Neuroprotective effects of carbenoxolone against amyloid-beta 1-42 oligomer-induced neuroinflammation and cognitive decline in rats.

The aggregation of Aß plays a major role in the progression of Alzheimer's disease (AD) and induces neuroinflammation, neurodegeneration and cognitive decline. Recent studies have shown that the soluble aggregates of Aß are the major culprits in the development of these aberrations inside the brain. In this study, we investigated the neuroprotective potential of carbenoxolone (Cbx), which has been found to possess anti-inflammatory and nootropic properties. Male SD rats (250-300 g) were divided into the four groups (n = 8 per group): (1) sham control rats injected with vehicles, (2) Aß 1-42 group rats injected i.c.v. with Aß 42 oligomers (10 µl/rat), (3) Aß 1-42+Cbx group rats injected i.c.v. with Aß 42 oligomers (10 µl/rat) and i.p. with carbenoxolone disodium (20 mg/kg body weight) for six-weeks and (4) Cbx group rats injected i.p. with carbenoxolone disodium (20 mg/kg body weight) for six-weeks. Progressive learning and memory deficits were seen through a battery of behavioral tests and a significant increase in the expressions of GFAP and Iba-1 was observed which resulted in the release of pro-inflammatory cytokines post Aß oligomer injection. The levels of BDNF, Bcl-2 and pCREB were decreased while Bax, caspase-3, caspase-9 and cytochrome c levels were induced. Also, neurotransmitter levels were altered and neuronal damage was observed through histopathological studies. After Cbx supplementation, the expressions of GFAP, IBA-1, pro-inflammatory cytokines, iNOS, nNOS and nitric oxide levels were normalized. The expression levels of pro-apoptotic markers were decreased and neurotrophin levels were restored. Also, neurotransmitter levels and neuronal profile were improved and progressive improvements in behavioural performance were observed. Our results demonstrated that Cbx might have prevented the Aß induced neurodegeneration and cognitive decline by inhibiting the neuroinflammation and inducing BDNF/CREB signalling. These findings suggest that Cbx can be explored as a potential therapeutic agent against the progression of AD.

The Neuroprotective Effect of Zingiber cassumunar Roxb. Extract on LPS-Induced Neuronal Cell Loss and Astroglial Activation within the Hippocampus.

The systemic administration of lipopolysaccharide (LPS) has been recognized to induce neuroinflammation which plays a significant role in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. In this study, we aimed to determine the protective effect of Zingiber cassumunar (Z. cassumunar) or Phlai (in Thai) against LPS-induced neuronal cell loss and the upregulation of glial fibrillary acidic protein (GFAP) of astrocytes in the hippocampus. Adult male Wistar rats were orally administered with Z. cassumunar extract at various doses (50, 100, and 200 mg/kg body weight) for 14 days before a single injection of LPS (250 µg/kg/i.p.). The results indicated that LPS-treated animals exhibited neuronal cell loss and the activation of astrocytes and also increased proinflammatory cytokine interleukin- (IL-) 1ß in the hippocampus. Pretreatment with Z. cassumunar markedly reduced neuronal cell loss in the hippocampus. In addition, Z. cassumunar extract at a dose of 200 mg/kg BW significantly suppressed the inflammatory response by reducing the expression of GFAP and IL-1ß in the hippocampus. Therefore, the results suggested that Z. cassumunar extract might be valuable as a neuroprotective agent in neuroinflammation-induced brain damage. However, further investigations are essential to validate the possible active ingredients and mechanisms of its neuroprotective effect.

Evolution and resolution of brain involvement associated with SARS- CoV2 infection: A close Clinical - Paraclinical follow up study of a case.

The new severe acute respiratory syndrome- coronavirus 2 is reported to affect the nervous system. Among the reports of the various neurological manifestations, there are a few documented specific processes to explain the neurological signs. We report a para-infectious encephalitis patient with clinical, laboratory, and imaging findings during evolution and convalescence phase of coronavirus infection. This comprehensive overview can illuminate the natural history of similar cases. As the two previously reported cases of encephalitis associated with this virus were not widely discussed regarding the treatment, we share our successful approach and add some recommendations about this new and scarce entity.

Obesity after neonatal overfeeding is independent of hypothalamic microgliosis.

