NF-κB通路在单核细胞诱导肾小管上皮细胞转分化中的作用

目的 观察单核细胞（U937细胞）对人近端肾小管上皮细胞（HK-2细胞）转分化的影响及其分子机制。 方法 将HK-2细胞与人单核细胞系U937细胞共培养;倒置相差显微镜观察HK-2细胞形态;Western印迹、实时荧光定量PCR法检测α平滑肌肌动蛋白（α-SMA）、纤连蛋白（FN）、E钙黏蛋白（E-cadherin）和胞间黏附分子1（ICAM-1）表达;BCECF-AM荧光染色法测定单核细胞黏附;流式细胞仪法检测HK-2细胞表面分子ICAM-1表达;基因芯片筛选HK-2细胞基因变化;利用信号阻断剂阻断基因芯片筛选出的信号通路,进一步验证单核细胞诱导肾小管上皮细胞转分化的分子机制。 结果 单核细胞可直接诱导HK-2细胞发生形态变化,减少HK-2细胞E-cadherin表达（均P < 0.05）,并上调α-SMA、FN表达（均P < 0.05）。应用CD18抗体阻断CD18-ICAM-1可抑制单核细胞黏附及其诱导的HK-2细胞形态变化。基因芯片结果显示,NF-κB信号通路分子CC亚族趋化因子配体20（CCL20）、白细胞介素（IL）2、IL-8、脂磷壁酸（LTA）及血小板内皮细胞黏附分子1（PECAM1）表达明显增加（均P < 0.05）。NF-κB信号阻断剂吡咯烷二硫氨基甲酸（PDTC）能显著抑制HK-2细胞形态变化及表面ICAM-1表达,抑制单核细胞诱导的肾小管上皮细胞转分化。 结论 单核细胞通过CD18分子与HK-2细胞表面ICAM-1结合,从而启动NF-κB信号通路介导的特定基因转录,最终导致肾小管上皮细胞发生转分化。     

阻断IgG-Fcγ受体结合的短肽对粒细胞与内皮细胞黏附及内皮细胞细胞间黏附分子1表达的影响

目的 观察阻断IgG-FcγR结合的短肽tg19320对粒细胞与内皮细胞黏附以及内皮细胞细胞间黏附分子1（ICAM-1）表达的影响，并探讨其作用机制。 方法 培养人脐静脉内皮细胞（HUVEC）。提纯活动期血管炎患者血清抗中性粒细胞胞质抗体（ANCA） IgG。以多肽固相合成tg19320。分离健康人新鲜外周血中性粒细胞。分别以肿瘤坏死因子α（TNF-α）、健康人IgG、ANCA IgG及ANCA IgG+tg19320处理HUVEC，用细胞直接计数法检测粒细胞与内皮细胞间的黏附率；应用Western印迹及实时定量PCR方法检测HUVEC ICAM-1蛋白和mRNA表达；ELISA检测细胞培养上清液中可溶性ICAM-1（sICAM-1）的水平；Western印迹检测HUVEC磷酸化核因子κB抑制物（p-IκB）的表达。 结果 ANCA IgG显著上调中性粒细胞与内皮细胞间的黏附率（P ＜ 0.05），但ANCA IgG+tg19320组较ANCA IgG组黏附率显著降低（P ＜ 0.05）。ANCA IgG组与健康人IgG组相比，HUVEC ICAM-1 mRNA及蛋白表达显著增加（P ＜ 0.05）。tg19320分别从mRNA和蛋白水平阻断ANCA对ICAM-1的作用（P ＜ 0.05），并显著降低ANCA IgG引起的细胞培养上清液中sICAM水平增高（P ＜ 0.05）。ANCA IgG增加HUVEC p-IκB表达，tg19320显著降低p-IκB的表达。 结论 tg19320通过抑制IκB磷酸化进而干预NF-κB活化；抑制ANCA IgG对内皮细胞与中性粒细胞间黏附的促进作用，并阻断ICAM-1上调表达。短肽tg19320对原发性小血管炎具有体外保护作用。     

血红素加氧酶-1对TNF-α引起内皮细胞炎症损伤的保护作用

目的探讨血红素加氧酶-1(HO-1)在肿瘤坏死因子-α(TNF-α)导致肺微血管内皮细胞损伤中的保护作用。方法采用TNF-α刺激人肺微血管内皮细胞(HPMECs)模拟重症急性胰腺炎肺损伤的体外模型,锌原卟啉-IX(ZNPP-IX)作为HO-1抑制剂预处理细胞。试验分为对照组、TNF-α组、ZNPP-IX组。CCK8比色法检测细胞活性,采用Western blotting法及RT-PCR法检测HO-1、细胞间黏附分子-1(ICAM-1)的表达,黏附试验检测HPMECs对多形核细胞(PMN)的黏附力。结果 1与对照组相比,TNF-α组(78.69%±5.54%)、ZNPP-IX组(62.00%±4.27%)细胞活性明显降低(P0.01);2与对照组相比,TNF-α组(1.59±0.19)HO-1表达增高(P0.05),ZNPP-IX组(0.01±0.01)比TNF-α组显著降低(P0.01);3与对照组相比,TNF-α组(32.72±0.95)、ZNPP-IX组(85.33±2.37)ICAM-1表达明显升高(P0.01),且ZNPP-IX组比TNF-α组更显著(P0.01);4TNF-α引起HPMECs对PMN黏附力增高,抑制HO-1表达后,黏附作用增强。结论 HO-1可能通过下调ICAM-1的表达降低炎症时HPMECs对PMN的黏附,从而改善重症急性胰腺炎引起的肺损伤。     

