Knockout of OR39 reveals redundancy in the olfactory pathway regulating the acquisition of host seeking in Anopheles coluzzii

The attraction of anthropophilic mosquitoes to human host cues, such as body odour and carbon dioxide, gradually increases during adult maturation. This acquisition of host-seeking behaviour correlates with age-dependent changes in odorant receptor (OR) transcript abundance and sensitivity of olfactory sensory neurons (OSNs). One OR gene of the human malaria vector, Anopheles coluzzii, AcolOR39, is significantly downregulated in mature females, and a cognate ligand of AcolOR39, sulcatone, a major component of human emanations, mediates the observed behavioural inhibition of newly emerged (teneral) females to human body odour. Knockout of AcolOR39, using CRISPR-Cas9 mutagenesis, selectively abolished sulcatone detection in OSNs, housed in trichoid sensilla. However, knockout of AcolOR39 altered neither the response rate nor the flight behaviour of teneral females in a wind tunnel, indicating the involvement of other genes, and thus a redundancy, in regulating the acquisition of host seeking in mosquitoes.

Contribution of the MP2RAGE 7T Sequence in MS Lesions of the Cervical Spinal Cord

BACKGROUND AND PURPOSE

The detection of spinal cord lesions in patients with MS is challenging. Recently, the 3D MP2RAGE sequence demonstrated its usefulness at 3T. Benefiting from the high spatial resolution provided by ultra-high-field MR imaging systems, we aimed to evaluate the contribution of the 3D MP2RAGE sequence acquired at 7T for the detection of MS lesions in the cervical spine.

MATERIALS AND METHODS

Seventeen patients with MS participated in this study. They were examined at both 3T and 7T. The MR imaging examination included a Magnetic Imaging in MS (MAGNIMS) protocol with an axial T2*-WI gradient recalled-echo sequence ("optimized MAGNIMS protocol") and a 0.9-mm isotropic 3D MP2RAGE sequence at 3T, as well as a 0.7-mm isotropic and 0.3-mm in-plane-resolution anisotropic 3D MP2RAGE sequences at 7T. Each data set was read by a consensus of radiologists, neurologists, and neuroscientists. The number of lesions and their topography, as well as the visibility of the lesions from one set to another, were carefully analyzed.

RESULTS

A total of 55 lesions were detected. The absolute number of visible lesions differed among the 4 sequences (linear mixed effect ANOVA, P = .020). The highest detection was observed for the two 7T sequences with 51 lesions each (92.7% of the total). The optimized 3T MAGNIMS protocol and the 3T MP2RAGE isotropic sequence detected 41 (74.5%) and 35 lesions (63.6%), respectively.

CONCLUSIONS

The 7T MP2RAGE sequences detected more lesions than the 3T sets. Isotropic and anisotropic acquisitions performed comparably. Ultra-high-resolution sequences obtained at 7T improve the identification and delineation of lesions of the cervical spinal cord in MS.

A mosquito-specific antennal protein is critical for the attraction to human odor in the malaria vector Anopheles gambiae

Mosquitoes rely mainly on the sense of smell to decipher their environment and locate suitable food sources, hosts for blood feeding and oviposition sites. The molecular bases of olfaction involve multigenic families of olfactory proteins that have evolved to interact with a narrow set of odorants that are critical for survival. Understanding the complex interplay between diversified repertoires of olfactory proteins and ecologically-relevant odorant signals, which elicit important behaviors, is fundamental for the design of novel control strategies targeting the sense of smell of disease vector mosquitoes. Previously, large multigene families of odorant receptor and ionotropic receptor proteins, as well as a subset of odorant-binding proteins have been shown to mediate the selectivity and sensitivity of the mosquito olfactory system. In this study, we identify a mosquito-specific antennal protein (MSAP) gene as a novel molecular actor of odorant reception. MSAP is highly conserved across mosquito species and is transcribed at an extremely high level in female antennae. In order to understand its role in the mosquito olfactory system, we generated knockout mutant lines in Anopheles gambiae, and performed comparative analysis of behavioral and physiological responses to human-associated odorants. We found that MSAP promotes female mosquito attraction to human odor and enhances the sensitivity of the antennae to a variety of odorants. These findings suggest that MSAP is an important component of the mosquito olfactory system, which until now has gone completely unnoticed.

High sensitivity (zeptomole) detection of BODIPY-labelled heparan sulfate (HS) disaccharides by ion-paired RP-HPLC and LIF detection enables analysis of HS from mosquito midguts

The fine structure of heparan sulfate (HS), the glycosaminoglycan polysaccharide component of cell surface and extracellular matrix HS proteoglycans, coordinates the complex cell signalling processes that control homeostasis and drive development in multicellular animals. In addition, HS is involved in the infection of mammals by viruses, bacteria and parasites. The current detection limit for fluorescently labelled HS disaccharides (low femtomole; 10^-15 mol), has effectively hampered investigations of HS composition in small, functionally-relevant populations of cells and tissues that may illuminate the structural requirements for infection and other biochemical processes. Here, an ultra-high sensitivity method is described that utilises a combination of reverse-phase HPLC, with tetraoctylammonium bromide (TOAB) as the ion-pairing reagent and laser-induced fluorescence detection of BODIPY-FL-labelled disaccharides. The method provides an unparalleled increase in the sensitivity of detection by ∼six orders of magnitude, enabling detection in the zeptomolar range (∼10^-21 moles; <1000 labelled molecules). This facilitates determination of HS disaccharide compositional analysis from minute samples of selected tissues, as demonstrated by analysis of HS isolated from the midguts of Anopheles gambiae mosquitoes that was achieved without approaching the limit of detection.

