丝裂原活化的蛋白激酶在高迁移率族蛋白1诱导内皮细胞释放炎性细胞因子中的作用

目的 研究重组人高迁移率族蛋白1(HMGB1)诱导内皮细胞释放趋化因子白介素-8(IL-8)和单核细胞趋化蛋白-1(MCP-1)的规律及其与脂多糖(LPS)的协同作用;探讨丝裂原活化的蛋白激酶(MAPK)信号通路在上述作用中的地位.方法 用LiquiChip液相蛋白芯片系统检测不同浓度重组HMGB1(0～75 ng/ml),或者HMGB1(15 ng/ml)刺激后不同时间点人脐静脉内皮细胞(HUVEC)分泌IL-8、MCP-1的水平变化以及HMGB1(15 ng/ml)与LPS(10ng/ml)共同刺激后IL-8、MCP-1的水平变化;探讨MAPK信号通路在HMGB1诱导内皮细胞释放趋化因子中的作用时首先加入抑制剂SB203580(20 mol/L)、PD98059(20 mol/L)和JNK inhibitor Ⅱ(50 nmol/L)预处理细胞1 h,再加入HMGB1和LPS刺激.结果 在HMGB1蛋白刺激后3～6h,IL-8和MCP-1水平开始增加,12～24h持续增高(P<0.01);随着 HMGB1浓度的增加,IL-8和MCP-1水平也明显升高,与基础值相比差异有统计学意义(P<0.01).如果用LPS(10ng/ml)和HMGB1(15 ng/ml)共同刺激HUVEC,IL-8和MCP-1的生成量较单独刺激时大大增加(P<0.01),二者存在协同效应(P<0.01).SB203580、PD98059及JNK inhibitor Ⅱ对HMGB1和LPS协同诱导趋化因子的释放均有不同程度的抑制作用,其中以p38 MAPK抑制剂SB203580的抑制作用最为明显;同时用SB203580、PD98059和JNK inhibitor Ⅱ预处理细胞则完全抑制趋化因子的释放.结论 HMGB1蛋白以时间和剂量依赖方式诱导HUVEC表达趋化因子IL-8和MCP-1的上调;并协同LPS刺激HUVEC释放趋化因子IL-8和MCP-1从而加重炎症反应.MAPK信号通路在HMGB1与LPS协同诱导内皮细胞释放趋化因子的过程中发挥了重要作用.

Abstract：

Objective To examine the synergistic effect of recombinant human high mobility group box 1 (HMGB1) protein and lipopolysaccharides (LPS) on the release of interleukin-8 (IL-8) and monocyte chemotactic protein 1 (MCP-1) in human umbilic vein endothelial cells (HUVECs), and explore the role of mitogen-activated protein kinases (MAPK) signal transduction in cytokine release. Methods HUVECs were incubated with recombinant HMGB1(0-75 ng/ml) for 24 h and the culture medium supernatant was harvested for detection of IL-8 and MCP-1 with LiquiChip system. At 0, 1, 3, 6, 12 and 24 h after stimulation with 15 ng/ml HMGB1 or 15 ng/ml HMGB1 plus 10 ng/ml LPS, the levels of IL-8 and MCP-1 in the HUVECs were examined, To test the effect of MAPK inhibitors, HUVCs were pretreated with the inhibitors SB203580 (20 mol/L), PD98059 (20 mol/L), and JNK inhibitor II (50 nmol/L) 1 h before HMGB1 and LPS stimulation. Results The levels of IL-8 and MCP-1 were significantly increased in the HUVECs stimulated with HMGB1 protein at the concentrations of 3, 15 and 75 ng/ml in comparison with the control levels (P<0.01). Since 3-6 h after the stimulation with HMGB1, the levels of IL-8 and MCP-1 began to increase gradually, and steadily increased at 12 and 24 h, all significantly higher than those of the control group (P<0.01). Stimulation of the HUVECs with LPS (10 ng/ml) or HMGB1 (15 ng/ml) alone resulted in significantly increased levels of IL-8 and MCP-1 (P<0.01), which were further increased after costimulation with LPS and HMGB1,suggesting a synergistic effect between HMGB1 and LPS (P<0.01). This synergistic effect was significantly inhibited by pretreatment with MAPK signaling kinases inhibitors, especially the p38 MAP kinase inhibitor SB203580, and the cocktail of MAP kinase inhibitors almost totally blocked the expression of these chemokines in HUVECs treated with HMGB1 and LPS. Conclusion HMGB1 protein can activate HUVECs to produce the chemokines IL-8 and MCP-1 in a dose-and time-dependent manner. HMGB1 also acts synergisrically with LPS to induce IL-8 and MCP-1 release, which might play an important role in the development of sepsis.MAPK signal transduction plays an important role in HMGB1 and LPS-induced IL-8 and MCP-1 release.     

