神经病理性疼痛中星形胶质细胞被激活后的p38丝裂原活化蛋白激酶信号转导通路

目的:探索神经性病理痛中星形胶质细胞被激活后的p38丝裂原活化蛋白激酶(p38MAPK)信号转导通路.方法:SD大鼠分为坐骨神经慢性结扎模型组(CCI组)和假手术组(Sham组),并于术前ld和术后1、3、7、14d取第4～5腰段脊髓做石蜡切片,免疫荧光组织化学标记p38MAPK的表达,免疫荧光双标技术检测其与脊髓神经细胞之间的关系.结果:CCI组术后术侧脊髓背角p38MAPK免疫阳性细胞数量增多;p38MAPK平均荧光强度明显增高并在术后第7天显示为最高.p38MAPK和小胶质细胞在CCI组脊髓背角术侧的分布有较好的一致性.结论:在神经病理性疼痛巾,p38MAPK信号转导通路被激活但未参与星形胶质细胞的痛觉信号转导.     

Infectious bursal disease virus infection induces macrophage activation via p38 MAPK and NF-kappaB pathways

In the present study, we show that infection with infectious bursal disease virus (IBDV) causes activation of macrophages, the key cells involved in inflammatory and immune-regulatory functions. Exposure of cultured spleen macrophages (SM) from SPF chickens to IBDV resulted in the production of nitric oxide (NO). In addition, there was upregulation of mRNA expression of inducible nitric oxide synthase (iNOS), IL-8 and cyclooxygenase-2 (COX-2). The signal transduction pathways involved in macrophage activation were examined. The role of mitogen-activated protein kinases (MAPKs) and nuclear factor-kappaB (NF-kappaB) was tested by using specific pharmacological inhibitors. Addition of p38 MAPK inhibitor, SB-203580 and NF-kappaB inhibitor Bay 11-7082, suppressed IBDV-induced NO production and mRNA expression of iNOS, IL-8 and COX-2. The results suggest that IBDV uses cellular signal transduction machinery, in particular the p38 MAPK and NF-kappaB pathways, to elicit macrophage activation. The increased production of NO, IL-8 and COX-2 by macrophages may contribute to bursa inflammatory responses commonly seen during the acute IBDV infection.     

PM2.5通过p38 MAPK信号通路影响血管平滑肌细胞增殖和迁移

目的:研究细颗粒物(PM2.5)对血管平滑肌细胞增殖和迁移的影响,以及p38 MAPK信号通路在其中的作用。方法:体外培养人血管平滑肌细胞,分为对照组和不同浓度PM2.5染毒组,分别用PBS及6.25、12.5和25 mg/L的PM2.5作用于细胞,用CCK-8法和EdU染色法检测细胞增殖能力的变化,用划痕实验和Transwell法检测细胞的迁移能力,然后根据结果选取PM2.5最强作用浓度染毒细胞,在不同时点用Western blot法检测p38MAPK信号分子的磷酸化改变,并观察用特异性抑制剂阻断p38 MAPK信号后细胞在PM2.5刺激下的增殖和迁移情况。结果:与对照组比较,PM2.5染毒可明显促进血管平滑肌细胞的增殖和迁移能力,在设定的浓度范围内以12.5 mg/L浓度组的作用最为明显(P<0.05)。Western blot结果显示,12.5 mg/L PM2.5染毒可上调血管平滑肌细胞p38 MAPK的磷酸化水平;而加入p38 MAPK抑制剂SB203580预处理后,PM2.5诱导的细胞增殖和迁移明显受到抑制,说明p38 MAPK可能介导PM2.5的毒性作用。结论:PM...     