The human odorant receptor OR10A6 is tuned to the pheromone of the commensal fruit fly Drosophila melanogaster

All living things speak chemistry. The challenge is to reveal the vocabulary, the odorants that enable communication across phylogenies and to translate them to physiological, behavioral, and ecological function. Olfactory receptors (ORs) interface animals with airborne odorants. Expression in heterologous cells makes it possible to interrogate single ORs and to identify cognate ligands. The cosmopolitan, anthropophilic strain of the vinegar fly Drosophila melanogaster depends on human resources and housing for survival. Curiously, humans sense the pheromone (Z)-4-undecenal (Z4-11Al) released by single fly females. A screening of all human ORs shows that the most highly expressed OR10A6 is tuned to Z4-11Al. Females of an ancestral African fly strain release a blend of Z4-11Al and Z4-9Al that produces a different aroma, which is how we distinguish these fly strains by nose. That flies and humans sense Z4-11Al via dedicated ORs shows how convergent evolution shapes communication channels between vertebrate and invertebrate animals.

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Humans sense the sex pheromone Z411-Al released by single Drosophila melanogaster females

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The most highly expressed human olfactory receptor OR10A6 is tuned to Z411-Al

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An African fly strain emits two aldehydes, which we distinguish from Z411-Al by nose

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Convergent evolution shapes chemical communication between phylogenies

AB0863 Emergence of spondyloarthritis following B cell-depleting monoclonal antibody therapy for multiple sclerosis

Background

Anti-CD20 B-cell-depleting therapies, including rituximab and ocrelizumab, have demonstrated their efficacy in patients with relapsing–remitting multiple sclerosis (RRMS).

Objectives

Herein we report a series of patients with RRMS treated with anti-CD20 monoclonal antibodies (mAb) who developed a de novo spondyloarthritis (SpA).

Methods

Following the presentation of an index case, we collected all cases of de novo SpA in the anti-CD20-treated RRMS cohort of our institution’s referral center.

Clinical, biochemical, and imaging characteristics of the cases were identified through a clinical assessment. Information was collected via a standardized form to obtain key characteristics on the onset and type of disease development at baseline and on outcomes up to 12 months. All patients had a magnetic resonance imaging (MRI) of the sacroiliac joints and, depending on the clinical presentation, a spine MRI and/or a musculoskeletal grayscale and power Doppler (PD) ultrasound (US) examination.

Results

De novo SpA developed in 6 of 480 patients with RRMS treated with anti-CD20 mAb, accounting for an incidence of 1.25%. All but one received rituximab treatment. The median time from the last anti-CD20 mAb infusion to SpA onset was 1.5 months [IQR: 1-4]. At the time of SpA emergence, the RRMS activity was controlled.

The most frequent clinical SpA phenotype identified was peripheral SpA (4/6), with Power Doppler ultrasound-detected synovitis. The 2 patients with axial SpA phenotype had bilateral sacroiliitis on MRI. Five of the 6 patients had a personal or family history of psoriasis, whereas the prevalence of psoriasis in the entire RRMS cohort was 3.33% (16/480). No other extra-articular manifestation was observed. All patients were HLA B27 negative and fulfilled at least one classification criteria of SpA. None required hospitalization and the SpA onset did not affect the management of MS. The 2 patients with axial SpA were successfully treated with NSAIDs. Among the patients with peripheral SpA, 3 of four had inadequate response to NSAIDs, 2 were treated with methotrexate and 1 with leflunomide. Only one patient required initiation of an IL-17 inhibitor to control the SpA activity.

Conclusion

We report a pattern of patients with MS successfully treated with B cell-depleting drug developing axial or peripheral SpA, predominantly HLA-B27 negativity and associated with psoriasis.

Disclosure of Interests

None declared

Impact of methodological choices in comparative effectiveness studies: application in natalizumab versus fingolimod comparison among patients with multiple sclerosis

Background

Natalizumab and fingolimod are used as high-efficacy treatments in relapsing–remitting multiple sclerosis. Several observational studies comparing these two drugs have shown variable results, using different methods to control treatment indication bias and manage censoring. The objective of this empirical study was to elucidate the impact of methods of causal inference on the results of comparative effectiveness studies.

Methods

Data from three observational multiple sclerosis registries (MSBase, the Danish MS Registry and French OFSEP registry) were combined. Four clinical outcomes were studied. Propensity scores were used to match or weigh the compared groups, allowing for estimating average treatment effect for treated or average treatment effect for the entire population. Analyses were conducted both in intention-to-treat and per-protocol frameworks. The impact of the positivity assumption was also assessed.

Results

Overall, 5,148 relapsing–remitting multiple sclerosis patients were included. In this well-powered sample, the 95% confidence intervals of the estimates overlapped widely. Propensity scores weighting and propensity scores matching procedures led to consistent results. Some differences were observed between average treatment effect for the entire population and average treatment effect for treated estimates. Intention-to-treat analyses were more conservative than per-protocol analyses. The most pronounced irregularities in outcomes and propensity scores were introduced by violation of the positivity assumption.

Conclusions

This applied study elucidates the influence of methodological decisions on the results of comparative effectiveness studies of treatments for multiple sclerosis. According to our results, there are no material differences between conclusions obtained with propensity scores matching or propensity scores weighting given that a study is sufficiently powered, models are correctly specified and positivity assumption is fulfilled.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01623-8.

Sensitivity of the Inhomogeneous Magnetization Transfer Imaging Technique to Spinal Cord Damage in Multiple Sclerosis

BACKGROUND AND PURPOSE

The inhomogeneous magnetization transfer technique has demonstrated high specificity for myelin, and has shown sensitivity to multiple sclerosis-related impairment in brain tissue. Our aim was to investigate its sensitivity to spinal cord impairment in MS relative to more established MR imaging techniques (volumetry, magnetization transfer, DTI).

