Nogo-B受体(Nogo-B receptor,NgBR)参与脂肪肝和胰岛素敏感性的形成,但是并不清楚肝X受体(liver X receptor,LXR)激动剂是否能够调控NgBR的表达。文章使用人工合成的LXR激动剂(T0901317和GW3965)分析其对肝源细胞系中NgBR表达的影响,构...Nogo-B受体(Nogo-B receptor,NgBR)参与脂肪肝和胰岛素敏感性的形成,但是并不清楚肝X受体(liver X receptor,LXR)激动剂是否能够调控NgBR的表达。文章使用人工合成的LXR激动剂(T0901317和GW3965)分析其对肝源细胞系中NgBR表达的影响,构建正常或突变NgBR启动子,通过双荧光素酶报告基因系统检测LXR激动剂对启动子活性的影响;采用CRISPR-CAS9方法建立LXRα或LXRβ基因敲除的HepG2细胞系,通过Western Blot检测相关基因的表达变化;向ApoE-/-小鼠腹腔注射LXR激动剂T0901317,分析小鼠肝脏中NgBR的表达变化。结果发现,LXR激动剂能够通过激活LXR促进NgBR蛋白的表达,该诱导作用是以LXRE依赖的方式进行的,并且LXR的表达发挥着重要作用。在体内实验中,也证明了LXR激动剂T0901317上调NgBR蛋白表达。结果表明,NgBR是LXR的靶蛋白,LXR通过结合NgBR启动子LXRE序列促进其转录和翻译。展开更多
目的检测肝脏X受体(Liver X receptor alpha,LXRα)在HBV阳性肝硬化组织及原发性肝癌中的表达情况及临床意义。方法收集20例揭阳市人民医院及汕头大学医学院第一附属医院手术切除的HBV阳性肝硬化原发性肝癌组织标本,应用免疫组化染色检...目的检测肝脏X受体(Liver X receptor alpha,LXRα)在HBV阳性肝硬化组织及原发性肝癌中的表达情况及临床意义。方法收集20例揭阳市人民医院及汕头大学医学院第一附属医院手术切除的HBV阳性肝硬化原发性肝癌组织标本,应用免疫组化染色检测LXRα表达。Huh7细胞中分别过表达小鼠mLXRα,及共过表达HBx(HBV X protein)和mLXRα,并检测mLXRα及HBx对内源性LXRα信号通路下游靶基因SREBP-1(Sterol regulatory element-binding protein 1)的影响;双荧光素酶报告系统检测人肝癌Huh7细胞中HBx对LXRα转录活性的影响。结果 LXRα在肝硬化组织中阳性表达率为95%,高于癌组织的25%。HBx上调SREBP-1的表达可能与HBx调控LXRα的转录活性有关。结论 HBx通过调节癌前高表达的LXRα的转录活性,并影响其信号通路可能与HCC发生相关。展开更多
Aim: We aimed to investigate whether the agonists for liver X receptor (LXR) ameliorate lupus-like phenotypes in mice mediated by the clearance of apoptotic cells, and compare with peroxisome proliferator-activated re...Aim: We aimed to investigate whether the agonists for liver X receptor (LXR) ameliorate lupus-like phenotypes in mice mediated by the clearance of apoptotic cells, and compare with peroxisome proliferator-activated receptor (PPAR) γ plus PPARδ agonists, which also facilitate the clearance of apoptotic cells and exert anti-inflammatory effects in systemic lupus erythematosus (SLE). Methods: We investigated the efficacy of LXR agonist (GW3965) or dual treatment of PPARγ (pioglitazone) and PPARδ (GW0742) agonists in SLE animal models, female MRL/MpJ-Fas/J mice and BALB/cAJcl mice treated with pristane. The data were analyzed with one-way analysis of variance and Tukey’s honestly significant difference tests. Results: The treatment with LXR or PPARγ/δ agonists did not significantly alter the swelling of lymph nodes, ds-DNA production, albuminuria, histological score of glomerular lesions, and mRNA expression of target genes including Abca1, C1qa, Icam1, Mertk and Tnf. Conclusion: LXR or PPARγ/δ agonists targeting the impaired clearance for apoptosis cells may not be efficient in the remission induction therapy in SLE.展开更多
