背景:我们先前发现韩国红参水提物(RGAE)增强了TMEM16A通道,在体外CF鼻上皮细胞中改善的粘膜纤毛运输(MCT)参数,因此可以作为一种治疗策略来挽救囊性纤维化(CF)气道中的MCT缺陷。本研究的假设是RGAE可以改善上皮Cl-分泌,MCT,和体内CF大鼠模型的组织病理学。
方法:将17只4月龄CFTR-/-大鼠随机分配接受每日口服对照(生理盐水,n=9)或RGAE(人参皂苷0.4mg/kg/天,n=8)持续4周。结果包括用鼻电位差(NPD)测量的鼻Cl-分泌,使用显微光学相干断层扫描对气管进行功能显微解剖,组织病理学,和TMEM16a的免疫组织化学染色。
结果:RGAE治疗的CF大鼠在UTP下具有更大的平均NPD极化(对照=-5.48+/-2.87mV,RGAE=-9.49+/-2.99mV,p<0.05),指示,至少在某种程度上,通过TMEM16A增强UTP介导的Cl-分泌。所有测得的气管MCT参数(气道表面液体,纤毛液体,纤毛搏动频率,MCT)在RGAE处理的CF大鼠中显著增加,MCT表现出3倍的增加(对照,0.45+/-0.31vs.RGAE,1.45+/-0.66mm/min,p<0.01)。上颌粘膜组织病理学在RGAE治疗的队列中显著改善(细胞内粘液减少,杯状细胞没有扩张,和较短的上皮高度)。TMEM16A表达在组间相似。
结论:RGAE改善TMEM16A介导的跨上皮Cl-分泌,功能显微解剖学,和CF大鼠的组织病理学。利用TMEM16A增效剂治疗CF气道疾病的治疗策略是适当的,并且为不依赖突变的治疗提供了新的途径。
BACKGROUND: We previously discovered that Korean red ginseng aqueous extract (RGAE) potentiates the TMEM16A channel, improved mucociliary transport (MCT) parameters in CF nasal epithelia in vitro, and thus could serve as a therapeutic strategy to rescue the MCT defect in cystic fibrosis (CF) airways. The hypothesis of this study is that RGAE can improve epithelial Cl- secretion, MCT, and histopathology in an in-vivo CF rat model.
METHODS: Seventeen 4-month old CFTR-/- rats were randomly assigned to receive daily oral control (saline, n = 9) or RGAE (Ginsenosides 0.4mg/kg/daily, n = 8) for 4 weeks. Outcomes included nasal Cl- secretion measured with the nasal potential difference (NPD), functional microanatomy of the trachea using micro-optical coherence tomography, histopathology, and immunohistochemical staining for TMEM16a.
RESULTS: RGAE-treated CF rats had greater mean NPD polarization with UTP (control = -5.48 +/- 2.87 mV, RGAE = -9.49 +/- 2.99 mV, p < 0.05), indicating, at least in part, potentiation of UTP-mediated Cl- secretion through TMEM16A. All measured tracheal MCT parameters (airway surface liquid, periciliary liquid, ciliary beat frequency, MCT) were significantly increased in RGAE-treated CF rats with MCT exhibiting a 3-fold increase (control, 0.45+/-0.31 vs. RGAE, 1.45+/-0.66 mm/min, p < 0.01). Maxillary mucosa histopathology was markedly improved in RGAE-treated cohort (reduced intracellular mucus, goblet cells with no distention, and shorter epithelial height). TMEM16A expression was similar between groups.
CONCLUSIONS: RGAE improves TMEM16A-mediated transepithelial Cl- secretion, functional microanatomy, and histopathology in CF rats. Therapeutic strategies utilizing TMEM16A potentiators to treat CF airway disease are appropriate and provide a new avenue for mutation-independent therapies.