HMGB1 Concentration Research Articles

High mobility group box 1 protein (HMGB-1): A pathogenic role in preeclampsia?

We evaluated whether preeclampsia is associated with elevated circulating levels of High mobility group box 1 protein (HMGB-1), a nuclear protein with proinflammatory effects when released extracellularly. We enrolled 48 women, 32 in third trimester pregnancy (16 with, 16 without preeclampsia), and 16 healthy non pregnant. In the peripheral blood of pregnant women, HMGB-1 concentration was assessed serially, before and after delivery. With or without preeclampsia, third trimester pregnancy was associated with elevated levels of HMGB-1. This elevation is exaggerated in preeclampsia. The source of HMGB-1 observed in these conditions is likely to involve tissues other than the placenta itself.

Markers of endothelial dysfunction in patients with non-alcoholic fatty liver disease and coronary artery disease.

AbstractBackgroundNon‐alcoholic fatty liver disease (NAFLD) has been associated with coronary artery disease (CAD) and cardiac‐related mortality.AimTo assess the association between endothelial dysfunction markers (Endocan, high mobility group box 1 [HMGB1], and anti‐endothelial cell antibodies [AECAs]) and the risk of CAD in NAFLD.MethodsNinety‐one patients scheduled for coronary angiography for chest pain were included. Of these, 77 had NAFLD (85% with documented CAD). NAFLD was diagnosed after exclusion of other causes of liver diseases and by hepatic ultrasound and/or fatty liver index. Diagnosis and severity of CAD were established with coronary angiography. Endocan (ng/mL) and HMGB1 (ng/mL) concentrations were determined in the serum using enzyme‐linked immunosorbent assay technique. AECAs were quantified in sera using flow cytometry.ResultsNAFLD patients with CAD had higher serum endocan level as compared with NAFLD without CAD (P = 0.006). Furthermore, levels of endocan (odds ratio [OR] 38.66 [95% confidence interval {CI} 1.10–999.99]) and hyperlipidemia (OR 5.62 [95% CI 1.36–23.19]) were significantly associated with the risk of CAD and high serum high‐density lipoprotein cholesterol level (OR 0.92 [95% CI 0.87–0.97]) was protective against CAD. On the other hand, serum level of HMGB1 was significantly lower in NAFLD patients with CAD than NAFLD patients without CAD (P = 0.0003). Interestingly, in our NAFLD cohort, serum endocan levels positively correlated the severity of CAD (r = 0.27; P < 0.05), whereas HMGB1 levels negatively correlated with severity of CAD (r = −0.35; P < 0.05). The levels of AECA were not significantly associated with CAD in NAFLD.ConclusionMarkers of endothelial dysfunction in patients NAFLD patients may be associated with the risk for CAD.

Plasma levels of high mobility group box 1 increase in patients with posttraumatic stress disorder after severe blunt chest trauma: a prospective cohort study

BackgroundHigh-mobility group box 1 (HMGB1), a key late mediator of systemic inflammation, is a potentially useful biomarker for predicting outcome in patients with severe blunt chest trauma. The purpose of this study was to define the relationship between plasma levels of HMGB1 and posttraumatic stress disorder (PTSD) in patients with severe blunt chest trauma. MethodsAll patients with severe blunt chest trauma (abbreviated injury score ≥3) who were admitted to traumatic surgery department and ultimately survived to follow-up at 6 mo were eligible for the study. HMGB1 was sampled every other day from day 1–day 7 after admission, and plasma concentrations of HMGB1 were measured by a quantitative enzyme-linked immunosorbent assay test. Multivariate regression analysis was used to define the independent contribution of possible risk factors selected by univariate analysis. ResultsPTSD was identified in 43 patients including acute PTSD (n = 21), chronic PTSD (n = 18), and delayed-onset PTSD (n = 4) after 6-mo follow-up, in whom significant higher plasma levels of HMGB1 on days three, five, and seven after blunt chest trauma were noted compared with those seen in patients without PTSD (n = 10). Multivariate logistic analysis showed that transfusion, injury severity score, and HMGB1 levels at day 7 were the valuable risk factors for PTSD. ConclusionsIn blunt chest trauma, plasma HMGB1 levels were significantly higher in patients with PTSD compared with patients with non-PTSD. Our data indicate that patients with high plasma levels of HMGB1 may be more prone to develop PTSD including acute and chronic PTSD.

