title: Effects of VIP on corneal reconstitution and homeostasis following Pseudomonas aeruginosa induced keratitis.
abstract: OBJECTIVE
  Studies from our laboratory have demonstrated that vasoactive intestinal peptide (VIP) directly converts the normally susceptible C57BL/6J (B6) mouse to resistant after ocular infection through modulation of the inflammatory response. This study examines mechanisms by which VIP influences the healing phase following infection--specifically reconstitution of the extracellular matrix (ECM).
  
  
  METHODS
  B6 mice received daily intraperitoneal (IP) injections of VIP, while control mice were similarly injected with sterile phosphate buffered saline (PBS). Real-time RT-PCR, ELISA, and immunofluorescent staining were used to assess the effects of VIP treatment on ECM molecule expression after Pseudomonas aeruginosa-induced keratitis. We also compared the effect of VIP treatment on lipopolysaccharide (LPS)-stimulated B6- and BALB/c-derived fibroblasts.
  
  
  RESULTS
  In vivo analyses revealed that VIP treatment of P. aeruginosa-infected B6 corneas led to a significant increase in ECM molecules associated with healing/homeostasis, while those associated with ECM degradation were significantly down-regulated when compared to wild-type (WT) controls. In vitro studies revealed that VIP treatment of lipopolysaccharide-stimulated fibroblasts derived from susceptible B6 and resistant BALB/c mice expressed distinct differences in ECM molecule expression, whereby the latter expressed higher levels of ECM molecules aimed at reconstitution. Furthermore, differential expression of VIP receptor-1/VIP receptor-2 (VIPR1/VIPR2) was observed between B6 and BALB/c after VIP treatment of LPS-stimulated fibroblasts.
  
  
  CONCLUSIONS
  VIP treatment functions to enhance ECM reconstitution, which appears to be carried out in large part by fibroblasts via VIPR2. Overall, the data from this study suggest that VIP not only regulates disease pathogenesis, but also functions to restore integrity of the corneal stroma.
authors.affiliation: Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA. eberger@med.wayne.edu
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Berger
authors.forename: Kerry S
authors.initials: KS
authors.lastname: Vistisen
authors.forename: Ronald P
authors.initials: RP
authors.lastname: Barrett
authors.forename: Linda D
authors.initials: LD
authors.lastname: Hazlett
mesh_terms: D000818:Animals; D003315:Cornea / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D004195:Disease Models, Animal; D015536:Down-Regulation / Q000187:drug effects; D004797:Enzyme-Linked Immunosorbent Assay; D005109:Extracellular Matrix / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D015818:Eye Infections, Bacterial / Q000188:drug therapy* / Q000378:metabolism / Q000382:microbiology; D005260:Female; D006706:Homeostasis; D007634:Keratitis / Q000188:drug therapy* / Q000378:metabolism / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018696:Neuroprotective Agents / Q000494:pharmacology; D011552:Pseudomonas Infections / Q000188:drug therapy* / Q000378:metabolism / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification*; D012333:RNA, Messenger / Q000235:genetics; D051239:Receptors, Vasoactive Intestinal Peptide, Type II / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D051238:Receptors, Vasoactive Intestinal Polypeptide, Type I / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
chemical_list: D018696:Neuroprotective Agents; D012333:RNA, Messenger; D051239:Receptors, Vasoactive Intestinal Peptide, Type II; D051238:Receptors, Vasoactive Intestinal Polypeptide, Type I; C495507:Vipr1 protein, mouse; C495510:Vipr2 protein, mouse; D014660:Vasoactive Intestinal Peptide