Advanced oxidation protein products induce monocyte chemoattractant protein-1 expression via p38 mitogen-activated protein kinase activation in rat vascular smooth muscle cells

Background Advanced oxidation protein products (AOPPs) are new uremic toxins reported by Witko-Sarsat in 1996, which are associated with the pathogenesis of atherosclerosis. However, the mechanisms by which AOPPs enhance atherosclerosis have not been fully understood. Monocyte chemoattractant protein-1 (MCP-1) is a chemokine which stimulates migration of monocytes and plays a critical role in the development of atherosclerosis. In this study, we investigated the effect of AOPPs on MCP-1 expression in cultured vascular smooth muscle cells (VSMCs). Methods VSMCs were cultured and then co-incubated with AOPP (200μmol/L, 400μmol/L) for different times with or without pretreatment with specific p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580. RT-PCR and Western blott were used to detect MCP-1 mRNA and protein expression at different time points after AOPP stimulation in rat smooth muscle cells. Western blot was used to detect the expression of phosphorylated p38 MAPK. Results Treatment of VSMC with AOPPs resulted in a significant increase of the expression of MCP-1 mRNA and protein in time- and dose-dependent manner, and could activated p38 MAPK. Pretreatment of VSMCs with SB203580 resulted in a dose-dependent inhibition of AOPPs-induced MCP-1 mRNA and protein expression. Conclusions AOPPs can stimulate MCP-1 expression via p38 MAPK in VSMCs. This suggests that AOPPs might contribute to the formation of atherosclerosis through this proinflammatory effect.     

Expression of NF-κB in hRPE Cells Stimulated by PDTC and IL-1β

The constitutive expression of nuclear-factor-κB (NF-κB) in human pigment epithelial (hRPE) cells cultivated in vitro and the possible changes when incubated with PDTC and IL-I were investigated. The synchronized hRPE cells in vitro were divided into two groups. In nonPDTC group, hRPE cells were exposed respectively to IL-1β and NS (for detecting the constitutive expressions of NF-κB in hRPE cells) ; In PDTC group, PDTC-pretreated hRPE cells were exposed respectively to IL-1β?Aand NS. (for detecting the constitutive expression of NF-κB in PDTC-pretreated hRPE cells). The expression of NF-κB in hRPE cells in two groups was detected by immunofluorescence stain and flow cytometry. The results showed that the constitutive expression of NF-κB in hRPE cells in vitro was 8.05 %, and increased to 30.26 % by IL-1β. After PDTC pretreatment, the constitutive expression of NF-κB in hRPE cells was decreased to 3.74%, and 3.66 % by IL-l,respectively. It was concluded that the expressions of NF-κB in hRPE cells could be increased significantly by IL-1βand depressed effectively by PDTC. Also, PDTC could significantly inhibit the activation of NF-κB induced by IL-1β.     

Effects of Liandou Qingmai Recipe(连豆清脉方) on Endothelin-1,Nitric Oxide,Interleukin-6 and Interleukin-10 Levels in Patients with Coronary Heart Disease

Objective:To observe effects of Liandou Qingmai Recipe(连豆清脉方) on endothelin-1(ET-1),nitric oxide(NO),interleukin-6(IL-6) and IL-10 levels in patients with coronary heart disease.Methods:Total 101 cases with coronary heart disease were randomly divided into a treatment group(n=45) treated by Liandou Qingmai Recipe and a standard treatment group(control group,n=56),with a normal group of 16 health persons set up.Changes of ET-1,NO,IL-6 and IL-10 levels were measured before treatment and after treatment for two weeks.And the data were analyzed by SPSS 16.0 statistic software.Results:Before treatment,the levels of ET-1,IL-6 and IL-10 levels were significantly higher and NO was significantly lower in the patients with coronary heart disease than those in the normal group(90.7±12.7 ng/L vs 41.8±13.5 ng/L,9.17±0.18 ng/L vs 1.10±0.08 ng/L,1.94±0.26 ng/L vs 1.09±0.06 ng/L,and 92.2±17.7 μmol/L vs 124.5±27.2 μmol/L;all P<0.05),with no significant differences in the levels of ET-1,NO,IL-6 and IL-10 between the treatment group and the control group(P>0.05);After treatment,ET-1 and IL-6 significantly decreased in the treatment group and the control group,and NO increased in the treatment group;And IL-6 level was significantly lower and NO level was higher in the treatment group than those in the control group(4.48±1.22 ng/L vs 5.13±1.85 ng/L,117.4±22.3 μmol/L vs 92.4±17.1 μmol/L;both P<0.05);There was a positive correlation between IL-6 and IL-10,and a negative correlation between NO and IL-10(r=0.142,r=-0.152;both P<0.05).Conclusion:Liandou Qingmai Recipe can decline IL-6,IL-10 and ET-1 levels,and raise NO level in patients with coronary heart disease on the basis of standard treatment,so as to inhibit endothelial inflammatory response,improve vascular endothelial function,with stronger anti-AS action;And vascular endothelial lesion is related with inflammatory response.     

