O-005 Reducing inter-observer and intra-observer variability of embryo quality assessment using deep learning

Study question

Does deep learning for embryo quality assessment reduce inter-observer variability?

Summary answer

An AUC of 87.65% was obtained for predicting blastocyst quality with a deep-learning algorithm trained by five embryologists who had good agreement between themselves

What is known already

Time-Lapse (TL) allows continuous observation of embryo development in a controlled and stable environment. Recently the use of deep learning, in particular convolutional neural networks have been introduced to enhance blastocyst image classification using the growing TL image and video data.

Study design, size, duration

A total of 409 embryos (5 images per embryo for a total of 2 045 images) were included in this retrospective study between 2016 and 2020.

Participants/materials, setting, methods

A machine-learning algorithm (Retinanet) was trained to recognize 2 045 blastocyst images from 409 embryos on 2560x1928 images and output 500x500 images with the blastocyst centered on the image. Five embryologists classified the blastocysts using Gardner’s grading system. Each image was associated with one final grade using a majority voting system. The dataset was split into a training and validation set (1 640 images plus data augmentation) and a testing set (405 images).

Main results and the role of chance

Fair agreement was found between the 5 embryologists when grading the embryo using Gardner’s grading system, with a maximum weighted kappa score of 39.60% reached.

As for the intra-observer variability, we show that for the same embryologist grading the same embryo after a 3 month “wash out” period, in 12% of the cases the embryologist changes the grade and the fate of the embryo, meaning that an embryo that was transferred/frozen during the first annotation period was discarded during the second one, or an embryo that was discarded during the first annotation period was transferred/frozen during the second one.

An Area Under the Curve (AUC) of 87.65% was obtained when testing the quality of 81 embryos (405 images) after training our algorithm on 54 038 images.

For external validation we tested the algorithm with annotations of the test set from embryologists coming from another fertility center. An AUC of 82.72% was obtained.

Limitations, reasons for caution

The scarce number of images available in our training set compared with data sets from other more consequent clinics, and the fact that the algorithm was trained by embryologists does not suppress variability entirely. The GoogLeNet algorithm was not fined tune and was used as is.

Wider implications of the findings

AI is showing precious value the field of embryology, from enhancing blastocyst quality prediction to removing inter-observer subjectivity. A possible evolution to our framework would be to predict the Gardner’s grading system for each morphological parameter.

Trial registration number

not applicable

Insight into the structure-elastic property relationship of calcium silicate glasses: a multi-length scale approach

Based on a combination of molecular dynamics simulations, and Raman and Brillouin light scattering spectroscopies, we investigate the structure and elastic properties relationship in an archetypical calcium silicate glass system. From molecular dynamics and Raman spectroscopy, we show that the atomic structure at the short and intermediate length scales is made up of long polymerized silicate chains, which adjusts itself by closing the Si-O-Si angles and leaving more space to [CaO]_n edge shared polyhedra to strengthen the glass. Using Brillouin spectroscopy, we observe an increase of elastic constants of the glass with the calcium content, as the cohesion of the glass structure is enhanced through an increase of the binding between the cross-linked calcium-silicate frameworks. This result, albeit being simple in its nature, illustrates for the first time the implication of the calcium framework in the elastic behavior of the glass and will contribute substantially to the understanding of the composition-structure-property relationships in multi-component industrial glasses.

P–793 Validation of French in vitro fertilization (IVF) guideline during Covid–19 pandemic by the research of Sars-Cov–2 RNA in the follicular fluid (FF) after egg retrieval

Study question

Is it possible to find viral Sars-Cov–2 RNA in FF of women undergoing treatment during Covid–19 pandemic that may compromise gamete and embryo safety?

Summary answer

No viral RNA was detected in tested FF of women undergoing IVF in compliance with recommendations. This was reassuring and supported good medical practice.

What is known already

Risks due to SARS-CoV–2 during IVF remain difficult to assess despite the screening recommended by French health authorities based on a symptom questionnaire of the couple (systematic testing by RT-PCR for the virus before egg retrieval (ER) is not mandatory). In this context, this is a real challenge for IVF laboratory to guarantee procedure, patients, gametes and embryos safety. Most studies have reported the absence of virus in sperm. No data are available for FF and only one study looked for the presence of the virus in oocytes of Covid-affected patients (Barragan M et al, 2020).

Study design, size, duration

Between June 17 and September 24, 2020, FF of consenting women were prospectively collected and symptom questionnaire recorded. During this period, women undergoing IVF in our center did not benefit from systematic PCR testing for the virus within 72 hours prior to ER through our health authorities’ recommendations. All collected FF were retrospectively tested to research viral RNA by RT-PCR and patients were recalled to answer an epidemiological follow-up questionnaire.

