doi: 10.1161/hs1001.097243
(Stroke. 2001;32:2394.)
© 2001 American Heart Association, Inc.
Original Contributions |
Triflusal Posttreatment Inhibits Glial Nuclear Factor-
B, Downregulates the Glial Response, and Is Neuroprotective in an Excitotoxic Injury Model in Postnatal Brain
From the Unit of Histology, School of Medicine, Department of Cell Biology, Physiology, and Immunology, Autonomous University of Barcelona, Bellaterra, Spain.
Correspondence to Laia Acarin, PhD, Unitat Histologia, Facultat Medicina, Torre M5, Universitat Autònoma Barcelona, Bellaterra 08193, Spain. E-mail lacarin{at}servet.uab.es
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Abstract |
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Background and Purpose—— Nuclear factor-
B (NF-B) and the signal transducer and activator of transcription 3 (STAT3) are important transcription factors regulating inflammatory mechanisms and the glial response to neural injury, determining lesion outcome. In this study we evaluate the ability of triflusal (2-acetoxy-4-trifluoromethylbenzoic acid), an antiplatelet agent inhibitor of NF-B activation, to improve lesion outcome after excitotoxic damage to the immature brain.
Methods—— Postnatal day 9 rats received an intracortical injection of the excitotoxin N-methyl-D-aspartate (NMDA) and oral administration of triflusal (30 mg/kg) either as 3 doses before NMDA injection (pretreatment) or as a single dose 8 hours after NMDA injection (posttreatment). After survival times of 10 and 24 hours, brains were processed for toluidine blue staining, tomato lectin histochemistry, and glial fibrillary acidic protein, NF-B, and STAT3 immunocytochemistry.
Results—— NMDA-lesioned animals that were not treated with triflusal showed activation of NF-B in neuronal cells at first and in glial cells subsequently. Animals that received pretreatment with triflusal showed a strong downregulation of neuronal and glial NF-B but a similar development of the glial response and an equivalent lesion volume compared with nontreated animals. In contrast, animals receiving triflusal posttreatment showed increased early neuronal NF-B but a reduction in the subsequent glial NF-B, accompanied by important downregulation of the microglial and astroglial response and a drastic reduction in the lesion size. STAT3 activation was not affected by triflusal treatment.
Conclusions—— Triflusal posttreatment diminishes glial NF-B, downregulates the glial response, and improves the lesion outcome, suggesting a neuroprotective role of this compound against excitotoxic injury in the immature brain.
Key Words: anti-inflammatory agents, nonsteroidal • antiplatelet agents • astrocytes • excitotoxicity • microglia • neuroglia • neuroprotection • newborn • salicylates • stroke, experimental • transcription factors
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Introduction |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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The transcription factor nuclear factor-
B (NF-B) is increased in acute neuropathological situations as well as in neurodegenerative diseases. Elevated levels of NF-B have been observed after ischemia,1,2 excitotoxicity,3–5 and traumatic injury6 but also in Alzheimer’s and Parkinson’s disease7,8 and demyelinating conditions.9 Because activation of NF-B is associated with cell death in these different situations, NF-B has been proposed to contribute to the degenerating process.10–12 However, other studies have suggested that it represents a cytoprotective response preventing apoptosis,13–15 indicating that NF-B actions in death processes may be dependent on the type of stimulus and the specific conditions, either promoting or preventing cell death.16 Besides the acute neuronal death occurring after pathological insults, clinical and experimental findings point to the glial response and inflammatory processes as the cause of the delayed damage in most neurodegenerative conditions.17,18 This glial inflammatory response is partly modulated by the activation of transcription factors such as NF-B and the signal transducer and activator of transcription 3 (STAT3), which are activated by injury-induced signals and modulate the expression of genes involved in the glial and inflammatory reactions,19–21 determining the final extent of tissue damage.
Several lines of evidence suggest that endogenous excitatory amino acids contribute to the pathophysiology of neuronal injury in major neurological disorders. Specifically, the excitotoxic mechanism may underlie hypoxic/ischemic neuronal degeneration in conditions such as stroke, cardiac arrest, and perinatal asphyxia (see References 22 and 23 for review). Accordingly, neuropathological findings after postnatal hypoxia/ischemia are similar to those induced by exogenous glutamate agonists.22,23 In this sense, it has been shown that ischemia/excitotoxicity triggers a rapid NF-B increase in neurons followed by a sustained glial activation of NF-B.2–4,24 After postnatal excitotoxic injury, neuronal NF-B is rapidly increased within a few hours after injury until neuronal loss occurs at day 1, whereas glial NF-B is consistently activated from 10 hours after injury and remains activated in the glial scar,3,4 contributing to the lesion outcome.
Triflusal (2-acetoxy-4-trifluoromethylbenzoic acid) is an antiplatelet agent related to salicylates and used for its antiaggregant activity.25 Recently, it has been demonstrated that triflusal blocks the activation of NF-B in vitro, decreases the expression of NF-B–regulated genes,26,27 and downregulates constitutive NF-B in the postnatal brain.28 Thus, the aim of the present study was to analyze the ability of triflusal to inhibit NF-B activity after a postnatal excitotoxic lesion and to evaluate its efficacy as a putative neuroprotective drug.
