Defective interleukin-2 production and interleukin-2 receptor expression in pulmonary tuberculosis

The evolution of Mycobacterium tuberculosis as an intracellular pathogen has led to a complex relationship between it and its host, the human mononuclear phagocyte. The products of M. tuberculosis-specific T lymphocytes are essential for macrophage activation for intracellular mycobacterial killing. However, dysfunction cell-mediated immune response to infection with M. tuberculosis may contribute to progressive primary infection or reactivation of endogenous foci of mycobacteria. Th1 cells produce IL-2, which is essential for proper cellular immunity. The aim of this study was to identify the variation in IL-2 activity and soluble IL-2 receptor (IL-2 R) in peripheral blood lymphocyte in patients suffering with pulmonary tuberculosis. A significant decrease in IL-2 and IL-2 receptor level was observed in patients with pulmonary tuberculosis when compared to normal controls. Our results suggested that patients with pulmonary tuberculosis had a defect in IL-2 production. Better understanding of these interactions will allow the development of increasingly specific immune-based interventions for prevention and treatment of tuberculosis.     

Interaction between monocytes and vascular endothelial cells induces adrenomedullin production

Adrenomedullin (AM), a potent vasodilator peptide, has natriuretic effects, and its plasma concentration is elevated in cardiovascular diseases. In the present study, we investigated the induction of AM expression due to interactions between THP-1 cells (human monocytic cell line) and human umbilical cord vein endothelial cells (HUVECs). AM levels in the culture medium were measured by radioimmunoassay. The luciferase vector containing the 5'-flanking region of the human AM gene was transfected into either HUVECs or THP-1 cells. Addition of THP-1 cells to HUVECs for 48 h induced marked increases in AM levels, which were 16-fold higher than those of HUVECs alone. Luciferase vectors containing the 5'-flanking region of human AM gene (pLCF-1534) were transferred into THP-1 cells or HUVECs. Addition of THP-1 cells to pLCF-1534-transfected HUVECs induced an increase in luciferase activity in cell lysates, which was 5-fold higher than that of the transfected HUVECs alone. In contrast, the luciferase activity of lysates from pLCF-1534-transfected THP-1 cells was not affected by coculture with HUVECs. A separate coculture experiment revealed that direct contact of THP-1 cells and HUVECs contributed to enhanced AM production in the cocoulture. Co-incubation of the cell membrane fraction from THP-1 cells augmented AM production by HUVECs. Both anti-interleukin (IL)-1alpha antibody and IL-1 receptor antagonist significantly inhibited AM production in the cocultures. The cell-to-cell interaction between monocytes and HUVECs induces AM production by HUVECs, which may play an important role in the pathogenesis of vascular disorders.     

Interaction between monocytes and vascular smooth muscle cells induces expression of hepatocyte growth factor

OBJECTIVE: To investigate the expression of hepatocyte growth factor (HGF)--a multifunctional factor implicated in tissue regeneration, wound healing and angiogenesis--that is induced by cell-to-cell interactions between monocytes and vascular smooth muscle cells (VSMCs), using coculture of human VSMCs and cells of the human monocytoid cell line, THP-1. METHODS: We collected supernatant from the coculture medium and measured HGF concentrations with an enzyme-linked immunosorbent assay. Northern blot analysis of HGF mRNA was performed using a specific cDNA. To explore which types of cells produce HGF, we performed immunohistochemistry. RESULTS: Coculture of VSMCs with THP-1 cells for 24 h caused a fivefold increase in HGF concentrations over that in control VSMC culture. Northern blot analysis showed an induction of HGF mRNA in the coculture with a peak at 3 h. Separated cocultures demonstrated that both direct contact and soluble factors contribute to the production of HGF. Immunohistochemistry demonstrated that both types of cells in the coculture produce HGF. Neutralizing antibodies against tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6 inhibited the HGF production in THP-1 cells and VSMCs that was induced by the coculture conditioned medium. The protein kinase C inhibitors H-7, calphostin C and K252b, and the tyrosine kinase inhibitor, genistein, significantly inhibited the production of HGF in the coculture. CONCLUSIONS: Cell-to-cell interactions between monocytes and VSMCs induced HGF synthesis in both types of cells, suggesting that local HGF production induced by this cell-to-cell interaction has an important role in the pathogenesis of hypertension, atherosclerosis or vascular remodelling.     

