Lipoprotein lipase and sphingomyelinase synergistically enhance the association of atherogenic lipoproteins with smooth muscle cells and extracellular matrix. A possible mechanism for low density lipoprotein and lipoprotein(a) retention and macrophage foam cell formation.
Key result
Incubation of smooth muscle cells with LDL in the presence of lipoprotein lipase and sphingomyelinase led to a 50-100-fold greater LDL cell association compared to the absence of both enzymes.
Population
Bovine aortic smooth muscle cells, mutant Chinese hamster ovary cells lacking cell-surface proteoglycans…
Comparison
Incubation with low density lipoprotein or… vs Incubation in the absence of the two enzymes or…
Design
Preclinical
Follow-up
18 to 42 hours
Authors
Discussion
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Member takes
Implication
Supports LpL/SMase synergy in LDL retention by smooth muscle cells; leaves open whether targeting these enzymes alters human atherosclerosis.
Structured PICO
P
Population
Bovine aortic smooth muscle cells, mutant Chinese hamster ovary cells lacking cell-surface proteoglycans, mouse peritoneal macrophages, and smooth muscle cell extracellular matrix
I
Intervention
Incubation with low density lipoprotein (LDL) or lipoprotein(a) (Lp(a)) in the presence of lipoprotein lipase (LpL) and sphingomyelinase (SMase)
C
Comparator
Incubation in the absence of the two enzymes or in the presence of either enzyme alone
O
Outcome
Aggregation and cell association of LDL or Lp(a) on the surface of cells and extracellular matrixsurrogate
Main Result
Effect estimate: 50-100-fold increase
The synergistic interaction of LpL and SMase enhances the retention and aggregation of atherogenic lipoproteins in the arterial wall, providing a mechanism for macrophage foam cell formation.
Cite This Study
Tabas et al. (1993) studied Atherosclerosis. Lipoprotein lipase (LpL) and sphingomyelinase (SMase) vs. Absence of the two enzymes or either enzyme alone was evaluated on 125I-LDL cell association (50-100-fold increase). Incubation of smooth muscle cells with LDL in the presence of lipoprotein lipase and sphingomyelinase led to a 50-100-fold greater LDL cell association compared to the absence of both enzymes.