OBJECTIVE: To investigate the effect of high mobility group protein box 1 (HMGB1) on apoptosis of astrocytes after oxygen glucose deprivation/reoxygenation (OGD/R), and to investigate the possible mechanism by evaluating the expression of apoptosis related protein Bcl-2 and Bax. METHODS: The cerebral cortex astrocytes of neonatal rats were divided into normal group, model group, interference group and control group. Lentivirus vector of rat HMGB1 short hairpin RNA (shRNA) was used to suppress the HMGB1 protein expression in the astrocytes. Then the detection was made after astrocytes were deprived of oxygen and glucose 6 h, reoxygenation for 24 h. The effect of RNA interference was evaluated by Western blotting. The cell survival rate was measured by MTT assay. The apoptosis of astrocytes was determined by TUNEL assay. The expressions of Bcl-2 and Bax were detected by Western blotting. RESULTS: Compared with the normal group, the protein expression of HMGB1 was significantly increased in model group after OGD/R (P<0.001), the astrocytes survival rate was decreased (P<0.001), the number of apoptotic cells labeled with TUNEL was increased (P<0.001), and the ratio of Bcl-2/Bax was decreased (P<0.001). Compared with the model group, RNA interference effectively inhibited the expression of HMGB1 in interference group (P<0.001), the astrocytes survival rate was increased (P<0.001), the number of apoptotic cells labeled with TUNEL was reduced (P<0.01), and the ratio of Bcl-2/Bax was increased (P<0.001). CONCLUSION The apoptosis of astrocytes can be induced by HMGB1 after OGD/R, and the mechanism may be related to regulating the expression of apoptosis related proteins Bcl-2 and Bax.
Animals ; Apoptosis ; Astrocytes ; Cell Hypoxia ; Cells, Cultured ; Glucose/metabolism* ; HMGB1 Protein/physiology* ; Oxygen ; Proto-Oncogene Proteins c-bcl-2 ; Rats ; Rats, Sprague-Dawley ; bcl-2-Associated X Protein/metabolism*

OBJECTIVETo investigate the effect of heat shock factor 1 (HSF1) on airway hyperresponsiveness and airway inflammation in mice with asthma and possible mechanisms.

METHODSA total of 36 mice were randomly divided into four groups: control, asthma, HSF1 small interfering RNA negative control (siHSF1-NC), and siHSF1 intervention (n=9 each). Ovalbumin (OVA) sensitization and challenge were performed to induce asthma in the latter three groups. The mice in the siHSF1-NC and siHSF1 groups were treated with siHSF1-NC and siHSF1, respectively. A spirometer was used to measure airway responsiveness at 24 hours after the last challenge. The direct count method was used to calculate the number of eosinophils. ELISA was used to measure the serum level of OVA-specific IgE and levels of interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-13 (IL-13), and interferon-γ (IFN-γ) in lung tissues and bronchoalveolar lavage fluid (BALF). Quantitative real-time PCR was used to measure the mRNA expression of HSF1 in asthmatic mice. Western blot was used to measure the protein expression of HSF1, high-mobility group box 1 (HMGB1), and phosphorylated c-Jun N-terminal kinase (p-JNK).

RESULTSThe asthma group had significant increases in the mRNA and protein expression of HSF1 compared with the control group (P<0.05). The siHSF1 group had significantly reduced mRNA and protein expression of HSF1 compared with the siHSF1-NC group (P<0.05). The knockdown of HSF1 increased airway wall thickness, airway hyperresponsiveness, OVA-specific IgE content, and the number of eosinophils (P<0.05). Compared with the siHSF1-NC group, the siHSF1 group had significantly increased levels of IL-4, IL-5, and IL-13 and significantly reduced expression of IFN-γ in lung tissues and BALF (P<0.05), as well as significantly increased expression of HMGB1 and p-JNK (P<0.05).

CONCLUSIONSKnockdown of HSF1 aggravates airway hyperresponsiveness and airway inflammation in asthmatic mice, and its possible mechanism may involve the negative regulation of HMGB1 and JNK.