Wegener autoantigen induces maturation of dendritic cells and licenses them for Th1 priming via the protease-activated receptor-2 pathway

Autoantibodies to proteinase 3 (PR3) are involved in the pathogenesis of autoimmune-mediated vasculitis in Wegener granulomatosis (WG). To address the question how the autoantigen PR3 becomes a target of adaptive immunity, we investigated the effect of PR3 on immature dendritic cells (iDCs) in patients with WG, healthy blood donors, and patients with Crohn disease (CD), another granulomatous disease. PR3 induces phenotypic and functional maturation of a fraction of blood monocyte-derived iDCs. PR3-treated DCs express high levels of CD83, a DC-restricted marker of maturation, CD80 and CD86, and HLA-DR. Furthermore, the DCs become fully competent antigen-presenting cells and can induce stimulation of PR3-specific CD4(+) T cells, which produce IFN-gamma. PR3-maturated DCs derived from WG patients induce a higher IFN-gamma response of PR3-specific CD4(+) T cells compared with patients with CD and healthy controls. The maturation of DCs mediated through PR3 was inhibited by a serine protease inhibitor, by antibodies directed against the protease-activated receptor-2 (PAR-2), and by inhibition of phospholipase C, suggesting that the interactions of PR3 with PAR-2 are involved in the induction of DC maturation. Wegener autoantigen interacts with a "gateway" receptor (PAR-2) on iDCs in vitro triggering their maturation and licenses them for a T helper 1 (Th1)-type response potentially favoring granuloma formation in WG.     

Oncostatin M induces interleukin-6 and cyclooxygenase-2 expression in human vascular smooth muscle cells : synergy with interleukin-1beta

Oncostatin M (OSM), a cytokine first identified from activated monocytes and T lymphocytes, is one of the most potent autocrine growth factor for AIDS and Kaposi's sarcoma. Little is known about the effects of OSM on normal vascular cells. We thus exposed human aortic smooth muscle cells (hASMCs) to OSM, examined cell proliferation and morphology, and determined interleukin-6 (IL-6) and cyclooxygenase-2 (COX-2) expression. OSM had a weak antiproliferative effect. After a 4-day incubation with 100 ng/mL OSM, cell count decreased to 69+/-3% of control. However, OSM induced striking changes in hASMC morphology, characterized by a polyclonal shape, in contrast to the spindle morphological feature of control hASMCs. OSM stimulated the release of IL-6 by hASMCs in a dose-dependent way; after a 48-hour exposure, values were 8.5+/-0.7, 29.7+/-3.5, 50.9+/-4.4, and 73.8+/-7.6x10(3) U/mL (n=6) at OSM concentrations of 0, 1, 10, and 100 ng/mL, respectively. OSM induced marked expression of COX-2 protein and mRNA. Leukemia inhibitory factor had no effect on hASMCs, indicating that OSM effects on hASMCs were mediated by the OSM type II receptor and not by the leukemia inhibitory factor receptor. OSM used the JAK/STAT signaling pathway, as demonstrated by rapid phosphorylation of JAK1 and specific activation of STAT1. Interestingly, OSM acted in synergy with IL-1beta on IL-6 production and COX-2 expression. In conclusion, OSM is a novel regulator of human smooth muscle cell functions, acting in concert with IL-1beta, and OSM may play a role in major vascular diseases such as atherosclerosis.     

乳凝集素调节EEI-10细胞IL-2,IL-4及IFN-γ的分泌表达

目的:探讨乳凝集素调节肠相关淋巴组织淋巴细胞分泌表达细胞因子的作用.方法:应用基因重组技术从MCF-7乳腺癌细胞中提取总RNA,通过逆转录PCR方法得到目的基因(乳凝集素)片段,利用酶切,连接等技术,将目的基因构建至PET28载体内,转化入DH5a细胞后,鉴定阳性质粒;将含有目的基因的阳性质粒转化入表达细胞BL-21,IPTG诱导表达目的蛋白乳凝集素,应用特异性镍鏊合的亲和层析柱得到纯化的目的蛋白.利用H3-Tdr法明确乳凝集素剂量与人类肠上皮内淋巴细胞株EEI-10细胞增殖之间的关系.给予适当剂量乳凝集素作用于EEI-10细胞后,利用ELISA方法检测EEI-10分泌IL-2,IL-4及IFN-γ浓度,应用RT-PCR方法检测IL-2,IL-4及IFN-γmRNA表达.结果:酶切阳性的质粒经测序证实与基因文库一致.所得纯化的目的蛋白进行SDS-PAGE电泳和特异性抗体鉴定,明确为目的蛋白乳凝集素.利用H3-Tdr法检测乳凝集素剂量与细胞增殖之间的关系,结果显示乳凝集素作用剂量为250mg/L时淋巴细胞增殖显著.给予乳凝集素处理后细胞培养上清中IL-2(P=0.0394)和IFN-γ(P=0.0082)的含量高于未处理细胞组,而IL-4没有显著的增高;同时处理后IL-2mRNA表达量升高,IL-4mRNA表达量无显著性改变,IFN-γmRNA表达量明显增高并高于PHA刺激组.结论:乳凝集素具有上调EEI-10细胞分泌和表达IL-2和IFN-γ的作用.     

