齐墩果酸抑制肿瘤坏死因子-α诱导的成纤维细胞样滑膜细胞炎症因子表达及其机制研究

探讨齐墩果酸(Oleanolic acid,OA)对肿瘤坏死因子-α(TNF-α)诱导成纤维细胞样滑膜细胞的炎症因子表达的影响及其机制。首先复苏培养人成纤维细胞样滑膜细胞(FLS),通过RT-PCR检测细胞IL-6及IL-1βmRNA表达,采用Western blot方法检测p38MAPK及NF-κB蛋白表达变化,通过ELISA法检测细胞上清液中IL-6及IL-1β浓度。与对照组比较,TNF-α明显诱导FLS细胞IL-6及IL-1βmRNA的表达及上清液中IL-6及IL-1β的分泌(P0.05),同时磷酸化p38蛋白和核NF-κB明显增加(P0.05),且p38MAPK阻断剂SB203580能抑制TNF-α诱导的核NF-κB增加。OA呈浓度依赖性抑制TNF-α诱导的FLS细胞p38蛋白磷酸化和核NF-κB增加(P0.05)。且OA、p38MAPK通路抑制剂SB203580或NF-κB阻断剂BAY 11-7082均能抑制TNF-α诱导的IL-6及IL-1β分泌增加(P0.05)。综上所述,OA能抑制TNF-α诱导的FLS细胞炎症因子IL-6及IL-1β的产生,其机制可能与抑制p38MAPK/NF-κB信号通路有关。     

呼吸窘迫综合症患儿外周血单个核细胞中CD24和炎症因子mRNA的表达水平及其预后价值

目的:通过检查呼吸窘迫综合症患儿外周血单个核细胞中CD24和TNF-α、IL-6、和IL-17A炎症因子mRNA的表达,探讨其对呼吸窘迫综合症的诊断和预后价值。方法:选择2015年1月至12月在我院接受治疗的32例非感染型呼吸窘迫综合症患儿为研究组,选择同期的30例健康新生患儿为对照组,采集研究组治疗前后和对照组的外周血,分离单个核细胞,采用RT-PCR检测CD24和TNF-α、IL-6、和IL-17A炎症因子mRNA的表达水平。结果:研究组治疗前CD24mRNA表达水平明显高于对照组,差异有统计学意义(P0.01),而TNF-α、IL-6、和IL-17A mRNA表达水平比较,差异无统计学意义(P0.05)。研究组治疗后CD24mRNA表达水平明显低于治疗前,差异有统计学意义(P0.01),而TNF-α、IL-6、和IL-17A mRNA表达水平比较,差异无统计学意义(P0.05)。结论:呼吸窘迫综合症患儿外周血单个核细胞中CD24mRNA表达水平升高,可能是其诊断和预后的分子标记物。     

亚硝基化谷胱甘肽还原酶: 一个调控炎症反应的新分子

炎症因子的表达调控是炎症反应的关键步骤,与自身免疫疾病以及癌症等密切相关．一氧化氮(nitric oxide,NO)在炎症因子表达调控中具有重要作用,但已有的研究多关注于NO合成对炎症因子的调控作用,而对NO代谢的作用知之甚少．亚硝基化谷胱甘肽还原酶(S-nitrosoglutathione reductase,GSNOR)是体内NO信号通路代谢调控的关键蛋白．本研究发现脂多糖(lipopolysaccharide,LPS)在RAW264.7细胞中上调诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOS)的同时下调GSNOR的转录和蛋白质表达,该下调作用依赖MEK1/2、p38和PI3K信号通路．抑制GSNOR可促进LPS诱导的炎症因子IL-1β、IL-6和TNF-α表达,而过表达GSNOR作用相反．抗炎症药物曲古抑菌素A (trichostatin A,TSA)能够挽回LPS对GSNOR的下调作用,并且GSNOR抑制剂削弱了TSA对炎症因子IL-6和TNF-α转录的抑制效应．这些结果表明：GSNOR是一个新的重要炎症调控分子,它可能成为调控NO介导的炎症相关信号通路的新的潜在靶点,上调GSNOR可能是抑制炎症的新思路．本研究揭示了巨噬细胞通过上调iNOS和下调GSNOR共同增强免疫炎症反应的新机制,拓展了对NO代谢在炎症反应中作用机制的认识．     

