Evaluation of Epithelial Integrity in Human Precision‐Cut Kidney Slices

Renal epithelial cells are pivotal in renal regulation of body fluid and electrolyte balance. While rodent models are commonly used to study renal physiology, species-specific differences limit their translational relevance. To bridge this gap, we used human precision-cut kidney slices (PCKS), an ex vivo tissue-based model that maintains native tissue architecture and cellular diversity. This study had two aims: (1) to determine whether PCKS preserve short-term aquaporin-2 (AQP2) trafficking in response to desmopressin (dDAVP), and (2) to assess whether cortical PCKS maintain epithelial integrity during 24-48 h incubation. In medullary PCKS, 30 min dDAVP stimulation resulted in accumulation of AQP2 at the apical membrane, indicating preserved signaling. In cortical PCKS, AQP2 already showed substantial apical localization under baseline conditions, and no additional redistribution was detected after dDAVP stimulation. In cortical PCKS, incubation for 24 h and 48 h led to mislocalization of AQP2, the Na/K-ATPase and uromodulin, and to altered localization of the adhesion proteins E-cadherin and N-cadherin and the tight junction protein ZO-1 with a shift towards apical localization, indicating loss of epithelial integrity. Thus, short-term signaling was preserved at 30 min, whereas epithelial transport and adhesion proteins became mislocalized after 24-48 h in human PCKS.