Plasma Histone Research Articles

Elevated Plasma Histone H4 Levels Are an Important Risk Factor in the Development of Septic Cardiomyopathy

Background:Myocardial impairment is a major complication and an important prognostic predictor of sepsis. Therefore, early and accurate diagnosis as well as timely management of septic cardiomyopathy is critical to achieve favorable outcomes.Aims:To investigate the risk factors of septic cardiomyopathy.Study Design:Cross-sectional study.Methods:This study performed between May 2016 and June 2018 recruited 93 septic patients from the intensive care unit. All patients received standardized treatments. Septic patients were divided into two groups: non cardiomyopathy (n=45) and septic cardiomyopathy group (n=48). Blood samples were collected and transthoracic echocardiography was performed within 24 hours of intensive care unit admission. Septic patients with one ultrasound abnormality but no history of heart disease were diagnosed as having septic cardiomyopathy. Plasma histones, cardiac troponin I, and N-terminal pro-brain natriuretic peptide were measured using ELISA. Sequential Organ Failure Assessment scores, vasopressor use, and the outcomes of intensive care unit stay were analyzed. Spearman rank analysis was used to determine the correlation between plasma histone H4 and other parameters. Binary logistic regression and receiver operating characteristic curve analysis were used to determine the risk factors for septic cardiomyopathy.Results:Compared with the non-cardiomyopathy group, the septic cardiomyopathy group had significantly higher plasma H4 and cardiac troponin I levels, a higher Sequential Organ Failure Assessment score, more frequent vasopressor use, and a higher mortality rate (p<0.05). Plasma histone H4 levels positively correlated with cardiac troponin I (r=0.577, p<0.001), N-terminal pro-brain natriuretic peptide (r=0.349, p=0.001), and Sequential Organ Failure Assessment scores (r=0.469, p<0.001). Binary logistic regression and receiver operating characteristic curve analyses revealed that elevated plasma histone H4 levels and vasopressor use were important risk factors for septic cardiomyopathy (p<0.05).Conclusion:Elevated plasma histone H4 levels could be used to predict septic cardiomyopathy in patients with sepsis.

Activation of lung endothelial cells by extracellular histone in mice with acute respiratory distress syndrome

Objective: To observe the changes of extracellular histones and pulmonary microvascular endothelial cells, and study the activating role of extracellular histones to pulmonary microvascular endothelial cells in the pathogenesis of acute respiratory distress syndrome (ARDS) . Methods: The correlation of the severity of acute lung injury with extracellular histones and pulmonary endothelial damage was studied through mice model, and acute lung injury was produced by aspiration of different concentrations of hydrochloric acid (0.01、0.1、0.3 and 0.5 mol/L, 2 ml/kg). Tumor necrosis factor-α (TNF-α), soluble thrombomodulin (sTM) and lung pathological change were measured. The pro-inflammatory role of extracellular histones was tested by injecting calf thymus histones (CTH) or specific anti-H4 antibody through tail vein. The direct activating role of extracellular histones to pulmonary microvascular endothelial cells was studied through pulmonary endothelial model. Results: The extracellular histones in plasma were increased obviously 6h after aspiration of different concentrations of hydrochloric acid in mice. A positive correlation was seen between extracellular histones and concentrations of aspirated hydrochloric acid (r=0.9180, P<0.05). The sTM in plasma also showed a positive correlation with concentrations of aspirated hydrochloric acid (r=0.8701, P<0.05). Merely administering CTH could not only increase TNF-α and sTM in plasma but also cause obvious lung injury, while specific anti-H4 antibody could relieve the inflammation and lung damage caused by CTH. Extracellular histones could directly damage pulmonary endothelial cells to release sTM in pulmonary endothelial model in vitro, while anti-H4 antibody could protect the endothelial cells. Conclusion: Extracellular histones are the key endogenic inflammatory mediators during the pathogenesis of ARDS caused by aspiration of hydrochloric acid, which could promote inflammation by directly activating pulmonary endothelial cells.

