Sex differences in the corticotropin-releasing factor receptor

描述（由申请人提供）：与压力有关的精神疾病，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）是一种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系统的性别差异并没有很好地表征。我们实验室最近的研究发现，神经元对CRF的反应存在性别差异。具体来说，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，游泳应激仅在雄性大鼠中使LC神经元对CRF敏感。下面的建议将扩展这些发现，以确定这些差异的潜在细胞机制。具体目的如下：1)确定CRF受体偶联和信号传导的性别差异。CRF受体免疫沉淀将用于确定应激和非应激条件下不同g蛋白与CRF受体的偶联是否存在性别差异。此外，CRF受体信号的性别差异将通过使用PKA和PKC检测来评估。初步数据表明，与非应激雄性相比，非应激雌性的CRF受体与Gs蛋白的偶联更强。游泳应激后，Gs与CRF受体的偶联仅在雄性中增加。这些数据首次表明，受体与不同g蛋白的偶联存在性别差异。CRF受体结构和功能的性别差异可能导致女性压力易感性增加。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应激后雄性和雌性大鼠的CRF受体运输是否不同。初步数据表明，应激后，雌性CRF受体内化可能受到损害。如果得到支持，这将表明雌性大鼠缺乏这种代偿性应激反应。妇女患与压力有关的精神疾病，如抑郁症和焦虑症的可能性是男子的两倍。拟议的实验将确定CRF受体的性别差异，CRF是一种重要的压力神经调节剂，这可能是女性对压力和压力相关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.