as crucial players in stroke-induced brain damage. Induction of brain tolerance against ischemia by pretreatment with nonlethal stressors (preconditioning) has been found to influence expression of different molecules, in addition to reduction of infarct size. It remains unclear, however, whether and how preconditioning changes expression of cytokines after subsequent brain ischemia. We sought to analyze cortical expression of interleukin (IL)-1beta, IL-6, tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta, Fas, and Fas ligand (FasL) mRNA after a transient, focal brain ischemia in rats subjected to preconditioning. The mRNA levels were determined using a semiquantitative RT-PCR in the ischemic and contralateral cortex, separately. Transient ischemia was induced by 90-min middle cerebral artery occlusion (MCAo) and neurologic deficits as well as infarct size were quantified. Preconditioning was carried out by a short-term MCAo or an injection of 3-nitropropionic acid 3 days before MCAo. In both preconditioning paradigms, similar effects on investigated mRNA levels were observed. IL-1beta and IL-6 levels were decreased in tolerant rats compared to those in nontolerant ones. Changes in TNF-alpha, TGF-beta, and Fas levels were comparable independently of tolerance state. FasL mRNA was at similar level in rats subjected to chemical preconditioning but lower after ischemic preconditioning. Our findings demonstrate that both preconditioning methods exert a very similar effect on the expression of investigated cytokines. Interestingly, we observed a selective effect of preconditioning on IL-1beta and IL-6 expression that suggests different functional properties as well as different regulation of analyzed molecules during an induction of the brain tolerance against ischemia.

II genotype of the angiotensin-converting enzyme gene increases the risk for subarachnoid hemorrhage from ruptured aneurysm.

BACKGROUND AND PURPOSE: Evidence exists in support of a role of genetic factors in susceptibility to aneurysmal subarachnoid hemorrhage (SAH) in humans. Meta-analysis of 2 previous studies showed that the I allele of angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism was a weak, but significant, risk factor for aneurysmal SAH. Moreover, a recent study has shown that the local renin-angiotensin system (RAS) is involved in the development of intracranial aneurysm. The aim of this study was to investigate the association between ACE I/D polymorphism and a risk for aneurysmal SAH in a Polish population. METHODS: Ninety patients with aneurysmal SAH (mean age: 48.9+/-14.0 years) and 128 healthy controls matched for age and sex were genotyped for the ACE I/D polymorphism. Aneurysmal SAH was diagnosed by cranial computed tomography and/or lumbar puncture and digital subtraction angiography. ACE gene polymorphism was detected by polymerase chain reaction amplification of the intron 16-specific I/D fragments, 490-bp and 190-bp, respectively. RESULTS: The ACE genotype distribution in patients with aneurysmal SAH (II, 52.2%; ID, 15.6%; DD, 32.2%) differed significantly from controls (II, 23.4%; ID, 50.8%; DD, 25.8%) (P<0.001). A logistic regression model showed that the II genotype of ACE gene was independent from female sex and smoking as a risk factor for aneurysmal SAH (OR, 4.57; 95% CI, 2.35 to 8.90). CONCLUSIONS: Here we report that II genotype of ACE gene is a risk factor for aneurysmal SAH.