Biochemistry Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City, Cairo, Egypt.
Biochemistry Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City, Cairo, Egypt; Biochemistry Department, Faculty of Pharmacy, Nahda University (NUB), Beni Suef, Egypt.
Life Sci. 2020 Jun 15;251:117628. doi: 10.1016/j.lfs.2020.117628. Epub 2020 Apr 2.
Investigation whether androgen/androgen receptor (AR) might regulate megalin expression and/or functionality and thus affecting Gentamicin-induced nephrotoxicity (GIN).
Male Wistar rats were treated with gentamicin with/out AR ligands (testosterone as agonist and flutamide as antagonist). Megalin expression in the kidney tissues was determined by real-time RT-PCR and western blot. Besides, megalin functionality was assessed using immunofluorescence imaging of fluorescein isothiocyanate (FITC) conjugated bovine serum albumin (BSA) (FITC-BSA). The effects of different treatments on the kidney were assessed at the structural level by histopathological evaluation and the biochemical level by colorimetric assay of blood urea nitrogen (BUN), serum creatinine (SCr) and urinary albumin/creatinine (A/C) ratio, besides, kidney expression of neutrophil gelatinase-associated lipocalin (NGAL) by immunoblotting.
Our results revealed that treatment with testosterone either alone or combined with gentamicin increased megalin expression at mRNA and protein levels as well as at the functional level. These effects were paralleled by increased GIN as manifested by increased SCr, BUN, A/C ratio, renal expression of NGAL or histopathological changes. On the other hand, treatment with flutamide ameliorated GIN and megalin expression and functionality. Computational analysis of megalin promotor revealed the presence of multiple response elements that mediate androgen response.
Androgen/AR regulates megalin expression at the transcriptional level and consequently GIN. This may explain the sexual dimorphism in GIN and might represent a druggable target for treatment or prevention of GIN.
研究雄激素/雄激素受体（AR）是否可能调节 megalin 的表达和/或功能，从而影响庆大霉素诱导的肾毒性（GIN）。
雄性 Wistar 大鼠用庆大霉素加/不加 AR 配体（睾酮作为激动剂，氟他胺作为拮抗剂）处理。通过实时 RT-PCR 和 Western blot 测定肾脏组织中 megalin 的表达。此外，通过荧光素异硫氰酸酯（FITC）结合牛血清白蛋白（BSA）（FITC-BSA）的免疫荧光成像评估 megalin 的功能。通过组织病理学评估和比色法测定血液尿素氮（BUN）、血清肌酐（SCr）和尿白蛋白/肌酐（A/C）比值，以及免疫印迹法测定肾脏中性粒细胞明胶酶相关脂质运载蛋白（NGAL）的表达，评估不同处理方法对肾脏的结构和生化水平的影响。
我们的结果表明，单独或联合使用睾酮治疗可增加 megalin 在 mRNA 和蛋白水平以及功能水平上的表达。这些作用与 GIN 增加平行，表现为 SCr、BUN、A/C 比值升高，肾脏 NGAL 表达或组织病理学变化。另一方面，氟他胺治疗可改善 GIN 和 megalin 的表达和功能。对 megalin 启动子的计算分析显示存在多个介导雄激素反应的应答元件。
雄激素/AR 可在转录水平调节 megalin 的表达，从而影响 GIN。这可能解释了 GIN 的性别二态性，并可能代表治疗或预防 GIN 的可治疗靶点。