聚合度7-15的壳寡糖抑制脂多糖刺激的单核细胞产生TNF-α和IL-8的作用研究

本文通过建立脂多糖刺激的单核细胞炎症损伤模型,观察聚合度7-15的壳寡糖对炎性单核细胞白细胞介素-8(IL-8)和肿瘤坏死因子-α(TNF-α)表达的影响,及对p38丝裂原激活的蛋白激酶(p38 mitogen-activated protein kinases,p38MAPK)信号通路磷酸化的影响。采用p38信号通路抑制剂(SB203580)验证抑制p38信号通路对脂多糖诱导的单核细胞表达IL-8和TNF-α的作用,从而探索壳寡糖抑制单核细胞炎性损伤的分子机制。结果表明壳寡糖可抑制脂多糖诱导的单核细胞表达IL-8和TNF-α,并且抑制p38信号蛋白的磷酸化水平。因此,初步认为壳寡糖可能通过抑制炎性U937细胞中p38MAPK信号通路抑制IL-8和TNF-α的表达。     

miR-181b-5p调控TIMP3对apoE~(-/-)鼠动脉粥样硬化炎症影响及相关因子检验

为探究mi R-181b-5p靶向调控TIMP3对apo E~(-/-)鼠动脉粥样硬化炎症的影响,本研究基于生物信息学预测筛选,并采用双荧光素酶报告基因系统验证mi R-181b-5p靶基因。同时在ox-LDL刺激THP-1巨噬细胞及apo E~(-/-)动脉粥样硬化模型小鼠中检测mi R-181b-5p靶基因m RNA及蛋白水平的表达情况,并且检测转染mi R-181b-5p后细胞水平和动物体内炎症因子TNF-α、INF-γ、IL-1β、IL-18、CCL2的表达变化。此外,通过病理切片方法检测转染mi R-181b-5p后小鼠主动脉窦处病变情况。研究通过双荧光素酶报告基因系统验证TIMP3为mi R-181b-5p靶基因,并在ox-LDL刺激THP-1巨噬细胞及apo E~(-/-)动脉粥样硬化模型小鼠中证明了mi R-181b-5p可以降低TIMP3转录水平从而降低其蛋白水平表达,同时研究发现mi R-181b-5p在细胞水平和动物体内均会增强炎症因子TNF-α、INF-γ、IL-1β、IL-18、CCL2的表达,并可以增加小鼠主动脉窦处病变面积。研究认为在动脉粥样硬化发生中,mi R-181b-5p可以增加病变面积并且提升相关炎症因子的表达、分泌,其作用机理很可能是通过抑制靶基因TIMP3表达,进而降低TIMP3蛋白水平实现的,为研究动脉粥样硬化机制提供了理论依据。     

人博卡病毒HBoV1非结构蛋白NP1对细胞转录因子的调控

研究人博卡病毒非结构蛋白NPl对细胞转录因子的调控作用及对炎症细胞因子TNF-α和IL-6表达的影响,从而为进一步探究病毒非结构蛋白在HBoV1引起机体炎症反应中的潜在作用及其可能分子机制提供依据。通过双荧光素酶报告基因系统分析NP1对转录因子的调控作用,通过ELISA和荧光定量PCR分别从蛋白质和RNA水平检测NP1是否影响TNF-α、IL-6的表达,最后利用哺乳动物双杂交系统分析NP1是否通过寡聚化发挥功能。在293T细胞中,NP1可分别提高AP-1、STAT3和GAS转录因子报告载体荧光素酶活性3.69倍、2.45倍和3.03倍,但对NF-κB转录因子报告载体荧光素酶活性无明显影响(P0.05)。转染24h和48h后,NP1表达细胞和对照细胞培养基中IL-6和TNF-α蛋白浓度没有显著性差异(P0.05),但TNF-αmRNA的表达水平上调。哺乳动物双杂交实验表明NP1蛋白自身没有相互作用。NP1可以调节转录因子AP-1、STAT3和STAT1的活性,但对NF-κB激活没有影响;NP1对IL-6和TNF-α的细胞外分泌水平没有明显的影响,但在mRNA水平上对TNF-α的表达有一定的调节作用;NP1蛋白发挥其调节作用的功能不通过自身的二聚化来实现。     

