title: Consumption of soy protein isolate reduces hepatic SREBP-1c and lipogenic gene expression in wild-type mice, but not in FXR-deficient mice.
abstract: We examined to determine whether hepatic gene expression is affected in mice in which blood lipid levels remain unchanged fed soy protein isolate (SPI) for a short time. We also examined SPI-mediated effects in farnesoid X receptor (FXR)-deficient mice. Compared with casein, SPI affected the expression of various hepatic genes related to lipid metabolism in the wild-type mice. No effects of SPI were observed in the FXR-deficient mice, suggesting the importance of FXR. Hepatic peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) gene expression was reduced by SPI, and this might be associated with a decrease in FXR expression. Decreased FXR led to decreased expression of its target, the bile-salt export pump necessary for bile acid secretion and dietary lipid absorption. The earliest response to SPI was a decrease in hepatic sterol regulatory element-binding protein (SREBP)-1c mRNA, on day 3. SPI activated hepatic adenosine monophosphate-activated protein kinase (AMPK), which can lead to a reduction in SREBP-1c mRNA. These data indicate the importance of SREBP-1c and PGC-1α/FXR in SPI-mediated alterations in hepatic gene expression.
authors: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo.
authors: Tsutomu
authors: T
authors: Hashidume
authors: Takashi
authors: T
authors: Sasaki
authors: Jun
authors: J
authors: Inoue
authors: Ryuichiro
authors: R
authors: Sato
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D015536:Down-Regulation / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects*; D050155:Lipogenesis / Q000187:drug effects*; D008099:Liver / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D047495:PPAR gamma / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D060888:Real-Time Polymerase Chain Reaction; D018160:Receptors, Cytoplasmic and Nuclear / Q000172:deficiency* / Q000235:genetics; D030262:Soybean Proteins / Q000378:metabolism / Q000494:pharmacology*; D051780:Sterol Regulatory Element Binding Protein 1 / Q000235:genetics / Q000378:metabolism; D000099150:Receptor, Farnesoid X-Activated
chemical_list: D055372:AMP-Activated Protein Kinases; D047495:PPAR gamma; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D030262:Soybean Proteins; D051780:Sterol Regulatory Element Binding Protein 1; D000099150:Receptor, Farnesoid X-Activated