Department of Biology, Wake Forest University, Winston-Salem, NC 27109, USA.
Center of Molecular Signaling, Wake Forest University, Winston-Salem, NC 27109, USA.
Int J Mol Sci. 2021 Jul 13;22(14):7515. doi: 10.3390/ijms22147515.
All organisms confront the challenges of maintaining metabolic homeostasis in light of both variabilities in nutrient supplies and energetic costs of different physiologies and behaviors. While all cells are nutrient sensitive, only relative few cells within Metazoans are nutrient sensing cells. Nutrient sensing cells organize systemic behavioral and physiological responses to changing metabolic states. One group of cells present in the arthropods, is the adipokinetic hormone producing cells (APCs). APCs possess intrinsic nutrient sensors and receive contextual information regarding metabolic state through other endocrine connections. APCs express receptors for different hormones which modulate APC physiology and the secretion of the adipokinetic hormone (AKH). APCs are functionally similar to alpha cells in the mammalian pancreas and display a similar physiological organization. AKH release results in both hypertrehalosemia and hyperlipidemia through high affinity binding to the AKH receptor (AKHR). Another hallmark of AKH signaling is heightened locomotor activity, which accompanies starvation and is thought to enhance foraging. In this review, we discuss mechanisms of nutrient sensing and modulation of AKH release. Additionally, we compare the organization of AKH/AKHR signaling in different taxa. Lastly, we consider the signals that APCs integrate as well as recent experimental results that have expanded the functional repertoire of AKH signaling, further establishing this as both a metabolic and stress hormone.
所有生物体都面临着在营养供应的变化和不同生理和行为的能量成本的情况下维持代谢稳态的挑战。虽然所有细胞都对营养敏感，但在后生动物中只有相对较少的细胞是营养感应细胞。营养感应细胞组织全身行为和生理反应以适应代谢状态的变化。在节肢动物中存在的一组细胞是生酮激素产生细胞（APCs）。APCs 具有内在的营养传感器，并通过其他内分泌连接接收有关代谢状态的上下文信息。APCs 表达不同激素的受体，这些受体调节 APC 的生理学和生酮激素（AKH）的分泌。APCs 在功能上类似于哺乳动物胰腺中的 alpha 细胞，并表现出相似的生理组织。AKH 释放通过与 AKH 受体（AKHR）的高亲和力结合导致高海藻血症和高血脂症。AKH 信号的另一个标志是运动活性增强，这伴随着饥饿并被认为可以增强觅食。在这篇综述中，我们讨论了营养感应和 AKH 释放的调节机制。此外，我们比较了不同分类群中 AKH/AKHR 信号的组织。最后，我们考虑 APCs 整合的信号以及最近的实验结果，这些结果扩展了 AKH 信号的功能范围，进一步将其确立为代谢和应激激素。
