胰岛素样生长因子1对血管平滑肌细胞凋亡的影响

目的探讨胰岛素样生长因子1(IGF-1)对血管平滑肌细胞凋亡的影响。方法脂多糖(LPS)诱导RAW264.7细胞制备炎症模型即条件培养基(CM),未加LPS诱导组为对照组即非条件培养基(n CM)。体外培养血管平滑肌细胞,分别予n CM、CM、CM+IGF-1 60 ng/ml、CM+IGF-1 90 ng/ml、CM+IGF-1 120 ng/ml干预,用AnnexinⅤ-异硫氰酸荧光素(FITC)/碘化丙啶(PI)流式细胞术检测平滑肌细胞凋亡率。结果 RAW264.7细胞分别在LPS 0 ng/ml,10 ng/ml,100 ng/ml,1μg/ml,10μg/ml刺激下各组上清液中IL-6的浓度分别为(6.75±0.12)pg/ml,(7.82±1.53)pg/ml,(44.09±1.58)pg/ml,(155.71.0±23.93)pg/ml,(436.59±3.15)pg/ml,差异有统计学意义(P<0.01);n CM、CM、CM+IGF-1 60 ng/ml、CM+IGF-1 90 ng/ml、CM+IGF-1 120 ng/ml条件下血管平滑肌细胞的凋亡率分别为(4.89±0.09)%,(10.86±0.15)%,(9.64±0.65)%,(3.85±0.51)%,(4.82±0.08)%,差异有统计学意义(P<0.05)。结论炎症可促进平滑肌细胞凋亡,但给予IGF-1后可减少平滑肌细胞凋亡,本实验中IGF-1抑制平滑肌凋亡的最适浓度为90 ng/ml。     

KGF对IEC-6的辐射防护作用与抑制JNK/SAPK的激活研究

目的利用离体培养肠上皮细胞(IEC-6)观察角质细胞生长因子(KGF)的辐射防护作用,并从c-Jun氨基末端激酶(JNK)/应激活化蛋白激酶(SAPK)细胞信号传导途径的变化来探讨其作用的分子机制。方法离体培养IEC-6分别经过KGF不同处理,接受剂量率为0.589Gy/min,~(60)Coγ射线一次性照射,进行细胞增殖活性、蛋白磷酸激酶活性和JNK/SAPK蛋白磷酸检测。结果 KGF(10ng/mL)预处理IEC-6 24h可显著地降低细胞辐射敏感性,增高辐射抗性;KGFl预处理抑制辐射诱导JNK/SAPK(thr183/thr185)磷酸化激活。结论抑制JNK/SAPK分子的激活是KGF对小肠上皮辐射防护作用重要环节。     

大鼠血管平滑肌细胞迁移与西洛他唑的干预效应

目的:探讨西洛他唑对原代培养大鼠血管平滑肌细胞迁移能力的影响及其可能的调控作用。方法:实验于2003-03/12在解放军沈阳军区总医院全军心血管病研究所完成。使用胶原酶消化法处理健康雄性SD大鼠,获得原代培养的鼠血管平滑肌细胞,加入终浓度为0.5μmol/L西洛他唑培养72h为西洛他唑组,对照组为加入等量的Dulbecco改良的Eagle培养液培养的血管平滑肌细胞。应用细胞刮伤实验和基质金属蛋白酶活性测定分析西洛他唑对原代培养血管平滑肌细胞迁移能力的影响。应用蛋白质印记杂交方法分析给药前后血管平滑肌细胞内基质金属蛋白酶2,9和细胞外信号调节激酶蛋白的表达情况。结果:①细胞刮伤实验显示,与对照组比较,西洛他唑组血管平滑肌细胞迁移能力明显受抑,迁移距离明显缩短。明胶酶活性分析发现,西洛他唑组细胞基质金属蛋白酶活性明显低于对照组。②蛋白质印迹杂交分析发现,西洛他唑可引起原代培养血管平滑肌细胞迁移能力下降。西洛他唑组细胞内基质金属蛋白酶2,9蛋白表达明显低于对照组(14.34±0.70,12.65±0.98;93.67±1.90,83.67±1.05,t=67.86,85.65,P<0.05)。③蛋白质印迹杂交分析检测显示,西洛他唑组与对照组血管平滑肌细胞内信号调节激酶1,2蛋白表达无明显差异(P>0.05);细胞内磷酸化信号调节激酶蛋白表     

