Project description:We have here followed the transcriptional effect of stimulation with the phorbol ester PMA in mouse fibroblasts from HP1gamma null mice recomplemented with either wild-type HP1gamma or an HP1g with an S83A mutation
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:A variety of airborne pathogens can induce inflammatory responses in airway epithelial cells, which is a crucial component of host defence. However, excessive inflammatory responses and chronic inflammation also contribute to different diseases in the respiratory system. We hypothesized that the activation of protein kinase C (PKC) is one of the essential mechanisms of inflammatory responses in airway epithelial cells. In the present study, we stimulated human bronchial lung epithelial (BEAS-2B) cells with phorbol ester Phorbol 12, 13-dibutyrate (PDBu), and examined gene expression profile with microarray analysis. Bioinformatics suggested that PKC activation induced dramatic changes in gene expression related to multiple cellular functions. The top two functional networks of genes were centered on NFκB and TNF-α, which are two commonly known pathways for cell death and inflammation. Subsequent tests confirmed the decrease in cell viability and increase in the production of various cytokines. Interestingly, each of the increased cytokines was differentially regulated at mRNA and/or protein levels by different sub-class of PKC isozymes. We conclude that many pathogen-induced cell death and cytokine production in airway epithelial cells may be mediated through PKC related signaling pathways. These findings suggest that PKCs can be new targets for treatments of lung diseases.
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:Dendritic cells (DC) arise from a diverse group of hematopoietic progenitors and have marked phenotypic and functional heterogeneity. We have found previously that activation of protein kinase C beta 2 (PRKCB2) by cytokines or phorbol esters drives normal human CD34(+) hematopoietic progenitors and myeloid leukemic blasts (KG1, K562 cell lines, and primary patient blasts) to differentiate into DC, but the genetic program triggered by PRKCB2 activation that results in DC differentiation is only beginning to be characterized. Of the cPKC isoforms, only PRKCB2 was consistently activated by DC differentiation-inducing stimuli in normal and leukemic progenitors. To examine early changes in gene expression following PRKCB2 activation, we employed the following cell lines: (1) the CD34(+) human acute myeloid leukemia derived cell line KG1, which undergoes DC differentiation following phorbol ester treatment; (2) KG1a, a spontaneously arising differentiation-resistant daughter cell line of KG1 that has lost PRKCB2 expression; (3) clones established from KG1a that stably express exogenous PRKCB2-GFP fusion proteins and are once again able to undergo DC differentiation (KG1a-PRKCB2-GFP Clone E9 and Clone E11). We examined changes in gene expression in these cells following treatment with the phorbol ester PMA (phorbol 12-myristate 13-acetate) for 2 hours. Since KG1 and KG1a differ in PRKCB2 expression but have similar expression of the other protein kinase C isoforms, this protocol will allow for the identification of genes regulated by PRKCB2 activation. KG1, KG1a, E9, and E11 were cultured for 2 hours in normal media +/- PMA (10 ng/ml). RNA was then isolated using RNeasy mini-columns (Qiagen) following the standard protocol. Samples were then sent to Expression Analysis, who carried out quality control, sample processing/labeling, hybridization to Affymetrix GeneChip arrays (Human U133 2.0 Plus), imaging, and analysis according to their standard protocols. Gene expression profiles were generated for each cell line in the presence and absence of phorbol ester stimulation, for a total of 12 samples (E9 +/- PMA and E11 +/- PMA were run in duplicate).
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:A variety of airborne pathogens can induce inflammatory responses in airway epithelial cells, which is a crucial component of host defence. However, excessive inflammatory responses and chronic inflammation also contribute to different diseases in the respiratory system. We hypothesized that the activation of protein kinase C (PKC) is one of the essential mechanisms of inflammatory responses in airway epithelial cells. In the present study, we stimulated human bronchial lung epithelial (BEAS-2B) cells with phorbol ester Phorbol 12, 13-dibutyrate (PDBu), and examined gene expression profile with microarray analysis. Bioinformatics suggested that PKC activation induced dramatic changes in gene expression related to multiple cellular functions. The top two functional networks of genes were centered on NFM-NM-:B and TNF-M-NM-1, which are two commonly known pathways for cell death and inflammation. Subsequent tests confirmed the decrease in cell viability and increase in the production of various cytokines. Interestingly, each of the increased cytokines was differentially regulated at mRNA and/or protein levels by different sub-class of PKC isozymes. We conclude that many pathogen-induced cell death and cytokine production in airway epithelial cells may be mediated through PKC related signaling pathways. These findings suggest that PKCs can be new targets for treatments of lung diseases. Three groups of BEAS-2B cells were prepared: control, 0.5 hour of PDBu stimulation, and 4 hours of PDBu stimulation. Each group consisted of three biological replicates.