Patterns of gene dysregulation in the frontal cortex of patients with HIV encephalitis
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE3489 | GEO | 2005/10/22
SECONDARY ACCESSION(S): PRJNA93309
REPOSITORIES: GEO
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Project description:The neurodegenerative process in HIV encephalitis (HIVE) is associated with extensive damage to the dendritic and synaptic structure that often leads to cognitive impairment. Several mechanisms might be at play, including release of neurotoxins, oxidative stress and decreased activity of neurotrophic factors. Furthermore, HIV-mediated dysregulation of genes involved in neuronal maintenance might play an important role. For this purpose, cRNA was prepared from the brains of 17 AIDS patients for analysis with the Affymetrix Human U95Av2 GeneChip and analyzed with the GeneSpring Expression Analysis Software. Out of 12,625 genes analyzed, 74 were downregulated and 59 were upregulated compared to controls. Initial alternative analysis of RNA was performed by ribonuclease protection assay (RPA). In cases with HIVE, downregulated genes included neuronal molecules involved in synaptic plasticity and transmission (ion channels, synaptogyrin, synapsin II), cell cycle (p35, p39, CDC-L2, CDC42, PAK1) and signaling molecules (PI3K, Ras-Raf-MEK1), transcription factors and cytoskeletal components (MAP-1B, MAP-2, tubulin, adducin-2). Upregulated genes included those involved in neuroimmune (IgG, MHC, ?2microglobulin) and anti-viral responses (interferon-inducible molecules), transcription (STAT1, OLIG2, Pax-6) and signaling modulation (MEK3, EphB1) of the cytoskeleton (myosin, aduccin-3, radixin, dystrobrevin). Taken together, this study suggests that HIV proteins released from infected macrophages might not only induce a neuroinflammatory response, but also may promote neurodegeneration by interfering with neuronal transcription of genes involved in regulating signaling and cytoskeletal molecules important in maintaining synapto-dendritic functioning and integrity. RNA was obtained from brain slabs that are rapidly frozen after removal and stored at ?80 °C for subsequent molecular and biochemical analysis. From each case, a frontal cortex (Broadmann area 46) block (1 mm3) was dissected from the frozen brain slabs. The underlying white matter was dissected out with a blade, thus most of the RNA obtained is isolated from a sample of gray matter. Total RNA (approximately 50 ?g) was purified from 250 mg of this frozen tissue block with TRIzol Reagent (Invitrogen, Carlsbad, CA) following the manufacturer's protocol, with an additional centrifugation step to remove unwanted cellular debris. RNA was then further purified using the RNeasy mini kit (Qiagen, Valencia, CA) and the quantity of total RNA was assessed by 260-nm UV absorption, with quality analyzed by gel electrophoresis and analysis of the ribosomal RNA bands. This analysis confirmed that in the samples included for this study, the 18S and 28S bands were clearly identified, indicating that the RNA was well preserved (Fig. 1). For the protocol, 10 ?g of total RNA was utilized per experiment. This was prepared to synthesize cDNA that was then used as a template to produce biotinylated cRNA. Affymetrix Test 2 chips were used to assess RNA quality by examining the 3? to 5? ratios for actin and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). A total of 15 ?g cRNA was prepared in a hybridization cocktail of 300 ml total volume, of which 200 ?l was placed on an Affymetrix Human U95Av2 GeneChip, containing 12,625 independent probe sets to analyze gene expression. After hybridization, this sample was returned to the original aliquot, which was then frozen. For the frontal lobe samples, a further 200 ?l was sampled from the original cocktail and hybridized to a separate duplicate GeneChip within 30 days. Hybridization and subsequent washing and staining were carried out using the Affymetrix Fluidics Station 400 following supplied protocols. Chips were then double stained and scanned according to basic Affymetrix protocol to create GeneChip image files that were converted to text-bases files using Microarray Suite 5.0 software (Affymetrix, Santa Clara, CA). Experiments were repeated at least once to verify the specificity of the results.