High mobility group box 1 in the inflammatory pathogenesis of epilepsy: profiling circulating levels after experimental and clinical seizures

BackgroundHigh mobility group box 1 (HMGB1) is a chromatin binding protein that is passively released by necrotic cells and actively secreted in response to inflammatory stimuli in a hyperacetylated form. HMGB1 is upregulated in the brain after injury and can regulate localised inflammatory reactions resulting in seizures. Antiepileptic drugs prevent seizures but have no disease modifying effect or influence on natural history. Immunomodulatory antiepileptic drugs have huge potential, but can have serious adverse effects. Patient stratification is required to maximise the benefit to risk ratio. We investigated serum and brain concentrations of HMGB1 in rodent models of seizures and epilepsy and in people with refractory epilepsy. MethodsWe used three experimental models in this study. Adult male C57BL/6J mice received repeated intraperitoneal injections of kainic acid (KA) until the onset of convulsive status epilepticus; status epilepticus was terminated after 2 h with diazepam, with brain and blood samples obtained at 3, 6, 24, and 72 h and 7 and 14 days thereafter. Tonic seizures were induced in adult male CF1 mice by maximal electroshock (MES) delivered via corneal electrodes, with brain and blood samples obtained at 1, 4, 8, 16, and 24 h after seizure induction. Finally, serial samples were obtained at baseline, 1, 4, 8, and 12 h after an observed seizure from people with drug refractory epilepsy undergoing videoelectroencephalograph telemetry. Total HMGB1 expression was measured by western blot and immunohistochemistry in brain and by ELISA in serum. Expression of individual HMGB1 isoforms was determined by liquid-chromatography tandem mass-spectrometry (LC-MS/MS). FindingsHMGB1 expression was significantly raised in hippocampus and cortex (p<0·001) at 24 h after KA-induced status epilepticus. Increased cytoplasmic HMGB1 staining was observed at 24 h and associated with an increase in the hyperacetylation of HMGB1 in the hippocampus. In the MES model, there was a significant increase in hippocampal (p<0·05) and cortical (p<0·05) HMGB1 expression at 24 h after a single tonic seizure. Serum concentrations of HMGB1 peaked 3 h after KA-induced status epilepticus (baseline mean 5·0 ng/mL [SD 0·6] vs 3 h 16·5 [1·5], p<0·0001) and 4 h after MES seizures (baseline 9·2 [2·5] vs 4 h 19·7 [11·3], p<0·05). 14 days after status epilepticus, serum HMGB1 remained significantly raised (18·0 [11·5], p<0·05) and the isoform was hyperacetylated. An analogous rise in the total HMGB1 serum concentration occurred after seizures in patients with epilepsy (baseline 7·1 [1·4] vs 4 h 15·2 [7·0], p<0·05). Mean serum HMGB1 was significantly higher in patients with drug refractory epilepsy than in healthy controls (8·6 ng/mL [3·5] vs 0·7 [0·3], p<0·002) and in patients with epilepsy who had been seizure free for more than 6 months (8·6 [3·5] vs 1·25 [0·71], p<0·0001). InterpretationThese findings suggest that blood and brain HMGB1 concentrations are increased as a result of seizures in both animal models and patients with epilepsy. Increases in HMGB1 might occur as a consequence of seizures. Patients with refractory epilepsy have higher baseline HMGB1, which might predispose them to recurrent seizure activity. The association between HMGB1 and seizures requires further exploration. FundingUK Medical Research Council, ICON, GlaxoSmithKline, AstraZeneca, the Medical Evaluation Unit.

Simultaneous changes in serum HMGB1 and IFN-α levels and in LAIR-1 expression on plasmatoid dendritic cells of patients with juvenile SLE.. New therapeutic options?

