Nona-D-arginine amide suppresses corneal cytokines in Pseudomonas aeruginosa keratitis.
OBJECTIVE
Nona-D-arginine (D9R) amide suppressed interleukin 1β production during Pseudomonas aeruginosa corneal infection. The purpose of this study was to determine the cellular disposition of D9R and its effect on other inflammatory mediators induced by infection.


METHODS
Mouse eyes received 5 μL of either phosphate-buffered saline (PBS, pH 7.4) or 100-μM D9R hourly for 5 hours (total of 6 drops per eye) immediately after corneal wounding and infection with 1 × 10 colony-forming units (CFUs) of P. aeruginosa strain PAO1. At 6, 12, and 24 hours postinfection, eyes were scored on a scale of 0 (normal eye) to +4 (corneal perforation). After scoring, mice were killed and eyes enucleated. Whole eyes were used for determining viable CFUs per eye. Corneas were excised for quantitation of tumor necrosis factor α, interferon γ, interleukin 10, and granulocyte-macrophage colony-stimulating factor. The fate of D9R in cells was determined using a labeled peptide.


RESULTS
Eyes treated with D9R had significantly lower disease scores (P ≤ 0.001) and fewer CFUs (P ≤ 0.01) than those in PBS-treated eyes. No corneal cytokines were detected in any D9R-treated eyes. In contrast, beginning at 12 hours postinfection, increasing amounts of tumor necrosis factor alpha, interleukin 10, and granulocyte-macrophage colony-stimulating factor were detectible in corneas of PBS-treated eyes. Within 60 minutes, D9R accumulated in the cell nucleus and nucleolus and remained for over 24 hours.


CONCLUSIONS
D9R reduces the severity of P. aeruginosa ocular infection in part by reducing bacterial burden and in part by controlling a destructive proinflammatory response. D9R might be a useful alternative to steroids in treating other inflammation-mediated pathologies of the eye.
Karicherla
Priyanka
P
Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA.
Aras
Siddhesh
S
Aiyar
Ashok
A
Hobden
Jeffery A
JA
D000818:Animals; D058491:Bacterial Load; D003315:Cornea / Q000378:metabolism*; D016207:Cytokines / Q000037:antagonists & inhibitors*; D005260:Female; D017930:Genes, Reporter; D007634:Keratitis / Q000382:microbiology* / Q000473:pathology; D008156:Luciferases / Q000235:genetics; D008297:Male; D051379:Mice; D009842:Oligopeptides / Q000493:pharmacokinetics / Q000494:pharmacology*; D011552:Pseudomonas Infections / Q000378:metabolism*; D011550:Pseudomonas aeruginosa; D012720:Severity of Illness Index; D014158:Transcription, Genetic / Q000187:drug effects
D016207:Cytokines; D009842:Oligopeptides; C555621:nonaarginine amide; D008156:Luciferases
Int J Oncol. 2008 Feb;32(2):289-305
18202751
Science. 1992 Jun 5;256(5062):1445-8
1604320
Immunol Cell Biol. 1999 Apr;77(2):164-6
10234552
Curr Eye Res. 2009 Feb;34(2):92-8
19219679
Infect Immun. 2003 Mar;71(3):1328-36
12595449
DNA Cell Biol. 2002 May-Jun;21(5-6):383-90
12167240
Invest Ophthalmol Vis Sci. 1987 Dec;28(12):1978-85
3119512
Prog Retin Eye Res. 2004 Jan;23(1):1-30
14766315
Invest Ophthalmol Vis Sci. 2005 Nov;46(11):4209-16
16249500
Biochemistry. 2004 Mar 9;43(9):2438-44
14992581
Arch Ophthalmol. 1972 Nov;88(5):553-74
4343997
Infect Immun. 1997 Jul;65(7):2754-8
9199446
J Virol. 2004 Nov;78(21):11487-505
15479791
PLoS Pathog. 2009 Jun;5(6):e1000469
19521517
Acta Ophthalmol. 2010 Mar;88(2):251-6
19053961
Infect Immun. 2000 Mar;68(3):1655-63
10678985
Invest Ophthalmol Vis Sci. 1993 Nov;34(12):3429-41
7693609
Cell. 1988 Dec 23;55(6):1189-93
2849510
J Biol Chem. 2001 Feb 23;276(8):5836-40
11084031
J Immunol. 1997 Dec 15;159(12):6283-90
9550433
J Immunol. 2003 May 15;170(10):5219-27
12734370
J Virol. 2009 May;83(9):4227-35
19244333
Invest Ophthalmol Vis Sci. 2009 Jan;50(1):256-62
18775859
Invest Ophthalmol Vis Sci. 2007 Feb;48(2):797-807
17251480
Microb Pathog. 2005 Jan;38(1):13-21
15652291
Vaccine. 2002 Oct 4;20(29-30):3498-508
12297395
J Biol Chem. 1997 Jun 20;272(25):16010-7
9188504
J Immunol. 2000 Jun 15;164(12):6576-82
10843717
Cornea. 1990;9 Suppl 1:S36-8; discussion S39-40
2189678