Animals ; Asthma ; etiology ; Bronchial Hyperreactivity ; etiology ; immunology ; Cytokines ; biosynthesis ; DNA-Binding Proteins ; analysis ; physiology ; Eosinophils ; physiology ; Female ; HMGB1 Protein ; analysis ; Heat Shock Transcription Factors ; Immunoglobulin E ; blood ; Mice ; Mice, Inbred BALB C ; Transcription Factors ; analysis ; physiology

OBJECTIVETo investigate the changes in the mRNA and protein expression of high-mobility group box 1 (HMGB1), Toll-like receptor 4 (TLR4), and nuclear factor-kappa B (NF-κB) in lung tissues of asthmatic mice and the interventional effect of vitamin D.

METHODSA total of 48 BALB/c mice were randomly divided into control group, asthma group, and 1,25-(OH)Dintervention group, with 16 mice in each group. An animal model of asthma was established, and lung tissue samples were taken in each group at weeks 1 and 2 of ovalbumin challenging. Conventional hematoxylin-eosin staining was used to measure airway wall thickness. Immunohistochemical staining was used to observe the expression of HMGB1, TLR4, and NF-κB in lung tissues. Quantitative real-time PCR and Western blot were used to investigate the changes in the mRNA and protein expression of HMGB1, TLR4, and NF-κB.

RESULTSAt weeks 1 and 2 of ovalbumin challenging, compared with the control group, the asthma group had a significant increase in airway wall thickness and the intervention group had a significant reduction compared with the asthma group (P<0.05). The asthma group had significantly higher mRNA expression of HMGB1, TLR4, and NF-κB in lung tissues than the control group, and the intervention group had significantly lower mRNA expression of TLR4 and NF-κB than the asthma group (P<0.05). At week 1 of ovalbumin challenging, there was no significant difference in the mRNA expression of HMGB1 between the intervention group and the asthma group (P>0.05). At week 2, the intervention group had a significant reduction in the mRNA expression of HMGB1 compared with the asthma group (P<0.05). At weeks 1 and 2 of ovalbumin challenging, the asthma group had significantly higher protein expression of HMGB1, TLR4, and NF-κB in lung tissues than the control group, and the intervention group had significantly lower expression than the asthma group (P<0.05). Airway wall thickness was positively correlated with the mRNA expression of HMGB1, TLR4, and NF-κB in lung tissues (r=0.804, 0.895, and 0.834; P<0.05).

CONCLUSIONSThe HMGB1/TLR4/NF-κB signaling pathway plays an important role in the pathogenesis of asthma, and an appropriate amount of 1,25-(OH)Dhas a regulatory effect on this pathway and may prevent the progression of asthma. Therefore, 1,25-(OH)Dis expected to become a new choice for the treatment of asthma.

Animals ; Asthma ; drug therapy ; etiology ; pathology ; Calcitriol ; therapeutic use ; Female ; HMGB1 Protein ; analysis ; physiology ; Lung ; pathology ; Mice ; Mice, Inbred BALB C ; NF-kappa B ; analysis ; physiology ; Signal Transduction ; physiology ; Toll-Like Receptor 4 ; analysis ; physiology

To observe the effect of high-mobility group box 1 (HMGB1) on autophagy and chemotherapy resistance in human leukemiacell line (K562) cells, and to explore the underlying mechanisms.
 Methods: The K562 cells were cultured in vitro and divided into 6 groups: a chemotherapeutic group, a chemotherapeutic control group, a HMGB1 preconditioning group, a HMGB1 preconditioning control group, a HMGB1 siRNA group and a siRNA control group. The chemotherapeutic group was further divided into a vincristine (VCR) group, an etoposide (VP-16) group, a cytosine arabinoside (Ara-C) group, a adriamycin (ADM) group and a arsenic trioxide (As2O3) group. The cell activity was evaluated by cell counting kit-8. The protein levels of HMGB1, microtubule-associate protein1light chain3 (LC3), AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (m-TOR) were determined by Western blotting. The level of serum HMGB1 was evaluated by enzyme-linked immunosorbent assay (ELISA). The autophagy was examined by monodansylcadaverine staining and observed under transmission electron microscopy.
 Results: Compared with the control group, the cell activity was significantly decreased and the level of serum HMGB1 was significantly increased in the chemotherapeutic (VCR, VP-16, Ara-C, ADM and As2O3) groups (all P<0.05). Compared with the control group, the cell activity and the level of serum HMGB1 were significantly increased in the HMGB1 preconditioning group (both P<0.05). Compared with the siRNA control group, the cell activity and the level of serum HMGB1 were significantly decreased in the HMGB1 siRNA group (both P<0.05). Compared with the control group, the expression of LC3-II and the formation of autophagic bodies were increased in the HMGB1 preconditioning group (both P<0.05), the p-AMPK expression was increased and p-mTOR expression was decreased (both P<0.05).
 Conclusion: HMGB1 can increase the autophagy and promote chemotherapy resistance through the pathway of AMPK/m-TOR in K562 cells.
AMP-Activated Protein Kinases ; genetics ; physiology ; Arsenic Trioxide ; Arsenicals ; Autophagy ; genetics ; Cytarabine ; Doxorubicin ; Drug Resistance, Neoplasm ; genetics ; physiology ; Etoposide ; HMGB1 Protein ; genetics ; physiology ; Humans ; K562 Cells ; physiology ; Microtubule-Associated Proteins ; Oxides ; RNA, Small Interfering ; Signal Transduction ; TOR Serine-Threonine Kinases ; genetics ; physiology ; Vincristine

