Intake of soy protein isolate alters hepatic gene expression in rats.
Soy protein isolate (SPI) can elicit various physiological effects such as cholesterol lowering and antiobesity effects. To examine whether hepatic gene expression is altered by SPI intake, rats were fed an SPI or casein diet for 8 weeks. After 8 weeks of feeding, liver weight and plasma triglyceride and cholesterol levels were significantly lower in the SPI group than in the casein group. Hepatic gene expression was investigated using DNA microarrays. The expression profiles and statistical analysis showed clear and significant differences between the SPI and casein groups (p < 0.05); in the SPI group, 63 genes were up-regulated and 57 genes were down-regulated, most involved in various physiological functions such as lipid metabolism, antioxidant activity, transcriptional regulation, and energy metabolism. Especially in lipid metabolism, the down-regulated genes are related to fatty acid synthesis and the up-regulated genes are related to cholesterol synthesis and steroid catabolism. These results suggest that SPI intake could maintain homeostasis primarily by modulating lipid and energy metabolism.
Tachibana
Nobuhiko
N
Food Science Research Institute, Fuji Oil Company, Ltd., 1 Sumiyoshi-cho, Izumisano City, Osaka 598-8540, Japan. 010110@so.fujioil.co.jp
Matsumoto
Ichiro
I
Fukui
Kensuke
K
Arai
Soichi
S
Kato
Hisanori
H
Abe
Keiko
K
Takamatsu
Kiyoharu
K
D000818:Animals; D000975:Antioxidants / Q000032:analysis; D002364:Caseins / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage*; D004734:Energy Metabolism / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects*; D008055:Lipids / Q000097:blood; D008099:Liver / Q000378:metabolism*; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D030262:Soybean Proteins / Q000008:administration & dosage*
D000975:Antioxidants; D002364:Caseins; D004044:Dietary Proteins; D008055:Lipids; D030262:Soybean Proteins