MATERIALS AND METHODS

Anatomic images covering the cervical spinal cord from the C1 to C6 levels and DTI, magnetization transfer/inhomogeneous magnetization transfer images at the C2/C5 levels were acquired in 19 patients with MS and 19 paired healthy controls. Anatomic images were segmented in spinal cord GM and WM, both manually and using the AMU₄₀ atlases. MS lesions were manually delineated. MR metrics were analyzed within normal-appearing and lesion regions in anterolateral and posterolateral WM and compared using Wilcoxon rank tests and z scores. Correlations between MR metrics and clinical scores in patients with MS were evaluated using the Spearman rank correlation.

RESULTS

AMU₄₀-based C1-to-C6 GM/WM automatic segmentations in patients with MS were evaluated relative to manual delineation. Mean Dice coefficients were 0.75/0.89, respectively. All MR metrics (WM/GM cross-sectional areas, normal-appearing and lesion diffusivities, and magnetization transfer/inhomogeneous magnetization transfer ratios) were observed altered in patients compared with controls (P < .05). Additionally, the absolute inhomogeneous magnetization transfer ratio z scores were significantly higher than those of the other MR metrics (P < .0001), suggesting a higher inhomogeneous magnetization transfer sensitivity toward spinal cord impairment in MS. Significant correlations with the Expanded Disability Status Scale (ρ = -0.73/P = .02, ρ = -0.81/P = .004) and the total Medical Research Council scale (ρ = 0.80/P = .009, ρ = -0.74/P = .02) were observed for inhomogeneous magnetization transfer and magnetization transfer ratio z scores, respectively, in normal-appearing WM regions, while weaker and nonsignificant correlations were obtained for DTI metrics.

CONCLUSIONS

With inhomogeneous magnetization transfer being highly sensitive to spinal cord damage in MS compared with conventional magnetization transfer and DTI, it could generate great clinical interest for longitudinal follow-up and potential remyelinating clinical trials. In line with other advanced myelin techniques with which it could be compared, it opens perspectives for multicentric investigations.

Improved Cervical Cord Lesion Detection with 3D-MP2RAGE Sequence in Patients with Multiple Sclerosis

Spinal cord lesions have a real diagnostic and prognostic role in multiple sclerosis. Thus, optimizing their detection on MR imaging has become a central issue with direct therapeutic impact. In this study, we compared the 3D-MP2RAGE sequence with the conventional Magnetic Resonance Imaging in Multiple Sclerosis (MAGNIMS) set for cervical cord lesion detection in 28 patients with multiple sclerosis. 3D-MP2RAGE allowed better detection of cervical lesions (+62%) in this population, with better confidence, due to optimized contrast and high spatial resolution.

Inaugural tumor-like multiple sclerosis: clinical presentation and medium-term outcome in 87 patients

BACKGROUND

Tumefactive demyelinating lesions of the central nervous system can be the initial presentation in various pathological entities [multiple sclerosis (the most common), Balo's concentric sclerosis, Schilder's disease and acute disseminated encephalomyelitis] with overlapping clinical presentation. The aim of our study was to better characterize these patients.

METHODS

Eighty-seven patients (62 women and 25 men) from different MS centers in France were studied retrospectively. Inclusion criteria were (1) a first clinical event (2) MRI showing one or more large demyelinating lesions (20 mm or more in diameter) with mass-like features. Patients with a previous demyelinating event (i.e. confirmed multiple sclerosis) were excluded.

RESULTS

Mean age at onset was 26 years. The most common initial symptoms (67% of the patients) were hemiparesis or hemiplegia. Aphasia, headache and cognitive disturbances (i.e. atypical symptoms for demyelinating diseases) were observed in 15, 18 and 15% of patients, respectively. The mean largest diameter of the tumefactive lesions was 26.9 mm, with gadolinium enhancement in 66 patients (81%). Twenty-one patients (24%) had a single tumefactive lesion. During follow-up (median time 5.7 years) 4 patients died, 70 patients improved or remained stable and 12 worsened. 86% of patients received initial corticosteroid treatment, and 73% received disease-modifying therapy subsequently. EDSS at the end of the follow-up was 2.4 ± 2.6 (mean ± SD).

CONCLUSION

This study provides further evidence that the clinical course of MS presenting with large focal tumor-like lesions does not differ from that of classical relapsing-remitting MS, once the noisy first relapsing occurred.

How much progress has there been in the second-line treatment of multiple sclerosis: A 2017 update

In 1993, the US Food and Drug Administration (FDA) approved the first drug specifically for treating multiple sclerosis (MS). More than two decades later, a dozen such treatments are now available. Of these, four are considered second-line treatments for use in escalation strategies and two new drugs are currently undergoing accreditation procedures. Soon, they will provide clinicians with a range of six effective disease-modifying treatments (DMTs) to thwart the inflammatory processes in MS patients with active disease. However, while such a large number of DMTs for MS can help to control early inflammation, any decisions to be made by clinicians have also been made substantially more complex. This complexity is increased by the lack of head-to-head studies comparing these second-line therapies and the benefit-risk profiles for each of these drugs, which are likely to vary among patients. Ultimately, good awareness of the benefits and, more important, the risks of each MS DMT is crucial for the effective management of inflammation in MS.

Evaluation of the Sensitivity of Inhomogeneous Magnetization Transfer (ihMT) MRI for Multiple Sclerosis

BACKGROUND AND PURPOSE

Inhomogeneous magnetization transfer is a new endogenous MR imaging contrast mechanism that has demonstrated high specificity for myelin. Here, we tested the hypothesis that inhomogeneous magnetization transfer is sensitive to pathology in a population of patients with relapsing-remitting MS in a way that both differs from and complements conventional magnetization transfer.