OBJECTIVETo study the effects of 1,25-(OH)(2)D(3) on airway remodeling and expression of high mobility group box 1 (HMGB1) and IL-17 in asthmatic mice.

METHODSFifty female mice were randomly divided into 5 groups: control, asthma, low-dose, middle-dose, and high-dose intervention groups (n=10 each). Asthma was induced by intraperitoneal injections of ovalbumin (OVA) and aerosol inhalation of OVA solution. The low-dose, middle-dose, and high-dose intervention groups were administered with 1,25-(OH)(2)D(3) solution at the dosage of 1, 4 and 10 μg/kg respectively by intraperitoneal injections before asthma challenge. The airway structural changes were assessed by hematoxylin and eosin staining. mRNA expression levels of HMGB1 and IL-17 in the lung tissues were evaluated by RT-PCR. The protein levels of HMGB1 and IL-17 in the lung tissues were observed by immunohistochemistry.

RESULTSThe airway wall thickness, protein and mRNA expression levels of HMGB1 and IL-17 were higher in the untreated asthma group than in the control group (P<0.05). The airway wall thickness, protein and mRNA expression levels of HMGB1 and IL-17 were lower in the middle-dose and low-dose intervention groups than in the untreated asthma group, and the middle-dose intervention group demonstrated lower airway wall thickness, protein and mRNA expression levels of HMGB1 and IL-17 than in the low-dose intervention group (P<0.05). However, the airway wall thickness, protein and mRNA expression levels of HMGB1 and IL-17 in the high-dose intervention group were higher than in the untreated asthma group (P<0.05).

CONCLUSIONSHMGB1 and IL-17 may be involved in the airway remodeling process in asthmatic mice. A moderate amount of HMGB1 and IL-17 may be involved in the airway remodeling process in asthmatic mice. A moderate amount of 1,25-(OH)(2)D(3) can improve the airway remodeling, but a higher dose of 1,25-(OH)(2)D(3) may affect adversely the airway remodeling process.

Airway Remodeling ; drug effects ; Animals ; Asthma ; drug therapy ; metabolism ; pathology ; Calcitriol ; pharmacology ; Dose-Response Relationship, Drug ; Female ; HMGB1 Protein ; analysis ; genetics ; physiology ; Interleukin-17 ; analysis ; genetics ; physiology ; Lung ; metabolism ; pathology ; Mice ; Mice, Inbred BALB C

With growing accounts of inflammatory diseases such as sepsis, greater understanding the immune system and the mechanisms of cellular immunity have become primary objectives in immunology studies. High mobility group box 1 (HMGB1) is a ubiquitous nuclear protein that is implicated in various aspects of the innate immune system as a damage-associated molecular pattern molecule and a late mediator of inflammation, as well as in principal cellular processes, such as autophagy and apoptosis. HMGB1 functions in the nucleus as a DNA chaperone; however, it exhibits cytokine-like activity when secreted by injurious or infectious stimuli. Extracellular HMGB1 acts through specific receptors to promote activation of the NF-kappaB signaling pathway, leading to production of cytokines and chemokines. These findings further implicate HMGB1 in lethal inflammatory diseases as a crucial regulator of inflammatory, injurious, and infectious responses. In this paper, we summarize the role of HMGB1 in inflammatory and non-inflammatory states and assess potential therapeutic approaches targeting HMGB1 in inflammatory diseases.
Amino Acid Sequence ; HMGB1 Protein/chemistry/metabolism/*physiology ; Humans ; Immunity, Innate/*physiology ; *Models, Immunological ; Molecular Sequence Data ; Protein Structure, Tertiary ; Signal Transduction

