High glucose treatment promotes extracellular matrix proteome remodeling in Müller glial cells

The underlying pathomechanisms in diabetic retinopathy (DR) remains incompletely understood. The aim of this study was to add to the current knowledge about the particular role of retina Müller glial cells (RMG) in the initial processes of DR. Applying a mass spectrometric workflow, we investigated proteome changes of primary porcine RMG under short term diabetic cell culture treatment. We revealed global changes in RMG proteome indicated by a fundamental remodeling of ECM and focal adhesion processes which potentially leads to destabilization of the retinal inner limiting membrane. This is in line with our previous findings of a disrupted ILM in the retinae of a diabetic pig model and suggests an involvement of RMG in this process. Additionally, employing porcine organotypic retinal explant cultures, we demonstrate a specific decrease of RMG-associated SPP1 expression as a result of osmotic challenge induced by high glucose levels. We assume a loss of neuroprotective potential administrated by RMG and subsequent acceleration of neurodegenerative processes in DR.