Parkin protects against neurotoxicity in the 6-hydroxydopamine rat model for Parkinson's disease

Loss-of-function mutations in the PARK2 gene are the major cause of early onset familial Parkinson's disease. The gene product, parkin, is an E3 ligase of the ubiquitin-proteasome pathway involved in protein degradation. Dopaminergic neuron loss may result from the toxic accumulation of parkin substrates, suggesting a key role for parkin in dopaminergic neuron survival. In this study, we have investigated the neuroprotective capacity of parkin in the 6-OHDA rat model for Parkinson's disease. 6-OHDA induces the generation of reactive oxygen species leading to the degeneration of catecholaminergic neurons, but may also impair proteasome activity. Lentiviral vectors encoding human wild-type parkin or green fluorescent protein were stereotactically injected into the substantia nigra 2 weeks prior to a striatal 6-OHDA lesion. Histological analysis 1 and 3 weeks after lesioning showed a significant preservation of dopaminergic cell bodies and nerve terminals. Moreover, lesioned rats overexpressing parkin displayed a corresponding behavioral improvement as measured by the amphetamine-induced rotation test and the cylinder test. The improved performance in the amphetamine-induced rotation test lasted until 20 weeks after lesioning. Our results demonstrate that parkin acts as a potent neuroprotective agent in vivo against 6-OHDA toxic insults. These data support the therapeutic potential of parkin for the treatment of not only familial but also sporadic Parkinson's disease.status: publishe

Differential interaction of HIV-1 integrase and JPO2 with the C Terminus of LEDGF/p75

The transcriptional co-activator lens epithelium-derived growth factor (LEDGF) has been shown to protect cells against environmental stress. The protein has been implicated in auto-immunity and cancer, and is present in cells as the p52 or p75 splice variant. Recently, LEDGF/p75, but not p52, was identified as the prominent interaction partner of human immunodeficiency virus type 1 (HIV-1) integrase. This interaction of HIV-1 integrase with the C-terminal integrase-binding domain of LEDGF/p75 is crucial for HIV-1 replication. To gain insight into the cell biology of LEDGF/p75, we were interested in identifying cellular binding partners of its C-terminal domain. By yeast-two-hybrid screening with a CEMC7 cDNA-library, we were able to identify JPO2 as a binding partner of the C-terminal part of LEDGF/p75. The specific interaction between JPO2 and LEDGF/p75 was verified by pull-down, AlphaScreen, and co-immunoprecipitation. Competition assays using recombinant proteins show a mutually exclusive binding of either JPO2 or HIV-1 integrase to LEDGF/p75. However, differing mechanisms of binding were suggested by continuing interaction of JPO2 with some LEDGF/p75 mutants (I365A, D366A, F406A) that are totally defective for interaction with HIV-1 integrase. This finding is of significance for the development of specific inhibitors targeting only the interaction between LEDGF/p75 and HIV-1 integrase, without disturbing interaction with other cellular factors. Over-expression of JPO2 resulted in a modest but reproducible inhibition of HIV-1 replication, consistent with competition between integrase and JPO2 for binding to LEDGF/p75. Furthermore, JPO2 over-expression activated transcription from the HIV-1 LTR.status: publishe

Safety and efficacy in geese of a PER.C6-based inactivated West Nile virus vaccine

Studies were performed with an inactivated vaccine against the mosquito-borne flavivirus, West Nile virus (WNV). The mammalian cell line, PER.C6, was selected as the platform for WNV growth since both the neurovirulent strains NY99 and ISR98 that cause epidemics in humans and high mortality in geese, respectively, could be propagated to high titers (10(9) to 10(10)TCID(50)/ml) on these cells. Based on the high DNA homology of the WNV envelope (E) protein and non-structural protein 5 (NS5), and identical neurovirulence in mice and geese, we concluded that NY99 and ISR98 viruses are closely related and therefore vaccine studies were performed with ISR98 as a model for NY99. A robust challenge model in domestic geese was set up resulting in 100% mortality within 7 days of intracranial challenge with 500 TCID(50) WNV. Geese were used to assess the efficacy and safety of an inactivated WNV vaccine produced on PER.C6 cells. Efficacy studies demonstrated 91.4% (53/58) protection of geese compared to no protection (0/13) in geese receiving a sham vaccine. A follow-up study in 1800 geese showed that the vaccine was safe with a survival rate of 96.6% (95% lower CL 95.7%). Initial studies on the correlates of protection induced by the vaccine indicate an important role for antibodies since geese were protected when injected intra-cranial with a mixture of serum from vaccinated, non-challenged geese and WNV. In all, these results provide a scientific basis for the development of an inactivated WNV vaccine based on NY99 produced on PER.C6 cells for human and equine us

Werken aan de robotsamenleving : Visies en inzichten uit de wetenschap over de relatie technologie en werkgelegenheid

Visies en inzichten uit de wetenschap over de relatie technologie en werkgelegenheid. Steeds vaker komen we in aanraking met robots en verregaande automatisering. Denk aan robotstofzuigers, zelfscankassa's of online tools waarmee je zelf juridische contracten kunt opstellen. De discussie over wat deze automatisering gaat betekenen voor toekomstige werkgelegenheid is inmiddels losgebarsten in de media, de wetenschap en de politiek. De een ziet kansen met nieuwe mogelijkheden voor meer comfort, gezondheid en economische groei. De ander maakt zich zorgen over de vraag of 'slimme technologie' banen gaat vervangen. Over die laatste vraag gaat dit rapport. Wat betekent de inzet van slimme technologie voor de werkgelegenheid? Welke taken kan slimme technologie overnemen van de mens en waar vullen mens en machine elkaar aan? Hoe verandert de organisatie van arbeids- en productieprocessen en welke invloed heeft dat op automatisering van werk? Zijn bepaalde groepen op de arbeidsmarkt kwetsbaarder dan andere? Met welke beleidsmaatregelen kunnen we de kansen van automatisering benutten en negatieve effecten zoveel mogelijk voorkomen? Het rapport Werken aan de robotsamenleving brengt in kaart, wat er in de wetenschap bekend is over de relatie technologie en werkgelegenheid. Het werpt een blik op de toekomst en geeft een beeld van de beleidsopties. Het rapport legt zo een gezamenlijke kennisbasis voor het maatschappelijke en politieke debat over de vraag, hoe Nederland ervoor kan zorgen dat we de robotsamenleving zo inrichten dat deze samenleving voor iedereen een aantrekkelijk perspectief is

Induction of Peroxisome Proliferator-Activated Receptor γ (PPARγ)-Mediated Gene Expression by Tomato (<i>Solanum lycopersicum</i> L.) Extracts

Since beneficial effects related to tomato consumption partially overlap with those related to peroxisome proliferator-activated receptor γ (PPARγ) activation, our aim was to test extracts of tomato fruits and tomato components, including polyphenols and isoprenoids, for their capacity to activate PPARγ using the PPARγ2 CALUX reporter cell line. Thirty tomato compounds were tested; seven carotenoids and three polyphenols induced PPARγ2-mediated luciferase expression. Two extracts of tomato, one containing deglycosylated phenolic compounds and one containing isoprenoids, also induced PPARγ2-mediated expression at physiologically relevant concentrations. Furthermore, enzymatically hydrolyzed extracts of seven tomato varieties all induced PPARγ-mediated expression, with a 1.6-fold difference between the least potent and the most potent variety. The two most potent varieties had high flavonoid content, while the two least potent varieties had low flavonoid content. These data indicate that extracts of tomato are able to induce PPARγ-mediated gene expression <i>in vitro</i> and that some tomato varieties are more potent than others