BACKGROUNDAerobic exercise can improve symptoms, reduce airway inflammation, and even ameliorate airway remodeling in asthmatic animals and patients. However, previous studies have focused mainly on the effect of aerobic exercise on steroid-sensitive asthma (SSA). The goals of this study were to determine the effect of low-intensity aerobic exercise training on airway hyperresponsiveness, inflammation, and remodeling in a rat model of steroid-resistant asthma (SRA) and to identify the potential mechanisms underlying these effects.

METHODSEndotoxin-free ovalbumin with or without lipopolysaccharide were applied to establish rat models of SRA and SSA, respectively. Airway hyperresponsiveness, inflammation, remodeling, expression of interleukin (IL)-25, IL-33, thymic stromal lymphopoietin (TSLP), high mobility group box-1 (HMGB1), and IL-17 in bronchoalveolar lavage fluid (BALF), and the role of dexamethasone (DXM) were compared between these two asthmatic rat models. The effect of low-intensity aerobic exercise training and anti-HMGB1 treatment on airway hyperresponsiveness, inflammation, and remodeling in SRA rats also was evaluated.

RESULTSSRA rats developed neutrophil-dominated airway inflammation ((29.5±4.1)% of the total cell numbers in BALF), whereas SSA rats developed eosinophil-dominated airway inflammation ((24.0±6.1)% of the total cell numbers in BALF). Compared with SSA rats, SRA rats had more severe airway hyperresponsiveness, lower levels of IL-25 ((33.6±10.3) vs. (104.8±24.9) pg/ml), IL-33 ((87.5±25.0) vs. (226.6±40.7) pg/ml), and TSLP ((1 933.2±899.5) vs. (7 224.0±992.1) pg/ml), and higher levels of HMGB1 ((21.2±4.5) vs. (5.4±1.6) ng/ml) and IL-17 ((780.5±261.7) vs. (291.4±76.4) pg/ml) in BALF (all P < 0.05). However, there was no significant difference in goblet cell hyperplasia, subepithelial collagen thickness, and airway smooth muscle remodeling between the two groups. Compared with control SSA rats, airway hyperresponsiveness, inflammation, and remodeling in SRA rats were less sensitive to DXM treatment. Anti-HMGB1 treatment attenuated airway hyperresponsiveness, inflammation, and remodeling in SRA rats to a certain extent and was accompanied by lower levels of IL-17 ((369.2±126.7) vs. (780.5±261.7) pg/ml in control SRA rats) in BALF (P < 0.05). Low-intensity aerobic exercise training decreased the expression of both HMGB1 ((14.1±2.9) vs. (21.2±4.5) ng/ml in control SRA rats) and IL-17 ((545.3±148.6) vs. (780.5±261.7) pg/ml in control SRA rats) in BALF (all P < 0.05) and was accompanied by improved airway hyperresponsiveness, inflammation, and remodeling in SRA rats (all P < 0.05).

CONCLUSIONSLow-intensity aerobic exercise training attenuated airway hyperresponsiveness, inflammation, and remodeling in a rat model of SRA. Decreased HMGB1 and IL-17 levels in BALF by aerobic exercise training at least partly contributed to the improvements of SRA.

Airway Remodeling ; physiology ; Animals ; Asthma ; drug therapy ; metabolism ; therapy ; HMGB1 Protein ; metabolism ; Male ; Physical Conditioning, Animal ; methods ; Rats ; Rats, Sprague-Dawley ; Respiratory System ; physiopathology

