Modulation of Extravascular Binding of Recombinant Factor IX Impacts the Duration of Efficacy in Mouse Models.

BACKGROUND: There is an emerging concept that in addition to circulating coagulation factor IX (FIX), extravascular FIX contributes to hemostasis. OBJECTIVE: Our objective was to evaluate the efficacy of extravascular FIX using animal models of tail clip bleeding and ferric chloride-induced thrombosis. METHODS: Mutant rFIX proteins with described enhanced (rFIXK5R) or reduced (rFIXK5A) binding to extracellular matrix were generated and characterized using in vitro aPTT, one-stage clotting, and modified FX assays. Using hemophilia B mice, pharmacokinetic (PK) parameters and in vivo efficacy of these proteins were compared against rFIX wild-type protein (rFIXWT) in a tail clip bleeding and FeCl3-induced thrombosis model. Respective tissue disposition of FIX was evaluated using immunofluorescence. RESULTS: In vitro characterization demonstrated comparable clotting activity of rFIX proteins. The PK profile showed that rFIXK5A displayed the highest plasma exposure compared to rFIXWT and rFIXK5R. Immunofluorescence evaluation of liver tissue showed that rFIXK5R was detectable up to 24 hours, whereas rFIXWT and rFIXK5A were detectable only up to 15 minutes. In the tail clip bleeding model, rFIXK5R displayed significant hemostatic protection against bleeding incidence for up to 72 hours postintravenous administration of 50 IU/kg, whereas the efficacy of rFIXK5A was already reduced at 24 hours. Similarly, in the mesenteric artery thrombus model, rFIXK5R and rFIXWT demonstrated prolonged efficacy compared to rFIXK5A. CONCLUSION: Using two different in vivo models of hemostasis and thrombosis, we demonstrate that mutated rFIX protein with enhanced binding (rFIXK5R) to extravascular space confers prolonged hemostatic efficacy in vivo despite lower plasma exposure, whereas rFIXK5A rapidly lost its efficacy despite higher plasma exposure.

Key role of MIF-related neuroinflammation in neurodegeneration and cognitive impairment in Alzheimer's disease.

BACKGROUND: Macrophage Migration Inhibitory Factor (MIF) is a potent proinflammatory cytokine that promotes the production of other immune mediators. MIF is produced by most cell types in the brain including microglia, astrocytes and neurons. Enhanced expression of MIF might contribute to the persistent activation of glial, chronic neuroinflammation and neurodegeneration. Here, we investigated the effect of MIF on inflammatory markers and spatial learning in a mouse model of sporadic AD and on tau pathology in AD patients. METHODS: We examined the effects of MIF deficiency and pharmacological MIF inhibition in vitro and in vivo. In vitro, quantitative PCR and ELISA were used to assess cytokine production of STZ-treated glial cells. In vivo, C57BL/6 mice were subjected to intracerebroventricular streptozotocin injection (3 mg/kg, ICV-STZ). Neuroinflammation and contextual learning performance were assessed using quantitative PCR and fear conditioning, respectively. Pharmacological MIF inhibition was achieved with intraperitoneal injections of ISO-1 (daily, IP, 20 mg/kg in 5% DMSO in 0.9% NaCl) for 4 weeks following ICV-STZ injection. The findings from ISO-1 treated mice were confirmed in MIF knockout C57BL/6. To assess the role of MIF in human AD, cerebrospinal fluid levels of MIF and hyperphosphorylated tau were measured using ELISA. RESULTS: Administration ICV-STZ resulted in hippocampal dependent cognitive impairment. MIF inhibition with ISO-1 significantly improved the STZ-induced impairment in contextual memory performance, indicating MIF-related inflammation as a major contributor to ICV-STZ-induced memory deficits. Furthermore, inhibition of the MIF resulted in reduced cytokine production in vitro and in vivo. In human subjects with AD at early clinical stages, cerebrospinal fluid levels of MIF were increased in comparison with age-matched controls, and correlated with biomarkers of tau hyper-phosphorylation and neuronal injury hinting at MIF levels as a potential biomarker for early-stage AD. CONCLUSIONS: The present study indicates the key role of MIF in controlling the chronic cytokine release in neuroinflammation related to tau hyperphosphorylation, neurodegeneration, and clinical manifestations of AD, suggesting the potential of MIF inhibition as therapeutic strategy to slow down neurodegeneration and clinical disease progression.

