Chondrocytes (from
Greek chondros cartilage +
kytos cell) are the only cells found in
cartilage. They produce and maintain the cartilaginous matrix, which consists mainly of
collagen and
proteoglycans. Although
chondroblast is still commonly used to describe an immature chondrocyte, use of the term is discouraged, for it is technically inaccurate since the progenitor of chondrocytes (which are
mesenchymal stem cells) can also differentiate into
osteoblasts.
Differentiation
From least- to terminally-differentiated, the chondrocytic lineage is:
- Colony-forming unit-fibroblast (CFU-F)
- Mesenchymal stem cell / marrow stromal cell (MSC)
- Chondrocyte
- Hypertrophic chondrocyte
When referring to bone or cartilage, mesenchymal stem cells (MSC) are commonly known as osteochondrogenic (or osteogenic, chondrogenic, osteoprogenitor, etc.) cells since a single MSC has shown the ability to differentiate into chondrocytes or osteoblasts, depending on the medium. In vivo, differentiation of an MSC in a vascularized area (such as bone) yields an osteoblast, whereas differentiation of an MSC in a non-vascularized area (such as cartilage) yields a chondrocyte. Chondrocytes undergo terminal differentiation when they become hypertrophic during endochondral ossification. This last stage is characterized by major phenotypic changes in the cell.
References
- Dominici M, Hofmann T, Horwitz E "Bone marrow mesenchymal cells: biological properties and clinical applications". J Biol Regul Homeost Agents 15 (1): 28–37.
- Bianco P, Riminucci M, Gronthos S, Robey P (2001). "Bone marrow stromal stem cells: nature, biology, and potential applications". Stem Cells 19 (3): 180–92.
- Stem cell information
External links
