CSF high-mobility group box 1 is associated with drug-resistance and symptomatic etiology in adult patients with epilepsy.

PURPOSE: Extracellular high-mobility group box 1 (HMGB1) is considered a proinflammatory mediator and is involved in various neurological disorders. This study aims to determine the expression profiles of HMGB1 in cerebrospinal fluid (CSF) and paired serum, and to explore whether there is a relationship between CSF HMGB1 concentrations with seizure parameters in adult patients with epilepsy. METHODS: CSF and paired serum HMGB1 concentrations were measured in patients with drug-refractory epilepsy (DRE, n = 27), newly diagnosed epilepsy (NDE, n = 56), and other non-inflammatory neurological disorders (ONNDs, n = 22). The correlations in HMGB1 levels between CSF and blood were performed. The associations between HMGB1 levels and seizure parameters were analyzed. RESULTS: Mean (± SD) CSF HMGB1 concentrations were 5.08 ± 3.06, 3.03 ± 2.25, 0.83 ± 0.77 ng/mL in patients with DRE, NDE, and ONNDs, respectively. Corresponding mean (± SD) serum concentrations were 4.53 ± 2.81, 2.32 ± 1.54, 1.56 ± 0.84 ng/mL. The CSF HMGB1 concentrations were significantly higher in the DRE and NDE groups compared with the ONNDs group (p < 0.001). There were no correlations in HMGB1 levels between CSF and serum in the DRE, NDE, and ONNDs groups. Furthermore, patients with symptomatic etiology showed significantly high levels of CSF HMGB1. Patients without remission expressed elevated levels of CSF HMGB1 at one-year follow-up. Additionally, the CSF HMGB1 levels were positively associated with seizure frequency. CONCLUSION: Our study shows that HMGB1 may be a critical player in seizure mechanisms and CSF HMGB1 might be predictive in determining epilepsy etiology and prognosis.

High mobility group box 1 and angiogenetic growth factor levels in children with central nerve system infections.

INTRODUCTION: To clarify the pathology of children with acute encephalopathy and other neurological disorders, the involvement of high-mobility group box 1 (HMGB1), which is a representative of danger-associated molecular patterns, and angiogenesis-related growth factors were investigated. PATIENTS AND METHODS: Participants were 12 children with acute encephalopathy (influenza, rotavirus, and others), 7 with bacterial meningitis, and 6 with epilepsy disease (West syndrome). Twenty-four patients with non-central nervous system (CNS) infections as a control group were admitted to our hospital. We examined the levels of HMGB1, platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and other cytokines in the serum and cerebrospinal fluid (CSF) of the subjects. RESULTS: Serum and CSF HMGB1 levels were significantly higher in the encephalopathy and meningitis groups than in the West syndrome and control groups. CSF HMGB1 levels correlated with those of interleukin-6 and -8. CSF HMGB1 and VEGF levels were correlated, and PDGF showed a positive relationship. CONCLUSION: HMGB1 and angiogenesis-related growth factors appear to play pivotal roles in the pathophysiology of CNS infections.

Targeting High Mobility Group Box 1 in Subarachnoid Hemorrhage: A Systematic Review.

Aneurysmal subarachnoid hemorrhage (aSAH) is a complex and potentially deadly disease. Neurosurgical clipping or endovascular coiling can successfully obliterate ruptured aneurysms in almost every case. However, despite successful interventions, the clinical outcomes of aSAH patients are often poor. The reasons for poor outcomes are numerous, including cerebral vasospasm (CVS), post-hemorrhagic hydrocephalus, systemic infections and delayed cerebral ischemia. Although CVS with subsequent cerebral ischemia is one of the main contributors to brain damage after aSAH, little is known about the underlying molecular mechanisms of brain damage. This review emphasizes the importance of pharmacological interventions targeting high mobility group box 1 (HMGB1)-mediated brain damage after subarachnoid hemorrhage (SAH) and CVS. We searched Pubmed, Ovid medline and Scopus for "subarachnoid hemorrhage" in combination with "HMGB1". Based on these criteria, a total of 31 articles were retrieved. After excluding duplicates and selecting the relevant references from the retrieved articles, eight publications were selected for the review of the pharmacological interventions targeting HMGB1 in SAH. Damaged central nervous system cells release damage-associated molecular pattern molecules (DAMPs) that are important for initiating, driving and sustaining the inflammatory response following an aSAH. The discussed evidence suggested that HMGB1, an important DAMP, contributes to brain damage during early brain injury and also to the development of CVS during the late phase. Different pharmacological interventions employing natural compounds with HMGB1-antagonizing activity, antibody targeting of HMGB1 or scavenging HMGB1 by soluble receptors for advanced glycation end products (sRAGE), have been shown to dampen the inflammation mediated brain damage and protect against CVS. The experimental data suggest that HMGB1 inhibition is a promising strategy to reduce aSAH-related brain damage and CVS. Clinical studies are needed to validate these findings that may lead to the development of potential treatment options that are much needed in aSAH.

