[show abstract][hide abstract] ABSTRACT: This study evaluated the anti-inflammatory effects of Resolvin-D1 (RV-D1) and its mechanism of action in human corneal epithelial (HCE) cells.
HCE cells were incubated with different concentrations of RV-D1 for different time periods. Oleic acid (OA) and Dexamethasone (DM) served as negative and positive controls, respectively. Cells were stimulated with polyriboinosinic:polyribocytidylic acids (poly I:C). The protein contents and mRNA expression levels of Tumor necrosis factor-alpha (TNF-alpha), Interleukin (IL)-6, IL-1beta and IL-8 were evaluated with multiplex fluorescent bead immunoassay (FBI) and real time-PCR, respectively. In addition, the expression of inhibitory factor-kappaBalpha (I-kappaBalpha) was evaluated with real time-PCR.
The protein level of pro-inflammatory cytokines TNF-alpha, IL-6, IL-1beta and IL-8 significantly increased after stimulation with Poly I:C. RV-D1 treatment at concentration of 1 muM decreased the protein level of TNF-alpha to 20.76 +/- 9.3% (P < 0.05), IL-6 to 43.54 +/- 14.16% (P < 0.001), IL-1beta to 46.73 +/- 15.93% (P > 0.05) and IL-8 to 51.15 +/- 13.01% (P < 0.05) compared with cells stimulated with poly I:C alone. Similarly, the mRNA levels of TNF-alpha, IL-6, IL-1beta and IL-8 were significantly reduced after treatment with RV-D1. A highly significant dose response curve was demonstrated for RV-D1 treated HCE cells for TNF-alpha and IL-1beta.DM treatment decreased the protein content for all of the pro-inflammatory cytokines, similar results were demonstrated at the mRNA level. The anti-inflammatory effects of RV-D1 were similar to those of DM for TNF-alpha, IL-6 and IL-8.
RV-D1 may serve as a potent anti-inflammatory agent in ocular surface inflammation, as evaluated in cultured HCE cells. The anti-inflammatory effects of RV-D1 were comparable to those of DM, and were mediated through nuclear factor kappa B (NF-kappaB) signal transduction.
Journal of Inflammation 03/2014; 11(1):6. · 2.55 Impact Factor
[show abstract][hide abstract] ABSTRACT: Toll-like receptors (TLRs) are recognized as important contributors to the initiation and modulation of the inflammatory response in the eye. This study investigated the precise expression patterns and functionality of TLRs in human corneal epithelial cells (HCE) and in conjunctival fibroblasts (HCF).
The cell surface expression of TLRs 2-4, TLR7 and TLR9 in HCE and HCF was examined by flow cytometry with or without stimulation with lipopolysaccharide (LPS) or polyinosinic:polycytidylic acid (poly I:C). The mRNA expression of the TLRs was determined by real-time PCR. The protein content levels of interleukin (IL)-6, IL-8, IL-1beta and tumor necrosis factor-alpha (TNF-alpha) were measured in HCE and HCF using multiplex fluorescent bead immunoassay (FBI).
The surface expression of TLR3 and TLR4 was detected on both HCE and HCF. Following incubation with LPS, the percentage of HCE cells staining for TLR4 decreased from 10.18% to 0.62% (P < 0.001). Incubation with poly I:C lowered the percentage of HCE cells positive for TLR3 from 10.44% to 2.84% (P < 0.001). The mRNA expression of TLRs2, 4, 7 and 9 was detected in HCE only. Activation of HCE with LPS complex elicited protein secretion up to 4.51 +/- 0.85-fold higher levels of IL-6 (P < 0.05), 2.5 +/- 0.36-fold IL-8 (P > 0.05), 4.35 +/- 1.12-fold IL-1beta (P > 0.05) and 29.35 +/- 2.3-fold TNFalpha (P < 0.05) compared to cells incubated in medium.
HCF and HCE both express TLRs that are respond to specific ligands by increased cytokines expression. Following activation, the surface expression of TLR3 and TLR4 on HCE is decreased, thus creating a negative feedback loop, mitigating the effect of TLR activation.
