High Mobility Group Box Protein 1 Levels Research Articles

Effects of anterior approach to quadratus lumborum block on postoperative cognitive function following hip surgery in older people: a randomized controlled clinical trial

BackgroundPeripheral nerve block, including the quadratus lumborum block (QLB), has been used for postoperative analgesia in hip surgery. However, the effects of QLB on cognitive function after hip surgery remain unknown. This study aimed to assess the effects of the anterior approach to QLB on postoperative cognitive function in older people undergoing hip surgery.MethodsSixty older people who underwent hip surgery from May 2021 to May 2022 were randomly divided into the QLB (n = 30) and control groups (n = 30). The Montreal Cognitive Assessment (MoCA) score (mean ± SD) was measured one day preoperatively and seven and 30 days postoperatively. The frequency (%) of postoperative cognitive dysfunction (POCD) was examined seven and 30 days postoperatively. The visual analog scale (VAS) scores at rest and Bruggrmann comfort scale (BCS) scores [Median (IQR)] 6 h (t1), 12 h (t2), 24 h (t3), and 48 h (t4) after surgery were assessed. The plasma high mobility group box protein 1 (HMGB1) and levels of interleukin-6 (IL-6) (mean ± SD) were evaluated 1 h preoperatively (baseline) and 24 h postoperatively (day 1). The requirement for rescue analgesia [Median (IQR)], time to first off-bed activity (mean ± SD), and adverse effects after surgery were also recorded.ResultsCompared with the control group, the frequency of POCD was significantly lower in the QLB group seven days postoperatively (10.7% vs. 34.5%, P = 0.033), but no difference at 30 days postoperatively (3.6% vs. 10.3%, P = 0.319). There was no significant difference in MoCA scores between the two groups at one day preoperatively and 30 days postoperatively. However, the MoCA scores at seven days postoperatively were higher in the QLB group than in the control group (27.4 ± 1.81 vs. 26.4 ± 1.83, P = 0.043). In the QLB group, the VAS scores at t1, t2, and t3 were lower [3(2–4) vs. 4(3–4), P = 0.028; 3(2–3) vs. 4(3–5), P = 0.009; 2(1–3) vs. 2(2–3), P = 0.025], and the BCS scores at t1, t2, and t3 were higher than those in the control group [3(1–3) vs. 1(1–2), P = 0.006; 3(2–3) vs. 2(1–3), P = 0.011; 3(2–4) vs. 2(2–3), P = 0.041]. The patients in the QLB group reported significantly fewer requirements for rescue analgesia [0(0–1) vs. 1(0–2), P = 0.014]. The plasma levels of HMGB1 and IL-6 at 24 h postoperatively in the QLB group were significantly lower than in the control group (749.0 ± 185.7 vs. 842.1 ± 157.9, P = 0.046; 24.8 ± 8.1 vs. 31.9 ± 5.5, P < 0.001). The time to first off-bed activity from the end of surgery was shorter in the QLB group (25.3 ± 5.3 vs. 29.7 ± 6.9, P = 0.009). There was no significant difference in the incidence of postoperative complications between the two groups.ConclusionsAnterior QLB given to older people undergoing hip surgery could promote early postoperative cognitive function recovery, provide adequate postoperative analgesia, and inhibit the release of inflammatory factors.Trial registrationChictr.org.cn identifier ChiCTR2000040724 (Date of registry: 08/12/2020, prospectively registered).

Dynamic changes and clinic significance of serum high mobility group box 1 in patients with total hip arthroplasty.

Deeper understanding on the risk factors and seeking potential predicted biomarkers for prognosis of total hip arthroplasty (THA) patients are of great significance. Limited researches focused the correlation between high mobility group box protein-1 (HMGB1) and the prognosis of THA patients. The objective of this study was to investigate the role of HMGB1 and inflammatory factors in patients underwent total hip arthroplasty (THA). The present prospective study enrolled 208 THA patients who went to our hospital during January 2020 to January 2022. Serum levels of HMGB1, C-reactive protein (CRP), interleukin-1b (IL-1β), and IL-6 were detected at the admission, 1 day, 3 days, 7 days, 30 days, and 90 days after surgery. The levels of Harris score, Fugl-Meyer, 36-item short-form health survey (SF-36), and Pittsburgh sleep quality index (PSQI) were detected on 90 days after surgery in two groups. Receiver operating characteristic curve (ROC) was performed for analyzing the diagnostic value of HMGB1 and logistic regression model was used for identifying the risk factor for poor prognosis of THA patients. Serum levels of HMGB1 and inflammatory factors increased after surgery compared with the baselines. A positive correlation was found between HMGB1 and CRP on 1 day after surgery, and positive correlations were found among HMGB1, IL-1β, and IL-6 on 3 day after surgery. Besides, low HMGB1 reduced the incidence of post-operative complications and improved prognosis of THA patients. Serum HMGB1 was correlated with inflammatory factors and the prognosis of THA patients.

