The inhibitory effect of S-nitrosoglutathione on blood-brain barrier disruption and peroxynitrite formation in a rat model of experimental stroke.

The hallmark of stroke injury is endothelial dysfunction leading to blood-brain barrier (BBB) leakage and edema. Among the causative factors of BBB disruption are accelerating peroxynitrite formation and the resultant decreased bioavailability of nitric oxide (NO). S-nitrosoglutathione (GSNO), an S-nitrosylating agent, was found not only to reduce the levels of peroxynitrite but also to protect the integrity of BBB in a rat model of cerebral ischemia and reperfusion (IR).

S-nitrosoglutathione reduces oxidative injury and promotes mechanisms of neurorepair following traumatic brain injury in rats.

Background: Traumatic brain injury (TBI) induces primary and secondary damage in both the endothelium and the brain parenchyma, collectively termed the neurovascular unit. While neurons die quickly by necrosis, a vicious cycle of secondary injury in endothelial cells exacerbates the initial injury in the neurovascular unit following TBI. In activated endothelial cells, excessive superoxide reacts with nitric oxide (NO) to form peroxynitrite.

Very long-chain fatty acid accumulation causes lipotoxic response via 5-lipoxygenase in cerebral adrenoleukodystrophy.

Childhood adrenoleukodystrophy (cALD) is a metabolic disorder in which very long-chain fatty acids (VLCFA) accumulate due to ALD protein gene defects, ultimately leading to lipotoxicity-induced neuroinflammatory demyelinating disease. Therefore, we examined VLCFA-mediated alterations in the metabolism of lipoxidative enzymes and inflammatory mediators in the cALD brain. 5-Lipoxygenase (5-LOX)-derived leukotrienes were significantly elevated in all the areas of white matter in the cALD brain.

Administration of S-nitrosoglutathione after traumatic brain injury protects the neurovascular unit and reduces secondary injury in a rat model of controlled cortical impact.

Background: Traumatic brain injury (TBI) is a major cause of preventable death and serious morbidity in young adults. This complex pathological condition is characterized by significant blood brain barrier (BBB) leakage that stems from cerebral ischemia, inflammation, and redox imbalances in the traumatic penumbra of the injured brain. Once trauma has occurred, combating these exacerbations is the keystone of an effective TBI therapy.

Oxidative imbalance in nonstimulated X-adrenoleukodystrophy-derived lymphoblasts.

X-Adrenoleukodystrophy (X-ALD) is a peroxisomal disorder characterized by accumulation of very-long-chain (VLC) fatty acids, which induces inflammatory disease and alterations in cellular redox, both of which are reported to play a role in the pathogenesis of the severe form of the disease (childhood cerebral ALD). Here, we report on the status of oxidative stress (NADPH oxidase activity) and inflammatory mediators in an X-ALD lymphoblast cell line under nonstimulated conditions. X-ALD lymphoblasts contain nearly 7 times higher levels of the C(26:0) fatty acid compared to controls; these levels were downregulated by treatment with sodium phenylacetate (NaPA), lovastatin or the combination of both drugs.

Hyaluronan regulates ceruloplasmin production by gliomas and their treatment-resistant multipotent progenitors.

Ceruloplasmin (glycosylphosphatidylinositol-linked ferroxidase associated with normal astrocytes) can also be secreted by glioma cells, where its function is unknown. Ceruloplasmin is not only present in glioma cells and in human glioma specimens but also is enriched in highly malignant glioma stem-like cells. Hyaluronan is a large extracellular glycosaminoglycan that enhances malignant glioma behaviors by interacting with CD44 receptors and by downstream activation of signaling proteins and transporters associated with malignancy.

Targeting hyaluronan interactions in spinal cord astrocytomas and diffuse pontine gliomas.

Although significant advances have been made in treating malignant pediatric central nervous system tumors such as medulloblastoma, no effective therapy exists for diffuse pontine glioma or intramedullary spinal astrocytoma. Biology of these 2 tumors is poorly understood, in part because diffuse pontine gliomas are not treated surgically, and tumor specimens from intramedullary spinal astrocytomas are rare and minuscule. At the 2007 Neurobiology of Disease in Children Symposium, we presented evidence that malignant glioma behaviors, including antiapoptosis, invasiveness, and treatment resistance, are enhanced by hyaluronan, an extracellular glycosaminoglycan.