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。     

辛伐他汀通过抑制p38 MAPK活化降低肝硬化门静脉高压大鼠门静脉压力

 目的:探讨p38 MAPK信号通路在辛伐他汀降低肝硬化门静脉高压症大鼠门静脉压力（PP）中的作用。方法:采用四氯化碳复合因素法构建大鼠肝硬化门静脉高压症模型,成模后将存活大鼠随机分为模型组（n=10）、辛伐他汀治疗组（n=11）和p38 MAPK信号通路抑制剂SB203580处理组（n=10）,后2组分别给予辛伐他汀及SB203580干预处理;另设正常对照组（n=8）。处理结束后检测大鼠PP、肝脏总p38 MAPK蛋白、磷酸化p38 MAPK蛋白、总eNOS蛋白、磷酸化eNOS蛋白表达水平以及肝脏一氧化氮（NO）含量的变化。结果:（1）模型组大鼠PP明显高于正常对照组;辛伐他汀治疗组及SB203580处理组PP均明显低于模型组（P＜0.01）,辛伐他汀治疗组PP明显低于SB203580处理组（P＜0.01）。（2）与正常大鼠相比,模型组大鼠肝脏总p38 MAPK蛋白及总eNOS蛋白表达水平无明显变化（P＞0.05）,而磷酸化p38 MAPK蛋白及磷酸化eNOS蛋白表达水平分别增高与降低（P＜0.01）;辛伐他汀治疗组大鼠肝脏磷酸化p38 MAPK蛋白及磷酸化eNOS蛋白表达水平分别降低与增高（P＜0.01）;SB203580处理组大鼠肝脏磷酸化p38 MAPK蛋白及磷酸化eNOS蛋白表达水平分别降低与增高（P＜0.01）,但磷酸化eNOS蛋白表达水平增高的程度低于辛伐他汀治疗组（P＜0.01）。(3)辛伐他汀治疗组肝脏NO含量［（15.73±1.59） μmol/(g protein)］及SB203580处理组肝脏NO含量［（13.98±1.27) μmol/(g protein)］明显高于模型组［（9.81±1.12） μmol/（g protein）］（P＜0.01）,辛伐他汀治疗组NO含量明显高于SB203580处理组（P＜0.01）。结论: 辛伐他汀降低肝硬化门静脉高压症大鼠门静脉压力可能与其抑制p38 MAPK信号通路的活化有关。     

Protective effect of sauchinone against regional myocardial ischemia/reperfusion injury: inhibition of p38 MAPK and JNK death signaling pathways

Sauchinone has been known to have anti-inflammatory and antioxidant effects. We determined whether sauchinone is beneficial in regional myocardial ischemia/reperfusion (I/R) injury. Rats were subjected to 20 min occlusion of the left anterior descending coronary artery, followed by 2 hr reperfusion. Sauchinone (10 mg/kg) was administered intraperitoneally 30 min before the onset of ischemia. The infarct size was measured 2 hr after resuming the perfusion. The expression of cell death kinases (p38 and JNK) and reperfusion injury salvage kinases (phosphatidylinositol-3-OH kinases-Akt, extra-cellular signal-regulated kinases [ERK1/2])/glycogen synthase kinase (GSK)-3β was determined 5 min after resuming the perfusion. Sauchinone significantly reduced the infarct size (29.0% ± 5.3% in the sauchinone group vs 44.4% ± 6.1% in the control, P < 0.05). Accordingly, the phosphorylation of JNK and p38 was significantly attenuated, while that of ERK1/2, Akt and GSK-3β was not affected. It is suggested that sauchinone protects against regional myocardial I/R injury through inhibition of phosphorylation of p38 and JNK death signaling pathways.     

Phosphatase inhibition potentiates IL-6 production by mast cells in response to FcepsilonRI-mediated activation: involvement of p38 MAPK

Mast cells are crucial effector cells in the immune response through mediator secretion and release of cytokines. A coordinated balance between protein kinases and phosphatases plays an essential role in the regulation of mast cell mediator secretion. We have previously shown that treatment of mast cells with okadaic acid (OA), a protein phosphatase 2A (PP2A) inhibitor, results in a dose-dependent increase in interleukin (IL)-6 production. We show here for the first time a synergism between OA and immunoglobulin E (IgE)-mediated IL-6 secretion by murine bone marrow-derived mast cells (BMMC). Selective p38 mitogen-activated protein kinase (p38 MAPK) inhibition reduces OA and IgE-mediated IL-6 production. Regulation of p38 MAPK by PP2A was demonstrated, as OA treatment caused a dose-dependent increase in p38 MAPK phosphorylation. Antigen-mediated activation of murine mast cells also resulted in an increase in p38 MAPK phosphorylation, which was potentiated by cotreatment of the cells with OA. Lastly, in two mast cell lines (human mast cell-1 5C6 and murine MC/9) and primary-cultured murine BMMC, we show by coimmunoprecipitation an interaction between p38 MAPK and PP2A. These data support a role for PP2A through interaction with p38 MAPK in the regulation of IgE-dependent mast cell activation.     