Atrial fibrillation (AF) is the most common sustained dysrhythmia in clinical practice. The bulk of evidence suggests that inflammatory processes, oxidative stress and matrix metalloproteinase are associated with development of AF. However, these agents may be involved in high mobility group box 1 protein (HMGB1). We hypothesized that HMGB1 may be a possible pathogenic link to AF. A growing body of evidence supports these hypotheses. First, the level of serum HMGB1 is significantly increased in patients with AF including paroxysmal and persistent AF. Second, HMGB1 has been identified as a new pro-inflammatory cytokine in cardiovascular diseases, along with tumor necrosis factor (TNF)-α, interleukin (IL)-6, and C-reactive protein, and there is cross-talk between HMGB1 and inflammatory cytokines. Third, oxidative stress is involved in the release of the pro-inflammatory cytokine, HMGB1, indicating there is cross-talk between oxidative stress and inflammation, and oxidative stress may reinforce the effect of inflammation on the pathogenesis of AF and inflammation may play a more important role in the pathogenesis of AF. Fourth, HMGB1 can promote matrix metalloproteinase-9 upregulation and activation. Fifth, HMGB1 receptors (receptor for advanced glycation end products, Toll-like receptor-2,4) may mediate the atrial structural remodeling or be up-regulated in patients with non-valvular AF. These results suggest that HMGB1 may participate in the pathogenesis of AF and provide a potential target for pharmacological interruption of AF.
Atrial Fibrillation ; metabolism ; HMGB1 Protein ; metabolism ; Humans ; Metalloendopeptidases ; metabolism ; Oxidative Stress ; physiology

OBJECTIVETo study the effect of hyperoxia exposure on high mobility group protein-B1 (HMGB1) expression in neonatal mice and the role of HMGB1 in the pathogenesis of bronchopulmonary dysplasia (BPD).

METHODSC57BL/6 mice were randomly exposed to 60% O2 or air 1 day after birth. BPD was induced by 60% O2 exposure. The pulmonary tissue samples were harvested 3, 7 and 14 days after exposure. The pathologic changes of pulmonary tissues were observed by hematoxylin and eosin staining, Masson staining and radical alveolar count. The expression of HMGB1 protein in lungs was detected by immunofluorescence. The expression of HMGB1 mRNA was detected by real-time fluorescent quantitative PCR.

RESULTSIn the BPD group, the lungs developed decreased alceolar septation, swollen alveolar epithelium, stroma edema, interstitial fibrosis and developmental lag when compared with the control group. These changes became more obvious with more prolonged hyperoxia exposure. The expression of HMGB1 protein and mRNA 7 and 14 days after exposure increased significantly in the BPD group compared with that in the control group.

CONCLUSIONSHyperoxia exposure results in an increase in lung HMGB1 expression. The increased HMGB1 expression may be associated with the development of BPD.

Animals ; Bronchopulmonary Dysplasia ; etiology ; HMGB1 Protein ; analysis ; genetics ; physiology ; Humans ; Hyperoxia ; complications ; Infant, Newborn ; Lung ; pathology ; Mice ; Mice, Inbred C57BL ; RNA, Messenger ; analysis

Dominant inflammatory cytokines might be different depending on the underlying causes of acute lung injury (ALI). The role of kertinocyte-derived chemokine (KC), a potent chemoattractant for neutrophils, has not been clearly established in hemorrhage-induced ALI. In this study, lung injury and cytokine expressison were evaluated in LPS- or hemorrhage-induced ALI models of BALB/c mice. The myeloperoxidase activities at 4 hr after hemorrhage and LPS-injection were 47.4+/-13.0 and 56.5+/-16.4 U/g, respectively. NF-kappa B activity peaked at 4 hr after hemorrhage, which was suppressed to the control level by anti-high mobility group B1 (HMGB1) antibody. Lung expressions of TNF-alpha, MIP-2, and IL-1beta were increased by LPS injection. However, there was only a minimal increase in IL-1beta and no expressions of TNF-alpha or MIP-2 in hemorrhage-induced ALI. In contrast, lung KC increased significantly at 4 hr after hemorrhage compared to control levels (83.1+/-12.3 vs. 14.2+/-1.6 pg/mL/mg by ELISA) (P<0.05). By immunohistochemical staining, lung neutrophils stained positive for KC. Increased KC was also observed in bronchoalveolar lavage fluid and plasma. KC plays an important role in hemorrhage-induced ALI.
Acute Lung Injury/etiology/*metabolism ; Animals ; Antibodies/immunology/metabolism ; Chemokine CXCL2/analysis ; Chemokines/analysis/blood/*physiology ; Chickens ; HMGB1 Protein/metabolism ; Humans ; Interleukin-1beta/analysis ; Lipopolysaccharides/toxicity ; Mice ; Mice, Inbred BALB C ; NF-kappa B/metabolism ; Neutrophils/immunology/metabolism ; Peroxidase/analysis ; Shock, Hemorrhagic/*complications ; Time Factors ; Tumor Necrosis Factor-alpha/analysis