YAP-dependent necrosis occurs in early stages of Alzheimer's disease and regulates mouse model pathology.

The timing and characteristics of neuronal death in Alzheimer's disease (AD) remain largely unknown. Here we examine AD mouse models with an original marker, myristoylated alanine-rich C-kinase substrate phosphorylated at serine 46 (pSer46-MARCKS), and reveal an increase of neuronal necrosis during pre-symptomatic phase and a subsequent decrease during symptomatic phase. Postmortem brains of mild cognitive impairment (MCI) rather than symptomatic AD patients reveal a remarkable increase of necrosis. In vivo imaging reveals instability of endoplasmic reticulum (ER) in mouse AD models and genome-edited human AD iPS cell-derived neurons. The level of nuclear Yes-associated protein (YAP) is remarkably decreased in such neurons under AD pathology due to the sequestration into cytoplasmic amyloid beta (Aß) aggregates, supporting the feature of YAP-dependent necrosis. Suppression of early-stage neuronal death by AAV-YAPdeltaC reduces the later-stage extracellular Aß burden and cognitive impairment, suggesting that preclinical/prodromal YAP-dependent neuronal necrosis represents a target for AD therapeutics.

Chloroquine pretreatment attenuates ischemia-reperfusion injury in the brain of ob/ob diabetic mice as well as wildtype mice.

Chloroquine, a prototype anti-malaria drug, has been reported to possess anti-inflammatory effects. Moreover, chloroquine pretreatment could improve DNA damage repair. It is therefore reasonable to hypothesize that chloroquine pretreatment could attenuate ischemia/reperfusion injury in the brain. Considering the fact that chloroquine could also improve glucose metabolism, we speculated that the potential effects of chloroquine on ischemia/reperfusion injury might be particularly pronounced in diabetic mice. In this study, chloroquine pretreatment protected neurons from Oxygen Glucose Deprivation (OGD) induced cytotoxicity and apoptosis. In vivo, Ob/ob mice and wildtype (WT) mice were pretreated with chloroquine for 3 weeks. Then, ischemic stroke was induced by 60 min Middle Cerebral Artery Occlusion (MCAO). We found that chloroquine pretreatment normalized blood glucose in diabetic ob/ob mice, and reduced cerebral damage after ischemic stroke especially for diabetic mice. In addition, chloroquine pretreatment reduced High-mobility group box 1 (HMGB1) content in the cerebrospinal fluid (CSF) and serum and lowered myeloperoxidase (MPO) activity and inflammatory cytokines gene expression both in the ob/ob diabetic mice and WT mice. Moreover, harmful DNA damage-signaling responses, including PARP activation and p53 activation, were also attenuated by chloroquine pretreatment in these two kinds of mice. In conclusion, chloroquine pretreatment could reduce cerebral damage after ischemic stroke especially in diabetic mice through multiple mechanisms, which include reducing neural cell DNA injury, restoring euglycemia and anti-inflammatory effects. The findings may provide potential for the development of chloroquine in the prevention and treatment of stroke in diabetic high-risk patients.

Relationship of High-mobility group box 1 levels and multiple sclerosis: A systematic review and meta-analysis.