大黄素(emodin)对多种肿瘤细胞有较强的抑制增殖和诱导凋亡的作用,但其作用机制尚不清楚。本研究通过配体-受体竞争结合实验以及报告基因检测了大黄素对维甲酸X受体(retinoid X receptor alpha,RXRα)的结合和转录活性的调控,并研究了...大黄素(emodin)对多种肿瘤细胞有较强的抑制增殖和诱导凋亡的作用,但其作用机制尚不清楚。本研究通过配体-受体竞争结合实验以及报告基因检测了大黄素对维甲酸X受体(retinoid X receptor alpha,RXRα)的结合和转录活性的调控,并研究了大黄素对肺癌细胞H460和肝癌细胞SMMC-7721生长和凋亡的作用。结果发现,大黄素对两种癌细胞有很强的抑制增殖作用,加入RXRα的天然配体9-顺式视黄酸(9-cis-retinoid acid,9-cis-RA)共同处理可显著缓解这种抑制作用。大黄素能浓度依赖地引起两种癌细胞系的凋亡,使细胞核出现碎裂和染色质浓染。报告基因实验发现大黄素对RXRα同源和异源二聚体的转录激活有显著抑制作用。体外的配体竞争结合实验发现,大黄素不直接结合RXRα的配体结合区。蛋白质免疫印迹实验发现,大黄素不影响RXRα的蛋白表达。结果提示,大黄素具有诱导肺癌细胞H460和肝癌细胞SMMC-7721凋亡和抑制细胞生长的作用,大黄素抑制9-cis-RA对RXR转录激活作用以及9-cis-RA具有一定程度拮抗大黄素对肺癌细胞H460和肝癌细胞SMMC-7721的生长抑制作用,提示大黄素的抗癌作用可能与细胞内RXR的功能有关,并以RXR转录非依赖性的方式起作用。配体竞争结合实验结果提示大黄素可能间接作用于RXR。展开更多
为了探讨紫花苜蓿对猪骨骼肌细胞中肝X受体(liver X receptors,LXRs)表达的影响及其与胴体肉质的关系,采用免疫组织化学方法检测LXRs蛋白的分布,通过酶联免疫方法(enzyme-linked immunosorbent assay,ELISA)研究LXRs蛋白总量的改变,以...为了探讨紫花苜蓿对猪骨骼肌细胞中肝X受体(liver X receptors,LXRs)表达的影响及其与胴体肉质的关系,采用免疫组织化学方法检测LXRs蛋白的分布,通过酶联免疫方法(enzyme-linked immunosorbent assay,ELISA)研究LXRs蛋白总量的改变,以荧光定量PCR方法分析猪骨骼肌细胞中LXRs基因mRNA的表达变化。结果表明,LXRs定位于骨骼肌细胞的细胞质、细胞膜和细胞核内;与对照组相比,日粮中添加4%紫花苜蓿能使LXRs基因和蛋白表达量明显上升(P<0.05),并使猪的瘦肉率降低(P>0.05),肌内脂肪含量显著增高(P<0.05),同时大理石纹评分较好(P<0.05),滴水损失下降(P<0.05),细胞间隙变小(P<0.05);添加6%紫花苜蓿使LXRs基因和蛋白表达量上升(P<0.05),但低于4%紫花苜蓿组(P>0.05),同时大理石纹评分及失水率增高(P<0.05),板油重下降(P<0.05)。结果提示,紫花苜蓿添加量的不同对猪肉品质的作用效果不同,为紫花苜蓿在养猪业的科学应用奠定了理论基础。展开更多
肝X受体(liver X receptors,LXRs)包括LXRα(NR1H3)和LXRβ(NR1H2)两种亚型,对机体的生理活动尤其代谢过程具有重要的调节作用。近年研究发现,LXRs可通过调控一系列信号转导通路抑制癌细胞增殖、侵袭、诱导凋亡等进而影响前列腺癌、乳...肝X受体(liver X receptors,LXRs)包括LXRα(NR1H3)和LXRβ(NR1H2)两种亚型,对机体的生理活动尤其代谢过程具有重要的调节作用。近年研究发现,LXRs可通过调控一系列信号转导通路抑制癌细胞增殖、侵袭、诱导凋亡等进而影响前列腺癌、乳腺癌、肝癌、黑色素瘤、白血病等多种恶性肿瘤的发生发展,成为癌症治疗新靶点。因此本文主要就LXRs在癌症网络调控的研究进展进行综述。展开更多
Objectives:To investigate acute toxicity of Bajitian(Morinda officinalis)in zebrafish embryos.Methods:Zebrafish embryos at 48-h post fertilization(hpf)were exposed to Bajitian ethanol extract for72 h.The causative act...Objectives:To investigate acute toxicity of Bajitian(Morinda officinalis)in zebrafish embryos.Methods:Zebrafish embryos at 48-h post fertilization(hpf)were exposed to Bajitian ethanol extract for72 h.The causative action of a delay in yolk sac absorption by Bajitian was investigated by RT-PCR analysis