MOLECULAR MECHANISMS OF CARDIOVASCULAR REMODELING INDUCED BY CHRONIC INHIBITION OF NITRIC OXIDE SYNTHESIS : ROLE OF NF-κB AND MCP-1

通过给予大鼠N^ω-硝基-L-精氨酸甲酯（L-NAME）慢性抑制内皮一氧化氮（NO）合成诱导冠状血管炎症[单核细胞浸润，单核细胞趋化蛋白-1（MCP-1）表达，和核因子-κ B（NF-κB）活化]和随后的动脉粥样硬化变化（中膜增厚和血管周围纤维化）。MCP-1被认为是单核细胞的有效趋化因子。NF-κB是一种氧化应激敏感性转录因子，调节包括MCP-1在内的促炎基因的转录。然而，在这种慢性抑制NO合成的模型中，没有直接证据表明NF-κB和MCP-1在这种心血管重构的发展中的作用。在第一个实验方案中，我们检查了针对NF-κB的顺式元件诱饵体内转染到心脏的效果。转染NF-κB诱饵可抑制L-NAME诱导的NF-κB活性升高、血管炎症和MCP-1表达。在第二个方案中，我们研究了中和抗MCP-1抗体的作用。用抗MCP-1抗体治疗防止了L-NAME诱导的早期炎症变化，从而使晚期冠状动脉血管中膜增厚正常化。相比之下，NF-κB诱饵转染和抗体都不能减少血管周围纤维化的发展，TGF-β1的基因表达，这些结果表明，内皮源性NO通过抑制氧化应激敏感的转录因子如NF-κB B降低MCP-1。本研究可能为内皮源性NO如何参与抗MCP-1的作用提供一个新的方面。体内血管内皮的炎症和抗动脉炎特性。

Chronic inhibition of endothelial nitric oxide (NO) synthesis by the administration of N^ω-nitro-L-arginine methyl ester (L-NAME) to rats induces coronary vascular inflammation [monocytes infiltration, monocyte chemoattractant protein-1 (MCP-1) expression, and nuclear factor-kB (NF-κB) activation] in the early phase (day 3) and subsequent arteriosclerotic changes (medial thickening and perivascular fibrosis) in the late phase (day 28). MCP-1 is presumed to be a potent chemotactic factor for monocytes. NF-κB is an oxidative stress-sensitive transcription factor that regulates transcription of inflammation-promoting genes including MCP-1. However, no direct evidence for the role of NF-κB and MCP-1 in the development of such cardiovascular remodeling has been addressed in this model with chronic inhibition of NO synthesis. In the first experimental protocol, we examined the effect of in vivo transfection of cis element decoy against NF-κB to the heart. The transfection of NF-κB decoy prevented the L-NAME-induced increase in NF-κB activity, vascular inflammation and MCP-1 expression. In the second protocol, we investigated the effect of the neutralizing anti-MCP-1 antibody. Treatment with the anti-MCP-1 antibody prevented the L-NAME-induced early inflammatory changes and thus normalized coronary vascular medial thickening in the late phase. In contrast, neither NF-κB decoy transfection nor the antibody reduce the development of perivascular fibrosis, the gene expression of TGF-β1, or systolic pressure overload induced by L-NAME.These results suggest that endotheliumderived NO decreases MCP-1 by suppressing oxidative stress-sensitive transcription factors such as NF-κB.The present study may provide a new aspect of how endothelium-derived NO contributes to anti-inflammatory and anti arteriosclerotic properties of the vascular endothelium in vivo.