肿瘤坏死因子受体在肾小球系膜细胞中的基因表达及蛋…

探讨肿瘤坏死因子α对肾小球系膜细胞作用和机理。方法逆转录－多聚酶链反应、原位杂交和免疫组织化学方法检测培养大鼠和ＭＣ肿瘤坏死因子Ⅰ型受体的基因表达及蛋白合成；原位杂交方法观察５例系膜增生性肾小球肾炎肾穿刺组织的ＴＮＦ－Ｒ１基因表达。结论：ＴＮＦ－α通过与ＭＣ表面特异性受体相结合而发挥作用。     

糖皮质激素受体对肾小球系膜细胞表达细胞间黏附分子-1的影响

近年来免疫病理学研究已经证实细胞间黏附分子１（ＩＣＡＭ１）作为细胞黏附分子中免疫球蛋白超家族成员之一,通过与炎性细胞表面同族型配体之间相互作用形成黏附,在免疫监督、炎症反应、吞噬过程、动脉粥样硬化等过程中起着重要的作用［１,２］。目前证实,肾小球系膜细胞（ＭＣ）表面低表达ＩＣＡＭ１,而细胞因子白细胞介素１β（ＩＬ１β）、肿瘤坏死因子α（ＴＮＦα）、干扰素γ（ＩＦＮγ）等刺激并上调系膜细胞表达ＩＣＡＭ１。本研究目的是进一步探讨糖皮质激素（ＧＣ）,如氟美松（Ｄｅｘ）对ＴＮＦα诱…     

5—FU,TNF和干扰素联合诱导结肠癌细胞凋亡的实验研究

目的　观察联合应用５ＦＵ、天然人体肿瘤坏死因子α（ｎＨｕ ＴＮＦα） 和天然人体干扰素α（ｎＨｕ ＩＦＮα）诱导ＲＰＭＩ４７８８ 人体结肠癌细胞凋亡。方法　应用ＢＭ１／ＪＩＭＲＯ抗ＬｅＹ 小鼠ＩｇＭ 单克隆抗体（ＢＭ１ Ｍａｂ） ,以免疫组织化学方法进行检测。结果　与对照组相比,应用５ＦＵ、ｎＨｕ ＴＮＦα或／和ｎＨｕＩＦＮα处理２４ ～４８ｈ 后,ＢＭ１ Ｍａｂ 染色阳性细胞数明显增多,且具有时间依存性和剂量敏感性。结论　联合应用５ＦＵ、ｎＨｕ ＴＮＦα和ｎＨｕ ＩＦＮα具有协同诱导ＲＰＭＩ４７８８ 肿瘤细胞凋亡的作用。     

类风湿关节炎病人血清细胞因子水平以及与炎症指标的相关性

目的：进一步研究细胞因子在类风湿关节炎（ＲＡ）中的作用以及与疾病的关系。方法：随机就诊的７２名门诊及住院ＲＡ病人红细胞沉降率（ＥＳＲ）、Ｃ反应蛋白（ＣＲＰ）以及细胞因子白细胞介素１α（ＩＬ１α）、ＩＬ１β、ＩＬ２、ＩＬ６、肿瘤坏死因子α（ＴＮＦα）、粒细胞单核细胞集落刺激因子（ＧＭＣＳＦ）被测定。全部数据用于ＲＡ病人细胞因子水平的研究，并对细胞因子与炎症指标的相关性进行探讨。结果：ＲＡ病人血清ＧＭＣＳＦ、ＴＮＦα水平较健康对照组明显增高（Ｐ＜０００１）。ＩＬ６、ＧＭＣＳＦ与炎性指标ＥＳＲ（ｒ＝０２６，Ｐ＜００１；ｒ＝０２８，Ｐ＜００２）和ＣＲＰ（ｒ＝０４０，Ｐ＜００００１；ｒ＝０４７，Ｐ＜００００１）呈正相关。结论：ＲＡ病人血清ＩＬ６、ＧＭＣＳＦ、ＴＮＦα较其他细胞因子与ＲＡ疾病有更密切的相关性。细胞因子作为重要的免疫物质参与炎症反应在ＲＡ的病理过程中起到了重要作用。     

