Title

Development of the osteoblast phenotype: molecular mechanisms mediating osteoblast growth and differentiation

UMMS Affiliation

Department of Cell Biology

Date

1-1-1995

Document Type

Article

Subjects

Animals; Cell Differentiation; Cell Division; Cell Line; Extracellular Matrix; Gene Expression; Gene Expression Regulation, Neoplastic; Histones; Humans; Osteoblasts; Osteocalcin; Osteosarcoma; Phenotype; Promoter Regions (Genetics); Transforming Growth Factor beta

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

The formation of bone tissue involves multiple activities of the osteoblast. The combined application of molecular, biochemical, histochemical and ultrastructural approaches has defined stages in the development of the osteoblast phenotype with each subpopulation of cells exhibiting unique morphologic and functional properties in relation to the ordered deposition of the mineralized bone extracellular matrix (ECM). Peak levels of expressed genes reflect a maturational sequence of osteoblast growth and differentiation characterized by three principal periods: proliferation, ECM maturation and mineralization. A plethora of new information in the past several years provides the basis for insight into molecular mechanisms regulating the development and activities of differentiating osteoblasts. These new concepts will be discussed within the context of understanding cellular responses of bone tissue. To be considered are the following: 1) maturational stages of the osteoblast reflected by the selective expression of transcription factors (e.g., oncogenes, cyclins, homeodomain proteins) and phenotypic genes that provide signals for differentiation through the osteoblast lineage; 2) role of the extracellular matrix in mediating osteoblast growth and differentiation; 3) osteoblast stage specific responses to physiologic mediators (e.g., growth factors and hormones); 4) the developmentally regulated expression and selective responses of osteoblast phenotypic genes are supported by cooperative, synergistic and/or antagonistic activities at multiple basal and enhancer or suppressor sequences in gene promoters; and 5) deregulation of these control mechanisms in transformed osteoblasts and osteosarcoma cells.

Rights and Permissions

Citation: Iowa Orthop J. 1995;15:118-40.

Related Resources

Link to Article in PubMed

Journal Title

The Iowa orthopaedic journal

PubMed ID

7634023