Development of a new HPLC method using fluorescence detection without derivatization for determining purine nucleoside phosphorylase activity in human plasma

Giuliani, Patricia; Zuccarini, Mariachiara; Buccella, Silvana; Rossini, Margherita; D’Alimonte, Iolanda; Ciccarelli, Renata; Marzo, M; Marzo, A; Iorio, Patrizia Di; Caciagli, Francesco

doi:10.1016/j.jchromb.2015.12.012

Cited by 26 publications

(23 citation statements)

References 35 publications

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“…HPLC analysis was carried out following a recently published procedure (Giuliani et al . ). In this case, the Agilent HPLC was equipped with a thermostated column compartment, a diode array detector, and a fluorescence detector (Agilent Technologies).…”

Section: Methodsmentioning

confidence: 97%

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Evidence for purine nucleoside phosphorylase (PNP) release from rat C6 glioma cells

Giuliani

Zuccarini

Buccella

et al. 2017

Journal of Neurochemistry

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Intracellular purine turnover is mainly oriented to preserving the level of triphosphate nucleotides, fundamental molecules in vital cell functions that, when released outside cells, act as receptor signals. Conversely, high levels of purine bases and uric acid are found in the extracellular milieu, even in resting conditions. These compounds could derive from nucleosides/bases that, having escaped to cell reuptake, are metabolized by extracellular enzymes similar to the cytosolic ones. Focusing on purine nucleoside phosphorylase (PNP) that catalyzes the reversible phosphorolysis of purine (deoxy)-nucleosides/bases, we found that it is constitutively released from cultured rat C6 glioma cells into the medium, and has a molecular weight and enzyme activity similar to the cytosolic enzyme. Cell exposure to 10 μM ATP or guanosine triphosphate (GTP) increased the extracellular amount of all corresponding purines without modifying the levels/activity of released PNP, whereas selective activation of ATP P2Y or adenosine A metabotropic receptors increased PNP release and purine base formation. The reduction to 1% in oxygen supply (2 h) to cells decreased the levels of released PNP, leading to an increased presence of extracellular nucleosides and to a reduced formation of xanthine and uric acid. Conversely, 2 h cell re-oxygenation enhanced the extracellular amounts of both PNP and purine bases. Thus, hypoxia and re-oxygenation modulated in opposite manner the PNP release/activity and, thereby, the extracellular formation of purine metabolism end-products. In conclusion, extracellular PNP and likely other enzymes deputed to purine base metabolism are released from cells, contributing to the purinergic system homeostasis and exhibiting an important pathophysiological role.

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Section: Methodsmentioning

confidence: 97%

“…; Giuliani et al . ), where their presence was generally ascribed to cell death or membrane alterations as a result of tissue damages or cancer (Brass and Mody ; Roberts et al . ).…”

mentioning

confidence: 99%

Evidence for purine nucleoside phosphorylase (PNP) release from rat C6 glioma cells

Giuliani

Zuccarini

Buccella

et al. 2017

Journal of Neurochemistry

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“…Thermodynamically, the equilibrium of the reaction is shifted in favor of nucleoside synthesis. However, phosphorolysis is highly favored over nucleoside synthesis, due to coupling with two additional enzymatic reactions: (1) oxidation and (2) phosphoribosylation of the liberated purine bases by xanthine oxidase (Xox) and hypoxanthine-guanine phosphoribosyltransferase (HGPRT), respectively (modified from Giuliani et al, 2016).…”

Section: Localisationmentioning

confidence: 99%

“…dGTP accumulation can also interfere with DNA synthesis or repair directly (Arpaia et al, 2000;Ghodke-Puranik et al, 2017) (Figure 4). Abnormal activity of the enzyme is associated with different pathologies (Giuliani et al, 2016). Phosphorolysis of the products of the ADA reaction, inosine and deoxyinosine, is catalyzed by PNP to yield hypoxanthine and ribose-1-phosphate.…”

Section: Functionmentioning

confidence: 99%

PNP (Purine Nucleoside Phosphorylase)

Gurbanov¹,

Tunçer²

2018

Atlas of Genetics and Cytogenetics in Oncology and Haematology

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“…A few number of reports have indicated that some enzymes of the metabolism of purine nucleosides, such as ADO deaminase, purine nucleoside phosphorylase (PNP), Guanase and Xanthine Oxidase (XO), are detectable in plasma ( Roberts and Newton, 2004 ; Roberts et al, 2004 ; Karabulut et al, 2005 ; Chittiprol et al, 2007 ; Lopez-Cruz et al, 2014 ; Giuliani et al, 2016 ). Furthermore, some of these enzymes have been proposed as potential diagnostic or prognostic markers for different pathological conditions.…”

Section: Release Of Enzymes Metabolizing Purinesmentioning

confidence: 99%

The Guanine-Based Purinergic System: The Tale of An Orphan Neuromodulation

et al. 2016

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Guanine-based purines (GBPs) have been recently proposed to be not only metabolic agents but also extracellular signaling molecules that regulate important functions in the central nervous system. In such way, GBPs-mediated neuroprotection, behavioral responses and neuronal plasticity have been broadly described in the literature. However, while a number of these functions (i.e., GBPs neurothophic effects) have been well-established, the molecular mechanisms behind these GBPs-dependent effects are still unknown. Furthermore, no plasma membrane receptors for GBPs have been described so far, thus GBPs are still considered orphan neuromodulators. Interestingly, an intricate and controversial functional interplay between GBPs effects and adenosine receptors activity has been recently described, thus triggering the hypothesis that GBPs mechanism of action might somehow involve adenosine receptors. Here, we review recent data describing the GBPs role in the brain. We focus on the involvement of GBPs regulating neuronal plasticity, and on the new hypothesis based on putative GBPs receptors. Overall, we expect to shed some light on the GBPs world since although these molecules might represent excellent candidates for certain neurological diseases management, the lack of putative GBPs receptors precludes any high throughput screening intent for the search of effective GBPs-based drugs.

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Development of a new HPLC method using fluorescence detection without derivatization for determining purine nucleoside phosphorylase activity in human plasma

Cited by 26 publications

References 35 publications

Evidence for purine nucleoside phosphorylase (PNP) release from rat C6 glioma cells

Evidence for purine nucleoside phosphorylase (PNP) release from rat C6 glioma cells

PNP (Purine Nucleoside Phosphorylase)

The Guanine-Based Purinergic System: The Tale of An Orphan Neuromodulation

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