Content of bone morphogenetic protein-4 in human demineralized bone: relationship to donor age and ability to induce new bone formation.
BACKGROUND
Bone morphogenetic proteins (BMPs) are also called growth and differentiation factors (GDFs) and form a subfamily of related proteins within the TGF-beta superfamily. BMP-4 is one ofmultifuntional growth factors with pleiotropic roles in many different cell types and is predominantly present in human bone tissue.


OBJECTIVE
To analyze the content of extractable BMP-4 in human demineralized bone as a function of age.


METHODS
Bone samples were ground and demineralized by exposure to 0.5 N HCl and then extracted by collagenase digestion. Extractable BMP-4 was analyzed using a commercially available enzyme-linked immunosorbent assay (ELISA).


RESULTS
63 samples of demineralized bone matrix (DBM) derived from 36 men and 27 women between the ages of 15-65 years. The extractable BMP-4 content appears to be age-dependent, with DBM from younger donors being most likely to have higher BMP-4 quantity. In addition, DBM with high osteoinductivity contained greater amounts of extractable BMP-4 than DBM samples with low osteoinductivity.


CONCLUSIONS
The BMP-4 in demineralized bone undergoes age-related decrease that may contribute to the reduction of bone volume observed with aging.
Honsawek
Sittisak
S
Department of Biochemistry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. fmedshs@md.chula.ac.th
Dhitiseith
Dhakoon
D
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology*; D018775:Bone Demineralization Technique; D001846:Bone Development / Q000502:physiology*; D001857:Bone Matrix / Q000737:chemistry* / Q000637:transplantation; D055415:Bone Morphogenetic Protein 4; D052004:Bone Morphogenetic Protein Receptors; D019485:Bone Morphogenetic Proteins / Q000032:analysis*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D010012:Osteogenesis; D014019:Tissue Donors
C525809:BMP4 protein, human; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D052004:Bone Morphogenetic Protein Receptors