Ecto-lysophospholipase C controls lysophospholipid uptake and metabolism in porcine kidney epithelial cell line LLC-PK1.
Lysophosphatidylcholine (LPC) has diverse biological activities through different mechanisms including its conversion into other types of lipid mediators such as lysophosphatidic acid and 2-arachidonoylglycerol. Previously, we found that a large portion of the fluorescent analog of alkyl type LPC (Bodipy-lysoPAF) on porcine kidney epithelial cells (LLC-PK1) was degraded to monoalkylglycerol by lysophospholipase C-like activity and then quickly internalized into the cells. In this study, we investigated whether exogenous fluorescently labeled LPC (NBD-LPC) itself was also metabolized and internalized by a similar mechanism. LLC-PK1 cells converted NBD-LPC to either NBD-MG, possibly due to lysophospholipase C-like activity of ecto-nucleotide pyrophosphatase/phosphodiesterase-6, or to free fatty acid (FA), due to lysophospholipase activity in the culture medium at both sites. The resultant NBD-MG was further degraded to NBD-FA by lipase activity before or after its uptake into the cells, and a portion of NBD-FA was finally released into the culture medium on the opposite side.
Tsutsumi
Toshihiko
T
Faculty of Pharmaceutical Sciences, Kyushu University of Health and Welfare, 1714 Yoshinocho, Nobeoka 882-8508, Japan.
Adachi
Mika
M
Yoshioka
Yasuko
Y
Tokumura
Akira
A
D000818:Animals; D002460:Cell Line; D004847:Epithelial Cells / Q000201:enzymology*; D007668:Kidney / Q000166:cytology; D008245:Lysophospholipase / Q000378:metabolism*; D008246:Lysophospholipids / Q000378:metabolism*; D013058:Mass Spectrometry; D013552:Swine; D013997:Time Factors
D008246:Lysophospholipids; D008245:Lysophospholipase