丙酮酸乙酯抑制LPS诱导RAW264.7巨噬细胞HMGB1的表达

目的:探讨丙酮酸乙酯(EP)抑制脂多糖(LPS)诱导巨噬细胞高迁移族率蛋白B1 (HMGB1)的表达及分子机制.方法:培养小鼠巨噬细胞株RAW264.7,分为LPS( 100 ng/mL)组及LPS( 100 ng/mL)+EP(5 mmol/L)组,刺激后0、6、12、18、24、30、36 h提取总RNA及胞质胞核蛋白,用RT-PCR法测细胞培养液中HMGB1 mRNA 表达;用Western blot测胞质和胞核HMGB1蛋白含量;用ELISA法测培养上清中HMGB1、TNF-α和IL-6的含量;用免疫细胞化学共聚焦显微镜观察细胞内HMGB1的转位分布.结果:LPS+EP组HMGB1 mRNA基因表达于24、36、48 h比LPS组明显减少;Western blot结果示,LPS+ EP组HMGB1蛋白含量胞质明显低于LPS组,而胞核明显高于LPS组;ELISA结果示,LPS+EP组细胞培养上清中HMGB1、TNF-α和IL-6的含量明显低于LPS组;免疫荧光、激光共聚焦显微镜结果示,LPS+ EP组细胞质内绿色荧光染色明显弱于LPS组,细胞核内绿色荧光染色明显强于LPS组.结论:EP能有效抑制LPS诱导的小鼠腹腔巨噬细胞HMGB1的表达和释放.     

Effects of Granulocyte Colony-Stimulating Factor (G-CSF) and Neutrophil Elastase Inhibitor (ONO-5046) on Acid-Induced Lung Injury in Rats

It has been suggested that neutrophils play an important role in acid-aspirated lung injury. We examined the effects of the high dose of granulocyte-colony stimulating factor (G-CSF), which is capable of increasing peripheral neutrophils, and a specific neutrophil elastase inhibitor (ONO-5046) on acid lung injury in rats. Animals were anesthetized and normal saline (NS, 2 mL kg⁻¹) or hydrochloric acid (HCl, 0.1 N 2 mL kg⁻¹) was then instilled into trachea. Thirty minutes before HCl instillation, G-CSF (150 μg kg⁻¹) was injected subcutaneously or ONO-5046 (10 mg kg⁻¹ h⁻¹) was infused continuously into the right jugular vein. Animals were ventilated during the experiments. Five hours after HCl or NS instillation, bronchoalveolar lavage fluid (BALF) and lung tissue samples were obtained. Total nuclear cell count, absorbance, albumin, tumor necrosis factor (TNF)-α, interleukin (IL)-6, cytokine-induced neutrophil chemoattractant (CINC), neutrophil elastase in BALF, wet-to-dry (W/D) ratio were measured. HCl aspiration markedly increased these values in BALF and W/D ratio. Both ONO-5046 and G-CSF attenuated the parameters increased by acid-induced lung injury in rats. The data suggests that neutrophils play an important role in acid-induced lung injury. However, high-dose G-CSF does not exacerbate acid-aspirated lung injury in rats, although this agent causes an increase in peripheral neutrophils.     

Ulinastatin Preconditioning Attenuates Inflammatory Reaction of Hepatic Ischemia Reperfusion Injury in Rats via High Mobility Group Box 1(HMGB1) Inhibition

Objective It has been found that ulinastatin (UTI) can attenuate hepatic injury in a rat model of ischemia reperfusion (IR), but the specific mechanism is unclear. This study aims to investigate possible pathomechanism of ulinastatin in reducing the inflammatory response after hepatic IR.Methods A male sprague-dawley(SD) rat model of hepatic ischemia reperfusion injury was used. The rats were randomly divided into 4 groups on average, which were 0.9% saline and IR group as control, ulinastatin preconditioning (UPC) group, UPC+rHMGB1 (recombinant HMGB1) group and UPC +anti-HMGB1 group. Serum aminotransferases, TNF-α, IL-1 and Myeloperoxidase (MPO) levels were measured. Histopathology examination and apoptotic cell detection and the different expression of HMGB1 protein were also assessed.Results Serum levels of aminotransferases, cytokines and hepatic MPO in UPC and UPC+anti-HMGB1 groups were significantly lower than those in control group (p<0.05). Decreased histologic damage and apoptosis were also seen in these two groups (p<0.05).Conclusions HMGB1 expressions in UPC and UPC+anti-HMGB1 groups were significantly lower than those in the two control groups (p<0.05), pretreatment with ulinastatin attenuated liver IR injury by reducing HMGB1 expression through its anti-inflammatory effects.     

