Angiotensin II elicits robust calcium oscillations coordinated within juxtaglomerular cell clusters to suppress renin secretion.

Background: Juxtaglomerular (JG) cells are sensors that control blood pressure and fluid-electrolyte homeostasis. In response to a decrease in perfusion pressure or changes in the composition and/or volume of the extracellular fluid, JG cells release renin, which initiates an enzymatic cascade that culminates in the production of angiotensin II (Ang II), a potent vasoconstrictor that restores blood pressure and fluid homeostasis. In turn, Ang II exerts a negative feedback on renin release, thus preventing excess circulating renin and the development of hypertension.

Tcf21 as a founder transcription factor in specifying Foxd1 cells to the juxtaglomerular cell lineage.

Renin is crucial for blood pressure regulation and electrolyte balance, and its expressing cells arise from Forkhead box D1-positive (Foxd1) stromal progenitors. However, factors guiding these progenitors toward renin-secreting cell fate remain unclear. Tcf21, a basic helix-loop-helix (bHLH) transcription factor, is essential in kidney development.

An efficient inducible model for the control of gene expression in renin cells.

Fate mapping and genetic manipulation of renin cells have relied on either noninducible lines that can introduce the developmental effects of gene deletion or bacterial artificial chromosome transgene-based inducible models that may be prone to spurious and/or ectopic gene expression. To circumvent these problems, we generated an inducible mouse model in which is under the control of the endogenous gene, an independent marker of renin cells that is expressed in a few extrarenal tissues. We confirmed the proper expression of using ; mice in which Akr1b7/renin cells become green fluorescent protein (GFP) upon tamoxifen administration.

Inhibition of Renin Expression Is Regulated by an Epigenetic Switch From an Active to a Poised State.

Background: Renin-expressing cells are myoendocrine cells crucial for the maintenance of homeostasis. Renin is regulated by cAMP, p300 (histone acetyltransferase p300)/CBP (CREB-binding protein), and Brd4 (bromodomain-containing protein 4) proteins and associated pathways. However, the specific regulatory changes that occur following inhibition of these pathways are not clear.