Division of Natural Sciences, University of Maine at Farmington, Farmington, ME, 04938, USA.
Tropical Aquaculture Laboratory, Program in Fisheries and Aquatic Sciences, School of Forest, Fisheries, and Geomatics Sciences, Institute of Food and Agricultural Sciences, University of Florida, Ruskin, FL, 33570, USA.
Sci Rep. 2022 Jun 8;12(1):9454. doi: 10.1038/s41598-022-13695-z.
Phoenixin (PNX) is a highly conserved, novel hormone with diverse functions, including hypothalamic control of reproduction, appetite modulation, and regulation of energy metabolism and inflammation. While some functions appear conserved across vertebrates, additional research is required to fully characterize these complex pleiotropic effects. For instance, very little is known about transcriptome level changes associated with PNX exposure, including responses in the hypothalamic-pituitary-gonadal (HPG) axis, which is critical in vertebrate reproduction. In addition, the PNX system may be especially complex in fish, where an additional receptor is likely present in some species. The purpose of this study was to assess hypothalamic and ovarian transcriptomes after PNX-14 administration in female vitellogenic green-spotted puffer (Dichotomyctere nigroviridis). Steroid-related changes were also assessed in the liver and blood plasma. Hypothalamic responses included pro-inflammatory signals such as interleukin 1β, possibly related to gut-brain axis functions, as well as suppression of cell proliferation. Ovarian responses were more widely downregulated across all identified pathways, which may reflect progression to a less transcriptionally active state in oocytes. Both organs shared regulation in transforming growth factor-β and extracellular matrix remodeling (periostin) pathways. Reproductive processes were in general downregulated, but both inhibiting (bone morphogenetic protein 15 and follistatin) and promoting (17-hydroxyprogesterone) factors for oocyte maturation were identified. Select genes involved in reproduction (vitellogenins, estrogen receptors) in the liver were unresponsive to PNX-14 and higher doses may be needed to induce reproductive effects in D. nigroviridis. These results reinforce the complexity of PNX actions in diverse tissues and highlight important roles for this hormone in regulating the immune response, energy metabolism, and cell growth.
凤凰素（PNX）是一种高度保守的新型激素，具有多种功能，包括下丘脑对生殖、食欲调节以及能量代谢和炎症的控制。虽然一些功能在脊椎动物中似乎是保守的，但需要进一步的研究来充分描述这些复杂的多效性效应。例如，对于与 PNX 暴露相关的转录组水平变化，包括在下丘脑-垂体-性腺（HPG）轴中的反应，人们知之甚少，而 HPG 轴在脊椎动物的生殖中至关重要。此外，PNX 系统在鱼类中可能特别复杂，因为在某些物种中可能存在额外的受体。本研究的目的是评估 PNX-14 给药后雌性卵黄发生绿斑河豚（Dichotomyctere nigroviridis）下丘脑和卵巢的转录组。还评估了肝脏和血浆中的类固醇相关变化。下丘脑的反应包括白细胞介素 1β等促炎信号，可能与肠道-大脑轴功能有关，以及细胞增殖的抑制。卵巢的反应在所有鉴定的途径中都被更广泛地下调，这可能反映了卵母细胞向转录活性较低的状态的进展。两个器官在转化生长因子-β和细胞外基质重塑（periostin）途径中共享调节。生殖过程总体下调，但鉴定到的促卵母细胞成熟的抑制因子（骨形态发生蛋白 15 和卵泡抑素）和促进因子（17-羟孕酮）。肝脏中与生殖相关的某些基因（卵黄蛋白原、雌激素受体）对 PNX-14 无反应，可能需要更高剂量才能在 D. nigroviridis 中诱导生殖效应。这些结果强化了 PNX 在不同组织中的作用的复杂性，并强调了该激素在调节免疫反应、能量代谢和细胞生长方面的重要作用。
