How a kidney microenvironment atlas can advance kidney tissue engineering.

Despite advances in cellular knowledge through kidney cell and protein atlases, tissue-engineered kidney models remain functionally incomplete. A major gap lies in our limited knowledge of the extracellular matrix (ECM) and the mechanical properties of the kidney microenvironment - key factors that influence cell behavior, differentiation, and function. Current data, that are often based on animal models, lack human-specific, segment-level, and disease-related insights regarding the ECM and mechanical properties. To close this gap, we propose the development of a segment-specific Kidney Microenvironment Atlas: a comprehensive resource that details ECM composition, mechanical characteristics, disease-associated changes, interspecies differences, and measurement techniques. This atlas will inform the creation of more physiologically accurate in vitro models, and thus enhance disease modeling, drug testing, and future clinical applications.