Pancreatic bile salt‐dependent lipase activity in serum of normolipidemic patients

Abstract

Bile salt-dependent lipase (BSDL, E.C. 3.1.1.-) is a digestive enzyme secreted by the pancreatic acinar cell. Once in the duodenum, the enzyme, upon activation by primary bile salts, hydrolyzes dietary lipid esters such as cholesteryl esters and lipid-soluble vitamin esters. This enzyme is partially transferred from the duodenum or pancreas to the circulation where it has been postulated to exert a systemic action on atheroma-generating oxidized-low density lipoprotein (LDL). In the present study, sera from 40 healthy normolipidemic volunteers were used to investigate the possible linkage between circulating BSDL, lipids, and lipoproteins. We showed, firstly, that pancreatic-like BSDL activity can be detected in these serums. Secondly, BSDL activity increased significantly with the level of LDL-cholesterol and was also positively linked to the serum concentration of Apo B100 and Apo A-I. Thirdly, we also established that BSDL was associated with LDL, in part by a specific interaction with Apo B100, while no interaction was found with Apo A-I. No linkage with other recorded parameters (triglycerides, phospholipids, and high density lipoprotein-cholesterol) was detected. Because an increase in LDL-cholesterol represents an important risk factor for atheroma, the concomitant increase in BSDL, which can metabolize atherogenic LDL, suggests for the first time that this circulating enzyme may exert a positive effect against atherosclerosis.

Site-directed Mutagenesis of the Basic N-terminal Cluster of Pancreatic Bile Salt-dependent Lipase

“…BSDL was also detected in blood (30), where it is associated with atherogenic light density lipoproteins (31). BSDL is synthesized to a limited extent by human-monocytes-macrophages (32), endothelial cells (33,34), eosinophils (35), and the liver (22,36,37).…”

Pancreatic Bile Salt-Dependent Lipase Induces Smooth Muscle Cells Proliferation

“…2 The presence of the enzyme in the circulation could be the result of an orchestrated transepithelial movement through the enterocyte. 3 BSDL was also detected in the vascular endothelium, 4 where it could originate from macrophages, 5 be produced by endothelial cells, 6 or be derived from LDL-associated BSDL.…”

“…3 BSDL was also detected in the vascular endothelium, 4 where it could originate from macrophages, 5 be produced by endothelial cells, 6 or be derived from LDL-associated BSDL. 2 The role of endothelial BSDL in atherosclerosis 4 -6 is speculative. BSDL in the endothelial wall could be protective in hydrolyzing lysophosphatidylcholine (lysoPC) formed in the intima during the oxidative modification of LDL.…”

The Affinity Binding Sites of Pancreatic Bile Salt-Dependent Lipase in Pancreatic and Intestinal Tissues

“…Although secreted into the duodenum, where the enzyme exerts its digestive function, BSDL has been shown to transit through the enterocyte (Lechêne de la Porte et al 1987;Bruneau et al 1998). This enzyme is found in the blood of normolipidemic patients (Caillol et al 1997), in whom it has been postulated to exert a systemic action on atheroma-generating oxidized lowdensity lipoproteins (Shamir et al 1995). BSDL is found in pancreatic secretions of all examined species from fish to human and has been cloned in several species (see, e.g., Sbarra et al 1998).…”