Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA274123 | ENA |
REPOSITORIES: ENA
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Project description:Objective: When primary chondrocytes are cultured in monolayer, they undergo dedifferentiation during which they lose their phenotype and their capacity to form cartilage. Dedifferentiation is an obstacle for cell therapy for cartilage degeneration. In this study, we aimed to systemically evaluate the changes in gene expression during dedifferentiation of human articular chondrocytes to identify underlying mechanisms. Methods: RNA was isolated from monolayer-cultured primary human articular chondrocytes at serial passages. Gene expression was analyzed by microarray. Based on the microarray analysis, relevant genes and pathways were identified. Their functions in chondrocyte dedifferentiation were further investigated in detail. Results: In vitro expanded human chondrocytes showed progressive changes in gene expression during dedifferentiation. Strikingly, an overall decrease in total gene expression was detected. Genes in the Wnt and BMP pathways exhibited significant changes in expression. The non-canonical rather than the canonical Wnt pathway was found to be involved in the loss of collagen II synthesis. BMP2 was able to decelerate the dedifferentiation and reinforce the maintenance of chondrocyte phenotype in monolayer culture. DNA methylation was in part responsible for the expression downregulation of a set of genes. Conclusion: Our study revealed the roles of ERK, Wnt and BMP pathways as well as DNA methylation in chondrocyte dedifferentiation in monolayer culture. RNA human chondrocytes were allowed to dedifferentiate for 8 passages. RNA was isolated at week 0, 2 ,4, 6 and 8, which was subjected to whole genome gene expression analysis.
2012-11-14 | E-GEOD-42235 | biostudies-arrayexpress
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.
2011-08-25 | GSE23936 | GEO
Project description:Objective: When primary chondrocytes are cultured in monolayer, they undergo dedifferentiation during which they lose their phenotype and their capacity to form cartilage. Dedifferentiation is an obstacle for cell therapy for cartilage degeneration. In this study, we aimed to systemically evaluate the changes in gene expression during dedifferentiation of human articular chondrocytes to identify underlying mechanisms. Methods: RNA was isolated from monolayer-cultured primary human articular chondrocytes at serial passages. Gene expression was analyzed by microarray. Based on the microarray analysis, relevant genes and pathways were identified. Their functions in chondrocyte dedifferentiation were further investigated in detail. Results: In vitro expanded human chondrocytes showed progressive changes in gene expression during dedifferentiation. Strikingly, an overall decrease in total gene expression was detected. Genes in the Wnt and BMP pathways exhibited significant changes in expression. The non-canonical rather than the canonical Wnt pathway was found to be involved in the loss of collagen II synthesis. BMP2 was able to decelerate the dedifferentiation and reinforce the maintenance of chondrocyte phenotype in monolayer culture. DNA methylation was in part responsible for the expression downregulation of a set of genes. Conclusion: Our study revealed the roles of ERK, Wnt and BMP pathways as well as DNA methylation in chondrocyte dedifferentiation in monolayer culture.
2012-11-14 | GSE42235 | GEO
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. Two-condition experiment, KP MSCs vs. 3A6 MSCs.
2011-08-24 | E-GEOD-23936 | biostudies-arrayexpress
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.
2010-09-25 | GSE24338 | GEO
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.
2011-02-19 | GSE20463 | GEO
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.
| S-EPMC2531291 | biostudies-literature
Project description:SPO11-promoted DNA double-strand breaks (DSBs) formation is a crucial step for meiotic recombination, and it is indispensable to detect the broken DNA ends accurately for dissecting the molecular mechanisms behind. Here, we report a novel technique, named DEtail-seq (DNA End tailing followed by sequencing), that can directly and quantitatively capture the meiotic DSB 3’ overhang hotspots at single-nucleotide resolution.
2023-01-08 | GSE154227 | GEO
Project description:Autologous chondrocyte implantation (ACI) is an effective method to treat chronic articular cartilage injury in recent years, which requires a large number of human hyaline chondrocytes. Unfortunately, human hyaline chondrocytes often undergo dedifferentiation in vitro. Thus, it is important to elucidate the mechanism of dedifferentiation for the application of ACI technology. Long noncoding RNAs (lncRNA) play a regulatory role in gene expression in many pathological and physiological processes. However, the role of lncRNAs in human hyaline chondrocyte dedifferentiation remains unclear. The aim of this study was to investigate the expression profiles of lncRNAs in human hyaline chondrocyte dedifferentiation during in vitro culture. First, we cultured human hyaline chondrocytes in vitro and detected the expression of COL1A1, COL2A1, and SOX-9 in passage 1 (P1) and 5 (P5) chondrocytes using quantitative real-time polymerase chain reaction (qRT-PCR), immunofluorescence, and western blotting. Then, we analyzed the expression profiles of lncRNAs and mRNAs in P1 and P5 chondrocytes by microarray analysis.
2020-02-25 | GSE145817 | GEO
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes
2014-08-06 | GSE58734 | GEO