High Mobility Group Box 1 mRNA Expression Research Articles

Association of High-Mobility Group Box 1 (HMGB1) Gene Polymorphisms with Susceptibility and Better Survival Prognosis in Chinese Han Neonatal Necrotizing Enterocolitis.

BackgroundHigh-mobility group box 1 (HMGB1) plays a crucial role in a variety of diseases, including neonatal necrotizing enterocolitis (NEC). The purpose of this study was to investigate the association of HMGB1 gene single-nucleotide polymorphisms (SNPs) with susceptibility and survival prognosis in Chinese Han neonates with NEC.Material/MethodsThe HMGB1 gene rs1360485, rs1045411, and rs2249825 site SNPs were genotyped in all participants. The mRNA expression of serum HMGB1 was examined using quantitative reverse transcription-polymerase chain reaction. The correlation of the HMGB1 rs1360485 SNP with NEC neonatal survival prognosis was evaluated by univariate analysis and logistic multivariate regression analysis.ResultsThe TC and CC genotype and C allele distribution frequencies of the rs1360485 SNP were lower in the NEC group, and the differences were statistically significant (all P<0.05). Individuals carrying the TC and CC genotype or C allele had a low risk of being affected by NEC. However, the genotype and allele distributions of rs1045411 and rs2249825 were not significantly different between the patient and control groups (P>0.05). NEC neonates with HMGB1 gene rs1360485 site mutations had lower mRNA levels of serum HMGB1 than those with rs1360485 site wild-type, and the rs1360485 genotypes TC and CC could independently predict better survival outcomes in NEC neonates.ConclusionsThis study demonstrated that the rs1360485 SNP of the HMGB1 gene is associated with susceptibility of NEC in neonates, and the rs1360485 genotypes TC and CC may affect HMGB1 expression and are associated with the survival prognosis of neonates with NEC.

WITHDRAWN: Tanshinone-IIA inhibits the inflammatory response and proliferation of PAECs under hypoxic conditions by repressing HMGB1 via the TLR4/NF-κB signalling pathway

To explore the potential molecular mechanism of Tanshinone-IIA (Tan-IIA) in pulmonary artery endothelial cells (PAECs) under hypoxic conditions. Rat PAECs were observed under an inverted microscope, and the biomarkers CD31 and factor VIII related antigen (FVIII-Rag) were identified by immunofluorescence (IF). The PAECs were divided into a 20% normoxia group and a 4% hypoxia group, and the cells were subjected to Tan-IIA treatment, high mobility group box 1 (HMGB1) overexpression, or the relevant controls. ELISA and MTT were performed to evaluate proinflammatory factor production and cell proliferation, respectively. RT-qPCR was used to measure HMGB1 mRNA expression, and western blotting was performed to evaluate the protein levels of HMGB1, Toll-like receptor 4 (TLR4) and nuclear factor kappa-B (NF-κB)-p65. Immunocytochemistry (ICC) and western blotting indicated the subcellular distribution of NF-κB-p65. Rat PAECs were round or short spindle-shaped and abundantly expressed CD31 and FVIII-Rag. Compared with the normoxia group, the hypoxia group produced significantly increased levels of proinflammatory factors, which decreased with increasing concentrations of Tan-IIA (p<0.05). The expression of HMGB1 and TLR4 and the phosphorylation of NF-κB-p65 presented gradually decreasing trends in the 4% hypoxia group with increasing concentrations of Tan-IIA. Moreover, ICC indicated that in the 4% hypoxia group, NF-κB-p65 translocated to the nucleus (p<0.05), and western blotting analysis showed that the higher the Tan-IIA concentration was, the lower the NF-κBp65 level in the nucleus was. Compared with the Hypoxia + Vector group, the Hypoxia+ pHMGB1 group exhibited significantly enhanced effects of the hypoxia-induced inflammatory response (p<0.05), and the inhibitory effects of Tan-IIA on the hypoxia-induced inflammatory response were reversed in the Hypoxia+Tan-IIA+pHMGB1 group due to the overexpression of HMGB1 (p<0.05); HMGB1 exerted similar effects on cell proliferation, as illustrated by MTT assay. Tan-IIA inhibits the proliferation and inflammatory response of PAECs by downregulating the expression of HMGB1 via the TLR4/NF-κB signalling pathway under hypoxic conditions.

Long Non-Coding RNA PITPNA-AS1 Accelerates the Progression of Colorectal Cancer Through miR-129-5p/HMGB1 Axis.

