系统性斑狼疮小鼠脾细胞中IL—12信号传递途径的研究

目的 探讨在狼疮小鼠脾细胞中是否存在IL-12通过Lck/p38/c-jun传递信号及其对脾细胞的影响。方法 以慢性移植物抗宿主病（graft versus host disease,CVHD)小鼠为狼疮小鼠模型。分别采用放射自显影、Western blot和Northern blot，检测培养的脾细胞中Lck的活性、p38磷酸化活化及c-jun基因表达的变化。结果 狼疮小鼠脾细胞经IL-12刺激后，与正常对照组相比较，Lck抑制剂PP1组Lck的活性及p38磷酸化消失，无c-jun基因的表达；加入p38抑制剂SB203580组亦无p38磷酸化及c-jun基因的表达。结果 狼疮小鼠的脾细胞异常，IL-12可通过Lck/p38/c-jun在细胞内传递信号，直接参考免疫损伤。     

白细胞介素2对淋巴细胞特异性蛋白酪氨酸激酶在肾小管上皮细胞中表达的影响

目的：探讨IL-2对肾小管上皮细胞中淋巴细胞特异性蛋白酪氨酸激酶（Lck） mRNA及蛋白表达的影响以及Lck在狼疮肾炎中的致病作用.方法：采用BALB/c小鼠及BXSB狼疮小鼠肾小管上皮细胞为实验对象,分别给予 IL-2（100 U/ml）刺激.应用逆转录聚合酶链反应（RT-PCR）方法检测肾小管上皮细胞Lck mRNA的表达,免疫印迹法检测Lck蛋白的表达,比较IL-2刺激前后Lck mRNA及蛋白表达水平的变化.结果：正常BALB/c小鼠及BXSB狼疮小鼠肾小管上皮细胞中仅有微量Lck mRNA及蛋白表达,经IL-2刺激后二者的Lck mRNA及蛋白表达水平均有增加,以狼疮小鼠肾小管上皮细胞增加更为显著.结论：（1）肾小管上皮细胞中有Lck基因的表达.（2）肾小管上皮细胞经IL-2刺激后Lck mRNA及蛋白表达水平增加,提示IL-2可活化肾小管上皮细胞诱导Lck表达,进而可能通过一系列信号传导作用,发挥生物学作用.相对于BALB/c小鼠,狼疮小鼠肾小管上皮细胞在IL-2刺激后Lck表达更明显,提示狼疮小鼠肾小管上皮细胞可能更易激活.（3）由于Lck在狼疮肾炎小鼠肾小管上皮细胞中异常表达,推测Lck可能作为细胞因子或炎症因子的重要信号分子,促进狼疮肾炎的发生.     

白细胞介素—12信号转导参与小鼠肾小管上皮细胞炎性损伤

为观察白细胞介素-12（IL-12）在小鼠肾小管上皮细胞（TEC）炎症损伤的信号传递,以培养的正常小鼠TEC作为空白对照组,狼疮肾炎（LN）TEC作为实验组,以IL-12（10μg/L)刺激5min,利用放射自显影检测发现正常对照及LN组lck活性增强,后者更明显,应用lck抑制剂PP1后其活性消失。再以等浓度IL-12刺激TEC15min,采用免疫印迹观察到LN组P38磷酸化强于正常对照组,应用PP1或P38抑制剂SB203580则不发生P38磷酸化。给予IL-12刺激时发现LN组c-Jun基因表达水平强于正常对照组,应用PP1或SB203580后则未有c-Jun基因表达,提示IL-12可通过lck/P38/c-Jun信号途径参与对狼疮小鼠TEC的炎症损伤。     

