title: Heterologous expression of C. elegans fat-1 decreases the n-6/n-3 fatty acid ratio and inhibits adipogenesis in 3T3-L1 cells.
abstract: In general, a diet enriched in polyunsaturated fatty acids (PUFAs) inhibits the development of obesity and decreases adipose tissue. The specific impacts of n-3 and n-6 PUFAs on adipogenesis, however, have not been definitively determined. Traditional in vivo and in vitro supplementation studies have yielded inconsistent or even contradictory results, which likely reflect insufficiently controlled experimental systems. Caenorhabditiselegans fat-1 gene encodes an n-3 fatty acid desaturase, and its heterologous expression represents an effective method both for altering the n-6/n-3 PUFA ratio and for evaluating the biological effects of n-3 and n-6 PUFAs. We sought to determine whether a reduced n-6/n-3 ratio could influence adipogenesis in 3T3-L1 cells. Lentivirus-mediated introduction of the fat-1 gene into 3T3-L1 preadipocytes significantly reduced the n-6/n-3 ratio and inhibited preadipocyte proliferation and differentiation. In mature adipocytes, fat-1 expression reduced lipid deposition, as measured by Oil Red O staining, and induced apoptosis. Our results indicate that a reduced n-6/n-3 ratio inhibits adipogenesis through several mechanisms and that n-3 PUFAs more effectively inhibit adipogenesis (but not lipogenesis) than do n-6 PUFAs.
authors.affiliation: Ministry of Agriculture Key Laboratory of Animal Genetics, Breeding and Reproduction, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China. anleim@yahoo.com.cn
authors.forename: Lei
authors.initials: L
authors.lastname: An
authors.forename: Yun-Wei
authors.initials: YW
authors.lastname: Pang
authors.forename: Hong-Mei
authors.initials: HM
authors.lastname: Gao
authors.forename: Li
authors.initials: L
authors.lastname: Tao
authors.forename: Kai
authors.initials: K
authors.lastname: Miao
authors.forename: Zhong-Hong
authors.initials: ZH
authors.lastname: Wu
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Tian
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology / Q000378:metabolism; D050156:Adipogenesis; D000818:Animals; D017209:Apoptosis; D017173:Caenorhabditis elegans / Q000201:enzymology*; D029742:Caenorhabditis elegans Proteins / Q000096:biosynthesis* / Q000235:genetics; D049109:Cell Proliferation; D044943:Fatty Acid Desaturases / Q000096:biosynthesis* / Q000235:genetics; D015525:Fatty Acids, Omega-3 / Q000378:metabolism*; D043371:Fatty Acids, Omega-6 / Q000378:metabolism*; D051379:Mice
chemical_list: D029742:Caenorhabditis elegans Proteins; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; C466741:fat-1 protein, C elegans; D044943:Fatty Acid Desaturases