DataSheet_4_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：神经网络在调节肠道免疫中发挥着至关重要的作用，而肠道菌群亦参与此过程。然而，关于肠道-大脑-菌群交互作用的角色与机制仍不明确。为解决此问题，本研究采用果蝇作为模式生物。我们先前已证实，与大脑和肠道相连的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：我们对经过基因敲除NP3253神经元的成年果蝇肠道进行了RNA测序分析。在口腔细菌感染和正常喂养条件下饲养果蝇。此外，我们还制备了无菌条件下的样本，以评估菌群在肠道基因表达中的作用。我们敲低由NP3253神经元调控的基因，并检测其对抗口腔细菌感染的敏感性。结果：我们发现，与对照果蝇相比，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，表明在NP3253神经元失活的果蝇中，免疫反应被菌群异常激活。此外，氧化还原相关基因的表达在NP3253神经元失活的果蝇中下调，并在无菌果蝇中也观察到这种下调。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神经元以菌群非依赖的方式调节肠道免疫的氧化还原反应。结论：这些结果揭示了NP3253神经元调节肠道中适当的基因表达模式，并有助于在口腔感染期间维持稳态。