Pseudomonas aeruginosa (P. aeruginosa) is a Gram-negative, opportunistic pathogen associated with bacterial keratitis, especially in contact lens usage. With the increasing incidence of antibiotic resistance, our goal is to determine the role of the pro- inflammatory neuropeptide, Substance P (SP) and the anti-inflammatory neuropeptide, vasoactive intestinal peptide (VIP) in regulation of inflammation, innate immunity and restoration of corneal homeostasis.
The aims of this proposal are: 1) to test the hypothesis that VIP modulates TLRs and TLR-related adaptor molecules;down- regulates the expression of adhesion molecules, decreases the migration/persistence of inflammatory cells (PMN, M?, Langerhans cells) in the infected cornea;and promotes restoration of corneal homeostasis and re-modeling of the ECM, 2) to test the hypothesis that SP exacerbates disease pathogenesis through the up-regulation of TLRs and TLR- related adaptor molecules;up-regulates adhesion molecule expression and enhances the migration/persistence of inflammatory cells (PMN, M?, Langerhans cells) in the infected cornea and degradation of the ECM. Experiments will include use of techniques such as real-time RT-PCR, short interfering RNA (siRNA), as well as plate counts, enzyme linked immunosorbant assay (ELISA), myeloperoxidase assay (MPO) for neutrophil (PMN) quantitation, dual antibody immunostaining, histopathology, and Western blotting. Our findings will be particularly significant for development of novel therapeutics for bacterial keratitis, targeting not only regulation of corneal infection and inflammation, but also the critical aspect of promoting tissue repair. Since in the United States alone the incidence of microbial keratitis is 25,000-30,000 cases annually with cost of treatment estimated at $15-30 million, the studies are relevant to human health and have considerable medical and economic impact.
P. aeruginosa is a Gram-negative pathogen associated with bacterial keratitis, particularly in contact lens wearers, with considerable medical and economic consequences. Understanding the mechanisms of neuropeptide regulation of Toll-like receptor and associated adaptor molecule activation and modulation of adhesion molecules and extracellular matrix components will provide substantive insight and novel therapeutic potential to regulate disease pathogenesis in cornea and perhaps other infectious and immune-based inflammatory diseases.
|McClellan, Sharon A; Ekanayaka, Sandamali A; Li, Cui et al. (2015) Thrombomodulin Protects Against Bacterial Keratitis, Is Anti-Inflammatory, but Not Angiogenic. Invest Ophthalmol Vis Sci 56:8091-100|
|McClellan, Sharon; Jiang, Xiaoyu; Barrett, Ronald et al. (2015) High-mobility group box 1: a novel target for treatment of Pseudomonas aeruginosa keratitis. J Immunol 194:1776-87|
|Jiang, Xiaoyu; McClellan, Sharon A; Barrett, Ronald et al. (2014) HGF signaling impacts severity of Pseudomonas aeruginosa keratitis. Invest Ophthalmol Vis Sci 55:2180-90|
|Li, Cui; McClellan, Sharon A; Barrett, Ronald et al. (2014) Interleukin 17 regulates Mer tyrosine kinase-positive cells in Pseudomonas aeruginosa keratitis. Invest Ophthalmol Vis Sci 55:6886-900|
|Hazlett, Linda D; Jiang, Xiaoyu; McClellan, Sharon A (2014) IL-10 function, regulation, and in bacterial keratitis. J Ocul Pharmacol Ther 30:373-80|
|Foldenauer, Megan E B; McClellan, Sharon A; Berger, Elizabeth A et al. (2013) Mammalian target of rapamycin regulates IL-10 and resistance to Pseudomonas aeruginosa corneal infection. J Immunol 190:5649-58|
|Berger, Elizabeth A; McClellan, Sharon A; Vistisen, Kerry S et al. (2013) HIF-1? is essential for effective PMN bacterial killing, antimicrobial peptide production and apoptosis in Pseudomonas aeruginosa keratitis. PLoS Pathog 9:e1003457|
|Berger, Elizabeth A; Vistisen, Kerry S; Barrett, Ronald P et al. (2012) Effects of VIP on corneal reconstitution and homeostasis following Pseudomonas aeruginosa induced keratitis. Invest Ophthalmol Vis Sci 53:7432-9|
|Jiang, Xiaoyu; McClellan, Sharon A; Barrett, Ronald P et al. (2012) The role of VIP in cornea. Invest Ophthalmol Vis Sci 53:7560-6|
|Foldenauer, Megan E B; McClellan, Sharon A; Barrett, Ronald P et al. (2012) Substance P affects growth factors in Pseudomonas aeruginosa-infected mouse cornea. Cornea 31:1176-88|
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