A novel method for determining peroxisomal fatty acid ß-oxidation.

ABSTRACT

The purpose of this study is to establish an assay method to screen for chemical compounds that stimulate peroxisomal fatty acid ß-oxidation activity in X-linked adrenoleukodystropy (X-ALD) fibroblasts. In this investigation, we used 12-(1-pyrene)dodecanoic acid (pyrene-C120), a fluorescent fatty acid analog, as a substrate for fatty acid ß-oxidation. When human skin fibroblasts were incubated with pyrene-C120, ß-oxidation products such as pyrene-C100 and pyrene-C80 were generated time-dependently. These ß-oxidation products were scarcely detected in the fibroblasts from patients with Zellweger syndrome, a peroxisomal biogenesis disorder. In contrast, in fibroblasts with mitochondrial carnitine-acylcarnitine translocase deficiency, the ß-oxidation products were detected at a level similar to control fibroblasts. These results indicate that the ß-oxidation of pyrene-C120 takes place in peroxisomes, but not mitochondria, so pyrene-C120 is useful for measuring peroxisomal fatty acid ß-oxidation activity. In X-ALD fibroblasts, the ß-oxidation activity for pyrene-C120 was approximately 40 % of control fibroblasts, which is consistent with previous results using [1-(14)C]lignoceric acid as the substrate. The present study provides a convenient procedure for screening chemical compounds that stimulate the peroxisomal fatty acid ß-oxidation in X-ALD fibroblasts.