The early-life environment is important in programming brain development, and metabolic disruptions at this time can have long-lasting effects. Previously, we have shown that rats overfed for the first 3 weeks of their neonatal life maintain obesity into adulthood. Neonatal overfeeding also leads to primed hypothalamic and hippocampal microglia that are hyper-responsive to an immune challenge in adulthood. However, whether this microglial priming contributes to the obese phenotype and whether it is possible to reverse either the obesity or the microglial priming are not clear. In the present study, we hypothesised that an intervention with minocycline during the juvenile period (postnatal day 21-42) would normalise both the microglial priming and obesity. To induce obesity in neonatal Wistar rats, we manipulated the litter sizes in which they were suckled, yielding litters of 12 (control-fed) or four (neonatally overfed). After weaning, we administered minocycline i.p. every second day for a 3-week period and examined body composition and microglial profiles 24 hours following an immune challenge with lipopolysaccharide. As demonstrated previously, neonatal overfeeding resulted in prolonged weight gain. However, minocycline failed to reverse this effect. Minocycline did reverse microglial priming in feeding-related regions of the hypothalamus, with minimal effects on pro-inflammatory cytokines and on microglial number and morphology in the hippocampus. Thus, the programming effect of neonatal overfeeding on microglial priming can be ameliorated by minocycline later in life. However, the persistent obesity seen after neonatal overfeeding is likely not driven by changes in hypothalamic inflammation and microglial activity.

HSP-70-Mediated Hyperbaric Oxygen Reduces Brain and Pulmonary Edema and Cognitive Deficits in Rats in a Simulated High-Altitude Exposure.

High-mountain sickness is characterized by brain and pulmonary edema and cognitive deficits. The definition can be fulfilled by a rat model of high-altitude exposure (HAE) used in the present study. This study aimed to investigate the protective effect of hyperbaric oxygen therapy (HBO2T) and to determine the underlying mechanisms. Rats were subjected to an HAE (9.7% O2 at 0.47 absolute atmosphere of 6,000 m for 3 days). Immediately after termination of HAE, rats were treated with HBO2T (100% O2 at 2.0 absolute atmosphere for 1 hour per day for 5 consecutive days) or non-HBO2T (21% O2 at 1.0 absolute atmosphere for 1 hour per day for 5 consecutive days). As compared to non-HAE+non-HBO2T controls, the HAE+non-HBO2T rats exhibited brain edema and resulted in cognitive deficits, reduced food and water consumption, body weight loss, increased cerebral inflammation and oxidative stress, and pulmonary edema. HBO2T increased expression of both hippocampus and lung heat shock protein (HSP-70) and also reversed the HAE-induced brain and pulmonary edema, cognitive deficits, reduced food and water consumption, body weight loss, and brain inflammation and oxidative stress. Decreasing the overexpression of HSP-70 in both hippocampus and lung tissues with HSP-70 antibodies significantly attenuated the beneficial effects exerted by HBO2T in HAE rats. Our data provide in vivo evidence that HBO2T works on a remodeling of brain/lung to exert a protective effect against simulated high-mountain sickness via enhancing HSP-70 expression in HAE rats.

Cell and molecular mechanisms behind diet-induced hypothalamic inflammation and obesity.

Diet-induced obesity (DIO) is associated with chronic, low-grade inflammation in the hypothalamus, a key regulator of energy homeostasis. Current studies have revealed the involvement of different cell types, as well as cell and molecular mechanisms, that contribute to diet-induced hypothalamic inflammation (DIHI) and DIO. Subsequent to the discovery that high-fat diet and saturated fatty acids increase the expression of hypothalamic cytokines prior to weight gain, research has focused on understanding the cellular and molecular mechanisms underlying these changes, in addition to the role of inflammation in the pathogenesis of obesity. Recent studies have proposed that the inhibition of pro-inflammatory pathways in microglia and astrocytes is sufficient to protect against DIHI and prevent obesity. In addition, impairment of intracellular and epigenetic mechanisms, such as hypothalamic autophagy and changes in the methylation pattern of certain genes, have been implicated in susceptibility to DIHI and DIO. Interestingly, a sexual dimorphism has been found during DIO in hypothalamic inflammation, glial activation and metabolic diseases, and recent data support an important role of sex steroids in DIHI. These new exciting findings uncover novel obesity pathogenic mechanisms and provide targets to develop therapeutic approaches.

Hashimoto encephalopathy in pediatric patients: Homogeneity in clinical presentation and heterogeneity in antibody titers.