脑外伤患者血浆HMGB1的检测及临床意义

目的:揭示脑外伤患者血浆高迁移率族蛋白B1(HMGB1)浓度的变化,探讨其在脑损伤中的作用及对预后的预测价值.方法:收集重型脑外伤患者作为脑外伤组,共112例.收集同期健康体检人群作为正常对照组,共40例.对照组静脉血体检时获得.脑外伤组静脉血在入院时获得.ELISA测定血浆HMGB1浓度.结果:脑外伤后1个月内死亡3...     

Hyaluronan inhibits cytokine production by lipopolysaccharide-stimulated U937 macrophages through down-regulation of NF-κB via ICAM-1

Objective: This study investigated the inhibitory mechanism of hyaluronan (HA) on lipopolysaccharide (LPS)-stimulated production of proinflammatory cytokines in U937 macrophages. Methods: HA was added to U937 macrophage cultures in the presence of LPS, with or without pretreatment with anti-intercellular adhesion molecule-1 (ICAM-1) antibody. Secreted levels of tumor necrosis factor α (TNFα), interleukin (IL)-1β, and IL-6 were determined by enzyme-linked immunosorbent assay. The phosphorylation of nuclear factor (NF)-κB, IκBα, and mitogen-activated protein kinases (MAPKs) was analyzed by immunoblotting. Results: LPS stimulated production of TNFα, IL-1β, and IL-6. In contrast to 800 kDa HA, 2700 kDa HA at 1 mg/ml inhibited LPS-induced cytokine production. Anti-ICAM-1 antibody blocked the effects of HA on the LPS actions on U937 cells. LPS activated NF-κB and MAPK pathways, whereas HA down-regulated p65 NF-κB and IκBα phosphorylation by LPS without affecting MAPKs. Inhibition studies revealed the requirement of NF-κB for LPS-stimulated cytokine production. Anti-ICAM-1 antibody reversed the inhibitory effects of HA on phosphorylation of p65 NF-κB and IκBα. Conclusion: HA of intrinsic molecular weight suppresses LPS-stimulated production of proinflammatory cytokines via ICAM-1 through down-regulation of NF-κB and IκB. Exogenous HA injected into arthritic joints could act as an anti-NF-κB agent by the mechanism demonstrated in the present study. Received 23 September 2006; returned for revision 12 October 2006; accepted J. Di Battista 18 December 2006     

Recombinant thrombomodulin ameliorates experimental autoimmune encephalomyelitis by suppressing high mobility group box 1 and inflammatory cytokines

Recombinant thrombomodulin (rTM) has pleiotrophic properties, including anti‐coagulation and anti‐inflammation; however, its effectiveness as a treatment for multiple sclerosis (MS) has not been evaluated fully. High mobility group box 1 (HMGB1) and proinflammatory cytokines, working as inflammatory mediators, are reportedly involved in the inflammatory pathogenesis of MS. The aim of this study was to determine whether rTM can be a potential therapeutic agent for experimental autoimmune encephalomyelitis (EAE). EAE mice received rTM treatment (1 mg or 0·1 mg/kg/day) from days 11 to 15 after immunization. The clinical variables, plasma levels of inflammatory cytokines and HMGB1 and pathological findings in EAE were evaluated. rTM administration ameliorated the clinical and pathological severity of EAE. An immunohistochemical study of the spinal cord showed weaker cytoplasmic HMGB1 staining in the rTM‐treated EAE mice than in the untreated EAE mice. Plasma levels of inflammatory cytokines and HMGB1 were suppressed by rTM treatment. In conclusion, rTM down‐regulated inflammatory mediators in the peripheral circulation and prevented HMGB1 release from nuclei in the central nervous system, suppressing EAE‐related inflammation. rTM could have a novel therapeutic potential for patients with MS.     

Role of inducible nitric oxide synthase expressed by alveolar macrophages in High Mobility Group Box 1- induced acute lung injury

