Aims Peripartum cardiomyopathy (PPCM) is a life-threatening heart disease occurring in previously heart-healthy women. A common pathomechanism in PPCM involves the angiostatic 16 kDa-prolactin (16 kDa-PRL) fragment, which via NF-κB-mediated up-regulation of microRNA-(miR)-146a induces vascular damage and heart failure. We analyse whether the plasminogen activator inhibitor-1 (PAI-1) is involved in the pathophysiology of PPCM. Methods and results In healthy age-matched postpartum women (PP-Ctrl, n = 53, left ventricular ejection fraction, LVEF > 55%), PAI-1 plasma levels were within the normal range (21 ± 10 ng/mL), but significantly elevated (64 ± 38 ng/mL, P Conclusion In PPCM patients, circulating and cardiac PAI-1 expression are up-regulated. While circulating PAI-1 may add 16 kDa-PRL to induce vascular impairment via the uPAR/NF-κB/miR-146a pathway, experimental data suggest that cardiac PAI-1 expression seems to protect the PPCM heart from fibrosis. Thus, measuring circulating PAI-1 and miR-146a, together with an uPAR/NF-κB-activity assay could be developed into a specific diagnostic marker assay for PPCM, but unrestricted reduction of PAI-1 for therapy may not be advised.
