Niemann-pick protein C1(NPC1) is a large integral membrane glycoprotein that resides in late endosomes,whereas niemann-pick protein C2(NPC2) is a small soluble protein found in the lumen of lysosomes.NPC1 protein is b...Niemann-pick protein C1(NPC1) is a large integral membrane glycoprotein that resides in late endosomes,whereas niemann-pick protein C2(NPC2) is a small soluble protein found in the lumen of lysosomes.NPC1 protein is believed to facilitate the transport of lipids,particularly cholesterol,from late endosomes/lysosomes to the Golgi apparatus,endoplasmic reticulum and plasma membrane.NPC2 primarily plays a role in the egress of cholesterol and glycolipids from lysosomes.Mutations in either NPC1 or NPC2 result in aberrant lipid transport from endocytic compartments,which results in lysosomal storage of a complex mixture of lipids,primarily cholesterol and glycosphingolipids.The NPC proteins regulate sterol homeostasis through production of LDL cholesterol-derived oxysterols.Oxysterols are endogenous ligands for the liver X receptors(LXRs),which can upregulate ATP binding cassette transporter A1(ABCA1) expression.ABCA1 may have antiatherogenic effects through the efflux of it-mediated cholesterol.Meanwhile,NPC1 heterozygote mutation confers substantial resistance to lesional necrosis and lesional macrophage apoptosis.Study of the NPC proteins will help us for further understanding of the mechanisms involved in atherogenesis.展开更多
目的观察C型尼曼-匹克蛋白2(Niemann-Pick protein C2,NPC2)在胃癌中的表达情况,分析其预后意义,初步探讨NPC2对胃癌的调控作用。方法利用胃癌数据库和组织芯片,比较NPC2在胃癌与正常胃黏膜中的表达差异;列联表分析NPC2表达与胃癌患者...目的观察C型尼曼-匹克蛋白2(Niemann-Pick protein C2,NPC2)在胃癌中的表达情况,分析其预后意义,初步探讨NPC2对胃癌的调控作用。方法利用胃癌数据库和组织芯片,比较NPC2在胃癌与正常胃黏膜中的表达差异;列联表分析NPC2表达与胃癌患者临床病理参数的相关性;Kaplan-Meier分析和COX回归分析NPC2表达在胃癌中的预后判断意义;通过GSEA挖掘NPC2调控胃癌细胞的可能分子机制;利用Transwell试验检测下调NPC2后胃癌细胞迁移能力的变化。结果相较于正常胃黏膜,NPC2在胃癌中高表达[GSE33335:(7.917±0.077)vs(7.601±0.074),P=0.0096;GSE63089:(9.083±0.123)vs(8.435±0.148),P=0.0001;组织芯片:(4.596±0.230)vs(3.336±0.176),P<0.0001];其表达水平与胃癌患者的AJCC临床分期(GSE15459:P=0.009;组织芯片:P=0.04)、区域淋巴结转移(组织芯片:P=0.04)等临床病理参数相关;NPC2高表达者预后不良(TCGA:P<0.0001;GSE15459:P=0.0023;组织芯片:P=0.0032),其表达水平是胃癌的独立预后预测因素(TCGA:风险比为2.140,95%CI为1.523~3.006,P<0.0001;组织芯片:风险比为1.926,95%CI为1.108~3.348,P=0.02);细胞黏附分子相关基因在NPC2高表达胃癌中显著富集,提示其或与胃癌细胞的侵袭迁移相关;下调胃癌细胞中的NPC2表达后,显著抑制其迁移能力(NC组vs si-1组:P=0.00004;NC组vs si-2组:P=0.000449)。结论NPC2表达与胃癌患者预后密切相关,并在细胞迁移中发挥重要调控作用,可作为胃癌的潜在诊疗靶标。展开更多