MATERIALS AND METHODS

Twenty-five patients with relapsing-remitting MS and 20 healthy volunteers were enrolled in a prospective MR imaging research study, whose protocol included anatomic imaging, standard magnetization transfer, and inhomogeneous magnetization transfer imaging. Magnetization transfer and inhomogeneous magnetization transfer ratios measured in normal-appearing brain tissue and in MS lesions of patients were compared with values measured in control subjects. The potential association of inhomogeneous magnetization transfer ratio variations with the clinical scores (Expanded Disability Status Scale) of patients was further evaluated.

RESULTS

The magnetization transfer ratio and inhomogeneous magnetization transfer ratio measured in the thalami and frontal, occipital, and temporal WM of patients with MS were lower compared with those of controls (P < .05). The mean inhomogeneous magnetization transfer ratio measured in lesions was lower than that in normal-appearing WM (P < .05). Significant (P < .05) negative correlations were found between the clinical scores and inhomogeneous magnetization transfer ratio measured in normal-appearing WM structures. Weaker nonsignificant correlation trends were found for the magnetization transfer ratio.

CONCLUSIONS

The sensitivity of the inhomogeneous magnetization transfer technique for MS was highlighted by the reduction in the inhomogeneous magnetization transfer ratio in MS lesions and in normal-appearing WM of patients compared with controls. Stronger correlations with the Expanded Disability Status Scale score were obtained with the inhomogeneous magnetization transfer ratio compared with the standard magnetization transfer ratio, which may be explained by the higher specificity of inhomogeneous magnetization transfer for myelin.

Neuraxial analgesia is not associated with an increased risk of post-partum relapses in MS

Background:

Obstetrical analgesia remains a matter of controversy because of the fear of neurotoxicity of local anesthetics on demyelinated fibers or their potential relationship with subsequent relapses.

Objective:

To assess the impact of neuraxial analgesia on the risk of relapse during the first 3 months post-partum, with a focus on women who experienced relapses during pregnancy.

Methods:

We analyzed data of women followed-up prospectively during their pregnancies and at least 3 months post-partum, collected in the Pregnancy in Multiple Sclerosis (PRIMS) and Prevention of Post-Partum Relapses with Progestin and Estradiol in Multiple Sclerosis (POPARTMUS) studies between 1992–1995 and 2005–2012, respectively. The association of neuraxial analgesia with the occurrence of a post-partum relapse was estimated by logistic regression analysis.

Results:

A total of 389 women were included, 215 from PRIMS and 174 from POPARTMUS. In total, 156 women (40%) had neuraxial analgesia. Overall, 24% experienced a relapse during pregnancy and 25% in the 3 months post-partum. Women with a pregnancy relapse were more likely to have a post-partum relapse (odds ratio (OR) = 1.83, p = 0.02), independently of the use of neuraxial analgesia. There was no association between neuraxial analgesia and post-partum relapse (OR = 1.08, p = 0.78).

Conclusion:

Neuraxial analgesia was not associated with an increased risk of post-partum relapses, whatever multiple sclerosis (MS) activity during pregnancy.

New brain lesions with no impact on physical disability can impact cognition in early multiple sclerosis: A ten-year longitudinal study

OBJECTIVE

In early multiple sclerosis, although brain T2 lesions accrual are hallmark of the disease, only weak correlations were found between T2 lesions accrual and EDSS progression, the disability scale commonly used in multiple sclerosis studies. This may be related to the very poor sensitivity of EDSS to cognitive dysfunctions that may occur and progress from the first stage of the disease. In the present study, we aimed to demonstrate that cognitive deficits progress during the first ten years of MS and are significantly impacted by new T2 lesions.

METHODS

EDSS and extensive neuropsychological battery (22 measures) exploring memory, attention/speed of information processing and executive functions were assessed at baseline, Year 1 and Year 10 in 26 patients enrolled after their first clinical attack. To limit the bias of test-retest effect, only measures obtained at Year 1 and Year 10 were reported in the analysis. Raw scores of patients were transformed into z-scores using published normative data when available or scores of matched controls. Lesion probability mapping was used to assess the potential relationships between T2 lesions accumulation, cognitive decline and EDSS progression (P<0.05, FWE-corrected).

RESULTS

At Year 1, 27% of patients showed attention/speed of information processing deficits, 11.5% executive dysfunction and 11.5% memory impairment. During the follow-up, frequency and severity of executive dysfunction increased (from 11.5% of patients at Year 1 to 42% at Year 10, p<0.01) while no significant changes were evidenced for the other cognitive domains. Median EDSS increased from 0.5 [range: 0-3] at Year 1 to 2.5 [range: 0-6.5] at Year 10 (p<0.001). During the ten-year follow-up, lesions accumulation in the left cerebellum and semi-ovale centers was associated with EDSS progression. In contrast, most lesions accumulation in the frontal, parietal and temporal lobes were associated with cognitive decline but had no effect on EDSS progression.

CONCLUSION

The present study provides strong evidence that clinically silent T2 lesions impact cognition in early MS. In daily practice, early prevention of T2 lesions accrual may be useful to limit cognitive decline.

TC-PTP regulates the IL-7 transcriptional response during murine early T cell development

Cytokines play a critical role in directing the discrete and gradual transcriptional changes that define T cell development. The interleukin-7 receptor (IL-7R), via its activation of the JAK-STAT pathway, promotes gene programs that change dynamically as cells progress through T cell differentiation. The molecular mechanism(s) directing differential gene expression downstream of the IL-7R are not fully elucidated. Here, we have identified T cell protein tyrosine phosphatase (TC-PTP), also known as PTPN2, as a negative regulator of IL-7R-STAT signaling in T cell progenitors, contributing to both the quantitative and qualitative nature of STAT-gene targeting. Novel genetic strategies used to modulate TC-PTP expression demonstrate that depletion of TC-PTP expression heightens the phosphorylation of STAT family members, causing aberrant expression of an interferon-response gene profile. Such molecular re-programming results in deregulation of early development checkpoints culminating in inefficient differentiation of CD4⁺CD8⁺ double positive cells. TC-PTP is therefore shown to be required to safeguard the dynamic transcriptome necessary for efficient T cell differentiation.

