The signaling mechanisms underlying ischemia-induced nerve cell apoptosis are poorly understood. We investigated the effects of apoptosis-related signal transduction pathways following ischemic spinal cord injury, inc...The signaling mechanisms underlying ischemia-induced nerve cell apoptosis are poorly understood. We investigated the effects of apoptosis-related signal transduction pathways following ischemic spinal cord injury, including extracellular signal-regulated kinase（ERK）, serine-threonine protein kinase（Akt） and c-Jun N-terminal kinase（JNK） signaling pathways. We established a rat model of acute spinal cord injury by inserting a catheter balloon in the left subclavian artery for 25 minutes. Rat models exhibited notable hindlimb dysfunction. Apoptotic cells were abundant in the anterior horn and central canal of the spinal cord. The number of apoptotic neurons was highest 48 hours post injury. The expression of phosphorylated Akt（pAkt） and phosphorylated ERK（p-ERK） increased immediately after reperfusion, peaked at 4 hours（p-Akt） or 2 hours（p-ERK）, decreased at 12 hours, and then increased at 24 hours. Phosphorylated JNK expression reduced after reperfusion, increased at 12 hours to near normal levels, and then showed a downward trend at 24 hours. Pearson linear correlation analysis also demonstrated that the number of apoptotic cells negatively correlated with p-Akt expression. These findings suggest that activation of Akt may be a key contributing factor in the delay of neuronal apoptosis after spinal cord ischemia, particularly at the stage of reperfusion, and thus may be a target for neuronal protection and reduction of neuronal apoptosis after spinal cord injury.展开更多
放疗是肿瘤的重要治疗手段之一,仍有部分患者在接受放疗后存在复发或抗拒。哺乳动物雷帕霉素靶蛋白(mamma-lian target of rapamycin,mTOR)是PI3K/AKT信号通路的主要效应分子,分为mTORC1和mTORC2,对细胞生长及增殖、细胞周期进展及蛋白...放疗是肿瘤的重要治疗手段之一,仍有部分患者在接受放疗后存在复发或抗拒。哺乳动物雷帕霉素靶蛋白(mamma-lian target of rapamycin,mTOR)是PI3K/AKT信号通路的主要效应分子,分为mTORC1和mTORC2,对细胞生长及增殖、细胞周期进展及蛋白翻译等均有重要调节作用。mTOR异常表达与肿瘤发生及治疗反应密切相关。肿瘤的放疗敏感性与"4R"效应有关。mTOR抑制剂可通过影响细胞周期进展、DNA损伤修复及抗血管形成等多种途径发挥放疗增敏作用。初期研究证实依维莫司具有放疗增敏作用并且毒性可耐受。应用mTOR抑制剂后不同细胞及个体反应不同,可能与基因表达状态有关,需进一步研究证实。展开更多
TOR(target of rapamycin)是真核细胞中一种高度保守的与磷脂酰肌醇激酶相关的蛋白激酶(PIKK),它是免疫抑制剂/抗癌药物雷帕霉素(rapamycin)的靶物质。TOR是细胞生长的中枢控制因子,外界营养因素通过TOR的作用控制酵母、果蝇和哺乳动物...TOR(target of rapamycin)是真核细胞中一种高度保守的与磷脂酰肌醇激酶相关的蛋白激酶(PIKK),它是免疫抑制剂/抗癌药物雷帕霉素(rapamycin)的靶物质。TOR是细胞生长的中枢控制因子,外界营养因素通过TOR的作用控制酵母、果蝇和哺乳动物细胞的生长。TOR根据细胞环境的营养条件做出相应的应答,参与调控蛋白激酶和蛋白磷酸酯酶的活性,从而控制与蛋白质合成和基因转录相关基因的表达。现对酵母细胞中TOR信号转导途径的研究进行简明的阐述。展开更多
子痫前期(preeclampsia,PE)是临床常见的妊娠期特发性疾病,其病情变化呈动态性进展,临床表现多样化,病因机制迄今尚未完全阐明,主要认为与遗传因素、免疫因素、营养因素和环境因素等密切相关。近年有研究表明,哺乳动物雷帕霉素靶蛋白(ma...子痫前期(preeclampsia,PE)是临床常见的妊娠期特发性疾病,其病情变化呈动态性进展,临床表现多样化,病因机制迄今尚未完全阐明,主要认为与遗传因素、免疫因素、营养因素和环境因素等密切相关。近年有研究表明,哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)信号通路通过调控细胞增殖、侵袭、迁移和凋亡能力,参与胎盘滋养细胞与血管内皮细胞活性的调节,且胰岛素信号通过激活mTOR信号通路启动下游分子调节细胞代谢,导致母体血管内皮损伤、子宫螺旋小动脉重构受损,以及炎症免疫反应异常等,参与PE的发生。通过探讨mTOR信号通路与PE发病的相关性,为PE的病理生理学研究及疾病的治疗提供理论基础。展开更多
Throughout the globe,diabetes mellitus（DM） is increasing in incidence with limited therapies presently available to prevent or resolve the significant complications of this disorder.DM impacts multiple organs and af...Throughout the globe,diabetes mellitus（DM） is increasing in incidence with limited therapies presently available to prevent or resolve the significant complications of this disorder.DM impacts multiple organs and affects all components of the central and peripheral nervous systems that can range from dementia to diabetic neuropathy.The mechanistic target of rapamycin（m TOR） is a promising agent for the development of novel regenerative strategies