OBJECTIVE: Hashimoto encephalopathy is an autoimmune encephalopathy characterized by elevated antithyroid antibodies and a favorable response to corticosteroid. This study delineated the clinical characteristics of pediatric Hashimoto encephalopathy and the significance of low antithyroid antibody titers in diagnosis and treatment. SUBJECTS AND METHODS: Clinical manifestations, antibody titers, and treatment responses were retrospectively reviewed in six consecutive children diagnosed with Hashimoto encephalopathy between August 2008 and July 2016. RESULTS: Age at diagnosis was 10-17years. Presenting symptoms were seizures, altered consciousness, behavioral changes, psychosis, tremor, and dystonia. Thyroid function was normal in five patients, and one had hypothyroidism prior to the encephalopathy. Antithyroid antibody titer was increased at presentation in five patients and one week later in the other. Antibody levels were extremely varied (anti-thyroglobulin, 20.5-2318.0U/ml; anti-thyroid peroxidase, 12.5-2231.0U/ml; reference range, <60U/ml) and <180U/ml in two patients. Electroencephalogram was abnormal in five patients. Brain magnetic resonance imaging was unremarkable. Four patients responded to high-dose corticosteroid and one improved with additional intravenous immunoglobulin. The remaining patient did not respond to both treatments and normalized after plasmapheresis. Autoantibody titers decreased with treatment response in the acute stage. Two patients with low antibody titers showed similar clinical presentations and responses. CONCLUSIONS: The clinical presentations and treatment responses in Hashimoto encephalopathy were similar, irrespective of antithyroid antibody titer. Because the initial antithyroid antibody titers can be normal or mildly-elevated, follow-up testing of antithyroid antibodies is required in patients who are clinically suspect for Hashimoto encephalopathy.

Magnetic resonance imaging as a tool to image neuroinflammation in a rat model of Parkinson's disease--phagocyte influx to the brain is promoted by bilberry-enriched diet.

Neuroinflammation is a chronic event in neurodegenerative disorders. In the rat model of Parkinson's disease, including a striatal injection of the neurotoxin 6-hydroxydopamine (6-OHDA), antioxidant treatment affects the inflammatory process. Despite a heavy accumulation of microglia early after the injury, dopamine nerve fibre regeneration occurs. It remains unclear why this heavy accumulation of microglia is found early after the lesion in antioxidant-treated animals, or even more, what is the origin of these microglia. In this study magnetic resonance imaging (MRI) was used to elucidate whether the inflammatory response was generated from the blood or from activated brain microglia. Superparamagnetic iron oxide (SPIO) nanoparticles were injected intravenously prior to a striatal 6-OHDA injection to tag phagocytes in the blood. Rats were fed either with bilberry-enriched or control diet. T2*-weighted MRI scans were performed 1 week after the lesion, and hypointense areas were calculated from T2*-weighted images, to monitor the presence of SPIO particles. The results revealed that feeding the animals with bilberries significantly promoted accumulation of blood-derived immune cells. Gadolinium-enhanced MRI demonstrated no difference in leakage of the blood-brain barrier independent of diets. To conclude, bilberry-enriched diet promotes an influx of periphery-derived immune cells to the brain early after injury.

Collateral Damage: Contribution of Peripheral Inflammation to Neurodegenerative Diseases.

Neurodegenerative diseases are characterized by a progressive deterioration of brain function, with a consequent significant decline in the quality of life of patients and their families. Due to the concurrent increase in life expectancy, the incidence of these diseases has been increasing over the last years and thus there is a growing interest in finding potential risk factors. This review focuses on the correlation between peripheral inflammatory diseases and neurodegeneration, in particular on the relationship between gastrointestinal disorders and Parkinson's disease, especially through the so called gut-brain axis.

6-Shogaol, an active constituent of ginger, attenuates neuroinflammation and cognitive deficits in animal models of dementia.

Recently, increased attention has been directed towards medicinal extracts as potential new drug candidates for dementia. Ginger has long been used as an important ingredient in cooking and traditional herbal medicine. In particular, ginger has been known to have disease-modifying effects in Alzheimer's disease (AD). However, there is no evidence of which constituents of ginger exhibit therapeutic effects against AD. A growing number of experimental studies suggest that 6-shogaol, a bioactive component of ginger, may play an important role as a memory-enhancing and anti-oxidant agent against neurological diseases. 6-Shogaol has also recently been shown to have anti-neuroinflammatory effects in lipopolysaccharide (LPS)-treated astrocytes and animal models of Parkinson's disease, LPS-induced inflammation and transient global ischemia. However, it is still unknown whether 6-shogaol has anti-inflammatory effects against oligomeric forms of the Aß (AßO) in animal brains. Furthermore, the effects of 6-shogaol against memory impairment in dementia models are also yet to be investigated. In this study, we found that administration of 6-shogaol significantly reduced microgliosis and astrogliosis in intrahippocampal AßO-injected mice, ameliorated AßO and scopolamine-induced memory impairment, and elevated NGF levels and pre- and post-synaptic marker in the hippocampus. All these results suggest that 6-shogaol may play a role in inhibiting glial cell activation and reducing memory impairment in animal models of dementia.

