Elsevier

Neuroscience Research

Volume 57, Issue 2, February 2007, Pages 277-288
Neuroscience Research

In vitro effect of quinolinic acid on energy metabolism in brain of young rats

https://doi.org/10.1016/j.neures.2006.10.013Get rights and content

Abstract

Quinolinic acid (QA) is found at increased concentrations in brain of patients affected by various common neurodegenerative disorders, including Huntington's and Alzheimer's diseases. Considering that the neuropathology of these disorders has been recently attributed at least in part to energy deficit, in the present study we investigated the in vitro effect of QA (0.1–100 μM) on various parameters of energy metabolism, such as glucose uptake, 14CO2 production and lactate production, as well as on the activities of the respiratory chain complexes I–V, the citric acid cycle (CAC) enzymes, creatine kinase (CK), lactate dehydrogenase (LDH) and Na+,K+-ATPase and finally the rate of oxygen consumption in brain of 30-day-old rats. We initially observed that QA significantly increased glucose uptake (55%), whereas 14CO2 generation from glucose, acetate and citrate was inhibited (up to 60%). Furthermore, QA-induced increase of brain glucose uptake was prevented by the NMDA receptor antagonist MK-801. Complex II activity was also inhibited (up to 35%) by QA, whereas the other activities of the respiratory chain complexes, CAC enzymes, CK and Na+,K+-ATPase were not affected by the acid. Furthermore, inhibition of complex II activity was fully prevented by pre-incubating cortical homogenates with catalase plus superoxide dismutase, indicating that this effect was probably mediated by reactive oxygen species. In addition, lactate production was also not altered by QA, in contrast to the conversion of pyruvate to lactate catalyzed by LDH, which was significantly decreased (17%) by this neurotoxin. We also observed that QA did not change state III, state IV and the respiratory control ratio in the presence of glutamate/malate or succinate, suggesting that its effect on cellular respiration was rather weak. The data provide evidence that QA provokes a mild impairment of brain energy metabolism in vitro and does not support the view that the brain energy deficiency associated to certain neurodegenerative disorders could be solely endorsed to QA accumulation.

Introduction

Neurotoxic actions have been attributed to quinolinic acid (QA), an important intermediate of the kynurenine pathway of tryptophan metabolism (Wolfensberger et al., 1983). Since QA is an endogenous glutamate agonist with a relative selectivity to the N-methyl-d-aspartate (NMDA) receptor, it has been hypothesized that part of its deleterious effects are due to its ability to induce excessive activation of NMDA receptors, associated with increased cytosolic Ca2+ concentrations, ATP and γ-aminobutyric acid (GABA) depletion and specific GABAergic and cholinergic neuronal death (Foster et al., 1983, Schwarcz et al., 1984, Santamaria and Rios, 1993, Stone, 1993, Moroni et al., 1999, Chiarugi et al., 2001).

Furthermore, a number of studies indicate that intrastriatal injection of 240 nmol of QA induces oxidative stress, giving support to a possible relationship between the excitotoxicity and oxidative processes following QA administration (Santamaria and Rios, 1993, Perez-Severiano et al., 1998, Perez-Severiano et al., 2004, Cabrera et al., 2000, Rodriguez-Martinez et al., 2000, Santamaria et al., 2001, Rossato et al., 2002, Ganzella et al., 2006). More recently it has been shown that micromolar concentrations of QA (20–100 μM) elicits lipid peroxidation and decrease of the brain antioxidant defenses in vitro, indicating its capability to induce oxidative stress itself by a NMDA-independent mechanism (Rios and Santamaria, 1991, Behan et al., 1999, Rodriguez-Martinez et al., 2000, Santamaria et al., 2001, Leipnitz et al., 2005).

On the other hand, it was postulated that QA may be involved in the pathogenesis of various disorders in which it is accumulated, such as infectious, as well as in inflammatory and non-inflammatory human neurological diseases (Stone and Perkins, 1981, Moroni et al., 1986, Schwarcz et al., 1988, Heyes et al., 1990, Heyes et al., 1992, Stone, 1993, Heyes, 1996). Experiments in rodents have demonstrated that a single unilateral intrastriatal injection of 100 nmol of QA mimics many of the neurochemical and histological features of Huntington's disease (HD), including GABA depletion and striatal spiny cell loss (Schwarcz et al., 1983, Beal et al., 1986). Thus, this neurotoxin has been used as a chemically-induced animal model of this disease (Schwarcz et al., 1983, Schwarcz et al., 1984, Beal et al., 1986, Ferrante et al., 1993). Interestingly, abnormal energy metabolism has been demonstrated in postmortem HD brain, most notably reduced activity of succinate-linked oxidation and of the activities of the respiratory chain complexes (Brennan et al., 1985, Mann et al., 1990, Gu et al., 1996). Further evidence has shown that the mitochondrial abnormality in HD brain is similar to that induced by malonate and 3-nitropropionic acid, the complex II inhibitors of the respiratory chain (Ludolph et al., 1992, Beal et al., 1993).

