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: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:ABSTRACT Background: Primary human distal lung/parenchymal fibroblasts (DLF) exhibit a different phenotype from airway fibroblasts (AF), including the expression of high levels of alpha-SMA. The scope of the differences and the mechanisms driving them are unknown. We hypothesized that the distinct fibroblast characteristics based on lung region predicted a broad range of genomic differences which contribute to distinctly different functional pathway activation in AF and DLF. Methods and Findings: To investigate whether comprehensive gene expression patterns vary between AF and DLF, we compared global gene expression profiles of 3 matched pairs of primary human fibroblasts isolated from proximal and distal lung. 194 transcripts were upregulated in AF, and 290 transcripts upregulated in DLF. Quantitative real-time PCR (qRT-PCR) from both asthmatic and normal subjects confirmed the validity of microarray data (n = 8). Further analysis identified distinct pathway activation patterns, including the identification of the TGF-β receptor/SMAD3 signaling pathway as critical to the phenotypic differences in AF and DLF. The functional impact of these molecular differences on AF and DLF was then analyzed using Western blot, qRT-PCR, ELISA and gene knock-down approaches. TGF-β receptor/SMAD2-3 pathway analysis confirmed the contribution of higher TGF-β1 expression and accompanying SMAD3 and JNK activation to the increased alpha-SMA level seen in DLF. There are two limitations associated with our work. First, the microarray sample size was small. Second, for ethical reasons, a large majority of our data were from asthmatic subjects, only one pair of airway and distal lung tissues from a subject without knowing preexisting lung disease matched for age and smoking status was available. In this single normal subject, the same pattern of differences existed, supporting the concept that these genomic differences are regional, rather than disease-related. Conclusions: These findings demonstrated marked molecular and functional differences for these two lung regional fibroblast populations. These results suggest that airway and parenchymal fibroblasts differ in their responses to injury, repair, and remodeling in the lungs. There are likely profound implications of these observations for understanding mechanisms of development of fibrotic lung diseases as well as approaching therapy. In order to identify the underlying molecular differences between airway- and distal lung fibroblasts, microarray analysis was performed on 3 different matched pairs of fibroblasts.
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. One-condition experment, gene expression of 3A6
Project description:Gene methylation profiling of immortalized human mesenchymal stem cells comparing HPV E6/E7-transfected MSCs cells with human telomerase reverse transcriptase (hTERT)- and HPV E6/E7-transfected MSCs. hTERT may increase gene methylation in MSCs. Goal was to determine the effects of different transfected genes on global gene methylation in MSCs.
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. Two-condition experiment, Normoxic MSCs vs. Hypoxic 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.