Functional and Nonfunctional Forms of CquiOR91, an Odorant Selectivity Subunit of Culex quinquefasciatus

In Culex quinquefasciatus, CquiOR91 is the ortholog of 2 larvae-specific odorant receptors (ORs) from Anopheles gambiae (Agam\Or40, previously shown to respond to several odorant ligands including the broad-spectrum repellent N,N-diethyl-3-methylbenzamide, DEET) and Aedes aegypti (Aaeg\Or40). When we cloned full-length CquiOR91 from a Culex quinquefasciatus larval head RNA sample, we found 2 alleles of this OR, differing at 9 residues. Functional analysis using the Xenopus oocyte expression system and 2-electrode voltage clamp electrophysiology revealed one allele (CquiOR91.1) to be nonfunctional, whereas the other allele (CquiOR91.2) was functional. Receptors formed by CquiOR91.2 and Cqui\Orco responded to (-)-fenchone, (+)-fenchone, and DEET, similar to what has been reported for Agam\Or40. We also identified 5 novel odorant ligands for the CquiOR91.2 + Cqui\Orco receptor: 2-isobutylthiazole, veratrole, eucalyptol, d-camphor, and safranal, with safranal being the most potent. To explore possible reasons for the lack of function for CquiOR91.1, we generated a series of mutant CquiOR91.2 subunits, in which the residue at each of the 9 polymorphic residue positions was changed from what occurs in CquiOR91.2 to what occurs in CquiOR91.1. Eight of the 9 mutant versions of CquiOR91.2 formed functional receptors, responding to (-)-fenchone. Only the CquiOR91.2 Y183C mutant was nonfunctional. The reverse mutation (C183Y) conferred function on CquiOR91.1 , which became responsive to (-)-fenchone and safranal. These results indicate that the "defect" in CquiOR91.1 that prevents function is the cysteine at position 183.

Monitoring CD27+ memory B-cells in neuromyelitis optica spectrum disorders patients treated with rituximab: Results from a bicentric study

BACKGROUND

Rituximab (RTX) is increasingly used in the treatment of neuromyelitis optica spectrum disorder (NMO-SD). Administration regimen is not consensual as there is no reliable biomarker of RTX efficacy. In most cases, after induction, RTX is administered systematically every 6months.

OBJECTIVE

To assess efficacy and safety of a maintenance regimen based on CD19+ CD27+ memory B-cell (mBc) detection.

METHODS

We conducted a study in two French centers, including patients with NMO-SD who received an induction therapy with RTX. We compared the number of administered infusions, relapses and EDSS depending on two maintenance schemes (S1: administration of 1g RTX infusion every 6months or S2: a scheme based on regular mBc detection. 1g RTX was administered if mBc was >0.05%) RESULTS: 40 patients were included (mean age: 40.2years, F/M sex ratio: 5/1). Aquaporin-4 antibodies were positive in 75% patients. Under S1 regimen, all patients received 2 infusions per year, whereas under S2, they received 1.62 infusion per year. The mean interval between infusions under S2 was 7.4months, without decrease of clinical efficacy.

CONCLUSION

In our study, mBc-based administration of RTX allowed personalizing treatment administration and in several cases to lower the cumulative dose without loss of efficacy.

Heparin prevents Zika virus induced-cytopathic effects in human neural progenitor cells

The recent Zika virus (ZIKV) outbreak, which mainly affected Brazil and neighbouring states, demonstrated the paucity of information concerning the epidemiology of several flaviruses, but also highlighted the lack of available agents with which to treat such emerging diseases. Here, we show that heparin, a widely used anticoagulant, while exerting a modest inhibitory effect on Zika Virus replication, fully prevents virus-induced cell death of human neural progenitor cells (NPCs).

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Recent outbreak of Zika virus in Brazil included widespread neurological effects.

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One approach to tackling emerging infection is to re-purpose existing pharmaceuticals.

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The anticoagulant, heparin, inhibits infection weakly, but completely prevents cell death.

The expression of NTPDase1 and -2 of Leishmania infantum chagasi in bacterial and mammalian cells: Comparative expression, refolding and nucleotidase characterization

Visceral Leishmaniasis (VL) represents an important global health problem in several warm countries around the world. The main targets in this study are the two nucleoside triphosphate diphosphohydrolases (NTPDases) from Leishmania infantum chagasi that are the main etiologic agent of VL in the New World. These enzymes, called LicNTPDase1 and -2, are homologous to members 5 and 6 of the mammalian E-NTPDase/CD39 superfamily of enzymes. These enzymes hydrolyze nucleotides and accordingly can participate in the purine salvage pathways and in the modulation of purinergic signaling through the extracellular nucleotide-dependent host immune responses. They can therefore affect adhesion and infection of host cells and the parasite virulence. To further characterize these enzymes, in this work, we expressed LicNTPDase1 and -2 in the classical bacterial system Escherichia coli and mammalian cell system COS-7 cells. Our data demonstrate that changes in refolding after expression in bacteria can increase the activity of recombinant (r) rLicNTPDase2 up to 20 times but has no significant effect on rLicNTPDase1. Meanwhile, the expression in COS-7 led to a significant increase in activity for rLicNTPDase1.

