Yong-Soo Byun1, Borami Kang2, Young-Sik Yoo3, Choun-Ki Joo1. 1. Department of Ophthalmology and Visual Science, Seoul St. Mary's Hospital, Catholic University of Korea, College of Medicine, Seoul, Korea Catholic Institute for Visual Science, Catholic University of Korea, College of Medicine, Seoul, Korea. 2. Division of Endocrinology and Metabolism, Department of Internal Medicine, Seoul St. Mary's Hospital, Catholic University of Korea, College of Medicine, Seoul, Korea. 3. Catholic Institute for Visual Science, Catholic University of Korea, College of Medicine, Seoul, Korea.
Abstract
PURPOSE: We evaluated the effect of poly(ADP-ribose) polymerase (PARP) inhibition by using 1,5-isoquinolinediol (ISO) on corneal epithelial innervation in diabetic rats. METHODS: ISO (3 mg/kg, intraperitoneal) or vehicle was administered to rats with diabetes induced by streptozotocin for 4 weeks. Epithelial innervation, epithelial wound healing, and corneal sensation were evaluated in diabetic rats (DM rats), diabetic rats treated with ISO (DM-ISO rats), and nondiabetic (non-DM) rats. The density of epithelial innervation was calculated separately as nerve terminals and sub-basal nerve plexus by analyzing the images of whole-mount corneas. Healed areas of epithelial defect were measured at 0, 18, and 36 hours after creating a 4-mm wound on the cornea. Corneal sensitivity test was conducted using a Cochet-Bonnet handheld esthesiometer. Additionally, PARP1 and poly(ADP-ribosyl)ated polymers (pADPr) as its products, were identified in trigeminal ganglions (TGs) by Western blot analysis and immunofluorescence staining. RESULTS: In DM rats, the density of nerve terminals (5.57% ± 0.94%) and sub-basal nerve plexus (22.08 ± 1.78 mm/mm(2)) was significantly reduced in comparison with that in DM-ISO rats (8.64% ± 1.42%, 30.82 ± 2.01 mm/mm(2), respectively) and non-DM rats (9.02 ± 1.14%, 34.77 ± 4.45 mm/mm(2), respectively). The percentages of healed area of the epithelial defects at 18 and 36 hours were significantly smaller in DM rats (23.8 ± 5.2%, 53.2 ± 4.6%, respectively) than in DM-ISO rats (43.2 ± 1.4%, 75.8 ± 2.2%, respectively) and non-DM rats (48.1 ± 8.6%, 86.1 ± 3.3%, respectively). Corneal sensitivity decreased in DM rats (51.1 ± 0.3 mm) but not in DM-ISO rats (57.8 ± 0.2 mm). There were no differences between parameters in DM-ISO rats and those in non-DM rats. CONCLUSIONS: Diabetic corneas showed loss of epithelial innervation, resulting in delayed epithelial healing and decreased corneal sensitivity. Inhibition of poly(ADP-ribose) polymerase (PARP) with 1,5-isoquinolinediol alleviated these diabetes-induced alterations in the corneal epithelium in the diabetic rats. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.
PURPOSE: We evaluated the effect of poly(ADP-ribose) polymerase (PARP) inhibition by using 1,5-isoquinolinediol (ISO) on corneal epithelial innervation in diabeticrats. METHODS:ISO (3 mg/kg, intraperitoneal) or vehicle was administered to rats with diabetes induced by streptozotocin for 4 weeks. Epithelial innervation, epithelial wound healing, and corneal sensation were evaluated in diabeticrats (DM rats), diabeticrats treated with ISO (DM-ISOrats), and nondiabetic (non-DM) rats. The density of epithelial innervation was calculated separately as nerve terminals and sub-basal nerve plexus by analyzing the images of whole-mount corneas. Healed areas of epithelial defect were measured at 0, 18, and 36 hours after creating a 4-mm wound on the cornea. Corneal sensitivity test was conducted using a Cochet-Bonnet handheld esthesiometer. Additionally, PARP1 and poly(ADP-ribosyl)ated polymers (pADPr) as its products, were identified in trigeminal ganglions (TGs) by Western blot analysis and immunofluorescence staining. RESULTS: In DM rats, the density of nerve terminals (5.57% ± 0.94%) and sub-basal nerve plexus (22.08 ± 1.78 mm/mm(2)) was significantly reduced in comparison with that in DM-ISOrats (8.64% ± 1.42%, 30.82 ± 2.01 mm/mm(2), respectively) and non-DM rats (9.02 ± 1.14%, 34.77 ± 4.45 mm/mm(2), respectively). The percentages of healed area of the epithelial defects at 18 and 36 hours were significantly smaller in DM rats (23.8 ± 5.2%, 53.2 ± 4.6%, respectively) than in DM-ISOrats (43.2 ± 1.4%, 75.8 ± 2.2%, respectively) and non-DM rats (48.1 ± 8.6%, 86.1 ± 3.3%, respectively). Corneal sensitivity decreased in DM rats (51.1 ± 0.3 mm) but not in DM-ISOrats (57.8 ± 0.2 mm). There were no differences between parameters in DM-ISOrats and those in non-DM rats. CONCLUSIONS:Diabetic corneas showed loss of epithelial innervation, resulting in delayed epithelial healing and decreased corneal sensitivity. Inhibition of poly(ADP-ribose) polymerase (PARP) with 1,5-isoquinolinediol alleviated these diabetes-induced alterations in the corneal epithelium in the diabeticrats. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.
Authors: Ruchi Shah; Cynthia Amador; Kati Tormanen; Sean Ghiam; Mehrnoosh Saghizadeh; Vaithi Arumugaswami; Ashok Kumar; Andrei A Kramerov; Alexander V Ljubimov Journal: Exp Eye Res Date: 2021-01-21 Impact factor: 3.467