Retina expresses microsomal triglyceride transfer protein: implications for age-related maculopathy

Journal of Lipid Research

J. Brett Presley¹  Christine A. Curcio¹  Byong Hong Chung¹  Nancy E. Medeiros²  Xueming Zhang²  Chuan-Ming Li³  Nassrin Dashti³  Clyde Guidry³ 

[1] Division of Gerontology and Atherosclerosis Research Program, Department of Medicine, University of Alabama School of Medicine, Birmingham, AL;Retina Specialists of North Alabama, Huntsville, AL;Department of Ophthalmology, Department of Medicine, University of Alabama School of Medicine, Birmingham, AL;

关键词: lipoprotein assembly;    esterified cholesterol;    retinal pigment epithelium;    Bruch's membrane;    abetalipoproteinemia;   

DOI  :  

来源: DOAJ

【 摘 要 】

The principal extracellular lesions of age-related maculopathy (ARM), the leading cause of vision loss in the elderly, involve Bruch's membrane (BrM), a thin vascular intima between the retinal pigment epithelium (RPE) and its blood supply. With age, 80–100 nm solid particles containing esterified cholesterol (EC) accumulate in normal BrM, and apolipoprotein B (apoB) immunoreactivity is detectable in BrM- and ARM-associated lesions. Yet little evidence indicates that increased plasma cholesterol is a risk factor for ARM. To determine if RPE is capable of assembling its own apoB-containing lipoprotein, we examined RPE for the expression of microsomal triglyceride transfer protein (MTP), which is required for this process. Consistent with previous evidence for apoB expression, MTP is expressed in RPE, the ARPE-19 cell line, and, unexpectedly, retinal ganglion cells, which are neurons of the central nervous system. De novo synthesis and secretion of neutral lipid by ARPE-19 was supported by high levels of radiolabeled EC and triglyceride in medium after supplementation with oleate. Lipoprotein assembly and secretion is implicated as a constitutive retinal function and a plausible candidate mechanism involved in forming extracellular cholesterol-containing lesions in ARM.The pigmentary retinopathy and neuropathy of abetalipoproteinemia (Mendelian Inheritance of Man 200100; Bassen-Kornzwieg disease), which is caused by mutations in the MTP gene, may involve loss of function at the retina.

【 授权许可】

Unknown