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Materials and Methods |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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Excitotoxic Lesions
Experimental animal work using Long-Evans black-hooded rats was conducted according to Spanish regulations, in agreement with European Union directives. As previously described,29,30 9-day-old pups were placed in a stereotaxic frame adapted for newborns (Kopf Instruments) under ether anesthesia. The skull was opened with a surgical blade, and 37 nmol of N-methyl-D-aspartate (NMDA) (Sigma, M-3262) diluted in 0.15 µL of saline solution (0.9% NaCl, pH 7.4) was injected into the right sensorimotor cortex (at the level of the coronal suture, 2 mm lateral of bregma and at a depth of 0.5 mm) with a 0.5-µL Hamilton microsyringe. Saline control animals followed the same procedure but received an injection of 0.15 µL of the vehicle saline solution. After being sutured, the pups were placed on a thermal pad inside an incubator and maintained at normothermia for 2 hours before being returned to their mothers. This experimental procedure was approved by the ethical commission of Autonomous University of Barcelona.
Triflusal Treatment
Rat pups received oral administration of triflusal supplied by Uriach & Cia by means of a gastric probe, a 3-cm-long rubber tube attached to a 5-mL syringe, which was introduced into the pup’s esophagus. Triflusal was administered at a dose of 30 mg/kg in a 3-mg/mL solution. Because the weight of the pups ranged from 16 to 19 g, volumes administered were 0.16 to 0.19 mL. Triflusal administrations were made either before (pretreatment) or after (posttreatment) the intracerebral injection of NMDA or saline. All pretreated rats received 3 oral administrations of triflusal at 48 hours, 24 hours, and 1 hour before the NMDA/saline injection. Posttreated rats received a single dose of triflusal 8 hours after the NMDA/saline injection. Nontreated 9-day-old rat pups were injected with NMDA/saline and used as controls for drug treatment. Animals were divided into the different experimental groups as detailed in Figure 1.
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Fixation and Histology
At 10 or 24 hours after NMDA or saline injection, rats were anesthetized by ether inhalation and perfused intracardially for 10 minutes with 4% paraformaldehyde in 0.1 mol/L phosphate buffer (pH 7.4). Brains were immediately removed, immersed in the same fixative for 4 hours, and cryoprotected in a 30% sucrose solution before being frozen with dry CO2. Frozen coronal sections (30 µm thick) were obtained with a Leitz cryostat. Alternate sections were mounted on gelatin-coated slides or stored free-floating in antifreeze buffer. Parallel sections were mounted on slides and stained with toluidine blue for routine histological examination and quantification of lesion volume.
Determination of Lesion Volume
Lesion volume was quantified with the use of toluidine blue–stained sections of all NMDA-lesioned animals at 24 hours after injury, ie, those not treated with triflusal (n=6), triflusal pretreated (n=4), and triflusal posttreated (n=18) (Figure 1). Camera lucida drawings of the degenerating area were made every 270 µm from the rostral to the caudal end of the lesion. Lesion volumes were calculated by image analysis. Statistical analysis was performed with the use of Statview 4.5 software. ANOVA and Fisher’s protected least significant difference post hoc comparisons were used.
Immunocytochemistry for NF-B, STAT3, and Glial Fibrillary Acidic Protein
Parallel free-floating sections were processed for the demonstration of NF-B and STAT3 or the astroglial protein glial fibrillary acidic protein (GFAP). After endogenous peroxidase blocking, sections were treated with blocking buffer (10% fetal calf serum in Tris-buffered saline [pH 7.4]) for 30 minutes and incubated at 4°C in 1 of the following primary antibodies diluted in blocking buffer: (1) rabbit anti-mouse STAT3 antibody (Santacruz, sc-482) (1:100); (2) rabbit anti-human NF-B (p65) antibody (Santacruz, sc-109) (1:100); or (3) rabbit anti-human GFAP (Dakopatts, Z-0334) (1:1800). After they were washed, sections were incubated for 1 hour with biotinylated anti-rabbit antibody (Amersham, RPN-1004) (1:200). Sections were rinsed again and incubated for 1 hour with avidin-peroxidase (Dakopatts, P0364) (1:400). Peroxidase reaction product was visualized with100 mL of Tris buffer containing 50 mg 3'-diaminobenzidine and 33 µL hydrogen peroxide. For each of the 3 different immunomarkers, an optimal developing duration was chosen, and all sections were incubated during that selected amount of time. Sections were mounted on gelatin-coated slides, dehydrated in alcohol, cleared in xylene, and coverslipped in mounting media. As controls, primary antibodies were omitted.
Tomato Lectin Histochemistry
Tomato lectin histochemistry for the visualization of microglial cells has been described previously.31 Briefly, after endogenous peroxidase blocking with 2% H2O2 in 70% methanol, sections were rinsed in Tris-buffered saline plus 0.5% Triton X-100 and incubated with the biotinylated lectin from Lycopersicon esculentum (tomato) (Sigma, L-9389) (6 µg/mL, 2 hours, room temperature). Sections were washed and incubated with avidin-peroxidase (Dakopatts, P-0364) (1: 400, 1 hour). The peroxidase reaction product was visualized as described above. Sections were mounted on gelatin-coated slides, dehydrated, cleared in xylene, and coverslipped in mounting media.
