A paternal cardiac lesion induces cardiac adaptation in the offspring

Background: Following cardiac injury, whether the heart is permanently damaged or regenerating, distal organs are subjected to changes in physiological function. It remains largely unknown whether a cardiac lesion can affect gametes and transmit heritable changes to subsequent generations. Here, we report the influence of paternal cardiac injury on the following generation. Methods: We studied the intergenerational influence of neonatal cardiac injury in the mouse. Neonatal male mice were subjected to ventricular cryoinjury, crossed at adulthood, and their sires were compared with litters derived from uninjured male mice. We used echocardiography, histology, and single nuclei RNA-sequencing to thoroughly characterize cardiac morphology, composition, function, and response to cardiac insult. Results: We show that paternal cardiac injury affects the heart morphology of offspring under physiological conditions. Furthermore, in response to the same injury, the F1 generation derived from injured fathers shows better systemic and cardiac recovery, with non-pathological left ventricular enlargement and improved cardiac function. This is accompanied by the activation of the immune system healing program at 3 weeks post-injury, together with enhanced transcription of genes associated with physiological hypertrophy. Conclusions: The memory of a paternal neonatal lesion can be transmitted to offspring and improve their recovery from a cardiac insult. Whole heart processing was performed following the protocol from Cui & Olson with some adaptations. One whole heart per sample was extracted from euthanized male mice 21 days post injury (dpi) with injury performed at 1 day post partum, snap frozen, and stored at -80°C until all samples were available. Two replicates per condition (injured offspring form either uninjured or injured fathers) were used.