Deregulation of microRNAs by HIV-1 Vpr protein leads to the development of neurocognitive disorders
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ABSTRACT: Studies have shown that HIV-infected patients develop neurocognitive disorders characterized by neuronal dysfunction. The lack of productive infection of neurons by HIV suggests that viral and cellular proteins, with neurotoxic activities, released from HIV-1-infected target cells can cause this neuronal deregulation. The viral protein R (Vpr), a protein encoded by HIV-1, has been shown to alter the expression of various important cytokines and inflammatory proteins in infected and uninfected cells; however the mechanisms involved remain unclear. Using a human neuronal cell line, we found that Vpr can be taken up by neurons causing: (i) deregulation of calcium homeostasis, (ii) endoplasmic reticulum-calcium release, (iii) activation of the oxidative stress pathway, (iv) mitochondrial dysfunction and v- synaptic retraction. In search for the cellular factors involved, we performed microRNAs and gene array assays using human neurons (primary cultures or cell line, SH-SY5Y) that we treated with recombinant Vpr proteins. Interestingly, Vpr deregulates the levels of several microRNAs (e.g. miR-34a) and their target genes (e.g. CREB), which could lead to neuronal dysfunctions. Therefore, we conclude that Vpr plays a major role in neuronal dysfunction through deregulating microRNAs and their target genes, a phenomenon that could lead to the development of neurocognitive disorders. Human fetal neurons were chosen to examine the impact of HIV-1 Vpr protein on gene expression
Project description:Studies have shown that HIV-infected patients develop neurocognitive disorders characterized by neuronal dysfunction. The lack of productive infection of neurons by HIV suggests that viral and cellular proteins, with neurotoxic activities, released from HIV-1-infected target cells can cause this neuronal deregulation. The viral protein R (Vpr), a protein encoded by HIV-1, has been shown to alter the expression of various important cytokines and inflammatory proteins in infected and uninfected cells; however the mechanisms involved remain unclear. Using a human neuronal cell line, we found that Vpr can be taken up by neurons causing: (i) deregulation of calcium homeostasis, (ii) endoplasmic reticulum-calcium release, (iii) activation of the oxidative stress pathway, (iv) mitochondrial dysfunction and v- synaptic retraction. In search for the cellular factors involved, we performed microRNAs and gene array assays using human neurons (primary cultures or cell line, SH-SY5Y) that we treated with recombinant Vpr proteins. Interestingly, Vpr deregulates the levels of several microRNAs (e.g. miR-34a) and their target genes (e.g. CREB), which could lead to neuronal dysfunctions. Therefore, we conclude that Vpr plays a major role in neuronal dysfunction through deregulating microRNAs and their target genes, a phenomenon that could lead to the development of neurocognitive disorders. Using primary cultures and neuronal cell lines, we examined the impact of a viral protein (HIV-1 Vpr) on the expression of miRNAs and mRNAs.
Project description:Over the last decade, small noncoding RNA molecules such as microRNAs (miRNAs) have emerged as critical regulators in the expression and function of eukaryotic genomes. It has been suggested that viral infections and neurological disease outcome may also be shaped by the influence of small RNAs. This has prompted us to suggest that HIV infection alters the endogenous miRNA expression patterns, thereby contributing to neuronal deregulation and AIDS dementia. Therefore, using primary cultures and neuronal cell lines, we examined the impact of a viral protein (HIV-1 Tat) on the expression of miRNAs due to its characteristic features such as release from the infected cells and taken up by noninfected cells. Using microRNA array assay, we demonstrated that Tat deregulates the levels of several miRNAs. Interestingly, miR-34a was among the most highly induced miRNAs in Tat-treated neurons. Tat also decreases the levels of miR-34a target genes such as CREB protein as shown by real time PCR. The effect of Tat was neutralized in the presence of anti-miR-34a. Using in situ hybridization assay, we found that the levels of miR-34a increase in Tat transgenic mice when compared with the parental mice. Therefore, we conclude that deregulation of neuronal functions by HIV-1 Tat protein is miRNA-dependent. Human fetal neurons were chosen to examine the impact of HIV-1 Tat protein on gene expression
Project description:It is well known that HIV-1 does not infect neurons, however neurons are the most affected cells by the virus. Several studies linked the deregulation of neuronal transcriptional machinery to single HIV proteins, however the impact of the all the viral proteins on neurons remain unknown. In here we infected U-937 cells with JR-FL strain of HIV-1. 21 days later, the supernatants were collected and subjected to p24ELISA to measure the level of the virus. Supernatant was then added to SH-SY5Y cells in culture for 24hrs. The cells were then collected, RNA isolated and subjected to gene array analysis. Human neuronal cell line, SH-SY5Y were chosen to examine the impact of HIV-1 supernatant prepared from U-937 infected cells on gene expression in neuronal cells.
