哺乳类动物雷帕霉素靶蛋白(mammalian target of rapa-mycin,mTOR)是调控蛋白质翻译起始阶段的一种蛋白激酶。mTOR在脑信号转导通路中的重要作用决定了mTOR可调控脑突触可塑性改变和长时记忆形成。该文就mTOR的结构、组成及近年来mTOR...哺乳类动物雷帕霉素靶蛋白(mammalian target of rapa-mycin,mTOR)是调控蛋白质翻译起始阶段的一种蛋白激酶。mTOR在脑信号转导通路中的重要作用决定了mTOR可调控脑突触可塑性改变和长时记忆形成。该文就mTOR的结构、组成及近年来mTOR在脑记忆功能中的作用作了阐述和总结。展开更多
目的:观察高迁移率族蛋白1(high-mobility group box 1,HMGB1)对急性髓系白血病细胞株(human leukemiacell line,K562)自噬及化学治疗(化疗)耐药的影响,并探讨其相关的分子机制。方法:体外培养K562细胞,分为化疗药物处理组、化疗药物处...目的:观察高迁移率族蛋白1(high-mobility group box 1,HMGB1)对急性髓系白血病细胞株(human leukemiacell line,K562)自噬及化学治疗(化疗)耐药的影响,并探讨其相关的分子机制。方法:体外培养K562细胞,分为化疗药物处理组、化疗药物处理对照组、HMGB1纯化蛋白预处理组、HMGB1纯化蛋白预处理对照组、HMGB1si RNA转染组和HMGB1 si RNA转染对照组,其中化疗药物处理组又分为长春新碱(v incristine,VCR)、足叶乙甙(etoposide,VP-16)、阿糖胞苷(cytosine arabinoside,Ara-C)、阿霉素(adriamycin,ADM)和三氧化二砷(arsenic trioxide,As2O3)处理组。细胞计数试剂盒-8检测细胞活性;Western印迹检测HMGB1,微管相关蛋白1轻链3(microtubule-associate protein1light chain3,LC3),腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)和哺乳动物雷帕霉素靶点(mammalian target of rapamycin,m-TOR)磷酸化蛋白表达水平;ELISA法检测细胞上清液HMGB1蛋白含量;单丹磺酰尸胺染色和透射电镜观察细胞自噬状态。结果:与相应对照组比较,各化疗药物处理组(VCR,VP-16,Ara-C,ADM和As2O3)的细胞活性均显著降低,HMGB1蛋白表达均显著上调(均P<0.05)。与相应对照组比较,HMGB1纯化蛋白预处理组的细胞活性显著增加(P<0.05),HMGB1蛋白表达显著上调(P<0.05)。与HMGB si RNA转染对照组比较,HMGB1si RNA转染组的细胞活性显著降低(P<0.05),HMGB1蛋白表达显著下调(P<0.05);与相应对照组比较,HMGB1纯化蛋白处理组中LC3-II表达明显增强(P<0.05),光镜下观察到自噬小体和自噬泡数量明显增加。同时,与相应对照组比较,HMGB1纯化蛋白处理组p-AMPKa的蛋白表达明显增强,而p-m TOR表达明显减弱(均P<0.05)。结论:HMGB1可能通过AMPK/m-TOR信号通路增强K562细胞自噬发挥化疗耐药性。展开更多
Defects in autophagy-mediated clearance of α-synuclein may be one of the key factors leading to progressive loss of dopaminergic neurons in the substantia nigra. Moxibustion therapy for Parkinson’s disease has been ...Defects in autophagy-mediated clearance of α-synuclein may be one of the key factors leading to progressive loss of dopaminergic neurons in the substantia nigra. Moxibustion therapy for Parkinson’s disease has been shown to have a positive effect, but the underlying mechanism remains unknown. Based on this, we explored whether moxibustion could protect dopaminergic neurons by promoting autophagy mediated by mammalian target of rapamycin （mTOR）, with subsequent elimination of α-syn. A Parkinson’s disease model was induced in rats by subcutaneous injection of rotenone at the back of their necks, and they received moxibustion at Zusanli （ST36）, Guanyuan （CV4）and Fengfu （GV16）, for 10 minutes at every point, once per day, for 14 consecutive days. Model rats without any treatment were used as a sham control. Compared with the Parkinson’s disease group, the moxibustion group showed significantly greater tyrosine hydroxylase immunoreactivity and expression of light chain 3-II protein in the substantia nigra, and their behavioral score, α-synuclein immunoreactivity,the expression of phosphorylated mTOR and phosphorylated ribosomal protein S6 kinase （p-p70S6K） in the substantia nigra were significantly lower. These results suggest that moxibustion can promote the autophagic clearance of α-syn and improve behavioral performance in Parkinson’s disease model rats. The protective mechanism may be associated with suppression of the mTOR/p70S6K pathway.展开更多