Objective and design The role of inducible nitric oxide synthase (iNOS) expressed by alveolar macrophages in acute lung injury induced by high mobility group box 1 (HMGB1) was explored. Treatments Primary rat alveolar macrophages (PRAMs) were stimulated with HMGB1 to analyze iNOS expression. Alveolar macrophages and iNOS were inhibited by gadolinium chloride and 1400W in rats challenged by HMGB1 intratracheally. Methods Western Blot was applied to assay iNOS expression in PRAMs. Indices for acute lung injury in rats were measured. Immunocytochemistry was used to localize iNOS in□bronchoalveolar lavage (BAL) cells. The enzyme activities of iNOS and constitutive nitric oxide synthase (cNOS) for BAL cells were determined. Results A time- and concentration-dependent response of iNOS expression in PRAMs to HMGB1 induction was observed. Intratracheal instillation of HMGB1 produced persistently exacerbated acute lung inflammation, induction of iNOS in alveolar macrophages and increased lung nitric oxide production in rats. Abrogation of iNOS or macrophages attenuated lung inflammation, nitric oxide in BAL fluid, and iNOS activity of BAL cells, but had no significant effect on cNOS activity of BAL cells in rats challenged by HMGB1. Conclusions Inducible nitric oxide synthase expressed by alveolar macrophages facilitates the development of HMGB1-induced acute lung injury. Received 12 March 2005; returned for revision 11 January 2006; accepted by M. Parnham 24 January 2006     

CHD合并DM2患者血清HMGB1与hs-CRP水平及临床意义

目的：探讨血清高迁移率族蛋白1（HMGB1）与超敏C反应蛋白（hs-CRP）在冠心病（CHD）合并2型糖尿病（DM2）患者中的表达及临床意义。方法：入选20例CHD合并DM2患者（C组）,30例CHD患者（B组）及30例正常对照组（A组）,ELISA测HMGB1值。分析三组间HMGB1与hs-CRP及总胆固醇（TC）、三酰甘油（TG）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）之间的关系。结果：C组与B组患者的HMGB1、hs-CRP水平均显著高于A组,C组hs-CRP水平显著高于B组（P〈0.05）。HMGB1水平与HDL-C呈负相关（r=-0.271,P〈0.05）。结论：CHD与DM2均有慢性炎症反应参与,HMGB1升高可能与脂质代谢异常有关,HMGB1和CRP相互促进在动脉粥样硬化及糖尿病的发生、发展中起着重要作用。     

The novel inflammatory cytokine high mobility group box protein 1 (HMGB1) is expressed by human term placenta

High mobility group box protein 1 (HMGB1) was previously considered a strict nuclear protein, but lately data are accumulating on its extranuclear functions. In addition to its potent proinflammatory capacities, HMGB1 has a prominent role in a number of processes of specific interest for the placenta. Our overall aim was to investigate the expression of HMGB1 in human term placenta and elucidate a potential difference in HMGB1 expression comparing vaginal deliveries with elective Caesarean sections. In addition, placentas from normal pregnancies were compared with placentas from pregnancies complicated by pre-eclampsia. Twenty-five placentas, 12 from normal term pregnancies and 13 from pregnancies complicated by pre-eclampsia were analysed with immunohistochemistry for HMGB1 and its putative receptors; receptor for advanced glycation end-products (RAGE), Toll-like receptor 2 (TLR2) and TLR4. We present the novel finding that in addition to a strong nuclear HMGB1 expression in almost all cells in investigated placentas, an individual variation of cytoplasmic HMGB1 expression was detected in the syncytiotrophoblast covering the peripheral chorionic villi, by cells in the decidua and in amnion. Production of HMGB1 was confirmed by in situ hybridization. Although labour can be described as a controlled inflammatory-like process no differences in HMGB1 expression could be observed comparing active labour and elective Caesarean sections. However, a tendency towards a higher expression of cytoplasmic HMGB1 in the decidua from women with pre-eclampsia was demonstrated. The abundant expression of the receptors RAGE, TLR2 and TLR4 implicates a local capability to respond to HMGB1, although the precise role in the placenta remains to be elucidated.     

HMGB1在高温致金黄地鼠神经管畸形神经上皮细胞中的表达变化

为了探讨高温致神经管畸形(NTDs)作用的分子机制,为预防人类NTDs的发生提供理论依据,本研究在高温致金黄地鼠NTDs模型的基础上,研究HMGB1在高温致金黄地鼠NTDs神经上皮细胞中的表达变化。将孕鼠随机分为实验组和对照组,分别于水浴处理后8、16、24、40、64 h(相当于胚龄第8、8.5、9、9.5、10.5 d)处死孕鼠,剖腹取鼠胚,制备石蜡切片,应用免疫荧光染色技术检测NTDs发生过程中HMGB1在神经上皮细胞中的表达变化。结果显示:对照组和模型组孕鼠在水浴处理后8、16、24h,HMGB1免疫阳性产物分布于鼠胚神经上皮细胞和周围间充质细胞的胞浆中;水浴后40、64 h,HMGB1表达部位出现了由胞浆向胞核的转移;高温处理后,HMGB1在实验组各期胚胎神经上皮细胞内的表达均比对照组减弱。上述结果提示,HMGB1的表达变化与神经管发育密切相关,其表达降低是高温致神经管畸形发生的重要途径之一。     