沙眼衣原体质粒蛋白Pgp3经NOD1/RIP2信号通路诱导HeLa细胞产生IL-8

目的探讨沙眼衣原体质粒蛋白Pgp3诱导HeLa细胞产生IL-8的机制。方法选择不同质量浓度的Pgp3蛋白刺激HeLa细胞并在不同时间点收集细胞,Real-time PCR检测Pgp3刺激HeLa细胞后IL-8转录水平,Western blot和Real-time PCR分别检测NOD1的表达水平及下游蛋白RIP2的转录水平;Western blot检测ERK1/2和p38磷酸化水平;HeLa细胞用NOD1抑制剂ML130、RIP2抑制剂GSK583、ERK抑制剂PD98059和p38抑制剂LY2228820分别预处理后,再用Pgp3蛋白刺激细胞,ELISA和Real-time PCR检测IL-8的表达水平。结果 0~24μg/ml的Pgp3蛋白刺激HeLa细胞后,IL-8的含量呈时间和质量浓度依赖性,Pgp3蛋白刺激HeLa细胞能调控NOD1及RIP2的表达,同时ERK1/2和p38磷酸化水平显著升高;NOD1和RIP2抑制剂并不影响Pgp3蛋白诱导的ERK和p38磷酸化水平;用4种抑制剂预处理HeLa细胞后,Pgp3刺激HeLa细胞,IL-8表达量均出现下降。结论 Pgp3经NOD1/RIP2以及活化ERK1/2和p38信号通路诱导HeLa细胞调控IL-8的产生。     

八肽胆囊收缩素对脂多糖诱导小鼠分泌IL-12的影响及其机制研究

目的：观察八肽胆囊收缩素（CCK-8）对脂多糖诱导小鼠分泌IL-12的影响，探讨核因子-κB（NF-κB）和p38丝裂原活化蛋白激酶（p38 MAPK）的信号转导作用。方法：雌性BALB/c小鼠经LPS诱导后分别给予CCK及CCK-A、B受体拮抗剂。ELISA法检测小鼠血清及肺、脾组织中IL-12p40、p70的表达；Western blotting法检测肺脏、脾脏IκB、p38 MAPK的表达；EMSA法检测肺、脾组织中NF-κB/DNA的结合活性。结果：CCK-8进一步提高了LPS诱导的小鼠血清及肺、脾组织中IL-12p40、p70的表达；抑制IκB磷酸化和NF-κB/DNA结合活性；促进p38 MAPK磷酸化。而CCK-A受体拮抗剂（CR-1409）及CCK-B受体拮抗剂（CR-2945）部分逆转了CCK-8的效应。结论：CCK-8可促进LPS诱导小鼠分泌IL-12，p38 MAPK可能参与了其信号转导机制，而NF-κB途径可能并未参与CCK-8促IL-12分泌这一过程。     

红景天苷通过细胞外信号调节蛋白激酶(ERK)通路诱导树突状细胞抗肿瘤作用

目的探讨丝裂原活化蛋白激酶/细胞外信号调节激酶(MAPK/ERK)信号通路在红景天苷(SAL)调控树突状细胞(DC)抗肿瘤的作用。方法建立Lewis肺癌荷瘤小鼠模型,分别体内给予生理盐水(0.2 mL/d)、 SAL[500 mg/(kg·d)]和环磷酰胺(CTX)[10 mg/(kg·d)]治疗。检测Lewis肺癌荷瘤小鼠的生存期和肿瘤质量。同时,体外分离Lewis肺癌荷瘤小鼠骨髓来源的DC诱导培养。经磁珠分选后,分别与PBS、 0.05 mg/mL SAL、 200 ng/mL脂多糖(LPS)或0.05 mg/mL SAL联合ERK抑制剂U0126共培养48 h,流式细胞术检测磷酸化的ERK(p-ERK)水平。另外,将DC分别与PBS、 0.05 mg/mL SAL或200 ng/mL LPS共培养48 h,流式细胞术检测磷酸化的p38丝裂原激活蛋白激酶(p38MAPK)和磷酸化的JNK(p-JNK)表达量。此外,收取磁珠分选后DC与PBS、 0.05 mg/mL SAL、 200 ng/mL LPS或0.05 mg/mL SAL联合ERK抑制剂U0126共培养后的细胞上清, ELISA检测DC分泌IL-12p70的能力。最后,将Lewis肺癌荷瘤小鼠骨髓来源的致敏DC经SAL刺激后与尼龙毛柱吸附纯化的C57BL/6正常小鼠脾T淋巴细胞共培养作为效应细胞,再按照10∶1、 25∶1、 50∶1效靶比加入3LL靶细胞, CCK-8法检测体外细胞毒性T淋巴细胞(CTL)活性。结果 SAL可以显著抑制Lewis肺癌荷瘤小鼠肿瘤的生长并提高其生存期;与PBS处理的DC相比, SAL组DC中ERK磷酸化水平显著升高,使用ERK抑制剂U0126后,磷酸化ERK的表达量显著降低; SAL对p38MAPK通路和JNK通路的磷酸化无明显影响; SAL组DC的IL-12p70分泌水平显著升高,使用ERK阻断剂U0126后DC分泌IL-12p70水平显著上升; SAL增强CTL的杀伤能力。结论 SAL抑制Lewis肺癌荷瘤的肿瘤生长,激活ERK信号通路,促进DC分泌IL-12p70并增强CTL杀伤能力。     

