Rapamycin inhibits human laryngotracheal stenosis-derived fibroblast proliferation, metabolism, and function in vitro

Otolaryngol Head Neck Surg. 2015 May;152(5):881-8. doi: 10.1177/0194599815573708. Epub 2015 Mar 9.


Objective: To determine if rapamycin inhibits the growth, function, and metabolism of human laryngotracheal stenosis (LTS)-derived fibroblasts.

Study design: Controlled in vitro study.

Setting: Tertiary care hospital in a research university.

Subjects and 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.

Keywords: collagen; fibroblasts; human; laryngotracheal stenosis; rapamycin; trachea.

MeSH terms

  • Cell Culture Techniques
  • Cell Proliferation / drug effects*
  • Collagen / metabolism
  • Fibroblasts / drug effects*
  • Fibroblasts / metabolism
  • Fibroblasts / physiology*
  • Humans
  • Immunosuppressive Agents / pharmacology*
  • Laryngostenosis / immunology
  • Laryngostenosis / pathology*
  • Real-Time Polymerase Chain Reaction
  • Sirolimus / pharmacology*


  • Immunosuppressive Agents
  • Collagen
  • Sirolimus