Prenatal dexamethasone and postnatal high-fat diet have a synergistic effect of elevating blood pressure through a distinct programming mechanism of systemic and adipose renin–angiotensin systems

Abstract

BACKGROUND: Hypertension may result from high-fat (HF) diet induced-obesity and overexposure to glucocorticoids in utero. Recent studies demonstrated the potent contribution of adipose tissue's renin-angiotensin system (RAS) to systemic RAS, which plays a key role in regulating blood pressure (BP). In this study, we investigated the effects of prenatal dexamethasone (DEX) exposure and postnatal HF diet on RAS of adipose tissue. METHODS: RAS and BP of 6-month old rats exposed to prenatal DEX and/or postnatal HF diet were examined. RESULTS: Prenatal DEX plus postnatal HF exerted a synergistic effect on systolic BP. Prenatal DEX exposure suppressed plasma angiotensin (ANG) I and ANG II, whereas postnatal HF suppressed plasma ANG-(1-7) level. Prenatal DEX increased prorenin receptor and renin levels, but suppressed angiotensinogen (AGT) and angiotensin-converting-enzyme 1 (ACE1) mRNA expressions in adipose tissue. Postnatal HF increased AGT mRNA expression, but suppressed prorenin receptor, renin, ACE2, ANG II type 2 receptor (AT2R), and Mas receptor (MasR) mRNA expression levels. CONCLUSIONS: Prenatal GC exposure altered the ACE1/ANG II/ANG II type 1 receptor (AT1R) axis, whereas postnatal HF negatively impacted the ACE2/ANG-(1-7)/MasR axis. Prenatal DEX exposure and postnatal HF synergistically elevated BP through a distinct programming mechanism of systemic and adipose RAS. Adipose RAS might be a target for precise hypertension treatment.