The damage‐associated molecular pattern HMGB1 is elevated in human alcoholic hepatitis,but does not seem to be a primary driver of inflammation

The role of sterile inflammation caused by release of damage‐associated molecular patterns (DAMP) remains unclear in human alcoholic hepatitis (AH). The DAMP, high mobility group box‐1 protein (HMGB1) is released by tissue damage and inflammation. We aimed to investigate whether HMGB1 is a primary inflammatory driver in AH by determining HMGB1 serum levels and effects on inflammatory cells from AH patients. We measured serum HMGB1 in 34 AH patients and 10 healthy controls using ELISA. Toll‐like receptor 4 (TLR4) and CD14 expressions were assessed by flow cytometry on HMGB1‐stimulated peripheral blood mononuclear cells (PBMC) and ELISA was used to measure TNF‐α and IL‐1β in the supernatants. We observed 5‐fold higher serum levels of HMGB1 in AH patients at the day of diagnosis and day 30, but no associations to clinical outcome. HMGB1 stimulation increased the expression of TLR4 on CD14+‐monocytes compared with unstimulated cells in the AH patients. The TNF‐α and IL‐1β production in response to HMGB1 was diminished in AH patients. In conclusion, AH patients have increased levels of HMGB1 in their blood. This combined with an increased TLR4 expression, but an unaffected cytokine response to HMGB1 suggest that HMGB1 is not the primary driver of inflammation in AH.     

HMGB1 translocation and expression is caused by warm ischemia reperfusion injury, but not by partial hepatectomy in rats

Mechanical injury or ischemia/reperfusion (I/R) injury induces high mobility of group box 1 (HMGB1) translocation and release. However, the surgical procedure itself can initiate pathophysiologic processes causing damage to the respective organ. A liver resection, as an example, leads to portal hyperperfusion injury of the remnant liver. Therefore, we aimed to elucidate the impact of different hepatic surgical injury models on cellular localization and expression of HMGB1. Focal warm I/R injury was induced by clamping the vascular blood supply to the median and left lateral liver lobes for 90 min followed by 0.5 h, 6 h and 24 h reperfusion, as reported previously. Liver injury by PH was induced by subjecting rats to 30%, 70% or 90% partial hepatectomy (PH) followed by a 24 h observation period. Additional 12 rats were subjected to 90% PH and sacrificed at 1 h and 6 h to investigate the expression and release pattern of HMGB1. Elevation of serum liver enzymes indicating hepatic injury peaked at 6 h and recovered thereafter in models, warm I/R injury and PH. Liver injury was confirmed by liver histology. HMGB1 was translocated from the nucleus to the cytoplasm in livers subjected to warm I/R; but not in livers subjected to PH. Both protein and mRNA expression of HMGB1 were significantly up-regulated in livers subjected to warm I/R. In contrast, neither 30% PH, 70% PH nor 90% PH caused an elevation of hepatic HMGB1 mRNA and protein expression. High serum levels of HMGB1 (30 ng/ml) were measured at 0.5 h reperfusion period after warm I/R, much lower levels thereafter (< 5 ng/ml). Similar low serum levels were measured at all time points after 90% PH. Subsequently expression levels of TNF-a should be changed to tumor necrosis factor-alpha (TNF-α) reached a peak (26-fold elevation) at 6 h and decreased down to 5-fold at 24 h after warm I/R. TNF-α expression levels after PH never exceeded a 5-fold elevation. In conclusion, HMGB1 translocation and expression depends on the type of liver injury as it is induced by ischemia, but not by liver resection/hyperperfusion. These results suggest that HMGB1 may be used as molecular marker to visualize ischemic damage. Mechanic injury in hepatic surgery is associated with focal warm ischemia, and thereby HMGB1 translocation reflects surgical quality in experimental PH. Expression of hepatic TNF-α follows the kinetic pattern of HMGB1, pointing to a muss less pronounced inflammatory response after successful PH compared to warm I/R injury.     

