Increased cytokine release by leucocytes in survivors of stroke at young age

Il-6 and UGT1A1 variations may related to furosemide resistance in heart failure patients

Furosemide is a diuretic and is used for the treatment of patients with heart failure (HF). It has been found that in some HF patients, the drug does not treat patients efficiently. This condition is named as furosemide resistance. In this study, it is aimed to investigate the relationship between UDP-glucuronosyltransferase 1 (UGT1A1) and interleukine-6 (IL-6) variations with furosemide resistance in HF patients. Sixty HF patients using furosemide (patient group) and 30 healthy individuals (control group) were enrolled in this study. Patients were divided into two subgroups as non-responders (furosemide resistant) group (n = 30) and the responders (non-resistant) group (n = 30) according to the presence of furosemide resistance (n = 30). Variations in the first exon of UGT1A1 and rs1800795 and rs1800796 variations in IL-6 were analyzed by direct sequencing and real-time polymerase chain reaction (RT-PCR), respectively. The effects of newly detected mutations on 3-D protein structure were analyzed by in silico analysis. At the end of the study, 11 variations were detected in UGT1A1, of which nine of them are novel and eight of them cause amino acid change. Also, rs1800795 and rs1800796 variations were detected in all the groups. When patient and control groups were compared with each other, rs1800796 mutation in IL-6 was found statistically high in the patient group (p = 0.027). When the three groups were compared with each other, similarly, rs1800796 mutation in IL-6 was found statistically high in the non-responders group (p = 0.043). When allele distributions were compared between the patient and control groups, the C allele of rs1800795 mutation in IL-6 was found statistically high in the patient group (p = 0.032). When allele distributions were compared between the three groups, 55T-insertion in UGT1A1 was found statistically high in the non-responders group (p = 0.017). According to in silico analysis results, two variations were found deleterious and six variations were detected as probably damaging to protein functions. Our study may contribute to the elucidation of pharmacogenetic features (drug response-gene relationship) and the development of individual-specific treatment strategies in HF patients using furosemide.

Multicellular 3D Neurovascular Unit Model for Assessing Hypoxia and Neuroinflammation Induced Blood-Brain Barrier Dysfunction

The blood-brain barrier (BBB) is a dynamic component of the brain-vascular interface that maintains brain homeostasis and regulates solute permeability into brain tissue. The expression of tight junction proteins between adjacent endothelial cells and the presence of efflux proteins prevents entry of foreign substances into the brain parenchyma. BBB dysfunction, however, is evident in many neurological disorders including ischemic stroke, trauma, and chronic neurodegenerative diseases. Currently, major contributors to BBB dysfunction are not well understood. Here, we employed a multicellular 3D neurovascular unit organoid containing human brain microvascular endothelial cells, pericytes, astrocytes, microglia, oligodendrocytes and neurons to model the effects of hypoxia and neuroinflammation on BBB function. Organoids were cultured in hypoxic chamber with 0.1% O2 for 24 hours. Organoids cultured under this hypoxic condition showed increased permeability, pro-inflammatory cytokine production, and increased oxidative stress. The anti-inflammatory agents, secoisolariciresinol diglucoside and 2-arachidonoyl glycerol, demonstrated protection by reducing inflammatory cytokine levels in the organoids under hypoxic conditions. Through the assessment of a free radical scavenger and an anti-inflammatory endocannabinoid, we hereby report the utility of the model in drug development for drug candidates that may reduce the effects of ROS and inflammation under disease conditions. This 3D organoid model recapitulates characteristics of BBB dysfunction under hypoxic physiological conditions and when exposed to exogenous neuroinflammatory mediators and hence may have potential in disease modeling and therapeutic development.

Association between CD14 rs2569190 C>T polymorphism and ischemic stroke susceptibility: a meta-analysis based on 5,277 subjects

INTRODUCTION

Previous epidemiological studies have suggested that CD14 rs2569190 C>T polymorphism plays an important role in ischemic stroke (IS) risk, but the results were inconsistent. Therefore, we conducted a meta-analysis to determine the association between CD14 rs2569190 C>T polymorphism and IS susceptibility.

METHODS

Online databases were searched from inception up to July 1, 2018, for studies concerning CD14 rs2569190 C>T polymorphism and its association with IS susceptibility. ORs and corresponding 95% CIs were calculated in the genetic models of each polymorphism locus with Stata Version 14.0. Furthermore, heterogeneity, meta-regression, accumulative analyses, sensitivity analyses, and publication bias were examined.

RESULTS

Overall, 10 observed studies involving 5,277 subjects were included in this meta-analysis on CD14 rs2569190 C>T polymorphism. Generally, no significant associations were found between CD14 rs2569190 C>T polymorphism and IS risk (allele contrast of T vs C: OR =1.03, 95% CI =0.96-1.12, P=0.41, I2=27.8%; co-dominant models of CT vs CC: OR =1.01, 95% CI =0.81-1.25, P=0.95, I2=51.9%; co-dominant models of TT vs CC: OR =1.04, 95% CI =0.89-1.22, P=0.62, I2=25.1%; dominant model of CT + TT vs CC: OR =1.02, 95% CI =0.84-1.25, P=0.82, I2=51.4%; recessive model of TT vs CC + CT: OR =1.07, 95% CI =0.95-1.22, P=0.28, I2=0%), similar to the results in the subgroup analysis.