Effect of intercellular adhesion molecule-1 and hyaluronic acid on monocyte-renal tubular epithelial cell adhesion induced by tumor necrosis factor α

Objective To investigate the effect of tumor necrosis factor ot (TNF-α) on monocyte-renal tubular epithelial cell adhesion and to explore its associated mechanism. Methods Human renal proximal tubular epithelial cell line (HK2 cells)and monocyte cell line (U937)were used to perform cell co-culture. TNF-α (10 μg/L)was used to stimulate HK2 cells and then U937 was put into the HK2 monolayers. Three locational parts of hyaluronan around HK2 cells were extracted by different ways and the HA expression was detected by enzyme-linked binding protein assay. Monocyte adhesion was detected by florescence recording assay. Flow cytometry was applied to assess intercellular adhesion molecule-1 (ICAM-1) expression in HK2 cells. Results Stimulation of HK2 cells with TNF-α significantly increased U937 binding to HK2 cell monolayer [(2.25±0.05) folds vs control, P<0.01]. Incubation of TNF-α (10 μg/L) with HK2 cells for 24 hours did not induce the change of total HA expression surrounding the HK2 cells, whereas HA redistribution happened with conditioned medium fraction (CM-HA) increased [(1.17±0.16) fold vs control, P<0.05], the pericellular fraction (trypsin extract fraction, TE-HA) decreased (83%±11% vs control, P<0.05) and the remaining cells-associated HA (cell associated fraction, CA) did not change significantly. In addition, pre-treatment of HK2 cells with TNF-α significantly increased the ICAM-1 expression [(1.85±0.22) folds vs control, P<0.01] and ICAM-1-dependent monocytes binding. Removal of HA from the surface of confluent monolayers of HK2 cells by hyaluronidase before addition of U937 cells increased monocyte binding[ (1.35±0.06) folds vs control, P<0.05]. In contrast, the presence of either sICAM-1 (400 μg/L) or anti-CDI8 antibody (10 mg/L) led to a significant decrease in ICAM-1-dependent monocyte binding (78%±7%, P<0.05; 75%±8%, P<0.01 vs those before adding sICAM-1 or anti-CD18 antibody, respectively). Conclusion HA redistribution induced by TNF-α may facilitate ICAM-1-dependent monocyte-epithelium binding, and pericellular HA plays a protective role in monocyte-driven tissue inflammation.     

Effect of intercellular adhesion molecule-1 and hyaluronic acid on monocyte-renal tubular epithelial cell adhesion induced by tumor necrosis factor α

Objective To investigate the effect of tumor necrosis factor ot (TNF-α) on monocyte-renal tubular epithelial cell adhesion and to explore its associated mechanism. Methods Human renal proximal tubular epithelial cell line (HK2 cells)and monocyte cell line (U937)were used to perform cell co-culture. TNF-α (10 μg/L)was used to stimulate HK2 cells and then U937 was put into the HK2 monolayers. Three locational parts of hyaluronan around HK2 cells were extracted by different ways and the HA expression was detected by enzyme-linked binding protein assay. Monocyte adhesion was detected by florescence recording assay. Flow cytometry was applied to assess intercellular adhesion molecule-1 (ICAM-1) expression in HK2 cells. Results Stimulation of HK2 cells with TNF-α significantly increased U937 binding to HK2 cell monolayer [(2.25±0.05) folds vs control, P<0.01]. Incubation of TNF-α (10 μg/L) with HK2 cells for 24 hours did not induce the change of total HA expression surrounding the HK2 cells, whereas HA redistribution happened with conditioned medium fraction (CM-HA) increased [(1.17±0.16) fold vs control, P<0.05], the pericellular fraction (trypsin extract fraction, TE-HA) decreased (83%±11% vs control, P<0.05) and the remaining cells-associated HA (cell associated fraction, CA) did not change significantly. In addition, pre-treatment of HK2 cells with TNF-α significantly increased the ICAM-1 expression [(1.85±0.22) folds vs control, P<0.01] and ICAM-1-dependent monocytes binding. Removal of HA from the surface of confluent monolayers of HK2 cells by hyaluronidase before addition of U937 cells increased monocyte binding[ (1.35±0.06) folds vs control, P<0.05]. In contrast, the presence of either sICAM-1 (400 μg/L) or anti-CDI8 antibody (10 mg/L) led to a significant decrease in ICAM-1-dependent monocyte binding (78%±7%, P<0.05; 75%±8%, P<0.01 vs those before adding sICAM-1 or anti-CD18 antibody, respectively). Conclusion HA redistribution induced by TNF-α may facilitate ICAM-1-dependent monocyte-epithelium binding, and pericellular HA plays a protective role in monocyte-driven tissue inflammation.     

