AA-861抑制5-LO途径对KC和HSC的影响

Objective To investigate the effects of AA-861, the specific inhibitor of 5-lipoxyge-nase (5-LO), on the activation, proliferation and gene expression of kupffer cell (KC) and hepatic stellate cell (HSC). Methods 1) After being exposed to AA-861, the gene expression, proliferative ability and apoptosis of activated KC induced by lipopolysaecharide (LPS) were detected; 2) After the activated KC being exposed to AA-861, the supernatant of KC was added into quiescent HSC, then the proliferative ability and gene expression of quiescent HSC were observed. Results 1) After being activated by LPS, the mRNA and protein expression of 5-LO in KC increased remarkably while the mRNA and protein expression of 5-LO and 5-LO production decreased significantly after KC being ex-posed to AA-861. 2) After the supernatant of activated KC was added into quiescent HSC, the prolif-erative ability and gene expression of Collagen-1, α-SMA and TIMP-1 were increased significantly. However, after the supernatant of activated KC being exposed to AA-861 was added to quiescent HSC, it inhibited the activation of quiescent HSC and the proliferative ability and gene expression of HSC were decreased. Conclusion Inhibition of the 5-LO pathway by AA-861 can induce the over-pro-liferated KC to undergo apoptosis, and then inhibit the activation and proliferation of HSC and de-crease the production of ECM.     

5-脂氧合酶抑制剂AA-861治疗肝纤维化的实验研究

目的 探讨5-脂氧合酶(5-LO)特异性抑制剂AA-861对四氯化碳(CCI4)诱导的大鼠肝纤维化形成的影响.方法 在CCI4诱导的肝纤维化模型中,在注射CCI4的前2 d开始腹腔内注射AA-861(0.2 mg/100 g,1次/d),分别在注射CCI4的第2、4、6周处死大鼠.应用实时定量PCR检测肝脏中5-LO、平滑肌肌动蛋白-α(α-SMA)、Ⅰ型胶原(collagen-1)、基质金属蛋白酶-2(MMP-2)和金属蛋白酶组织抑制剂-1(TIMP-1)等基因的表达,Western blot榆测肝脏5-LO蛋白的表达;检测肝功能和肝脏组织中羟脯氨酸(Hyp)的含量和组织学变化,并对肝纤维化程度进行半定量计分系统(SSS)分级评分.结果 随着肝纤维化程度的加重,大鼠肝组织中5-LO、α-SMA、Collagen-1、MMP-2和TIMP-1等基因的表达显著增加,同时肝功能ALT、TBA等指标明显升高;而大鼠注射AA-861后各种基因表达明显降低,相对于MMP-2基因,TIMP-1基因mRNA表达的降低更为明显,Hyp、肝功能和肝纤维化程度评分也明显降低. 结论 AA-861可通过抑制5-LO途径,显著降低TIMP-1 Collagen-1和α-SMA等基因的表达,减轻CCI4诱导的大鼠肝纤维化程度.     

CD14的表达及其在库普弗细胞激活中的意义

目的　探讨LPS对库普弗细胞 (KC)CD14表达的影响及CD14在LPS激活KC中的意义。　方法　在分离培养大鼠KC的基础上 ,应用免疫组织化学染色、RT PCR等方法分别测定CD14表达的变化、培养KC中上清中TNFα、IL 6和NO浓度。　结果　 (1)不同浓度的LPS使KC中CD14mRNA的表达及其蛋白合成明显增加 ,其表达量与LPS浓度呈剂量依赖性相关 ;(2 )同一浓度的LPS可使KC中CD14mRNA的表达及其蛋白合成明显增加 ,且在 3～ 6h左右达到高峰 ;(3)LPS刺激KC后产生的活性介质能明显上调新培养KC中CD14mRNA的表达及其蛋白合成 ;(4)在血清存在的情况下加入抗CD14单抗或在无血清的情况下单独加入LPS ,可明显降低KCTNFα、IL 6和NO的释放。而后者如果同时加入LBP ,则可明显上调培养KC中的TNFα、IL 6和NO浓度。　结论　 (1)LPS及其刺激KC后产生的活性介质与CD14mRNA的表达及其蛋白合成密切相关 ,并推测在实验 1～ 3h的CD14表达的增强可能主要由LPS引起 ,而此后CD14表达的进一步增强可能与KC释放的细胞因子密切相关 ;(2 )低浓度LPS对KC的激活是CD14依赖的。     

