Superoxide production: a procalcifying cell signalling event in osteoblastic differentiation of vascular smooth muscle cells exposed to calcification media.
Recent studies showed that hydrogen peroxide (H(2)O(2)) enhanced bone markers expression in vascular smooth muscle cells (VSMCs) implicated in osteoblastic differentiation. This study aimed at investigating the role of NAD(P)H oxidase in vascular calcification processes. A7r5 rat VSMCs were incubated with beta-glycerophosphate (10 mm) or uremic serum to induce a diffuse mineralization. H(2)O(2) production by VSMCs was determinated by chemiluminescence. NAD(P)H oxidase sub-unit (p22(phox)), Cbfa-1, ERK phosphorylation and bone alkaline phosphatase (ALP) expressions were measured by Western blotting. VSMCs exhibited higher production of H(2)O(2) and early expression of p22(phox) with beta-glycerophosphate or uremic serum within 24 h of treatment. beta-glycerophosphate-induced oxidative stress was associated with Cbfa-1 expression followed by ALP expression and activity, meanwhile the VSMCs expressing ALP diffusely calcified their extracellular matrix. Interestingly, diphenyleneiodonium partly prevented the osteoblastic differentiation. Results from this model strongly suggest a major implication of vascular NAD(P)H oxidase in vascular calcification supported by VSMCs osteoblastic differentiation.
Sutra
Thibault
T
EA 4188 Nutrition humaine, Biodisponibilité et Athérogénèse, Institut Universitaire de Recherche Clinique, Université Montpellier 1, France.
Morena
Marion
M
Bargnoux
Anne-Sophie
AS
Caporiccio
Bertrand
B
Canaud
Bernard
B
Cristol
Jean-Paul
JP
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002113:Calcification, Physiologic; D002454:Cell Differentiation; D002460:Cell Line; D005994:Glycerophosphates / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000378:metabolism; D010006:Osteoblasts / Q000378:metabolism*; D018384:Oxidative Stress; D010766:Phosphorylation; D051381:Rats; D015398:Signal Transduction; D013481:Superoxides / Q000378:metabolism*
D005994:Glycerophosphates; D013481:Superoxides; D006861:Hydrogen Peroxide; D000469:Alkaline Phosphatase; C031463:beta-glycerophosphoric acid