BackgroundLong non-coding RNAs (lncRNAs) are essential regulators in colorectal cancer (CRC) progression. This work aimed to delve into the characteristics of lncRNA PITPNA-AS1 in CRC.MethodsQuantitative real-time polymerase chain reaction (qRT-PCR) was adopted to examine PITPNA-AS1, miR-129-5p, high-mobility group box-1 (HMGB1) mRNA expressions in CRC tissues and cell lines. Functionally, cell counting kit-8 (CCK-8) and 5-ethynyl-2-deoxyuridine (EdU) incorporation assays were employed to examine cell proliferation; wound healing assay was utilized to detect cell migration; and flow cytometry was used to detect the cell apoptosis. Luciferase reporter assay, RNA immunoprecipitation assay and Western blot were conducted to detect the regulatory relationships among PITPNA-AS1, miR-129-5p and HMGB1.ResultsPITPNA-AS1 and HMGB1 mRNA expressions were observably elevated in CRC tissues and cell lines. Knocking down PITPNA-AS1 could significantly inhibit cell proliferation and migration, and promote apoptosis of CRC cells. PITPNA-AS1 could serve as a competitive endogenous RNA, and up-regulate HMGB1 expression by adsorbing miR-129-5p.ConclusionPITPNA-AS1 can expedite CRC cell proliferation and migration, and inhibit apoptosis through miR-129-5p/HMGB1 axis.

MiR-708 affords protective efficacy in anoxia/reoxygenation-stimulated cardiomyocytes by blocking the TLR4 signaling via targeting HMGB1

Ischemic heart disease is a proverbial and common cardiovascular disease, and constitutes a leading cause of disability and mortality globally. Myocardial ischemic/reperfusion (MI/R) injury is a highly orchestrated phenomenon that involves the excessive activation of high mobility group box 1 (HMGB1) signaling. In the present study, we sought to investigate the function of miR-708 in MI/R injury due to the predicted binding to HMGB1. Intriguingly, down-regulation of miR-708 and up-regulation of HMGB1 were observed in MI/R rat model and H9c2 cardiomyocytes exposed to hypoxia/reoxygenation (H/R) conditions. Dual luciferase reporter assays substantiated that HMGB1 was a direct target of miR-708. Moreover, miR-708 overexpression suppressed the mRNA and protein expression of HMGB1. Noticeably, elevation of miR-708 antagonized H/R-induced inhibition in cell viability; whilst, increased cell apoptosis evoked by H/R was restrained after miR-708 up-regulation. Simultaneously, miR-708 elevation suppressed H/R exposure-increased lactate dehydrogenase (LDH) release and reactive oxygen species (ROS) generation, but elevated the activity of anti-oxidative stress superoxide dismutase (SOD). Additionally, H/R-increased production of pro-inflammatory cytokine TNF-α and IL-6 was offset following miR-708 overexpression. Moreover, enhancement of miR-708 inhibited H/R-evoked activation of the HMGB1-TLR4-NF-κB pathway by inhibiting the protein levels of HMGB1, TLR4 and p-p65 NF-κB. Specially, restoring this pathway offset the protective effects of miR-708 on H/R-induced cardiomyocyte injury. Together, these data indicate that miR-708 may protect against H/R-induced cardiomyocyte damage by directing targeting HMGB1 signaling, implying a promising therapeutic agent against ischemic heart disease including myocardial infarction.

Effect of Mineral Pitch on the Proliferation of Human Adipose Derived Stem Cells on Acellular Scaffold.

Purpose: Acellular scaffold extracted from extracellular matrix (ECM) have been used for constructive and regenerative medicine. Adipose derived stem cells (ADSCs) can enhance the vascularization capacity of scaffolds. High mobility group box 1 (HMGB1) and stromal derived factor1 (SDF1) are considered as two important factors in vascularization and immunologic system. In this study, the effect of mineral pitch on the proliferation of human ADSCs was evaluated. In addition to HMGB1 and SDF1, factors expression in acellular scaffold was also assessed. Methods: To determine acellular scaffold morphology and the degree of decellularization, hematoxylin & eosin (H&E), 6-diamidino-2-phenylindole (DAPI), and Masson’s trichrome staining were applied. The scaffolds were treated with mineral pitch. Also, ADSCs were seeded on the scaffolds, and adhesion of the cells to the scaffolds were assessed using field emission scanning electron microscopy (FE-SEM). In addition, the efficiency of mineral pitch to induce the proliferation of ADSCs on the scaffolds was evaluated using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. To measure HMGB1 and SDF1 mRNA expression, real-time polymerase chain reactions (RT-PCR) was used. Results: FE-SEM showed that decellularized matrix possesses similar matrix morphology with a randomly oriented fibrillar structure and interconnecting pores. No toxicity was observed in all treatments, and cell proliferation were supported in scaffolds. The important point is that, the proliferation capacity of ADSCs on Mineral pitch loaded scaffolds significantly increased after 48 h incubation time compared to the unloaded scaffold (P<0.001). Conclusion: The results of this study suggest that mineral pitch has potentials to accelerate proliferation of ADSCs on the acellular scaffolds.

