Stability and Robustness of a Generalized Pump-Leak Model for Epithelial Vesicles
by Kerry Tarrant, Alan R. Kay, Zahra Aminzare
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Cells counter osmotic water influx driven by impermeant intracellular molecules to maintain stable volume and function. Epithelial tissues achieve this through ion pumps and channels. Classical pump–leak equations (PLEs) describe these processes in single cells but cannot capture epithelial systems surrounding fluid-filled lumens. We develop a 2-compartment PLE model coupling an epithelial cell and lumen and derive analytical stationary solutions. Stability and robustness analyses identify key determinants of ion and volume homeostasis. For epithelial systems, we find asymmetry between apical and basolateral membrane potentials and show that apical pump placement with insufficient potassium recycling can lead to luminal volume expansion.
Image Description: A comprehensive mathematical framework that reveals how pump localization and membrane properties shape epithelial function and dysfunction.