Oral Delivery of Pentameric Glucagon-Like Peptide-1 by Recombinant Lactobacillus in Diabetic Rats

Glucagon-like peptide-1 (GLP-1) is an incretin hormone produced by intestinal cells and stimulates insulin secretion from the pancreas in a glucose-dependent manner. Exogenously supplied GLP-1 analogues are used in the treatment of type 2 diabetes. An anti-diabetic effect of Lactobacillus in lowering plasma glucose levels and its use as a vehicle for delivery of protein and antibody fragments has been shown previously. The aim of this study was to employ lactobacilli as a vehicle for in situ production and delivery of GLP-1 analogue to normalize blood glucose level in diabetic GK (Goto-Kakizaki) rats. In this study, we designed pentameric GLP-1 (5×GLP-1) analogues which were both expressed in a secreted form and anchored to the surface of lactobacilli. Intestinal trypsin sites were introduced within 5×GLP-1, leading to digestion of the pentamer into an active monomeric form. The E. coli-produced 5×GLP-1 peptides delivered by intestinal intubation to GK rats resulted in a significant improvement of glycemic control demonstrated by an intraperitoneal glucose tolerance test. Meanwhile, the purified 5×GLP-1 (trypsin-digested) from the Lactobacillus cultures stimulated insulin secretion from HIT-T15 cells, similar to the E. coli-produced 5×GLP-1 peptides. When delivered by gavage to GK rats, non-expressor L. paracasei significantly lowered the blood glucose level but 5×GLP-1 expression did not provide an additional anti-diabetic effect, possibly due to the low levels produced. Our results indicate that lactobacilli themselves might be used as an alternative treatment method for type 2 diabetes, but further work is needed to increase the expression level of GLP-1 by lactobacilli in order to obtain a significant insulinotropic effect in vivo.

MRI/MRS of corpus callosum in patients with clinically isolated syndrome suggestive of multiple sclerosis

A trophy of corpus callosum (C C) related to axonal loss has previously been observed in patients at the early stage of clinically definite multiple sclerosis (CDMS). Atrophy increases with the progression of the disease. Nevertheless, no data concerning the onset of atrophy of C C are currently available. The purpose of this study is to determine if damage in callosal tissue was present at the earliest stage of MS, in a subgroup of patients presenting with a clinically isolated syndrome suggestive of MS (C ISSMS), fulfilling the dissemination in space criteria according to McDonald. Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) techniques were applied to measure C C volume, magnetization transfer ratio (MTR), mean diffusivity (MD), N-acetyl aspartate/choline-containing compounds (NAA/C ho) ratio, N-acetyl aspartate/total creatine (NA A/C r) ratio and C ho/C r ratio inside the C C of 46 C ISSMS patients and 24 sexand age-matched controls. No atrophy of C C was observed in the C ISSMS group. C C of patients was character ized by decreased MTR and increased MD. No change in the NA A/C r ratio was observed while the NA A/C ho ratio decreased and C ho/C r ratio increased in the splenium and the central anterio r part of C C. These abnormalities were present in patients with, but also without, macroscopic lesions inside the C C. O ur results indicate that diffuse structural and metabolic changes, which may be interpreted as representing predominantly myelin patho logy, occur in the C C at the earliest stage of MS before any atrophy is detected.

Onset and underpinnings of white matter atrophy at the very early stage of multiple sclerosis - a two-year longitudinal MRI/MRSI study of corpus callosum

Backgrounds Atrophy of corpus callosum (CC), a white matter structure linking the two hemispheres, is commonly observed in multiple sclerosis (MS). However, the occurrence and processes leading to this alteration are not yet determined.

Goal and methods To better characterize the onset and progression of CC atrophy from the early stage of MS, we performed a two-year follow-up magnetic resonance imaging/magnetic resonance spectroscopic imaging (MRI/MRSI) exploration of CC in 24 patients with clinically isolated syndrome. These patients were explored using the same protocol at month (M)6, M12 and M24. MRI/MRSI techniques were applied to measure CC volume, and relative concentrations of N-acetylaspartate (NAA), creatine/phosphocreatine (Cr) and choline-containing compounds (Cho). A group of matched controls was also explored.

Results Atrophy of CC, not present at baseline, was observed at M12 and progressed over the second year (M24). At baseline, a decrease in relative NAA level was observed in the anterior and posterior body of CC, with normalization during the follow-up period. In the anterior body, an increase in relative Cho level was observed, with normalization at M6. Normal relative Cr levels were observed at all time points in all sub-regions. The rate of CC atrophy was correlated with the change in the Expanded Disability Status Scale (EDSS) during the follow-up period.

Conclusion These results suggest that CC atrophy appears over a period of one year after the first acute inflammatory episode, and that this atrophy is accompanied, especially in the anterior body of CC, by a normalization of the relative Cho levels, marker of acute inflammation, and NAA levels, marker of neuronal dysfunction and/or loss.

Randomized study of once-weekly interferon β-1a therapy in relapsing multiple sclerosis: three-year data from the OWIMS study

Background: Once weekly interferon β-1a for multiple sclerosis (OWIMS) demonstrated modest, but significant, magnetic resonance imaging (MRI) benefit of once-weekly (qw) interferon (IFN) β-1a at 48 weeks, but no significant effect on relapses. Objective: An OWIMS extension permitted assessment of longer-term efficacy/safety of qw IFN β-1a in relapsing-remitting multiple sclerosis (RRMS). Methods: Placebo patients were rerandomized to IFN β-1a, 22 or 44 mcg qw, for two additional 48-week intervals. Primary outcome was MRI lesion activity. Relapse rate and other MRI measures were secondary outcomes. Results: After three years, median (mean) T2 lesion count/patient/scan was 1.3 (2.6) for 44 mcg, 1.7 (3.3) for 22 mcg, 1.7 (3.4) for placebo/22 mcg, 2.0 (3.6) for placebo/44 mcg (all differences not significant). Annualized relapse rates were lowest for 44 mcg (0.77) versus other groups (0.83-0.86, not significant). Persistent neutralizing antibodies did not affect relapse rates, but MRI active lesions were increased in antibody-positive patients receiving 44 mcg compared to antibody negative patients. Conclusions: In RRMS, once weekly IFN β-1a, particularly 44 mcg, can induce a significant MRI, but not relapse, effect, compared with placebo. No significant dose effect was seen. In contrast to the significant effect observed with three-times-weekly dosing of subcutaneous IFN β-1a compared with placebo, this study confirms the lack of meaningful clinical benefit with once-weekly dosing.