CONCLUSION

The current evidence indicated that CD14 rs2569190 C>T polymorphism was not a critical risk factor for IS development.

Glia-immune interactions post-ischemic stroke and potential therapies

IMPACT STATEMENT

This article reviews glial cell interactions with the immune system post-ischemic stroke. Research has shown that glial cells in the brain play a role in altering phenotypes of other glial cells and have downstream immune cell targets ultimately regulating a neuroinflammatory response. These interactions may play a deleterious as well as beneficial role in stroke recovery. Furthermore, they may provide a novel way to approach potential therapies, since current stroke drug therapy is limited to only one Food and Drug Administration-approved drug complicated by a narrow therapeutic window. Until this point, most research has emphasized neuroimmune interactions, but little focus has been on bidirectional communication of glial-immune interactions in the ischemic brain. By expanding our understanding of these interactions through a compilation of glial cell effects, we may be able to pinpoint major modulating factors in brain homeostasis to maintain or discover ways to suppress irreversible ischemic damage and improve brain repair.

Interleukin 8 (CXCL8)-CXC chemokine receptor 2 (CXCR2) axis contributes to MiR-4437-associated recruitment of granulocytes and natural killer cells in ischemic stroke

Granulocytes and natural killer (NK) cells have been linked to brain injury in ischemic stroke. However, their recruitment from peripheral leucocytes in stroke patients is not well understood. Here, the expression of the interleukin 8 (CXCL8) in plasma, and CXC chemokine receptor 2 (CXCR2) in peripheral leucocytes of patients with ischemic stroke were evaluated. Based on the results, CXCR2 expression positively correlated with granulocytes and NK cells, which were in turn attracted by CXCL8. The results also indicated that CXCR2 was a direct target of microRNA (miR)-4437, a negative regulator of CXCR2, which was downregulated in peripheral leucocytes from patients with ischemic stroke. Furthermore, serum CXCL8 levels were associated with the infarct volume and functional outcomes in patients with ischemic stroke. The results of the receiver operating characteristic curve analysis with an optimal cut-off value of 34 pg/mL indicated serum CXCL8 levels could be a prognostic indicator for ischemic stroke. In conclusion, these data highlighted the involvement of the CXCL8-CXCR2 chemotactic axis in the recruitment of granulocytes and NK cells in ischemic stroke. Furthermore, miR-4437 was suggested as a novel target for treating ischemic stroke, while the serum CXCL8 level could be a prognostic factor for ischemic stroke.

Measurement of Elevated IL-37 Levels in Acute Ischemic Brain Injury: A Cross-sectional Pilot Study

Interleukin (IL)-37 is a new member of the IL-1 cytokine family with a defined role as a negative feedback inhibitor of proinflammatory responses. IL-37 has yet to be evaluated in non-immune-mediated neurological diseases, such as ischemic or hemorrhagic strokes. This study aimed to measure urine and serum IL-37 levels in patients with ischemic stroke. Twelve patients consented for our study. Two sets of serum and urine samples were obtained and analyzed, one upon admission to the hospital and the second the next morning. The trends in serum levels of IL- 37 in six stroke patients and the trends in the urine levels of eight stroke patients were measured by real-time polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Our pilot study showed IL-37 levels in urine in stroke patients ranging between 210 and 4,534. Serum IL-37 levels were in the range of 44 - 5,235 in patients with ischemic stroke. Three patients who presented within three hours of stroke onset had IL-37 serum levels of 2,655 pg/ml, 3,517 pg/ml, and 5,235 pg/ml, respectively. In all others, it ranged much less than that, with the trend of delayed presentation giving lower IL-37 levels. The study shows a rather stable early elevation of serum IL-37 levels post-ischemic stroke. IL-37 plays a certain role in mediating post-stroke inflammation with a significant increase in serum levels of this novel cytokine observed in ischemic stroke patients. Further large-scale studies need to be done to establish its definite role. A prospective "CRISP" trial is registered with the ClinicalTrials.gov (Identifier: NCT03297827) to determine the role of IL-37 in modulating post-stroke inflammation.

Stroke and Risks of Development and Progression of Kidney Diseases and End-Stage Renal Disease: A Nationwide Population-Based Cohort Study

BACKGROUND

There is little information about the association between stroke and kidney diseases. We aimed to investigate the impact of stroke on long-term renal outcomes.

METHODS

In this large population-based retrospective cohort study, we identified 100,353 subjects registered in the National Health Insurance Research Database of Taiwan from January 1, 2000, through December 31, 2012, including 33,451 stroke patients and 66,902 age-, sex- and Charlson's comorbidity index score-matched controls.

