Sutra Thibault, Morena Marion, Bargnoux Anne-Sophie, Caporiccio Bertrand, Canaud Bernard, Cristol Jean-Paul
EA 4188 Nutrition humaine, Biodisponibilité et Athérogénèse, Institut Universitaire de Recherche Clinique, Université Montpellier 1, France.
Free Radic Res. 2008 Sep;42(9):789-97. doi: 10.1080/10715760802400766.
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.
近期研究表明，过氧化氢（H₂O₂）可增强参与成骨细胞分化的血管平滑肌细胞（VSMC）中骨标志物的表达。本研究旨在探讨NAD(P)H氧化酶在血管钙化过程中的作用。将A7r5大鼠VSMC与β-甘油磷酸（10 mM）或尿毒症血清孵育以诱导弥漫性矿化。通过化学发光法测定VSMC产生的H₂O₂。通过蛋白质印迹法检测NAD(P)H氧化酶亚基（p22phox）、Cbfa-1、ERK磷酸化和骨碱性磷酸酶（ALP）的表达。在处理24小时内，VSMC在β-甘油磷酸或尿毒症血清作用下表现出更高的H₂O₂产生和p22phox早期表达。β-甘油磷酸诱导的氧化应激与Cbfa-1表达相关，随后是ALP表达和活性，同时表达ALP的VSMC使其细胞外基质发生弥漫性钙化。有趣的是，二亚苯基碘鎓部分阻止了成骨细胞分化。该模型的结果强烈表明，血管NAD(P)H氧化酶在VSMC成骨细胞分化支持的血管钙化中起主要作用。
