NETWORK ANALYSIS OF NITRIC OXIDE PATHWAY IN ENDOTHELIAL CELLS

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。一氧化氮（NO）在生物学中发挥着多种作用，在血管张力调节、宿主免疫防御、神经传递等生物反应中发挥作用。一氧化氮是由精氨酸合成的三种一氧化氮合成酶（NOS）亚型：神经元型、诱导型和内皮型。NO在体内的代谢途径非常复杂。除了产生一氧化氮外，精氨酸还是合成尿素、多胺、磷酸肌酸、谷氨酸和氧-谷氨酸的前体。精氨酸可以通过阳离子氨基酸转运体从血液转运到细胞。精氨酸是由瓜氨酸经过尿素循环的第三和第四酶精氨酸琥珀酸合成酶和精氨酸琥珀酸裂解酶的连续作用合成的。此外，NO可以被氧化成亚硝酸盐、硝酸盐和过氧亚硝酸盐。为了推断这一复杂通路的拓扑结构并确定作用模式，我们采用了稳态下的网络摄动表达谱分析方法。我们在网络中指定了37种可能的代谢物（或节点）。毛细管区带电泳是在扰动后的稳态下同时测量多种代谢物的首选技术。我们在干扰精氨酸、鸟氨酸和Ca2+水平后获得了时间过程数据。我们正在与博士合作。James J. Collins和Timothy S. Gardner在波士顿大学生物医学工程系进行数据分析。网络方法将使我们更好地了解体内NO产生的调控。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Nitric oxide (NO) plays multiple roles in biology, functioning in vascular tone regulation, host immune defense, neurotransmission, and other biological responses. NO is synthesized from arginine by three NO synthase (NOS) isoforms: neuronal, inducible and endothelial. The NO metabolic pathway in vivo is very complex. In addition to producing NO, arginine is a precursor for synthesis of urea, polyamines, creatine phosphate, glutamate and oxo-glutarate. Arginine can be transported from blood into cells by cationic amino acid transporter isoforms. Arginine is synthesized from citrulline by successive actions of argininosuccinate synthetase and argininosuccinate lyase, the third and fourth enzymes of the urea cycle. Furthermore, NO can be oxidized to nitrite, nitrate, and peroxynitrite. To infer the topology of this complex pathway and to determine the mode of action, we have adopted the approach of network perturbation expression profiling analysis at steady-state. We have assigned 37 possible metabolites (or nodes) in the network. Capillary zone electrophoresis is the technology of choice to measure simultaneously multiple metabolites in the steady-state after perturbation. We have obtained time course data after perturbing arginine, ornithine, and Ca2+ levels. We are collaborating with Drs. James J. Collins and Timothy S. Gardner in the Department of Biomedical Engineering at Boston University on data analysis. The network approach will provide us a better understanding of the regulation of NO production in vivo.