for the treatment of DM.m TOR and its related signaling pathways impact multiple metabolic parameters that include cellular metabolic homeostasis,insulin resistance,insulin secretion,stem cell proliferation and differentiation,pancreatic β-cell function,and programmed cell death with apoptosis and autophagy.m TOR is central element for the protein complexes m TOR Complex 1（m TORC1） and m TOR Complex 2（m TORC2） and is a critical component for a number of signaling pathways that involve phosphoinositide 3-kinase（PI 3-K）,protein kinase B（Akt）,AMP activated protein kinase（AMPK）,silent mating type information regulation 2 homolog 1（Saccharomyces cerevisiae）（SIRT1）,Wnt1 inducible signaling pathway protein 1（WISP1）,and growth factors.As a result,m TOR represents an exciting target to offer new clinical avenues for the treatment of DM and the complications of this disease.Future studies directed to elucidate the delicate balance m TOR holds over cellular metabolism and the impact of its broad signaling pathways should foster the translation of these targets into effective clinical regimens for DM.展开更多
Methylotrophic yeast Pichia pastoris is an object of modern biotechnology. Decisive understanding of gene regulation mechanisms is essential for successful protein production. In this study, we investigated the effect...Methylotrophic yeast Pichia pastoris is an object of modern biotechnology. Decisive understanding of gene regulation mechanisms is essential for successful protein production. In this study, we investigated the effect of deletions in P. pastoris genes encoding proteins, homologous to S. serevisiae Rtg1p, Rtg 2p, Msn2p and Msn4p. It was shown, that deletion in PpRTG1 gene results in inability of P. pastoris to grow on medium with methanol as a carbon source and ammonium sulfate as a source of nitrogen. We also demonstrate that deletions in PpRTG1 and PpRTG2 decrease activity of AOX1 promoter.展开更多
基金supported by the National Natural Science Foundation of ChinaNo.81271387+3 种基金the Research Special Fund of Public Welfare and Health Department of ChinaNo.201402009the National Key Technology R&D Program in ChinaNo.Z141107002514031
文摘The signaling mechanisms underlying ischemia-induced nerve cell apoptosis are poorly understood. We investigated the effects of apoptosis-related signal transduction pathways following ischemic spinal cord injury, including extracellular signal-regulated kinase（ERK）, serine-threonine protein kinase（Akt） and c-Jun N-terminal kinase（JNK） signaling pathways. We established a rat model of acute spinal cord injury by inserting a catheter balloon in the left subclavian artery for 25 minutes. Rat models exhibited notable hindlimb dysfunction. Apoptotic cells were abundant in the anterior horn and central canal of the spinal cord. The number of apoptotic neurons was highest 48 hours post injury. The expression of phosphorylated Akt（pAkt） and phosphorylated ERK（p-ERK） increased immediately after reperfusion, peaked at 4 hours（p-Akt） or 2 hours（p-ERK）, decreased at 12 hours, and then increased at 24 hours. Phosphorylated JNK expression reduced after reperfusion, increased at 12 hours to near normal levels, and then showed a downward trend at 24 hours. Pearson linear correlation analysis also demonstrated that the number of apoptotic cells negatively correlated with p-Akt expression. These findings suggest that activation of Akt may be a key contributing factor in the delay of neuronal apoptosis after spinal cord ischemia, particularly at the stage of reperfusion, and thus may be a target for neuronal protection and reduction of neuronal apoptosis after spinal cord injury.