RESULTS

The incidence rate of chronic kidney disease (CKD) was higher in the stroke than in the control cohort (17.5 vs. 9.06 per 1000 person-years). After multivariate adjustment, the risk of developing CKD was significantly higher in patients with stroke (adjusted hazard ratio [aHR] 1.43, 95% confidence interval [CI] 1.36-1.50, P<0.001). Subgroup analysis showed that stroke patients <50 years (aHR 1.61, P<0.001) and those with concomitant diabetes mellitus (aHR 2.12, P<0.001), hyperlipidemia (aHR 1.53, P<0.001) or gout (aHR 1.84, P<0.001) were at higher risk of incident CKD. Additionally, the risks of progression to advanced CKD and end-stage renal disease (ESRD) were significantly higher for stroke patients (aHRs, 1.22 and 1.30; P = 0.04 and P = 0.008, respectively), independent of age, sex, comorbidities and long-term medications.

CONCLUSIONS

Stroke is associated with higher risks for incident CKD, decline in renal function and ESRD. Younger stroke patients, as well as those with concomitant diabetes mellitus, hyperlipidemia or gout are at greater risk for kidney diseases.

Effect of the +781C/T polymorphism in the interleukin-8 gene on atherosclerotic cerebral infarction, and its interaction with smoking and drinking

OBJECTIVE

The aims of this study were to investigate the association between the +781C/T polymorphism of interleukin-8 (IL-8) and atherosclerotic cerebral infarction and the interaction between the +781C/T polymorphism and smoking or drinking in cerebral infarction in the Han Chinese population.

METHODS

We investigated the +781C/T polymorphism of IL-8 in 308 consecutive Han Chinese patients who were diagnosed with atherosclerotic cerebral infarction and in 294 age- and gender-matched healthy control subjects. The patients were classified using the Oxfordshire Community Stroke Project (OCSP) classification. The patients and subjects' histories of smoking and drinking were recorded, and atherosclerosis (AS) of the internal carotid artery (ICA) was evaluated in the patients. The +781C/T polymorphism was determined by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis.

RESULTS

The +781C/T polymorphism and allele frequencies were not significantly different between the patients and controls and were not significantly associated with the OCSP classifications. We found that the 781C allele was significantly associated with AS of the ICA in the patients (p = 0.017), and the CT genotype was more prevalent in patients without AS of the ICA (p = 0.035). No interactions were observed between the +781C/T polymorphism and smoking or drinking.

CONCLUSION

Our results demonstrated that the +781C/T polymorphism of IL-8 did not play a role and had no interaction with smoking or drinking in the occurrence of cerebral infarction in the Han Chinese population. However, the C allele and the CT genotype might be associated with AS of the ICA in patients with ischemic stroke.

Association of TNF-857C>T, TNFRSF1A36A>G, and TNFRSF1B676T>G Polymorphisms with Ischemic Stroke in a Greek Population

Background. The role of genetic factors in the predisposition to develop ischemic stroke has been assessed by previous studies. The main goal of the current study was to determine any possible role of TNF-857C>T,TNFRSF1A36A>G, and TNFRSF1B676T>G polymorphisms in risk for stroke. Materials and Methods. One hundred seventy-three patients with first ever ischemic stroke of solely atherosclerotic etiology in Northwest Greece and a control group of 179 healthy unrelated subjects were evaluated. Results. TNFα-857TT, TNFR136AA, and TNFR2676TT genotypes were significantly increased in the patient group compared to controls (P = .008, OR = 2.47 (1.26–4.84), P = .005, OR = 1.97 (1.22–3.17), and P = .003, OR = 2.2 (1.43–3.37), resp.). In addition, the TNFR136A and the TNFR2676T alleles were found significantly increased in patients compared to controls (P = .009, OR = 1.48 (1.1–2) and P = .001, OR = 1.75 (1.25–2.46), resp.). Conclusion. The high incidence of these genotypes and alleles in patient group suggests that they are potentially predisposing factors for stroke in the Greek population studied. Large-scale multicenter controlled studies are needed to verify these polymorphisms effects on stroke susceptibility.

Immunological consequences of ischemic stroke: immunosuppression and autoimmunity

Stroke may be accompanied by immunological consequences including local autoimmunity and peripheral immune suppression. Since the blood brain barrier is disturbed cells of the immune system gain direct access to the brain parenchyma. Here local autoimmunity contributes to lesion formation and, in experimental stroke, inhibition of this immune response has been shown to be beneficial. More recently, however, stroke has been shown to also induce severe peripheral immune suppression which predisposes for subsequent bacterial infections that impair the clinical outcome. Here we summarize current knowledge on the immunological consequences of ischemic stroke and will discuss implications of these findings for our understanding of the immunopathogenesis of Multiple Sclerosis.

