New therapeutic possibility of blocking cytokine-induced neutrophil chemoattractant on transient ischemic brain damage in rats

Investigation of therapeutic effects of calcium dobesilate in cerebral hypoxia/ reperfusion injury in rats

OBJECTIVES

Cerebral stroke is a serious clinical condition in which oxidative stress, inflammation, necrosis, apoptosis, and autophagy play important roles in its pathogenesis. This study investigated the neuroprotective and healing effects of calcium dobesilate (CD) on cerebral hypoxia/reperfusion injury in rats.

METHODS

Forty Wistar albino male rats, each weighing 300-350 g, were separated into the Control group (no surgery and no pharmacological agent was administered); Sham-A group (only surgery was performed); DBL-A group (surgery was performed and CD 100 mg/kg/day was administered intraperitoneally for 3 days); Sham-C group (only surgery was performed); and DBL-C group (surgery was performed and 100 mg/kg/day CD was administered intraperitoneally for 10 days). Under sedation anesthesia, the bilateral common carotid arteries of all rats except the Control group were clipped for 30 min. After 4 h, the CD was given to the relevant groups, and then, all subjects were euthanized at scheduled times. The brain of each animal was removed for histopathological (hematoxylin and eosin staining), immunohistochemical (beclin-1, anti-MHC class II and anti-CD-68 staining), and biochemical (TNF, IL-1β, IL-6, caspase-3, GSH/GSSG, malondialdehyde, protein carbonyl, LC3II/LC3I, and beclin-1 levels) evaluations.

RESULTS

It was observed that CD could reduce necrosis and mitigate polarization of microglia to the M1 phenotype, autophagy, free oxygen radicals, protein carbonylation, lipid peroxidation, IL-1β, IL6, TNF, caspase-3, beclin-1, and LC3II/LC3I levels in acute and chronic periods of hypoxia/reperfusion injury.

CONCLUSION

From these results, it was observed that CD treatment could reduce neuronal necrosis and create anti-inflammatory, anti-edema, anti-oxidant, anti-apoptotic, and anti-autophagic effects in hypoxia/reperfusion injury in rats.

Viral mimetic triggers cerebral arteriopathy in juvenile brain via neutrophil elastase and NETosis

Stroke is among the top ten causes of death in children but has received disproportionally little attention. Cerebral arteriopathies account for up to 80% of childhood arterial ischemic stroke (CAIS) cases and are strongly predictive of CAIS recurrence and poorer outcomes. The underlying mechanisms of sensitization of neurovasculature by viral infection are undefined. In the first age-appropriate model for childhood arteriopathy-by administration of viral mimetic TLR3-agonist Polyinosinic:polycytidylic acid (Poly-IC) in juvenile mice-we identified a key role of the TLR3-neutrophil axis in disrupting the structural-functional integrity of the blood-brain barrier (BBB) and distorting the developing neurovascular architecture and vascular networks. First, using an array of in-vivo/post-vivo vascular imaging, genetic, enzymatic and pharmacological approaches, we report marked Poly-IC-mediated extravascular leakage of albumin (66kDa) and of a small molecule DiI (∼934Da) and disrupted tight junctions. Poly-IC also enhanced the neuroinflammatory milieu, promoted neutrophil recruitment, profoundly upregulated neutrophil elastase (NE), and induced neutrophil extracellular trap formation (NETosis). Finally, we show that functional BBB disturbances, NETosis and neuroinflammation are markedly attenuated by pharmacological inhibition of NE (Sivelestat). Altogether, these data reveal NE/NETosis as a novel therapeutic target for viral-induced cerebral arteriopathies in children.

Predictive ability of admission neutrophil to lymphocyte ratio on short-term outcome in patients with spontaneous cerebellar hemorrhage

As one of the prototypical intracranial hemorrhage (ICH), spontaneous cerebellar hemorrhage (SCH) is treated with different strategies by comparing with supratentorial hemorrhage (SH). Additionally, SCH patients usually suffer from worse prognosis than patients with other types of ICH. It is well documented that the unique anatomic structures of posterior cranial fossa lead to a higher risk for brainstem compression and/or brain edema in SCH patients. Recently, neutrophil to lymphocyte ratio (NLR) was reported to possess an excellent predictive ability for the prognosis of patients with ICH, and most of those cases are SH. Thus, the potential association between NLR and the prognosis of SCH patients remains to be elucidated. Here, we aim to assess the predictive role of admission NLR and other available inflammatory parameters for the outcomes of patients with SCH.All patients with acute SCH admitting to West China Hospital from February 2010 to October 2017 were retrospectively enrolled. According to the absolute neutrophil count, absolute lymphocyte count, white blood count and absolute monocyte count extracted from electronic medical records, NLR was calculated. The multivariable logistic regression analysis was applied to analyze the associations between disease outcome and laboratory biomarkers. The comparisons of predictive powers of each biomarker were assessed by receiver operating curves (ROCs). The spearman analyses and multiple linear analyses were also conducted to identify the independent predictors for admission NLR.Admission NLR independently associated with 30-day status (odds ratio [OR] 1.785, 95% confidence interval [CI] 1.463-2.666, P <.01) and exhibited a better predictive value (AUC 0.751, 95% CI 0.659-0.830, P <.001) with the best predictive cutoff point of 7.04 in 62 patients with unfavorable outcomes. Moreover, absolute neutrophil count, absolute lymphocyte count, presence of intraventricular hemorrhage (IVH) and Glasgow coma scale (GCS) score were also correlated with admission NLR, respectively.Admission NLR is a potential marker to independently predict the 30 days functional outcome of SCH patients. Based on our results, systemic inflammation in admission might be considered as an important player in participating the pathological process of patients with SCH.

Predictive Accuracy of Neutrophil-to-Lymphocyte Ratio on Long-Term Outcome in Patients with Spontaneous Intracerebral Hemorrhage

BACKGROUND

It is well established that inflammation plays a critical role in the progression of intracerebral hemorrhage (ICH). Recently the neutrophil-to-lymphocyte ratio (NLR) was identified as a predictor for the short-term outcome in ICH patients. However, the association of NLR with the long-term outcome in patients with ICH remains unknown. Here, we aimed to assess the relationship between NLR and the long-term prognosis in ICH patients.

METHODS

All patients with spontaneous ICH who were hospitalized at West China Hospital of Sichuan University from October 2013 to May 2017 were retrospectively enrolled. White blood count, absolute count of neutrophils, and lymphocytes were extracted from electronic medical records, and NLR was calculated according to admission neutrophil count (ANC) and lymphocyte count (ALC). The associations between long-term outcomes and laboratory biomarkers were estimated by multivariable logistic regression analysis. Receiver operating characteristic (ROC) curves were also determined to compare the predictive powers between each inflammatory factor.

