Sex differences in the corticotropin-releasing factor receptor

描述(申请人提供)：与压力相关的精神疾病，如抑郁症和焦虑症，在女性中比男性更普遍。促肾上腺皮质激素释放因子(CRF)是协调应激反应的神经肽，其功能障碍与抑郁症和焦虑症有关。然而，CRF系统中的性别差异并没有得到很好的描述。我们实验室最近的研究发现，CRF对神经元的反应存在性别差异。具体地说，雌性大鼠蓝斑(LC)神经元对CRF的突触后敏感性高于雄性大鼠。此外，游泳应激仅使雄性大鼠LC神经元对CRF敏感。下面的提案将在这些发现的基础上展开，以确定这些差异的潜在细胞机制。具体目的如下：1)明确CRF受体偶联和信号传递的性别差异。CRF受体免疫沉淀将被用来确定在应激和非应激条件下，不同的G蛋白与CRF受体的偶联是否存在性别差异。此外，还将使用PKA和PKC分析来评估CRF受体信号的性别差异。初步数据显示，与非应激男性相比，非应激女性的CRF受体与Gs蛋白的偶联程度更高。游泳应激后，与CRF受体偶联的Gs仅在男性增加。这些数据首次表明，在受体与不同G蛋白的偶联过程中存在性别差异。CRF受体结构和功能的性别差异可能导致女性对应激的敏感性增加。2)确定应激后CRF受体转运的性别差异。在这里，我们将使用CRF受体的免疫沉淀，以及免疫电子显微镜来确定CRF受体在应激后在雄性和雌性大鼠中的运输方式是否不同。初步数据表明，在应激后，女性体内CRF受体的内在化可能会有所缓解。如果得到支持，这将表明雌性大鼠缺乏这种补偿性应激反应。与公共健康相关女性患抑郁症和焦虑症等与压力相关的精神障碍的可能性是男性的两倍。这项拟议的实验将确定CRF受体的性别差异，CRF是压力的重要神经调节器，这可能是女性对压力和与压力相关的病理的脆弱性增加的基础。重要的是，由于CRF拮抗剂正在开发用于治疗抑郁症和焦虑症，CRFR中的性别差异可能会影响这些化合物在女性中的疗效。

DESCRIPTION (provided by applicant): Stress-related mental illnesses, such as depression and anxiety disorders, are more prevalent in women than men. Dysfunctions in corticotropin-releasing factor (CRF), the neuropeptide that orchestrates the stress response, have been linked to depression and anxiety disorders. However, sex differences in the CRF system are not well characterized. Recent work from our laboratory identified sex differences in neuronal responses to CRF. Specifically, postsynaptic sensitivity of locus coeruleus (LC) neurons to CRF was greater in female vs. male rats. Moreover, swim stress sensitized LC neurons to CRF in male rats only. The following proposal will expand on these finding to determine the underlying cellular mechanism of these differences. The specific aims are as follows: 1) Identify sex differences in the coupling and signaling of the CRF receptor. CRF receptor immunoprecipitation will be used to determine whether there are sex differences in coupling of different G-proteins to the CRF receptor under stressed and unstressed conditions. Additionally, sex differences in CRF receptor signaling will be evaluated by using PKA and PKC assays. Preliminary data indicate that the CRF receptor is coupled more strongly to the Gs protein in unstressed females compared to unstressed males. Following swim stress, Gs coupling to the CRF receptor increases in males only. These are the first data to suggest sex differences in the coupling of a receptor to different G-proteins. Sex differences in CRF receptor structure and function may contribute to increased stress-susceptibility in women. 2) Identify sex differences in CRF receptor trafficking following stress. Here we will use immunoprecipitation of the CRF receptor, along with immunoelectron microscopy to determine whether the CRF receptor is trafficked differently in male vs. female rats after stress. Preliminary data suggest that following stress, CRF receptor internalization in females may be comprimised. If supported, this would suggest that female rats lack this compensatory stress response. PUBLIC HEALTH RELEVANCE Women are twice as likely to suffer from stress-related psychiatric disorders, like depression and anxiety disorders, as men. The proposed experiments will identify sex differences in the receptor for CRF, an important neuromodulator of stress, which may underlie the increased vulnerability of females to stress and stress-related pathology. Importantly, because CRF antagonists are being developed to treat depression and anxiety disorders, sex differences in the CRFr could impact the efficacy of these compounds in women.