Adipose Angiotensin AT2 Receptors Modulate Thermogenesis

The brain renin-angiotensin system (RAS) stimulates resting metabolic rate in part through a mechanism involving suppression of the circulating RAS. This effect appears to be mediated through a reduction in angiotensin AT2 receptor (AT2R) signaling within inguinal fat. To examine the molecular mechanisms underlying this effect, mice with hyperactivity of the brain RAS (“sRA” mice, expressing human renin via the synapsin promoter and human angiotensinogen via its own promoter) and littermate controls were chronically infused with vehicle or the AT2R specific agonist, CGP-42112a (CGP, 90 ng/hr, 8 wk, sc). To identify altered signaling pathways, total RNA was isolated from inguinal adipose tissue and transcript abundance was quantitated by RNA-Seq. Overall design: Four groups of mice were studied: controls receiving either a saline infusion (CON) or a specific angiotensin type 2 receptor agonist (CON_CGP), transgenic mice with specific activation of the brain renin-angiotensin receiving either a saline infusion (SRA) or a specific angiotensin type 2 receptor agonist (SRA_CGP). A sample size of N=3-4 was used for each of the four groups.

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Littlejohn NK, Keen HL, Weidemann BJ, Claflin KE, Tobin KV, Markan KR, Park S, Naber MC, Gourronc FA, Pearson NA, Liu X, Morgan DA, Klingelhutz AJ, Potthoff MJ, Rahmouni K, Sigmund CD, Grobe JL