PROJECT SUMMARY/ABSTRACT OVERALL The Jackson Laboratory (JAX) Cellular Senescence Network Mouse Tissue Mapping Center (JAX-Sen) represents a multi-modal interdisciplinary effort that draws upon existing, longstanding aging research programs at JAX, our role as a consortium site of KAPP-Sen, a funded SenNet human Tissue Mapping Center, and JAX’s close collaboration with UConn Health. JAX-Sen is organized around three cores nested in the well-resourced environment for aging research and multi-omics profiling at JAX. JAX-Sen will profile senescent cells in kidney, adipose tissue, placenta, pancreas, heart, and hypothalamus, selected for their clinical relevance to chronic diseases of aging, the domain expertise of the JAX-Sen leadership team in the biology of these tissues, and the overlap of four of the tissues with KAPP-Sen. We will leverage cutting-edge mouse resources including the Diversity Outbred, which offers unparalleled genetic diversity for modelling a range of molecular senescence phenotypes, and new inbred (C57BL/6J) transgenic mice that express p16 and p21 driven fluorescent tags to allow visualization enrichment for specific senescent cell subsets. The Biological Analysis Core will apply a multitude of analytical modalities to selected tissues (bulk and single cell and single nucleus RNAseq, Visium spatial transcriptomics, multiplexed antibody-based imaging, multiplexFISH, imaging mass spectrometry including lipidomics, metabolomics, proteomics, 3D tissue reconstruction from serial sections), and will re- evaluate these technologies throughout the project period to ensure our approaches align with those of other centers and that we maximally benefit from the technology development efforts in SenNet. These profiling activities will yield subcellular resolution of biomolecular content in senescent cells not possible with human samples, along with an expanded set of senescent cell biomarkers. The Data Analysis Core will combine robust computational capability with scalable and reproducible scientific workflows to develop and implement Network- wide open data and metadata standards. The Data Analysis Core will benefit from JAX’s unique mouse research resources to establish the diversity of senescence by integrating with expression quantitative trait locus and protein quantitative trait locus data in DO mice and JAX bioinformatics resources, e.g., Mouse Genome Informatics, Mouse Phenome Database, Monarch Initiative. The integrative mining of JAX-Sen data will lead to novel methods for multi-modal 3D map reconstruction from imaging data and will yield an important resource for SenNet interpretation and enrichment of human senescent cell data. Finally, the Administrative Core will provide strong oversight of project progress and nurture a culture of collaborative, dynamic scientific exchange within JAX-Sen. It will also maximize JAX-Sen’s engagement in the consortium through collaborative activities that will help optimize data generation activities and create new research synergies. In so doing, JAX-Sen will help achieve the goal of SenNet to generate a unprecedented atlas of mouse senescent cells and new biomarkers of senescence for human analysis and therapeutic application.

PROJECT NARRATIVE OVERALL Senescence refers to the loss of cell function with aging and is associated with many chronic diseases of aging, but the mechanisms by which this happens is poorly understood at a molecular level. The proposed project seeks to advance knowledge of the molecular features of senescence through cutting-edge profiling techniques and mouse resources that will complement efforts at the human level to map senescence in human cells and tissues.