The use of glutaminase inhibitors represents one way to achieve this goal.
M Mar Díaz-Herrero, José A del Campo, Pilar Carbonero-Aguilar, José M Vega-Pérez,Fernando Iglesias-Guerra, Ignacio Periñán, Francisco J Miñano, Juan Bautista, ManuelRomero-Gómez 2014, 'THDP17 decreases ammonia production through glutaminase inhibition. A new drug forhepatic encephalopathy therapy.', PLoS ONEhttp://europepmc.org/articles/PMC4201470?pdf=render. Retrieved from PLOS CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
So, we used genetic pharmacotherapy to test the therapeutic potential of glutaminase inhibition.
Susana eMingote, Susana eMingote, Justine eMasson, Justine eMasson, Celia eGellman,Gretchen Miller Thomsen, Gretchen Miller Thomsen, Chyuan-Sheng eLin, Robert J. Merker,Inna eGaisler-Salomon, Inna eGaisler-Salomon, Yvonne eWang, Rachel eErnst, Rene eHen,Rene eHen, Stephen eRayport, Stephen eRayport 2016, 'Genetic pharmacotherapy as an early CNS drug development strategy: testing glutaminaseinhibition for schizophrenia treatment in adult mice', Frontiers in Systems Neurosciencehttp://journal.frontiersin.org/Journal/10.3389/fnsys.2015.00165/full. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
However, this has been difficult to test given the dearth of neuroactive glutaminase inhibitors.
Susana eMingote, Susana eMingote, Justine eMasson, Justine eMasson, Celia eGellman,Gretchen Miller Thomsen, Gretchen Miller Thomsen, Chyuan-Sheng eLin, Robert J. Merker,Inna eGaisler-Salomon, Inna eGaisler-Salomon, Yvonne eWang, Rachel eErnst, Rene eHen,Rene eHen, Stephen eRayport, Stephen eRayport 2016, 'Genetic pharmacotherapy as an early CNS drug development strategy: testing glutaminaseinhibition for schizophrenia treatment in adult mice', Frontiers in Systems Neurosciencehttp://journal.frontiersin.org/Journal/10.3389/fnsys.2015.00165/full. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
A highly conserved hypothetical protein shares a promoter with the gene encoding the protein-glutaminase enzyme.
Ruidan Qu, Xiaoyu Zhu, Min Tian, Yingjie Liu, Wenjuan Yan, Jian Ye, Hongliang Gao,Jing Huang 2018, 'Complete Genome Sequence and Characterization of a Protein-Glutaminase Producing Strain,Chryseobacterium proteolyticum QSH1265', Frontiers in Microbiologyhttps://www.frontiersin.org/article/10.3389/fmicb.2018.01975/full. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
To analyze the impact of metformin on glutaminase activity and ammonia production in vitro.
Javier Ampuero, Isidora Ranchal, David Nuñez, María del Mar Díaz-Herrero, Marta Maraver,José Antonio del Campo, Ángela Rojas, Inés Camacho, Blanca Figueruela, Juan D Bautista,Manuel Romero-Gómez 2012, 'Metformin inhibits glutaminase activity and protects against hepatic encephalopathy.',PLoS ONEhttp://europepmc.org/articles/PMC3499552?pdf=render. Retrieved from PLOS CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Cell growth and differentiation were assessed using immunohistochemistry and glutaminase enzyme assay.
Neus Gomila Pelegri, Catherine A. Gorrie, Jerran Santos 2019, 'Rat Hippocampal Neural Stem Cell Modulation Using PDGF, VEGF, PDGF/VEGF, and BDNF',Stem Cells Internationalhttp://dx.doi.org/10.1155/2019/4978917. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
However, the expression and the functionality of glutaminase in astrocytes during neuroinflammation remain unknown.
Kaizhe Wang, Ling Ye, Hongfang Lu, Huili Chen, Yanyan Zhang, Yunlong Huang, JialinC. Zheng 2017, 'TNF-α promotes extracellular vesicle release in mouse astrocytes through glutaminase',Journal of Neuroinflammationhttp://link.springer.com/article/10.1186/s12974-017-0853-2. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Their intrinsic low-rate glutaminase activity, however, causes serious side-effects, including neurotoxicity, hepatitis, coagulopathy and other dysfunctions.
Meraj Pourhossein, Hassan Korbekandi 2014, 'Cloning, expression, purification and characterisation of Erwinia carotovora L-asparaginasein Escherichia coli', Advanced Biomedical Researchhttp://www.advbiores.net/article.asp?issn=2277-9175;year=2014;volume=3;issue=1;spage=82;epage=82;aulast=Pourhossein. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Hence, additional purification steps are required to remove toxicity induced by the amalgamation of other enzymes like glutaminase and urease.
Anup Ashok, Kruthi Doriya, Jyothi Vithal Rao, Asif Qureshi, Anoop Kumar Tiwari, DevaraiSanthosh Kumar 2019, 'Microbes Producing L-Asparaginase free of Glutaminase and Urease isolated from ExtremeLocations of Antarctic Soil and Moss', Scientific Reportshttp://link.springer.com/article/10.1038/s41598-018-38094-1. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
We apply this assay to quantitatively measure glutamine-derived ammonia in lung cancer cell lines with differential expression of glutaminase.
Jessica B. Spinelli, Liam P. Kelley, Marcia C. Haigis 2017, 'An LC-MS Approach to Quantitative Measurement of Ammonia Isotopologues', Scientific Reportshttp://link.springer.com/article/10.1038/s41598-017-09993-6. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)