IL-6 trans-signaling system in intra-amniotic inflammation, preterm birth, and preterm premature rupture of the membranes

Classic IL-6 signaling is conditioned by the transmembrane receptor (IL-6R) and homodimerization of gp130. During trans-signaling, IL-6 binds to soluble IL-6R (sIL-6R), enabling activation of cells expressing solely gp130. Soluble gp130 (sgp130) selectively inhibits IL-6 trans-signaling. To characterize amniotic fluid (AF) IL-6 trans-signaling molecules (IL-6, sIL-6R, sgp130) in normal gestations and pregnancies complicated by intra-amniotic inflammation (IAI), we studied 301 women during second trimester (n = 39), third trimester (n = 40), and preterm labor with intact (n = 131, 85 negative IAI and 46 positive IAI) or preterm premature rupture of membranes (PPROM; n = 91, 61 negative IAI and 30 positive IAI). ELISA, Western blotting, and real-time RT-PCR were used to investigate AF, placenta, and amniochorion for protein and mRNA expression of sIL-6R, sgp130, IL-6R, and gp130. Tissues were immunostained for IL-6R, gp130, CD15(+) (polymorphonuclear), and CD3(+) (T cell) inflammatory cells. The ability of sIL-6R and sgp130 to modulate basal and LPS-stimulated release of amniochorion matrix metalloprotease-9 was tested ex vivo. We showed that in physiologic gestations, AF sgp130 decreases toward term. AF IL-6 and sIL-6R were increased in IAI, whereas sgp130 was decreased in PPROM. Our results suggested that fetal membranes are the probable source of AF sIL-6R and sgp130. Immunohistochemistry and RT-PCR revealed increased IL-6R and decreased gp130 expression in amniochorion of women with IAI. Ex vivo, sIL-6R and LPS augmented amniochorion matrix metalloprotease-9 release, whereas sgp130 opposed this effect. We conclude that IL-6 trans-signaling molecules are physiologic constituents of the AF regulated by gestational age and inflammation. PPROM likely involves functional loss of sgp130.     

Increased expression of high mobility group box 1 (HMGB1) in the cytoplasm of placental syncytiotrophoblast from preeclamptic placentae

BackgroundPreeclampsia is a pregnancy-specific disorder characterised by an inappropriate maternal inflammatory response during pregnancy. High mobility group box 1 (HMGB1) was originally characterised as a nuclear protein but when released into the extracellular environment following necrotic cell death, it is proinflammatory. HMGB1 is expressed in the syncytiotrophoblast of human placenta. Higher levels of uric acid are reported in preeclampsia. The aim of this study was to investigate whether the expression of HMGB1differed between early onset and late onset preeclampsia or severe and mild preeclampsia and whether its expression correlated with the levels of uric acid.Methods74 preeclamptic placentae and 110 normotensive placentae were included in this study. The levels of uric acid in women with preeclampsia were measured. The expression of HMGB1 in preeclamptic placentae or in first trimester and term placentae that had been treated with uric acid was measured.ResultsHMGB1 was expressed predominantly in the syncytiotrophoblast of the placenta and the expression of HMGB1 in the cytoplasm of the syncytiotrophoblast was significantly increased in both severe preeclampsia and early onset preeclampsia compared to normotensive pregnancies. The circulating levels of uric acid were significantly increased in preeclampsia and correlated with the expression of HMGB1. Increased levels of HMGB1 were significantly correlated with the severity and the time of onset of preeclampsia, but pathologic levels of uric acid did not increase the expression of HMGB1.ConclusionOur data provides a better understanding of the function of HMGB1, a danger molecule in the pathogenesis of preeclampsia.     

