What happens to hypertrophic chondrocytes?
We show that hypertrophic chondrocytes can survive the cartilage-to-bone transition and become osteoblasts and osteocytes during endochondral bone formation and in bone repair.
Where do chondrocytes undergo apoptosis?
Chondrocyte apoptosis is generally observed prior to the transition of calcified cartilage to bone.
Do chondrocytes undergo apoptosis?
The term “chondroptosis” was coined to describe the type of cell death that is commonly observed in chondrocytes, reflecting the fact that chondrocytes do not undergo apoptosis in a classical manner.
Why do chondrocytes undergo apoptosis?
Chondrocyte apoptosis in osteoarthritis may be the conse- quence of aberrant hypertrophic chondrocyte differentiation or induced by extracellular stimuli such as Fas ligand and other cytokines. The degradation or absence of extra- cellular matrix may predispose chondrocytes to undergo apoptosis.
What are hypertrophic chondrocytes?
Hypertrophic chondrocytes are specialized cells consid- ered to be the end state of the chondrocyte differentiation pathway, and are essential for bone growth. They are characterized by expression of type X collagen encoded by the Col10a1 gene, and synthesis of a calcified cartilage matrix.
What do hypertrophic chondrocytes secrete?
Hypertrophic chondrocytes, which are identified by their specific expression of type X collagen (COL10A1), are ultimately responsible for secreting additional proteins such as Vascular Endothelial Growth Factor alpha (VEGFα), Platelet Derived Growth Factor beta (PDGFβ), and Indian Hedgehog (IHH) among other factors to …
What is chondrocyte apoptosis?
Chondrocyte apoptosis alters the synthesis of the cartilage matrix, leading to cartilage degeneration and destruction, and finally to OA. Accumulated evidence indicates that oxidative stress is involved in chondrocyte apoptosis in OA pathogenesis [8.
What is the hypertrophic zone?
The germinal zone of the physis borders the epiphysis. The epiphyseal cartilage cells grow toward the metaphysis and form columns of cells. These columns degenerate, undergo hypertrophy, and then calcify at the metaphysis to form new bone. The hypertrophic zone (shaded red) is the usual site of physeal fractures.
What is happening to the size of the chondrocytes in the zone of hypertrophy?
The hypertrophic zone also plays a key role in endochondral bone formation. Hypertrophic chondrocytes are generated by terminal differentiation of the proliferative zone chondrocytes farthest from the epiphysis. These cells cease dividing and then enlarge, contributing substantially to the growth process (4, 5).
What occurs in the hypertrophic zone in a developing bone?
Which of the following describes the zone of cell hypertrophy in an epiphyseal plate?
Which of the following describes the zone of cell hypertrophy in an epiphyseal plate? Chondrocytes in this zone are no longer dividing, but are enlarging; there is a thinning of lacunae walls.