We investigated the simultaneous changes in serum levels of HMGB1 and IFN-α as well as in LAIR-1 expression on plasmatoid dendritic cells (pDCs) of juvenile systemic lupus erythematosus (jSLE) patients in order to explore their involvement in the disease pathogenesis and their correlation with disease activity and other characteristics. In total, 62 blood samples were studied from 26 jSLE patients (18 girls), aged 8-16 years. Twenty healthy subjects (16 girls) of comparable age were included as healthy controls (HCs). Concentrations of serum HMGB1 and IFN-α were assessed by ELISA and LAIR-1 expression on pDCs by five-color flow cytometry. The disease activity index was assessed by SLEDAI and ECLAM scores. It was found that mean serum levels both of HMGB1 and IFN-α were significantly increased in jSLE patients compared to HCs and in jSLE patients with active disease with or without active nephritis compared to those with inactive disease. Mean serum levels of HMGB1 were positively correlated with levels of IFN-α and both were positively correlated with the SLEDAI and ECLAM scores. The expression of LAIR -1 on pDCs of jSLE patients was significantly lower than that of HCs. In conclusion, our findings indicate that serum HMGB1 not only represents a potential marker of disease activity but together with the lack of LAIR-1 inhibitory function may contribute to the sustained inflammatory action of IFN-α in jSLE. In this regard, blocking the action of HMGB1 and its receptors or enhancing the expression/inhibitory function of LAIR-1 on pDCs should be included in future immune interventions for controlling jSLE.

Usefulness of high mobility group box 1 protein as a plasma biomarker in patient with peripheral artery disease.

Atherosclerosis is often associated with chronic vascular inflammation. High-mobility group box 1 protein (HMGB1) plays various roles, not only as a transcriptional regulatory factor in the nucleus, but also as an inflammatory mediator. A previous study suggested that fibrinogen is an important factor associated with atherosclerosis progression. The present study was performed to examine the levels of plasma HMGB1 protein in atherosclerosis patients. We studied 24 patients with peripheral artery disease (PAD) with atherosclerosis, and 10 healthy controls. We found that the concentrations of HMGB1 were increased in the plasma of the patients with atherosclerosis, and there were significant correlations between the plasma HMGB1 and fibrinogen levels. Plasma HMGB1 may play a key role in the pathogenesis of clinical and experimental atherosclerosis.

High plasma levels of high mobility group box 1 is associated with the risk of sepsis in severe blunt chest trauma patients: a prospective cohort study

BackgroundHigh mobility group box 1 (HMGB1) is a late mediator of systemic inflammation. Extracellular HMGB1 play a central pathogenic role in critical illness. The purpose of the study was to investigate the association between plasma HMGB1 concentrations and the risk of poor outcomes in patients with severe blunt chest trauma.MethodsThe plasma concentrations of HMGB1 in patients with severe blunt chest trauma (AIS ≥ 3) were measured by a quantitative enzyme-linked immunosorbent assay at four time points during seven days after admission, and the dynamic release patterns were monitored. The biomarker levels were compared between patients with sepsis and non-sepsis, and between patients with multiple organ dysfunction syndrome (MODS) and non-MODS. The related factors of prognosis were analyzed by using multivariate logistic regression analysis. The short-form 36 was used to evaluate the quality of life of patients at 12 months after injury.ResultsPlasma HMGB1 levels were significantly higher both in sepsis and MODS group on post-trauma day 3, 5, and 7 compared with the non-sepsis and non-MODS groups, respectively. Multivariate analysis showed that HMGB1 levels and ISS were independent risk factors for sepsis and MODS in patients with severe blunt chest trauma.ConclusionsPlasma HMGB1 levels were significantly elevated in patients with severe blunt chest trauma. HMGB1 levels were associated with the risk of poor outcome in patients with severe blunt chest trauma. Daily HMGB1 levels measurements is a potential useful tool in the early identification of post-trauma complications. Further studies are needed to determine whether HMGB1 intervention could prevent the development of sepsis and MODS in patients with severe blunt chest trauma.

