当前位置: X-MOL 学术Am. J. Respir. Cell Mol. Biol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Diacylglycerol Kinase Inhibition Reduces Airway Contraction by Negative Feedback Regulation of Gq-Signaling
American Journal of Respiratory Cell and Molecular Biology ( IF 6.4 ) Pub Date : 2021-12-01 , DOI: 10.1165/rcmb.2021-0106oc
Pawan Sharma 1 , Santosh K Yadav 1 , Sushrut D Shah 1 , Elham Javed 1 , John M Lim 1 , Shi Pan 1 , Ajay P Nayak 1 , Reynold A Panettieri 2 , Raymond B Penn 1 , Taku Kambayashi 3 , Deepak A Deshpande 1
Affiliation  

Exaggerated airway smooth muscle (ASM) contraction regulated by the Gq family of G protein-coupled receptors causes airway hyperresponsiveness in asthma. Activation of Gq-coupled G protein-coupled receptors leads to phospholipase C (PLC)-mediated generation of inositol triphosphate (IP3) and diacylglycerol (DAG). DAG signaling is terminated by the action of DAG kinase (DGK) that converts DAG into phosphatidic acid (PA). Our previous study demonstrated that DGKζ and α isoform knockout mice are protected from the development of allergen-induced airway hyperresponsiveness. Here we aimed to determine the mechanism by which DGK regulates ASM contraction. Activity of DGK isoforms was inhibited in human ASM cells by siRNA-mediated knockdown of DGKα and ζ, whereas pharmacological inhibition was achieved by pan DGK inhibitor I (R59022). Effects of DGK inhibition on contractile agonist-induced activation of PLC and myosin light chain (MLC) kinase, elevation of IP3, and calcium levels were assessed. Furthermore, we used precision-cut human lung slices and assessed the role of DGK in agonist-induced bronchoconstriction. DGK inhibitor I attenuated histamine- and methacholine-induced bronchoconstriction. DGKα and ζ knockdown or pretreatment with DGK inhibitor I resulted in attenuated agonist-induced phosphorylation of MLC and MLC phosphatase in ASM cells. Furthermore, DGK inhibition decreased Gq agonist-induced calcium elevation and generation of IP3 and increased histamine-induced production of PA. Finally, DGK inhibition or treatment with DAG analog resulted in attenuation of activation of PLC in human ASM cells. Our findings suggest that DGK inhibition perturbed the DAG:PA ratio, resulting in inhibition of Gq-PLC activation in a negative feedback manner, resulting in protection against ASM contraction.



中文翻译:

二酰基甘油激酶抑制通过 Gq 信号的负反馈调节减少气道收缩

由 G 蛋白偶联受体 Gq 家族调节的过度气道平滑肌 (ASM) 收缩导致哮喘患者气道高反应性。Gq 偶联 G 蛋白偶联受体的激活导致磷脂酶 C (PLC) 介导的三磷酸肌醇 (IP 3) 和甘油二酯 (DAG)。DAG 信号由将 DAG 转化为磷脂酸 (PA) 的 DAG 激酶 (DGK) 的作用终止。我们之前的研究表明,DGKζ 和 α 同种型敲除小鼠可以免受过敏原诱导的气道高反应性的发展。在这里,我们旨在确定 DGK 调节 ASM 收缩的机制。通过 siRNA 介导的 DGKα 和 ζ 敲低,人类 ASM 细胞中 DGK 同种型的活性受到抑制,而泛 DGK 抑制剂 I (R59022) 则实现了药理抑制。DGK 抑制对收缩激动剂诱导的 PLC 和肌球蛋白轻链 (MLC) 激酶激活、IP 3 升高的影响,和钙水平进行了评估。此外,我们使用精确切割的人肺切片并评估 DGK 在激动剂诱导的支气管收缩中的作用。DGK 抑制剂 I 减弱组胺和乙酰甲胆碱诱导的支气管收缩。DGKα 和 ζ 敲低或用 DGK 抑制剂 I 预处理导致 ASM 细胞中 MLC 和 MLC 磷酸酶的减弱激动剂诱导的磷酸化。此外,DGK 抑制降低了 Gq 激动剂诱导的钙升高和 IP 3的产生并增加组胺诱导的 PA 产生。最后,DGK 抑制或用 DAG 类似物处理导致人类 ASM 细胞中 PLC 活化减弱。我们的研究结果表明,DGK 抑制扰乱了 DAG:PA 比率,导致以负反馈方式抑制 Gq-PLC 激活,从而防止 ASM 收缩。

更新日期:2021-12-01
down
wechat
bug