Project description:Assessment of the putative differential gene expression profiles in high osmolality-treated bovine nucleus pulposus intervertebral disc cells for a short (5 h) and a long (24 h) time period. Identification of novel genes up- or down-regulated as an early or a late response to hyperosmotic stress. A 5 and 24 h-hyperosmotic treatment of nucleus pulposus cells led to transcriptional changes in >100 and 200 genes, respectively. Nucleus pulposus intervertebral disc cells were exposed to hyperosmotic stress for 5 and 24 h before RNA extraction and transcriptomics analysis. Three biological replicates were tested for each condition. Selected genes found to be differentially expressed were validated by RT-qPCR. Functional experiments were performed in order to assess the role of specific proteins encoded by genes found to be up-regulated in the osmo-reguatory response of intervertebral disc cells.
Project description:Assessment of the putative differential gene expression profiles in high osmolality-treated bovine nucleus pulposus intervertebral disc cells for a short (5 h) and a long (24 h) time period. Identification of novel genes up- or down-regulated as an early or a late response to hyperosmotic stress. A 5 and 24 h-hyperosmotic treatment of nucleus pulposus cells led to transcriptional changes in >100 and 200 genes, respectively.
Project description:Failure of intervertebral disc components, e.g. the nucleus pulposus causes intervertebral disc disease and associated low-back pain. Despite the high prevalence of disc disease, the changes in intervertebral disc cells and their regenerative potential with ageing and degeneration are not fully elucidated. Understanding the cell lineage, cell differentiation and maintenance of nucleus pulposus may have therapeutic application for the regeneration of degenerative disc, with significant impact for healthy ageing. Here we found that TAGLN expressing cells are present in human healthy nucleus pulposus, but diminish in degenerative disc. By lineage analyses in mice, we found cells in the nucleus pulposus are derived from a peripherally located population of notochord-derived Tagln expressing cells (PeriNP cells). The PeriNP cells are proliferative and can differentiate into the inner part of the nucleus pulposus. The Tagln+ cells and descendants diminish during aging and puncture induced disc degeneration. The maintenance and differentiation of PeriNP cells is partially regulated by Smad4 dependent signaling. Removal of Smad4 by nucleus pulposus specific Cre (Foxa2mNE-Cre), results in decreased Tagln+ cells and abnormal disc morphology, leading to disc degeneration. Our findings propose that the PeriNP Tagln expressing cells are a pool of notochord-derived progenitors that are important for maintenance of the nucleus pulposus and provide insights for regenerative therapy against intervertebral disc degeneration.
Project description:MicroRNAs expression profiling of human nucleus pulposus cells derived from patients with disc degeneration in comparison with those derived from patients with scoliosis as control. Two-condition experiment: control nucleus pulposus cells vs. degenerative nucleus pulposus cells. Biological replicates: 3 control, 3 degenerated, independently harvested. Four replicates per array. The supplementary file 'GSE19943_fold_pvalue.txt' contains fold-changes and p-values.
Project description:The aim of this transcription profiling study was to identify novel genes that could be used to distinguish bovine Nucleus pulposus (NP) cells from articular cartilage (AC) and annulus fibrosus (AF) cells and to further determine their expression in normal and degenerate human intervertebral disc (IVD). This study has identified a number of novel genes that characterise the bovine and human NP and IVD cell phenotypes and allows for discrimination between AC, AF and NP cells.<br><br>
Project description:Intervertebral disc degeneration is a leading cause of chronic low back pain. Cell-based strategies that seek to treat disc degeneration by regenerating the central nucleus pulposus hold significant promise, but key challenges remain. One of these is the inability of therapeutic cells to effectively mimic the performance of native nucleus pulposus cells, which are unique amongst skeletal cell types in that they arise from the embryonic notochord. In this study we use single cell RNA sequencing to demonstrate emergent heterogeneity amongst notochord-derived nucleus pulposus cells in the postnatal mouse disc. Specifically, we established the existence of early and late stage nucleus pulposus cells, corresponding to notochordal progenitor and mature cells, respectively. Late stage cells exhibited significantly higher expression levels of extracellular matrix genes including aggrecan, and collagens II and VI, along with elevated TGF-β and PI3K-Akt signaling. Additionally, we identified Cd9 as a novel surface marker of late stage nucleus pulposus cells, and demonstrated that these cells were localized to the nucleus pulposus periphery, increased in numbers with increasing postnatal age, and co-localized with emerging glycosaminoglycan-rich extracellular matrix.
Project description:In order to discover the cell type in nucleus pulposus and find the cell type specific genetic change during intervertebral disc degeneration, we applied single cell RNA sequencing of nucleus pulposus tissue from degenerated and non-degenerated disc.
Project description:MicroRNA expression profiling of human nucleus pulposus derived from patients with IDD in comparison with those derived from cadaveric disc as normal control. We have identified the expression profiles of miRNAs in IDD using scoliotic nucleus pulposus as controls (GSE19943). It is noteworthy that scoliotic discs are not strictly normal discs. Therefore, the microRNA expression profiles were revisited using normal discs as control. Two-condition experiment: control nucleus pulposus vs. degenerative nucleus pulposus. Biological replicates: 5 control, 5 degenerated, independently harvested (the same samples as in GSE56081). Four replicates per array.