Effect of naturally occurring α-synuclein-antibodies on toxic α-synuclein-fragments.

Alpha-synuclein (α-Syn) is a soluble protein primarily expressed in presynaptic terminals in the central nervous system (CNS). Aggregates of fibrillated α-Syn are the major component of Lewy bodies (LB), a pathologic hallmark of idiopathic Parkinson's disease (PD). Recently, naturally occurring autoantibodies against human α-Syn (nAbs α-Syn) were detected in the peripheral blood of PD patients and controls. Here, we investigated the inhibitory effects of nAbs α-Syn on distinct α-Syn fragments, as well as inflammatory responses and cytotoxicity evoked by nAbs α-Syn in primary microglia. All α-Syn fragments induced the release of the pro-inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) from microglia in primary culture. Cotreatment with nAbs α-Syn alleviated the release of pro-inflammatory cytokines induced by α-Syn fragments α-Syn 1-95, α-Syn 61-140, α-Syn 96-140 and α-Syn 112. Treatment with the α-Syn fragments α-Syn 1-95, α-Syn 61-140 and α-Syn 112 impaired the viability of primary microglia. This effect could not be counteracted by cotreatment with nAbs α-Syn. Data suggest an important role of nAbs α-Syn in the α-Syn-induced inflammation cascade, and indicate the potential importance of nAbs in the pathogenesis of PD. This could provide an experimental therapeutic target for patients with PD.

Blood-brain barrier breakdown, neuroinflammation, and cognitive decline in older adults.

INTRODUCTION: Blood-brain barrier (BBB) breakdown is observed in older versus younger adults and in late-onset Alzheimer's disease versus age-matched controls, but its causes and consequences in aging are unclear. We tested the hypothesis that BBB breakdown is associated with cognitive decline and inflammation in nondemented elders. METHODS: Cerebrospinal fluid and serum inflammatory markers were measured using sandwich immunoassays in 120 subjects. Least Absolute Shrinkage and Selection Operator-logistic regression selected cerebrospinal fluid and serum signatures that best classified BBB impairment defined by the cerebrospinal fluid albumin index ≥9. Linear regression examined changes in Clinical Dementia Rating sum of boxes as a function of BBB integrity at baseline. RESULTS: Mean age was 70 years, mean Mini­Mental State Examination was 27, and BBB impairment was recorded in 13.5%. BBB breakdown was associated with cognitive decline (P = .015). Cerebrospinal fluid intercellular adhesion molecule-1, vascular endothelial growth factor, interleukin-8, serum amyloid A, macrophage derived chemokine, and gender generated an area under the curve of 0.95 for BBB impairment, and serum IL-16, VEGF-D, IL-15, and other variables generated an AUC of 0.92 for BBB impairment. DISCUSSION: BBB breakdown is associated with more rapid cognitive decline. Inflammatory mechanisms, including cell adhesion, neutrophil migration, lipid metabolism, and angiogenesis may be implicated.

Macrophage Migration Inhibitory Factor is Associated with Biomarkers of Alzheimer's Disease Pathology and Predicts Cognitive Decline in Mild Cognitive Impairment and Mild Dementia.

