Aubin Vega Mélissa, Girault Alban, Adam Damien, Chebli Jasmine, Privé Anik, Maillé Émilie, Robichaud Annette, Brochiero Emmanuelle
Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada.
Département de Médecine, Université de Montréal, Montréal, QC, Canada.
Front Physiol. 2023 Jan 9;13:1069466. doi: 10.3389/fphys.2022.1069466. eCollection 2022.
Alveolar ion and fluid absorption is essential for lung homeostasis in healthy conditions as well as for the resorption of lung edema, a key feature of acute respiratory distress syndrome. Liquid absorption is driven by active transepithelial sodium transport, through apical ENaC Na channels and basolateral Na/K-ATPase. Our previous work unveiled that KvLQT1 K channels also participate in the control of Na/liquid absorption in alveolar epithelial cells. Our aim was to further investigate the function of KvLQT1 channels and their interplay with other channels/transporters involved in ion/liquid transport using adult wild-type (WT) and KvLQT1 knock-out (KO) mice under physiological conditions and after thiourea-induced lung edema. A slight but significant increase in water lung content (WLC) was observed in naïve KvLQT1-KO mice, relative to WT littermates, whereas lung function was generally preserved and histological structure unaltered. Following thiourea-induced lung edema, KvLQT1-KO did not worsen WLC or lung function. Similarly, lung edema was not aggravated by the administration of a KvLQT1 inhibitor (chromanol). However, KvLQT1 activation (R-L3) significantly reduced WLC in thiourea-challenged WT mice. The benefits of R-L3 were prevented in KO or chromanol-treated WT mice. Furthermore, R-L3 treatment had no effect on thiourea-induced endothelial barrier alteration but restored or enhanced the levels of epithelial alveolar AQP5, Na/K-ATPase, and ENaC expressions. Altogether, the results indicate the benefits of KvLQT1 activation in the resolution of lung edema, probably through the observed up-regulation of epithelial alveolar channels/transporters involved in ion/water transport.
在健康状态下,肺泡离子和液体吸收对于肺内环境稳定至关重要,对于急性呼吸窘迫综合征的关键特征——肺水肿的吸收也很重要。液体吸收由活跃的跨上皮钠转运驱动,通过顶端的ENaC钠通道和基底外侧的钠钾ATP酶。我们之前的研究表明,KvLQT1钾通道也参与肺泡上皮细胞中钠/液体吸收的调控。我们的目的是在生理条件下以及硫脲诱导肺水肿后,使用成年野生型(WT)和KvLQT1基因敲除(KO)小鼠,进一步研究KvLQT1通道的功能及其与其他参与离子/液体转运的通道/转运体之间的相互作用。相对于野生型同窝小鼠,在未经处理的KvLQT1基因敲除小鼠中观察到肺含水量(WLC)略有但显著增加,而肺功能总体保持正常,组织结构未改变。硫脲诱导肺水肿后,KvLQT1基因敲除并未使WLC或肺功能恶化。同样,给予KvLQT1抑制剂(色满醇)也未加重肺水肿。然而,KvLQT1激活剂(R-L3)显著降低了硫脲刺激的野生型小鼠的WLC。在基因敲除小鼠或色满醇处理的野生型小鼠中,R-L3的益处被消除。此外,R-L3处理对硫脲诱导的内皮屏障改变没有影响,但恢复或增强了肺泡上皮水通道蛋白5(AQP5)、钠钾ATP酶和ENaC的表达水平。总之,结果表明激活KvLQT1对肺水肿的消退有益,可能是通过观察到的参与离子/水转运的肺泡上皮通道/转运体的上调实现的。