局灶性脑缺血后再灌注损伤的炎症机制与治疗前景

溶栓治疗血循环重建后中性白细胞聚集至缺血区（炎症的第１步）涉及多种蛋白,包括内皮细胞（ＥＣ）和白细胞上调细胞间粘附分子１（ＩＣＡＭ１）和整合素,肿瘤坏死因子α（ＴＮＦα）、白介素１（ＩＬ１）和血小板活化因子（ＰＡＦ）也参与了白细胞聚集和活化。干预这些因子的功能有望减轻再灌注损伤,减小梗死范围,成为溶栓疗法的辅助疗法。     

2型糖尿病患者血清白细胞介素-6、肿瘤坏死因子-α水平与T细胞亚群变化的研究

近年研究表明,糖尿病患者体液和细胞免疫均明显异常〔１〕,其血清白细胞介素６（ＩＬ６）、肿瘤坏死因子α（ＴＮＦα）有异常表达〔２,３〕,但其与Ｔ细胞亚群的关系尚未见报道。为此,我们检测了５８例２型糖尿病患者血清ＩＬ６、ＴＮＦα水平及Ｔ细胞亚群（ＣＤ３、ＣＤ４、ＣＤ８）的变化,以探讨其相关性及意义。一、对象和方法１．对象：２型糖尿病组５８例,系住院患者,符合１９８５年ＷＨＯ糖尿病诊断标准,男２８例,女３０例,年龄（５６．５±１０．１）岁,病程（５．７±３．９）年。正常对照组３６名,系正常…     

强力宁对慢性肝炎患者IL—6及TNF—α的影响

强力宁对慢性肝炎患者ＩＬ６及ＴＮＦα的影响李昌平刘厚钰胡德昌侯健周康强力宁主要成分为甘草甜素，具有多种免疫调节作用，但作者尚未见对慢性肝炎（ＣＨ）患者白介素６（ＩＬ６）、肿瘤坏死因子α（ＴＮＦα）影响的报道。我们观察强力宁对ＣＨ患者血清及...     

胃炎患者胃窦IL-6活性和TNF-а含量的检测

目的：探讨幽门螺杆菌（Ｈｐ）感染对胃粘膜白细胞介素６（ＩＬ６）和肿瘤坏死因子（ＴＮＦ）产生的影响及ＩＬ６和ＴＮＦα在Ｈｐ相关性胃炎发病机理中的作用。方法：用生物活性法和放免法检测慢性胃炎患者粘膜体外培养２４小时后ＩＬ６和ＴＮＦα的水平。结果：Ｈｐ阳性胃炎患者胃窦ＩＬ６活性和ＴＮＦα含量均明显高于Ｈｐ阴性的患者和正常对照组；且ＩＬ６活性和ＴＮＦα含量呈正相关。合并活动性胃炎者胃窦ＴＮＦα含量也明显高于非活动性胃炎，但两者胃窦ＩＬ６活性却没有明显的差异。结论：Ｈｐ感染可诱导胃粘膜的炎症细胞合成和释放ＩＬ６和ＴＮＦα，可能参与了Ｈｐ相关性胃炎的病理过程     

冠心病肿瘤坏死因子和可溶性肿瘤坏死因子受体活性

本研究旨在通过测定冠心病患者血清肿瘤坏死因子（ＴＮＦα）和可溶性肿瘤坏死因子受体（ＳＴＮＦＲⅡ）以探讨其在冠心病发病中的意义。１对象和方法冠心病患者３０例,男性２４例,女性６例,平均年龄５９．８±１４．０岁;正常对照者３０例,男性２４例,女性６例...     