Down Regulation of HMGB1‐RAGE pathway by Ethyl Pyruvate

HMGB1 (high Mobility Group Box 1) protein is released by nuclear after that binds to DNA. HMGB1 can also be secreted from cells, it can bind receptor for advanced glycation end products (RAGE) that inflammatory receptor. Interaction between HMGB1 and RAGE causes upregulation of NF‐kB that leads to increased production of cytokines. Ethyl pyruvate (EP) is the ethyl ester of pyruvic acid. In recent research, EP has shown HMGB1 inhibitory effecting in many inflammation‐related diseases through pathway inhibition. In this study, we measured that expression of HMGB1 mRNA and proteins stimulated by LPS in presence of ethyl pyruvate (EP) or other inflammatory stimulants was measured as RT‐qPCR and immunoblotting analysis in BMDMs. Furthermore, levels of cytokine in the supernatant of BMDM stimulated by LPS in presence of EP or other inflammatory stimulants or mouse serum were measured by ELISA. Here in we found that EP inhibits HMGB1 pathway leading to reduced RAGE expression and NF‐κB activation. Moreover, we demonstrated EP reduced HMGB1 in serum levels of mice. Our results suggested that EP is effective inhibitors of HMGB1/RAGE signaling pathway, offering a novel potential therapeutic approach to patients and HMGB1 has been proposed as a target for inflammatory disease.Support or Funding InformationACKNOWLEDGEMENTSThis work was supported by the NRF grant funded by the Korea government (MSIP) 2019R1I1A2A01064237.

Melatonin reduces OGD/R-induced neuron injury by regulating redox/inflammation/apoptosis signaling.

To investigate the roles and underlying mechanisms of melatonin in oxygen-glucose deprivation/reoxygenation (OGD/R)-insulted SH SY5Y cells. SH SY5Y cells were cultured for OGD/R stimulation. Cell viability and cytotoxicity were measured by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide, lactate dehydrogenase (LDH), and Hoechst 33258/propidium iodide (PI) staining assays. The mRNA levels of high mobility group box-1 (HMGB1), tumor necrosis factor α (TNF-α), and inducible nitric oxide synthase (iNOS) were analyzed by quantitative Real Time-PCR assays. Nitric oxide (NO) production was assessed by Griess reagent. Reactive oxygen species (ROS) production was detected by fluorescent probe. Malondialdehyde (MDA), 4-hydroxynonenal (4-HNE), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were examined by commercial kits. Cell apoptosis was analyzed by flow cytometry and caspase-3 activity. The protein levels were detected by Western blot. Melatonin enhanced the viability and reduced the death and LDH release of OGD/R exposed SH SY5Y cells. Melatonin repressed the HMGB1, TNF-α, and iNOS mRNA expression, NO production, and nuclear factor κB (NF-κB) activation in OGD/R challenged SH SY5Y cells. Melatonin reduced the ROS, MDA, 4-HNE, and 8-OHdG contents but further enhanced the levels of the nuclear factor E2-related factor-2 (Nrf2) and heme oxygenase (HO-1). Melatonin-increased viability and melatonin-decreased LDH release were also mediated by the blockage of NF-κB or reversed by Nrf2 or HO-1 knockdown. Melatonin exerted antiapoptotic effect on OGD/R treated SH SY5Y cells partly by activating Akt signaling. OGD/R challenged SH SY5Y cell autophagy was also repressed by melatonin, as evidenced by the decreased levels of LC-II and beclin-1 and the increased phosphorylation of mammalian target of rapamycin (mTOR), p70 ribosomal protein S6 kinase (p70S6K), and eukaryotic initiation factor 4E binding protein 1 (4E-BP-1). Melatonin protected SH SY5Y cells from OGD/R induced oxidative stress, inflammation, apoptosis, and autophagy by blocking NF-κB signaling and activating Nrf2/HO-1, Akt, and mTOR/p70S6K/4E-BP-1 pathways, thereby indicating that melatonin is a potential and novel therapeutic drug for ischemic stroke.

High Mobility Group Box 1 and TLR4 Signaling Pathway in Gnotobiotic Piglets Colonized/Infected with L. amylovorus, L. mucosae, E. coli Nissle 1917 and S. Typhimurium.

High mobility group box 1 (HMGB1) is a DNA-binding nuclear protein that can be actively secreted by immune cells after different immune stimuli or passively released from cells undergoing necrosis. HMGB1 amplifies inflammation, and its hypersecretion contributes to multiple organ dysfunction syndrome and death. We tested possible immunomodulatory effect of commensal Lactobacillus amylovorus (LA), Lactobacillus mucosae (LM) or probiotic Escherichia coli Nissle 1917 (EcN) in infection of gnotobiotic piglets with Salmonella Typhimurium (ST). Transcription of HMGB1 and Toll-like receptors (TLR) 2, 4, and 9 and receptor for advanced glycation end products (RAGE), TLR4-related molecules (MD-2, CD14, and LBP), and adaptor proteins (MyD88 and TRIF) in the ileum and colon were measured by RT-qPCR. Expression of TLR4 and its related molecules were highly upregulated in the ST-infected intestine, which was suppressed by EcN, but not LA nor LM. In contrast, HMGB1 expression was unaffected by ST infection or commensal/probiotic administration. HMGB1 protein levels in the intestine measured by ELISA were increased in ST-infected piglets, but they were decreased by previous colonization with E. coli Nissle 1917 only. We conclude that the stability of HMGB1 mRNA expression in all piglet groups could show its importance for DNA transcription and physiological cell functions. The presence of HMGB1 protein in the intestinal lumen probably indicates cellular damage.