肺炎链球菌热休克蛋白40通过p38MAPK和JNK通路诱导小鼠巨噬细胞免疫应答

目的探讨肺炎链球菌热休克蛋白40(HSP40)引起小鼠巨噬细胞免疫应答的机制。方法表达、纯化重组HSP40蛋白(r HSP40),去除其中的脂多糖(LPS)。r HSP40处理C57BL/6野生小鼠骨髓来源巨噬细胞(BMDM)后,反转录PCR检测BMDM中肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)、IL-1β、IL-23p19、IL-12p40、IL-12p35、IL-10的mRNA水平,ELISA检测TNF-α、IL-6、IL-12p40水平;r HSP40刺激后,ELISA检测野生型、Toll样受体2(TLR2)和TLR4缺陷的BMDM中TNF-α和IL-6的表达水平;丝裂原活化蛋白激酶(MAPK)抑制剂预处理BMDM后,ELISA检测其对r HSP40诱导TNF-α和IL-6水平的影响;Western blot法检测p38MAPK和c-Jun氨基末端激酶(JNK)磷酸化水平。结果获得纯度90%以上的r HSP40;r HSP40可显著增强p38MAPK、JNK的磷酸化水平和TNF-α、IL-6的表达;p38MAPK和JNK抑制剂可显著抑制TNF-α和IL-6的表达;与野生BMDM相比较,TLR4缺陷的BMDM表达TNF-α和IL-6显著降低。结论 HSP40诱导小鼠巨噬细胞产生免疫应答受JNK及p38MAPK信号通路调控,并且此过程依赖TLR4。     

CPSIT_p7通过激活JNK/ERK信号通路诱导宿主细胞炎症

目的初步探讨鹦鹉热嗜衣原体蛋白CPSIT_p7对宿主细胞炎症反应的调节作用及其分子机制。方法佛波酯(PMA)处理THP-1细胞过夜,诱导其分化为贴壁的巨噬细胞,之后用CPSIT_p7蛋白刺激贴壁细胞,或先用30μmol/L ERK抑制剂PD98059、JNK抑制剂SP600125和p38抑制剂SB202190分别预处理贴壁细胞,再用CPSIT_p7蛋白处理贴壁细胞;Western blot检测ERK、JNK和p38磷酸化水平,ELISA检测各种炎症因子的表达水平。结果 0~10μg/ml CPSIT_p7蛋白刺激PMA诱导的THP-1细胞24 h后,随着CPSIT_p7质量浓度升高,IL-6、IL-1β、IL-8及TNF-α的含量呈剂量依赖性增加;10μg/ml的CPSIT_p7处理细胞0、6、12、24和36 h,在24 h时IL-6、IL-8及IL-1β表达水平达到高峰,而TNF-α在12 h就达到高峰;CPSIT_p7蛋白处理细胞后其ERK和JNK磷酸化水平显著升高,p38磷酸化水平改变不明显;JNK和ERK抑制剂能明显降低CPSIT_p7蛋白诱导的IL-6、IL-1β、IL-8及TNF-α表达。结论 CPSIT_p7通过JNK/MAPKs和ERK/MAPKs信号传导途径诱导THP-1产生IL-1β、IL-6、IL-8及TNF-α炎症因子,与p38/MAPKs信号传导通路无关。     

