Liu Xinxin, Walimbe Tanaya, Schrock William Pierre, Zheng Wei, Sivasankar M Preeti
School of Health Sciences, Purdue University, West Lafayette, Indiana.
Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana.
J Voice. 2017 Nov;31(6):662-668. doi: 10.1016/j.jvoice.2017.03.014. Epub 2017 Apr 21.
Airway exposure to nanoparticles is common in occupational settings. Inhaled nanoparticles have toxic effects on respiratory tissue. Vocal folds are also at direct risk from inhaled nanoparticles. This study investigated the effects of single-walled carbon nanotubes (SWCNT), a type of nanoparticle, on vocal fold epithelium and fibroblasts. These cell types were selected for study as the epithelium is the outer layer of the vocal folds and fibroblasts are the most common cell type in connective tissue underlying the epithelium.
Native porcine vocal fold epithelium and cultured human vocal fold fibroblasts were exposed to SWCNTs (100 ng/mL) and control (no SWCNT) in vitro. Epithelial and fibroblast viability was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Epithelial barrier integrity was assessed with transepithelial resistance and sodium fluorescein permeability. Epithelial tight junctional protein occludin expression was measured with Western blot. Gene expressions of the fibroblast-specific protein 1 (FSP-1), α-smooth muscle actin (α-SMA), and collagen III (Col-III) were assessed using quantitative polymerase chain reaction.
Transcriptional expression of genes encoding FSP-1 and Col-III was increased significantly following SWCNT exposure. There were no significant differences between control and SWCNT groups on any of the other measures.
SWCNT exposure induces vocal fold fibroblasts to a fibrotic phenotype. These data help us understand vocal fold defense mechanisms and lay the groundwork for studying the physiological effects of nanoparticle exposure in vivo.
在职业环境中，气道暴露于纳米颗粒很常见。吸入的纳米颗粒对呼吸组织有毒性作用。声带也直接面临吸入纳米颗粒的风险。本研究调查了一种纳米颗粒——单壁碳纳米管（SWCNT）对声带上皮细胞和成纤维细胞的影响。选择这些细胞类型进行研究是因为上皮细胞是声带的外层，而成纤维细胞是上皮细胞下方结缔组织中最常见的细胞类型。
将天然猪声带上皮细胞和培养的人声带成纤维细胞在体外暴露于SWCNT（100 ng/mL）和对照组（无SWCNT）。使用3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）法测量上皮细胞和成纤维细胞的活力。通过跨上皮电阻和荧光素钠通透性评估上皮屏障完整性。用蛋白质印迹法测量上皮紧密连接蛋白闭合蛋白的表达。使用定量聚合酶链反应评估成纤维细胞特异性蛋白1（FSP-1）、α-平滑肌肌动蛋白（α-SMA）和胶原蛋白III（Col-III）的基因表达。
暴露于SWCNT后，编码FSP-1和Col-III的基因转录表达显著增加。在其他任何测量指标上，对照组和SWCNT组之间均无显著差异。
暴露于SWCNT会诱导声带成纤维细胞转变为纤维化表型。这些数据有助于我们了解声带防御机制，并为研究纳米颗粒体内暴露的生理效应奠定基础。