Associations between interleukin-10 polymorphisms and susceptibility to rheumatoid arthritis: a meta-analysis and meta-regression

This study aimed to explore whether interleukin-10 polymorphisms are associated with susceptibility to rheumatoid arthritis (RA). Studies that have analyzed the associations of the interleukin-10-1082G>A, -592C>A, and -819C>T polymorphisms with RA were searched for in PubMed and EMBASE. Sensitivity and cumulative analyses were conducted to measure the robustness of our findings. Egger’s linear regression and Begg’s funnel plots were performed to analyze publication bias. The source of heterogeneity was analyzed by subgroup analysis and meta-regression. This meta-analysis involved 2661 RA patients and 3249 controls in 16 studies. There were significant associations with RA in the AG vs AA model (OR?=?0.79, 95% CI?=?0.67–0.93, P?<?0.01) and the AG + GG vs AA model (OR?=?0.80, 95% CI?=?0.69–0.93, P?<?0.01) for the interleukin-10-1082G>A polymorphism, in the TC vs TT model (OR?=?0.61, 95% CI?=?0.44–0.84, P?<?0.01) and the CC vs TT model (OR?=?0.64, 95% CI?=?0.46–0.89, P?<?0.01) for the interleukin-10-819C>T polymorphism, and in the AC vs AA model (OR?=?0.73, 95% CI?=?0.56–0.96, P?=?0.03) and the AC + CC vs AA model (OR?=?0.68, 95% CI?=?0.47–0.98, P?=?0.04) for the interleukin-10-592C>A polymorphism. Meta-regression revealed that the genotyping method was a major cause of heterogeneity in the AC vs AA model and the AC + CC vs AA model for the interleukin-10-592C>A polymorphism. This meta-analysis showed the interleukin-10-1082G>A, -592C>A, and -819C>T polymorphisms are correlated with the susceptibility to RA. Meta-regression indicated that the genotyping method is a major driver of heterogeneity in the relationship between the interleukin-10-592C>A polymorphism and RA.     

Interaction between human monocytes and vascular smooth muscle cells induces vascular endothelial growth factor expression

The objective of this study was to investigate whether synthesis of vascular endothelial growth factor (VEGF), a major mitogen for vascular endothelial cells, was induced by a cell-to-cell interaction between monocytes and vascular smooth muscle cells (VSMCs). Human VSMCs and THP-1 cells (human monocytoid cell) were cocultured. VEGF levels in the coculture medium were determined by enzyme-linked immunosorbent assay. Northern blot analysis of VEGF mRNA was performed using a specific cDNA probe. Immunohistochemistry was performed to determine which types of cell produce VEGF. Adding THP-1 cells to VSMCs for 24 h increased VEGF levels of the culture media, 8- and 10-fold relative to those of THP-1 cells and VSMCs alone, respectively. Northern blot analysis showed that VEGF mRNA expression was induced in the cocultured cells and peaked after 12 h. Immunohistochemistry disclosed that both types of cell in the coculture produced VEGF. Separate coculture experiments revealed that both direct contact and a soluble factor(s) contributed to VEGF production. Neutralizing anti-interleukin (IL)-6 antibody inhibited VEGF production by the coculture of THP-1 cells and VSMCs. A cell-to-cell interaction between monocytes and VSMCs induced VEGF synthesis in both types of cell. An IL-6 mediated mechanism is at least partially involved in VEGF production by the cocultures. Local VEGF production induced by a monocyte-VSMC interaction may play an important role in atherosclerosis and vascular remodeling.     

