Portal de Periódicos da CAPES

Matrix Gla protein (MGP) and bone morphogenetic protein-2 in aortic calcified lesions of aging rats

2003; Elsevier BV; Volume: 1; Issue: 1 Linguagem: Inglês

10.1046/j.1538-7836.2003.00023.x

1538-7933

Andrew J. Sweatt, David C. Sane, S.M. Hutson, Reidar Wallin,

Coagulation, Bradykinin, Polyphosphates, and Angioedema

Summary. The vitamin K-dependent protein, matrix Gla protein (MGP) is a binding protein for bone morphogenetic protein-2 (BMP-2). Here we present additional evidence that the Ca2+-induced conformer of the vitamin K-dependent Gla region in MGP is involved in BMP-2 binding. Recombinant BMP-2 binds to the Gla-containing region of MGP in the presence of Ca2+. Immunohistochemistry showed that calcified lesions in the aortic wall of aging rats contained elevated concentrations of MGP that was poorly γ-carboxylated and did not bind BMP-2. In contrast, we were able to identify glandular structures in the mucosa of the rat nasal septum that gave bright fluorescent signals with both antigens; confocal microscopy confirmed their colocalization. These results demonstrate that the BMP-2/MGP complex exists in vivo, consistent with a role for MGP as a BMP-2 inhibitor. Age-related arterial calcification may be a consequence of under-γ-carboxylation of MGP, allowing unopposed BMP-2 activity.