Developing a Model of Urosepsis Using a Kidney and Lung-on-a-Chip System

Background: The emergence of organ-on-a-chip models has revolutionized preclinical investigations, yet a crucial gap persists in the absence of an in vitro model for lung injury resulting from urosepsis. To address this, we engineered a novel 3D microfluidic chip capable of mimicking urosepsis within the kidney, lung, and vascular microenvironments. Methods: Our kidney and lung-on-a-chip platforms were designed with five channels, facilitating co-culture of HK-2 (human kidney proximal tubule epithelial) cells, HUVEC (human umbilical vein endothelial) cells, lung fibroblasts, and BEAS-2B (immortalized bronchial epithelial cell) cells. Confocal imaging was employed to assess tubular formation induced by shear stress. Urosepsis was simulated by administering LPS (lipopolysaccharide) to HK-2 cells over a 3-day period. Subsequent to LPS treatment, cell injury was evaluated, including cell-to-cell distance measurement via CK8 staining, cadherin expression analysis in HUVEC cells to gauge cell adhesion, and assessment of cell permeability and protein expression using FITC and dot blot analysis. The observation of Beas2B cell death due to LPS was inconclusive in our findings. Results: Application of shear stress during cell culture led to increased cell proliferation and the formation of well-defined tubular structures. Following induction of urosepsis via LPS exposure to HK-2 cells, we observed a dose-dependent increase in FITC permeability, compromised cell integrity. This was concomitant with an elevation in cell-to-cell distance among HK-2 cells and a reduction in cadherin expression in HUVEC cells, suggesting rapid dissemination of LPS to lung cells. Urosepsis-induced lung injury was associated with heightened expression of IL-6 and NGAL. But, The observation of Beas2B cell death due to LPS was inconclusive in our findings Conclusion: Utilizing a kidney and lung-on-a-chip system, we developed a model for urosepsis, enabling the sequential observation of tubular damage, vascular impairment, and the effects of urosepsis on bronchial cells. This approach enhances our comprehension of urosepsis-related lung injury, thereby providing a promising platform for future therapeutic investigations.