Journal of Inflammation 02/2014; 11(1):3. · 2.55 Impact Factor
[show abstract][hide abstract] ABSTRACT: comMultipurpose solutions (MPSs) are the leading method for cleaning and disinfecting soft contact lenses (CLs). During recent years, numerous clinical studies have evaluated the MPS damage to the ocular surface. This study examined the cytotoxic and the inflammatory effects of MPSs and hydrogen peroxide disinfection system (H202) compared to appropriate controls on human corneal epithelial (HCE) cells. Primary cultured HCE cells were exposed to eight different commercially available MPS products (MPS A, ReNu MultiPlus®; MPS B, Opti Free® EverMoist; MPS C, Solo-care Aqua®; MPS-D, Complete®; MPS-E, Unica Sensitive®; MPS-F, Options Multi®; MPS-G, Biotrue®; MPS-H, COMPLETE® RevitaLens). Morphological changes and cytotoxic effects were examined with FITC-Annexin V/ PI and MTT assays. The protein contents of the inflammatory cytokines interleukin (IL)-1β, TNF-α, IL-6 and IL-8 were examined by multiplex fluorescent bead immunoassay (FBI), and the mRNA expression was examined by real time PCR. Lipopolysaccharide (LPS) with 500 ng/ml CD14 and 500 ng/ml LBP (LPS complex), polyinosinic: polycytidylic acid (Poly I:C) and un-neutralized H202 served as positive controls, respectively. Phosphate-buffered saline (PBS) was added as a negative control. The study demonstrated that most of the MPSs induced varying degrees of cytotoxicity to HCE cells, and increased production of pro-inflammatory cytokines compared to the negative control. In addition, several MPS increased the mRNA level of inhibitory factor-κBα (I-κBα). Among the various MPSs, MPS-H induced the highest protein contents of the pro-inflammatory cytokines (14.37±2.2-fold for TNF-α, 41.39±2.5-fold for IL-1β and 5.24±0.6-fold for IL-6) compared to the negative control (p<0.05). In contrast, no significant differences were noted between the neutralized H202 and the negative control. We conclude that most of the currently used MPSs induce significant damage and inflammatory response in corneal epithelial cells. MPS-induced inflammation was mediated through NF-κB signal transduction. This study demonstrates for the first time inflammatory responses at the molecular level in primary HCE cells following exposure to a large series of commercially available and commonly used MPSs. These findings strongly suggest that certain MPSs may be partially involved in the pathogenesis of contact lens intolerance. Therefore, we recommended that practitioners advise patients as to the preferable disinfecting contact lens solutions, and to consider using the hydrogen peroxide disinfection systems instead.
European Journal of Inflammation 02/2013; 1(1):145-160. · 5.23 Impact Factor
[show abstract][hide abstract] ABSTRACT: Inflammatory demyelinative diseases of the central nervous system are mostly idiopathic and represent the major cause of neurological disability in young adults. These diseases differ in terms of clinical symptoms, severity, pathological characteristics and epidemiology. However, there are also significant similarities between these diseases, which sometimes bring to a misleading diagnosis. Neuromyelitis optica (NMO) is a demyelinative disease in which the optic nerve and the spinal cord are predominantly affected. The detection of specific antibodies to aquaporin-4 (NMO-IgG) led to a modification of the diagnostic criteria for NMO.
We performed a retrospective study on NMO-IgG positive patients referred to the Department of Neurology MS Center (2006-2011) with suspected NMO. Based on the presenting symptomatology of the patients, we identified the cases with optic neuritis and various parameters that may differentiate between NMO and MS. NMO-IgG were evaluated by ELISA.
A total of 50% of the 107 patients with NMO-IgG fulfilled the revised criteria of NMO; 38 patients had a single attack of optic neuritis or long lesion in the spinal cord and 15 patients presented with an opticospinal type of MS. The visual acuity following a single attack of optic neuritis remained significantly lower in NMO patients as compared to MS patients. Most of the NMO patients with NMO-IgG had additional attacks of optic neuritis within a short time from the initial event.
The finding of NMO-IgG in patients with optic neuritis foreshadows a bad prognosis and relapses. These patients are at high risk of experiencing a second event in the central nervous system and fulfilling the clinical criteria for NMO. Due to the difference in the severity of inflammation of the optic nerve between NMO and MS, it is highly recommended to seek a laboratory check-up for NMO-IgG in serum, immediately after the first event, in order to determine the necessity and the kind of treatment for the patient.