丙酮酸通过抑制p38丝裂原激活蛋白激酶(p38MAPK)磷酸化减轻低氧对PC12细胞的损伤北大核心CSCD

目的观察丙酮酸对低氧诱导神经细胞损伤的保护作用及机制。方法采用丙酮酸处理PC12细胞,10 m L/L O2的低氧环境暴露12、24、48 h。MTT法观察细胞增殖情况,检测胱天蛋白酶3(caspase-3)活性观察细胞凋亡情况,ELISA检测白细胞介素1β(IL-1β)、IL-6、肿瘤坏死因子α(TNF-α)的水平,Western blot法检测p38丝裂原激活蛋白激酶(p38MAPK)、磷酸化的p38MAPK(p-p38MAPK)蛋白水平。结果低氧暴露24、48 h,抑制PC12细胞增殖,caspase-3活性增强,IL-1β、IL-6、TNF-α和p-p38MAPK水平增高;丙酮酸处理可显著增加PC12细胞增殖,减少细胞凋亡,降低IL-1β、IL-6、TNF-α水平,抑制p38MAPK的磷酸化水平。结论丙酮酸通过抑制p38MAPK的磷酸化而抑制低氧暴露引起PC12细胞炎症因子的表达,对低氧暴露导致的神经元损伤起保护作用。     

Fractalkine通过激活p38MAPK信号通路调控狼疮性肾炎小鼠Treg细胞凋亡北大核心CSCD

目的:探讨趋化因子Fractalkine(FKN)对狼疮性肾炎(LN)小鼠Treg细胞凋亡的影响及机制。方法:构建LN小鼠模型,使用FKN中和抗体(Anti-FKN)、p38MAPK信号通路的抑制剂(SB203580)、p38MAPK信号通路的激活剂(U-46619)作用于正常小鼠及模型小鼠,采用免疫组化检测小鼠肾组织中FKN、磷酸化p38(p-p38)及Foxp3的蛋白表达;采用免疫磁珠法分选模型小鼠脾脏CD4^(+)CD25^(+)Treg细胞,使用腺病毒转染细胞的方式敲低FKN的表达水平,同时使用p38MAPK信号通路抑制剂(SB203580)及激活剂(U-46619)干预细胞。采用Western blot验证FKN敲低的成功转染、检测p38、p-p38、Foxp3、凋亡相关因子(Bax、Bcl-2及Cyt-c)的蛋白表达。结果:LN小鼠肾组织中的FKN及磷酸化p38MAPK的表达明显上调,低表达FKN可降低LN小鼠肾组织及Treg细胞中FKN和p-p38的表达,增加Foxp3的表达,同时增加细胞内抗凋亡因子Bcl-2蛋白的表达,而减少促凋亡因子Bax及Cyt-c蛋白的表达。p38MAPK信号通路抑制剂对上述因子的作用与低表达FKN相似,其激活剂可以逆转这些因子在LN小鼠Treg细胞中的表达。结论:FKN可能通过激活p38MAPK信号通路参与调控LN小鼠Treg细胞凋亡,为阐明LN的发病机制提供了实验依据。     

Differential regulation of mast cell cytokines by both dexamethasone and the p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580

