The Inducible Response of the Nematode Caenorhabditis elegans to Members of Its Natural Microbiota Across Development and Adult Life

The biology of all organisms is influenced by the associated community of microorganisms. In spite of its importance, it is usually not well understood how exactly this microbiota affects host functions and what are the underlying molecular processes. To rectify this knowledge gap, we took advantage of the nematode Caenorhabditis elegans as a tractable, experimental model system and assessed the inducible transcriptome response after colonization with members of its native microbiota. For this study, we focused on two isolates of the genus Ochrobactrum. These bacteria are known to be abundant in the nematode's microbiota and are capable of colonizing and persisting in the nematode gut, even under stressful conditions. The transcriptome response was assessed across development and three time points of adult life, using general and C. elegans-specific enrichment analyses to identify affected functions. Our assessment revealed an influence of the microbiota members on the nematode's dietary response, development, fertility, immunity, and energy metabolism. This response is mainly regulated by a GATA transcription factor, most likely ELT-2, as indicated by the enrichment of (i) the GATA motif in the promoter regions of inducible genes and (ii) of ELT-2 targets among the differentially expressed genes. We compared our transcriptome results with a corresponding previously characterized proteome data set, highlighting a significant overlap in the differentially expressed genes, the affected functions, and ELT-2 target genes. Our analysis further identified a core set of 86 genes that consistently responded to the microbiota members across development and adult life, including several C-type lectin-like genes and genes known to be involved in energy metabolism or fertility. We additionally assessed the consequences of induced gene expression with the help of metabolic network model analysis, using a previously established metabolic network for C. elegans. This analysis complemented the enrichment analyses by revealing an influence of the Ochrobactrum isolates on C. elegans energy metabolism and furthermore metabolism of specific amino acids, fatty acids, and also folate biosynthesis. Our findings highlight the multifaceted impact of naturally colonizing microbiota isolates on C. elegans life history and thereby provide a framework for further analysis of microbiota-mediated host functions

Comparative analysis of amplicon and metagenomic sequencing methods reveals key features in the evolution of animal metaorganisms

Background The interplay between hosts and their associated microbiome is now recognized as a fundamental basis of the ecology, evolution, and development of both players. These interdependencies inspired a new view of multicellular organisms as “metaorganisms.” The goal of the Collaborative Research Center “Origin and Function of Metaorganisms” is to understand why and how microbial communities form long-term associations with hosts from diverse taxonomic groups, ranging from sponges to humans in addition to plants. Methods In order to optimize the choice of analysis procedures, which may differ according to the host organism and question at hand, we systematically compared the two main technical approaches for profiling microbial communities, 16S rRNA gene amplicon and metagenomic shotgun sequencing across our panel of ten host taxa. This includes two commonly used 16S rRNA gene regions and two amplification procedures, thus totaling five different microbial profiles per host sample. Conclusion While 16S rRNA gene-based analyses are subject to much skepticism, we demonstrate that many aspects of bacterial community characterization are consistent across methods. The resulting insight facilitates the selection of appropriate methods across a wide range of host taxa. Overall, we recommend single- over multi-step amplification procedures, and although exceptions and trade-offs exist, the V3 V4 over the V1 V2 region of the 16S rRNA gene. Finally, by contrasting taxonomic and functional profiles and performing phylogenetic analysis, we provide important and novel insight into broad evolutionary patterns among metaorganisms, whereby the transition of animals from an aquatic to a terrestrial habitat marks a major event in the evolution of host-associated microbial composition

Efficacy and tolerability of adjunctive brivaracetam in adults with uncontrolled partial-onset seizures: A phase IIb, randomized, controlled trial

