Evaluating the properties of extracellular vesicles that are affected by diabetic keratopathy.




Hefley, Brenna
Shrestha, Pawan
Ma, Jian-Xing
Karamichos, Dimitrios


Journal Title

Journal ISSN

Volume Title



Purpose: Extracellular Vesicles (EVs) are small-sphere like structures that are released from cells. They play a role in cell-cell communication by passing genetic information from one cell to another. EVs are thought to be critical in future diagnostic targets for various diseases and conditions. Diabetic Keratopathy (DK) can often lead to different manifestations such as scarring and corneal erosions. One of the receptors that plays a role in DK is Peroxisome Proliferator-Activated Receptor alpha (PPARα), but its functions in the cornea is unknown, including its impact on the EVs formation. Our goal was to investigate the influence of PPARα in the production of EVs and its role in cell-cell interaction.

Methods: Healthy Corneal Fibroblasts (HCFs), Type 1 Diabetes Mellitus (T1DM), and Type 2 Diabetes Mellitus (T2DM) corneal stromal cells were cultured on polycarbonate membranes for 4 weeks at a density of 1x106 cell/well in culture medium + 0.5mM stable Vitamin C. The culture media were processed and analyzed with the EV-TETRA-C chips paired with the ExoView R100.

Results: The results showed that total particle counts were upregulated in HCF compared to T1DM and T2DM, but were downregulated in T1DM when compared with T2DM, during weeks 2 and 4. The total particle count for HCFs were downregulated during week 4 when compared to weeks 1 and 3. When comparing week 1 to weeks 2, 3, and 4, week 1 revealed the most significance for changes of CD63+, CD63+/CD81+, CD81+/CD9+, and CD63+/CD81+/CD9+ in HCFs and T1DMs. CD9+ showed significance during weeks 2, 3, and 4 in HCFs and T1DMs. During week 1, T2DMs had significant downregulation of CD63+, whereas CD9+, CD63+/CD9+, and CD63+/CD81+/CD9+ showed significant upregulation. During week 4, T2DMs showed significant downregulation in CD63+/CD81+ and significant upregulation of CD81+/CD9+. T1DMs were the only cell type to show significance in CD81+, which was during week 4 when compared to week 2. CD63+, CD81+, and CD9+ showed significance during week 1 and 2 in HCF, T1DM, and T2DM. The co/triple colocalizations showed significance in weeks 1, 2, and 4 in HCF, T1DM, and T2DM.

Conclusion: EV formation (based on CD63+), immune system regulation (CD81+ and CD9+), and EV particle counts showed distinct phenotypes between HCF, T1DM, and T2DM. These distinctions could potentially serve as a diagnostic tool in the future and ultimately help individuals suffering from DK.