Acylation-stimulating protein (ASP) increases triglyceride (TG) storage (fatty acid trapping) in adipose tissue and plays an important role in postprandial TG clearance. We examined the capacity of ASP and insulin to stimulate the activity of lipoprotein lipase (LPL) and the trapping of LPL-derived nonesterified fatty acid (NEFA) in 3T3-L1 adipocytes. Although insulin increased total LPL activi...

Lipoprotein lipase (LPL) hydrolyzes circulating lipoprotein triglyceride molecules while it is associated with the luminal surface of capillary endothelial cells. The precise molecular mechanism by which LPL attaches to these cells is unknown. LPL and a number of other molecules, including growth factors and clotting factors, bind to heparin-affinity gels and are eluted using high concentration...

Lipoprotein lipase (LPL) is predominantly expressed in adipose and muscle where it plays a crucial role in the metabolism of triglyceride-rich plasma lipoproteins. LPL is also expressed in the brain with highest levels found in the pyramidal cells of the hippocampus, suggesting a possible role for LPL in the regulation of cognitive function. However, very little is currently known about the spe...

GPIHBP1, a glycosylphosphatidylinositol-anchored protein of capillary endothelial cells, shuttles lipoprotein lipase (LPL) from subendothelial spaces to the capillary lumen. An absence of GPIHBP1 prevents the entry of LPL into capillaries, blocking LPL-mediated triglyceride hydrolysis and leading to markedly elevated triglyceride levels in the plasma (i.e., chylomicronemia). Earlier studies hav...

The regulation of adipose tissue lipoprotein lipase (LPL) by feeding and fasting occurs through post-translational changes in the LPL protein. In addition, LPL activity and secretion are decreased when N-linked glycosylation is inhibited. To better understand the role of oligisaccharide processing in the development of LPL activity and in LPL secretion, primary cultures of rat adipocytes were t...

Macrophages are important cells in the pathogenesis of atherosclerosis because of their tendency to accumulate lipid and become transformed into foam cells. Cultured human monocyte-derived macrophages spontaneously secrete lipoprotein lipase (LPL), and LPL has been linked to increased lipid uptake by these cells. Because secretion of various macrophage products depends on activation by lymphoki...

Hypertriglyceridemic very low density lipoproteins (HTG-VLDL, S(f) 60-400) are not taken up by HepG2 cells. However, addition of bovine milk lipoprotein lipase (LPL) at physiological concentrations markedly stimulates uptake. In the present study, we determined whether: a) LPL catalytic activity is required for uptake, b) LPL functions as a ligand, and c) cell surface hepatic triglyceride lipas...

Human monocyte-derived macrophages secrete lipoprotein lipase (LPL) in culture. The regulation of human macrophage LPL production is poorly understood. Since bacterial lipopolysaccharide (LPS) alters production of several macrophage secretory products, its effect on human monocyte-derived macrophage LPL was tested. LPS treatment produced a dramatic dose-dependent decrease in LPL activity in mac...