RESULTS

A total of 481 ICH patients were included in the study. Of those, 204 presented with unfavorable outcomes, and 142 were dead within 6 months. Age, Glasgow Coma Scale (GCS) scores, WBC, ANC, NLR, hematoma size, and hydrocephalus were independently associated with poor prognosis of ICH. Multiple linear analysis showed GCS, hematoma volume, WBC, ANC, and ALC to be correlated with NLR. Moreover, in comparison with other single laboratory determinations, NLR also showed better predictive capacity for long-term mortality and morbidity, for which the best predictive cutoff values were 9.07 and 8.69, respectively.

CONCLUSIONS

NLR independently predicts 180-day morbidity and 180-day mortality in patients with spontaneous ICH.

Neutrophil and Platelet to Lymphocyte Ratios in Associating with Blood Glucose Admission Predict the Functional Outcomes of Patients with Primary Brainstem Hemorrhage

BACKGROUND

Because of a lack of markers for predicting prognosis and an underlying mechanism, patients with primary brainstem hemorrhage (PBH) are currently treated with multiple strategies, but most of them have poor outcomes in a comparison with patients with supratentorial intracranial hemorrhage. Recently, it has been reported that the neutrophil-to-lymphocyte ratio (NLR) represents a novel composite inflammatory marker to predict the prognosis of patients with intracranial hemorrhage, a majority of whom have supratentorial hemorrhage. In this report, we aim to assess the potential predictive value of NLR in patients with PBH. In addition, other available laboratory parameters, including platelet-to-lymphocyte ratio (PLR), and admission blood glucose level (ABG), will be also investigated as markers for prognosis in patients with PBH.

METHODS

This study retrospectively enrolled 225 patients with acute PBH who were admitted West China Hospital from January 2012 to December 2016. ABG and absolute numbers of neutrophils, lymphocytes, white blood cells, and platelets were extracted from electronic medical records. ABG, NLR, and PLR were calculated and further assessed using multivariable logistic regression analysis for understanding the associations of treatment outcomes. The comparison of predictive power of independent predictors was evaluated using receiver operating characteristic.

RESULTS

Of 225 inpatients, NLR (odds ratio [OR], 1.82; 95% confidence interval [CI], 1.24-2.62, P < 0.01), PLR (OR, 1.43; 95% CI, 1.11-2.36; P = 0.013), and ABG (OR, 6.57; 95% CI, 2.78-15.52; P < 0.01) were independently associated with 90-day status in 112 patients with unfavorable outcomes. All 3 parameters also correlated with admission Glasgow Coma Scale score (r = -0.244, P < 0.001; r = -0.292, P < 0.001; r = -0.661, P < 0.01) and absolute neutrophil counts (r = 0.645, P < 0.001; r = 0.347, P < 0.001; r = 0.695, P < 0.01). Meanwhile, NLR exhibits a comparable predictive power by comparing with PLR (area under the curve [AUC], 0.694; 95% CI, 0.626-0.764; P < 0.001; versus AUC, 0.662; 95% CI, 0.596-0.724; P < 0.001). In addition, ABG shows a positive predictive value (AUC, 0.784; 95% CI, 0.725-0.832; P < 0.001). The best independent predictive cutoff points were 6.65, 59.3, and 7.81 mmol/L for NLR, PLR, and ABG, respectively. Nevertheless, a combination of 3 parameters shows the best predictive ability (AUC, 0.835; 95% CI, 0.781-0.883; P < 0.001).

CONCLUSIONS

NLR, PLR, and ABG can be used to independently predict 90-day functional outcome in patients after PBH. When combined, they have better predictive power in identifying PBH patients with a poor prognosis. To our knowledge, this study is the first to reveal the associations between NLR, PLR, and hyperglycemia and the functional outcomes of patient with PBH. In associating with previously studies on hemorrhage site, our results provide a good opportunity to elucidate the underlying mechanisms of PBH.

Cerebral ischemic damage in diabetes: an inflammatory perspective

Stroke is one of the leading causes of death worldwide. A strong inflammatory response characterized by activation and release of cytokines, chemokines, adhesion molecules, and proteolytic enzymes contributes to brain damage following stroke. Stroke outcomes are worse among diabetics, resulting in increased mortality and disabilities. Diabetes involves chronic inflammation manifested by reactive oxygen species generation, expression of proinflammatory cytokines, and activation/expression of other inflammatory mediators. It appears that increased proinflammatory processes due to diabetes are further accelerated after cerebral ischemia, leading to increased ischemic damage. Hypoglycemia is an intrinsic side effect owing to glucose-lowering therapy in diabetics, and is known to induce proinflammatory changes as well as exacerbate cerebral damage in experimental stroke. Here, we present a review of available literature on the contribution of neuroinflammation to increased cerebral ischemic damage in diabetics. We also describe the role of hypoglycemia in neuroinflammation and cerebral ischemic damage in diabetics. Understanding the role of neuroinflammatory mechanisms in worsening stroke outcome in diabetics may help limit ischemic brain injury and improve clinical outcomes.

Neutrophil-to-Lymphocyte Ratio and 30-Day Mortality in Patients with Acute Intracerebral Hemorrhage

BACKGROUND

Although a highly significant association has been described between neutrophil-to-lymphocyte ratio (NLR) and mortality in patients with various types of stroke, the association between NLR and mortality in intracerebral hemorrhage (ICH) patients remains unclear.

METHODS

In this observational study, we enrolled 224 ICH patients. They were divided into 2 groups based on their 30-day outcomes. Multivariate logistic regression was performed to identify independent risk factors of 30-day mortality. An optimal cutoff value for the continuous NLR was calculated by applying a receiver operating curve analysis to discriminate between the survival and death groups.

RESULTS

Among 224 patients, 26 died. No significant difference in NLR at admission was observed between the 2 groups (surviving: 2.39 ± 1.75 versus nonsurviving: 3.09 ± 2.16, P= .065), whereas NLR on the next morning following admission was significantly higher in the patients who died (12.53 ± 9.33) than in those who survived (5.53 ± 4.68) (P <.001). On multivariate logistic analysis, Glasgow Coma Scale score (odds ratio [OR] .805, 95% confidence interval [CI] .661-.979, P = .030), age (≥80 years; OR .203, CI .055-.750, P = .017), ICH volume (≥30 cm(3); OR .112, CI .108-.699, P = .019), and NLR on the next morning (OR 1.091, CI 1.002-1.188, P = .044) were independent risk factors of 30-day mortality. An NLR of 7.35 was identified as the optimal cutoff value. The area under the curve of NLR for 30-day mortality was .762 (P < .001). The mortality was significantly higher in patients with an NLR of 7.35 or higher than in those with an NLR less than 7.35 (31.6% versus 4.8%, P <.001).

