1. Exploration of cardiometabolic and developmental significance of angiotensinogen expression by cells expressing the leptin receptor or agouti-related peptide
- Author
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Justin L. Grobe, Lisa L. Morselli, Guorui Deng, Nicole A Pearson, Kirthikaa Balapattabi, Vanessa Oliveira, Katherine N. Gibson-Corley, Matthew J. Potthoff, Kristin E. Claflin, Curt D. Sigmund, Sarah A. Sapouckey, Chetan N Patil, and Javier Gomez
- Subjects
Male ,0301 basic medicine ,medicine.medical_specialty ,Physiology ,Angiotensinogen ,030204 cardiovascular system & hematology ,Biology ,Kidney ,03 medical and health sciences ,Paracrine signalling ,0302 clinical medicine ,Physiology (medical) ,Internal medicine ,Adrenal Glands ,Paracrine Communication ,parasitic diseases ,medicine ,Animals ,Agouti-Related Protein ,Autocrine signalling ,Receptor ,Serum Albumin ,Mice, Knockout ,Leptin receptor ,Adrenal gland ,Myocardium ,Leptin ,digestive, oral, and skin physiology ,Arcuate Nucleus of Hypothalamus ,Gene Expression Regulation, Developmental ,Angiotensin II ,Autocrine Communication ,030104 developmental biology ,Endocrinology ,medicine.anatomical_structure ,Receptors, Leptin ,Female ,Energy Metabolism ,Agouti-related peptide ,hormones, hormone substitutes, and hormone antagonists ,Research Article ,Signal Transduction - Abstract
Angiotensin II (ANG II) Agtr1a receptor (AT1A) is expressed in cells of the arcuate nucleus of the hypothalamus that express the leptin receptor ( Lepr) and agouti-related peptide ( Agrp). Agtr1a expression in these cells is required to stimulate resting energy expenditure in response to leptin and high-fat diets (HFDs), but the mechanism activating AT1Asignaling by leptin remains unclear. To probe the role of local paracrine/autocrine ANG II generation and signaling in this mechanism, we bred mice harboring a conditional allele for angiotensinogen ( Agt, encoding AGT) with mice expressing Cre-recombinase via the Lepr or Agrp promoters to cause cell-specific deletions of Agt ( AgtLepr-KOand AgtAgrp-KOmice, respectively). AgtLepr-KOmice were phenotypically normal, arguing against a paracrine/autocrine AGT signaling mechanism for metabolic control. In contrast, AgtAgrp-KOmice exhibited reduced preweaning survival, and surviving adults exhibited altered renal structure and steroid flux, paralleling previous reports of animals with whole body Agt deficiency or Agt disruption in albumin ( Alb)-expressing cells (thought to cause liver-specific disruption). Surprisingly, adult AgtAgrp-KOmice exhibited normal circulating AGT protein and hepatic Agt mRNA expression but reduced Agt mRNA expression in adrenal glands. Reanalysis of RNA-sequencing data sets describing transcriptomes of normal adrenal glands suggests that Agrp and Alb are both expressed in this tissue, and fluorescent reporter gene expression confirms Cre activity in adrenal gland of both Agrp-Cre and Alb-Cre mice. These findings lead to the iconoclastic conclusion that extrahepatic (i.e., adrenal) expression of Agt is critically required for normal renal development and survival.
- Published
- 2020