Increased serum HMGB1 is related to oxidative stress in patients with atrial fibrillation

To investigate the relationship between the serum concentration of high mobility group box 1 protein (HMGB1) and oxidative stress in patients with atrial fibrillation (AF). Patients with AF (paroxysmal or persistent) and matched control subjects were recruited. Serum HMGB1 concentration and malondialdehyde (MDA) and superoxide dismutase (SOD) activity were determined. Serum hs-CRP and HMGB1 concentrations and MDA activity were significantly higher in patients with persistent AF (n = 33) or paroxysmal AF (n = 53) than in controls (n = 30). Serum SOD activity was significantly lower in both patient groups than in controls. In the patient group, HMGB1 concentration was significantly positively correlated with MDA activity (r = 0.535), and negatively correlated with SOD activity (r = -0.491). MDA, SOD, hs-CRP and HMGB1 were significant independent predictors of AF. Increased oxidative stress may contribute to increased HMGB1 concentrations in patients with AF. Inhibition of oxidative stress may provide a potential therapeutic strategy for AF.

Serum levels and roles of high mobility group box-1 protein in patients with acute suppurative cholangitis

Objective To observe the serum levels of high mobility group box-1 protein （ HMGBI ） in patients with acute cholangitis （AC） and to investigate contributions of HMGB1 in AC. Methods Serum HMGB1 concentrations were determined by an enzyme-linked immunosorbent assay in 30 patients with AC of severe type （ACST） and 42 patients with mild acute cholangitis at the time of admission （ within 72 h after the onset）. A total of 50 heahhy subjects were recruited as the control group. Fluorescent quantitative PCR （FQPCR） was used to detect the HMGB1 mRNA expression and the relationship between serum HMGB1 levels and clinical factors was analyzed. Results The serum HMGB1 levels in healthy control group, mild group and ACST group were （ 1.82 ± 0. 64） μg/L, （ 10. 46 ± 3.75 ）μg/L, （ 18. 89 ± 6. 86 ） μg/L, respectively. The mean value of serum HMGB1 level in mild group was significantly higher than that in control group, while significantly lower than that in ACST group （ P 〈 0. 05 ）. Compared to the control group, the HMGB1 mRNA level in patients of AC increased significantly and the level of ACST group was higher than that of mild group. The serum HMGB1 levels of patients with positive bile or/and blood cultures were higher than that of negative. After emergency endoscopic nasal biliary drainage, the serum HMGB1 levels of pa- tients significantly decreased compared to preoperational （P 〈 O. 05 ）. The HMGB1 levels were significantly positively correlated with white cell counts, C-reactive protein （CRP） , total serum bilirubin, direct bilirubin and alkaline phosphatase （ALP）. By logistic regression analysis, serum HMGB1 levels had correlation with severity of disease. Conclusion Serum HMGB1 levels significantly increased in patients with AC and the serum concentrations of ACST group were higher than those of mild group. Serum HMGB1 level has a correlation with sepsis. ENBD could lower its serum levels. Serum HMGB1 has predictive value to severity of disease. Key words: Cholangitis, Acute ; High mobility group proteins ; Drainage ; Forecasting

Caracterización de la expresión de nCD64 en neutrófilos y de los niveles de s-TREM-1 y HMGB-1 en pacientes con sospecha de infección admitidos en el departamento de emergencias

The nCD64 receptor, the soluble triggering receptor expressed in myeloid cells (s-TREM-1), and the high mobility group-box 1 protein (HMGB-1) have been proposed as significant mediators in sepsis. To evaluate the prognostic value of these markers in patients with suspected infection recently admitted in an emergency department (ED). All patients who presented to the ED with suspected infection were eligible for enrollment in this study. Baseline clinical data, Sequential Organ Failure Assessment score (SOFA) score, APACHE II score, HMGB-1 levels, s-TREM-1 levels, and nCD64 levels were analyzed. The HMGB-1 and sTREM-1 serum concentrations were determined using commercially available ELISA kits, and CD64 on the surface of neutrophils was measured by flow cytometry. . A total of 579 patients with suspected infection as their admission diagnosis were enrolled in this study. The median patient age was 50 years (IQR = 35-68). Morbidity during the 28-day followup period was 11.1% (n=64). The most frequent diagnosis at the time of admission was communityacquired pneumonia (CAP) in 23% (n=133) patients, followed by soft tissue infection in 16.6% (n=96), and urinary tract infection in 15% (n=87). After multivariable analysis, no significant association was identified between any biomarker and 28-day mortality. In the context of a tertiary care hospital emergency department in a Latin-American city, the nCD64 receptor, s-TREM-1, and HMGB-1 biomarkers do not demonstrate prognostic utility in the management of patients with infection. The search continues for more reliable prognostic markers in the early stages of infection.

