title: Nerve Growth Factor Attenuates Apoptosis and Inflammation in the Diabetic Cornea.
abstract: To examine the effects of nerve growth factor (NGF) on apoptosis and inflammation in the diabetic cornea.
  
  
  
  To investigate the effects of NGF on glucose-induced apoptosis, we stained human corneal epithelial cells (HCECs) for annexin-V and propidium iodide (PI), and measured expression of cleaved caspase-3 and the Bcl-2-associated X protein (BAX). Moreover, to examine the effects of NGF on inflammation, we quantified the expression of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) using multiplex cytokine analysis, and analyzed nuclear factor-κB (NF-κB) activation and NF-κ-B inhibitor α (IκBα) degradation using Western blot analysis. To investigate the effects in vivo, we induced diabetes in male Sprague-Dawley rats using streptozotocin. The rats were divided into three groups: control, diabetic control, and diabetic NGF; topical NGF was applied three times daily for 3 weeks. We used the TUNEL assay to detect apoptosis in corneal tissue, and immunohistochemistry to identify cleaved caspase-3 and IL-1β.
  
  
  
  In HCECs, high glucose concentration (≥25 mM) led to reactive oxygen species (ROS) generation, apoptosis, and the release of inflammatory cytokines. Nerve growth factor markedly reduced ROS activation, annexin-PI-positive cells, and levels of cleaved caspase-3, BAX, IL-1β, and TNF-α. In the diabetic rat cornea, apoptosis and inflammation were enhanced, as were levels of cleaved caspase-3 and IL-1β. These responses were markedly reduced by NGF.
  
  
  
  Apoptosis and inflammation are enhanced in the diabetic cornea; NGF attenuates these responses-both in vivo and in vitro. Therefore, NGF therapy may represent a novel approach for the management of diabetic keratopathy.
authors.affiliation: Miso Eye Clinic, Seoul, Republic of Korea 2Research Institute for Biomacromolecules, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Jin Hyoung
authors.initials: JH
authors.lastname: Park
authors.affiliation: Research Institute for Biomacromolecules, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Soon-Suk
authors.initials: SS
authors.lastname: Kang
authors.affiliation: Research Institute for Biomacromolecules, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea 3Department of Ophthalmology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Jae Yong
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Research Institute for Biomacromolecules, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea 3Department of Ophthalmology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Hungwon
authors.initials: H
authors.lastname: Tchah
mesh_terms: D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D002460:Cell Line; D016207:Cytokines / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental; D019573:Epithelium, Corneal / Q000378:metabolism* / Q000473:pathology; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D007634:Keratitis / Q000209:etiology / Q000235:genetics / Q000378:metabolism*; D008297:Male; D020932:Nerve Growth Factor / Q000096:biosynthesis / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D016207:Cytokines; C502240:NGF protein, human; D012333:RNA, Messenger; D020932:Nerve Growth Factor