Glutathione Conjugation at the Blood-CSF Barrier Efficiently Prevents Exposure of the Developing Brain Fluid Environment to Blood-Borne Reactive Electrophilic Substances.

Exposure of the developing brain to toxins, drugs, or deleterious endogenous compounds during the perinatal period can trigger alterations in cell division, migration, differentiation, and synaptogenesis, leading to lifelong neurological impairment. The brain is protected by cellular barriers acting through multiple mechanisms, some of which are still poorly explored. We used a combination of enzymatic assays, live tissue fluorescence microscopy, and an in vitro cellular model of the blood-CSF barrier to investigate an enzymatic detoxification pathway in the developing male and female rat brain. We show that during the early postnatal period the choroid plexus epithelium forming the blood-CSF barrier and the ependymal cell layer bordering the ventricles harbor a high detoxifying capacity that involves glutathione S-transferases. Using a functional knock-down rat model for choroidal glutathione conjugation, we demonstrate that already in neonates, this metabolic pathway efficiently prevents the penetration of blood-borne reactive compounds into CSF. The versatility of the protective mechanism results from the multiplicity of the glutathione S-transferase isoenzymes, which are differently expressed between the choroidal epithelium and the ependyma. The various isoenzymes display differential substrate specificities, which greatly widen the spectrum of molecules that can be inactivated by this pathway. In conclusion, the blood-CSF barrier and the ependyma are identified as key cellular structures in the CNS to protect the brain fluid environment from different chemical classes of potentially toxic compounds during the postnatal period. This metabolic neuroprotective function of brain interfaces ought to compensate for the liver postnatal immaturity.SIGNIFICANCE STATEMENT Brain homeostasis requires a stable and controlled internal environment. Defective brain protection during the perinatal period can lead to lifelong neurological impairment. We demonstrate that the choroid plexus forming the blood-CSF barrier is a key player in the protection of the developing brain. Glutathione-dependent enzymatic metabolism in the choroidal epithelium inactivates a broad spectrum of noxious compounds, efficiently preventing their penetration into the CSF. A second line of detoxification is located in the ependyma separating the CSF from brain tissue. Our study reveals a novel facet of the mechanisms by which the brain is protected at a period of high vulnerability, at a time when the astrocytic network is still immature and liver xenobiotic metabolism is limited.

Potential biomarkers relating pathological proteins, neuroinflammatory factors and free radicals in PD patients with cognitive impairment: a cross-sectional study.

BACKGROUND: Cognitive impairment strikingly reduces the quality of life of Parkinson's disease (PD) patients. Studies find that pathological proteins, neuroinflammatory factors and free radicals may involve in the pathogenesis of cognitive impairment of PD, however, results are inconclusive. METHODS: We recruited 62 PD patients and 31 healthy controls. PD patients were identified with cognitive impairment, including PD with mild cognitive impairment (PD-MCI) and PD with dementia (PDD) according to the diagnostic criteria for PD-MCI and PDD issued by Movement Disorder Society Task Force. The levels of pathological proteins, including ß-amyloid 1-42 (Aß1-42),Total-tau (T-tau) and phosphorelated tau (P-tau), neuroinflammatory factors,including tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), interferon-γ (INF-γ) and prostaglandin E2 (PGE2), free radicals, including hydroxyl radical (·OH), hydrogen peroxide (H2O2) and nitric oxide (NO) in cerebrospinal fluid(CSF) were detected. The levels of above factors in CSF were compared among healthy controls and patients with and without cognitive impairment. Correlation analyses were performed between Montreal Cognitive Assessment (MoCA) score and the levels of above factors in CSF. RESULTS: T-tau level in CSF from PD-CI patients are significantly elevated comparing with those without cognitive impairment and controls (P = 0.016 and 0.004, respectively). The levels of P-tau (S396) and · OH in PD-CI patients are significantly higher than controls (P = 0.001 and 0.014, respectively). IL-6 levels in PD-CI patients are strikingly enhanced comparing with those without cognitive impairment (P = 0.005). MoCA score is negatively correlated with the levels of T-tau (r = -0.340), P-tau (S396) (r = -0.448), IL-6 (r = -0.489) and · OH (r = -0.504) in PD-CI patients. CONCLUSIONS: Elevated levels of T-tau, P-tau (S396), IL-6 and · OH in CSF are significantly correlated with cognitive impairment in PD patients. This investigation may suggest the potential biomarkers relating pathological proteins, neuroinflammatory factors and free radicals in PD patients with cognitive impairment.

