Spyryx Biosciences, Durham, NC 27713, United States.
Spyryx Biosciences, Durham, NC 27713, United States.
J Cyst Fibros. 2019 Mar;18(2):244-250. doi: 10.1016/j.jcf.2018.06.002. Epub 2018 Jun 20.
In healthy lungs, epithelial sodium channel (ENaC) is regulated by short, palate, lung, and nasal clone 1 (SPLUNC1). In cystic fibrosis (CF), ENaC is hyperactivated in part due to a loss of SPLUNC1 function. We have developed SPX-101 to replace the lost function of SPLUNC1 in the CF lung.
Expression of SPLUNC1 was determined in sputum from healthy and CF donors. Stability of SPLUNC1, S18 (the ENaC regulatory domain of SPLUNC1), and SPX-101 was determined in sputum from CF donors and towards neutrophil elastase. Activity of SPX-101 after exposure to CF sputum was determined in airway epithelial cells from CF donors and in the βENaC transgenic mouse model.
SPLUNC1 protein expression is significantly reduced in CF as compared to healthy sputum. SPLUNC1 is rapidly degraded in CF sputum as well as by a number of individual proteases known to be found in the sputum. SPX-101, but not S18, is stable in CF sputum. Finally, SPX-101 retains its ability to internalize ENaC, regulate airway surface liquid height, and increase survival of βENaC mice after exposure to CF sputum.
Our results demonstrate that SPX-101, but not SPLUNC1 or S18, is stable in CF sputum. These results support the therapeutic development of SPX-101 for the treatment of cystic fibrosis.
在健康的肺部中，上皮钠离子通道（ENaC）受短 palate lung and nasal clone 1（SPLUNC1）的调节。在囊性纤维化（CF）中，ENaC 的过度激活部分归因于 SPLUNC1 功能的丧失。我们开发了 SPX-101 以替代 CF 肺部中 SPLUNC1 的丢失功能。
测定健康和 CF 供体的痰液中 SPLUNC1 的表达。测定 CF 供体痰液中 SPLUNC1、S18（SPLUNC1 的 ENaC 调节域）和 SPX-101 的稳定性以及它们对中性粒细胞弹性蛋白酶的稳定性。在 CF 供体的气道上皮细胞和βENaC 转基因小鼠模型中测定 SPX-101 在暴露于 CF 痰液后的活性。
与健康痰液相比，CF 中的 SPLUNC1 蛋白表达显著降低。SPLUNC1 在 CF 痰液中以及在许多已知存在于痰液中的单个蛋白酶的作用下迅速降解。SPX-101 而不是 S18 在 CF 痰液中稳定。最后，SPX-101 在暴露于 CF 痰液后仍保留其内化 ENaC、调节气道表面液体高度和增加βENaC 小鼠存活率的能力。
我们的结果表明，SPX-101 而不是 SPLUNC1 或 S18 在 CF 痰液中稳定。这些结果支持 SPX-101 治疗囊性纤维化的治疗开发。