Newborn histone modifications and gestational exposure to particulate matter air pollution

OPS 48: Air pollution and epigenetics, Room 417, Floor 4, August 26, 2019, 4:30 PM - 5:30 PM Background: Exposure to particulate air pollution has been linked with risk of disease in later life. Changes in DNA histone modifications might have long-term adverse health effects. We aimed to investigate the association between prenatal exposure to air pollution and levels of total histone H3 and specific trimethylation marks in cord blood. Methods: We measured cord plasma total histone H3, H3k4me3 and H3K36me3 in 614 samples from the ENVironmental Influence ON early AGEing (ENVIRONAGE) birth cohort. We used a high-resolution air pollution model to estimate exposure to particulate matter with a diameter less than 2·5 μm (PM2·5) and black carbon (BC), and NO2 over the different trimesters of pregnancy and the entire pregnancy on the basis of maternal address. The association between prenatal air pollution exposure and specific methylation marks was analysed with a linear regression model, while accounting for covariates and potential confounders. Findings: PM2.5 exposure averaged (SD) 13.4 µg/m3 (2.6) for the duration of pregnancy, black carbon exposure 1.29 µg/m3 (0.31) and NO2 exposure 17.98 µg/m3 (4.57). H3K4me3 was positively associated with gestational PM2.5 exposure, a 24.1% (p=0.0007) was observed for each 5 µg/m3 increase in PM2.5 exposure. Cord blood H3K36me3 levels were inversely associated with entire pregnancy exposure with an 18.3% (p= 0.03) decrease in association with a 5 µg/m3 increment in PM2.5 exposure. For the entire pregnancy a 14.7% (p<0.001) increase in total histone H3 levels was associated with a 5 µg/m3 increment in exposure. Results for other exposures were similar. In conclusion, exposure to particulate air pollution during pregnancy is significantly associated with levels of cord plasma histone H3 modifications at birth. Particulate air pollution induced changes in cord plasma histone H3 modifications during early life and might be a risk factor in the development of air-pollution related disease, later in life.

Tissue damage in the heart after cardiac arrest induced by asphyxia and hemorrhage in newborn pigs.

Asphyxia of newborns is a severe and frequent challenge of the peri- and postnatal period. Forty-four neonatal piglets underwent asphyxia and hemorrhage (AH), followed by resuscitation with blood or crystalloid transfusion. In this study, 15 piglets (blood n = 9, NaCl n = 6, mean age 31 h) were randomly chosen. Four hours after return of spontaneous circulation, heart tissue and blood were collected. Analyses of heart fatty acid binding protein (HFABP), cardiac troponin I (TnI) levels, and activation of the complement system were performed. Histological staining for connexin 43 (Cx43) and complement C5a receptor 1 (C5aR1) was performed. Following AH, systemic elevation of cardiac TnI and HFABP revealed cardiac damage in both groups. Systemic activation of the complement system and the appearance of extracellular histones in plasma of the blood transfusion group were observed. The Cx43 was translocated from the intercalated discs to the cytosol after AH. Cardiac glycogen concentration was reduced in both groups. A significant reduction of C5aR1 in the left ventricle and a significant elevation of the heart injury score were investigated after blood transfusion. AH leads to alteration of the heart, particularly in Cx43 and glycogen reserves, as well as local inflammation.

