Infliximab-Associated Chronic Inflammatory Central Nervous System Disease and Peroneal Nerve Injury in a Psoriatic Patient Refractory to Treatment: Case Report with 10-Year Follow-Up.

The tumor necrosis factor-α (TNF-α) antagonists infliximab, adalimumab, and etanercept have been approved for the treatment of chronic inflammatory diseases such as rheumatoid arthritis, ankylosing spondylitis, psoriasis, and psoriatic arthritis. Manifestations of demyelinating disease have been reported for patients receiving TNF-α antagonists. We describe a rare manifestation of a chronic inflammatory process affecting both the central and peripheral nervous system in a patient who received infliximab for the treatment of psoriasis and psoriatic arthritis. Infliximab therapy was discontinued and symptoms improved under high-dose intravenous glucocorticoid pulse therapy.

Scedosporium apiospermum brain abscesses in a patient after near-drowning - a case report with 10-year follow-up and a review of the literature.

Scedosporium apiospermum is known to be a fungal pathogen affecting immunocompromised as well as non-immunodeficient patients. Although this fungus is found rarely, an infection can lead to severe and even fatal disease. Here, we describe the case of a 41-year-old female who developed multiple Scedosporium apiospermum brain abscesses after near-drowning with aspiration of contaminated mud and water. She showed various neurological symptoms. The patient recovered after removal of abscesses in combination with long-term antifungal treatment.

Alpha-synuclein mutations impair axonal regeneration in models of Parkinson's disease.

The dopaminergic (DAergic) nigrostriatal tract has an intrinsic regenerative capacity which can be impaired in Parkinson's disease (PD). Alpha-synuclein (aSyn) is a major pathogenic component in PD but its impact on DAergic axonal regeneration is largely unknown. In this study, we expressed pathogenic variants of human aSyn by means of recombinant adeno-associated viral vectors in experimental paradigms of DAergic regeneration. In a scratch lesion model in vitro, both aSyn(A30P) and aSyn(A53T) significantly reduced DAergic neurite regeneration and induced loss of TH-immunopositive cells while aSyn(WT) showed only minor cellular neurotoxic effects. The striatal density of TH-immunopositive axons in the striatal 6-OHDA lesion mouse model was attenuated only by aSyn(A30P). However, striatal expression levels of the regeneration marker GAP-43 in TH-immunopositive fibers were reduced by both aSyn(A30P) and aSyn(A53T), but not by aSyn(WT), which was associated with an activation of the ROCK signaling pathway. Nigral DAergic cell loss was only mildly enhanced by additional overexpression of aSyn variants. Our findings indicate that mutations of aSyn have a strong impact on the regenerative capacity of DAergic neurons, which may contribute to their pathogenic effects.

CDK5 protects from caspase-induced Ataxin-3 cleavage and neurodegeneration.

Spinocerebellar ataxia type 3 (SCA3) is one of at least nine inherited neurodegenerative diseases caused by an expansion of a polyglutamine tract within corresponding disease-specific proteins. In case of SCA3, mutation of Ataxin-3 results in aggregation of misfolded protein, formation of intranuclear as well as cytosolic inclusion bodies and cell death in distinct neuronal populations. Since cyclin-dependent kinase-5 (CDK5) has been shown to exert beneficial effects on aggregate formation and cell death in various polyglutamine diseases, we tested its therapeutic potential for SCA3. Our data show increased caspase-dependent Ataxin-3 cleavage, aggregation, and neurodegeneration in the absence of sufficient CDK5 activity. This disease-propagating effect could be reversed by mutation of the caspase cleavage site in Ataxin-3. Moreover, reduction of CDK5 expression levels by RNAi in vivo enhances SCA3 toxicity as assayed in a Drosophila model for SCA3. In summary, we present CDK5 as a potent neuroprotectant, regulating cleavage and thereby toxicity of Ataxin-3 and other polyglutamine proteins. We propose that increased caspase-dependent cleavage of mutated Ataxin-3, because of missing CDK5 shielding, leads to aggregation and cell death. Moreover, reduction of CDK5 expression levels by RNAi in vivo enhances SCA3 toxicity as assayed in a Drosophila model for SCA3. We think that CDK5 functions as a shield against cleavage-induced toxification and thereby is an interesting target for therapeutic intervention in polyQ disease in general.

Dropped head sign induced by transdermal application of the dopamine agonist rotigotine in parkinsonian syndrome: a case report.

