LAUSR

Tissue Homeostasis To stay healthy, tissues must maintain proper ratios of their constituent cell types. Adler et al. developed a framework for describing a range of circuit topologies between two cell types where each secretes a signal that is sensed by the other. Without regulation, both cell types grow to a stable cell number close to the carrying capacity of the system. To maintain one cell type at lower numbers, production of the signal that it senses could be down-regulated by the signal that it secretes, or it could remove its cognate signal by endocytosis. Endocytosis allows a faster response and is more robust to parameter variation. The concepts also apply to three- and four-cell circuits and provide a basis for understanding tissue homeostasis. Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1714377115 (2018).