白介素-10基因多态性与肠易激综合征易感性关系的Meta分析

目的:评价白细胞介素-10(interleukin-10,IL-10)基因多态性与肠易激综合征(irritable bowel syndrome,IBS)遗传易感性的关系.方法:检索PubMed、EMBASE数据库、Cochrane图书馆(1966/2011-12)、中国学术期刊全文数据库(CNKI)、中国生物医学文献数据库(CBM)、万方数据库(1979/2011-12).应用RevMan5.0对各研究结果进行异质性检验和效应值合并.结果:8篇文献被纳入分析,其中涉及IL-10-592多态性的文献4篇、IL-10-819多态性的文献4篇、IL-10-1082多态性的文献7篇.-592位点A等位基因的OR值为1.26,95%CI:1.03-1.54,P=0.02;-592位点AA型基因的OR值为1.67,95%CI:0.71-3.93,P=0.24;-819位点T等位基因的OR值为1.24,95%CI:1.02-1.52,P=0.03;-819位点TT型基因的OR值为1.31,95%CI:0.59-2.91,P=0.50;-1082位点G等位基因的OR值为1.00,95%CI:0.86-1.17,P=0.98;-1082位点GG型基因的OR值为0.68,95%CI:0.51-0.92,P=0.01.分层分析显示:西方人种-1082位点GG型基因的OR值为0.71,95%CI:0.52-0.97,P=0.03;东方人种-1082位点GG型基因的OR值为0.42,95%CI:0.13-1.31,P=0.13.结论:西方人种-1082位点GG型基因与IBS遗传易感性相关,-592位点A等位基因和-819位点T等位基因可能会增加东方人种患IBS的危险性.     

Upregulation of macrophage endothelial lipase by toll-like receptors 4 and 3 modulates macrophage interleukin-10 and -12 production

Limited data suggest that endothelial lipase (EL) is synthesized not only by endothelial cells but also by macrophages. Previous studies showed that proinflammatory cytokines upregulate EL in endothelial cells, but there are very few data regarding EL expression, regulation, and functional consequences in macrophages. In the present study, RAW cells and mouse peritoneal macrophages were treated with Toll-like receptor (TLR) ligands and EL expression and its consequences were assessed. We demonstrate that lipopolysaccharide, a TLR4 ligand; and polyinosinic:polycytidylic acid (poly I:C), a TLR3 ligand; but not lipoteichoic acid, a TLR2 ligand, upregulate macrophage EL expression both ex vivo and in vivo. In contrast, macrophage lipoprotein lipase expression is significantly repressed by lipopolysaccharide or poly I:C. Using C3HJ and TLR3 knockout mice, we further show that upregulation of macrophage EL expression by lipopolysaccharide or poly I:C is TLR4 or TLR3 dependent, respectively. Furthermore, we demonstrate that lipopolysaccharide induced interleukin (IL)-10 production was significantly reduced, whereas IL-12 production is significantly increased in J744 macrophages and mouse peritoneal macrophages overexpressing human EL. Conversely, significantly increased IL-10 and significantly decreased IL-12 expression were observed in mouse peritoneal macrophages isolated from EL knockout mice. Finally we show that the catalytic activity is required for EL to modulate the balance of macrophage IL-10 and IL-12 production. These results suggest that macrophage EL may play important roles in modulating the macrophage inflammatory response through local hydrolysis of HDL.     

Down-modulation of toll-like receptor 2 expression on granulocytes and suppression of interleukin-8 production due to in vitro treatment with cellulose acetate beads

The Adacolumn, which is filled with cellulose acetate beads (CA beads), has been used as a medical device for inflammatory diseases. The CA beads selectively adsorb granulocytes and monocytes and remove them from the peripheral blood. The anti-inflammatory effects of the Adacolumn are possibly caused by removal of these cells but also due to the functional changes in the processed cells. In this study, we investigated the effects of CA beads treatment on modulation of the expression of innate immunity receptors such as the Toll-like receptor (TLR) family and production of an inflammatory cytokine, interleukin-8 (IL-8). Changes in the expressions of TLR1, 2, 4 and 6 in peripheral leukocytes exposed to CA beads were examined by flow cytometry. TLR2 expression on the surface of granulocytes exposed to CA beads was decreased, but the amount of intracellular TLR2 was increased, possibly by internalization. These changes were not observed in monocytes or lymphocytes. Peptidoglycan (PGN) treatment produced similar changes in TLR2 on granulocytes. We also measured the amounts of IL-8 in cultured blood treated with lipopolysaccharide (LPS) and PGN, which are known TLR agonists. PGN-induced IL-8 production was lower in CA beads-treated leukocytes than that in non-treated leukocytes, but LPS did not induce these changes. Based on these findings, we conclude that the down-modulation of TLR2 and suppression of IL-8 production on granulocytes by CA beads, may play an important role in the anti-inflammatory effects of the Adacolumn.     

