Contribution of canonical and non-canonical NO signaling pathways to aortic disease in Marfan syndrome

• Autores: Andrea de la Fuente Alonso
• Directores de la Tesis: Juan Miguel Redondo Moya (dir. tes.), Miguel Campanero Garcia (dir. tes.)
• Lectura: En la Universidad Autónoma de Madrid ( España ) en 2023
• Idioma: inglés
• Número de páginas: 200
• Títulos paralelos:
  • Contribución de las rutas de señalización canónica y no canónica del NO a la enfermedad aórtica en el síndrome de Marfan
• Enlaces
  • Tesis en acceso abierto en: Biblos-e Archivo
• Resumen

  • Thoracic aortic aneurysm (TAA) is generally asymptomatic but often leads to acute aortic dissection (AD), which is associated with high mortality and morbidity. TAA and dissection (TAAD) is a common feature in Marfan syndrome (MFS), a disease caused by mutations in the fibrillin-1 encoding gene (FBN1) and characterized by progressive aortic dilation and risk of AD. There is no pharmacological approach that effectively prevents AD, leaving surgical intervention as the only efficient therapy for TAAD. Therefore, there is an urgent need of therapies that slow down TAA growth and a deeper understanding of the cellular and molecular mechanisms underlying TAAD will undoubtedly facilitate this task. Previous studies in our laboratory have shown that nitric oxide (NO) overproduction contributes to TAA in the Fbn1C1039G/+ and Adamts1+/- mouse models of MFS and syndromic TAA disease, respectively, and that TAA can be reversed by pharmacological inhibition of NO synthase 2 (iNOS) in these mice. However, the molecular mechanisms by which NO mediates TAAD remained poorly understood. Here, we have investigated the NO signaling pathways, their cross-talk and relevance in MFS-associated aortopathy, and we have searched for potential biomarkers and therapeutic targets that may help in the diagnosis, monitoring, and treatment of this disease. We show that overactivation of the canonical NO signaling pathway dysregulates actin cytoskeleton dynamics in MFS vascular smooth muscle cells and induces their phenotypic switch. We found that NO donors induce MFS-like aortopathy in wild-type mice, indicating that NO overproduction suffices to induce aortopathy. Protein nitration, a post-translational modification induced by nitrosative stress, was higher in plasma from MFS patients and mice and in aortic tissue from MFS mice than in control samples, indicating elevated circulating and tissue NO levels. Soluble guanylate cyclase (sGC) and cGMP-dependent protein kinase 1 (PKG1 or PRKG1) were both overactivated in MFS patients and mice and in wild-type mice treated with NO donors, as evidenced by increased cGMP in plasma and pVASP-S239 in aortic tissue, indicating that the canonical NO signaling pathway is overactivated in MFS. Importantly, MFS aortopathy in mice was reverted by pharmacological inhibition of sGC or Prkg1 and by lentiviral Prkg1 silencing. Of note, we also found that the non-canonical NO pathway, mediated by Prkg1 activation via oxidation-induced Prkg1 disulfide bond formation at Cys42, is activated in MFS-associated aortic disease and might also contribute to aortopathy in MFS. High levels of reactive oxygen species (ROS) have been reported in the aortic tissue of MFS patients and we show that antioxidants inhibit Prkg1 disulfide bond formation and regress aortic dilation and medial degeneration in MFS mice. Importantly, the iNos inhibitor 1400W not only regressed aortopathy in MFS mice but also impaired Prkg1 disulfide bond formation, strongly suggesting that uncoupled iNos is a major source of ROS in the aorta of MFS mice. Intriguingly, NO donor administration did not induce aortic disease in Prkg1αC42S mice that harbor a Prkg1 mutation that hampers the formation of the disulfide bond. Taken together, our findings identify potential biomarkers for diagnosis and/or prognosis of MFS patients, urge evaluation of sGC and PRKG1 as therapeutic targets, and suggest the possibility that the canonical and non-canonical Prkg1 activation pathways act in concert to induce aortopathy in MFS