Quantitative Analysis of Immunocytochemical Staining
Sections processed for the demonstration of NF-B, STAT3, and GFAP were quantified as previously described.29,30 Briefly, sections were digitized by a video camera mounted on a Leitz microscope and interfaced to a Macintosh computer. National Institutes of Health Image software was used to quantify the immunocytochemical staining. The quantification measure, referred to as the "reactivity grade," was defined as the ratio between density values of a specific area of 0.25 mm2 in the cortex ipsilateral to the NMDA injection versus the same area in the contralateral control hemisphere. A reactivity grade was obtained for each marker and for each animal (mean of 2 sections). The researcher was blinded to sample identity. Six animals were analyzed in the nontreated group, 4 animals in the triflusal-pretreated group, and 6 animals in the triflusal-posttreated group (those with lesion volume closest to the mean). Statistical analysis was performed with Statview 4.5 software. ANOVA and Fisher’s protected least significant difference post hoc comparisons were used.
Double Staining for NF-B and Neuronal or Glial Markers
We used double-staining techniques for the simultaneous visualization of NF-B and microglial cells (by tomato lectin binding), astroglial cells (by GFAP labeling), and neuronal cells (by demonstration of the anti–neuronal nuclei [NeuN] antigen). Sections were immunoreacted for NF-B as reported above but with the use of Cy3-conjugated anti-rabbit secondary antibody (Amersham, PA-43004) (1:1000). Sections were then further processed for GFAP or NeuN immunocytochemistry by using the primary antibodies rabbit anti-GFAP (Dakopatts, Z-0334) (1:1800) and mouse anti-NeuN (Chemicon, MAB377) (1:1000), biotinylated secondary antibodies, and Cy2-conjugated avidin (Amersham, PA-42000) at 1:1000. Sections for double staining with tomato lectin histochemistry were incubated with the biotinylated lectin and visualized with Cy2-conjugated avidin. Double-stained sections were analyzed with a LEICA TCS 4D confocal microscope.
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Results |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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We have previously described the neuronal and glial response to NMDA-induced excitotoxic injury in the immature brain, including the activation and cellular localization of the transcription factors STAT3 and NF-
B by double labeling and electron microscopy.3,4,29,30,32
Neuronal Degeneration and Lesion Volume
No neuronal damage was observed in saline-injected controls (Figure 2A and 2B). Postnatal animals not treated with triflusal that received an intracortical injection of NMDA showed an area of neuronal injury including the entire thickness of the cortex at the level of the sensorimotor area (Figures 2C and 3), covering a mean volume of 38.57 mm3 (SEM=2.72 mm3) (Figures 3 and 4). Signs of tissue damage were seen within a few hours after injection, when neuropil vacuolation and incipient signs of neuronal affectation were observed in the degenerating area. At 24 hours after injection, some necrotic and apoptotic-like figures were still noted, but a massive loss of neuronal cells was evident (Figure 2D). Subcortical white matter tracts apparently showed no axonal degeneration but an increase in glial cell nuclei.
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Triflusal Pretreatment
Animals that received an intracortical injection of NMDA after being treated for 3 days with triflusal (referred to as the T+NMDA group) showed an area of neuronal injury that included the entire thickness of the cortex (Figures 2E and 3) and covered a mean volume of 43.01 mm3 (SEM=5.35 mm3), which was not significantly different from nontreated NMDA-injected animals (Figure 4). Accordingly, the degenerating area showed apoptotic/necrotic figures and an important loss of neuronal cells at 24 hours after injection (Figure 2F), very similar to nontreated littermates.
Triflusal Posttreatment
In contrast, animals that were given an oral administration of triflusal 8 hours after receiving an injection of NMDA (referred to as the NMDA+T group) displayed an area of neuronal injury that was restricted to the level of the injection site (Figures 2, 4G, and 4H), covering a mean volume of 19.81 mm3 (SEM=2.48 mm3), which was significantly reduced (P>0.0005) in comparison to the lesion volume of nontreated NMDA-injected or T+NMDA animals (Figure 4).
NF-B and STAT3 Immunoreactivity
In saline-injected controls, both in the injected hemisphere as well as contralaterally, there was mild constitutive NF-B immunoreactivity in neurons throughout the brain, especially in the hypothalamus and specific cortical layers (Figure 5A). Moreover, astroglial cells in the corpus callosum showed constitutive NF-B and STAT3 immunoreactivity (Figure 5B and 5C). Within a few hours after NMDA injection, in the absence of triflusal treatment, signs of neuronal affectation were accompanied by an increase in neuronal NF-B labeling in the degenerating area (Figure 5D). Although at this early time point most NF-B–positive cells were identified as neuronal cells by double staining with a neuronal marker (Figure 6), a few astroglial and microglial cells also showed NF-B labeling. At 24 hours after lesion, the induced neuronal NF-B labeling decreased as a consequence of massive neuronal death, and maximal NF-B labeling was observed in glial cells (Figure 5E), mainly astrocytes (Figure 6). STAT3 was also noted in astroglial cells within a few hours after lesion and peaked at 24 hours (Figure 5F) (see Reference 4 for details).
