• DOI:10.1161/CIRCRESAHA.117.311194
• Corpus ID: 46858443

Deficiency of Natriuretic Peptide Receptor 2 Promotes Bicuspid Aortic Valves, Aortic Valve Disease, Left Ventricular Dysfunction, and Ascending Aortic Dilatations in Mice

@article{Blaser2017DeficiencyON,
  title={Deficiency of Natriuretic Peptide Receptor 2 Promotes Bicuspid Aortic Valves, Aortic Valve Disease, Left Ventricular Dysfunction, and Ascending Aortic Dilatations in Mice},
  author={Mark C. Blaser and Kuiru Wei and Rachel L. E. Adams and Yu-Qing Zhou and Laura-lee Caruso and Zahra Mirzaei and Alan Y L Lam and R Tam and Hangjun Zhang and Scott P. Heximer and R. Mark Henkelman and Craig A. Simmons},
  journal={Circulation Research},
  year={2017},
  volume={122},
  pages={405–416}
}

• M. Blaser, Kuiru Wei, +9 authors C. Simmons
• Published 22 December 2017
• Biology, Medicine, Engineering
• Circulation Research

Rationale: Aortic valve disease is a cell-mediated process without effective pharmacotherapy. CNP (C-type natriuretic peptide) inhibits myofibrogenesis and osteogenesis of cultured valve interstitial cells and is downregulated in stenotic aortic valves. However, it is unknown whether CNP signaling regulates aortic valve health in vivo. Objective: The aim of this study is to determine whether a deficient CNP signaling axis in mice causes accelerated progression of aortic valve disease. Methods and Results: In cultured porcine valve interstitial cells, CNP inhibited pathological differentiation via the guanylate cyclase NPR2 (natriuretic peptide receptor 2) and not the G-protein–coupled clearance receptor NPR3 (natriuretic peptide receptor 3). We used Npr2+/− and Npr2+/−;Ldlr−/− mice and wild-type littermate controls to examine the valvular effects of deficient CNP/NPR2 signaling in vivo, in the context of both moderate and advanced aortic valve disease. Myofibrogenesis in cultured Npr2+/− fibroblasts was insensitive to CNP treatment, whereas aged Npr2+/− and Npr2+/−;Ldlr−/− mice developed cardiac dysfunction and ventricular fibrosis. Aortic valve function was significantly impaired in Npr2+/− and Npr2+/−;Ldlr−/− mice versus wild-type littermates, with increased valve thickening, myofibrogenesis, osteogenesis, proteoglycan synthesis, collagen accumulation, and calcification. 9.4% of mice heterozygous for Npr2 had congenital bicuspid aortic valves, with worse aortic valve function, fibrosis, and calcification than those Npr2+/− with typical tricuspid aortic valves or all wild-type littermate controls. Moreover, cGK (cGMP-dependent protein kinase) activity was downregulated in Npr2+/− valves, and CNP triggered synthesis of cGMP and activation of cGK1 (cGMP-dependent protein kinase 1) in cultured porcine valve interstitial cells. Finally, aged Npr2+/−;Ldlr−/− mice developed dilatation of the ascending aortic, with greater aneurysmal progression in Npr2+/− mice with bicuspid aortic valves than those with tricuspid valves. Conclusions: Our data establish CNP/NPR2 signaling as a novel regulator of aortic valve development and disease and elucidate the therapeutic potential of targeting this pathway to arrest disease progression.