Matrix γ-carboxyglutamic acid protein is a key regulator of PTH-mediated inhibition of mineralization in MC3T3-E1 osteoblast-like cells

被引:34
作者
Gopalakrishnan, R
Ouyang, H
Somerman, MJ
McCauley, LK
Franceschi, RT [1 ]
机构
[1] Univ Michigan, Sch Dent, Dept Periodont Prevent Geriatr, Ann Arbor, MI 48109 USA
[2] Univ Michigan, Sch Dent, Dept Cardiol Restorat Sci & Endodont, Ann Arbor, MI 48109 USA
[3] Univ Michigan, Sch Med, Dept Pharmacol, Ann Arbor, MI 48109 USA
[4] Univ Michigan, Sch Med, Dept Biol Chem, Ann Arbor, MI 48109 USA
关键词
D O I
10.1210/en.142.10.4379
中图分类号
R5 [内科学];
学科分类号
1002 ; 100201 ;
摘要
As part of its overall function as a major regulator of calcium homeostasis, PTH stimulates bone resorption and inhibits osteoblast-mediated biomineralization. To determine the basis for the inhibitory actions of this hormone, we compared the time course of PTH-dependent inhibition of mineralization in MC3T3-E1 osteoblast-like cells with changes in mRNA levels for several extracellular matrix proteins previously associated either with induction or inhibition of mineralization. Mineralizing activity was rapidly lost in PTH-treated cells (similar to 30% inhibition after 3 h, 50% inhibition at 6 h). Of the proteins examined, changes in matrix gamma -carboxyglutamic acid protein were best correlated with PTH-dependent inhibition of mineralization. Matrix gamma -carboxyglutamic acid protein mRNA was rapidly induced 3 h after PTH treatment, with a 6- to S-fold induction seen after 6 h. Local in vivo injection of PTH over the calvaria of mice also induced a 2-fold increase in matrix gamma -carboxyglutamic acid protein mRNA. Warfarin, an inhibitor of matrix gamma -carboxyglutamic acid protein gamma -carboxylation, reversed the effects of PTH on mineralization in MC3T3-E1 cells, whereas vitamin K enhanced PTH activity, as would be expected if a gamma -carboxyglutamic acid-containing protein were required for PTH activity. Levels of the other mRNAs examined were not well correlated with the observed changes in mineralization. Osteopontin, an in vitro inhibitor of mineralization, was induced approximately 4-fold 12 h after PTH addition. Bone sialoprotein mRNA, which encodes an extracellular matrix component most frequently associated with mineral induction, was inhibited by 50% after 12 h of PTH treatment. Osteocalcin mRNA, encoding the other known gamma -carboxyglutamic acid protein in bone, was also inhibited by PTH, but, again, with a significantly slower time course than was seen for mineral inhibition. Taken together, these results show that the rapid inhibition of osteoblast mineralization induced by in vitro PTH treatment is at least in part explained by induction of matrix gamma -carboxyglutamic acid protein.
引用
收藏
页码:4379 / 4388
页数:10
相关论文
共 63 条
[11]   THE EFFECT OF OSTEOCALCIN ON INVITRO LIPID-INDUCED HYDROXYAPATITE FORMATION AND SEEDED HYDROXYAPATITE GROWTH [J].
BOSKEY, AL ;
WIANS, FH ;
HAUSCHKA, PV .
CALCIFIED TISSUE INTERNATIONAL, 1985, 37 (01) :57-62
[12]   THE DUAL ROLE OF POLY-ELECTROLYTES AND PROTEINS AS MINERALIZATION PROMOTERS AND INHIBITORS OF CALCIUM-OXALATE MONOHYDRATE [J].
CAMPBELL, AA ;
EBRAHIMPOUR, A ;
PEREZ, L ;
SMESKO, SA ;
NANCOLLAS, GH .
CALCIFIED TISSUE INTERNATIONAL, 1989, 45 (02) :122-128
[13]   ISOLATION OF THE HUMAN-GENE FOR BONE GLA PROTEIN UTILIZING MOUSE AND RAT CDNA CLONES [J].
CELESTE, AJ ;
ROSEN, V ;
BUECKER, JL ;
KRIZ, R ;
WANG, EA ;
WOZNEY, JM .
EMBO JOURNAL, 1986, 5 (08) :1885-1890
[14]   THE INHIBITORY EFFECT OF CARTILAGE PROTEOGLYCANS ON HYDROXYAPATITE GROWTH [J].
CHEN, CC ;
BOSKEY, AL ;
ROSENBERG, LC .
CALCIFIED TISSUE INTERNATIONAL, 1984, 36 (03) :285-290
[15]   LOCALIZATION OF BONE SIALOPROTEIN (BSP) EXPRESSION TO SITES OF MINERALIZED TISSUE FORMATION IN FETAL-RAT TISSUES BY INSITU HYBRIDIZATION [J].
CHEN, JK ;
SHAPIRO, HS ;
WRANA, JL ;
REIMERS, S ;
HEERSCHE, JNM ;
SODEK, J .
MATRIX, 1991, 11 (02) :133-143
[16]   Effects of fibronectin on hydroxyapatite formation [J].
Couchourel, D ;
Escoffier, C ;
Rohanizadeh, R ;
Bohic, S ;
Daculsi, G ;
Fortun, Y ;
Padrines, M .
JOURNAL OF INORGANIC BIOCHEMISTRY, 1999, 73 (03) :129-136
[17]   Mapping of the human and mouse bone sialoprotein and osteopontin loci [J].
Crosby, AH ;
Lyu, MS ;
Lin, K ;
McBride, OW ;
Kerr, JM ;
Aplin, HM ;
Fisher, LW ;
Young, MF ;
Kozak, CA ;
Dixon, MJ .
MAMMALIAN GENOME, 1996, 7 (02) :149-151
[18]   ANABOLIC ACTIONS OF PARATHYROID-HORMONE ON BONE [J].
DEMPSTER, DW ;
COSMAN, F ;
PARISIEN, M ;
SHEN, V ;
LINDSAY, R .
ENDOCRINE REVIEWS, 1993, 14 (06) :690-709
[19]   Increased bone formation in osteocalcin-deficient mice [J].
Ducy, P ;
Desbois, C ;
Boyce, B ;
Pinero, G ;
Story, B ;
Dunstan, C ;
Smith, E ;
Bonadio, J ;
Goldstein, S ;
Gundberg, C ;
Bradley, A ;
Karsenty, G .
NATURE, 1996, 382 (6590) :448-452
[20]  
Fitzpatrick Lorraine A., 1996, P339