Effect of Korean Magnolia obovata Extract on Platelet-Derived Growth Factor-Induced Vascular Smooth Muscle Cells

Objective: To investigate the effects of Korean Magnolia obovata crude extract(KME) on plateletderived growth factor(PDGF)-BB-induced proliferation and migration of vascular smooth muscle cells(VSMCs). Methods: KME composition was analyzed by high-performance liquid chromatography(HPLC). VSMCs were isolated from the aorta of a Sprague-Dawley rat, incubated in serum free-Dulbecco's modified Eagle's medium in the presence or absence of KME(10, 30, 100, and 300 μg/m L), then further treated with PDGF-BB(10 ng/m L). VSMC proliferation was detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and VSMC migration was determined using the Boyden chamber and scratch wound healing assays. Western blot analysis was used to detect phosphorylation of extracellular signal-regulated protein kinases 1 and 2(p-ERK1/2), protein kinase B(p-Akt), and stress-activated protein kinase/c-Jun NH2-terminal kinase(p-SAPK/JNK). The antimigration and proliferation effects of KME were tested using aortic sprout outgrowth. Results: The HPLC analysis identified honokiol(0.45 mg/g) and magnolol(0.34 mg/g) as the major components of KME. KME(30, 100, and 300 μg/mL) significantly decreased the proliferation and migration of PDGF-BB-stimulated(10 ng/m L) VSMCs and the PDGF-BB-induced phosphorylation of EKR1/2, Akt, and SAPK/JNK(P0.05). Furthermore, PDGF-BBinduced VSMCs treated with 300 μg/m L of KME showed reduction in aortic sprout outgrowth. Conclusion: KME could inhibit abnormal proliferation and migration of VSMCs by down-regulating the phosphorylation of EKR1/2 and Akt. Thus, KME might be a functional food for preventing vascular disorders.     

The Effects of PDTC plus Leflunomide and Cyclosporine on the NF-κB Signaling Pathway in Mouse-to-rat Cardiac Xenografts

In this study, the effects of pirrolidine dithiocarbamate （PDTC） plus leflunomide （Lef） and cyclosporine （CsA） on the NF-κB signaling pathway in mouse-to-rat cardiac xeno-transplantation models were investigated. NIH mice and Wistar rats served as donors and recipients respectively. Mouse-to-rat cardiac xenotransplantation was performed. The recipients were divided into 5 groups： group A （the control group）, group B （PDTC group）, group C （PDTC plus CsA group）, group D （PDTC plus Lef group） and group E （PDTC plus Lef and CsA group）. The expressions of IKKa/[3, NF-κB-P65, IκBct, ICAM-1 and NF-κB DNA binding activity in xenograft tissues were determined by immunohistochemistry and Western blot as well as electrophoretic mobility shift assay （EMSA）. The median survival time of cardiac xenografts in the control group, PDTC group, PDTC plus CsA group, PDTC plus Lef group and PDTC plus Lef and CsA group was （2.17±0.41）, （2.33±0.52）, （4.67±1.21）, （7.00±1.79） and （9.00±1.41） days respectively. The survival time of xenografts in the PDTC plus Lef and CsA group was significantly longer than that in other four groups （P〈0.05 for all）, that in the PDTC plus Lef group longer than that in the control group, PDTC group and PDTC plus CsA group （P〈0.05 for all）, that in PDTC plus CsA group longer than the control group and PDTC group （P〈0.05 for all）. The expressions of IKKα/β, NF-κB-P65, IκBα and ICAM-1 and NF-κ3 DNA binding activity were notably increased in mouse-to-rat cardiac xenografts. The expressions were decreased in the control group, PDTC group, PDTC plus CsA group, PDTC plus Lef and PDTC plus Lef and CsA group in turn. It was concluded that PDTC plus Lef and CsA can significantly suppress the expressions of IKKα/β, NF-κB-P65, IκBα, ICAM-1 and NF-κB DNA binding activity, thereby prolonging the survival of the cardiac xenografts.     