Administration of interleukin-2 induces major histocompatibility complex class II expression on the biliary epithelial cells, possibly through endogenous interferon-gamma production.

In various organ-specific autoimmune diseases, aberrant expression of major histocompatibility complex class II antigens on each target epithelial cell has been reported. Some researchers have attempted to link this phenomenon to the antigen-presenting capacity and the induction of autoimmunity, whereas others think it might serve as a peripheral mechanism for the induction and the maintenance of self-tolerance in autoreactive T cells. In this study, we showed that intraperitoneal administration of interleukin-2 (1.2 x 10(6) IU/kg) to 4-wk-old male BALB/c mice for 35 consecutive days induced lymphocyte infiltration around bile ducts in the liver and major histocompatibility complex class II expression on biliary epithelial cells, which was immunoelectron microscopically confined to the luminal cell surface. Immunohistochemically, lymphocytes accumulating around bile ducts were mainly T cells, positive for CD3, L3T4 and H-2 class II molecules, and a few of them were positive for Lyt-2 and negative for immunoglobulin. Half of the infiltrates were positive for asialo GM1, and one-third was positive for interferon-gamma. Interferon-gamma-positive, L3T4-positive cells were detected in mirror sections. However, neither the destruction of biliary epithelial cells nor the presence of granulomas was observed. Autoantibodies were serologically undetectable. The existence of interferon-gamma-positive cells in the lesion and the fact that intravenous administration of anti-interferon-gamma twice a week completely inhibited the lymphocyte infiltration and the major histocompatibility complex class II expression on biliary epithelial cells suggested that these changes were induced through endogenous interferon-gamma production.(ABSTRACT TRUNCATED AT 250 WORDS)     

Calcium signaling inhibits interleukin-12 production and activates CD83(+) dendritic cells that induce Th2 cell development

Mature dendritic cells (DCs), in addition to providing costimulation, can define the Th1, in contrast to the Th2, nature of a T-cell response through the production of cytokines and chemokines. Because calcium signaling alone causes rapid DC maturation of both normal and transformed myeloid cells, it was evaluated whether calcium-mobilized DCs polarize T cells toward a Th1 or a Th2 phenotype. After human monocytes were cultured for 24 hours in serum-free medium and granulocyte-macrophage colony-stimulating factor to produce immature DCs, additional overnight culture with either calcium ionophore (CI) or interferon gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), and soluble CD40L resulted in phenotypically mature DCs that produced interleukin-8 (IL-8) and displayed marked expression of CD80, CD86, CD40, CD54, CD83, DC-LAMP, and RelB. DCs matured by IFN-gamma, TNF-alpha, and soluble CD40L were additionally distinguished by undetectable CD4 expression, marked secretion of IL-12, IL-6, and MIP-1beta, and preferential ability to promote Th1/Tc1 characteristics during T-cell sensitization. In contrast, DCs matured by CI treatment were distinguished by CD4 expression, modest or absent levels of IL-12, IL-6, and MIP-1beta, and preferential ability to promote Th2/Tc2 characteristics. Calcium signaling selectively antagonized IL-12 production by mature DCs activated with IFN-gamma, TNF-alpha, and soluble CD40L. Although the activation of DCs by calcium signals is largely mediated through calcineurin phosphatase, the inhibition of IL-12 production by calcium signaling was independent of this enzyme. Naturally occurring calcium fluxes in immature DCs, therefore, negatively regulate Dc1 differentiation while promoting Dc2 characteristics and Th2/Tc2 polarization. Calcium-mobilized DCs may have clinical usefulness in treating disease states with excessive Th1/Tc1 activity, such as graft-versus-host disease or autoimmunity.     

The expression of toll-like receptors 3 and 7 in rheumatoid arthritis synovium is increased and costimulation of toll-like receptors 3, 4, and 7/8 results in synergistic cytokine production by dendritic cells