Reduction in the free radical status and clinical benefit of repeated intrathecal triamcinolone acetonide application in patients with progressive multiple sclerosis.

BACKGROUND: Previous open trials performed repeated intrathecal application of the sustained release steroid triamcinolone acetonide every third day in patients with progressive multiple sclerosis and described enhanced walking abilities. OBJECTIVES: The objectives of this study were to demonstrate the efficacy of 5 triamcinolone administrations every other day and to describe their effects on the amount of inducible free radicals in cerebrospinal fluid. SUBJECTS/METHODS: Clinical ratings, determinations of maximum walking distance, and execution of an instrumental peg insertion test were performed at baseline and on each day after a triamcinolone injection in 21 patients with progressive multiple sclerosis. Induction of free radicals was assessed in cerebrospinal fluid before each triamcinolone application by electron spin resonance spectroscopy. RESULTS: Scores for multiple sclerosis improved, walking distance increased, and necessary intervals for the peg insertion procedure were shortened. The amount of inducible free radicals decreased. CONCLUSIONS: Repeat triamcinolone application improves dysfunction of upper and lower extremities even when administered 5 times only and in series every other day. The declined potential for free radical synthesis may be caused by the anti-inflammatory effect of triamcinolone. It may contribute to suppress the smoldering, chronic inflammation, particularly in spinal lesions of patients with progressive multiple sclerosis. The enhanced arm function hypothetically reflects the effect on cervical and brain lesions due to the hypobaric features of triamcinolone.

Free radical peroxidation products in cerebrospinal fluid and serum of patients with multiple sclerosis after glucocorticoid therapy.

Multiple sclerosis (MS) patients were found to have elevated thiobarbituric acid reactive material levels, increased soluble sulfhydryl groups and reduced protein sulfhydryl groups in cerebrospinal fluid and serum, and slightly reduced superoxide dismutase in serum, which suggested disease activating free radical peroxidation. Moreover, levels of these varied across methylprednisolone (MP) therapy. We observed significant differences in the levels of peroxidation products between MS patients and controls. These changes were most evident in relapse. After MP therapy, levels of these indicators approached control values, especially in the remission period. Our findings suggest that MP protects against free radical attack.

Cerebrospinal fluid Diacron-Reactive Oxygen Metabolite levels in pediatric patients with central nervous system diseases.

This study assessed the validity of cerebrospinal fluid oxidative status of pediatric patients with central nervous system diseases, using the Diacron-Reactive Oxygen Metabolites test (d-Roms; Diacron International s.r.l.; Grosseto, Italy). Eighty-seven pediatric patients (8 with bacterial meningitis, 18 with aseptic meningitis, 23 with febrile seizures, 6 with rotavirus gastroenteritis-induced convulsions, 16 with epilepsy, 2 with adrenoleukodystrophy, 2 with multiple sclerosis, and 12 control subjects) were enrolled. An analysis of the infection-associated group (bacterial meningitis, aseptic meningitis, febrile seizures, and rotavirus gastroenteritis-induced convulsions) indicated that cerebrospinal fluid Diacron-Reactive Oxygen Metabolite levels in the bacterial meningitis group were significantly higher than in other infection-associated groups. In the bacterial meningitis group, the cerebrospinal fluid Diacron-Reactive Oxygen Metabolite levels obtained after improvement were significantly decreased compared with pre-improvement values. In the noninfection-associated group (epilepsy, adrenoleukodystrophy, and multiple sclerosis), the cerebrospinal fluid Diacron-Reactive Oxygen Metabolite levels in symptomatic epilepsy patients were higher than in cryptogenic epilepsy patients and control subjects, but not significantly. Progressive patients with adrenoleukodystrophy or multiple sclerosis demonstrated high Diacron-Reactive Oxygen Metabolite levels compared with another early-stage adrenoleukodystrophy patient. Oxidative stress may be associated with the pathogenesis of various pediatric central nervous system diseases. Cerebrospinal fluid Diacron-Reactive Oxygen Metabolite levels may correlate with clinical status in these diseases.

Viral loads of cerebrospinal fluid in infants with enterovirus meningitis.