Prediction value of plasma histone in prognosis of sepsis patients

To explore the value of plasma histones in predicting the prognosis of sepsis patients. The patients with sepsis admitted to intensive care unit (ICU) of Subei People's Hospital of Jiangsu Province Affiliated to Yangzhou University from May 2016 to June 2018 were enrolled as the research subjects, and healthy volunteers were selected as healthy control at the same period. The plasma levels of histones, cardiac troponin I (cTnI), N-terminal pro-brain natriuretic peptide (NT-proBNP), sequential organ failure assessment (SOFA) score, lactate (Lac), procalcitonin (PCT) on admission 24 hours, and use of vasoconstrictor agents, the length of ICU stay and ICU mortality were recorded. The patients were divided into survival group and death group according to the prognosis, and the differences of each index between the two groups were compared. Multivariate binary Logistic regression analysis was carried out to identify the independent risk factors of death. The correlation between histone and the levels of cTnI, NT-proBNP, PCT and Lac was analyzed. The value of plasma histone, cTnI, NT-proBNP, PCT and Lac in predicting the prognosis of patients was analyzed by receiver operating characteristic (ROC) curve. According to the threshold value of histone in predicting prognosis, the patients were divided into two groups, and the differences of various indicators between the two groups were compared. (1) A total of 93 sepsis patients were included, with 29 cases of ICU death, and the mortality was 31.2%. (2) Compared with the healthy control group, histones, cTnI, NT-proBNP were significant increased, besides, histones, cTnI in the death group were further increased compared with the survival group; in addition, SOFA, proportion of vasoconstrictor use were also significant higher than those in the survival group [histones (mg/L): 0.33 (0.28,0.45) vs. 0.22 (0.17,0.29), cTnI (μg/L): 0.25±0.13 vs. 0.20±0.08, SOFA: 11 (8, 12) vs. 9 (8, 11), the rate of vasopressor use: 93.1% (27/29) vs. 68.8% (44/64), all P < 0.05]. Statistically significant indicators between the two groups were included in multivariate binary Logistic regression analysis. The result showed that the independent risk factors affecting the prognosis of patients were the rate of vasopressor use [odds ratio (OR) = 5.277, P = 0.043] and the level of histone (OR = 79.244, P = 0.036). (3) The plasma histone level were positively correlated with cTnI (r = 0.577, P = 0.000), SOFA (r = 0.469, P = 0.000), NT-proBNP (r = 0.349, P = 0.001) and Lac (r = 0.357, P = 0.000), while there was no significant correlation between histone and PCT (r = 0.133, P = 0.205). (4) ROC curve analysis showed that the area under ROC curve (AUC) of histone predicting prognosis was 0.769 (P = 0.000); when the cut-off point was 0.30 mg/L, the sensitivity and specificity were 72.4% and 81.2% respectively. The AUC of SOFA score was 0.653 (P = 0.018), and the sensitivity and specificity were 58.6% and 70.3% respectively when the cut-off point was 10.50; while cTnI, NT-proBNP, Lac and PCT had little value in predicting the prognosis of patients. (5) Compared with the group with histone level lower than 0.3 mg/L, the group with histones level greater than 0.3 mg/L had higher SOFA score, more doses of vasopressor, higher cTnI, NT-proBNP, Lac and PCT levels, and higher ICU mortality [SOFA: 11 (10, 12) vs. 9 (8, 10), use of vasopressor: 84.8% (28/33) vs. 76.7% (46/60), cTnI (μg/L): 0.28 (0.19, 0.32) vs. 0.18 (0.12, 0.22), NT-proBNP (ng/L): 3 624.0 (2 800.0, 5 260.0) vs. 2 512.0 (1 361.8, 3 590.8), Lac (mmol/L): 2.25 (1.85, 3.50) vs. 1.60 (1.25, 2.35), PCT (μg/L): 2.10 (1.30, 4.03) vs. 1.60 (1.26, 2.33), ICU mortality: 48.5% (16/33) vs. 21.7% (13/60), all P < 0.05], while no statistical difference in the length of ICU stay was found. The independent risk factors for ICU mortality of sepsis patients were high histone level and the use of vasopressor. Plasma histone can be regarded as an indicator in predicting the prognosis of patients with sepsis.

Extracellular Histones Promote Pulmonary Fibrosis in Patients With Coal Workers’ Pneumoconiosis

This investigation assessed the profibrotic role that extracellular histones play in the pathogenesis of coal workers' pneumoconiosis (CWP). The correlation of extracellular histones with small opacity profusion (SOP) and transforming growth factor-β (TGF-β) was analyzed. The stimulating effect of extracellular histones on pulmonary fibroblast was assessed in vitro. The levels of extracellular histones in plasma were positively correlated with SOP and TGF-β in the coal miners investigated. Plasma collected from patients with CWP caused apparent lung fibroblast proliferation, while anti-H4 antibody antagonized the stimulating effect of the patient plasma by blocking histone H4. In vitro experiments showed that extracellular histones directly stimulated fibroblast proliferation. Consistent with our hypothesis, the concentrations of extracellular histones were indices of the severity of pulmonary fibrosis in simple CWP, and extracellular histones-targeted intervention could inhibit the proliferation of lung fibroblast.

