Chemogenetic approach to treat Obstructive Sleep Apnea

项目摘要 阻塞性睡眠呼吸暂停（OSA）是由于上呼吸道肌肉的丧失而引起的反复发作的上呼吸道阻塞 睡眠中的紧张，导致间歇性缺氧和睡眠碎片。阻塞性睡眠呼吸暂停综合征是一种常见的疾病 影响25-30%的成年人口，是心血管疾病发病率和死亡率的主要原因。连续 气道正压通气可缓解阻塞性睡眠呼吸暂停，但依从性差严重限制了其应用。迫切需要 替代疗法，逆转上呼吸道功能的神经肌肉缺陷。上呼吸道通畅 由舌前突调节，包括最大的上呼吸道扩张器、颏舌肌（GG）肌肉， 但是呼吸器和牵开器两者可以协同作用以在睡眠期间稳定上气道。的 治疗策略的发展由于缺乏对不同的药物作用的了解而受到阻碍。 舌肌在OSA的发病机制中起重要作用，因为选择性地操纵这些肌肉的方法还没有 迄今为止，已提供。我们已经证明小鼠上呼吸道生理学与人类相同 肥胖的老鼠会患上阻塞性睡眠呼吸暂停综合症。我们将使用阻塞性睡眠呼吸暂停综合征的小鼠模型和其他新颖的研究工具， 即化学遗传学和动态磁共振成像（MRI），以检查特定的影响， 舌下神经运动神经元支配舌伸肌和缩肌对咽部开放的影响 和阻塞性睡眠呼吸暂停。我们的建议利用一种新的化学遗传学方法， 运动神经元群体选择性地与设计受体专门激活的设计药物 （梦想）。兴奋性和抑制性DREADD将用于解决以下主要假设： 刺激舌下神经运动神经元的特定群体是必要的并且足以 稳定咽部开放和治疗OSA。具体目标1和2将审查不同的 舌下神经运动神经元群在维持上呼吸道通畅和OSA发展中的作用。 我们假设（A）单独或结合牵开器的GG纤维的化学发生刺激 肌肉将增加上呼吸道的开放性并治疗OSA，而（B）化学发生抑制将 降低气道通畅性并诱发OSA。Cre-dependent DREADD将在舌下神经中部署 核和选择性表达的运动神经元支配的舌背单独或背和 牵开器使用Cre重组酶与逆行神经元载体一起施用。具体目标1，动态 MRI将在通过DREADD特异性配体氯氮平-N-甲基-N- 氧化物（CNO），在瘦和肥胖的雄性和雌性小鼠。在具体目标2中，将进行睡眠研究， 或不通过CNO激活DREADD，以鉴定不同马达的化学遗传操纵的效果。 神经元池对NREM和REM睡眠期间睡眠呼吸暂停的影响。该提案将集中在未来的治疗 特定舌下神经运动神经元的电刺激和药物刺激策略。

PROJECT SUMMARY Obstructive sleep apnea (OSA) is recurrent upper airway obstruction caused by a loss of upper airway muscle tone during sleep, which leads to intermittent hypoxia and sleep fragmentation. OSA is a common disorder affecting 25-30% of adult population and a major cause of cardiovascular morbidity and mortality. Continuous positive airway pressure relieves OSA, but poor adherence severely limits its use. There is an urgent need for alternative therapies that reverse neuromuscular defects in upper airway function. The upper airway patency is regulated by lingual protrudors, including the biggest upper airway dilator, the genioglossus (GG) muscle, but both protrudors and retractors may act synergistically to stabilize the upper airway during sleep. The development of therapeutic strategies has been hindered by the lack of knowledge about the role of different tongue muscles in the pathogenesis of OSA, since methods to manipulate these muscles selectively have not hitherto been available. We have demonstrated that mouse upper airway physiology is identical to humans and that obese mice develop OSA. We will use our mouse model of OSA and other novel investigative tools, i.e. chemogenetics and dynamic magnetic resonance imaging (MRI), to examine the impact of specific hypoglossal motor neurons innervating lingual protrudor and retractor muscles on pharyngeal patency and obstructive sleep apnea. Our proposal utilizes a novel chemogenetic approach for targeting specific motor neuron populations selectively with designer receptors exclusively activated by designer drugs (DREADDs). Excitatory and inhibitory DREADDs will be used to address the main hypothesis that stimulation of specific populations of hypoglossal motor neurons is both necessary and sufficient to stabilize pharyngeal patency and treat OSA. Specific Aim 1 and 2 will examine the role of different populations of hypoglossal motor neurons in maintaining upper airway patency and the development of OSA. We hypothesize that (A) chemogenetic stimulation of GG fibers in isolation OR in combination with retractor muscles will increase patency of the upper airway and treat OSA, whereas (B) chemogenetic inhibition will decrease airway patency and induce OSA. Cre-dependent DREADDs will be deployed in the hypoglossal nucleus and selectively expressed in motor neurons innervating tongue protrudors alone OR protrudors and retractors using Cre-recombinase administered with a retrograde neuronal vector. In Specific Aim 1, dynamic MRI will be performed before and after motor neuron manipulation by a DREADD specific ligand, clozapine-N- oxide (CNO), in lean and obese male and female mice. In Specific Aim 2, sleep studies will be performed with or without DREADD activation by CNO to identify the effect of chemogenetic manipulation of different motor neuron pools on sleep apnea during NREM and REM sleep. The proposal will focus future therapeutic strategies on specific hypoglossal motor neurons for electrical and pharmacological stimulation.