Betaine is an osmolyte in RAW 264.7 mouse macrophages

FEBS Letters

Häussinger, Dieter¹  Wettstein, Matthias¹  Warskulat, Ulrich¹ 

[1] Medizinische Universitätsklinik, Klinik für Gastroenterologie, Hepatologie und Infektiologie, Heinrich-Heine-Universität, Moorenstrasse 5, D-40225 Düsseldorf, Germany

关键词: Macrophage;    Betaine transport;    Osmolyte;    Cell volume;    BGT-1;    Anisoosmolarity;    BGT-1;    betaine gamma-aminobutyric acid transporter;    GABA;    gamma-aminobutyrate;    GAPDH;    glyceraldehyde-3-phosphate dehydrogenase;    LPS;    lipopolysaccharide;    MeAIB;    methylaminoisobutyrate;   

DOI  :  10.1016/0014-5793(95)01317-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Hyperosmotic (405 mosmol/l) exposure of RAW 264.7 mouse macrophages led to a stimulation of betaine uptake and an increase in betaine transporter (BGT-1) mRNA levels. Conversely, hypoosmotic (205 mosmol/l) exposure decreased betaine uptake and diminished BGT-1 mRNA levels. Betaine uptake was Na⁺-dependent and was inhibited by about 90% by GABA, whereas inhibition by methylaminoisobutyrate and myoinositol was less than 15%. Addition of betaine strongly diminished BGT-1 mRNA levels in cells exposed to normoosmotic or hyperosmotic media. When mouse macrophages were preloaded with betaine, lowering of the extracellular osmolarity was followed by a rapid betaine efflux from the cells. This study identifies a constitutively expressed and osmosensitive betaine transporter in RAW 264.7 macrophages and the use of betaine as an osmolyte in these cells.

【 授权许可】

Unknown