Background： Nucleoside reverse transcriptase inhibitors （NRTIs） are the earliest and most commonly used anti-human immunodeficiency virus drugs and play an important role in high active antiretroviral therapy. Howe...Background： Nucleoside reverse transcriptase inhibitors （NRTIs） are the earliest and most commonly used anti-human immunodeficiency virus drugs and play an important role in high active antiretroviral therapy. However, NRTI drug therapy can cause peripheral neuropathic pain. In this study, we aimed to investigate the mechanisms ofrapamycin on the pain sensitization of model mice by in vivo experiments to explore the effect of mammalian target of rapamycin （mTOR） in the pathogenesis ofneuropathic pain caused by NRTIs. Methods： Male Kun Ming （KM） mice weighing 20-2 g were divided into control, 2 mg/kg rapamycin, 12 mg/kg stavudine, and CMC-Na groups. Drugs were orally administered to mice for 42 consecutive days. The von Frey filament detection and thermal pain tests were conducted on day 7, 14, 21, 28, 35, and 42 after drug administration. After the last behavioral tests, immunohistochemistry and western blotting assay were used for the measurement of mTOR and other biomarkers. Multivariate analysis of variance was used. Results： The beneficial effects ofrapamycin on neuropathic pain were attributed to a reduction in mammalian target of rapamycin sensitive complex 1 （mTORC1）-positive cells （70.80± 2.41 vs. 112.30 ± 5.66, F = 34.36, P 〈 0.01 ） and mTORC1 activity in the mouse spinal cord. Mechanistic studies revealed that Protein Kinase B （Akt）/mTOR signaling pathway blockade with rapamycin prevented the phosphorylation of mTORC1 in stavudine-intoxicated mice （0.72 ± 0.04 vs. 0.86 ± 0.03, F=4.24, P = 0.045）, as well as decreased the expression of phospho-pTOS6K （0.47 ± 0.01 vs. 0.68 ± 0.03, F=6.01, P = 0.022） and phospho-4EBP1 （0.90 ± 0.04 vs. 0.94 ± 0.06, F= 0.28, P = 0.646）. Conclusions： Taken together, these results suggest that stavudine elevates the expression and activity of mTORC1 in the spinal cord through activating the Akt/mTOR signaling pathway. The data also provide evidence that rapamycin might be useful for the treatment of peripheral neuropathic p展开更多
The mammalian target of rapamycin （mTOR） pathway plays an important role in neuronal growth, proliferation and differentiation. To better understand the role of mTOR pathway involved in the induction of spinal cord ...The mammalian target of rapamycin （mTOR） pathway plays an important role in neuronal growth, proliferation and differentiation. To better understand the role of mTOR pathway involved in the induction of spinal cord injury, rat models of spinal cord injury were established by modified Allen＇s stall method and interfered for 7 days by intraperitoneal administration of mTOR activator adenosine triphosphate and mTOR kinase inhibitor rapamycin. At 1-4 weeks after spinal cord injury induction, the Basso, Beattie and Bresnahan locomotor rating scale was used to evaluate rat locomotor function, and immunohistochemical staining and western blot analysis were used to detect the expression of nestin （neural stem cell marker）, neuronal nuclei （neuronal marker）, neuron specific enolase, neurofilament protein 200 （axonal marker）, glial fibrillary acidic protein （astrocyte marker）, Akt, mTOR and signal transduction and activator of transcription 3 （STAT3）. Results showed that adenosine triphosphate-mediated Akt/mTOR/STAT3 pathway increased endogenous neural stem cells, induced neurogenesis and axonal growth, inhibited excessive astrogliosis and improved the locomotor function of rats with spinal cord injury.展开更多