CONCLUSIONS

Higher NLR exhibited an increased mortality in ICH patients. NLR could be used to predict 30-day outcome in ICH patients.

ELR-CXC chemokine antagonism is neuroprotective in a rat model of ischemic stroke

Inflammation-related cerebral damage mediated by infiltrating neutrophils following reperfusion plays a role in reperfusion-induced brain damage subsequent to a stroke event. The ELR-CXC family of chemokines are CXCR1 and CXCR2 agonists that are known to drive neutrophil migration and activation. The present study demonstrated the benefit of anti-inflammatory therapy in the treatment of ischemic stroke with the administration of the competitive ELR-CXC chemokine antagonist, CXCL8(3-72)K11R/G31P (G31P). Male Sprague-Dawley rats were anaesthetized, and the middle cerebral artery (MCA) was occluded for 30 min followed by 5.5 h of reperfusion. Pretreatment with G31P resulted in a significant, dose-dependent (approximately 61-72%) decrease in infarct volumes compared to vehicle-treated animals, but neuroprotection was also observed when G31P (0.5 mg/kg) was administered 1 or 3 h following the start of reperfusion. The neuroprotection observed following the administration of this competitive CXCR1/CXCR2 antagonist may present therapeutic opportunities for addressing reperfusion-induced inflammatory damage in patients presenting with transient ischemic episodes.

Clinical implications of leukocyte infiltration at the choroid plexus in (neuro)inflammatory disorders

The choroid plexus (CP) is a highly vascularized organ located in the brain ventricles and contains a single epithelial cell layer forming the blood-cerebrospinal fluid barrier (BCSFB). This barrier is crucial for immune surveillance in health and is an underestimated gate for entry of immune cells during numerous inflammatory disorders. Several of these disorders are accompanied by disturbance of the BCSFB and increased leukocyte infiltration, which affects neuroinflammation. Understanding the mechanism of immune cell entry at the CP might lead to identification of new therapeutic targets. Here, we focus on current knowledge of leukocyte infiltration at the CP in inflammatory conditions and its therapeutic implications.

Barrier mechanisms in neonatal stroke

Clinical data continue to reveal that the incidence of perinatal stroke is high, similar to that in the elderly. Perinatal stroke leads to significant morbidity and severe long-term neurological and cognitive deficits, including cerebral palsy. Experimental models of cerebral ischemia in neonatal rodents have shown that the pathophysiology of perinatal brain damage is multifactorial. Cerebral vasculature undergoes substantial structural and functional changes during early postnatal brain development. Thus, the state of the vasculature could affect susceptibility of the neonatal brain to cerebral ischemia. In this review, we discuss some of the most recent findings regarding the neurovascular responses of the immature brain to focal arterial stroke in relation to neuroinflammation. We also discuss a possible role of the neonatal blood-CSF barrier in modulating inflammation and the long-term effects of early neurovascular integrity after neonatal stroke on angiogenesis and neurogenesis.

Blood-brain barrier pathophysiology in traumatic brain injury

The blood-brain barrier (BBB) is formed by tightly connected cerebrovascular endothelial cells, but its normal function also depends on paracrine interactions between the brain endothelium and closely located glia. There is a growing consensus that brain injury, whether it is ischemic, hemorrhagic, or traumatic, leads to dysfunction of the BBB. Changes in BBB function observed after injury are thought to contribute to the loss of neural tissue and to affect the response to neuroprotective drugs. New discoveries suggest that considering the entire gliovascular unit, rather than the BBB alone, will expand our understanding of the cellular and molecular responses to traumatic brain injury (TBI). This review will address the BBB breakdown in TBI, the role of blood-borne factors in affecting the function of the gliovascular unit, changes in BBB permeability and post-traumatic edema formation, and the major pathophysiological factors associated with TBI that may contribute to post-traumatic dysfunction of the BBB. The key role of neuroinflammation and the possible effect of injury on transport mechanisms at the BBB will also be described. Finally, the potential role of the BBB as a target for therapeutic intervention through restoration of normal BBB function after injury and/or by harnessing the cerebrovascular endothelium to produce neurotrophic growth factors will be discussed.

Therapeutic antibodies in stroke

Immunotherapy represents an active area of biomedical research to treat cancer, autoimmune diseases, and neurodegenerative disorders. In stroke, recanalization therapy is effective in reducing brain tissue damage after acute ischemic stroke. However, the narrow time window restricts its application for the majority of stroke patients. There is an urgent need to develop adjuvant therapies such as immunotherapy, stem cell replacement, and neuroprotective drugs. A number of molecules have been targeted for immunotherapy in stroke management, including myelin-associated proteins and their receptors, N-methyl-d-aspartic acid receptors, cytokines, and cell adhesion molecules. Both active vaccination and passive antibodies were tested in animal models of acute ischemic stroke. However, the mechanisms underlying the efficacy of immunotherapy are different for each target protein. Blocking myelin-associated proteins may enhance neuroplasticity, whereas blocking adhesion molecules may yield neuroprotection by suppressing the immune response after stroke. Although results from animal studies are encouraging, clinical trials using therapeutic antibodies failed to improve stroke outcome due to severe side effects. It remains a challenge to generate specific therapeutic antibodies with minimal side effects on other organs and systems.

Blockade of CXCR1/2 chemokine receptors protects against brain damage in ischemic stroke in mice

OBJECTIVE

Ischemic stroke may result from transient or permanent reductions of regional cerebral blood flow. Polymorphonuclear neutrophils have been described as the earliest inflammatory cells to arrive in ischemic tissue. CXCR1/2 receptors are involved in the recruitment of these cells. However, the contribution of these chemokine receptors during transient brain ischemia in mice remains poorly understood. In this work, we investigated the effects of reparixin, an allosteric antagonist of CXCR1/2 receptors, in a model of middle cerebral artery occlusion and reperfusion in mice.

METHODS

C57BL/6J male mice treated with reparixin or vehicle were subjected to a middle cerebral artery occlusion procedure 1 h after the treatment. Ninety minutes after ischemia induction, the monofilament that prevented blood flow was removed. Twenty-four hours after the reperfusion procedure, behavioral changes, including motor signs, were analyzed with the SmithKline/Harwell/lmperial College/Royal Hospital/Phenotype Assessment (SHIRPA) battery. The animals were sacrificed, and brain tissue was removed for histological and biochemical analyses. Histological sections were stained with hematoxylin and eosin, neutrophil infiltration was estimated by myeloperoxidase activity and the inflammatory cytokine IL-iβ was measured by ELISA.

RESULTS

Pre-treatment with reparixin reduced the motor deficits observed in this model of ischemia and reperfusion. Myeloperoxidase activity and IL-iβ were reduced in the reparixin-treated group. Histological analysis revealed that ischemic injury was also attenuated by reparixin pre-treatment.