Mechanism of reduction of albumin expression induced by lipopolysaccharide in rat hepatocytes

Background The severity of hypoalbuminemia has been shown to be related to morbidity and mortality in some critical illnesses, illustrating the need for better understanding of molecular mechanism of hypoalbuminemia. Lipopolysaccharide (LPS) is a key mediator inducing hypoalbuminemia in sepsis and septic shock. The present study was designed to identify if the reduction of albumin expression is directly induced by LPS and modulated by activated extracellular signal-regulated protein kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) in rat hepatocytes.Methods Primary rat hepatocytes were divided into five groups. In two of them, hepatocytes were treated with normal saline or 1 μg/ml LPS, then albumin mRNA expression was observed at 0, 2, 8, 12 and 24 hours after treatment. In another group, hepatocytes were pretreated with 100, 40 or 20 μmol/L of cycloheximide (CHX, an inhibitor of protein synthesis) for 30 minutes followed by 1 μg/ml LPS for 24 hours. Then the RNA was extracted from the cells for RT-PCR to detect the expression of albumin. The other two groups were administered 1 μmol/L, 10 μmol/L and 50 μmol/L of SB203580 (p38 MAPK inhibitor) or PD98059 (ERK inhibitor) 30 minutes prior to 1 μg/ml LPS treatment. After 24 hours of LPS treatment, the supernatant was collected and assayed for albumin concentrations. Data were analyzed by one-way analysis of variance, followed by the Newman-Keul test; a P&lt;0.05 was considered significant.Results There was no marked change in albumin mRNA expression in the control group during 24-hours treatment with normal saline. The reduction did not occur until 24 hours after LPS treatment, and albumin mRNA decreased by 30% approximately compared to the control group at 24 hours (0.587 vs 0.832, P=0.007). CHX could inhibit the decline of albumin mRNA induced by LPS and the effect was correlated with the dose of CHX. The ERK inhibitor PD98059 caused a significant increase in LPS-induced albumin production at the three concentrations (119.7, 111.4 and 80.0 ng/ml vs 44.4 ng/ml, P=0.0013, 0.0025 and 0.009, respectively), whereas SB203580 obviously blocked albumin reduction in LPS-treated cells at the concentrations of 10 and 50 μmol/L (87.5 and 93.6 ng/ml vs 44.4 ng/ml, P=0.0076 and 0.0049, respectively).Conclusions LPS can induce the reduction of albumin expression by new synthesized proteins indirectly, and the process may be related to the signal proteins of ERK and p38 kinase. The ERK and p38 kinase are critical signaling pathways in LPS-induced hypoalbuminemia which is worthwhile to understand in studying the molecular mechanism of hypoalbuminemia in sepsis and septic shock.     

姜黄素对氧化型低密度脂蛋白诱导的大鼠血管平滑肌细胞单核细胞趋化蛋白-1表达、细胞增殖和凋亡的影响

目的探讨姜黄素对大鼠血管平滑肌细胞单核细胞趋化蛋白-1表达、增殖和凋亡的影响。方法分离SD大鼠血管平滑肌细胞进行培养传代,采用不同浓度的姜黄素作用于氧化型低密度脂蛋白（Ox-LDL）诱导的大鼠平滑肌细胞,根据作用药物浓度进行分组,对照组（不加任何药物）,Ox-LDL 100μg/mL组,Ox-LDL 100μg/mL＋姜黄素20μmol/L组,Ox-LDL 100μg/mL＋姜黄素40μmol/L组,Ox-LDL 100μg/mL＋姜黄素80μmol/L组。分析姜黄素对大鼠血管平滑肌细胞单核细胞趋化蛋白-1（MCP-1）的表达、对细胞的增殖的影响。按照加入药物浓度进行分组,对照组（不加任何药物）,姜黄素50μmol/L组,姜黄素100μmol/L组,姜黄素120μmol/L组,分析姜黄素对细胞凋亡的影响。结果 Ox-LDL 100μg/mL组MCP-1分泌[（812.6±78.7）ng/L]及MCP-1 mRNA表达水平[（1.18±0.11）]较对照组[（91.3±6.1）ng/L,（0.16±0.04）]显著升高,差异有高度统计学意义（P〈0.01）。姜黄素对OxLDL诱导的大鼠血管平滑肌细胞MCP-1分泌及MCP-1 mRNA表达、细胞增殖具有显著的抑制作用,对细胞凋亡有诱导作用,并且随着姜黄素浓度的增加,作用越明显（P〈0.01）。结论姜黄素能够抑制Ox-LDL诱导的大鼠细胞平滑肌细胞MCP-1表达以及细胞增殖,诱导大鼠细胞平滑肌细胞凋亡。     

