HIV-associated dementia(HAD)is a public health problem and is particularly prevalent in drug abusers.The neuropathogenesis of human immunodeficiency virus(HIV)infection involves a complex cascade of inflammatory event...HIV-associated dementia(HAD)is a public health problem and is particularly prevalent in drug abusers.The neuropathogenesis of human immunodeficiency virus(HIV)infection involves a complex cascade of inflammatory events,including monocyte/macrophage infiltration in the brain,glial immune activation and release of neurotoxic substances.In these events,astrocytic-derived monocyte chemoattractant protein-1(MCP-1)plays an important role,whose release is elevated by HIV transactivator of transcription(HIV tat)and could be further elevated by opiates.This review will also consider some critical factors and events in MCP-1 enhancement induced by the interactions of opiate and HIV tat,including the mediating role of mu opioid receptor(MOR)and CCR2 as well as the possible signal transduction pathways within the cells.Finally,it will make some future perspectives on the exact pathways,new receptors and target cells,and the vulnerability to neurodegeneration with HIV and opiates.展开更多
The HIV-1 LTR controls the expression of HIV-1 viral genes and thus is critical for viral propagation and pathology. Numerous host factors have been shown to participate in the regulation of the LTR Promoter. Among th...The HIV-1 LTR controls the expression of HIV-1 viral genes and thus is critical for viral propagation and pathology. Numerous host factors have been shown to participate in the regulation of the LTR Promoter. Among them is the thyroid hormone (T3) receptor (TR). TR has been shown to bind to the critical region of the promoter that contain the NFkB and Sp1 binding sites. Interestingly, earlier transient transfection studies in tissue culture cells have yielded contradicting conclusions on the role of TR in LTR regulation, likely due to the use of different cell types and/or lack of proper chromatin organization. Here, using the frog oocyte as a model system that allows replication-coupled chromatin assembly, mimicking that in somatic cells, we demonstrate that unliganded heterodimers of TR and RXR (9-cis retinoic acid receptor) repress LTR while the addition of T3 relieves the repression and further activates the promoter. More importantly, we show that chromatin and unliganded TR/RXR synergize to repress the promoter in a histone deacetylase- dependent manner.展开更多
病毒颗粒蛋白表达调节因子(regulator of virion protein expression,Rev)是人免疫缺陷病毒1型(human immunodeficiency virus type 1,HIV-1)转录过程中不可缺少的调控蛋白。Rev与病毒mRNA的Rev应答元件(Rev response element,RRE)相互...病毒颗粒蛋白表达调节因子(regulator of virion protein expression,Rev)是人免疫缺陷病毒1型(human immunodeficiency virus type 1,HIV-1)转录过程中不可缺少的调控蛋白。Rev与病毒mRNA的Rev应答元件(Rev response element,RRE)相互作用,加速mRNA向核外转运。Rev缺乏或者不能进入细胞核,未剪接和部分剪接的mRNA将在核内完全降解,导致HIV-1的复制被阻断。Rev在HIV-1复制周期中起着重要的反式调节作用,是艾滋病药物研究的新靶点之一。本文综述了Rev蛋白的结构、功能以及针对Rev-RRE作用机制的相关抑制剂的研究进展。展开更多
AIM:To determine whether SP-TAT-apoptin induces apoptosis and also maintains its tumor cell specificity. METHODS:In this study,we designed a secretory protein by adding a secretory signal peptide(SP) to the N terminus...AIM:To determine whether SP-TAT-apoptin induces apoptosis and also maintains its tumor cell specificity. METHODS:In this study,we designed a secretory protein by adding a secretory signal peptide(SP) to the N terminus of Transactivating Transcription(TAT)-apoptin(SP-TAT-apoptin),to test the hypothesis that it gains an additive bystander effect as an anti-cancer therapy. We used an artificial human secretory SP whose amino acid sequence and corresponding cDNA sequence were generated by the SP hidden Markov model. RESULTS:In human liver carcinoma HepG2 cells,SP-TAT-apoptin expression showed a diffuse pattern in the early phase after transfection. After 48 h,however,it translocated into the nuclear compartment and caused massive apoptotic cell death,as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay and annexin-V binding assay. SP-TAT-apoptin did not,however,cause any cell death in non-malignant human umbilical vein endothelial cells(HUVECs). Most importantly,the conditioned medium from Chinese hamster ovary(CHO) cells transfected with SP-TAT-apoptin also induced significant cell deathin HepG2 cells,but not in HUVECs. CONCLUSION:The data demonstrated that SP-TAT-apoptin induces apoptosis only in malignant cells,and its secretory property might greatly increase its potency once it is delivered in vivo for cancer therapy.展开更多
