Content of Bone Morphogenetic Protein-4 in Human Demineralized Bone: Relationship to Donor Age and Ability to Induce New Bone Formation
Sittisak Honsawek*, Dhakoon Dhitiseith*
Affiliation : * Department of Biochemistry, Faculty of Medicine, Chulalongkorn University
Background : Bone morphogenetic proteins (BMPs) are also called growth and differentiation factors (GDFs)
and form a subfamily of related proteins within the TGF-β superfamily. BMP-4 is one of multifuntional growth
factors with pleiotropic roles in many different cell types and is predominantly present in human bone tissue.
Objectives : To analyze the content of extractable BMP-4 in human demineralized bone as a function of age
Materials and 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 en-
zyme-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.
Conclusion : The BMP-4 in demineralized bone undergoes age-related decrease that may contribute to the
reduction of bone volume observed with aging.
Keywords : Bone, Demineralized, BMP-4, Donor age, Osteoinductivity
