Elevated Opioid Growth Factor Alters the Limbus in Type 1 Diabetic Rats

Area of Science:

• Ophthalmology
• Endocrinology
• Molecular Biology

Background:

• Diabetes mellitus is a leading cause of ocular surface complications, significantly impacting the cornea.
• The limbus plays a crucial role in corneal health by supplying growth factors and maintaining homeostasis.
• Dysregulation of the Opioid Growth Factor (OGF)-Opioid OGF Receptor (OGFr) axis is implicated in diabetic complications, with elevated OGF levels observed in corneal tissue.

Purpose of the Study:

• To investigate the impact of OGF-OGFr axis dysregulation on limbal constituents in a diabetic rat model.
• To assess the effect of blocking the OGF-OGFr axis on limbal morphology and function in diabetic rats.

Main Methods:

• Adult Sprague-Dawley rats were induced with type 1 diabetes (T1D) using streptozotocin.
• A subset of T1D rats received topical naltrexone (NTX) to block the OGF-OGFr axis.
• Limbal morphology, OGF, OGFr, cytokeratin 15 (CK15), and Ki-67 expression were assessed.

Main Results:

• Diabetic rats exhibited altered limbal epithelial morphology, with decreased CK15 expression and increased OGF and OGFr levels.
• Topical NTX treatment reversed limbal epithelial defects and normalized OGF levels in diabetic rats.
• These findings suggest OGF-OGFr axis dysregulation contributes to altered limbal morphology and impaired corneal healing in diabetes.

Conclusions:

• The OGF-OGFr axis is dysregulated in the limbus of diabetic rats, affecting limbal cell function and corneal homeostasis.
• Targeting the OGF-OGFr axis with NTX demonstrates potential for ameliorating ocular surface complications in diabetes.
• Further research is warranted to explore therapeutic strategies involving the OGF-OGFr axis for diabetic eye disease.