Abstract: TH-PO1125
Micropatterning Enables a Polarized Human Proximal Tubule Tubuloid Model to Study Hypoxia-Induced Injury and Regeneration
Session Information
- Bioengineering: Emerging Research
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Bioengineering
- 400 Bioengineering
Authors
- Klumph, Kaitlyn J., Boehringer Ingelheim Corp USA, Ridgefield, Connecticut, United States
- Gathey, Vasudha, Boehringer Ingelheim Corp USA, Ridgefield, Connecticut, United States
- Hoch, Eitan, Boehringer Ingelheim Corp USA, Ridgefield, Connecticut, United States
- Warren, Curtis, Boehringer Ingelheim Corp USA, Ridgefield, Connecticut, United States
Background
The parenchymal cell of the renal proximal tubule is the Proximal Tubule Epithelial Cell (PTEC). PTECs are columnar epithelial cells, displaying the hallmarks of polarized epithelia, including tight junctions and apical-basal polarity, enabling essential nutrient reabsorption and metabolic waste processing functions. Current in-vitro systems do not recapitulate PTEC physiology, lacking distinct functional, morphological, and transcriptional hallmarks of these cells. This dedifferentiated and non-functional phenotype reduces confidence in the biological relevance of results generated in these systems and hinders the accurate in vitro assessment of PTEC-mediated drug efficacy and toxicity. In this work, we engineered a novel in vitro model that recapitulates physiological tubule morphology and supports hypoxic injury and regeneration paradigms for tight junction-focused screening applications.
Methods
UV photolithography was used to generate micropatterned substrates for spatial definition of PTEC cultures. Matrigel and extracellular matrix protein coatings were optimized to support tube formation. PTEC polarity was determined by measuring gene expression levels by qRT-PCR. High-content imaging was used to assess tubular morphology, apical-basal polarity, and tight junction organization. Injury response markers (e.g. KIM-1) were quantified to assess epithelial stress and atrophy during hypoxic injury. Model validation was performed using HIF-1a targeting siRNA to attenuate hypoxia-induced injury and assess tight junction preservation.
Results
mRNA analysis revealed increased expression of proximal tubule transporters and differentiation markers, including Megalin, ABCB1, ABCC1, OAT1, OAT3, OCT2, and GGT1, compared to non-patterned controls. Micropatterned human PTEC tubuloids contained a central lumen, enriched apical expression of GGT1 and megalin, and OCT2 localized to the basolateral membrane, as determined by 3D imaging. Tight junction proteins ZO1 and claudin displayed continuous apical localization. Disruption of tight junction organization was observed under hypoxic conditions. Knockdown of HIF1a attenuated hypoxia-induced tight junction disruption.
Conclusion
Here, we show that micropatterning enables a polarized human proximal tubule tubuloid model that supports studies of tight junction regulation during hypoxia-induced injury and regeneration.
Funding
- Commercial Support – Boehringer Ingelheim