Cervical-artery dissections: predisposing factors, diagnosis, and outcome

Cervical-artery dissection (CAD) is a major cause of cerebral ischaemia in young adults and can lead to various clinical symptoms, some of which are benign (eg, headache, neck pain, Horner's syndrome, and cranial-nerve palsy), but most patients have a stroke or transient ischaemic attack. In addition to trauma to the neck, other risk factors have been suggested, such as infection, migraine, hyperhomocysteinaemia, and the 677TT genotype of the 5,10-methylenetetrahydrofolate reductase gene (MTHFR 677TT), although evidence is sparse. An underlying arteriopathy, which could in part be genetically determined, is believed to have a role in the development of CAD. Importantly, both research on and optimum management of CAD strongly rely on diagnostic accuracy. Although the functional outcome of CAD is good in most patients, socioprofessional effects can be important. Incidence of the disorder in the general population is underestimated. Mortality and short-term recurrence rates are low but possibly also underestimated. Further research is warranted to improve our understanding of the underlying pathophysiology, to assess the long-term outcome, and ultimately to provide treatment and prevention strategies.

Role of TNF-alpha gene variation in idiopathic childhood ischemic stroke: a case-control study

Etiology of the idiopathic childhood stroke remains unknown. In previous studies, the immunologic process may be involved in the idiopathic stroke. Tumor necrosis factor- alpha (TNF-alpha), an important immune mediator, may contribute to the initiation and progression in the stroke. The main purpose of this study was to investigate correlation of TNF-alpha genetic variation and idiopathic childhood ischemic stroke. Using the direct DNA sequencing method, polymorphisms in the TNF-alpha promoter region were genotyped in 67 Chinese patients with idiopathic childhood stroke and 70 controls. Among totally 7 single nucleotide polymorphisms identified in the TNF-alpha promoter region, the variant of the -863C/A is associated with increased risk of idiopathic childhood ischemic stroke in our study group. TNF-alpha molecule may have genetically as well as functionally an important role in the pathogenesis of idiopathic childhood ischemic stroke in the Chinese population.

The relation between cytokines, soluble endothelial protein C receptor, and factor VIII levels in Turkish pediatric stroke patients

The aim of the authors is to examine the relationship between the cytokine levels that are thought to be involved in stroke etiopathogenesis (tumor necrosis factor [TNF]-alpha, interleukin [IL]-2, IL-6, IL-8, IL-11), soluble protein C receptor (sEPCR), and factor VIII (FVIII) levels. The study included 27 patients with stroke and 30 healthy controls, aged 0 to 18. In the comparison of the sEPCR, cytokine, and FVIII levels between patient and control groups, median levels of TNF-alpha, IL-2, IL-6, and IL-8 are found to be high in the patient group when compared with controls, whereas there is no difference in sEPCR, IL-11, and FVIII levels. In the patient group, a positive correlation is seen between TNF-alpha levels and IL-2 and IL-6 levels, between IL-2 and IL-6 levels, and between IL-6 and IL-8 levels, whereas a negative relationship is seen between sEPCR and FVIII. In the control group apart from the patient group, a negative relationship is seen between TNF-alpha and FVIII, whereas there is a positive relationship between IL-11 and sEPCR levels. Median sEPCR levels in patients who have normal or low FVIII levels are significantly high when compared with those with high FVIII levels. In conclusion, in the pediatric population, an increase in TNF-alpha, IL-2, IL-6, and IL-8 levels is seen. Also, an inverse relationship of sEPCR and FVIII levels is shown for the first time. This study provides a basis for ongoing studies that aim to clarify stroke etiopathogenesis. Studies with larger series of patients are warranted to confirm this hypothesis.

Cerebral small vessel disease: genetic risk assessment for prevention and treatment

Cerebrovascular disease is a major burden to individuals and their communities worldwide. Stroke is one of the leading causes of death and disability, and the prevention and treatment of stroke can be improved with a better understanding of its causation. Cerebral small vessel disease (SVD) is a subset of cerebrovascular disease, and has an equally large impact on an individual's quality of life. Although many risk factors are involved, we propose that genetics has a significant role in the pathogenesis of SVD through a complex interplay of environmental and multigenetic factors. Advances in molecular technology have enabled the human genome to be investigated both at a population and, more recently, an individual level. A better understanding of the molecular basis of SVD will enable the development of therapies to help in its prevention and treatment. This review assesses the molecular genetics underlying cerebral SVD.

Clinical outcome following acute ischaemic stroke relates to both activation and autoregulatory inhibition of cytokine production

BACKGROUND

As critical mediators of local and systemic inflammatory responses, cytokines are produced in the brain following ischaemic stroke. Some have been detected in the circulation of stroke patients, but their role and source is unclear. Focusing primarily on interleukin(IL)-1-related mechanisms, we serially measured plasma inflammatory markers, and the production of cytokines by whole blood, from 36 patients recruited within 12 h and followed up to 1 year after acute ischaemic stroke (AIS).