四嗪二甲酰胺诱导肺癌细胞株EBC-1凋亡及作用机制的研究

目的研究四嗪二甲酰胺(ZGDHu-1)诱导肺癌细胞株EBC-1凋亡及分子机制。方法将不同浓度的ZGDHu-1与EBC-1细胞在体外培养,用5′-溴-2′脱氧尿苷(Brdu)-ELISA法观察ZGDHu-1抑制EBC-细胞增殖作用;用Annexin-V/PI双标记和ELISA法测定凋亡细胞核小体等技术观察ZGDHu-1诱导EBC-细胞凋亡率。用流式细胞术检测经ZGDHu-1作用后EBC-1细胞P38MAPK和Stat3磷酸化表达的变化,同时用Western blot法检测bcl-2、bax、P53、Fas、Caspase-3等蛋白质的变化。结果 ZGDHu-1能抑制EBC-1细胞增殖,呈现作用时间和剂量的量效关系,24h、48h、72h后的IC50分别为(295±25)ng/ml,(112±8)ng/ml和(23±2)ng/ml。EBC-1细胞与ZGDHu-1作用后,Annexin-V+/PI-表达升高,细胞内核小体含量显著增加,二者均呈现剂量依赖性。EBC-1细胞与50ng/ml、200ng/ml、500ng/ml等浓度的ZGDHu-1培养48h后,磷酸化P38MAPK的表达率为67.4%、88.2%和91.1%,对照组为10.6%;而磷酸化Stat3表达率分别为56.5%、43.6%和34.6%,对照组为89.1%。Western blot法检测发现bax、P53和Fas蛋白的表达随药物作用浓度的升高而显著上调,bcl-2的表达没有变化,Caspase-3蛋白的表达则明显下调。结论 ZGDHu-1能显著抑制EBC-1细胞增殖,并诱导其细胞凋亡。Fas介导的线粒体的途径可能是ZG-DHu-1诱导EBC-1细胞凋亡通路之一;P38MAPK和Stat3激活也参与了ZGDHu-1诱导EBC-1细胞的凋亡。     

参麦注射液对人气道平滑肌细胞增殖的影响

目的：探讨参麦注射液（SMI）对人气道平滑肌细胞（HASMCs）细胞外信号调节激酶（ERK）表达的影响及SMI与ERK、细胞增殖的关系。方法：将体外培养的HASMCs随机分为对照组和参麦干预组,采用Western-blot检测磷酸化的细胞外信号调节激酶（p-ERK）蛋白的表达,采用流式细胞术观察细胞的周期,四甲基偶氮唑盐（MTT）微量比色分析法检测细胞的增殖,免疫细胞化学技术检测增殖细胞核抗原（PCNA）的表达,以观察参麦注射液对培养的HAMSCsERK表达及增殖的影响。结果：参麦干预组p-ERK蛋白的表达下降,参麦可显著降低HASMCs吸光度值及PCNA的表达,并使增殖期（S＋G2M期）细胞数显著减少（均P〈0.05）。结论：SMI通过剂量依赖效应抑制HAMSCs的ERK信号传导途径,从而阻止气道平滑肌细胞增生和气道重塑。     

粉防己碱对转化生长因子-β1诱导的人近端小管上皮细胞转分化的干预作用及机制

目的探讨粉防己碱(tetrandrine,Tet)对转化生长因子-β1(TGF-β1)诱导的人近端肾小管上皮细胞(HK-2)转分化的拮抗效应及其机制。方法体外培养的HK-2随机分为正常对照组、Tet组(100ng/ml)、TGF-β1(5ng/ml)组和TGF-β1(5ng/ml)+Tet(100ng/ml)组。Westernblot法检测细胞中TβRI蛋白、SnoN蛋白水平、Smad7蛋白水平和Smad2/3磷酸化水平的改变;半定量反转录-聚合酶链式反应(RT-PCR)方法观察细胞中TβRI mRNA、Smad7 mRNA、SnoN mRNA表达的改变。免疫荧光检测间充质细胞标记物α-平滑肌肌动蛋白(α-SMA)的表达。结果 Tet能抑制TGF-β1诱导α-SMA的表达,显著上调SnoN mRNA和蛋白的表达(P<0.01);Tet对TβRI表达、Smad2/3的磷酸化及Smad7的表达没有影响。结论 Tet能抑制人近端小管上皮细胞转分化,其机制与Tet上调SnoN表达有关。     