Contributors to HMGB1 Release by Urothelial Carcinoma Cells in Response to Bacillus Calmette-Guérin

Our group previously noted that HMGB1 release by urothelial carcinoma cells occurs as a consequence of bacillus Calmette-Guérin induced nonapoptotic cell death. Additional studies demonstrated that HMGB1 release in response to bacillus Calmette-Guérin is required for the invivo tumor response to bacillus Calmette-Guérin. We evaluated the steps required for HMGB1 release by human urothelial carcinoma cells in response to bacillus Calmette-Guérin exposure. We used the T24 and 253J human urothelial carcinoma cell lines. HMGB1 concentrations in cell culture supernatant with and without bacillus Calmette-Guérin treatment served as the principal end point to assess the role of potentially involved variables. Specific techniques were used to determine the role of α5β1 antigen receptor cross-linking, TLR signaling, inducible nitric oxide synthase expression/nitric oxide production, p21 expression, and bacillus Calmette-Guérin adherence, internalization and viability. Cross-linking of α5β1 integrin or signaling through TLR2/4 did not contribute to HMGB1 release. Optimal HMGB1 release required bacillus Calmette-Guérin adherence and internalization. Bacillus Calmette-Guérin viability correlated with the magnitude of HMGB1 release. Inhibition of oxidative stress and p21 expression in response to bacillus Calmette-Guérin decreased the magnitude of HMGB1 release. Bacillus Calmette-Guérin induced nonapoptotic cell death and HMGB1 release occur as a consequence of a complex multistep process. Understanding the steps and mechanisms involved in the induced HMGB1 release would provide an opportunity for targeted strategies to improve bacillus Calmette-Guérin treatment efficacy.

Diagnostic value of serum concentrations of high‐mobility group‐box protein 1 and soluble hemoglobin scavenger receptor in brucellosis

Both cluster of differentiation (CD)4(+) and CD8(+) T lymphocytes play key roles in immunity to Brucella, in part because they secrete interferon (IFN)-γ and activate bactericidal functions in macrophages. Therefore, use of markers of macrophage activation may have diagnostic and prognostic significance. High-mobility group-box 1 protein (HMGB1), a late-onset pro-inflammatory cytokine, is secreted by activated macrophages. Soluble hemoglobin scavenger receptor (sCD163) is a specific marker of anti-inflammatory macrophages. The aim of this study was to investigate the diagnostic value of HMGB1 and sCD163 concentrations in brucellosis and its various clinical forms. Serum HMGB1 and sCD163 concentrations in 49 brucellosis patients were compared with those in 52 healthy control subjects. Both serum HMGB1 and sCD163 concentrations were significantly higher in brucellosis patients than in healthy controls (P < 0.001). There were no statistically significant differences in serum concentrations of HMGB1 and sCD163 between cases of acute, subacute and chronic brucellosis. Additionally, serum HMGB1 concentrations were positively correlated with sCD163 concentrations, whereas neither HMGB1 nor sCD163 concentrations were correlated with C-reactive protein concentrations, white cell counts or erythrocyte sedimentation rates. Therefore, serum concentrations of HMGB1 and sCD163 may be diagnostic markers for brucellosis, but neither can be used to differentiate the three different forms of this disease (acute, subacute and chronic).

Ursolic Acid Attenuates Lipopolysaccharide-Induced Acute Lung Injury in a Mouse Model

To assess whether ursolic acid (UA) can attenuate lipopolysachharide (LPS)-induced acute lung injury and improve the survival time in a mouse model. The mice were challenged with LPS and survival time was monitored from 0-96 h after LPS treatment. TNF-α, IL-6, IL-1β, HMGB1, nitric oxide (NO) and IL-10 concentration in serum were measured by ELISA. Myeloperoxidase activity, malondialdehyde, lung wet:dry weight ratio and lung permeability in lung tissues were detected. NF-κB, HMGB1 and inducible NO synthase in the lungs were detected by western blot. UA markedly rescued lethality, improved survival time and lung pathological changes, inhibited TNF-α, IL-6, IL-1β, HMGB1 and NO, and increased IL-10 expression. In addition, UA can also decrease myeloperoxidase, malondialdehyde, lung wet:dry weight ratio and lung permeability. UA attenuated NF-κB, HMGB1 and inducible NO synthase protein expression in the lungs. The results suggest that UA is capable of improving survival time and LPS-induced acute lung injury. UA has a potentially therapeutic role in septic shock.