RESULTS

Admission plasma IL-1 receptor antagonist (IL-1ra) concentration was elevated, relative to age-, sex-, and atherosclerosis-matched controls. IL-1beta, soluble IL-1 receptor type II, tumour necrosis factor (TNF)-alpha, TNF-RII, IL-10 and leptin concentrations did not significantly differ from controls, but peak soluble TNF receptor type I (sTNF-RI) in the first week correlated strongly with computed tomography infarct volume at 5-7 days, mRS and BI at 3 and 12 months. Neopterin was raised in patients at 5-7 d, relative to controls, and in subjects with significant atherosclerosis. Spontaneous IL-1beta, TNF-alpha and IL-6 gene and protein expression by blood cells was minimal, and induction of these cytokines by lipopolysaccharide (LPS) was significantly lower in patients than in controls during the first week. Minimum LPS-induced cytokine production correlated strongly with mRS and BI, and also with plasma cortisol.

CONCLUSION

Absence of spontaneous whole blood gene activation or cytokine production suggests that peripheral blood cells are not the source of cytokines measured in plasma after AIS. Increased plasma IL-1ra within 12 h of AIS onset, the relationship between sTNF-RI and stroke severity, and suppressed cytokine induction suggests early activation of endogenous immunosuppressive mechanisms after AIS.

The etiology of poststroke depression: a review of the literature and a new hypothesis involving inflammatory cytokines

Although poststroke depression is unlikely to represent a single disorder and numerous etiologies for different kinds of poststroke depression will likely emerge as the result of future research, we believe that a number of poststroke depressive disorders are likely to be the result of specific changes in brain pathology and neurophysiology. Nevertheless, there are relatively few hypotheses about the pathophysiology of poststroke depression. This paper, therefore, proposes a new hypothesis for poststroke depression involving increased production of proinflammatory cytokines resulting from brain ischemia in cerebral areas linked to the pathogenesis of mood disorders. This paper reviews the evidence supporting the hypothesis that proinflammatory cytokines are involved in the occurrence of stroke as well as mood disorders linked to the brain damage. The increased production of proinflammatory cytokines such as IL-1beta, TNF-alpha or IL-18 resulting from stroke may lead to an amplification of the inflammatory process, particularly in limbic areas, and widespread activation of indoleamine 2,3-dioxygenase (IDO) and subsequently to depletion of serotonin in paralimbic regions such as the ventral lateral frontal cortex, polar temporal cortex and basal ganglia. The resultant physiological dysfunction may lead to poststroke depression. Future investigations may explore this hypothesis through more extensive studies on the role of proinflammatory cytokines, such as IL-1beta, TNF-alpha or even IL-18, in patients with poststroke depression.

Inflammatory measures in children with obstructive sleep apnoea

AIM

To evaluate a range of inflammatory measures in children with obstructive sleep apnoea (OSA).

METHODS

In total, 44 children with polysomnographically defined OSA (30 boys; mean age: 7.3 +/- 3.7 years) and 69 control subjects (44 boys; mean age: 7.6 +/- 4 years) were recruited. Controls were screened for symptoms of OSA by questionnaire at the time of elective surgery that was unrelated to the upper airway. Blood samples were analysed for C-reactive protein, and cytokines IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, GM-CSF, IFN-gamma and TNF-alpha.

RESULTS

The majority of the children had mild OSA (32/44). Children with OSA (respiratory disturbance index 5.3 +/- 6.5 events/h) had significantly higher IFN-gamma and IL-8 levels than controls (P < 0.001 and 0.003, respectively), although correction for age, sex and body mass index reduced these differences (IFN-gammaP = 0.002, and IL-8 P = 0.051). There were no significant correlations between inflammatory measures and body mass index, respiratory disturbance index, or other sleep, desaturation, or arousal parameters including respiratory or spontaneous arousal indices, desaturation index or severity, sleep efficiency, or apnoea/hypopnoea duration in the OSA group.

CONCLUSION

Children with OSA, even of mild severity, have significantly elevated IFN-gamma levels and a trend towards elevated IL-8 levels compared with asymptomatic controls, consistent with a pro-inflammatory effect of OSA. These changes seen in mild OSA may precede changes in other pro-inflammatory cytokines found in studies of adults with more severe and long-standing disease, implying a potential benefit from early disease identification and intervention.

Analysis of G(-174)C IL-6 polymorphism and plasma concentrations of inflammatory markers in patients with type 2 diabetes and peripheral arterial disease

AIMS

To determine whether the G(-174)C interleukin 6 (IL-6) polymorphism influences the development of peripheral arterial disease (PAD) in individuals with type 2 diabetes. This was investigated by comparing the distribution of G(-174)C genotypes between patients with type 2 diabetes and PAD (PAD+) and those with type 2 diabetes but without PAD (PAD-). Plasma concentrations of IL-6, fibrinogen, C reactive protein (CRP), and vascular endothelial growth factor (VEGF) were also compared in PAD+ and PAD- patients.

METHODS

Blood samples were collected from 146 PAD+ and 144 PAD- patients. SfaNI was used to determine the G(-174)C genotype. Plasma concentrations of IL-6, fibrinogen, CRP, and VEGF were measured by an enzyme linked immunosorbent assay.