Association between circulating inflammatory biomarkers and functional outcome or perihaematomal oedema after ICH: a systematic review &amp; meta-analysis

Background: Currently, there are no specific medical treatments for intracerebral haemorrhage (ICH), but the inflammatory response may provide a potential route to treatment. Given the known effects of acute brain injury on peripheral immunity, we hypothesised that inflammatory biomarkers in peripheral blood may be associated with clinical outcome following ICH, as well as perihaematomal oedema (PHO), which is an imaging marker of the neuroinflammatory response. Methods: We searched OVID Medline and EMBASE on 07 April 2021 for studies of humans with ICH measuring an inflammatory biomarker in peripheral blood and PHO or clinical outcome. Risk of bias was assessed using a scale comprising features of the Newcastle-Ottawa Assessment Scale, STROBE-ME and REMARK guidelines. We used random effects meta-analysis to pool standardised mean differences (SMD) if ≥1 study quantified the association between identical biomarkers and measures of PHO or functional outcome. Results: Of 8,615 publications, 16 examined associations between 21 inflammatory biomarkers and PHO (n=1,299 participants), and 93 studies examined associations between ≥1 biomarker and clinical outcome (n=17,702 participants). Overall, 20 studies of nine biomarkers (n=3,199) met criteria for meta-analysis of associations between inflammatory biomarkers and clinical outcome. Death or dependency (modified Rankin Scale (mRS) 3–6) 90 days after ICH was associated with higher levels of C-reactive protein (CRP) (SMD 0.80; 95%CI [0.44, 1.17]; p&lt;0.0001), fibrinogen (SMD 0.32; 95%CI [0.04, 0.61]; p=0.025), white blood cell (WBC) count (SMD 0.27; 95%CI [0.11, 0.44]; p=0.001) and high mobility group box protein 1 (HMGB1) (SMD 1.67; 95%CI [0.05, 3.30]; p=0.04). Conclusions: Higher circulating levels of WBC, CRP, fibrinogen and HMGB1 are associated with poorer outcomes after ICH. This study highlights the clinical importance of the inflammatory response to ICH and identifies additional research needs in determining if these associations are mediated via PHO and are potential therapeutic targets. Registration: PROSPERO (CRD42019132628; 28/05/2019).

Glycyrrhizin regulates the HMGB1/P38MAPK signalling pathway in status epilepticus.

In recent decades, studies have reported that inflammation serves key roles in epilepsy and that high mobility group box protein‑1 (HMGB1) may be involved in status epilepticus. However, it has not been reported whether HMGB1 participates in the pathogenesis of status epilepticus through the regulation of the p38 mitogen‑activated protein kinase (p38MAPK) signalling pathway. In the present study, Sprague‑Dawley rats were randomly divided into four groups as follows: Control, status epilepticus (SE), dimethyl sulfoxide treatment (DMSO + SE), and glycyrrhizin treatment (GL + SE) groups. Behavioural changes were then evaluated using the Racine score. In the hippocampus, the protein expression levels of HMGB1 were assessed using western blotting, the neuronal damage was evaluated using haematoxylin and eosin staining and transmission electron microscopy, and the activation of microglia was assessed using immunochemistry and immunofluorescence. The results demonstrated that, in the hippocampal region, HMGB1 existed in neurons and astrocytes and the protein expression levels of HMGB1, p38MAPK and phosphorylated‑p38MAPK were significantly inhibited after treatment with GL. Furthermore, GL could alleviate neuronal injury in the CA1 region of the hippocampus and prevented HMGB1 translocation from the nucleus into the cytoplasm in these areas. These findings expand the understanding of how HMGB1 may participate in SE and lay a foundation for evaluation of HMGB1 as a drug target.

High mobility group box protein 1 (HMGB1) serum and urinary levels and gene polymorphism in Egyptian patients with systemic lupus erythematosus: A possible relation to lupus nephritis.

The aim of this study was to evaluate the effects of the high mobility group box protein 1 (HMGB1) serum and urinary levels and gene polymorphisms on systemic lupus erythematosus (SLE) development and investigate their link to lupus nephritis (LN). We enrolled 120 Egyptian SLE patients and 120 healthy controls. Thorough medical and clinical evaluation were carried out, and SLE disease activity index (SLEDAI) was assessed. Lupus patients were divided into two groups according to the presence of LN. Measurement of HMGB1 serum and urinary levels was done using ELISA and genotyping for HMGB1 (rs1045411) was performed. There were statistically significantly higher HMGB1 serum and urinary levels in SLE patients (p < 0.001). There was a marginally significant association between lupus and alleles (p = 0.059, φ = -0.086). 'C' allele was marginally significant risk allele for SLE. After classifying SLE patients based on the presence or absence of LN, there was no significant difference as regard sex (p = 0.387), age (p = 0.208) and disease duration (p = 0.094).However, there was a significant difference between the 2 groups in regard to the frequency of musculoskeletal manifestations (p = 0.035), SLEDAI score (p < 0.001), both serum (p < 0.001) and urinary HMGB1 levels (p < 0.001) in addition to the frequency of HMGB1 genotypes (p = 0.003). Lupus patients with C/T-T/T HMGB1 genotypes had 3.5-times higher odds to exhibit LN. Serum and urine HMGB1 measurements are helpful in the diagnosis of SLE and the prediction of LN. There is a link between HMGB1 gene variations and the risk of SLE, with evidence that the C/T-T/T HMGB1 genotype is linked to a significantly greater risk of LN in the Egyptian population.