Prediction of preterm delivery by second trimester inflammatory biomarkers in the amniotic fluid

ObjectiveTo search for a correlation between mid-pregnancy altered levels of inflammatory markers and preterm delivery.MethodsA prospective cohort series included 39 patients undergoing amniocentesis one additional milliliter of amniotic fluid (AF) was stored for later dosage of interleukin-6 (Il-6), matrix metalloproteinase-9 (MMP-9), glucose and C-reactive protein (CRP). Maternal serum CRP and glucose levels were also obtained. Exclusion criteria were multiple pregnancies, chorioamnionitis, group B streptococcus colonization, bacterial vaginosis and cases with proven aneuploidy. We searched for correlation between AF and plasmatic markers and also for a difference between patients with term and preterm delivery.Results33 participants were eligible and one third had preterm delivery. Levels of the plasmatic biomarkers did not correlate with the AF biomarkers except for plasmatic glucose and AF IL-6 levels (r = 0.350; p = 0.016). The levels of all AF biomarkers did not differ significantly between the pre-term and the term groups (p > 0.05). The optimal screening cutoffs for identifying pregnancies at risk were different than the ones initially indicated.ConclusionMid-pregnancy amniotic fluid biomarker levels do not correlate with preterm delivery. Plasma CRP is not correlated with these markers. Cutoff levels suggested are sparse and heterogeneous. Larger studies are needed before advising routine measurement of these markers.     

Telomere Fragment Induced Amnion Cell Senescence: A Contributor to Parturition?

Oxidative stress (OS)-induced senescence of the amniochorion has been associated with parturition at term. We investigated whether telomere fragments shed into the amniotic fluid (AF) correlated with labor status and tested if exogenous telomere fragments (T-oligos) could induce human and murine amnion cell senescence. In a cross-sectional clinical study, AF telomere fragment concentrations quantitated by a validated real-time PCR assay were higher in women in labor at term compared to those not in labor. In vitro treatment of primary human amnion epithelial cells with 40 μM T-oligos ([TTAGGG]₂) that mimic telomere fragments, activated p38MAPK, produced senescence-associated (SA) β-gal staining and increased interleukin (IL)-6 and IL-8 production compared to cells treated with complementary DNA sequences (Cont-oligos, [AATCCC]₂). T-oligos injected into the uteri of pregnant CD1 mice on day 14 of gestation, led to increased p38MAPK, SA-β-gal (SA β-gal) staining in murine amniotic sacs and higher AF IL-8 levels on day 18, compared to saline treated controls. In summary, term labor AF samples had higher telomere fragments than term not in labor AF. In vitro and in situ telomere fragments increased human and murine amnion p38MAPK, senescence and inflammatory cytokines. We propose that telomere fragments released from senescent fetal cells are indicative of fetal cell aging. Based on our data, these telomere fragments cause oxidative stress associated damages to the term amniotic sac and force them to release other DAMPS, which, in turn, provide a sterile immune response that may be one of the many inflammatory signals required to initiate parturition at term.     

Cervical intraepithelial neoplasia and the risk of spontaneous preterm birth: A Dutch population-based cohort study with 45,259 pregnancy outcomes

