Dietary sphingolipids lower plasma cholesterol and triacylglycerol and prevent liver steatosis in APOE*3Leiden mice.
BACKGROUND
The prevalence of dyslipidemia and obesity resulting from excess energy intake and physical inactivity is increasing. The liver plays a pivotal role in systemic lipid homeostasis. Effective, natural dietary interventions that lower plasma lipids and promote liver health are needed.


OBJECTIVE
Our goal was to determine the effect of dietary sphingolipids on plasma lipids and liver steatosis.


METHODS
APOE*3Leiden mice were fed a Western-type diet supplemented with different sphingolipids. Body cholesterol and triacylglycerol metabolism as well as hepatic lipid concentrations and lipid-related gene expression were determined.


RESULTS
Dietary sphingolipids dose-dependently lowered both plasma cholesterol and triacylglycerol in APOE*3Leiden mice; 1% phytosphingosine (PS) reduced plasma cholesterol and triacylglycerol by 57% and 58%, respectively. PS decreased the absorption of dietary cholesterol and free fatty acids by 50% and 40%, respectively, whereas intestinal triacylglycerol lipolysis was not affected. PS increased hepatic VLDL-triacylglycerol production by 20%, whereas plasma lipolysis was not affected. PS increased the hepatic uptake of VLDL remnants by 60%. Hepatic messenger RNA concentrations indicated enhanced hepatic lipid synthesis and VLDL and LDL uptake. The net result of these changes was a strong decrease in plasma cholesterol and triacylglycerol. The livers of 1% PS-fed mice were less pale, 22% lighter, and contained 61% less cholesteryl ester and 56% less triacylglycerol than livers of control mice. Furthermore, markers of liver inflammation (serum amyloid A) and liver damage (alanine aminotransferase) decreased by 74% and 79%, respectively, in PS-fed mice.


CONCLUSIONS
Sphingolipids lower plasma cholesterol and triacylglycerol and protect the liver from fat- and cholesterol-induced steatosis.
Duivenvoorden
Ilse
I
TNO Biomedical Research, Leiden, Netherlands.
Voshol
Peter J
PJ
Rensen
Patrick C N
PC
van Duyvenvoorde
Wim
W
Romijn
Johannes A
JA
Emeis
Jef J
JJ
Havekes
Louis M
LM
Nieuwenhuizen
Willem F
WF
D000818:Animals; D053318:Apolipoprotein E3; D001057:Apolipoproteins E / Q000235:genetics; D002784:Cholesterol / Q000097:blood*; D002791:Cholesterol, Dietary / Q000493:pharmacokinetics; D004305:Dose-Response Relationship, Drug; D005230:Fatty Acids, Nonesterified / Q000493:pharmacokinetics; D005234:Fatty Liver / Q000517:prevention & control*; D005243:Feces / Q000737:chemistry; D005260:Female; D015870:Gene Expression; D007408:Intestinal Absorption / Q000187:drug effects; D050356:Lipid Metabolism / Q000187:drug effects* / Q000502:physiology; D008066:Lipolysis / Q000187:drug effects / Q000502:physiology; D008079:Lipoproteins, VLDL / Q000737:chemistry / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D012313:RNA / Q000378:metabolism; D011897:Random Allocation; D013107:Sphingolipids / Q000008:administration & dosage* / Q000494:pharmacology; D014280:Triglycerides / Q000097:blood*
D053318:Apolipoprotein E3; D001057:Apolipoproteins E; D002791:Cholesterol, Dietary; D005230:Fatty Acids, Nonesterified; D008079:Lipoproteins, VLDL; D013107:Sphingolipids; D014280:Triglycerides; C052720:apolipoprotein E3 (Leidein); D012313:RNA; D002784:Cholesterol