부산대학교 도서관

Introduction: Atrial natriuretic peptide (ANP) is the most potent endogenous activator of the guanylyl cyclase A receptor (GC-A) mediating cardiorenal protective actions by increasing cGMP production. To test the hypothesis that acute decompensated heart failure (ADHF) is associated with increased circulating ANP but with reduced GC-A potency, we developed an ex-vivo precision medicine assay to quantify the potency of circulating ANP in plasma from healthy and ADHF subjects. Further, we assessed the ex-vivo potency of MANP, a novel ANP analog with greater cGMP activation than ANP, also using plasma of healthy and ADHF subjects.Methods: For the potency assay, we engineered HEK293 cells to overexpress human GC-A. Plasma from individual healthy (n=4) and ADHF (n=4) subjects was incubated in the assay and cGMP was assessed. The endogenous ANP derived cGMP was evaluated against the cGMP response of equimolar synthetic ANP (SANP) to assess potency of ANP from each cohort. MANP mediated cGMP generation was also assessed in the assay using healthy and ADHF plasma.Results: Healthy plasma, in which plasma ANP was 26±5 pg/mL, generated 10.3±0.7 pmol/mL of cGMP. SANP added to the assay to mimic endogenous ANP levels in healthy subjects produced 7.8±0.5 pmol/mL of cGMP. ADHF plasma with markedly elevated ANP (350±57pg/mL) generated 23.5±3.1 pmol/mL of cGMP. SANP mimicking plasma ANP in ADHF produced 59.7±13.8 pmol/mL of cGMP, which was greater than cGMP generated from ADHF patient-derived plasma (p<0.05), consistent with reduced potency of endogenous ANP in ADHF. Low treatment dose of MANP (LDMANP; 10M) in healthy plasma increased cGMP to 45±5.5 pmol/ml while high treatment dose (HDMANP; 10M) increased cGMP to 167.1±14.1 pmol/mL. In markedly elevated ANP ADHF plasma, LDMANP increased cGMP to 60.4±9.7 pmol/mL while HDMANP increased cGMP to 200.8±5.4 pmol/mL (p<0.03 for both) demonstrating similar cGMP production by MANP in healthy and ADHF plasma.Conclusions: Employing a novel ex-vivo precision medicine ANP/GC-A/cGMP assay, we conclude that ADHF is characterized by elevated ANP yet with impaired potency in GC-A activation and cGMP generation. MANP overcomes this impairment and serves as a potential efficacious GC-A activating therapeutic in heart failure.