Mechanism(s) of butyrate transport in Caco-2 cells: role of monocarboxylate transporter 1

• Published in: American journal of physiology: Gastrointestinal and liver physiology Vol. 279; no. 4; pp. G775 - G780
• Main Authors: Hadjiagapiou, C, Schmidt, L, Dudeja, P K, Layden, T J, Ramaswamy, K
• Format: Journal Article
• Language: English
• Published: United States 01.10.2000
• Subjects: 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid - pharmacology; Biological Transport - drug effects; Butyrates - metabolism; Caco-2 Cells; Carrier Proteins - genetics; Carrier Proteins - metabolism; Humans; Kinetics; Lactates - pharmacology; Membrane Transport Proteins; Monocarboxylic Acid Transporters; Muscle Proteins; Propionates - pharmacology; Protein Isoforms - genetics; Protein Isoforms - metabolism; Recombinant Proteins - metabolism; Transfection
• ISSN: 0193-1857; 1522-1547
• DOI: 10.1152/ajpgi.2000.279.4.g775

The short-chain fatty acid butyrate was readily taken up by Caco-2 cells. Transport exhibited saturation kinetics, was enhanced by low extracellular pH, and was Na(+) independent. Butyrate uptake was unaffected by DIDS; however, alpha-cyano-4-hydroxycinnamate and the butyrate analogs propionate and L-lactate significantly inhibited uptake. These results suggest that butyrate transport by Caco-2 cells is mediated by a transporter belonging to the monocarboxylate transporter family. We identified five isoforms of this transporter, MCT1, MCT3, MCT4, MCT5, and MCT6, in Caco-2 cells by PCR, and MCT1 was found to be the most abundant isoform by RNase protection assay. Transient transfection of MCT1, in the antisense orientation, resulted in significant inhibition of butyrate uptake. The cells fully recovered from this inhibition by 5 days after transfection. In conclusion, our data showed that the MCT1 transporter may play a major role in the transport of butyrate into Caco-2 cells.