HMGB1 Protein Levels Research Articles

Electroacupuncture Relieves Pain by Down-regulating Expression of Hippocampal High Mobility Group Protein 1 and Contents of TNF-α and IL-1 β in Rats with Chronic Neuropathic Pain

To observe the effect of electroacupuncture (EA) on expression of high mobility group protein 1 (HMGB 1) and related downstream effectors of proinflammatory cytokines in the hippocampus in chronic neuropathic pain rats, so as to investigate its mechanism underlying neuropathic pain relief. Male SD rats were randomized into sham, model, and EA groups, with 12 rats in each group. The neuropathic pain model was established by ligature of the left sciatic nerve to induce chronic constriction injury (CCI). EA was applied to bilateral "Zusanli"(ST 36) and "Yanglingquan"(GB 34) for 30 min, once daily for 7 days. The mechanical withdrawal threshold (WMT) was detected using an electronic von Frey anesthesiometer. The expression level of HMGB 1 in the hippocampus was determined using quantitative RT-PCR and Western blot, separately, and the contents of hippocampal TNF-α and IL-1 β were detected by ELISA. Compared with the sham group, the MWT values were markedly decreased on day 7, 10 and 14 after modeling in the model group (P<0.001). On day 10 and 14 after modeling, the MWT values were significantly up-regulated in the EA group relevant to those of the model group (P<0.05, P<0.01). The expression levels of HMGB1 mRNA and protein, and the contents of hippocampal TNF-α and IL-1 β were markedly increased in the model group relevant to the sham group (P<0.001), and significantly down-regulated in the EA group relevant to the model group (P<0.001, P<0.01, P<0.05). EA stimulation of ST 36-GB 34 can relieve pain in chronic neuropathic pain rats, which may be related to its actions in down-regulating the levels of HMGB 1 and its downstream proinflammatory cytokines TNF-α and IL-1 β in the hippocampus.

Abstract 4395: KP-1339 (IT-139) induces the hallmarks of immunogenic cell death in a colon cancer 3D model in vitro

Abstract Chemotherapeutic drugs exert their activity by directly killing tumor cells through a variety of cellular targets eventually leading to apoptosis. Apoptosis is regarded as non-inflammatory and non-immunogenic, however, recent data confirm that the induction of damage-associated molecular patterns by dying cancer cells treated with certain chemotherapeutic agents, such as oxaliplatin, lead to their recognition by the immune system, and result in dendritic cell maturation and immune responses, a mechanism described as Immunogenic Cell Death (ICD). The main hallmarks of ICD are: Calreticulin (CRT) exposure on the cell membrane and release of high mobility group box-1 (HMGB-1) and ATP from dying cells. We have recently shown that the mode of action of KP-1339, a clinically investigated ruthenium-based metal complex, involves the enhancement of endoplasmic reticulum stress (ERS) and the induction of apoptosis-like events. We next investigated the ability of KP-1339 to trigger ICD. There is currently no reliable method to study ICD in vitro, and therefore we aimed at a more suitable model that better mimics the tumor microenvironment in comparison to 2D monolayer cultures. For this reason, ICD was assessed in human colorectal cancer HCT-116 3D multicellular spheroids in vitro. We demonstrate that spheroids treated with KP-1339 activate the PERK/Phospho-eIF-2alpha pathway of the ERS, a prerequisite for CRT exposure on the cell membrane. HMGB1 protein levels decrease considerably during a 72 hours drug treatment, as shown by Immunoblotting, suggesting the depletion of the protein. Additionally, treated spheroids released significantly more ATP than untreated controls. Immunofluorescence of cryosections of KP-1339 treated spheroids stained for CRT and HMGB1 confirmed the above observations and, clearly showed the translocation of CRT to the cell membrane. In conclusion, we have established a 3D tumor spheroid model as an alternative to the 2D monolayer cultures to study ICD in vitro. This model more closely resembles the tumor microenvironment and recapitulates relevant aspects of the in vivo situation. We successfully employed this model to demonstrate that the clinically investigated compound KP-1339 triggers the main hallmarks of ICD, which suggests enhanced induction anti-tumor immunity in colorectal cancer. Citation Format: Debora Wernitznig, Giorgia Del Favero, Konstantinos Kiakos, Nathalie Harrer, Herwig Machat, Doris Marko, Michael Jakupec, Wolfgang Sommergruber, Bernhard K. Keppler. KP-1339 (IT-139) induces the hallmarks of immunogenic cell death in a colon cancer 3D model in vitro [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4395.

High mobility group box 1 protein in bronchoalveolar lavage fluid and correlation with other inflammatory markers in pulmonary diseases.