Plasma Histone H4 and H4K20 Trimethylation Levels Differ Between Colon Cancer and Precancerous Polyps

No blood-based biomarkers are available to differentiate between colonic tumors and precancerous polyps. Previously we demonstrated levels of trimethylated H4K20 (H4K20me3) to be lower in blood plasma from patients with colon cancer than those from cancer-free individuals. Herein, we added individuals with precancerous polyps for the first time in order to analyze and investigate the usefulness of plasma H4K20me3 and histone H4 to discriminate colon tumors from precancerous polyps. The study included a cohort of 185 individuals undergoing colonoscopy. H4K20me3 and histone H4, measured by an enzyme-linked immunosorbent assay-like assay in plasma, were analyzed according to colonoscopy findings. Levels of H4K20me3 were lower in patients with colon cancer than in individuals with normal colonoscopy and those with precancerous polyps (p=0.02 and p=0.01, respectively). In contrast, highest quantities of histone H4 were measured in those with colon cancer compared to other groups (all p<0.01). Beside H4K20me3, plasma histone H4 is a useful marker to discriminate colonic tumors from precancerous polyps and other conditions.

Circulating histone H3 levels are increased in septic mice in a neutrophil-dependent manner: preclinical evaluation of a novel sandwich ELISA for histone H3

BackgroundNuclear histone proteins are released into the extracellular space during sepsis and act as major mediators of death. However, circulating histone levels have not been precisely quantified.MethodsWe developed a novel enzyme-linked immunosorbent assay (ELISA) for detection of circulating histone H3 levels and evaluated its performance. Using the ELISA, we measured plasma histone H3 levels in C57BL/6 J mice subjected to cecal ligation and puncture (CLP)-induced sepsis.ResultsThe newly developed ELISA enabled reproducible measurement of histone H3 levels with a working range up to 250 ng/mL. Using the ELISA, we found that plasma histone H3 levels were elevated in septic mice compared with sham-operated mice (p < 0.01). The elevation of histone H3 levels was abrogated when neutrophils were depleted (p < 0.01).ConclusionsOur novel ELISA provides reproducible measurements of histone H3 levels. Circulating histone H3 levels are increased in septic mice in a neutrophil-dependent manner. Further studies are needed to evaluate the clinical utility of histone H3 levels in patients with sepsis.

Damage-associated molecular patterns in intensive care unit patients with acute liver injuries: A prospective cohort study.

Acute liver injury (ALI) is frequently detected in an intensive care unit (ICU) and reportedly affects prognosis. Experimental animal studies suggested that increased extracellular histone and high morbidity group box-1 (HMGB1) levels might contribute to ALI development. Whether these damage-associated molecular patterns (DAMPs) play a crucial role in ALI remains unclear in the human clinical setting.We consecutively enrolled the patients admitted to our ICU. The patients with ALI were included in the analysis together with those without ALI by using frequency matching. Extracellular histone, HMGB1, soluble thrombomodulin (sTM), and interleukin-6 (IL-6) levels were measured in plasma collected at ICU admission. ALI was defined as an acute elevation in serum aminotransferase levels to >200 IU/L.A total of 805 patients were enrolled. Twenty ALI and forty non-ALI patients were analyzed. Plasma histone levels were significantly higher in the ALI group than in the non-ALI group, whereas HMGB1 levels were significantly lower in the ALI group. Furthermore, sTM was significantly increased in the ALI patients, whereas IL-6 levels were comparable between the groups. Multivariate logistic regression analysis demonstrated that histones were independently associated with ALI. There was no significant impact of ALI on in-hospital mortality.Extracellular histones showed an independent association with ALI. Histone elevation might be one of the possible pathogenic mechanisms in the development of ALI of ICU patients.

Harmful Roles of TLR3 and TLR9 in Cardiac Dysfunction Developing during Polymicrobial Sepsis.