For a better understanding of the role of the viral load, free radicals, and cytokines in viral meningitis, we surveyed cerebrospinal fluid (CSF) obtained from patients below 1 year of age who showed positive for enterovirus. In their first examinations interleukin (IL)-6 and free radicals increased whereas pleocytosis was rarely observed. IL-6 decreased within the short period. Viral loads and free radicals increased simultaneously. IL-6 and free radicals of CSF are helpful for diagnosis and treatment of viral meningitis at an early stage.

Acute encephalopathy with refractory status epilepticus: bilateral mesial temporal and claustral lesions, associated with a peripheral marker of oxidative DNA damage.

We describe a 12-year-old girl, who had been medicated with theophylline for bronchial asthma and developed acute encephalopathy with refractory status epilepticus, showing bilateral mesial temporal and claustral lesions, which were evident on fluid-attenuated inversion recovery images, obtained with 1.5 T magnetic resonance imaging. To date, oxidative stress has been implicated in aging or various disorders, including inflammatory or degenerative neurological disorders. One of the oxidative stress markers, 8-hydroxydeoxyguanosine, was increased in our patient's cerebro-spinal fluid, plasma and urine. We speculate that augmented oxidative stress was associated with refractory status epilepticus in our patient, accompanying bilateral mesial temporal, claustral lesions and severe neuronal damage. Serial measurements of oxidative stress markers in acute encephalitis, encephalopathy, or status epilepticus could clarify the relationships between acute brain damage and free radicals.

Diagnostic and predictive value of CSF d-ROM level in influenza virus-associated encephalopathy.

The aim of this study was to assess the validity of serum and CSF oxidative status of patients with IE in their initial stage through the d-ROM (Diacron-Reactive Oxygen Metabolites, Italy) test, compared to those with other neurological diseases. The study was conducted on the following four groups: (1) influenza virus-associated encephalopathy (IE, n = 8), including four patients showing neurological sequelae or mortal; (2) influenza virus-associated febrile seizures (IFS, n = 11); (3) febrile convulsion (FC, n = 10): (4) enterovirus-associated encephalopathy (EE, n = 4), including one patient with neurological sequelae. The CSF d-ROM levels in the IE group were significantly higher than those in the IFS and the FC groups but not in the EE group. In addition, general laboratory findings such as leukocytes, platelets, C-reactive protein, aspartate aminotransferase, creatinine, creatinine kinase and LDH, including interleukin-6 (IL-6), were analyzed in each group. The CSF d-ROM levels in the IE group were significantly higher than those in the IFS and FC groups but not in the EE group. As for the serum d-ROM levels and general laboratory findings, with the exception of CSF IL-6 levels in IE, no significant differences were detected compared with the other groups. In patients with IE, the CSF d-ROM levels could be a valid predictive biomarker of the severity, and oxidative stress may be related to the pathogenesis of IE.

Thiobarbituric acid reactive substances in the cerebrospinal fluid in schizophrenia.

Increased levels of lipid peroxidation products (thiobarbituric acid reactive substances [TBARS]) are reported in plasma/serum from patients with schizophrenia. CSF TBARS levels were assessed in 10 neuroleptic-free patients with schizophrenia and in 9 normal controls. Controlling for duration of storage, CSF TBARS content was significantly lower in patients with schizophrenia vs. controls (p<0.002). No significant correlations were found between CSF TBARS and patients' age, gender, or duration of illness. The likely source of reported elevated plasma/serum TBARS in schizophrenia is therefore in the periphery. Degeneration of central neuronal membranes in schizophrenia is not supported by the present study.

Cerebrospinal fluid free-radical peroxidation products and cognitive functioning patterns differentiate varieties of normal pressure hydrocephalus.