Project description:Over the last decade, small noncoding RNA molecules such as microRNAs (miRNAs) have emerged as critical regulators in the expression and function of eukaryotic genomes. It has been suggested that viral infections and neurological disease outcome may also be shaped by the influence of small RNAs. This has prompted us to suggest that HIV infection alters the endogenous miRNA expression patterns, thereby contributing to neuronal deregulation and AIDS dementia. Therefore, using primary cultures and neuronal cell lines, we examined the impact of a viral protein (HIV-1 Tat) on the expression of miRNAs due to its characteristic features such as release from the infected cells and taken up by noninfected cells. Using microRNA array assay, we demonstrated that Tat deregulates the levels of several miRNAs. Interestingly, miR-34a was among the most highly induced miRNAs in Tat-treated neurons. Tat also decreases the levels of miR-34a target genes such as CREB protein as shown by real time PCR. The effect of Tat was neutralized in the presence of anti-miR-34a. Using in situ hybridization assay, we found that the levels of miR-34a increase in Tat transgenic mice when compared with the parental mice. Therefore, we conclude that deregulation of neuronal functions by HIV-1 Tat protein is miRNA-dependent. Using primary cultures and neuronal cell lines, we examined the impact of a viral protein (HIV-1 Tat) on the expression of miRNAs and mRNAs.
Project description:Studies have shown that HIV-infected patients develop neurocognitive disorders characterized by neuronal dysfunction. The lack of productive infection of neurons by HIV suggests that viral and cellular proteins, with neurotoxic activities, released from HIV-1-infected target cells can cause this neuronal deregulation. The viral protein R (Vpr), a protein encoded by HIV-1, has been shown to alter the expression of various important cytokines and inflammatory proteins in infected and uninfected cells; however the mechanisms involved remain unclear. Using a human neuronal cell line, we found that Vpr can be taken up by neurons causing: (i) deregulation of calcium homeostasis, (ii) endoplasmic reticulum-calcium release, (iii) activation of the oxidative stress pathway, (iv) mitochondrial dysfunction and v- synaptic retraction. In search for the cellular factors involved, we performed microRNAs and gene array assays using human neurons (primary cultures or cell line, SH-SY5Y) that we treated with recombinant Vpr proteins. Interestingly, Vpr deregulates the levels of several microRNAs (e.g. miR-34a) and their target genes (e.g. CREB), which could lead to neuronal dysfunctions. Therefore, we conclude that Vpr plays a major role in neuronal dysfunction through deregulating microRNAs and their target genes, a phenomenon that could lead to the development of neurocognitive disorders. Human neurons SH-SY5Y were chosen to examine the impact of HIV-1 Vpr protein on gene expression
Project description:Over the last decade, small noncoding RNA molecules such as microRNAs (miRNAs) have emerged as critical regulators in the expression and function of eukaryotic genomes. It has been suggested that viral infections and neurological disease outcome may also be shaped by the influence of small RNAs. This has prompted us to suggest that HIV infection alters the endogenous miRNA expression patterns, thereby contributing to neuronal deregulation and AIDS dementia. Therefore, using primary cultures and neuronal cell lines, we examined the impact of a viral protein (HIV-1 Tat) on the expression of miRNAs due to its characteristic features such as release from the infected cells and taken up by noninfected cells. Using microRNA array assay, we demonstrated that Tat deregulates the levels of several miRNAs. Interestingly, miR-34a was among the most highly induced miRNAs in Tat-treated neurons. Tat also decreases the levels of miR-34a target genes such as CREB protein as shown by real time PCR. The effect of Tat was neutralized in the presence of anti-miR-34a. Using in situ hybridization assay, we found that the levels of miR-34a increase in Tat transgenic mice when compared with the parental mice. Therefore, we conclude that deregulation of neuronal functions by HIV-1 Tat protein is miRNA-dependent. Human neurons SH-SY5Y were chosen to examine the impact of HIV-1 Tat protein on gene expression
Project description:HIV-1 Vpr protein is a multifunctional protein which perturbs human transcriptome and interacts with a number of cellular proteins. In this study, we have attempted to explore the efffects of Vpr on human transcriptome and have identified several genes which are involved in innate immune respone and cell signaling pathways. We used the microarray analysis to elucidate the differnetail expression pattern of differnet genes in human macrophages infected with HIV-1 Vpr. As result we found that HIV-1 Vpr protein leads to the induction of various interferon stimualted genes (ISGs) and chemokines in human macrophages. Human monocytes-derived macrophages (MDMs) were isolated from peripheral blood mononuclear cells (PBMCs) from two healthy donors and were infected with recombinant adenoviruses either expressing HIV-1 Vpr or ZsGreen1 as a control. At 48 hours post-infection, RNA was isolated and subjected to microarray analysis.
