Mesoderm-specific transcript is associated with fat mass expansion in response to a positive energy balance.
A 50-fold variation in mRNA and protein levels of the mesoderm-specific transcript gene (Mest) in white fat of C57BL/6J (B6) mice fed an obesogenic diet is positively correlated with expansion of fat mass. MEST protein was detected only in adipocytes, in which its induction occurred with both unsaturated and saturated dietary fat. To test the hypothesis that MEST modulates fat mass expansion, its expression was compared to that of stearoyl CoA desaturase (Scd1) in B6 mice exposed to diets and environmental temperatures that generated conditions separating the effects of food intake and adiposity. Under a range of conditions, Mest expression was always associated with variations in adiposity, whereas Scd1 expression was associated with the amount of saturated fat in the diet. Mest mRNA was expressed at its highest levels during early postnatal growth at the onset of the most rapid phase of fat mass expansion. MEST is localized to the endoplasmic reticulum/Golgi apparatus where its putative enzymatic properties as a lipase or acyltransferase, predicted from sequence homology with members of the alpha/beta fold hydrolase superfamily, can enable it to function in lipid accumulation under conditions of positive energy balance. Variations in adiposity and Mest expression in genetically identical mice also provides a model of epigenetic regulation.
Nikonova
Larissa
L
Pennington Biomedical Research Center, 6400 Perkins Rd., Baton Rouge, LA 70808, USA.
Koza
Robert A
RA
Mendoza
Tamra
T
Chao
Pei-Min
PM
Curley
James P
JP
Kozak
Leslie P
LP
D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism; D052436:Adipose Tissue, White / Q000378:metabolism*; D050154:Adiposity / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D004032:Diet; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage; D004435:Eating / Q000187:drug effects / Q000502:physiology; D004721:Endoplasmic Reticulum / Q000235:genetics / Q000378:metabolism; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology*; D044127:Epigenesis, Genetic / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006056:Golgi Apparatus / Q000235:genetics / Q000378:metabolism; D008049:Lipase / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013230:Stearoyl-CoA Desaturase / Q000096:biosynthesis / Q000235:genetics
D004042:Dietary Fats, Unsaturated; D011506:Proteins; D012333:RNA, Messenger; C103637:mesoderm specific transcript protein; C490333:Scd1 protein, mouse; D013230:Stearoyl-CoA Desaturase; D000217:Acyltransferases; D008049:Lipase