BackgroundExcisional procedures of cervical intraepithelial neoplasia (CIN) may increase the risk of preterm birth. It is unknown whether this increased risk is due to the excision procedure itself, to the underlying CIN, or to secondary risk factors that are associated with both preterm birth and CIN. The aim of this study is to assess the risk of spontaneous preterm birth in women with treated and untreated CIN and examine possible associations by making a distinction between the excised volume of cervical tissue and having cervical disease.Methods and findingsThis Dutch population-based observational cohort study identified women aged 29 to 41 years with CIN between 2005 and 2015 from the Dutch pathology registry (PALGA) and frequency matched them with a control group without any cervical abnormality based on age at and year of pathology outcome (i.e., CIN or normal cytology) and urbanization (<100,000 inhabitants or ≥100,000 inhabitants). All their 45,259 subsequent singleton pregnancies with a gestational age ≥16 weeks between 2010 and 2017 were identified from the Dutch perinatal database (Perined). Nineteen potential confounders for preterm birth were identified. Adjusted odds ratios (ORs) were calculated for preterm birth comparing the 3 different groups of women: (1) women without CIN diagnosis; (2) women with untreated CIN; and (3) women with treated CIN prior to each childbirth.In total, 29,907, 5,940, and 9,412 pregnancies were included in the control, untreated CIN, and treated CIN group, respectively. The control group showed a 4.8% (1,002/20,969) proportion of spontaneous preterm birth, which increased to 6.9% (271/3,940) in the untreated CIN group, 9.5% (600/6,315) in the treated CIN group, and 15.6% (50/321) in the group with multiple treatments. Women with untreated CIN had a 1.38 times greater odds of preterm birth compared to women without CIN (95% confidence interval (CI) 1.19 to 1.60; P < 0.001). For women with treated CIN, these odds 2.07 times increased compared to the control group (95% CI 1.85 to 2.33; P < 0.001). Treated women had a 1.51 times increased odds of preterm birth compared to women with untreated CIN (95% CI 1.29 to 1.76; P < 0.001). Independent from cervical disease, a volume excised from the cervix of 0.5 to 0.9 cc increased the odds of preterm birth 2.20 times (37/379 versus 1,002/20,969; 95% CI 1.52 to 3.20; P < 0.001). These odds further increased 3.13 times and 5.93 times for women with an excised volume of 4 to 8.9 cc (90/724 versus 1,002/20,969; 95% CI 2.44 to 4.01; P < 0.001) and ≥9 cc (30/139 versus 1,002/20,969; 95% CI 3.86 to 9.13; P < 0.001), respectively. Limitations of the study include the retrospective nature, lack of sufficient information to calculate odds of preterm birth <24 weeks, and that the excised volume could only be calculated for a select group of women.ConclusionsIn this study, we observed a strong correlation between preterm birth and a volume of ≥0.5 cc excised cervical tissue, regardless of the severity of CIN. Caution should be taken when performing excisional treatment in women of reproductive age as well as prudence in case of multiple biopsies. Fertile women with a history of performing multiple biopsies or excisional treatment for CIN may benefit from close surveillance during pregnancy.

In a population-based study, Diede Loopik and colleagues investigate associations between cervical intraepithelial neoplasia and risk of preterm birth among Dutch women.     

High mobility group box 1 levels in large vessel vasculitis are not associated with disease activity but are influenced by age and statins

IntroductionTakayasu arteritis (TA) and giant cell arteritis (GCA) are large vessel vasculitides (LVV) that usually present as granulomatous inflammation in arterial walls. High mobility group box 1 (HMGB1) is a nuclear protein that acts as an alarmin when released by dying or activated cells. This study aims to evaluate whether serum HMGB1 can be used as a biomarker in LVV.MethodsTwenty-nine consecutive TA patients with 29 healthy controls (HC) were evaluated in a cross-sectional study. Eighteen consecutive GCA patients with 16 HC were evaluated at the onset of disease and some of them during follow-up. Serum HMGB1 levels were measured by enzyme-linked immunosorbent assay.ResultsIn GCA patients at disease onset mean serum HMGB1 levels did not differ from HC (5.74 ± 4.19 ng/ml vs. 4.17 ± 3.14 ng/ml; p = 0.230). No differences in HMGB1 levels were found between GCA patients with and without polymyalgia rheumatica (p = 0.167), ischemic manifestations (p = 0.873), systemic manifestations (p = 0.474) or relapsing disease (p = 0.608). During follow-up, no significant fluctuations on serum HMGB1 levels were observed from baseline to 3 months (n = 13) (p = 0.075), 12 months (n = 6) (p = 0.093) and at the first relapse (n = 4) (p = 0.202). Serum HMGB1 levels did not differ between TA patients and HC [1.19 (0.45–2.10) ng/ml vs. 1.46 (0.89–3.34) ng/ml; p = 0.181] and no difference was found between TA patients with active disease and in remission [1.31 (0.63–2.16) ng/ml vs. 0.75 (0.39–2.05) ng/ml; p = 0.281]. HMGB1 levels were significantly lower in 16 TA patients on statins compared with 13 patients without statins [0.59 (0.29–1.46) ng/ml vs. 1.93 (0.88–3.34) ng/ml; p = 0.019]. Age was independently associated with higher HMGB1 levels regardless of LVV or control status.ConclusionsPatients with TA and GCA present similar serum HMGB1 levels compared with HC. Serum HMGB1 is not useful to discriminate between active disease and remission. In TA, use of statins was associated with lower HMGB1 levels. HMGB1 is not a biomarker for LVV.     