INTRODUCTION: 'Dropped head sign' relates to a severe disproportionate antecollis in parkinsonism. We present the first report of a rotigotine-induced dropped head sign in a patient with suspected idiopathic Parkinson's disease, which was later defined as multiple system atrophy. The 'dropped head sign' is considered a rare symptom of unknown etiology in parkinsonian disorders, though a disproportionate antecollis is frequently observed in multiple system atrophy. It has also been described as a side effect of dopamine agonist medication with cabergoline and pramipexole. Rotigotine is a transdermally applied, non-ergot dopamine agonist, resulting in a continuous stimulation of dopamine receptors, which is widely used in the treatment of patients with Parkinson's disease. CASE PRESENTATION: We report a case of a 64-year-old Caucasian woman with a rapidly progressive two-and-a-half-year history of a hypokinetic Parkinson's syndrome with asymmetric development of symptoms and an initially good response to levodopa medication. Due to side effects of other dopamimetic medications the patient was switched to rotigotine medication five weeks before clinical admission. Progressive antecollis without muscle weakness and prominent paraspinal muscle contraction developed within two weeks of treatment and resolved within a week after discontinuation of rotigotine and initiation of levodopa/cabergoline medication. CONCLUSION: While the pathophysiology still remains unresolved, this case supports the concept of a dopaminergic imbalance as a cause of certain axial dystonias like disproportionate antecollis including the 'dropped head sign'. We believe this case is specifically useful for neurologists and general practitioners, as the easily recognizable symptom should prompt a thorough reevaluation of diagnosis and medication in patients with Parkinson's disease.

Quantitative evaluation of chaperone activity and neuroprotection by different preparations of a cell-penetrating Hsp70.

Cell-penetrating peptides (CPPs), such as the one derived from the human immunodeficiency virus Tat protein, facilitate the delivery of cargoes across cellular membranes. However, questions about the therapeutic potential of CPP-mediated delivery remain. For instance, the impact of the purification procedure on the functionality of Tat-fusion proteins has not been systematically examined. Here, we isolated fusion proteins of the chaperone heat shock protein 70 (Hsp70) and the Tat CPP under denaturing or native conditions. To investigate the therapeutic potential of different recombinant protein preparations, we examined Tat-Hsp70 transduction efficiency and quantified Tat-Hsp70-mediated folding of a chaperone-dependent yellow fluorescent protein in vitro. Transduction efficiency and chaperone activity of Tat-Hsp70-treated cells was significantly higher compared to cells treated with Hsp70. The application of native isolated Tat-Hsp70 had the strongest effect. This chaperone activity correlates with increased viability of cells treated with the recombinant protein after cell death induction with 6-hydroxydopamine. This suggests that the method of recombinant Tat-fusion protein purification influences its functionality. For Tat-Hsp70, the method of choice seems to be isolation under native conditions, for which we present a purification protocol. Our results may contribute to improve Tat-fusion protein application in basic research and may facilitate its use as therapeutic tool, for instance in Parkinson's disease.

Subcellular distribution affects BAG1 function.

BAG1 is a potent neuroprotectant as well as a marker of differentiation in neuronal cells. It is known that BAG1 mainly localizes to the nucleus during neuronal development, whereas BAG1 shifts to the cytosol upon neuronal differentiation suggesting that distinct BAG1 functions depend on its subcellular localization. Here, we show that forced BAG1 expression within the nucleus when compared to full-length BAG1 expression and to control cells completely abolishes the neuroprotective effects of BAG1 supporting the notion that cytosolic interaction with Hsp70 is mandatory for BAG1 mediated neuroprotection. At the same time, we observed that cells can no longer differentiate into post-mitotic neurons when BAG1 is only present in the nucleus. In addition, phospho-Erk levels are decreased in those cells indicating that BAG1 has to translocate to the cytosol for Raf-dependent MAPK activation.

Unsupervised fluorescence lifetime imaging microscopy for high content and high throughput screening.