siRNA干扰ADAMTS2基因对肝星状细胞的影响

目的 探讨siRNA干扰大鼠含Ⅰ型血小板结合蛋白基序的解聚蛋白样金属蛋白酶2(ADAMTS2)基因后对大鼠肝星状细胞(HSC)生物学特性的影响及其机制,评估ADAMTS2基因作为一种新的靶向基因在抗肝纤维化治疗中的应用前景.方法 设计并化学合成3对针对大鼠ADAMTS2 mRNA 2237、2597及690位点的siRNAs.用筛选出的抑制效率最高的siRNA体外转染HSC-T6,应用实时PCR、Westem blot及MTT等方法研究沉默ADAMTS2基因对大鼠HSC活化、增殖等生物学特性及对基因ADAMTS2、α-SMA、COL1α1、COL(I)、TGF-β1、MMP-2和TIMP-3表达的影响.结果 在相同注射剂量(50 nmol/L)及时间(48 h)下,2237位点的siRNA-ADAMTS2具有最高的抑制效率;能显著抑制ADAMTS2基因mRNA和蛋白表达(抑制率80％以上);显著抑制COL(I)、α-SMA和TGF-β1在HSC中的表达.HSC的增殖能力显著降低.结论 化学合成的siRNA-ADAMTS2干扰载体能有效抑制ADAMTS2基因在大鼠HSC-T6细胞系中的表达,抑制HSC的活化和增殖,同时显著降低COL(I)、α-SMA和TGF-β1的表达,具有潜在的阻止甚至逆转肝纤维化的作用.ADAMTS2可能是抗肝纤维化治疗的有效靶位,抑制ADAMTS2在肝脏的表达可能是一种有效的抗肝纤维化治疗策略.     

视黄醇类核内受体-α基因慢病毒载体的构建及其对肝星状细胞的影响

目的:通过视黄醇类核内受体-α(retinoid X receptor-alpha,RXR-α)基因慢病毒表达载体的构建,及其对肝星状细胞(hepatic stellate cells,HSC)活化、增殖影响的研究,探讨RXR-α基因在肝纤维化中的作用。方法:①构建RXR-α基因慢病毒表达载体;②分离和体外培养大鼠HSC;③将自发活化的HSC分成3组,即正常对照组、阴性对照组和RXR-α载体组;分别将空白慢病毒载体和RXR-α慢病毒载体转染自体活化的HSC,采用Western印迹法检测各组细胞中RXR-α、α-SMA和Ⅰ型胶原蛋白表达变化,用MTT法检测各组HSC培养24、48、72及96 h后的增殖情况。结果:正常对照组及阴性对照组HSC中几乎没有RXR-α蛋白的表达,而RXR-α载体转染组的HSC中出现RXR-α蛋白的明显表达。与正常对照组及阴性对照组相比,RXR-α载体组转染的HSC中α-SMA蛋白表达量显著下降(t=3.767,P0.01和t=8.491,P0.05),Ⅰ型胶原蛋白表达也显著降低(t分别为10.449和10.756,P值均0.01),同时HSC的增殖能力也显著下降(t分别为4.381和1.778,P值均0.05)。而阴性对照组与正常对照组相比,α-SMA和Ⅰ型胶原蛋白表达量和HSC增殖能力无明显变化(P0.05)。结论:RXR-α基因在HSC内的增强表达能显著抑制HSC的活化和增殖,具有潜在的抑制肝纤维化的作用。     