Smoothened表达对类风湿关节炎成纤维样滑膜细胞RhoA/ROCK通路的影响

目的初步探讨Sonic Hedgehog(Shh)信号通路分子Smoothened(Smo)对类风湿关节炎(RA)成纤维滑膜细胞(FLS)RhoA/ROCK通路相关分子的影响。方法收集病情活动(DAS28≥3.2)RA患者关节镜手术或关节置换术切除的滑膜组织,组织块培养法培养RA-FLS作为细胞模型,流式细胞术检测CD55阳性率鉴定细胞,然后分别予Smo分子激动剂Purmorphamine或抑制剂KAAD-Cyclopamine处理,应用GST-pull down法检测RhoA活性,Western blot检测ROCK活性与Smo蛋白表达。结果与对照组相比,RA-FLS经Purmorphamine刺激后,活性RhoA蛋白、磷酸化MYPT1蛋白及Smo蛋白均上调(P<0.05);经KAAD-Cyclopamine处理后,活性RhoA蛋白、磷酸化MYPT1蛋白及Smo蛋白均下调(P<0.05)。结论 RA-FLS Smo表达可影响RhoA/ROCK信号的传导。Smo可能参与了RA-FLS中Shh信号通路非经典途径的调控。     

高迁移率族蛋白B1对小鼠巨噬细胞细胞因子和黏附分子表达的影响

目的 观察高迁移率族蛋白B1(HMGB1)对小鼠腹腔巨噬细胞肿瘤坏死因子(TNF)-α、白细胞介素(IL)-10及细胞间黏附分子-1(ICAM-1)表达的影响.方法 分离小鼠腹腔巨噬细胞,经不同质量浓度(0、1、10、100、1000ng/ml)HMGB1的刺激,于不同时间点(0、6、12、24、48、72 h)采用实时荧光定量PCR方法测定细胞TNF-α、IL-10及ICAM-1 mRNA表达的变化,同时应用酶联免疫吸附试验检测细胞培养上清液中TNF-α、IL-10以及sICAM-1蛋白水平的变化.数据采用单因素方差分析.结果 1～1000 ng/ml的HMGB1作用24h,可使巨噬细胞的TNF-α、ICAM-1基因表达增加,与对照组比较差异具有统计学意义(P＜0.01),其中1000 ng/ml HMGB1的作用最强,呈剂量-效应关系.而IL-10仅在1000 ng/ml HMGB1作用时表达有所增加.以100 ng/ml的HMGB1作用不同时间后,培养上清液TNF-α与sICAM-1的浓度48 h达高峰(P＜0.01),呈时间-效应关系,HMGB1对巨噬细胞TNF-α的分泌呈"双峰"特征,而IL-10水平无明显变化.结论 一定浓度的HMGB1可诱导巨噬细胞合成、释放促炎细胞因子与黏附分子,具有显著的促炎特性.     

白介素-17对人宫颈腺癌细胞株HeLa体外增殖的影响

目的观察IL-17对人宫颈腺癌细胞株HeLa细胞体外增殖的影响,并探讨可能的机制。方法分别采用0、1、10、50、100 ng/ml的r IL-17刺激人宫颈腺癌HeLa细胞24小时,MTT法检测细胞增殖情况,根据筛选出的浓度进行后续实验。用r IL-17(0、50、100 ng/ml)刺激经饥饿诱导凋亡的细胞24小时,FCM法检测细胞凋亡情况;用r IL-17刺激细胞48小时,检测促血管生成因子VEGF mRNA和蛋白的表达量。结果 r IL-17刺激细胞一定时间后,1、10及100 ng/ml浓度组细胞增殖无明显变化,50 ng/ml组细胞增殖明显增加(P0.01);50 ng/ml组细胞的晚期凋亡率和总凋亡率较正常对照组均明显下降(P0.01;P0.05),100 ng/ml组细胞下降更为显著(P0.01);50 ng/ml和100 ng/ml两组细胞内VEGF mRNA和蛋白的表达量均升高,以50 ng/ml组最为明显(P0.05)。结论 IL-17可能通过抑制细胞凋亡及上调VEGF mRNA和蛋白水平的表达促进宫颈腺癌HeLa细胞体外增殖。     