Participants/materials, setting, methods

For all couples, symptom questionnaires were prospectively recorded and verified at each step of IVF procedure. For all consenting women, a sample of 1 ml of FF was collected the day of ER and stored at –80 °C. After thawing, a Sars-Cov2 multiplex RT-PCR using CFX96 (Biorad*) was performed, after RNA extraction using Nimbus (Seegene*). A comprehensive epidemiological evaluation was made afterwards by phone interview and data were recorded and analyzed.

Main results and the role of chance

A total of 183 women was included out of the 214 treated during this period (85.5%). Retrospective epidemiological evaluation showed that 8 patients contracted Covid more than 2 months before the ER, 6 more than 2 months after and only one patient 1 month after ER (diagnosis based on pathognomonic signs as agueusia and anosmia or/and positive PCR ). We observed a prevalence of symptomatic Covid forms in our IVF population of 8.2% during a 6-month period surrounding their IVF cycle. Moreover, until the introduction of systematic testing by RT-PCR for the virus before ER since the end of September 2020, 3 patients have been cancelled out of the 403 planned for positive PCR despite a negative questionnaire, which represents a prevalence of asymptomatic forms on the day of the ER at 0.7%. All the 183 FF tested did not reveal any viral RNA detection, which was reassuring concerning our medical practice and patient compliance and transparency. The absence of detected viral RNA may be due to several reasons: 1) women were not infected the day of ER 2) women had an asymptomatic form of the disease with low viral load 3) FF is not a virus reservoir.

Limitations, reasons for caution

Not all patients were included (85.5%). Post-diagnosis stays uncertain because PCR tests at the beginning of the epidemic were not mandatory and hardly available.

Wider implications of the findings: The absence of viral RNA in FF of women only screened through a symptom questionnaire is reassuring concerning the safety of IVF during Covid pandemic.

Trial registration number

Not applicable

Structural properties of oil/water microemulsion with surface grafted PEO polymers

In this study, we investigated the structural properties of oil/water microemulsions with surface grafted polymers. In particular, we determined the effect of the addition of two kinds of hydrophobically modified polymers, PEO-m with one hydrophobic end and PEO-2m with two hydrophobic extremities. We used Molecular Dynamics simulations with the appropriate interaction potential that considers the VDW interactions, the electrostatic interactions, and the interaction induced by the polymers. Our results showed that the PEO-m introduces a steric repulsive interaction between the microemulsions in the diluted and concentrated systems, respectively, Φ=2.8% and Φ=14%. Thus, PEO-m favorises the stability and dispersion of the microemulsions. Besides, the PEO-2m introduces an attractive interaction between the droplets in the diluted case. Both PEO-2m and PEO-m strengthen the repulsive potential between the microemulsions in the concentrated case.

Probing the balance of Telechelic Polymers Bridging and Screened-Coulomb Interactions in Microemulsion System

The structural properties of neutral oil-in-water (O/W) microemulsions nanodroplets in the presence of telechelic polymers PEO modified with two hydrophobic end functions (PEO- 2m) were studied by Small-Angle Neutron Scattering (SANS). We show that the unknown attractive interaction introduced by the addition of PEO-2m, can could be balanced by a known repulsion interaction due to the addition of a cationic surfactant Cp +, which causes a progressive transformation of the bridges connecting the nanodroplets into loops. For this, we compute the structure factor S(q) with an effective pair potential, using the Ornstein Zernicke (OZ) integral equation approach with the Hypernetted Chain (HNC) closure relation. Generally, the agreement between the neutron scattering spectra and the numerical study is reasonable and allows a detailed description for each sample.

SHIRPA as a Neurological Screening Battery in Mice

The SmithKline, Harwell, Imperial College, Royal Hospital, Phenotype Assessment (SHIRPA) is a rapid battery of tests comprising 42 measurements of motor activity, coordination, postural control, muscle tone, autonomic functions, and emotional reactivity, as well as reflexes dependent on visual, auditory, and tactile modalities. Individual scores in SHIRPA are sensitive in detecting phenotypes of several experimental models of neural disease, especially cerebellar degeneration and Alzheimer disease, and combined subscores have been useful in estimating the impact of vascular anomalies and exposure to infectious agents. In cerebellar degeneration, weak forelimb grip, impaired wire maneuver and air righting, and negative geotaxis appear as prevalent features. Most of the measures in the battery are susceptible to change after gene modifications or physiological alterations. SHIRPA can be used both in adult mice and mice in the preweaning period to screen for sensorimotor function and emotional reactivity, not selective attention or memory. © 2021 Wiley Periodicals LLC Basic Protocol: Step-by-step procedure for SHIRPA.