CONCLUSIONS

Our results suggest that the blockade of the CXCR1/2 receptors by reparixin promotes neuroprotective effects by reducing the levels of polymorphonuclear infiltration in the brain and the tissue damage associated with middle cerebral artery occlusion and reperfusion.

Blood-brain barrier permeability is increased after acute adult stroke but not neonatal stroke in the rat

The immaturity of the CNS at birth greatly affects injury after stroke but the contribution of the blood-brain barrier (BBB) to the differential response to stroke in adults and neonates is poorly understood. We asked whether the structure and function of the BBB is disrupted differently in neonatal and adult rats by transient middle cerebral artery occlusion. In adult rats, albumin leakage into injured regions was markedly increased during 2-24 h reperfusion but leakage remained low in the neonates. Functional assays employing intravascular tracers in the neonates showed that BBB permeability to both large (70 kDa dextran) and small (3 kDa dextran), gadolinium (III)-diethyltriaminepentaacetic acid tracers remained largely undisturbed 24 h after reperfusion. The profoundly different functional integrity of the BBB was associated with the largely nonoverlapping patterns of regulated genes in endothelial cells purified from injured and uninjured adult and neonatal brain at 24 h (endothelial transcriptome, 31,042 total probe sets). Within significantly regulated 1266 probe sets in injured adults and 361 probe sets in neonates, changes in the gene expression of the basal lamina components, adhesion molecules, the tight junction protein occludin, and matrix metalloproteinase-9 were among the key differences. The protein expression of collagen-IV, laminin, claudin-5, occludin, and zonula occludens protein 1 was also better preserved in neonatal rats. Neutrophil infiltration remained low in acutely injured neonates but neutralization of cytokine-induced neutrophil chemoattractant-1 in the systemic circulation enhanced neutrophil infiltration, BBB permeability, and injury. The markedly more integrant BBB in neonatal brain than in adult brain after acute stroke may have major implications for the treatment of neonatal stroke.

Posttraumatic invasion of monocytes across the blood-cerebrospinal fluid barrier

The invasion of inflammatory cells occurring after ischemic or traumatic brain injury (TBI) has a detrimental effect on neuronal survival and functional recovery after injury. We have recently demonstrated that not only the blood-brain barrier, but also the blood-cerebrospinal fluid (CSF) barrier (BCSFB), has a role in posttraumatic recruitment of neutrophils. Here, we show that TBI results in a rapid increase in synthesis and release into the CSF of a major chemoattractant for monocytes, CCL2, by the choroid plexus epithelium, a site of the BCSFB. Using an in vitro model of the BCSFB, we also show that CCL2 is released across the apical and basolateral membranes of the choroidal epithelium, a pattern of chemokine secretion that promotes leukocyte migration across epithelial barriers. Immunohistochemical and electron microscopic analyses of choroidal tissue provide evidence for the movement of monocytes, sometimes in tandem with neutrophils, along the paracellular pathways between adjacent epithelial cells. These data further support the pathophysiological role of BCSFB in promoting the recruitment of inflammatory cells to the injured brain.

Participation of MCP-induced protein 1 in lipopolysaccharide preconditioning-induced ischemic stroke tolerance by regulating the expression of proinflammatory cytokines

Background

Lipopolysaccharide (LPS) preconditioning-induced neuroprotection is known to be related to suppression of the inflammatory response in the ischemic area. This study seeks to determine if monocyte chemotactic protein-induced protein 1 (MCPIP1), a recently identified CCCH Zn finger-containing protein, plays a role in focal brain ischemia and to elucidate the mechanisms of LPS-induced ischemic brain tolerance.

Methods

Transcription and expression of MCPIP1 gene was monitored by qRT-PCR and Western blot. Mouse microglia was prepared from cortices of C57BL/6 mouse brain and primary human microglia was acquired from Clonexpress, Inc. Wild type and MCPIP1 knockout mice were treated with LPS (0.2 mg/kg) 24 hours before brain ischemia induced by transient middle cerebral artery occlusion (MCAO). The infarct was measured by 2,3,5-triphenyltetrazolium chloride (TTC) staining.

Results

MCPIP1 protein and mRNA levels significantly increased in both mouse and human microglia and mouse brain undergoing LPS preconditioning. MCPIP1 mRNA level significantly increased in mice ipsilateral brain than that of contralateral side after MCAO. The mortality of MCPIP1 knockout mice was significantly higher than that of wild-type after MCAO. MCPIP1 deficiency caused significant increase in the infarct volume compared with wild type mice undergoing LPS preconditioning. MCPIP1 deficiency caused significant upregulation of proinflammatory cytokines in mouse brain. Furthermore, MCPIP1 deficiency increased c-Jun N terminal kinase (JNK) activation substantially. Inhibition of JNK signaling decreased the production of proinflammatory cytokines in MCPIP1 knock out mice after MCAO.

Conclusions

Our data indicate that absence of MCPIP1 exacerbates ischemic brain damage by upregulation of proinflammatory cytokines and that MCPIP1 participates in LPS-induced ischemic stroke tolerance.

Cytokines and neurodevelopmental outcomes in extremely low birth weight infants

OBJECTIVE

To determine if selected pro-inflammatory and anti-inflammatory cytokines and/or mediators of inflammation reported to be related to the development of cerebral palsy (CP) predict neurodevelopmental outcome in extremely low birth weight infants.

STUDY DESIGN

Infants with birth weights ≤1000 g (n = 1067) had blood samples collected at birth and on days 3 ± 1, 7 ± 1, 14 ± 3, and 21 ± 3 to examine the association between cytokines and neurodevelopmental outcomes. The analyses were focused on 5 cytokines (interleukin [IL] 1β; IL-8; tumor necrosis factor-α; regulated upon activation, normal T-cell expressed, and secreted (RANTES); and IL-2) reported to be most predictive of CP in term and late preterm infants.

RESULTS

IL-8 was higher on days 0-4 and subsequently in infants who developed CP compared with infants who did not develop CP in both unadjusted and adjusted analyses. Other cytokines (IL-12, IL-17, tumor necrosis factor-β, soluble IL rα, macrophage inflammatory protein 1β) were found to be altered on days 0-4 in infants who developed CP.

CONCLUSIONS

CP in former preterm infants may, in part, have a late perinatal and/or early neonatal inflammatory origin.