Objectives: Analysis of new markers in bronchoalveolar lavage fluid (BALF) provides new insights into the immunopathogenesis and may be helpful in differential diagnosis of lung diseases. High mobility group box 1 protein (HMGB1) is a non-histone nuclear protein and its release into the extracellular environment may be associated with the inflammatory response. The aim of the study is the analysis of HMGB1 in BALF, correlations with other markers of inflammation and differences in extracellular HMGB1 levels in various lung diagnoses. Methods: The concentration of HMGB1 was tested by an Elisa test. We calculated correlations with other inflammatory markers (leukocytes, total protein, albumin, IgG, IgA, IgM, C3 complement component, alpha-2macroglobuline, CD3, CD4, CD8, TREM-1 and TREM-2) and specified HMGB1 level in various diagnoses. Results: A positive correlation was found between the level of HMGB1 and total protein levels (p=0.0001), albumin (p=0.0058), IgA (p=0.011), IgM (0.0439) and TREM-2 (p=0.0188). Conversely, a negative correlation was revealed between HMGB1 and TREM-1 (p=0.0009). HMGB1 level varied in different diagnoses: the highest level was detected in QuantiFERON TB-positive subjects (median: 30.2) and hypersensitivity pneumonitis (median: 33.2), followed by pulmonary sarcoidosis (median: 16.8) and idiopathic pulmonary fibrosis (median: 8.8). Conclusion: HMGB1 correlates with other inflammatory markers tested in BALF. Its level varies in different lung diagnoses. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 268-275).

Trypsinogen Activation Peptide Induces HMGB1 Release from Rat Pancreatic Acinar Cells.

BackgroundThe development of acute pancreatitis (AP) is associated with intracellular events in pancreatic cells, as well as with early and late inflammatory responses; however, their underlying mechanisms remain unclear. This study investigated trypsinogen activation peptide (TAP)-induced release of high mobility group box-l (HMGB1) from pancreatic acinar cells and how ethyl pyruvate (EP) affects this release.MethodologyPancreatic acinar cells from Sprague Dawley rats were divided into control, TAP (administered TAP), and EP (administered TAP and EP) groups. Cells were collected at 3, 6, 12, and 24 hours after TAP administration to detect HMGB1 mRNA and protein levels using quantitative PCR (qPCR) and Western blotting, respectively.ResultsThe TAP and EP groups exhibited higher levels of HMGB1 mRNA and protein expression (P<0.05) than the control group. The HMGB1 mRNA and protein expression levels also increased with prolonged TAP activity (P<0.05)–especially at 12 and 24 hours (P<0.01)–and showed positive correlations with TAP activity duration (3, 6, 12, and 24 hours) (r=0.971, P<0.01; r=0.966, P<0.01, respectively).ConclusionTAP induces HMGB1 release from pancreatic acinar cells. A positive temporal link exists between early TAP activity and late HMGB1 expression in AP, and EP inhibits HMGB1 release.

Study on applications of rheum sterile solution in rats following sepsis and effect on inflammatory factors

Objective To study the therapeutic effect of rheum(Chinese herbal medicine) preparation made by using ultrasonic technique on pro-inflammatory cytokines and sepsis in rats. In order to offer novel measure for the treatment of critically ill patients. Methods Firstly, rheum sterile solution was prepared through ultrasonic technique. Secondly, fifty healthy male SD rats were randomly(random number) divided to CLP group and rheum group. Moderate degree of sepsis model was established by using cecal ligation and puncture(CLP). Rats in group rheum received the liquid rheumpreparation via intragastric administration, while rats in group CLP received saline instead. The 7-day survival rate was recorded and was compared between two groups. In addition, another fifty-four rats were randomly(random number) divided to sham group, CLP group and rheum group(n=18 in each group). CLP was performed to induce sepsis in CLP group and rheum group. Then rats in rheum group received rheum sterile solution via intragastric administration, while rats in CLP group received saline instead. At 12 hours, 24 hours and 48 hours after modeling, six rats in each group were randomly sacrificed. Serum TNF-α and HMGB1 levels were detected by ELISA method. Levels of RAGE, HMGB1 and NF-κB P65 in small intestine were detected by Western Blot. Results Level of anthraquinones extracted from rheum by ultrasonic technique was higher than that by conwentional decoction method. The 7-day survival rate of rats in rheum group(76%) was higher than that in CLP group(48%)(P 0.05). At 24 hours and 48 hours after modeling, serum HMGB1 levels were significantly lower in rheum group than those in CLP group(P<0.05). Compared with sham group, protein levels of HMGB1, RAGE and NF-κB in small intestine were elevated in CLP group and rheum group at 48 hours after modeling(P<0.01), while protein levels of above biomarker were higher in CLP group than those in rheum group(P<0.05). Conclusions Rheum sterile solution could down-regulate the level of pro-inflammatory cytokines, modulate the inflammatory response, and improve the survival rate in rats with sepsis. Key words: Ultrasonic technique; Rheum sterile solution; Stability; Sepsis; Proinflammatory cytokines

Glucan phosphate inhibits HMGB-1 release from rat myocardial H9C2 cells in sepsis via TLR4/NF-кB signal pathway.

