title: Corneal complications in streptozocin-induced type I diabetic rats.
abstract: PURPOSE. This study seeks to characterize corneal functions and complications in a streptozocin (STZ)-induced rat model of type I diabetes mellitus (DM) and to understand the pathogenesis of diabetic keratopathy. METHODS. DM was induced via STZ injection in Sprague-Dawley rats. Body weight, length, and corneal size were measured and compared with the age-matched normal controls. Corneal morphology and histology were evaluated with slit lamp, digital confocal microscopy and hematoxylin and eosin staining. Tear secretion was measured with cotton threads, and corneal sensitivity was determined with an esthesiometer. Protein expression and distribution were assessed with Western blotting and immunohistochemistry. Wound healing was determined using an in vivo corneal epithelial debridement model. RESULTS. Compared with the normal control rats, STZ rats had reduced body weight, and body length, but minimally affected corneal size. No significant changes in ocular surface regularity, corneal thickness, and morphology were noted in diabetic corneas. STZ rats showed stronger Rose Bengal staining, decreased tear secretion, slightly attenuated sensitivity, less innervation, delayed epithelial wound healing, and impaired epidermal growth factor receptor signaling in their corneas. While the expression of adherens junction protein β-catenin, and tight junction proteins occludin and ZO-1 was unchanged, the formation of these junctions after wound closure was delayed. CONCLUSIONS. Pathogenesis of diabetic keratopathy involves multiple tissues and/or cell types and several events including reduced tear secretion, impaired innervation, weakened cell junction, and altered wound responses. These insights may prove useful for the clinical translation of evolving strategies for the management and treatment of diabetic corneal complications.
authors.affiliation: Kresge Eye Institute, Departments of Ophthalmology and Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA.
authors.forename: Jia
authors.initials: J
authors.lastname: Yin
authors.forename: Jenny
authors.initials: J
authors.lastname: Huang
authors.forename: Cynthia
authors.initials: C
authors.lastname: Chen
authors.forename: Nan
authors.initials: N
authors.lastname: Gao
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.forename: Fu-Shin X
authors.initials: FS
authors.lastname: Yu
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001824:Body Constitution; D003315:Cornea / Q000294:innervation; D003316:Corneal Diseases / Q000209:etiology* / Q000378:metabolism / Q000503:physiopathology; D003921:Diabetes Mellitus, Experimental / Q000150:complications* / Q000378:metabolism / Q000503:physiopathology; D003922:Diabetes Mellitus, Type 1 / Q000150:complications* / Q000378:metabolism / Q000503:physiopathology; D066246:ErbB Receptors / Q000378:metabolism; D007150:Immunohistochemistry; D007766:Lacrimal Apparatus Diseases / Q000209:etiology; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D018613:Microscopy, Confocal; D062793:Occludin; D009882:Ophthalmic Nerve / Q000503:physiopathology; D010750:Phosphoproteins / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D013666:Tears / Q000378:metabolism; D020433:Trigeminal Nerve Diseases / Q000209:etiology / Q000503:physiopathology; D014945:Wound Healing; D062826:Zonula Occludens-1 Protein; D051176:beta Catenin / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D062793:Occludin; C568987:Ocln protein, rat; D010750:Phosphoproteins; C569044:Tjp1 protein, rat; D062826:Zonula Occludens-1 Protein; D051176:beta Catenin; C483803:Egfr protein, rat; D066246:ErbB Receptors