[The Parkinson puzzle]. / A Parkinson-puzzle.

Parkinson's disease is one of the most frequent progressive degenerative disorders with unknown origin of the nervous system. The commutation of the disease on Guam led to the discovery of a neurotoxin which was also found in other continents. This neurotoxin was identified in the common cyanobacteria (blue-green algae). Early clinical observations suggested some loose correlations with gastric and duodenal ulcer and Parkinson's disease, while recent studies revealed a toxin, almost identical to that found in cyanobacteria in one strain of Helicobacter pylori, which proved to cause Parkinson like symptoms in animals. Therefore, it cannot be ruled out that there is a slowly progressive poisoning in Parkinson's disease. The disease specific alpha-sinuclein inclusions can be found in nerve cells of the intestinal mucosa far before the appearance of clinical symptoms indicating that the disease may start in the intestines. These results are strengthened by the results of Borody's fecal transplants, after which in Parkinson patients showed a symptomatic improvement. Based on these observations the Parkinson puzzle is getting complete. Although these observations are not evidence based, they may indicate a new way for basic clinical research, as well as a new way of thinking for clinicians. These new observations in psycho-neuro-immunology strengthen the fact that immunological factors may also play a critical factor facilitating local cell necrosis which may be influenced easily.

Mycoplasma pneumoniae-related postencephalitic epilepsy in children.

PURPOSE: Mycoplasma pneumoniae, a common respiratory pathogen, has been implicated as an etiology of encephalitis, but there are few reports about it and postencephalitic epilepsy. This study aimed to investigate clinical factors, electroencephalography, and neuroradiologic features of M. pneumoniae-related encephalitis in a series of children with postencephalitic epilepsy and to examine possible prognostic factors. METHODS: Cases of M. pneumoniae-related encephalitis between January 2001 and June 2010 were retrospectively reviewed. Systematic clinical data were evaluated. KEY FINDINGS: The 99 enrolled patients with M. pneumoniae-related encephalitis were all positive by serology and 47 (47.5%) of them developed postencephalitic epilepsy. During the acute phase, 53 patients (53.5%) had seizures, the most common type of which was primary focal with secondary generalized tonic-clonic seizure (39.6%). The most common initial electroencephalography was focal/diffuse cortical dysfunction (37.4%) and focal epileptiform discharge (26.4%). The time of follow-up ranged from 6-131 months. At the end of the study, 19 (40.4%) of the 47 children with postencephalitic epilepsy had intractable seizures. SIGNIFICANCE: Postencephalitic epilepsy is not a rare complication of M. pneumoniae-related encephalitis. Seizures in the acute phase and focal epileptiform discharges in initial electroencephalography are significant prognostic factors.

Transcranial direct current stimulation in adolescent and adult Rasmussen's encephalitis.

Rasmussen's encephalitis is a rare, progressive inflammatory disease that typically affects one cerebral hemisphere and causes intractable partial-onset seizures. Currently, the only effective therapy is hemispherectomy; however, this procedure is associated with irreversible neurological deficits. Novel therapeutic approaches to this condition are therefore necessary. One possible option that has not yet been extensively studied is electrical cathodal transcranial direct current stimulation (cTDCS). We describe the cases of two patients with atypical-onset Rasmussen's encephalitis who underwent cTDCS at 1- and 2-mA intensity for 60 minutes in four sessions (on days 0, 7, 30, and 60). No complications were recorded during their therapy. At follow-up evaluations 6 and 12 months later, one patient had a significant reduction in seizure frequency and one was seizure free. Additionally, both patients had improved levels of alertness and language. This is the first time that cTDCS has been applied in serial sessions to treat Rasmussen's encephalitis to avoid or delay surgical treatment.

Transient basal ganglia and thalamic involvement following Mycoplasma pneumoniae infection associated with antiganglioside antibodies.