RESULTS

The GG genotype was more common in PAD+ patients than in PAD- patients. PAD+ patients also had increased mean plasma concentrations of IL-6, fibrinogen, CRP, and VEGF compared with PAD- patients. Mean plasma concentrations of IL-6, fibrinogen, and CRP in both PAD+ and PAD- patients were higher in those with the GG genotype than in those with the GC or CC genotypes. In contrast, mean plasma concentrations of VEGF in PAD+ and PAD- patients were not significantly different between those with different G(-174)C genotypes.

CONCLUSIONS

These results support a model in which the GG genotype promotes PAD development among individuals with type 2 diabetes by inducing increased release of IL-6. Higher concentrations of IL-6 among those with the GG genotype is associated with increased plasma concentrations of fibrinogen and CRP.

Angiogenesis and stem cell transplantation as potential treatments of cerebral ischemic stroke

Ischemic stroke is a leading cause of human death and disability. Although stroke survivors may gain spontaneous partial functional recovery, they often suffer from sensory-motor dysfunctions, behavioral/neurological alterations, and various degrees of paralysis. Currently, limited clinical intervention is available to prevent ischemic damage and restore lost function in stroke victims. In addition to the extensive research on protective maneuvers against ischemia-induced cell death, increasing attention has been focused on potential strategies of promoting tissue repair and functional recovery in the damaged post-ischemic brain. Angiogenesis, or the growth of new blood vessels, may contribute to cell survival and functional recovery of the area of insult. The study of angiogenesis will increase the understanding of the mechanism underlying post-ischemia neurovascular plasticity and regeneration. Additionally, stem cell transplantation has emerged in the last few years as a potential therapy for ischemic stroke, because of their capability to differentiate into multiple cell types and the possibility that they may provide trophic support for cell survival, tissue repair, and functional recovery.

Platelet-Leukocyte Interaction and Platelet Activation in Acute Stroke With and Without Preceding Infection

Objective— Acute coronary syndromes and ischemic cerebral stroke share similarities regarding elevated platelet activation. In coronary syndromes, the importance of inflammation with platelet-leukocyte interaction has been demonstrated. Recent infection is an established risk factor for ischemic stroke; the role of platelet-leukocyte interaction in these patients had not been investigated.

Methods and Results— Using a flow cytometric assay we investigated 58 stroke patients, 21 with and 37 without infection 1 week before acute cerebral ischemia, and compared them to 58 controls with regard to platelet-leukocyte aggregation and platelet activation on admission and on day 7. Patients with previous infection were significantly up-regulated with regard to platelet activation and platelet-leukocyte aggregation compared with patients without infection. On day 7, these increases in the postinfective group had drawn level with the lower values of the other patients. As reported previously, recent infection was associated with a more severe postischemic deficit.

Conclusions— These results suggest an important role of intercellular platelet-leukocyte interaction in the pathophysiology of acute cerebral ischemia which may also contribute to the increased incidence and clinical severity of ischemic stroke following infection. This may lead to therapeutic considerations of blocking intercellular adhesion molecules like P-selectin or the P-selectin glycoprotein ligand.

A systematic review of the risk factors for cervical artery dissection

BACKGROUND AND PURPOSE

Cervical artery dissection (CAD) is a recognized cause of ischemic stroke among young and middle-aged individuals. The pathogenesis of dissections is unknown, although numerous constitutional and environmental risk factors have been postulated. To better understand the quality and nature of the research on the pathogenesis of CAD, we performed a systematic review of its risk factors.

METHODS

PubMed [MEDLINE (1966 to February 22, 2005)] and Embase (1980 to February 22, 2005) were searched to identify studies fulfilling the inclusion criteria. Two reviewers independently assessed methodological quality of the primary studies. Relevant data were extracted, including the risk factor(s) investigated, characteristics of the study population, and strength of the association(s).

RESULTS

Thirty-one case-control studies were included for analysis. Selection bias, lack of control for confounding, and inadequate method of data analysis were the most common identified methodological shortcomings. Strong associations were reported from individual studies for the following risk factors: aortic root diameter >34 mm (odds ratio [OR=14.2; 95% confidence interval [CI], 3.2 to 63.6), migraine (ORadj, 3.6; 95% CI, 1.5 to 8.6), relative diameter change (>11.8%) during the cardiac cycle of the common carotid artery (ORadj, 10.0; 95% CI, 1.8 to 54.2), and trivial trauma (in the form of manipulative therapy of the neck) (ORadj, 3.8; 95% CI, 1.3 to 11). A weak association was found for homocysteine (2 studies: ORcrude, unknown; 95% CI, 1.05 to 1.52; ORcrude, 1.3; 95% CI, 1.0 to 1.7), and recent infection (ORadj, 1.60; 95% CI, 0.67 to 3.80). Two studies had conflicting findings for low levels of alpha1-antitrypsin, with the methodologically stronger study suggesting no association with CAD.

CONCLUSIONS

CAD is a multi-factorial disease. Many of the reviewed studies contained 2 or more major sources of bias commonly found in case-control studies. Only one study (of homocysteine) used healthy controls, a robust sample size, and had a low risk of biased results. The relationship between atherosclerosis and CAD has been insufficiently examined.