Effect of hydrophobically modified PEO polymers (PEO-dodecyl) on oil/water microemulsion properties: in vitro and in silico investigations

Microemulsions are excellent systems for transdermal delivery of multifunctional drugs because they have the potential to improve drug absorption/permeation and handling limitations. Biocompatible polymers are used as a coating of microemulsions to avoid the interactions that can occur between the microemulsions and the skin. Thus, they protect and lubricate these transporter nanovesicles. In this paper, we studied decane/water microemulsions covered with hydrophobically modified PEO polymer (PEO-m). To reveal the effect of hydrophobically modified PEO (PEO-m) polymer on the shape, the micro-arrangement and the dynamics of the microemulsions, we used an integrated strategy combining Molecular Dynamics simulation (MD), Small-Angle Neutron Scattering experiments (SANS), and the Ornstein-Zernike integral equations with the Hypernetted Chain (HNC) closure relation. We determined the microemulsion shape in vitro using the renormalized intensities spectra from SANS experiments. We discussed the micro arrangements of microemulsions, in vitro and in silico, employing the pair correlation function g(r) and the structure factor S(q), obtained from the three approaches with good agreement. Thus, we used the validated MD simulations to calculate the microemulsion's dynamics properties that we discussed using the mean-squared displacement (MSD) and the diffusion coefficients. We found that the presence of moderate quantities of PEO-m, from 4 to 12 PEO-m per microemulsion, does not influence the microemulsion shape, increases the stability of the microemulsion, and slightly decrease the dynamics. Our in vitro and in silico results suggest that polymer incorporation, which has interesting in vivo implications, has no disadvantageous effects on the microemulsion properties.

Correction: Effect of hydrophobically modified PEO polymers (PEO-dodecyl) on oil/water microemulsion properties: in vitro and in silico investigations

Correction for ‘Effect of hydrophobically modified PEO polymers (PEO-dodecyl) on oil/water microemulsion properties: in vitro and in silico investigations’ by M. Khatouri et al., RSC Adv., 2021, 11, 7059–7069, DOI: 10.1039/D0RA09804C.

Sol/gel transition of oil/water microemulsions controlled by surface grafted triblock copolymer dodecyl–PEO227–dodecyl: molecular dynamics simulations with experimentally validated interaction potential

We studied a large range of identical spherical oil/water microemulsion (O/W-MI) volume fractions. The O/W-MIs are stabilized by cetylpyridinium chloride ionic surfactant (CpCl) and octanol cosurfactant and dispersed in salt water. We grafted different numbers of dodecyl–(polyEthylene oxide)₂₂₇–dodecyl triblock copolymer that we note (n(D–PEO₂₂₇–D)), where n varies from 0 to 12. We accomplished the grafting process by replacing a small amount of CpCl and octanol with the appropriate n(D–PEO₂₂₇–D). The aim is to determine the interaction/structure relationship of the covered microemulsions. Precisely, we are interested in a quantitative investigation of the influence of volume fraction Φ, temperature (T), and n(D–PEO₂₂₇–D) on the microemulsion sol/gel transition. To this end, we first study the uncoated microemulsion structure depending only on Φ. Second, we determine the coated microemulsions structure as a function of n(D–PEO₂₂₇–D) for different Φ. Third, we examine the effect of temperature on the uncoated and coated microemulsion. We show that the sol/gel transition is controlled by the three main parameters, Φ, T, and n(D–PEO₂₂₇–D). Accordingly, the uncoated microemulsion sol/gel transition, at ambient temperature, occurred for Φ ≃ 33.65%. By increasing Φ, the O/W-MIs show a glass state, which occurs, along with the gel state, at Φ ≃ 37% and arises clearly at Φ ≃ 60%. The coated O/W-MI sol/gel transition is found to be linearly dependent on n(D–PEO₂₂₇–D) and takes place for Φ ≃ 26.5% for n(D–PEO₂₂₇–D) = 12. Ordinarily, the decrease in temperature leads to gel formation of microemulsions for low Φ. Additionally, in this work, we found that the gelation temperature increases linearly with n(D–PEO₂₂₇–D). Thus, the parameter n(D–PEO₂₂₇–D) can control the sol/gel transition of the O/W-MIs at ambient temperature and moderate Φ.

We studied the sol/gel transition of oil/water microemulsion (O/W-MI) covered with dodecyl–(polyEthylene oxide)₂₂₇–dodecyl triblock copolymer.

Static and dynamic properties of decane/water microemulsions stabilized by cetylpyridinium chloride cationic surfactant and octanol cosurfactant

Molecular dynamics simulation (MD) is used to study the static and dynamic properties of positively charged decane/water microemulsions, for various volume fractions Φ (2.8%, 6.98%, 14%, and 26.5%). An effective hybrid potential combining three potentials, namely the hard-sphere repulsive potential, the van der Waals attractive potential, and the Yukawa repulsive potential, is used to describe the microemulsion interactions. The microemulsion shape is determined using the renormalized spectra in Porod representation. The appropriate potential parameters are tested using the Ornstein–Zernike integral equation approach with the Hypernetted Chain (HNC) closure relation by a comparison between the structure factor calculated from HNC and that obtained from Small Angle Neutron Scattering experiments (SANS). Thus, the micro arrangements of microemulsions have been analyzed using the pair correlation function g(r) and the structure factor S(q) obtained from HNC, SANS, and MD simulation using these parameters. The microemulsion dynamic properties were discussed using the mean-square displacement (MSD) and the diffusion coefficient D_c calculated from MD simulations.

