The largest risk factor for age-related macular degeneration (ARMD) is advanced age. With aging, there is a striking accumulation of neutral lipids in Bruch's membrane (BrM) of normal eye that continues through adulthood. This accumulation has the potential to significantly impact the physiology of the retinal pigment epithelium (RPE). It also ultimately leads to the creation of a lipid wall at the same locations where drusen and basal linear deposit, the pathognomonic extracellular, lipid-containing lesions of ARMD, subsequently form. Here, we summarize evidence obtained from light microscopy, ultrastructural studies, lipid histochemistry, assay of isolated lipoproteins, and gene expression analysis. These studies suggest that lipid deposition in BrM is at least partially due to accumulation of esterified cholesterol-rich, apolipoprotein B-containing lipoprotein particles produced by the RPE. Furthermore, we suggest that the formation of ARMD lesions and their aftermath may be a pathological response to the retention of a sub-endothelial apolipoprotein B lipoprotein, similar to a widely accepted model of atherosclerotic coronary artery disease (Tabas, I., K. J. Williams, and J. Borén. 2007. Subendothelial lipoprotein retention as the initiating process in atherosclerosis: update and therapeutic implications. Circulation. 116:1832-1844). This view provides a conceptual basis for the development of novel treatments that may benefit ARMD patients in the future.
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http://dx.doi.org/10.1194/jlr.R002238 | DOI Listing |
JCI Insight
January 2025
Department of Foundations of Medicine, NYU Grossman Long Island School of Medicine, Mineola, New York, USA.
High apolipoprotein B-containing (apoB-containing) low-density lipoproteins (LDLs) and low apoA1-containing high-density lipoproteins (HDLs) are associated with atherosclerotic cardiovascular diseases. In search of a molecular regulator that could simultaneously and reciprocally control both LDL and HDL levels, we screened a microRNA (miR) library using human hepatoma Huh-7 cells. We identified miR-541-3p that both significantly decreases apoB and increases apoA1 expression by inducing mRNA degradation of 2 different transcription factors, Znf101 and Casz1.
View Article and Find Full Text PDFUnlabelled: Genome- and epigenome-wide association studies have associated variants and methylation status of carnitine palmitoyltransferase 1a (CPT1a) to reductions in very low-density lipoprotein (VLDL) cholesterol and triglyceride levels. We report significant associations between the presence of SNPs and reductions in plasma cholesterol, as well as positive associations between hepatic Cpt1a expression and plasma cholesterol levels across inbred mouse strains. Mechanistic studies show that both wild type and human apolipoprotein B100 (apoB)-transgenic mice with liver-specific deletion of (LKO) display lower circulating apoB levels consistent with reduced LDL-cholesterol (LDL-C) and LDL particle number.
View Article and Find Full Text PDFEnviron Pollut
January 2025
SKL-ESPC & SEPKL-AERM, College of Environmental Sciences and Engineering, and Center for Environment and Health, Peking University, Beijing, China. Electronic address:
The biological pathways connecting ambient fine particulate matter (PM)-induced initial adverse effects to the development of atherosclerotic cardiovascular diseases are not fully understood. We hypothesize that lysoglycerophospholipids (LysoGPLs) are pivotal mediators of atherosclerosis induced by exposure to PM. This study investigated the changes of LysoGPLs in response to PM exposure and the mediation role of LysoGPLs in the pro-atherosclerotic effects of PM exposure.
View Article and Find Full Text PDFNat Rev Cardiol
January 2025
Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria.
J Lipid Res
December 2024
Department of Foundations of Medicine, NYU Grossman Long Island School of Medicine, Mineola, NY, USA. Electronic address:
Microsomal triglyceride transfer protein (MTP) plays crucial roles in the assembly and secretion of apolipoprotein B-containing lipoproteins and loss of function MTP variants are associated with abetalipoproteinemia, a disease characterized by the absence of these lipoproteins. MTP is a heterodimeric protein of two subunits, MTP and protein disulfide isomerase (PDI). In this study, we report a proband with abetalipoproteinemia who was monitored annually for 10 years in her third decade and had very low plasma lipids and undetectable apoB-containing lipoproteins.
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