[show abstract][hide abstract] ABSTRACT: Background: Brain irradiation (BI) in humans may cause behavioral changes, cognitive impairment and neuroendocrine dysfunction. The effect of BI on the hypothalamic-pituitary-adrenal (HPA) axis is not fully understood. Objectives: To evaluate the effect of BI on HPA axis responses under basal and stressful conditions as well as following pretreatment with dexamethasone (Dex). Methods: Adult male rats were exposed to whole BI. HPA axis responses were examined at 2, 4, 9 and 20 weeks after BI. Histological evaluations of the irradiated rats and matched controls were conducted at 4 and 20 weeks after BI. Results: In contrast to the control group, the basal and stress-induced corticosterone levels were enhanced at 9 and 20 weeks after BI and the inhibitory effect of Dex was reduced. BI also caused hyposuppression of the adrenocortical response to stress. Histological assessment of the irradiated brains revealed hippocampal atrophy at 20 weeks after BI. The neuronal counts were lower only in the CA1 region of the irradiated brains. BI caused a decrease in the binding capacity of Dex to the hippocampal cytosolic fraction. Conclusions: Enhanced stress-induced HPA axis responses and the reduced effect of Dex suggest that BI has delayed effects on HPA axis responses as manifested by impairment of the negative feedback exerted by glucocorticoids (GCs). The mechanisms underlying these effects of BI are unknown. It is possible that the marked BI-induced damage in the hippocampus, which plays an important role in the regulation of the feedback effect of GCs, may cause abnormal HPA axis responses following BI.
[show abstract][hide abstract] ABSTRACT: Background: Central nervous system (CNS) irradiation has detrimental effects which become evident within hours to few days and after a long latency of months and years. However, the delayed effect of irradiation on neuroimmune diseases has not been thoroughly examined. Objectives: We evaluated the delayed effects of irradiation on the course of experimental autoimmune encephalomyelitis (EAE), which is used as a model for neuroimmune inflammation and multiple sclerosis. Methods: Adult male rats were exposed to a dose of 15 Gy given to the thoracolumbar spinal cord. Six months later, EAE was induced by inoculation of rat spinal cord homogenate in complete Freund's adjuvant (CFA). The disease was evaluated by clinical, histopathological and immunological parameters. Results: Irradiated rats developed clinical signs of EAE earlier than the control group and their disease was much more severe. Unlike the control group, all rats in the EAE-irradiated group died within 5 days after the onset of clinical signs. Sections taken from irradiated rats showed diffuse and large hemorrhagic infiltrates of lymphocytes and granulocytes. In contrast, control rats displayed fewer infiltrates, which were less prominent and not hemorrhagic. Conclusions: CNS irradiation has a delayed effect that caused a marked aggravation of the clinical and pathological signs of EAE. The severity of the disease may be a consequence of the effect of irradiation on the CNS vascular bed and impaired blood-brain barrier.
[show abstract][hide abstract] ABSTRACT: Neuromyelitis optica (NMO) is an idiopathic demyelinating disease of the CNS that can be clearly distinguished from multiple sclerosis (MS) by clinical, neuroradiogic, and pathologic criteria and the presence of the highly specific serum autoantibodies against the water channel aquaporin-4 (AQP4).(1) Although studies support a central role of the anti-AQP4 antibodies in the pathogenesis of NMO, their exact involvement in the immunopathogenetic cascade of the disease is still not clear, and T cells seem to be equally crucial for the full development of clinical and histopathologic NMO.
[show abstract][hide abstract] ABSTRACT: Systemic polyunsaturated fatty acids (PUFAs) were shown to improve the symptoms of dry eye syndrome due to their anti-inflammatory effects. This study evaluated the in vitro anti-inflammatory effects of PUFAs on human corneal epithelial (HCE) cells.
HCE cells were incubated for 2 hours with different concentrations of PUFAs: alpha-linolenic acid (ALA), gamma-linolenic acid (GLA), and linoleic acid (LA). Oleic acid (OA) and dexamethasone (DM) served as negative and positive controls, respectively. Cells were stimulated with either polyinosinic:polycytidylic acid (poly I:C) or lipopolysaccharide (LPS) complex. The protein contents and mRNA expression levels of IL-6, IL-8, IL-1β, and TNF-α were evaluated with multiplex fluorescent bead immunoassay and real-time PCR, respectively. The expression of inhibitory factor-κBα (I-κBα) was evaluated with real-time PCR.