We report a molecular dynamics simulation using a proven effective interaction potential to study the physical properties of decane/water microemulsions.

Human centered AI design for clinical monitoring and data management

Background

In clinical settings, significant resources are spent on data collection and monitoring patients' health parameters to improve decision-making and provide better care. With increased digitization, the healthcare sector is shifting towards implementing digital technologies for data management and in administration. New technologies offer better treatment opportunities and streamline clinical workflow, but the complexity can cause ineffectiveness, frustration, and errors. To address this, we believe digital solutions alone are not sufficient. Therefore, we take a human-centred design approach for AI development, and apply systems engineering methods to identify system leverage points. We demonstrate how automation enables monitoring clinical parameters, using existing non-intrusive sensor technology, resulting in more resources toward patient care. Furthermore, we provide a framework on digitization of clinical data for integration with data management.

Methods

Activities of Daily Living (ADLs) are essential parameters, necessary for evaluating patients in mental health wards. Ideally logging the parameters should take place at hourly intervals; however, time constraints and lack of resources restrict the nursing staff to consolidating the overall impression during the day, relying on what they recall. Using design methods, sensors (e.g. infrared, proximity, pressure) are used to automate the acquisition of data for machine learning that correspond to the ADLs, considering privacy and other medical requirements.

Results

We present a concept of a room with sensors that can be deployed in clinical settings. Sensor data log ADLs, and provide machine learning data. A theoretical framework demonstrates how collected data can be used in electronic/medical health records.

Conclusions

Data acquisition of the ADLs with automation enable variable specificity and sensitivity on-demand. It further facilitates interoperability and provides data for machine learning.

Key messages

Our research demonstrates automated data acquisition techniques for clinical monitoring. Human centered AI design approach enables on-demand analysis of ADLs for mental health treatment.

HIV self-testing in adolescents living in Sub-Saharan Africa

Less than 20% of African adolescents aged 10-19 years are aware of their HIV status, whereas HIV screening remains the gateway to care and while AIDS has become the leading cause of death among adolescents in Sub-Saharan Africa. According to the UNAIDS target, scalable HIV testing strategies specific to various age groups, populations, and geographical areas must be implemented to end the AIDS epidemic by 2030. Many African countries have implemented policies supporting HIV self-testing (HIVST). Evidence of practicability and efficiency of HIVST in Sub-Saharan Africa settings has been reported, including HIVST data among adolescents. Adapted strategies of HIVST are urgently needed to promote HIV testing among adolescents living in sub-Saharan Africa.

Tissue-Plasminogen Activator Attenuates Alzheimer's Disease-Related Pathology Development in APPswe/PS1 Mice

Alzheimer's disease (AD) is the leading cause of dementia among elderly population. AD is characterized by the accumulation of beta-amyloid (Aβ) peptides, which aggregate over time to form amyloid plaques in the brain. Reducing soluble Aβ levels and consequently amyloid plaques constitute an attractive therapeutic avenue to, at least, stabilize AD pathogenesis. The brain possesses several mechanisms involved in controlling cerebral Aβ levels, among which are the tissue-plasminogen activator (t-PA)/plasmin system and microglia. However, these mechanisms are impaired and ineffective in AD. Here we show that the systemic chronic administration of recombinant t-PA (Activase rt-PA) attenuates AD-related pathology in APPswe/PS1 transgenic mice by reducing cerebral Aβ levels and improving the cognitive function of treated mice. Interestingly, these effects do not appear to be mediated by rt-PA-induced plasmin and matrix metalloproteinases 2/9 activation. We observed that rt-PA essentially mediated a slight transient increase in the frequency of patrolling monocytes in the circulation and stimulated microglia in the brain to adopt a neuroprotective phenotype, both of which contribute to Aβ elimination. Our study unraveled a new role of rt-PA in maintaining the phagocytic capacity of microglia without exacerbating the inflammatory response and therefore might constitute an interesting approach to stimulate the key populations of cells involved in Aβ clearance from the brain.

Effect of charge polydispersity and charge residence time on the dynamics of a micellar system

We use dynamic light scattering to investigate the effects of charge polydispersity and charge residence time on the dynamics of a micellar system. While in the corresponding uncharged system only one exponential relaxation is observed, two relaxation modes are seen when charging the micelles by adding charged co-surfactant molecules with a long residence time. We attribute the existence of these two relaxation modes to the combined effect of size polydispersity and charge polydispersity, i.e. frozen fluctuations of the number of charges per micelle. Further support to this scenario is provided by control experiments on a similar charged system, but where the charge residence time is short compared to the time scales probed by dynamic light scattering. Here, charge polydispersity is effectively suppressed due to the rapid exchange of charged molecules between micelles and only one single relaxation mode is seen, thereby demonstrating the key role of frozen charge fluctuations in the complex dynamics of our micellar system.

