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Lumenal lipid metabolism: implications for lipoprotein assembly
Richard Lehner1, Jihong Lian, Ariel D Quiroga
1Department of Pediatrics and Cell Biology, Group on Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Alberta, Canada. richard.lehner@ualberta.ca
Arteriosclerosis, Thrombosis, and Vascular Biology
|April 21, 2012
Summary
Insulin resistance and type 2 diabetes increase apolipoprotein B (apoB) lipoproteins, raising cardiovascular risk. This review explores how lipids transfer to the endoplasmic reticulum lumen for apoB lipidation and storage in distinct lipid droplets.
Area of Science:
- Biochemistry
- Cell Biology
- Metabolic Diseases
Background:
- Overproduction of apolipoprotein B (apoB)-containing lipoproteins is linked to insulin resistance, type 2 diabetes, and cardiovascular disease.
- Lipid availability for apoB lipoprotein assembly involves neutral lipid core formation and lipoprotein monolayer composition.
- While cytosolic lipid droplet (LD) metabolism is understood, lipid transfer to the endoplasmic reticulum lumen for apoB lipidation remains unclear.
Purpose of the Study:
- To review current knowledge on lumenal lipid metabolism concerning apoB assembly.
- To discuss mechanisms of lipid transfer and storage in the endoplasmic reticulum lumen for lipoprotein production.
Main Methods:
- This is a review article, synthesizing existing research.
- Focuses on analyzing current understanding of lipid droplet formation and protein association within the endoplasmic reticulum lumen.
Main Results:
- ApoB-synthesizing organs utilize at least three types of lipid droplets for neutral lipid deposition.
- These include perilipin-decorated cytosolic LDs and two types of lumenal LDs within the endoplasmic reticulum.
- Lumenal LDs are distinguished by their association with apoB (secretion-destined) or with microsomal triglyceride transfer protein and exchangeable apolipoproteins (resident).
Conclusions:
- Understanding lumenal lipid metabolism is crucial for comprehending apoB lipoprotein assembly and storage.
- Further research into the mechanisms governing lipid transfer to the ER lumen is needed to address metabolic and cardiovascular disease implications.
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