Adipose depot-specific modulation of angiotensinogen gene expression in diet-induced obesity.
Adipose tissue represents an important source of angiotensinogen (AGT). We investigated the effect of obesity induced by a high-fat diet on the expression of mouse (mAGT) and human AGT (hAGT) genes in liver, kidney, and heart and different adipose depots in normal mice (C57BL/6J), and in transgenic mice expressing the hAGT gene under the control of its own promoter. Mice were fed a high-fat diet (45% kcal) or normal chow (10% kcal) for 10 and 20 wk. The expression of mAGT and hAGT mRNA was quantified using an RNAse protection assay. Mice on the high-fat diet exhibited increased weight, fat mass, and plasma leptin. Expression of mAGT or hAGT genes was not affected by high-fat diet in nonadipose tissues, brown adipose tissue, or subcutaneous white fat. In contrast, high-fat diet increased both mAGT and hAGT gene expression in visceral adipose depots (omental, reproductive, and perirenal fat). Thus obesity-induced by a high-fat diet is associated with a tissue-specific increased expression of both mouse and human AGT genes in intra-abdominal adipose tissue. Our findings also suggest that 1.2 kb of regulatory sequences present in the hAGT transgene are sufficient to transcriptionally respond to a high-fat diet in an adipose-specific and depot-specific manner.
Rahmouni
Kamal
K
Hypertension Genetics Specialized Center of Research, Cardiovascular Center, Department of Internal Medical, University of Iowa Carver College of Medicine, Iowa City 52242, USA.
Mark
Allyn L
AL
Haynes
William G
WG
Sigmund
Curt D
CD
D000273:Adipose Tissue / Q000502:physiology*; D000808:Angiotensinogen / Q000235:genetics*; D000818:Animals; D001835:Body Weight; D004041:Dietary Fats / Q000494:pharmacology*; D015870:Gene Expression; D006973:Hypertension / Q000503:physiopathology; D020738:Leptin / Q000097:blood; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009765:Obesity / Q000503:physiopathology*; D012333:RNA, Messenger / Q000032:analysis
D004041:Dietary Fats; D020738:Leptin; D012333:RNA, Messenger; D000808:Angiotensinogen