硫化氢对高肺血流性肺动脉高压大鼠血管炎症反应的调节作用

目的 探讨硫化氢(H2S)对高肺血流性肺动脉高压大鼠血管炎症反应的调节作用.方法 44只雄性SD大鼠,随机分为4周对照组(7只)、4周分流组(7只)、4周分流+炔丙基甘氨酸(PPG)组(8只)、11周对照组(7只)、11周分流组(7只)及11周分流+硫氢化钠(NaHS)组(8只).采用右心导管测定肺动脉平均压(mPAP),应用免疫组织化学方法检测肺动脉内皮细胞炎症分子细胞间黏附分子1(ICAM-1)、核因子-кB信号转导通路关键分子核因子-кB p65和核因子-кB抑制蛋白(IкBα)的表达,通过酶联免疫吸附试验(ELISA)检测大鼠血浆及肺组织ICAM-1、白细胞介素8(IL-8)、单核细胞趋化蛋白1(MCP-1)含量.结果 4周分流组大鼠血浆和肺组织中ICAM-1、IL-8及MCP-1含量均明显高于4周对照组大鼠(P<0.05或P<0.01);4周分流+PPG组大鼠mPAP,中、小型肺动脉内皮细胞ICAM-1和核因子-кB p65蛋白表达均显著高于4周分流组(P<0.05或P<0.01),而中、小型肺动脉内皮细胞IкBα蛋白表达均低于4周分流组(P<0.05),肺组织ICAM-1含量,血浆IL-8含量和肺组织MCP-1含量均高于4周分流组[(27.3±5.0) μmol/g蛋白vs(21.9±2.1)μmol/g蛋白,(148±29)μmol/L vs(118±23)μmol/L,(12.9±1.1)μmoL/g蛋白vs(10.2±1.4)μmol/g蛋白,P<0.05或P<0.01].11周分流组大鼠mPAP高于11周对照组(P<0.01),大、中、小型肺动脉内皮细胞ICAM-1和核因子-кB p65蛋白表达均高于11周对照组(P<0.05或P<0.01),但IкBα蛋白表达低于11周对照组(P<0.05或P<0.01),血浆和肺组织中ICAM-1、IL-8及MCP-1均高于11周对照组(均P<0.01);11周分流+NaHS组mPAP明显低于11周分流组[(23.2±3.0)mm Hg vs(27.5±1.9)mm Hg,1 mm Hg=0.133 kPa,P<0.05],大、中、小型肺动脉内皮细胞ICAM-1和核因子-кB p65蛋白表达均低于11周分流组(P<0.05或P<0.01),而中、小型肺动脉内皮细胞IкBα蛋白表达高于11周分流组(均P<0.05),血浆和肺组织中ICAM-1以及IL-8均低于11周分流组[(124±11)μmol/L vs(154±20)μmol/L、(19.9±2.5)μmol/g蛋白vs(23.9±3.6)μmol/g蛋白,(92±11)μmol/L vs(121±17)μmol/L、(15.0±1.7)μmol/g蛋白vs(19.0±3.9)μmoL/g蛋白,均P<0.01],肺组织MCP-1也低于11周分流组[(10.8±1.6)μmol/g蛋白vs(13.5±1.4)μmol/g蛋白,P<0.01].结论 H2S可通过抑制高肺血流性肺动脉高压大鼠血管炎症反应拮抗肺动脉高压形成.H2S的抗血管炎症效应可能通过上调肺动脉内皮细胞IкBα的表达,降低核因子-кB p65的表达,进而抑制相关炎症因子的表达来实现.     

地塞米松抑制聚肌胞苷酸诱导人气道上皮细胞趋化因子表达及机制的初步研究

目的 初步探讨地塞米松对聚肌胞苷酸刺激气道上皮细胞后趋化因子表达的影响及其机制.方法 将人气道上皮细胞16hBE给予不同浓度的聚肌胞苷酸(0.001、0.01、0.1、1 μg/ml)及地塞米松(0.1、1、10 μmol/L)处理,用RT-PCR检测刺激6h后IL-8、IP-10 mRNA的表达水平,用ELISA法检测刺激24 h后培养上清液中IL-8和IP-10蛋白含量,用免疫组化方法检测细胞NF-κB p65亚单位的表达强度.结果 0.001、0.01、0.1 μg/ml聚肌胞苷酸处理16hBE细胞后IL-8和IP-10mRNA表达水平和蛋白分泌量呈浓度依赖性升高,在0.01 μg/ml及0.1 μg/ml浓度时,与对照组比较差异有统计学意义(P＜0.05,P＜0.01);但在聚肌胞苷酸浓度为1μg/ml时,IL-8和IP-10 mRNA表达水平和蛋白分泌量都出现了下降.地塞米松(1、10 μmol/L)预处理0.5h明显抑制聚肌胞苷酸诱导的IL-8和IP-10 mRNA表达及蛋白分泌(P＜0.05,P＜0.01).1 μmol/L地塞米松预处理明显抑制了聚肌胞苷酸诱导的NF-κB p65表达强度(P＜0.01).结论 糖皮质激素可抑制聚肌胞苷酸诱导的气道上皮细胞趋化因子的表达,其机制可能与NF-κB的活化有关.     