A case of acute and reversible bilateral basal ganglia with thalami involvement associated with serological evidence of Mycoplasma pneumoniae infection is reported. Increased titers of immunoglobulin M antibodies against GM1 ganglioside components were found during an acute phase of neurological illness. Brain magnetic resonance imaging (MRI) showed bilateral involvement of the basal ganglia and thalamus, which disappeared 1 month later. The child recovered fully after corticosteroid and immunoglobulin therapy, and antiganglioside antibodies returned to within the normal range. The authors speculate on the diagnostic hypothesis regarding selective basal ganglia and thalamic involvement and the relationship with anti-GM1 ganglioside immunoglobulin M antibodies.

Re-balancing of inflammation and abeta immunity as a therapeutic for Alzheimer's disease-view from the bedside.

Morbidities of aging and Alzheimer's disease (AD) have been related to defective functions of both T cells and macrophages leading to brain amyloidosis and inflammation. In AD patients, "inflammaging" may be associated with an increase of incompetent memory T cells and inflammatory cytokines produced by macrophages, whereas defective clearance of amyloid-beta 1-42 (Abeta) may be related to defective transcription of immune genes necessary for Abeta phagocytosis, beta-1,4-mannosyl-glycoprotein 4-beta-N-acetylglucosaminyltransferase and Toll-like receptors. However, AD shows considerable heterogeneity of disease manifestations and mechanisms. The approaches to re-balancing Abeta immunity and inflammation are being pursued in transgenic animal models and peripheral blood mononuclear cells of patients. The regulatory signaling pathways of microglial phagocytosis and inflammation involving co-receptors and transforming growth factor-beta have been considerably clarified in animal studies. Natural immunostimulating therapies using vitamin D3 and curcuminoids have been developed in macrophages of AD patients. AD patients possess two types of macrophages: a majority has "Type I", which are improved by curcuminoids and vitamin D3; whereas a minority has "Type II" responding positively to vitamin D3 but not to curcuminoids. Other nutritional substances, such as plant polyphenols and omega-3 fatty acids, may inhibit inflammation and stimulate immunity. More invasive immune approaches involve Abeta vaccine and cytokine antagonists. Increased inflammation may represent the "first hit", and defective transcription of immune genes the "second hit" in the pathogenesis of AD.

Raf inhibitors as therapeutic agents against neurodegenerative diseases.

The active form of the serine/threonine kinase cRaf-1 is upregulated postmortem in the brains of Alzheimer's disease (AD) patients and in transgenic mouse models of AD pathology. The persistent activation of cRaf-1 can activate the proinflammatory factor NFkappaB and consequently, upregulate the expression of several of its downstream factors such as the amyloid precursor protein (APP), Cox-2 and iNOS. These factors have been found upregulated in numerous neurodegenerative conditions including AD, epilepsy, brain trauma, and psychological stress. The Raf kinase inhibitors, GW5074 and ZM336372, are neuroprotective against many different neurotoxic insults in vitro, including the Abeta peptide, glutamate and glutathione depletion. Recently, we have reported that the multi-kinase and potent Raf inhibitor sorafenib reversed memory impairment and reduced the expression of APP, Cox-2, and iNOS in the brain of the transgenic mouse model of AD, APPswe. Similar improvement of behavioral outcome was attained after acute treatment with GW5074 in a mouse model of Huntington's disease. Several Raf inhibitors have been developed to treat aggressive forms of cancer showing an upregulation of Raf kinases. These Raf inhibitors offer a great promise as therapeutic tools against neurological disorders. The negative and positive aspects of these inhibitors as anti-neurodegenerative agents are discussed.

Efficiency and safety of a standardized protocol for intravenous insulin therapy in ICU patients with neurovascular or head injury.

BACKGROUND: To evaluate the safety and efficiency of a protocol for glycemic control in intensive care unit (ICU) patients with neurovascular or head injury. METHODS: Two cohorts of 50 consecutive patients admitted to the ICU with an admission diagnosis of neurovascular or head injury before and after protocol implementation were evaluated. All patients in the interventional cohort received insulin using a standardized intravenous insulin infusion protocol targeting blood glucose levels of 7-9 mmol/l. Efficiency (time to reach and time within target range), safety (hypoglycemia), and nursing compliance (protocol violations) were evaluated. RESULTS: The median time to reach the target blood glucose range was shorter in the interventional cohort than the conventional cohort (5.0 h [0.5-20.5 h] vs. 12.9 h [1.3-90.3 h]; P < 0.001). More time was spent within target range in the interventional cohort than in the conventional cohort (36.4 +/- 16.3% vs. 27.1 +/- 19.0%; P < 0.001). The median prevalence of mild (<4.9 mmol/l) hypoglycemia (0 [0-1.11]% vs. 0.58 [0-2.79]%; P < 0.001) and moderate (<3.9) hypoglycemia (0[0-0.55]% vs. 0 [1-1.25]%; p < 0.001) was significantly lower in the interventional cohort. CONCLUSIONS: The intravenous insulin infusion protocol improved the safety and efficiency of glycemic control for ICU patients with neurovascular or head injury.