The aims of the study were as follows: first, to verify the hypothesis that free radical peroxidation may be one of the factors implicated in pathophysiology of normal pressure hydrocephalus (NPH) and, second, to find out whether these biochemical characteristics together with neuropsychological cognitive deficits can differentiate between various types of NPH. This provides prognostic criteria for selection of patients for shunt surgery. Lipid peroxidation was measured in terms of thiobarbituric acid-reactive material (TBAR) and protein sulphydryl (SH) groups were measured as CSF content. Cognitive deficits were assessed using a number of neuropsychological tests. In the sample of NPH patients (n = 24), three categories were distinguished using these criteria: idiopathic active hydrocephalus (A), arrested hydrocephalus (AH), and post-traumatic hydrocephalus (PT). TBAR levels for NPH patients were higher than that of controls without CNS pathology (n = 2). Moreover, NPH patients had increased levels of total and soluble protein groups, and decreased levels of protein SH groups, which suggests the occurrence of processes that activate peroxidation of free radicals in normal pressure hydrocephalus. Levels of these indicators varied across NPH types. Two categories of NPH patients, with active (A) or posttraumatic (PT) hydrocephalus differed significantly from the controls (C)--their TBAR levels were 0.58, 0.56 and 0.28 nmol/mg protein, respectively; soluble SH levels: 41.5; 58.15 and 11.3 nmol/mg protein, and protein SH levels: 34.3, 21.8 and 57.5 nmol/mg protein. In PT group, many individual differences were noticed. These findings seem promising because the studied biochemical indicators may serve as additional diagnostic criteria for selection of NPH patients for shunting.

Effect of phenobarbital on free radicals in neonates with hypoxic ischemic encephalopathy--a randomized controlled trial.

BACKGROUND: Phenobarbital is one of the oldest, cheapest and easily available cerebroprotective drugs for the hypoxic brain. However, its potential and various actions have not been fully explored. AIM: To evaluate the effects of Phenobarbital on levels of oxidants and anti-oxidants in term and near term neonates with hypoxic ischemic encephalopathy. METHODS: Design--randomized controlled trial. Setting--tertiary care referral perinatal centre. Procedure--asphyxiated neonates (gestation > or = 34 weeks) with HIE were randomized to receive Phenobarbital 20 mg/kg i.v. within first six hours of life or to control group. CSF levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx) and blood levels of vitamins A and E were estimated at 10-12 hours of age. RESULTS: CSF levels of MDA, SOD, GPx and blood levels of vitamins A and E were significantly lower in the Phenobarbital group (p<0.001). There was a trend towards lower levels of CSF MDA, SOD, GPx and blood vitamins A and E in babies with normal outcome as compared to babies with adverse outcome (death or neurologically abnormal at discharge). CONCLUSION: Phenobarbital in the dose of 20 mg/kg i.v. given within 6 hours of life in term and near-term neonates with HIE, was associated with a decrease in lipid peroxides, anti-oxidant enzymes and anti-oxidant vitamins.

[Free radicals and antioxidants in cerebrospinal fluid in central nervous system diseases]. / Vysetrování mozkomísního moku z hlediska volných radikálu a antioxidantu u nekterých onemocnení CNS.

Free radicals and antioxidants may play a role in the etiology and pathogenesis of some central nervous diseases. The brain tissue is relatively insufficiently protected by antioxidants against the free radical induced damage. The brain situation may be reflected by the cerebrospinal fluid examination, which has not enough attention. It seems, that from this point of view subarachnoical hemorrhagy, meningitis, hydrocephalus, Alzheimer's, Parkinson's and Huntington's diseases, multiple sclerosis and probably schizophrenia should receive a special attention.

Elevated free radical products in the cerebrospinal fluid of VLBW infants with cerebral white matter injury.

Free radical mediated cellular injury has been hypothesized to play a key role in the pathogenesis of white matter injury in the premature infant, although direct evidence is lacking. Between April 1999 and May 2001, 22 very low birthweight infants, 30 term infants, and 17 adults had samples of cerebrospinal fluid (CSF) collected for clinical indications. Only CSF samples without any evidence of meningeal inflammation were analyzed for the levels of the lipid peroxidation products, 8-isoprostane and malondialdehyde (MDA), and protein carbonyls as a measure of protein oxidation. Chlorotyrosine was monitored as a measure of neutrophil oxidative activity. In the premature infants with subsequent evidence of white matter injury on magnetic resonance imaging at term, there was a significant elevation in the CSF level of protein carbonyls in comparison with the level in healthy premature infants, term infants, and adult controls (all p < 0.001). A significant difference in the levels of the lipid peroxidation products, 8-isoprostane and MDA, was apparent between premature infants with white matter injury and adult controls (isoprostanes p = 0.02, MDA p = 0.014). There was a trend toward higher levels of 8-isoprostane in the premature infants with white matter injury in comparison with those without white matter injury (p = 0.08), with 5 of the 14 infants with white matter injury having levels that were more than 10-fold higher than the top of the adult range. There was no significant difference in the level of chlorotyrosines among any of the groups. These preliminary data provide evidence of an association of elevated oxidative products during the evolution of white matter injury in the human premature infant.