Effect of intercellular adhesion molecule-1 and hyaluronic acid on monocyte-renal tubular epithelial cell adhesion induced by tumor necrosis factor α

Objective To investigate the effect of tumor necrosis factor ot (TNF-α) on monocyte-renal tubular epithelial cell adhesion and to explore its associated mechanism. Methods Human renal proximal tubular epithelial cell line (HK2 cells)and monocyte cell line (U937)were used to perform cell co-culture. TNF-α (10 μg/L)was used to stimulate HK2 cells and then U937 was put into the HK2 monolayers. Three locational parts of hyaluronan around HK2 cells were extracted by different ways and the HA expression was detected by enzyme-linked binding protein assay. Monocyte adhesion was detected by florescence recording assay. Flow cytometry was applied to assess intercellular adhesion molecule-1 (ICAM-1) expression in HK2 cells. Results Stimulation of HK2 cells with TNF-α significantly increased U937 binding to HK2 cell monolayer [(2.25±0.05) folds vs control, P<0.01]. Incubation of TNF-α (10 μg/L) with HK2 cells for 24 hours did not induce the change of total HA expression surrounding the HK2 cells, whereas HA redistribution happened with conditioned medium fraction (CM-HA) increased [(1.17±0.16) fold vs control, P<0.05], the pericellular fraction (trypsin extract fraction, TE-HA) decreased (83%±11% vs control, P<0.05) and the remaining cells-associated HA (cell associated fraction, CA) did not change significantly. In addition, pre-treatment of HK2 cells with TNF-α significantly increased the ICAM-1 expression [(1.85±0.22) folds vs control, P<0.01] and ICAM-1-dependent monocytes binding. Removal of HA from the surface of confluent monolayers of HK2 cells by hyaluronidase before addition of U937 cells increased monocyte binding[ (1.35±0.06) folds vs control, P<0.05]. In contrast, the presence of either sICAM-1 (400 μg/L) or anti-CDI8 antibody (10 mg/L) led to a significant decrease in ICAM-1-dependent monocyte binding (78%±7%, P<0.05; 75%±8%, P<0.01 vs those before adding sICAM-1 or anti-CD18 antibody, respectively). Conclusion HA redistribution induced by TNF-α may facilitate ICAM-1-dependent monocyte-epithelium binding, and pericellular HA plays a protective role in monocyte-driven tissue inflammation.     

Effect of intercellular adhesion molecule-1 and hyaluronic acid on monocyte-renal tubular epithelial cell adhesion induced by tumor necrosis factor α

Objective To investigate the effect of tumor necrosis factor ot (TNF-α) on monocyte-renal tubular epithelial cell adhesion and to explore its associated mechanism. Methods Human renal proximal tubular epithelial cell line (HK2 cells)and monocyte cell line (U937)were used to perform cell co-culture. TNF-α (10 μg/L)was used to stimulate HK2 cells and then U937 was put into the HK2 monolayers. Three locational parts of hyaluronan around HK2 cells were extracted by different ways and the HA expression was detected by enzyme-linked binding protein assay. Monocyte adhesion was detected by florescence recording assay. Flow cytometry was applied to assess intercellular adhesion molecule-1 (ICAM-1) expression in HK2 cells. Results Stimulation of HK2 cells with TNF-α significantly increased U937 binding to HK2 cell monolayer [(2.25±0.05) folds vs control, P<0.01]. Incubation of TNF-α (10 μg/L) with HK2 cells for 24 hours did not induce the change of total HA expression surrounding the HK2 cells, whereas HA redistribution happened with conditioned medium fraction (CM-HA) increased [(1.17±0.16) fold vs control, P<0.05], the pericellular fraction (trypsin extract fraction, TE-HA) decreased (83%±11% vs control, P<0.05) and the remaining cells-associated HA (cell associated fraction, CA) did not change significantly. In addition, pre-treatment of HK2 cells with TNF-α significantly increased the ICAM-1 expression [(1.85±0.22) folds vs control, P<0.01] and ICAM-1-dependent monocytes binding. Removal of HA from the surface of confluent monolayers of HK2 cells by hyaluronidase before addition of U937 cells increased monocyte binding[ (1.35±0.06) folds vs control, P<0.05]. In contrast, the presence of either sICAM-1 (400 μg/L) or anti-CDI8 antibody (10 mg/L) led to a significant decrease in ICAM-1-dependent monocyte binding (78%±7%, P<0.05; 75%±8%, P<0.01 vs those before adding sICAM-1 or anti-CD18 antibody, respectively). Conclusion HA redistribution induced by TNF-α may facilitate ICAM-1-dependent monocyte-epithelium binding, and pericellular HA plays a protective role in monocyte-driven tissue inflammation.     

