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.
HIV-1 Tat protein promotes neuronal dysfunction through disruption of microRNAs.
Specimen part, Cell line, Treatment
View SamplesStudies 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.
Deregulation of microRNAs by HIV-1 Vpr protein leads to the development of neurocognitive disorders.
Specimen part, Cell line, Treatment
View SamplesThe heat-shock stress response was studied at the level of exons using Affymetrix Exon-array profiling for both sense and anti-sense transcripts. Sense transcript profiling was done as per the protocol of Affymetrix Exon 1.0 ST array and anti-sense transcript array profiling was done using a modified protocol (Xijin Ge et al., BMC Genomics. 2008 Jan 22;9:27).
Heat shock factor binding in Alu repeats expands its involvement in stress through an antisense mechanism.
Sex, Specimen part, Cell line
View SamplesThe repertoire of transcripts that are differentially regulated in response to Heat-shock were studied using Illumina WG-6 v2.0 BeadChip.
Heat shock factor binding in Alu repeats expands its involvement in stress through an antisense mechanism.
Sex, Specimen part, Cell line
View SamplesIn this study we used Illumina Microarray to compare the induction of immune related genes following enteric virus infection. Results show that infection of T3D mammalian reovirus from the basolateral side lead to a higher induction of all genes compared to apical infection.
Asymmetric distribution of TLR3 leads to a polarized immune response in human intestinal epithelial cells.
Specimen part
View SamplesThe hair of all mammals consists of terminally differentiated cells that undergo a specialized form of apoptosis called cornification. While DNA is destroyed during cornification, the extent to which RNA is lost is unknown. Here we find that multiple types of RNA are incompletely degraded after hair shaft formation in both mouse and human. Notably, mRNAs and short regulatory microRNAs (miRNAs) are stable in the hair as far as 10 cm from the scalp. To better characterize the post-apoptotic RNAs that escape degradation in the hair, we performed sequencing (RNA-seq) on RNA isolated from hair shafts pooled from several individuals. This hair shaft RNA library, which encompasses different hair types, genders, and populations, revealed 7,193 mRNAs, 449 miRNAs and thousands of unannotated transcripts that remain in the post-apoptotic hair. A comparison of the hair shaft RNA library to that of viable keratinocytes revealed surprisingly similar patterns of gene coverage and indicates that degradation of RNA is highly inefficient during apoptosis of hair lineages. The generation of a hair shaft RNA library could be used as months of accumulated transcriptional history useful for retrospective detection of disease, drug response and environmental exposure.
The post-apoptotic fate of RNAs identified through high-throughput sequencing of human hair.
No sample metadata fields
View SamplesCultured epidermal keratinocyte controls used for IFNg, TNFa and IL1 treatment.
Unique keratinocyte-specific effects of interferon-gamma that protect skin from viruses, identified using transcriptional profiling.
No sample metadata fields
View SamplesOver expression of recombinant proteins is known to cause a metabolic burden to the host cells which leads to down regulation of both growth rates and protein expression. Most studies in this regard have been conducted in low density shake flask cultures which does not capture the essential features of an industrial scale bioprocess. In the present work we studied the transcriptomic profiling at different specific growth rates while expressing the recombinant human interferon beta in fed batch cultures with complex media. These conditions mimicked the industrial fermentations for recombinant proteins.
Comparative transcriptomic profile analysis of fed-batch cultures expressing different recombinant proteins in Escherichia coli.
No sample metadata fields
View SamplesThe objective of this work was to design an improved host platform for recombinant protein expression in E. coli. The approach involves first to create a library of the E. coli genomic DNA in different expression vectors and screen for probable transcripts which may lead to slow growing colonies and also simultaneously over-expression of recombinant proteins. To observe its effect on host performance, these genes were knocked out from the E. coli genome. A CG2 strain has been created by knocking in vhb gene gene downstream of the acetate promoter and knocking down ribB gene in DH5 and transformed with Recombinant GFP cloned in pBAD33.
Comparative transcriptomic profile analysis of fed-batch cultures expressing different recombinant proteins in Escherichia coli.
No sample metadata fields
View SamplesIdentifying PDEF regulated genes may shed light on the mechanism by which PDEF may induce breast cancer progression. To that purpose, we have used the MCF-7 human breast tumor cell line model to identify PDEF induced genes. Briefly, PDEF expression was down regulated by shRNA in MCF-7 cells and RNA probes from PDEF-down regulated and control MCF-7 cells were used to screen the Affymetrics HG-U133A Gene Chips. This analysis found 62 genes that were induced 2-fold or higher by PDEF. Further analysis of 3 of these genes namely S100A7, CEACAM6 and B7-H4 in primary breast tumors showed CEACAM6 as a frequently elevated and co-exressed gene with PDEF in these tumors.
Prostate derived Ets transcription factor and Carcinoembryonic antigen related cell adhesion molecule 6 constitute a highly active oncogenic axis in breast cancer.
Cell line
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