Evaluation of free radical status in CSF in childhood meningitis.

The study was undertaken to investigate the possible role of free radicals and antioxidants in childhood meningitis. Sixty children suffering from acute bacterial meningitis (ABM) or tuberculous meningitis (TBM) according to their clinical and laboratory findings were enrolled in the study. The production of superoxide anions (O2.-), hydrogen peroxide (H2O2) and malondialdehyde (MDA) and the activities of xanthine oxidase (XO), superoxide dismutase (SOD) and glutathione peroxidase (GPx) were monitored in the study groups and findings compared with those in 20 age-matched controls. Children with ABM and TBM who died registered significant increases in the production of O2.- and MDA and in the activities of SOD and CPK compared with survivors. The rate of production of oxidants and MDA and the activities of XO, SOD and CPK were of a much higher magnitude in deceased ABM and in ABM survivors than in fatal TBM and survivors, respectively. The abnormalities in most of the biochemical parameters investigated were more marked in the children with ABM than in TBM and controls (p < 0.001). Increased MDA production and creatine phosphokinase (CPK) activity of different magnitudes in the two study groups suggest varying degrees of tissue damage. The alterations observed in 20 children who died (14 from ABM, 6 from TBM) revealed elevated levels of oxidants, antioxidants and toxicity markers, particularly in ABM patients, which suggests the possibility that natural or synthetic antioxidants might prevent disease progression and tissue damage in childhood meningitis.

CSF interleukin-1 beta, tumor necrosis factor-alpha and free radicals production in relation to clinical outcome in acute bacterial meningitis.

OBJECTIVE: To study the relationship of CSF IL-1 beta and TNF-alpha with free radicals in acute bacterial meningitis (ABM) and to evaluate the clinical outcome in relation to the levels of these cytokines and free radicals in CSF. DESIGN: Prospective with controls. SETTING: Referral unit of a teaching hospital. METHODS: 32 children between 3m-12 yrs of age with proven acute bacterial meningitis comprised the study group. In the control group, 20 children with febrile seizures were included. CSF cytokines- Interleukin Ib and tumour necrosis factor a,free radicals O(2)-, H(2)O(2) and enzymes SOD and CPK were measured in all the children. RESULTS: CSF IL-Ib and TNF-a concentration were markedly elevated in children with ABM (441.5 +/- 216.1 pg/ml, and 1009 +/- 529.1 pg/ml, respectively) as compared to controls (52.67 +/- 6.92 pg/ml, and 86.42 +/- 16.24 pg/ml) (p <0.0001). Free radicals viz., superoxide anion, hydrogen peroxide production and enzymes creatinine phosphokinase and superoxide dismutase were also significantly elevated in ABM as compared to controls. There was direct correlation of CSF cytokines with CSF cytology, protein and free radicals production in ABM. Patients who expired or had neurological sequelae had markedly elevated concentrations of cytokines and free radicals. CONCLUSION: IL-I beta, TNF-alpha and free radicals are significantly elevated in CSF of patients with ABM. The concentration of these cytokines correlated well with free radical production, and with routinely measured CSF parameters and had a direct bearing on outcome of ABM

[The role of biochemical processes in the pathogenesis of complicated hydrocephalus in children]. / O roli biokhimicheskikh protsessov v patogeneze oslozhnennoi vodianki golovnogo mozga u detei.

Spinal fluid radical formation levels, malonic dialdehyde concentrations, and intrinsic antioxidative activity were studied in 84 patients with hydrocephalus. The findings suggest that there is a considerable activation of free radical reactions and lipid peroxidation, as well as a reduction in antioxidative activity. These changes were most drastically profound in children with inflammation-complicated hydrocephalus with spinal fluid hemorrhagic changes in particular. Timely correction of impaired energy exchange in children by using antioxidants and nootropics promotes the arrest of inflammation and prevents a number of postoperative complications.

Indices of free radical activity in the cerebrospinal fluid in motor neuron disease.

Indices of free-radical activity and lipid peroxidation were studied in cerebrospinal fluid samples obtained from 11 patients with motor neuron disease and 11 reference subjects. No differences were found between the two groups. The significance of this finding is discussed in relation to current views of the possible pathogenesis of this disease.