An indel polymorphism in the 3' untranslated region of HMGB1 confers risk for hepatocellular carcinoma by regulating HMGB1 transcriptional activity in a Chinese population.

The present study aimed to assess the association of rs34000982 polymorphism located in the 3'untranslated region (3'UTR) of high mobility group box 1 (HMGB1) gene and the risk of hepatocellular carcinoma (HCC), and further to explore the underlying mechanism. Genomic DNA was extracted from peripheral blood of 320 patients with HCC and 360 matched controls. Rs34000982 polymorphism was genotyped by a polymerase chain reaction-polyacrylamide gel electrophoresis assay. The genotype-phenotype association of HMGB1 mRNA and protein expression in HCC tissues with different genotypes was detected by quantitative (q) PCR assay and western blot. Vectors containing the insertion (ins)/ins or deletion (del)/del genotype of the rs34000982 polymorphism were constructed and the HMGB1 transcriptional activity affected by the rs34000982 polymorphism was detected by the luciferase assay. It was identified that the ins/ins genotype of rs34000982 significantly increased the risk of HCC compared with the del/del genotype. Further the qPCR results demonstrated that the HMGB1 mRNA expression level in HCC tissues with ins/ins genotype was 2.24 times that of HCC tissues with ins/del and del/del genotypes and there was a similar trend at protein level. In addition, the insertion allele of rs34000982 disturbed the binding of miR-636 with the 3'UTR of HMGB1, thereby increasing HMGB1 transcriptional activity in vitro. These data suggest that the rs34000982 polymorphism may contribute to HCC susceptibility, in full or at least partially through the effect on HMGB1 transcriptional activity by disturbing the binding of miR-636 with the 3'UTR of HMGB1.

Anti-Inflammatory Effects of Shenfu Injection against Acute Lung Injury through Inhibiting HMGB1-NF-κB Pathway in a Rat Model of Endotoxin Shock.

Shenfu injection (SFI), a Chinese herbal medicine with substances extracted from Ginseng Radix et Rhizoma Rubra and Aconiti Lateralis Radix Praeparata, is widely used as an anti-inflammatory reagent to treat endotoxin shock in China. However, the mechanism of SFI in endotoxin shock remains to be illuminated. High mobility group box 1 (HMGB1), a vital inflammatory factor in the late stage of endotoxin shock, may stimulate multiple signalling cascades, including κB (NF-κB), a nuclear transcription factor, as well as tumour necrosis factor (TNF)-α and interleukin (IL)-1β, among others in the overexpression of downstream proinflammatory cytokines. An investigation into the effects of SFI on the inhibition of the HMGB1-NF-κB pathway revealed the contribution of SFI to acute lung injury (ALI) in a rat model of endotoxin shock. To assess the anti-inflammatory activity of SFI, 5 ml/kg, 10 ml/kg, or 15 ml/kg of SFI was administered to different groups of rats following an injection of LPS, and the mean arterial pressure (MAP) at 5 h and the survival rate at 72 h were measured. 24 h after LPS injection, we observed pathological changes in the lung tissue and measured the mRNA expression, production, translocation, and secretion of HMGB1, as well as the expression of the NF-κB signal pathway-related proteins inhibitor of NF-κB (IκB)-α, P50, and P65. We also evaluated the regulation of SFI on the secretion of inflammatory factors including interleukin-1 beta (IL-1β) and TNF-α. SFI effectively prevented the drop in MAP, relieved lung tissue damage, and increased the survival rate in the endotoxin shock model in dose-dependent manner. SFI inhibited the transcription, expression, translocation, and secretion of HMGB1, increased the expression of toll-like receptor (TLR4), increased the production of IκB-α, and decreased the levels of P65, P50, and TNF-α in the lung tissue of endotoxin shock rats in a dose-dependent manner. Furthermore, SFI decreased the secretion of proinflammatory cytokines TNF-α and IL-1β. In summary, SFI improves the survival rate of endotoxin shock, perhaps through inhibiting the HMGB1-NF-κB pathway and thus preventing cytokine storm.

Co-Delivery Of Dihydroartemisinin And HMGB1 siRNA By TAT-Modified Cationic Liposomes Through The TLR4 Signaling Pathway For Treatment Of Lupus Nephritis.

