Project description:The intervertebral disc is a specialized fibrocartilage structure of the spinal column that is pivotal for spinal mobility and function. It is composed of 3 distinct anatomical components: the annulus fibrosus, nulceus pulposus and cartilage endplates. We used 10x single cell seq to identify the various cell components of the disc as well as discover novel cell populations and signaling networks.
Project description:We report the single-cell RNA-seq (scRNA-seq) data for human neonatal and adult human intervertebral disc (IVD) scRNA-seq. We sequenced cells harvested from three IVDs of a neonatal baby and one IVD from an adult cadaver.
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:The pathophysiology of intervertebral disc (IVD) degeneration is not entirely understood; however, environmental and endogenous factors under genetic predisposition are considered to initiate the degenerative changes of human IVDs. Aberrant epigenetic alterations play a pivotal role in several diseases, including osteoarthritis. However, epigenetic alternations, including DNA methylation, in IVD degeneration have not been evaluated. The purpose of this study was to comprehensively compare the genome-wide DNA methylation profiles of human IVD tissues, specifically nucleus pulpous (NP) tissues, with early and advanced stages of disc degeneration. We conducted, for the first time, a genome-wide DNA methylation profile comparative study and observed significant differences in DNA methylation profiles between early and advanced stages of human IVD degeneration. The overview of the DNA methylation profile in the current study revealed that differentially methylated loci were identified in many genes associated with known molecules that have been reported to be relevant to IVD degeneration. Importantly, changes in DNA methylation profiles were also found in genes that regulate the major signaling pathways, such as NF-κB, MAPK, and Wnt signaling, that are well known to be responsible for the pathogenesis of human disc degeneration.