APN/CD13对乌苯美司增强全反式维甲酸诱导急性早幼粒白血病细胞株NB4细胞分化的影响

本研究探讨细胞表面APN/CD13在乌苯美司(bestatin)增强全反式维甲酸(ATRA)诱导急性早幼粒细胞白血病(APL)细胞株NB4细胞分化过程中的作用.采用四氮唑蓝还原实验检测细胞分化;Western blot检测细胞P38MAPK及p-P38MAPK蛋白表达.结果显示:APN/CD13中和抗体WM-15能够完全阻断乌苯美司对ATRA诱导分化作用的增强效应.WM-15能够部分阻断乌苯美司抑制NB4细胞P38 MAPK磷酸化的作用.100μg/ml乌苯美司呈时间依赖性抑制APL细胞株NB4细胞及MR2细胞的P38MAPK磷酸化水平,l00 μg/ml乌苯美司对CD13表达低下的K562细胞的P38 MAPK磷酸化水平无明显影响.100μg/ml乌苯美司不能恢复MR2细胞及难治复发患者原代APL细胞对ATRA的敏感性.结论:氨肽酶N/CD13抑制剂乌苯美司可能通过细胞表面APN/CD13分子的介导抑制NB4细胞P38 MAPK的磷酸化,从而增强ATRA诱导NB4细胞分化的作用.     

雷公藤内酯醇抑制小鼠肾小球系膜细胞表达CXCL10的实验研究

目的探讨雷公藤内酯醇(triptolide,TPL)对γ干扰素(interferon-γ,IFN-γ)诱导的小鼠肾小球系膜细胞(SV40MES13)表达趋化因子CXCL10 m RNA的影响及其可能机制。方法将对数生长期SV40MES13随机分为空白组、刺激组、干预组,用不同浓度的IFN-γ(0U/ml~2000U/ml)刺激细胞不同时间(0h~48h)后,观察细胞表达CXCL10 m RNA的变化;用CCK-8法检测不同浓度(2ng/ml~20ng/ml)TPL对SV40MES13生存率的影响,选用细胞生存率大于90%的TPL用于后续实验,观察TPL对SV40MES13表达CXCL10 m RNA的影响;选用JAK/STAT信号通路特异性抑制剂AG490干预细胞,探讨IFN-γ是否通过JAK/STAT信号通路诱导CXCL10表达;收集以上细胞,用Real-Time PCR技术检测各组CXCL10 m RNA表达水平。结果 IFN-γ能诱导SV40MES13表达CXCL10 m RNA,并呈时间、剂量依赖性;AG490具有抑制IFN-γ诱导的SV40MES13表达CXCL10 m RNA;TPL具有抑制IFN-γ诱导的SV40MES13表达CXCL10 m RNA的作用。结论 IFN-γ可能通过激活JAK/STAT信号通路,诱导SV40MES13表达CXCL10 m RNA;TPL具有抑制IFN-γ诱导的SV40MES13表达CXCL10的作用。     

细菌脂蛋白耐受中核转录因子核转位机制研究

目的 探讨细菌脂蛋白(BLP)耐受所致核转录因子-κB(NF-κB)活化受抑制的分子机制.方法 以不同浓度BLP(10、100、1 000 ng/ml)预处理人急性单核细胞白血病细胞(THP-1)诱导BLP耐受,再以不同浓度BLP(0、10、100、1 000 ng/m1)刺激经BLP预处理(耐受组)或未经BLP预处理(对照组)的THP-1细胞,采用酶联免疫吸附法(ELISA)检测培养上清中肿瘤坏死因子-α(TNF-α)的释放,确定最适的BLP预处理和刺激浓度.然后按此条件处理细胞不同时间(0、0.5、1、2、6 h)并提取蛋白,用蛋白质免疫印迹法(Western blotting)检测NF-κB亚单位p50和p65的表达、核转位及磷酸化情况.结果 对照组中10、100、1 000 ng/mlBLP可剂量依赖性刺激THP-1活化并产生TNF-α(pg/ml:184.86±32.51、3 215.88±167.09、6 042.96±245.37),耐受组中100 ng/ml BLP预处理几乎完全抑制不同剂量BLP诱导的TNF-α释放.故最适BLP预处理浓度为100 ng/ml,刺激浓度为1 000 ng/ml.Western blotting检测表明,在BLP耐受的细胞质中p50蛋白表达明显高于对照组(0 h:542.9±15.6比272.8±13.2,0.5 h:558.0±16.9比236.4±11.8,1 h:524.7±17.5比211.6±9.8,2 h:584.9±15.6比222.4±12.3,均P＜0.01),而两组间p65蛋白无明显差异.BLP刺激还可诱导对照组细胞中p50和p65发生核转位,即细胞核中p50和p65蛋白增加(1 h p50:344.2±13.6比79.0±5.2,p65:78.4±4.5比0,均P＜0.05),而耐受组细胞核中p50和p65均无明显变化.另外,BLP刺激还可诱导对照组细胞中p65的536位丝氨酸发生快速磷酸化(0.5 h:0.67±0.08比0.04±0.01,1 h:0.71±0.11比0.04±0.01,均P＜0.05).但是在BLP刺激的耐受组细胞中磷酸化p65蛋白水平无明显变化.结论 BLP耐受的THP-1细胞中抑制性NF-κB亚单位p50表达上调,而具有转活化能力的亚单位p65的核转位及磷酸化均受到抑制,可能是BLP耐受中TNF-α等NF-κB依赖的基因表达减少的分子机制之一.

