Peroxisome proliferator-activated receptor-γ ligands regulate endothelial membrane superoxide production
Peroxisome proliferator-activated receptor-γ ligands regulate endothelial membrane superoxide production
复制标题
DOI：
10.1152/ajpcell.00474.2004
复制
发表时间：
2005-04-01
影响因子：
5.5
通讯作者：
Hart, CM
中科院分区：
文献类型：
--
作者：
Hwang, JN;Kleinhenz, DJ;Hart, CM
最近，我们证明过氧化物酶体增殖体激活受体γ (ppar - γ)配体，15-脱氧- δ(12,14)-前列腺素J(2) （15d-PGJ(2)）或西格列酮，增加内皮一氧化氮（中心点NO）的释放，而不改变内皮一氧化氮合酶（eNOS）的表达(4)。然而，ppar - γ刺激内皮中心NO释放的确切分子机制仍有待明确。超氧阴离子自由基(O（2)（-）中心点）与中心点NO结合，降低中心点NO的生物利用度。生成O(2)（-）中心点的NADPH氧化酶和降解O(2)（-）中心点的Cu/ zn -超氧化物歧化酶（Cu/Zn-SOD）共同调控内皮细胞中心点NO代谢。因此，我们研究了ppar - γ配体通过改变NADPH氧化酶或Cu/Zn-SOD的表达和活性来调节内皮O(2)（-）中心点代谢的能力。用电子自旋共振光谱检测10 μ M 15d-PGJ(2)或西格列酮处理24 h，可降低人脐静脉内皮细胞（HUVEC）膜nadph依赖性O(2)（-）中心点的产生。通过实时PCR分析，15d-PGJ(2)或西格列酮也降低了NADPH氧化酶亚基nox-1、gp91(phox) （nox-2）和nox-4的相对mRNA水平。Western blot分析显示15d-PGJ(2)或西格列酮降低了nox-2和nox-4蛋白的表达。ppar - γ配体也能刺激HUVEC中Cu/Zn-SOD的活性和表达。这些数据表明，ppar - γ配体除了对内皮中心点NO产生直接影响外，还通过抑制NADPH氧化酶和诱导Cu/Zn-SOD来改变内皮O(2)（-）中心点代谢，从而提高内皮中心点NO的生物利用度。这些发现进一步阐明了ppar - γ配体直接改变血管内皮功能的分子机制。
Recently, we demonstrated that the peroxisome proliferator-activated receptor-gamma (PPAR-gamma) ligands, either 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) or ciglitazone, increased endothelial nitric oxide (center dot NO) release without altering endothelial nitric oxide synthase ( eNOS) expression ( 4). However, the precise molecular mechanisms of PPAR-gamma-stimulated endothelial center dot NO release remain to be defined. Superoxide anion radical (O(2)(-)center dot) combines with center dot NO to decrease center dot NO bioavailability. NADPH oxidase, which produces O(2)(-)center dot, and Cu/Zn-superoxide dismutase ( Cu/Zn-SOD), which degrades O(2)(-)center dot, thereby contribute to regulation of endothelial cell center dot NO metabolism. Therefore, we examined the ability of PPAR-gamma ligands to modulate endothelial O(2)(-)center dot metabolism through alterations in the expression and activity of NADPH oxidase or Cu/Zn-SOD. Treatment with 10 mu M 15d-PGJ(2) or ciglitazone for 24 h decreased human umbilical vein endothelial cell ( HUVEC) membrane NADPH-dependent O(2)(-)center dot production detected with electron spin resonance spectroscopy. Treatment with 15d-PGJ(2) or ciglitazone also reduced relative mRNA levels of the NADPH oxidase subunits, nox-1, gp91(phox) (nox-2), and nox-4, as measured using real-time PCR analysis. Concordantly, Western blot analysis demonstrated that 15d-PGJ(2) or ciglitazone decreased nox-2 and nox-4 protein expression. PPAR-gamma ligands also stimulated both activity and expression of Cu/Zn-SOD in HUVEC. These data suggest that in addition to any direct effects on endothelial center dot NO production, PPAR-gamma ligands enhance endothelial center dot NO bioavailability, in part by altering endothelial O(2)(-)center dot metabolism through suppression of NADPH oxidase and induction of Cu/Zn-SOD. These findings further elucidate the molecular mechanisms by which PPAR-gamma ligands directly alter vascular endothelial function.