Acute Acrolein Exposure Induces Impairment of Vocal Fold Epithelial Barrier Function

Abstract

Acrolein is a ubiquitous pollutant abundant in cigarette smoke, mobile exhaust, and industrial waste. There is limited literature on the effects of acrolein on vocal fold tissue, although there are clinical reports of voice changes after pollutant exposures. Vocal folds are responsible for voice production. The overall objective of this study was to investigate the effects of acrolein exposure on viable, excised vocal fold epithelial tissue and to characterize the mechanism underlying acrolein toxicity. Vocal fold epithelia were studied because they form the outermost layer of the vocal folds and are a primary recipient of inhaled pollutants. Porcine vocal fold epithelia were exposed to 0, 50, 100, 500, 900 or 1300 μM of acrolein for 3 hours; the metabolic activity, epithelial resistance, epithelial permeability, tight junction protein (occludin and claudin 3) expression, cell membrane integrity and lipid peroxidation were investigated. The data demonstrated that acrolein exposure at 500 μM significantly reduced vocal fold epithelial metabolic activity by 27.2% (p≤0.001). Incubation with 100 μM acrolein caused a marked increase in epithelial permeability by 130.5% (p<0.05) and a reduction in transepithelial electrical resistance (TEER) by 180.0% (p<0.001). While the expression of tight junctional protein did not change in acrolein-treated samples, the cell membrane integrity was significantly damaged with a 45.6% increase of lipid peroxidation as compared to controls (p<0.05). Taken together, these data provide evidence that acute acrolein exposure impairs vocal fold epithelial barrier integrity. Lipid peroxidation-induced cell membrane damage may play an important role in reducing the barrier function of the epithelium.

Acute Nanoparticle Exposure to Vocal Folds: A Laboratory Study

“…Previous data have shown that short duration exposure to acidic challenges and pollutants reduce the vocal fold epithelia resistance. 9,35 However, epithelial barrier integrity was preserved for 5 hours after SWCNT exposure, suggesting that the vocal folds may be able to effectively defend against nanoparticles in the short-term.…”

“…This epithelial barrier can be adversely affected by pollutants found in ciagarettes. 9–12 Though no study has investigated the effect of CNTs on vocal fold epithelium, CNTs are reported to reduce epithelial resistance in a tracheobronchial epithelial cell line. 13 Fibroblasts are the most common cell type in the vocal folds and are important for synthesizing extracellular matrix (ECM) components such as collagen and elastin.…”

Subacute acrolein exposure to rat larynx in vivo

“…iTaq Universal SYBR Green Supermix kit (Bio‐Rad) was used for the qPCR detection. The qPCR was performed using a protocol described previously . Relative expressions of the target genes were assessed using ΔΔ Ct.…”

“…There is some research on the effects of acrolein exposure to the larynx. In excised porcine vocal folds, acute acrolein exposure reduced epithelial sodium ion transport, induced lipid peroxidation, and impaired epithelial integrity and barrier function . However, in vivo studies are needed to fully understand the mechanisms underlying pathological changes from specific pollutant exposures such as acrolein.…”

“…In excised porcine vocal folds, acute acrolein exposure reduced epithelial sodium ion transport, induced lipid peroxidation, and impaired epithelial integrity and barrier function. 14,15 However, in vivo studies are needed to fully understand the mechanisms underlying pathological changes from specific pollutant exposures such as acrolein. The underlying mechanisms for acrolein-induced inflammation in the distal airway have been investigated.…”