Ac2‑26 alleviates hepatic ischemia‑reperfusion injury based on inhibiting the positive feedback loop of HMGB1/TLR4/NF‑κB/neutrophils.

Inflammation is one of the most crucial mechanism underlying hepatic ischemia-reperfusion injury (HIRI). Several studies have shown that Ac2-26, the active N-terminal peptide of Annexin A1, could modulate anti-inflammatory processes and protect the organs from ischemia-reperfusion injury (IRI). However the effects of Ac2-26 on an HIRI model have not been reported to date. The purpose of the present study was to determine whether Ac2-26 pretreatment could protect hepatocytes against acute HIRI by inhibiting neutrophil infiltration through regulation of the high mobility group box protein 1 (HMGB1)/Toll-like receptor 4 (TLR4)/NF-κB signaling pathway. To this end, a total of 72 adult C57BL/6 mice were randomly divided into sham operation (sham), ischemia-reperfusion (I/R), I/R + Ac2-26 and Ac2-26 groups. The HIRI model was established by occluding the branch of the hepatic pedicle to the left and median liver lobes with an atraumatic vascular clamp for 45 min, followed by reperfusion for 24 h. The expression of HMGB1, TLR4, NF-κB, IκBα and lymphocyte antigen 6 complex locus G6D (Ly6G) was detected using reverse transcription-quantitative PCR, western blotting and immunohistochemical staining; serum levels of HMGB1 were evaluated using an enzyme-linked immunosorbent assay. Flow cytometry was used to detect the proportion of neutrophil. The results indicated that Ac2-26 preconditioning rescued hepatocyte dysfunctions induced by HIRI. In addition, HIRI was associated with a significant increase in HMGB1 expression and release, accompanied by increased expression of TLR4, which was significantly inhibited by Ac2-26. Furthermore, the expression of phosphorylated (p)-NF-κB and the ratio of p-NF-κB to NF-κB were markedly increased, while the expression of IκBα was decreased in the I/R group compared with those in the sham group; however, these effects were reversed by Ac2-26 administration. Additionally, Ac2-26 administration significantly inhibited neutrophil infiltration and resulted in low levels of neutrophils and Ly6G as well as reduced myeloperoxidase activity. Taken together, these results indicated that Ac2-26 pretreatment serves a protective role against HIRI by regulating the HMGB1/TLR4/NF-κB signaling pathway and inhibiting neutrophil infiltration.

Oxaliplatin Induces Immunogenic Cell Death in Human and Murine Laryngeal Cancer

Background Cisplatin resistance is observed in patients with laryngeal cancer. The present study was designed to explore the efficacy of oxaliplatin on laryngeal cancer and elucidate the underlying mechanisms. Methods Cell viability was determined by using MTT assays. Cell apoptosis was determined by using annexin V and propidium iodide (PI) staining. Flow cytometry and immunofluorescence were applied to determine the levels of calreticulin (CALR) and DiD (1,1-dioctadecyl-3,3,3,3-tetramethylindodicarbocyanine). Flow cytometry was applied to analyze the levels of CD83, CD86, IFN-γ-producing CD8+ T cells, and CD4+CD25+FoxP3+ Tregs. The levels of adenosine triphosphate (ATP) were determined by using a chemiluminescent ATP kit and cytokines were determined by using specific enzyme-linked immunosorbent assays (ELISAs). The levels of HMGB1 were determined by using Western blot and ELISA, respectively. The xenograft animal model was constructed to evaluate the antitumor effects of oxaliplatin. Results Oxaliplatin inhibited cell growth, promoted cell apoptosis, and induced the levels of CALR, ATP, and high mobility group box protein 1 (HMGB1) in Hep-2 cells. Oxaliplatin-treated Hep-2 cells increased the intensity of DiD and the levels of CD83 and CD86 in dendritic cells (DCs), as well as induced the supernatant IL-6 and TNF-α. Oxaliplatin-treated primary laryngeal cancer cell-pulsed DCs increased the IFN-γ-producing CD8+ T cells and suppressed CD4+CD25+FoxP3+ Tregs. In vivo data showed that oxaliplatin suppressed tumor growth and increased the populations of CD86+CD80+ and CD8+CD45+ cells in the tumor tissues. Conclusion Treatment with oxaliplatin inhibited laryngeal cancer cells by inducing immunogenic cell death.

