Vol. 283, Issue 2, F328-F334, August 2002
Effects of fatty acids on mitochondrial 
-oxidation enzyme
gene expression in renal cell lines
Fetta
Ouali,
Fatima
Djouadi, and
Jean
Bastin
Institut National de la Santé et de la Recherche
Médicale U319, Université Paris VII, 75015 Paris,
France
Regulatory effects of fatty acids on gene
expression of medium-chain acyl-CoA dehydrogenase (MCAD), a
mitochondrial 
-oxidation enzyme, were investigated in rabbit kidney
cell lines derived from proximal tubule (RC.SV1), thick ascending limb
of Henle's loop (RC.SV2), or collecting duct (RC.SV3). Exposure to
long-chain fatty acids led to significant increases (2-fold) in MCAD
mRNA abundance in RC.SV1 and RC.SV2 cells; kinetics and dose-response studies established that maximal MCAD gene stimulation was reached 4 h after addition of 50 µM oleate (C18:1) in the culture
medium. These effects of fatty acids were totally abolished in the
presence of 1 µg/ml actinomycin D, a transcription inhibitor.
Staining of cellular lipids revealed that fatty acid-induced gene
stimulation could occur in the absence of cellular fatty acid
accumulation. Altogether, these data indicate that small changes in
cellular fatty acid flux can have direct short-term effects on fatty
acid oxidation enzyme gene expression in renal cells, and this might take part in the regulation of cellular fatty acid homeostasis in
response to changes in tubular fluid composition.
fatty acid metabolism; regulation; cell culture