The effect of glucan phosphate (GP) on the release of HMGB-1 from rat myocardial cells (H9C2) during lipopolysaccharide-induced sepsis, and the underlying mechanisms, were investigated. H9C2 cells were divided into three groups: normal; lipopolysaccharide (LPS) (1 mg/ml LPS); and, LPS+GP (2 mg/ml GP). Western blot was used to determine toll-like receptor 4 (TLR4) levels, and electrophoretic mobility-shift assays (EMSA) was used to determine nuclear factor-кB (NF-кB) activity 3, 6 and 9 h after treatment. HMGB-1 mRNA levels in cultured cells were determined by real-time PCR and supernatant HMGB-1 protein levels were evaluated by ELISA at 12, 24, 36 and 48 h after treatment. Following the transfection of H9C2 cells with Ad5-IкBα, which inhibits NF-кB activity, TLR4, NF-кB and HMGB-1 levels were determined. Intracellular TLR4 levels and NF-кB activity in LPS and LPS+GP groups increased 3-9 h after stimulation, but the increased levels of TLR4 and elevated activity of NF-кB were significantly lower in the LPS+GP group vs. the LPS group. HMGB-1 mRNA levels in both LPS and LPS+GP groups, increased gradually from 24 h after stimulation, but the increase was more obvious in the LPS group vs. the LPS+GP group. Supernatant HMGB-1 levels in the LPS and LPS+GP groups increased gradually from 9 h after stimulation, and also increased markedly in the LPS group. After the inhibition of NF-кB activity, LPS-induced HMGB-1 release decreased significantly (p.

Down-regulation of LncRNA TUG1 enhances radiosensitivity in bladder cancer via suppressing HMGB1 expression

BackgroundLong non-coding RNAs (lncRNAs) have been reported to regulate the sensitivity of different cancer cells to chemoradiotherapy. Aberrant expression of lncRNA Taurine-upregulated gene 1 (TUG1) has been found to be involved in the development of bladder cancer, however, its function and underlying mechanism in the radioresistance of bladder cancer remains unclear.MethodsQuantitative real-time PCR (qRT-PCR) was conducted to measure the expression of TUG1 and HMGB1 mRNA in bladder cancer tissues and cell lines. HMGB1 protein levels were tested by western blot assays. Different doses of X-ray were used for radiation treatment of bladder cancer cells. Colony survival and cell viability were detected by clonogenic assay and CCK-8 Kit, respectively. Cell apoptosis was determined by flow cytometry. A xenograft mouse model was constructed to observe the effect of TUG1 on tumor growth in vivo.ResultsThe levels of TUG1 and HMGB1 were remarkably increased in bladder cancer tissues and cell lines. Radiation treatment markedly elevated the expression of TUG1 and HMGB1. TUG1 knockdown inhibited cell proliferation, promoted cell apoptosis and decreased colony survival in SW780 and BIU87 cells under radiation. Moreover, TUG1 depletion suppressed the HMGB1 mRNA and protein levels. Furthermore, overexpression of HMGB1 reversed TUG1 knockdown-induced effect in bladder cancer cells. Radiation treatment dramatically reduced the tumor volume and weight in xenograft model, and this effect was more obvious when combined with TUG1 silencing.ConclusionLncRNA TUG1 knockdown enhances radiosensitivity of bladder cancer by suppressing HMGB1 expression. TUG1 acts as a potential regulator of radioresistance of bladder cancer, and it may represent a promising therapeutic target for bladder cancer patients.

Pre-conditioning with tanshinone IIA attenuates the ischemia/reperfusion injury caused by liver grafts via regulation of HMGB1 in rat Kupffer cells.

We have evaluated the protective mechanism of tanshinone IIA in ischemia/reperfusion injury (IRI) induced by liver grafts, revealing novel supplementary immunotherapy for liver transplantation. The tanshinone IIA preconditioning group (TP group) was pretreated with tanshinone IIA via intraperitoneal injection for 1 week before receiving orthotopic liver transplantation with hepatic arterial ischemia for 30min. The sham-operation group (SO group), control graft group (CG group) and IRI group were pretreated with an equivalent volume of normal saline. The IRI group and CG group received orthotopic liver transplantation with or without hepatic arterial ischemia. Rats were sacrificed at each time point, serum was collected for ELISA detection, and Kupffer cells (KCs) were isolated to extract total protein and RNA for western blotting and real-time PCR, respectively. The levels of TNF-α and IL-4 in the TP group were significantly lower than those of in the IRI group; meanwhile the IL-10 and TGF-β levels were significantly higher than in the IRI group. The protein and mRNA expression levels of HMGB1 were significantly lower in TP group than in the IRI group at each time point. The TLR-4, Myd88, NLRP3 and p-NF-κb p65 expression levels in the TP groups were significantly lower than those in the IRI group, while the PTEN, PI3K and AKT phosphorylation levels in the TP groups were significantly higher than those in the IRI group. Tanshinone IIA attenuates IRI caused by liver grafts via down-regulation of the HMGB1-TLR-4/NF-κb pathway in KCs and activation of PTEN/PI3K/AKT pathway, suggesting a potential role for prevention of liver cell IRI during liver transplantation.

