羟基补骨脂酚对应激/去卵巢动物抗抑郁作用及其雌激素受体调控途径

Perimenopausal depression is often a serious menance to woman, however, there is a dearth of effective intervention. Perimenopausal depression devepoment involves estrogen receptor signaling down-regulation in the hippocampus, thus offering a potential target for therapeutic drug development. Our previous studies showed that hydroxylbakuchiol produced antidepressant-like effects upon general types of depression models through a pathway involving monoamine transporter inhibition. On the other hand, bakuchiol was shown to act as an estrogen receptor agonist in vitro. These results indicate a potential role for hydroxylbakuchiol in the treatment of perimenopausal depression. Accordingly, we will, by using ovariectomized, stressed animals as in vivo models of perimenopausal depression and in vitro platforms, focus our studies as follows: 1) test the effects of hydroxylbakuchiol on depression behaviors (despair, locomotion, pleasure, etc.) in perimenopausal depression models; 2) search for an underlying hydroxylbakuchiol antidepression mechanism, i.e. regulating action on the pathway of estrogen receptors→glycogen synthase kinase-3β (an integrating molecular within signaling pathways)→hippocampus remodeling (in vitro models of cells and brain slices will be used to explore whether hydroxylbakuchiol has the ability to affect estrogen receptors, glycogen synthase kinase-3β, and markers of hippocampal remoldeling, and will be checked to see whether the hydroxylbakuchiol-induced hippocampal remoldeling is blocked following down-regulation of estrogen receptors or up-regulation of glycogen synthase kinase-3β-- for the purpose of uncovering hydroxylbakuchiol's estrogen receptor-subtype regulation and pathway integration). The meaningfulness of this study lies in exploring an effective intervention for perimenopausal depression and its primary pharmacological mechanism, and for further understanding the pathogenesis of perimenopausal depression.

围绝经期抑郁症发病率高、危害大，但干预药物匮乏。该病的发生，与海马雌激素受体(ERs)信号下调有关，ERs调控途径可为该病新药发现提供靶向。我们前期研究发现，羟基补骨脂酚可通过单胺能途径抗普通型抑郁症，而补骨脂酚对ER有体外激动作用，提示羟基补骨脂酚可能对围绝经期抑郁症同样有效。因此，本项目采用去卵巢/应激动物（围绝经期抑郁症模型）和体外模型研究：1)羟基补骨脂酚对模型动物行为(绝望、运动、快感等)影响；2)抗抑郁机制，即对ERs→糖原合成酶激酶3β(GSK3β，系信号整合分子)→海马重塑路径的影响，从体外细胞→脑片水平，观测该药物对海马ERs、GSK3β、海马重塑标记物的影响，及ERs下调或GSK3β上调对该药物海马重塑效应的阻碍作用；以期解析其ERs亚型调控规律和信号通路整合特性。本项目旨在寻找新的抗围绝经期抑郁症药物，并初步明确其药理机制，进一步加深对围绝经期抑郁症发病机制的了解。

围绝经期抑郁症(Perimenopausal Depression, PMD)发病率高，目前多采用雌激素替代疗法（Estrogen replacement therapy，ERT）联合单胺能类抗抑郁药物进行治疗；但雌激素有增加肿瘤发生的风险，而单胺转运体靶向药物只对约半数患者有效。寻找PMD新的治疗药物成为当务之急。有研究表明，动物海马神经再生和可塑性易遭受长期皮质酮或应激事件的损伤，并在严重抑郁症中起主要作用； 雌激素受体（ERs）的激活,通过调节海马神经发生和可塑性在卵巢切除（OVX）大鼠中产生抗抑郁药样作用。有文献报道，补骨脂酚是ER受体激动剂。据此，提出如下假设：羟基补骨脂酚[(+)-Δ3-2-hydroxybakuchiol; ohB]（补骨脂酚类似物）对OVX/应激动物可能具有抗抑郁药样作用（前期工作证明ohB为单胺神经递质转运蛋白抑制剂），该作用可能与海马ERs-糖原合成酶激酶3β(GSK3β)通路有关。本项目主要内容是回答这些问题。研究结果表明，在急性抑郁模型（数据从略）、亚急性抑郁模型以及慢性抑郁动物模型上，羟基补骨脂酚对雌激素缺乏的动物具有抗抑郁样作用，且效强优于雄性模型和非致瘤性。另外，与雄性亚急性抑郁模型比较(HPA轴功能比正常动物亢进)，OVX/Stress抑郁模型HPA轴功能低下（低于正常动物），ohB对两类模型HPA轴分别具有下调(雄性)和上调（雌性）作用。再者，ohB对ERs有激动作用，其优势亚型为ERα；ER介导ohB海马神经元保护作用和抗抑郁样效应。ohB对GSK3β活性有抑制作用，GSK3β介导ohB海马神经元保护作用。ERα可介导ohB对GSK3β活性抑制及海马保护作用。 通过对ohB海马神经元保护作用的ERs介导机制、GSK3β调控机制以及ERs→GSK3β通路机制的评价，初步证实ohB通过ERs→GSK3β机制达到海马保护作用。总之，ohB具有抗PMD作用，且具有药效优势和安全优势性；其作用机制与ERs→GSK3β→海马重塑有关。本项目结果对目前发病率高的围绝经期抑郁症新的治疗药物开发提供重要的实验依据,即ohB具有较高的开发潜力和临床应用价值；明确了ohB抗围绝经抑郁症的“ERs→GSK3β→海马重塑”通路机制，具有较高的学术价值。