Therapeutic concentrations of cyclosporine A, but not FK506, increase P-glycoprotein expression in endothelial and renal tubule cells
Therapeutic concentrations of cyclosporine A, but not FK506, increase P-glycoprotein expression in endothelial and renal tubule cells
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DOI：
10.1046/j.1523-1755.1998.00095.x
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发表时间：
1998-10-01
影响因子：
19.6
通讯作者：
Thévenod, F
中科院分区：
文献类型：
--
作者：
Hauser, IA;Koziolek, M;Thévenod, F
背景免疫抑制药物环孢素A（CsA）和他克莫司（FK 506）被多药耐药P-糖蛋白（P-gp）从细胞中挤出，这可能限制它们的治疗效果和/或毒副作用的发生。在本研究中，我们研究了治疗浓度的CsA和FK 506对培养的内皮细胞和近曲小管细胞P-gp表达的影响。用免疫印迹法和免疫细胞化学法测定人动脉内皮细胞（HAEC）和大鼠近曲小管细胞（RPTC）中P-糖蛋白（P-gp）的表达，并通过测定荧光探针钙黄绿素的胞内增殖，将其与P-gp介导的转运相关联。结果HAEC与治疗浓度为0.1 - 1.6 μ M的CsA孵育7天后，P-gp表达以时间和浓度依赖性方式增加，最高为0.8 μ M CsA孵育7天对照的291 +/- 42%。CsA在RPTC中观察到类似的作用。相比之下，治疗浓度的FK 506（0.01 - 0.2 μ M，持续7天）未改变任一细胞类型中的P-gp表达，但在更高的超治疗浓度FK 506（0.5 - 1.2 μ M）下，P-gp表达也增加。免疫细胞化学显示0.8 μ M CsA处理后HAEC和RPTC细胞质膜P-gp表达增加，这反映在两种细胞类型中P-gp介导的钙黄绿素积累减少。这些数据表明，在HAEC和RPTC中，CsA或FK 506浓度高于0.5 μ M时诱导P-gp表达是细胞对药物毒性浓度的保护性应答的一部分，因此可能干扰CsA在体内的治疗效果。
Background. The immunosuppressive drugs cyclosporine A (CsA) and tacrolimus (FK506) are extruded from cells by the multidrug resistance P-glycoprotein (P-gp), an efflux pump for drugs and xenobiotics, which may limit their therapeutic effectiveness and/or incidence of toxic side effects. In the present study, we investigated the effect of therapeutic concentrations of CsA and FK506 on the expression of P-gp in cultured endothelial and proximal tubule cells.Methods. P-gp expression in human arterial endothelial (HAEC) and rat proximal tubule cells (RPTC) was determined by immunoblotting and immunocytochemistry, and correlated with P-gp-mediated transport by measuring the intracellular accumu lation of the fluorescent probe calcein. Results. Following incubation of HAEC with therapeutic concentrations of 0.1 to 1.6 mu M CSA UP to seven days, P-gp expression increased in a time- and concentration-dependent manner, max imally to 291 +/- 42% of controls with 0.8 mu M CsA for seven days. Similar effects of CsA were observed in RPTC. In contrast, therapeutic concentrations of FK506 (0.01 to 0.2 mu M up to 7 days) did not change P-gp expression in either cell type, though at higher, supratherapeutic concentrations of FK506 (0.5 to 1.2 mu M) P-gp expression was also increased. Immunocytochemistry revealed increased P-gp expression in the plasma membrane of HAEC and RPTC treated with 0.8 mu M CsA, which was reflected by a decrease of P-gp-mediated accumulation of calcein in both cell types.Conclusions. The data suggest that the induction of P-gp expression in HAEC and RPTC at concentrations of CsA or FK506 above 0.5 mu M is part of the protective answer of cells to toxic concentrations of the drugs and could therefore interfere with the therapeutic effectiveness of CsA in vivo.