Elucidation of energy homeostasis of corpora cardiaca and corpora allata in insect

在不适宜居住的环境和有限的营养条件下，通过协调神经肽来维持能量的动态平衡对动物的生存至关重要。神经肽如何响应循环中的营养物质并导致随后的生理事件，目前还知之甚少。在这里，我们介绍了一个包括两个神经肽的调节途径，甲壳动物心脏活性多肽(CCAP)和肌肉抑制素，基于先前的结果，CCAP在重新摄食后通过对循环血糖水平的增加而增强。MS还参与能量动态平衡的控制。我们随后发现，GbCCAP引起的海藻糖升高诱导了GBMS的表达。在高浓度葡萄糖作用下，GbCCAP的信号增强，提示CCAP和MS对循环中不同的碳水化合物作出反应，这可能是循环变化的神经激素激活的可能性。鉴于ILP和AKH在糖稳态调节中的主要作用，我们进一步探讨了ILP和AKH作为GbCCAP和GBMS下游调控糖稳态的可能性。令人惊讶的是，GbCCAP被证明是独立于GbILP和GbAKH的，这是一个深刻的发现，表明昆虫中可能存在一种新的碳水化合物调节途径。随后，当GbCCAP和GBMS的受体被敲除时，海藻糖磷酸合成酶被增强。结果表明，GbCCAP的调节作用需要GbTps的作用，这意味着GbCCAP通过参与海藻糖合成途径来发挥其碳水化合物的调节作用。

Maintaining energy homeostasis in inhospitable environment and limited nutrient by orchestration of neuropeptides is crucial for survival of animals. Little is known about how neuropeptide respond to circulating nutrients and lead subsequent physiology event. Here we introduced a regulatory pathway including two neuropeptides, Crustacean cardioactive peptide (CCAP) and MyosuppressinBased on the previous result that CCAP was enhanced after refeeding by responding to the increased circulating glucose level. And MS was also involved in controlling energy homeostasis. We then found that the subsequent elevation of trehalose caused by GbCCAP induced the expression of GbMS. An enhanced signal of GbCCAP was observed by high concentrated glucose, suggesting that CCAP and MS answer to different carbohydrate in circulation, which give the possibility of neurohormonal activation of circulating alterations.Given the predominant roles of ILP and AKH in the carbohydrate homeostasis regulation, we then examined the possibility of ILP and AKH as the downstream of GbCCAP and GbMS in the regulation of carbohydrate homeostasis. Surprisingly, GbCCAP was proved to be independent of GbILP and GbAKH, which is a profound find that a novel carbohydrate regulatory pathway may be exist in insects. Followingly, trehalose phosphate synthase was enhanced when knockdown the receptors of GbCCAP and GbMS. Results showed that regulatory role of GbCCAP requires the function of GbTps, which imply that GbCCAP exert its carbohydrate regulatory function by the involvement of trehalose synthesis pathway.