Eadon Michael T, Hause Ronald J, Stark Amy L, Cheng Ying-Hua, Wheeler Heather E, Burgess Kimberly S, Benson Eric A, Cunningham Patrick N, Bacallao Robert L, Dagher Pierre C, Skaar Todd C, Dolan M Eileen
Division of Nephrology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
Division of Clinical Pharmacology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
Int J Mol Sci. 2017 Mar 18;18(3):661. doi: 10.3390/ijms18030661.
Colistin sulfate (polymixin E) is an antibiotic prescribed with increasing frequency for severe Gram-negative bacterial infections. As nephrotoxicity is a common side effect, the discovery of pharmacogenomic markers associated with toxicity would benefit the utility of this drug. Our objective was to identify genetic markers of colistin cytotoxicity that were also associated with expression of key proteins using an unbiased, whole genome approach and further evaluate the functional significance in renal cell lines. To this end, we employed International HapMap lymphoblastoid cell lines (LCLs) of Yoruban ancestry with known genetic information to perform a genome-wide association study (GWAS) with cellular sensitivity to colistin. Further association studies revealed that single nucleotide polymorphisms (SNPs) associated with gene expression and protein expression were significantly enriched in SNPs associated with cytotoxicity ( ≤ 0.001 for gene and = 0.015 for protein expression). The most highly associated SNP, chr18:3417240 ( = 6.49 × 10), was nominally a -expression quantitative trait locus (eQTL) of the gene (transforming growth factor β (TGFβ)-induced factor-1; = 0.021) and was associated with expression of the protein HOXD10 (homeobox protein D10; = 7.17 × 10). To demonstrate functional relevance in a murine colistin nephrotoxicity model, HOXD10 immunohistochemistry revealed upregulated protein expression independent of mRNA expression in response to colistin administration. Knockdown of resulted in decreased protein expression of HOXD10 and increased resistance to colistin cytotoxicity. Furthermore, knockdown of in renal cells also resulted in increased resistance to colistin cytotoxicity, supporting the physiological relevance of the initial genomic associations.
硫酸黏菌素（多黏菌素E）是一种用于治疗严重革兰氏阴性菌感染且处方频率日益增加的抗生素。由于肾毒性是一种常见的副作用，发现与毒性相关的药物基因组学标志物将有助于该药物的应用。我们的目标是使用无偏倚的全基因组方法识别与黏菌素细胞毒性相关的遗传标志物，这些标志物也与关键蛋白的表达相关，并进一步评估其在肾细胞系中的功能意义。为此，我们采用了具有已知遗传信息的约鲁巴族裔国际人类基因组单体型图淋巴母细胞系（LCLs），对细胞对黏菌素的敏感性进行全基因组关联研究（GWAS）。进一步的关联研究表明，与基因表达和蛋白表达相关的单核苷酸多态性（SNP）在与细胞毒性相关的SNP中显著富集（基因方面≤0.001，蛋白表达方面=0.015）。关联度最高的SNP，即chr18:3417240（=6.49×10），名义上是基因（转化生长因子β（TGFβ）诱导因子-1）的一个基因表达定量性状位点（eQTL）（=0.021），并与蛋白HOXD10（同源盒蛋白D10；=7.17×10）的表达相关。为了在小鼠黏菌素肾毒性模型中证明功能相关性，HOXD10免疫组化显示，在给予黏菌素后，蛋白表达上调，且与mRNA表达无关。敲低该基因导致HOXD10蛋白表达降低，对黏菌素细胞毒性的抗性增加。此外，在肾细胞中敲低该基因也导致对黏菌素细胞毒性的抗性增加，这支持了最初基因组关联的生理相关性。