There is a major transformation in gene expression between mature B cells （including follicular, marginal zone, and germinal center cells） and antibody secreting cells （ASCs）, i.e. , ASCs, （including plasma blas...There is a major transformation in gene expression between mature B cells （including follicular, marginal zone, and germinal center cells） and antibody secreting cells （ASCs）, i.e. , ASCs, （including plasma blasts, splenic plasma cells, and long-lived bone marrow plasma cells）. This signifcant change-over occurs to accommodate the massive amount of secretory-specific immunoglobulin that ASCs make and the export processes itself. It is well known that there is an up-regulation of a small number of ASC-specific transcription factors Prdm1 （B-lymphocyte-induced maturation protein 1）, interferon regulatory factor 4, and Xbp1, and the reciprocal down-regulation of Pax5, Bcl6 and Bach2, which maintain the B cell program. Less well appreciated are the major alterations in transcription elongation and RNA proce-ssing occurring between B cells and ASCs. The three ELL family members ELL1, 2 and 3 have different protein sequences and potentially distinct cellular roles in transcription elongation. ELL1 is involved in DNA repair and small RNAs while ELL3 was previously described as either testis or stem-cell specifc. After B cell stimulation to ASCs, ELL3 levels fall precipitously while ELL1 falls off slightly. ELL2 is induced at least 10-fold in ASCs relative to B cells. All of these changes cause the RNA Polymerase Ⅱ in ASCs to acquire different properties, leading to differences in RNA processing and histone modifcations.展开更多
脉管畸形是一种先天性疾患,主要发生在头颈部,其无法自行消退,且随着患者的生长而逐渐加重。脉管畸形的传统治疗方式包括:激光治疗、硬化治疗、介入栓塞、手术切除等。但是对于一些范围较大的病变,传统治疗方式效果不佳。随着分子遗传...脉管畸形是一种先天性疾患,主要发生在头颈部,其无法自行消退,且随着患者的生长而逐渐加重。脉管畸形的传统治疗方式包括:激光治疗、硬化治疗、介入栓塞、手术切除等。但是对于一些范围较大的病变,传统治疗方式效果不佳。随着分子遗传学的发展,基因突变目前被认为是脉管畸形发生的根本原因,基因突变引起的相关通路的活化进一步促进了脉管畸形病变的进展。低流速脉管畸形主要涉及磷脂酰肌醇3⁃激酶(phosphatidylinositol 3⁃kinase,PI3K)/蛋白激酶B(protein kinase B,AKT)/哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)通路的激活;而高流速的脉管畸形主要涉及大鼠肉瘤(rat sarcoma,RAS)/快速加速纤维肉瘤(rapidly accelerated fibrosarcoma,RAF)/促分裂原活化蛋白激酶激酶(mitogen⁃activated protein kinase kinase,MAPKK)/细胞外信号调节激酶(extracellular⁃signalregulated protein kinase,ERK)通路的激活。目前,针对相关基因突变及信号通路的靶向药物也逐渐应用到脉管畸形的治疗中。mTOR抑制剂——雷帕霉素被广泛应用于低流速脉管畸形的靶向治疗;PI3K抑制剂——阿培利司在静脉畸形的治疗中也具有良好的前景;MAPKK抑制剂——曲美替尼在动静脉畸形的治疗中取得了良好的疗效。因此,传统治疗辅以靶向药物的方式或为脉管畸形治疗带来新的突破。展开更多
文摘哺乳类动物雷帕霉素靶蛋白(mammalian target of rapa-mycin,mTOR)是调控蛋白质翻译起始阶段的一种蛋白激酶。mTOR在脑信号转导通路中的重要作用决定了mTOR可调控脑突触可塑性改变和长时记忆形成。该文就mTOR的结构、组成及近年来mTOR在脑记忆功能中的作用作了阐述和总结。
文摘目的:观察高迁移率族蛋白1(high-mobility group box 1,HMGB1)对急性髓系白血病细胞株(human leukemiacell line,K562)自噬及化学治疗(化疗)耐药的影响,并探讨其相关的分子机制。方法:体外培养K562细胞,分为化疗药物处理组、化疗药物处理对照组、HMGB1纯化蛋白预处理组、HMGB1纯化蛋白预处理对照组、HMGB1si RNA转染组和HMGB1 si RNA转染对照组,其中化疗药物处理组又分为长春新碱(v incristine,VCR)、足叶乙甙(etoposide,VP-16)、阿糖胞苷(cytosine arabinoside,Ara-C)、阿霉素(adriamycin,ADM)和三氧化二砷(arsenic trioxide,As2O3)处理组。细胞计数试剂盒-8检测细胞活性;Western印迹检测HMGB1,微管相关蛋白1轻链3(microtubule-associate protein1light chain3,LC3),腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)和哺乳动物雷帕霉素靶点(mammalian target of rapamycin,m-TOR)磷酸化蛋白表达水平;ELISA法检测细胞上清液HMGB1蛋白含量;单丹磺酰尸胺染色和透射电镜观察细胞自噬状态。结果:与相应对照组比较,各化疗药物处理组(VCR,VP-16,Ara-C,ADM和As2O3)的细胞活性均显著降低,HMGB1蛋白表达均显著上调(均P<0.05)。与相应对照组比较,HMGB1纯化蛋白预处理组的细胞活性显著增加(P<0.05),HMGB1蛋白表达显著上调(P<0.05)。与HMGB si RNA转染对照组比较,HMGB1si RNA转染组的细胞活性显著降低(P<0.05),HMGB1蛋白表达显著下调(P<0.05);与相应对照组比较,HMGB1纯化蛋白处理组中LC3-II表达明显增强(P<0.05),光镜下观察到自噬小体和自噬泡数量明显增加。同时,与相应对照组比较,HMGB1纯化蛋白处理组p-AMPKa的蛋白表达明显增强,而p-m TOR表达明显减弱(均P<0.05)。结论:HMGB1可能通过AMPK/m-TOR信号通路增强K562细胞自噬发挥化疗耐药性。
基金supported by the National Natural Science Foundation of China,No.81403456,81473788a grant from the Hubei Provincial Collaborative Innovation Center of Preventive Treatment by Acupuncture and Moxibustion,No.HBPCIC-2016-003