2007-12-14 | E-GEOD-3489 | biostudies-arrayexpress
Project description:This project will help us to have a more accurate and useful explanation at molecular level, of the damage caused by HIV when it infects the central nervous sythem (CNS) in Humans. CNS dysfunction is an important cause of morbidity and mortality in patients with human immunodeficiency virus-I (HIV-1) infection and the acquired immunodeficiency virus syndrome (AIDS). Minor cognitive/motor dysfunction (MCMD) and HIV-1-associated dementia (HAD) develop in the absence of opportunistic infections and lymphoma, cerebrovascular disease and metabolic disorders. Patients with HAD may or may not present an associated HIV encephalitis with viral replication limited to cells of monocyte origin. The inflammatory infiltrates of HIVE include activated microglia and perivascular and parenchymal monocytes, multinucleated giant cells and lymphocytes. In addition, HIVE may be accompanied by significant loss of neurons, presynaptic terminals and abnormal dendrites. To determine if altered expression of neuronal growth factor, chemokine and cell death genes identified possible mechanisms of brain injury in AIDS patients with and without HIVE; Changes of gene expression occurring in brain of AIDS patients with and without HIVE, induce development of brain atrophy, mild gliosis, enhanced vascular permeability, along with alterations in neuronal HIV-1 chemokine coreceptors. In the cases of HIVE more remarkable gene expression changes result in significant loss of neurons, presynaptic terminals and abnormal dendrites. All these changes can be evaluated by microarray gene expression analysis and validated by Q-RT-PCR; The procedure includes 10 steps: 1-Frontal Cortex dissection from fresh frozen autopsy human brain samples (fragments of 0.8-1 cm3 are used) 2-totalRNA extraction using RNeasy Maxi Kit and following hand book protocol; Quiagen Inc., 3-RNA quantity determination using the NanoDrop ND-1000 UV-Vis Spectrophotometer: Nanodrop-Technologies 4-RNA quality analyzed by ribosomal fractions 28s/18s ratio, using by Agilent RNA 6000 Assay Microchips: Agilent Technologies 5-mRNA suitability by RT-PCR test for housekeeping genes and genes of interest. 6-mRNA amplification and labeling in two steps: a-Generation of T7-conatining double stranded cDNA using T7-Poly-T Strategy (Invitrogen) b-mRNA amplification and labeling (aRNA) by in vitro transcription using T7 RNA polymerase, T7-cDNA as template and biotin-labeled ribonucleotides 7-Biotin-labeled aRNA quantity assess, as in step 3 8-Biotin-labeled aRNA determination by amplified RNA electropherogram. Agilent RNA 6000 Assay Microchips: Agilent Technologies 9-Biotin-labeled aRNA fractionation, hybridization onto HG-95aVer2 oligonucleotide array and scanning, using Affymetrix platform: Affymetrix 10-Statistical gene expression analysis: Using GeneSpring Software (Slicon Gnetics) a-Normalization to the 50th percentile and per gene to specific control samples, using 'Disease vs. Normal' as the main parameter. b-Fold of expression filter (2 folds cutoff) using signal data in ratio mode interpretation c-Welch t-test, with p< 0.05 for significance, using log of ratio mode interpretation d-Differentially expressed genes clustering by K-means, experiment and gene trees e-Differentially expressed genes analysis and classes classification by Gene Ontology and GeneMapp pathways
2008-06-13 | E-GEOD-4755 | biostudies-arrayexpress
Project description:This project will help us to have a more accurate and useful explanation at molecular level, of the damage caused by HIV when it infects the central nervous sythem (CNS) in Humans. CNS dysfunction is an important cause of morbidity and mortality in patients with human immunodeficiency virus-I (HIV-1) infection and the acquired immunodeficiency virus syndrome (AIDS). Minor cognitive/motor dysfunction (MCMD) and HIV-1-associated dementia (HAD) develop in the absence of opportunistic infections and lymphoma, cerebrovascular disease and metabolic disorders. Patients with HAD may or may not present an associated HIV encephalitis with viral replication limited to cells of monocyte origin. The inflammatory infiltrates of HIVE include activated microglia and perivascular and parenchymal monocytes, multinucleated giant cells and lymphocytes. In addition, HIVE may be accompanied by significant loss of neurons, presynaptic terminals and abnormal dendrites. To determine if altered expression of neuronal growth factor, chemokine and cell death genes identified possible mechanisms of brain injury in AIDS patients with and without HIVE Changes of gene expression occurring in brain of AIDS patients with and without HIVE, induce development of brain atrophy, mild gliosis, enhanced vascular permeability, along with alterations in neuronal HIV-1 chemokine coreceptors. In the cases of HIVE more remarkable gene expression changes result in significant loss of neurons, presynaptic terminals and abnormal dendrites. All these changes can be evaluated by microarray gene expression analysis and validated by Q-RT-PCR The procedure includes 10 steps: 1-Frontal Cortex dissection from fresh frozen autopsy human brain samples (fragments of 0.8-1 cm3 are used) 2-totalRNA extraction using RNeasy Maxi Kit and following hand book protocol; Quiagen Inc., 3-RNA quantity determination using the NanoDrop ND-1000 UV-Vis Spectrophotometer: Nanodrop-Technologies 4-RNA quality analyzed by ribosomal fractions 28s/18s ratio, using by Agilent RNA 6000 Assay Microchips: Agilent Technologies 5-mRNA suitability by RT-PCR test for housekeeping genes and genes of interest. 