胃癌患者血清sICAM-1,sVCAM-1水平的研究

ＩＣＡＭ１（ＣＤ５４）和ＶＣＡＭ１均属于免疫球蛋白（Ｉｇ）超家族成员,其表达对炎性细胞因子ＩＬ１、ＩＦＮγ、ＴＮＦα的诱导高度敏感［１,２］。它们的配体分别为ＬＦＡ１（ＣＤ１１ａ）、ＭＡＣ１（ＣＤ１１ｂ）和ＶＬＡ４。ＩＣＡＭ１有５个...     

Regulation of hepatic stellate cell proliferation and collagen synthesis by proteinase-activated receptors

BACKGROUND/AIMS: Thrombin and MC tryptase, which are agonists for proteinase-activated receptors-1 and -2, respectively, are both increased in injured liver. We have examined if rat stellate cells express these receptors and if receptor agonists influence stellate cell activation. METHODS: Expression of mRNA for proteinase activated receptors-1 and -2 were examined by RT-PCR and Northern blotting in lysates of cultured stellate cells and receptor protein examined by Western blotting. The effects of receptor agonists on cell proliferation and collagen synthesis were examined by 3H-thymidine and 3H-proline incorporation assays, respectively. RESULTS: Rat stellate cells activated by culture on plastic showed a progressive increase in expression of proteinase-activated receptor-1 and -2 mRNA and proteinase-activated receptor-2 protein as they transformed to a myofibroblastic phenotype. Proteinase-activated receptor-1 agonists thrombin and the peptide SFFLRN, and proteinase-activated receptor-2 agonists tryptase and the peptide SLIGRL induced stellate cell proliferation and the rapid phosphorylation of 44 and 42 kDa mitogen-activated protein kinases. PD98059, an inhibitor of these kinases, inhibited this proliferative response. Both tryptase and SLIGRL increased collagen secretion by stellate cells. CONCLUSIONS: This study indicates that the natural proteinase-activated receptor agonists thrombin and MC tryptase might sustain liver fibrosis by promoting stellate cell proliferation and collagen synthesis.     

Activation of human synovial mast cells from rheumatoid arthritis or osteoarthritis patients in response to aggregated IgG through Fcγ receptor I and Fcγ receptor II

Objective

Substantial evidence suggests that human synovial mast cells (MCs) are involved in the pathogenesis of rheumatoid arthritis (RA). A plausible pathway for the activation of synovial MCs is through IgG receptors, given the prevalence of circulating IgG isotype autoantibodies and synovial immune complexes in patients with RA. However, IgG receptor expression on human synovial MCs remains uncharacterized. The aim of this study was to identify which IgG receptor(s) on synovial MCs are responsible for MC activation in immune complexes.

Methods

Synovial tissue specimens were obtained from patients with RA or patients with osteoarthritis (OA) who were undergoing joint replacement surgery, and synovial MCs were enzymatically dispersed. Cultured synovium‐derived MCs were generated by culturing synovial cells with stem cell factor, and receptor expression was analyzed using fluorescence‐activated cell sorting. Mediators released from MCs were measured using enzyme immunoassays or enzyme‐linked immunosorbent assays.

Results

Primary synovial MCs and cultured synovium‐derived MCs obtained from both patients with RA and patients with OA expressed Fcε receptor I (FcεRI), FcγRI, and FcγRII but not FcγRIII. Cultured synovium‐derived MCs induced degranulation and the production of prostaglandin D₂ and tumor necrosis factor α (TNFα) through FcγRI. The aggregation of FcγRII caused histamine release from cultured MCs but not from primary MCs. Histamine release induced by aggregated IgG was significantly inhibited by neutralizing anti‐FcγRI monoclonal antibody and anti‐FcγRII monoclonal antibody.

Conclusion

With regard to the FcR expression profile, synovial MCs from patients with RA and patients with OA were similar. FcγRI was responsible for producing abundant TNFα from synovial MCs in response to aggregated IgG. Immune complexes may activate synovial MCs through FcγRI and FcγRII.