BACKGROUND: Multiple sclerosis (MS) is a chronic inflammatory demyelinating disorder of the central nervous system (CNS) affecting more than 2.5 million people worldwide. However, the exact etiology of MS remains unknown, recent research indicated that High-mobility group box 1(HMGB1) might contribute to MS pathogenesis. By evaluating HMGB1 levels of peripheral blood mononuclear cells (PBMC), serum and cerebrospinal fluid (CSF) in multiple sclerosis (MS) patients and the controls, to reveal the relationship of HMGB1 levels and MS patients. METHODS: The PubMed, EMBASE, the Cochrane library, China National Knowledge Infrastructure (CNKI) and WanFangData were searched for relevant studies. Pooled standardized mean difference (SMD) and 95% confidence interval (CI) were calculated as effect size, random-effects model was used when I2 > 50%. Subgroup analysis was conducted by subtype of MS, categories of controls, country and mean age. RESULTS: A total of 7 studies with 364 patients of MS and 222 controls were included. The results of this study showed that HMGB1 protein levels of PBMC and CSF in patients with MS were significantly higher than those of controls (SMD = 4.36, 95% CI = 3.69-5.02, and SMD = 0.85, 95% CI = 0.42-1.28, respectively), but we found no significant difference in HMGB1 mRNA level of PBMC and serum HMGB1 protein level between MS patients and controls. In the subgroup analysis, RRMS patients had a higher HMGB1 level in serum (p < 0.05) and CSF (p < 0.01) compared to healthy controls and non-inflammatory neurological disorder controls. In Asians, MS patients had a considerably higher HMGB1 level in serum (p < 0.05), PBMC (protein) (p < 0.01) and CSF (p < 0.01) compared to healthy controls and non-inflammatory neurological disorder controls. CONCLUSION: MS patients had higher HMGB1 protein levels in PBMC and CSF compared to controls. HMGB1 might be a new treatment target for MS.

Fueling the FIRES: Hemophagocytic lymphohistiocytosis in febrile infection-related epilepsy syndrome.

OBJECTIVES: Although secondary hemophagocytic lymphohistiocytosis (HLH) has been reported in children with critical illness of various etiologies, it has not been reported in patients with febrile infection-related epilepsy syndrome (FIRES). We describe a series of patients with concurrent HLH and FIRES in an effort to establish common pathophysiologic abnormalities. METHODS: Five patients with FIRES who were assessed for HLH were identified from a neurocritical care database. All were previously healthy and had extensive diagnostic testing. All had clinical deterioration with multiorgan dysfunction prompting HLH screening 20-29 days after hospitalization. Markers for inflammatory dysregulation were assessed in cerebrospinal fluid (CSF) and serum at various time points. Outcomes were assessed 6 months after presentation. RESULTS: Three patients met clinical criteria for secondary HLH. Elevation of specific cytokines/chemokines was variable. CSF neopterin, high mobility group box 1 (HMGB1), and C-X-C motif chemokine ligand 8 (CXCL8) were significantly elevated in all. Interleukin-1ß (IL-1ß) and IL-18 were not elevated in any of the samples. Treatment and outcomes were variable. SIGNIFICANCE: We describe 3 patients with HLH and FIRES. The co-occurrence of these 2 rare disorders suggests the possibility of a common immune dysregulation phenotype prolonging epileptogenesis. HLH screening in critically ill patients with FIRES may yield a broader understanding of shared inflammatory processes.

Assessment of HMGB-1 concentration in tick-borne encephalitis and neuroborreliosis.

