Osteogenic protein-1 enhances phenotypic expression in ros 17/2.8
cells.
Kitten, Allison M., John C. Lee, and Merle S. Olson.
Department of Biochemistry, University of Texas Health Science
Center, 7703 Floyd Curl Drive, San Antonio, Texas 78284-7760
APStracts 2:0148E, 1995.
Osteogenic protein-1 (OP-1) stimulates bone morphogenesis in vivo and
modulates osteoblast growth and differentiation in vitro. Treatment
of ROS 17/2.8 cells with OP-1 resulted in a time- and concentration
-dependent inhibition of [3H]thymidine incorporation. In contrast, OP
-1 treatment stimulated phenotypic differentiation in ROS 17/2.8
cells, as indicated by enhanced 1) alkaline phosphatase activity (4
-fold); 2) alkaline phosphaste mRNA (5-fold); 3) parathyroid hormone
receptor mRNA (2-fold), and 4) parathyroid hormone-stimulated cAMP
accumulation (2-fold). OP-1-induced changes in cell growth and gene
expression were sensitive to cycloheximide and actinomycin D.
Measurement of [3H]thymidine incorporation and alkaline phosphatase
activity in situ revealed heterogeneity in the cellular responses to
OP-1. Proliferating cells exhibited less alkaline phosphatase
activity than non-proliferating cells, while cells expressing high
levels of alkaline phosphatase incorporated little [3H]thymidine. Our
data delineating the responses of mature, differentiated osteoblasts
to OP-1 suggest that potentiation of osteoblast differentiated
function is an important component of bone morphogenesis in vivo .
Received 7 February 1995; accepted in final form 22 June 1995.
APS Manuscript Number E55-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 18 July 1995.