p38 MAPK抑制剂SB203580对雨蛙肽诱导的小鼠胰腺组织损伤的影响

 目的：探讨p38 MAPK抑制剂SB203580（SB）对雨蛙肽（caerulein,CAE）诱导的小鼠离体胰腺组织损伤的影响,并探讨其可能的机制。方法：分离小鼠离体胰腺组织后培养4 h,用CAE(10-5mol/L)刺激,加用或不加用SB (10-5mol/L)进行干预,以生理盐水（NS）作为对照。在刺激1 h和4 h后测定胰腺组织活力（MTT）、培养上清液中淀粉酶和脂肪酶活性（生化法）以及白细胞介素6（IL-6）和细胞因子诱导的中性粒细胞趋化因子1（CINC-1）的水平（ELISA法）;同时测定胰腺组织中热休克蛋白60（HSP60)和HSP70蛋白水平（ELISA法）,并用Western blotting测定胰腺组织p38及磷酸化p38 （p-p38）MAPK蛋白的表达。结果：CAE刺激后胰腺组织活力与NS组比较有所下降,尤其在刺激后4 h明显降低（P<0.05）;CAE刺激后1 h,离体胰腺组织培养上清液中淀粉酶、脂肪酶、IL-6和CINC-1水平较NS组均明显升高（P<0.05）;胰腺组织中HSP60、HSP70、p38及p-p38 MAPK蛋白的表达较NS组有所升高（P<0.05）,而SB可不同程度干预CAE引起的这些指标的改变。结论：CAE对离体胰腺组织具有损伤作用,SB可减轻CAE造成的胰腺组织的损伤,其机制可能与其对p38 MAPK抑制进而使炎症反应受到抑制有关;HSP60和HSP70的变化是因为炎症反应减轻而使细胞应激程度降低所致,还是失去了p38 MAPK的调控作用所致,还有待进一步研究。     

Inducible IL-23p19 expression in human microglia via p38 MAPK and NF-kappaB signal pathways

Activated microglia can release a variety of proinflammatory cytokines that play a crucial role in the pathogenesis of multiple sclerosis (MS). IL-23, a novel proinflammatory cytokine, is required for the induction of experimental autoimmune encephalomyelitis. Previously we demonstrated that IL-23 is expressed in MS lesions and that microglia are one cellular source of IL-23 in MS patients. In the present study we investigated the inducible expression and regulation of p19, a key subunit of IL-23, in human microglia. We demonstrated the inducible expression of IL-23p19 by lipopolysaccharide-stimulated microglial cells. Using signaling pathway-specific inhibitors, we showed that blocking p38 MAP kinase or NF-kappaB signaling pathway significantly reduced p19 expression in microglia. The regulatory role of p38 MAP kinase in p19 expression was further confirmed by decreased expression in microglia transduced with dominant-negative p38. We concluded that the p38 MAP kinase and NF-kappaB signaling pathways play an important role in regulation of IL-23p19 expression on human microglia, and are thus potential therapeutic targets in the treatment of MS.     

Up-regulation of TLR9 gene expression by LPS in mouse macrophages via activation of NF-kappaB, ERK and p38 MAPK signal pathways

Toll-like receptors (TLR) are critical in the activation of macrophages by bacterial products. It has been shown that TLR2 and TLR4 mediate lipopolysaccharide (LPS) and lipoproteins signal transduction, respectively. Regulation of TLR2 and TLR4 expression by LPS was considered to be one of the mechanisms to control the overall responses of immune cells to bacteria. However, little is known about whether the other members of TLR family are regulated by LPS. Recently, TLR9 was demonstrated to be essential for CpG DNA signaling. Given the effective immune modulation by CpG DNA, regulation of TLR9 expression might play important role in controlling the overall responses of immune cells to bacteria. In this study, regulation of TLR9 gene expression in mouse macrophage cell line RAW264.7 by LPS was investigated. Semiquantitative RT-PCR was performed to determine gene expression of TLR9. Following LPS stimulation, TLR9 gene expression was upregulated within 1 h and reached peak level at about 3 h. LPS stimulation activated NF-kappaB, ERK and p38 MAPK signal pathways. Pretreatment of macrophages with inhibitors of NF-kappaB, ERK and p38 MAPK signal pathways inhibited LPS-induced upregulation of TLR9 mRNA expression. Our results demonstrated that LPS stimulation could upregulate gene expression of TLR9 via NF-kappaB, ERK, and p38 MAPK signal pathways in macrophages, indicating that macrophages with increased TLR9 expression induced by LPS might respond to invading bacteria more effectively.     

