建立稳定表达人有机阴离子转运体OAT1细胞的活性检测方法及抑制剂的筛选

目的:建立稳定表达人有机阴离子转运体OAT1的细胞(hOAT1)中6-羧基荧光素浓度测定的荧光分析方法,并用于hOAT1细胞活性的测定及其抑制剂的筛选。方法:采用荧光分光光度法,检测波长为激发波长485 nm,发射波长520 nm,BCA法检测样品蛋白浓度。以6-羧基荧光素的荧光强度对蛋白浓度的比值作为衡量转运体OAT1活性的指标。结果:在hOAT1细胞中,6-羧基荧光素检测浓度的线性范围为0.08~3.2μmol·L^(-1)(r=0.9991),低、中、高浓度6-羧基荧光素溶液测定的日内RSD分别为6.08%、2.66%、0.86%,日间RSD分别为7.83%、3.73%、0.72%,绝对回收率分别为(111.35±9.8)%、(86.61±3.89)%、(100.15±1.10)%。抑制剂筛选结果显示1mmol·L^(-1)缬沙坦、奥美沙坦、厄贝沙坦、替米沙坦、辛伐他汀、瑞舒伐他汀对hOAT1抑制率分别为103.45%、110.34%、93.41%、90.33%、79.84%、95.22%。结论:本方法简单易行,可用于hOAT1细胞活性测定,缬沙坦、奥美沙坦、厄贝沙坦、替米沙坦、辛伐他汀、瑞舒伐他汀对hOAT1存在抑制作用。

Cilastatin protects against imipenem-induced nephrotoxicity via inhibition of renal organic anion transporters(OATs)

Imipenem is a carbapenem antibiotic. However, Imipenem could not be marketed owing to its instability and nephrotoxicity until cilastatin, an inhibitor of renal dehydropeptidase-I(DHP-I),was developed. In present study, the potential roles of renal organic anion transporters(OATs) in alleviating the nephrotoxicity of imipenem by cilastatin were investigated in vitro and in rabbits. Our results indicated that imipenem and cilastatin were substrates of h OAT1 and h OAT3. Cilastatin inhibited h OAT1/3-mediated transport of imipenem with IC50 values comparable to the clinical concentration, suggesting the potential to cause a clinical drug–drug interaction(DDI). Moreover,imipenem exhibited h OAT1/3-dependent cytotoxicity, which was alleviated by cilastatin and probenecid. Furthermore, cilastatin and probenecid ameliorated imipenem-induced rabbit acute kidney injury, and reduced the renal secretion of imipenem. Cilastatin and probenecid inhibited intracellular accumulation of imipenem and sequentially decreased the nephrocyte toxicity in rabbit primary proximal tubule cells. Renal OATs, besides DHP-I, was also the target of interaction between imipenem and cilastatin, and contributed to the nephrotoxicity of imipenem. This therefore gives in part the explanation about the mechanism by which cilastatin protected against imipenem-induced nephrotoxicity. Thus, OATs can potentially be used as a therapeutic target to avoid the renal adverse reaction of imipenem in clinic.

苯并呋喃羧酸类特异性尿酸盐转运体抑制剂的设计、合成及活性研究

目的:设计合成新型的、具有一定特异性的苯并呋喃类人尿酸盐转运体(human urate anion transporter-1,h URAT1)抑制剂,并对其进行活性测试。方法:以苯并呋喃为骨架,引入羧基,设计合成3个新化合物。将所得目标化合物分别对稳定转染h URAT1基因或人有机阴离子转运体(human organic anion transporter-1,h OAT1)基因的MDCK细胞进行[^(14)C]尿酸摄取抑制试验或6-羧基荧光素(6-carboxyfluorescein,6-CFL)试验,探究化合物抑制细胞尿酸或6-CFL摄取能力。结果:成功合成了目标化合物B-1,B-2,B-3,并经过1H-NMR,MS的结构确证。体外h URAT1和h OAT1抑制活性筛选的结果显示,单羧酸化合物B-1,B-2具有较强的抑制h URAT1[14C]尿酸摄取活性,且化合物B-1表现出良好的h URAT1选择性。结论:设计合成了新型的具有一定h URAT1特异性的降尿酸化合物,化合物B-1的抑制活性及选择性均优于阳性对照药丙磺舒。