Host Mentor: Dr. Charles Chan
Stanford University Institute for Stem Cell Biology and Regenerative Medicine
Lower back pain is the leading cause of disability and activity limitation worldwide. Previous research has indicated an association to lower back pain and fibrocartilage degeneration of the intervertebral disc (IVD). This degeneration is inevitable and occurs over time through daily strain from daily activities such as bending, lifting, and walking. Currently there is no treatment that effectively reverses fibrocartilage damage to the IVD. Previous research has used heterogeneous mixtures isolated from bone marrow or adipose tissue. However, their fibrocartilage potential have been inconclusive. Through our panel of cell surface markers we have identified for the first time a population of skeletal stem cells (SSCs) in the IVD of young adult mice. SSCs of the various spinal regions were isolated and assayed for chondrogenic and osteogenic potential in vitro. Results revealed both chondrogenic and osteogenic potential in the SSC’s of the spine while also revealing regional distinction from one another. Skeletogenic potential was also assessed in vivo through transplantation of the femur and different spinal regions under the kidney capsule. Results demonstrated that the grafts formed from the various spinal regions were morphologically distinct from the femur. This data suggests that SSC’s for the spinal regions are morphologically distinct in the skeletogenic output and are primed for making tissue specific to the spinal regions. Skeletogenic potential has also been observed in human IVD and femur SSCs. This proposed research will ultimately bring a broader understanding of SSC diversity and create a basis for clinical translation of stem cell-based therapies for IVD deterioration.