Mouse Cardiac Regeneration Database (MCAREDB): a single-cell atlas of neonatal cardiac regeneration in mice

Background The adult mammalian heart exhibits minimal regenerative capacity, rendering most major cardiac injuries irreversible. In contrast, neonatal mice retain the ability to regenerate cardiac tissue for a brief period after birth. Although single-cell RNA sequencing (scRNA-seq) has deepened our understanding of this regenerative window, existing datasets remain dispersed across studies, hindering integrative and comparative analyses. Methods and Results To address this gap, we developed the Mouse CArdiac REgeneration DataBase (MCAREDB), a freely accessible, web-based resource that consolidates scRNA-seq datasets from multiple mouse cardiac regeneration studies. MCAREDB enables cell type-specific exploration of differential gene expression and pathway enrichment across key biological contexts, including neonatal versus postnatal stages and sham versus myocardial infarction surgeries. Core features include an interactive genome browser with epigenetic tracks, comparative gene expression visualization, pathway enrichment analysis, and bulk data download options. Conclusion By integrating diverse datasets into a unified and interactive framework, MCAREDB lowers technical barriers to data exploration and accelerates hypothesis generation in cardiac regeneration research. The resource is freely available at https://MCAREDB.org:3305 .