Abstract
The nucleus pulposus (NP) in the intervertebral disc (IVD) arises from embryonic notochord. Loss of notochordal-like cells in humans correlates with onset of IVD degeneration, suggesting that they are critical for healthy NP homeostasis and function. Comparative transcriptomic analyses identified expression of progenitor-associated genes (GREM1, KRT18, and TAGLN) in the young mouse and non-degenerated human NP, with TAGLN expression reducing with aging. Lineage tracing using Tagln-Cre ERt2 mice identified peripherally located proliferative NP (PeriNP) cells in developing and postnatal NP that provide a continuous supply of cells to the entire NP. PeriNP cells were diminished in aged mice and absent in puncture-induced degenerated discs. Single-cell transcriptomes of postnatal Tagln-Cre ERt2 IVD cells indicate enrichment for TGF-β signaling in Tagln descendant NP sub-populations. Notochord-specific removal of TGF-β/BMP mediator Smad4 results in loss of Tagln + cells and abnormal NP morphologies. We propose Tagln + PeriNP cells are potential progenitors crucial for NP homeostasis.
Original language | English |
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Pages (from-to) | 114342 |
Journal | Cell Reports |
Volume | 43 |
Issue number | 6 |
DOIs | |
Publication status | Published - 25 Jun 2024 |
Keywords
- Nucleus Pulposus/metabolism
- Intervertebral Disc Degeneration/pathology
- Animals
- Humans
- Mice
- Stem Cells/metabolism
- Intervertebral Disc/metabolism
- Transforming Growth Factor beta/metabolism