结缔组织生长因子对Kupffer细胞诱导的肝星状细胞激活的影响

目的 探讨肝星状细胞(hepatic stellate cell,HSC)结缔组织生长因子(connective tissue growth factor,CTGF)表达对Kupffer细胞(Kc)诱导的HSC激活的影响.方法 构建含CTGF的RNA干扰载体.将肝星状细胞系rHSC-99分为3组:对照组、空载体组和RNA干扰组.采用RT-PCR方法 检测HSC的CTGF表达.分离培养KC,建立各组HSC与KC的共培养体系,MTT检测HSC的增殖情况;RT-PCR检测HSC的TGF-β1、I型前胶原的表达;Western Blot检测HSC的TGF-β1表达,ELISA检测共培养上清中I型胶原的表达;免疫荧光化学检测HSC的α-SMA的表达. 结果 构建CTGF的RNA干扰载体Psilencer 3.1H1-Neo-CTGF.RNA干扰后CTGF表达降低22%.KC得率为5×107,活率＞98%.在HSC和KC共培养体系中,RNA干扰HSC的CTGF表达后,与KC共培养的HSC活化和增殖明显被抑制,与对照组相比,HSC的增殖降低29%(t:20.17,P＜0.01).Ⅰ型前胶原和α-SMA的表达下降38%,细胞培养上清中Ⅰ型胶原的分泌量下降48%(t=12.18,t=7.81,t=15.96,均P＜0.05).TGF-β表达则没有明显的变化.结论 阻断HSC的CTGF表达能抑制由KC诱导的HSC激活.     

氧化苦参碱对大鼠肝星状细胞旁分泌活化途径的抑制作用

目的观察氧化苦参碱对大鼠激活肝星状细胞(HSC)这一旁分泌活化途径的影响.方法分离正常及CCl4损伤肝库普弗细胞(KC),进行体外培养,收集损伤肝KC条件培养液(IKCM)及药物(氧化苦参碱,Oxy)干预后的条件培养液(Oxy-IKCM),以IKCM及Oxy-IKCM添加于原代培养的未活化HSC培养体系中,观察Oxy对KC旁分泌激活HSC的影响,生物学方法检测Oxy对活化的KC分泌TGFβ1的影响.结果急性损伤肝KC对HSC的增殖有促进作用,氧化苦参碱可抑制KC对HSC增殖的促进作用,并可抑制活化KC分泌的TGFβ1.结论氧化苦参碱可通过抑制旁分泌途径抑制HSC活化及活化KC分泌的TGFβ1.     

肿瘤坏死因子α对脂多糖诱导的肝星状细胞表达结缔组织生长因子的影响

目的 观察脂多糖(LPS)体外作用于大鼠肝星状细胞(HSC)时肿瘤坏死因子-α(TNF-α)和结缔组织生长因子(CTGF)表达变化,探讨TNF-α对LPS诱导的HSC中CTGF表达的影响.方法 用一步密度梯度离心法分离大鼠HSC,体外培养LPS处理HSC,逆转录-聚合酶链反应(RT-PCR)方法检测不同LPS浓度处理的HSC CTGF mRNA表达水平,并用ELISA双抗体夹心法测定TNF-α浓度.结果 TNF-α水平随LPS浓度增加而增加,LPS可上调CTGF mRNA的表达,TNF-α浓度及CTGF mRNA表达水平呈一定的平行关系.结论 LPS可上调HSC中CTGF mRNA表达,该过程可能是通过TNF-α介导的.     

白细胞介素-10对与枯否细胞共培养的肝星状细胞表达转移生长因子-β和血小板源生长因子的影响

目的　探讨白细胞介素 (IL) 10对与枯否细胞 (KC)共培养的肝星状细胞 (HSC)表达转移生长因子 (TGF) β和血小板源生长因子 (PDGF)的影响。 方法　分离培养大鼠的KC ,建立HSC与KC的共培养系统 ,分为 4组 :1组为HSC单独培养组 ;2组为HSC与KC共培养组 ,不加IL 10 ;3组为HSC与KC共培养组 ,加入 1.5 μg/LIL 10 ;4组为HSC与KC共培养组 ,加入 15 .0μg/LIL 10。培养 48h后 ,逆转录 聚合酶链反应 (RT PCR )法检测各组细胞中TGF β和PDGFmRNA的表达。Westernblot法检测各组细胞TGF β和PDGF蛋白的表达。 结果　KC能促进HSC表达TGF β和PDGF ;IL 10能抑制与KC共培养的HSC的TGF β和PDGF的表达。 结论　IL 10能通过KC对HSC的生物学活性产生影响。     

