Effects of acute and chronic activation of oxytocin receptor on intraneuronal signaling cascades: implications for anxiety-like behaviour

人们对神经肽催产素（OXT）作为包括焦虑症在内的各种精神病理的治疗选择的行为效应的兴趣日益浓厚，这就需要更深入地了解急性，尤其是慢性OXT受体（OXTR）激活后的分子过程。令人惊讶的是，与大量的动物和人类行为研究相比，OXT效应的神经元和分子机制很少被报道，特别是在慢性激活的细胞内信号级联及其下游靶蛋白和基因的背景下。因此，本项目旨在揭示急性治疗后oxtr介导的下丘脑神经元内效应，并将这些效应与体内和体外慢性应用OXT后的细胞质或遗传改变进行比较。我们的目标是确定与OXT抗焦虑作用有关的信号级联和转录因子，即我们将在雄性和雌性大鼠中使用siRNA、CRISPR/cas9和拮抗剂对选定因子进行特定的药物遗传操作后，研究焦虑相关行为的改变。虽然一些候选信号级联和转录因子已经与肌层或神经元细胞中的OXTR相关，但这些级联是否参与任何行为的调节尚不清楚。这使我们能够将该应用程序的重点缩小到可能参与焦虑样行为调节的7个神经元因子（TRPV2, MEK1/2, ERK5, CaMKII， PKC， CREB, MEF-2）。在体内鉴定了急性（Aim 1）或慢性（Aim 2） OXT调控的神经元内靶因子后，我们将评估分子细节，并在体外证明级联、转录因子和基因转录之间的因果关系。我们假设信号级联的独特组合导致oxt特异性效应，这取决于治疗的剂量和持续时间、性别和组织（脑或外周，Aim 3）。总的来说，我们的目标是揭示OXT的详细神经元作用机制，这对于设计有效和特定的治疗方法至关重要，例如患有焦虑症的患者。

The growing interest in the behavioral effects of the neuropeptide oxytocin (OXT) as treatment option for various psychopathologies including anxiety disorders creates the need for a deeper understanding of the molecular processes following acute, but especially chronic OXT receptor (OXTR) activation. Surprisingly, compared to the high number of behavioural studies in animals and humans, neuronal and molecular mechanisms underlying the OXT effects are rarely reported, especially in the context of chronically activated intracellular signaling cascades and their downstream target proteins and genes.Therefore, the present project aims to reveal OXTR-mediated intraneuronal effects in hypothalamic neurons after acute treatment, and to compare these effects with cytoplasmic or genetic alterations after chronic application of OXT in vivo and in vitro. We aim to identify signalling cascades and transcription factors that are essentially involved in the anxiolytic effect of OXT, i.e. we will study alterations in anxiety-related behavior following specific pharmacogenetic manipulation of selected factors using siRNA, CRISPR/cas9, and antagonists in male and female rats. Although some candidate signaling cascades and transcription factors have already been associated with the OXTR in myometrial or neuronal cells, the involvement of those cascades in the regulation of any behavior is unknown. This allowed us to narrow the focus of this application down to a selected set of 7 neuronal factors that are likely to be involved in the regulation of anxiety-like behavior (TRPV2, MEK1/2, ERK5, CaMKII, PKC, CREB, MEF-2). After identifying intraneuronal target factors regulated by acute (Aim 1) or chronic (Aim 2) OXT in vivo, we will assess the molecular details and prove causal links between cascades, transcription factors, and gene transcription in vitro. We hypothesize that the unique combination of signaling cascades causes OXT-specific effects, which are dependent on the dose and duration of treatment, sex, and tissue (brain or periphery, Aim 3). Overall, we aim to reveal detailed neuronal mechanisms of action of OXT essential for the design of an effective and specific therapeutic treatment, e.g. of patients suffering from anxiety disorders.