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Triflusal Pretreatment
In triflusal-pretreated animals that received an intracortical injection of saline, a strong inhibition of constitutive neuronal and glial NF-B was observed, as described previously in the intact postnatal brain.28 In T+NMDA animals, a strong downregulation of NF-B was noted throughout the brain, observed as a reduction in the number of labeled cells as well as in the intensity of staining. Both the early neuronal NF-B increase observed at 10 hours after NMDA injection and the glial NF-B upregulation peaking at 24 hours were strongly inhibited (Figures 5G, 5H, and 7). However, no changes were seen in the injury-induced STAT3 activation in glial cells (Figures 5I and 7).
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Triflusal Posttreatment
Saline-injected and triflusal-posttreated animals showed inhibition of constitutive NF-B and were indistinguishable from triflusal-pretreated saline controls (see above). In NMDA+T animals, we observed an induction of NF-B in neuronal cells located in the degenerating area at 10 hours after injury (Figure 5J), comparable to that observed in their nontreated littermates (Figure 7). However, a significant inhibition of the delayed induction of glial NF-B was observed at 24 hours (Figures 5K and 7). STAT3 labeling was maintained and showed no differences compared with nontreated animals (Figures 5L and 7).
Astroglial and Microglial Response
In postnatal day 9 to 10 saline-injected controls, microglial cells displayed a primary ramified morphology in gray matter areas (Figure 8A) and were ameboid in shape in white matter tracts such as the corpus callosum. Astroglial cells presented a stellated morphology and were faintly GFAP-positive in the gray matter (Figure 8B) but strongly labeled in the corpus callosum. In response to the NMDA-induced neurodegenerative process, both astrocytes and microglial cells exhibited a characteristic response.29,30 Briefly, microglial reactivity was detected within a few hours after injection as mild morphological changes and an increase in tomato lectin binding, showing characteristic pseudopodic/ameboid shapes by 10 to 24 hours after injury (Figure 8C). Changes in astroglial cells of the degenerating area were noted within the first 10 hours after injury as a mild increase in GFAP immunoreactivity. Stronger upregulation of GFAP expression as well as astroglial hypertrophy was evident at 24 hours after injury (Figure 8D).
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Triflusal Pretreatment
In T+NMDA animals, no changes were observed in the appearance of the glial response: reactive microglia/macrophages displayed an ameboid morphology (Figure 8E), and astroglial cells showed hypertrophy and GFAP staining comparable to nontreated littermates (Figures 8F and 9).
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Triflusal Posttreatment
In NMDA+T animals, microglial cells appeared as reactive cells showing a ramified morphology that contrasted with the normal appearance of pseudopodic/ameboid reactive microglial cells in nontreated animals (compare Figure 8C with 8G). Moreover, reactive astroglial cells were mildly hypertrophied and showed an increase in GFAP staining that was significantly reduced in comparison to nontreated NMDA-injected animals at the same survival time (Figures 8H and 9).
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Discussion |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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In the present study we have shown that, in a short-term outcome, triflusal posttreatment provides neuroprotection against an excitotoxic injury in the immature rat brain. In contrast, triflusal pretreatment is not beneficial for neuronal survival and does not change the lesion volume. One possible explanation for these results may be the specific cellular pattern and time course of NF-
B activation following this excitotoxic lesion. Accordingly, pretreatment with triflusal inhibits inducible NF-B both in neurons (acute activation) and in glial cells (delayed activation), whereas posttreatment with triflusal provides the specific inhibition of delayed NF-B activation in glial cells, sparing the acute activation of this transcription factor in neuronal cells.