Renal expression and serum levels of high mobility group box 1 protein in lupus nephritis

Introduction

High mobility group box 1 protein (HMGB1) is a nuclear DNA binding protein acting as a pro-inflammatory mediator following extracellular release. HMGB1 has been increasingly recognized as a pathogenic mediator in several inflammatory diseases. Elevated serum levels of HMGB1 have been detected in autoimmune diseases including Systemic lupus erythematosus (SLE). However, the local expression of HMGB1 in active lupus nephritis (LN) is not known. Here we aimed to study both tissue expression and serum levels of HMGB1 in LN patients with active disease and after induction therapy.

Methods

Thirty-five patients with active LN were included. Renal biopsies were performed at baseline and after standard induction therapy; corticosteroids combined with immunosuppressive drugs. The biopsies were evaluated according to the World Health Organization (WHO) classification and renal disease activity was estimated using the British Isles lupus assessment group (BILAG) index. Serum levels of HMGB1 were analysed by western blot. HMGB1 expression in renal tissue was assessed by immunohistochemistry at baseline and follow-up biopsies in 25 patients.

Results

Baseline biopsies showed WHO class III, IV or V and all patients had high renal disease activity (BILAG A/B). Follow-up biopsies showed WHO I to II (n = 14), III (n = 6), IV (n = 3) or V (n = 12), and 15/35 patients were regarded as renal responders (BILAG C/D). At baseline HMGB1 was significantly elevated in serum compared to healthy controls (P < 0.0001). In all patients, serum levels decreased only slightly; however, in patients with baseline WHO class IV a significant decrease was observed (P = 0.03). Immunostaining revealed a pronounced extranuclear HMGB1 expression predominantly outlining the glomerular endothelium and in the mesangium. There was no clear difference in HMGB1 expression comparing baseline and follow-up biopsies or any apparent association to histopathological classification or clinical outcome.

Conclusions

Renal tissue expression and serum levels of HMGB1 were increased in LN. The lack of decrease of HMGB1 in serum and tissue after immunosuppressive therapy in the current study may reflect persistent inflammatory activity. This study clearly indicates a role for HMGB1 in LN.     

Hydrogen Sulfide Delays LPS-Induced Preterm Birth in Mice via Anti-Inflammatory Pathways

A major cause of preterm labor in pregnant women is intra-amniotic infection, which is mediated by an inflammatory process. Hydrogen sulfide (H₂S), a gaseous transmitter, has been implicated to be involved in inflammatory responses. We sought to investigate whether H₂S affects infectious preterm birth using the mouse model of lipopolysaccharides (LPS)-induced preterm birth. Administration of LPS at 0.4 mg/kg with two injections intraperitoneally (i.p.) on gestational day 14.5 induced preterm labor. LPS significantly increased leukocyte infiltration in uterus, stimulated the expression of pro-inflammatory cytokines interleukin 1β (IL-1β), IL-6, tumor necrosis factor α (TNF-α), CCL2 and CXCL15 in myometrium. Administration of NaHS (i.p.) delayed the onset of labor induced by LPS in a dose-dependent manner. NaHS prevented leukocyte infiltration into intrauterine tissues and inhibited the production of pro-inflammatory cytokines in myometrium and decreased the levels of these cytokines in maternal circulation. H₂S also decreased LPS-activated extracellular signal-regulated kinase (ERK) 1/2/ nuclear factor (NF)-κB signaling pathways in myometrium. This study provides new in vivo evidence for the roles of H₂S in attenuating inflammation, and a potential novel therapeutic strategy for infection-related preterm labor.     

