RT Journal Article SR Electronic T1 204 The cardiac hepcidin/ferroportin axis is essntial for cardiac iron homeostasis and function JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP A137 OP A137 DO 10.1136/heartjnl-2017-311726.202 VO 103 IS Suppl 5 A1 Samira Lakhal-Littleton A1 Magda Wolna A1 Yu-Jin Chung A1 Helen Christian A1 Lisa Heather A1 Marcella Brescia A1 Vicky Ball A1 Rebeca Diaz A1 Ana Santos A1 Daniel Biggs A1 Kieran Clarke A1 Benjamin Davies A1 Peter Robbins YR 2017 UL http://heart.bmj.com/content/103/Suppl_5/A137.2.abstract AB Background Iron deficiency and chronic heart failure are two of the most common disorders worldwide. Recent evidence has demonstrated that they are linked. Moreover, clinical trials have demonstrated the benefits of intravenous iron supplementation in chronic heart failure. However, cardiac iron homeostasis remains unexplored. Recently, our laboratory demonstrated that cardiac-specific deletion of the ?iron-?exporting protein ferroportin causes fatal cardiac iron overload1. Ferroportin is known to be downregulated by the liver-derived hormone hepcidin. But hepcidin is also found in cardiomyocytes where its function remains unknown.Methods and results To explore the function of cardiomyocyte hepcidin, we generated mice with a cardiomyocyte-specific deletion of hepcidin or with a cardiomyocyte-specific knock-in of a hepcidin-resistant ferroportin mutant. While both models maintain normal systemic iron homeostasis, they nevertheless develop cardiomyocyte metabolic dysfunction followed by fatal contractile impairment as a consequence of cardiomyocyte iron deficiency. Intravenous iron supplementation prevents both the development of metabolic dysfunction and contractile impairment.2 Conclusions We conclude that regulation of iron export from cardiomyocytes by the cardiac hepcidin/ferroportin axis is essential to cardiomyocyte iron homeostasis and that its disruption leads to fatal cardiac dysfunction, even against a background of intact systemic iron homeostasis. These findings raise the possibility that hepcidin agonists/antagonists developed for disorders of systemic iron homeostasis could also modulate cardiac function.References 1. Lakhal-Littletonet al. An essential cell-autonomous role for hepcidin in cardiac iron homeostasis. Elife. 2016Nov 29;5. pii: e19804. doi: 10.7554/eLife.19804.2. Lakhal-Littletonet al. Cardiac ferroportin regulates cellular iron homeostasis and is important for cardiac function. PNAS, 2015;112, 3164–3169.