Open AccessAnti-inflammatory and anti-apoptotic effects of N-acetylcysteine in diabetic rat corneal epithelium
Author(s) -
Sae-Byeok Hwang,
Ji-Yun Park,
Suk-Yun Kang,
Ho Seok Chung,
Hun Lee,
Jae Yong Kim,
Hungwon Tchah
Publication year - 2021
Publication title -
international journal of ophthalmology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.634
H-Index - 29
eISSN - 2227-4898
pISSN - 2222-3959
DOI - 10.18240/ijo.2021.12.01
Subject(s) - propidium iodide , apoptosis , streptozotocin , glycation , medicine , corneal epithelium , annexin , tunel assay , microbiology and biotechnology , tumor necrosis factor alpha , rage (emotion) , poly adp ribose polymerase , intraperitoneal injection , diabetes mellitus , endocrinology , epithelium , chemistry , immunohistochemistry , biology , pathology , biochemistry , programmed cell death , neuroscience , polymerase , gene
AIM: To characterize the anti-inflammatory and anti-apoptotic effects of N-acetylcysteine (NAC) in streptozotocin (STZ)-induced diabetic rat corneal epithelium and human corneal epithelial cells (HCECs) exposed to a high-glucose environment.METHODS: HCECs were incubated in 0, 5, 50 mmol/L glucose medium, or 50 mmol/L glucose medium with NAC for 24h. Diabetes was induced in rats by intraperitoneal injection of 65 mg/kg STZ and some of these rats were topically administered NAC to corneas with 3 mice per group. We characterized receptor for advanced glycation end-products (RAGE) expression using immunofluorescence, and interleukin (IL)-1β and cleaved caspase-3 (CCAP-3) expression using immunohistochemistry. Circulating tumor necrosis factor (TNF)-α concentration was measured by ELISA and cleaved poly-ADP ribose polymerase (PARP) concentration was quantified by Western blotting. Apoptotic cells were detected using TUNEL assay and annexin V and propidium iodide staining.RESULTS: Diabetic rats had higher expression of RAGE (2.46±0.13 fold), IL-1β, and CCAP-3 in apoptotic cells of their corneas than control rats. The expression of RAGE (1.83±0.11 fold), IL-1β, and CCAP-3, and the number of apoptotic cells, were reduced by topical NAC treatment. HCECs incubated in 50 mmol/L glucose medium showed high concentrations of TNF-α (310±2.00 pg/mL) and cleaved PARP (7.43±0.56 fold), and more extensive apoptosis than cells in 50 mmol/L glucose medium. However, the addition of NAC reduced the concentrations of TNF-α (153.67±2.31 pg/mL) and cleaved PARP (5.55±0.31 fold) and the number of apoptotic cells.CONCLUSION: NAC inhibits inflammation and apoptosis in the corneas of diabetic rats and HCECs maintained in a high-glucose environment.