GSK3β and VDAC Involvement in ER Stress and Apoptosis Modulation during Orthotopic Liver Transplantation

We investigated the involvement of glycogen synthase kinase-3β (GSK3β) and the voltage-dependent anion channel (VDAC) in livers subjected to cold ischemia–reperfusion injury (I/R) associated with orthotopic liver transplantation (OLT). Rat livers were preserved in University of Wisconsin (UW) and Institute Georges Lopez (IGL-1) solution, the latter enriched or not with trimetazidine, and then subjected to OLT. Transaminase (ALT) and HMGB1 protein levels, glutamate dehydrogenase (GLDH), and oxidative stress (MDA) were measured. The AKT protein kinase and its direct substrates, GSK3β and VDAC, as well as caspases 3, 9, and cytochrome C and reticulum endoplasmic stress-related proteins (GRP78, pPERK, ATF4, and CHOP), were determined by Western blot. IGL-1+TMZ significantly reduced liver injury. We also observed a significant phosphorylation of AKT, which in turn induced the phosphorylation and inhibition of GSK3β. In addition, TMZ protected the mitochondria since, in comparison with IGL-1 alone, we found reductions in VDAC phosphorylation, apoptosis, and GLDH release. All these results were correlated with decreased ER stress. Addition of TMZ to IGL-1 solution increased the tolerance of the liver graft to I/R injury through inhibition of GSK3β and VDAC, contributing to ER stress reduction and cell death prevention.

Electroacupuncture pretreatment attenuates spinal cord ischemia-reperfusion injury via inhibition of high-mobility group box 1 production in a LXA4 receptor-dependent manner

Paraplegia caused by spinal cord ischemia is a severe complication following surgeries in the thoracic aneurysm. HMGB1 has been recognized as a key mediator in spinal inflammatory response after spinal cord injury. Electroacupuncture (EA) pretreatment could provide neuroprotection against cerebral ischemic injury through inhibition of HMGB1 release. Therefore, the present study aims to test the hypothesis that EA pretreatment protects against spinal cord ischemia-reperfusion (I/R) injury via inhibition of HMGB1 release. Animals were pre-treated with EA stimulations 30min daily for 4 successive days, followed by 20-min spinal cord ischemia induced by using a balloon catheter placed into the aorta. We found that spinal I/R significantly increased mRNA and cytosolic protein levels of HMGB1 after reperfusion in the spinal cord. The EA-pretreated animals displayed better motor performance after reperfusion along with the decrease of apoptosis, HMGB1, TNF-α and IL-1β expressions in the spinal cord, whereas these effects by EA pretreatment was reversed by rHMGB1 administration. Furthermore, EA pretreatment attenuated the down-regulation of LXA4 receptor (ALX) expression induced by I/R injury, while the decrease of HMGB1 release in EA-pretreated rats was reversed by the combined BOC-2 (an inhibitor of LXA4 receptor) treatment. In conclusion, EA pretreatment may promote spinal I/R injury through the inhibition of HMGB1 release in a LXA4 receptor-dependent manner. Our data may represent a new therapeutic technique for treating spinal cord ischemia-reperfusion injury.

P2.05-001 α7-nAchR Agonist GTS-21 Reduces Radiation-Induced Lung Injury by Inhibiting HMGB1/TLR-4/NF-κB Pathway: Topic: Biology

The cholinergic anti-inflammatory signaling pathway allows the autonomic nervous system to modulate immunologic stimuli and inflammatory processes α7 nicotinic acetylcholine receptor (α7-nAChR) is a major component in this pathway. GTS-21, a selective α7 nicotinic acetylcholine receptor agonist, has been demonstrated as a promising treatment for inflammation. So, the aim of this study is to determine whether treatment GTS-21 can mitigate the radiation induced lung injury. C57BL/6 mice were randomly divided into three groups: a control group, a 12 Gy thoracic irradiation group, a 12 Gy thoracic irradiation group treated with 4mg/kg GTS-21 immediately after irradiation. Each of group were sacrificed at 1, 3, 7, 14, 21d and 3m, 6m post-irradiation, and the sections were respectively stained with hematoxylin and eosin (HE) and Masson’s trichrome to assess the degree of inflammation and fibrosis. Serum concentrations of TNF-α, IL-1β and IL-6 were quantitatively measured by Cytometric Bead Array (CBA) kit. Real-time PCR and Western blot were used to detect the mRNA and protein levels of HMGB1, TLR-4, NF-κB, MyD88 and TGF-β in lung tissue from GTS-21 group and irradiation control group at different time after radiation. The result from HE and Masson staining showed that GTS-21 could dramatically reduce radiation-induced lung inflammation and following mitigate lung fibrosis. Then, we found that radiation-induced TNF-α, IL-1β and IL-6 in serum were also inhibited by GTS-21. Comparing to the control group, the mRNA levels of HMGB1,TLR-4 and NF-κB were decreased at the early time of radiation pneumonitis, and the most significant difference was observed at 21d post-irradiation(P<0.05). the mRNA levels of TGF-β was decrease in GTS-21group at 3m and 6m post -irradiation when compared to control (P<0.05). However, there did not have any different on MyD88 between GTS-21and control groups. The result from western blot showed that the protein levels of HMGB1, TLR-4 and NF-κB in GTS-21 group were also significantly decreased at 21d after radiation. After 3m and 6m from radiation, the protein level of TGF-β was decreased dramatically at GTS-21 group. GTS-21 can reduce radiation pneumonitis and fibrosis by inhibiting HMGB1/TLR-4/NF-κB pathway which subsequently decrease TGF-β expression.

