Kidney Week

Abstract: PO0337

Human Kidney Proximal Tubule-on-a-Chip to Model Acute Hypoxic Tubular Injury in AKI

Session Information

• AKI: Mechanisms of Injury
  November 04, 2021 | Location: On-Demand, Virtual Only
  Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

• 103 AKI: Mechanisms

Authors

• Çam, Sefa Burak, Hacettepe University, Faculty of Medicine, Dept. of Histology and Embryology, Ankara, Ankara, Turkey

Sefa Burak Çam, DrMed

• Altun, Bulent, Hacettepe University Faculty of Medicine Dept. of Nephrology, Ankara, Turkey

Bulent Altun,

• Korkusuz, Petek, Hacettepe University, Faculty of Medicine, Dept. of Histology and Embryology, Ankara, Ankara, Turkey

Petek Korkusuz,

Background

Acute kidney injury (AKI), with high mortality, is a serious public health issue. Hypoxic injury in proximal tubules (PT) sets the course of ischemic AKI. Microfluidic organ-on-a-chip technology mimics 3D kidney structures in vitro. We asked if AKI-related hypoxic injury may be modelled on a microfluidic 3D PT system comprising human epithelial cells and extracellular matrix (ECM).

Methods

A 2-lane microfluidic device without membrane was set to model 3D PT. Human PT epithelial cells (HK-2) were cultured with K-SFM media against ECM. Hypoxic conditions was designed as 1% O₂, 5% CO₂ and 94% N₂ in humidified multi-gas incubator. Tubular injury was assessed by immunofluorescence (IF) labelling and barrier integrity assay for 48 hours.

Results

Proximal tubules formed successfully at normoxia by phase contrast microscope. Hypoxia increased tubular leakage by 6-fold for 20 kDa (Fig. 1B, p=0.001) and 4-fold for 155 kDa molecules (Fig. 1C, p=0.001) compared to normoxia on 24h. Leakage for 20 kDa molecules remained 2-fold high compared to normoxia on 48h (Fig. 1B, p=0.001). Leakage for 155 kDa molecules restored with similar data as normoxia (Fig. 1C, p=0.268) on 48h. IF data supported impairment of the barrier.

Conclusion

In this study, a novel human kidney PT-on-a-chip was designed and successfully optimized for real time-modelling acute hypoxic tubular injury in AKI. Our human PT-on-a-chip mimics reversible tubule injury of clinical AKI more accurately compared to severe animal tubular damage models and presents a reliable and adjustable platform for testing potential therapeutic interventions.

Hacettepe University Research Fund financially supported this work (TSA-2020-18383).

Figure 1. Representative micrographs (A) and quantitative analysis (B, C) of barrier permeability index assay. 20 kDa-Dextran-FITC (A, 1^st and 2^nd column, B) and 155 kDa-Dextran-TRITC (A, 3^rd and 4^th columns, C) fluorophore-tagged molecules were utilized.

Funding

• Government Support – Non-U.S.