title: Topical administration of diminazene aceturate decreases inflammation in endotoxin-induced uveitis.
abstract: OBJECTIVE
  Our previous study demonstrated that an intraperitoneal injection of Diminazene Aceturate (DIZE) attenuated uveitis by activating ocular angiotensin-converting enzyme 2 (ACE2). Here, we investigated the anti-inflammatory effects on the ocular anterior segment of a topical administration of a DIZE solution and explored the downstream target molecules involved in the anti-inflammatory mechanism after ACE2 activation.
  
  
  METHODS
  Endotoxin-induced uveitis (EIU) in rats was induced by a subcutaneous injection of lipopolysaccharides (LPS, 200 μg) in 0.1 ml of sterile saline. DIZE (0.025, 0.05, or 0.1%) and dexamethasone (0.1%) solutions were applied topically (10 μl eyedrops) to both eyes 6X every two hours before and after LPS injection. The inflammation of the ocular anterior segment was observed and the clinical scores were evaluated 24 h after LPS injection. The total protein concentration and levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the aqueous humor were determined. CD11b-positive cells adjacent to the iris ciliary body (ICB) were stained by immunohistochemistry. The mRNA levels of inflammatory cytokines and mediators, including IL-1β, TNF-α, COX-2, and iNOS or NF-κB subunit p65 in the ICB, were analyzed by real time RT-PCR. The protein expression of NF-κB p65 and the phosphorylated protein of p38 MAPK were detected by western blotting.
  
  
  RESULTS
  A topical administration of DIZE decreased clinical scores and the total protein concentration, as well as TNF-α and IL-6 levels in the aqueous humor. Meanwhile, the mRNA levels of inflammatory cytokines and mediators, including IL-1β, TNF-α, COX-2, and iNOS in the ICB, were downregulated. DIZE reduced the recruitment of CD11b-positive cells adjacent to the ICB. Furthermore, DIZE downregulated the expressions of NF-κB subunit p65 at protein and mRNA levels and inhibited the phosphorylation of p38 MAPK protein in the ICB.
  
  
  CONCLUSIONS
  A topical administration of DIZE suppressed ocular inflammation in EIU and decreased the levels of inflammatory cytokines. DIZE attenuated the activation of NF-κB and p38 MAPK in EIU, which may be associated with ACE2-mediated anti-inflammatory effects. Our data provided further evidence that DIZE may represent a novel class of drug for the management of ocular inflammation.
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China.
authors.forename: Changwei
authors.initials: C
authors.lastname: Zheng
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Lei
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China.
authors.forename: Zihe
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China.
authors.forename: Shijie
authors.initials: S
authors.lastname: Zheng
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Yang
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China.
authors.forename: Yiguo
authors.initials: Y
authors.lastname: Qiu
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Lei
mesh_terms: D060433:Administration, Ophthalmic; D000085962:Angiotensin-Converting Enzyme 2; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D001082:Aqueous Humor / Q000737:chemistry; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology*; D004133:Diminazene / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D007274:Injections, Intraperitoneal; D053583:Interleukin-1beta / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D008070:Lipopolysaccharides; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D009883:Ophthalmic Solutions; D007703:Peptidyl-Dipeptidase A / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D051996:Transcription Factor RelA / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D014602:Uvea / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D014605:Uveitis / Q000139:chemically induced / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D000093242:Interleukin-6 Inhibitors
chemical_list: D000085962:Angiotensin-Converting Enzyme 2; D000893:Anti-Inflammatory Agents; D051546:Cyclooxygenase 2; D003907:Dexamethasone; D004133:Diminazene; D053583:Interleukin-1beta; D015850:Interleukin-6; D008070:Lipopolysaccharides; D052247:Nitric Oxide Synthase Type II; D009883:Ophthalmic Solutions; D007703:Peptidyl-Dipeptidase A; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; D048051:p38 Mitogen-Activated Protein Kinases; D000093242:Interleukin-6 Inhibitors; C498145:Rela protein, rat; C496318:Nos2 protein, rat; C489691:Ptgs2 protein, rat; C000705329:Ace2 protein, rat; C003915:diminazene aceturate