PURPOSE: To evaluate the efficacy and tolerability of adjunctive brivaracetam (BRV), a novel high-affinity synaptic vesicle protein 2A ligand that also displays inhibitory activity at neuronal voltage-dependent sodium channels, in adult epilepsy patients with uncontrolled partial-onset seizures. METHODS: A phase IIb, double-blind, randomized, placebo-controlled, parallel-group, dose-ranging study (N01114; NCT00175929) was conducted in patients aged 16-65 years. To be included in the study, patients were required to have experienced four or more partial-onset seizures during a 4-week prospective baseline, despite treatment with 1-2 concomitant antiepileptic drugs. Patients were randomized in a ratio of 1:1:1 to receive BRV 50 mg/day (BRV50), 150 mg/day (BRV150), or placebo. A 3-week up-titration period was followed by a 7-week maintenance period (total treatment period of 10 weeks). KEY FINDINGS: A total of 157 patients were randomized (intent-to-treat [ITT] population; BRV50 n = 53, BRV150 n = 52, placebo n = 52) and overall 148 (94.3%) completed the study. The percent reduction in baseline-adjusted partial-onset seizure frequency/week over placebo during the 7-week maintenance period (primary efficacy outcome) did not reach statistical significance (14.7% for BRV50 [p = 0.093] and 13.6% for BRV150 [p = 0.124]). However, during the entire 10-week treatment period a statistically significant difference was observed for both BRV groups (17.7% for BRV50 [p = 0.026] and 16.3% for BRV150 [p = 0.043]). The median percent reduction from baseline in partial-onset seizure frequency/week during the maintenance period was 38.2% for BRV50 (p = 0.017) and 30.0% for BRV150 (p = 0.113) versus 18.9% in the placebo group. During the treatment period, this was 34.9% for BRV50 (p = 0.004) and 28.3% for BRV150 (p = 0.070) compared with 16.3% for placebo. Fifty percent responder rates during the maintenance period were 23.1% for placebo compared with 39.6% for BRV50 (odds ratio [OR] 2.17, p = 0.077) and 33.3% for BRV150 (OR 1.66, p = 0.261). During the treatment period, 50% responder rates were 17.3% for placebo compared with 35.8% for BRV50 (OR 2.69, p = 0.038) and 30.8% for BRV150 (OR 2.15, p = 0.114). Nine patients were free from partial-onset seizures during the 10-week treatment period (five patients [9.4%] in the BRV50 group and three [5.8%] in the BRV150 group compared with one patient [1.9%] in the placebo group). Treatment-emergent adverse events (TEAEs) reported during the treatment period were mostly mild-to-moderate with similar incidence across treatment groups (BRV50 36/53, 67.9%; BRV150 35/52, 67.3%; placebo 37/52, 71.2%). The most frequently reported TEAEs in BRV groups were headache, fatigue, nasopharyngitis, nausea, somnolence, and dizziness, although nausea had a higher incidence in the placebo group. SIGNIFICANCE: In this double-blind, placebo-controlled, phase IIb study of adjunctive BRV (50 and 150 mg/day) in adults with uncontrolled partial-onset seizures, the primary efficacy analysis did not reach statistical significance; however, statistically significant differences compared with placebo were observed on several secondary efficacy outcomes. BRV was well tolerated.status: publishe

Assessment of cardiac safety during fingolimod treatment initiation in a real-world relapsing multiple sclerosis population: a phase 3b, open-label study.

The aim of this study was to evaluate short-term safety and tolerability of fingolimod in a real-world population with relapsing multiple sclerosis, focusing on cardiac safety during treatment initiation. Patients received fingolimod 0.5 mg once daily for four months. Patients excluded from the pivotal studies with certain pre-existing cardiac conditions or baseline cardiac findings (PCCs), and those receiving beta blockers (BBs) and/or calcium channel blockers (CCBs), were eligible. Heart rate (HR) and electrical conduction events were monitored using ambulatory electrocardiography for at least 6 h after the first dose. Of 2,417 enrolled patients, 2,282 (94.4 %) completed the study. Fingolimod initiation was associated with a transient, mostly asymptomatic decrease in HR. Bradycardia adverse events occurred in 0.6 % of patients and were more frequent in individuals receiving BBs/CCBs (3.3 %) than in other patient subgroups (0.5-1.4 %); most events were asymptomatic, and all patients recovered without pharmacological intervention. In the 6 h post-dose, the incidences of Mobitz type I second-degree atrioventricular block (AVB) and 2:1 AVB were higher in patients with PCCs (4.1 and 2.0 %, respectively) than in those without (0.9 and 0.3 %, respectively); at pre-dose screening, patients with PCCs had the same incidence of Mobitz type I second-degree AVB (4.1 %) and a slightly lower incidence of 2:1 AVB (0.7 %) than 6 h post-dose. All recorded conduction abnormalities were asymptomatic. This study adds to the evidence showing that cardiac effects during fingolimod initiation remain consistent with those known from previous, controlled studies, even if patients with PCCs are included

Switching from natalizumab to fingolimod: A randomized, placebo-controlled study in RRMS