Triflusal Pretreatment Inhibits Both Neuronal and Glial NF-B
The lack of lesion size reduction in pretreated animals may be partly attributed to the downregulation of neuronal NF-B. In this sense, Mattson and coworkers33,34 have proposed that NF-B could represent a signaling pathway designed to protect neurons against potential damaging effects. Gene targets that could mediate the protective action of NF-B in neurons include the antioxidant enzyme manganese superoxide dismutase and the calcium-binding protein calbindin D28 k.14,15 Thus, modulation of the expression of proteins involved in the regulation of cellular antioxidant pathways and calcium homeostasis could provide the mechanisms whereby NF-B intends to protect against excitotoxicity and apoptosis. However, other studies suggest that activation of NF-B mediates neuronal cell death.11,35 Therefore, although it is largely assumed that excitotoxicity induced in neuronal cells by glutamate or glutamate-receptor agonists is accompanied by NF-B activation, the objective of this response remains speculative.16 The different stage of neural development and the special cellular contexts due to other events occurring simultaneously are potential influences that could determine the balance between NF-B–caused cell death or survival.16
In the last few years, several studies have shown a protective effect of NF-B blocking by salicylic or acetylsalicylic acid in different models of excitotoxicity and hypoxic-ischemic damage, both in vitro36,37 and in vivo.38–41 Although this neuroprotection was attributed to an inhibition of neuronal NF-B activity, it could also be explained as a consequence of the well-known antioxidant and anti-inflammatory actions of these pharmacological compounds.15 In fact, studies using specific nonpharmacological NF-B blockers such as proteasome inhibitors, administration of B decoy DNA, or infusion of a transdominant negative form of IB
have shown that the specific inhibition of neuronal NF-B is deleterious for cell survival.13,15,42 Moreover, it should be taken into account that although NF-B activation may prevent apoptosis of the cell in which is activated, it can indirectly lead to neuronal cell death by promoting the production of inflammatory proteins that can exacerbate tissue damage. In fact, inflammation is now recognized as a common factor in the development of brain damage in neuropathological conditions.18,43
Triflusal Posttreatment Spares NF–B Activation in Neurons But Not in Glial Cells
After an excitotoxic lesion in the postnatal cortex, glial NF-B is consistently activated at 10 hours after injury, showing its peak at day 1.4 Therefore, when triflusal is orally administered 8 hours after the NMDA injection, it preferentially targets NF-B induced in glial cells, as the inducible neuronal NF-B is starting to decrease when triflusal reaches the brain. Glial NF-B is probably induced by injury-related signals that occur in the degenerating area. They may include reactive oxygen species, produced in excitotoxically damaged cells,44 and the proinflammatory cytokines interleukin-1ß and tumor necrosis factor-, which are expressed by neurons and glial cells in this excitotoxic lesion model, showing a peak of expression at 10 hours after injury.45 On activation, NF-B translocates to the cell nucleus and modulates the expression of several genes implicated in the development of the glial and inflammatory responses. Target genes containing a NF-B–binding site include the astroglial cytoskeletal protein GFAP,46 several cytokines,21,47,48 major histocompatibility complexes,49 adhesion molecules,50 and inflammation-related enzymes such as inducible nitric oxide synthase51 and cyclooxygenase-2.52 In previous studies we have observed the expression of several of these NF-B target genes in reactive glial cells,29,30,45 suggesting an important role of NF-B in triggering the glial and inflammatory response associated with postnatal excitotoxic injury.
Besides NF-B, another important transcription factor related to early gene activation in glial reactivity is STAT3, which is activated by several cytokines and growth factors and is also implicated in the production of glial and inflammatory products.19,53 The upregulation of STAT3 activation in astrocytes and microglial cells has been reported after excitotoxicity and ischemia3,4,54,55 and is not apparently affected by triflusal treatment. Finally, it should be noted that both triflusal pretreatment and posttreatment inhibit glial NF-B, but downregulation in astroglial hypertrophy and decreased microglia/macrophage activation are only observed after triflusal posttreatment. Interestingly, this downregulated glial response resembles that observed in secondarily affected distal areas, where no massive neurodegeneration occurs and the associated glial activation lacks NF-B induction.4,29,30 On the contrary, the presence of neuronal degeneration and massive tissue damage in triflusal-pretreated animals occurs together with a glial response indistinguishable from nontreated NMDA-lesioned animals.
Recently, several studies have also reported a downregulation of the glial response after administration of other anti-inflammatory drugs,56–59 a treatment that is clearly accompanied by a decrease in neuronal damage and a better lesion outcome. However, most of the anti-inflammatory and neuroprotective drugs present their efficacy when administered either before or very shortly after the injury,38,39,56,57,60 limiting their clinical suitability. Interestingly, triflusal shows its neuroprotective effect when administered several hours after injury, indicating that this drug could be a good therapeutic choice in pathological situations in which the regulation of NF-B activation constitutes an important step in the evolution of the neurodegenerative process. Nevertheless, it should be noted that in this study we have evaluated the short-term outcome of excitotoxic damage in the postnatal brain, and additional studies would be required to demonstrate the long-term consequences of triflusal administration in the postnatal brain as well as in the adult and aged nervous system.
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Acknowledgments |
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This work was supported by DGES project PB98-0892, Uriach & Cia, and "la Caixa" project 00/074-00. We would like to thank Miguel A. Martil for his outstanding technical help.
Received January 3, 2001; revision received June 15, 2001; accepted July 6, 2001.
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References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
1. Terai K, Matsuo A, Mcgeer EG, Mcgeer PL. Enhancement of immunoreactivity for NF-kappa B in human cerebral infarctions. Brain Res. 1996; 739: 343–349.[Medline] [Order article via Infotrieve]
2. Gabriel C, Justicia C, Camins A, Planas AM. Activation of nuclear factor-kappaB in the rat brain after transient focal ischemia. Mol Brain Res. 1999; 65: 61–69.[Medline] [Order article via Infotrieve]
3.
Acarin L, González B, Castellano B. Stat3 and NFB glial expression after excitotoxic damage to the postnatal brain. Neuroreport. 1998; 9: 2869–2873.[Medline]
[Order article via Infotrieve]
4.