Circ-CSPP1 knockdown suppresses hepatocellular carcinoma progression through miR-493-5p releasing-mediated HMGB1 downregulation

BackgroundHepatocellular carcinoma (HCC) accounts for over 80% of primary liver cancers and leads to a high death rate. Research on circular RNAs (circRNAs) suggests that circRNAs are promising biomarkers for cancer treatment. This study aimed to explore the function of a novel circRNA (circ-CSPP1) in HCC.MethodsCirc-CSPP1 was obtained from the microarray data downloaded from the Gene Expression Omnibus (GEO) database. The expression of circ-CSPP1, miR-493-5p and high mobility group box 1 (HMGB1) was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, colony formation ability, migration and invasion were monitored using cell counting kit-8 (CCK-8) assay, colony formation assay, wound healing assay and transwell assay, respectively. The protein levels of CyclinD1, Vimentin, matrix metallopeptidase 9 (MMP-9) and HMGB1 were detected by western blot. Xenograft models were established to investigate the function of circ-CSPP1 in vivo. The association between miR-493-5p and circ-CSPP1 or HMGB1 was predicted by the online tool starBase and ensured by dual-luciferase reporter assay.ResultsThe expression of circ-CSPP1 and HMGB1 was elevated, while the expression of miR-493-5p was declined in HCC tissues and cells. Circ-CSPP1 knockdown not only depleted HCC cell proliferation, formation, migration and invasion in vitro but also inhibited tumor growth in vivo. MiR-493-5p was a target of circ-CSPP1, and HMGB1 was a target of miR-493-5p. Rescue experiments presented that miR-493-5p deficiency reversed the effects of circ-CSPP1 knockdown, and HMGB1 overexpression reversed the effects of miR-493-5p restoration. Circ-CSPP1 sponged miR-493-5p to regulate HMGB1 expression.ConclusionKnockdown of circ-CSPP1 suppressed HCC development both in vitro and in vivo by upregulation of miR-493-5p and downregulation of HMGB1, hinting that circ-CSPP1 participated in HCC pathogenesis.     

Association of high mobility group box-1 protein levels with sepsis and outcome of severely burned patients

BackgroundThe study was performed to observe the systemic release and kinetics of high mobility group box-1 protein (HMGB1) in burned patients.Methods106 patients were included, and they were divided into three groups with different burn sizes: group I, group II and group III. Healthy volunteers served as normal controls (n = 25). The peripheral blood samples were collected on postburn days (PBD) 1, 3, 7, 14, and 21. The blood samples were used to detect levels of HMGB1 in plasma by ELISA kits for human. Gene expression of HMGB1 in peripheral blood mononuclear cells was assessed by real-time quantitative PCR taking GAPDH as the internal standard.ResultsThe levels of HMGB1 were significantly elevated on PBD 1–21 in patients with various burn sizes compared with normal controls, and there were obvious differences between group I and group III. The HMGB1 levels were significantly higher in septic patients than those without sepsis on PBD 7–21. Among septic patients, the HMGB1 levels in the survival group were markedly lower than those with fatal outcome on PBD 3–21.ConclusionsExtensive burn injury could result in significantly increased HMGB1 levels, which appears to be associated with the development of sepsis and fatal outcome of major burns.     

Shizukaol A exerts anti-inflammatory effect by regulating HMGB1/Nrf2/HO-1 pathway

BackgroundSarcandra glabra (Thunb.) Makino (Chloranthaceae) has a long history of being used in Traditional Chinese medicines (TCMs) to treat painful joints, fractures, arthritis, and other diseases caused by inflammation. It has been reported that lindenane-type sesquiterpenoid dimers are main anti-inflammatory ingredient of S. glabra. Meanwhile, shizukaol A, the precursor of these sesquiterpene dimers, possesses a good inhibitory effect on nitric oxide (NO) in our previous study. But its anti-inflammatory mechanism is still unclear.PurposeThis study aimed to explore the possible anti-inflammatory mechanism and potential targets of shizukaol A in lipopolysaccharide (LPS)-induced RAW 264.7 cells.MethodsThe release of NO and inflammatory cytokines in LPS-stimulated RAW 264.7 cells were measured by Griess reagent and ELISA, respectively. The relevant proteins including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), nuclear factor kappa B (NF-κB) p65, High mobility group box 1 (HMGB1) were detected by western blot. Nuclear translocation of p65, HMGB1 and nuclear factor E2-related factor 2 (Nrf2) were examined by immunofluorescence. The level of reactive oxygen species (ROS) was tested by flow cytometry. The target of shizukaol A was investigated by molecular docking and Drug Affinity Responsive Target Stability (DARTS).ResultsShizukaol A had a good inhibitory effect on NO with half maximal inhibitory concentration (IC₅₀) of 13.79 ± 1.11 μM. Shizukaol A could down-regulate the expression of iNOS and COX-2. Further studies demonstrated that shizukaol A can significantly inhibit phosphorylation and nuclear translocation of NF-κB. Meanwhile, shizukaol A decreased the level of ROS and enhanced the expression of heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO1). Furthermore, shizukaol A up-regulated the expression of Nrf2 and its nuclear translocation. More importantly, shizukaol A could inhibit activation of HMGB1 by targeting HMGB1.ConclusionShizukaol A inhibited inflammation by targeting HMGB1 to regulate the Nrf2/HO-1 signaling pathway. Thus, shizukaol A may be an attractive therapeutic candidate for inflammatory diseases.     

