Project description:Cartilage injury does not naturally repair and lead to osteoarthritis. Engineered chondrocyte sheets are readily transplantable and create neocartilage in vivo. This experiment compares global mRNA profiling of adult and juvenile chondrocyte sheets.
Project description:The pathology of failure in currently used biological treatments (cell therapies and microfracture) for cartilage repair or early osteoarthritis (OA) is poorly understood. We aimed to identify a reliable panel of biological predictors, present in synovial fluid, which can be used in the preoperative setting to optimise patient selection and therapy efficacy. The-long term aim is to reduce the number of patients who progress to end-stage OA and require knee replacement by making earlier, less invasive treatments more effective. In this first stage, we have taken synovial fluid aspirates from patients undergoing autologous chondrocyte implantation (ACI) at our centre in Oswestry, UK. Synovial fluids (SFs) were obtained from 14 ACI responders (mean Lysholm improvement of 33 (17-54)) and 13 non-responders (mean Lysholm decrease of 14 (4-46)) at the two stages of surgery (cartilage harvest and chondrocyte implantation). Dynamic range compression of synovial fluids coupled with label-free quantification mass spectrometry (MS), was used in an unbiased approach to identify predictive markers of ACI success or failure and to investigate the biological pathways involved in the clinical response to ACI.
Project description:Transcriptional profiling of adult forestomach epithelium comparing K5-CreER controsl with K5-CreER;Rosa26Sox2/Sox2 mutants. Two doses of tamoxifen were given and four weeks later the epithelal sheets were harvested for RNA extraction. Goal was to determine the effects of Sox2 overexpression on epithelial phenotypic changes.
Project description:To investigate target molecules of HES1, we transduced GFP or HES1 into mouse chondrocyte cell line ATDC5, and performed the microarray analysis. HES1 overexpression increased inflammation-related genes including Il6 and Il1rl1. We established stable ATDC5 cells overexpressing GFP or HES1 by lentiviral transduction. We harvested mRNA from these cells, and performed microarray analysis.
Project description:Using large-scale patient data sets and genetically engineered (inducible conditional knockout and knockin) mouse models, we show that a novel transcript of long noncoding RNA ELDR is essential for the development of chondrocyte senescence.
Project description:Using large-scale patient data sets and genetically engineered (inducible conditional knockout and knockin) mouse models, we show that a novel transcript of long noncoding RNA ELDR is essential for the development of chondrocyte senescence.
Project description:To further differentiate the gene expression of HPL-cultured or FBS-cultured ASC sheets, we have employed microarray analysis. ASCs were isolated from the subcutaneous fat tissue of four non-diabetic, non-smoking female donors with an average age of 45 y (32–57 y) and an average body mass index of 24.6 (21.0–26.6). Significantly up-regulated or down-regulated genes are highlighted in the HPL-cultured ASC sheets. Pathway enrichment analysis showcasing the top 10 hallmark gene-sets from MSigDB significantly enriched in up-regulated (top) or down-regulated (bottom) genes. The heatmap represented the expression patterns of angiogenesis-related genes between the HPL-cultured and FBS-cultured ASC sheets.
Project description:Osteoarthritis (OA) is a chronic debilitating joint disease which is strongly associated with ageing. OA involves pathological cellular processes in all joint structures and affects articular cartilage integrity, leading to dysfunctional joint articulation. The biomolecular processes that catalyze the disturbances in the articular chondrocyte phenotype leading to OA are poorly understood, and it is expected that a comprehensive understanding of the avenues leading to catabolic changes and disruption of articular chondrocyte homeostasis will provide important cues for future treatments of the condition. Chondrocytes are specialized secretory cells with highly active protein translational machinery, enabling the synthesis and maintenance of the protein-rich cartilage extracellular matrix (ECM). Disturbances in chondrocyte protein translation in cartilage development and OA are connected to mTOR activity, ER stress, unfolded protein response (UPR)and CHOP-mediated apoptosis. These responses change the downstream translational activity of the biosynthesized ribosome. The assembled mammalian ribosome is built from ribosomal RNAs (rRNAs), together with more than 80 different protein subunits. At the heart of the ribosome, the 18S rRNA guides the decoding of the mRNA message, while an ancient ribozyme activity in the 28S rRNA forms the core of the peptidyltransferase center that polymerizes the amino acid sequence encoded by the mRNA into functional proteins. Post-transcriptional maturation of rRNAs is an integral part of the biosynthesis of ribosomes and ribonucleolytic processing of the major 47S rRNA precursor into mature 18S, 5.8S, and 28S rRNAs is rate limiting for ribosome biogenesis. The U3 small nucleolar RNA (snoRNA) is an evolutionarily highly conserved box C/D-class snoRNA which catalyzes the endoribonucleolytic processing of the 5’ external transcribed spacer (ETS) of the 47S pre-rRNA by base complementarity-guided pre-rRNA substrate recognition and plays a crucial role in the maturation of 18S rRNA. Although extensively studied in yeast, it was only recently demonstrated that U3 snoRNA is indispensable for rRNA maturation in human cells. Pathways controlling ribosome activity have previously been described in the regulation of chondrocyte homeostasis. We here now postulate that not only ribosome activity is involved in chondrocyte homeostasis, but that OA pathophysiological situations can also cause alterations in chondrocyte ribosome biogenesis with consequences for cellular protein translation. Since U3 snoRNA-driven rRNA production is rate-limiting in ribosome biogenesis, we hypothesized that the U3 snoRNA is critical for chondrocyte homeostasis. In this study we therefor aimed to determine whether OA pathophysiological conditions interact with chondrocyte U3 snoRNA levels, thereby influencing rRNA levels and chondrocyte translation capacity.