Project description:Mice lacking equilibrative nucleoside transporter 1 demonstrate progressive calcification of spinal tissues including the annulus fibrosus (AF) of the intervertebral disc (IVD). To identify cellular pathways altered by loss of ENT1, we conducted microarray analysis of AF tissue from wild-type (WT) and ENT1-null mice before calcification (2 months) and associated with calcification (6 months).
Project description:This study sought to elucidate the transcriptomic changes in the murine nucleus pulposus (NP) with age. These findings will contribute to the understanding of murine intervertebral disc (IVD) aging and degeneration.
Project description:IVDs are composed of heterogeneous cell groups, a further understanding of marker genes and cell phenotypes of healthy mature IVD cells is essential.
Project description:The intervertebral disc (IVD) is a spinal joint that accumulates damage with age but has limited tissue repair capabilities. IVD damage progresses into degeneration, and IVD degeneration is a leading cause of lower back pain. There are no effective therapies to treat IVD degeneration, but understanding the cell populations that change and respond to injury will uncover targets to restore IVD function. Mesenchymal stem cells (MSCs) are cells within the IVD that can potentially replenish the cells lost after IVD damage. To identify the cell populations of the IVD and how they change with injury, we performed single cell RNA sequencing of IVD tissue 7 days post injury and analyzed the differences in gene regulation. We identified diverse cells populations such as IVD specific tissues, immune cells, vascular cells, and MSCs. We discovered the presence of Saa2 and Grem1 expressing MSCs that become less stem cell-like and express higher levels of IVD gene markers after injury. We also determined that Saa2 and Grem1 have slightly different expression patterns in IVD tissues, and this expression becomes reduced after injury. These MSCs could be used in future stem cell therapies to prevent IVD degeneration.
Project description:Neonatal mouse intervertebral discs lose regenerative potential between postnatal day 14 and day 28during a period of Intervertebral disc (IVD) defects heal poorly and can cause back pain and disability. We identified that IVD herniation injury heals regeneratively in neonatal mice until postnatal day 14 (p14) and shifts to fibrotic healing by p28. This age coincides with the shift in expansive IVD growth from cell proliferation to matrix elaboration, implicating collagen crosslinking. -aminopropionitrile treatment reduced IVD crosslinking and caused fibrotic healing without affecting cell proliferation. Bulk sequencing on naïve IVDs were depleted for matrix structural organization from p14 to p28 to validating the importance of crosslinking in regenerative healing. We conclude that matrix changes are key drivers in the shift to fibrotic healing, and a stably crosslinked matrix is needed for IVD regeneration.
Project description:Here we performed single-cell RNA sequencing to address repertoire stability and subset plasticity during IL-15 driven homeostatic proliferation. Sorted NK cell subsets representing discrete stages of NK cell differentiation are compared with the corresponding subsets after proliferation and further sorted into two subsets depending on the rate of proliferation.