Figure 4.

Genes identified in the JG cell signature are expressed in JG cells and vessels. (A–D) In situ hybridization in newborn kidneys. (A) Mef2c expression in developing vessel (arrow). (B) Hey1 is expressed in the vessels (arrows) and in glomeruli of the nephrogenic zone. (C) Nr4a1 expression in an afferent arteriole (arrow). (D) Nkx3–1 is expressed in JG cells and afferent arteriole (arrow, G, glomerulus). (E) Immunostaining shows that Nkx3–1 localizes to JG cells and the afferent arteriole in kidney of a captopril-treated adult (arrow). (F–O) Immunostaining in adult kidneys. (F) Nfat is expressed in JG cells (arrow), vessels (short arrows), and some tubules. (G) Creb is expressed in renin-expressing JG cells (outline). (H) Consecutive section of (G) showing renin expression (outline). (I) Notch3 (brown) is expressed in JG cells. (L) Double staining for Notch3 (brown) and renin (purple) in a consecutive section of (I) shows coincidence of expression. Arrows in (I) and (L), JG cells. (J) Costaining for αSMA (purple) and renin (brown) shows expression of αSMA in JG cells as well as afferent arterioles. (K) Renin expression in JG cells for comparison with (J) Arrows in (J) and (K), JG cells. (M, N) Crip1 localizes to renin expressing JG cells as well as some tubules. Arrows in (M) and (N), JG cells. (O) S1P receptor is expressed in JG cells (arrow). (P) RT-PCR of RNA extracted from FACS isolated YFP⁺ cells confirms the expression of Akr1b7 and RBP-J mRNAs. (Q) Chromatin immunoprecipitation shows enrichment of phopspho-Creb at the cAMP responsive element in the renin enhancer in renin-expressing kidney cortex cells but not in skeletal muscle cells, which do not express renin. (R) RBP-J is enriched at the RBP-J element in cells from primary cultures of kidney arterial smooth muscle cells.