6-mRNA amplification and labeling in two steps: a-Generation of T7-conatining double stranded cDNA using T7-Poly-T Strategy (Invitrogen) b-mRNA amplification and labeling (aRNA) by in vitro transcription using T7 RNA polymerase, T7-cDNA as template and biotin-labeled ribonucleotides 7-Biotin-labeled aRNA quantity assess, as in step 3 8-Biotin-labeled aRNA determination by amplified RNA electropherogram. Agilent RNA 6000 Assay Microchips: Agilent Technologies 9-Biotin-labeled aRNA fractionation, hybridization onto HG-95aVer2 oligonucleotide array and scanning, using Affymetrix platform: Affymetrix 10-Statistical gene expression analysis: Using GeneSpring Software (Slicon Gnetics) a-Normalization to the 50th percentile and per gene to specific control samples, using 'Disease vs. Normal' as the main parameter. b-Fold of expression filter (2 folds cutoff) using signal data in ratio mode interpretation c-Welch t-test, with p< 0.05 for significance, using log of ratio mode interpretation d-Differentially expressed genes clustering by K-means, experiment and gene trees e-Differentially expressed genes analysis and classes classification by Gene Ontology and GeneMapp pathways Keywords: other
2006-05-02 | GSE4755 | GEO
Project description:MicroRNAs (miRNAs) have important roles in regulating a plethora of physiological and pathophysiogical processes including neurodegeneration. In both human immunodeficiency virus (HIV)-associated dementia in humans and its monkey model simian immunodeficiency virus encephalitis (SIVE), we find miR-21, a miRNA largely known for its link to oncogenesis, to be significantly upregulated in the brain. In situ hybridization of the diseased brain sections revealed induction of miR-21 in neurons. miR-21 can be induced in neurons by prolonged N-methyl-D-aspartic acid receptor stimulation, an excitotoxic process active in HIV and other neurodegenerative diseases. Introduction of miR-21 into human neurons leads to pathological functional defects. Furthermore, we show that miR-21 specifically targets the mRNA of myocyte enhancer factor 2C (MEF2C), a transcription factor crucial for neuronal function, and reduces its expression. MEF2C is dramatically downregulated in neurons of HIV-associated dementia patients, as well as monkeys with SIVE. Together, this study elucidates a novel role for miR-21 in the brain, not only as a potential signature of neurological disease, but also as a crucial effector of HIV-induced neuronal dysfunction and neurodegeneration. Total cellular RNA was isolated from frozen (−80°C) brain specimens by using TRIzol (Invitrogen, Carlsbad, CA, USA) for the monkey samples, and RNAzol (Biotecx Laboratories, Houston, TX, USA) for the human samples, followed by column purification (miRNeasy, Qiagen, Valencia, CA, USA) as per manufacture's instructions. For the monkeys, four samples were from uninfected animals and four from SIV-infected animals that developed simian AIDS with SIV encephalitis. For the human samples, six samples were from individuals who were HIV negative with no history of dementia or neurocognitive disability and showed no significant neuropathology. Five samples were from HIV positive individuals that were neurocognitively impaired (NNTC clinical rating >6)38 and a neuropathological diagnosis of HIV encephalitis. Clinical information is provided in the supplemental material. For microarray analysis, only three of the HAD specimens were sufficient for use, but all five were used for the qRT-PCR studies.
2014-02-18 | E-GEOD-55069 | biostudies-arrayexpress
Project description:We investigated the link between HIV-1 integration by using B-HIVE and LEDGINs. B-HIVE tracks insert-specific HIV expression by tagging a unique barcode in the HIV genome. LEDGINs are antivirals that inhibit the interaction between HIV-IN and its chromatin tethering cofactor LEDGF/p75. They are known to retarget HIV-1 integration sites. Here, we confirmed that LEDGIN treatment retargets integration out of transcriptionally active regions and reduce HIV expression. Silent provirus was located at increased distance to H3K36me3, the recognition marker of LEDGF/p75, after treatment with LEDGINs. Viral RNA expression was also influenced by the proximity of enhancers, regardless of the presence of LEDGINs.
2020-07-03 | GSE135295 | GEO
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.
2013-02-12 | E-GEOD-44266 | biostudies-arrayexpress
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.
2013-02-12 | E-GEOD-44265 | biostudies-arrayexpress
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
2012-12-07 | E-GEOD-42423 | biostudies-arrayexpress
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
2013-01-17 | E-GEOD-43534 | biostudies-arrayexpress
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 fetal neurons were chosen to examine the impact of HIV-1 Vpr protein on gene expression
2012-12-07 | E-GEOD-42424 | biostudies-arrayexpress