title: Rapamycin inhibits human laryngotracheal stenosis-derived fibroblast proliferation, metabolism, and function in vitro.
abstract: OBJECTIVE
  To determine if rapamycin inhibits the growth, function, and metabolism of human laryngotracheal stenosis (LTS)-derived fibroblasts.
  
  
  METHODS
  Controlled in vitro study.
  
  
  METHODS
  Tertiary care hospital in a research university.
  
  
  METHODS
  Fibroblasts isolated from biopsies of 5 patients with laryngotracheal stenosis were cultured. Cell proliferation, histology, gene expression, and cellular metabolism of LTS-derived fibroblasts were assessed in 4 conditions: (1) fibroblast growth medium, (2) fibroblast growth medium with dimethylsulfoxide (DMSO), (3) fibroblast growth medium with 10(-10) M (low-dose) rapamycin dissolved in DMSO, and (4) fibroblast growth medium with 10(-9) M (high-dose) rapamycin dissolved in DMSO.
  
  
  RESULTS
  The LTS fibroblast count and DNA concentration were reduced after treatment with high-dose rapamycin compared to DMSO (P = .0007) and normal (P = .0007) controls. Collagen I expression decreased after treatment with high-dose rapamycin versus control (P = .0051) and DMSO (P = .0093) controls. Maximal respiration decreased to 68.6 pMoles of oxygen/min/10 mg/protein from 96.9 for DMSO (P = .0002) and 97.0 for normal (P = .0022) controls. Adenosine triphosphate (ATP) production decreased to 66.8 pMoles from 88.1 for DMSO (P = .0006) and 83.3 for normal (P = .0003) controls. Basal respiration decreased to 78.6 pMoles from 108 for DMSO (P = .0002) and 101 for normal (P = .0014) controls.
  
  
  CONCLUSIONS
  Rapamycin demonstrated an anti-fibroblast effect by significantly reducing the proliferation, metabolism, and collagen deposition of human LTS fibroblast in vitro. Rapamycin significantly decreased oxidative phosphorylation of LTS fibroblasts, suggesting at a potential mechanism for the reduced proliferation and differentiation. Furthermore, rapamycin's anti-fibroblast effects indicate a promising adjuvant therapy for the treatment of laryngotracheal stenosis.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Daryan R
authors.initials: DR
authors.lastname: Namba
authors.affiliation: Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Garret
authors.initials: G
authors.lastname: Ma
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Idris
authors.initials: I
authors.lastname: Samad
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Dacheng
authors.initials: D
authors.lastname: Ding
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Vinciya
authors.initials: V
authors.lastname: Pandian
authors.affiliation: Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Powell
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Maureen R
authors.initials: MR
authors.lastname: Horton
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA ahillel@jhmi.edu.
authors.forename: Alexander T
authors.initials: AT
authors.lastname: Hillel
mesh_terms: D018929:Cell Culture Techniques; D049109:Cell Proliferation / Q000187:drug effects*; D003094:Collagen / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007829:Laryngostenosis / Q000276:immunology / Q000473:pathology*; D060888:Real-Time Polymerase Chain Reaction; D020123:Sirolimus / Q000494:pharmacology*
chemical_list: D007166:Immunosuppressive Agents; D003094:Collagen; D020123:Sirolimus
keywords: collagen; fibroblasts; human; laryngotracheal stenosis; rapamycin; trachea