Abstract：

Objective To approach the nuclear factor-κB (NF-κB) nuclear translocation mechanism in bacterial lipoprotein (BLP) tolerance. Methods Human monocytic THP-1 cells were first pretreated with 10, 100, 1 000 ng/ml BLP for 20 hours to induce BLP tolerance. Then THP-1 cells without BLP pretreatment (control group) or with BLP pretreatment (tolerance group) were stimulated with 0, 10, 100,1 000 ng/ml BLP again for 6 hours. The tumor necrosis factor-α (TNF-α) content in culture medium was measured by enzyme linked immunosorbent assay (ELISA) in order to determine the most suitable BLP pretreatment and stimulation concentration. Western blotting was used to detect the protein level, nuclear translocation and phosphorylation of NF-ΚB p50 and p65 in the cells of control and tolerance groups treated with respective conditions for 0, 0.5, 1, 2 and 6 hours. Results In control group BLP stimulation (10,100, 1 000 ng/ml) could induce THP-1 activation and TNF-α production (pg/ml: 184.86 ± 32. 51,3 215. 88±167. 09, 6 042. 96±245. 37) in a dose-dependent manner. In tolerance group, 100 ng/ml BLP pretreatment resulted in almost complete inhibition of TNF-α production as induced by 10-1 000 ng/ml BLP stimulation. Therefore, 100 ng/ml BLP pretreatment and 1 000 ng/ml stimulation were selected for following cell treatment. Western blotting analysts showed that there was an increase of p50 protein level in BLP-tolerant cells comparing with control group (0 hour: 542. 9±15. 6 vs. 272. 8±13. 2, 0. 5 hour: 558. 0±16. 9 vs. 236. 4±11.8, 1 hour: 524. 7±17. 5 vs. 211. 6±9. 8, 2 hours: 584. 9±15. 6 vs. 222. 4±12. 3, all P＜0. 01), whereas the p65 protein level was similar between the two groups. BLP stimulation also induced the nuclear translocation of p50 and p65 in control group (1-hour p50: 344. 2±13. 6 vs. 79. 0±5. 2, p65:78. 4 ±4.5 vs. 0, both P＜0. 05), but not in tolerance group. In addition, the phosphorylation of p65 at serine 536 was induced after BLP stimulation in control THP-1 cells (0. 5 hour: 0. 67±0. 08 vs. 0. 04±0. 01,1 hour: 0.71±0.11 vs. 0.04±0.01, both P＜0.05), but this change was not detected in BLP-tolerant cells. Conclusion It was found that in BLP-tolerant cells, the expression of inhibitory subunit p50 was increased and the nuclear translocation and phosphorylation of p65 with trans-activation ability was inhibited.These changes are likely responsible for the reduced gene expression of NF-ΚB dependent genes in BLP-tolerant cells.     