Vasopressin amplifies the production of proinflammatory mediators in traumatic brain injury

Arginine vasopressin (AVP) has previously been shown to promote disruption of the blood-brain barrier, exacerbate edema, and augment the loss of neural tissue in various forms and models of brain injury. However, the mechanisms underlying these AVP actions are not well understood. These mechanisms were studied in AVP-deficient Brattleboro rats (Avp(di/di)), and their parental Long-Evans strain, using a controlled cortical impact model of traumatic brain injury (TBI). The increased influx of inflammatory cells into the injured cortex in wild-type versus Avp(di/di) rats was associated with higher levels of cortical synthesis of the CXC and CC chemokines found in wild-type versus Avp(di/di) rats. These chemokines were predominantly produced by the cerebrovascular endothelium and astrocytes. In astrocyte and brain endothelial cell cultures, AVP acted synergistically with tumor necrosis factor-alpha (TNF-alpha) to increase the TNF-alpha-dependent production of CXC and CC chemokines. These AVP actions were mediated by c-Jun N-terminal kinase (JNK), as shown by Western blotting and pharmacological inhibition of JNK activity. The activity of JNK was increased in response to injury, and the differences in the magnitude of its post-traumatic activation between Avp(di/di) and wild-type rats were observed. These data demonstrate that AVP plays an important role in exacerbating the brain inflammatory response to injury.

The dual role of the neuroinflammatory response after ischemic stroke: modulatory effects of hypothermia

Neuroinflammation is a key element in the ischemic cascade after cerebral ischemia that results in cell damage and death in the subacute phase. However, anti-inflammatory drugs do not improve outcome in clinical settings suggesting that the neuroinflammatory response after an ischemic stroke is not entirely detrimental. This review describes the different key players in neuroinflammation and their possible detrimental and protective effects in stroke. Because of its inhibitory influence on several pathways of the ischemic cascade, hypothermia has been introduced as a promising neuroprotective strategy. This review also discusses the influence of hypothermia on the neuroinflammatory response. We conclude that hypothermia exerts both stimulating and inhibiting effects on different aspects of neuroinflammation and hypothesize that these effects are key to neuroprotection.

Shiga toxin 1-induced inflammatory response in lipopolysaccharide-sensitized astrocytes is mediated by endogenous tumor necrosis factor alpha

Hemolytic-uremic syndrome (HUS) is generally caused by Shiga toxin (Stx)-producing Escherichia coli. Endothelial dysfunction mediated by Stx is a central aspect in HUS development. However, inflammatory mediators such as bacterial lipopolysaccharide (LPS) and polymorphonuclear neutrophils (PMN) contribute to HUS pathophysiology by potentiating Stx effects. Acute renal failure is the main feature of HUS, but in severe cases, patients can develop neurological complications, which are usually associated with death. Although the mechanisms of neurological damage remain uncertain, alterations of the blood-brain barrier associated with brain endothelial injury is clear. Astrocytes (ASTs) are the most abundant inflammatory cells of the brain that modulate the normal function of brain endothelium and neurons. The aim of this study was to evaluate the effects of Stx type 1 (Stx1) alone or in combination with LPS in ASTs. Although Stx1 induced a weak inflammatory response, pretreatment with LPS sensitized ASTs to Stx1-mediated effects. Moreover, LPS increased the level of expression of the Stx receptor and its internalization. An early inflammatory response, characterized by the release of tumor necrosis factor alpha (TNF-alpha) and nitric oxide and PMN-chemoattractant activity, was induced by Stx1 in LPS-sensitized ASTs, whereas activation, evidenced by higher levels of glial fibrillary acid protein and cell death, was induced later. Furthermore, increased adhesion and PMN-mediated cytotoxicity were observed after Stx1 treatment in LPS-sensitized ASTs. These effects were dependent on NF-kappaB activation or AST-derived TNF-alpha. Our results suggest that TNF-alpha is a pivotal effector molecule that amplifies Stx1 effects on LPS-sensitized ASTs, contributing to brain inflammation and leading to endothelial and neuronal injury.

The role of the choroid plexus in neutrophil invasion after traumatic brain injury

Traumatic brain injury (TBI) frequently results in neuroinflammation, which includes the invasion of neutrophils. After TBI, neutrophils infiltrate the choroid plexus (CP), a site of the blood-cerebrospinal fluid (CSF) barrier (BCSFB), and accumulate in the CSF space near the injury, from where these inflammatory cells may migrate to brain parenchyma. We have hypothesized that the CP functions as an entry point for neutrophils to invade the injured brain. Using the controlled cortical impact model of TBI in rats and an in vitro model of the BCSFB, we show that the CP produces CXC chemokines, such as cytokine-induced neutrophil chemoattractant (CINC)-1 or CXCL1, CINC-2alpha or CXCL3, and CINC-3 or CXCL2. These chemokines are secreted both apically and basolaterally from the choroidal epithelium, a prerequisite for neutrophil migration across epithelial barriers. Consistent with these findings, we also provide electron microscopic evidence that neutrophils infiltrate the choroidal stroma and subsequently reach the intercellular space between choroidal epithelial cells. This is the first detailed analysis of the BCSFB function related to neutrophil trafficking. Our observations support the role of this barrier in posttraumatic neutrophil invasion.

Inflammatory profile of awake function-controlled craniotomy and craniotomy under general anesthesia

Background. Surgical stress triggers an inflammatory response and releases mediators into human plasma such as interleukins (ILs). Awake craniotomy and craniotomy performed under general anesthesia may be associated with different levels of stress. Our aim was to investigate whether those procedures cause different inflammatory responses. Methods. Twenty patients undergoing craniotomy under general anesthesia and 20 patients undergoing awake function-controlled craniotomy were included in this prospective, observational, two-armed study. Circulating levels of IL-6, IL-8, and IL-10 were determined pre-, peri-, and postoperatively in both patient groups. VAS scores for pain, anxiety, and stress were taken at four moments pre- and postoperatively to evaluate physical pain and mental duress. Results. Plasma IL-6 level significantly increased with time similarly in both groups. No significant plasma IL-8 and IL-10 change was observed in both experimental groups. The VAS pain score was significantly lower in the awake group compared to the anesthesia group at 12 hours postoperative. Postoperative anxiety and stress declined similarly in both groups. Conclusion. This study suggests that awake function-controlled craniotomy does not cause a significantly different inflammatory response than craniotomy performed under general anesthesia. It is also likely that function-controlled craniotomy does not cause a greater emotional challenge than tumor resection under general anesthesia.