of lipid metabolism-related microsomal triglyceride transfer protein(MTP),apolipoprotein CII(ApoC2)and lipogenesis-related liver x receptor(LXR)genes.The effect of Bajitian eliciting an inflammatory response was studied by exposing 72 hpf myeloperoxidase(MPO):GFP transgenic zebrafish embryos to Bajitian extract for 4 h.Assessment was done by TUNEL,caspase-3/7,and RT-PCR analysis of the apoptosis related pathway B-cell lymphoma 2 associated X protein(Bax),Nuclear factor kappa-lightchain-enhancer of activated B cells(NF-k B)genes,neutrophil development-related stem cell leukaemia(SCL)and transcription factor PU.1 genes,to reveal the causative action of Bajitian reducing neutrophils.Results:RT-PCR analysis found that Bajitian extract had no effect on the expression of MTP or ApoC2 genes,but upregulated LXR gene,which might explain the delay in yolk sac absorption.Analysis of the inflammatory response showed that compared with negative controls,Bajitian extract significantly(P<.05)reduced the number of neutrophils in MPO:GFP embryos.TUNEL,caspase-3/7,and RT-PCR analysis of Bax and NF-k B genes found that Bajitian extract did not trigger the cell apoptosis.Further RT-PCR analysis found that Bajitian extract did not affect SCL expression,but did lead to down-regulation of PU.1.The inhibition of neutrophil development/differentiation may explain the decline in the total number of neutrophils following Bajitian treatment,which could be attributed to the anti-inflammatory effects found clinically for this drug.Conclusions:This study demonstrated that Bajitian caused a delay in yolk sac absorption and a decrease neutrophil in zebrafish embryos,which may be related to the inhibition of neutrophil development.展开更多
文摘Nogo-B受体(Nogo-B receptor,NgBR)参与脂肪肝和胰岛素敏感性的形成,但是并不清楚肝X受体(liver X receptor,LXR)激动剂是否能够调控NgBR的表达。文章使用人工合成的LXR激动剂(T0901317和GW3965)分析其对肝源细胞系中NgBR表达的影响,构建正常或突变NgBR启动子,通过双荧光素酶报告基因系统检测LXR激动剂对启动子活性的影响;采用CRISPR-CAS9方法建立LXRα或LXRβ基因敲除的HepG2细胞系,通过Western Blot检测相关基因的表达变化;向ApoE-/-小鼠腹腔注射LXR激动剂T0901317,分析小鼠肝脏中NgBR的表达变化。结果发现,LXR激动剂能够通过激活LXR促进NgBR蛋白的表达,该诱导作用是以LXRE依赖的方式进行的,并且LXR的表达发挥着重要作用。在体内实验中,也证明了LXR激动剂T0901317上调NgBR蛋白表达。结果表明,NgBR是LXR的靶蛋白,LXR通过结合NgBR启动子LXRE序列促进其转录和翻译。