Acarin L, González B, Castellano B. STAT3 and NFB activation precedes glial reactivity in the excitotoxically injured young cortex but not in the corresponding distal thalamic nuclei. J Neuropathol Exp Neurol. 2000; 59: 151–163.[Medline]
[Order article via Infotrieve]
5.
Perez-Otaño I, McMillian NK, Chen J, Bing GY, Hong JS, Pennypacker KR. Induction of NF-B-like transcription factors in brain areas susceptible to kainate toxicity. Glia. 1996; 16: 306–315.[Medline]
[Order article via Infotrieve]
6.
Yang K, Mu XS, Hayes RL. Increased cortical nuclear factor-B (NFB) DNA binding activity after traumatic brain injury in rats. Neurosci Lett. 1995; 197: 101–104.[Medline]
[Order article via Infotrieve]
7.
Terai K, Matsuo A, McGeer PL. Enhancement of immunoreactivity for NF-B in the hippocampal formation and cerebral cortex of Alzheimer’s disease. Neurosci Lett. 1996; 735: 159–168.
8.
Hunot S, Brugg B, Ricard D, Michel PP, Muriel MP, Ruberg M, Faucheux BA, Agid Y, Hirsch EC. Nuclear translocation of NF-kappa B is increased in dopaminergic neurons of patients with Parkinson disease. Proc Natl Acad Sci UtStA. 1997; 94: 7531–7536.
9. Kaltschmidt C, Kaltschmidt B, Lannesvieira J, Kreutzberg GW, Wekerle H, Baeuerle PA, Gehrmann J. Transcription factor NF-kappa B is activated in microglia during experimental autoimmune encephalomyelitis. J Neuroimmunol. 1994; 55: 99–106.[Medline] [Order article via Infotrieve]
10. Grilli M, Memo M. Nuclear factor-kappa B/Rel proteins: a point of convergence of signalling pathways relevant in neuronal function and dysfunction. Biochem Pharmacol. 1999; 57: 1–7.[Medline] [Order article via Infotrieve]
11.
Qin ZH, Wang YM, Nakai M, Chase TN. Nuclear factor-kappa B contributes to excitotoxin-induced apoptosis in rat striatum. Mol Pharmacol. 1998; 53: 33–42.
12. Schneider A, MartinVillalba A, Weih F, Vogel J, Wirth T, Schwaninger M. NF-kappa B is activated and promotes cell death in focal cerebral ischemia. Nature Med. 1999; 5: 554–559.[Medline] [Order article via Infotrieve]
13.
Kaltschmidt B, Uherek M, Wellmann H, Volk B, Kaltschmidt C. Inhibition of NF-kappa B potentiates amyloid beta-mediated neuronal apoptosis. Proc Natl Acad Sci UtStA. 1999; 96: 9409–9414.
14. Mattson MP, Goodman Y, Luo H, Fu WM, Furukawa K. Activation of NF-kappa B protects hippocampal neurons against oxidative stress-induced apoptosis: evidence for induction of manganese superoxide dismutase and suppression of peroxynitrite production and protein tyrosine nitration. J Neurosci Res. 1997; 49: 681–697.[Medline] [Order article via Infotrieve]
15.
Yu Z, Zhou D, Bruce-Keller AJ, Kindy MS, Mattson MP. Lack of the p50 subunit of nuclear factor-kappaB increases the vulnerability of hippocampal neurons to excitotoxic injury. J Neurosci. 1999; 19: 8856–8865.
16. Lipton SA. Janus faces of NF-kappa B: neurodestruction versus neuroprotection. Nat Med. 1997; 3: 20–22.[Medline] [Order article via Infotrieve]
17. Dirnagl U, Iadecola C, Moskowitz MA. Pathobiology of ischaemic stroke: an integrated view. Trends Neurosci. 1999; 22: 391–397.[Medline] [Order article via Infotrieve]
18. McGeer EG, McGeer PL. Brain inflammation in Alzheimer disease and the therapeutic implications. Curr Pharmacol Design. 1999; 5: 821–836.[Medline] [Order article via Infotrieve]
19. Schindler C, Darnell JE Jr. Transcriptional responses to polypeptide ligands: the JAK-STAT pathway. Annu Rev Biochem. 1995; 64: 621–651.[Medline] [Order article via Infotrieve]
20.
O’Neill LAJ, Kaltschmidt C. NF-B: a crucial transcription factor for glial and neuronal cell function. Trends Neurosci. 1997; 20: 252–258.[Medline]
[Order article via Infotrieve]
21. Baeuerle PA. Pro-inflammatory signaling: last pieces in the NF-kappa B puzzle. Curr Biol. 1998; 8: R19–R22.[Medline] [Order article via Infotrieve]
22. Olney JW. Role of excitotoxins in developmental neuropathology. APMIS Suppl. 1993; 101: 103–112.
23. Olney JW, Ishimaru MJ. Excitotoxic cell death.In: Koliatsos VE, Ratan RR, eds. Cell Death and Diseases of the Nervous System. Totowa, NJ: Humana Press Inc; 1999: 197–219.