HMGB1-activatied NLRP3 inflammasome induces thrombocytopenia in heatstroke rat.

BackgroundThrombocytopenia, an early common complication in heatstroke (HS), has been widely considered as a mortality predictor of HS. The mechanism underlying thrombocytopenia in HS remains unknown. It is not known whether NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is activated in HS platelet, which, in turn, induces platelet activation and thrombocytopenia. This study tried to clarify the activation of the NOD-like receptor signaling pathway under HS conditions and investigate its roles in mediating HS-induced thrombocytopenia.MethodsRat HS models were established in a certain ambient temperature and humidity. Platelets, isolated from blood, were counted and CD62P, an index of platelet activation, was measured by flow cytometry in all rats. The colocalization of NLRP3 inflammasome in platelet was detected by confocal fluorescence microscopy. Mitochondrial-derived reactive oxygen species (ROS) was detected using the molecular probes. Plasma HMGB1 and IL-1β levels were measured by ELISA.ResultsPlatelet activation, showed by upregulated CD62P, and thrombocytopenia were observed in HS rats. HS activated the NLRP3 inflammasome, which was induced by elevated levels of ROS, while the upregulated CD62P and thrombocytopenia triggered by NLRP3 inflammasome were attributed to the high mobility group box protein 1 (HMGB1) inplasma. Moreover, inhibition of the NOD-like receptor signaling pathway in rats with HS suppressed platelet activation and the decline of platelet count. Similar results were obtained when the receptor toll-like receptor 4 (TLR4)/advanced glycation end product (RAGE) was blocked.ConclusionsThe NOD-like receptor signaling pathway induces platelet activation and thrombocytopenia in HS rats. These findings suggested that the NLRP3 inflammasome might be the potential target for HS treatment.

Remote ischemic preconditioning causes transient cell cycle arrest and renal protection by a NF-κB-dependent Sema5B pathway.

Acute kidney injury increases morbidity and mortality, and previous studies have shown that remote ischemic preconditioning (RIPC) reduces the risk of acute kidney injury after cardiac surgery. RIPC increases urinary high mobility group box protein-1 (HMGB1) levels in patients, and this correlates with kidney protection. Here, we show that RIPC reduces renal ischemia-reperfusion injury and improves kidney function in mice. Mechanistically, RIPC increases HMGB1 levels in the plasma and urine, and HMGB1 binds to TLR4 on renal tubular epithelial cells, inducing transcriptomic modulation of renal tubular epithelial cells and providing renal protection, whereas TLR4 activation on nonrenal cells was shown to contribute to renal injury. This protection is mediated by activation of induction of AMPKα and NF-κB; this induction contributes to the upregulation of Sema5b, which triggers a transient, protective G1 cell cycle arrest. In cardiac surgery patients at high risk for postoperative acute kidney injury, increased HMGB1 and Sema5b levels after RIPC were associated with renal protection after surgery. The results may help to develop future clinical treatment options for acute kidney injury.

High-Mobility Group Box Protein 1 Is an Independent Prognostic Marker for All-Cause Mortality in Patients With Dilated Cardiomyopathy

High-mobility group box protein 1 (HMGB1) is released during tissue damage and activates the innate immune system through toll-like receptor 4. Because mortality in dilated cardiomyopathy (DCM) is associated with activation of the innate immune system, we hypothesized that HMGB1 possesses a prognostic value in estimating mortality in patients with DCM. We determined HMGB1 and N-terminal B-type natriuretic peptide (NT-proBNP) levels in 67 patients with DCM (12 women, mean age 53.6 ± 1.5 years). Kaplan-Meier analyzes revealed that higher levels of HMGB1 and NT-proBNP are related to increased all-cause mortality. Multivariable Cox regression confirmed HMGB1 as a risk factor for mortality in patients with DCM, independent of NT-proBNP, age, and gender (hazard ratio per 1 SD 1.920, 95% confidence interval 1.401 to 2.631, p &lt;0.001). HMGB1 is a promising candidate to estimate the prognosis of patients with DCM.

A Porcine Sepsis Model With Numerical Scoring for Early Prediction of Severity.

