Nucleus Pulposus Progenitor Cells: Key to Intervertebral Disc Regeneration

Progenitor cells are cells that can differentiate into a specific cell type. In the intervertebral disc (IVD), there are two types of progenitor cells: the annulus fibrosus (AF) progenitor cells and the nucleus pulposus (NP) progenitor cells.

The AF progenitor cells reside in the outer layer of the disc, the annulus fibrosus. These cells can become fibroblasts, responsible for producing collagen and other extracellular matrix proteins that make up the annulus fibrosus.

The NP progenitor cells, on the other hand, are found in the center of the disc, the nucleus pulposus. These cells can differentiate into chondrocytes, which produce proteoglycans and other extracellular matrix proteins that make up the nucleus pulposus.

Both types of progenitor cells are crucial for maintaining the health and function of the IVD. However, as we age, the number and function of these cells can decrease, contributing to the development of degenerative disc disease. Therefore, researchers are exploring ways to use these progenitor cells to stimulate disc regeneration and repair.