Brain physiological QA concentrations range from 0.03 to 0.1 μM in humans, rats and mice (Stone, 1993), whereas in neurodegenerative and neuroinflammatory diseases QA levels may achieve 10–246-fold higher (10–40 μM), especially due to macrophage invasion and microglia activation (Stone, 2001, Beagles et al., 1998). Furthermore, QA activates NMDA receptors in vitro at 20–50 μM and higher concentrations, as measured by electrophysiological studies (Schurr and Rigor, 1993).

Although QA-induced excitotoxicity and free radical generation have been extensively studied as mechanisms of neural cell damage, very few studies were designed to examine the role of QA on brain energy metabolism despite the fact that increased concentrations of QA and mitochondrial energy dysfunction have been found in the brain of HD patients and of other neurodegenerative disorders. In this scenario, it was demonstrated that intrastriatal injection of 60 nmol of QA provokes a progressive time-dependent mitochondrial dysfunction reflected by a low respiratory chain ratio (decreased respiration) and a reduction of ATP, NAD+, aspartate and glutamate concentrations (Bordelon et al., 1997). Furthermore, disturbances in neuronal activity and ion gradients secondarily to metabolic impairment have been also attributed to QA administered in vivo (Bordelon et al., 1998). Although these studies revealed that electrical activity and cellular respiration are reduced by intrastriatal administration of QA, they did not evaluate the underlying involved mechanisms. Furthermore, these QA-induced effects may be indirect secondary to excitotoxicity and to our mind there is no report in the literature on effects of QA on brain energy metabolism in vitro.

Thus, the present study was undertaken to investigate the in vitro influence of QA on important parameters of energy metabolism, such as glucose uptake, 14CO2 production from [U-14C] glucose, [1-14C] acetate and [1,5-14C] citrate and lactate production, as well as on the activities of the respiratory chain complexes I–V, of the citric acid cycle (CAC) enzymes, creatine kinase (CK), lactate dehydrogenase (LDH) and Na+,K+-ATPase in cerebral cortex of young rats in order to clarify the mechanisms involved in the mitochondrial dysfunction provoked by QA.

Section snippets

Reagents

All chemicals were purchased from Sigma Chemical Co., St. Louis, MO, USA, except for [U-14C] glucose, [1-14C] acetate and [1,5-14C] citrate, which were purchased from Amersham International plc, UK.

Animals

A total of 109 thirty-day-old Wistar rats obtained from the Central Animal House of the Departamento de Bioquímica, ICBS, UFRGS, were used. Rats were kept with dams until weaning at 21 days of age. The animals had free access to water and to a standard commercial chow and were maintained on a 12:12 h

QA stimulates glucose uptake by rat cortical prisms

We initially investigated the in vitro effect of QA on glucose uptake by rat cerebral cortex. For these experiments a total of six rats were used. Fig. 1A shows that 100 μM QA significantly increased glucose uptake (up to 55%) by rat cortical prisms [F(3, 20) = 6.62; P < 0.01] in a dose-dependent manner [β = 0.66; P < 0.001]. These results indicate that QA activated glucose utilization by the brain. Next, we pre-incubated 100 μM QA with the NMDA receptor antagonist MK-801 in an attempt to clarify whether

Discussion

Quinolinic acid (QA) neurotoxicity has been mainly attributed to overstimulation of NMDA receptors and to oxidative stress induction (Perkins and Stone, 1983, Foster and Schwarcz, 1989, Rios and Santamaria, 1991, Winn et al., 1991, Santamaria and Rios, 1993, Stone, 1993, Stipek et al., 1997, Perez-Severiano et al., 1998, Perez-Severiano et al., 2004, Behan et al., 1999, Moroni et al., 1999, Cabrera et al., 2000, Rodriguez-Martinez et al., 2000, Stone et al., 2000, Chiarugi et al., 2001,

Acknowledgements

This work was supported by grants from CNPq, PRONEX II, FAPERGS and PROPESQ/UFRGS.

References (83)

  • R.A. Gabbay

    Quinolinate inhibition of gluconeogenesis is dependent on cytosolic oxalacetate concentration. An explanation for the differential inhibition of lactate and pyruvate gluconeogenesis

    FEBS Lett.

    (1985)
  • M. Ganzella et al.

    Time course of oxidative events in the hippocampus following intracerebroventricular infusion of quinolinic acid in mice

    Neurosci. Res.

    (2006)
  • B.P. Hughes

    A method for the estimation of serum creatine kinase and its use in comparing creatine kinase and aldolase activity in normal and pathological sera

    Clin. Chim. Acta

    (1962)
  • H. Iwahashi et al.

