GW3965在Raji细胞中对BLyS表达的影响

目的探讨肝X受体(liver X receptors,LXRs)的特异性激动剂GW3965在Raji细胞中对B淋巴细胞刺激因子(B lymphocyte stimulator,BLyS)表达的影响。方法 MTT法检测不同浓度的GW3965(浓度分别为0.5、5、10μmol/L)对Raji细胞活性的影响,观察时间为加入GW3965共孵育后24 h。用LXR的特异性激动剂GW3965刺激人B细胞淋巴瘤株Raji细胞,经RT-PCR检测LXR特异性靶基因三磷酸腺苷结合盒A1(ATP-binding cassette,ABCA1)mRNA的表达;经RT-PCR和Western blot检测BLyS的表达。结果对照组1‰DMSO D(492)为(0.632±0.055),0.5、5μmol/L和10μmol/L的GW3965 D(492)为(0.609±0.073)、(0.612±0.052)和(0.628±0.055)。LXR的特异性配体GW3965对细胞活性无影响(P>0.05)。GW3965作用于Raji细胞后,ABCA1 mRNA表达剂量依赖性上调,LXR活化后可在转录和翻译水平剂量依赖性下调抑制BLyS的表达。结论 LXR在Raji细胞中可抑制BLyS的表达。

人前列腺癌细胞中肝X受体特异性激动剂GW3965对核受体结合蛋白1的影响

目的探讨人前列腺癌细胞系DU145细胞中肝X受体(liver X receptor,LXR)特异性激动剂GW3965对核受体结合蛋白1(nuclear receptor binding protein 1,NRBP1)的表达调控作用。方法采用MTT法检测不同浓度GW3965(浓度分别为0.5、5、10μmol/L)作用24 h后对DU145细胞增殖的影响。在人前列腺癌DU145细胞中用LXR的特异性激动剂GW3965处理24 h后,经逆转录-聚合酶链反应(RT-PCR)检测LXR特异性靶基因三磷腺苷结合A1(ATP-bindingcassette A1,ABCA1)转录水平的表达情况;随后在转录水平和翻译水平检测NRBP1的表达。结果 LXR特异性激动剂GW3965各实验组对细胞的活性和增殖无影响(P>0.05)。GW3965作用于DU145细胞后,ABCA1转录水平呈剂量依赖性升高,表明LXR在DU145细胞中具有功能活性。LXR经过活化后在转录和翻译水平对NRBP1的抑制作用呈剂量依赖性降低。结论 LXR在DU145细胞中可抑制NRBP1的表达。

GW3965抑制p38丝裂原活化蛋白激酶信号通路表达减轻百草枯致小鼠急性肺损伤

目的 研究肝X受体（liver X receptors, LXRs）激动剂GW3965抑制百草枯（paraquat, PQ）诱导的小鼠急性肺损伤的作用及可能的机制。方法 40只雄性c57小鼠随机（随机数字法）分为4组,每组10只小鼠。对照组：0.1 mL生理盐水腹腔注射，10 min后再次0.1 mL生理盐水腹腔注射；百草枯染毒组：百草枯28 mg/kg腹腔注射，10 min后0.1 mL生理盐水腹腔注射；GW3965低剂量处理组：百草枯染毒后10 min给予GW3965 10 mg/kg腹腔注射；GW3965高剂量处理组：百草枯染毒后10 min给予GW3965 50 mg/kg腹腔注射。在百草枯染毒后72 h处死小鼠，收集肺组织及血液标本；采用硫代巴比妥酸法（TBA）检测血清中丙二醛（MDA）含量；采用酶联免疫吸附法（ELISA）检测血清及肺组织中白介素1β（IL-1β）和肿瘤坏死因子-α（TNF-α）含量；肺脏取出后测定小鼠肺湿/干质量比，肺脏切片后HE染色并评估肺组织病理学改变，Western blot方法检测肺组织p38丝裂原活化蛋白激酶（mitogen activated protein kinases, MAPK）、Bax和Bcl-2表达情况；TUNEL法检测肺组织细胞凋亡情况；多组间比较采用单因素方差分析（ANOVA），组间两两比较采用LSD-t法。结果 与对照组比较，百草枯染毒小鼠肺湿/干质量比明显增加（P〈0.05），肺组织损伤明显，血液中MDA含量增加（P〈0.05），血液及肺组织中IL-1β和TNF-α含量显著增加（P〈0.05），p38MAPK表达显著上调（P〈0.05），Bax/Bcl-2显著增加（P〈0.05），肺组织细胞凋亡明显增加（P〈0.05）。GW3965处理组小鼠上述改变明显减轻（P〈0.05），GW3965高剂量处理组效果更显著（P〈0.05）。结论 LXRs激动剂GW3965能有效减轻百草枯中毒引起的小鼠急性肺损伤，这一作用可能与LXRs激活后抑制p38MAPK信号通路有关。

ATF4/TXNIP/REDD1/mTOR signaling mediates the antitumor activities of liver X receptor in pancreatic cancers

Background:Limited by difficulties in early detection and availabilities of effective treatments,pancreatic cancer is a highly malignant disease with poor prognosis.Nuclear receptors are a family of ligand‐dependent transcription factors that are highly druggable therapeutic targets playing critical roles in human physiological and pathological development,including cancer.In this study,we explored the therapeutic potential as well as the molecular mechanisms of liver X receptor(LXR)agonist GW3965 in pancreatic cancer.Methods:Soft‐agar colony formation assay,xenograft tumors,Oligonucleotide microarray,Reverse transcription real‐time polymerase chain reaction,Western immunoblotting and Immunohistochemistry were used in this study.Results:We demonstrated pleotropic in vitro activities of GW3965 in pancreatic cell lines MIA PaCa‐2 and BXPC3 including reduction of cell viability,inhibition of cell proliferation,stimulation of cell death,and suppression of colony formation,which translated to significant inhibition of xenograft tumor growth in vitro.By mapping the gene expression profiles,we identified the up‐regulations of 188 and the down‐regulations of 92 genes common to both cell lines following GW3965 treatment.Genes responsive to GW3965 represent a variety of biological pathways vital for multiple cellular functions.Specifically,we identified that the activating transcription factor 4/thioredoxin‐interacting protein/regulated in development and DNA damage responses 1/mechanistic target of rapamycin(ATF4/TXNIP/REDD1/mTOR)signaling critically controls GW3965‐mediated regulation of cell proliferation/death.The significance of the ATF4/TXNIP/REDD1/mTOR pathway was further supported by associated expressions in xenograft tumors as well as human pancreatic cancer samples.Conclusions:This study provides the pre‐clinical evidence that LXR agonist is a promising therapy for pancreatic cancer.