Abstract
Purpose :
Previous studies from our lab and other groups have demonstrated that diabetes mellitus compromises ocular surface epithelial barrier function. Impaired barrier function can predispose the ocular surface to microbial toxins and pathogens, potentially triggering an innate immune response. Macrophages and neutrophils are among the first-line immune cells protecting the mucosal surfaces. The current study was designed to evaluate the time-dependent effects of diabetes mellitus on corneal, conjunctival, and lacrimal gland neutrophils and macrophages.
Methods :
Type 1 diabetes was induced in male C57BL/6 mice by a single i.p. injection of streptozotocin (200 mg/kg). The induction of diabetes was confirmed by measuring the blood glucose. The cornea, conjunctiva, and lacrimal glands were harvested at various time points after the onset of hyperglycemia. Neutrophils and macrophages were immunostained for CD11b, CD206, F4/80, and CD86 and quantified using flow cytometry and confocal microscopy.
Results :
Our data shows that diabetes mellitus causes significant changes in the neutrophil and macrophage population in the cornea, conjunctiva, and lacrimal gland. Early on, after the onset of diabetes mellitus, a transient influx of neutrophils and macrophages in the cornea, conjunctiva, and lacrimal gland was observed. This was followed by the restoration of their population comparable to the non-diabetic control. With the further progression of the disease, a second and more robust increase was observed. Moreover, a significant increase in the macrophages with proinflammatory phenotype also was noted compared to non-diabetic control animals.
Conclusions :
Our results demonstrate that diabetes mellitus is associated with a significant influx of neutrophils and macrophages in the cornea, conjunctiva, and lacrimal gland. The resultant chronic inflammatory response could potentially be a pathogenic mechanism underlying the increased incidence of dry eye associated with diabetes mellitus.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.