The IL-6R alpha chain controls lung CD4+CD25+ Treg development and function during allergic airway inflammation in vivo

The cytokine IL-6 acts via a specific receptor complex that consists of the membrane-bound IL-6 receptor (mIL-6R) or the soluble IL-6 receptor (sIL-6R) and glycoprotein 130 (gp130). In this study, we investigated the role of IL-6R components in asthma. We observed increased levels of sIL-6R in the airways of patients with allergic asthma as compared to those in controls. In addition, local blockade of the sIL-6R in a murine model of late-phase asthma after OVA sensitization by gp130-fraction constant led to suppression of Th2 cells in the lung. By contrast, blockade of mIL-6R induced local expansion of Foxp3-positive CD4+CD25+ Tregs with increased immunosuppressive capacities. CD4+CD25+ but not CD4+CD25- lung T cells selectively expressed the IL-6R alpha chain and showed IL-6-dependent STAT-3 phosphorylation. Finally, in an in vivo transfer model of asthma in immunodeficient Rag1 mice, CD4+CD25+ T cells isolated from anti-IL-6R antibody-treated mice exhibited marked immunosuppressive and antiinflammatory functions. IL-6 signaling therefore controls the balance between effector cells and Tregs in the lung by means of different receptor components. Furthermore, inhibition of IL-6 signaling emerges as a novel molecular approach for the treatment of allergic asthma.     

Reduction of microemulsion propofol-induced injection pain via target-controlled remifentanil infusion

The intravenous injection of microemulsion propofol to induce anaesthesia causes more intense and frequent pain than lipid emulsion propofol. This study investigated whether different target effect-site concentrations of remifentanil could prevent pain due to microemulsion propofol injection. In total, 96 patients were randomly assigned to one of three groups receiving target effect-site concentrations of remifentanil 0 (control group), 4 or 6 ng/ml, followed by injection with microemulsion propofol. Remifentanil pretreatment significantly reduced the incidence and severity of injection pain compared with the control group. Although no difference in pain reduction between the two remifentanil-treated groups was observed, those receiving a target effect-site concentration of 6 ng/ml exhibited an increased rate of complications, compared with those receiving 4 ng/ml. In conclusion, prior administration of remifentanil at a target effect-site concentration of 4 ng/ml is a useful strategy to decrease the injection pain of microemulsion propofol.     

Thrombin stimulates tissue plasminogen activator release from cultured human endothelial cells

The effect of thrombin on the release of tissue plasminogen activator from endothelial cells was studied in primary cultures of human umbilical vein endothelial cells. Tissue plasminogen activator concentration in conditioned medium was measured by a two-site radioimmunometric assay. The addition of increasing concentrations (0.01 to 10 U/ml) of thrombin to confluent cultures produced a saturable, dose-dependent increase in the rate of release of tissue plasminogen activator. A sixfold increase in tissue plasminogen activator concentration (from 2 to 12 ng/ml) occurred after the addition of 1 U/ml thrombin (8 X 10(-9) M) to cultures containing 5 X 10(4) cells/cm2. Enhanced release was not observed until 6 h after thrombin addition, reached a maximum rate of 1.3 ng/ml per h between 8 and 16 h, and then declined to 0.52 ng/ml per h after 16 h. The 6-h lag period before increased tPA release was reproducible and independent of thrombin concentration. Thrombin inactivated with diisopropylfluorophosphate or hirudin did not induce an increase in tissue plasminogen activator levels. A 50-fold excess of diisopropylfluorophosphate-treated thrombin, which inhibits binding of active thrombin to endothelial cell high affinity binding sites, did not inhibit the thrombin-induced increase. It is concluded that proteolitically active thrombin causes an increase in the rate of release of tissue plasminogen activator from cultured human endothelial cells. The 6-h interval between thrombin treatment and enhanced tissue plasminogen activator release may reflect a delaying mechanism that transiently protects hemostatic plugs from the sudden increase in the local concentration of this fibrinolytic enzyme.     

Detection of receptors for interleukin-6, interleukin-11, leukemia inhibitory factor, oncostatin M, and ciliary neurotrophic factor in bone marrow stromal/osteoblastic cells.