文摘目的观察肠道胆固醇吸收抑制剂依泽替米贝(ezetimibe)对RAW264.7细胞源性荷脂细胞脂质蓄积的影响并对其机制进行初步探讨。方法采用油红O染色、高效液相色谱法检测细胞内脂滴数量和细胞内脂质含量,Western blot对NPC1L1(Niemann-Pick type C1Like-1)进行定性和半定量检测。结果RAW264.7细胞中有NPC1L1蛋白表达。不同浓度(0、0.003、0.01和0.03mol.L-1)依泽替米贝预先孵育RAW264.7细胞24h或最佳浓度(0.03mol.L-1)预先孵育不同时间(0、6、12和24h)后,换50mg.L-1oxLDL继续孵育24h,结果显示不同浓度ezetimibe预先孵育后,细胞内脂滴数量与面积随着浓度的增加而逐渐减少;Ezetimibe预先孵育可减少细胞内脂质蓄积,并呈浓度和时间依赖性。其中0.03mol.L-1ezetimibe预先孵育24h组作用最明显,CE百分比较oxLDL单独孵育组减少了约47%±0.1%。结论小鼠源性巨噬细胞RAW264.7中存在NPC1L1蛋白表达;依泽替米贝能够减少RAW264.7细胞中NPC1L1蛋白表达;依泽替米贝抑制RAW264.7细胞中脂质蓄积。
文摘Niemann-pick protein C1(NPC1) is a large integral membrane glycoprotein that resides in late endosomes,whereas niemann-pick protein C2(NPC2) is a small soluble protein found in the lumen of lysosomes.NPC1 protein is believed to facilitate the transport of lipids,particularly cholesterol,from late endosomes/lysosomes to the Golgi apparatus,endoplasmic reticulum and plasma membrane.NPC2 primarily plays a role in the egress of cholesterol and glycolipids from lysosomes.Mutations in either NPC1 or NPC2 result in aberrant lipid transport from endocytic compartments,which results in lysosomal storage of a complex mixture of lipids,primarily cholesterol and glycosphingolipids.The NPC proteins regulate sterol homeostasis through production of LDL cholesterol-derived oxysterols.Oxysterols are endogenous ligands for the liver X receptors(LXRs),which can upregulate ATP binding cassette transporter A1(ABCA1) expression.ABCA1 may have antiatherogenic effects through the efflux of it-mediated cholesterol.Meanwhile,NPC1 heterozygote mutation confers substantial resistance to lesional necrosis and lesional macrophage apoptosis.Study of the NPC proteins will help us for further understanding of the mechanisms involved in atherogenesis.
文摘目的观察C型尼曼-匹克蛋白2(Niemann-Pick protein C2,NPC2)在胃癌中的表达情况,分析其预后意义,初步探讨NPC2对胃癌的调控作用。方法利用胃癌数据库和组织芯片,比较NPC2在胃癌与正常胃黏膜中的表达差异;列联表分析NPC2表达与胃癌患者临床病理参数的相关性;Kaplan-Meier分析和COX回归分析NPC2表达在胃癌中的预后判断意义;通过GSEA挖掘NPC2调控胃癌细胞的可能分子机制;利用Transwell试验检测下调NPC2后胃癌细胞迁移能力的变化。结果相较于正常胃黏膜,NPC2在胃癌中高表达[GSE33335:(7.917±0.077)vs(7.601±0.074),P=0.0096;GSE63089:(9.083±0.123)vs(8.435±0.148),P=0.0001;组织芯片:(4.596±0.230)vs(3.336±0.176),P<0.0001];其表达水平与胃癌患者的AJCC临床分期(GSE15459:P=0.009;组织芯片:P=0.04)、区域淋巴结转移(组织芯片:P=0.04)等临床病理参数相关;NPC2高表达者预后不良(TCGA:P<0.0001;GSE15459:P=0.0023;组织芯片:P=0.0032),其表达水平是胃癌的独立预后预测因素(TCGA:风险比为2.140,95%CI为1.523~3.006,P<0.0001;组织芯片:风险比为1.926,95%CI为1.108~3.348,P=0.02);细胞黏附分子相关基因在NPC2高表达胃癌中显著富集,提示其或与胃癌细胞的侵袭迁移相关;下调胃癌细胞中的NPC2表达后,显著抑制其迁移能力(NC组vs si-1组:P=0.00004;NC组vs si-2组:P=0.000449)。结论NPC2表达与胃癌患者预后密切相关,并在细胞迁移中发挥重要调控作用,可作为胃癌的潜在诊疗靶标。
