OBJECTIVE To clarify the role of very low density lipoprotein (VLDL) and apolipoprotein E (apoE) in adipogenesis, we studied newly developed hyperlipidemic obese (ob/ob;apoE-/-) mice. Because hydrolysis of VLDL is believed to be the major source of adipogenic free fatty acids, a higher plasma level of VLDL in these mice should exaggerate obesity. METHODS AND RESULTS When fed a high-fat, high-...

McArdle disease, also termed ‘glycogen storage disease type V’ is a disorder of skeletal muscle carbohydrate metabolism originated by inherited deficiency of the musclespecific isoform of glycogen phosphorylase (GP-MM). It is an autosomic recessive disorder caused by mutations in the PYGM gene which typically presents with exercise intolerance, i.e., episodes of early exertional fatigue frequen...

Apolipoprotein (apo) C-III plays a regulatory role in VLDL lipolysis and clearance. In this study, we determined a potential intracellular role of apoC-III in hepatic VLDL assembly and secretion. Stable expression of recombinant apoC-III in McA-RH7777 cells resulted in increased secretion efficiency of VLDL-associated triacylglycerol (TAG) and apoB-100 in a gene-dosage-dependent manner. The sti...

To investigate the role in lipoprotein metabolism of lipoprotein lipase (LPL) secreted by tissues, we established two cell lines. Fusion plasmids containing either human LPL cDNA or antisense LPL cDNA under control of the cytomegalovirus promoter were transfected into Chinese hamster ovary (CHO) cells, designated as CHO-LPL and CHO-anti-LPL, respectively. CHO-LPL constitutively produced a high ...

We examined whether administration of very low-density lipoproteins (VLDL) to pregnant rats increases surfactant phosphatidylcholine (PtdCho) content in fetal pre-type II alveolar epithelial cells. VLDL-triglycerides are hydrolyzed to fatty acids by lipoprotein lipase (LPL), an enzyme activated by heparin. Fatty acids released by LPL can incorporate into the PtdCho molecule or activate the key ...

Apolipoprotein E (apoE) is the primary recognition signal on triglyceride-rich lipoproteins responsible for interacting with low density lipoprotein (LDL) receptors and LDL receptor-related protein (LRP). It has been shown that lipoprotein lipase (LPL) and hepatic triglyceride lipase (HTGL) promote receptor-mediated uptake and degradation of very low density lipoproteins (VLDL) and remnant part...

Beta-migrating very low density lipoproteins (beta--VLDL) and chemically modified low density lipoproteins (LDL), labeled with the fluorescent probe 3,3'-dioctadecylindocarbocyanine (Dil), were used to determine whether foam cells from atherosclerotic lesions have lipoprotein receptors similar to those of macrophages. The advantage of the Dil probe is that it produces a brilliant fluorescence d...

We have previously shown that beta-very low density lipoprotein (beta-VLDL) incubated with bovine aortic endothelial cells (ECs) is bound and internalized more readily by cultured rabbit aortic smooth muscle cells (SMCs) than is beta-VLDL incubated in the absence of ECs, resulting in enhanced accumulation of cholesterol. To investigate the mechanism by which this occurs, beta-VLDL from hypercho...

The relationship between tissue plasminogen activator (tPA) levels and the potential regulation by hypertriglyceridemic very low density lipoprotein (HTG-VLDL) was examined in a human umbilical vein endothelial cell (HUVEC) culture model system. HUVEC cultures were incubated in the absence/presence of HTG-VLDL or normal (NTG)-VLDL (0 to 50 microg/mL) at 37 degrees C for various times (0 to 24 h...