Endothelium-targeted transgenic GTP-cyclohydrolase I overexpression inhibits neointima formation in mouse carotid artery
Endothelium-targeted transgenic GTP-cyclohydrolase I overexpression inhibits neointima formation in mouse carotid artery
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DOI：
10.1111/j.1440-1681.2007.04719.x
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发表时间：
2007-12-01
影响因子：
2.9
通讯作者：
Chen, Alex F.
中科院分区：
文献类型：
--
作者：
Liao, Song-Jie;Lin, Li;Chen, Alex F.
1.四氢生物蝶呤（BH 4）是维持内皮型一氧化氮（NO）合酶正常功能的重要辅助因子。呼吸困难是腔内血管成形术后的主要并发症。鸟苷5 '-三磷酸环化水解酶I（GTPCH）是BH_4从头合成的第一个限速酶。然而，GTPCH在再狭窄中的作用尚未完全了解。本研究验证了内皮靶向GTPCH过表达延缓小鼠颈动脉新生内膜形成（再狭窄的标志）的假设.在成年雄性野生型C57 BL/6（WT）和内皮GTPCH转基因（Tg-GCH）小鼠的左颈动脉中诱导经腔金属丝损伤。用体内伊文思蓝染色证实再内皮化。内皮依赖性和非依赖性舒张使用等长张力记录。在颈动脉损伤后2周和4周进行形态学分析以评估新生内膜形成。使用基于荧光的高效液相色谱（HPLC）来测定GTPCH活性和BH 4水平。采用N-G-硝基-L-精氨酸甲酯诱导的血管收缩反应检测颈动脉损伤后基础NO的释放.在经腔导丝损伤后完全去除内皮，并在第10天实现完全再内皮化。颈动脉损伤后10天和4周内皮依赖性舒张功能受损，而内皮非依赖性舒张功能未受影响。形态学分析显示，GTPCH的内皮特异性过表达减少了颈动脉损伤后2周和4周的新生内膜形成和中膜肥大。与WT小鼠相比，Tg-GCH小鼠动脉GTPCH酶活性和BH 4水平均显著升高，Tg-GCH小鼠损伤颈动脉基础NO释放有增加的趋势.这些结果表明，内皮细胞GTPCH的过度表达增加了内皮细胞BH 4的合成，并在内皮剥脱诱导的新生内膜形成中发挥了预防作用。
1. Tetrahydrobiopterin (BH4) is an essential cofactor that maintains the normal function of endothelial nitric oxide (NO) synthase. Restenosis is a key complication after transluminal angioplasty. Guanosine 5'-triphosphate-cyclohydrolase I (GTPCH) is the first rate-limiting enzyme for de novo BH4 synthesis. However, the role of GTPCH in restenosis is not fully understood. The present study tested the hypothesis that endothelial-targeted GTPCH overexpression retards neointimal formation, a hallmark of restenosis, in mouse carotid artery.2. Transluminal wire injury was induced in the left carotid arteries of adult male wild-type C57BL/6 (WT) and endothelial GTPCH transgenic (Tg-GCH) mice. Re-endothelialization was confirmed with in vivo Evans blue staining. Endothelium-dependent and -independent relaxations were measured using isometric tension recording. Morphological analysis was performed 2 and 4 weeks after carotid injury to assess neointimal formation. Fluorescence-based high-performance liquid chromatography (HPLC) was used to determine GTPCH activity and BH4 levels. Basal NO release following carotid injury was assessed by N-G-nitro-L-arginine methyl ester-induced vascular contraction.3. The endothelium was completely removed upon transluminal wire injury and full re-endothelialization was achieved at Day 10. Endothelium-dependent relaxation was impaired 10 days and 4 weeks after carotid injury, whereas endothelium-independent relaxation remained unaffected. Morphological analysis revealed that the endothelial-specific overexpression of GTPCH reduced neointimal formation and medial hypertrophy 2 and 4 weeks after carotid injury. Both arterial GTPCH enzyme activity and BH4 levels were significantly elevated in Tg-GCH mice compared with WT mice and basal NO release of the injured carotid artery tended to increase in Tg-GCH mice.4. These findings suggest that the endothelial overexpression of GTPCH increased endothelial BH4 synthesis and played a preventive role in neointimal formation induced by endothelium denudation.