Vitamin C inhibits p53-induced replicative senescence through suppression of ROS production and p38 MAPK activity

We previously reported that tumor cells expressing p53 increase intracellular levels of reactive oxygen species (ROS). In this study, we described an inhibitory effect of vitamin C on replicative senescence. Vitamin C was found to inhibit p53-induced senescence in human bladder cancer EJ cells. The senescence-like phenotype (SLP) induced by p53, which showed a morphological change and an irreversible cell cycle arrest, was not observed in vitamin C-treated EJ cells. In addition, vitamin C did not significantly affect normal cell proliferation. We investigated the molecular mechanisms of the inhibitory effect of vitamin C on the development of replicative senescence in EJ cells. We found that vitamin C inhibited this p53-induced ROS generation. Moreover, p38 kinase which was activated during p53-induced senescence was not observed in vitamin C-treated EJ cells. SB203580, a chemical inhibitor of p38 kinase, was found to consistently inhibit p53-induced senescence. Therefore, it is suggested that vitamin C inhibits p53-induced senescence by preventing ROS generation, which in turn leads to the activation of p38 MAPKinase. These results reveal the inhibitory mechanism of vitamin C on cellular senescence.     

利拉鲁肽通过p38 MAPK通路改善高同型半胱氨酸血症诱导的大鼠海马氧化应激及炎症损伤

目的:探讨胰高血糖素样肽1(GLP-1)类似物利拉鲁肽(Lir)对高同型半胱氨酸血症(Hhcy)大鼠海马损伤的保护作用及其机制。方法:40只SD大鼠随机分为对照(Ctrl)组、模型(Hhcy)组、Lir低剂量(12.5μg·kg~(-1)·h~(-1))组、Lir中剂量(25.0μg·kg~(-1)·h~(-1))组和Lir高剂量(37.5μg·kg~(-1)·h~(-1))组,采用Western blot法检测大鼠海马组织内丝裂原活化蛋白激酶(MAPK)信号通路中p38、JNK和ERK1/2的蛋白表达及活性依赖的磷酸化水平,同时采用Western blot和免疫组织化学法检测内质网应激标志蛋白免疫球蛋白重链结合蛋白(BIP)和C/EBP同源蛋白(CHOP)的表达水平;采用酶标法检测超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性及丙二醛(MDA)含量;酶联免疫吸附法检测炎症因子白细胞介素1β(IL-1β)、白细胞介素6(IL-6)和肿瘤坏死因子α(TNF-α)水平。结果:Hhcy可明显上调p-p38、BIP和CHOP的蛋白表达量,降低SOD和GSH的活性,升高MDA含量及IL-1β、IL-6和TNF-α水平;腹腔注射Lir可浓度依赖性地改善Hhcy引起的上述内质网应激和炎症反应,并伴有p38 MAPK通路的抑制。结论:Lir可改善Hhcy诱导的大鼠海马组织氧化应激和炎症损伤,其机制可能与抑制p38 MAPK信号通路的过度激活有关。     

PAN-811 provides neuroprotection against glutamate toxicity by suppressing activation of JNK and p38 MAPK

In an earlier study, we demonstrated that PAN-811 (3-aminopyridine-2-carboxaldehyde thiosemicarbazone), a novel neuroprotectant, provides protection against glutamate, staurosporine, veratridine, or hypoxia/hypoglycemia toxicities in primary cortical neuronal cultures by upregulating Bcl-2 expression [R.-W. Chen, C. Yao, X.C. Lu, Z.-G. Jiang, R. Whipple, Z. Liao, H.A. Ghanbari, B. Almassian, F.C. Tortella, J.R. Dave. PAN-811 (3-aminopyridine-2-carboxaldehyde thiosemicarbazone), a novel neuroprotectant, elicits its function in primary neuronal cultures by upregulating Bcl-2 expression. Neuroscience 135 (2005) 191–201]. Both JNK (c-Jun N-terminal kinase) and p38 MAP (mitogen-activated protein) kinase activation have a direct inhibitory action on Bcl-2 by phosphorylation. In the present study, we continued to explore the mechanism of PAN-811 neuroprotection. Our results indicate that treatment of cultured cortical neurons with glutamate (100 μM) induces phosphorylation of both JNK and p38 MAPK. Specifically, pretreatment of neurons with 10 μM PAN-811 (an optimal neuroprotective concentration) for 1 h, 4 h, or 24 h significantly suppresses glutamate-mediated activation of both JNK and p38 MAPK. Furthermore, the p38 MAPK-specific inhibitor SB203580 and the JNK-specific inhibitor SP600125 prevented glutamate-induced neuronal death in these primary cultures. Our results demonstrate that glutamate-induced phosphorylation of JNK and p38 MAPK is suppressed by PAN-811, which might contribute to Bcl-2 upregulation and PAN-811 neuroprotection.     