BACKGROUND: The aim of this study was to determine the concentration of HMGB-1 (high mobility group box 1) in the serum and cerebrospinal fluid (CSF) of patients suffering from tick-borne encephalitis (TBE) and neuroborreliosis (NB). Focus was placed on HMGB-1 measurement in the CSF or serum in order to establish whether this could help to differentiate between NB and TBE. METHODS: Eighty patients with meningitis and meningoencephalitis were enrolled in the study. The patients were divided into two groups: group I comprised patients with NB (n=40) and group II comprised patients with TBE (n=40). The diagnosis was made based on the clinical picture, CSF examination, and the presence of specific antibodies in the serum and CSF. The control group for the evaluation of the parameters in serum were healthy blood donors (n=25), while the control group for the evaluation of parameters in the CSF were patients in whom a central nervous system (CNS) inflammatory process was excluded. The concentrations of HMGB-1 were measured by ELISA method using a commercial kit (HMGB-1 ELISA Kit; EIAab, China). The results were analyzed using Statistica 10, Gretl, receiver operating characteristics curve (ROC), and the Pearson correlation coefficient. RESULTS AND CONCLUSIONS: HMGB-1 is associated with the development of inflammatory processes in the CNS caused by both tick-borne pathogens: viral (TBE) and bacterial (Lyme borreliosis). Measurement of the serum HMGB-1 concentration in the early stages of both diseases of the CNS may contribute to the differentiation between TBE and NB, which may have a clinical impact for patients bitten by ticks.

The HMGB1 is increased in CSF of patients with an Anti-NMDAR encephalitis.

BACKGROUND: Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disorder of the central nervous system (CNS). Interleukin (IL)-6 and IL-17A may play important roles in the pathogenesis of this disease. High-mobility group box protein 1 (HMGB1), a small but highly conserved ubiquitous protein, is recognized to be a potent innate inflammatory mediator that can activate the nuclear factor light chain enhancer of activated B cells and release cytokines such as IL-6 and IL-17A when released extracellularly. However, whether cerebrospinal fluid (CSF) HMGB1 levels are altered in anti-NMDAR encephalitis is still unclear. OBJECTIVE: The aim of this study was to determine whether a correlation exists between the CSF concentrations of HMGB1 and IL-6 and IL-17A in anti-NMDAR encephalitis patients. We also sought to assess whether HMGB1 influences the clinical outcomes in anti-NMDAR encephalitis patients. METHODS: Thirty-three patients with anti-NMDAR antibodies and 38 controls were recruited. CSF HMGB1 was measured using an enzyme-linked immunosorbent assay. The main clinical outcomes were evaluated using the modified Rankin scale (mRS). The data were extracted using microarray analysis software. RESULTS AND CONCLUSION: Our results showed significant increases in CSF HMGB1, IL-6, and IL-17A (P < .05) in anti-NMDAR encephalitis patients. But between 3 months' mRS scores in anti-NMDAR encephalitis patients and CSF data, there was no correlation. Our study suggests that HMGB1 CSF levels are increased in patients with anti-NMDAR encephalitis and reflect the underlying neuroinflammatory process.

Cerebrospinal fluid high mobility group box 1 is associated with neuronal death in subarachnoid hemorrhage.

We aim to determine the cerebrospinal fluid levels of high mobility group box 1 in subarachnoid hemorrhage patients and to investigate the involvement of the receptor for advanced glycation end products and high mobility group box 1 in the pathogenesis of post-subarachnoid hemorrhage neuronal death. The study included 40 patients (mean age, 59 ± 19 years) with Fisher's grade ≥ III aneurysmal subarachnoid hemorrhage. Cerebrospinal fluid was collected on the seventh day post-hemorrhage. Receptor for advanced glycation end products expression was examined in rat brain tissue following subarachnoid hemorrhage and in cultured neurons exposed to post-subarachnoid hemorrhage cerebrospinal fluid. Therapeutic effects of the recombinant soluble form of RAGE on subarachnoid hemorrhage models were also investigated. The results indicated that a higher level of cerebrospinal fluid high mobility group box 1 was independently associated with unfavorable outcome at three months post-subarachnoid hemorrhage (OR = 1.061, 95% CI: 1.005-1.121). Expression of RAGE increased in post-subarachnoid hemorrhage rat brain cells and in cultured neuron with stimulation of post-subarachnoid hemorrhage cerebrospinal fluid. Administration of recombinant soluble form of RAGE significantly reduced the number of positive TUNEL staining cells in subarachnoid hemorrhage rat and improved cell viability in post-subarachnoid hemorrhage cerebrospinal fluid-treated cultured neurons. Thus, the level of cerebrospinal fluid high mobility group box 1 can be a prognostic indicator for patients with Fisher's grade ≥ III aneurysmal subarachnoid hemorrhage and that treatment with soluble form of RAGE is a novel approach for subarachnoid hemorrhage.