    Quinolinic acid, alpha-picolinic acid, fusaric acid, and 2,6-pyridinedicarboxylic acid enhance the Fenton reaction in phosphate buffer

    Chem. Biol. Interact.

    (1999)
  • D.H. Jones et al.

    Isolation of synaptic plasma membrane from brain by combined flotation-sedimentation density gradient centrifugation

    Biochim. Biophys. Acta

    (1974)
  • G. Leipnitz et al.

    Quinolinic acid reduces the antioxidant defenses in cerebral cortex of young rats

    Int. J. Dev. Neurosci.

    (2005)
  • O.H. Lowry et al.

    Protein measurement with the Folin phenol reagent

    J. Biol. Chem.

    (1951)
  • M.J. MacDonald et al.

    Inhibition of phosphoenolpyruvate carboxykinase, glyceroneogenesis and fatty acid synthesis in rat adipose tissue by quinolinate and 3-mercaptopicolinate

    Biochim. Biophys. Acta

    (1981)
  • V.M. Mann et al.

    Mitochondrial function and parental sex effect in Huntington's disease

    Lancet

    (1990)
  • J.R. Maxwell et al.

    Responses of hepatic phosphoenolypyruvate carboxykinase activities from normal and diabetic rats to quinolinate inhibition and ferrous ion activation

    Biochim. Biophys. Acta

    (1980)
  • M.C. O’Hare et al.

    Purification and structural comparisons of the cytosolic and mitochondrial isoenzymes of fumarase from pig liver

    Biochim. Biophys. Acta

    (1985)
  • F. Perez-Severiano et al.

    S-Allylcysteine, a garlic-derived antioxidant, ameliorates quinolinic acid-induced neurotoxicity and oxidative damage in rats

    Neurochem. Int.

    (2004)
  • G.W.E. Plaut

    Isocitrate dehydrogenase from bovine heart

  • E. Rodriguez-Martinez et al.

    Effect of quinolinic acid on endogenous antioxidants in rat corpus striatum

    Brain Res.

    (2000)
  • J.I. Rossato et al.

    Ebselen blocks the quinolinic acid-induced production of thiobarbituric acid reactive species but does not prevent the behavioral alterations produced by intra-striatal quinolinic acid administration in the rat

    Neurosci. Lett.

    (2002)
  • P. Rustin et al.

    Inborn errors of complex II-unusual human mitochondrial diseases

    Biochim. Biophys. Acta

    (2002)
  • P. Rustin et al.

    A biochemical and molecular investigations in respiratory chain deficiencies

    Clin. Chim. Acta

    (1994)
  • A. Santamaria et al.

    MK-801, an N-methyl-d-aspartate receptor antagonist, blocks quinolinic acid-induced lipid peroxidation in rat corpus striatum

    Neurosci. Lett.

    (1993)
  • A. Santamaria et al.

    Copper blocks quinolinic acid neurotoxicity in rats: contribution of antioxidant systems

    Free Radic. Biol. Med.

    (2003)
  • A. Schurr et al.

    Quinolinate potentiates the neurotoxicity of excitatory amino acids in hypoxic neuronal tissue in vitro

    Brain Res.

    (1993)
  • R. Schwarcz et al.

    Excitotoxic models for neurodegenerative disorders

    Life Sci.

    (1984)
  • P.A. Srere

    Citrate synthase

    Methods Enzymol.

    (1969)
  • S. Stipek et al.

    The effect of quinolinate on rat brain lipid peroxidation is dependent on iron

    Neurochem. Int.

    (1997)
  • T.W. Stone

    Kynurenines in the CNS: from endogenous obscurity to therapeutic importance

    Prog. Neurobiol.

    (2001)
  • T.W. Stone et al.

    Quinolinic acid: a potent endogenous excitant at amino acid receptors in CNS

    Eur. J. Pharmacol.

    (1981)
  • M. Wolfensberger et al.

    Identification of quinolinic acid in rat and human brain tissue

    Neurosci. Lett.

    (1983)
  • J. Arenas et al.

    Complex I defect in muscle from patients with Huntington's disease

    Ann. Neurol.

    (1998)
  • K.B. Beagles et al.

    Quinolinic acid in vivo synthesis rates, extracellular concentrations, and intercompartmental distributions in normal and immune-activated brain as determined by multiple-isotope microdialysis

    J. Neurochem.

    (1998)
  • M.F. Beal

    Excitotoxicity and nitric oxide in Parkinson's disease pathogenesis

    Ann. Neurol.

    (1998)
  • M.F. Beal et al.

    Replication of the neurochemical characteristics of Huntington's disease by quinolinic acid

    Nature

    (1986)
  • M.F. Beal et al.

    Age-dependent striatal excitotoxic lesions produced by endogenous mitochondrial inhibitor malonate

    J. Neurochem.

    (1993)
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