Nitric Oxide (NO) is an essential signaling molecule for diverse physiological and disease processes. While the regulation of NO flux has focused primarily on the study of the three NO synthases (NOS), their respective genetic deficiencies exhibit relatively modest phenotypes. This has led to difficulties in dissecting the specific cellular contributions to NO in different disease processes. In contrast, the hypothesized intracellular compartmentalized availability of arginine substrate in specifying NO flux may explain the """"""""arginine paradox."""""""" In humans, the natural history of urea cycle disorders and specifically of argininosuccinic aciduria (ASA) caused by deficiency of argininosuccinic acid lyase (ASL) shows systemic and chronic features that may reflect global dysregulation of NO homeostasis. We propose that ASL is in fact the central regulator of NO homeostasis because it is essential for both the intracellular production of arginine and the utilization of extracellular arginine. In preliminary data, we identify a distinct subcellular and biochemical compartment where local cellular arginine production and channeling by ASL regulates systemic NO production. We have generated a conditional genetic model of Asl deficiency that will allow us to study the consequences of cell autonomous loss of NO in brain (neurons vs. glial cells), the cardiovascular system (endothelial vs. smooth muscle cells), and the pancreatic beta cell with broad implications on understanding the contribution of NO to models of neurodegeneration, cardiovascular disease, and metabolic syndrome. On a biochemical level, we will assess how ASL controls arginine availability for NO production. Our studies may identify novel and more effective strategies for manipulation NO in multi-system disease.

Public Health Relevance

Nitric oxide (NO) is an important molecule in the cause of almost all human diseases. We propose to study a new way on how NO is produced in the body. A chemical called argininosuccinate lyase (ASL) is used to produce arginine which is required for NO production. We will determine whether inhibiting ASL may be the most effective way for controlling NO production in diseases affecting the brain, heart, and pancreas.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
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Special Emphasis Panel (ZRG1-BCMB-A (51))
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Anderson, Vernon
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Baylor College of Medicine
Schools of Medicine
United States
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Premkumar, M H; Sule, G; Nagamani, S C et al. (2014) Argininosuccinate lyase in enterocytes protects from development of necrotizing enterocolitis. Am J Physiol Gastrointest Liver Physiol 307:G347-54
Jiang, Hong; Tang, Yaoping; Garg, Harsha K et al. (2012) Concentration- and stage-specific effects of nitrite on colon cancer cell lines. Nitric Oxide 26:267-73
Nagamani, Sandesh C S; Shchelochkov, Oleg A; Mullins, Mary A et al. (2012) A randomized controlled trial to evaluate the effects of high-dose versus low-dose of arginine therapy on hepatic function tests in argininosuccinic aciduria. Mol Genet Metab 107:315-21
Nagamani, Sandesh C S; Campeau, Philippe M; Shchelochkov, Oleg A et al. (2012) Nitric-oxide supplementation for treatment of long-term complications in argininosuccinic aciduria. Am J Hum Genet 90:836-46
Nagamani, Sandesh C S; Lee, Brendan; Erez, Ayelet (2012) Optimizing therapy for argininosuccinic aciduria. Mol Genet Metab 107:10-4
Nagamani, Sandesh C S; Erez, Ayelet; Lee, Brendan (2012) Argininosuccinate lyase deficiency. Genet Med 14:501-7
Erez, Ayelet; Shchelochkov, Oleg A; Plon, Sharon E et al. (2011) Insights into the pathogenesis and treatment of cancer from inborn errors of metabolism. Am J Hum Genet 88:402-21
Erez, Ayelet; Nagamani, Sandesh C Sreenath; Lee, Brendan (2011) Argininosuccinate lyase deficiency-argininosuccinic aciduria and beyond. Am J Med Genet C Semin Med Genet 157C:45-53
Erez, Ayelet; Nagamani, Sandesh C S; Shchelochkov, Oleg A et al. (2011) Requirement of argininosuccinate lyase for systemic nitric oxide production. Nat Med 17:1619-26
Brunetti-Pierri, Nicola; Erez, Ayelet; Shchelochkov, Oleg et al. (2009) Systemic hypertension in two patients with ASL deficiency: a result of nitric oxide deficiency? Mol Genet Metab 98:195-7