Evaluation of High-Mobility Group Box 1 Protein Concentration in Serum of Patients with M. tuberculosis Infection

Infection with Mycobacterium tuberculosis is accompanied by an intense inflammatory response. Recently, a new mediator of inflammation, HMGB1 protein has been identified that contributes to acute lung injury. However, its role in the systemic inflammatory response in tuberculosis has not been thoroughly investigated. We investigated the systemic levels of HMGB1 and TNF-α in patients with active and latent lung tuberculosis as a prognostic marker of disease activity. The study was performed to 70 patients with confirmed Mycobacterium tuberculosis infection and other than tuberculosis lung diseases and in 20 healthy persons. Serum HMGB1 and TNF-α concentrations were measured by ELISA. The highest concentration of HMGB1 was detected in the bloodstream of people with Mtb infection (latent and active). Its concentration increased significantly in sera of patients with active tuberculosis (47.5 ng/ml), compared to patients with other lung diseases (36.87 ng/ml). TNF-α had significantly higher concentration in a patients group compared to healthy controls, with the highest concentration in the LTBI group of patients (0.136 ng/ml). We observed a strong positive correlation between TNF-α and HMGB1 concentrations in patients with tuberculosis infections. We conclude that HMGB1 is secreted during active and latent tuberculosis in the highest amounts compared to other lung diseases.

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Introduction: It is widely accepted that excess inflammatory cytokines play a pivotal role in severe sepsis and septic shock. Various blood purification techniques have proven to be effective at removing these cytokines. At SCCM 2012, we reported on the use of a polymethyl methacrylate (PMMA) membrane hemofilter for removal of high concentrations of IL-6 and HMGB1 in human waste plasma. The initial concentration of IL-6 in the plasma was 470,000 pg/ml, which was extremely high. At 6 hrs after the initiation, the IL-6 concentration had dramatically decreased to 11,000 and 6,600 pg/ml in continuous veno-venous hemodialysis (CVVHD) and continuous veno-venous hemofiltration (CVVH). These results indicated that a PMMA membrane hemofilter has very high adsorption properties. Therefore, we decided to study the differences between PMMA and polyarylonitrile (AN69ST) membranes; both membrane are considered which have high adsorption capacity. Hypothesis: To verify whether there is a difference in effect between PMMA and AN69ST membrane hemofilters. Methods: This study was conducted using human plasma (2,000 ml). Informed consent was obtained from the family. The plasma was divided into 2 parts, one for the PMMA (1,000 ml), the other for AN69ST (1,000 ml). This study was conducted using the following operating conditions: plasma flow rate (QP), 80 ml/min; replacement flow rate (QR), 400 ml/hr; filtration rate (QF), 400 ml/hr; body fluid removal rate, 0 ml/hr. The plasma samples from the inlet side of the hemofilter and the sample of filtrated solution was collected at the start and after 0.5, 1, 3, 6, 12, 18, 24, 30, 36, 48 hours. Parameters including original concentration, clearance of plasma (CLp), sieving coefficient (SC), trans-membrane pressure (TMP) of IL-6 and HMGB1 were assessed. Results: At 0, 0.5, 1, 6 h, in PMMA and AN69ST, the IL-6 was 2,600/2,600, 1,600/1,900, 1,200/1,500, 320/600 pg/ml, respectively. At 0, 0.5, 1, 6 h, in PMMA and AN69ST, the HMGB1 was 530/530, 280/68, 180/18, 14/7 ng/ml, respectively. Conclusions: IL-6 concentration was quickly reduced by use of the PMMA hemofilter, whereas HMGB1 concentration went down with use of the AN69ST hemofilter. These two membranes therefore have different adsorption characteristics, suggesting the possibility of membrane selection specific to the disease.