Targeting hyaluronan interactions in malignant gliomas and their drug-resistant multipotent progenitors.

Purpose: To determine if hyaluronan oligomers (o-HA) antagonize the malignant properties of glioma cells and treatment-resistant glioma side population (SP) cells in vitro and in vivo.

Experimental Design: A single intratumoral injection of o-HA was given to rats bearing spinal cord gliomas 7 days after engraftment of C6 glioma cells. At 14 days, spinal cords were evaluated for tumor size, invasive patterns, proliferation, apoptosis, activation of Akt, and BCRP expression.

N-acetyl-L-cysteine ameliorates the inflammatory disease process in experimental autoimmune encephalomyelitis in Lewis rats.

We report that N-acetyl-L-cysteine (NAC) treatment blocked induction of TNF-alpha, IL-1beta, IFN-gamma and iNOS in the CNS and attenuated clinical disease in the myelin basic protein induced model of experimental allergic encephalomyelitis (EAE) in Lewis rats. Infiltration of mononuclear cells into the CNS and induction of inflammatory cytokines and iNOS in multiple sclerosis (MS) and EAE have been implicated in subsequent disease progression and pathogenesis. To understand the mechanism of efficacy of NAC against EAE, we examined its effect on the production of cytokines and the infiltration of inflammatory cells into the CNS.

S-Nitrosoglutathione reduces inflammation and protects brain against focal cerebral ischemia in a rat model of experimental stroke.

Preservation of endothelial functions with low-dose nitric oxide (NO) and inhibition of excessive production of NO from inducible NO synthase (iNOS) is a potential therapeutic approach for acute stroke. Based on this hypothesis, an NO modulator, S-nitrosoglutathione (GSNO) was used, which provided neuroprotection in a rat model of focal cerebral ischemia. Administration of GSNO after the onset of ischemia reduced infarction and improved cerebral blood flow.

Regulation of gene expression associated with acute experimental autoimmune encephalomyelitis by Lovastatin.

The attenuation of experimental autoimmune encephalomyelitis (EAE) by Lovastatin (LOV) has now been well established. The present study was designed to explore the global effect of LOV treatment on expression of immune-related genes in lumbar spinal cord (LSC) during acute EAE by using Affymetrix DNA microarrays. LOV treatment demonstrated the limited infiltration of inflammatory cells into the LSC, and microarray analysis further validated those interpretations by demonstrating relatively less alteration in expression of immune response genes in LOV-treated EAE rats on peak clinical day and recovery vs.

Administration of N-acetylcysteine after focal cerebral ischemia protects brain and reduces inflammation in a rat model of experimental stroke.

Free radicals and inflammatory mediators are involved in transient focal cerebral ischemia (FCI). Preadministration of N-acetylcysteine (NAC) has been found to attenuate the cerebral ischemia-reperfusion injury in a rat model of experimental stroke. This study was undertaken to investigate the neuroprotective potential of NAC administered after ischemic events in experimental stroke.

Correlation of very long chain fatty acid accumulation and inflammatory disease progression in childhood X-ALD: implications for potential therapies.

This study was designed to understand the role of inflammatory mediators involved in the neurobiology of childhood adrenoleukodystrophy (cALD) by comparing the differential expression of the inflammatory mediators with metabolite very long chain fatty acids that accumulate in this disease. Histopathological examinations indicated extensive demyelination and accumulation of infiltrates in perivascular cuffs in plaque area (PA) and inflammatory area (IA) compared to normal looking area (NLA) of the cALD brain and controls. The PA had excessive accumulation of cholesterol ester (25-30-fold), VLC fatty acids (8-12-fold), and exhaustive depletion of cholesterol (60-70%) and sphingomyelin (50-55%) in comparison to controls.

Immunomodulation of experimental autoimmune encephalomyelitis in the Lewis rats by Lovastatin.

Previous studies have demonstrated the immunomodulatory potential of Lovastatin, a hydroxy methyl glutaryl-CoA reductase inhibitor, in lessening the clinical and histological manifestations in the neuroinflammatory animal model experimental autoimmune encephalomyelitis (EAE) (Neurosci. Lett., 269 (1999) 71, and J.