Activated mast cells generate multiple cytokines but it is not known if these can be differentially regulated by pharmacological agents. We report here that the glucocorticoid dexamethasone (DEX) preferentially inhibited Ag-induced expression of IL-4 and IL-6 mRNA relative to TNF-alpha mRNA in RBL-2H3 cells. Likewise, the drug more readily inhibited release of IL-4 than TNF-alpha protein. SB203580, an inhibitor of p38 mitogen-activated protein kinase (MAPK), enhanced Ag-induced TNF-alpha mRNA expression without affecting IL-4 or IL-6 mRNA. At the protein level, SB203580 exerted little effect on TNF-alpha release but inhibited IL-4 release; notably, the ratio of TNF-alpha : IL-4 increased markedly with the concentration of SB203580, confirming the differential regulation of these cytokines. PD98059, an inhibitor of MAPK kinase (MEK), a component of the p44/42 MAPK pathway, partially inhibited Ag-induced expression of mRNA for all three cytokines while cyclosporin A inhibited Ag-induced IL-4 and IL-6 mRNA more readily than TNF-alpha mRNA. Ag activation of the cells led to phosphorylation of p38 and p44/42 MAPK but this was not influenced by DEX. In conclusion, mast cell cytokines can be differentially regulated pre- and post-translationally by DEX and SB203580 but there does not appear to be a direct mechanistic link between the actions of these two drugs.     

Caveolin-1 confers antiinflammatory effects in murine macrophages via the MKK3/p38 MAPK pathway

Caveolin-1 has been reported to regulate apoptosis, lipid metabolism, and endocytosis in macrophages. In the present study, we demonstrate that caveolin-1 can act as a potent immunomodulatory molecule. We first observed caveolin-1 expression in murine alveolar macrophages by Western blotting and immunofluorescence microscopy. Loss-of-function experiments using small interfering RNA showed that down regulating caveolin-1 expression in murine alveolar and peritoneal macrophages increased LPS-induced proinflammatory cytokine TNF-alpha and IL-6 production but decreased anti-inflammatory cytokine IL-10 production. Gain-of-function experiments demonstrated that overexpression of caveolin-1 in RAW264.7 cells decreased LPS-induced TNF-alpha and IL-6 production and augmented IL-10 production. p38 mitogen-activated protein kinase (MAPK) phosphorylation was increased by overexpressing caveolin-1 in RAW264.7 cells, whereas c-Jun N-terminal kinase, extracellular signal-regulated kinase MAPK, and Akt phosphorylation were inhibited. The antiinflammatory modulation of LPS-induced cytokine production by caveolin-1 was significantly abrogated by the administration of p38 inhibitor SB203580 in RAW264.7 cells. Peritoneal macrophages isolated from MKK3 null mice did not demonstrate any modulation of LPS-induced cytokine production by caveolin-1. LPS-induced activation of NF-kappaB and AP-1 determined by electrophoretic mobility shift assay were significantly reduced by overexpressing caveolin-1 in RAW264.7 cells. The reductions were attenuated by the administration of p38 inhibitor SB203580. Taken together, our data suggest that caveolin-1 acts as a potent immunomodulatory effector molecule in immune cells and that the regulation of LPS-induced cytokine production by caveolin-1 involves the MKK3/p38 MAPK pathway.     

The p38 mitogen-activated protein kinases can have opposing roles in the antigen-dependent or endotoxin-stimulated production of IL-12 and IFN-gamma.

The p38 mitogen-activated protein kinases (p38 MAPK) are activated in lymphocytes and acessory cells during innate and antigen-specific responses. We show that an inhibitor of two isoforms of p38 MAPK, SB 203580, inhibited the antigen-initiated production of IL-12, and IFN-gamma by cultures of splenic APC and naive CD4(+) T cells. Paradoxically, SB 203580 enhanced the LPS plus IFN-gamma-initiated production of IL-12 by peritoneal exudate macrophages, and the LPS-initiated of the production of both IL-12 and IFN-gamma by non-T non-B (scid) splenocytes. The enhancing effect of SB 203580 on the production of IL-12 by peritoneal exudate macrophages stimulated by LPS and IFN-gamma was dose dependent (EC(50) 0.3 microM), was only seen at lower concentrations of IFN-gamma and was due, at least in part, to a dose-dependent (IC(50) 0.3 microM) inhibition of the production of IL-10. These results indicate first, that p38 MAP kinase activity is required for the production of IL-10, as well as that of proinflammatory cytokines such as IL-12 and IFN-gamma, and, second, that the net effects of SB 203580 on the production of IL-12 and IFN-gamma can be positive or negative, depending on stimuli, cell populations, and levels of cytokines such as IFN-gamma and IL-10.     

