Receptor activator of nuclear factor κB ligand and osteoprotegerin regulate aortic valve calcification
JJ Kaden, S Bickelhaupt, R Grobholz, KK Haase… - Journal of molecular and …, 2004 - Elsevier
JJ Kaden, S Bickelhaupt, R Grobholz, KK Haase, A Sarιkoç, M Brueckmann, S Lang, I Zahn…
Journal of molecular and cellular cardiology, 2004•ElsevierObjective.–Recent studies have suggested that valvular calcification in calcific aortic
stenosis (AS) may be actively regulated.“Receptor Activator of Nuclear factor κB
Ligand”(RANKL) and osteoprotegerin (OPG) are members of a cytokine system involved in
bone turnover and vascular calcification. Their role in calcific AS is not known. Methods and
Results.–By immunohistochemistry using human aortic valves, RANKL was not expressed at
relevant levels in controls but detectable in AS. OPG expression was marked in controls but …
stenosis (AS) may be actively regulated.“Receptor Activator of Nuclear factor κB
Ligand”(RANKL) and osteoprotegerin (OPG) are members of a cytokine system involved in
bone turnover and vascular calcification. Their role in calcific AS is not known. Methods and
Results.–By immunohistochemistry using human aortic valves, RANKL was not expressed at
relevant levels in controls but detectable in AS. OPG expression was marked in controls but …
Objective
Recent studies have suggested that valvular calcification in calcific aortic stenosis (AS) may be actively regulated. “Receptor Activator of Nuclear factor κB Ligand” (RANKL) and osteoprotegerin (OPG) are members of a cytokine system involved in bone turnover and vascular calcification. Their role in calcific AS is not known.
Methods and Results
By immunohistochemistry using human aortic valves, RANKL was not expressed at relevant levels in controls but detectable in AS. OPG expression was marked in controls but significantly lower in AS. Areas containing focal calcification exhibited significantly less OPG-positive cells as compared to non-calcified regions. Stimulation with RANKL lead to a significant rise in matrix calcification, nodule formation, alkaline phosphatase activity, expression of the bone-type isoenzyme of alkaline phosphatase, and expression of osteocalcin in cultured human aortic valve myofibroblasts. Moreover, RANKL increased DNA binding of the essential osteoblast transcription factor cbfa-1.
Conclusion
RANKL and OPG are differentially expressed in calcific AS. In cultured human aortic valve myofibroblasts, RANKL promotes matrix calcification and induces the expression of osteoblast-associated genes, indicating a transition towards an osteogenic phenotype. These results suggest that the RANKL-OPG pathway may regulate valvular calcification in calcific AS?
Elsevier