Severe Stroke Induces Long-Lasting Alterations of High-Mobility Group Box 1

The signals that initiate the poststroke inflammatory response are unknown. High-mobility group box (HMGB) 1 protein is a nuclear protein that is passively released from necrotic tissue and is able to activate leukocytes, which in turn secrete HMGB1. HMGB1 is also able to activate antigen-presenting cells and therefore stands at the crossroads of innate and adaptive immunity. Plasma HMGB1 concentrations were determined at multiple time points after ischemic stroke (N=110) and correlated to stroke severity and biomarkers of inflammation. The relationships between HMGB1, stroke outcome, and autoimmune responses to brain antigens were also assessed. Stroke resulted in an increase in HMGB1 that persisted for 30 days. Plasma HMGB1 was correlated with the number of circulating leukocytes but was not predictive of either stroke outcome or the development of autoimmune responses to brain antigens. Patients with a Th1(+) response to myelin basic protein at 90 days after stroke, however, had higher plasma HMGB1. HMGB1 appears to be involved in the postischemic inflammatory response, but it remains unclear whether HMGB1 initiates this response or merely reflects activation of leukocytes by another signal.

Immunological effect of high mobility group box-1 protein on regulatory dendritic cells and corresponding mechanism

Objective To observe the effects of high mobility group box-1 protein ( HMGB1 ) on function of murine spleen IL-10-producing dendritic cells (DCs) subset CD11clowCD45RBhighDCs.Methods Splenic CD11clowCD45RBhighDCs and CD4 +T cells in Balb/c mice were purified by magnetic beads sorting.CD11clowCD45RBhighDCs were treated with various doses of HMGB1 (0,20,100,500ng/ml).Flow cytometry was used to determine expressions of CD11clowCD45RBhighDC surface molecules including CD40,CD80,CD86,Ⅰ-a/e and Toll-like receptor (TLR) 4.IL-10 level in CD11clow CD45RBhighDC culture supernatants was determined by ELISA method.The CD4+ T cells were divided into four groups: control group (without only treatment),untreated group (HMGB1-untreated CD11clow CD45RBhigh DCs plus CD4+T cells),high-dose HMGB1-treated group (500 ng/ml HMGB1-treated CD11clowCD45RBhigh DCs plus CD4 +T cells),high-dose HMGB1-treated + antibody 1 group (500 ng/ml HMGB1-treated CD11clowCD45RBhigh DCs plus IL-10 antibody and CD4+T cells),high-dose HMGB1-treated + antibody 2 group (500 ng/ml HMGB1-treated CD11clow CD45RBhigh DCs plus homotype IL-10 antibody and CD4 +T cells).IL-4 as well as interferon( IFN-γ) contents in CD4 + T cell culture supernatants were determined by flow cytometry.Results HMGB1 could markedly enhance the expressions of CD40,CD86 and TLR4 on CD11clowCD45RBhigh DC surface as well as level of IL-10 secreted by CD11clow CD45RBhigh DCs as compared with the non-HMGB1 treatment.Meantime,the secretion of IL-10 was HMGB1 concentration dependent.IFN-γ level in high-dose HMGB1-treated group was (279 ± 17) pg/ml,which was markedly lower than that in the untreated group [ (963 ± 11 ) pg/ml,P ＜ 0.05 ].IL-4 level in high-dose HMGB1-treated group was (372 ± 14) pg/ml,which was significantly higher than that in the untreated group [ (213 ± 10) pg/ml,P ＜0.05) \].Conclusions HMGB1 promotes IL-10 production in CD11clowCD45RBhighDCs,induces the differentiation of CD4 +T cells to Th2 cells and downregulates the immune response via activating CD11clowCD45RBhigh DCs. Key words: High mobility group proteins; T-lymphocytes, regulatory; Immunity