OBJECTIVE: To evaluate the expression of Toll-like receptors (TLRs) 3 and 7 in synovium and to study potential differences in the maturation and cytokine production mediated by TLR-2, TLR-3, TLR-4, and TLR-7/8 by dendritic cells (DCs) from rheumatoid arthritis (RA) patients and DCs from healthy controls. METHODS: Synovial expression of TLR-3 and TLR-7 in RA was studied using immunohistochemistry. Monocyte-derived DCs from RA patients and healthy controls were cultured for 6 days and subsequently stimulated for 48 hours via TLR-mediated pathways (lipoteichoic acid, Pam(3)Cys, and fibroblast-stimulating lipopeptide 1 for TLR-2, poly[I-C] for TLR-3, lipopolysaccharide and extra domain A for TLR-4, and R848 for TLR-7/8). Phenotypic DC maturation was measured using flow cytometry. The secretion of tumor necrosis factor alpha (TNFalpha), interleukin-6 (IL-6), IL-10, and IL-12 was measured using the Bio-Plex system. Cell lines expressing TLR-2 and TLR-4 were used for the detection of TLR-2 and TLR-4 ligands in serum and synovial fluid from RA patients. RESULTS: TLR-3 and TLR-7 were highly expressed in RA synovium. All TLR ligands elicited phenotypic DC maturation equally between DCs from RA patients and those from healthy controls. TLR-2- and TLR-4-mediated stimulation of DCs from RA patients resulted in markedly higher production of inflammatory mediators (TNFalpha and IL-6) compared with DCs from healthy controls. In contrast, upon stimulation of TLR-3 and TLR-7/8, the level of cytokine production was equal between DCs from RA patients and those from healthy controls. Remarkably, both TLR-3 and TLR-7/8 stimulation resulted in a skewed balance toward IL-12. Intriguingly, the combined stimulation of TLR-4 and TLR-3-7/8 resulted in a marked synergy with respect to the production of inflammatory mediators. As a proof of concept, TLR-4 ligands were increased in the serum and synovial fluid of RA patients. CONCLUSION: TLRs are involved in the regulation of DC activation and cytokine production. We hypothesize that various TLR ligands in the joint trigger multiple TLRs simultaneously, favoring the breakthrough of tolerance in RA.     

人白细胞介素-10真核表达载体的构建及其在兔滑膜细胞中的表达

目的 构建人白细胞介素-10(hIL-10)高效真核表达载体,观察其在家兔滑膜细胞(RSCs)中表达.方法 提取人外周血单个核细胞(PBMCs)总RNA作为模板,根据基因库(NM 000572)中hIL-10全长开放读框设计特异性引物,反转录-聚合酶链反应(RT-PCR)一步法扩增hIL-10 mRNA全长开放读框,扩增产物定向克隆人真核表达载体pcDNA4/HisMaxA,并对克隆人真核表达载体的扩增产物进行酶切及DNA测序鉴定,构建的真核表达载体pcDNA4/HisMaxA-hIL-10经阳离子脂质体介导转染兔滑膜细胞RSCs.酶联免疫吸附试验(ELISA)检测转染后12、24、48、72 h和7、14 d RSCs培养上清中hIL-10水平.结果 RT-PCR产物约0.54 kb,克隆人真核表达载体pcDNA4/HisMaxA的扩增产物经酶切及DNA测序鉴定与读码框架序列无差别.转染后12 h到第7天细胞培养上清检测出hIL-10,且水平显著性高于对照组(F=21.878,P＜0.01).结论 hIL-10真核高效表达载体pcDNA4/HisMaxA-hIL-10构建成功.     

靶向封闭EEF1A2对胰腺癌细胞凋亡的作用及其机制研究

目的 观察靶向封闭EEF1A2基因对胰腺癌细胞株凋亡的影响,并探讨其可能的作用机制.方法 体外转录制备2对EEF1A2 siRNA,应用脂质体技术转染胰腺癌细胞株BxPC-3,半定量RT-PCR、蛋白质印迹法检测转染前后EEF1A2基因表达的变化.运用膜联蛋白V/碘化丙啶法检测细胞凋亡率;蛋白质印迹法检测细胞中caspase-3、caspase-8、caspase-9、聚二磷酸腺苷核糖多聚酶(PARP)细胞色素C和Bid等凋亡相关蛋白表达变化.结果 2对EEF1A2 siRNA均能有效降低BxPC-3细胞中EEF1A2的表达,其中第2对siRNA静默效果更佳,EEF1A2在mRNA和蛋白质水平的表达抑制率均达75%左右.抑制BxPC-3细胞中EEF1A2的表达后,细胞的早期凋亡率为15.28%±3.65%,显著高于阴性对照组的10.11%±3.05%和空白组的9.41%±4.14%,同时伴随出现caspase-3、caspase-8、caspase-9、PARP和Bid的蛋白活化增强和细胞色素C表达增加.结论 抑制EEF1A2表达能明显诱导胰腺癌细胞BxPC-3的凋亡,而死亡受体途径和线粒体途径的激活可能均参与凋亡的发生.