Effect of intercellular adhesion molecule-1 and hyaluronic acid on monocyte-renal tubular epithelial cell adhesion induced by tumor necrosis factor α

Objective To investigate the effect of tumor necrosis factor ot (TNF-α) on monocyte-renal tubular epithelial cell adhesion and to explore its associated mechanism. Methods Human renal proximal tubular epithelial cell line (HK2 cells)and monocyte cell line (U937)were used to perform cell co-culture. TNF-α (10 μg/L)was used to stimulate HK2 cells and then U937 was put into the HK2 monolayers. Three locational parts of hyaluronan around HK2 cells were extracted by different ways and the HA expression was detected by enzyme-linked binding protein assay. Monocyte adhesion was detected by florescence recording assay. Flow cytometry was applied to assess intercellular adhesion molecule-1 (ICAM-1) expression in HK2 cells. Results Stimulation of HK2 cells with TNF-α significantly increased U937 binding to HK2 cell monolayer [(2.25±0.05) folds vs control, P<0.01]. Incubation of TNF-α (10 μg/L) with HK2 cells for 24 hours did not induce the change of total HA expression surrounding the HK2 cells, whereas HA redistribution happened with conditioned medium fraction (CM-HA) increased [(1.17±0.16) fold vs control, P<0.05], the pericellular fraction (trypsin extract fraction, TE-HA) decreased (83%±11% vs control, P<0.05) and the remaining cells-associated HA (cell associated fraction, CA) did not change significantly. In addition, pre-treatment of HK2 cells with TNF-α significantly increased the ICAM-1 expression [(1.85±0.22) folds vs control, P<0.01] and ICAM-1-dependent monocytes binding. Removal of HA from the surface of confluent monolayers of HK2 cells by hyaluronidase before addition of U937 cells increased monocyte binding[ (1.35±0.06) folds vs control, P<0.05]. In contrast, the presence of either sICAM-1 (400 μg/L) or anti-CDI8 antibody (10 mg/L) led to a significant decrease in ICAM-1-dependent monocyte binding (78%±7%, P<0.05; 75%±8%, P<0.01 vs those before adding sICAM-1 or anti-CD18 antibody, respectively). Conclusion HA redistribution induced by TNF-α may facilitate ICAM-1-dependent monocyte-epithelium binding, and pericellular HA plays a protective role in monocyte-driven tissue inflammation.     

Effect of intercellular adhesion molecule-1 and hyaluronic acid on monocyte-renal tubular epithelial cell adhesion induced by tumor necrosis factor α

Objective To investigate the effect of tumor necrosis factor ot (TNF-α) on monocyte-renal tubular epithelial cell adhesion and to explore its associated mechanism. Methods Human renal proximal tubular epithelial cell line (HK2 cells)and monocyte cell line (U937)were used to perform cell co-culture. TNF-α (10 μg/L)was used to stimulate HK2 cells and then U937 was put into the HK2 monolayers. Three locational parts of hyaluronan around HK2 cells were extracted by different ways and the HA expression was detected by enzyme-linked binding protein assay. Monocyte adhesion was detected by florescence recording assay. Flow cytometry was applied to assess intercellular adhesion molecule-1 (ICAM-1) expression in HK2 cells. Results Stimulation of HK2 cells with TNF-α significantly increased U937 binding to HK2 cell monolayer [(2.25±0.05) folds vs control, P<0.01]. Incubation of TNF-α (10 μg/L) with HK2 cells for 24 hours did not induce the change of total HA expression surrounding the HK2 cells, whereas HA redistribution happened with conditioned medium fraction (CM-HA) increased [(1.17±0.16) fold vs control, P<0.05], the pericellular fraction (trypsin extract fraction, TE-HA) decreased (83%±11% vs control, P<0.05) and the remaining cells-associated HA (cell associated fraction, CA) did not change significantly. In addition, pre-treatment of HK2 cells with TNF-α significantly increased the ICAM-1 expression [(1.85±0.22) folds vs control, P<0.01] and ICAM-1-dependent monocytes binding. Removal of HA from the surface of confluent monolayers of HK2 cells by hyaluronidase before addition of U937 cells increased monocyte binding[ (1.35±0.06) folds vs control, P<0.05]. In contrast, the presence of either sICAM-1 (400 μg/L) or anti-CDI8 antibody (10 mg/L) led to a significant decrease in ICAM-1-dependent monocyte binding (78%±7%, P<0.05; 75%±8%, P<0.01 vs those before adding sICAM-1 or anti-CD18 antibody, respectively). Conclusion HA redistribution induced by TNF-α may facilitate ICAM-1-dependent monocyte-epithelium binding, and pericellular HA plays a protective role in monocyte-driven tissue inflammation.     

Effect of intercellular adhesion molecule-1 and hyaluronic acid on monocyte-renal tubular epithelial cell adhesion induced by tumor necrosis factor α