H2O2诱导的肝星状细胞凋亡后胶原的变化

目的 观察Ⅰ型胶原(COL Ⅰ)和Ⅲ型胶原(COLⅢ)在H2O2诱导的肝星状细胞(HSC)凋亡后的变化.方法 用流式细胞术检测100 nmol/L的H2O2诱导HSC不同程度的凋亡;应用半定量逆转录-聚合酶链反应(RT-PCR)检测细胞内COL Ⅰ、COLⅢ mRNA的表达及变化.结果 用100 nmol/L H2O2诱导HSC凋亡(凋亡率分别5.86%、58.55%、71.98%),COL Ⅰ、COL Ⅲ在活化的HSC-T6细胞内均高表达,且伴随凋亡的增加,表达急剧下降,COL Ⅰ的变化更明显.结论 诱导HSC凋亡可减少胶原基因的表达.     

Interleukin-6 production by endotoxin-stimulated Kupffer cells is regulated by prostaglandin E2

Although its impact on the acute phase response is clear, little is known regarding the regulation of interleukin-6 (hepatocyte-stimulating factor) production. We evaluated its relationship with the potent immunosuppressive eicosanoid PGE2 in endotoxin (LPS)-stimulated Kupffer cells (KC). KC were harvested from collagenase-digested Wistar-Furth rat livers and purified (greater than 95% by phagocytosis) by adherence. Following overnight culture with or without the cyclooxygenase inhibitor indomethacin (10 microM), 5 X 10(5) KC were repleted with fresh media with or without 2.5 micrograms/ml LPS. Supernatant IL-6 levels (ng/ml) were measured with the B9.9 hybridoma proliferative bioassay, and PGE2 levels (ng/ml) by radioimmunoassay. Negligible supernatant IL-6 and PGE2 were measured at all culture intervals in unstimulated KC or those cultured with the LPS-inhibitor polymyxin-B (10 micrograms/ml). With LPS, KC IL-6 production increased in parallel with PGE2 for 24 hr before decreasing as PGE2 continued to rise. When indomethacin treatment blocked KC PGE2 production, IL-6 levels significantly increased. We conclude that PGE2 produced by activated Kupffer cells appears to down-regulate IL-6 secretion. Autocrine effects by PGE2 may locally regulate the hepatic acute phase response by limiting the KC-derived IL-6 available to act on neighboring hepatocytes.     

热打击联合脂多糖刺激对人肠上皮细胞SW480释放细胞因子的影响

目的：观察脂多糖（LPS）与热打击分别单独作用与联合作用对人肠上皮细胞SW480释放细胞因子的影响。方法：于37℃、5％CO2标准培养箱中培养人肠上皮细胞株SW480。实验分4组：空白对照组直接收集细胞上清;LPS单独刺激组（LPS组）分别使用0、0．01、0．1、1和10μg／ml的LPS刺激SW480细胞,24h后收集细胞上清;热打击组将SW480细胞进行热打击（42℃,1h）后在标准孵箱分别培养1h和24h后收集细胞上清;LPS＋热打击组将SW480细胞42℃热打击1h后给予上述浓度的LPS刺激,再重新置于标准孵箱中培养,24h后收集细胞上清。各组细胞上清用LiquiChip液相蛋白芯片系统分别检测粒细胞-巨噬细胞集落刺激因子（GM—CSF）、7干扰素（IFN-7）、白细胞介素-1β（IL-1β）、IL-2、IL-4、IL-6、IL-8、IL-10、IL-12、肿瘤坏死因子-α（TNF-α）等10种细胞因子／趋化因子的表达分泌水平。结果：单独LPS刺激时呈剂量依赖性诱导SW480表达分泌IL-8,对其余9种细胞因子／趋化因子的表达分泌水平影响不明显。单纯热打击仅诱导SW480细胞表达分泌IL-8的水平升高,且与空白对照组比较,仅热打击24h后IL-8的水平显著增加（P〈0．01）。热打击联合不同浓度的LPS刺激SW480细胞,LPS浓度低时并不影响SW480表达分泌IL-8的水平（P〉O．05）,而高浓度LPS可以显著减少其表达分泌水平（P〈0．05）。结论：人肠上皮细胞SW480作为脏器实质细胞,对炎性刺激仅能产生单一种类的细胞因子,其中LPS单独刺激和一定强度的热打击均可上调SW480分泌IL-8;但高浓度LPS在热环境下可抑制SW480细胞的IL-8表达分泌水平。     

