Project description:Pax1 and Pax9 play redundant, synergistic functions in the patterning and differentiation of the sclerotomal cells that give rise to the vertebral bodies and intervertebral discs (IVD) of the axial skeleton. Gene expression profiling of an enriched population of Pax1/Pax9-expressing cells of the embryonic IVD revealed that Pax1 and Pax9 regulate cell proliferation, cartilage development, collagen fibrillogenesis and other processes vital in early IVD morphogenesis. Twenty-nine of the Pax1/Pax9 targets are also associated with axial skeletal defects that phenocopy Pax1/Pax9-deficient mice. Pax1 likely auto-regulates itself and is up-regulated in the absence of Pax9, clarifying how it compensates for the loss of Pax9, while Pax9 is unaffected by the loss of Pax1. Pax1 and Pax9 positively regulate several of the cartilage development genes known to be regulated by the “Sox trio” (Sox5/Sox6/Sox9).
Project description:Recapitulation of developmental signals represents a promising strategy for treating intervertebral disc degeneration. During development, embryonic notochord-derived cells (NDCs) are the direct progenitors of cells that populate the adult nucleus pulposus (NP) and are an important source of secreted signaling molecules. The objective of this study was to define global gene expression profiles of NDCs at key stages of embryonic disc formation. NDCs were isolated from Shh-cre;ROSA:YFP mice at embryonic day 12.5 and postnatal day 0, representing opposite ends of the notochord to NP transformation. Differences in global mRNA abundance across this developmental window were established using RNA-Seq. Principal component analysis revealed clustering of gene expression at each developmental stage with more than 5000 genes significantly differentially expressed between E12.5 and P0. This study represents the first transcriptome-wide analysis of embryonic NDCs. Results suggest signaling and biosynthesis of NDCs change dramatically as a function of developmental stage.
Project description:The adult nucleus pulposus originates from the embryonic notochord, but loss of notochordal cells with skeletal maturity in humans is believed to initiate intervertebral disc degeneration. Thus, defining the phenotype of human embryonic/fetal notochordal cells is essential for understanding their roles and for development of novel therapies. However, a detailed transcriptomic profiling of human notochordal cells has never been achieved. In this study, the notochord-specific marker CD24 was used to specifically label and isolate (using FACS) notochordal cells from human embryonic and fetal spines (7.5-14 weeks post-conception), which were studied by microarray analysis.
Project description:We selected humann intervertebral disc samples to perform proteomics analysis. There were 1 case of grade I , 1 case of grade II, 3 cases of grade Ⅲ and 3 cases of grade Ⅳ according to Pfirrmann classfication. RNA seqencing analysis and single-cell RNA sequencing were integrated with proteomics data to identify the hub genes for intervertebral disc degeneration using bioinformatic method.
Project description:This SuperSeries is composed of the following subset Series: GSE18647: Gene expression in embryonic intervertebral disc and vertebrae. GSE18648: TGF-beta and BMP mediated gene expression in cultured sclerotome. Refer to individual Series
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: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:Research on disc degeneration has been heterogeneous in their use of control discs used for comparison with diseased discs. Discs from scoliosis, cadavers and voluntary organ donors are the common controls used in intervertebral disc research. In order to find out the ideal control among these discs, the characters of scoliotic discs and discs from MRI normal voluntary organ donors controls used in disc research has been analysed using proteomics and to establish 'True Controls' that can be utilized for future Intervertebral disc (IVD) research.
Project description:Our studies show that TonEBP-deficiency causes pronounced degeneration of all three intervertebral disc compartments with greater incidence of herniation in the mouse. The disc phenotype is marked by extracellular matrix remodeling, actin cytoskeleton rearrangements, and suppressed proinflammatory gene expression, advancing our understanding of the contributions of TonEBP in intervertebral disc homeostasis and disease. We used microarray to explore the transcriptomics of differentially expressed genes of annulus fibrosus (AF) and nucleus pulposus (NP) tissue in TonEBP haploinsufficient mice on a C57BL/6 background.