shRNA干扰NLRP3对晚期糖基化终末产物诱导的心肌细胞炎症反应的影响

目的  探讨沉默NOD 样受体家族pyrin域3 (NOD-like receptor family,pyrin domain containing 3, NLRP3)炎性小体对晚期糖基化终末产物(advanced glycation end products, AGEs)诱导的心肌细胞损伤的调节作用及机制。 方法  H9c2心肌细胞分为4组:对照组、 AGEs组、AGEs+sh-Ctrl组、 AGEs+sh-NLRP3组,后两组细胞首先将短发夹RNA（shRNA）对照（sh-Ctrl）和shRNA干扰NLRP3（sh-NLRP3）质粒分别转染入H9c2细胞,然后后3组细胞用100 mg/L AGEs处理24 h,建立H9c2损伤模型,对照组细胞用溶剂处理24 h。Western blot检测NLRP3、凋亡相关微粒蛋白(apoptosis-associated speck-like protein containing CARD, ASC)、 Caspase-3、 Caspase-9、核转录因子κB(nuclear factor κB, NF-κB) P65和磷酸化P65（p-P65）的表达,酶联免疫吸附实验(ELISA)检测白细胞介素(interleukin, IL)-6、IL-18和IL-1β的水平,流式细胞术检测细胞凋亡,免疫荧光染色检测细胞核中NF-κB P65的水平。结果  AGEs组和AGEs+sh-Ctrl组NLRP3、 ASC、Caspase-3和Caspase-9的表达均高于对照组( P<0.05)。与AGEs组相比,AGEs+sh-NLRP3组NLRP3、ASC、Caspase-3和Caspase-9的表达均下降( P<0.05)。与对照组相比,AGEs组和AGEs+sh-Ctrl组IL-6、IL-18、IL-1β水平升高,细胞凋亡率上升(P<0.05)。AGEs+sh-NLRP3组IL-6、IL-18、IL-1β水平和细胞凋亡率低于AGEs组( P<0.05)。AGEs组和AGEs+sh-Ctrl组NF-κB P65磷酸化水平及细胞核的NF-κB P65水平高于对照组(P<0.05)。与AGEs组相比,AGEs+sh-NLRP3组NF-κB P65磷酸化水平及细胞核的NF-κB P65水平降低( P<0.05)。结论  沉默NLRP3可通过抑制NF-κB P65的活化减轻AGEs诱导的心肌细胞凋亡及炎症反应。     

三磷酸腺苷对脂多糖诱导内皮祖细胞表达炎症因子的影响及其机制

目的：分析三磷酸腺苷(adenosine triphosphate,ATP)对脂多糖(lipopolysaccharide,LPS)诱导内皮祖细胞 (endothelial progenitor cells,EPCs)表达炎症细胞因子的影响,并探讨其机制。方法：采用密度梯度离心法分离人脐 血单个核细胞,用RT-PCR检测LPS(1 mg/mL)诱导EPCs表达炎症细胞因子的情况,低浓度的ATP(5 μmol/L)对LPS诱 导EPCs表达细胞炎症因子的影响,不同浓度(5,50 μmol/L)的ATP对EPCs中TLR4,MyD88和CD14 mRNA表达的影 响;Western印迹检测LPS(1 mg/mL)对EPCs表达TLR4调节蛋白MyD88和CD14的影响以及信号通路的活化情况,低浓 度ATP(1,5 μmol/L)对LPS诱导EPCs表达TLR4,MyD88和CD14的影响以及信号通路的活化情况。结果：EPCs高表达 TLR4,其配体LPS(1 mg/mL)显著上调IL-1β,MCP-1和ICAM-1的mRNA表达(均P<0.01),并呈时间依赖性上调MyD88和 CD14蛋白的表达,同时活化ERK和NF-κB信号通路。低浓度ATP抑制LPS诱导的IL-1β,MCP-1和ICAM-1 mRNA的表达 (均P<0.05),同时也下调LPS诱导的TLR4,MyD88和CD14蛋白的表达(P<0.01或P<0.05),并抑制LPS诱导的NF-κB信号 通路的活化(P<0.05)。结论：ATP在低浓度时通过负性调节TLR4信号通路而抑制LPS诱导的炎症细胞因子在EPCs中的 表达。     

