Programa de Pós-Graduação em Ciências da Saúde da Universidade Estadual de Maringá, Maringá, PR, Brazil.
Departamento de Análises Clínicas e Biomedicina da Universidade Estadual de Maringá, Maringá, PR, Brazil.
J Antimicrob Chemother. 2018 Jul 1;73(7):1770-1776. doi: 10.1093/jac/dky091.
Since resistance of Mycobacterium tuberculosis (Mtb) partially derives from efflux pumps (EPs) in the plasma membrane, the current study evaluates EPs in Mtb exposed to rifampicin in the presence of the EP inhibitor verapamil, within a macrophage environment.
Human acute monocytic leukaemia cell line THP-1 was infected with Mtb H37Rv and exposed to rifampicin and verapamil alone and in combination for 24 and 72 h. After RNA extraction, quantitative PCR was carried out for 11 EP genes using SYBR green PCR master mix in the StepOne™ Real-Time PCR System.
After 24 h of exposure to rifampicin, Mtb H37Rv showed that 10 EP genes were up-regulated when compared with the control. The rifampicin/verapamil combination induced down-regulation of 54.5% (6/11) of the EP genes. At 72 h, rifampicin exposure induced up-regulation of 10 EP genes and rifampicin/verapamil induced down-regulation of 8 EP genes, which suggests effective EP-inhibitory activity of verapamil against Mtb H37Rv in an intramacrophage environment.
The current study demonstrated that rifampicin/verapamil caused down-regulation of several EP genes in Mtb inside the macrophage environment. In vivo trials may show that rifampicin/verapamil therapy could be of value in enhancing anti-TB treatment.
由于结核分枝杆菌（Mtb）的耐药性部分源于质膜中的外排泵（EPs），因此本研究在巨噬细胞环境中评估了 Rif 存在时暴露于 Rif 的 Mtb 中的 EPs。
用 Mtb H37Rv 感染人急性单核细胞白血病细胞系 THP-1，分别单独和联合用 Rif 和维拉帕米处理 24 和 72 小时。提取 RNA 后，使用 SYBR green PCR 主混合物在 StepOne™实时 PCR 系统中对 11 个 EP 基因进行定量 PCR。
Rif 暴露 24 小时后，与对照相比，H37Rv 显示 10 个 EP 基因上调。Rif/Ver 联合诱导 54.5%（6/11）的 EP 基因下调。72 小时时，Rif 暴露诱导 10 个 EP 基因上调，Rif/Ver 诱导 8 个 EP 基因下调，表明维拉帕米在巨噬细胞内环境中对 H37Rv 具有有效的 EP 抑制活性。
本研究表明 Rif/Ver 可下调巨噬细胞内 Mtb 中的几个 EP 基因。体内试验可能表明 Rif/Ver 治疗可能有助于增强抗结核治疗。