Sensorimotor skills in Fxn KO/Mck mutants deficient for frataxin in muscle

Friedreich ataxia is the most common autosomal recessive disorder of the cerebellum, causing degeneration of spinal sensory neurons and spinocerebellar tracts. The disease is caused by severely reduced levels of frataxin, a mitochondrial protein involved in iron metabolism. An experimental model has been generated by crossing mice homozygous for a conditional allele of the Fxn gene with mice heterozygous for a deleted exon 4 of Fxn carrying a tissue-specific Cre transgene under control of the muscle creatine kinase promoter. Relative to wild-type, Fxn null mutants were impaired on tests of motor coordination comprising horizontal bar, vertical pole, and the rotorod as well as displaying gait anomalies and the hindlimb clasping response. The Fxn KO/Mck model reproduces some key features of patients with Friedreich ataxia and provides an opportunity of ameliorating their symptoms with experimental therapies.

GPR84 deficiency reduces microgliosis, but accelerates dendritic degeneration and cognitive decline in a mouse model of Alzheimer's disease

Microglia surrounds the amyloid plaques that form in the brains of patients with Alzheimer's disease (AD), but their role is controversial. Under inflammatory conditions, these cells can express GPR84, an orphan receptor whose pathophysiological role is unknown. Here, we report that GPR84 is upregulated in microglia of APP/PS1 transgenic mice, a model of AD. Without GPR84, these mice display both accelerated cognitive decline and a reduced number of microglia, especially in areas surrounding plaques. The lack of GPR84 affects neither plaque formation nor hippocampal neurogenesis, but promotes dendritic degeneration. Furthermore, GPR84 does not influence the clinical progression of other diseases in which its expression has been reported, i.e., experimental autoimmune encephalomyelitis (EAE) and endotoxic shock. We conclude that GPR84 plays a beneficial role in amyloid pathology by acting as a sensor for a yet unknown ligand that promotes microglia recruitment, a response affecting dendritic degeneration and required to prevent further cognitive decline.

Motor activity in young APPswe + PS1/A246E bigenic mice as a predicting variable for memory decline

Reports of individuality in rodent species have been a subject of debate in pharmacology and other fields. In the current study, APPswe  + PS1/A246E bigenic mice with Alzheimer's-like pathogenesis and wild-type controls were subdivided at 3 months of age into low, intermediate, and high responders in open-field activity. The mice were then evaluated longitudinally at 3 and 9 months for object recognition. Irrespective of genotype, mice with a high level of motor activity had better scores in object recognition. However, a significant correlation was established between open-field activity measured at 3 months of age and recognition memory measured at 9 months of age in the bigenic group only. These results indicate that motor activity in young mice with amyloid neuropathology may serve as a predicting variable for cognitive dysfunction in more mature mice.

Interactions between microemulsion droplets decorated with hydrophobically modified polymers: a small-angle neutron scattering study

The shape and interactions between microemulsion droplets (R = 8.2 nm, polydispersity 20%) either decorated with PEO modified with a single hydrophobic end function (PEO-m: C12H25 - (EO)n, M(PEO) = 5.2 kg/mol), or with telechelic polymers of twice the mass (PEO-2m: C12H25 - (EO)2n - C12H25, M(PEO) = 10.4 kg/mol) have been studied by small-angle neutron scattering (SANS). The results as a function of droplet and polymer concentration have been compared to the reference case of the bare microemulsion which was shown to be unchanged using Porod representations. The interactions between bare and decorated droplets have been analyzed using the structure factor S(q), at first in a model-free way based on its low-q limit S(q → 0). This analysis provides clear evidence on the concentration-dependent repulsive or attractive nature of the contributions to the pair droplet-droplet pair potential of the polymers. Model pair potentials describing the steric repulsions and attractions by copolymer bridging are used to describe the low-q behavior of the structure factor based on an integral equation approach, giving an estimate of the range and amplitude of the potentials. Moreover, they provide an explanation for the observed transient clustering in terms of a shallow minimum of the total potential, as they establish the respective repulsive and attractive contributions of the polymer molecules.

Protein phosphatase 2A family members (PP2A and PP6) associate with U1 snRNP and the spliceosome during pre-mRNA splicing

Protein phosphorylation and dephosphorylation are both important for multiple steps in the splicing pathway. Members of the PP1 and PP2A subfamilies of phospho-serine/threonine phosphatases play essential but redundant roles in the second step of the splicing reaction. PP6, a member of the PP2A subfamily, is the mammalian homolog of yeast Sit4p and ppe1, which are involved in cell cycle regulation; however, the involvement of PP6 in the splicing pathway remains unclear. Here we show that PP2A family members physically associate with the spliceosome throughout the splicing reaction. PP2A holoenzyme and PP6 were found stably associated with U1 snRNP. Together our findings indicate that these phosphatases regulate splicing catalysis involving U1 snRNP and suggest an important evolutionary conserved role of PP2A family phosphatases in pre-mRNA splicing.