Proteomics and cellomics clearly benefit from the molecular insights in cellular biochemical events that can be obtained by advanced quantitative microscopy techniques like fluorescence lifetime imaging microscopy and Förster resonance energy transfer imaging. The spectroscopic information detected at the molecular level can be combined with cellular morphological estimators, the analysis of cellular localization, and the identification of molecular or cellular subpopulations. This allows the creation of powerful assays to gain a detailed understanding of the molecular mechanisms underlying spatiotemporal cellular responses to chemical and physical stimuli. This work demonstrates that the high content offered by these techniques can be combined with the high throughput levels offered by automation of a fluorescence lifetime imaging microscope setup capable of unsupervised operation and image analysis. Systems and software dedicated to image cytometry for analysis and sorting represent important emerging tools for the field of proteomics, interactomics, and cellomics. These techniques could soon become readily available both to academia and the drug screening community by the application of new all-solid-state technologies that may results in cost-effective turnkey systems. Here the application of this screening technique to the investigation of intracellular ubiquitination levels of alpha-synuclein and its familial mutations that are causative for Parkinson disease is shown. The finding of statistically lower ubiquitination of the mutant alpha-synuclein forms supports a role for this modification in the mechanism of pathological protein aggregation.

alpha-Synuclein and its disease-related mutants interact differentially with the microtubule protein tau and associate with the actin cytoskeleton.

alpha-Synuclein is a primarily neuronal protein that is enriched at the pre-synapse. alpha-Synuclein and the microtubule binding protein tau have been implicated in neurodegenerative diseases. alpha-Synuclein is known to associate with phospholipid vesicles, regulates dopamine metabolism and exhibits chaperone activity, but its main role remains largely unknown. Furthermore, knowledge on its interactions and post-translational modifications is essential for a molecular understanding of alpha-synucleinopathies. We investigated alpha-synuclein mutations, causative for autosomal dominant forms of Parkinson's disease (A30P, A53T and E46K), and phosphorylation mutants at serine 129 (S129A and S129D) using fluorescently labelled alpha-synuclein, actin and tau. The investigation of colocalization, and protein-protein interactions by Förster resonance energy transfer and fluorescence lifetime imaging showed that alpha-synuclein associates with the actin cytoskeleton and interacts with tau. The A30P mutation and cytoskeletal destabilization decreased this interaction. Given the concurrent loss of membrane binding by this mutation, we propose a membrane-bound functional complex with tau that might involve the actin cytoskeleton.

Bax inhibitor-1 protects neurons from oxygen-glucose deprivation.

Bax ihibitor-1 (BI-1) has been characterized as an inhibitor of Bax-induced cell death in plants and various mammalian cell systems. To explore the function of BI-1 in neurons, we overexpressed BI-1 tagged to HA or GFP in rat nigral CSM14.1 and human SH-SY5Y neuroblastoma cells. Stable BI-1 expression proved marked protection from cell death induced by thapsigargine, a stress agent blocking the Ca2+-ATPase of the endoplasmic reticulum (ER) but failed to inhibit cell death induced by staurosporine, a kinase inhibitor initiating mitochondria-dependent apoptosis. Moreover, BI-1 was neuroprotective in a paradigm mimicking ischemia, namely oxygen-glucose as well as serum deprivation. Examination of the subcellular distribution revealed that BI-1 predominantly locates to the ER and nuclear envelope but not mitochondria. Taken together, BI-1 overexpression in the ER is protective in neurons, making BI-1 an interesting target for future studies aiming at the inhibition of neuronal cell death during neurodegenerative diseases and stroke.

Interaction of BAG1 and Hsp70 mediates neuroprotectivity and increases chaperone activity.

It was recently shown that Bcl-2-associated athanogene 1 (BAG1) is a potent neuroprotectant as well as a marker of neuronal differentiation. Since there appears to exist an equilibrium within the cell between BAG1 binding to heat shock protein 70 (Hsp70) and BAG1 binding to Raf-1 kinase, we hypothesized that changing BAG1 binding characteristics might significantly alter BAG1 function. To this end, we compared rat CSM14.1 cells and human SHSY-5Y cells stably overexpressing full-length BAG1 or a deletion mutant (BAGDeltaC) no longer capable of binding to Hsp70. Using a novel yellow fluorescent protein-based foldase biosensor, we demonstrated an upregulation of chaperone in situ activity in cells overexpressing full-length BAG1 but not in cells overexpressing BAGDeltaC compared to wild-type cells. Interestingly, in contrast to the nuclear and cytosolic localizations of full-length BAG1, BAGDeltaC was expressed exclusively in the cytosol. Furthermore, cells expressing BAGDeltaC were no longer protected against cell death. However, they still showed accelerated neuronal differentiation. Together, these results suggest that BAG1-induced activation of Hsp70 is important for neuroprotectivity, while BAG1-dependent modulation of neuronal differentiation in vitro is not.