We determined the roles of TLR3 and TLR9 in adverse events of polymicrobial sepsis, with a focus on development of septic cardiomyopathy, progression of which we have recently shown to be complement- and histones-dependent. So Wt, TLR3-knocked out (K.O.), and TLR9-K.O. mice were subjected to polymicrobial sepsis following cecal ligation and puncture (CLP). In the absence of either TLR3 or TLR9, the intensity of echocardiogram (Echo)-Doppler dysfunction during development of cardiomyopathy was substantially reduced in the K.O. mice. Based on our prior studies emphasizing the adverse effects of plasma C5a and histones in the cardiomyopathy of sepsis, in TLR3- and TLR9-K.O. mice, there were striking reductions in plasma levels of C5a and histones as well as reduced levels of cytokines in plasma and heart tissue after CLP. Since we know that histones cause cardiac dysfunction, rat cardiomyocytes (CMs) were exposed in vitro to the histones (purified from calf thymus), which caused bleb formation on the surfaces of CMs, suggesting histones may perturb the cell membrane of CMs. In vitro, exposure of CMs to the histones for 3 hours caused lactate dehydrogenase release from CMs. These data indicate that sepsis-induced cardiac dysfunction requires presence of TLR3 and TLR9 and may be linked to histone-induced damage of CMs.

Acute Traumatic Coagulopathy: The Value of Histone in Pediatric Trauma Patients.

Objective:Acute traumatic coagulopathy occurs after trauma with impairment of hemostasis and activation of fibrinolysis. Some endogenous substances may play roles in this failure of the coagulation system. Extracellular histone is one such molecule that has recently attracted attention. This study investigated the association between plasma histone-complexed DNA (hcDNA) fragments and coagulation abnormalities in pediatric trauma patients.Materials and Methods:This prospective case-control study was conducted in pediatric patients with trauma. Fifty trauma patients and 30 healthy controls were enrolled. Demographic data, anatomic injury characteristics, coagulation parameters, computerized tomography findings, trauma, and International Society on Thrombosis and Haemostasis disseminated intravascular coagulation (ISTH DIC) scores were recorded. Blood samples for hcDNA were collected and assessed by enzyme-linked immunosorbent assay.Results:Thirty-two patients had multiple trauma, while 18 patients had isolated brain injury. hcDNA levels were significantly higher in trauma patients than healthy controls (0.474 AU and 0.145 AU, respectively). There was an association between plasma hcDNA levels and trauma severity. Thirteen patients had acute coagulopathy of trauma shock (ACoTS). ACoTS patients had higher plasma histone levels than those without ACoTS (0.703 AU and 0.398 AU, respectively). Plasma hcDNA levels were positively correlated with the ISTH DIC score and length of stay in the intensive care unit and were negatively correlated with fibrinogen level.Conclusion:This study indicated that hcDNA levels were increased in pediatric trauma patients and associated with the early phase of coagulopathy. Further studies are needed to clarify the role of hcDNA levels in mortality and disseminated intravascular coagulation.

Acute exercise and periodized training in different environments affect histone deacetylase activity and interleukin-10 levels in peripheral blood of patients with type 2 diabetes

AimsOur purpose was to investigate the effects of aerobic periodized training in aquatic and land environments on plasma histone deacetylase (HDAC) activity and cytokines levels in peripheral blood of diabetes mellitus type 2 (T2DM) patients. MethodsThe patients underwent 12 weeks of periodized training programs that including walking or running in a swimming pool (aquatic group) or in a track (dry land group). Blood samples were collected immediately before and after both first and last sessions. Plasma cytokine levels and HDAC activity in peripheral blood mononuclear cell (PBMC) was measured. ResultsThe exercise performed in both environments similarly modulated the evaluated acetylation mark, global HDAC activity. However, a differential profile depending on the evaluated time point was detected, since exercise increased acutely HDAC activity in sedentary and after 12 weeks of training period, while a reduced HDAC activity was observed following periodized training (samples collected before the last session). Additionally, the 12 weeks of periodized exercise in both environments increased IL-10 levels. ConclusionsOur data support the hypothesis that the modulation of HDAC activity and inflammatory status might be at least partially related to exercise effects on T2DM. The periodized training performed in both aquatic and land environments impacts similarly epigenetic and inflammatory status.

