The Neuroregulatory Effects of Gonadal Steroids in Humans

本报告包括以下临床方案产生的工作：NCT00026832、NCT00100360、NCT00001177和NCT00001322。 有证据表明，性类固醇受体或受性类固醇调节的系统中的基因组变异可能是PMDD患者卵巢激素敏感性的原因。因此，作为第一步，我们检查了在GnRH激动剂诱导的性腺功能减退和卵巢类固醇补充方案中确定的每种激素条件下，女性中常见的基因变异的影响。我们已经测试了两个特定的、常见的功能变体(BDNFVal66Met和COMT Val158Met)，它们都由性类固醇调节，并分别已知会改变特定大脑区域的大脑功能，包括海马体和前额叶皮质。因此，在我们的研究中，我们使用这些基因变异作为探针，研究遗传底物对卵巢类固醇对女性大脑功能的影响。 HOC后的敏感性分析表明，BDNF和COMT两种基因型的影响仅在雌二醇存在的情况下才明显，与WM相关的rCBF的差异是脑区特有的：COMT基因的影响仅在DLPFC中观察到，而无论BDNF基因如何，而BDNF基因之间的rCBF差异仅限于海马区，而无论COMT基因如何。总体而言，这些研究的结果表明，在女性中，被认为受卵巢类固醇调控的基因变异以大脑区域和激素特有的方式影响功能神经回路，具体而言，BDNF和COMT基因型与雌二醇之间的相互作用分别对海马区(BDNF高表达)和DLPFC(COMT在多巴胺运输中起主导作用)中的功能神经回路的激活产生影响。尽管性类固醇在中枢神经系统内表现出多效性，但它们的作用往往是组织特有的，反映了局部组织特异性调节剂的作用，这些调节剂促进了一个组织中的性类固醇信号传递，并抑制或抑制了另一个组织中的信号。我们的发现表明，遗传环境如何调节性类固醇对特定大脑区域功能的调节作用，这些区域涉及神经精神疾病的病理生理学，包括PFC和海马体。此外，这些数据表明，考虑到它们相互作用的影响，如果单独检查基因或激素的影响，可能无法识别它们的影响。这些发现对于了解女性卵巢类固醇认知/行为影响的个体差异的神经生物学基础也具有临床意义，并可能为理解与生殖激素相关的神经精神障碍以及疾病表达的性别差异提供一个神经遗传学框架。最后，我们将探索性类固醇调节基因的变异在青春期大脑发育中的作用，青春期是大脑在性腺形成时再次暴露于性类固醇的时期。 我们对PMDD患者和非PMDD患者的细胞系进行了功能基因组学研究，初步发现PMDD患者ESC/E(Z)基因复合体的功能发生了以下变化：首先，从PMDD患者和对照女性的诱导多能干细胞(IPSCs)中成功分化出神经前体细胞(NPC)(经免疫荧光染色和转录组分析证实)。淋巴母细胞系(LCLS)和鼻咽癌之间的重叠基因表达揭示了几个对PMDD病理生理学具有潜在重要性的基因和基因途径在两者中的表达。事实上，LCLS和NPC都显示出差异基因沉默的特征，在基线和对卵巢类固醇的反应中，通过类似的机制。在NPC中的这些发现揭示了PMDD妇女和对照组在基线和卵巢类固醇治疗后的神经元差异，包括ESC/E(Z)靶点。其次，我们采用了两种原代神经元细胞系：Luhmes细胞系，它是永生化的神经元前体细胞系(包括未分化/神经元前体和分化/成熟的多巴胺能神经元)，以及SH-SY5Y，一种永生化的神经母细胞系，以肾上腺素能和多巴胺能表型为特征。两种原代神经细胞系都含有ESC/E(Z)基因复合体的功能和对卵巢类固醇的反应性证据。因此，这些数据提供了强有力的证据，证明了我们在淋巴母细胞系(免疫来源组织)中的初步发现与几个更具病理生理学意义的组织(即人鼻咽癌，两种原始神经细胞系)的神经相关性。 我们正在完成一项高密度的纵向研究，研究对象是处于更年期的女性。我们以前的研究表明，在年轻的绝经前妇女中，没有卵巢类固醇暴露的急性丧失(即性腺功能减退)的影响。我们现在确认了一个类似的效应模式，在老年女性更年期过渡时，认知表现没有差异。我们将考察更年期相关认知变化的个体差异；然而，该小组作为一个整体证明，在卵巢老化的背景下，健康、非抑郁的女性缺乏绝经过渡的影响。

This report includes work arising from the following clinical protocols: NCT00026832, NCT00100360, NCT00001177, and NCT00001322. Evidence suggests that genomic variation in sex-steroid receptors or in the systems regulated by sex steroids may contribute to the ovarian hormone-sensitivity observed in PMDD. Thus, as a first step, we examined the effects of common genetic variations in women during each of the hormonal conditions established within the GnRH agonist-induced hypogonadism and ovarian steroid addback protocol. We have tested two specific, common functional variants (BDNF Val66Met and COMT Val158Met) that are both regulated by sex steroids and that are known to alter brain function in specific brain regions including the hippocampus and prefrontal cortex, respectively. In our studies, therefore, we employ these gene variants as probes for the impact of genetic substrates on the effects of ovarian steroids on womens brain function. A post hoc sensitivity analysis demonstrated that the effects of both BDNF and COMT genotypes were only evident in the presence of estradiol, and the differences in WM-related rCBF were brain region-specific: the effects of COMT genotype were only observed in the DLPFC regardless of the BDNF genotype, whereas the differences in rCBF between the BDNF genotype were confined to the hippocampus regardless of the COMT genotype. Overall, the findings from these studies demonstrate that in women, variations in genes putatively regulated by ovarian steroids impact functional neurocircuitry in a brain-region- and hormone-specific manner here, specifically, interactions between BDNF and COMT genotypes and estradiol on the activation of functional neurocircuitry in the hippocampus (where BDNF is highly expressed) and the DLPFC (where COMT has