J Korean Orthop Assoc.  2001 Oct;36(5):479-484.

Expression of Senescence-related Proteins in Rat Fracture Callus

• Song SH
• Park YE
• Choi YH
• Shim CG
• Cho SW

Abstract

PURPOSE
To evaluate the expression of senescence-related proteins according to the aging process and to determine the role of senescence-related proteins in the bone tissue and their effects on the process of bone union.
MATERIALS AND METHODS
18 Sprague-Dawley rats (8 weeks old: 7, 32 weeks old: 6, and 70 weeks old: 5) were used in the experiment. A unilateral closed femur fracture was made, and the fracture callus was obtained 2 weeks after the fracture. The ossification process was observed in proliferative chondrocytes, the hypertrophic chondrocytes, and in the mesenchymal layer individually by immunohistochemistry, using p16, p21, c-fos and c-jun antibodies.
RESULTS
There was no significant differences in the manifestation of p-16, p-21, c-fos, c-jun gene according to the age. The positive ratio of p-16 was maximal in proliferative chondrocytes (54.93%) and decreased in the mesenchymal layer (46.48%), and in hypertrophic chondrocytes (10.85%), in order. The positive ratio of c-fos was maximal in proliferative chondrocytes (73.32%) and decreased in the mesenchymal layer (51.84%), and in hypertrophic chondrocytes (9.64%), in order.
CONCLUSION
We believe that senescent genes in the bone tissue participate in the differentiation of osteochondral cells and in the process of fracture callus ossification.

Keyword

Senescence-related protein; Callus; Immunohistochemistry; Aging; p16; p21; c-fos; c-jun

MeSH Terms

Aging
Animals
Antibodies
Bone and Bones
Bony Callus*
Chondrocytes
Femur
Genes, jun
Immunohistochemistry
Rats*
Rats, Sprague-Dawley
Antibodies