DataSheet_3_Neural control of redox response and microbiota-triggered inflammation in Drosophila gut.csv

BackgroundThe neural system plays a critical role in controlling gut immunity, and the gut microbiota contributes to this process. However, the roles and mechanisms of gut-brain-microbiota interactions remain unclear. To address this issue, we employed Drosophila as a model organism. We have previously shown that NP3253 neurons, which are connected to the brain and gut, are essential for resistance to oral bacterial infections. Here, we aimed to investigate the role of NP3253 neurons in the regulation of gut immunity.MethodsWe performed RNA-seq analysis of the adult Drosophila gut after genetically inactivating the NP3253 neurons. Flies were reared under oral bacterial infection and normal feeding conditions. In addition, we prepared samples under germ-free conditions to evaluate the role of the microbiota in gut gene expression. We knocked down the genes regulated by NP3253 neurons and examined their susceptibility to oral bacterial infections.ResultsWe found that immune-related gene expression was upregulated in NP3253 neuron-inactivated flies compared to the control. However, this upregulation was abolished in axenic flies, suggesting that the immune response was abnormally activated by the microbiota in NP3253 neuron-inactivated flies. In addition, redox-related gene expression was downregulated in NP3253 neuron-inactivated flies, and this downregulation was also observed in axenic flies. Certain redox-related genes were required for resistance to oral bacterial infections, suggesting that NP3253 neurons regulate the redox responses for gut immunity in a microbiota-independent manner.ConclusionThese results show that NP3253 neurons regulate the appropriate gene expression patterns in the gut and contribute to maintain homeostasis during oral infections.

背景：神经网络在调控肠道免疫过程中发挥着至关重要的作用，而肠道微生物群也对这一过程产生影响。然而，关于肠道-大脑-微生物群相互作用的角色和机制尚不明确。为解决这一问题，本研究以果蝇作为模式生物进行实验。我们先前已证实，连接大脑和肠道的NP3253神经元对于抵抗口腔细菌感染至关重要。在本研究中，我们旨在探究NP3253神经元在调节肠道免疫中的作用。方法：我们通过对成年果蝇肠道进行RNA测序分析，研究了在基因敲除NP3253神经元后的情况。果蝇在口腔细菌感染和正常喂养条件下进行饲养。此外，我们还制备了无菌条件下的样本，以评估微生物群在肠道基因表达中的作用。我们下调了由NP3253神经元调控的基因，并考察了其对抗口腔细菌感染的敏感性。结果：我们发现，与对照组相比，NP3253神经元失活的果蝇中免疫相关基因的表达上调。然而，这种上调在无菌果蝇中消失，表明微生物群在NP3253神经元失活的果蝇中异常激活了免疫反应。此外，NP3253神经元失活的果蝇中氧化还原相关基因的表达下调，且这种下调也在无菌果蝇中观察到。某些氧化还原相关基因对于抵抗口腔细菌感染是必需的，这表明NP3253神经元通过微生物群独立的方式调节肠道免疫的氧化还原反应。结论：这些结果表明，NP3253神经元调节肠道中适宜的基因表达模式，有助于维持口腔感染时的稳态。