BACKGROUND: Macrophage migration inhibitory factor (MIF) is a pro-inflammatory protein playing a regulatory role in the immune response. First evidence from in vitro and animal studies suggests that MIF may be involved in the development of Alzheimer's disease (AD) pathology. OBJECTIVE: To address in older subjects (i) the relationships between AD pathology and MIF plasma and cerebrospinal fluid (CSF) levels; and (ii) to investigate whether increased MIF-related systemic and CNS inflammation is associated with clinical disease progression. METHODS: CSF and plasma concentrations of MIF as well as biomarkers of amyloid, neuronal injury, and tau hyperphosphorylation (CSF Aß1-42, tau, and ptau, respectively) were assessed in 97 subjects with MCI or mild dementia (cognitive impairment, CI) and 52 healthy volunteers with normal cognition. Clinical and neuropsychological evaluations were performed at inclusion and at follow up visits. RESULTS: CSF MIF levels were higher in participants with CI with an AD CSF biomarker profile, but not in CI with a non-AD profile, compared to the healthy controls. Higher MIF CSF levels were associated with higher CSF tau and ptau and lower CSF Aß1-42 after adjusting for potential confounders. In CI, MIF CSF independently predicted cognitive decline at a follow-up visit after controlling for potential confounders including CSF Aß1-42 and tau levels. CONCLUSION: Our study provides evidence that MIF-related inflammation is related to amyloid pathology, tau hyperphosphorylation, and neuronal injury at the early clinical stages of AD. Higher MIF CSF levels are associated with accelerated cognitive decline in MCI and mild dementia.

Markers of neuroinflammation associated with Alzheimer's disease pathology in older adults.

BACKGROUND: In vitro and animal studies have linked neuroinflammation to Alzheimer's disease (AD) pathology. Studies on markers of inflammation in subjects with mild cognitive impairment or AD dementia provided inconsistent results. We hypothesized that distinct blood and cerebrospinal fluid (CSF) inflammatory markers are associated with biomarkers of amyloid and tau pathology in older adults without cognitive impairment or with beginning cognitive decline. OBJECTIVE: To identify blood-based and CSF neuroinflammation marker signatures associated with AD pathology (i.e. an AD CSF biomarker profile) and to investigate associations of inflammation markers with CSF biomarkers of amyloid, tau pathology, and neuronal injury. DESIGN/METHODS: Cross-sectional analysis was performed on data from 120 older community-dwelling adults with normal cognition (n=48) or with cognitive impairment (n=72). CSF Aß1-42, tau and p-tau181, and a panel of 37 neuroinflammatory markers in both CSF and serum were quantified. Least absolute shrinkage and selection operator (LASSO) regression was applied to determine a reference model that best predicts an AD CSF biomarker profile defined a priori as p-tau181/Aß1-42 ratio >0.0779. It was then compared to a second model that included the inflammatory markers from either serum or CSF. In addition, the correlations between inflammatory markers and CSF Aß1-42, tau and p-tau181 levels were assessed. RESULTS: Forty-two subjects met criteria for having an AD CSF biomarker profile. The best predictive models included 8 serum or 3 CSF neuroinflammatory markers related to cytokine mediated inflammation, vascular injury, and angiogenesis. Both models improved the accuracy to predict an AD biomarker profile when compared to the reference model. In analyses separately performed in the subgroup of participants with cognitive impairment, adding the serum or the CSF neuroinflammation markers also improved the accuracy of the diagnosis of AD pathology. None of the inflammatory markers correlated with the CSF Aß1-42 levels. Six CSF markers (IL-15, MCP-1, VEGFR-1, sICAM1, sVCAM-1, and VEGF-D) correlated with the CSF tau and p-tau181 levels, and these associations remained significant after controlling for age, sex, cognitive impairment, and APOEε4 status. CONCLUSIONS: The identified serum and CSF neuroinflammation biomarker signatures improve the accuracy of classification for AD pathology in older adults. Our results suggest that inflammation, vascular injury, and angiogenesis as reflected by CSF markers are closely related to cerebral tau pathology.

The multi-target effects of CNI-1493: convergence of anti-amylodogenic and anti-inflammatory properties in animal models of Alzheimer's disease.

After several decades of Alzheimer's disease (AD) research and failed clinical trials, one can speculate that targeting a single pathway is not sufficient. However, a cocktail of novel therapeutics will constitute a challenging clinical trial. A more plausible approach will capitalize on a drug that has relevant and synergistic multiple-target effects in AD. We have previously demonstrated the efficacy of CNI-1493 in the CRND8 transgenic AD mouse model. Similar to many anti-inflammatory drugs that were tested in preclinical model of AD, it was speculated that the significant effect of CNI-1493 is due to its established anti-inflammatory properties in rodents and humans. In the present study, we set out to elucidate the protective mechanism of CNI-1493 as a drug simultaneously targeting several aspects of AD pathology. Using C1213, a highly similar analogue of CNI-1493 that lacks anti-inflammatory properties, we show that both compounds directly interact with soluble and insoluble Amyloid ß (Aß) aggregates and attenuate Aß cytotoxicity in vitro. Additionally, CNI-1493 and C1213 ameliorated Aß-induced behavioral deficits in nematodes. Finally, C1213 reduced Aß plaque burden and cognitive deficits in transgenic CRND8 mice to a similar extent as previously shown with CNI-1493. Taken together, our findings suggest anti-amyloidogenic activity as a relevant component for the in-vivo efficacy of CNI-1493 and its analogue C1213. Thus, CNI-1493, a drug with proven safety in humans, is a viable candidate for novel multi-target therapeutic approaches to AD.