The protein and mRNA levels of IL-6, IL-8, IL-1β, and TNF-α were significantly increased after stimulation with LPS or poly I:C. Following treatment with ALA, a significant decrease was demonstrated in the protein content of TNF-α to 23.81% (P < 0.001), IL-6 to 46.71% (P < 0.001), IL-1β to 20.86% (P < 0.05), and IL-8 to 52.21% (P < 0.001). Similar results were demonstrated at the mRNA level. The anti-inflammatory effects of ALA were similar to those of DM for all of the pro-inflammatory cytokines. The ALA inhibition of the pro-inflammatory cytokines was associated with a significant reduction of I-κBα.
ALA may serve as a potent anti-inflammatory agent in ocular surface inflammation. The anti-inflammatory effects of ALA are comparable to those of corticosteroids, and are mediated through NF-κB signal transduction.
[show abstract][hide abstract] ABSTRACT: Prions, composed of a misfolded protein designated PrP(Sc), are infectious agents causing fatal neurodegenerative diseases. We have shown previously that, following induction of experimental autoimmune encephalomyelitis, prion-infected mice succumb to disease significantly earlier than controls, concomitant with the deposition of PrP(Sc) aggregates in inflamed white matter areas. In the present work, we asked whether prion disease acceleration by experimental autoimmune encephalomyelitis results from infiltration of viable prion-infected immune cells into the central nervous system.
C57Bl/6 J mice underwent intraperitoneal inoculation with scrapie brain homogenates and were later induced with experimental autoimmune encephalomyelitis by inoculation of MOG(35-55) in complete Freund's adjuvant supplemented with pertussis toxin. Spleen and lymph node cells from the co-induced animals were reactivated and subsequently injected into naïve mice as viable cells or as cell homogenates. Control groups were infected with viable and homogenized scrapie immune cells only with complete Freund's adjuvant. Prion disease incubation times as well as levels and sites of PrP(Sc) deposition were next evaluated.
We first show that acceleration of prion disease by experimental autoimmune encephalomyelitis requires the presence of high levels of spleen PrP(Sc). Next, we present evidence that mice infected with activated prion-experimental autoimmune encephalomyelitis viable cells succumb to prion disease considerably faster than do mice infected with equivalent cell extracts or other controls, concomitant with the deposition of PrP(Sc) aggregates in white matter areas in brains and spinal cords.
Our results indicate that inflammatory targeting of viable prion-infected immune cells to the central nervous system accelerates prion disease propagation. We also show that in the absence of such targeting it is the load of PrP(Sc) in the inoculum that determines the infectivity titers for subsequent transmissions. Both of these conclusions have important clinical implications as related to the risk of prion disease contamination of blood products.
Journal of Neuroinflammation 03/2012; 9:58. · 4.35 Impact Factor
[show abstract][hide abstract] ABSTRACT: We characterized the effect of acute ischemic stroke on the activation of the hypothalamic-pituitary-adrenal (HPA) axis and evaluated the role of glucocorticoids (GC) in the clinical outcome following ischemic stroke. Male spontaneous hypertensive rats underwent permanent middle cerebral artery occlusion (PMCAO) and developed a cortical infarct. At 4h post-PMCAO or sham operation, serum levels of ACTH and corticosterone (CS) were elevated 5 and 4 fold respectively as compared to controls and then returned to basal levels at 24h post surgery. In these experimental groups we found also a significant depletion of median eminence (ME)-CRH(41). In adrenalectomized (Adx) rats that underwent PMCAO the degree of motor disability and infarct volume was similar to that of intact rats. Administration of dexamethasone (Dex) to Adx-PMCAO rats significantly improved the motor disability and decreased the infarct volume. However, in sham-Adx with PMCAO, Dex had no effect on these two parameters. In rats with PMCAO or sham-PMCAO, brain production of PGE(2) was significantly increased. This effect was further enhanced in Adx-PMCAO rats and significantly inhibited by Dex. In conclusion, activation of the HPA axis following PMCAO is due to stress induced by surgery. This activation is mediated by hypothalamic CRH(41). Absence of endogenous GC or administration of Dex in naïve rats does not alter motor and pathological parameters in the acute stage following PMCAO. In contrast, administration of Dex significantly improved the outcome following cerebral ischemia in Adx rats which may be due to increased glucocorticoid receptors. Brain production of PGE(2) does not play an important role in the pathophysiology of the acute phase of cerebral ischemia.
