Proteomic profiling of prechylomicron transport vesicles (PCTVS) involved in the assembly and secretion of apoB-48-containing chylomicrons by the intestine

Intestinal lipoprotein overproduction is increasingly being recognized as an important feature of dyslipidemia of insulin resistant states. Chylomicrons are transported from the ER to the Golgi using a specialized compartment called the prechylomicron transport vesicle (PCTV). In normal hamsters, the small intestine constitutively secretes small chylomicrons to prime for fat ingestion. However, fructose-feeding induces an overproduction of chylomicrons which may change the formation of PCTVs. We report proteomic profiles of PCTVs isolated from chow-fed (normal) and fructose-fed hamsters, the latter being an established model of diet-induced insulin resistance. We have characterized the PCTV and developed proteomic profiles of PCTV-associated proteins from insulin-resistant and control enterocytes. A number of PCTV-associated proteins were found to be differentially expressed, including proteins involved in lipoprotein assembly and vesicular transport. These findings have increased our understanding of the intracellular assembly and transport of nascent chylomicrons and lipoprotein overproduction in insulin resistance.