title: LL-37 induced cystitis and the receptor for advanced glycation end-products (RAGE) pathway.
abstract: To elucidate pathways in bladder inflammation, we employed our physiologically relevant LL-37 induced cystitis model. Based on inflammatory studies involving other organ systems implicating the receptor for advanced glycation end-products (RAGE), we first hypothesized that RAGE is critically involved in LL-37 induced cystitis. We further hypothesized a common RAGE ligand - high mobility group box 1 (HMGB1) is up-regulated in bladders challenged with LL-37. Finally, we hypothesized NF-κB dependent inflammatory genes are activated in LL-37 induced cystitis. Testing our first hypothesis, C57Bl/6 mice were challenged with either saline (control) or 320 μM of LL-37 intravesically for 1 hr. After 12 or 24 hours, tissues were examined with immunohistochemistry (IHC) for RAGE, and both mRNA and protein isolation for respective qRT-PCR and Western Blot analysis. Our second hypothesis was tested by employing HMGB1 IHC. Testing our final hypothesis, qRT-PCR was performed investigating five genes: TNFα, IL-6, IL-1β, GM-CSF, COX-2. In control and LL-37 challenged tissues, IHC for RAGE revealed similar qualitative expression. Evaluation with qRT-PCR and Western Blot for RAGE revealed diminished expression at the mRNA and protein level within LL-37 challenged bladders. IHC for HMGB1 revealed a moderate qualitative increase within LL-37 challenged tissues. Finally, with the exception of TNFα, all NF-κB dependent inflammatory genes yielded substantial up-regulation. We have employed our LL-37 induced cystitis model to gain insight towards a possible mechanistic pathway involved in bladder inflammation. This work provides data for future studies involving the inflammatory ligand HMGB1, RAGE, and receptor pathways that activate NF-κB.
authors.affiliation: Department of Surgery and Division of Pediatric Urology: Primary Children's Medical Center, Salt Lake City, Utah.
authors.forename: Lindsi McCoard
authors.initials: LM
authors.lastname: Roundy
authors.affiliation: Department of Surgery and Division of Pediatric Urology: Primary Children's Medical Center, Salt Lake City, Utah.
authors.forename: Wanjian
authors.initials: W
authors.lastname: Jia
authors.affiliation: Department of Medicinal Chemistry and Center for Therapeutic Biomaterials: University of Utah, Salt Lake City, Utah.
authors.forename: Jianxing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Pharmacotherapy: Primary Children's Medical Center, University of Utah, Salt Lake City, Utah.
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Ye
authors.affiliation: Department of Medicinal Chemistry and Center for Therapeutic Biomaterials: University of Utah, Salt Lake City, Utah.
authors.forename: Glenn D
authors.initials: GD
authors.lastname: Prestwich
authors.affiliation: Department of Surgery and Division of Pediatric Urology: Primary Children's Medical Center, Salt Lake City, Utah.
authors.forename: Siam
authors.initials: S
authors.lastname: Oottamasathien
keywords: HMGB1; LL-37; NF-kappa B; RAGE; bladder fibrosis; bladder inflammation; cathelicidin; interstitial cystitis; myelomeningocele; spina bifida