Iron plays a key role in Parkinson＇s disease （PD）. Increased iron content of the substantia nigra （SN） has been found in PD patients, and divalent metal transporter 1 （DMT1） has been shown to be up-regulated in...Iron plays a key role in Parkinson＇s disease （PD）. Increased iron content of the substantia nigra （SN） has been found in PD patients, and divalent metal transporter 1 （DMT1） has been shown to be up-regulated in the SN of both MPTP-induced PD models and PD patients. However, the mechanisms underlying DMT1 up-regulation are largely unknown. In the present study, we observed that in the SN of 6-hydroxydopamine （6-OHDA）-induced PD rats, DMT1 with the iron responsive element （IRE, DMTI＋IRE）, but not DMT1 without IRE （DMTI-IRE）, was up- regulated, suggesting that increased DMTI＋IRE expression might account for nigral iron accumulation in PD rats. This possibility was further assessed in an in vitro study using 6-OHDA-treated and DMTl＋IRE-over-expressing MES23.5 cells. In 6-OHDA-treated MES23.5 cells, increased iron regulatory protein （IRP） 1 and IRP2 expression was observed, while silencing of IRPs dramatically diminished 6-OHDA-indueed DMTI＋IRE up-regulation. Pre- treatment with N-acetyl-L-cysteine fully suppressed IRPs up-regulation by inhibition of 6-OHDA-indueed oxidative stress. Increased DMTI＋IRE expression resulted in increased iron influx by MES23.5 cells. Our data provide direct evidence that DMTI＋IRE up-regulation can account for IRE/IRP-dependent 6-OHDA-induced iron accumulation initiated by 6-OHDA-induced intracellular oxidative stress and that increased levels of intracellular iron result in ag- gravated oxidative stress. The results of this study provide novel evidence supporting the use of anti-oxidants in the treatment of PD, with the goal of inhibiting iron accumulation by regulation of DMT1 expression.展开更多
The hexanucleotide repeat mutation in the intron-1 of the chromosome 9 open reading frame (C9orf72) is a frequent cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Altered RNA folding pla...The hexanucleotide repeat mutation in the intron-1 of the chromosome 9 open reading frame (C9orf72) is a frequent cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Altered RNA folding plays a role in ALS pathogenesis in two ways: non-ATG translation of the repeat can lead to aggregates of the known C9orf72 specific dipeptide polymer, whereas the repeat also can form neurotoxic RNA inclusions that dose-responsively kill motor neurons. We report the presence of a homology in the 5’untranslated region (UTR) of the messenger RNA encoding C9orf72 with the iron responsive elements (IRE) that control expression of iron-associated transcripts and predict that this RNA structure may iron-dependently regulate C9orf72 translation. We previously report altered serum ferritin levels track with severity of ALS in patients. Here, we conduct bioinformatics analyses to determine the secondary structure of the 5’UTR in C9orf72 mRNA and find it aligned with IREs in the human mitochondrial cis-aconitase and L and H-ferritin transcripts. Comparison of the role of RNA repeats in Friedriech’s ataxia and fragile X mental retardation suggests the utility of RNA based therapies for treatment of ALS. Antisense oligonucleotides (ASO) have been reported to therapeutically target these GGGGCC repeats. At the same time, because the function of C9orf72 is unknown, knockdown strategies carry some risk of inducing or compounding haploinsufficiency. We propose, for consideration, an approach that may enhance its therapeutic dynamic range by increasing the 5’UTR driven translation of C9orf72 protein to compensate for any potential ALS-specific or ASO-induced haploinsufficieny.展开更多