文摘目的检测肝脏X受体(Liver X receptor alpha,LXRα)在HBV阳性肝硬化组织及原发性肝癌中的表达情况及临床意义。方法收集20例揭阳市人民医院及汕头大学医学院第一附属医院手术切除的HBV阳性肝硬化原发性肝癌组织标本,应用免疫组化染色检测LXRα表达。Huh7细胞中分别过表达小鼠mLXRα,及共过表达HBx(HBV X protein)和mLXRα,并检测mLXRα及HBx对内源性LXRα信号通路下游靶基因SREBP-1(Sterol regulatory element-binding protein 1)的影响;双荧光素酶报告系统检测人肝癌Huh7细胞中HBx对LXRα转录活性的影响。结果 LXRα在肝硬化组织中阳性表达率为95%,高于癌组织的25%。HBx上调SREBP-1的表达可能与HBx调控LXRα的转录活性有关。结论 HBx通过调节癌前高表达的LXRα的转录活性,并影响其信号通路可能与HCC发生相关。
文摘Aim: We aimed to investigate whether the agonists for liver X receptor (LXR) ameliorate lupus-like phenotypes in mice mediated by the clearance of apoptotic cells, and compare with peroxisome proliferator-activated receptor (PPAR) γ plus PPARδ agonists, which also facilitate the clearance of apoptotic cells and exert anti-inflammatory effects in systemic lupus erythematosus (SLE). Methods: We investigated the efficacy of LXR agonist (GW3965) or dual treatment of PPARγ (pioglitazone) and PPARδ (GW0742) agonists in SLE animal models, female MRL/MpJ-Fas/J mice and BALB/cAJcl mice treated with pristane. The data were analyzed with one-way analysis of variance and Tukey’s honestly significant difference tests. Results: The treatment with LXR or PPARγ/δ agonists did not significantly alter the swelling of lymph nodes, ds-DNA production, albuminuria, histological score of glomerular lesions, and mRNA expression of target genes including Abca1, C1qa, Icam1, Mertk and Tnf. Conclusion: LXR or PPARγ/δ agonists targeting the impaired clearance for apoptosis cells may not be efficient in the remission induction therapy in SLE.
文摘大黄素(emodin)对多种肿瘤细胞有较强的抑制增殖和诱导凋亡的作用,但其作用机制尚不清楚。本研究通过配体-受体竞争结合实验以及报告基因检测了大黄素对维甲酸X受体(retinoid X receptor alpha,RXRα)的结合和转录活性的调控,并研究了大黄素对肺癌细胞H460和肝癌细胞SMMC-7721生长和凋亡的作用。结果发现,大黄素对两种癌细胞有很强的抑制增殖作用,加入RXRα的天然配体9-顺式视黄酸(9-cis-retinoid acid,9-cis-RA)共同处理可显著缓解这种抑制作用。大黄素能浓度依赖地引起两种癌细胞系的凋亡,使细胞核出现碎裂和染色质浓染。报告基因实验发现大黄素对RXRα同源和异源二聚体的转录激活有显著抑制作用。体外的配体竞争结合实验发现,大黄素不直接结合RXRα的配体结合区。蛋白质免疫印迹实验发现,大黄素不影响RXRα的蛋白表达。结果提示,大黄素具有诱导肺癌细胞H460和肝癌细胞SMMC-7721凋亡和抑制细胞生长的作用,大黄素抑制9-cis-RA对RXR转录激活作用以及9-cis-RA具有一定程度拮抗大黄素对肺癌细胞H460和肝癌细胞SMMC-7721的生长抑制作用,提示大黄素的抗癌作用可能与细胞内RXR的功能有关,并以RXR转录非依赖性的方式起作用。配体竞争结合实验结果提示大黄素可能间接作用于RXR。
文摘为了探讨紫花苜蓿对猪骨骼肌细胞中肝X受体(liver X receptors,LXRs)表达的影响及其与胴体肉质的关系,采用免疫组织化学方法检测LXRs蛋白的分布,通过酶联免疫方法(enzyme-linked immunosorbent assay,ELISA)研究LXRs蛋白总量的改变,以荧光定量PCR方法分析猪骨骼肌细胞中LXRs基因mRNA的表达变化。结果表明,LXRs定位于骨骼肌细胞的细胞质、细胞膜和细胞核内;与对照组相比,日粮中添加4%紫花苜蓿能使LXRs基因和蛋白表达量明显上升(P<0.05),并使猪的瘦肉率降低(P>0.05),肌内脂肪含量显著增高(P<0.05),同时大理石纹评分较好(P<0.05),滴水损失下降(P<0.05),细胞间隙变小(P<0.05);添加6%紫花苜蓿使LXRs基因和蛋白表达量上升(P<0.05),但低于4%紫花苜蓿组(P>0.05),同时大理石纹评分及失水率增高(P<0.05),板油重下降(P<0.05)。结果提示,紫花苜蓿添加量的不同对猪肉品质的作用效果不同,为紫花苜蓿在养猪业的科学应用奠定了理论基础。