TNF-α −308G/A and IL-6 −174 G/C polymorphisms in the Turkish pediatric stroke patients

INTRODUCTION

Introduction: Stroke is an important cause of mortality and morbidity in the pediatric age group. There is increasing evidence on the role of proinflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) in the occurrence and outcome of stroke. These proinflammatory cytokines carry functional polymorphisms (IL-6 -174 G/C and TNF-alpha -308 G/A) in their promoter regions, affecting their transcription rate and plasma cytokine levels. The aim of this study was to investigate the association of these polymorphisms with the occurrence of stroke in the Turkish pediatric stroke patients.

MATERIAL AND METHODS

Eighty six arterial stroke patients (aged between 0 and 14) and 83 healthy unrelated adult controls without personal or family history of stroke were investigated by PCR and restriction endonuclease analysis for IL-6 -174 G/C and TNF-alpha -308 G/A polymorphisms.

RESULTS

The allele distribution, allele frequencies, and combined distribution of genotypes for both polymorphisms did not differ significantly between control and patient groups.

CONCLUSIONS

The two polymorphisms did not associate with the occurrence of stroke in our study group.

Susceptibility for ischemic stroke in Korean population is associated with polymorphisms of the interleukin-1 receptor antagonist and tumor necrosis factor-α genes, but not the interleukin-1β gene

Enhanced release of proinflammatory cytokines may contribute to the pathogenesis of ischemic stroke. Interleukin-1 receptor antagonist (IL-1Ra) is an anti-inflammatory cytokine, and tumor necrosis factor (TNF)-alpha and IL-1beta are proinflammatory cytokine. To determine the role of cytokines in genetic susceptibility to ischemic stroke, we genotyped ischemic stroke patients (n = 152) and the healthy control subjects (n = 165) for IL-1Ra, TNF-alpha and IL-1beta polymorphism by polymerase chain reaction-restriction fragment length polymorphism methods. The analysis shown the association of IL1RN*1, IL1RN*2 allele (IL1RN*1, OR=0.44, P = 0.0206 IL1RN*2, OR=2.90, P = 0.0141) and TNF1, TNF2 allele (TNF1, OR=2.16, P = 0.0225; TNF2, OR=2.16, P = 0.0225) to ischemic stroke. However, the genetic polymorphism of IL-1beta was not associated with ischemic stroke. Our results suggest that IL-1Ra and TNF-alpha gene polymorphism is associated with the susceptibility to ischemic stroke.

Plasma cytokine levels in patients with obstructive sleep apnea syndrome: a preliminary study

The levels of some pro- and anti-inflammatory cytokines [interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, IL-6, IL-10, and transforming growth factor (TGF)-beta], were measured by enzyme-linked immunosorbent assay (ELISA) method in the plasma of patients affected by obstructive sleep apnea syndrome (OSAS) at 22:00 hours before polysomnographic recording and immediately after the first obstructive apnea causing an SaO2 below 85%. Significantly higher levels of TNF-alpha were found in OSAS patients assessed before polysomnography compared with the control group (P < 0.01). A slight but significant increase in the plasma levels of IL-6 was also present (P < 0.05). Conversely, a significant decrease in the plasma levels of IL-10 was evident at baseline in OSAS patients (P < 0.04). No significant difference emerged between the mean values of IL-1alpha and TGF-beta between OSAS patients and controls. The present data support a prevailing activation of the Th1-type cytokine pattern in OSAS patients, which is not associated with the severity and duration of OSAS. This can have important consequences for the outcome of OSAS patients, especially with regard to the increased risk for developing atherosclerosis and cardiovascular and cerebrovascular diseases. Immediately after the first obstructive apnea causing an SaO2 <85%, a significant variation was observed in the plasma levels of TNF-alpha in OSAS patients compared with those measured before the beginning of polysomnographic recording (P < 0.001). The role played by this further increase in TNF-alpha levels after the obstructive apnea in OSAS patients remains to be established in the light of the pathogenic mechanisms of this sleep disorder.

Inflammation and infections as risk factors for ischemic stroke

BACKGROUND

Inflammatory processes have fundamental roles in stroke in both the etiology of ischemic cerebrovascular disease and the pathophysiology of cerebral ischemia. We summarize clinical data on infection and inflammation as risk or trigger factors for human stroke and investigate current evidence for the hypothesis of a functional interrelation between traditional risk factors, genetic predisposition, and infection/inflammation in stroke pathogenesis.

SUMMARY OF REVIEW

Several traditional vascular risk factors are associated with proinflammatory alterations, including leukocyte activation, and predispose cerebral vasculature to thrombogenesis on inflammatory stimulation. Furthermore, accumulation of inflammatory cells, mainly monocytes/macrophages, within the vascular wall starts early during atherogenesis. During later disease stages, their activation can lead to plaque rupture and thrombus formation, increasing stroke risk. Inflammatory markers (eg, leukocytes, fibrinogen, C-reactive protein) are independent predictors of ischemic stroke. Chronic infections (eg, infection with Chlamydia pneumoniae or Helicobacter pylori) were found to increase the risk of stroke; however, study results are at variance, residual confounding is not excluded, and causality is not established at present. In case-control studies, acute infection within the preceding week was a trigger factor for ischemic stroke. Acute and exacerbating chronic infection may act by activating coagulation and chronic infections and may contribute to atherogenesis. Genetic predisposition of the inflammatory host response may be an important codeterminant for atherogenesis and stroke risk.