24p3-24p3受体系统：一种新的铁转运途径

小鼠24p3是脂质运载蛋白lipocalin家族的成员之一,可在白介素3(interleukin-3,IL-3)缺乏时诱导细胞发生凋亡,并参与细胞的铁转运过程.最近,Devireddy等又成功克隆到了24p3的细胞表面受体(24p3 receptor,24p3R),进一步确定了24p3-24p3R这一新的铁转运途径.该途径的发现不仅增加了对铁转运理论新的认识,更重要的是,这一发现为铁代谢调控细胞凋亡理论的建立奠定了基础.     

α7nAChR调控STAT3磷酸化在星形胶质细胞机械性损伤后炎症反应中的作用

目的:通过建立星形胶质细胞机械性损伤模型,研究烟碱型乙酰胆碱受体α7亚单位(α7nAChR)在创伤性脑损伤后星形胶质细胞炎症反应中的作用及调控机制。方法:建立星形胶质细胞机械性损伤模型,通过ELISA检测炎症因子IL-1β、TNF-α、IL-10和TGF-β的表达;利用α7n ACh R抑制剂α-BGT和激动剂PHA-543613处理星形胶质细胞,检测相关炎症因子表达,并通过Western blot检测信号传导及转录活化因子3(STAT3)和磷酸化STAT3(p-STAT3)的表达;利用α-BGT和STAT3抑制剂Stattic处理星形胶质细胞,检测相关炎症因子表达。结果:①星形胶质细胞机械性损伤后,促炎因子IL-1β、TNF-α表达增加,抗炎因子IL-10、TGF-β表达降低(P0.05)。②利用α-BGT抑制α7nAChR可增加损伤后IL-1β、TNF-α的表达,减少IL-10、TGF-β的表达(P0.05);而利用PHA-543613激活α7nAChR功能,则发挥相反作用(P0.05)。③α-BGT可促进STAT3磷酸化,而PHA-543613抑制STAT3磷酸化(P0.05)。④STAT3抑制剂Stattic可减少IL-1β和TNF-α的表达,增加IL-10和TGF-β的表达,并部分阻断α-BGT对IL-1β、TNF-α、IL-10及TGF-β表达的影响(P0.05)。结论:机械性损伤后,激活α7nAChR可减轻星形胶质细胞炎症反应,而抑制STAT3磷酸化是其重要的下游机制。     

IL-27增强TNF-α介导上调的炎症因子的表达

目的:动脉粥样硬化是慢性炎症疾病,免疫细胞及炎症因子在其发病过程中起重要调节作用。本研究在于探讨IL-27对血管内皮细胞的直接作用。方法:采用ELISA方法,研究IL-27和TNF-α对人冠状动脉内皮细胞产生炎症相关细胞因子和趋化因子的作用。结果:IL-27显著增强TNF-α介导上调的炎症相关细胞因子IL-6和趋化因子CCL5的表达。IL-6和CCL5的表达受特异性信号分子抑制剂显著抑制。结论:人冠状动脉内皮细胞诱导释放IL-6和CCL5可能受JNK,p38MAPK和NF-κB通路差异调控。这些结果为阐明IL-27与TNF-α在动脉粥样硬化血管炎症发生中的作用提供重要生物化学基础。     

