Modulation of thrombospondin gene expression during osteoblast differentiation in MC3T3-E1 cells.
The levels of expression of two related extracellular matrix protein genes, thrombospondins 1 and 2 (TSP1 and TSP2), were analyzed in the mouse osteogenic cell line, MC3T3-E1. To monitor differentiation, we also measured two potential markers of the osteoblastic phenotype, alkaline phosphatase (ALP) activity, and alpha 1(I) collagen mRNA levels. TSP1 mRNA levels increased 10- to 15-fold during the first nine days of osteoblastic conversion, and then dropped to a level still significantly above baseline values. This increase in TSP1 mRNA closely paralleled that observed in ALP activity. In contrast, TSP2 mRNA levels were unchanged throughout the 21-day time course. These findings suggest that TSP1 is a marker for osteoblast differentiation and could play a role in the cellular changes that accompany acquisition of the osteoblastic phenotype in MC3T3-E1 cells.
Sherbina
N V
NV
Department of Biochemistry, University of Washington, Seattle 98195.
Bornstein
P
P
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D002460:Cell Line; D003094:Collagen / Q000235:genetics; D005786:Gene Expression Regulation / Q000502:physiology*; D037102:Lectins / Q000235:genetics*; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D010980:Platelet Membrane Glycoproteins / Q000235:genetics*; D019699:Thrombospondins
D037102:Lectins; D010980:Platelet Membrane Glycoproteins; D019699:Thrombospondins; D003094:Collagen; D000469:Alkaline Phosphatase