Substrate stiffness and pressure alter retinal Müller glia response and extracellular matrix production

Background

The retina is highly influenced by its mechanical environment, with Müller glia (MG) acting as key mechanosensors and extracellular matrix (ECM) producers. This study examined MG responses to substrate stiffness and high pressure (HP), and whether TGF-β1 modulation could mitigate these effects.

Methods

Primary MG from adult rat retinas were cultured on glass (Young’s modulus E’=∼1 gigapascal (GPa)) and polyacrylamide gels (10 kPa and 100 kPa). MG were exposed to atmospheric and 70 mmHg (HP) conditions, with TGF-β1 pharmacologically blocked.

Results

On glass and 100 kPa gels, MG survival, cell area, and ECM deposition (collagen I, IV, and fibronectin) increased, with cells adopting a fusiform shape and more dedifferentiated state. Under HP, survival decreased on stiffer substrates, though cell area and morphology remained unchanged. HP increased ECM deposition, which was reduced by TGF-β1 inhibition.

Conclusions

Our findings suggest that MG response to mechanical stress alter their survival and cell area, and increases ECM secretion, highlighting TGF-β1 as a potential therapeutic target.