A new mass spectrometry-based method for the quantification of histones in plasma from septic shock patients

The aim of this study was to develop a novel method to detect circulating histones H3 and H2B in plasma based on multiple reaction monitoring targeted mass spectrometry and a multiple reaction monitoring approach (MRM-MS) for its clinical application in critical bacteriaemic septic shock patients. Plasma samples from 17 septic shock patients with confirmed bacteraemia and 10 healthy controls were analysed by an MRM-MS method, which specifically detects presence of histones H3 and H2B. By an internal standard, it was possible to quantify the concentration of circulating histones in plasma, which were significantly higher in patients, and thus confirmed their potential as biomarkers for diagnosing septic shock. After comparing surviving patients and non-survivors, a correlation was found between higher levels of circulating histones and unfavourable outcome. Indeed, histone H3 proved a more efficient and sensitive biomarker for septic shock prognosis. In conclusion, these findings suggest the accuracy of the MRM-MS technique and stable isotope labelled peptides to detect and quantify circulating plasma histones H2B and H3. This method may be used for early septic shock diagnoses and for the prognosis of fatal outcomes.

Complement-induced activation of MAPKs and Akt during sepsis: role in cardiac dysfunction.

Polymicrobial sepsis in mice causes myocardial dysfunction after generation of the complement anaphylatoxin, complement component 5a (C5a). C5a interacts with its receptors on cardiomyocytes (CMs), resulting in redox imbalance and cardiac dysfunction that can be functionally measured and quantitated using Doppler echocardiography. In this report we have evaluated activation of MAPKs and Akt in CMs exposed to C5a in vitro and after cecal ligation and puncture (CLP) in vivo In both cases, C5a in vitro caused activation (phosphorylation) of MAPKs and Akt in CMs, which required availability of both C5a receptors. Using immunofluorescence technology, activation of MAPKs and Akt occurred in left ventricular (LV) CMs, requiring both C5a receptors, C5aR1 and -2. Use of a water-soluble p38 inhibitor curtailed activation in vivo of MAPKs and Akt in LV CMs as well as the appearance of cytokines and histones in plasma from CLP mice. When mouse macrophages were exposed in vitro to LPS, activation of MAPKs and Akt also occurred. The copresence of the p38 inhibitor blocked these activation responses. Finally, the presence of the p38 inhibitor in CLP mice reduced the development of cardiac dysfunction. These data suggest that polymicrobial sepsis causes cardiac dysfunction that appears to be linked to activation of MAPKs and Akt in heart.-Fattahi, F., Kalbitz, M., Malan, E. A., Abe, E., Jajou, L., Huber-Lang, M. S., Bosmann, M., Russell, M. W., Zetoune, F. S., Ward, P. A. Complement-induced activation of MAPKs and Akt during sepsis: role in cardiac dysfunction.

Associations between post translational histone modifications, myelomeningocele risk, environmental arsenic exposure, and folate deficiency among participants in a case control study in Bangladesh

ABSTRACTArsenic exposure may contribute to disease risk in humans through alterations in the epigenome. Previous studies reported that arsenic exposure is associated with changes in plasma histone concentrations. Posttranslational histone modifications have been found to differ between the brain tissue of human embryos with neural tube defects and that of controls. Our objectives were to investigate the relationships between plasma histone 3 levels, history of having an infant with myelomeningocele, biomarkers of arsenic exposure, and maternal folate deficiency. These studies took place in Bangladesh, a country with high environmental arsenic exposure through contaminated drinking water. We performed ELISA assays to investigate plasma concentration of total histone 3 (H3) and the histone modification H3K27me3. The plasma samples were collected from 85 adult women as part of a case-control study of arsenic and myelomeningocele risk in Bangladesh. We found significant associations between plasma %H3K27me3 levels and risk of myelomeningocele (P<0.05). Mothers with higher %H3K27me3 in their plasma had lower risk of having an infant with myelomeningocele (odds ratio: 0.91, 95% confidence interval: 0.84, 0.98). We also found that arsenic exposure, as estimated by arsenic concentration in toenails, was associated with lower total H3 concentrations in plasma, but only among women with folate deficiency (β = −9.99, standard error = 3.91, P=0.02). Our results suggest that %H3K27me3 in maternal plasma differs between mothers of infants with myelomeningocele and mothers of infants without myelomeningocele, and may be a marker for myelomeningocele risk. Women with folate deficiency may be more susceptible to the epigenetic effects of environmental arsenic exposure.