右侧颈交感干离断对大鼠心肌梗死后炎症反应的抑制作用及对HMGB1/TLR4/NF-κB通路的影响

目的:观察右侧颈交感干离断(TCST)对大鼠心肌梗死后炎症反应的抑制作用及高迁移率族蛋白B1(HMGB1)的表达和TLR4/NF-κB信号通路的影响。方法:结扎左冠状动脉前降支制备急性心肌梗死(acute myocardial infarction,AMI)模型,将造模成功的大鼠随机分为心肌梗死(MI)组和心肌梗死+右侧颈交感干离断(MI+TCST)组,MI+TCST组在左冠状动脉前降支结扎后立即离断右侧颈交感神经干。MI组和MI+TCST组分别按模型制备及干预后1、3、7、14和28 d分为5个亚组,另设假手术(sham)组,只穿线不结扎,每组8只。建模后4周,超声心动图检测大鼠心脏功能,然后处死大鼠,取心脏计算心脏肥厚指数,并取梗死周围心肌组织采用HE染色观察心肌病理形态改变。Real-time PCR法检测不同时点梗死边缘区HMGB1、肿瘤坏死因子α(TNF-α)和白细胞介素6(IL-6)的m RNA表达。Western blot分析MI后不同时点梗死边缘区HMGB1和TLR4蛋白的表达变化,并进一步分析右侧TCST对HMGB1和TLR4/NF-κB信号通路蛋白表达的影响。结果:与MI组比较,MI+TCST组左心室射血分数(LVEF)和左心室短轴缩短分数(LVFS)显著升高(P0.05),左心室舒张末期内径(LVEDd)、左心室收缩末期内径(LVESd)和心脏肥厚指数显著降低(P0.05),梗死边缘区各时点HMGB1、TNF-α和IL-6的m RNA表达水平显著降低(P0.05)。Western blot检测结果显示,与sham组比较,HMGB1蛋白的表达在MI后3 d开始升高,并于7 d达到高峰,之后逐渐下降,28 d时仍明显高于假手术组(P0.05);TLR4蛋白的表达变化与HMGB1一致。进一步研究发现右侧TCST可显著降低心肌组织HMGB1和TLR4/NF-κB信号通路蛋白的表达(P0.05)。结论:右侧颈交感干离断可改善MI后心室重构,发挥保护心功能的作用,其机制可能与其抑制HMGB1/TLR4/NF-κB信号通路,减轻炎症反应有关。     

益气化瘀化痰方对UUO诱导的肾间质纤维化大鼠KLF15、HMGB1、NF-κB及其下游炎症因子表达的影响

目的:观察益气化瘀化痰方(YHHD)对单侧输尿管结扎(UUO)模型大鼠肾间质纤维化的作用及其可能机制。方法:48只雌性SD大鼠,随机分为假手术组、UUO模型组、替米沙坦组及YHHD低、中、高剂量组,每组8只。除假手术组外,其余各组采用UUO法建立肾间质纤维化模型。各药物干预组以相应浓度的药物灌胃,模型组及假手术组以等体积生理盐水灌胃,每日1次,连续用药12周后采集标本并处死大鼠,检测大鼠血清胱抑素C(Cys-C)和尿酸(UA)的水平,PAS染色观察肾组织形态学改变,Masson染色计算肾间质胶原纤维沉积率,realtime PCR检测肾组织Krüppel样因子15(KLF15)、高迁移率族盒蛋白1(HMGB1)、核因子κB(NF-κB)及其抑制蛋白IκB、单核细胞趋化蛋白1(MCP-1)、白细胞介素1β(IL-1β)、肿瘤坏死因子α(TNF-α)、纤维连接蛋白(FN)、I型胶原(Col I)和Ⅳ型胶原(ColⅣ)的m RNA表达水平,Western blot检测KLF15、HMGB1和NF-κB的蛋白表达,免疫组化检测MCP-1的蛋白表达。结果:与假手术组相比,模型组的胶原纤维沉积率及Cys-C水平显著升高(P0.05),KLF15的m RNA及蛋白表达显著下调(P0.05),HMGB1、NF-κB、IκB、MCP-1、IL-1β、TNF-α、FN、Col I和ColⅣ的m RNA及HMGB1、NF-κB和MCP-1的蛋白表达显著上调(P0.05);与模型组相比,YHHD中、高剂量组及替米沙坦组的胶原纤维沉积率显著降低(P0.05),且HMGB1和NF-κB的蛋白表达以及IL-1β和TNF-α的m RNA表达显著下调(P0.05);YHHD高剂量组及替米沙坦组KLF15的蛋白表达显著上调(P0.05),MCP-1的蛋白表达及FN的m RNA表达显著下调(P0.05);YHHD高剂量组KLF15的m RNA表达显著上调(P0.05),MCP-1、Col I和ColⅣ的m RNA表达明显下调(P0.05);YHHD各剂量组及替米沙坦组NF-κB和IκB的m RNA表达及Cys-C水平明显降低(P0.05)。各组间UA水平的差异无统计学显著性。结论:益气化瘀化痰方对肾间质纤维化的抑制作用呈剂量依赖性,高剂量组作用最明显;其机制可能与上调KLF15表达、抑制肾组织HMGB1和NF-κB及其下游炎症相关因子的表达有关。