sábado, 20 de marzo de 2010

Endochondral bone formation is involved in media calcification in rats and in men

Arterial media calcification is often considered a cell-regulated
process resembling intramembranous bone formation, implying a
conversion of vascular tissue into a bone-like structure without a
cartilage intermediate. In this study, we examined the association of
chondrocyte-specific marker expression with media calcification in
arterial samples derived from rats with chronic renal failure (CRF)
and from human transplant donors. CRF was induced in rats with a diet
supplemented with adenine. Vascular calcification was evaluated
histomorphometrically on Von Kossa-stained sections and the expression
of the chondrocyte markers sox9 and collagen II with the osteogenic
marker core-binding factor alpha1 (cbfa1) was determined
immunohistochemically. Media calcification was detected in more than
half of the rats with CRF. In over half of the rats with severe media
calcification, a typical cartilage matrix was found by morphology. All
of the animals with severe calcification showed the presence of
chondrocyte-like cells expressing the markers sox9, collagen II, and
cbfa1. Human aorta specimens showing mild to moderate media
calcification also showed sox9, collagen II, and cbfa1 expression. The
presence of chondrocytes in association with calcification of the
media in aortas of rats with CRF mimics endochondral bone formation.
The relevance of this association is further demonstrated by the
chondrogenic conversion of medial smooth muscle cells in the human
aorta. Kidney International (2007) 72, 574–581;
doi:10.1038/sj.ki.5002353; published online 30 May 2007

No hay comentarios:

Publicar un comentario