IntroductionSepsis can lead to organ dysfunctions with disturbed oxygen dynamics and life-threatening consequences. Since the results of organ-protective treatments cannot always be transferred from laboratory models into human therapies, increasing the translational potential of preclinical settings is an important goal. Our aim was to develop a standardized research protocol, where the progression of sepsis-related events can be characterized reproducibly in model experiments within clinically-relevant time frames.MethodsPeritonitis was induced in anesthetized minipigs injected intraperitoneally with autofeces inoculum (n = 27) or with saline (sham operation; n = 9). The microbial colony-forming units (CFUs) in the inoculum were retrospectively determined. After awakening, clinically relevant supportive therapies were conducted. Nineteen inoculated animals developed sepsis without a fulminant reaction. Sixteen hours later, these animals were re-anesthetized for invasive monitoring. Blood samples were taken to detect plasma TNF-α, IL-10, big endothelin (bET), high mobility group box protein1 (HMGB1) levels and blood gases, and sublingual microcirculatory measurements were conducted. Hemodynamic, respiratory, coagulation, liver and kidney dysfunctions were detected to characterize the septic status with a pig-specific Sequential Organ Failure Assessment (pSOFA) score and its simplified version (respiratory, cardiovascular and renal failure) between 16 and 24 h of the experiments.ResultsDespite the standardized sepsis induction, the animals could be clustered into two distinct levels of severity: a sepsis (n = 10; median pSOFA score = 2) and a septic shock (n = 9; median pSOFA score = 8) subgroup at 18 h of the experiments, when the decreased systemic vascular resistance, increased DO2 and VO2, and markedly increased ExO2 demonstrated a compensated hyperdynamic state. Septic animals showed severity-dependent scores for organ failure with reduced microcirculation despite the adequate oxygen dynamics. Sepsis severity characterized later with pSOFA scores was in correlation with the germ count in the induction inoculum (r = 0.664) and CFUs in hemocultures (r = 0.876). Early changes in plasma levels of TNF-α, bET and HMGB1 were all related to the late-onset organ dysfunctions characterized by pSOFA scores.ConclusionsThis microbiologically-monitored, large animal model of intraabdominal sepsis is suitable for clinically-relevant investigations. The methodology combines the advantages of conscious and anesthetized studies, and mimics human sepsis and septic shock closely with the possibility of numerical quantification of host responses.

Cysteine 106 Controls HMGB1 Nucleocytoplasmic Distribution and Function: Role of Sex and Implication to Pulmonary Hypertension

IntroductionHigh mobility group box protein 1 (HMGB1) is a nuclear protein that gets released during cell damage and stimulates inflammatory and proliferative pathways in the survived neighboring cells. Our previous research discovered a significant sex difference in HMGB1 release and downstream signaling and confirmed its critical importance in the pathobiology of pulmonary hypertension (PH).HypothesisHMGB1 contains three cysteine residues (23/45/106) involved in the extracellular HMGB1 oligomerization and receptor binding, with Cys106 being especially critical for HMGB1 signaling. However, the role of cysteines in the intracellular HMGB1 activity is less established. We hypothesize that Cys106 regulates intracellular HMGB1 homeostasis and function and contributes to the pathogenic mechanisms relevant to PH.MethodsTo study the activities of HMGB1 cysteines, we designed peptides that bind to the specific regions of HMGB1 and, by shielding either Cys106 or Cys23/45, prevent their interaction with the downstream targets. The peptides with cell‐penetrating TAT sequences were used to study the intracellular role of HMGB1 cysteines, while peptides without TAT served as extracellular controls. Fractionating of pulmonary artery smooth muscle cells (PASMC) allowed the evaluation of HMGB1 cytosol/nuclear distribution. Calf thymus double‐stranded DNA cellulose was used to study the binding of recombinant fully reduced HMGB1 in the presence or absence of shielding peptide. The protective role of peptide in vivo was estimated using the rat Sugen/Hypoxia model of PH. Given the discovered sex difference in the HMGB1‐mediated signaling, the in vitro and in vivo studies were replicated in male and female animals and cells.ResultsThe cytosol and nuclear levels of HMGB1 were affected by cell‐penetrating peptide designed to shield Cys106 (TAT‐α‐HMGB1Cys106, or α‐Cys106) and not any other peptide. Further investigation revealed that α‐Cys106 peptide produced ~ 5.9 fold decrease in HMGB1 binding to DNA, enhanced the exit of nuclear HMGB1 to the cytosol, which was especially evident in male cells, and induced its proteasomal degradation (1±0.097 vs. 0.428±0.045 vs. 0.885±0.049 in untreated, α‐Cys106 and α‐Cys106/proteasome inhibitor (MG132, 10μM, 1hr) treated PASMC, p&lt;0.001 and p&lt;0.003, N=6). The peptide‐mediated decrease in HMGB1/DNA binding negatively affected the expression of TLR4 and p53 and reduced cell apoptosis. In females, treatment with α‐Cys106 (2.5 mg/kg/day, i.p during the wks 1‐2 or wks 3‐5) produced an anti‐apoptotic effect and reduced plasma HMGB1 levels, which corresponded to a decreased right ventricle (RV) systolic pressure at the early stage of PH and protected the RV at the later stage. In contrast, male PH rats showed no apoptosis activation in the lungs, and α‐Cys106 treatment produced no changes in plasma HMGB1 or hemodynamic parameters.ConclusionHMGB1Cys106 is the critical regulator of intracellular HMGB1 function, including HMGB1/DNA binding, regulation of p53 expression and apoptosis activation, the intracellular distribution of HMGB1, and its extracellular release. This study also confirms the significant sex difference in the levels of pulmonary apoptosis, HMGB1 release, and its contribution to the pathobiology of PH.