Rodent models of neuroinflammation for Alzheimer's disease.

Alzheimer's disease remains incurable, and the failures of current disease-modifying strategies for Alzheimer's disease could be attributed to a lack of in vivo models that recapitulate the underlying etiology of late-onset Alzheimer's disease. The etiology of late-onset Alzheimer's disease is not based on mutations related to amyloid-ß (Aß) or tau production which are currently the basis of in vivo models of Alzheimer's disease. It has recently been suggested that mechanisms like chronic neuroinflammation may occur prior to amyloid-ß and tau pathologies in late-onset Alzheimer's disease. The aim of this study is to analyze the characteristics of rodent models of neuroinflammation in late-onset Alzheimer's disease. Our search criteria were based on characteristics of an idealistic disease model that should recapitulate causes, symptoms, and lesions in a chronological order similar to the actual disease. Therefore, a model based on the inflammation hypothesis of late-onset Alzheimer's disease should include the following features: (i) primary chronic neuroinflammation, (ii) manifestations of memory and cognitive impairment, and (iii) late development of tau and Aß pathologies. The following models fit the pre-defined criteria: lipopolysaccharide- and PolyI:C-induced models of immune challenge; streptozotocin-, okadaic acid-, and colchicine neurotoxin-induced neuroinflammation models, as well as interleukin-1ß, anti-nerve growth factor and p25 transgenic models. Among these models, streptozotocin, PolyI:C-induced, and p25 neuroinflammation models are compatible with the inflammation hypothesis of Alzheimer's disease.

The α7 nAChR agonist PNU-282987 reduces inflammation and MPTP-induced nigral dopaminergic cell loss in mice.

BACKGROUND: Parkinson's disease (PD) is associated with neurodegeneration of dopaminergic neurons and an accompanying neuroinflammatory process in the substantia nigra (SN). The cholinergic anti-inflammatory signalling pathway allows the autonomic nervous system to modulate immunologic stimuli and inflammatory processes. A major component of this pathway is the α7 nicotinic acetylcholine receptor (α7 nACh receptor), which is expressed on immune cells such as microglia. OBJECTIVE: To determine the role of this cholinergic anti-inflammatory signalling pathway, we investigated the effects of the selective α7 nACh agonist PNU-282987 and of the non-competitive nACh antagonist mecamylamine on microglia-induced neuroinflammation and toxin-induced degeneration of dopaminergic neurons in a mouse model of PD. METHODS: PNU-282987, mecamylamine or placebo administration was started one day before MPTP intoxication and repeated daily until sacrifice after MPTP intoxication. C57Bl/6 mice were injected intraperitoneally four times at 2 h intervals with either 20 mg/kg MPTP-HCl or a corresponding volume of saline. Two or seven days after the end of the MPTP intoxication, the animals were killed and their brains were processed for further analysis. RESULTS: Treatment with PNU-282987 resulted in an attenuation of neuroinflammation in the MPTP-lesioned SN. Furthermore, PNU-282987 attenuated MPTP-induced dopaminergic cell loss in the SN and reduced striatal dopamine depletion. Unexpectedly, mecamylamine lowered neuroinflammation as well, though it did not show a neuroprotective potential at the nigral level. CONCLUSIONS: Our results demonstrate the therapeutic potential of the selective α7 nicotinic acetylcholine agonist PNU-282987 in attenuating neuroinflammation and toxin-induced loss of dopaminergic neurons in the acute MPTP mouse model of PD.