Objective To investigate the effect of tumor necrosis factor ot (TNF-α) on monocyte-renal tubular epithelial cell adhesion and to explore its associated mechanism. Methods Human renal proximal tubular epithelial cell line (HK2 cells)and monocyte cell line (U937)were used to perform cell co-culture. TNF-α (10 μg/L)was used to stimulate HK2 cells and then U937 was put into the HK2 monolayers. Three locational parts of hyaluronan around HK2 cells were extracted by different ways and the HA expression was detected by enzyme-linked binding protein assay. Monocyte adhesion was detected by florescence recording assay. Flow cytometry was applied to assess intercellular adhesion molecule-1 (ICAM-1) expression in HK2 cells. Results Stimulation of HK2 cells with TNF-α significantly increased U937 binding to HK2 cell monolayer [(2.25±0.05) folds vs control, P<0.01]. Incubation of TNF-α (10 μg/L) with HK2 cells for 24 hours did not induce the change of total HA expression surrounding the HK2 cells, whereas HA redistribution happened with conditioned medium fraction (CM-HA) increased [(1.17±0.16) fold vs control, P<0.05], the pericellular fraction (trypsin extract fraction, TE-HA) decreased (83%±11% vs control, P<0.05) and the remaining cells-associated HA (cell associated fraction, CA) did not change significantly. In addition, pre-treatment of HK2 cells with TNF-α significantly increased the ICAM-1 expression [(1.85±0.22) folds vs control, P<0.01] and ICAM-1-dependent monocytes binding. Removal of HA from the surface of confluent monolayers of HK2 cells by hyaluronidase before addition of U937 cells increased monocyte binding[ (1.35±0.06) folds vs control, P<0.05]. In contrast, the presence of either sICAM-1 (400 μg/L) or anti-CDI8 antibody (10 mg/L) led to a significant decrease in ICAM-1-dependent monocyte binding (78%±7%, P<0.05; 75%±8%, P<0.01 vs those before adding sICAM-1 or anti-CD18 antibody, respectively). Conclusion HA redistribution induced by TNF-α may facilitate ICAM-1-dependent monocyte-epithelium binding, and pericellular HA plays a protective role in monocyte-driven tissue inflammation.     

Effect of intercellular adhesion molecule-1 and hyaluronic acid on monocyte-renal tubular epithelial cell adhesion induced by tumor necrosis factor α

Objective To investigate the effect of tumor necrosis factor ot (TNF-α) on monocyte-renal tubular epithelial cell adhesion and to explore its associated mechanism. Methods Human renal proximal tubular epithelial cell line (HK2 cells)and monocyte cell line (U937)were used to perform cell co-culture. TNF-α (10 μg/L)was used to stimulate HK2 cells and then U937 was put into the HK2 monolayers. Three locational parts of hyaluronan around HK2 cells were extracted by different ways and the HA expression was detected by enzyme-linked binding protein assay. Monocyte adhesion was detected by florescence recording assay. Flow cytometry was applied to assess intercellular adhesion molecule-1 (ICAM-1) expression in HK2 cells. Results Stimulation of HK2 cells with TNF-α significantly increased U937 binding to HK2 cell monolayer [(2.25±0.05) folds vs control, P<0.01]. Incubation of TNF-α (10 μg/L) with HK2 cells for 24 hours did not induce the change of total HA expression surrounding the HK2 cells, whereas HA redistribution happened with conditioned medium fraction (CM-HA) increased [(1.17±0.16) fold vs control, P<0.05], the pericellular fraction (trypsin extract fraction, TE-HA) decreased (83%±11% vs control, P<0.05) and the remaining cells-associated HA (cell associated fraction, CA) did not change significantly. In addition, pre-treatment of HK2 cells with TNF-α significantly increased the ICAM-1 expression [(1.85±0.22) folds vs control, P<0.01] and ICAM-1-dependent monocytes binding. Removal of HA from the surface of confluent monolayers of HK2 cells by hyaluronidase before addition of U937 cells increased monocyte binding[ (1.35±0.06) folds vs control, P<0.05]. In contrast, the presence of either sICAM-1 (400 μg/L) or anti-CDI8 antibody (10 mg/L) led to a significant decrease in ICAM-1-dependent monocyte binding (78%±7%, P<0.05; 75%±8%, P<0.01 vs those before adding sICAM-1 or anti-CD18 antibody, respectively). Conclusion HA redistribution induced by TNF-α may facilitate ICAM-1-dependent monocyte-epithelium binding, and pericellular HA plays a protective role in monocyte-driven tissue inflammation.     

Effect of intercellular adhesion molecule-1 and hyaluronic acid on monocyte-renal tubular epithelial cell adhesion induced by tumor necrosis factor α

