DataSheet_1_Isolating the Role of Corticosterone in the Hypothalamic-Pituitary-Gonadal Transcriptomic Stress Response.docx

Investigation of the negative impacts of stress on reproduction has largely centered around the effects of the adrenal steroid hormone, corticosterone (CORT), and its influence on a system of tissues vital for reproduction—the hypothalamus of the brain, the pituitary gland, and the gonads (the HPG axis). Research on the action of CORT on the HPG axis has predominated the stress and reproductive biology literature, potentially overshadowing other influential mediators. To gain a more complete understanding of how elevated CORT affects transcriptomic activity of the HPG axis, we experimentally examined its role in male and female rock doves (Columba livia). We exogenously administrated CORT to mimic circulating levels during the stress response, specifically 30 min of restraint stress, an experimental paradigm known to increase circulating CORT in vertebrates. We examined all changes in transcription within each level of the HPG axis as compared to both restraint-stressed birds and vehicle-injected controls. We also investigated the differential transcriptomic response to CORT and restraint-stress in each sex. We report causal and sex-specific effects of CORT on the HPG transcriptomic stress response. Restraint stress caused 1567 genes to uniquely differentially express while elevated circulating CORT was responsible for the differential expression of 304 genes. Only 108 genes in females and 8 in males differentially expressed in subjects that underwent restraint stress and those who were given exogenous CORT. In response to elevated CORT and restraint-stress, both sexes shared the differential expression of 5 genes, KCNJ5, CISH, PTGER3, CEBPD, and ZBTB16, all located in the pituitary. The known functions of these genes suggest potential influence of elevated CORT on immune function and prolactin synthesis. Gene expression unique to each sex indicated that elevated CORT affected more gene transcription in females than males (78 genes versus 3 genes, respectively). To our knowledge, this is the first study to isolate the role of CORT in HPG genomic transcription during a stress response. We present an extensive and openly accessible view of the role corticosterone in the HPG transcriptomic stress response. Because the HPG system is well conserved across vertebrates, these data have the potential to inspire new therapeutic strategies for reproductive dysregulation in multiple vertebrate systems, including our own.

针对应激对生殖负面影响的研究，长期以来主要聚焦于肾上腺类固醇激素皮质酮（corticosterone, CORT）的作用，以及其对生殖关键组织系统——大脑下丘脑、垂体与性腺（即HPG轴）的影响。有关皮质酮对HPG轴作用的研究，在应激与生殖生物学领域的学术文献中占据主导地位，这可能掩盖了其他具有影响力的调控介质的作用。为更全面地阐明升高的皮质酮如何影响HPG轴的转录组活性，我们通过实验在家鸽（Columba livia）的雌雄个体中探究了其作用机制。我们通过外源性注射皮质酮，模拟应激反应时的循环激素水平——具体为30分钟束缚应激，该实验范式已被证实可升高脊椎动物体内的循环皮质酮水平。我们对比了束缚应激组、溶剂注射对照组，分析了HPG轴各层级的转录组变化。我们还探究了雌雄个体对皮质酮与束缚应激的差异化转录组响应。本研究揭示了皮质酮对HPG轴转录组应激响应的因果性与性别特异性效应。束缚应激仅使1567个基因呈现独特的差异表达，而循环皮质酮水平升高则导致304个基因发生差异表达。在同时接受束缚应激与外源性皮质酮处理的受试个体中，雌性仅108个基因呈现差异表达，雄性则仅为8个。在应对升高的皮质酮与束缚应激时，雌雄两性共有的差异表达基因共有5个，即KCNJ5、CISH、PTGER3、CEBPD与ZBTB16，这些基因均位于垂体中。上述基因的已知功能提示，循环皮质酮水平升高可能对免疫功能与催乳素（prolactin）合成产生潜在影响。各性别特有的基因表达特征显示，循环皮质酮水平升高对雌性基因转录的影响多于雄性（分别为78个与3个基因）。据我们所知，本研究是首个在应激反应过程中，分离出皮质酮对HPG轴基因组转录调控作用的研究。我们全面且公开地呈现了皮质酮在HPG轴转录组应激响应中的作用机制。由于HPG系统在脊椎动物中高度保守，本研究数据有望为包括人类在内的多种脊椎动物生殖功能紊乱的新型治疗策略提供研究思路。