p38 MAPK的活化促进小鼠T细胞增殖

研究p38丝裂原活化蛋白激酶(MAPK)在小鼠T细胞增殖中的作用。以活体染料羧基荧光素乙酰乙酸琥珀酰亚胺酯染色,通过流式细胞术分析p38 MAPK的特异性抑制剂SB203580和p38 MAPK的激活剂茴香霉素在不同剂量下对ConA刺激的T细胞增殖作用,并测定其增殖的相关指数;采用碘化丙锭染色分析SB203580和茴香霉素对ConA或佛波醇酯(PDB)加离子霉素(Ion)刺激的小鼠T细胞周期变化的影响。结果显示:0.5μmol/L～15.0μmol/L SB203580对ConA诱导的T细胞增殖有明显的抑制作用,呈剂量依赖关系(r=-0.97,P<0.01);该浓度范围的SB203580能够呈明显剂量依赖性地阻止ConA或PDB加Ion诱导的T细胞进入S期或G2/M期(r_s=-0.98,P<0.01;r_(G2)/M=-0.97,P<0.01)。茴香霉素浓度在0.01～0.5ng/ml时能够增强ConA对T细胞的促增殖作用,并能够促进ConA诱导的T细胞进入G2/M期,促进PDB加Ion诱导的T细胞进入S期。以上提示p38信号通路的活化在促进小鼠T细胞增殖中可能起着重要作用。     

周期性张应力对骨性关节炎软骨细胞p38 MAPK表达及其磷酸化的影响

目的: 观察周期性张应力(cyclic tensile strain,CTS)对兔骨性关节炎(osteoarthritis,OA)软骨细胞中p38丝裂原活化蛋白激酶(p38 MAPK)表达及其磷酸化的影响,探讨力学载荷在骨性关节炎的病理过程中的作用。方法: 实验动物行一侧前交叉韧带切断术(ACLT)制作OA动物模型,术后10周消化分离兔膝软骨细胞体外培养,非手术侧软骨细胞为正常组, OA细胞随机分为低应力组、高应力组以及对照组,分别加载0.1 Hz、1.0 Hz、0 Hz的周期性张应力。加载应力24 h、1周和2周后RT-PCR和Western blotting测定各组p38 MAPK及其磷酸化产物表达水平。结果: 在各时点各组p38 MAPK均有不同程度的表达,其中加载CTS前,正常组与OA对照组相比差异非常显著(P<0.01);加载CTS 1周后,高应力组与低应力组差异有统计学意义(P<0.05);加载CTS 2周后,低应力组与对照组差异非常显著(P<0.01)。Western blotting显示p38 MAPK磷酸化产物在对照组和OA+高应力组持续表达,而OA+低应力组在24 h、1周、2周3个时点的表达逐渐下降。结论: 力学载荷可影响p38 MAPK的表达及磷酸化程度,骨性关节炎的发展发生与应力在细胞分子水平上相互影响。     

TPX2通过p38 MAPK信号通路诱导直肠癌HR-8348细胞凋亡

目的:研究下调非洲爪蟾驱动蛋白样蛋白2靶蛋白(TPX2)对直肠癌细胞凋亡的影响及机制。方法:用TPX2小干扰RNA(si RNA)转染直肠癌HR-8348细胞,记为TPX2 si RNA组;以不做转染的细胞作为正常对照(control)组;以转染si RNA阴性对照(si RNA-NC)的细胞作为si RNA-NC组;用p38 MAPK抑制剂处理敲减TPX2表达后的直肠癌HR-8348细胞记为TPX2 si RNA+SB203580组。RT-qPCR和Western blot测定TPX2的表达水平,MTT法测定细胞存活率,流式细胞术测定细胞凋亡,Western blot测定细胞中p38 MAPK、p-p38 MAPK、cleaved caspase-3和Bcl-2的蛋白水平。结果:TPX2 si RNA转染后HR-8348细胞中TPX2的m RNA和蛋白表达水平显著下降(P 0. 05),而转染si RNA-NC对HR-8348细胞中TPX2的m RNA和蛋白水平没有影响。敲减TPX2表达后的直肠癌HR-8348细胞存活率降低,凋亡率升高,细胞中的cleaved caspase-3、p-p38 MAPK/p38 MAPK蛋白水平明显升高,Bcl-2水平水平降低,与control组比较,差异有统计学意义(P 0. 05)。与TPX2 si RNA组相比,TPX2 si RNA+SB203580组的HR-8348细胞凋亡率、cleaved caspase-3水平和p-p38 MAPK/p38 MAPK蛋白水平明显降低,存活率明显升高(P 0. 05)。结论:TPX2表达下调可以通过激活p38 MAPK促进直肠癌HR-8348细胞凋亡。     