Project description:HIV-1 Vpr protein is a multifunctional protein which perturbs human transcriptome and interacts with a number of cellular proteins. In this study, we have attempted to explore the efffects of Vpr on human transcriptome and have identified several genes which are involved in innate immune responses. We used the microarray analysis to elucidate the differnetail expression pattern of differnet genes in human dendritic cells infected with HIV-1 Vpr. As result we found that HIV-1 Vpr protein leads to the induction of various interferon stimualted genes (ISGs) in human monocyte derived dendritic cells. Human monocytes-derived dendritic cells (MDDCs) were isolated from peripheral blood mononuclear cells (PBMCs) from two healthy donors and were infected with recombinant adenoviruses either expressing HIV-1 Vpr or ZsGreen1 as a control. At 48 hours post-infection, RNA was isolated and subjected to microarray analysis.
Project description:Studies have shown that HIV-infected patients develop neurocognitive disorders characterized by neuronal dysfunction. The lack of productive infection of neurons by HIV suggests that viral and cellular proteins, with neurotoxic activities, released from HIV-1-infected target cells can cause this neuronal deregulation. The viral protein R (Vpr), a protein encoded by HIV-1, has been shown to alter the expression of various important cytokines and inflammatory proteins in infected and uninfected cells; however the mechanisms involved remain unclear. Using a human neuronal cell line, we found that Vpr can be taken up by neurons causing: (i) deregulation of calcium homeostasis, (ii) endoplasmic reticulum-calcium release, (iii) activation of the oxidative stress pathway, (iv) mitochondrial dysfunction and v- synaptic retraction. In search for the cellular factors involved, we performed microRNAs and gene array assays using human neurons (primary cultures or cell line, SH-SY5Y) that we treated with recombinant Vpr proteins. Interestingly, Vpr deregulates the levels of several microRNAs (e.g. miR-34a) and their target genes (e.g. CREB), which could lead to neuronal dysfunctions. Therefore, we conclude that Vpr plays a major role in neuronal dysfunction through deregulating microRNAs and their target genes, a phenomenon that could lead to the development of neurocognitive disorders.
Project description:The high mutation rate of HIV is linked to the generation of viruses expressing proteins with altered function whose impact on disease progression is unknown. We investigated the effects of HIV-1 viruses lacking Env, Vpr and Nef on CD4+ T cell gene expression using high-density DNA microarray analysis and functional assays. Experiment Overall Design: Human activated CD4+ T-lymphocytes from three independent donors were infected with HIV-1 viruses that lack Env and Nef (pNL4-3.eGFP.R+E- or HIVD2GFP) or Env, Vpr and Nef. (pNL4-3.eGFP.R-E- or HIVD3GFP) were pseudotyped with VSVG envelope. As a control, CD4+ T-lymphocytes were infected with VSVG-pseudotyped eGFP. CD4+ T-cells were sorted 48 hours after infection using GFP as a marker of infectivity. RNA was isolated 10 hours after sorting, labeled, and prepared for microarray analysis.