Meteorin-like controls metabolic adaptations and physiological myocardial remodeling in pregnancy and lactation.

Introduction: The gestation-lactation period involves profound but reversible cardiac remodeling. Meteorin-like (Metrnl) has emerged as a regulator of cardiac metabolism in pathological settings, but its role in physiological reproductive adaptations remains unclear. This study aimed to define the contribution of Metrnl to cardiometabolic remodeling during the reproductive cycle. Methods: Circulating Metrnl levels were assessed in murine and human late-pregnancy models. Wild-type (wt) and Metrnl knockout ( Results: Late pregnancy increased circulating METRNL, largely of placental origin. In wt mice, cardiac hypertrophy induced by pregnancy was further enhanced during lactation and fully reversed after weaning. These changes were associated with increased fatty acid metabolism during gestation and its suppression during lactation, paralleling cardiac Metrnl expression and normalizing after weaning. By contrast, Conclusion: Metrnl is essential for physiological cardiometabolic adaptation during the reproductive cycle, coordinating metabolic remodeling to ensure appropriate and reversible cardiac changes.