Interference of HMGB1 Lead to Increased Vulnerability of MM Cells to Dexamethasone and Doxorubicin

Background: Multiple myeloma (MM) is the second mostly diagnosed disease among hematological malignancies after lymphoma. With the novel agents, the survival of MM patients has been improved significantly but still remains incurable because of drug resistance. Studies have found that high-mobility group box 1 protein (HMGB1) was involved in inflammation, angiogenesis, and cancer invasion progression, metastasis, and drug resistance. Our research was aimed at exploring the role of HMGB1 in MM cell proliferation and drug resistance.Methods: First, semi-quantitative real time-polymerase chain (qRT-PCR) and western blot was used to determine the levels of HMGB1 mRNA and protein expression in MM cell lines (RPMI8226, CAG, and MM.1S) and primary MM samples. Second, MM cells were transfected with HMGB1-knockdown lentivirus and the Cell Counting Kit 8 (CCK8) assay was used to determine the proliferation of MM cells with or without chemotherapeutic drugs dexamethasone (Dex) and doxorubicin (ADM). Then cell apoptosis was detected by flow cytometry. Third, Affymetrix HTA 2.0 Array was used to compare changes in gene expression levels between HMGB1-knockdown cells and the control cells and qRT-PCR was used to verify the array results. Last, Western bolt was performed to analyze changes in signaling pathways after HMGB1 knockdown.Results: MM cell lines and primary MM samples expressed high levels of HMGB1 mRNA and protein. Although there was no difference in MM cell proliferation between HMGB1-knockdown group and the control group (P>0.05), HMGB1-knockdown significantly enhanced inhibitory effect of chemotherapy with Dex and ADM in comparison with the wildtype HMGB1 control (P<0.05). Flow cytometry results showed that apoptosis of MM cells induced by Dex and ADM was increased when HMGB1 expression was suppressed (P<0.05). Furthermore, gene array analysis on RPMI8226 and CAG cell lines showed that anti-apoptotic genes (bcl-2, HIAP1) and MM survival related genes (DEPTOR, CXCL12) were decreased and pro-apoptotic genes (TNFRSF1B, TRAIL, CXCL10) were increased in knockdown cells compared to the controls. In addition, expression levels of genes that play important roles in signaling pathways such as mTOR, NF-κB, PI3K-AKt, and p38-MAPK were also significantly changed. The gene expression microarray results were verified by qRT-PCR and Western blot demonstrated that phosphorylation of p70S6K (substrate of mTORC1 complex) and AKT-ser473 (substrate of mTORC2 complex) were both elevated in HMGB1-knockdown MM cells compared to that in the control cells.Conclusions: Our research showed that downregulation of HMGB1 increased sensitivity of MM cells to Dex and ADM through increasing apoptosis and regulating mTOR, NF-κB, PI3K-AKt, and p38-MAPK pathways. DisclosuresNo relevant conflicts of interest to declare.

Edaravone attenuates hippocampal damage in an infant mouse model of pneumococcal meningitis by reducing HMGB1 and iNOS expression via the Nrf2/HO-1 pathway.

Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) is a free radical scavenger that has shown potent antioxidant, anti-inflammatory and neuroprotective effects in variety of disease models. In this study, we investigated whether edaravone produced neuroprotective actions in an infant mouse model of pneumococcal meningitis. C57BL/6 mice were infected on postnatal d 11 by intracisternal injection of a certain inoculum of Streptococcus pneumoniae. The mice received intracisternal injection of 10 μL of saline containing edaravone (3 mg/kg) once a day for 7 d. The severity of pneumococcal meningitis was assessed with a clinical score. In mice with severe meningitis, the survival rate from the time of infection to d 8 after infection was analyzed using Kaplan-Meier curves. In mice with mild meningitis, the CSF inflammation and cytokine levels in the hippocampus were analyzed d 7 after infection, and the clinical neurological deficit score was evaluated using a neurological scoring system d 14 after infection. The nuclear factor (erythroid-derived 2)-like 2 knockout (Nrf2 KO) mice and heme oxygenase-1 knockout (HO-1 KO) mice were used to confirm the involvement of Nrf2/HO-1 pathway in the neuroprotective actions of edaravone. In mice with severe meningitis, edaravone treatment significantly increased the survival rate (76.4%) compared with the meningitis model group (32.2%). In mice with mild meningitis, edaravone treatment significantly decreased the number of leukocytes and TNF- levels in CSF, as well as the neuronal apoptosis and protein levels of HMGB1 and iNOS in the hippocampus, but did not affect the high levels of IL-10 and IL-6 in the hippocampus. Moreover, edaravone treatment significantly improved the neurological function of mice with mild meningitis. In Nrf2 KO or HO-1 KO mice with the meningitis, edaravone treatment was no longer effective in improving the survival rate of the mice with severe meningitis (20.2% and 53.6%, respectively), nor it affected the protein levels of HMGB1 and iNOS in the hippocampus of the mice with mild meningitis. Edaravone produces neuroprotective actions in a mouse model of pneumococcal meningitis by reducing neuronal apoptosis and HMGB1 and iNOS expression in the hippocampus via the Nrf2/HO-1 pathway. Thus, edaravone may be a promising agent for the treatment of bacterial meningitis.

Increased adipose tissue secretion of Fetuin-A, lipopolysaccharide-binding protein and high-mobility group box protein 1 in metabolic syndrome

ObjectiveAdipose Tissue (AT) dysregulation contributes to the pro-inflammatory state and insulin resistance of Metabolic Syndrome (MetS). We examined AT secretion of the hepatokine, Fetuin-A, LBP, sCD14 and HMGB-1, and toll-like receptor 2 and 4 protein levels in MetS and controls. Design and methodsSecreted levels of Fetuin-A, LBP, HMGB-1 and sCD14 and TLR2 and TLR4 protein in AT of controls and MetS patients were assayed. Also mRNA and protein for Fetuin-A, LBP, sCD14 and HMGB-1 were studied in subcutaneous fat depot of mice and during adipocyte differentiation. ResultsSecretion of Fetuin-A, LBP and HMGB-1 from AT were significantly increased in MetS (n = 28) compared to controls (n = 25), even after adjustment for adiposity. There were no significant differences in sCD14. Both LBP and Fetuin-A correlated significantly with HOMA-IR and increased significantly with increasing features of MetS. There was a significant increase in AT TLR2 and TLR4 protein in MetS compared to controls. Expression of Fetuin-A and LBP were significantly higher in subcutaneous white adipose tissue of HFD fed mice as well as in ob/ob mice compared to C57BL6/J control mice (n = 6 per group). Additionally mRNA and protein levels of FetA, LBP and HMGB-1 increased during differentiation of 3T3-L1 adipocytes. ConclusionsWe make the novel observation of increased secretion of Fetuin A, LBP and HMGB-1 from AT and hypothesize that these engage TLRs in AT and other tissues contributing to the pro-inflammatory state and insulin resistance of MetS.

Effects of propofol on lipopolysaccharide-induced expression and release of HMGB1 in macrophages.

This study aimed to determine the effects of different concentrations of propofol (2,6-diisopropylphenol) on lipopolysaccharide (LPS)-induced expression and release of high-mobility group box 1 protein (HMGB1) in mouse macrophages. Mouse macrophage cell line RAW264.7 cells were randomly divided into 5 treatment groups. Expression levels of HMGB1 mRNA were detected using RT-PCR, and cell culture supernatant HMGB1 protein levels were detected using enzyme-linked immunosorbent assay (ELISA). Translocation of HMGB1 from the nucleus to the cytoplasm in macrophages was observed by Western blotting and activity of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in the nucleus was detected using ELISA. HMGB1 mRNA expression levels increased significantly in the cell culture supernatant and in cells after 24 h of stimulating RAW264.7 cells with LPS (500 ng/mL). However, HMGB1 mRNA expression levels in the P2 and P3 groups, which received 500 ng/mL LPS with 25 or 50 μmol/mL propofol, respectively, were significantly lower than those in the group receiving LPS stimulation (P<0.05). After stimulation by LPS, HMGB1 protein levels were reduced significantly in the nucleus but were increased in the cytoplasm (P<0.05). Simultaneously, the activity of NF-κB was enhanced significantly (P<0.05). After propofol intervention, HMGB1 translocation from the nucleus to the cytoplasm and NF-κB activity were inhibited significantly (each P<0.05). Thus, propofol can inhibit the LPS-induced expression and release of HMGB1 by inhibiting HMGB1 translocation and NF-κB activity in RAW264.7 cells, suggesting propofol may be protective in patients with sepsis.