Brain research 08/2011; 1407:90-6. · 2.46 Impact Factor
[show abstract][hide abstract] ABSTRACT: Depressive disorders are among the world's greatest public health problems. Na(+), K(+)-ATPase is the established receptor for the steroidal digitalis-like compounds (DLC). Alteration in brain Na(+), K(+)-ATPase and DLC have been detected in depressive disorders raising the hypothesis of their involvement in these pathology. The present study was designed to further elaborate this hypothesis by investigating the behavioral and biochemical consequences of neutralization in brain DLC activity attained by anti-ouabain antibodies administrations, in normal Sprague-Dawley (SD) and in the Flinders Sensitive Line (FSL) of genetically depressed rats. Chronic i.c.v. administration of anti-ouabain antibodies to FSL rats elicited anti-depressive behavior. Administration of anti-ouabain antibodies intracerebroventriculary (i.c.v.) to SD rats significantly changed the levels of catecholamines and their metabolites in the hippocampus, ventral tegmentum and nucleus accumbence. These results are in accordance with the notion that endogenous DLC may be involved in the manifestation of depressive disorders and suggests that alteration in their levels may be of significant therapeutic value.
European neuropsychopharmacology: the journal of the European College of Neuropsychopharmacology 06/2011; 22(1):72-9. · 3.68 Impact Factor
[show abstract][hide abstract] ABSTRACT: Experimental autoimmune encephalomyelitis (EAE) is a widely used model of multiple sclerosis (MS) and both conditions have been reported to exhibit reduced endocannabinoid activity. The purpose of this study was to address the effect of exogenously administered 2-arachidonoylglycerol (2AG), an endocannabinoid receptor ligand, on acute phase and chronic disability in EAE.
Acute and chronic EAE models were induced in susceptible mice and 2AG-treatment was applied for 14 days from day of disease induction.
2AG-treatment ameliorated acute phase of disease with delay of disease onset in both EAE models and reduced disease mortality and long-term (70 days post-induction) clinical disability in chronic EAE. Reduced axonal pathology in the chronic EAE- (p<0.0001) and increased activation and ramification of microglia in the 2AG-treated acute EAE- (p<0.05) model were noticed. The latter was accompanied by a 2- to 4-fold increase of the M2-macrophages in the perivascular infiltrations (p<0.001) of the 2AG-treated animals in the acute (day 22), although not the chronic (day 70), EAE model. Expression of cannabinoid receptors 1 (CB1R) and 2 (CB2R) was increased in 2AG-treated animals of acute EAE vs. controls (p<0.05). In addition, ex vivo viability assays exhibited reduced proliferation of activated lymph node cells when extracted from 2AG-treated EAE animals, whereas a dose-dependent response of activated lymphocytes to 2AG-treatment in vitro was noticed.
Our data indicate for the first time that 2AG treatment may provide direct (via CBRs) and immune (via M2 macrophages) mediated neuroprotection in EAE.
Brain research 03/2011; 1390:126-41. · 2.46 Impact Factor
[show abstract][hide abstract] ABSTRACT: Herpes simplex virus-1 (HSV-1) is a common cause of viral encephalitis manifested by activation of the adrenocortical axis, fever and behavioral changes. We investigated the early effects of HSV-1 on constitutive (c) and inducible (i) nitric oxide synthase (NOS) activity in rat brain and in mixed glial cell culture. The effect of glucocorticoids (GCs) on NOS responses to HSV-1 was also determined.
NOS activity was evaluated by the conversion of ³H-arginine to ³H-citrulline. Nitrites were measured in supernatants of activated glial cells.
Under basal conditions, the highest cNOS activity was found in the cerebellum, while activity was much lower in the pons and negligible in the hypothalamus and hippocampus. Forty-eight hours after intracerebral injection of HSV-1, serum corticosterone was increased and NOS activity in the cerebellum and pons was inhibited. Adrenalectomy had no effect on the basal NOS activity but completely abrogated the inhibitory effect of HSV-1. Administration of the iNOS inhibitor aminoguanidine did not significantly change NOS activity, suggesting that the activity found in the cerebellum and pons can be attributed to the cNOS isoform. In mixed glial cell culture infected with HSV-1 and then activated with lipopolysaccharide, NOS activity and nitrite production were inhibited by 77 and 53%, respectively.