Therapeutic and preventive effects of methylene blue on Alzheimer's disease pathology in a transgenic mouse model

Methylene blue (MB) belongs to the phenothiazinium family. It has been used to treat a variety of human conditions and has beneficial effects on the central nervous system in rodents with and without brain alteration. The present study was designed to test whether chronic MB treatment taken after (therapeutic effect) or before (preventive effect) the onset of beta-amyloid pathology influences cognition in a transgenic mouse model (APP/PS1). In addition, the present study aims at revealing whether these behavioral effects might be related to brain alteration in beta-amyloid deposition. To this end, we conducted an in vivo study and compared two routes of drug administration, drinking water versus intraperitoneal injection. Results showed that transgenic mice treated with MB orally or following intraperitoneal injection were protected from cognitive impairments in a variety of social, learning, and exploratory tasks. Immunoreactive beta-amyloid deposition was significantly reduced in the hippocampus and adjacent cortex in MB-treated transgenic mice. Interestingly, these beneficial effects were observed independently of beta-amyloid load at the time of MB treatment. This suggests that MB treatment is beneficial at both therapeutic and preventive levels. Using solid-state High Resolution Magic Angle Spinning Nuclear Magnetic Resonance (HRMAS-NMR), we showed that MB administration after the onset of amyloid pathology significantly restored the concentration of two metabolites related to mitochondrial metabolism, namely alanine and lactate. We conclude that MB might be useful for the therapy and prevention of Alzheimer's disease. This article is part of the Special Issue entitled 'The Synaptic Basis of Neurodegenerative Disorders'.

MyD88 deficiency results in both cognitive and motor impairments in mice

The myeloid differentiation primary response gene 88 (MyD88) product is the most common adaptor protein implicated in Toll-like and interleukin receptor (TIR) domain signaling and thus plays an important role in the innate immune system. Despite the fact that the MyD88-dependent pathway has emerged as an important player in cell death processes described in several animal models of neurodegenerative disorders, the contribution of this pathway to specific behavioral phenotypes has been largely ignored. To understand the full implication of this pathway, we tested MyD88(-/-) mice for both motor and cognitive functions in normal conditions. MyD88(-/-) mice displayed impaired spatial and working memory as detected by the Barnes maze, the water T-maze and the passive avoidance tests. Furthermore, MyD88(-/-) mice demonstrated hypolocomotion in the open-field and wheel activity systems, as well as impairments in motor coordination and balance using the pole test and the rotarod. Our findings shed light on behavioral alterations that are associated with the deletion of the MyD88 protein in physiological conditions. These behavioral effects should be taken into consideration when assessing the role of the MyD88-dependent pathway in various infectious and non-infectious conditions.

Cognitive and non-cognitive behaviors in the triple transgenic mouse model of Alzheimer's disease expressing mutated APP, PS1, and Mapt (3xTg-AD)

3xTg-AD mutant mice are characterized by parenchymal Aβ plaques and neurofibrillary tangles resembling those found in patients with Alzheimer's disease. The mutants were compared with non-transgenic controls in sensorimotor and learning tests. 3xTg-AD mutants were deficient in T-maze reversal, object recognition, and passive avoidance learning. In addition, the mutants showed hypoactivity in two open-field tests, fewer fecal boli in an observation jar, and reduced enclosed arm entries and head-dipping in the elevated plus-maze. On the contrary, the mutants did not differ from controls in pain thresholds, nest-building, and various reflexes determined by the SHIRPA primary screen and were even better on the rotorod test of motor coordination.

Anomalies in social behaviors and exploratory activities in an APPswe/PS1 mouse model of Alzheimer's disease

Alzheimer's disease is characterized by deficits in social communication, associated with generalized apathy or agitation, as well as social memory. To assess social behaviors in 6-month-old male APPswe/PS1 bigenics relative to non-transgenic controls, the 3-chamber test was used, together with open-field and elevated plus-maze tests of exploration. APPswe/PS1 mice were less willing to engage in social interaction than wild-type, avoiding an unfamiliar stimulus mouse, probably not due to generalized apathy because in both tests of exploratory activity the mutants were hyperactive. This study reveals reduced "sociability" combined with hyperactivity in an APPswe/PS1 mouse model of Alzheimer dementia.