目的探讨血清铁调节蛋白2(iron-regulated protein 2,IRP2)、诱饵受体3(decoy receptor 3,DcR3)水平与老年慢性阻塞性肺疾病急性加重期(acute exacerbation of chronic obstructive pulmonary disease,AECOPD)患者疾病转归的关系。方法...目的探讨血清铁调节蛋白2(iron-regulated protein 2,IRP2)、诱饵受体3(decoy receptor 3,DcR3)水平与老年慢性阻塞性肺疾病急性加重期(acute exacerbation of chronic obstructive pulmonary disease,AECOPD)患者疾病转归的关系。方法选择AECOPD患者(AECOPD组)88例,检测血清IRP2、DcR3水平,追踪AECOPD患者临床疾病转归,根据临床疾病转归将其分为恶化组(22例)和好转组(66例)。多因素Logistic回归分析AECOPD患者疾病转归的影响因素。受试者工作特征曲线(receiver operating characteristic curve,ROC)分析IRP2、DcR3预测AECOPD患者疾病转归的价值。结果恶化组近1年AECOPD发作次数、急性生理和慢性健康状况评分、合并休克、呼吸困难评分(modified medical research council,mMRC)分级3~4级高于好转组(P<0.05)。恶化组治疗前和治疗2周后血清IRP2、DcR3水平高于好转组,治疗2周后好转组血清IRP2、DcR3水平低于治疗前(P<0.05);恶化组血清IRP2、DcR3水平与治疗前比较差异无统计学意义(P>0.05)。多因素Logistic回归分析结果显示,近1年AECOPD发作次数、mMRC分级、治疗前IRP2、治疗前DcR3是AECOPD患者疾病恶化的危险因素(P<0.05)。治疗前IRP2、DcR3预测AECOPD患者疾病转归的曲线下面积为0.781、0.795,联合IRP2、DcR3预测AECOPD患者疾病转归的曲线下面积为0.918,大于单独IRP2、DcR3预测(P<0.05)。结论AECOPD患者血清IRP2、DcR3水平均显著增高,且与肺功能降低以及疾病恶化有关,检测血清IRP2、DcR3水平有助于对AECOPD患者疾病转归的预测。展开更多
目的利用非酒精性脂肪性肝病(NAFLD)大鼠模型观察铁调素(Hepc)、IL-6在肝脏炎症进程中表达水平的变化。方法NAFLD肝组织标本均来自本课题组前期利用高脂乳剂灌胃法成功构建的大鼠NAFLD模型(M组)及同期生理盐水灌胃替代构建的正常大鼠对...目的利用非酒精性脂肪性肝病(NAFLD)大鼠模型观察铁调素(Hepc)、IL-6在肝脏炎症进程中表达水平的变化。方法NAFLD肝组织标本均来自本课题组前期利用高脂乳剂灌胃法成功构建的大鼠NAFLD模型(M组)及同期生理盐水灌胃替代构建的正常大鼠对照组(C组)。Hepc、IL-6单克隆抗体应用免疫组织化学法分别检测4、8、12周M组(M_4、M_8、M_(12))和12周C组大鼠肝组织中Hepc、IL-6的表达水平,同期评估各组肝脂肪炎症程度积分。检测2组大鼠肝组织Hepc和IL-6的表达水平,并计算肝组织NAS积分。多组间比较采用单因素方差分析,组间进一步两两比较采用LSD-t相关法。相关性分析均采用Pearson相关法。结果随试验周期延长,Hepc和IL-6在M_4组、M_8组、M_(12)组表达水平呈逐渐升高的趋势,且与C_(12)组相比差异均有统计学意义(Hepc:0.372±0.216、1.213±0.193、2.390±0.192 vs 0.166±0.192;IL-6:0.499±0.218、1.290±0.210、2.644±0.441 vs0.240±0.109,P值均<0.05);M组大鼠肝组织Hepc和IL-6表达呈正相关(r=0.944,P<0.05);M组大鼠肝组织Hepc和IL-6表达水平均与NAS呈正相关(r值分别为0.927和0.907,P值均<0.001)。结论初步观察到实验性NAFLD炎症进程可影响肝组织Hepc、IL-6表达且Hepc与肝组织炎症损伤因子IL-6表达强度相关性明显。Hepc和IL-6作为NAFLD疾病进展的预测因子值得进一步研究。展开更多
目的探讨肌萎缩性侧索硬化症(ALS)转基因鼠脊髓内铁转运相关蛋白表达变化与铁稳态失衡的关联。方法选取h SOD1G93A转基因鼠(ALS鼠)和同窝野生型鼠(WT鼠),分别于生后70、95和122 d分离脊髓,每时间点每组各9只实验动物。Western blotting...目的探讨肌萎缩性侧索硬化症(ALS)转基因鼠脊髓内铁转运相关蛋白表达变化与铁稳态失衡的关联。方法选取h SOD1G93A转基因鼠(ALS鼠)和同窝野生型鼠(WT鼠),分别于生后70、95和122 d分离脊髓,每时间点每组各9只实验动物。Western blotting检测脊髓组织内铁转运蛋白二价金属转运蛋白-1(DMT1)、铁转运蛋白-1(FPN1)及调节蛋白铁调节蛋白-1(IRP1)的表达;免疫荧光双重标记检测脊髓腰段前角内细胞共定位情况。结果Western blotting显示,与WT鼠比较,各时间点ALS鼠脊髓内DMT1表达均显著降低(P<0.05,P<0.01);70 d FPN1表达升高(P<0.05),95 d和122 d表达下降(P<0.01);95 d、122 d IRP1表达降低(P<0.01)。免疫荧光双重标记显示,在70 d WT鼠和ALS鼠腰段脊髓中DMT1主要与β-微管蛋白Ⅲ(β-tubulinⅢ)共表达。与WT组相比,95 d ALS鼠脊髓腰段前角神经元内DMT1免疫反应强,而FPN1荧光强度减弱。随疾病进展,DMT1、FPN1与反应性胶质细胞共定位表达增多。IRP1随疾病进展表达强度降低。结论随ALS病程进展,发病早期神经元铁转入增加,转出减少,反应性神经胶质细胞铁转运活性增强,参与局部铁稳态失衡及脊髓前角运动神经元进行性丢失。IRP1表达降低,部分参与局部铁代谢调节。展开更多
基金We thank Dr Wei-dong Le for providing the MES23.5 cell line. This work was supported by grants from the National Program of Basic Research sponsored by the Ministry of Science and Tech- nology of China （2006CB500704）, the National Natural Science Foundation of China （30930036, 30770757, 30870858） and the Natural Science Fund of Shandong Province for Distinguished Young Scholars （JQ200807）.
