ß1-adrenergic receptor and sphingosine-1-phosphate receptor 1 (S1PR1) reciprocal downregulation influences cardiac hypertrophic response and progression to heart failure: protective role of S1PR1 cardiac gene therapy.

BACKGROUND: The sphingosine-1-phosphate receptor 1 (S1PR1) and ß1-adrenergic receptor (ß1AR) are G-protein-coupled receptors expressed in the heart. These 2 receptors have opposing actions on adenylyl cyclase because of differential G-protein coupling. Importantly, both of these receptors can be regulated by the actions of G-protein-coupled receptor kinase-2, which triggers desensitization and downregulation processes. Although classic signaling paradigms suggest that simultaneous activation of ß1ARs and S1PR1s in a myocyte would simply result in opposing action on cAMP production, in this report we have uncovered a direct interaction between these 2 receptors, with regulatory involvement of G-protein-coupled receptor kinase-2. METHODS AND RESULTS: In HEK (human embryonic kidney) 293 cells overexpressing both ß1AR and S1PR1, we demonstrated that ß1AR downregulation can occur after stimulation with sphingosine-1-phosphate (an S1PR1 agonist), whereas S1PR1 downregulation can be triggered by isoproterenol (a ß-adrenergic receptor agonist) treatment. This cross talk between these 2 distinct G-protein-coupled receptors appears to have physiological significance, because they interact and show reciprocal regulation in mouse hearts undergoing chronic ß-adrenergic receptor stimulation and in a rat model of postischemic heart failure. CONCLUSIONS: We demonstrate that restoration of cardiac plasma membrane levels of S1PR1 produces beneficial effects that counterbalance the deleterious ß1AR overstimulation in heart failure.

Percutaneous treatment of patients with heart diseases: selection, guidance and follow-up. A review.

Aortic stenosis and mitral regurgitation, patent foramen ovale, interatrial septal defect, atrial fibrillation and perivalvular leak, are now amenable to percutaneous treatment. These percutaneous procedures require the use of Transthoracic (TTE), Transesophageal (TEE) and/or Intracardiac echocardiography (ICE). This paper provides an overview of the different percutaneous interventions, trying to provide a systematic and comprehensive approach for selection, guidance and follow-up of patients undergoing these procedures, illustrating the key role of 2D echocardiography.

Percutaneous treatment of a aorto-caval fistula in a old high risk patient.

BACKGROUND: To remark the feasibility of endovascular treatment of an aorto-caval fistula in a old high risk patient with "hostile" abdomen for previous surgeries. METHODS: In September 2009 a 81-years-old patient was admitted in emergency at our department because of abdominal pain and massive oedema of the lower extremities associated to dyspnoea (New York Heart Association (NYHA) functional class III). A CT scan showed an aorto-caval fistula involving the abdominal aorta below the renal arteries. This abnormal communication was likely due to the previous abdominal surgeries, was complicated by occlusion of the inferior vena cava at the diaphragm and was responsible for the massive oedema of the lower extremities. Because of unstable conditions and hostile abdomen the patient was considered unfit for conventional surgery and an endovascular approach was planned. After unsuccessful attempt by positioning of an Amplatzer vascular ring into the fistula, a Medtronic covered stent-grafts were implanted from the renal arteries to the both common iliac arteries. The patient had an impressive improvement characterized by a 18 Kg weight loss and a complete restoration of the functional capacity (from NYHA class III to NYHA class I) associated to a complete resolution of the lower extremities oedema as confirmed at the a month-CT-scan. CONCLUSION: Endovascular surgery of aorto-caval fistula represents a good option in alternative to conventional surgery mostly in old high risk patient.