     

Paracrine hypertrophic factors from cardiac non-myocyte cells downregulate the transient outward current density and Kv4.2 K+ channel expression in cultured rat cardiomyocytes.

OBJECTIVES: Cardiac hypertrophy is characterized by a prolongation of action potential duration (APD) and a reduction of outward K+ currents, primarily the transient outward current (Ito). Since the interaction between cardiac non-myocyte cells (NMCs) and cardiomyocytes (MCs) plays a critical role during the process of myocardial hypertrophy, in the present study, we investigated the effects of NMCs on cell growth and K+ channel expression in cultured newborn rat ventricular cells. METHODS: Single MCs were isolated from day-old Wistar rat ventricles and cultured for a period of five days. The effects of NMCs were examined by MC-NMC co-culture or incubating pure MCs in NMC-conditioned growth medium (NCGM). Whole-cell voltage-clamp recording and Western blot analysis using a polyclonal antibody against rat Kv4.2 channel protein were performed. RESULTS: A marked increase in surface area and total cell protein concentration of MCs was observed in the MC-NMC co-culture. In the pure MC culture, this hypertrophic effect could be mimicked by a 72-h addition of NCGM, with a significant prolongation of APD25 (APD at 25% repolarization) and a 42% decrease in Ito density (at +30 mV). The rates of inactivation and recovery from inactivation of Ito were unchanged. In the NCGM-treated MC culture, Western blots of MC proteins also showed a 36% reduction of the Kv4.2 K+ channel protein level. In addition, the NCGM-induced MC hypertrophy was partially inhibited by anti-insulin-like growth factor-1 (IGF-1) antibody, while it revealed no effects on Ito density and Kv4.2 channel expression. CONCLUSIONS: These findings first demonstrate that some paracrine hypertrophic factors released from cardiac NMCs, although unidentified, downregulate cardiac K+ channel expression.     

3-Hydroxy-3-methylglutaryl CoA reductase inhibitors prevent high glucose-induced proliferation of mesangial cells via modulation of Rho GTPase/ p21 signaling pathway: Implications for diabetic nephropathy

Inhibitors of 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) reductase, also known as statins, are lipid-lowering agents widely used in the prevention of coronary heart disease. Recent experimental and clinical data, however, indicate that the overall benefits of statin therapy may exceed its cholesterol-lowering properties. We postulate that statins may ameliorate the detrimental effects of high glucose (HG)-induced proliferation of mesangial cells (MCs), a feature of early stages of diabetic nephropathy, by preventing Rho isoprenylation. Rat MCs cultured in HG milieu were treated with and without simvastatin, an HMG-CoA reductase inhibitor. Simvastatin inhibited HG-induced MC proliferation as measured by [(3)H]thymidine incorporation. This inhibitory effect was reversed with geranylgeranyl pyrophosphate, an isoprenoid intermediate of the cholesterol biosynthetic pathway. At the cell-cycle level, the HG-induced proliferation of MCs was associated with a decrease in cyclin dependent kinase (CDK) inhibitor p21 protein expression accompanied by an increase in CDK4 and CDK2 kinase activities. Simvastatin reversed the down-regulation of p21 protein expression and decreased CDK4 and CDK2 kinase activities. Exposure of MCs to HG was associated with an increase in membrane-associated Ras and Rho GTPase protein expression. Cotreatment of MCs with simvastatin reversed HG-induced Ras and Rho membrane translocation. Immunofluorescence microscopy revealed that the overexpression of the dominant-negative RhoA led to a significant increase in p21 expression. Our data suggest that simvastatin represses the HG-induced Rho GTPase/p21 signaling in glomerular MCs. Thus, this study provides a molecular basis for the use of statins, independently of their cholesterol-lowering effect, in early stages of diabetic nephropathy.     