Neuronal injury induces cytokine-induced neutrophil chemoattractant-1 (CINC-1) production in astrocytes

Accumulating evidence indicates a pivotal role for neuroinflammation in ischemic and excitotoxic brain injury. Cytokine-induced neutrophil chemoattractant-1 (CINC-1) is a CXC chemokine implicated in the infiltration of inflammatory cells into the brain parenchyma. In this study, we investigated the effect of N-methyl-D-aspartate (NMDA)-induced neuronal injury on CINC-1 production in the organotypic cortico-striatal slice cultures. Treatment with 50 microM NMDA for 3 - 4 h caused devastating neuronal damage and increased CINC-1 production. Immunohistochemical analysis revealed that the CINC-1 immunoreactivity was predominantly detected in astrocytes. NMDA failed to induce CINC-1 production in enriched astrocyte cultures or neuron-depleted slice cultures, suggesting that NMDA acted on neuronal cells to induce astrocytic CINC-1 production. NMDA-induced CINC-1 mRNA expression was significantly inhibited by U0126, a mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitor. These results suggest that NMDA-evoked neuronal injury induced astrocytic CINC-1 production via a MEK/ERK signaling pathway. Manipulation of this signaling pathway may serve as a target for suppressing neuroinflammation and, thereby, treating ischemic brain injury.

Sasim attenuates LPS-induced TNF-alpha production through the induction of HO-1 in THP-1 differentiated macrophage-like cells

AIM OF THE STUDY

Sasim, a traditional prescription composed of seven herbal mixtures, has been widely used as an oriental medicine for the treatment of cerebral infarction in Korea. However, the regulatory mechanisms by which the formula affects immune processing in cerebral infarction patients remain unknown.

MATERIALS AND METHODS

The levels of secretory protein of tumor necrosis factor (TNF)-alpha were determined in both THP-1 differentiated macrophage-like (THP-1/M) cells and Peripheral blood mononuclear cells (PBMCs) from cerebral infarction patients. Also, the levels of protein and mRNA of TNF-alpha and heme oxygenase-1 (HO-1) were detected in THP-1/M cells under our experimental condition.

RESULTS

Sasim markedly suppressed lipopolysaccharide (LPS)-induced TNF-alpha at the levels of secretory protein and mRNA in both PBMCs from cerebral infarction patients and THP-1/M cells. Interestingly, Sasim strongly induced HO-1, the rate-limiting enzyme of heme catabolism, at both the protein and mRNA levels in THP-1/M cells. Treatment with tin protoporphyrin IX (SnPP), an inhibitor of the catalytic activity of HO, significantly abolished the suppressive effect of Sasim on LPS-induced TNF-a production in THP-1/M cells.

CONCLUSIONS

These data indicate that Sasim may be beneficial in the cessation of inflammatory processes associated with cerebral infarction through the induction of HO-1 expression.

Can the immune system be harnessed to repair the CNS?

Experimental and clinical data have demonstrated that activating the immune system in the CNS can be destructive. However, other studies have shown that enhancing an immune response can be therapeutic, and several clinical trials have been initiated with the aim of boosting immune responses in the CNS of individuals with spinal cord injury, multiple sclerosis and Alzheimer's disease. Here, we evaluate the controversies in the field and discuss the remaining scientific challenges that are associated with enhancing immune function in the CNS to treat neurological diseases.

Alarm or curse? The pain of neuroinflammation

The nociceptive nervous system and the immune system serve to defend and alarm the host of imminent or actual damage. However, persistent or recurring exposure of neurons to activated immune cells is associated with an increase in painful behavior following experimental neuropathic injuries. Our understanding of the functional consequences of immune cell-neuron interaction is still incomplete. The purpose of this review is to focus on a seriously detrimental consequence of chronic activation of these two systems, by discussing the contributions of microglia and polymorphonuclear neutrophils to neuropathic pain following experimental spinal cord injury or peripheral nerve injury. Identification of molecules mediating pro-nociceptive signaling between immune cells and neurons, as well as the distinction between neuroprotective versus neuroexcitatory effects of activated immune cells, may be useful in the development of pharmacotherapy for the management of chronic pain and restoration of the beneficial alarm function of pain.

Mechanisms of ischemic brain damage

In the United States stroke is the third leading cause of death and the leading cause of disability. Brain injury following stroke results from the complex interplay of multiple pathways including excitotoxicity, acidotoxicity, ionic imbalance, peri-infarct depolarization, oxidative and nitrative stress, inflammation and apoptosis. There are very few treatments for stroke and the development of new treatments requires a comprehensive understanding of the diverse mechanisms of ischemic brain damage that are responsible for neuronal death. Here, we discuss the underlying pathophysiology of this devastating disease and reveal the intertwined pathways that are the target of therapeutic intervention.

Soluble epoxide hydrolase: regulation by estrogen and role in the inflammatory response to cerebral ischemia

The protection from ischemic brain injury enjoyed by females is linked to the female sex hormone 17beta-estradiol. We tested the hypothesis that neuroprotection by estradiol entails the prevention of ischemia-induced inflammatory response, through suppression of the P450 eicosanoids-metabolizing enzyme soluble epoxide hydrolase (sEH). Ovariectomized female rats with and without estradiol replacement underwent 2-hour middle cerebral artery occlusion (MCAO). SEH expression was determined using Western blot, and inflammatory cytokine mRNA levels were measured at 6, 24 and 48 hours after MCAO. Cytokine mRNA was also measured in sEH-knockout mice, and in rats treated with sEH inhibitors. Estradiol reduced basal and post-ischemic sEH expression. MCAO strongly induced mRNA levels of tumor necrosis factor-alpha, interleukin 6, and interleukin 1beta, which was attenuated in sEH-knockouts, but not by sEH inhibitors. Estradiol replacement exhibited a bimodal effect on cytokine mRNA, with increased early and reduced delayed expression. While estradiol suppresses cerebral sEH expression, and sEH suppression diminishes inflammation after MCAO, our findings suggest that the effect of estrogen on inflammation is complex, and only partially explained by sEH suppression.

Activated polymorphonuclear cells promote injury and excitability of dorsal root ganglia neurons

Therapies aimed at depleting or blocking the migration of polymorphonuclear leukocytes (PMN or neutrophils) are partially successful in the treatment of neuroinflammatory conditions and in attenuating pain following peripheral nerve injury or subcutaneous inflammation. However, the functional effects of PMN on peripheral sensory neurons such as dorsal root ganglia (DRG) neurons are largely unknown. We hypothesized that PMN are detrimental to neuronal viability in culture and increase neuronal activity and excitability. We demonstrate that isolated peripheral PMN are initially in a relatively resting state but undergo internal oxidative burst and activation by an unknown mechanism within 10 min of co-culture with dissociated DRG cells. Co-culture for 24 h decreases neuronal count at a threshold<0.4:1 PMN:DRG cell ratio and increases the number of injured and apoptotic neurons. Within 3 min of PMN addition, fluorometric calcium imaging reveals intracellular calcium transients in small size (<25 microm diam) and large size (>25 microm diam) neurons, as well as in capsaicin-sensitive neurons. Furthermore, small size isolectin B4-labeled neurons undergo hyperexcitability manifested as decreased current threshold and increased firing frequency. Although co-culture of PMN and DRG cells does not perfectly model neuroinflammatory conditions in vivo, these findings suggest that activated PMN can potentially aggravate neuronal injury and cause functional changes to peripheral sensory neurons. Distinguishing the beneficial from the detrimental effects of PMN on neurons may aid in the development of more effective drug therapies for neurological disorders involving neuroinflammation, including painful neuropathies.