人博卡病毒HBoV1非结构蛋白NP1对细胞转录因子的调控

【目的】研究人博卡病毒非结构蛋白NP1对细胞转录因子活性和炎症细胞因子TNF-α和IL-6表达的调控作用。【方法】通过双荧光素酶报告基因系统分析NP1对转录因子的调控作用,通过ELISA和荧光定量PCR分别从蛋白质和RNA水平检测NP1是否影响TNF-α、IL-6的表达,最后利用哺乳动物双杂交系统分析NP1是否通过寡聚化发挥功能。【结果】在293T细胞中,NP1可分别提高AP-1、STAT3和GAS转录因子报告载体荧光素酶活性3.69倍、2.45倍和3.03倍,但对NF-κB转录因子报告载体荧光素酶活性无明显影响(P>0.05)。转染24 h和48 h后,NP1表达细胞和对照细胞培养基中IL-6和TNF-α蛋白浓度没有显著性差异(P>0.05),但TNF-αmRNA的表达水平上调。哺乳动物双杂交实验表明NP1蛋白自身没有相互作用。【结论】结果首次表明HBoV1非结构蛋白NP1对细胞转录因子和炎症细胞因子具有调节作用,揭示NP1可能与HBoV1致病性有关,为进一步探究HBoV1病毒致病的分子机制提供参考。     

Dexamethasone causes sustained expression of mitogen-activated protein kinase (MAPK) phosphatase 1 and phosphatase-mediated inhibition of MAPK p38

The stress-activated protein kinase p38 stabilizes a number of mRNAs encoding inflammatory mediators, such as cyclooxygenase 2 (Cox-2). In HeLa cells the anti-inflammatory glucocorticoid dexamethasone destabilizes Cox-2 mRNA by inhibiting p38 function. Here we demonstrate that this effect is phosphatase dependent. Furthermore, in HeLa cells dexamethasone induced the sustained expression of mitogen-activated protein kinase phosphatase 1 (MKP-1), a potent inhibitor of p38 function. The inhibition of p38 and the induction of MKP-1 by dexamethasone occurred with similar dose dependence and kinetics. No other known p38 phosphatases were induced by dexamethasone, and other cell types which failed to express MKP-1 also failed to inhibit p38 in response to dexamethasone. The proinflammatory cytokine interleukin 1 (IL-1) induced MKP-1 expression in a p38-dependent manner and acted synergistically with dexamethasone to induce MKP-1 expression. In HeLa cells treated with IL-1 or IL-1 and dexamethasone, the dynamics of p38 activation mirrored the expression of MKP-1. These observations suggest that MKP-1 participates in a negative-feedback loop which regulates p38 function and that dexamethasone may inhibit proinflammatory gene expression in part by inducing MKP-1 expression.     

Suppressed production of pro-inflammatory cytokines by LPS-activated macrophages after treatment with Toxoplasma gondii lysate

During Toxoplasma gondii infection, macrophages, dendritic cells, and neutrophils are important sources of pro-inflammatory cytokines from the host. To counteract the pro-inflammatory activities, T. gondii is known to have several mechanisms inducing down-regulation of the host immunity. In the present study, we analyzed the production of proand anti-inflammatory cytokines from a human myelomonocytic cell line, THP-1 cells, in response to treatment with T. gondii lysate or lipopolysaccharide (LPS). Treatment of THP-1 cells with LPS induced production of IL-12, TNF-alpha, IL-8, and IL-10. Co-treatment of THP-1 cells with T. gondii lysate inhibited the LPS-induced IL-12, IL-8 and TNF-alpha expression, but increased the level of IL-10 synergistically. IL-12 and IL-10 production was down-regulated by anti-human toll-like receptor (TLR)-2 and TLR4 antibodies. T. gondii lysate triggered nuclear factor (NF)-kappaB-dependent IL-8 expression in HEK293 cells transfected with TLR2. It is suggested that immunosuppression induced by T. gondii lysate treatment might occur via TLR2-mediated NF-kappaB activation.     

Colchicine acts as a progression factor to initiate DNA synthesis in quiescent Balb/c 3T3 cells

In quiescent Balb/c 3T3 cells, competence factors such as 12-O-tetradecanoylphorbol-13-acetate (TPA) and platelet-derived growth factor (PDGF) synergize with progression factors such as insulin to initiate DNA synthesis. In this study, we found that colchicine, a microtubule-disrupting agent, acted synergistically with TPA, but not with insulin, to induce the maximal stimulation of DNA synthesis. Colchicine also synergized with PDGF in the presence of epidermal growth factor to elicit nearly the optimal induction of DNA synthesis. Moreover, it acted synergistically with fibroblast growth factor, another competence factor. These results suggest that colchicine acts as a progression factor like insulin in quiescent Balb/c 3T3 cells.     