Purple sweet potato color suppresses lipopolysaccharide-induced acute inflammatory response in mouse brain.

The neuroprotective effects of purple sweet potato color (PSPC), which is natural anthocyanin food colors, have been investigated in mice treated with lipopolysaccharide (LPS). In behavioral tests, oral administration of PSPC could significantly reverse the impairment of motor and exploration behavior induced by LPS in the open field tasks, and also improve learning and memory ability in step-through tests. Western blot analysis indicated that PSPC significantly suppressed LPS-induced cyclooxygenase-2 (COX-2) and inducible nitric oxide synthases (iNOS) expression in mouse brain. PSPC also markedly decreased the overproduction of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and interleukin-6 (IL-6) in LPS-stimulated mouse brain. Mechanistically, PSPC strongly inhibited LPS-induced phosphorylated extracellular signal-regulated kinase (ERK) and phosphorylated c-Jun N-terminal kinase (JNK) expression and nuclear factor kappa B (NF-kappaB) activation. Taken together, these data suggest that PSPC may be useful for mitigating inflammatory brain diseases by the inhibition of proinflammatory molecule production, at least in part, through blocking ERK, JNK and NF-kappaB signaling.

Beyond blood brain barrier breakdown - in vivo detection of occult neuroinflammatory foci by magnetic nanoparticles in high field MRI.

BACKGROUND: Gadopentate dimeglumine (Gd-DTPA) enhanced magnetic resonance imaging (MRI) is widely applied for the visualization of blood brain barrier (BBB) breakdown in multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). Recently, the potential of magnetic nanoparticles to detect macrophage infiltration by MRI was demonstrated. We here investigated a new class of very small superparamagnetic iron oxide particles (VSOP) as novel contrast medium in murine adoptive-transfer EAE. METHODS: EAE was induced in 17 mice via transfer of proteolipid protein specific T cells. MR images were obtained before and after application of Gd-DTPA and VSOP on a 7 Tesla rodent MR scanner. The enhancement pattern of the two contrast agents was compared, and correlated to histology, including Prussian Blue staining for VSOP detection and immunofluorescent staining against IBA-1 to identify macrophages/microglia. RESULTS: Both contrast media depicted BBB breakdown in 42 lesions, although differing in plaques appearances and shapes. Furthermore, 13 lesions could be exclusively visualized by VSOP. In the subsequent histological analysis, VSOP was localized to microglia/macrophages, and also diffusely dispersed within the extracellular matrix. CONCLUSION: VSOP showed a higher sensitivity in detecting BBB alterations compared to Gd-DTPA enhanced MRI, providing complementary information of macrophage/microglia activity in inflammatory plaques that has not been visualized by conventional means.

Involvement of oxidative pathways in cytokine-induced secretory phospholipase A2-IIA in astrocytes.

Recent studies have suggested the involvement of secretory phospholipase A2-IIA (sPLA2-IIA) in neuroinflammatory diseases. Although sPLA2-IIA is transcriptionally induced through the NF-kappaB pathway by pro-inflammatory cytokines, whether this induction pathway is affected by other intracellular signaling pathways has not been investigated in detail. In this study, we demonstrated the induction of sPLA2-IIA mRNA and protein expression in astrocytes by cytokines and detected the protein in the culture medium after stimulation. We further investigated the effects of oxidative pathways and botanical antioxidants on the induction pathway and observed that IL-1beta-induced sPLA2-IIA mRNA expression in astrocytes is dependent on ERK1/2 and PI-3 kinase, but not p38 MAPK. In addition to apocynin, a known NADPH oxidase inhibitor, botanical antioxidants, such as resveratrol and epigallocatechin gallate, also inhibited IL-1beta-induced sPLA2-IIA mRNA expression. These compounds also suppressed IL-1beta-induced ERK1/2 activation and translocation of the NADPH oxidase subunit p67 phox from cytosol to membrane fraction. Taken together, these results support the involvement of reactive oxygen species from NADPH oxidase in cytokine induction of sPLA2-IIA in astrocytes and promote the use of botanical antioxidants as protective agents for inhibition of inflammatory responses in these cells.