Sensorimotor and cognitive function of a NEFL(P22S) mutant model of Charcot-Marie-Tooth disease type 2E

Charcot-Marie-Tooth (CMT) disease is the most frequently encountered hereditary disease causing sensorimotor neuropathies and slowly progressive muscle weakness and atrophy. The P22S mutation of the NEFL gene encoding the light polypeptide neurofilament (NFL) is associated with CMT. To understand more clearly the pathogenesis of sensorimotor dysfunction in CMT, we generated transgenic mice with the NEFL(P22S) mutation under the tet-off tetracycline regulated system with involvement of the Thy1 neuron-specific promoter. NEFL(P22S) transgenic mice exhibited extended duration of the hindlimb clasping response and gait anomalies, as well as sensorimotor deficits in stationary beam and suspended bar tests. In addition, the NEFL(P22S) mice were deficient in the reversal phase of left-right discrimination learning in a water maze. This model mimics some aspects of human CMT pathology and provides an opportunity of ameliorating CMT symptoms with experimental therapies.

A critical role for chloride channel-3 (CIC-3) in smooth muscle cell activation and neointima formation

OBJECTIVE

We have shown that the chloride-proton antiporter chloride channel-3 (ClC-3) is required for endosome-dependent signaling by the Nox1 NADPH oxidase in SMCs. In this study, we tested the hypothesis that ClC-3 is necessary for proliferation of smooth muscle cells (SMCs) and contributes to neointimal hyperplasia following vascular injury.

METHODS AND RESULTS

Studies were performed in SMCs isolated from the aorta of ClC-3-null and littermate control (wild-type [WT]) mice. Thrombin and tumor necrosis factor-α (TNF-α) each caused activation of both mitogen activated protein kinase extracellular signal-regulated kinases 1 and 2 and the matrix-degrading enzyme matrix metalloproteinase-9 and cell proliferation of WT SMCs. Whereas responses to thrombin were preserved in ClC-3-null SMCs, the responses to TNF-α were markedly impaired. These defects normalized following gene transfer of ClC-3. Carotid injury increased vascular ClC-3 expression, and compared with WT mice, ClC-3-null mice exhibited a reduction in neointimal area of the carotid artery 28 days after injury.

CONCLUSIONS

ClC-3 is necessary for the activation of SMCs by TNF-α but not thrombin. Deficiency of ClC-3 markedly reduces neointimal hyperplasia following vascular injury. In view of our previous findings, this observation is consistent with a role for ClC-3 in endosomal Nox1-dependent signaling. These findings identify ClC-3 as a novel target for the prevention of inflammatory and proliferative vascular diseases.

Reversal of neuropathy phenotypes in conditional mouse model of Charcot-Marie-Tooth disease type 2E

Mutations in the gene encoding for the neurofilament light subunit (NF-L) are responsible for Charcot-Marie-Tooth (CMT) neuropathy type 2E. To address whether CMT2E disease is potentially reversible, we generated a mouse model with conditional doxycycline-responsive gene system that allows repression of mutant hNF-LP22S transgene expression in adult neurons. The hNF-LP22S;tTa transgenic (tg) mice recapitulated key features of CMT2E disease, including aberrant hindlimb posture, motor deficits, hypertrophy of muscle fibres and loss of muscle innervation without neuronal loss. Remarkably, a 3-month treatment of hNF-LP22S;tTa mice with doxycycline after onset of disease efficiently down-regulated expression of hNF-LP22S and it caused reversal of CMT neurological phenotypes with restoration of muscle innervation and of neurofilament protein distribution along the sciatic nerve. These data suggest that therapeutic approaches aimed at abolishing expression or neutralizing hNF-L mutants might not only halt the progress of CMT2E disease, but also revert the disabilities.

Powerful beneficial effects of macrophage colony-stimulating factor on beta-amyloid deposition and cognitive impairment in Alzheimer's disease

Alzheimer's disease is a major cause of dementia in humans. The appearance of cognitive decline is linked to the overproduction of a short peptide called beta-amyloid (Abeta) in both soluble and aggregate forms. Here, we show that injecting macrophage colony-stimulating factor (M-CSF) to Swedish beta-amyloid precursor protein (APP(Swe))/PS1 transgenic mice, a well-documented model for Alzheimer's disease, on a weekly basis prior to the appearance of learning and memory deficits prevented cognitive loss. M-CSF also increased the number of microglia in the parenchyma and decreased the number of Abeta deposits. Senile plaques were smaller and less dense in the brain of M-CSF-treated mice compared to littermate controls treated with vehicle solution. Interestingly, a higher ratio of microglia internalized Abeta in the brain of M-CSF-treated animals and the phagocytosed peptides were located in the late endosomes and lysosomes. Less Abeta(40) and Abeta(42) monomers were also detected in the extracellular protein enriched fractions of M-CSF-treated transgenic mice when compared with vehicle controls. Finally, treating APP(Swe)/PS1 mice that were already demonstrating installed Abeta pathology stabilized the cognitive decline. Together these results provide compelling evidence that systemic M-CSF administration is a powerful treatment to stimulate bone marrow-derived microglia, degrade Abeta and prevent or improve the cognitive decline associated with Abeta burden in a mouse model of Alzheimer's disease.