Accuracy of circulating histones in predicting persistent organ failure and mortality in patients with acute pancreatitis

BackgroundEarly prediction of acute pancreatitis severity remains a challenge. Circulating levels of histones are raised early in mouse models and correlate with disease severity. It was hypothesized that circulating histones predict persistent organ failure in patients with acute pancreatitis.MethodsConsecutive patients with acute pancreatitis fulfilling inclusion criteria admitted to Royal Liverpool University Hospital were enrolled prospectively between June 2010 and March 2014. Blood samples were obtained within 48 h of abdominal pain onset and relevant clinical data during the hospital stay were collected. Healthy volunteers were enrolled as controls. The primary endpoint was occurrence of persistent organ failure. The predictive values of circulating histones, clinical scores and other biomarkers were determined.ResultsAmong 236 patients with acute pancreatitis, there were 156 (66·1 per cent), 57 (24·2 per cent) and 23 (9·7 per cent) with mild, moderate and severe disease respectively, according to the revised Atlanta classification. Forty-seven healthy volunteers were included. The area under the receiver operating characteristic (ROC) curve (AUC) for circulating histones in predicting persistent organ failure and mortality was 0·92 (95 per cent c.i. 0·85 to 0·99) and 0·96 (0·92 to 1·00) respectively; histones were at least as accurate as clinical scores or biochemical markers. For infected pancreatic necrosis and/or sepsis, the AUC was 0·78 (0·62 to 0·94). Histones did not predict or correlate with local pancreatic complications, but correlated negatively with leucocyte cell viability (r = –0·511, P = 0·001).ConclusionQuantitative assessment of circulating histones in plasma within 48 h of abdominal pain onset can predict persistent organ failure and mortality in patients with acute pancreatitis. Early death of immune cells may contribute to raised circulating histone levels in acute pancreatitis.

Patients with HBV-related acute-on-chronic liver failure have increased concentrations of extracellular histones aggravating cellular damage and systemic inflammation.

Acute-on-chronic liver failure (ACLF) is the most common type of liver failure and associated with grave consequences. Systemic inflammation has been linked to its pathogenesis and outcome, but the identifiable triggers are absent. Recently, extracellular histones, especially H4, have been recognized as important mediators of cell damage in various inflammatory conditions. This study aimed to investigate whether extracellular histones have clinical implications in patients with hepatitis B virus (HBV)-related ACLF. One hundred and twelve patients with HBV-related ACLF, 90 patients with chronic hepatitis B, 88 patients with HBV-related liver cirrhosis and 40 healthy volunteers were entered into this study. Plasma histone H4 levels, cytokine profile and clinical data were obtained. Besides, patient's sera were incubated overnight with human L02 hepatocytes or monocytic U937 cells in the presence or absence of antihistone H4 antibody, and cellular damage and cytokine production were evaluated. We found that plasma histone H4 levels were greatly increased in patients with ACLF as compared with chronic hepatitis B, liver cirrhosis and healthy control subjects and were significantly associated with disease severity, systemic inflammation and outcome. Notably, ACLF patients' sera incubation decreased cultured L02 cell integrity and induced profound cytokine production in the supernatant of U937 cells. Antihistone H4 antibody treatment abrogated these adverse effects, thus confirming a cause-effect relationship between extracellular histones and organ injury/dysfunction. The data support the hypothesis that the increased extracellular histone levels in ACLF patients may aggravate disease severity by inducing cellular injury and systemic inflammation. Histone-targeted therapies may have potentially interventional value in clinical practice.

Neutralisation of the anti-coagulant effects of heparin by histones in blood plasma and purified systems.

