title: VIP and growth factors in the infected cornea.
abstract: OBJECTIVE
  Vasoactive intestinal peptide (VIP) is an anti-inflammatory neuropeptide that downregulates proinflammatory cytokines and promotes healing in a susceptible model of P. aeruginosa keratitis. Growth factors also play a role in corneal healing and restoration of tissue homeostasis after wounding. However, whether VIP treatment modulates growth factors to promote healing in the infected cornea remains untested and is the purpose of this study.
  
  
  METHODS
  C57BL/6 (B6) mice were injected with VIP and mRNA and protein levels, and immunostaining for EGF, FGF, HGF, and VEGF-A were done. Exogenous treatment with a mixture of the growth factors also was tested and levels of cytokines, defensins, and bacterial counts were determined.
  
  
  RESULTS
  Real-time RT-PCR, immunostaining, and ELISA data demonstrated that treatment with VIP enhanced levels of EGF, FGF, and HGF during disease, and that VEGF-A, and associated angiogenic molecules also were increased by VIP. Moreover, immunohistochemical studies confirmed that both epithelial and stromal cells participated in growth factor production. Most notably, treatment with a mixture of EGF, FGF, and HGF after disease onset, prevented corneal perforation when compared with controls. This outcome was associated with downregulation of proinflammatory cytokines such as macrophage inflammatory protein-2 (MIP-2), upregulation of anti-inflammatory cytokines such as TGF-β, and antimicrobials β-defensins 2 and 3, as well as decreased plate counts at 1 day postinfection (p.i.) (P = 0.0001).
  
  
  CONCLUSIONS
  Collectively, the data provide evidence that VIP treatment modulates growth factors, angiogenic molecules, and defensins in the infected cornea and that this in turn promotes healing and restoration of tissue homeostasis.
authors.affiliation: Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Jiang
authors.forename: Sharon A
authors.initials: SA
authors.lastname: McClellan
authors.forename: Ronald P
authors.initials: RP
authors.lastname: Barrett
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Berger
authors.forename: Yunfan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Linda D
authors.initials: LD
authors.lastname: Hazlett
mesh_terms: D000818:Animals; D015169:Colony Count, Microbial; D003315:Cornea / Q000187:drug effects*; D016510:Corneal Neovascularization / Q000517:prevention & control; D057112:Corneal Perforation / Q000517:prevention & control; D003320:Corneal Ulcer / Q000188:drug therapy* / Q000378:metabolism / Q000382:microbiology; D016207:Cytokines / Q000378:metabolism; D023082:Defensins / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D015818:Eye Infections, Bacterial / Q000188:drug therapy* / Q000378:metabolism / Q000382:microbiology; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D011552:Pseudomonas Infections / Q000188:drug therapy* / Q000378:metabolism / Q000382:microbiology; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism; D014660:Vasoactive Intestinal Peptide / Q000627:therapeutic use*
chemical_list: D016207:Cytokines; D023082:Defensins; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; D014660:Vasoactive Intestinal Peptide