primacy for dopamine trafficking), respectively. Although sex steroids display pleiotropic effects within the CNS, their actions are often tissue-specific and reflect the effects of local tissue-specific regulators that facilitate sex steroid signaling in one tissue and inhibit or repress the signal in another tissue. Our findings demonstrate how genetic context could modulate the regulatory actions of sex steroids on the functions of specific brain regions involved in the pathophysiology of neuropsychiatric conditions, including the PFC and hippocampus. Additionally, these data suggest that effects of genes or hormones may not be identified if examined in isolation, given the impact of their interactions. These findings also have clinical relevance for understanding the neurobiological basis of individual differences in the cognitive/behavioral effects of ovarian steroids in women, and may provide a neurogenetic framework for understanding neuropsychiatric disorders related to reproductive hormones as well as illnesses with sex differences in disease expression. Finally, we will probe the roles of variation in sex steroid-regulated genes on brain development across puberty, a time when the brain is re-exposed to sex steroids at gonadarche. Our functional genomic studies in cell lines from both women with and without PMDD have pursued our initial findings of altered function of the ESC/E(Z) gene complex in PMDD as follows: First, neuroprogenitor cells (NPCs) were successfully differentiated from induced pluripotent stem cells (iPSCs) made from women with PMDD and control women (confirmed by immunofluorescent staining and transcriptome analysis). Overlapping gene expression between lymphoblastoid cell lines (LCLs) and NPCs reveals that several genes and gene pathways potentially important for PMDD pathophysiology are expressed in both. Indeed, both LCLs and NPCs show signatures of differential gene silencing through similar mechanisms at baseline and in response to ovarian steroids. These findings in NPCs reveal neuronal differences between women with PMDD and controls both at baseline and after ovarian steroids, including ESC/E(Z) targets. Second, we employed two stock neuronal cell lines: Luhmes Cells, which are immortalized neuronal precursor cell lines (both undifferentiated/neuronal precursors and differentiated/mature dopaminergic neurons), as well as SH-SY5Y, an immortalized neuroblastoid cell line characterized by an adrenergic and dopaminergic phenotype. Both stock neuronal cell lines contained evidence of ESC/E(Z) gene complex function and responsivity to ovarian steroids. Thus, these data provide strong supportive evidence of the neural relevance of our initial findings in lymphoblastoid cell lines (immune-origin tissue) in several more pathophysiologically-relevant tissues (i.e., human NPCs, two stock neuronal cell lines). We are completing a high-density longitudinal study of women as they transition through the menopause. Our previous studies demonstrated the absence of an effect of acute loss of ovarian steroid exposure (i.e., hypogonadism) in younger premenopausal women. We now confirm a similar pattern of effects with no differences in cognitive performance in older women as they transition across the menopause. We will examine individual differences in menopause-related changes in cognition; however, the group as a whole demonstrates the lack of impact of the menopause transition in healthy, non-depressed women in the setting of ovarian aging.