Essential Role of Hypertrophic Chondrocytes in Endochondral Bone Development

Hypertrophic chondrocytes can become osteoblasts and osteocytes in endochondral bone formation.

According to current dogma, chondrocytes and osteoblasts are considered independent lineages derived from a common osteochondroprogenitor. In endochondral bone formation, chondrocytes undergo a series of differentiation steps to form the growth plate, and it generally is accepted that death is the ultimate fate of terminally differentiated hypertrophic chondrocytes (HCs). Osteoblasts, accompany...

FGFR1 signaling in hypertrophic chondrocytes is attenuated by the Ras-GAP neurofibromin during endochondral bone formation.

Aberrant fibroblast growth factor receptor 3 (FGFR3) signaling disrupts chondrocyte proliferation and growth plate size and architecture, leading to various chondrodysplasias or bone overgrowth. These observations suggest that the duration, intensity and cellular context of FGFR signaling during growth plate chondrocyte maturation require tight, regulated control for proper bone elongation. How...

Chondrocytes Transdifferentiate into Osteoblasts in Endochondral Bone during Development, Postnatal Growth and Fracture Healing in Mice

One of the crucial steps in endochondral bone formation is the replacement of a cartilage matrix produced by chondrocytes with bone trabeculae made by osteoblasts. However, the precise sources of osteoblasts responsible for trabecular bone formation have not been fully defined. To investigate whether cells derived from hypertrophic chondrocytes contribute to the osteoblast pool in trabecular bo...

Deletion Of ERK1 And ERK2 In Hypertrophic Chondrocytes Delays Endochondral Ossification

Endochondral calcification by hypertrophic chondrocytes in the Meckel's cartilage grafted into the isogenic mouse spleen.

We found that when the midsection of Meckel's cartilage bars obtained from mice on the eighteenth day of gestation were grafted into isogenic mouse spleen, chondrocytes induced an endochondral calcification. Concurrent with the onset of calcification throughout Meckel's cartilage matrix, periodic banded thick collagen fibrils and matrix vesicles were observed around the chondrocytes. Although m...