Anti-inflammatory effect of So-Pung-Tang, a Korean traditional prescription for cerebral infarction patients

So-Pung-Tang (Sopung), a prescription composed of 14 herbal mixtures, has been widely used in the treatment of cerebral infarction in Oriental Medicine. However, the mechanisms by which the formula affects on the production of pro-inflammatory cytokines in cerebral infarction patients remain unknown yet. The levels of secretory protein of pro-inflammatory cytokines, including tumor necrosis factor (TNF)-alpha, interlukin (IL)-1beta, and IL-6, were significantly increased in both THP-1 differentiated macrophage-like cells (THP-1/M) and peripheral blood mononuclear cells (PBMCs) from cerebral infarction patients after stimulation. However, pretreatment with Sopung markedly inhibited the secretion of TNF-alpha and IL-6, but not IL-1beta, in lipopolysaccharide (LPS)-stimulated THP-1/M cells and PBMCs treated with LPS and phytohemagglutinin (PHA). Furthermore, Sopung significantly inhibited LPS-induced phosphorylation of extracellular signal-regulated kinase (ERK1/2) and c-jun N-terminal kinase (JNK), but not p38 in THP-1/M cells. These data indicate that Sopung may be beneficial in the cessation of inflammatory processes of cerebral infarction through suppression of ERK1/2 and JNK activation.

Production of monocyte chemoattractant protein-1 and cytokine-induced neutrophil chemoattractant-1 in rat brain is stimulated by intracerebroventricular administration of an endothelin ETB receptor agonist

The role of endothelin (ET)B receptors in chemokine production in the brain of rats was examined. Intracerebroventricular administration of 500 pmol/day of Ala(1,3,11,15)-ET-1, a selective ETB agonist, for 3 or 7 days increased monocyte chemoattractant protein (MCP)-1 and cytokine-induced neutrophil chemoattractant (CINC)-1 mRNA in the caudate-putamen and cerebrum, whereas it had no effects on regulated on activation normal T-cell expressed and secreted (RANTES), fractalkine and stromal cell-derived factor (SDF)-1alpha mRNA expression. Immunoreactive MCP-1 and CINC-1 in the caudate-putamen and the cerebrum were increased by the ETB agonist. Immunohistochemical observations on the Ala(1,3,11,15)-ET-1-infused rats showed that glial fibrillary acidic protein-positive astrocytes had immunoreactivity for MCP-1 and CINC-1. These findings indicate that the activation of brain ETB receptors causes the production of MCP-1 and CINC-1, and suggest a pathophysiological role for brain ETB receptors in nervous system damage.

Anti-inflammatory effect of oyaksungisan in peripheral blood mononuclear cells from cerebral infarction patients

Oyaksungisan, the herbal prescription composed of eleven herbs, has been widely used in treatment of cerebral infarct in Oriental Medicine. However, the mechanisms by which the herbal formula affects on the production of pro- and anti-inflammatory cytokines in cerebral infarction patients remain unknown yet. The secretory levels of pro-inflammatory cytokines, including tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6, and IL-10 were significantly increased in both LPS and PHA-stimulated peripheral blood mononuclear cells (PBMCs) from cerebral infarction patients. However, pretreatment with oyaksungisan significantly inhibited the secretion of pro- and anti-inflammatory in PBMCs. Also, oyaksungisan induced a significant increase of transforming growth factor (TGF)-beta1 in PBMCs. Thus, these data indicate that oyaksungisan may be beneficial in the cessation of inflammatory processes of cerebral infarct through suppression of TNF-alpha, IL-1beta, IL-6, and IL-10 and induction of TGF-beta1.

Neuroprotection (including hypothermia)

There have been over 2000 publications in the last year addressing the topic of neuroprotection. Novel and emerging therapeutic targets that have been explored include cerebral inflammation, hypothermia, neural transplantation and repair and gene therapy. Unfortunately, with few exceptions, the successes of experimental neuroprotection have not been translated into clinical practice. The possible reasons for the discrepancy between experimental success and clinical benefit are explored.

Anti-inflammatory effect of Sasim extracts in PHA-stimulated THP-1 and peripheral blood mononuclear cells from cerebral infarction patients

Sasim, a prescription composed of seven herbal mixtures, has been widely used for the treatment of cerebral infarction as an oriental medicine in Korea. However, the mechanisms by which the formula affects on the production of pro-inflammatory cytokines in cerebral infarct patients remain unknown yet. The levels of secretory protein and mRNA of pro-inflammatory cytokines, including tumor necrosis factor (TNF)-alpha, interlukin (IL)-1beta, and IL-6, were significantly increased in both THP-1 differentiated macrophage-like cells (T/M) and peripheral blood mononuclear cells (PBMCs) from cerebral infarct patients at 24h after stimulation with phytohemagglutinin (PHA) (p<0.05). However, pretreatment of Sasim strongly suppressed the secretion of pro-inflammatory cytokines in PHA-stimulated T/M cells and PBMCs. Moreover, Sasim significantly suppressed the transcriptional levels of pro-inflammatory cytokines in PHA-stimulated THP-1/M cells. These data indicate that Sasim may be beneficial in the cessation of inflammatory processes of cerebral infarction through suppression on the production of pro-inflammatory cytokines via inhibition of mRNA expression.

Plasma interleukin-8 as a potential predictor of mortality in adult patients with severe traumatic brain injury

Because of complex pathophysiology and severe consequences, traumatic brain injuries (TBI) are an important medical problem. Pathophysiology of TBI includes local and systemic stress response, in which interleukin-8 (IL-8) is considered as a key mediator of neuroinflammation. However, prognostic relevance of IL-8 measurement in adult patients with severe TBI is not certain. Therefore, IL-8 was determined in blood samples from central venous and jugular bulb catheter and in cerebrospinal fluid of twenty patients with isolated TBI at admission to Intensive Care Unit. None of the patients had history of stroke, dementia, autoimmune diseases, acute infection or medication with anti-inflammatory drugs. Ten patients died due to traumatic brain injury, while the other ten recovered well. While there was no significant difference of IL-8 levels in cerebrospinal fluid between survivors and nonsurvivors, central venous plasma level of IL-8 was significantly lower in survivors (71.00 +/- 14.17 pg/ml), than in nonsurvivors (111.26 +/- 16.9 pg/ml). Receiver Operating Characteristic (ROC) analysis revealed significant prognostic value for IL-8 in the blood as well as for the age of patients, Glasgow Coma Scale (GCS) and Acute Physiologic and Chronic Health Evaluation (APACHE II). These findings suggest that the central venous plasma values of IL-8 at admission might be an early predictive marker in patients with severe TBI, comparative to standard clinical prognostic markers such as APACHE II and GCS.