A comparison of HMGB1 concentrations between cerebrospinal fluid and blood in patients with neurological disease.

AIMS: To determine whether a correlation exists between paired cerebrospinal fluid (CSF) and serum levels of a novel inflammatory biomarker, high-mobility group box 1 (HMGB1), in different neurological conditions. METHODS: HMGB1 was measured in the serum and CSF of 46 neurological patients (18 idiopathic intracranial hypertension [IIH], 18 neurological infection/inflammation [NII] and 10 Rasmussen's encephalitis [RE]). RESULTS: Mean serum (± SD) HMGB1 levels were 1.43 ± 0.54, 25.28 ± 27.9 and 1.89 ± 1.49 ng/ml for the patients with IIH, NII and RE, respectively. Corresponding mean (± SD) CSF levels were 0.35 ± 0.22, 4.48 ± 6.56 and 2.24 ± 2.35 ng/ml. Both CSF and serum HMGB1 was elevated in NII. Elevated CSF HMGB1 was demonstrated in RE. There was no direct correlation between CSF and serum levels of HMGB1. CONCLUSION: Serum HMGB1 cannot be used as a surrogate measure for CSF levels. CSF HMGB1 was elevated in NII and RE, its role as a prognostic/stratification biomarker needs further study.

HMGB1 Level in Cerebrospinal Fluid as a Marker of Treatment Outcome in Patients with Acute Hydrocephalus Following Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Attempts to clarify mechanisms of early brain injury in subarachnoid hemorrhage (SAH) revealed a high-mobility group box 1 (HMGB1) protein involvement in sterile inflammation initiated by aneurysm rupture. This study aims at assessing the prognostic value of HMGB1 in comparison with traditional biomarkers. METHODS: Ten patients with Fisher grade 4 SAH and acute hydrocephalus underwent endovascular coiling and ventriculostomy. HMGB1 level was measured in cerebrospinal fluid (CSF) samples collected on first, fifth, and 10th day. HMGB1 level in first sample was correlated with treatment outcome assessed in Glasgow outcome scale (GOS) at 3 months. Obtained results were compared with plasma inflammatory markers, clinical grading scales, and imaging grading scales. HMGB1 level in consecutive samples was analyzed in search of concentration trends correlating with patients' outcome. RESULTS: HMGB1 level in CSF of SAH patients, in contrast to control group, is significantly elevated (P < .001). Good (GOS > 3) and poor (GOS ≤ 3) outcome patients differ significantly in HMGB1 level on admission (P < .01). The strongest correlation to patients' outcome was found for Hunt and Hess scale (R = -.887, P < .01), HMGB1 level (R = -.859, P < .01), and World Federation of Neurological Surgeons scale (R = -.832, P < .01). Constant and high HMGB1 level of 10 ng/mL or more in consecutive CSF samples identifies nonsurvivors. CONCLUSIONS: HMGB1 protein is elevated in SAH patients. Changes in the concentration of HMGB1 in consecutive samples of the CSF correlate with outcome. Our results encourage further proteomic investigation.

Cerebrospinal fluid mitochondrial DNA: a novel DAMP in pediatric traumatic brain injury.