IL-18 enhances SCF production of melanoma cells by regulating ROI and p38 MAPK activity

It has been reported that interleukin-18 (IL-18) is secreted by B16 murine melanoma cells and that this endogenous IL-18 is involved in the immune escape of murine melanoma cells. The present study investigated whether interleukin (IL)-18 can regulate stem cell factor (SCF) expression, known to be associated with melanocyte proliferation, in B16F10 murine melanoma cells. SCF expression was examined by RT-PCR, intracellular FACS analysis, and ELISA in IL-18 antisense transfectants. Transfection with IL-18 antisense cDNA reduced SCF expression and the expression was enhanced by addition of exogenous IL-18. In addition, the effect of IL-18 was blocked by the antioxidant, N-acetyl-L-cysteine (NAC), indicating that IL-18 regulates ROI production, which is involved in SCF production. Furthermore, inhibitors of p38 mitogen-activated protein kinase (MAPK), such as SB203580, blocked enhanced SCF expression, indicating that p38 MAPK activity is required for IL-18-enhanced SCF production. Taken together, these results suggest that IL-18 plays a critical role as a regulatory factor of SCF expression via ROI and p38 MAPK activity in B16F10 murine melanoma cells.     

阿魏酸钠抑制Aβ25-35诱导的小鼠腹腔巨噬细胞p38MAPK活化

目的：探讨阿魏酸钠对β淀粉样肽（Aβ_25-35）介导的p38信号转导的影响。方法：培养小鼠腹腔巨噬细胞，采用Western 印迹分析p38 MAPK蛋白激酶水平。用ELISA法、免疫组化法、Griess反应，分别检测TNF-α生成量、iNOS表达和NO含量。结果： Aβ_25-35能诱导p38 MAPK的活化，显著增加腹腔巨噬细胞TNF-α、iNOS和NO水平，阿魏酸钠能显著降低Aβ_25-35诱导的腹腔巨噬细胞核蛋白p38 MAPK的含量及细胞的TNF-α、iNOS、NO水平。结论： 阿魏酸钠可抑制Aβ_25-35介导的p38 MAPK活性，使TNF-α、iNOS、NO水平降低。     

支原体污染经p38 MAPK途径降低人类细胞株28S和18S RNC-rRNA

目的:研究支原体感染对人类细胞株的核糖体新生肽链复合体(RNC)中rRNA组成的影响及其相关机制。方法:分别提取支原体阳性与阴性RNC-RNA进行琼脂糖凝胶电泳,分析RNC-rRNA组成改变情况;在支原体污染环境中培养人正常肺上皮(HBE)细胞,比较培养前后RNC-rRNA的变化;对RNC-RNA条带异常细胞进行抗支原体治疗,比较治疗前后RNC-rRNA的变化。利用免疫印迹分析支原体污染对丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)途径的影响。结果:不同组织来源的多株细胞中,支原体阴性和阳性细胞RNCRNA的琼脂糖电泳显示细胞中RNC-rRNA组成发生异常改变,主要体现为28S和18S真核rRNA的降低,以及16S和未知原核rRNA的增加。在污染环境中培养HBE细胞,其RNC-rRNA组成可由支原体阴性转变为阳性谱型。以环丙沙星抗支原体治疗可逆转上述RNC-rRNA谱型的改变。总蛋白和磷酸化蛋白的免疫印记结果表明,支原体污染显著抑制A549细胞的p38 MAPK途径的活化,而对该细胞的ERK1/2途径无显著改变。结论:支原体感染可通过抑制p38 MAPK活化严重改变人类细胞株中RNC-rRNA的组成,从而影响宿主细胞的翻译行为。