文摘Defects in autophagy-mediated clearance of α-synuclein may be one of the key factors leading to progressive loss of dopaminergic neurons in the substantia nigra. Moxibustion therapy for Parkinson’s disease has been shown to have a positive effect, but the underlying mechanism remains unknown. Based on this, we explored whether moxibustion could protect dopaminergic neurons by promoting autophagy mediated by mammalian target of rapamycin （mTOR）, with subsequent elimination of α-syn. A Parkinson’s disease model was induced in rats by subcutaneous injection of rotenone at the back of their necks, and they received moxibustion at Zusanli （ST36）, Guanyuan （CV4）and Fengfu （GV16）, for 10 minutes at every point, once per day, for 14 consecutive days. Model rats without any treatment were used as a sham control. Compared with the Parkinson’s disease group, the moxibustion group showed significantly greater tyrosine hydroxylase immunoreactivity and expression of light chain 3-II protein in the substantia nigra, and their behavioral score, α-synuclein immunoreactivity,the expression of phosphorylated mTOR and phosphorylated ribosomal protein S6 kinase （p-p70S6K） in the substantia nigra were significantly lower. These results suggest that moxibustion can promote the autophagic clearance of α-syn and improve behavioral performance in Parkinson’s disease model rats. The protective mechanism may be associated with suppression of the mTOR/p70S6K pathway.
文摘Background： Nucleoside reverse transcriptase inhibitors （NRTIs） are the earliest and most commonly used anti-human immunodeficiency virus drugs and play an important role in high active antiretroviral therapy. However, NRTI drug therapy can cause peripheral neuropathic pain. In this study, we aimed to investigate the mechanisms ofrapamycin on the pain sensitization of model mice by in vivo experiments to explore the effect of mammalian target of rapamycin （mTOR） in the pathogenesis ofneuropathic pain caused by NRTIs. Methods： Male Kun Ming （KM） mice weighing 20-2 g were divided into control, 2 mg/kg rapamycin, 12 mg/kg stavudine, and CMC-Na groups. Drugs were orally administered to mice for 42 consecutive days. The von Frey filament detection and thermal pain tests were conducted on day 7, 14, 21, 28, 35, and 42 after drug administration. After the last behavioral tests, immunohistochemistry and western blotting assay were used for the measurement of mTOR and other biomarkers. Multivariate analysis of variance was used. Results： The beneficial effects ofrapamycin on neuropathic pain were attributed to a reduction in mammalian target of rapamycin sensitive complex 1 （mTORC1）-positive cells （70.80± 2.41 vs. 112.30 ± 5.66, F = 34.36, P 〈 0.01 ） and mTORC1 activity in the mouse spinal cord. Mechanistic studies revealed that Protein Kinase B （Akt）/mTOR signaling pathway blockade with rapamycin prevented the phosphorylation of mTORC1 in stavudine-intoxicated mice （0.72 ± 0.04 vs. 0.86 ± 0.03, F=4.24, P = 0.045）, as well as decreased the expression of phospho-pTOS6K （0.47 ± 0.01 vs. 0.68 ± 0.03, F=6.01, P = 0.022） and phospho-4EBP1 （0.90 ± 0.04 vs. 0.94 ± 0.06, F= 0.28, P = 0.646）. Conclusions： Taken together, these results suggest that stavudine elevates the expression and activity of mTORC1 in the spinal cord through activating the Akt/mTOR signaling pathway. The data also provide evidence that rapamycin might be useful for the treatment of peripheral neuropathic p