糖基化终产物对心肌微血管内皮细胞表达MCP-1和ICAM-1的影响及机制研究

目的：观察体外孵育的牛血清白蛋白（BSA）非酶促糖基化终末产物（AGEs）对心肌微血管内皮细胞细胞间黏附分子（ICAM-1）和单核细胞趋化因子-1（MCP-）表达的影响及机制．方法：取50g／L牛血清白蛋白（BSA）、500g／LD-葡萄糖,于37℃孵箱内避光孵育12wk,制备外源性AGEs-BSA．体外培养大鼠心肌微血管内皮细胞（CMECs）．分设不同浓度梯度的AGEs实验组、BSA对照组,采用ELISA法测定MCP-1的表达,流式细胞术测定ICAM-1的表达,Western Blot法测定糖基化终末产物受体蛋白（RAGE）的表达,RT-PCR检测RAGE mRNA的表达．结果：100,200,400mg／L AGEs可显著增加心肌微血管内皮细胞ICAM-1（13．2％,14．5％,38．1％）,MCP—1[（52．5±5．5）,（116．0±3．1）,（139．6±8．7）μg/L]的表达（与对照组相比较,P〈0．05）,且在蛋白水平及mRNA水平均明显增加RAGE的表达（P〈0．05）,并呈浓度依赖性．结论：AGE—BSA可刺激心肌微血管内皮细胞过量表达ICAM-1和MCP-1,从而加速心肌微血管炎症的发生与发展．其机制可能是AGEs上调了心肌微血管内皮细胞RAGE的表达．也进一步证实了AGEs—RAGE信号系统的起动是糖尿病心肌微血管病变发生发展一个重要原因．     

白细胞介素1受体拮抗剂对大鼠过敏性哮喘的治疗作用及相关机制研究

目的 研究白细胞介素1受体拮抗剂(IL-1ra)对大鼠过敏性哮喘的治疗作用及相关机制.方法 雌性SD大鼠分为正常对照组、哮喘模型组、哮喘模型低剂量IL-1ra(6 mg/kg)治疗组(低剂量治疗组)和高剂量IL-1ra(30 mg/ks)治疗组(高剂量治疗组).每组10只.采用卵白蛋白腹腔及皮下注射致敏加雾化吸入激发的方法建立大鼠过敏性哮喘模型.激发前尾静脉注射不同剂量的IL-1ra.通过检测各组大鼠肺功能、肺泡灌洗液(BALF)炎性细胞构成、肺组织病理切片、血清总IgE含量等指标评价治疗效果,利用半定量RT-PCR检测信号转导子和转录激活子6(STAT6)mRNA以及核因子κB(NF-κB)mRNA表达情况.结果 哮喘模型组大鼠呼吸速率[(206±11)次/min]、呼气流量[(77±8)μl/s]、BALF嗜酸粒细胞比例(24.8%±1.3%)、血清总IgE含量[(72.5±8.1)ng/ml]、STAT6表达(0.294±0.048)和NF-κB表达(0.686±0.052)均明显高于低剂量治疗组[分别为(183±9)移c/min,(64±5)μl/,s,18.5%±3.1%,(63.4±4.8)ng/ml,0.229±0.038,0.613±0.062,均P＜0.05]和高剂量治疗组[分别为(181±11)次/min,(57±4)μl/s,14.7%±2.1%,(41.4±7.8)ng/ml,0.194±0.076,0.352±0.267,均P＜0.05].高剂量治疗组治疗效应优于低剂量治疗组(P＜0.05).肺组织病理检查与以上结果相近.结论 IL-1ra对大鼠过敏性哮喘具有明显的治疗效果,这种作用可能是通过同时调控STAT6 mRNA和NF-κB mRNA的表达实现的.     

AGEs通过JAK2/STAT3信号通路诱导结肠癌SW480细胞增殖、侵袭及上皮间质转化

目的 观察糖基化终末产物(advanced glycation end products,AGEs)对结肠癌SW480细胞增殖、凋亡、侵袭、迁移及上皮间质转化的影响,并探讨其相关机制.方法 将结肠癌SW480细胞分为对照组、AGEs组(200 μg/mL AGEs)、AGEs(200 μg/mL)+AG490(50 μmol/L)组,CCK-8检测细胞增殖活力,流式细胞术检测细胞周期、凋亡,Transwell实验检测细胞体外侵袭能力,划痕实验检测细胞体外迁移能力.不同浓度(0、50、100、200 μg/mL) AGEs和200 μg/mL AGEs、50 μmol/L AG490单独处理及二者联合处理SW480细胞后,Western blot检测上皮间质转化相关分子标志物E-cadherin、N-cadherin、Vimentin及JAK2/STAT3信号通路相关分子的变化.结果 与对照组比较,AGEs能明显促进结肠癌SW480细胞的增殖,减少G1/S期阻滞,抑制凋亡,增强体外的侵袭、迁移能力(P＜0.05).与AGEs组比较,AGEs+ AG490组结肠癌SW480细胞增殖减少,G1/S期阻滞增加,凋亡增加,侵袭、迁移能力降低,差异有统计学意义(P＜0.05).Western blot检测结果显示,AGEs处理结肠癌SW480细胞后E-cadherin表达降低,N-cadherin、Vimentin、p-STAT3、p-JAK2表达升高,而AG490可逆转AGEs对结肠癌SW480细胞的作用.结论 AGEs能够通过JAK2/STAT3信号通路促进结肠癌SW480细胞的增殖,抑制凋亡,增强侵袭、迁移能力,促进上皮间质转化.     