Objective To investigate the effect of tumor necrosis factor ot (TNF-α) on monocyte-renal tubular epithelial cell adhesion and to explore its associated mechanism. Methods Human renal proximal tubular epithelial cell line (HK2 cells)and monocyte cell line (U937)were used to perform cell co-culture. TNF-α (10 μg/L)was used to stimulate HK2 cells and then U937 was put into the HK2 monolayers. Three locational parts of hyaluronan around HK2 cells were extracted by different ways and the HA expression was detected by enzyme-linked binding protein assay. Monocyte adhesion was detected by florescence recording assay. Flow cytometry was applied to assess intercellular adhesion molecule-1 (ICAM-1) expression in HK2 cells. Results Stimulation of HK2 cells with TNF-α significantly increased U937 binding to HK2 cell monolayer [(2.25±0.05) folds vs control, P<0.01]. Incubation of TNF-α (10 μg/L) with HK2 cells for 24 hours did not induce the change of total HA expression surrounding the HK2 cells, whereas HA redistribution happened with conditioned medium fraction (CM-HA) increased [(1.17±0.16) fold vs control, P<0.05], the pericellular fraction (trypsin extract fraction, TE-HA) decreased (83%±11% vs control, P<0.05) and the remaining cells-associated HA (cell associated fraction, CA) did not change significantly. In addition, pre-treatment of HK2 cells with TNF-α significantly increased the ICAM-1 expression [(1.85±0.22) folds vs control, P<0.01] and ICAM-1-dependent monocytes binding. Removal of HA from the surface of confluent monolayers of HK2 cells by hyaluronidase before addition of U937 cells increased monocyte binding[ (1.35±0.06) folds vs control, P<0.05]. In contrast, the presence of either sICAM-1 (400 μg/L) or anti-CDI8 antibody (10 mg/L) led to a significant decrease in ICAM-1-dependent monocyte binding (78%±7%, P<0.05; 75%±8%, P<0.01 vs those before adding sICAM-1 or anti-CD18 antibody, respectively). Conclusion HA redistribution induced by TNF-α may facilitate ICAM-1-dependent monocyte-epithelium binding, and pericellular HA plays a protective role in monocyte-driven tissue inflammation.     

Effect of intercellular adhesion molecule-1 and hyaluronic acid on monocyte-renal tubular epithelial cell adhesion induced by tumor necrosis factor α

Objective To investigate the effect of tumor necrosis factor ot (TNF-α) on monocyte-renal tubular epithelial cell adhesion and to explore its associated mechanism. Methods Human renal proximal tubular epithelial cell line (HK2 cells)and monocyte cell line (U937)were used to perform cell co-culture. TNF-α (10 μg/L)was used to stimulate HK2 cells and then U937 was put into the HK2 monolayers. Three locational parts of hyaluronan around HK2 cells were extracted by different ways and the HA expression was detected by enzyme-linked binding protein assay. Monocyte adhesion was detected by florescence recording assay. Flow cytometry was applied to assess intercellular adhesion molecule-1 (ICAM-1) expression in HK2 cells. Results Stimulation of HK2 cells with TNF-α significantly increased U937 binding to HK2 cell monolayer [(2.25±0.05) folds vs control, P<0.01]. Incubation of TNF-α (10 μg/L) with HK2 cells for 24 hours did not induce the change of total HA expression surrounding the HK2 cells, whereas HA redistribution happened with conditioned medium fraction (CM-HA) increased [(1.17±0.16) fold vs control, P<0.05], the pericellular fraction (trypsin extract fraction, TE-HA) decreased (83%±11% vs control, P<0.05) and the remaining cells-associated HA (cell associated fraction, CA) did not change significantly. In addition, pre-treatment of HK2 cells with TNF-α significantly increased the ICAM-1 expression [(1.85±0.22) folds vs control, P<0.01] and ICAM-1-dependent monocytes binding. Removal of HA from the surface of confluent monolayers of HK2 cells by hyaluronidase before addition of U937 cells increased monocyte binding[ (1.35±0.06) folds vs control, P<0.05]. In contrast, the presence of either sICAM-1 (400 μg/L) or anti-CDI8 antibody (10 mg/L) led to a significant decrease in ICAM-1-dependent monocyte binding (78%±7%, P<0.05; 75%±8%, P<0.01 vs those before adding sICAM-1 or anti-CD18 antibody, respectively). Conclusion HA redistribution induced by TNF-α may facilitate ICAM-1-dependent monocyte-epithelium binding, and pericellular HA plays a protective role in monocyte-driven tissue inflammation.     

人白介素-13对牛主动脉内皮细胞表达黏附分子的影响

目的研究人白介素-13（hIL-13）对牛主动脉内皮细胞（BAECs）表达细胞间黏附分子-1（ICAM-1）和E-选择素的影响，为hIL-13应用于诱导异种移植免疫耐受、减轻异种移植排斥反应提供实验依据。方法用不同浓度的hIL-13（2、5、10、20及40ng／ml）孵育BAECs2h后，再与肿瘤坏死因子-α（TNF-α．4ng／ml）共孵育6h或18h；应用细胞-酶联免疫吸附分析方法（Cell—ELISA）检测BAECs表面的E-选择素和ICAM-1的表达；用MTT方法测定hIL-13对BAECs活性的影响。结果用hIL-13在5～20ng／ml浓度内预处理BAECs后，能明显抑制TNF-α诱导的E-选择素与ICAM-1的表达，并呈现一定的剂量依赖性（P〈0．01）。经不同浓度hIL-13处理的BAECs活性与未经hIL-13处理者相比差异无统计学意义。结论hIL-13能明显抑制BAECs表达E-选择素与ICAM-1，诱导异种移植的免疫耐受，且hIL-13对BAECs无损伤作用。     