These results suggest that brain NOS activity is inhibited in the early stages of HSV-1 infection and requires the presence of circulating GCs. HSV-1-induced brain NOS inhibition may play a role in neuronal viral invasion and in the activation of the adrenocortical axis.
[show abstract][hide abstract] ABSTRACT: Reciprocal pathways of interaction between the nervous and immune systems during stress may be regulated by stress-induced circulating glucocorticoids that act via type II glucocorticoid receptors (GRs). The aim of the present study was to investigate the effect of restraint stress on GRs in lymphocytes and the role of the sympathetic system in this effect.
We used male Balb/c mice which were adrenalectomized 3 days before exposure to restraint stress (4 h). Specific binding of 3H-dexamethasone (Dex) and the expression of GR protein were measured in the cytosol of spleen cells.
Restraint stress caused a significant increase in the maximal binding of 3H-Dex to GRs in the cytosol of spleen cells but not in the binding affinity. In correlation with this increase in binding, restraint stress caused an increase in the amount of GR protein. To establish the relation of the nervous system in this stress response, we blocked the autonomic innervations to the spleen with the ganglionic blocker chlorisondamine. This blocker abrogated the stress-induced increase in the binding of 3H-Dex to GRs and in the GR protein levels. Abrogation of the stress response was also achieved by blocking beta-adrenergic receptors.
These results suggest that stress-induced increase in the level of GRs is mediated by the sympathetic nervous system via beta-adrenergic receptors. It is possible that stress modulation of lymphocyte GR levels may be implicated in the bidirectional communication between the nervous and the immune systems.
[show abstract][hide abstract] ABSTRACT: Several microbial species, including probiotic lactic acid bacteria, have the ability to irreversibly bind a large variety of polyphenols (flavonoids) and anthocyanidins found in many colored fruits and vegetables and to enhance their total oxidant-scavenging capacities (TOSC). The binding of flavonoids to microbial surfaces was further increased by the cationic polyelectrolytes ligands poly-L-histidine, chlorhexidine and Copaxone. This phenomenon was confirmed visually, by the FRAP, DPPH, cyclic voltammetry, Folin-Ciocalteu as well as by luminol-dependent chemiluminescence techniques employed to assay TOSC. The possibility is considered that clinically, microbial cells in the oral cavity and in the gastro intestinal tract, complexed with antioxidant polyphenols from nutrients and with cationic ligands, might increase the protection of mammalian cells against damage induced by excessive generation of reactive oxygen species during infections and inflammation.
Experimental Biology and Medicine 07/2009; 234(8):940-51. · 2.80 Impact Factor
[show abstract][hide abstract] ABSTRACT: Reactive oxygen species are involved in the pathogenesis of multiple sclerosis (MS), Parkinson's disease and neurodegenerative diseases. Here we report that Tempamine (TMN), a stable radical with antioxidant and proapoptotic activities, when encapsulated in the intraliposome aqueous phase of pegylated (<100 nm) nanoliposomes (nSSL), is efficient in inhibiting experimental autoimmune encephalomyelitis (EAE) in mice. The TMN is remote-loaded into nSSL by an intraliposome high/extraliposome low transmembrane ammonium sulfate gradient. Biodistribution studies of nSSL-TMN labeled with the liposome non transferable non metabolizable (3)H-cholesteryl hexadecyl ether show that almost 3% of the injected dose of liposomes reached the brain of the EAE mice, compared with less than 1% in the control healthy mice. This accumulation in the brain, combined with the fact that TMN demonstrates a controlled slow release out of the nSSL, may explain the superior therapeutic activity of nSSL-TMN over free TMN. Our results suggest that the study of nSSL-TMN for therapy of MS, and other neurodegenerative diseases involving oxidative damage, is worth pursuing.
Journal of neuroimmunology 07/2009; 213(1-2):20-5. · 2.84 Impact Factor
[show abstract][hide abstract] ABSTRACT: S100B protein is a potential biomarker of central nervous system insult. This study quantitatively compared two methods for assessing serum concentration of S100B.
A prospective, observational study performed in a single tertiary medical center. Included were fifty two consecutive adult patients undergoing surgery for meningioma that provided blood samples for determination of S100B concentrations. Eighty samples (40 pre-operative and 40 postoperative) were randomly selected for batch testing. Each sample was divided into two aliquots. These were analyzed by ELISA (Sangtec) and a commercial kit (Roche Elecsys(R)) for S100B concentrations. Statistical analysis included regression modelling and Bland-Altman analysis.
