Activation of airway epithelial bitter taste receptors by Pseudomonas aeruginosa quinolones modulates calcium, cyclic-AMP, and nitric oxide signaling
Activation of airway epithelial bitter taste receptors by Pseudomonas aeruginosa quinolones modulates calcium, cyclic-AMP, and nitric oxide signaling
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DOI：
10.1074/jbc.ra117.001005
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发表时间：
2018-06-22
影响因子：
4.8
通讯作者：
Lee, Robert J.
中科院分区：
文献类型：
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作者：
Freund, Jenna R.;Mansfield, Corrine J.;Lee, Robert J.
苦味受体（味觉家族2苦味受体蛋白; T2 R），发现于舌外的许多组织中，最近已成为潜在的治疗靶点。我们先前已经表明，气道上皮细胞表达几种T2 R，其激活先天免疫应答，这对于治疗气道疾病如慢性鼻窦炎可能是重要的。必须更清楚地了解哪些化合物激活气道T2 R以及它们的全部功能。气道运动纤毛中的T2 R亚型（T2 R4、-14、-16和-38）产生杀菌水平的一氧化氮（NO），其也增加纤毛搏动，促进粘液和捕获的病原体的清除。细菌群体感应酰基高丝氨酸内酯激活T2 R并刺激初级气道细胞中的这些反应。喹诺酮是铜绿假单胞菌使用的另一种群体感应分子。为了阐明细菌喹诺酮类是否激活气道T2 R，我们使用荧光指示染料和基于FRET的蛋白质生物传感器的组合分析了钙、cAMP和NO动力学。用2-庚基-3-羟基-4-喹诺酮（称为假单胞菌喹诺酮信号; PQS）、2，4-二羟基喹诺酮和4-羟基-2-庚基喹诺酮（HHQ）测试T2 R转染的HEK 293 T细胞、几种肺上皮细胞系和在气液界面生长和分化的原代鼻窦细胞。在HEK 293 T细胞中，PQS激活T2 R4、-16和-38，而HHQ激活T2 R14。2，4-二羟基喹诺酮无作用。PQS和HHQ增加钙，降低培养和原代气道细胞的基线和刺激cAMP水平。在原代细胞中，PQS和HHQ激活NO合成水平，先前显示为杀菌的。这项研究表明，气道T2 R介导的免疫反应被细菌喹诺酮类以及酰基高丝氨酸内酯激活。
Bitter taste receptors (taste family 2 bitter receptor proteins; T2Rs), discovered in many tissues outside the tongue, have recently become potential therapeutic targets. We have shown previously that airway epithelial cells express several T2Rs that activate innate immune responses that may be important for treatment of airway diseases such as chronic rhinosinusitis. It is imperative to more clearly understand what compounds activate airway T2Rs as well as their full range of functions. T2R isoforms in airway motile cilia (T2R4, -14, -16, and -38) produce bactericidal levels of nitric oxide (NO) that also increase ciliary beating, promoting clearance of mucus and trapped pathogens. Bacterial quorum-sensing acyl-homoserine lactones activate T2Rs and stimulate these responses in primary airway cells. Quinolones are another type of quorum-sensing molecule used by Pseudomonas aeruginosa. To elucidate whether bacterial quinolones activate airway T2Rs, we analyzed calcium, cAMP, and NO dynamics using a combination of fluorescent indicator dyes and FRET-based protein biosensors. T2R-transfected HEK293T cells, several lung epithelial cell lines, and primary sinonasal cells grown and differentiated at the air-liquid interface were tested with 2-heptyl-3-hydroxy-4-quinolone (known as Pseudomonas quinolone signal; PQS), 2,4-dihydroxyquinolone, and 4-hydroxy-2-heptylquinolone (HHQ). In HEK293T cells, PQS activated T2R4, -16, and -38, whereas HHQ activated T2R14. 2,4-Dihydroxyquinolone had no effect. PQS and HHQ increased calcium and decreased both baseline and stimulated cAMP levels in cultured and primary airway cells. In primary cells, PQS and HHQ activated levels of NO synthesis previously shown to be bactericidal. This study suggests that airway T2R-mediated immune responses are activated by bacterial quinolones as well as acyl-homoserine lactones.