BackgroundHuntington's disease (HD) is a fatal inherited neurodegenerative disease, caused by a

The aggregation substance (AS) of Enterococcus faecalis, encoded on sex pheromone plasmids, is a surfacebound glycoprotein that mediates aggregation between bacteria thereby facilitating plasmid transfer. Sequencing of the pAD1-encoded Asa1 revealed that this surface protein contains two RGD motifs which are known to ligate integrins. Therefore, we investigated the influence of AS on the interaction of E. faecalis with human monocyte-derived macrophages which constitutively express ␤ 2 integrins (e.g., CD18). AS was found to cause a greater-than-fivefold increase in enterococcal adherence to macrophages and a greater-than-sevenfold increase in phagocytosis. Adherence was mediated by an interaction between the RGD motif and the integrin CD11b/CD18 (complement receptor type 3) as demonstrated by inhibition studies with monoclonal antibodies and RGD peptide. AS-bearing enterococci were significantly more resistant to macrophage killing during the first 3 h postinfection, probably due to inhibition of the respiratory burst as indicated by reduced concentrations of superoxide anion.Enterococci are gram-positive cocci which inhabit the gastrointestinal tract as well as the vagina and the oral cavity. Enterococcus faecalis accounts for 90% of human enterococcal infections, the most common being urinary tract infections, followed by abdominal infections, wound infections, bacteremia, and infective endocarditis (31, 39). Although infections due to E. faecalis have increased substantially during the last 10 years, the understanding of virulence mechanisms is still limited (24). One of the postulated virulence factors is the aggregation substance (AS), a sex pheromone plasmid-encoded surface protein which promotes the conjugative transfer of sex pheromone plasmids by formation of mating aggregates between donor and recipient cells (6,13,52). DNA sequencing of the structural gene for the pAD1-encoded AS revealed the presence of two Arg-Gly-Asp (RGD) sequences (16); RGD is a well-known motif recognized by a family of eukaryotic receptors, the integrins (38). Integrins consist of noncovalently linked ␣ and ␤ chains and are expressed on leukocytes, thrombocytes, endothelium, and various epithelial cells (21, 37, 42). Our group first suggested an interaction of AS with integrins, since we found that AS augmented adherence to porcine renal tubular cells which could be inhibited competitively by an RGD-Ser (RGDS) peptide (26). This hypothesis was corroborated by in vitro experiments with human polymorphonuclear leukocytes (PMN) which demonstrated that AS promotes opsonin-independent binding of E. faecalis via a ␤ 2 integrinmediated mechanism (46). It is assumed that many enterococcal infections are endogenous, originating from the intestinal tract (25, 51). Wells et al. speculated that macrophages may serve as a vehicle facilitating translocation from the intestinum into the lymph system and bloodstream (49, 50). However, this can occur only if enterococci are able to survive within macrophages. Indeed, Gentry-Weeks et al. demons...

BackgroundMultiple system atrophy (MSA) is a progressive neurodegenerative disorder characterized by parkinsonism, cerebellar ataxia and autonomic dysfunction. Pathogenic mechanisms remain obscure but the neuropathological hallmark is the presence of α-synuclein-immunoreactive glial cytoplasmic inclusions. Genetic variants of the α-synuclein gene, SNCA, are thus strong candidates for genetic association with MSA. One follow-up to a genome-wide association of Parkinson's disease has identified association of a SNP in SNCA with MSA.Methodology/FindingsWe evaluated 32 SNPs in the SNCA gene in a European population of 239 cases and 617 controls recruited as part of the Neuroprotection and Natural History in Parkinson Plus Syndromes (NNIPPS) study. We used 161 independently collected samples for replication. Two SNCA SNPs showed association with MSA: rs3822086 (P = 0.0044), and rs3775444 (P = 0.012), although only the first survived correction for multiple testing. In the MSA-C subgroup the association strengthened despite more than halving the number of cases: rs3822086 P = 0.0024, OR 2.153, (95% CI 1.3–3.6); rs3775444 P = 0.0017, OR 4.386 (95% CI 1.6–11.7). A 7-SNP haplotype incorporating three SNPs either side of rs3822086 strengthened the association with MSA-C further (best haplotype, P = 8.7×10−4). The association with rs3822086 was replicated in the independent samples (P = 0.035).Conclusions/SignificanceWe report a genetic association between MSA and α-synuclein which has replicated in independent samples. The strongest association is with the cerebellar subtype of MSA.Trial RegistrationClinicalTrials.gov NCT00211224. [NCT00211224]