基金supported by the National Natural Science Foundation of China(No.30671856 and No.30772536)
文摘HIV-associated dementia(HAD)is a public health problem and is particularly prevalent in drug abusers.The neuropathogenesis of human immunodeficiency virus(HIV)infection involves a complex cascade of inflammatory events,including monocyte/macrophage infiltration in the brain,glial immune activation and release of neurotoxic substances.In these events,astrocytic-derived monocyte chemoattractant protein-1(MCP-1)plays an important role,whose release is elevated by HIV transactivator of transcription(HIV tat)and could be further elevated by opiates.This review will also consider some critical factors and events in MCP-1 enhancement induced by the interactions of opiate and HIV tat,including the mediating role of mu opioid receptor(MOR)and CCR2 as well as the possible signal transduction pathways within the cells.Finally,it will make some future perspectives on the exact pathways,new receptors and target cells,and the vulnerability to neurodegeneration with HIV and opiates.
文摘The HIV-1 LTR controls the expression of HIV-1 viral genes and thus is critical for viral propagation and pathology. Numerous host factors have been shown to participate in the regulation of the LTR Promoter. Among them is the thyroid hormone (T3) receptor (TR). TR has been shown to bind to the critical region of the promoter that contain the NFkB and Sp1 binding sites. Interestingly, earlier transient transfection studies in tissue culture cells have yielded contradicting conclusions on the role of TR in LTR regulation, likely due to the use of different cell types and/or lack of proper chromatin organization. Here, using the frog oocyte as a model system that allows replication-coupled chromatin assembly, mimicking that in somatic cells, we demonstrate that unliganded heterodimers of TR and RXR (9-cis retinoic acid receptor) repress LTR while the addition of T3 relieves the repression and further activates the promoter. More importantly, we show that chromatin and unliganded TR/RXR synergize to repress the promoter in a histone deacetylase- dependent manner.
文摘病毒颗粒蛋白表达调节因子(regulator of virion protein expression,Rev)是人免疫缺陷病毒1型(human immunodeficiency virus type 1,HIV-1)转录过程中不可缺少的调控蛋白。Rev与病毒mRNA的Rev应答元件(Rev response element,RRE)相互作用,加速mRNA向核外转运。Rev缺乏或者不能进入细胞核,未剪接和部分剪接的mRNA将在核内完全降解,导致HIV-1的复制被阻断。Rev在HIV-1复制周期中起着重要的反式调节作用,是艾滋病药物研究的新靶点之一。本文综述了Rev蛋白的结构、功能以及针对Rev-RRE作用机制的相关抑制剂的研究进展。
基金the National Natural Science Foundation of China, No. 30672069 and No. 30470098
文摘AIM:To determine whether SP-TAT-apoptin induces apoptosis and also maintains its tumor cell specificity. METHODS:In this study,we designed a secretory protein by adding a secretory signal peptide(SP) to the N terminus of Transactivating Transcription(TAT)-apoptin(SP-TAT-apoptin),to test the hypothesis that it gains an additive bystander effect as an anti-cancer therapy. We used an artificial human secretory SP whose amino acid sequence and corresponding cDNA sequence were generated by the SP hidden Markov model. RESULTS:In human liver carcinoma HepG2 cells,SP-TAT-apoptin expression showed a diffuse pattern in the early phase after transfection. After 48 h,however,it translocated into the nuclear compartment and caused massive apoptotic cell death,as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay and annexin-V binding assay. SP-TAT-apoptin did not,however,cause any cell death in non-malignant human umbilical vein endothelial cells(HUVECs). Most importantly,the conditioned medium from Chinese hamster ovary(CHO) cells transfected with SP-TAT-apoptin also induced significant cell deathin HepG2 cells,but not in HUVECs. CONCLUSION:The data demonstrated that SP-TAT-apoptin induces apoptosis only in malignant cells,and its secretory property might greatly increase its potency once it is delivered in vivo for cancer therapy.