文摘放疗是肿瘤的重要治疗手段之一,仍有部分患者在接受放疗后存在复发或抗拒。哺乳动物雷帕霉素靶蛋白(mamma-lian target of rapamycin,mTOR)是PI3K/AKT信号通路的主要效应分子,分为mTORC1和mTORC2,对细胞生长及增殖、细胞周期进展及蛋白翻译等均有重要调节作用。mTOR异常表达与肿瘤发生及治疗反应密切相关。肿瘤的放疗敏感性与"4R"效应有关。mTOR抑制剂可通过影响细胞周期进展、DNA损伤修复及抗血管形成等多种途径发挥放疗增敏作用。初期研究证实依维莫司具有放疗增敏作用并且毒性可耐受。应用mTOR抑制剂后不同细胞及个体反应不同,可能与基因表达状态有关,需进一步研究证实。
文摘TOR(target of rapamycin)是真核细胞中一种高度保守的与磷脂酰肌醇激酶相关的蛋白激酶(PIKK),它是免疫抑制剂/抗癌药物雷帕霉素(rapamycin)的靶物质。TOR是细胞生长的中枢控制因子,外界营养因素通过TOR的作用控制酵母、果蝇和哺乳动物细胞的生长。TOR根据细胞环境的营养条件做出相应的应答,参与调控蛋白激酶和蛋白磷酸酯酶的活性,从而控制与蛋白质合成和基因转录相关基因的表达。现对酵母细胞中TOR信号转导途径的研究进行简明的阐述。
文摘子痫前期(preeclampsia,PE)是临床常见的妊娠期特发性疾病,其病情变化呈动态性进展,临床表现多样化,病因机制迄今尚未完全阐明,主要认为与遗传因素、免疫因素、营养因素和环境因素等密切相关。近年有研究表明,哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)信号通路通过调控细胞增殖、侵袭、迁移和凋亡能力,参与胎盘滋养细胞与血管内皮细胞活性的调节,且胰岛素信号通过激活mTOR信号通路启动下游分子调节细胞代谢,导致母体血管内皮损伤、子宫螺旋小动脉重构受损,以及炎症免疫反应异常等,参与PE的发生。通过探讨mTOR信号通路与PE发病的相关性,为PE的病理生理学研究及疾病的治疗提供理论基础。
基金supported by American Diabetes Association,American Heart Association,NIH NIEHS,NIH NIA,NIH NINDS,and NIH ARRA
文摘Throughout the globe,diabetes mellitus（DM） is increasing in incidence with limited therapies presently available to prevent or resolve the significant complications of this disorder.DM impacts multiple organs and affects all components of the central and peripheral nervous systems that can range from dementia to diabetic neuropathy.The mechanistic target of rapamycin（m TOR） is a promising agent for the development of novel regenerative strategies for the treatment of DM.m TOR and its related signaling pathways impact multiple metabolic parameters that include cellular metabolic homeostasis,insulin resistance,insulin secretion,stem cell proliferation and differentiation,pancreatic β-cell function,and programmed cell death with apoptosis and autophagy.m TOR is central element for the protein complexes m TOR Complex 1（m TORC1） and m TOR Complex 2（m TORC2） and is a critical component for a number of signaling pathways that involve phosphoinositide 3-kinase（PI 3-K）,protein kinase B（Akt）,AMP activated protein kinase（AMPK）,silent mating type information regulation 2 homolog 1（Saccharomyces cerevisiae）（SIRT1）,Wnt1 inducible signaling pathway protein 1（WISP1）,and growth factors.As a result,m TOR represents an exciting target to offer new clinical avenues for the treatment of DM and the complications of this disease.Future studies directed to elucidate the delicate balance m TOR holds over cellular metabolism and the impact of its broad signaling pathways should foster the translation of these targets into effective clinical regimens for DM.
文摘Methylotrophic yeast Pichia pastoris is an object of modern biotechnology. Decisive understanding of gene regulation mechanisms is essential for successful protein production. In this study, we investigated the effect of deletions in P. pastoris genes encoding proteins, homologous to S. serevisiae Rtg1p, Rtg 2p, Msn2p and Msn4p. It was shown, that deletion in PpRTG1 gene results in inability of P. pastoris to grow on medium with methanol as a carbon source and ammonium sulfate as a source of nitrogen. We also demonstrate that deletions in PpRTG1 and PpRTG2 decrease activity of AOX1 promoter.