The functional receptor complexes assembled in response to interleukin-6 and -11 (IL-6 and IL-11), leukemia inhibitory factor (LIF), oncostatin M (OSM), and ciliary neurotrophic factor (CNTF), all involve the signal transducer gp130: IL-6 and IL-11 induce homodimerization of gp130, while the rest heterodimerize gp130 with other gp130-related beta subunits. Some of these cytokines (IL-6, IL-11, and CNTF) also require a specificity-determining alpha subunit not directly involved in signaling. We have searched for functional receptor complexes for these cytokines in cells of the bone marrow stromal/osteoblastic lineage, using tyrosine phosphorylation of the beta subunits as a detection assay. Collectively, murine calvaria cells, bone marrow-derived murine cell lines (+/+LDA11 and MBA13.2), as well as murine (MC3T3-E1) and human (MG-63) osteoblast-like cell lines displayed all the previously recognized alpha and beta subunits of this family of receptors. However, individual cell types had different constellations of alpha and beta subunits. In addition and in difference to the other cell types examined, MC3T3-E1 cells expressed a heretofore unrecognized form of gp130; and MG-63 displayed an alternative form (type II) of the OSM receptor. These findings establish that stromal/osteoblastic cells are targets for the actions of all the members of the cytokine subfamily that shares the gp130 signal transducer; and suggest that different receptor repertoires may be expressed at different stages of differentiation of this lineage.     

Netrin-1在急性淋巴细胞白血病患者中的表达及意义

目的:研究Netrin-1蛋白在儿童急性淋巴细胞白血病(ALL)患者中的表达及其与临床指标的相关性,并探讨其可能的调控机制。方法:采用ELISA法检测48例ALL患儿(初诊、复发)外周血血清中Netrin-1的表达水平,并分析其与27例非恶性血液病患儿对照样本表达水平的差异,进而分析ALL外周血Netrin-1水平与临床指标的相关性。体外培养ALL细胞Jurkat、Molt-4、SUP-B15和Raji,经不同浓度重组人Netrin-1蛋白处理后,用Transwell法检测细胞的侵袭能力;CCK-8法测定Netrin-1对细胞增殖的作用;采用Western blot检测FAK、Erk1/2、PI3K、Akt等信号通路关键蛋白的表达及其磷酸化水平。结果:ALL患儿外周血中Netrin-1的表达量显著高于对照组(P<0.05)。随着Netrin-1表达水平的上调,WBC水平(r=-0.290,P<0.05)呈下降趋势,Plt水平(r=0.483,P<0.05)呈上升趋势,且与年龄、Hb水平、骨髓幼稚细胞比例无显著相关性;Netrin-1浓度在25-50 ng/ml水平时,Netrin-1水平与WBC(r=0.886,P<0.05)呈正相关;WBC>50×10^9/L和Plt<20×10^9/L的患儿Netrin-1表达水平显著降低(P=0.042,P=0.001);Netrin-1的表达水平在危险度分级中具有显著性差异(P=0.017),与低危组与中危组相比,高危组Netrin-1的表达水平显著提高;Netrin-1在性别、肝脾淋巴结肿大、MRD、复发、染色体异常等分组中的表达水平均无显著性差异;Netrin-1对4种细胞的侵袭能力有促进作用(P<0.05),随着Netrin-1浓度的提高,细胞数有先增加后降低的趋势,且均在Netrin-1浓度为100 ng/ml时,侵袭下室的细胞数最高;Netrin-1浓度为25 ng/ml时,4种细胞存活率显著增加(P<0.05),其中SUP-B15细胞在浓度为100 ng/ml时,细胞存活率最高;4种细胞存活率呈现低浓度升高及高浓度降低的趋势;Western blot结果显示,Netrin-1使FAK、Erk1/2、PI3K、Akt等信号通路关键分子磷酸化水平提高(P<0.05)。结论:ALL患儿血清中存在Netrin-1的异常表达,Netrin-1可能通过增加白血病细胞的增殖、侵袭能力来影响ALL的发生发展,可能成为ALL的危险因素或生物治疗中的潜在靶点。     

遗传性蛋白C缺陷症家系的一个基因突变

目的 研究一个遗传性蛋白C（PC）缺陷症家系的遗传表型及基因特征。方法 PC活性用凝固法测定，PC抗原用ELISA方法测定。用PCR扩增2代家系12个成员中4个PC活性及抗原减低的PCⅡ-Ⅸ号外显子片段，用单链构象多态性（SSCP）分析cDNA变性后的差异，用测序法检测突变点。用限制性酶切验证突变点，同时分析家系的基因型。结果 该家系2代4名成员PC抗原水平在34．3％－67．8％（参考值80％－120％）。PC活性在22％－49％（参考值70％－130％），较正常参考范围明显减低。限制性酶切分析该家系12名成员时发现9名成员存在基因的突变。基因突变位点在Ⅶ号外显子第6219位核苷酸G→A突变，使正常编码的CGG精氨酸突变为CAG谷氨酰胺。结论 该家系为I型PC缺陷症，基因分析证明先证为杂合子型。在PCⅦ号外显子上第6219位核苷酸G→A突变，在蛋白质合成过程中第169位精氨酸被谷氨酰胺替代（R→Q），为目前国内献中尚未报道的一个基因突变点。     