Tumor cell survival dependence on the DHX9 DExH-box helicase

The ATP-dependent DExH/D-box helicase DHX9 is a key participant in a number of gene regulatory steps, including transcriptional, translational, microRNA-mediated control, DNA replication, and maintenance of genomic stability. DHX9 has also been implicated in tumor cell maintenance and drug response. Here, we report that inhibition of DHX9 expression is lethal to human cancer cell lines and murine Eµ−Myc lymphomas. Using a novel conditional shDHX9 mouse model, we demonstrate that sustained and prolonged (6 months) suppression of DHX9 does not result in any deleterious effects at the organismal level. Body weight, blood biochemistry, and histology of various tissues were comparable to control mice. Global gene expression profiling revealed that although reduction of DHX9 expression resulted in multiple transcriptome changes, these were relatively benign and did not lead to any discernible phenotype. Our results demonstrate a robust tolerance for systemic DHX9 suppression in vivo and support the targeting of DHX9 as an effective and specific chemotherapeutic approach.

Repression of p53-target gene Bbc3/PUMA by MYSM1 is essential for the survival of hematopoietic multipotent progenitors and contributes to stem cell maintenance

p53 is a central mediator of cellular stress responses, and its precise regulation is essential for the normal progression of hematopoiesis. MYSM1 is an epigenetic regulator essential for the maintenance of hematopoietic stem cell (HSC) function, hematopoietic progenitor survival, and lymphocyte development. We recently demonstrated that all developmental and hematopoietic phenotypes of Mysm1 deficiency are p53-mediated and rescued in the Mysm1(-/-)p53(-/-) mouse model. However, the mechanisms triggering p53 activation in Mysm1(-/-) HSPCs, and the pathways downstream of p53 driving different aspects of the Mysm1(-/-) phenotype remain unknown. Here we show the transcriptional activation of p53 stress responses in Mysm1(-/-) HSPCs. Mechanistically, we find that the MYSM1 protein associates with p53 and colocalizes to promoters of classical p53-target genes Bbc3/PUMA (p53 upregulated modulator of apoptosis) and Cdkn1a/p21. Furthermore, it antagonizes their p53-driven expression by modulating local histone modifications (H3K27ac and H3K4me3) and p53 recruitment. Using double-knockout mouse models, we establish that PUMA, but not p21, is an important mediator of p53-driven Mysm1(-/-) hematopoietic dysfunction. Specifically, Mysm1(-/-)Puma(-/-) mice show full rescue of multipotent progenitor (MPP) viability, partial rescue of HSC quiescence and function, but persistent lymphopenia. Through transcriptome analysis of Mysm1(-/-)Puma(-/-) MPPs, we demonstrate strong upregulation of other p53-induced mediators of apoptosis and cell-cycle arrest. The full viability of Mysm1(-/-)Puma(-/-) MPPs, despite strong upregulation of many other pro-apoptotic mediators, establishes PUMA as the essential non-redundant effector of p53-induced MPP apoptosis. Furthermore, we identify potential mediators of p53-dependent but PUMA-independent Mysm1(-/-)hematopoietic deficiency phenotypes. Overall, our study provides novel insight into the cell-type-specific roles of p53 and its downstream effectors in hematopoiesis using unique models of p53 hyperactivity induced by endogenous stress. We conclude that MYSM1 is a critical negative regulator of p53 transcriptional programs in hematopoiesis, and that its repression of Bbc3/PUMA expression is essential for MPP survival, and partly contributes to maintaining HSC function.

In vitro effects of bis(1,2-dimethyl-3-hydroxy-4-pyridinonato)oxidovanadium(IV), or VO(dmpp)2, on insulin secretion in pancreatic islets of type 2 diabetic Goto-Kakizaki rats

Vanadium compounds have been explored as therapy of diabetes, and most studies have focussed on insulin mimetic effects, i.e. reducing hyperglycemia by improving glucose sensitivity and thus glucose uptake in sensitive tissues. We have recently shown that bis(1,2-dimethyl-3-hydroxy-4-pyridinonato)oxidovanadium(IV), VO(dmpp)2, has promising effects when compared to another vanadium compound, bis(maltolato)oxidovanadium(IV), BMOV, and insulin itself, in isolated adipocytes and in vivo in Goto-Kakizaki (GK) rats, an animal model of hereditary type 2 diabetes (T2D).We now have investigated in GK rats whether VO(dmpp)2 also modulates another important defect in T2D, impaired insulin secretion. VO(dmpp)2, but not BMOV, stimulated insulin secretion from isolated GK rat pancreatic islets at high, 16.7mM, but not at low–normal, 3.3 mM, glucose concentration. Mechanistic studies demonstrate that the insulin releasing effect of VO(dmpp)2 is due to its interaction with several steps in the stimulus-secretion coupling for glucose, including islet glucose metabolism and K-ATP channels, L-type Ca2+ channels, modulation by protein kinases A and C, as well as the exocytotic machinery. In conclusion, VO(dmpp)2 exhibits properties of interest for treatment of the insulin secretory defect in T2D, in addition to its well-described insulin mimetic activity.