Background and purposeSystemic lupus erythematous (SLE) is an autoimmune disease caused by many factors. Lupus nephritis (LN) is a common complication of SLE and represents a major cause of morbidity and mortality. Previous studies have shown the advantages of multi-targeted therapy for LN and that TLR4 signaling is a target of anti-LN drugs. High-mobility group box 1 (HMGB1), a nuclear protein with a proinflammatory cytokine activity, binds specifically to TLR4 to induce inflammation. We aimed to develop PEGylated TAT peptide-cationic liposomes (TAT-CLs) to deliver anti-HMGB1 siRNA and dihydroartemisinin (DHA) to increase LN therapeutic efficiency and explore their treatment mechanism.MethodsWe constructed the TAT-CLs-DHA/siRNA delivery system using the thin film hydration method. The uptake and localization of Cy3-labeled siRNA were detected by confocal microscopy and flow cytometry. MTT assays were used to detect glomerular mesangial cell proliferation. Real-time PCR, Western blot analysis, and ELISA evaluated the anti-inflammatory mechanism of TAT-CLs-DHA/siRNA.ResultsWe constructed the TAT-CLs-DHA/siRNA delivery system measuring approximately 140 nm with superior storage and serum stabilities. In vitro, it showed significantly greater uptake compared with unmodified liposomes and significant inhibition of glomerular mesangial cell proliferation. TAT-CLs-DHA/siRNA inhibited NF-κB activation in a concentration-dependent manner. Real-time PCR and Western blot analysis showed that TAT-CLs-DHA/siRNA downregulated expression of HMGB1 mRNA and protein. TAT-CLs-DHA/siRNA markedly diminished Toll-like receptor 4 (TLR4) expression and subsequent activation of MyD88, IRAK4, and NF-κB.ConclusionTAT-CLs-DHA/siRNA may have the potential for treatment of inflammatory diseases such as LN mediated by the TLR4 signaling pathway.

Ethyl pyruvate attenuates ventilation-induced diaphragm dysfunction through high-mobility group box-1 in a murine endotoxaemia model.

Mechanical ventilation (MV) can save the lives of patients with sepsis. However, MV in both animal and human studies has resulted in ventilator‐induced diaphragm dysfunction (VIDD). Sepsis may promote skeletal muscle atrophy in critically ill patients. Elevated high‐mobility group box‐1 (HMGB1) levels are associated with patients requiring long‐term MV. Ethyl pyruvate (EP) has been demonstrated to lengthen survival in patients with severe sepsis. We hypothesized that the administration of HMGB1 inhibitor EP or anti‐HMGB1 antibody could attenuate sepsis‐exacerbated VIDD by repressing HMGB1 signalling. Male C57BL/6 mice with or without endotoxaemia were exposed to MV (10 mL/kg) for 8 hours after administrating either 100 mg/kg of EP or 100 mg/kg of anti‐HMGB1 antibody. Mice exposed to MV with endotoxaemia experienced augmented VIDD, as indicated by elevated proteolytic, apoptotic and autophagic parameters. Additionally, disarrayed myofibrils and disrupted mitochondrial ultrastructures, as well as increased HMGB1 mRNA and protein expression, and plasminogen activator inhibitor‐1 protein, oxidative stress, autophagosomes and myonuclear apoptosis were also observed. However, MV suppressed mitochondrial cytochrome C and diaphragm contractility in mice with endotoxaemia (P < 0.05). These deleterious effects were alleviated by pharmacologic inhibition with EP or anti‐HMGB1 antibody (P < 0.05). Our data suggest that EP attenuates endotoxin‐enhanced VIDD by inhibiting HMGB1 signalling pathway.

Hyperbaric oxygen inhibits the HMGB1/RAGE signaling pathway by upregulating Mir-107 expression in human osteoarthritic chondrocytes

MicroRNA (miRNA)107 expression is downregulated but high mobility group box 1 (HMGB-1), Toll-like receptors (TLRs), and receptor for advanced glycation end products (RAGE) are upregulated in osteoarthritic (OA) cartilage. We investigated mir-107/HMGB-1 signaling in OA after hyperbaric oxygen (HBO) treatment. MiR-107 mimic was transfected and the HMGB-1 was analyzed in OA chondrocytes. MiRNA targets were identified using bioinformatics and a luciferase reporter assay. After HBO treatment, the mRNA or protein levels of HMGB-1, RAGE, TLR2, TLR4, and inducible nitric oxide (NO) synthase (iNOS) and phosphorylation of mitogen-activated protein kinase (MAPK) were evaluated. The secreted HMGB-1 and matrix metalloproteases (MMPs) levels were quantified. Finally, we detected the HMGB-1 and iNOS expression in rabbit cartilage defects. Overexpression of miR-107 suppressed HMGB-1 expression in OA chondrocytes. The 3'UTR of HMGB-1 mRNA contained a 'seed-matched-sequence' for miR-107. MiR-107 was induced by HBO and a marked suppression of HMGB-1 was observed simultaneously in OA chondrocytes. Knockdown of miR-107 upregulated HMGB-1 expression in hyperoxic cells. HBO downregulated the mRNA and protein expression of HMGB-1, RAGE, TLR2, TLR4, and iNOS, and the secretion of HMGB-1. HBO decreased the nuclear translocation of nuclear factor (NF)-κB, downregulated the phosphorylation of MAPK, and significantly decreased the secretion of MMPs. Morphological and immunohistochemical observation demonstrated that HBO markedly enhanced cartilage repair and the area stained positive for HMGB-1 and iNOS tended to be lower in the HBO group. HBO inhibits HMGB-1/RAGE signaling related pathways by upregulating miR-107 expression in human OA chondrocytes.

