11 research outputs found
Individual phospholipid contents and their fatty acid compositions in early normal human embryonic lung tissue
Effects of the components of Newcastle disease virus on the structural order of lipid assemblies
Surface Properties and Behavior of Lipid Extracts from Plasma Membranes of Cells Cultured as Monolayer and in Tissue-Like Conditions
The manipulation of polar head group composition of phospholipids in the wheat Miranovskaja 808 affects frost tolerance
Acid Sphingomyelinase Deficiency Prevents Diet-induced Hepatic Triacylglycerol Accumulation and Hyperglycemia in Mice*
Acid sphingomyelinase plays important roles in ceramide homeostasis, which
has been proposed to be linked to insulin resistance. To test this association
in vivo, acid sphingomyelinase deletion
(asm–/–) was transferred to mice lacking the
low density lipoprotein receptor (ldlr–/–),
and then offsprings were placed on control or modified (enriched in saturated
fat and cholesterol) diets for 10 weeks. The modified diet caused
hypercholesterolemia in all genotypes; however, in contrast to
asm+/+/ldlr–/–, the acid
sphingomyelinase-deficient littermates did not display hepatic
triacylglyceride accumulation, although sphingomyelin and other sphingolipids
were substantially elevated, and the liver was enlarged.
asm–/–/ldlr–/–
mice on a modified diet did not accumulate body fat and were protected against
diet-induced hyperglycemia and insulin resistance. Experiments with
hepatocytes revealed that acid sphingomyelinase regulates the partitioning of
the major fatty acid in the modified diet, palmitate, into two competitive and
inversely related pools, triacylglycerides and sphingolipids, apparently via
modulation of serine palmitoyltransferase, a rate-limiting enzyme in de
novo sphingolipid synthesis. These studies provide evidence that acid
sphingomyelinase activity plays an essential role in the regulation of glucose
metabolism by regulating the hepatic accumulation of triacylglycerides and
sphingolipids during consumption of a diet rich in saturated fats