Pharmacological manipulation of L-carnitine transport into L6 cells with stable overexpression of human OCTN2.
The high-affinity Na+-dependent carnitine transporter OCTN2 (SLC22A5) has a high renal expression and reabsorbs most filtered carnitine. To gain more insight into substrate specificity of OCTN2, we overexpressed hOCTN2 in L6 cells and characterized the structural requirements of substances acting as human OCTN2 (hOCTN2) inhibitors. A 1905-bp fragment containing the hOCTN2 complete coding sequence was introduced into the pWpiresGFP vector, and L6 cells were stably transduced using a lentiviral system. The transduced L6 cells revealed increased expression of hOCTN2 on the mRNA, protein and functional levels. Structural requirements for hOCTN2 inhibition were predicted in silico and investigated in vitro. Essential structural requirements for OCTN2 inhibition include a constantly positively charged nitrogen atom and a carboxyl, nitrile or ester group connected by a 2-4-atom linker. Our cell system is suitable for studying in vitro interactions with OCTN2, which can subsequently be investigated in vivo.
Todesco
L
L
Division of Clinical Pharmacology and Toxicology and Department of Research, University Hospital, Basel, Switzerland.
Bur
D
D
Brooks
H
H
Török
M
M
Landmann
L
L
Stieger
B
B
Krähenbühl
S
S
D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002331:Carnitine / Q000378:metabolism*; D002460:Cell Line; D016503:Drug Delivery Systems; D015195:Drug Design; D006801:Humans; D008954:Models, Biological; D008958:Models, Molecular; D032448:Myoblasts, Skeletal / Q000187:drug effects* / Q000378:metabolism; D027701:Organic Cation Transport Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D051381:Rats; D000074058:Solute Carrier Family 22 Member 5; D013329:Structure-Activity Relationship; D014162:Transfection
D000906:Antibodies; D027701:Organic Cation Transport Proteins; C492020:SLC22A5 protein, human; D000074058:Solute Carrier Family 22 Member 5; D002331:Carnitine