AIMSSelisistat, a selective SirT1 inhibitor is being developed as a potentially disease-modifying therapeutic for Huntington's disease (HD). This was the first study of selisistat in HD patients and was primarily aimed at development of pharmacodynamic biomarkers. METHODSThis was a randomized, double-blind, placebo-controlled, multicentre exploratory study. Fifty-five male and female patients in early stage HD were randomized to receive 10 mg or 100 mg of selisistat or placebo once daily for 14 days. Blood sampling, clinical and safety assessments were conducted throughout the study. Candidate pharmacodynamic markers included circulating soluble huntingtin and innate immune markers. RESULTSSelisistat was found to be safe and well tolerated, and systemic exposure parameters showed that the average steady-state plasma concentration achieved at the 10 mg dose level (125 nM) was comparable with the IC50 for SirT1 inhibition. No adverse effects on motor, cognitive or functional readouts were recorded. While circulating levels of soluble huntingtin were not affected by selisistat in this study, the biological samples collected have allowed development of assay technology for use in future studies. No effects on innate immune markers were seen. CONCLUSIONSSelisistat was found to be safe and well tolerated in early stage HD patients at plasma concentrations within the anticipated therapeutic concentration range. WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT• Modulation of the acetylation status of mutant huntingtin via SirT1 inhibition has been shown to restore transcriptional dysregulation in models of Huntington's disease (HD).• Both nicotinamide and butyrate inhibit SirT1, but have insufficient potency and selectivity to test the SirT1 concept in patients with HD. WHAT THIS STUDY ADDS• This was the first study with a selective SirT1 inhibitor in HD patients and shows that SirT1 inhibition is safe and well tolerated at plasma exposure levels providing benefit in non-clinical HD models, creating the basis for further studies of the pharmacodynamics of SirT1 modulation.

Because of the large overlap and quantitative similarity of eye movement alterations in Parkinson's disease (PD) and multiple system atrophy (MSA), a measurement of eye movement is generally not considered helpful for the differential diagnosis. However, in view of the pathophysiological differences between MSA and PD as well as between the cerebellar (MSA-C) and Parkinsonian (MSA-P) subtypes of MSA, we wondered whether a detailed investigation of oculomotor performance would unravel parameters that could help to differentiate between these entities. We recorded eye movements during sinusoidal pursuit tracking by means of video-oculography in 11 cases of MSA-P, 8 cases of MSA-C and 27 cases of PD and compared them to 23 healthy controls (CTL). The gain of the smooth pursuit eye movement (SPEM) component exhibited significant group differences between each of the three subject groups (MSA, PD, controls) but not between MSA-P and MSA-C. The similarity of pursuit impairment in MSA-P and in MSA-C suggests a commencement of cerebellar pathology in MSA-P despite the lack of clinical signs. Otherwise, SPEM gain was of little use for differential diagnosis between MSA and PD because of wide overlap. However, inspection of the saccadic component of pursuit tracking revealed that in MSA saccades typically correct for position errors accumulated during SPEM epochs ("catch-up saccades"), whereas in PD, saccades were often directed toward future target positions ("anticipatory saccades"). The differences in pursuit tracking between PD and MSA were large enough to warrant their use as ancillary diagnostic criteria for the distinction between these disorders.

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Chronic neurological diseases (CND) like amyotrophic lateral sclerosis (ALS), dementia or multiple sclerosis (MS) share a chronic progressive course of disease that frequently leads to the common pathological pathway of neurodegeneration, including neuroaxonal damage, apoptosis and gliosis. There is an ongoing search for biomarkers that could support early diagnosis of CND and help to identify responders to interventions in therapeutic treatment trials. Cerebrospinal fluid (CSF) is a promising source of biomarkers in CND, since the CSF compartment is in close anatomical contact with the brain interstitial fluid, where biochemical changes related to CND are reflected. We review recent advances in CSF biomarkers research in CND and thereby focus on markers associated with neurodegeneration.

This study provides evidence for aberrant connectivity of RSNs associated with motor function and cognition in early manifest HD when controlling for brain atrophy. This suggests clinically relevant changes of RSN activity in the presence of HD-associated cortical and subcortical structural abnormalities.