CNI-1493 attenuates neuroinflammation and dopaminergic neurodegeneration in the acute MPTP mouse model of Parkinson's disease.

BACKGROUND: Parkinson's disease (PD) is associated with neurodegeneration of dopaminergic neurons in the substantia nigra. Neuroinflammatory processes have been shown to be a key component of this neurodegeneration and, as such, small molecule compounds which inhibit these inflammatory events are a critical research focus. OBJECTIVE: CNI-1493 is an anti-inflammatory compound that strongly inhibits macrophages and also stimulates the cholinergic anti-inflammatory pathway. We have examined whether CNI-1493 has a neuroprotective effect in the acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. METHODS: CNI-1493 (8 mg/kg i.p.) or placebo administration was started 1 day before MPTP intoxication and repeated daily until sacrifice after MPTP intoxication. C57/Bl6 mice - either treated with CNI-1493 or with placebo - were injected intraperitoneally 4 times at 2-hour intervals with either 20 mg/kg MPTP-HCl or a corresponding volume of saline. Two or 7 days after the end of the MPTP intoxication, the animals were killed and their brains were processed for further analysis. RESULTS: Administration of CNI-1493 markedly protected tyrosine hydroxylase-positive substantia nigra neurons against MPTP neurotoxicity. CNI-1493 treatment in the MPTP model was also accompanied by a profound reduction of activated microglia within the substantia nigra, as measured by ionized calcium-binding adapter molecule-1 staining. CONCLUSIONS: These findings support that CNI-1493 could reduce the MPTP-induced toxicity likely by inhibition of neuroinflammatory responses. The neuroprotective effect of CNI-1493 suggests that CNI-1493 might be a valuable neuroprotective candidate in the future treatment of PD.

Naturally occurring α-synuclein autoantibody levels are lower in patients with Parkinson disease.

OBJECTIVE: Biomarkers are required for the diagnosis and monitoring of disease progression in Parkinson disease (PD). To date, most studies have concentrated on α-synuclein (α-Syn), a protein involved in Parkinson disease pathogenesis, as a potential biomarker, with inconsistent outcomes. Recently, naturally occurring autoantibodies against α-Syn (α-Syn-nAbs) have been detected in the serum of patients with PD. They represent a putative diagnostic marker for PD. METHODS: We established and validated an ELISA to quantify α-Syn-nAbs in serum samples. We analyzed serum samples from 62 patients with PD, 46 healthy controls (HC), and 42 patients with Alzheimer disease (AD) using this newly established ELISA. Additionally, serum levels of endogenous α-Syn were measured. RESULTS: There was a significant difference in α-Syn-nAbs levels between the investigated groups (p = 0.005; Kruskal-Wallis test). Levels of α-Syn-nAbs were significantly lower in patients with PD compared to HC (p < 0.05; Dunn multiple comparison post hoc test) or patients with AD (p < 0.05). Furthermore, we detected no difference between patients with AD and HC. The sensitivity and specificity of the assay for patients with PD vs. HC were 85% and 25%, respectively. The α-Syn-nAbs levels did not correlate with age, Hoehn & Yahr status, or duration of disease. Endogenous α-Syn had no influence on α-Syn-nAbs levels in sera. CONCLUSIONS: Using a well-validated assay, we detected reduced α-Syn-nAbs levels in patients with PD compared to patients with AD and HC. The assay did not achieve criteria for use as a diagnostic tool to reliably distinguish PD from HC. Further studies are needed to assess α-Syn-nAbs as a biomarker in PD.

Immunotherapy in prion disease.

Transmissible spongiform encephalopathies (TSEs), also known as prion diseases, describe a group of fatal neurodegenerative disorders affecting both humans and animals. Accumulation of misfolded prion proteins is the pathological hallmark of these disorders; such accumulation occurs in lymphoreticular tissue prior to CNS involvement in scrapie, experimental models and human variant Creutzfeldt-Jakob disease. Lymphoreticular accumulation of misfolded prion protein has not been demonstrated in human sporadic or genetic forms of TSE. Once clinical symptoms develop, all prion disorders have a rapidly progressive and lethal course, and no effective therapy exists. In the past 10 years, antibody-based immunotherapy has been considered for other neurodegenerative disorders associated with protein misfolding and, therefore, might also be an effective approach to prevention or treatment of prion disease. Self-tolerance to endogenous prion protein is, however, a major challenge to the development of effective immunotherapy, as is the risk of adverse effects from active immunization. This Review summarizes the evidence that immunization could slow disease progression or increase lifespan in animal models of prion diseases. The therapeutic potential of these strategies in treating patients with prion diseases is also discussed.