Tumor Necrosis Factor-Like Weak Inducer of Apoptosis (TWEAK) Mediates p38 Mitogen-Activated Protein Kinase Activation and Signal Transduction in Peripheral Blood Mononuclear Cells from Patients with Lupus Nephritis

Forty-two patients with systemic lupus erythematosus (SLE), including 26 patients with renal damage and 16 without, and 20 healthy controls were included in the study. The isolated peripheral blood mononuclear cells (PBMCs) were treated with a p38 inhibitor (SB203580) or anti-tumor necrosis factor-like weak inducer of apoptosis (TWEAK) mAb, with or without phytohemagglutinin/phorbol myristate acetate (PHA/PMA) stimulation. Western blot experiments were used to evaluate the protein expression of TWEAK and p38 MAPK in PBMCs .Next, the contents of interleukin-10 (IL-10) and monocyte chemoattractant protein-1 (MCP-1) in the supernatant were measured by ELISA. The results showed that expression of TWEAK protein in PBMCs from lupus nephritis patients was significantly higher than that from SLE patients without renal damage and healthy controls. PHA/PMA simulation could upregulate the productions of TWEAK and p-p38MAPK in PBMCs from patients with SLE. Anti-TWEAK mAb treatment downregulated both TWEAK and p-p38 MAPK expression in PBMCs, as well as IL-10 and MCP-1 in the supernatant; SB203580 had the same effect on cytokine production in PBMC, but had no effect on the expression of TWEAK. Our results suggested that TWEAK–p38 MAPK–IL-10, MCP-1 signaling pathway in PBMC played an important pathogenic role in lupus nephritis.     

p38 MAPK在顺铂诱导肾小管上皮细胞凋亡中的作用

目的:探讨p38 MAPK在顺铂诱导大鼠近端肾小管上皮细胞(RPTC)凋亡中的作用。方法:首先采用Western blot实验检测0、5、10和20μmol/L顺铂处理24 h对细胞凋亡的影响,确定最佳处理剂量;而后采用20μmol/L顺铂联合50 mg/L p38 MAPK抑制剂SB203580刺激RPTC,实验分为对照组、顺铂组及顺铂+SB203580(加入SB203580处理RPTC 1 h后再给予顺铂处理24 h)。采用相差荧光显微镜观察和流式细胞术分析顺铂处理后RPTC的凋亡情况;采用Ac-DEVD-AFC试剂盒检测RPTC裂解液中的caspase活性;Western blot实验检测p38、磷酸化p38、cleaved PARP和cleaved caspase-3等的蛋白水平;pH计检测顺铂处理后RPTC外环境pH值改变。结果:20μmol/L顺铂处理RPTC 24 h,可以明显诱导细胞凋亡;顺铂处理15 min后RPTC中p38 MAPK开始磷酸化并达到高峰。顺铂处理后12.08%的RPTC呈凋亡形态,具有增强的caspase活性,并且cleaved PARP和cleaved caspase-3水平明显升高(P0.05);p38 MAPK抑制剂SB203580可抑制p38的磷酸化,降低RPTC的凋亡率和caspase活性,并减少cleaved PARP和cleaved caspase-3的蛋白水平。同时,SB203580可逆转顺铂诱导的RPTC培养基pH值的改变。结论:p38 MAPK的磷酸化在顺铂诱导的RPTC凋亡中发挥作用。顺铂诱导RPTC凋亡后,可改变细胞外酸性环境,并可被p38 MAPK抑制剂SB203580所抑制。