The effect of continuous infusion of lidocaine on high mobility group box 1 expression in lung tissue of sepsis model rats

Objective To evaluate the effect and mechanism of intravenous infusion of lidocaine on the expression of high mobility group box 1 (HMGB1) mRNA in lung of sepsis model rats. Methods Senenty-five healthy male Sprague-Dawley (SD) rats were stochastically divided into 5 groups (n=15): S group (group S), cecal ligation and puncture (CLP) group (group CLP), pre-CLP infusion the lidocaine group (group L1), CLP immediately infused with lidocaine (group L2) and CLP infused with the lidocaine-treated group (group L3). Group S suture abdominal cavity after opening it while other groups were ligated with cecal ligation and puncture. groups L1, L2 and L3 were infused with lidocaine for 3 h before CLP, at the moment of CLP started and 3 h after CLP was completed respectively. The group S and the group CLP were replaced by the same amount of normal saline. The rats were sacrificed 24 h after the CLP model was successfully established. The serum levels of pro-inflammatory cytokines IL-6, TNF-α and HMGB1 concentration were measured by enzyme-limked immunosorbent assay(ELISA). The expression of HMGB1 mRNA in lung tissue was detected by qRT-PCR. Automated biochemical analysis was used to detect serum ALT, AST, and Cr. Another 50 rats were grouped and observed for 72 h. Results Compared with group S, CLP occurred in the group CLP, group L1, group L2 and group L3, IL-6, TNF-α, HMGB1 concentrations and the expression of HMGB1 mRNA were increased in lung tissues (P<0.05). The serum levels of HMGB1, IL-6, TNF-α and HMGB1 mRNA in lung tissues of the groups L1, L2 and L3 were significantly lower than those in the group CLP (P<0.05). Compared with group S, ALT, AST and Cr were increased in groups CLP, L1, L2, and L3(P<0.05). Compared with group CLP, ALT, AST and Cr were decreased in groups L1, L2 and L3(P<0.05). Compared with the group CLP, the survival rates of the groups L1, L2 and L3 were significantly improved. Conclusions CLP can increase the expression levels of pro-inflammatory cytokines in rats. Intravenous infusion of lidocaine can effectively reduce the expression of inflammatory factors in CLP rats and inhibit the expression of HMGB1 mRNA in lung tissues. Thus, it reduces the lung damage caused by CLP and improves the survival rate effectively. Key words: Lidocaine; Sepsis; High mobility group box 1

High-Mobility Group Box 1 Is Associated with the Inflammatory Pathogenesis of Graves' Orbitopathy.

Background: High-mobility group box 1 (HMGB1) has been implicated in the pathogenesis of inflammatory autoimmune diseases. This study investigated the influence and mechanisms of HMGB1 in Graves' orbitopathy (GO). Methods: HMGB1 and its receptors (receptor for advanced glycation end products [RAGE], Toll-like receptor [TLR] 2, and TLR4) mRNA levels were evaluated by real-time polymerase chain reaction (RT-PCR) in GO and non-GO orbital tissues. The mRNA expressions of HMGB1 and its receptors were evaluated in primary cultured orbital fibroblasts from six GO patients and five healthy control subjects under interleukin (IL)-1β or tumor necrosis factor (TNF)-α stimulation using RT-PCR. HMGB1 secretions under IL-1β or TNF-α stimulation were evaluated by enzyme-linked immunosorbent assay (ELISA). The effects of an anti-HMGB1 antibody, RAGE antagonist (FPS-ZM1), and anti-TLR2 antibody on the expressions of IL-1β or TNF-α induced pro-inflammatory cytokines and phosphorylated nuclear factor kappa-light-chain-enhancer of activated B cells were evaluated using ELISA and Western blot analysis, respectively. The plasma levels of HMGB1 were compared among patients with active GO (n = 51), inactive GO (n = 48), Graves' disease without GO (n = 30), and healthy control subjects (n = 46) by ELISA. Results: The genes encoding HMGB1 and its receptors, as well as HMGB1 protein expression, were increased in GO orbital tissues compared to non-GO tissues. IL-1β and TNF-α stimulation increased the mRNA levels of HMGB1, RAGE, and TLR2 and the secretion of HMGB1 protein further in GO cells. Anti-HMGB1 antibody, FPS-ZM1, and anti-TLR2 antibody reduced IL-1β- or TNF-α-induced production of pro-inflammatory cytokines and phosphorylated nuclear factor kappa-light-chain-enhancer of activated B cells. The plasma levels of HMGB1 were highly increased in patients with active GO, and were significantly correlated with the clinical activity score (r = 0.566, p = 0.002) and levels of thyrotropin binding inhibitory immunoglobulin (r = 0.506, p < 0.001). Conclusions: This study demonstrates an association of HMGB1 and its receptors in the inflammatory mechanisms of GO. HMGB1, RAGE, and TLR2 blockers reduced the production of pro-inflammatory molecules, providing a rationale for blocking the HMGB1 pathway to treat patients with GO. HMGB1 proteins were secreted further in the plasma of patients with active GO, suggesting that HMGB1 can be used as a biomarker of GO activity.