CONCLUSIONS

Inflammation contributes to stroke risk via various interrelated mechanisms. Infectious diseases, traditional risk factors, and genetic susceptibility may cooperate in stimulating inflammatory pathways. Final proof of a causal role of infectious/inflammatory mechanisms in stroke pathogenesis is still lacking and will require interventional studies.

Escherichia coli endotoxin enhances acute renal failure in rats after thermal injury

This study was designed to evaluate the burned rat model to determine whether there are any differences in endotoxin-sensitive kidney functions between an infant rat (10-day-old pup) and an adult rat (10-week-old rat). Renal failure was observed in the infant burned rat and histological changes showed the adhesion of inflammatory cells in the glomerular capillaries and vacuolar changes in the renal proximal tubular cell. A horseradish peroxidase (HRP) tracer experiment suggested that the intestinal barrier damage of the infant burned rat was more severe than that of the adult burned rat. Therefore, more bacterial translocation of the intestinal flora, rich in endotoxin, might be expected in the infant versus the adult rats. Renal failure was not observed in the adult burned rat, so we investigated to determine the effects of endotoxin on the kidney function of the adult burned rat with low lethal lipopolysaccharide (LPS) or carrageenan (CAR). CAR is known to increase sensitivity to the lethal effects of endotoxin in rodents. Our present data demonstrated that renal failure was observed in the LPS- or CAR-treated adult burned rat and LPS- and CAR-treated adult rat (non-burned). These results show the possibility that endotoxin enhances renal failure in a burned rat model and provide additional support for the hypothesis that postburn renal failure is mediated, in part, by endotoxin associated with bacterial translocation.

Inflammatory response in the elderly

PURPOSE OF REVIEW

During ageing there may be the onset of a chronic inflammatory state. This review examines the underlying causes of this phenomenon and the role that genotype plays in its intensity.

RECENT FINDINGS

There are predisposing factors for the chronic inflammation that occurs during ageing. These include increased oxidative stress, a decrease in ovarian function, a decrease in stress-induced glucocorticoid sensitivity of pro-inflammatory cytokine production in men, and an increased incidence of asymptomatic bacteriuria. Obesity induces chronic inflammation. Inflammation is a key factor in the progressive loss of lean tissue and impaired immune function observed in ageing. Polymorphisms in the promoter regions of pro- and anti-inflammatory cytokine genes influence the level of cytokine production and the ageing process. Thus, a genotype for high pro-inflammatory cytokine production results in high cytokine production and may accelerate the rate of tissue loss. Conversely, polymorphisms in the genes for anti-inflammatory cytokines may result in a slowing of tissue loss. In the healthy aged male population, the former polymorphisms are under-represented and the latter over-represented, indicating a genetically determined survival advantage in maintaining inflammation at a low level. Nutrients with anti-inflammatory properties, such as vitamin E and n-3 polyunsaturated fatty acid, may reduce the level of chronic inflammation and thereby ameliorate tissue and functional loss during ageing. New evidence suggests that, for the latter nutrient, gene-nutrient interactions occur that alter the effectiveness of dietary therapy.

SUMMARY

Ageing is associated with increased levels of chronic inflammation. This plays a major role in the decline in immune function and lean body mass. Anti-inflammatory nutrient therapy may slow the rate of decline. The pro- and anti-inflammatory cytokine genotype is linked negatively and positively, respectively, with life-span, because of its influence on inflammation.

The -174 G/C polymorphism of the interleukin-6 gene promoter is associated with peripheral artery occlusive disease

OBJECTIVE AND DESIGN

high plasma levels of Interleukin-6 (IL-6) are found in patients with atherosclerotic disorders. Recently, a common polymorphism of the IL-6 gene promoter, influencing the transcription rate of the gene, has been described and associated with atherosclerosis of carotid and coronary arteries. The objective of this study was to test whether IL-6 gene promoter polymorphism is associated with peripheral artery occlusive disease (PAOD) in a case-control study.

METHODS

IL-6 gene promoter polymorphism was evaluated by polymerase chain reaction followed by restriction enzyme analysis in 84 patients affected by PAOD and 183 controls.

RESULTS

the distribution of IL-6 genotypes was: patients with PAOD: 44 GG, 30 GC, 10 CC; control subjects: 53 GG, 80 GC, 50 CC. The GG genotype was significantly more common in the PAOD group (p<0.0001), while the CC genotype was significantly more common in control patients (p=0.005).

CONCLUSIONS

this study indicates a strong association between IL-6 gene polymorphism and PAOD and support the hypothesis that IL-6 and IL-6 gene polymorphism are important in the pathophysiology and evolution of ischaemic diseases of the lower limbs.