The Bradykinin B2 receptor gene is a target of angiotensin II type 1 receptor signaling

J Am Soc Nephrol. 2007 Apr;18(4):1140-9. doi: 10.1681/ASN.2006101127. Epub 2007 Mar 7.

Abstract

Cross-talk between G protein-coupled receptors (GPCR) is known to occur at multiple levels, including receptor heterodimerization and intracellular signaling. This study tested the hypothesis that GPCR cross-talk occurs at the transcriptional level. It was demonstrated that the bradykinin B2 receptor gene (BdkrB2) is a direct transcriptional target of the angiotensin II (AngII) type 1 receptor (AT(1)R) in collecting duct cells. AngII induced BdkrB2 mRNA expression in mouse inner medullary collecting duct cells, and this effect was abrogated by AT(1)R blockade; in contrast, AT(2)R blockade was ineffective. Actinomycin D, an inhibitor of gene transcription, abrogated AngII-stimulated BdkrB2 expression. In addition, AngII produced dosage- and time-dependent increases in B2 receptor protein levels (2.9 +/- 0.4 fold; P < 0.05). AngII stimulated phosphorylation of cAMP response element binding protein (CREB) on Ser-133 and assembly of p-CREB on the BdkrB2 promoter in vivo. Moreover, AngII induced hyperacetylation of BdkrB2 promoter-associated H4 histones, a chromatin modification that is associated with gene activation. Mutations of the CRE abrogated AngII-induced activation of the BdkrB2 promoter. AngII-treated inner medullary collecting duct cells exhibited augmented intracellular calcium signaling in response to bradykinin, confirming the functional relevance of AT(1)-B2 receptor signaling. Finally, studies that were conducted in angiotensin type 1 receptor (Agtr1)-null mice revealed that BdkrB2 mRNA levels were significantly lower in the renal medulla of Agtr1(A)(-/-) and Agtr1(A/B)(-/-) than in Agtr1(+/+) and Agtr1(B)(-/-) mice. It is concluded that BdkrB2 is a downstream target of the AT(1)R-CREB signaling pathway. Transcriptional regulation represents a novel form of cross-talk between GPCR that link the renin-angiotensin and kallikrein-kinin systems.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiotensin II / pharmacology
  • Animals
  • Calcium / metabolism
  • Cells, Cultured
  • Cyclic AMP Response Element-Binding Protein / metabolism
  • Dactinomycin / pharmacology
  • Gene Expression Regulation / drug effects
  • Kidney Tubules, Collecting / metabolism
  • Male
  • Mice
  • Phosphorylation
  • Promoter Regions, Genetic
  • Receptor, Angiotensin, Type 1 / physiology*
  • Receptor, Bradykinin B2 / genetics*
  • Signal Transduction / physiology*
  • Transcriptional Activation

Substances

  • Creb1 protein, mouse
  • Cyclic AMP Response Element-Binding Protein
  • Receptor, Angiotensin, Type 1
  • Receptor, Bradykinin B2
  • Angiotensin II
  • Dactinomycin
  • Calcium