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

Adult mammalian hearts exhibit minimal regenerative capacity, limiting most cardiac repair. In contrast, neonatal mice retain the ability to regenerate cardiac tissue for a brief period after birth. Although single-cell and single-nucleus RNA sequencing (sc/snRNA-seq) has deepened our understanding of this regenerative window, existing datasets remain dispersed across studies, hindering integrative and comparative analyses. To address this gap, we developed the Mouse CArdiac REgeneration DataBase (MCAREDB), the first freely accessible, web-based resource that consolidates and visualizes sc/snRNA-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 regenerative versus non-regenerative stages and sham versus myocardial infarction. Core features include an interactive genome browser with epigenetic tracks, comparative gene expression visualization, spatial transcriptomics interface, pathway enrichment analysis, and bulk data download options. 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.