L-4F对oxLDL刺激下脂肪细胞表达单核细胞趋化蛋白-1的影响

目的观察载脂蛋白A-I模拟肽L-4F对氧化型低密度脂蛋白(oxLDL)刺激下3T3-L1脂肪细胞分泌表达单核细胞趋化蛋白-1(MCP-1)的影响,并探讨其可能的作用机制。方法 3T3-L1脂肪细胞促分化成熟后,oxLDL(50μg/ml)刺激脂肪细胞,给予L-4F(1-50μg/ml),H-89(10μmol/L)及H-89+L-4F(50μg/ml)干预,收集细胞,测定脂肪细胞MCP-1上清液中的浓度和mRNA表达水平,以及脂肪细胞核因子C/EBPα、β的蛋白质水平;改良Boyden小室法检测不同干预组上清液对人外周血单核细胞趋化活性的影响。结果 OxLDL(50μg/ml)刺激使分化成熟的3T3-L1脂肪细胞表达及分泌MCP-1明显增加,并使得诱导的单核细胞移动距离明显增加。L-4F以浓度依赖的方式减少脂肪细胞MCP-1的表达和分泌,降低单核细胞趋化活性;50μg/ml L-4F使MCP-1 mRNA的表达降低(91±6)%(P<0.01)。PKA抑制剂H-89(10μmol/L)干预oxLDL刺激的脂肪细胞后MCP-1 m RNA的表达也显著减少(P<0.01),但是,在50μg/ml L-4F作用的基础上,H-89(10μmol/L)的孵育并未使得MCP-1 mRNA的表达进一步降低(P>0.05)。50μg/ml oxLDL刺激对脂肪细胞C/EBPα的含量无明显影响,但增加C/EBPβ蛋白量,且该作用呈时间依赖性;L-4F和H-89干预均降低C/EBPβ的蛋白质含量。结论 OxLDL时间依赖性地诱导脂肪细胞C/EBPβ的蛋白合成,并增强脂肪细胞MCP-1的表达分泌,L-4F以浓度依赖的方式对抗oxLDL的致炎作用,cAMP/PKA-C/EBPβ信号通道可能是L-4F的作用途径之一。     

螺内酯对醛固酮诱导的大鼠肾小球系膜细胞氧化应激及NF-κB、MCP-1表达的影响

目的观察螺内酯(SPI)对醛固酮(ALD)诱导的大鼠肾小球系膜细胞(MCs)氧化应激和核因子-κB(NF-κB)、单核细胞趋化蛋白-1(MCP-1)表达的影响,探讨其肾脏保护机制。方法体外培养的MCs随机分为正常对照组(NG组)、ALD组(10-7mol/L)、SPI 1组(ALD+SPI 10-7mol/L)、SPI2组(ALD+SPI 10-8mol/L)和SPI 3组(ALD+SPI 10-9mol/L)。以流式细胞仪法检测MCs内活性氧(ROS)水平。RT-PCR法检测NF-κB、MCP-1、醛固酮合成酶(CYP11B 2)、醛固酮受体(MR)和11β-羟类固醇脱氢酶2(11β-HSD 2)的mRNA表达。结果①MCs表达CYP11B 2、MR和11β-HSD 2 mRNA。②与NG组比较,ALD刺激MCs 48 h后,细胞内ROS水平、NF-κB及MCP-1 mRNA表达明显增加。③SPI干预48 h后,与ALD组相比较,SPI 1组、SPI 2组、SPI 3组细胞内ROS水平、NF-κB及MCP-1 mRNA表达明显减少,且呈一定的剂量依赖性。④相关分析显示MCs内ROS水平与NF-κB mRNA表达量呈显著正相关(P<0.01),NF-κBmRNA和MCP-1 mRNA表达量也呈显著正相关(P<0.01)。结论 SPI可在一定程度上抑制ALD诱导的MCs氧化应激,减少NF-κB和MCP-1的表达,该作用可能与其肾脏保护作用部分有关。