文摘Iron plays a key role in Parkinson＇s disease （PD）. Increased iron content of the substantia nigra （SN） has been found in PD patients, and divalent metal transporter 1 （DMT1） has been shown to be up-regulated in the SN of both MPTP-induced PD models and PD patients. However, the mechanisms underlying DMT1 up-regulation are largely unknown. In the present study, we observed that in the SN of 6-hydroxydopamine （6-OHDA）-induced PD rats, DMT1 with the iron responsive element （IRE, DMTI＋IRE）, but not DMT1 without IRE （DMTI-IRE）, was up- regulated, suggesting that increased DMTI＋IRE expression might account for nigral iron accumulation in PD rats. This possibility was further assessed in an in vitro study using 6-OHDA-treated and DMTl＋IRE-over-expressing MES23.5 cells. In 6-OHDA-treated MES23.5 cells, increased iron regulatory protein （IRP） 1 and IRP2 expression was observed, while silencing of IRPs dramatically diminished 6-OHDA-indueed DMTI＋IRE up-regulation. Pre- treatment with N-acetyl-L-cysteine fully suppressed IRPs up-regulation by inhibition of 6-OHDA-indueed oxidative stress. Increased DMTI＋IRE expression resulted in increased iron influx by MES23.5 cells. Our data provide direct evidence that DMTI＋IRE up-regulation can account for IRE/IRP-dependent 6-OHDA-induced iron accumulation initiated by 6-OHDA-induced intracellular oxidative stress and that increased levels of intracellular iron result in ag- gravated oxidative stress. The results of this study provide novel evidence supporting the use of anti-oxidants in the treatment of PD, with the goal of inhibiting iron accumulation by regulation of DMT1 expression.
文摘The hexanucleotide repeat mutation in the intron-1 of the chromosome 9 open reading frame (C9orf72) is a frequent cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Altered RNA folding plays a role in ALS pathogenesis in two ways: non-ATG translation of the repeat can lead to aggregates of the known C9orf72 specific dipeptide polymer, whereas the repeat also can form neurotoxic RNA inclusions that dose-responsively kill motor neurons. We report the presence of a homology in the 5’untranslated region (UTR) of the messenger RNA encoding C9orf72 with the iron responsive elements (IRE) that control expression of iron-associated transcripts and predict that this RNA structure may iron-dependently regulate C9orf72 translation. We previously report altered serum ferritin levels track with severity of ALS in patients. Here, we conduct bioinformatics analyses to determine the secondary structure of the 5’UTR in C9orf72 mRNA and find it aligned with IREs in the human mitochondrial cis-aconitase and L and H-ferritin transcripts. Comparison of the role of RNA repeats in Friedriech’s ataxia and fragile X mental retardation suggests the utility of RNA based therapies for treatment of ALS. Antisense oligonucleotides (ASO) have been reported to therapeutically target these GGGGCC repeats. At the same time, because the function of C9orf72 is unknown, knockdown strategies carry some risk of inducing or compounding haploinsufficiency. We propose, for consideration, an approach that may enhance its therapeutic dynamic range by increasing the 5’UTR driven translation of C9orf72 protein to compensate for any potential ALS-specific or ASO-induced haploinsufficieny.