罗格列酮通过核因子κB抑制脂多糖诱导的大鼠腹膜间皮细胞CD40和胞间黏附分子1的表达

目的 探讨罗格列酮对脂多糖（LPS）诱导的体外培养大鼠腹膜间皮细胞CD40和胞间黏附分子1（ICAM-1）表达的影响以及调节机制。 方法 分离及培养大鼠原代腹膜间皮细胞。将细胞随机分为正常对照组、LPS（5 mg/L）组、BAY11-7085（NF-κB抑制剂）组（5 μmol/L预刺激3 h后加入LPS作用3 h）、不同浓度罗格列酮（过氧化物酶体增殖蛋白激活性受体γ配体）组（10、20 μmol/L分别预处理3 h再加入LPS 5 mg/L）、GW9662（过氧化物酶体增殖蛋白激活性受体γ拮抗剂）预处理组（预处理3 h后加入罗格列酮10 μmol/L,3 h后再加入LPS 5 mg/L）和溶媒对照组。加入LPS后 1 h收集细胞检测核因子κB（NF-κB） p65水平;3 h收集细胞分别检测CD40和ICAM-1基因表达;24 h收集细胞分别检测CD40和ICAM-1蛋白表达。RT-PCR法检测基因表达;Western印迹和免疫荧光方法检测蛋白表达及核因子磷酸化。 结果 （1）常规培养的腹膜间皮细胞表达基础量CD40和ICAM-1,LPS显著上调其表达（P < 0.05）;LPS作用1 h时腹膜间皮细胞磷酸化NF-κB p65活化水平显著增高,与对照组差异有统计学意义 (1.10±0.17比0.55±0.06,P < 0.05)。（2）NF-κB抑制剂BAY11-7085预处理后LPS诱导的磷酸化NF-κB p65水平、CD40 和ICAM-1表达显著低于LPS组（0.22±0.11比1.10±0.17,P < 0.01;0.34±0.02 比 0.50±0.06,P < 0.05;0.35±0.16 比0.74±0.03,P < 0.05）。（3）罗格列酮预处理后,LPS诱导的磷酸化NF-κB p65水平、CD40以及ICAM-1蛋白表达亦显著低于LPS组（0.77±0.08比0.90±0.10,P < 0.01;0.79±0.16 比0.99±0.06,P < 0.05;0.83±0.20比1.22±0.13,P < 0.05）。GW9662和罗格列酮联合预处理后,LPS诱导的磷酸化NF-κB p65水平与罗格列酮预处理组差异无统计学意义,但CD40和ICAM-1表达显著高于罗格列酮预处理组（0.95±0.19比0.79±0.16;1.04±0.24比0.83±0.20,均P < 0.05）。 结论 NF-κB信号通路参与调节LPS诱导的腹膜间皮细胞表达CD40和ICAM-1。罗格列酮通过 NF-κB途径下调CD40和ICAM-1表达,从而发挥抗炎作用。     

急性坏死性胰腺炎肺组织炎性介质mRNA表达与肺损伤的关系

目的 探讨急性坏死性胰腺炎(ANP)大鼠肺组织白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)及细胞间黏附分子(ICAM-1)等炎性介质mRNA表达与肺损伤的关系.方法 33只Wistar大鼠随机分为正常对照和胰腺炎不同时间点(1、4、12和24 h)各组,应用3.5%牛磺胆酸钠逆行胰胆管注射制备ANP模型.采用RT-PCR法检测ANP肺组织IL-6、TNF-α及ICAM-1 mRNA表达,同时观察血淀粉酶及脂肪酶、胰腺和肺组织湿/干重比率及病理改变.结果 造模ANP 1 h后肺组织IL-6、TNF-α及ICAM-1 mRNA水平(1.25±0.16、0.33±0.09及082±0.03)较正常对照组(0.07±0.02、0.06±0.02及0.41±0.04)表达增高(P<0.05),并持续升高至12及24 h(分别为1.674±0.14、0.99±0.11、1.17士0.05及1.87±0.05、0.96士0.06、1.11士0.04),同时伴有肺组织病理损害,其严重程度与肺TNF-α及ICAM-1 mRNA表达、肺组织湿/干重比率与TNF-α、IL-6、ICAM-1 mRNA表达的相关系数分别为0.93及0.70(P<0.05).结论 大鼠ANP早期肺组织IL-6、TNF-α及ICAM-1mRNA即过度表达,肺IL-6、TNF-α及ICAM-1mRNA过度表达是ANP肺损害发生的原因之一,肺损伤严重程度与IL-6、TNF-α及ICAM-1mRNA表达的高低有关.     

下肢静脉高压大鼠后肢皮肤病变的组织学研究

目的探讨下肢静脉高压大鼠皮肤病变的生物分子学机制。方法通过建立合适的下肢静脉高压大鼠模型来观察大鼠后肢病变组织的组织学改变。将36只大鼠随机分成4组,A组为下肢静脉高压+舒洛地特组,B组为下肢静脉高压+生理盐水组,C组为单纯下肢静脉高压组,D组为正常对照组。A、B组分别腹腔注射舒洛地特和生理盐水2周, 1周、2周、2个月后分别检测大鼠后肢组织中血管细胞黏附分子-1(VCAM-1)、细胞间黏附分子-1(ICAM-1)、肿瘤坏死因子-α(TNF-α)和内皮一氧化氮合酶(eNOS)表达情况。结果免疫组化结果显示B、C组VCAM-1、ICAM-1、TNF-α阳性表达量逐渐增加,eNOS阳性表达量逐渐减低,和正常组比较差异有统计学意义(P0.05),B、C组间差异无统计学意义(P0.05)。A组VCAM-1、ICAM-1、TNF-α阳性表达量逐渐降低,eNOS阳性表达量逐渐增加,和B组间差异有统计学意义(P0.05),2个月时和正常组比较差异无统计学意义(P0.05)。结论下肢静脉高压时存在血管内皮损伤,VCAM-1、ICAM-1、TNF-α表达增加,eNOS表达降低;舒洛地特可以有效改善并修复损伤的血管内皮,调节VCAM-1、ICAM-1、TNF-α、eNOS的表达水平。     