Regulation of apoptosis in eicosapentaenoic acid-treated HL-60 cells

BACKGROUND: Neutrophil apoptosis is an important physiological process in the resolution of pulmonary inflammation. Previous studies have shown that eicosapentaenoic acid (EPA; 20:5n-3) increases the rate of apoptosis in a concentration- and time-dependent manner in HL-60 cells. However, it is not known if the EPA-induced apoptosis involves the lipoxygenase (LO) and cyclooxygenase (COX) enzymes or the downstream metabolic products of these enzymes. Thus, the objective of this study was to determine the effects of inhibitors LO and COX enzymes on apoptosis, viability, and necrosis in EPA-treated HL-60 cells. MATERIALS AND METHODS: Cells were incubated with 50 mum EPA in the presence of an enzyme inhibitor (1-10 microm) for 12 h. Compounds were used to inhibit COX 1 and 2 (ibuprofen), 5-, 12-, 15-LO (NDGA), 12-LO (baicalein), 5-LO (AA-861), and 5-LO activating protein (MK-886). Eicosanoid (0.001-1.0 mum) add-back experiments were also conducted; LTB(4) and 5-HETE with 5-LO inhibition and 12-HETE with 12-LO inhibition. Flow cytometry was used to assess apoptosis. RESULTS: Inhibition of COX 1 and 2 had no effect on apoptosis. Inhibition of 5-LO and 12-LO significantly increased apoptosis in EPA-treated HL-60 cells. Addition of LTB(4) reduced apoptosis to levels significantly lower than in HL-60 cells treated with EPA alone; 5-HETE and 12-HETE also lowered apoptosis to control levels. CONCLUSIONS: These data indicate that inhibition of LO, particularly 5-LO, increased apoptosis in EPA-treated HL-60 cells. Furthermore, this study demonstrated that the products of the LO enzymes, particularly LTB(4), are critical in the regulation of apoptosis in EPA-treated HL-60 cells.     

组织转谷氨酰胺酶基因RNA干扰慢病毒载体的构建及其对肝星状细胞的影响

目的 构建组织转谷氨酰胺酶(tTG)RNA干扰(RNAi)慢病毒载体,研究其对肝星状细胞(HSC)的影响.方法 设计、合成tTG基因RNAi有效靶序列,与慢病毒载体系统进行连接、转染,获得表达tTG基因的RNAi慢病毒载体质粒(Lenti-siRNA-tTG);将大鼠活化HSC分成阴性对照组(CON)、siRNA-GFP对照组(GFP)和siRNA-tTG组(nTG).应用real-time PCR、Western blot和MTT法检测Lenti-siRNA-tTG感染后HSC中tTG、α-平滑肌肌动蛋白(α-SMA)和Ⅰ型胶原(collagen-1)的mRNA和蛋白表达情况以及HSC的增殖情况.结果 成功构建siRNA-tTG慢病毒载体;Lenti-siRNA-tTG感染后,HSC中tTG和collagen-1的mRNA表达水平降低(P<0.05),HSC中tTG、lysine和collagen-1的蛋白表达水平下降(P<0.01),HSC的增殖能力降低(P<0.05).结论 Lenti-siRNA-tTG能通过抑制HSC中tTG基因的表达而抑制HSC的增殖,并降低HSC中collagen-1合成和交联的形成,具有潜在的抗纤维化形成的功能.     

