The natriuretic peptide/guanylyl cyclase–A system functions as a stress-responsive regulator of angiogenesis in mice
Michaela Kuhn, … , Jürgen Schrader, Hideo A. Baba
Michaela Kuhn, … , Jürgen Schrader, Hideo A. Baba
Published June 1, 2009
Citation Information: J Clin Invest. 2009;119(7):2019-2030. https://doi.org/10.1172/JCI37430.
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Research Article Vascular biology

The natriuretic peptide/guanylyl cyclase–A system functions as a stress-responsive regulator of angiogenesis in mice

Abstract

Cardiac atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) modulate blood pressure and volume by activation of the receptor guanylyl cyclase–A (GC-A) and subsequent intracellular cGMP formation. Here we report what we believe to be a novel function of these peptides as paracrine regulators of vascular regeneration. In mice with systemic deletion of the GC-A gene, vascular regeneration in response to critical hind limb ischemia was severely impaired. Similar attenuation of ischemic angiogenesis was observed in mice with conditional, endothelial cell–restricted GC-A deletion (here termed EC GC-A KO mice). In contrast, smooth muscle cell–restricted GC-A ablation did not affect ischemic neovascularization. Immunohistochemistry and RT-PCR revealed BNP expression in activated satellite cells within the ischemic muscle, suggesting that local BNP elicits protective endothelial effects. Since within the heart, BNP is mainly induced in cardiomyocytes by mechanical load, we investigated whether the natriuretic peptide/GC-A system also regulates angiogenesis accompanying load-induced cardiac hypertrophy. EC GC-A KO hearts showed diminished angiogenesis, mild fibrosis, and diastolic dysfunction. In vitro BNP/GC-A stimulated proliferation and migration of cultured microvascular endothelia by activating cGMP-dependent protein kinase I and phosphorylating vasodilator-stimulated phosphoprotein and p38 MAPK. We therefore conclude that BNP, produced by activated satellite cells within ischemic skeletal muscle or by cardiomyocytes in response to pressure load, regulates the regeneration of neighboring endothelia via GC-A. This paracrine communication might be critically involved in coordinating muscle regeneration/hypertrophy and angiogenesis.

Authors

Michaela Kuhn, Katharina Völker, Kristine Schwarz, Javier Carbajo-Lozoya, Ulrich Flögel, Christoph Jacoby, Jörg Stypmann, Martin van Eickels, Stepan Gambaryan, Michael Hartmann, Matthias Werner, Thomas Wieland, Jürgen Schrader, Hideo A. Baba

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Figure 2

Ischemia-induced formation of collateral vessels and angiogenesis were impaired in EC GC-A KO mice.

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Ischemia-induced formation of collateral vessels and angiogenesis were i...
(A) MRA depiction of collateral vessel formation (green) 2 weeks after hind limb ischemia (front view). The reference vessel segment on the contralateral side is colored blue. (B) Quantification of MRA images 14 and 35 days after ischemia demonstrated that collateral vessel formation and replenishment of flow in the distal vessels were significantly impaired in EC GC-A KO mice. Collateralization in the ischemic limb is expressed relative to that in the nonischemic limb. *P < 0.05 versus respective control mice (12 mice per each genotype). Two-way ANOVA results showed a significant genotype-treatment interaction; P < 0.05. (C and D) Gastrocnemius muscle tissue was harvested 7 days after ischemia. Sections were stained with the endothelial marker isolectin (brown) and PAS for quantification of capillary density and myocytes (C) and with anti-CD45 antibody (brown) for analysis of inflammation within areas of muscle regeneration (D). Representative muscle sections demonstrate fewer capillaries but similar numbers of infiltrating CD45-positive leukocytes (arrows in D) in the ischemic hind limb of EC GC-A KO mice as compared with respective control littermates. Data are summarized in the bar graphs. *P < 0.05 versus control mice (5 mice per genotype). Original magnification of all histological figures, ×400.