Developing a non-animal model system to investigate bitter tastants as new treatments for asthma

最近的观察表明，苦味化合物会导致肺部呼吸道的开放，这表明这些化合物在治疗哮喘方面具有一定的作用。这是意想不到的，因为苦味检测被认为是为了保护动物(包括人类)免受有害的、通常是苦涩的化合物的摄入。苦味化合物是由舌头上发现的一种名为TAS2Rs的受体家族检测到的。然而，有趣的是，目前还不清楚这些TAS2R是否参与哮喘的治疗，或者这种影响是否通过未知的蛋白质发生。越来越多的证据表明，这些化合物可能通过TAS2R独立靶点发挥作用，但这些靶点仍有待发现。对苦味化合物及其在哮喘中的作用方式的研究主要集中在使用从豚鼠和小鼠以及从人类获得的肺组织。这项研究涉及使用这种动物组织来识别苦味化合物引发肌肉放松的过程(与缓解哮喘诱导有关)。使用这种方法，预计可以绘制出每种苦味化合物的效果图，并将结果信息用于开发改进的慢性哮喘治疗方法。不幸的是，到目前为止，苦味化合物已被证明以多种方式调节其扩张作用，其中一些作用独立于这些动物组织中已知的TAS2Rs依赖过程。因此，确定这些机制是非常重要的。开发替代的非动物系统来研究苦味化合物的机制将大大减少动物在这一研究领域的使用。这项研究还将提供在动物模型中无法获得的实验方法，从而在治疗哮喘方面取得突破。我们建议开发一个两阶段系统的苦味研究，首先使用社会阿米巴Dictyostelials来确定这些味觉是如何工作的，然后使用人类细胞来确认我们的发现与哮喘的治疗有关。我们已经证明，网柄苔藓可以成功地用于识别与人类健康相关的化合物的新作用机制。这个模型的有效使用是毋庸置疑的，因为它已经被用来发现双相情感障碍药物的机制(Williams等人(2002)自然，417,292-5；Williams(2005)Prog。在神经性精神病药物中。还有比奥尔。这些研究包括：精神病学29,1029-37)，最广泛使用的癫痫治疗机制，丙戊酸(Xu等(2007)Euk Cell，6,899-90；Chang等(2012)疾病模型和机制，5,115-124；Chang等(2013)神经疾病生物学，62C，296-306)以及MCT生酮饮食的基本治疗机制(Chang等(2013)神经药理学，69,105-14；Williams and Walker(2013)Biochem)。SoC。译文，41,1625-8)。它还被用于为两种结构独立的苦味剂确定新的分子靶标(Roberg等(2013)Journal of Cell Science，126,5465-76；Waheed等(2014)British Journal of Pharmacology，171,2659-70)。因此，该项目将确定苦味化合物治疗哮喘的治疗相关靶点，将Dictyostelialas作为动物替代模型。最终，我们的目标是将Dictyostelials发展为一个非动物系统，以揭示苦味化合物调节其作用的机制，寻找治疗哮喘的新分子靶点。

The recent observation that bitter tasting compounds cause the opening of airways in the lung suggest a role for these compounds in the treatment of asthma. This is unexpected, since bitter taste detection was thought act to protect animals (including humans) from ingesting harmful, often bitter, compounds. Bitter tasting compounds are detected by a family of receptors called TAS2Rs that are found on the tongue. Intriguingly, however, it remains unclear if these TAS2Rs are involved in asthma treatment, or if this effect occurs through unidentified proteins. Increasing evidence suggests that these compounds may act through TAS2R independent targets, but these targets are still to be discovered. Research into bitter compounds and the way they work in asthma has focused on using lung tissue obtained from guinea pigs and mice, but also from humans. This research involves using this animal tissue to identify the process that bitter compounds trigger to cause muscle relaxation (related to relieving asthma induction). Using this approach, it was expected that the effect of each bitter compound could be mapped, and resulting information used to develop improved treatments for chronic asthma. Unfortunately, to date, bitter tasting compounds have been shown to mediate their dilatory effects in multiple ways, some acting independently of known TAS2Rs-dependent processes within these animal tissues. Identifying these mechanisms is thus highly important.Developing alternate non-animal systems to investigate the mechanisms of bitter tasting compounds will significantly reduce the use of animals in this research area. This research will also provide experimental approaches unavailable in animal models leading to breakthroughs in the treatment of asthma. We propose to develop a two stage system bitter tastant research, initially using the social amoeba Dictyostelium to identify how these tastants work, and then using human cells to confirm our discoveries are relevant to asthma treatment. We have shown that Dictyostelium can be successfully used to identify new mechanisms of action for compound relevant to human health. The effective use of this model is beyond doubt, as it has been used to find the mechanism of bipolar disorder drugs (Williams et al (2002) Nature, 417, 292-5; Williams (2005) Prog. in Neuro-Psychopharmacol. and Biol. Psychiatry 29, 1029-37), the mechanism of the most wildly used epilepsy treatment, valproic acid (Xu et al (2007) Euk Cell, 6, 899-90; Chang et al (2012) Disease Models and Mechanism, 5, 115-124; Chang et al (2013) Neurobiology of Disease, 62C, 296-306) and the underlying therapeutic mechanism of the MCT ketogenic diet (Chang et al (2013) Neuropharmacology, 69,105-14; Williams and Walker (2013) Biochem. Soc. Trans, 41,1625-8). It has also been used to identify novel molecular targets for two structurally independent bitter tastants been (Robery et al (2013) Journal of Cell Science, 126, 5465-76; Waheed et al (2014) British Journal of Pharmacology, 171, 2659-70). Hence therapeutically relevant targets for bitter compounds in the treatment of asthma will be identified in the project using Dictyostelium as an animal replacement model.Ultimately, our goal is to develop Dictyostelium as a non-animal system to uncover the mechanisms whereby bitter tasting compounds mediate their effects, to identify novel molecular targets for the treatment of asthma.