DOI: 10.1161/circ.148.suppl_1.15078 ISSN: 0009-7322

Abstract 15078: Atrial and Brain Natriuretic Peptides Expression and Release in Pulmonary Hypertension

Jessie Van Wezenbeek, Aida Llucia-Valldeperas, rowan Smal, Fjodor Bekedam, Frances S De Man
  • Physiology (medical)
  • Cardiology and Cardiovascular Medicine

Introduction: Precapillary pulmonary hypertension (PH) is characterized by progressive overload for the right ventricle and right heart failure (RHF). N-terminal Brain Natriuretic Peptides (NTproBNP) and Atrial Natriuretic Peptides (ANP) are secreted from cardiomyocytes upon stretch. NTproBNP is used as biomarker for RHF. Aim: To study the association between ANP and NTproBNP and pressure overload in blood, right heart tissue and induced pluripotent stem cell derived cardiomyocytes (iPSC-CMs) from PH-patients.

Methods: We analyzed NTproBNP in 344 PH-patients, 9 controls, and in 9 PH-patients before and 6-months after pulmonary endarterectomy (PEA). We measured NPPA and NPPB gene expression on end-stage human right ventricular (RV) and right atrial (RA) samples from 8 PH-patients and 5 controls. In addition, we performed immunofluoresence staining for ANP and BNP on RA tissue (N=4) and RV tissue (N=10) in PH and controls (N=5). iPSC-CMs from 1 male and 1 female PH-patients were stretched for 24h at 1Hz and 10% on the Flexcell FX-6000 system, and NTproBNP release was measured on static and stretched iPSC-CMs. NTproBNP levels were measured through ECLIA.

Results: NTproBNP serum levels were elevated in PH-patients versus controls (918 vs 25 pg/mL, Fig1A). Pressure unloading in CTEPH patients did not result in a decrease in NTproBNP (Fig1B). In RV tissue of PH-patients NPPA expression was upregulated, but NPPB was not (Fig1C). ANP and BNP content was higher in RA and RV tissue of PH-patients (Fig1D-E). Finally, ~5x higher NTproBNP was released from male vs female iPSC-CMs under static conditions and after mechanical stretch (Fig1F).

Conclusions: ANP and BNP showed important differences at gene and protein levels in relation to pressure overload. To confirm current results, further analyses on atrial and ventricular iPSC-CMs will be performed, in addition to mid-range proANP measurements in patients’ blood and iPSC-CMs conditioned medium.

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