# Regulation of corneal stromal cell behavior by modulating curvature using a hydraulically-controlled organ chip array

## TL;DR

A new organ chip array shows how corneal curvature changes cause cellular and molecular changes linked to corneal diseases like keratoconus.

## Contribution

The study introduces a hydraulically-controlled organ chip array to investigate curvature-induced mechanobiological effects on corneal cells.

## Key findings

- Curvature-induced stress triggers fibrotic activation in keratocytes with ALDH3A1 downregulation and α-SMA upregulation.
- Fibroblasts align orthogonally under curvature stress, mimicking native corneal structure without chemical signals.
- RNA sequencing reveals TGF-β/SMAD and ECM pathways activated by geometric stress, mirroring keratoconus pathology.

## Abstract

Corneal curvature abnormalities drive ectatic diseases, yet their mechanobiological effects on stromal cells remain poorly understood. We developed a hydraulically controlled curvature array chip recapitulating disease-relevant geometries (33-56D) to investigate how keratocytes, fibroblasts, and myofibroblasts respond to geometric stress. Curvature-induced mechanical stress triggered dramatic cellular remodeling keratocytes exhibited significant proliferative enhancement and phenotypic transformation with ALDH3A1 downregulation and α-SMA upregulation, indicating mechanobiologically driven fibrotic activation. Fibroblasts developed curvature-dependent orthogonal alignment that recapitulates native corneal lamellar organization without chemical cues, while myofibroblasts showed enhanced contractile responses. RNA sequencing revealed that geometric stress activates identical molecular pathways dysregulated in keratoconus, including TGF-β/SMAD signaling, ECM-receptor interactions, and inflammatory cascades. Extracellular matrix remodeling was cell-type specific, with keratocytes showing homeostatic control loss, fibroblasts promoting matrix deposition, and myofibroblasts driving degradation. These findings establish curvature-induced mechanotransduction as the fundamental driver of corneal ectatic disease progression, repositioning geometric stress from a passive consequence to an active determinant of pathology.

Kim and colleagues propose a curvature-controlled organ chip array to monitor how geometric stress drives corneal disease progression. The authors show that geometric stress triggers cellular changes that replicate keratoconus pathology and they identify dysregulated molecular pathways for potential therapeutic approaches.