利多卡因对LPS诱导大鼠腹腔巨噬细胞NF-κB活性的影响

目的 探讨利多卡因对LPS诱导大鼠腹腔巨噬细胞NF-κB活性的影响.方法 取wistar大鼠腹腔巨噬细胞,以2 × 106/ml的密度接种于12孔培养板,每孔1 ml.纯化处理后随机分为5组,每组10孔.正常对照组(C组)加入RPMI-1640培养液1 ml,L组加入含100 ng/ml LPS的RPMI1640培养液1 ml,LL1组、LL2组和LL3组分别加入含有2、20、200μg/ml利多卡因+100 ng/ml LPS的RPMI-1640培养液1 ml.孵育24 h后,收集上清液,测定高迁移率族蛋白B1(HMGB1)浓度;取细胞沉淀,测定HMGBl mRNA表达水平和NF-κB活性.结果 与C组比较,其他各组HMGB1浓度、HMGB1mRNA表达和NF-κB活性均升高(P＜0.05);与L组及LL1组比较,LL2组和LL3组上述指标降低(P＜0.05).LL3组HMGB1 mRNA表达水平低于LL2组(P＜0.05).结论 利多卡因可抑制LPS诱导大鼠腹腔巨噬细胞NF-κB活化,从而抑制HMGB1的合成与释放.     

Hepatocyte function in sepsis: Kupffer cells mediate a biphasic protein synthesis response in hepatocytes after exposure to endotoxin or killed Escherichia coli

Alterations in hepatic function are seen in sepsis and/or multiple system organ failure. We hypothesized that Kupffer cells (KC) within the liver may mediate functional alterations in adjacent hepatocytes (HC) in response to bacterial products. We have previously described decreases in rat HC protein synthesis during in vitro cocultivation with peritoneal macrophages in the presence of gentamicin-killed Escherichia coli (GKEC) or endotoxin (LPS). The present studies demonstrate that purified (greater than 95%), syngeneic, or allogeneic KC exposed to GKEC or LPS impart a biphasic response in cultured HC. When HC were cultured alone there was no alteration in 3H-leucine incorporation into HC protein after the addition of GKEC or LPS. When HC were cocultured with KC there was increased protein synthesis compared with HC alone (p less than 0.001). After the addition of GKEC or LPS there was an immediate increase in coculture HC protein synthesis. However, a marked decrease in coculture protein synthesis was seen 16 degrees later (p less than 0.001). To ensure that KC alone were responsible, splenic lymphocytes were added to HC alone or HC/KC coculture, but they did not alter the results. HC viability and appearance were unchanged throughout the experiments. These results show that exposure of KC to microbial products can profoundly alter HC function and support the concept of local KC modulation of HC function during sepsis.     

Effects of a thromboxane synthetase inhibitor (OKY-046) and a lipoxygenase inhibitor (AA-861) on bronchial responsiveness to acetylcholine in asthmatic subjects.

The effect of a selective thromboxane synthetase inhibitor, OKY-046, and a selective 5-lipoxygenase inhibitor, AA-861, on bronchial responsiveness to acetylcholine was studied in 23 asthmatic subjects. The provocative concentration of acetylcholine producing a 20% fall in forced expiratory volume in one second (PC20 FEV1) was measured before and after oral administration of OKY-046 (3000 mg over four days) and AA-861 (1100 mg over four days) and inhalation of OKY-046 (30 mg) in 10, 10, and nine asthmatic subjects respectively. Baseline values of FEV1 and forced vital capacity (FVC) were not altered by oral OKY-046, oral AA-861, or inhaled OKY-046. The geometric mean value of PC20 FEV1 increased significantly from 0.55 to 2.24 mg/ml after oral OKY-046, but was unchanged after inhalation of OKY-046 and after oral administration of AA-861. These results suggest that thromboxane A2 may play a part in bronchial hyperresponsiveness to acetylcholine.