Escin Increases the Survival Rate of LPS-Induced Septic Mice Through Inhibition of HMGB1 Release from Macrophages

Background: Previous studies have described the effects of Escin on improving the survival rate of endotoxemic animals. The purpose of this study was to explore the molecular mechanisms of this potentially beneficial treatment. Methods: First, the survival rate of endotoxemic mice was monitored for up to 2 weeks after Escin pretreatment, Escin post-treatment, or Escin post-treatment + rHMGB1. The effects of Escin on the release of pro-inflammatory cytokines such as TNF-a, IL-1ß, IL-6 and HMGB1 in the serum of endotoxemic mice and LPS-induced macrophages were evaluated by ELISA. Furthermore, the mRNA and protein levels of HMGB1 in LPS-induced macrophages were measured by qRT-PCR and Western blot, respectively. Additionally, the release of pro-inflammatory cytokines such as TNF-a, IL-1ß, IL-6 was evaluated by ELISA in rHMGB1-induced macrophages. Finally, the protein levels and the activity of NF-κB in macrophages were checked by Western blot and ELISA, respectively. Results: Both pretreatment and post-treatment with Escin could improve the survival rate of endotoxemic mice, while exogenous rHMGB1 reversed this effect. In addition, Escin decreased the level of the pro-inflammatory cytokines TNF-a, IL-1ß, IL-6 and HMGB1 in endotoxemic mice and in LPS-induced macrophages. Escin could also inhibit the mRNA levels and activity of HMGB1. The release of the pro-inflammatory cytokines TNF-a, IL-1ß, IL-6 could be suppressed in rHMGB1-induced macrophages by Escin. Finally, Escin could suppress the activation of NF-κB in LPS-induced macrophages. Conclusion: Escin could improve the survival of mice with LPS-induced endotoxemia. This effect maybe meditated by reducing the release of HMGB1, resulting in the suppression of the release of pro-inflammatory cytokines.

Overexpression of HMGB1 A-box reduced lipopolysaccharide-induced intestinal inflammation via HMGB1/TLR4 signaling in vitro.

To investigate the inhibitory effects and mechanism of high mobility group box (HMGB)1 A-box in lipopolysaccharide (LPS)-induced intestinal inflammation. Overexpression of HMGB1 A-box in human intestinal epithelial cell lines (SW480 cells) was achieved using the plasmid pEGFP-N1. HMGB1 A-box-overexpressing SW480 cells were stimulated with LPS and co-culturing with human monocyte-like cell lines (THP-1 cells) using a Transwell system, compared with another HMGB1 inhibitor ethyl pyruvate (EP). The mRNA and protein levels of HMGB1/toll-like receptor (TLR) 4 signaling pathways [including HMGB1, TLR4, myeloid differentiation factor88 (MYD88), Phosphorylated Nuclear Factor κB (pNF-κB) p65] in the stimulated cells were determined by real-time polymerase chain reaction and Western blotting. The levels of the proinflammatory mediators [including HMGB1, interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α] in the supernatants of the stimulated cells were determined by ELISA. EP downregulated the mRNA and protein levels of HMGB1, inhibited the TLR4 signaling pathways (TLR4, MYD88 and pNF-κB p65) and reduced the secretion of proinflammatory mediators (HMGB1, IL-1β, IL-6 and TNF-α) in the SW480 and THP-1 cells activated by LPS but not in the unstimulated cells. Activated by LPS, the overexpression of HMGB1 A-box in the SW480 cells also inhibited the HMGB1/TLR4 signaling pathways and reduced the secretion of these proinflammatory mediators in the THP-1 cells but not in the transfected and unstimulated cells. HMGB1 A-box, not only EP, can reduce LPS-induced intestinal inflammation through inhibition of the HMGB1/TLR4 signaling pathways.

TLR4-HMGB1-, MyD88- and TRIF-dependent signaling in mouse intestinal ischemia/reperfusion injury.

To characterize high-mobility group protein 1-toll-like receptor 4 (HMGB1-TLR4) and downstream signaling pathways in intestinal ischemia/reperfusion (I/R) injury. Forty specific-pathogen-free male C57BL/6 mice were randomly divided into five groups (n = 8 per group): sham, control, anti-HMGB1, anti-myeloid differentiation gene 88 (MyD88), and anti-translocating-chain-associating membrane protein (TRIF) antibody groups. Vehicle with the control IgG antibody, anti-HMGB1, anti-MyD88, or anti-TRIF antibodies (all 1 mg/kg, 0.025%) were injected via the caudal vein 30 min prior to ischemia. After anesthetization, the abdominal wall was opened and the superior mesenteric artery was exposed, followed by 60 min mesenteric ischemia and then 60 min reperfusion. For the sham group, the abdominal wall was opened for 120 min without I/R. Levels of serum nuclear factor (NF)-κB p65, interleukin (IL)-6, and tumor necrosis factor (TNF)-α were measured, along with myeloperoxidase activity in the lung and liver. In addition,morphologic changes that occurred in the lung and intestinal tissues were evaluated. Levels of mRNA transcripts encoding HMGB1 and NF-κB were measured by real-time quantitative PCR, and levels of HMGB1 and NF-κB protein were measured by Western blot. Results were analyzed using one-way analysis of variance. Blocking HMGB1, MyD88, and TRIF expression by injecting anti-HMGB1, anti-MyD88, or anti-TRIF antibodies prior to ischemia reduced the levels of inflammatory cytokines in serum; NF-κB p65: 104.64 ± 11.89, 228.53 ± 24.85, 145.00 ± 33.63, 191.12 ± 13.22, and 183.73 ± 10.81 (P < 0.05); IL-6: 50.02 ± 6.33, 104.91 ± 31.18, 62.28 ± 6.73, 85.90 ± 17.37, and 78.14 ± 7.38 (P < 0.05); TNF-α, 43.79 ± 4.18, 70.81 ± 6.97, 52.76 ± 5.71, 63.19 ± 5.47, and 59.70 ± 4.63 (P < 0.05) for the sham, control, anti-HMGB1, anti-MyD88, and anti-TRIF groups, respectively (all in pg/mL).Antibodies also alleviated tissue injury in the lung and small intestine compared with the control group in the mouse intestinal I/R model. The administration of anti-HMGB1, anti-MyD88, and anti-TRIF antibodies markedly reduced damage caused by I/R, for which anti-HMGB1 antibody had the most obvious effect. HMGB1 and its downstream signaling pathway play important roles in the mouse intestinal I/R injury, and the effect of the TRIF-dependent pathway is slightly greater.