七氟烷吸入麻醉对单肺通气患者血清IL-6、IL-10、MIP-2、SP-D及HMGB1水平的影响

目的:探讨七氟烷吸入麻醉对单肺通气患者血白细胞介素-6(IL-6)、白细胞介素-10(IL-10)、巨噬细胞炎性蛋白-2(MIP-2)、人肺表面活性特异蛋白(SP-D)及高迁移率族蛋白1(HMGB1)水平的影响。方法:选择2014年9月~2016年9月于我院行单肺通气的患者108例,参照抽签法分为两组,每组各54例。对照组行常规麻醉,实验组采用七氟烷麻醉,比较两组通气前后血清IL-6、IL-10、MIP-2、SP-D、HMGB1、丙二醇(MDA)、超氧化物歧化醇(SOD)、平均动脉压(MAP)、心率(HR)水平的变化及并发症的发生情况。结果:通气前,两组血清IL-6、IL-10、MIP-2、SP-D、HMGB1、MDA、SOD、MAP、HR水平比较差异均无统计学意义(P0.05)。通气后,两组血清IL-6、IL-10、MIP-2、SP-D、HMGB1、MDA水平均较治疗前显著上升,而实验组以上指标均明显低于对照组;两组血清SOD、MAP、HR均较治疗前显著降低,且研究组低于对照组,差异均有统计学意义(P0.05)。结论:七氟烷吸入麻醉能够抑制单肺通气患者血清IL-6、IL-10、MIP-2、SP-D及HMGB1水平上升,改善机体的氧化应激状态,利于血流动力学的稳定,发挥肺部保护作用。     

Inflammatory Biomarkers as Risk Factors for Future Atrial Fibrillation. An Eleven-Year Follow-Up of 6315 Men and Women: The Tromsø Study

BackgroundInflammatory biomarkers are reported as risk factors for atrial fibrillation (AF), but their impact is uncertain.ObjectiveWe investigated the associations between inflammatory biomarkers and future AF in a large general cohort.MethodsAvailable markers were white blood cells (WBCs) with subgroups, fibrinogen, high-sensitivity C-reactive protein (hs-CRP), and osteoprotegerin (OPG). A total of 6315 men and women from a population survey in Tromsø, Norway in 1994 to 1995 were followed for a mean of 10.9 years. Mean age at baseline was 60 years. Measurements of height, weight, blood pressure, heart rate, total cholesterol, high-density lipoprotein (HDL) cholesterol, WBC count, and information on diabetes, angina, myocardial infarction, and antihypertensive treatment, were obtained at baseline. Fibrinogen, hs-CRP, and OPG were obtained at a follow-up visit. The outcome measure was first-ever AF, documented on an electrocardiogram. The Cox proportional hazards regression model was used to estimate hazard ratios of AF.ResultsIn the multivariable analysis, adjusted for traditional cardiovascular risk factors and other inflammatory biomarkers, hs-CRP was associated with AF in men only (hazard ratio = 1.14 for a 1 SD increase; 95% CI, 1.02–1.28). There was a significant increase in AF across quartiles of WBCs in men (P = 0.007) and in the total study population (P = 0.004). OPG was associated with AF in patients free of coronary heart disease at baseline. Fibrinogen and subgroups of WBCs showed no significant association with AF.ConclusionThis population-based cohort study showed that hs-CRP was independently associated with AF in men, but apparently not in women, and that patients with WBCs in the upper quartile had increased risk of AF.     