HIV-1 p24 DNA和P24蛋白联合免疫小鼠的效果

DNA疫苗能够诱导机体产生特异的细胞免疫和体液免疫反应,在肿瘤和感染性疾病的疫苗开发中显示出巨大的潜能。以HIV-1核心蛋白P24为抗原基因,构建pVAX1-p24 DNA,经Western blotting和动物活体成像检测证明,pVAX1 DNA携带的外源基因可以在293T 细胞和小鼠肌肉组织有效表达。采用不同的免疫策略免疫BALB/c小鼠 (DNA/DNA,DNA/Protein),实验结果表明：pVAX1-p24单独免疫BALB/c小鼠,可诱导明显的体液免疫及细胞免疫反应;pVAX1-p24与P24蛋白联合免疫诱导的体液免疫反应高于pVAX1-p24单独免疫,所获得的抗体滴度是单独免疫的7.3~8.0倍,但细胞免疫反应则不及单独免疫组。研究结果表明采取不同的免疫策略可以诱导产生不同的免疫反应,根据具体情况调整免疫策略将获得更好的免疫效果。这些研究为艾滋病疫苗的研发提供了实验依据。     

The 24p3 gene is induced during involution of the mammary gland and induces apoptosis of mammary epithelial cells

To understand the molecular mechanism of mammary gland involution we identified involution-induced clones by differential screening of a mouse mammary gland cDNA library. Characterization of clones by sequencing and Northern analysis showed that expression of 24p3 was induced during involution of the mammary gland. RNA in situ hybridization showed that it was mainly expressed in the secretory epithelial cells surrounding the lumen of the mammary gland alveoli. Induction of 24p3 was also observed in apoptotic HC11 mammary epithelial cells under serum starvation. In these cells, dexamethasone increased 24p3 gene expression four-fold. Transient expression of 24p3 increased the percentage of apoptotic cells 3- to 4-fold over a period of 3 days after transfection. This study provides evidence that overexpression of 24p3 gene can induce apoptosis of mammary epithelial cells.     

Expression, purification, and characterization of recombinant human interleukin 24 in Escherichia coli

Interleukin-24 (IL-24) can induce apoptosis of a broad range of tumor cells, and this function of IL-24 is independent of classic tumor suppressor genes, such as p53, Rb and p16. Here, we report the expression, purification and preparation of a recombinant IL-24 protein (rIL-24) without post-translational modifications, which may selectively induce apoptosis of tumor cells in vitro. We found that non-fusion rIL-24 was not able to be expressed by vectors pET11c, 28a, and 22b in Escherichia coli. To obtain recombinant non-fusion IL-24 protein, the encoding region for IL-24 was cloned between KpnI and BamHI in pET32a. The Trx (Thioredoxin)/IL-24 fusion proteins were expressed in the form of inclusion bodies in E. coli host strain BL21 (DE21). The expression level was more than 30% of total cell lysate. Inclusion bodies were disrupted, washed, and isolated at pH 9.0, and were completely dissolved in a buffer containing 2M urea at pH 9.0. After nickel ion metal affinity chromatography, gel filtration chromatography, and renaturation, the refolded fusion proteins with a purity of >96% were obtained. Trx/IL-24 proteins were digested by enterokinase (EK) to both Trx and rIL-24 fragments which then were separated by cation exchange chromatography. Cell proliferation experiments proved that the rIL-24 (98% purity) retains its cancer-selective apoptosis-inducing properties. This result suggested that the rIL-24 may have cancer therapeutic applications.     

IL-24选择性诱导肿瘤细胞凋亡机制

白细胞介素24/MDA-7基因是在黑色素瘤分化过程中被分离得到的,具有抑制黑色素瘤增生和促进其终末分化的能力。IL-24作为细胞因子不仅具有免疫调节功能,而且能选择性诱导多种肿瘤细胞凋亡。这种抑制作用不依赖p53、Rb和p16等抑癌基因,对正常细胞没有影响。白细胞介素24具有显著的选择性抗肿瘤特性,成为肿瘤治疗的研究新热点。