24. Matsuoka Y, Kitamura Y, Okazaki M, Terai K, Taniguchi T. Kainic acid-induced activation of nuclear factor-kappaB in rat hippocampus. Exp Brain Res. 1999; 124: 215–222.[Medline] [Order article via Infotrieve]
25. McNeely W, Goa KL. Triflusal. Drugs. 1998; 55: 823–833; comment 834–835.[Medline] [Order article via Infotrieve]
26. Bayón Y, Alonso A, Sanchez Crespo M. 4-Trifluoromethyl derivatives of salicylate, triflusal and its main metabolite 2-hydroxy-4-trifluoromethylbenzoic acid, are potent inhibitors of nuclear factor kappaB activation. Br J Pharmacol. 1999; 126: 1359–1366.[Medline] [Order article via Infotrieve]
27.
Fernández de Arriba A, Cavalcanti F, Miralles A, Bayon Y, Alonso A, Merlos M, Garcia-Rafanell J, Forn J. Inhibition of cyclooxygenase-2 expression by 4-trifluoromethyl derivatives of salicylate, triflusal, and its deacetylated metabolite, 2-hydroxy-4-trifluoromethylbenzoic acid. Mol Pharmacol. 1999; 55: 753–760.
28.
Acarin L, González B, Castellano B. Oral administration of the anti-inflammatory substance triflusal results in the downregulation of constitutive transcription factor NF-B in the postnatal rat brain. Neurosci Lett. 2000; 288: 41–44.[Medline]
[Order article via Infotrieve]
29. Acarin L, González B, Hidalgo J, Castro AJ, Castellano B. Primary cortical glial reaction versus secondary thalamic glial response in the excitotoxically injured young brain: astroglial response and metallothionein expression. Neuroscience. 1999; 92: 827–839.[Medline] [Order article via Infotrieve]
30. Acarin L, González B, Castro AJ, Castellano B. Primary cortical glial reaction versus secondary thalamic glial response in the excitotoxically injured young brain: microglial/macrophage response and MHC class I and II expression. Neuroscience. 1999; 89: 549–565.[Medline] [Order article via Infotrieve]
31. Acarin L, Vela JM, Gonzalez B, Castellano B. Demonstration of poly-N-acetyl lactosamine residues in ameboid and ramified microglial cells in rat brain by tomato lectin binding. J Histochem Cytochem. 1994; 42: 1033–1041.[Abstract]
32. Acarin L, González B, Castro AJ, Castellano B. Glial response to excitotoxic injury in the immature rat brain.In: Castellano B, González B, Nieto-Sampedro M, eds. Understanding Glial Cells. Boston, Mass: Kluwer Academic Publishers; 1998: 271–295.
33. Mattson MP. Free radicals, calcium, and the synaptic plasticity cell death continuum: emerging roles of the transcription factor NF kappa B.In: Bradley RJ, Harris RA, Jenner P, eds. International Review of Neurobiology. San Diego, Calif: Academic Press Inc; 1998: 103–168.
34. Mattson MP, Culmsee C, Yu Z, Camandola S. Roles of nuclear factor kappaB in neuronal survival and plasticity. J Neurochem. 2000; 74: 443–456.[Medline] [Order article via Infotrieve]
35. Nakai M, Qin ZH, Chen JF, Wang Y, Chase TN. Kainic acid-induced apoptosis in rat striatum is associated with nuclear factor-kappaB activation. J Neurochem. 2000; 74: 647–658.[Medline] [Order article via Infotrieve]
36.
Grilli M, Pizzi M, Memo M, Spano P. Neuroprotection by aspirin and sodium salicylate through blockade of NF- kappaB activation. Science. 1996; 274: 1383–1385.
37.
Riepe MW, Kasischke K, Raupach A. Acetylsalicylic acid increases tolerance against hypoxic and chemical hypoxia. Stroke. 1997; 28: 2006–2011.
38. Aubin N, Curet O, Deffois A, Carter C. Aspirin and salicylate protect against MPTP-induced dopamine depletion in mice. J Neurochem. 1998; 71: 1635–1642.[Medline] [Order article via Infotrieve]
39. Khayyam N, Thavendiranathan P, Carmichael FJ, Kus B, Jay V, Burnham WM. Neuroprotective effects of acetylsalicylic acid in an animal model of focal brain ischemia. Neuroreport. 1999; 10: 371–374.[Medline] [Order article via Infotrieve]
40.
Nogawa S, Zhang F, Ross ME, Iadecola C. Cyclo-oxygenase-2 gene expression in neurons contributes to ischemic brain damage. J Neurosci. 1997; 17: 2746–2755.