Inhibitory functions of maslinic acid,a natural triterpene,on HMGB1-mediated septic responses

BackgroundMaslinic acid (MA), a natural triterpenoid from Olea europaea, prevents oxidative stress and pro-inflammatory cytokine generation. High mobility group box 1 (HMGB1) has been recognized as a late mediator of sepsis, and the inhibition of the release of HMGB1 and the recovery of vascular barrier integrity have emerged as attractive therapeutic strategies for the management of sepsis.MethodsWe tested the hypothesis that MA induces sirtuin 1 and heme oxygenase-1, which inhibit the release of HMGB1 in lipopolysaccharide (LPS)-stimulated cells, thus inhibiting HMGB1-induced hyperpermeability and increasing the survival of septic mice. MA was administered after LPS or HMGB1 challenge, and the antiseptic activity of MA was determined based on permeability, the activation of pro-inflammatory proteins, and the production of markers for tissue injury in HMGB1-activated human umbilical vein endothelial cells (HUVECs) and a cecal ligation and puncture (CLP)-induced sepsis mouse model.ResultsMA significantly reduced the release of HMGB1 in LPS-activated HUVECs and attenuated the CLP-induced release of HMGB1. Additionally, MA alleviated HMGB1-mediated vascular disruption and inhibited hyperpermeability in mice, and in vivo analysis revealed that MA reduced sepsis-related mortality and tissue injury.ConclusionTaken together, the present results suggest that MA reduced HMGB1 release and septic mortality and thus may be useful in the treatment of sepsis.     

High mobility group box 1 contributes to anti-neutrophil cytoplasmic antibody-induced neutrophils activation through receptor for advanced glycation end products (RAGE) and Toll-like receptor 4

IntroductionHigh mobility group box-1 (HMGB1), a typical damage-associated molecular pattern (DAMP) protein, is associated with inflammatory conditions and tissue damage. Our recent study found that circulating HMGB1 levels could reflect the disease activity of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). The current study aimed to investigate whether HMGB1 participated in ANCA-induced neutrophil activation, which is one of the most important pathogenic aspects in the development of AAV.MethodsThe various effects of HMGB1 in ANCA-induced neutrophil activation were measured. Antagonists for relevant receptors and signaling molecules were employed.ResultsANCA antigens translocation on neutrophils primed with HMGB1 was significantly higher than non-primed neutrophils. The levels of respiratory burst and degranulation increased significantly in HMGB1-primed neutrophils activated with ANCA-positive IgG, as compared with non-primed neutrophils. Furthermore, blocking Toll-like receptor 4 (TLR4) and receptor for advanced glycation end products (RAGE), rather than TLR2, resulted in a significant decrease in HMGB1-induced ANCA antigens translocation, respiratory burst and degranulation. Similar effects were also found when blocking MyD88 and NF-κB.ConclusionsHMGB1 could prime neutrophils by increasing ANCA antigens translocation, and the primed neutrophils could be further induced by ANCA, resulting in the respiratory burst and degranulation. This process is TLR4- and RAGE-dependent through the MyD88/NF-κB pathway.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0587-4) contains supplementary material, which is available to authorized users.     

Elevated Soluble Triggering Receptor Expressed on Myeloid Cells (sTREM)-1 Levels in Maternal Serum during Term and Preterm Labor

Background

Infection and inflammation are important mechanisms leading to preterm birth. Soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) belongs to a family of cell surface receptors that seems to play an important role in fine-tuning the immune response. It has been demonstrated that sTREM-1 is involved in bacterial infection as well as in non-infectious inflammatory conditions. Few studies have investigated serum sTREM-1 expression during preterm labor. Therefore, the purpose of this study was to assess sTREM-1 concentrations in maternal serum during term and preterm labor.

Methods

This case control study included 176 singleton pregnancies in the following groups: patients in (1) preterm labor, delivered before 34 weeks (PTB) (n = 52); (2) GA matched controls, not in labor, matched for gestational age (GA) with the PTB group (n = 52); (3) at term in labor (n = 40) and (4) at term not in labor (n = 32). sTREM-1 concentrations were determined by enzyme-linked immunoassay.

