新型S1PR1受体激动剂的转运代谢机制及药动-药效学研究

Sphingosine-1-phosphate receptor 1 (S1PR1) agonist is a new class drug for the oral treatment of autoimmune diseases, which can regulate immune system by the unique "acceleration of lymphocyte homing" mechanism through agitating S1PR1 expressed in lymphocyte membrane. Accordingly the research on transport and metabolic mechanism of S1PR1 agonist is involved in two sphingosine kinases (SPHK1 and SPHK2) catalyzing to form phosphorylated bioactive metabolite (S1PR1 agonist-P), ABC transporters and SPNS2 mediating release of synthesized S1PR1 agonist-P and CYP4F responsible for biotransformation of S1PR1 agonist. SYL compound is a novel S1PR1 agonist with high selectivity and less effect on normal heart rate. This study will be carried out to investigate the phosphorylation sites, transport and metabolic mechanism of SYL compound, and to identify the transporters and CYP4F isozymes responsible for transport and biotransformation of SYL compound in cells, human or rat liver microsome, recombinant human CYP4F enzymes in vitro and pharmacokinetics model in vivo with LC-MS/MS analysis. Based on the PK and biomarker information(e.g. blood lymphocyte number - pharmacodynamic index; heart rate -safety index),PK-PD modelling will be built and fitted to quantitatively describe the relationship of effect and drug concentration in target tissue, and help to predict human PK/PD profiles through correlation analysis between human and animal based on prelinical data.These research findings will provide valuable experiment basis for the design and optimization of early clinical trails.

S1PR1受体激动剂是治疗自身免疫性疾病的新型药物，通过独特的"诱导淋巴细胞归巢机制"发挥免疫调节作用。该类药物的体内转运代谢机制复杂，涉及到鞘胺醇激酶催化生成磷酸化活性产物，ABC转运蛋白、SPNS2参与外排转运及CYP4F参与氧化代谢。SYL化合物是一类结构新颖、受体选择性好、对心率无明显影响的S1PR1受体激动剂。本研究拟应用基因重组酶、转基因细胞、亚细胞组分及体内外动力学模型，结合LC-MS/MS分析方法，对SYL化合物的转运、代谢机制进行深入探讨，鉴定SYL-P体内合成场所及参与其外排的转运蛋白及代谢酶类，应用PK-PD模型，拟合血药浓度及效应（血淋巴细胞数及心率）经时变化曲线，推导产生效应部位的药物浓度，定量反映其与效应的关系。同时通过PK-PD模型，将动物试验数据与人体进行相关性分析及种属间外推，预测药物在人体的PK-PD特性，为设计和优化临床试验方案提供有价值的试验依据。

S1PR1受体激动剂是治疗自身免疫性疾病的新型药物，通过独特的"诱导淋巴细胞归巢机制"发挥免疫调节作用。该类药物的体内转运代谢机制复杂，涉及到鞘胺醇激酶催化生成磷酸化活性产物，ABC转运蛋白、SPNS2参与外排转运及CYP4F参与氧化代谢。SYL化合物是一类结构新颖、受体选择性好、对心率无明显影响的S1PR1受体激动剂。本研究拟应用基因重组酶、转基因细胞、亚细胞组分及体内外动力学模型，结合LC-MS/MS分析方法，对SYL化合物的转运、代谢机制进行深入探讨，鉴定SYL-P体内合成场所及参与其外排的转运蛋白及代谢酶类，应用PK-PD模型，定量反映血药浓度与效应的关系。研究结果表明，红细胞、血小板、血管内皮细胞是SYL-P生成的重要场所，SPHK1/2参与其生物转化，细胞内生成的SYL-P可经SPNS2转运蛋白及ABC转运蛋白家族中的ABCB1(MDR1)、ABCG2(BCRP)、ABCC1、ABCA1外排至细胞间，然后到达靶器官发挥免疫调控作用。SYL化合物物除了可逆性的生成SYL-P之外，还可经CYP1A1、2J2、3A4、4F2等主要同工酶催化成氧化代谢产物。SYL化合物的上述转运代谢过程可影响到药物的血药浓度进而影响疗效，PK-PD模型分析结果表明SYL-P的血药浓度与外周血淋巴细胞数降低具有明显相关性，本课题研究结果为SYL化合物临床试验方案的设计和优化提供有价值的试验依据。