OBJECTIVE: To investigate the effect of different natalizumab washout (WO) periods on recurrence of MRI and clinical disease activity in patients switching from natalizumab to fingolimod. METHODS: In this multicenter, double-blind, placebo-controlled trial (TOFINGO), patients with relapsing-remitting multiple sclerosis (RRMS) were randomized 1:1:1 to 8-, 12-, or 16-week WO followed by fingolimod treatment over 32 weeks from last natalizumab infusion (LNI). Brain MRI was performed at baseline and weeks 8, 12, 16, 20, and 24. RESULTS: Of 142 enrolled and randomized patients, 112 (78.9%) completed the study (8 weeks, n = 41/50; 12 weeks, n = 31/42; 16 weeks, n = 40/50). Number (95% confidence interval [CI]) of active (new/newly enlarged T2) lesions from LNI through 8 weeks of fingolimod treatment (primary outcome) was similar in the 8-week (2.1 [1.7-2.6]) and 12-week WO groups (1.7 [1.3-2.2]) and higher in the 16-week WO group (8.2 [7.3-9.1]). During the WO period only, the number (95% CI) of active lesions increased with increasing WO duration (8 weeks, 0.4 [0.2-0.6]; 12 weeks, 2.1 [1.6-2.6]; 16 weeks, 3.6 [3.0-4.2]). Over the 24 weeks from LNI, gadolinium-enhancing T1 lesion counts were lower in the 8-week WO group (14.1 [5.67-22.53]) than in the 12-week (21.3 [1.41-41.19]) or 16-week (18.5 [8.40-28.60]) WO groups. More patients were relapse-free in the 8-week (88%) and 12-week (91%) WO groups than the 16-week WO group (84%). Sixty-eight percent of patients experienced adverse events (mostly mild/moderate), with similar incidence across groups. No unusually severe relapses or opportunistic infections occurred. CONCLUSIONS: Initiating fingolimod therapy 8-12 weeks after natalizumab discontinuation is associated with a lower risk of MRI and clinical disease reactivation than initiation after 16-week WO. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that for patients with RRMS switching from natalizumab to fingolimod, shorter natalizumab WO periods are associated with less MRI disease activity than are longer WO periods

Safety and efficacy of fingolimod in patients with relapsing-remitting multiple sclerosis (FREEDOMS II): a double-blind, randomised, placebo-controlled, phase 3 trial

Fingolimod has shown reductions in clinical and MRI disease activity in patients with relapsing-remitting multiple sclerosis. We further assessed the efficacy and safety of fingolimod in such patients. We did this placebo-controlled, double-blind phase 3 study predominantly in the USA (101 of 117 centres). Using a computer-generated sequence, we randomly allocated eligible patients-those aged 18-55 years with relapsing-remitting multiple sclerosis-to receive fingolimod 0·5 mg, fingolimod 1·25 mg, or placebo orally once daily (1:1:1; stratified by study centre). On Nov 12, 2009, all patients assigned to fingolimod 1·25 mg were switched to the 0·5 mg dose in a blinded manner after a review of data from other phase 3 trials and recommendation from the data and safety monitoring board, but were analysed as being in the 1·25 mg group in the primary outcome analysis. Our primary endpoint was annualised relapse rate at month 24, analysed by intention to treat. Secondary endpoints included percentage brain volume change (PBVC) from baseline and time-to-disability-progression confirmed at 3 months. This trial is registered with ClinicalTrilals.gov, number NCT00355134. Between June 30, 2006, and March 4, 2009, we enrolled and randomly allocated 1083 patients: 370 to fingolimod 1·25 mg, 358 to fingolimod 0·5 mg, and 355 to placebo. Mean annualised relapse rate was 0·40 (95% CI 0·34-0·48) in patients given placebo and 0·21 (0·17-0·25) in patients given fingolimod 0·5 mg: rate ratio 0·52 (95% CI 0·40-0·66; p<0·0001), corresponding to a reduction of 48% with fingolimod 0·5 mg versus placebo. Mean PBVC was -0·86 (SD 1·22) for fingolimod 0·5 mg versus -1·28 (1·50) for placebo (treatment difference -0·41, 95% CI -0·62 to -0·20; p=0·0002). We recorded no statistically significant between-group difference in confirmed disability progression (hazard rate 0·83 with fingolimod 0·5 mg vs placebo; 95% CI 0·61-1·12; p=0·227). Fingolimod 0·5 mg caused more of the following adverse events versus placebo: lymphopenia (27 [8%] patients vs 0 patients), increased alanine aminotransferase (29 [8%] vs six [2%]), herpes zoster infection (nine [3%] vs three [1%]), hypertension (32 [9%] vs 11 [3%]), first-dose bradycardia (five [1%] vs one [<0·5%]), and first-degree atrioventricular block (17 [5%] vs seven [2%]). 53 (15%) of 358 patients given fingolimod 0·5 mg and 45 (13%) of 355 patients given placebo had serious adverse events over 24 months, which included basal-cell carcinoma (ten [3%] patients vs two [1%] patients), macular oedema (three [1%] vs two [1%]), infections (11 [3%] vs four [1%]), and neoplasms (13 [4%] vs eight [2%]). Our findings expand knowledge of the safety profile of fingolimod and strengthen evidence for its beneficial effects on relapse rates in patients with relapsing-remitting multiple sclerosis. We saw no effect of fingolimod on disability progression. Our findings substantiate the beneficial profile of fingolimod as a disease-modifying agent in the management of patients with relapsing-remitting multiple sclerosis. Novartis Pharma AG