Identification of the efflux transporter of the fluoroquinolone antibiotic ciprofloxacin in murine macrophages: studies with ciprofloxacin-resistant cells.
Antimicrob Agents Chemother
; 53(6): 2410-6, 2009 Jun.
Article
en En
| MEDLINE
| ID: mdl-19307362
ABSTRACT
Ciprofloxacin, the most widely used totally synthetic antibiotic, is subject to active efflux mediated by a MRP-like transporter in wild-type murine J774 macrophages. To identify the transporter among the seven potential Mrps, we used cells made resistant to ciprofloxacin obtained by long-term exposure to increasing drug concentrations (these cells show less ciprofloxacin accumulation and provide a protected niche for ciprofloxacin-sensitive intracellular Listeria monocytogenes). In the present paper, we first show that ciprofloxacin-resistant cells display a faster efflux of ciprofloxacin which is inhibited by gemfibrozil (an unspecific MRP inhibitor). Elacridar, at a concentration known to inhibit P-glycoprotein and breast cancer resistance protein (BCRP), only slightly increased ciprofloxacin accumulation, with no difference between resistant and wild-type cells. Analysis at the mRNA (real-time PCR) and protein (Western blotting) levels revealed an overexpression of Mrp2 and Mrp4. Mrp4 transcripts, however, were overwhelmingly predominant (45% [wild-type cells] to 95% [ciprofloxacin-resistant cells] of all Mrp transcripts tested [Mrp1 to Mrp7]). Silencing of Mrp2 and Mrp4 with specific small interfering RNAs showed that only Mrp4 is involved in ciprofloxacin transport in both ciprofloxacin-resistant and wild-type cells. The study therefore identifies Mrp4 as the most likely transporter of ciprofloxacin in murine macrophages but leaves open a possible common upregulation mechanism for both Mrp4 and Mrp2 upon chronic exposure of eukaryotic cells to this widely used antibiotic.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Ciprofloxacina
/
Macrófagos
/
Antiinfecciosos
Tipo de estudio:
Diagnostic_studies
Límite:
Animals
Idioma:
En
Revista:
Antimicrob Agents Chemother
Año:
2009
Tipo del documento:
Article
País de afiliación:
Bélgica