Interleukin 7 induces cytokine secretion and tumoricidal activity by human peripheral blood monocytes

Peripheral blood monocytes can be induced by stimuli such as bacterial lipopolysaccharide (LPS) to secrete an array of cytokines. We have studied the effects of interleukin 7 (IL-7) on human peripheral blood mononuclear cells (PBMC) and found that IL-7 is a relatively potent inducer of IL-6 secretion IL-6 protein levels were determined either by the B9 hybridoma growth factor assay or by enzyme-linked immunosorbent assay, and mRNA for IL-6 was analyzed by Northern hybridization. Detailed examination revealed that, among PBMC, monocytes, rather than lymphocytes, were secreting IL-6 in response to IL-7. In contrast to the low concentrations of IL-7 required to stimulate T cell growth and differentiation (as low as 0.1 ng/ml), relatively high concentrations of IL-7 were necessary to induce IL-6 secretion by monocytes (at least 10 ng/ml). An optimal concentration of IL-7 (100 ng/ml) induced monocytes to secrete 10-fold more IL-6 than an optimal concentration of IL-1 beta (10 ng/ml), and almost as much as LPS. However, significantly more IL-7 than IL-1 beta was required to induce detectable levels of IL-6. The kinetics of IL-6 secretion by monocytes were identical in response to IL-7, IL-1 beta, or LPS, with IL-6 protein detectable in culture supernatants as early as 2 h after the initiation of culture. IL-4 was found to markedly inhibit the ability of IL-7 or LPS to induce IL-6 mRNA and IL-6 secretion. In addition to promoting IL-6 production, IL-7 induced the secretion of immunoreactive IL-1 alpha, IL-1 beta, and tumor necrosis factor alpha (TNF-alpha) by monocytes. IL-7 also induced monocyte/macrophage tumoricidal activity against a human melanoma cell target, an activity that may be related to the secretion of IL-1 alpha, IL-1 beta, and TNF-alpha. Finally, we used a whole blood culture system as a bridge to in vivo analysis to demonstrate that IL-7 induces cytokine secretion in the absence of culture medium, fetal calf serum, and adherence to plastic. Our data suggest that IL-7, in addition to regulating lymphocyte growth and differentiation, has potent effects on cells of the monocytic lineage. Thus, IL-7 may be an important mediator in inflammation and in the macrophage immune response to tumors.     

Ciliary neurotropic factor, interleukin 11, leukemia inhibitory factor, and oncostatin M are growth factors for human myeloma cell lines using the interleukin 6 signal transducer gp130

Interleukin 6 (IL-6) is a major growth factor for tumor plasma cells involved in human multiple myeloma (MM). In particular, human myeloma cell lines (HMCL), whose growth is completely dependent on addition of exogenous IL-6, can be obtained reproducibly from every patient with terminal disease. Four cytokines, ciliary neurotropic factor (CNTF), IL- 11, leukemia inhibitory factor (LIF), and oncostatin M (OM), use the same transducer chain (signal transducer gp130) as IL-6 and share numerous biological activities with this IL. We found that these four cytokines stimulated proliferation and supported the long-term growth of two out of four IL-6-dependent HMCL obtained in our laboratory. Half- maximal proliferation was obtained with cytokine concentrations ranging from 0.4 to 1.2 ng/ml for IL-11, LIF, and OM. CNTF worked at high concentrations only (90 ng/ml), but addition of soluble CNTF receptor increased sensitivity to CNTF 30-fold. The growth-promoting effect of these four cytokines was abrogated by anti-gp130 antibodies, contrary to results for anti-IL-6 receptor or anti-IL-6 antibodies. No detectable changes in the morphology and phenotype were found when myeloma cells were cultured with one of these four cytokines instead of IL-6. Concordant with their IL-6-dependent growth, the four HMCL expressed membrane IL-6R and gp130 detected by FACS analysis. LIF- binding chain gene (LIFR) was expressed only in the two HMCL responsive to LIF and OM.