Nitrogen Metabolism in Aedes Aegypti Mosquitoes

描述（由申请人提供）：我们已经报道了埃及伊蚊雌性蚊子具有显著的生物系统，能够使用该生物体中存在的先前未知的代谢途径在由血粉消化释放的有毒氨浓度中存活。具体来说，我们发现，Ae。埃及伊蚊可以通过固氮植物和细菌使用的相同代谢途径来解毒氨，这与所有其他已研究的昆虫不同。蚊子也可以像脊椎动物一样利用谷氨酰胺的酰胺基中的氮来产生尿酸，更令人惊讶的是，蚊子通过一些鱼类和两栖动物使用的相同代谢途径将尿酸水解为尿素。由于这些多个代谢途径的协调运作防止了吸血后蚊子组织中致命的氨浓度，这促使我们了解这些代谢途径是如何相互关联和调节的。因此，该基金申请的主要目的是阐明氮废物的代谢调节，以及分析蚊子氨代谢中涉及的C和N分子的通量。这些研究将使用RNA干扰和质谱技术的组合进行。使用生物合理方法控制蚊子种群的尝试取决于对蚊子生物学和代谢的透彻理解。因此，如果我们提出的实验成功进行，它们将开辟新的和令人兴奋的发现，可以应用于设计和实施更好的蚊子控制策略。将追求以下具体目标：1-确定蚊子体内氮废物调节所涉及的机制。2-研究蚊子体内氨代谢过程中碳和氮分子的通量。根据我们的初步数据，氮废物的代谢调节似乎是严格的调节，在山慈菇。埃及蚊子。因此，我们的目标是了解这种调节机制如何控制成年雌蚊的氨代谢。 公共卫生相关性：蚊子是病原体的媒介，每年造成100多万人死亡。尽管全球努力根除这一严重的世界性问题，但抗药性蚊子、抗药性寄生虫和社会-政治-经济障碍使得努力不足以控制蚊子种群，因此不足以控制它们传播的疾病。因此，需要新的控制策略的基础上的新知识的生化和生理过程中运作的蚊子。我们观察到了。埃及女性具有强大的生物化学-生理机能，能够应对在消化血粉过程中产生的有毒氨浓度。这是一个关键的解毒过程，使女性保持氨水平低于致命浓度。在这项资助申请中，我们建议解开氮废物的代谢调节机制，以及氨代谢中涉及的C和N分子的通量。我们预计，这些研究收集的数据将确定关键的代谢目标，这些目标有可能被小分子选择性地抑制，这些小分子阻止蚊子体内氮废物的合成和/或排泄。

DESCRIPTION (provided by applicant): We have reported that Aedes aegypti female mosquitoes possess a remarkable biological system to survive toxic ammonia concentrations released by blood meal digestion using previously unknown metabolic pathways present in this organism. Specifically, we have found that Ae. aegypti can detoxify ammonia by the same metabolic pathways that nitrogen fixing plants and bacteria use, unlike all other insects that have been studied. Mosquitoes can also use the nitrogen from the amide group of glutamine to produce uric acid as vertebrates do, and more surprisingly, mosquitoes hydrolyze uric acid into urea through the same metabolic pathway that some fish and amphibians use. Since the coordinated operation of these multiple metabolic pathways prevents a lethal ammonia concentration in the mosquito tissues after a blood meal, it impels us to know how these metabolic pathways are interconnected and regulated. Therefore, the main purpose of the grant application is to elucidate the metabolic regulation of nitrogen waste, as well as to analyze the flux of C and N molecules involved in ammonia metabolism in mosquitoes. These studies will be performed using a combination of RNA interference and mass spectrometry techniques. Attempts to control mosquito populations using biorational approaches depend on a thorough understanding of mosquito biology and metabolism. So, if the experiments that we propose are conducted successfully, they will open up new and exciting discoveries that could be applied for the design and implementation of better strategies for mosquito control. The following specific aims will be pursued: 1- Identify the mechanisms involved in the regulation of nitrogen waste in mosquitoes. 2- Investigate the flux of C and N molecules involved in ammonia metabolism in mosquitoes. According to our preliminary data, the metabolic regulation of nitrogen waste appears to be tightly- regulated in Ae. aegypti mosquitoes. Therefore, our objective is to understand how this regulatory mechanism controls the ammonia metabolism in adult female mosquitoes. PUBLIC HEALTH RELEVANCE: Mosquitoes are vectors of etiological agents that cause more than one million deaths annually. In spite of the global efforts to eradicate this serious worldwide problem, the insecticide-resistant mosquitoes, drug- resistant parasites, and socio-politico-economic obstacles, have made the efforts insufficient for controlling the mosquito populations, and therefore the diseases that they transmit. Thus, new control strategies are needed based on the new knowledge of biochemical and physiological process that operate in mosquitoes. We have observed Ae. aegypti females have a powerful biochemical-physiological machine for coping with the toxic ammonia concentrations generated during a blood meal digestion. This is a critical detoxification process that allows the females to maintain ammonia levels below lethal concentration. In this grant application, we propose to unravel the mechanisms of metabolic regulation for nitrogen waste, as well as the fluxes of C and N molecules involved in ammonia metabolism. We anticipate that the data collected by these studies will identify critical metabolic targets that have the potential to be selectively inhibited by small molecules that block the synthesis and/or excretion of nitrogen waste in mosquitoes.