The Modulation of Interferon Regulatory Factor-1 via Caspase-1-Mediated Alveolar Macrophage Pyroptosis in Ventilator-Induced Lung Injury.

Background To examine the role of interferon regulatory factor-1 (IRF-1) and to explore the potential molecular mechanism in ventilator-induced lung injury. Methods Wild-type C57BL/6 mice and IRF-1 gene knockout mice/caspase-1 knockout mice were mechanically ventilated with a high tidal volume to establish a ventilator-related lung injury model. The supernatant of the alveolar lavage solution and the lung tissues of these mice were collected. The degree of lung injury was examined by hematoxylin and eosin staining. The protein and mRNA expression levels of IRF-1, caspase-1 (p10), and interleukin (IL)-1β (p17) in lung tissues were measured by western blot and quantitative real-time polymerase chain reaction, respectively. Pyroptosis of alveolar macrophages was detected by flow cytometry and western blotting for active caspase-1 and cleaved GSDMD. An enzyme-linked immunosorbent assay was used to measure the levels of IL-1β, IL-18, IL-6, TNF-α, and high mobility group box protein 1 (HMGB-1) in alveolar lavage fluid. Results IRF-1 expression and caspase-1-dependent pyroptosis in lung tissues of wild-type mice were significantly upregulated after mechanical ventilation with a high tidal volume. The degree of ventilator-related lung injury in IRF-1 gene knockout mice and caspase-1 knockout mice was significantly improved compared to that in wild-type mice, and the levels of GSDMD, IL-1β, IL-18, IL-6, and HMGB-1 in alveolar lavage solution were significantly reduced (P < 0.05). The expression levels of caspase-1 (p10), cleaved GSDMD, and IL-1β (p17) proteins in lung tissues of IRF-1 knockout mice with ventilator-related lung injury were significantly lower than those of wild-type mice, and the level of pyroptosis of macrophages in alveolar lavage solution was significantly reduced. Conclusions IRF-1 may aggravate ventilator-induced lung injury by regulating the activation of caspase-1 and the focal death of alveolar macrophages.

Increased expression of HMGB1 in the implantation phase endometrium is related to recurrent implantation failure.

Impaired endometrial receptivity was the main cause of recurrent implantation failure (RIF); however, its underlying mechanisms had not been elucidated. This study aimed to determine the expression level of high-mobility group box protein 1 (HMGB1) in the endometrium with RIF and its effect on endometrial receptivity. Genome-wide expression profiling, real-time reverse transcription PCR, immunohistochemical staining, western blot, and in vitro assays were performed in this study. We found that HMGB1 expression was significantly decreased in the implantation phase endometrium in the control group (patients with tubal infertility and successfully achieve conception after the first embryo transfer) (P = 0.006). However, the expression levels of HMGB1 mRNA and protein were significantly upregulated during the implantation phase in endometrial tissues obtained from patients with RIF compared to that in the control group (P = 0.001), consistent with the results of the genome-wide expression profiling. Moreover, in vitro assays showed that increased expression of HMGB1 in human endometrial epithelial cells dramatically displayed a marked deficiency in supporting blastocysts and human embryonic JAR cells adhesion, which mimic the process of embryo adhesion. These findings strongly indicated that increased HMGB1 levels suppressed the epithelial cell adhesion capability, therefore contributing to impaired endometrial receptivity in patients with recurrent implantation failure, which can be used as a target for the recognition and treatment of recurrent implantation failure in clinical practice.

NLRP3 Inflammasome-Dependent Increases in High Mobility Group Box 1 Involved in the Cognitive Dysfunction Caused by Tau-Overexpression.

Tau hyperphosphorylation is a characteristic alteration present in a range of neurological conditions, such as traumatic brain injury (TBI) and neurodegenerative diseases. Treatments targeting high-mobility group box protein 1 (HMGB1) induce neuroprotective effects in these neuropathologic conditions. However, little is known about the interactions between hyperphosphorylated tau and HMGB1 in neuroinflammation. We established a model of TBI with controlled cortical impacts (CCIs) and a tau hyperphosphorylation model by injecting the virus encoding human P301S tau in mice, and immunofluorescence, western blotting analysis, and behavioral tests were performed to clarify the interaction between phosphorylated tau (p-tau) and HMGB1 levels. We demonstrated that p-tau and HMGB1 were elevated in the spatial memory-related brain regions in mice with TBI and tau-overexpression. Animals with tau-overexpression also had significantly increased nucleotide-binding oligomerization domain-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome activation, which manifested as increases in apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), activating caspase-1 and interleukin 1 beta (IL-1β) levels. In addition, NLRP3–/– mice and the HMGB1 inhibitor, glycyrrhizin, were used to explore therapeutic strategies for diseases with p-tau overexpression. Compared with wild-type (WT) mice with tau-overexpression, downregulation of p-tau and HMGB1 was observed in NLRP3–/– mice, indicating that HMGB1 alterations were NLRP3-dependent. Moreover, treatment with glycyrrhizin at a late stage markedly reduced p-tau levels and improved performance in the Y- and T-mazes and the ability of tau-overexpressing mice to build nests, which revealed improvements in spatial memory and advanced hippocampal function. The findings identified that p-tau has a triggering role in the modulation of neuroinflammation and spatial memory in an NLRP3-dependent manner, and suggest that treatment with HMGB1 inhibitors may be a better therapeutic strategy for tauopathies.

