Effect of PKH-26-labeled exosomes derived from bone marrow mesenchymal stem cells on corneal epithelium regeneration in diabetic mice

Abstract

Background: It is known that bone marrow mesenchymal stem cells (BM-MSCs) could speed up the regeneration of diabetic corneal epithelium. To investigate the effect of exosomes derived from mouse BM-MSCs on corneal epithelium regeneration in diabetic mice.Methods: Diabetic mouse models were established using streptozotocin (STZ), and their central corneal epithelium was scratched under a microscope. The diabetic mice were randomly divided into three groups: the control group was injected with subconjunctival phosphate buffer saline; the exosomes group was treated with a subconjunctival injection of exosomes derived from BM-MSCs; and the BM-MSCs group was treated with a subconjunctival injection of BM-MSCs. The corneal epithelium repair rates in the three groups were compared, and the distribution of the exosomes derived from BM-MSCs labeled with PKH-26 was observed by immunofluorescence. Hematoxylin-eosin staining of the corneal tissue was observed 72 h after the treatments in the three groups.Results: The diabetic mice were successfully established by a blood glucose level >16.7 mmol/L after 8 weeks. The corneal epithelium healing rates in experimental groups 1 and 2 were significantly higher than those of the control group at 24, 48, and 72 h (P<0.05). However, there was no significant difference in the corneal epithelial healing rate between experimental groups 1 and 2 (P>0.05). The exosomes derived from BM-MSCs were found in the superficial corneal stroma in experimental groups 1 and 2, with the majority of the exosomes distributed in the limbal epithelium at the edge of the injury area. The proliferation of corneal epithelial cells in experimental groups 1 and 2 was more obvious than that in the control group. Conclusions:The exosomes derived from BM-MSCs labeled with PKH-26 significantly promoted the repair of corneal epithelial injury in diabetic mice. These exosomes might be a substitute for BM-MSCs in the repair of diabetic keratopathy, suggesting a new idea for the repair of diabetic keratopathy with "cell-free" stem cell therapy, which will require a clinical study.

Bone marrow mesenchymal stem cell‐derived extracellular vesicles promote corneal epithelial repair and suppress apoptosis via modulation of Caspase‐3 in vitro

“…Additionally, EVs originating from HCECs have exhibited ultrastructural changes in keratocytes and their transformation into myofibroblasts, aiding in corneal wound healing [43]. Experiments utilizing PKH-26-labeled exosomes derived from mouse BM have demonstrated accelerated regeneration of corneal epithelial cells in mice with diabetic keratopathy [44]. In line with these reports, this study reports accelerated corneal epithelial repair by BM-MSC-EVs.…”

Limbal Epithelial Stem Cells in the Diabetic Cornea

“…Recent studies demonstrated the benefits of administering healthy SC-derived exosomes in improving the corneal healing response in diabetes. The subconjunctival injection of healthy bone marrow mesenchymal SC-derived exosomes in diabetic mice, inflicted with a central corneal epithelial injury, displayed a significant reduction in corneal wound-healing rate [117]. Treatment with exosomes extracted from mouse adipose-derived mesenchymal SCs, in the form of eyedrops in STZ-induced T1D mice, also promoted significant improvements in corneal wound healing, nerve regeneration and sensitivity [118].…”

Mesenchymal Stem Cells and Exosomes: A Novel Therapeutic Approach for Corneal Diseases

“…In a study with a corneal epithelial defect model in diabetic mice, exosomes derived from BM-MSCs labeled with PKH-26 regenerated the corneal epithelium by inducing the proliferation, repair, and migration of corneal epithelial cells. Furthermore, infiltrating inflammatory cells were relatively diminished in the cornea treated with exosomes [ 187 ]. A study assessed the effectiveness of ADSCs compared to MSC-derived exosomes for treating corneal injuries induced by alkali in rats.…”