Absence of the chemokine receptor CCR2 protects against cerebral ischemia/reperfusion injury in mice

BACKGROUND AND PURPOSE

The chemokine, monocyte chemoattractant protein-1 (CCL2), is a major factor driving leukocyte infiltration into the brain parenchyma in a variety of neuropathologic conditions associated with inflammation, including stroke. In addition, recent studies indicate that CCL2 and its receptor (CCR2) could have an important role in regulating blood-brain barrier (BBB) permeability. This study evaluated the role of the CCL2/CCR2 axis in regulating postischemic inflammation, BBB breakdown, and vasogenic edema formation.

METHODS

CCR2(-/-) and CCR2(+/+) mice were subjected to focal transient cerebral ischemia. BBB permeability and brain edema formation were observed at days 1 and 5 of reperfusion by evaluating the product surface area for fluorescein isothiocyanate-albumin and measuring water and electrolyte contents. Immunohistochemistry was used to assess leukocyte infiltration. cDNA gene and protein arrays for inflammatory cytokines were used to assess inflammatory profiles in CCR2(+/+) and CCR2(-/-) mice.

RESULTS

CCR2(-/-) mice had reduced infarct sizes and significantly reduced BBB permeability and brain edema formation in the affected ischemic hemisphere compared with CCR2(+/+) mice. This reduction in injury was closely associated with reduced infiltration of not only monocytes but also neutrophils (7- and 4-fold decreases, respectively). In addition, CCR2(-/-) mice had reduced expression/production of inflammatory cytokines during reperfusion.

CONCLUSIONS

These data suggest that inhibiting the CCL2/CCR2 axis affects brain reperfusion outcome by reducing brain edema, leukocyte infiltration, and inflammatory mediator expression.

Brain Cytokines and Chemokines: Roles in Ischemic Injury and Pain

Cytokines and chemokines were originally identified as essential mediators for inflammatory and immune responses. Enhanced production and release of cytokines/chemokines are observed also in the central nervous system (CNS) under diverse pathological conditions. There is growing evidence showing that brain cytokines/chemokines play crucial roles in the neuro-glio-vascular interaction underlying the pathology of various brain disorders and therefore are potential targets for development of novel and effective therapeutics for CNS diseases. Here the evidence of the involvement of cytokines/chemokines in ischemic brain injury and pain is reviewed.

Inflammation following stroke

Stroke is one of the leading causes of mortality and morbidity. The stroke process triggers an inflammatory reaction that may last up to several months. Suppression of inflammation using a variety of drugs reduces infarct volume and improves clinical outcomes in animal models of stroke. This benefit occurs even with the initiation of therapy after 3 hours of onset of stroke, beyond the therapeutic window for thrombolysis with tPA. The use of neuroprotectants to suppress inflammation may widen the therapeutic time window for tPA while lessening its side-effects. Suppression of inflammation may also improve outcomes in animal models of haemorrhagic stroke. To date, clinical trials with anti-inflammatory agents in acute ischaemic stroke have failed to improve clinical outcomes. However, because of the potential for broader applicability across all aspects of stroke, a better understanding of anti-inflammatory mechanisms is important.

Basic fibroblast growth factor alleviates brain injury following global ischemia reperfusion in rabbits

The aim of this study was to explore the protective effect of basic fibroblast growth factor (bFGF) on brain injury following global ischemia reperfusion and its mechanisms. Brain injury following global ischemia was induced by four vessels occlusion and systemic hypotension. Twenty-four rabbits were randomized into three groups: group A, only dissection of vessels; group B, intravenous infusion of normal saline after reperfusion for 6 h; group C, 30 microg/kg bFGF injected intravenously at the onset of reperfusion, then infused with 10 microg/(kg.h) for 6 h. Serum neuron specific enolase (NSE), S-100B, tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), interleukin-8 (IL-8) were measured before ischemia, 30 min after ischemia, 0.5, 1, 3, 6 h after reperfusion. Brain water content was determined and cerebral histopathological damages were compared. NSE and S-100B were increased 1 h after reperfusion and reached their peaks 6 h after reperfusion, but were much higher in group B than those in group C 3, 6 h after reperfusion. In groups B and C, TNF-alpha was increased after ischemia and IL-1 and IL-8 were increased significantly 0.5 h after reperfusion, then reached their peaks 6 h, 3 h, 6 h after reperfusion respectively. TNF-alpha and IL-8 at the time points of 1 h and 3 h and IL-1 at 3 h and 6 h in group C were correspondingly lower than those in group B. These indices in group A were nearly unchanged. There were less severe cerebral histopathological damages in group C compared with group B, but no difference in brain water content. It could be concluded that bFGF alleviates brain injury following global ischemia and reperfusion by down-regulating expression of inflammatory factors and inhibiting their activities.

Interleukin 1beta and interleukin 6 relationship with paediatric head trauma severity and outcome

BACKGROUND

Based on the known inflammatory role of interleukins (IL), we evaluated IL-1beta and IL-6 expressions and their association with the severity of traumatic brain injury (TBI; Glasgow Coma Scale [GCS]) and the outcome (Glasgow Outcome Score [GOS]) recorded in a paediatric population.

DESIGN

The design was a perspective observational clinical study carried out in the paediatric intensive care unit of the University Hospital.

METHODS

We measured the IL-1beta and IL-6 levels in 14 children with severe TBI (patients) and in 12 children with obstructive hydrocephalus (control group). Cerebrospinal fluid (CSF) and plasma samples were collected 2 h (T1) and 24 h (T2) after TBI. Interleukins were assayed using the immunoenzymatic method.

RESULTS

The IL-1beta mean level was significantly lower than the IL-6 mean level both in the CSF and plasma of TBI children. In the CSF, the IL-1beta level increased from 55.71+/-72.79 pg/ml at T1 to 106.10+/-142.12 pg/ml at T2 and the IL-6 level increased from 405.43+/-280.28 pg/ml at T1 to 631.57+/-385.35 pg/ml at T2; a similar trend was observed in plasma. We found a statistically significant correlation between the increase in CSF and plasma interleukin levels between T1 and T2 and head injury severity (GCS<or=5) as well as poor outcome (GOS<or=3).

CONCLUSIONS

The increases in IL-1beta and IL-6 expression were correlated with head injury severity and were indicative of poor clinical outcome, reflecting an endogenous neuroinflammatory response after TBI.