A parsimonious linear model best described the prediction of commercial kit values by those determined by ELISA (y = 0.045 + 0.277*x, x = ELISA value, R2 = 0.732). ELISA measurements tended to be higher than commercial kit measurements. This discrepancy increased linearly with increasing S100B concentrations. At concentrations above 0.7 microg/L the paired measurements were consistently outside the limits of agreement in the Bland-Altman display. Similar to other studies that used alternative measurement methods, sex and age related differences in serum S100B levels were not detected using the Elecsys(R) (p = 0.643 and 0.728 respectively).
Although a generally linear relationship exists between serum S100B concentrations measured by ELISA and a commercially available kit, ELISA values tended to be higher than commercial kit measurements particularly at concentrations over 0.7 microg/L, which are suggestive of brain injury. International standardization of commercial kits is required before the predictive validity of S100B for brain damage can be effectively assessed in clinical practice.
[show abstract][hide abstract] ABSTRACT: The misfolding and aggregation of specific proteins has emerged as a key feature of several neurodegenerative diseases. In prion diseases, progressive disease and neuronal loss are associated with the accumulation of PrP(Sc), the misfolded isoform of PrP(C). Previous in vitro studies suggest that cholesterol-lowering drugs inhibit the conversion of PrP(C) to PrP(Sc) and the accumulation of the latter, possibly through the disturbance of cholesterol-rich membrane domains (lipid rafts).
To examine the effect of simvastatin, a cholesterol-lowering drug, on prion disease progression and survival.
Controlled animal study.
University medical center research laboratory.
Female mice from the FVB/N strain.
Peripheral and central nervous system inoculations with scrapie Rocky Mountain Laboratory inoculum.
Clinical, immunological, pathological, and molecular assays were performed.
Simvastatin delayed disease progression, leading to increased survival in peripheral as well as central nervous system inoculations. Simvastatin's beneficial effect is mediated through the l-mevalonate pathway; however, it is independent of brain cholesterol levels. Interestingly, simvastatin treatment induced PrP(Sc) accumulation in parallel with an induced neuroprotective effect. In accordance, we found that simvastatin induced immunomodulatory mechanisms in the brains of infected mice, affecting expression levels of specific microglial chemokines and cytokines.
Simvastatin delays prion disease progression and increases survival in vivo, independently of the pathogenic conversion of PrP(C) to PrP(Sc). We show that simvastatin's effects on neuroprotection are correlated with downregulation of Cox2 levels and induction of microglial activation in prion-infected mouse brains.
Archives of neurology 07/2008; 65(6):762-75. · 6.31 Impact Factor
[show abstract][hide abstract] ABSTRACT: During the years or decades of prion disease incubation, at-risk individuals are certain to encounter diverse pathological insults, such as viral and bacterial infections, autoimmune diseases, or inflammatory processes. Whether prion disease incubation time and clinical signs or otherwise the pathology of intercurrent diseases can be affected by the coinfection process is unknown. To investigate this possibility, mice infected with the scrapie agent at both high and low titers were subsequently induced for experimental autoimmune encephalomyelitis, an immune system-mediated model of central nervous system (CNS) inflammation. We show here that co-induced mice died from a progressive neurological disease long before control mice succumbed to classical scrapie. To investigate the mechanism of the co-induced syndrome, we evaluated biochemical and pathological markers of both diseases. Brain and spleen PrP(Sc) levels in the dying co-induced mice were comparable to those observed in asymptomatic scrapie-infected animals, suggesting that co-induced disease is not an accelerated form of scrapie. In contrast, inflammatory markers, such as demyelination, immune cell infiltrates, and gliosis, were markedly increased in co-induced mouse spinal cords. Activated astrocytes were especially elevated in the medulla oblongata. Furthermore, PrP(sc) depositions were found in demyelinated white matter areas in co-induced mouse spinal cords, suggesting the presence of activated infected immune cells that infiltrate into the CNS to facilitate the process of prion neuroinvasion. We hypothesize that inflammatory processes affecting the CNS may have severe clinical implications in subjects incubating prion diseases.
Journal of Virology 10/2007; 81(18):9942-9. · 5.08 Impact Factor