The involvement of high mobility group 1 cytokine and phospholipases A2 in diabetic retinopathy

BackgroundDiabetic retinopathy, the main microvascular complications of diabetes and one of the leading causes of blindness worldwide. Interesting reports on the role of inflammatory/proangiogenic high mobility group 1 (HMGB-1) cytokine and phospholipases A2 (PLA2) in neovascularization have diverted our concentration to reveal whether HMGB-1 and PLA2 plays role in diabetic retinopathy.MethodsWe performed our study in streptozotocin (STZ)-induced diabetic rat model. The expression levels of the cytokines, chemokines, and cell adhesion molecules in retinal tissues were evaluated by quantitative RT-PCR. HMGB-1 and PLA2 protein levels along with VEGF, TNF-α, IL-1β and ICAM-1 levels were also measured.ResultsWe observed the retinal pericytes, endothelial injury/death and breakdown of blood–retinal barrier (BRB). The protein expression of HMGB-1, PLA2 and IL-1β were significantly increased in micro vessels from retina of diabetic rats. Diabetic rats had also high retinal levels of VEGF, ICAM-1 and TNF-α. Further investigation revealed that pericyte death is mediated by HMGB-1-induced cytotoxic activity of glial cells, while HMGB-1 can directly mediate endothelial cell death. Similarly, increased expression of PLA2 represents the diabetic mediated alteration of BRB, perhaps up regulating the VEGF.ConclusionsOur data suggest that HMGB-1 and PLA2 involved in retinal pericyte and endothelial injury and cell death in diabetic retinopathy. From this study, we suggest that HMGB-1 and PLA2 may be interesting targets in managing diabetic retinopathy.

Abstract 3958: Investigation of HMGB1 as a potential marker for radiation response in muscle invasive bladder cancer

Abstract Purpose: Radical cystectomy remains the standard treatment for invasive Bladder Cancer (BC). Radiotherapy is an attractive alternative; however lack of local control of the disease and toxicity associated with it remain problematic. As HMGB1 plays a major role in the cancer associated radio-resistance pathways, our objective is to evaluate its role as a predictive marker for radiation response in BC. Methods: Expression of HMGB1 was characterized in a panel of eight BC cell lines via RT-PCR and Western Blotting. Knockdown of HMGB1 was carried out via shRNA lentiviral system. Correlation of HMGB1 expression and radiation response was done using clonogenic assays in control and shRNA transduced cell lines. Alkaline Comet Assay was used to measure the extent of DNA damage and repair in different cell lines 24hr post 5Gy radiation. Olive Tail moment was used as to quantify the DNA Damage. Results: All cell lines expressed different levels of HMGB1, with BV and UC3 having the lowest and the highest expression of HMGB1 simultaneously. Clonogenic assay results showed that UC3 was resistant to radiation while BV was sensitive. Knockdown of HMGB1 caused the radio-resistant UC3 cells to become highly radio-sensitive, with more than 60% cells dying at 2Gy. Comet assay suggest the involvement of HMGB1 in DNA repair, as a significant DNA damage post radiation was observed in the HMGB1 knockdown cell line. Conclusion: Our results demonstrate that high levels of HMGB1 protein are linked to a more radio-resistant outcome and HMGB1 knockdown leads to an increase in radio-sensitivity. Hence HMGB1 could potentially be used as a radiation response marker in invasive BC. Citation Format: Jose J. Mansure, Sanhita Shrivastava, Roland Nassim, Gerardo Ferbeyre, Wassim Kassouf. Investigation of HMGB1 as a potential marker for radiation response in muscle invasive bladder cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3958. doi:10.1158/1538-7445.AM2014-3958