Activation of KCNN3/SK3/K(Ca)2.3 channels attenuates enhanced calcium influx and inflammatory cytokine production in activated microglia.

In neurons, small-conductance calcium-activated potassium (KCNN/SK/K(Ca)2) channels maintain calcium homeostasis after N-methyl-D-aspartate (NMDA) receptor activation, thereby preventing excitotoxic neuronal death. So far, little is known about the function of KCNN/SK/K(Ca)2 channels in non-neuronal cells, such as microglial cells. In this study, we addressed the question whether KCNN/SK/K(Ca)2 channels activation affected inflammatory responses of primary mouse microglial cells upon lipopolysaccharide (LPS) stimulation. We found that N-cyclohexyl-N-[2-(3,5-dimethyl-pyrazol-1-yl)-6-methyl-4-pyrimidinamine (CyPPA), a positive pharmacological activator of KCNN/SK/K(Ca)2 channels, significantly reduced LPS-stimulated activation of microglia in a concentration-dependent manner. The general KCNN/SK/K(Ca)2 channel blocker apamin reverted these effects of CyPPA on microglial proliferation. Since calcium plays a central role in microglial activation, we further addressed whether KCNN/SK/K(Ca)2 channel activation affected the changes of intracellular calcium levels, [Ca(2+)](i), in microglial cells. Our data show that LPS-induced elevation of [Ca(2+)](i) was attenuated following activation of KCNN2/3/K(Ca)2.2/K(Ca)2.3 channels by CyPPA. Furthermore, CyPPA reduced downstream events including tumor necrosis factor alpha and interleukin 6 cytokine production and nitric oxide release in activated microglia. Further, we applied specific peptide inhibitors of the KCNN/SK/K(Ca)2 channel subtypes to identify which particular channel subtype mediated the observed anti-inflammatory effects. Only inhibitory peptides targeting KCNN3/SK3/K(Ca)2.3 channels, but not KCNN2/SK2/K(Ca)2.2 channel inhibition, reversed the CyPPA-effects on LPS-induced microglial proliferation. These findings revealed that KCNN3/SK3/K(Ca)2.3 channels can modulate the LPS-induced inflammatory responses in microglial cells. Thus, KCNN3/SK3/K(Ca)2.3 channels may serve as a therapeutic target for reducing microglial activity and related inflammatory responses in the central nervous system.

Cytomegalovirus upregulates vascular endothelial growth factor and its second cellular kinase domain receptor in human fibroblasts.

Human cytomegalovirus (HCMV) activation and elevated levels of vascular endothelial growth factor (VEGF) have been found to be associated with transplant rejection. However, information is lacking about whether elevated levels of this multifunctional factor are directly due to viral activation, or if they derive from impurities within the culture supernatant of infected cell cultures. We used purified as well as unpurified viral stocks to infect human fibroblasts in vitro and applied PCR, Western blot, ELISA, and immunofluorescence staining to investigate the expression of VEGF and its receptors. Our data suggest that HCMV infection triggers an early and sustained induction of VEGF and kinase insert domain receptor (KDR) mRNAs, whereas transcript levels of FLT-1 remain unchanged by viral infection. Analysis of the extracellular VEGF and cellular KDR protein expression after infection with purified and unpurified HCMV strains AD169 and TOLEDO showed, in clear contrast to UV-inactivated virus preparations, an increased release of VEGF and KDR proteins. In addition, immunofluorescence revealed that HCMV infection was also accompanied by a profound increase in intracellular VEGF and KDR levels. These results confirm that active HCMV infection is required to induce VEGF and the most important VEGF receptor KDR, and that the upregulation of VEGF and KDR are a direct viral effect and not a secondary effect mediated by inflammatory cytokines within the supernatant. The HCMV-dependent upregulation of VEGF and KDR contributes to the theory that viral-induced immune mediators play a key role in transplant rejection.