Possible role of the HMGB1 and RAGE inflammatory pathway in primary sclerosing cholangitis

BackgroundActivation of the receptor for advanced glycation end products (RAGE) and its ligand High Mobility Group Box Protein 1 (HMGB1), a nuclear protein with proinflammatory properties, has been implicated in several inflammatory disorders. ObjectiveTo analyse the influence of RAGE and HMGB1 signalling in patients with primary sclerosing cholangitis (PSC). MethodsLevels of HMGB1 and bile acid in serum and bile samples of 69 PSC patients and 32 controls were measured. Additionally, 640 patients with PSC and other liver diseases were analysed for the gain-of-function RAGE G82S SNP by PCR. Laboratory and clinical parameters were retrieved by chart review. ResultsELISA analysis showed significantly higher biliary HMGB1 concentrations in PSC patients (n=69, median 124,1 ng/ml) than in the control group (n=32, median 6,85 ng/ml, p<0,001). Median serum HMGB1 (n=22, median 2,4 ng/ml) was significantly lower than median biliary HMGB1 of the concomitant bile samples (n=22, median 151 ng/ml, p =0,001). There was no correlation of biliary HMGB1 levels with laboratory parameters or clinical end points. Analysis of the gain-of-function G82SSNP RAGE SNP in PSC patients showed 8 patients with heterozygote mutant alleles (8/324, 2,5%). Patients carrying the mutation developed more often dominant strictures of the large bile ducts (100.0% vs. 61.3%; p=0.04) and had reduced transplantation-free survival in the mutant allele group (p<0.001). ConclusionsBiliary HMGB1 levels are elevated in PSC patients compared to controls and a gain-of-function SNP in RAGE is associated with development of dominant strictures and reduced survival in PSC patients.

Systemic T Cell Exhaustion Dynamics Is Linked to Early High Mobility Group Box Protein 1 (HMGB1) Driven Hyper-Inflammation in a Polytrauma Rat Model.

We previously reported an early surge in high mobility group box protein 1 (HMGB1) levels in a polytrauma (PT) rat model. This study investigates the association of HMGB1 levels in mediating PT associated dysregulated immune responses and its influence on the cellular levels of receptor for advanced glycation end products (RAGE) and toll-like receptor 4 (TLR4). Using the same PT rat model treated with anti-HMGB1 polyclonal antibody, we evaluated changes in circulating inflammatory cytokines, monocytes/macrophages and T cells dynamics and cell surface expression of RAGE and TLR4 at 1, 3, and 7 days post-trauma (dpt) in blood and spleen. Notably, PT rats demonstrating T helper (Th)1 and Th2 cells type early hyper-inflammatory responses also exhibited increased monocyte/macrophage counts and diminished T cell counts in blood and spleen. In blood, expression of RAGE and TLR4 receptors was elevated on CD68+ monocyte/macrophages and severely diminished on CD4+ and CD8+ T cells. Neutralization of HMGB1 significantly decreased CD68+ monocyte/macrophage counts and increased CD4+ and CD8+ T cells, but not γδ+TCR T cells in circulation. Most importantly, RAGE and TLR4 expressions were restored on CD4+ and CD8+ T cells in treated PT rats. Overall, findings suggest that in PT, the HMGB1 surge is responsible for the onset of T cell exhaustion and dysfunction, leading to diminished RAGE and TLR4 surface expression, thereby possibly hindering the proper functioning of T cells.

Fecal High-Mobility Group Box 1 as a Marker of Early Stage of Necrotizing Enterocolitis in Preterm Neonates.