Danger-associated molecular patterns (DAMPs) are nuclear or cytoplasmic proteins that are released from the injured tissues and activate the innate immune system. Mitochondrial DNA (mtDNA) is a novel DAMP that is released into the extracellular milieu subsequent to cell death and injury. We hypothesized that cell death within the central nervous system in children with traumatic brain injury (TBI) would lead to the release of mtDNA into the cerebrospinal fluid (CSF) and has the potential to predict the outcome after trauma. Cerebrospinal fluid was collected from children with severe TBI who required intracranial pressure monitoring with Glasgow Coma Scale (GCS) scores of 8 or less via an externalized ventricular drain. Control CSF was obtained in children without TBI or meningoencephalitis who demonstrated no leukocytes in the diagnostic lumbar puncture. The median age for patients with TBI was 6.3 years, and 62% were male. The common mechanisms of injury included motor vehicle collision (35.8%), followed by falls (21.5%) and inflicted TBI (19%); six children (14.2%) died during their intensive care unit course. The mean CSF mtDNA concentration was 1.10E+05 ± 2.07E+05 and 1.63E+03 ± 1.80E+03 copies/µL in the pediatric TBI and control populations, respectively. Furthermore, the mean CSF mtDNA concentration in pediatric patients who later died or had severe disability was significantly higher than that of the survivors (1.63E+05 ± 2.77E+05 vs. 5.05E+04 ± 6.21E+04 copies/µL) (P < 0.0001). We found a significant correlation between CSF mtDNA and high mobility group box 1, another prototypical DAMP, concentrations (ρ = 0.574, P < 0.05), supporting the notion that both DAMPs are increased in the CSF after TBI. Our data suggest that CSF mtDNA is a novel DAMP in TBI and appears to be a useful biomarker that correlates with neurological outcome after TBI. Further inquiry into the components of mtDNA that modulate the innate immune response will be helpful in understanding the mechanism of local and systemic inflammation after TBI.

Decreased level of sRAGE in the cerebrospinal fluid of multiple sclerosis patients at clinical onset.

OBJECTIVES: Receptor for advanced glycation end products (RAGE) ligands/RAGE interactions have been proposed to have a pathogenic role in neuroinflammatory disorders. Our study aimed to assess changes in high-mobility group box (HMGB)1 and its receptor RAGE in peripheral blood (PBL) and cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) at the disease onset compared with control subjects. METHODS: PBL and CSF were collected from control subjects (n = 30) and MS patients (n = 27) at clinical onset. Soluble RAGE (sRAGE), HMGB1, S100 calcium-binding protein A12 (S100A12), interleukin (IL)-1ß and tumor necrosis factor (TNF)-α were measured in the CSF and plasma by enzyme-linked immunosorbent assay. Gene expression in PBL mononuclear cells (PBMCs) was detected by quantitative PCR for RAGE, HMGB1, S100A12 and several proinflammatory/immunoregulatory cytokines. RESULTS: We found a significantly lower expression of IL-10 (p = 0.031) in the PBMCs of MS patients. The level of sRAGE in the CSF of MS patients was lower (p = 0.021), with the ability to discriminate between MS patients and control subjects. Moreover, PBMC gene expression for HMGB1 and S100A12 positively correlated with IL-6. CONCLUSIONS: Our study confirmed that the cytokine network is disturbed in PBL and CSF at MS clinical onset. The deregulated HMGB1/RAGE axis found in our study may present an early pathogenic event in MS, proposing sRAGE as a possible novel therapeutic strategy for MS treatment.

High mobility group box 1 in patients with 2009 pandemic H1N1 influenza-associated encephalopathy.

BACKGROUND: Patients with 2009 pandemic H1N1 influenza-associated encephalopathy (pIE) have been reported in Japan. The most common clinical symptoms of this condition are seizures and progressive coma with high-grade fever. We previously highlighted the cytokine profile of pIE; our results suggest that proinflammatory cytokines play an important role in the pathogenesis. High mobility group box 1 (HMGB1) protein is a late mediator of inflammation or sepsis. However, there are few reports regarding the serum and cerebrospinal fluid (CSF) levels of HMGB1 in pIE patients. METHODS: We measured serum and CSF levels of HMGB1 in the following: pIE patients with poor outcomes, pIE patients without neurological sequelae, influenza patients without pIE, and control subjects. RESULTS: Serum HMGB1 levels were significantly higher in pIE patients with poor outcomes compared to those without neurological sequelae. In contrast, there was no difference in CSF HMGB1 levels among all groups. Regarding pIE patients, we found a significant positive correlation between HMGB1 levels and IL-6 in the serum but not in the CSF. CONCLUSIONS: Our results suggest that HMGB1 protein may be involved in the pathogenesis of pIE and that a high serum, but not CSF, level of inflammatory cytokines plays an important role in the severity of pIE.

Ethyl pyruvate inhibits HMGB1 phosphorylation and secretion in activated microglia and in the postischemic brain.

