Project description:Overexpression in IL6 in MCF10A vs. WT, MCF10A.ErbB2* with/without shRNA targeting STAT3 Overexpression in IL6 in MCF10A vs. WT, MCF10A.ErbB* with/without shSTAT3, duplicates, two STAT3 shRNAs
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:Mitochondrial DNA-depleted human skin fibroblasts (HSF rho0) with suppressed oxidative phosphorylation were characterized by significant changes in the expression of 2100 nuclear genes, encoding numerous protein classes, in NF-kappaB and STAT3 signaling pathways and by decreased activity of the mitochondrial death pathway, compared to the parent rho+ HSF. In contrast, the extrinsic TRAIL/TRAIL-Receptor-mediated death pathway remained highly active, and exogenous TRAIL induced higher levels of apoptosis in rho0 cells compared to rho+ HSF. Global gene expression analysis using microarray and quantitative RT-PCR demonstrated that expression levels of many growth factors and their adaptor proteins (FGF13, HGF, IGFBP4, IGFBP6, IGFL2), cytokines (IL6, IL17B, IL18, IL19, IL28B) and cytokine receptors (IL1R1, IL21R, IL31RA) were substantially decreased after mitochondrial depletion. Some of these genes were targets of NF-kappaB and STAT3, and their protein products could regulate the STAT3 signaling pathway. Alpha-irradiation induced expression of several NF-kappaB/STAT3 target genes, including IL1A, IL1B, IL6, PTGS2/COX2 and MMP12, in rho+ HSF, but this response was substantially decreased in rho0 HSF. Suppression of the IKK-NF-kappaB pathway by the small molecular inhibitor BMS-345541 and of the JAK2-STAT3 pathway by AG490 dramatically increased TRAIL-induced apoptosis in the control and irradiated rho+ HSF. Inhibitory antibodies against IL6, the main activator of JAK2-STAT3 pathway, added into the cell media, also increased TRAIL-induced apoptosis in rho+ HSF. However, NF-kappaB activation was partially lost in mitochondrial DNA-depleted HSF resulting in downregulation of the basal or radiation-induced expression of numerous NF-kappaB targets, further suppressing IL6-JAK2-STAT3, that in concert with NF-kappaB, regulated protection against TRAIL-induced apoptosis. There are 12 total samples, 3 biological replicates each of HSF rho+ and rho0 cells that were not irradiated (control=C) or irradiated (alpha=A). Cells were harvested at 4 hours after treatment.
Project description:As the evolution of miRNA genes has been found to be one of the important factors in formation of the modern type of man, we performed a comparative analysis of the evolution of miRNA genes in two archaic hominines, Homo sapiens neanderthalensis and Homo sapiens denisova, and elucidated the expression of their target mRNAs in bain.A comparative analysis of the genomes of primates, including species in the genus Homo, identified a group of miRNA genes having fixed substitutions with important implications for the evolution of Homo sapiens neanderthalensis and Homo sapiens denisova. The mRNAs targeted by miRNAs with mutations specific for Homo sapiens denisova exhibited enhanced expression during postnatal brain development in modern humans. By contrast, the expression of mRNAs targeted by miRNAs bearing variations specific for Homo sapiens neanderthalensis was shown to be enhanced in prenatal brain development.Our results highlight the importance of changes in miRNA gene sequences in the course of Homo sapiens denisova and Homo sapiens neanderthalensis evolution. The genetic alterations of miRNAs regulating the spatiotemporal expression of multiple genes in the prenatal and postnatal brain may contribute to the progressive evolution of brain function, which is consistent with the observations of fine technical and typological properties of tools and decorative items reported from archaeological Denisovan sites. The data also suggest that differential spatial-temporal regulation of gene products promoted by the subspecies-specific mutations in the miRNA genes might have occurred in the brains of Homo sapiens denisova and Homo sapiens neanderthalensis, potentially contributing to the cultural differences between these two archaic hominines.
Project description:RNA-sequencing (RNA-Seq) protocols and bioinformatic pipelines are designed to streamline downstream analyses on sequences believed to be the most important. Here, we have challenged this dogma by preserving ribosomal RNA (rRNA) in our samples and by lowering the minimal RNA size window of our small RNA-Seq analyses to 8 nt