Regulation of vocal fold transepithelial water fluxes

Abstract

Vocal fold hydration is critical to phonation. We hypothesized that the vocal fold generates bidirectional water fluxes, which are regulated by activity of the Na(+)-K(+)- ATPase. Western blots and immunohistochemistry demonstrated the presence of the alpha-subunit Na(+)-K(+)-ATPase in the canine vocal fold (n = 11). Luminal cells, basal and adjacent one to two layers of suprabasal cells within stratified squamous epithelium, were immunopositive, as well as basolateral membranes of submucosal seromucous glands underlying transitional epithelia. Canine (n = 6) and ovine (n = 14) vocal fold mucosae exhibited transepithelial potential differences of 8.1 +/- 2.8 and 9.3 +/- 1.3 mV (lumen negative), respectively. The potential difference and short-circuit current (ovine = 31 +/- 4 microA/cm(2); canine = 41 +/- 10 microA/cm(2)) were substantially reduced by luminal administration of 75 microM acetylstrophanthidin (P < 0.05). Ovine (n = 7) transepithelial water fluxes decreased from 5.1 +/- 0.3 to 4.3 +/- 0.3 microl x min(-1) x cm(-2) from the basal to luminal chamber and from 5.2 +/- 0.2 to 3.9 +/- 0.3 microl x min(-1) x cm(-2) from the luminal to basal chamber by luminal acetylstrophanthidin (P < 0.05). The presence of the Na(+)-K(+)-ATPase in the vocal fold epithelium and the electrolyte transport derived from its activity provide the intrinsic mechanisms to regulate cell volume as well as vocal fold hydration.

Human Embryonic Stem Cell-Derived Epithelial Cells in a Novel In Vitro Model of Vocal Mucosa

“…Therefore, in addition to demonstrating an epithelial phenotype, candidate tissue constructs must also demonstrate the presence of important components of the epithelial barrier, including intercellular junctions. The native vocal fold epithelium contains intercellular junctions, including tight junctions, 10,11 gap junctions, 12 adherens junctions, 11 and desmosomes. 10 While Long and colleagues 9 reported the presence of e-cadherin, a marker of adherens junctions, in their model, further evidence of intercellular junctions was not provided.…”

“…The native vocal fold epithelium contains intercellular junctions, including tight junctions, 10,11 gap junctions, 12 adherens junctions, 11 and desmosomes. 10 While Long and colleagues 9 reported the presence of e-cadherin, a marker of adherens junctions, in their model, further evidence of intercellular junctions was not provided. The presence of intercellular junctions in a model of vocal fold mucosa is important as these structural features render the native epithelium tight as evidenced by transepithelial resistance in animal models in excess of 300 ohms.…”

The Possibilities of Cell Technologies in the Treatment of Cicatricial Lesions of the Vocal Folds

“…Стволовые клетки способны мигрировать к поражен-ному участку органа не только при локальном введении, но и из системного кровотока; дифференцироваться в фибробласты, одновременно восполняя недостающий клеточный резерв, индуцируя регенерацию тканей, по-давляя воспалительные реакции, стимулируя ангиогенез и способствуя деградации грубой рубцовой ткани [6,70]. Однако системное введение МСК с целью зажив-ления повреждений голосовой складки представляется нецелесообразным в связи с миграцией и избирательным накоплением МСК в костном мозге, печени и легких ре-ципиента, где локализуется большая часть пересаженных клеток [70].…”

“…В свою очередь, способность голосовой складки к вибрации предопределена особы-ми биомеханическими свойствами ее ткани, которые определяются морфологическим строением. Слизистая оболочка голосовых складок покрыта многослойным плоским неороговевающим эпителием, состоящим из базальных, поверхностных клеток, имеющих микровор-синки, а также дендритных клеток, проникающих через базальную мембрану, состоящую в основном из якорных белков (коллаген VII типа, фибронектин) и обеспечива-ющую прикрепление эпителия к собственной пластинке [2,5,6].…”

Bioengineering the Vocal Fold: A Review of Mesenchymal Stem Cell Applications

“…The vocal folds are covered by stratified squamous epithelium, which serves as a protective barrier against chemical, pathogenic and mechanical insults (Sivasankar et al, 2010;Mogi et al, 1979;Gray & Titze, 1988;Gipson et al, 1995;Johnston et al, 2003). Laryngeal epithelial cells also help maintain local hydration, which is essential for healthy voice production (Fisher et al, 2001). The most abundant cell type in the lamina propria is the vocal fold fibroblast.…”