Ethyl pyruvate (EP) has been shown to have anti-inflammatory effects and confer protective effects in various pathological conditions. For example, EP inhibits secretion of high mobility group box 1 (HMGB1), which is known to be released from activated or dying cells and aggravate inflammatory pathways. In the present study, we investigated whether EP reduces HMGB1 phosphorylation and release in ischemic brain and in cultured microglia. In the postischemic brains (60 min middle cerebral artery occlusion (MCAO)), HMGB1 was released extracellularly, generating dual peaks in cerebrospinal fluid (CSF) around 1 and 7 days after ischemic insult, which were probably generated from damaged neurons and activated inflammatory cells, respectively. We showed that treatment with EP 30 min post-MCAO (5 mg/kg, i.v.), which has been shown to confer a robust neuroprotective effect in the postischemic brain, reduced both peaks. In addition, delayed EP treatment from 4 days post-MCAO reduced HMGB1 accumulation in CSF at 7 day post-MCAO in the absence of accompanying amelioration of ischemic brain damage, indicating that the suppression of HMGB1 release is a direct effect. We also found that EP markedly suppressed the LPS-induced nuclear translocations of protein kinase C alpha and calcium/calmodulin-dependent protein kinase IV, HMGB1 phosphorylation, and subsequent secretion of HMGB1 induced by LPS in BV2 cells and EP-mediated above-mentioned effects were also independent of cell death or survival. These results indicate that EP inhibits HMGB1 phosphorylation and release in activated microglia, which might be responsible for EP-mediated suppression of HMGB1 release in the postischemic brain.

Cerebrospinal fluid high-mobility group box protein 1 in neuromyelitis optica and multiple sclerosis.

BACKGROUND: Neuromyelitis optica (NMO) and multiple sclerosis (MS) are two autoimmune inflammatory demyelinating diseases in the central nervous system. Interleukin (IL)-6 and IL-17 may play important roles in the pathogenesis of these diseases. High-mobility group box protein 1 (HMGB1) can activate the nuclear factor light chain enhancer of activated B cells and release cytokines such as IL-6 and IL-17. However, whether cerebrospinal fluid (CSF) HMGB1 levels were altered in NMO and MS patients is still unclear. OBJECTIVES: It was our aim to measure the CSF HMGB1 concentration in NMO patients and explore their relationship with IL-6, IL-17 and disease activity. METHODS: CSF HMGB1 was measured by enzyme-linked immunosorbent assay in NMO (n = 22) and MS (n = 18) patients as well as in controls (n = 14). RESULTS: CSF HMGB1 was notably higher in the NMO group compared with controls (p = 0.007). CSF HMGB1 positively correlated with IL-6 and IL-17 in NMO patients (IL-6, p = 0.034; IL-17, p < 0.001). CONCLUSIONS: In conclusion, our study suggests that CSF levels of HMGB1 are increased in patients with NMO and reflect the neuroinflammatory process.

CSF high-mobility group box 1 is associated with intrathecal inflammation and astrocytic damage in neuromyelitis optica.

OBJECTIVE: High-mobility group box 1 (HMGB1) acts as a proinflammatory mediator when released by cells. Recent studies implicate extracellular HMGB1 in the pathogenesis of various autoimmune diseases. Our main aim of this study is to determine whether HMGB1 is involved in the neuromyelitis optica (NMO) inflammatory process. METHODS: Cerebrospinal fluid (CSF) and serum HMGB1 levels in 42 NMO patients were compared with those in 30 multiple sclerosis (MS) patients, and 30 patients with other noninflammatory neurological disorders (ONNDs). We also tested the possible correlation between CSF HMGB1 levels and the clinical and laboratory variables in NMO patients. RESULTS: CSF HMGB1 levels in NMO patients were higher than those in MS and ONNDs patients (p<0.001), and these levels in MS patients were higher than those in ONNDs patients (p<0.001). After treatment, the CSF HMGB1 levels in NMO patients decreased to normal. In addition, CSF HMGB1 levels correlated with CSF cell counts, CSF protein levels, CSF interleukin-6 levels, CSF glial fibrillary acidic protein levels, and CSF/serum albumin ratio (p≤0.001). Serum HMGB1 levels in MS patients were significantly higher than those in ONNDs patients (p=0.002). CONCLUSIONS: HMGB1 could play a key role in central nervous system inflammation in NMO patients.

