ABCD2 is abundant in adipose tissue and opposes the accumulation of dietary erucic acid (C22:1) in fat.
The ATP binding cassette transporter, ABCD2 (D2), is a peroxisomal protein whose mRNA has been detected in the adrenal, brain, liver, and fat. Although the role of this transporter in neural tissues has been studied, its function in adipose tissue remains unexplored. The level of immunoreactive D2 in epididymal fat is >50-fold of that found in brain or adrenal. D2 is highly enriched in adipocytes and is upregulated during adipogenesis but is not essential for adipocyte differentiation or lipid accumulation in day 13.5 mouse embryonic fibroblasts isolated from D2-deficient (D2(-/-)) mice. Although no differences were appreciated in differentiation percentage, total lipid accumulation was greater in D2(-/-) adipocytes compared with the wild type. These results were consistent with in vivo observations in which no significant differences in adiposity or adipocyte diameter between wild-type and D2(-/-) mice were observed. D2(-/-) adipose tissue showed an increase in the abundance of 20:1 and 22:1 fatty acids. When mice were challenged with a diet enriched in erucic acid (22:1), this lipid accumulated in the adipose tissue in a gene-dosage-dependent manner. In conclusion, D2 is a sterol regulatory element binding protein target gene that is highly abundant in fat and opposes the accumulation of dietary lipids generally absent from the triglyceride storage pool within adipose tissue.
Liu
Jingjing
J
Department of Pharmaceutical Sciences and Cardiovascular Research Center, Lexington, Kentucky, USA.
Sabeva
Nadezhda S
NS
Bhatnagar
Saloni
S
Li
Xiang-An
XA
Pujol
Aurora
A
Graf
Gregory A
GA
D000074061:ATP Binding Cassette Transporter, Subfamily D; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D017667:Adipocytes / Q000378:metabolism*; D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D004041:Dietary Fats / Q000378:metabolism*; D004883:Erucic Acids / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout
C508354:ABCD2 protein, mouse; D000074061:ATP Binding Cassette Transporter, Subfamily D; D018528:ATP-Binding Cassette Transporters; D001786:Blood Glucose; D004041:Dietary Fats; D004883:Erucic Acids; D005227:Fatty Acids; C049811:erucic acid