Functional regulation of osteoblastic cells by the interaction of activin-A with follistatin.
A high number of 125I-activin-A binding sites (an apparent Kd of 260 pM and 5,600 sites/cell) were observed on MC3T3-E1 cells, a well characterized osteoblastic cell line. Activin-A has a mitogenic effect on these cells, with the greatest influence being observed on cells in an undifferentiated state, as well as a suppressive effect on the alkaline phosphatase activity. Northern and ligand blotting analyses revealed that these osteoblastic cells produce follistatin, which was down-regulated by retinoic acid treatment. Because follistatin is an activin-A-binding protein, we suggest that activin-A modulates the function of osteoblastic cells by being regulated by follistatin during differentiation.
Hashimoto
M
M
Department of Biochemistry, Faculty of Medicine, University of Tokyo, Japan.
Shoda
A
A
Inoue
S
S
Yamada
R
R
Kondo
T
T
Sakurai
T
T
Ueno
N
N
Muramatsu
M
M
D028341:Activins; D000469:Alkaline Phosphatase / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D015152:Blotting, Northern; D002454:Cell Differentiation; D002460:Cell Line; D004261:DNA Replication / Q000187:drug effects; D038681:Follistatin; D006023:Glycoproteins / Q000494:pharmacology*; D006801:Humans; D007265:Inhibins / Q000378:metabolism / Q000494:pharmacology*; D004915:Leukemia, Erythroblastic, Acute / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D010006:Osteoblasts / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D012516:Osteosarcoma / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D014407:Tumor Cells, Cultured / Q000201:enzymology
D038681:Follistatin; D006023:Glycoproteins; D012333:RNA, Messenger; D028341:Activins; D007265:Inhibins; D000469:Alkaline Phosphatase