肺动脉高压肺组织炎症反应5-羟色胺上游调节机制与药物治疗靶点研究

Serotonin upper stream regulation and therapeutic target study on lung inflammation of pulmonary hypertension.Lung inflammation constituted one of the major pathological changes of pulmonary hypertension (PAH). However the pathophysiology and pharmacology on lung inflammation of PAH are absolutely unclear, which is certainly related with the difficulties of clinical drug therapy against PAH. The serotonin theory of PAH aroused in 1990's had been fully proved by increased evidence. It was found that the 5-HT level in plasma and the lung tissues regulated by the major elements of 5-hydroxytraptamine (5-HT) system, which includes the substrate L-tryptophan (L-Tp), the rate limited enzyme tryptophan hydroxylase (Tph), 5-HT receptors，serotonin transporter (SERT) and certain signal pathways. Our recent findings showed that the 5-HT downstream regulation including 5-HT1B receptor and 5-HT transporter play an important role in the pathophysiology of Lung inflammation of PAH. Yet, the 5-HT level in plasma and the lung tissues is also an important factor of Lung inflammation of PAH. These findings and the current progress of 5-HT system highlighted the possibility that the 5-HT upper stream regulation around tryptophan hydroxylase and 5-HT should be involved in the mechanism of lung inflammation of PAH. Therefore the present project was designed to study: ① the correlation between Lung inflammation of PAH and Tph; ② the regulatory mechanism of tryptophan hydroxylas and involvement of L-tryptophan(L-Tp), estrogen and monoamineoxidase (MAO) in the lung inflammation of PAH and related signal pathways to find the scientific evidence of therapeutic target against lung inflammation of PAH and ③ to deal with the possibility of improvement the outcome of PAH by the therapy targeted on the 5-HT upper stream regulation against lung inflammation. The achievement of this project in the recognition of serotonin upper stream regulation and therapeutic target on lung inflammation of pulmonary hypertension, and thereafter to improve the therapeutic outcomes of lung inflammation and eventually the PAH would be of importance in scientific significance and its potential clinical values.

肺组织炎症反应是肺动脉高压(PAH)基本病理改变之一，与肺血管重构、收缩性增强及肺内微血栓形成密切关联、互为因果。该炎症反应的病理学、药理学和临床治疗学目前仍处于空白状态，成为PAH难以治愈的重要原因之一。我们发现阻断5-羟色胺（5-HT）1B受体或转运体明显改善，但不能完全抑制PAH肺组织炎症反应。进展表明5-HT系统是从5-HT源头直至其调控部位的复杂系统。PAH肺组织炎症反应存在5-HT系统上游调节机制已初见端倪。因此，申请PAH肺组织炎症反应5-HT系统上游调节机制与治疗靶点研究。内容包括色氨酸羟化酶(Tph)、L-色氨酸、雌激素等在肺组织炎症反应的调节机制和药物治疗靶点；寻求针对肺组织炎症反应的药物改善PAH的可能性。该项目不仅在肺组织炎症反应病理学和药理学方面有重要科学价值，而且将揭示其5-HT上游环节药物治疗靶点，为改善肺组织炎症反应乃至PAH药物治疗开辟新途径提供科学依据。

本项目研究目标是应用SD大鼠研究PAH肺组织炎症反应的5-HT系统上游环节调节机制，探索5-HT系统上游环节中可能存在的治疗靶点及相关影响因素。.一、具体研究内容包括：.（1）肺组织炎症反应与色氨酸羟化酶1（Tph1）表达的关系.（2）Tph1抑制剂改善PAH肺组织炎症反应作用及作用机制.（3）改善肺组织炎症反应对改善PAH的影响. (2)探索Tph1作为PAH肺组织炎症反应的治疗靶点的可能性.二、研究结果如下：.（1）建立动物模型，完成PAH肺组织炎症反应与Tph1表达相关性研究，.建立大鼠PAH肺组织炎症反应动物模型，应用形态学、血流动力学、细胞生物学等研究方法，获得PAH肺组织炎症反应与Tph1表达、5-HT水平、SERT、5-HT亚型受体及有关信号的相关性。.（2）研究Tph1抑制剂抗肺组织炎症反应量效关系研究与作用机制.研究发现：① Tph抑制剂对PAH肺组织炎症反应和血管重构有明显抑制作用，量效关系说明Tph抑制剂对PAH肺组织炎症反应呈剂量依赖性抑制作用，明确Tph抑制剂作用机制；②Tph1抑制剂与阻断5-HT下游环节（5-HT受体阻断剂、SSRI）对抑制PAH肺组织炎症反应有明显协同作用； .（3）探讨通过抑制PAH肺组织炎症反应对改善PAH的影响.研究发现：①Tph1抑制剂在改善肺组织炎症反应同时，抑制MCT诱导的大鼠PAH；②为通过5-HT上游环节抑制/逆转肺组织炎症反应，改善PAH药物治疗效果提供科学依据。.四、发表研究论文2篇.1..Y. Wang, M. Liu, H.M. Wang, Y. Bai, X.H. Zhang, Y.X. Sun and H.L. WangInvolvement of serotonin mechanism in methamphetamine-induced chronic pulmonary toxicity in rats Hum Exp Toxicol 2013 32: 736–746 originally published online 20 March 2013 DOI: 10.1177/0960327112468174.2. Bai Y, Wang HM, Liu M, Wang Y, Lian GC, Zhang XH, Kang J, Wang HL. 4-Chloro-DL-phenyla