Differentially expressed gene profile in the 6-hydroxy-dopamine-induced cell culture model of Parkinson's disease.

Parkinson's disease (PD) is a chronic neurodegenerative disorder characterized by progressive loss of dopaminergic (DA) neurons of the substantia nigra pars compacta with unknown aetiology. 6-Hydroxydopamine (6-OHDA) treatment of neuronal cells is an established in vivo model for mimicking the effect of oxidative stress found in PD brains. We examined the effects of 6-OHDA treatment on human neuroblastoma cells (SH-SY5Y) and primary mesencephalic cultures. Using a reverse arbitrarily primed polymerase chain reaction (RAP-PCR) approach we generated reproducible genetic fingerprints of differential expression levels in cell cultures treated with 6-OHDA. Of the resulting sequences, 23 showed considerable homology to known human coding sequences. The results of the RAP-PCR were validated by reverse transcription PCR, real-time PCR and, for selected genes, by Western blot analysis and immunofluorescence. In four cases, [tomoregulin-1 (TMEFF-1), collapsin response mediator protein 1 (CRMP-1), neurexin-1, and phosphoribosylaminoimidazole synthetase (GART)], a down-regulation of mRNA and protein levels was detected. Further studies will be necessary on the physiological role of the identified proteins and their impact on pathways leading to neurodegeneration in PD.

The role of CNI-1493 in the function of primary microglia with respect to amyloid-ß.

Amyloid-ß (Aß) oligomer toxicity is a crucial factor in the development of Alzheimer's disease. Therefore, the aim of therapeutic research is to target the modification of secretase activity, increase Aß degradation, reduce Aß formation, and modulate Aß-induced neuroinflammation. Recently, the p38 MAP kinase inhibitor CNI-1493 has been shown to reduce plaque load and has led to an improvement in memory performance in a transgenic mouse model. We examined the role of CNI-1493 in the microglial inflammatory response to Aß using both a microglia cell line as well as primary microglia isolated from mesocortices. MTT assays were performed to quantify cell viability. FACS analysis was used to measure phagocytosis. We used ELISA to analyse cytokine concentrations in response to CNI-1493 treatment. Western-blot/Dot-blot techniques were used to show the interaction of CNI-1493 with Aß-oligomers as well as to measure apoptosis in microglia cells. RT-PCR was used to analyze secretase expression, and secretase function was determined using fluorimetric assays. CNI-1493 is able to prevent oligomer formation as well as apoptosis in microglia. A significant reduction was found in the Aß-induced release of IL-6 and TNF-α in the presence of CNI-1493. Phagocytosis is an essential Aß removal mechanism and was enhanced by CNI-1493 in primary microglia. CNI-1493 also influenced the α-secretase product C83 with an increase in the treated cells, while a simultaneous reduction in Aß secretion was also observed. We hypothesize that CNI-1493 not only reduces neuroinflammation and consequent neurodegeneration, but also leads to a shift in AßPP-processing towards the non-amyloidogenic pathway. Therefore, CNI-1493 is a promising candidate for the treatment of AD.

Naturally occurring autoantibodies against beta-amyloid: investigating their role in transgenic animal and in vitro models of Alzheimer's disease.

Alzheimer's disease (AD) is a neurodegenerative disorder primarily affecting regions of the brain responsible for higher cognitive functions. Immunization against ß-amyloid (Aß) in animal models of AD has been shown to be effective on the molecular level but also on the behavioral level. Recently, we reported naturally occurring autoantibodies against Aß (NAbs-Aß) being reduced in Alzheimer's disease patients. Here, we further investigated their physiological role: in epitope mapping studies, NAbs-Aß recognized the mid-/C-terminal end of Aß and preferentially bound to oligomers but failed to bind to monomers/fibrils. NAbs-Aß were able to interfere with Aß peptide toxicity, but NAbs-Aß did not readily clear senile plaques although early fleecy-like plaques were reduced. Administration of NAbs-Aß in transgenic mice improved the object location memory significantly, almost reaching performance levels of wild-type control mice. These findings suggest a novel physiological mechanism involving NAbs-Aß to dispose of proteins or peptides that are prone to forming toxic aggregates.