Triptolide Suppresses Growth of Breast Cancer by Targeting HMGB1 in Vitro and in Vivo.

Triptolide has been indicated potent anti-cancer effect involving multiple molecular targets and signaling pathways. High-mobility group box 1 (HMGB1) is a highly conserved DNA-binding protein taking part in breast cancer development. The therapeutic effect of triptolide on HMGB1 has not been reported. Thus, our study aims to clarify the role of HMGB1 in triptolide-induced anti-growth effect on breast cancer in vitro and in vivo. We demonstrated that triptolide significantly suppressed growth of breast cancer cells by inhibition of cell viability, clonogenic ability. Further studies evidenced that triptolide treatment not only inhibited HMGB1 mRNA expression, but also decreased supernatant level of HMGB1 in vitro. In line with these observations, exogenous recombinant HMGB1 (rHMGB1) promoted cell proliferation of breast cancer, and triptolide reversed the rHMGB1-promoted proliferative effect. As well, triptolide enhanced the anti-proliferative activity of ethyl pyruvate (EP) (HMGB1 inhibitor). Furthermore, downstream correlation factors (Toll-like receptor 4 (TLR4) and phosphorylated-nuclear factor-kappaB (NF-κB) p65) of HMGB1 were significantly decreased in vitro after triptolide treatment. Consistantly, we confirmed that tumor growth was significantly inhibited after triptolide treatment in vivo. Meanwhile, immunohistochemical analyses showed that triptolide treatment significantly decreased the level of cytoplasmic HMGB1 and TLR4 expression, whereas the expression of NF-κB p65 was relatively higher in cytoplasm, and conversely lower in nucleus as compared to the control group. Collectively, these results demonstrate that triptolide suppresses the growth of breast cancer cells via reduction of HMGB1 expression in vitro and in vivo, which may provide new insights into the treament of breast cancer.

Inhibition of HMGB1 improves necrotizing enterocolitis by inhibiting NLRP3 via TLR4 and NF-κB signaling pathways.

To explore the relationship between high-mobility group box 1 (HMGB1) and NLR pyrin domain containing 3 (NLRP3) in the development of necrotizing enterocolitis (NEC). NEC rat models were constructed and treated with HMGB1 inhibitor glycyrrhizin (GL) with different concentration. An inflammatory condition of intestinal tissue in newborn NEC rats was observed by hematoxylin and eosin staining. The messenger RNA (mRNA) and protein expression of HMGB1, NLRP3, toll-like receptor 4 (TLR4), nuclear factor-κB (NF-κB), and caspase 1 were determined by real-time polymerase chain reaction and western blot analysis, respectively. The content of interleukin (IL)-1β and tumor necrosis factor-α (TNF-α) was determined by enzyme-linked immunosorbent assay. Human intestinal epithelial cell lines were induced to NEC by lipopolysaccharides (LPSs). LPS-induced cells were transfected with small interfering RNA-HMGB1 and NLRP3 plasmid vector. The mRNA and protein expression of HMGB1, NLRP3, TLR4, NF-κB, caspase 1, IL-1β, and TNF-α were determined by real-time PCR and western blot analysis, respectively. The mRNA and protein expression of HMGB1 and NLRP3 in the NEC group was significantly higher than the control group. Inhibition of HMGB1 expression improved intestinal inflammation in newborn NEC rats. The expression of HMGB1, NLRP3, TLR4, NF-κB, and caspase 1 was upregulated in NEC and was weakened after treating with GL. LPS induction to intestinal epithelial cells markedly increased the expression of HMGB1, NLRP3, TLR4, NF-κB, caspase 1, IL-1β, and TNF-α. The knockdown of HMGB1 abolished the increase of expression, whereas further transfection with NLRP3 plasmid vector recovered the increase. HMGB1 and NLRP3 were all upregulated in the development of NEC. Inhibition on HMGB1 could improve the intestinal inflammation in NEC by inhibiting NLRP3 via TLR4 and NF-κB signaling pathways.

Increased HMGB1 expression correlates with higher expression of c-IAP2 and pERK in colorectal cancer.

