内皮源性吲哚胺2,3-双加氧酶抑制周细胞迁移及收缩蛋白表达

Endothelial indoleamine 2,3-dioxygenase inhibits migration and expression of contractile proteins in pericytes

目的：探讨内皮源性吲哚胺2,3-双加氧酶（IDO）对周细胞迁移及收缩蛋白表达的影响。方法：体外培养人肺动脉内皮细胞（HPAECs）及大鼠脑微血管周细胞。建立过表达IDO的HPAECs模型（IDO-HPAECs）。实验分为3组：对照组,以HPAECs条件培养基干预周细胞;处理组,以IDO-HPAECs条件培养基干预周细胞;抑制组,以含1-甲基色氨酸（1-mT）的IDO-HPAECs条件培养基干预周细胞。测定共培养体系一氧化氮（NO）、色氨酸及犬尿氨酸浓度。观察周细胞活性、迁移及收缩蛋白表达情况。结果：IDO-HPAECs条件培养基干预周细胞6～48 h对其活性无显著影响。处理组的周细胞迁移能力显著低于对照组（P〈0.01）,抑制组显著高于处理组（P〈0.01）。共培养体系的NO浓度在各组间差异无统计学意义（P〉0.05）。处理组的色氨酸浓度显著低于对照组（P〈0.01）,而抑制组显著高于处理组（P〈0.01）。处理组的犬尿氨酸浓度显著高于对照组（P〈0.01）,而抑制组显著低于处理组（P〈0.01）。处理组的α-平滑肌肌动蛋白与结蛋白表达水平显著低于对照组（P〈0.01）,抑制组显著高于处理组（P〈0.01）。结论：内皮源性IDO抑制周细胞迁移及收缩蛋白表达,可能参与机体微血管功能调控。

AIM： To explore the effects of endothelial indoleamine 2,3-dioxygenase （IDO） on the migration and the expression of contractile proteins in the pericytes. METHODS： Human pulmonary artery endothelial cells （HPAECs） and rat cerebral microvascular pericytes were cultured in vitro. Over-expression of IDO in the HPAECs （IDO- HPAECs） was established. The pericytes were treated with HPAEC-conditioned medium （control group）, IDO-HPAEC conditioned medium （ treatment group）, or IDO-HPAECs-conditioned medium containing 1-methyl-DL-tryptophan （1-mT） （ inhibition group）. The concentrations of nitric oxide （ NO）, tryptophan and kynurenine in the co-culture system were de- termined. The viability, migration and the expression of the contractile proteins in the pericytes were compared. RE- SULTS： No statistical difference of the pericyte viability after treatment with IDO-HPAEC-conditioned medium at 6 ～ 48 h was observed （P 〉 0.05）. The migratory ability of the pericytes significantly decreased in treatment group compared with control group （P 〈 0.01 ）, and significantly increased in inhibition group compared with treatment group （P 〈 0.01 ）. The concentration of NO in the co-culture system had no significant difference among groups （P 〉 0.05）. The concentration of tryptophan was significantly lower in treatment group than that in control group （P 〈 0.01 ）, and significantly higher in in- hibition group than that in treatment group （ P 〈 0.01 ）. The concentration of kynurenine was significantly higher in treat- ment group than that in control group （ P 〈 0.01 ）, and significantly lower in inhibition group than that in treatment group （ P 〈 0.01 ）. The expression of α-smooth muscle actin and desmin was significantly lower in treatment group than that in control group （P 〈0.01 ）, and significantly higher in inhibition group than that in treatment group （P 〈 0.01 ）. CON- CLUSION ： Endothelial 1DO inhibits the migration and the expression of the contractile proteins in the pericytes, and may play essential roles in the regulation of microvasculatures.