Role of macrophage migration inhibitory factor in primary glioblastoma multiforme cells.

Macrophage migration inhibitory factor (MIF) is a protein that is overexpressed in many tumors, such as colon and prostate cancer, melanoma, and glioblastoma multiforme (GBM). In its function as a cytokine, MIF induces angiogenesis, promotes cell cycle progression, and inhibits apoptosis. Recently, the molecular signal transduction has been specified: MIF has been found to be a ligand to the CD74/CD44-receptor complex and to activate the ERK1/2 MAPK cascade. In addition MIF binds to the chemokine receptors CXCR2 and CXCR4. This effects an integrin-dependent leukocyte arrest and mediates leukocyte chemotaxis. Recent work has described a clearer role of MIF in GBM tumor cell lines. The current study used human primary GBM cells. We show that inhibition of MIF with ISO-1, an inhibitor of the D-dopachrome tautomerase site of MIF, reduced the growth rate of primary GBM cells in a dose-dependent manner, and in addition ISO-1 increased protein expression of MIF and its receptors CD74, CXCR2, and CXCR4 in vitro but decreased expression of CD44. Furthermore, hypoxia as cell stressor increases the protein expression of MIF in primary GBM cells. These results underscore the importance of MIF in GBM and show that MIF and its receptors may be a promising target for the treatment of malignant gliomas.

Reducing sample complexity of polyclonal human autoantibodies by chromatofocusing.

Chromatofocusing was performed in order to separate a polyclonal antigen-specific mixture of human immunoglobulins (IgGs) that would then allow for further analyses of as few different IgGs as possible. Because polyclonal IgGs only differ by amino acid sequence and possible post-translational modifications but not by molecular weight, we chose chromatofocusing for protein separation by different isoelectric points. We isolated antigen-specific IgGs from commercially available intravenous immunoglobulins (IVIG) using a combination of affinity- and size exclusion-chromatography and in order to reduce the complexity of the starting material IVIG was then replaced by single-donor plasmapheresis material. Using two-dimensional gel electrophoresis (2-DE), we observed a clear decrease in the number of different light and heavy chains in the chromatofocusing peak as compared to the starting material. In parallel, we monitored slight problems with the selected peak in isoelectric focusing as the first dimension of 2-DE, displayed in by the less proper focusing of the spots. When we tested whether IgGs were binding to their specific antigen after chromatofocusing, we were able to show that they were still in native conformation. In conclusion, we showed that chromatofocusing can be used as a first step in the analysis of mixtures of very similar proteins, e.g. polyclonal IgG preparations, in order to minimize the amount of different proteins in separated fractions in a reproducible way.

Macrophage migration inhibitory factor in normal human skeletal muscle and inflammatory myopathies.

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine secreted by activated T cells and macrophages that has antiapoptotic, proproliferative, and chemotactic effects. Because these cells are major components of many muscle disorders with different etiologies, we investigated the amount and distribution of MIF in inflammatory myopathies. Concentrations of MIF in protein lysates from dermatomyositis (n = 6), polymyositis (n = 7), sporadic inclusion body myositis (n = 9) muscle samples and control biopsies without specific changes (n = 10) were determined by ELISA. In polymyositis, MIF concentrations were higher than in controls (p<0.05), whereas they were not significantly different in other inflammatory myopathies. By immunohistochemistry, MIF was detected not only in inflammatory cells, but also at muscle fiber membranes where they were invaded or bordered infiltrates or necrotic fibers; focal sarcoplasmic reactivity was also observed. A similar distribution was found in areas of infiltration, necrosis, myophagocytosis, degeneration, and regeneration in 8 muscular dystrophy samples. The expression of MIF was verified in human myogenic tissue cultures; MIF immunoreactivity decreased with progressive differentiation, and its distribution changed. These data suggest that MIF is a skeletal muscle cytokine with probable functions beyond inflammatory pathology in the complex regenerative response to muscle fiber damage.