Cerebrospinal fluid levels of high-mobility group box 1 and cytochrome C predict outcome after pediatric traumatic brain injury.

High-mobility group box 1 (HMGB1) is a ubiquitous nuclear protein that is passively released from damaged and necrotic cells, and actively released from immune cells. In contrast, cytochrome c is released from mitochondria in apoptotic cells, and is considered a reliable biomarker of apoptosis. Thus, HMGB1 and cytochrome c may in part reflect the degree of necrosis and apoptosis present after traumatic brain injury (TBI), where both are felt to contribute to cell death and neurological morbidity. Ventricular cerebrospinal fluid (CSF) was obtained from children admitted to the intensive care unit (ICU) after TBI (n=37). CSF levels of HMGB1 and cytochrome c were determined at four time intervals (0-24 h, 25-48 h, 49-72 h, and>72 h after injury) using enzyme-linked immunosorbent assay (ELISA). Lumbar CSF from children without TBI served as controls (n=12). CSF HMGB1 levels were: control=1.78±0.29, 0-24 h=5.73±1.45, 25-48 h=5.16±1.73, 49-72 h=4.13±0.75,>72 h=3.80±0.90 ng/mL (mean±SEM). Peak HMGB1 levels were inversely and independently associated with favorable Glasgow Outcome Scale (GOS) scores at 6 mo (0.49 [0.24-0.97]; OR [5-95% CI]). CSF cytochrome c levels were: control=0.37±0.10, 0-24 h=0.69±0.15, 25-48 h=0.82±0.48, 49-72 h=1.52±1.08,>72 h=1.38±1.02 ng/mL (mean±SEM). Peak cytochrome c levels were independently associated with abusive head trauma (AHT; 24.29 [1.77-334.03]) and inversely and independently associated with favorable GOS scores (0.42 [0.18-0.99]). In conclusion, increased CSF levels of HMGB1 and cytochrome c were associated with poor outcome after TBI in infants and children. These data are also consistent with the designation of HMGB1 as a "danger signal." Distinctly increased CSF cytochrome c levels in infants and children with AHT and poor outcome suggests that apoptosis may play an important role in this unique patient population.

Prediction of the neurological outcome with intrathecal high mobility group box 1 and S100B in cardiac arrest victims: a pilot study.

OBJECTIVES: To investigate whether high mobility group box 1 (HMGB1) and S100B in cerebrospinal fluid (CSF) and the serum predict the neurological outcome in patients resuscitated from out-of-hospital cardiac arrest (OHCA). MATERIALS AND METHODS: This study was designed as a prospective observational study. Twenty-five patients, who received standard cardiopulmonary resuscitation and post-resuscitation intensive care, were enrolled in this study. The patients were divided into two groups according to Glasgow-Pittsburgh Cerebral Performance categories (CPCs) at 6 months after return of spontaneous circulation (ROSC), Group G (n = 7, CPC 1 or 2) and Group P (n = 18, CPC ≥ 3). Their blood samples were taken at 6, 24, and 48h after ROSC. The patients, whose CSF was sampled at 48h, were also divided into either sub-Group G (n = 6) or sub-Group P (n = 8) at 6 months after ROSC. RESULTS: HMGB1 and S100B in CSF in sub-Group P were significantly higher than those in sub-Group G (HMGB1, <1.0 vs. 12.4 ng/ml, P = 0.009; S100B, 2.68 vs. 84.2 ng/ml, P = 0.007, respectively). HMGB1 in CSF was strongly correlated with S100B (σ = 0.81, P = 0.001). HMGB1 was elevated in serum at 6h and normalized within 48 h after ROSC without any significant differences between the two groups. Serum S100B in Group P was significantly higher than that in Group G at each time point. CONCLUSIONS: The significant elevations of HMGB1 and S100B in CSF, and S100B in serum are associated with the neurologically poor outcome in OHCA patients.