Introduction: An early diagnosis of necrotizing enterocolitis (NEC), a major gastrointestinal emergency in preterm newborns, is crucial to improve diagnostic approach and prognosis. We evaluated whether fecal high-mobility group box protein 1 (HMGB1) may early identify preterms at risk of developing NEC.Materials and Methods: A case-control study including neonates admitted at the Neonatal Intensive Care Unit (NICU) of the Sapienza University Hospital “Umberto I” in Rome, from July 2015 to December 2016. Stool samples obtained from cases (preterm newborns with NEC) and controls (newborns without NEC) were collected at the enrolment (T0) and within 7–14 days after the first sample collection (T1). HMGB1, extracted and measured with western blot, was reported as densitometry units (DUS).Results: HMGB1 levels in 30 cases (n = 28—Bell stage 1, n = 2 Bell stage 2) were higher [T0: 21,462 DUS (95% CI, 16,370–26,553 DUS)—T1: 17,533 DUS (95% CI, 13,052–22,014 DUS)] than in 30 preterm controls [T0: 9,446 DUS (95% CI, 6,147–12,746 DUS)—T1: 9,261 DUS (95% CI, 5,126–13,396 DUS), p < 0.001). Preterm newborns showed significant higher levels of HMGB1 (15,690 DUS (95% CI, 11,929–19,451 DUS)] in comparison with 30 full-term neonates with birth weight >2,500 g [6,599 DUS (95% CI, 3,141–10,058 DUS), p = 0.003]. Multivariate analysis showed that the risk of NEC was significantly (p = 0.012) related to the HMGB1 fecal levels at T0.Conclusions: We suggest fecal HMGB1 as a reliable marker of early NEC in preterm neonates. This study supports further investigation on the role of fecal HMGB1 assessment in managing preterm newborns at risk of NEC. Further studies are advocated to evaluate diagnostic accuracy of this marker in more severe forms of the disease.

Role of Glycated High Mobility Group Box-1 in Gastric Cancer.

Advanced glycation end products (AGEs) are produced in response to a high-glucose environment and oxidative stress and exacerbate various diseases. Nε-(Carboxymethyl)lysine (CML) is an AGE that is produced by the glycation of lysine residues of proteins. There are a few reports on alterations in protein function due to CML modification; however, its association with cancer is not clear. We investigated the significance of CML modification in high mobility group box protein-1 (HMGB1), a cytokine that is significantly associated with cancer progression. Treatment of the gastric cancer cell lines TMK1 and MKN74 with glyoxal or glucose resulted in increased CML modification compared to untreated cells. CML-HMGB1 was modified via oxidation and more pronouncedly activated the receptor for AGE and downstream AKT and NF-κB compared to naïve HMGB1 and oxidized HMGB1. CML-HMGB1 bound with reduced affinity to DNA and histone H3, resulting in enhanced extranuclear translocation and extracellular secretion. Treatment of gastric cancer cells with CML-HMGB1 enhanced cell proliferation and invasion, sphere formation, and protection from thapsigargin-induced apoptosis, and decreased 5-FU sensitivity in comparison to HMGB1. Further, CML-HMGB1 was detected at various levels in all the 10 gastric cancer tumor specimens. HMGB1 levels correlated with primary tumor progression and distant metastasis, whereas CML-HMGB1 levels were associated with primary tumor progression, lymph node metastasis, distant metastasis, and stage. In addition, CML-HMGB1 levels correlated with oxidative stress in cancer tissues and resistance to neoadjuvant therapy. Therefore, CML modification of HMGB1 enhanced the cancer-promoting effect of HMGB1. In this study, CML-HMGB1 has been highlighted as a new therapeutic target, and analysis of the molecular structure of CML-HMGB1 is desired in the future.

Celecoxib Decrease Seizures Susceptibility in a Rat Model of Inflammation by Inhibiting HMGB1 Translocation.

The risk of developing epilepsy is strongly linked to peripheral inflammatory disorders in humans. High-mobility group box protein 1 (HMGB1) has the most focus for being a suspect in this scenario. The current study aimed to detect the celecoxib effect, an anti-inflammatory drug, on decreasing seizure susceptibility and organ damage in lipopolysaccharides (LPS)/pilocarpine (PILO) pretreated Wistar rats. Rats were divided into 6 groups (8 each): group 1 (control), group 2 (PILO), group 3 (PILO+LPS), group 4 (PILO+LPS+(VPA) Valproic acid), group 5 (PILO+LPS+Celecoxib), and group 6 (PILO+LPS+VPA+Celecoxib). LPS was used to induce sepsis and PILO to induce seizures. Oxidative stress markers, pro-inflammatory cytokines, and HMGB1 levels in serum and brain homogenate were evaluated. Histopathological studies were conducted on the hippocampus, liver, lung, and kidney. Treatment with celecoxib either alone or in combination with VPA significantly reduced Racine score and delays latency to generalized tonic-clonic seizures onset with a significant decrease in hippocampal levels of pro-inflammatory cytokines, oxidative stress markers, and increase in reduced glutathione. In addition, celecoxib treatment either alone or in combination with VPA suppressed HMGB1translocation into peripheral circulation more than treatment with VPA alone. Furthermore, hippocampus, liver, lung, and kidney histopathological changes were improved in contrast to other epileptic groups. Celecoxib either alone or combined with VPA has antiepileptic and multiorgan protective effects on acute seizures and inflammatory models induced by PILO with LPS. It decreased histopathological findings, oxidative, and inflammatory effects induced by VPA and LPS. This might be due to its anti-oxidative, anti-inflammatory and anti-HMGB1 mediated effects.