Results

sTREM-1 was detected in all serum samples. Median sTREM-1 concentrations were significantly higher in women with PTB vs. GA matched controls (367 pg/ml, interquartile range (IQR) 304–483 vs. 273 pg/ml, IQR 208–334; P<0.001) and in women at term in labor vs. at term not in labor (300 pg/ml, IQR 239–353 vs. 228 pg/ml, IQR 174–285; P<0.001). Women with PTB had significantly higher levels of sTREM-1 compared to women at term in labor (P = 0.004). Multiple regression analysis, with groups recoded as three key covariates (labor, preterm and rupture of the membranes), showed significantly higher sTREM-1 concentrations for labor (+30%, P<0.001) and preterm (+15%, P = 0.005) after adjusting for educational level, history of PTB and sample age.

Conclusions

sTREM-1 concentrations in maternal serum were elevated during spontaneous term and preterm labor and sTREM-1 levels were significantly higher in preterm labor.     

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.     

Prognostic significance of combining high mobility group Box-1 and OV-6 expression in hepatocellular carcinoma

The inflammatory environment and existence of cancer stem cells are critical for progression and intrahepatic recurrence of hepatocellular carcinoma (HCC) after curative resections. Here, we investigated the prognostic significance of combining high mobility group box 1 (HMGB1) expression and hepatic progenitor marker OV6 in hepatocellular carcinoma. Expression of HMGB1 and OV6 was evaluated using immunohistochemistry profiling in tissue microarrays containing samples from 208 HCC patients. Invasive clinical or pathological factors were found in patients with high expression of HMGB1 or OV6. Higher HMGB1 was associated with poorer clinical outcomes, and independently related to elevated 5-year recurrence incidence (85.5% vs. 62.4%, P<0.001). We also found that more OV6 positive staining was correlated with poor prognosis of HCC patients (P<0.001). Notably, expression of HMGB1 was positively correlated with OV6 in density (R²=0.032, P<0.001) and reversely related to HCC outcomes. Abnormal expression of HMGB1 in combination with positive staining of OV6 displayed poorer prognostic performance than single biomarker alone (area under curve (AUC) survival=0.696). Therefore, HMGB1 and OV6 positive staining are promising prognostic parameters for HCC, and we propose that HMGB1 and OV6 may cooperate with each other and predict poor prognosis of HCC.     

Intestinal Microbiota is Different in Women with Preterm Birth: Results from Terminal Restriction Fragment Length Polymorphism Analysis

Preterm birth is a leading cause of perinatal morbidity and mortality. Studies using a cultivation method or molecular identification have shown that bacterial vaginosis is one of the risk factors for preterm birth. However, an association between preterm birth and intestinal microbiota has not been reported using molecular techniques, although the vaginal microbiota changes during pregnancy. Our aim here was to clarify the difference in intestinal and vaginal microbiota between women with preterm birth and women without preterm labor. 16S ribosomal ribonucleic acid genes were amplified from fecal and vaginal DNA by polymerase chain reaction. Using terminal restriction fragment length polymorphism (T-RFLP), we compared the levels of operational taxonomic units of both intestinal and vaginal flora among three groups: pregnant women who delivered term babies without preterm labor (non-PTL group) (n = 20), those who had preterm labor but delivered term babies (PTL group) (n = 11), and those who had preterm birth (PTB group) (n = 10). Significantly low levels of Clostridium subcluster XVIII, Clostridium cluster IV, Clostridium subcluster XIVa, and Bacteroides, and a significantly high level of Lactobacillales were observed in the intestinal microbiota in the PTB group compared with those in the non-PTL group. The levels of Clostridium subcluster XVIII and Clostridium subcluster XIVa in the PTB group were significantly lower than those in the PTL group, and these levels in the PTL group were significantly lower than those in non-PTL group. However, there were no significant differences in vaginal microbiota among the three groups. Intestinal microbiota in the PTB group was found to differ from that in the non-PTL group using the T-RFLP method.