ePrints

Mitochondrial fatty acid beta-oxidation in the retinal pigment epithelium

Lookup NU author(s): Professor Tiina Tyni, Dr Simon Eaton, Dr Morteza Pourfarzam, Dr Richard Andrews, Emeritus Professor Doug Turnbull

Downloads

Full text for this publication is not currently held within this repository. Alternative links are provided below where available.

Abstract

Pigmentary retinopathy is an important feature of long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency, a disorder of mitochondrial fatty acid beta-oxidation. Pathogenesis of this complication remains unknown. The retinal pigment epithelium (RPE) is affected early in this retinopathy. We wanted to determine whether there is evidence of mitochondrial fatty acid beta-oxidation in the RPE cells. Fatty acid oxidation was measured from cultured porcine RPE cells by incubating them with [U-C-13]-hexadecanoic acid. Acylcarnitine esters were analyzed by tandem mass spectrometry. The activity of LCHAD and carnitine uptake capacity were measured from the cultured cells. Antibodies to the human mitochondrial trifunctional protein (MTP) containing LCHAD activity were used to analyze the expression of the MTP in the cultured RPE cell lysate and in human retinal sections by immunoblotting and immunohistochemistry. Fatty acid oxidation analysis showed normal chain shortening of hexadecanoic acid and production of acetylcarnitine in cultured RPE cells. Immunoblotting revealed expression of the MTP and enzyme assay showed the activity of LCHAD in the RPE cells. RPE cells were also capable of carnitine uptake. Positive labeling to the MTP antibodies was detected in the RPE, photoreceptors, and ganglion cells. The results give strong in vitro evidence for the presence of mitochondrial fatty acid beta-oxidation in RPE cells and the expression of the MTP in the RPE and other layers of the retina. Further studies are required to clarify whether this pathway acts also in vivo in the retina.

Publication metadata

Author(s): Tyni T, Johnson M, Eaton S, Pourfarzam M, Andrews R, Turnbull DM

Publication type: Article

Publication status: Published

Journal: Pediatric Research

Year: 2002

Volume: 52

Issue: 4

Pages: 595-600

ISSN (print): 0031-3998

ISSN (electronic): 1530-0447

Publisher: Lippincott Williams & Wilkins

URL: http://dx.doi.org/10.1203/01.PDR.0000030874.20888.2D

DOI: 10.1203/01.PDR.0000030874.20888.2D

Altmetrics

Share