4. Stressful life events during pregnancy might modulate local inflammation during delivery

Cervical ripening is mediated by inflammatory cytokines. Stress could facilitate pro-inflammatory pathways. In this pilot study we explored possible associations between experience of stressful life events during pregnancy and levels of inflammatory cytokines in the cervix at delivery occurring preterm or term. Cervical biopsies were taken from five women with preterm birth and seven women with term birth. Protein concentrations of HMGB1, IL-4, IL-10 and IL-12 were determined using ELISA. After the birth, women filled out the Stressful Life Event Scale modified with specific questions on experiences during pregnancy. Events included e.g. divorce, close relative’s disease and unemployment. Two women in each group reported no stressful life events during pregnancy, while the others had experienced 1–3 events. Stressful events were negatively correlated with levels of HMGB1, ρ = −.769, p = .003 and IL-10, ρ = −.609, p = .035. No associations were found between stressful events and IL-4 and IL-12. This pilot study indicates an impact of antenatal stress on local inflammatory processes during delivery. Lower levels of HMGB1 after stress might be due to a release of HMGB1 from the nuclei to the cytoplasm and later to systemic circulation, a phenomenon seen in sepsis. Both IL-10 and HMGB1 are suggested to be associated with regulatory T cell activity that also is important for pregnancy maintenance. Further studies are needed to confirm the possible importance of these findings.

Plasma high-mobility group box 1 levels and prediction of outcome in patients with traumatic brain injury

BackgroundHigh-mobility group box 1 (HMGB1), a marker of inflammation, has been associated with poor outcome of critical illness. The present study was undertaken to investigate the plasma HMGB1 concentrations in patients with traumatic brain injury (TBI) and to analyze the correlation of HMGB1 with TBI outcome. MethodsWe performed an observational, clinical study. Plasma HMGB1 concentration of 106 healthy subjects and 106 patients with severe TBI was measured by ELISA. The correlation with 1-y mortality and unfavorable outcome (Glasgow Outcome Scale score of 1–3) was analyzed. ResultsThirty-one patients (29.2%) died and 48 patients (45.3%) had an unfavorable outcome at 1y after TBI. Plasma HMGB1 level was substantially higher in patients than in healthy controls. A multivariate analysis selected plasma HMGB1 level as an independent predictor for 1-y mortality and unfavorable outcome of patients. A receiver operating characteristic curve analysis showed plasma HMGB1 level statistically significantly predicted 1-y mortality and unfavorable outcome. The prognostic value of HMGB1 was similar to that of Glasgow Coma Scale score for 1-y clinical outcomes. ConclusionsPlasma HMGB1 concentration emerges as a novel biomarker for predicting 1-y clinical outcomes of TBI.

PP125. High mobility group box 1 protein (HMGB1): A pathogenic role in preeclampsia?

A central pathogenic mechanism of preeclampsia is believed to be the production by the hypoxic placenta of various mediators which promote inflammation and oxidative stress when released into the maternal circulation. The high mobility group box 1 protein (HMGB1) is a ubiquitous nuclear protein. In conditions of hypoxic cellular stress or necrosis, HMGB1 is released into the extracellular milieu. Extracellular HMGB1 has proinflammatory effects, due to the engagement of various cell membrane receptors, notably the receptor for advanced glycation products (RAGE). In preeclampsia, there is evidence for activation of RAGE, and enhanced amounts of HMGB1 have also been demonstrated in the placenta and amniotic fluid, but not, so far, in maternal blood. We hypothesize therefore that, in preeclampsia, the concentration of HMGB1 is abnormally high in maternal blood. We enrolled 16 women in third trimester pregnancy and suffering from preeclampsia (blood pressure > 140/90mmHg with significant proteinuria), 16 women with normal pregnancies who were matched pairwise with the former for BMI and gestation week, and 16 non pregnant healthy women, matched for age with the other two groups. HMGB1 was assessed in peripheral blood with a commercial ELISA kit. The variance between the three groups was appreciated using an ANOVA analysis. Significance was considered for a probability value of < 0.5. The median [interquartile range] HMGB1 concentrations (in ng/mL) were 2.1 [1.1-3.2] in preeclamptic pregnancies, 1.1 [1.0-1.2] in normal pregnancies (p<0.05 vs preeclamptic group), and 0.6 [0.5-0.8] in non pregnant women (p<0.01 vs both other groups). In third trimester pregnancy, the presence of preeclampsia is associated with an approximately two-fold increase of HMGB1 concentration in maternal peripheral blood. Considering its known proinflammatory effects, HMGB1 could be one mediator responsible for the maternal manifestations of preeclampsia.