文摘肝X受体(liver X receptors,LXRs)包括LXRα(NR1H3)和LXRβ(NR1H2)两种亚型,对机体的生理活动尤其代谢过程具有重要的调节作用。近年研究发现,LXRs可通过调控一系列信号转导通路抑制癌细胞增殖、侵袭、诱导凋亡等进而影响前列腺癌、乳腺癌、肝癌、黑色素瘤、白血病等多种恶性肿瘤的发生发展,成为癌症治疗新靶点。因此本文主要就LXRs在癌症网络调控的研究进展进行综述。
基金Infinitus(China)Company Ltd.internal research funding。
文摘Objectives:To investigate acute toxicity of Bajitian(Morinda officinalis)in zebrafish embryos.Methods:Zebrafish embryos at 48-h post fertilization(hpf)were exposed to Bajitian ethanol extract for72 h.The causative action of a delay in yolk sac absorption by Bajitian was investigated by RT-PCR analysis of lipid metabolism-related microsomal triglyceride transfer protein(MTP),apolipoprotein CII(ApoC2)and lipogenesis-related liver x receptor(LXR)genes.The effect of Bajitian eliciting an inflammatory response was studied by exposing 72 hpf myeloperoxidase(MPO):GFP transgenic zebrafish embryos to Bajitian extract for 4 h.Assessment was done by TUNEL,caspase-3/7,and RT-PCR analysis of the apoptosis related pathway B-cell lymphoma 2 associated X protein(Bax),Nuclear factor kappa-lightchain-enhancer of activated B cells(NF-k B)genes,neutrophil development-related stem cell leukaemia(SCL)and transcription factor PU.1 genes,to reveal the causative action of Bajitian reducing neutrophils.Results:RT-PCR analysis found that Bajitian extract had no effect on the expression of MTP or ApoC2 genes,but upregulated LXR gene,which might explain the delay in yolk sac absorption.Analysis of the inflammatory response showed that compared with negative controls,Bajitian extract significantly(P<.05)reduced the number of neutrophils in MPO:GFP embryos.TUNEL,caspase-3/7,and RT-PCR analysis of Bax and NF-k B genes found that Bajitian extract did not trigger the cell apoptosis.Further RT-PCR analysis found that Bajitian extract did not affect SCL expression,but did lead to down-regulation of PU.1.The inhibition of neutrophil development/differentiation may explain the decline in the total number of neutrophils following Bajitian treatment,which could be attributed to the anti-inflammatory effects found clinically for this drug.Conclusions:This study demonstrated that Bajitian caused a delay in yolk sac absorption and a decrease neutrophil in zebrafish embryos,which may be related to the inhibition of neutrophil development.
