Possible involvement of enhanced intestinal microsomal triglyceride transfer protein (MTP) gene expression in acceleration of lipid absorption by a western-type diet in apolipoprotein E knockout mice.
Evidence has been accumulating that triglyceride (TG)-rich lipoproteins are atherogenic. Microsomal TG transfer protein (MTP) is essential for the synthesis of both chylomicron in the intestine and very low density lipoprotein in the liver. To investigate whether a western-type diet, a so-called atherogenic diet, alters intestinal lipid absorption via change in intestinal MTP expression, the effects of two different diet regimes in apolipoprotein-E knockout (apoE KO) mice were examined. Male apoE KO mice aged 6 weeks were fed a western-type diet or a chow diet for 5 weeks. Then, measurement of plasma TG levels after oral fat-loading and analysis of jejunal MTP gene expression were performed. Both the maximum level and the 0-8 h area under the curve (AUC) of the increase in TG levels in the western-type diet-fed mice were almost three times greater than those in the chow diet-fed mice. MTP gene expression, determined by reverse transcriptase-polymerase chain reaction (RT-PCR), was obviously enhanced in the western-type diet-fed mice compared to the chow diet-fed mice. These results suggest that the enhancement of intestinal MTP gene expression is involved in the accelerated lipid absorption in the western-type diet-fed mice.
Ueshima
Koji
K
Medicinal Biology Research Laboratories, Fujisawa Pharmaceutical Co., Ltd., Kashima 2-1-6, Yodogawa-ku, Osaka 532-8514, Japan. koji_ueshima@po.fujisawa.co.jp
Akihisa-Umeno
Hitomi
H
Sawada
Masae
M
Nagayoshi
Akira
A
Ozaki
Tohru
T
Takakura
Shoji
S
Manda
Toshitaka
T
Mutoh
Seitaro
S
D000818:Animals; D001057:Apolipoproteins E / Q000235:genetics*; D001161:Arteriosclerosis / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics*; D004036:Diet, Atherogenic; D004041:Dietary Fats / Q000008:administration & dosage; D015870:Gene Expression / Q000235:genetics*; D007408:Intestinal Absorption; D007583:Jejunum / Q000378:metabolism*; D008055:Lipids / Q000097:blood / Q000493:pharmacokinetics*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D016133:Polymerase Chain Reaction
D001057:Apolipoproteins E; D002352:Carrier Proteins; D004041:Dietary Fats; D008055:Lipids; C106092:microsomal triglyceride transfer protein