文摘The mammalian target of rapamycin （mTOR） pathway plays an important role in neuronal growth, proliferation and differentiation. To better understand the role of mTOR pathway involved in the induction of spinal cord injury, rat models of spinal cord injury were established by modified Allen＇s stall method and interfered for 7 days by intraperitoneal administration of mTOR activator adenosine triphosphate and mTOR kinase inhibitor rapamycin. At 1-4 weeks after spinal cord injury induction, the Basso, Beattie and Bresnahan locomotor rating scale was used to evaluate rat locomotor function, and immunohistochemical staining and western blot analysis were used to detect the expression of nestin （neural stem cell marker）, neuronal nuclei （neuronal marker）, neuron specific enolase, neurofilament protein 200 （axonal marker）, glial fibrillary acidic protein （astrocyte marker）, Akt, mTOR and signal transduction and activator of transcription 3 （STAT3）. Results showed that adenosine triphosphate-mediated Akt/mTOR/STAT3 pathway increased endogenous neural stem cells, induced neurogenesis and axonal growth, inhibited excessive astrogliosis and improved the locomotor function of rats with spinal cord injury.
基金Supported by The National Science Foundation grant MCB-08-42725National Institutes of Health shared resources Grant No.P30CA047904 to the University of Pittsburgh Cancer Instituteinternal funding from the School of Medicine and Department of Immunology
文摘There is a major transformation in gene expression between mature B cells （including follicular, marginal zone, and germinal center cells） and antibody secreting cells （ASCs）, i.e. , ASCs, （including plasma blasts, splenic plasma cells, and long-lived bone marrow plasma cells）. This signifcant change-over occurs to accommodate the massive amount of secretory-specific immunoglobulin that ASCs make and the export processes itself. It is well known that there is an up-regulation of a small number of ASC-specific transcription factors Prdm1 （B-lymphocyte-induced maturation protein 1）, interferon regulatory factor 4, and Xbp1, and the reciprocal down-regulation of Pax5, Bcl6 and Bach2, which maintain the B cell program. Less well appreciated are the major alterations in transcription elongation and RNA proce-ssing occurring between B cells and ASCs. The three ELL family members ELL1, 2 and 3 have different protein sequences and potentially distinct cellular roles in transcription elongation. ELL1 is involved in DNA repair and small RNAs while ELL3 was previously described as either testis or stem-cell specifc. After B cell stimulation to ASCs, ELL3 levels fall precipitously while ELL1 falls off slightly. ELL2 is induced at least 10-fold in ASCs relative to B cells. All of these changes cause the RNA Polymerase Ⅱ in ASCs to acquire different properties, leading to differences in RNA processing and histone modifcations.
文摘脉管畸形是一种先天性疾患,主要发生在头颈部,其无法自行消退,且随着患者的生长而逐渐加重。脉管畸形的传统治疗方式包括:激光治疗、硬化治疗、介入栓塞、手术切除等。但是对于一些范围较大的病变,传统治疗方式效果不佳。随着分子遗传学的发展,基因突变目前被认为是脉管畸形发生的根本原因,基因突变引起的相关通路的活化进一步促进了脉管畸形病变的进展。低流速脉管畸形主要涉及磷脂酰肌醇3⁃激酶(phosphatidylinositol 3⁃kinase,PI3K)/蛋白激酶B(protein kinase B,AKT)/哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)通路的激活;而高流速的脉管畸形主要涉及大鼠肉瘤(rat sarcoma,RAS)/快速加速纤维肉瘤(rapidly accelerated fibrosarcoma,RAF)/促分裂原活化蛋白激酶激酶(mitogen⁃activated protein kinase kinase,MAPKK)/细胞外信号调节激酶(extracellular⁃signalregulated protein kinase,ERK)通路的激活。目前,针对相关基因突变及信号通路的靶向药物也逐渐应用到脉管畸形的治疗中。mTOR抑制剂——雷帕霉素被广泛应用于低流速脉管畸形的靶向治疗;PI3K抑制剂——阿培利司在静脉畸形的治疗中也具有良好的前景;MAPKK抑制剂——曲美替尼在动静脉畸形的治疗中取得了良好的疗效。因此,传统治疗辅以靶向药物的方式或为脉管畸形治疗带来新的突破。