血管紧张素Ⅱ及其受体拮抗剂对心肌细胞肥大的影响

目的观察血管紧张素Ⅱ（AngⅡ）、AT1受体拮抗剂氯沙坦和AT2受体拮抗剂PD123177对心肌细胞蛋白质合成速率和AT1受体mRNA表达的影响。方法采用3H-亮氨酸掺入法测定培养的心肌细胞蛋白质合成速率,RT-PCR方法检测心肌细胞AT1受体mRNA表达。结果在培养的心肌细胞中加入AngⅡ可明显增加心肌细胞3H-亮氨酸的掺入量,并呈剂量依赖性,氯沙坦可显著抑制AngⅡ引起的蛋白质合成增加,而PD123177对其无影响;AngⅡ上调AT1受体基因表达,氯沙坦抑制其上调,PD123177无影响。结论AngⅡ可通过上调AT1受体引起心肌细胞肥大,氯沙坦下调AT1受体,抑制心肌细胞肥大。     

高糖诱导的大鼠肾小球系膜细胞中eNOS/NO的变化及调节机制研究

目的:探讨高糖条件下大鼠肾小球系膜细胞(GMCs)中内皮一氧化氮合酶一氧化氮(eNOS/NO)的变化及可能的调节机制.方法:将大鼠GMCs常规培养在含5.5 mmol/L葡萄糖的RPMIl640培养液中,用胰蛋白酶-乙二胺四乙酸(EDTA)混合消化酶传代.用RT、实时-PCR和Western blot测定GMCs中eN...     

Expression of vascular endothelial growth factor in response to high glucose in rat mesangial cells

Diabetic nephropathy associated with hyperglycemia is characterized by glomerular hyperfiltration and endothelial dysfunction. Vascular endothelial growth factor (VEGF) is known to be primarily involved in neoangiogenesis and increased endothelial permeability. The purpose of this study was to investigate VEGF expression in response to high glucose in rat cultured mesangial cells and to identify its signal pathway via protein kinase C (PKC). Rat mesangial cells were cultured with different concentrations of glucose: normal (5 mM d-glucose), medium (15 mM d-glucose) and high (30 mm d-glucose). Calphostin-C as a PKC inhibitor and phorbol myristate acetate (PMA) as a PKC downregulator were instillated into culture media to evaluate the role of PKC in mediating the glucose-induced increase in VEGF expression. High glucose increased expression of VEGF at the mRNA and protein levels, identified by semi-quantitative RT-PCR and western blotting, within 3 h and in a time- and glucose concentration-dependent manner. Calphostin-C and PMA inhibited glucose-induced increases in VEGF expression at the mRNA and protein levels. In conclusion, high glucose can directly increase VEGF expression in rat mesangial cells via a PKC-dependent mechanism. These results suggest that VEGF could be a potential mediator of glomerular hyperfiltration and proteinuria in diabetic nephropathy.     

大黄素对SV－40转基因小鼠系膜细胞生长和c－mycmRNA表达的影响

利用从ＳＶ－４０病毒转基因小鼠肾脏分离得到的系膜细胞株（ＳＶ－４０ＭＣ），观察了大黄素对ＳＶ－４０和ＭＣ生长、增殖细胞核抗原（ＰＣＮＡ）及原癌基因ｃ－ｍｙｃｍＲＮＡ表达的影响，大黄素可明显抑制ＳＶ－４０ＭＣ３Ｈ－ＴｄＲ掺入且与剂量呈正相关。经大黄素（５μｇ／ｍｌ）作用的ＳＶ－４０ＭＣ，ＰＣＮＡ阴性细胞数明显高于对照（２８％ｖｓ。５．５％、ｐ＜０．００１）大黄素同样抑制ＳＶ－４０ＭＣ，ｃ－ｍｙｃｍＲＮＡ表达，且不受蛋白合成抑制剂放线菌酮的影响。结果表明：大黄素对异常增殖状态的系膜细胞生长也有明确抑制作用，细胞分裂周期受抑制、此过程与细胞周期基因ｃ－ｍｙｃ表达受抑有关。