文摘目的探讨血清铁调节蛋白2(iron-regulated protein 2,IRP2)、诱饵受体3(decoy receptor 3,DcR3)水平与老年慢性阻塞性肺疾病急性加重期(acute exacerbation of chronic obstructive pulmonary disease,AECOPD)患者疾病转归的关系。方法选择AECOPD患者(AECOPD组)88例,检测血清IRP2、DcR3水平,追踪AECOPD患者临床疾病转归,根据临床疾病转归将其分为恶化组(22例)和好转组(66例)。多因素Logistic回归分析AECOPD患者疾病转归的影响因素。受试者工作特征曲线(receiver operating characteristic curve,ROC)分析IRP2、DcR3预测AECOPD患者疾病转归的价值。结果恶化组近1年AECOPD发作次数、急性生理和慢性健康状况评分、合并休克、呼吸困难评分(modified medical research council,mMRC)分级3~4级高于好转组(P<0.05)。恶化组治疗前和治疗2周后血清IRP2、DcR3水平高于好转组,治疗2周后好转组血清IRP2、DcR3水平低于治疗前(P<0.05);恶化组血清IRP2、DcR3水平与治疗前比较差异无统计学意义(P>0.05)。多因素Logistic回归分析结果显示,近1年AECOPD发作次数、mMRC分级、治疗前IRP2、治疗前DcR3是AECOPD患者疾病恶化的危险因素(P<0.05)。治疗前IRP2、DcR3预测AECOPD患者疾病转归的曲线下面积为0.781、0.795,联合IRP2、DcR3预测AECOPD患者疾病转归的曲线下面积为0.918,大于单独IRP2、DcR3预测(P<0.05)。结论AECOPD患者血清IRP2、DcR3水平均显著增高,且与肺功能降低以及疾病恶化有关,检测血清IRP2、DcR3水平有助于对AECOPD患者疾病转归的预测。
文摘目的利用非酒精性脂肪性肝病(NAFLD)大鼠模型观察铁调素(Hepc)、IL-6在肝脏炎症进程中表达水平的变化。方法NAFLD肝组织标本均来自本课题组前期利用高脂乳剂灌胃法成功构建的大鼠NAFLD模型(M组)及同期生理盐水灌胃替代构建的正常大鼠对照组(C组)。Hepc、IL-6单克隆抗体应用免疫组织化学法分别检测4、8、12周M组(M_4、M_8、M_(12))和12周C组大鼠肝组织中Hepc、IL-6的表达水平,同期评估各组肝脂肪炎症程度积分。检测2组大鼠肝组织Hepc和IL-6的表达水平,并计算肝组织NAS积分。多组间比较采用单因素方差分析,组间进一步两两比较采用LSD-t相关法。相关性分析均采用Pearson相关法。结果随试验周期延长,Hepc和IL-6在M_4组、M_8组、M_(12)组表达水平呈逐渐升高的趋势,且与C_(12)组相比差异均有统计学意义(Hepc:0.372±0.216、1.213±0.193、2.390±0.192 vs 0.166±0.192;IL-6:0.499±0.218、1.290±0.210、2.644±0.441 vs0.240±0.109,P值均<0.05);M组大鼠肝组织Hepc和IL-6表达呈正相关(r=0.944,P<0.05);M组大鼠肝组织Hepc和IL-6表达水平均与NAS呈正相关(r值分别为0.927和0.907,P值均<0.001)。结论初步观察到实验性NAFLD炎症进程可影响肝组织Hepc、IL-6表达且Hepc与肝组织炎症损伤因子IL-6表达强度相关性明显。Hepc和IL-6作为NAFLD疾病进展的预测因子值得进一步研究。
文摘目的探讨肌萎缩性侧索硬化症(ALS)转基因鼠脊髓内铁转运相关蛋白表达变化与铁稳态失衡的关联。方法选取h SOD1G93A转基因鼠(ALS鼠)和同窝野生型鼠(WT鼠),分别于生后70、95和122 d分离脊髓,每时间点每组各9只实验动物。Western blotting检测脊髓组织内铁转运蛋白二价金属转运蛋白-1(DMT1)、铁转运蛋白-1(FPN1)及调节蛋白铁调节蛋白-1(IRP1)的表达;免疫荧光双重标记检测脊髓腰段前角内细胞共定位情况。结果Western blotting显示,与WT鼠比较,各时间点ALS鼠脊髓内DMT1表达均显著降低(P<0.05,P<0.01);70 d FPN1表达升高(P<0.05),95 d和122 d表达下降(P<0.01);95 d、122 d IRP1表达降低(P<0.01)。免疫荧光双重标记显示,在70 d WT鼠和ALS鼠腰段脊髓中DMT1主要与β-微管蛋白Ⅲ(β-tubulinⅢ)共表达。与WT组相比,95 d ALS鼠脊髓腰段前角神经元内DMT1免疫反应强,而FPN1荧光强度减弱。随疾病进展,DMT1、FPN1与反应性胶质细胞共定位表达增多。IRP1随疾病进展表达强度降低。结论随ALS病程进展,发病早期神经元铁转入增加,转出减少,反应性神经胶质细胞铁转运活性增强,参与局部铁稳态失衡及脊髓前角运动神经元进行性丢失。IRP1表达降低,部分参与局部铁代谢调节。