人IκBα突变体对大鼠肝移植缺血再灌注中炎性因子的影响

目的 探讨人IκBα突变体(IκBαM)对大鼠肝移植缺血再灌注中炎性因子的影响.方法 SD大鼠随机分4组组Ⅰ为假手术组,组Ⅱ为对照组,组Ⅲ为PcDNA 3.0组,组Ⅳ为PcDNA3.0-IκBαM组.应用免疫组织化学、逆转录-聚合酶链反应(RT-PCR)测定肝组织中肿瘤坏死因子-α(TNF-α)、细胞黏附分子-1(ICAM-1)的表达,酶联免疫吸附(ELISA)检测血清中TNF-α的表达,同时检测肝脏酶学的变化.结果 Ⅱ、Ⅲ组与Ⅳ组比较术后12 h TNF-α免疫组织化学阳性率分别为84%、80%、55%,ICAM-1免疫组织化学阳性率分别为74%、76%、47%,差异有统计学意义(P＜0.05);术后2、12 h TNF-α和术后12 h ICAM-1mRNA的表达差异有统计学意义(P＜0.05);术后2、12 h血清TNF-α表达差异有统计学意义,以2 h为显著(258.50±46.19 vs 147.45±36.04;244.83±18.08 vs 147.45±36.04,P＜0.05);肝脏酶学指标(ALT)在各时点差异有统计学意义(P＜0.05).结论 IκBαM通过抑制炎性因子的表达减轻大鼠肝移植缺血再灌注损伤.     

利拉鲁肽对肿瘤坏死因子α刺激下大鼠肾小球系膜细胞纤溶酶原激活物抑制物1和胞间黏附分子1表达的影响

目的 探讨肿瘤坏死因子α(TNF-α)对大鼠肾小球系膜细胞(RGMC)中纤溶酶原激活物抑制物1 (PAI-1)和胞间黏附分子1(ICAM-1)表达的影响以及利拉鲁肽(Liraglutide,Li)的干预作用.方法 将培养的RGMC株分为6组,分别为正常对照组、TNF-α组、Li低浓度( 10 nmol/L)组、中浓度(100 nmol/L)组、高浓度(1000 nmol/L)组,以及吡咯烷二硫代氨基甲酸盐( PDTC)组.用ELISA法测定各组RGMC的PAI-1以及ICAM-1蛋白表达.用RT-PCR法测定各组RGMC的PAI-1以及ICAM-1基因表达. 结果 TNF-α可上调RGMC中PAI-1、ICAM-1蛋白及基因表达(均P＜0.05),利拉鲁肽可抑制TNF-α诱导的RGMC中PAI-1、1CAM-1蛋白及基因的高表达(均P＜ 0.05).与TNF-α组比较,PDTC组PAI-1、ICAM-1表达量显著减少(均P＜ 0.05).结论 利拉鲁肽可减轻体外培养RGMC中TNF-α诱导的PAI-1和ICAM-1表达.     

模拟CO2气腹对胃癌细胞黏附分子表达的影响

目的研究体外模拟不同压力CO2气腹环境对人胃癌MKN,45细胞表面黏附分子表达的影响。方法体外建立模拟CO2气腹环境,实验组分为3个亚组,气腹压力分别为1．2、1．6和2．0kPa,作用时间均为4h。实验组经气腹处理后第0、24、48、72和96h,对照组普通细胞培养4h,用流式细胞仪检测胃癌MKN-45细胞表面黏附分子CD44v6、细胞间黏附分子1（ICAM-1）和上皮型钙黏蛋白（E-cadherin）表达。结果胃癌MKN-45细胞经1．2、1．6kPaCO2气腹作用后CD44v6和ICAM-1表达呈现先升高后回落,24h时与对照组的差异有统计学意义（P〈0．01）,48h时达到高峰,然后逐渐下降,72h时与对照组比较,差异无统计学意义（P〉0．05）,96h恢复至对照组水平：E-cadherin表达变化为先降低后回升,处理后即较对照组明显下降（P〈0．01）,然后开始回升,48h时与对照组比较,差异无统计学意义（P〉0．05）,96h恢复至对照组水平。2．0kPa组CD44v6、ICAM-1和E-cadherin表达变化均更为显著．CD44v6和ICAM-1在处理后即显著高于对照组（P〈0．05）．E-cadherin表达在48h仍然明显低于对照组（P〈0．05）。结论模拟临床常用的CO2气腹压力对胃癌MKN．45细胞表面黏附分子表达可产生一过性影响．但均能在较短时间内恢复。