41. Wakita H, Tomimoto H, Akiguchi I, Lin JX, Miyamoto K, Oka N. A cyclooxygenase-2 inhibitor attenuates white matter damage in chronic cerebral ischemia. Neuroreport. 1999; 10: 1461–1465.[Medline] [Order article via Infotrieve]
42. Taglialatela G, Kaufmann JA, Trevino A, Perez Polo JR. Central nervous system DNA fragmentation induced by the inhibition of nuclear factor kappa B. Neuroreport. 1998; 9: 489–493.[Medline] [Order article via Infotrieve]
43. Stoll G, Jander S, Schroeter M. Inflammation and glial responses in ischemic brain lesions. Prog Neurobiol. 1998; 56: 149–171.[Medline] [Order article via Infotrieve]
44. Schulz JB, Henshaw DR, Siwek D, Jenkins BG, Ferrante RJ, Bencipolloni P, Kowall NW, Rosen BR, Beal MF. Involvement of free radicals in excitotoxicity in vivo. J Neurochem. 1995; 64: 2239–2247.[Medline] [Order article via Infotrieve]
45. Acarin L, González B, Castellano B. Neuronal, astroglial and microglial cytokine expression after an excitotoxic lesion in the immature rat brain. Eur J Neurosci. 2000; 12: 3505–3520.[Medline] [Order article via Infotrieve]
46. Krohn K, Rozovsky I, Wals P, Teter B, Anderson CP, Finch CE. Glial fibrillary acidic protein transcription responses to transforming growth factor-beta1 and interleukin-1beta are mediated by a nuclear factor-1-like site in the near-upstream promoter. J Neurochem. 1999; 72: 1353–1361.[Medline] [Order article via Infotrieve]
47.
Kwon J, Lee SJ, Benveniste E. A 3' cis-acting element is involved in tumor necrosis factor- gene expression in astrocytes. J Biol Chem. 1996; 271: 22383–22390.
48. Sparacio SM, Zhang Y, Vileck J, Benveniste EN. Cytokine regulation of interleukin-6 gene expression in astrocytes involves activation of an NF-kappa B-like nuclear protein. J Neuroimmunol. 1992; 39: 231–242.[Medline] [Order article via Infotrieve]
49. Massa PT, Ozato K, McFarlin DE. Cell type-specific regulation of major histocompatibility complex (MHC) class I gene expression in astrocytes, oligodendrocytes, and neurons. Glia. 1993; 8: 201–207.[Medline] [Order article via Infotrieve]
50. Moynagh PN, Williams DC, O’Neill LA. Activation of NF-kappa B and induction of vascular cell adhesion molecule-1 and intracellular adhesion molecule-1 expression in human glial cells by IL-1: modulation by antioxidants. J Immunol. 1994; 153: 2681–2690.[Abstract]
51. Chao CC, Lokensgard JR, Sheng WS, Hu SX, Peterson PK. IL-1-induced iNOS expression in human astrocytes via NF-kappa B. Neuroreport. 1997; 8: 3163–3166.[Medline] [Order article via Infotrieve]
52. Bauer MKA, Lieb K, Schulze Osthoff K, Berger M, Gebicke Haerter PJ, Bauer J, Fiebich BL. Expression and regulation of cyclooxygenase-2 in rat microglia. Eur J Biochem. 1997; 243: 726–731.[Medline] [Order article via Infotrieve]
53. Cattaneo E, Conti L, De-Fraja C. Signalling through the JAK-STAT pathway in the developing brain. Trends Neurosci. 1999; 22: 365–369.[Medline] [Order article via Infotrieve]
54. Planas AM, Soriano MA, Berruezo M, Justicia C, Estrada A, Pitarch S, Ferrer I. Induction of Stat3, a signal transducer and transcription factor, in reactive microglia following transient focal cerebral ischaemia. Eur J Neurosci. 1996; 8: 2612–2618.[Medline] [Order article via Infotrieve]
55. Justicia C, Gabriel C, Planas AM. Activation of the JAK/STAT pathway following transient focal cerebral ischemia: signaling through Jak1 and Stat3 in astrocytes. Glia. 2000; 30: 253–270.[Medline] [Order article via Infotrieve]
56.
Rabuffetti M, Sciorati C, Tarozzo G, Clementi E, Manfredi AA, Beltramo M. Inhibition of caspase-1-like activity by Ac-tyr-val-ala-asp-chloromethyl ketone induces long-lasting neuroprotection in cerebral ischemia through apoptosis reduction and decrease of proinflammatory cytokines. J Neurosci. 2000; 20: 4398–4404.
57.
Yrjanheikki J, Keinanen R, Pellikka M, Hokfelt T, Koistinaho J. Tetracyclines inhibit microglial activation and are neuroprotective in global brain ischemia. Proc Nat Acad Sci UtStA. 1998; 95: 15769–15774.
58. Koppal T, Petrova TV, Van Eldik LJ. Cyclopentenone prostaglandin 15-deoxy-delta(12,14)-prostaglandin J(2) acts as a general inhibitor of inflammatory responses in activated BV-2 microglial cells. Brain Res. 2000; 867: 115–121.[Medline] [Order article via Infotrieve]
59. Hauss-Wegrzyniak B, Vraniak P, Wenk GL. The effects of a novel NSAID on chronic neuroinflammation are age dependent. Neurobiol Aging. 1999; 20: 305–313.[Medline] [Order article via Infotrieve]
60. Buchan AM, Li H, Blackburn B. Neuroprotection achieved with a novel proteasome inhibitor which blocks NF-kappa B activation. Neuroreport. 2000; 11: 427–430.[Medline] [Order article via Infotrieve]
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