Macrophages require distinct arginine catabolism and transport systems for proliferation and for activation.
In murine macrophages, as a result of arginine catabolism during activation, citruline isproduced under the effect of IFN-c and LPS, and ornithine and polyamines by IL-4 and IL-10. For proliferation, arginine is required from the extracellular medium and is used for protein synthesis. During activat...
| Autores: | , , , , , , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2006 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/206968 |
| Acceso en línea: | https://hdl.handle.net/2445/206968 |
| Access Level: | acceso abierto |
| Palabra clave: | Macròfags Proliferació cel·lular Macrophages Cell proliferation |
| Sumario: | In murine macrophages, as a result of arginine catabolism during activation, citruline isproduced under the effect of IFN-c and LPS, and ornithine and polyamines by IL-4 and IL-10. For proliferation, arginine is required from the extracellular medium and is used for protein synthesis. During activation, most arginine (>95% in 6 h) was metabolized, while under proliferation only half was incorporated into proteins. Under basal conditions, this amino acid was preferentially transported by y+L activity. During activation, arginine transport increased drastically (4–5-fold) through y+ cationic amino acid transporter (CAT) activity. By contrast, M-CSF induced only a modest increase in uptake (0.5-fold). The increase in arginine transport during activation, but not proliferation, was mediated by the SLC7A2/Cat2 gene. SLC7A1/Cat1 is constitutively expressed, and is not modified by proliferating or activating agents.M-CSF-dependent proliferation was not affected in the macrophages of SLC7A2 knockout mice; however, these cells showed a drastic reduction in the production of citruline or ornithine and polyamines during activation. The data show that a large increase in a specific transport system (CAT2) is necessary for activation-induced arginine metabolism, while arginine is in excess for the requirements of proliferation and a modest increase in transport occurs. |
|---|