Neutrophil extracellular traps (NETs) composed primarily of DNA and histones are a link between infection, inflammation and coagulation. NETs promote coagulation and approaches to destabilise NETs have been explored to reduce thrombosis and treat sepsis. Heparinoids bind histones and we report quantitative studies in plasma and purified systems to better understand physiological consequences. Unfractionated heparin (UFH) was investigated by activated partial thromboplastin time (APTT) and alongside low-molecular-weight heparins (LMWH) in purified systems with thrombin or factor Xa (FXa) and antithrombin (AT) to measure the sensitivity of UFH or LMWH to histones. A method was developed to assess the effectiveness of DNA and non-anticoagulant heparinoids as anti-histones. Histones effectively neutralised UFH, the IC50 value for neutralisation of 0.2 IU/ml UFH was 1.8 µg/ml histones in APTT and 4.6 µg/ml against 0.6 IU/ml UFH in a purified system. Histones also inhibited the activities of LMWHs with thrombin (IC50 6.1 and 11.0 µg/ml histones, for different LMWHs) or FXa (IC50 7.8 and 7.0 µg/ml histones). Direct interactions of UFH and LMWH with DNA and histones were explored by surface plasmon resonance, while rheology studies showed complex effects of histones, UFH and LMWH on clot resilience. A conclusion from these studies is that anticoagulation by UFH and LMWH will be compromised by high affinity binding to circulating histones even in the presence of DNA. A complete understanding of the effects of histones, DNA and heparins on the haemostatic system must include an appreciation of direct effects on fibrin and clot structure.

The study on the change of extracellular histones in human plasma during the pathogenesis of silicosis

To investigate the plasma level of extracellular histones in patients with silicosis, and to explore the role of extracellular histones in the pathogenesis of pulmonary fibrosis in silicosis. Sixty-two patients with silicosis were enrolled as the silicosis group, consisting of 23 patients with stage I silicosis, 25 with stage II silicosis, and 14 with stage III silicosis; sixty workers who had a history of occupational exposure to silica dust for more than 2 years and had not been diagnosed with silicosis were enrolled as the silica dust exposure group; sixty-five healthy workers without a history of occupational exposure to dust were enrolled as healthy controls. Enzyme-linked immunosorbent assay was applied to measure the plasma levels of plasma extracellular histone (H4) and transforming growth factor-β(TGF-β). Compared with healthy controls [(0.82±0.67) μg/ml], the silica dust exposure group[(4.14±2.85) μg/ml] and silicosis group[(9.50±5.04) μg/ml] had significant increases in plasma level of H4 (P<0.01). The plasma level of H4 was significantly correlated with the stage of silicosis(r=0.8955, P=0.0388). The silicosis group had a significantly higher plasma level of TGF-β than the silica dust exposure group and healthy controls(P <0.05). In the patients with silicosis, the plasma level of H4 was significantly correlated with that of TGF-β(r=0.5375, P<0.01). The plasma level of extracellular histones increases significantly in the pathogenesis of silicosis, and extracellular histones may play an important role in the progression of fibrosis in silicosis.

Increased Levels of Histone in Human Plasma in Septic Patients with DIC

<Background and Methods>Sepsis is a life-threatening condition that is characterized by a whole-body inflammatory state (called a systemic inflammatory response syndrome, SIRS). Histones are essential for packing DNA into the cell nucleus and also play role in regulating gene expression but the new study (Jun Xu et al, Nature Medicine 15. 1318, 2009) have shown histones released into blood stream at the onset of sepsis can have devastating effects (endothelial damage and organ failure etc). However, plasma levels of histone are unclear in septic patients with DIC. Therefore, We developed a sandwich ELISA to quantify serum or plasma histone H3 levels and measured plasma levels of histone H3 in septic patients with DIC (n=30).<Results>DIC was diagnosed on the Japanese Ministry of Health and Welfare (JMHW) DIC diagnostic criteria. The thrombin antithrombin complexes (TAT) levels were higher in septic patients with DIC as reported by others. The working range of this ELISA was 3-1000 ng/ml. In healthy volunteers, plasma levels of histone (H3) were not detectable. We detected high levels of extracellular hisotone (H3) in the plasma of all septic patients with DIC by sandwich ELISA. Mean plasma levels of hisotone (H3) were 70.5 ± 63.2 (12.9-336.5) ng/ml in septic patients with DIC. However, plasma levels of extracellular histone (H3) were negative in acute promyelocytic leukemia (APL)-induced DIC (n=5). Also, Plasma levels of histone were 10 ng/ml or less by sandwich ELISA in septic patients without DIC (n=8).<Conclusion>These results suggest that assess of extracellular hisotones in the plasma may be helpful in the making the diagnosis in septic patients with DIC. Also, it appears that extracellular hisotones in the plasma may contribute to develop DIC in septic patients. DisclosuresNo relevant conflicts of interest to declare.