Dixon Lab | R C L R | Nutritional Science | S E B S | Rutgers

Areas of Research in the Dixon Lab:

The lab is primarily interested in lipid and lipoprotein research. We are interested in the hepatic synthesis and degradation of apolipoprotein B100, the protein that surrounds VLDL and LDL particles. We are interested in the metabolic regulation of VLDL secretion and we are trying to understand all the key enzymes and proteins involved in this process.

Most recently we are interested in the proteonomics and lipidomics of the LDL particle. In 2007 we installed a state-of-the-art Liquid Chromatograph/Mass Spectrometry (LC/MS) system that has allowed us to enter the new field of Lipidomics.  Our goal is to determine which metabolic processes stimulate changes in the lipid composition of the VLDL particle and how these changes influence its role in health and disease.

Detailed projects can be found below:

Current Projects:

The Role of PGC1β and SCD1 in VLDL Secretion and Lipid Composition
Diana R. Johnson

My graduate work focuses on the metabolic regulation of VLDL secretion. Some of the key proteins and enzymes that I am interested in are PPARβ-coactivator 1β (PGC1β) and Stearoyl CoA Desaturase 1 (SCD1). When PGC1β is over-expressed in mouse liver, it drastically increases the amount of plasma VLDL. PGC1β is a nuclear coactivator that can affect the gene expression of many genes, including SREBP1c, FAS, ACC1 and several others. However, the exact mechanism in which PGC1β directly affects VLDL secretion remains unknown. I am also interested in VLDL lipid composition and if changes in gene expression will affect the lipids that are secreted with the VLDL particle. I will use the LCMS to determine lipid composition of the VLDL particles under different metabolic conditions to better understand how the lipid composition of VLDL changes and what effects this has on its metabolism.
Analysis of Plasma Lipoproteins using Proteomics and Lipidomics
Josh Thackray  (undergrad)

Plasma from pigs (a very good model for human lipoprotein metabolism) is run on a gel filtration FPLC column to fractionate LDL, VLDL, and HDL particles and their associated lipids and proteins. The fractions are then run on an electrophoresis gel to qualitatively separate component proteins. The same plasma will be separated using chemical precipitation, affinity chromatography, and ultracentrifugation. The samples will then be run on a gel and the component proteins from the different isolation methods are compared. When fractions from the FPLC are run on a gel, there is a dramatic increase in the number of proteins that show up on the gel compared to a fraction prepared by ultracentrifugation. The hypothesis is that there are more proteins associated with the lipoprotein particle than previously thought. To ensure that the proteins we have observed in the FPLC fractions are not co-eluting, several methods of isolating lipoproteins will be used and their protein compositions compared.
This page was last updated on Sunday, April 11, 2010 9:20 pm