The aim of this study was to investigate the relationship between high-mobility group box 1 (HMGB1) and colorectal cancer (CRC).In this prospective study, patients with CRC undergoing primary surgery and healthy subjects (control group) were enrolled from July 2013 to December 2014. The serum HMGB1 concentration and HMGB1 mRNA expression were determined using enzyme-linked immunosorbent assay reverse transcription-polymerase chain reaction, respectively. Immunohistochemical analysis was performed to determine HMGB1, pERK, and c-inhibitor of apoptosis protein 2 (c-IAP2) protein expression levels in the cancer tissues.A total 144 patients with CRC and 50 healthy subjects underwent serum HMGB1 testing. Resected specimens of 50 patients were used for HMGB1 mRNA and protein expression analyses. Mean serum HMGB1 level in the patients with CRC was higher than that of the control group (8.42 μg/L vs 1.79 μg/L, P < .05). Mean serum HMGB1 level in the patients with CRC with distant metastasis was significantly higher than that of the controls (13.32 μg/L vs 7.37 μg/L, P < .05). The HMGB1 mRNA and protein expression levels in the CRC tissues were significantly higher than those in the adjacent normal mucosa. HMGB1 protein expression positively correlated with the lymph node metastasis. There were positive correlations between HMGB1 and c-IAP2 (r = 0.457, P < .05), HMGB1 and pERK (r = 0.461, P < .05), as well as pERK and c-IAP2 (r = 0.399, P < .05).HMGB1 expression in CRC correlates with distant and lymph node metastasis. It may inhibit apoptosis by inducing activation of pERK and c-IAP2.

Role of Receptors for Advanced Glycation End Products and High-Mobility Group Box 1 in the Outcome of Human T Cell Lymphotropic Type 1 Infection

Human T cell lymphotropic type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a chronic viral neuroinflammatory disease, which leads to damage of the central nervous system. Inflammatory responses and mediators are both involved in the pathogenesis of the disease and in determining its outcome. High-Mobility Group Box 1 (HMGB1) is a chromatin-associated nuclear protein acting as a signaling molecule in cells after binding to its receptors. Receptor for advanced glycation end products (RAGE) is a transmembrane multiligand receptor that binds to HMGB1. HMGB1-RAGE signaling has an important role in inflammatory and infectious diseases. Inhibition of HMGB1 activity reduces the inflammation in immune-associated diseases. In the present study, we examined the gene expressions and plasma levels of HMGB1 and its receptor RAGE in HAM/TSP patients, HTLV-1-infected asymptomatic carriers (ACs), and healthy controls. Peripheral blood mononuclear cells were collected from all the groups and complementary DNA (cDNA) was synthesized. HMGB-1 messenger RNA (mRNA) expression was quantified by real-time polymerase chain reaction (PCR) TaqMan method, and plasma levels of HMGB1 and soluble RAGE (sRAGE) were measured by enzyme-linked immunosorbent assay (ELISA). The mRNA expression of HMGB1 was the same among the groups (p > 0.05). No significant difference in the plasma levels of HMGB1 was observed between the groups (p > 0.05). The plasma levels of sRAGE were higher in ACs than HAM/TSP patients, and a significant difference was observed between the two groups (p < 0.001). Our results showed that sRAGE could play a potential role in the control of inflammatory response in HTLV-1 carriers through the inhibition of HMGB1 signaling and potentially could be used as an indicator for evaluation of HAM/TSP developing in HTLV-1-infected individuals.

Long noncoding RNA PCA3 regulates prostate cancer through sponging miR-218-5p and modulating high mobility group box 1.

The purpose of this study was to investigate the mechanism of long noncoding RNA (lncRNA) prostate cancer antigen 3 (PCA3) in prostate cancer (PCa) via regulating the miR-218-5p/high mobility group box 1 (HMGB1) axis. The Cancer Genome Atlas database was used to divide differentially expressed lncRNAs, microRNAs, and messenger RNA (mRNAs). The mRNA expressions of lncRNA PCA3, miR-218-5p, and HMGB1 were determined by reverse transcription polymerase chain reaction. Cell propagation was evaluated using the Cell Counting Kit-8 assay and the apoptotic rate was examined by flow cytometry. Cell migration and invasion were observed through the wound healing assay and transwell assay. Target relationships among PCA3, miR-218-5p, and HMGB1 were validated via dual-luciferase reporter gene assay. A nude mouse model in vivo was designed to evaluate the effect of PCA3 on prostate tumor growth. PCA3 and HMGB1 were high-expressed in PCa, whereas miR-218-5p was low-expressed. PCA3 knockdown or miR-218-5p overexpression suppressed PCa cell proliferation, migration, and invasion, but promoted apoptosis. Besides, targeted relationships and interactions on the expression between miR-218-5p and PCA3 or HMGB1 were elucidated. PCA3 weakened cell viability and mobility whereas induced apoptosis through binding with miR-218-5p. Meanwhile, miR-218-5p also inhibited PCa tumorigenesis via downregulation of HMGB1. Knockdown of PCA3 impeded tumor growth by downregulating its downstream gene HMGB1. lncRNA PCA3 facilitated PCa progression through sponging miR-218-5p and regulating HMGB1.