TY - JOUR
T1 - Characterization of Fibroblasts in Iatrogenic Laryngotracheal Stenosis and Type II Diabetes Mellitus
AU - Lina, Ioan
AU - Tsai, Hsiu Wen
AU - Ding, Dacheng
AU - Davis, Ruth
AU - Motz, Kevin M.
AU - Hillel, Alexander T.
N1 - Funding Information:
This study was supported by the National Institute on Deafness and Other Communication Disorders (NIDCD) of the National Institutes of Health (NIH) under award numbers 1R01DC018567, 1K23DC014082, and R21DC017225. This study was also financially supported by the Triological Society and American College of Surgeons ( a.t.h. ). The authors have no other funding, financial relationships, or conflicts of interest to disclose.
Funding Information:
Research reported in this publication was supported by the National Institute on Deafness and Other Communication Disorders of the National Institutes of Health under award numbers 1R01DC018567, 1K23DC014082, and R21DC017225. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. This study was also financially supported by the Triological Society and American College of Surgeons ( a.t.h .).
Publisher Copyright:
© 2020 American Laryngological, Rhinological and Otological Society Inc, "The Triological Society" and American Laryngological Association (ALA)
PY - 2021/7
Y1 - 2021/7
N2 - Objectives: Iatrogenic laryngotracheal stenosis (iLTS) is the pathological narrowing of the glottis, subglottis, and/or trachea due to scar tissue. Patients with type 2 diabetes mellitus (T2DM) are over 8 times more likely to develop iLTS and represent 26% to 53% of all iLTS patients. In this investigation, we compared iLTS scar-derived fibroblasts in patients with and without T2DM. Study Design: Controlled ex vivo study. Methods: iLTS scar fibroblasts were isolated and cultured from subglottic scar biopsies in iLTS patients diagnosed with or without type 2 diabetes (non-T2DM). Fibroblast proliferation, fibrosis-related gene expression, and metabolic utilization of oxidative phosphorylation (OXPHOS) and glycolysis were assessed. Contractility was measured using a collagen-based assay. Metabolically targeted drugs (metformin, phenformin, amobarbital) were tested, and changes in fibrosis-related gene expression, collagen protein, and contractility were evaluated. Results: Compared to non-T2DM, T2DM iLTS scar fibroblasts had increased α-smooth muscle actin (αSMA) expression (8.2× increased, P =.020), increased contractility (mean 71.4 ± 4.3% vs. 51.7 ± 16% Δ area × 90 minute−1, P =.016), and reduced proliferation (1.9× reduction at 5 days, P <.01). Collagen 1 (COL1) protein was significantly higher in the T2DM group (mean 2.06 ± 0.19 vs. 0.74 ±.44 COL1/total protein [pg/μg], P =.036). T2DM iLTS scar fibroblasts had increased measures of OXPHOS, including basal respiration (mean 86.7 vs. 31.5 pmol/minute/10 μg protein, P =.016) and adenosine triphosphate (ATP) generation (mean 97.5 vs. 25.7 pmol/minute/10 μg protein, P =.047) compared to non-T2DM fibroblasts. Amobarbital reduced cellular contractility; decreased collagen protein; and decreased expression of αSMA, COL1, and fibronectin. Metformin and phenformin did not significantly affect fibrosis-related gene expression. Conclusion: T2DM iLTS scar fibroblasts demonstrate a myofibroblast phenotype and greater contractility compared to non-T2DM. Their bioenergetic preference for OXPHOS drives their increased contractility, which is selectively targeted by amobarbital. Level of Evidence: NA Laryngoscope, 131:1570–1577, 2021.
AB - Objectives: Iatrogenic laryngotracheal stenosis (iLTS) is the pathological narrowing of the glottis, subglottis, and/or trachea due to scar tissue. Patients with type 2 diabetes mellitus (T2DM) are over 8 times more likely to develop iLTS and represent 26% to 53% of all iLTS patients. In this investigation, we compared iLTS scar-derived fibroblasts in patients with and without T2DM. Study Design: Controlled ex vivo study. Methods: iLTS scar fibroblasts were isolated and cultured from subglottic scar biopsies in iLTS patients diagnosed with or without type 2 diabetes (non-T2DM). Fibroblast proliferation, fibrosis-related gene expression, and metabolic utilization of oxidative phosphorylation (OXPHOS) and glycolysis were assessed. Contractility was measured using a collagen-based assay. Metabolically targeted drugs (metformin, phenformin, amobarbital) were tested, and changes in fibrosis-related gene expression, collagen protein, and contractility were evaluated. Results: Compared to non-T2DM, T2DM iLTS scar fibroblasts had increased α-smooth muscle actin (αSMA) expression (8.2× increased, P =.020), increased contractility (mean 71.4 ± 4.3% vs. 51.7 ± 16% Δ area × 90 minute−1, P =.016), and reduced proliferation (1.9× reduction at 5 days, P <.01). Collagen 1 (COL1) protein was significantly higher in the T2DM group (mean 2.06 ± 0.19 vs. 0.74 ±.44 COL1/total protein [pg/μg], P =.036). T2DM iLTS scar fibroblasts had increased measures of OXPHOS, including basal respiration (mean 86.7 vs. 31.5 pmol/minute/10 μg protein, P =.016) and adenosine triphosphate (ATP) generation (mean 97.5 vs. 25.7 pmol/minute/10 μg protein, P =.047) compared to non-T2DM fibroblasts. Amobarbital reduced cellular contractility; decreased collagen protein; and decreased expression of αSMA, COL1, and fibronectin. Metformin and phenformin did not significantly affect fibrosis-related gene expression. Conclusion: T2DM iLTS scar fibroblasts demonstrate a myofibroblast phenotype and greater contractility compared to non-T2DM. Their bioenergetic preference for OXPHOS drives their increased contractility, which is selectively targeted by amobarbital. Level of Evidence: NA Laryngoscope, 131:1570–1577, 2021.
KW - Laryngotracheal stenosis
KW - contractility
KW - fibroblast
KW - myofibroblast
KW - oxidative phosphorylation
KW - posterior glottic stenosis
KW - type 2 diabetes mellitus
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U2 - 10.1002/lary.29026
DO - 10.1002/lary.29026
M3 - Article
C2 - 32857885
AN - SCOPUS:85089962039
VL - 131
SP - 1570
EP - 1577
JO - Laryngoscope
JF - Laryngoscope
SN - 0023-852X
IS - 7
ER -