Odorant receptor-based discovery of natural repellents of human lice

The body louse, Pediculus humanus humanus, is an obligate blood-feeding ectoparasite and an important insect vector that mediates the transmission of diseases to humans. The analysis of the body louse genome revealed a drastic reduction of the chemosensory gene repertoires when compared to other insects, suggesting specific olfactory adaptations to host specialization and permanent parasitic lifestyle. Here, we present for the first time functional evidence for the role of odorant receptors (ORs) in this insect, with the objective to gain insight into the chemical ecology of this vector. We identified seven putative full-length ORs, in addition to the odorant receptor co-receptor (Orco), and expressed four of them in the Xenopus laevis oocytes system. When screened with a panel of ecologically-relevant odorants, PhumOR2 responded to a narrow set of compounds. At the behavior level, both head and body lice were repelled by the physiologically-active chemicals. This study presents the first evidence of the OR pathway being functional in lice and identifies PhumOR2 as a sensitive receptor of natural repellents that could be used to develop novel efficient molecules to control these insects.

Expression of Protein Kinase C Isoforms in Pancreatic Islets and Liver of Male Goto-Kakizaki Rats, a Model of Type 2 Diabetes

Protein kinase C (PKC) is a family of protein kinases controlling protein phosphorylation and playing important roles in the regulation of metabolism. We have investigated expression levels of PKC isoforms in pancreatic islets and liver of diabetic Goto-Kakizaki (GK) rats with and without insulin treatment to evaluate their association with glucose homeostasis. mRNA and protein expression levels of PKC isoforms were assessed in pancreatic islets and liver of Wistar rats and GK rats with or without insulin treatment. PKCα and PKCζ mRNA expressions were down-regulated in islets of GK compared with Wistar rats. PKCα and phosphorylated PKCα (p-PKCα) protein expressions were decreased in islets of GK compared with insulin-treated GK and Wistar rats. PKCζ protein expression in islets was reduced in GK and insulin-treated GK compared with Wistar rats, but p-PKCζ was decreased only in GK rats. Islet PKCε mRNA and protein expressions were lower in GK compared with insulin-treated GK and Wistar rats. In liver, PKCδ and PKCζ mRNA expressions were decreased in both GK and insulin-treated GK compared with Wistar rats. Hepatic PKCζ protein expression was diminished in both GK rats with and without insulin treatment compared with Wistar rats. Hepatic PKCε mRNA expression was down-regulated in insulin-treated GK compared with GK and Wistar rats. PKCα, PKCε, and p-PKCζ expressions were secondary to hyperglycaemia in GK rat islets. Hepatic PKCδ and PKCζ mRNA expressions were primarily linked to hyperglycaemia. Additionally, hepatic PKCε mRNA expression could be under control of insulin.

[Is it always useful to perform lumbar puncture for the diagnosis of multiple sclerosis? No]

In the absence of a specific test for the diagnosis of multiple sclerosis (MS), cerebrospinal fluid analysis (CSF) remains discussed. There are robust evidences which demonstrated that an early diagnosis of MS must be done, due to the availability of disease-modifying drugs that could influence the natural history of the disease. However, several arguments can be put forward to assert that CSF analysis is not useful for the diagnosis of MS and thus should not be realized in a systematic way. First, MRI remains the most sensitive and specific marker to validate dissemination in space and in time and CSF analysis is not recommended by the 2010 McDonald criteria. The second argument is related to the low sensitivity and specificity of abnormalities detected in CSF analysis to confirm the diagnosis of MS. Moreover, there is currently no evidence that the presence of oligoclonal bands could represent a surrogate marker on an individual prognostic way. Furthermore, lumbar puncture could be traumatic, may entail some infrequent risks and represents unnecessary expense. Thus, there are strong reasons to not recommend systematic CSF examination to diagnose MS.

[Pituitary metastasis revealing a lung cancer]

INTRODUCTION

Pituitary metastases are rare and difficult to diagnose. Their optimal approach and management remains to be defined.

CASE REPORT

We report the case of a 56-year-old patient suffering from squamous cell lung carcinoma who developed pituitary metastasis with secondary hypopituitarism, the symptoms of which were initially attributed to depression.

CONCLUSION

Pituitary metastases can be difficult to diagnose, which may lead to delays in care, which can be fatal.

Conversion from clinically isolated syndrome to multiple sclerosis: A large multicentre study

Background and objective:

We explored which clinical and biochemical variables predict conversion from clinically isolated syndrome (CIS) to clinically definite multiple sclerosis (CDMS) in a large international cohort.

Methods:

Thirty-three centres provided serum samples from 1047 CIS cases with at least two years’ follow-up. Age, sex, clinical presentation, T2-hyperintense lesions, cerebrospinal fluid (CSF) oligoclonal bands (OCBs), CSF IgG index, CSF cell count, serum 25-hydroxyvitamin D3 (25-OH-D), cotinine and IgG titres against Epstein-Barr nuclear antigen 1 (EBNA-1) and cytomegalovirus were tested for association with risk of CDMS.

Results:

At median follow-up of 4.31 years, 623 CIS cases converted to CDMS. Predictors of conversion in multivariable analyses were OCB (HR = 2.18, 95% CI = 1.71–2.77, p < 0.001), number of T2 lesions (two to nine lesions vs 0/1 lesions: HR = 1.97, 95% CI = 1.52–2.55, p < 0.001; >9 lesions vs 0/1 lesions: HR = 2.74, 95% CI = 2.04–3.68, p < 0.001) and age at CIS (HR per year inversely increase = 0.98, 95% CI = 0.98–0.99, p < 0.001). Lower 25-OH-D levels were associated with CDMS in univariable analysis, but this was attenuated in the multivariable model. OCB positivity was associated with higher EBNA-1 IgG titres.

Conclusions:

We validated MRI lesion load, OCB and age at CIS as the strongest independent predictors of conversion to CDMS in this multicentre setting. A role for vitamin D is suggested but requires further investigation.