Oocyte in-vitro maturation: BCL2 mRNA content in cumulus cells reflects oocyte competency

BCL2-associated X protein (BAX) and B-cell leukaemia/lymphoma gene-2 (BCL2), which are, respectively, pro- and anti-apoptotic proteins of the BCL2 gene family, participate in the mitochondria-dependent apoptosis pathway. A correlation between low incidence of apoptosis in cumulus cells and oocyte maturation has previously been suggested in ovarian stimulation. However, little is known in unprimed ovaries. These authors have investigated whether BAX and BCL2 expression in cumulus cells affects the competency of in-vitro matured oocytes. We have studied 100 cumulus-oocyte-complexes (COC) recovered from unprimed ovaries of 13 women diagnosed with polycystic ovary syndrome (PCOS) and undergoing in-vitro maturation (IVM) with their informed consent. COC were matured for 24 h in a specific maturation medium and the cumulus was stripped from the oocyte. BAX and BCL2 mRNA content was measured in each COC using real-time polymerase chain reaction. We found that BCL2 mRNA expression was significantly higher in cumulus cells associated with mature oocytes than those associated with immature oocytes while BAX mRNA concentrations did not vary in cumulus cells. Regarding fertilization, higher BCL2 mRNA content was found in cumulus cells enclosing fertilized oocytes (0.140 versus 0.075; P = 0.03). These results suggest that BCL2 expression is strongly associated with the ability of oocytes to complete nuclear maturation and to be fertilized.

Toll-like receptor signaling is critical for Wallerian degeneration and functional recovery after peripheral nerve injury

Toll-like receptors (TLRs) bind specific components conserved among microorganisms as well as endogenous ligands produced by necrotic cells, injured axons, and the extracellular matrix. Here, we investigated whether TLRs are involved in regulating the immune response, Wallerian degeneration (WD), and nerve regeneration after sciatic nerve lesion. Early expression of interleukin-1beta and monocyte chemoattractant protein-1 was compromised in the sciatic nerve distal stump of mice deficient in TLR signaling. In addition, significantly fewer macrophages were recruited and/or activated in the sciatic nerve distal stump of TLR2-, TLR4-, and MyD88-deficient mice compared with wild-type littermates, whereas WD, axonal regeneration, and recovery of locomotor function were impaired. In contrast, animals that received a single microinjection of TLR2 and TLR4 ligands at the site of sciatic nerve lesion had faster clearance of the degenerating myelin and recovered earlier than saline-injected control rats. Finally, rats that had altered innate immune response through dexamethasone treatment exhibited three times more myelin debris in their sciatic nerve distal stump and a significant delay in recovery of locomotor function. Our results provide strong evidence that TLR signaling plays a critical role in orchestrating the innate immune response leading to efficient and rapid clearance of inhibitory myelin debris and nerve regeneration.

Cytokine activation of nuclear factor kappa B in vascular smooth muscle cells requires signaling endosomes containing Nox1 and ClC-3

Reactive oxygen species (ROS) are mediators of intracellular signals for a myriad of normal and pathologic cellular events, including differentiation, hypertrophy, proliferation, and apoptosis. NADPH oxidases are important sources of ROS that are present in diverse tissues throughout the body and activate many redox-sensitive signal transduction and gene expression pathways. To avoid toxicity and provide specificity of signaling, ROS production and metabolism necessitate tight regulation that likely includes subcellular compartmentalization. However, the constituent elements of NADPH oxidase-dependent cell signaling are not known. To address this issue, we examined cytokine generation of ROS and subsequent activation of the transcription factor nuclear factor kappaB in vascular smooth muscle cells (SMCs). Tumor necrosis factor-alpha and interleukin (IL)-1beta stimulation of SMCs resulted in diphenylene iodonium-sensitive ROS production within intracellular vesicles. Nox1 and p22(phox), integral membrane subunits of NADPH oxidase, coimmunoprecipitated with early endosomal markers in SMCs. ClC-3, an anion transporter that is primarily found in intracellular vesicles, also colocalized with Nox1 in early endosomes and was necessary for tumor necrosis factor-alpha and interleukin-1beta generation of ROS. Cytokine activation of nuclear factor kappaB in SMCs required both Nox1 and ClC-3. We conclude that in response to tumor necrosis factor-alpha and interleukin-1beta, NADPH oxidase generates ROS within early endosomes and that Nox1 cannot produce sufficient ROS for cell signaling in the absence of ClC-3. These data best support a model whereby ClC-3 is required for charge neutralization of the electron flow generated by Nox1 across the membrane of signaling endosomes.

Lasting increases in basolateral amygdala activity after emotional arousal: implications for facilitated consolidation of emotional memories

Manipulations that reduce or enhance the activity of basolateral amygdala (BLA) neurons in the minutes to hours after training have been shown to respectively impair or facilitate retention on the inhibitory avoidance task. Although this suggests that BLA activity is altered after emotional arousal, such changes have not been directly demonstrated. To test this, we devised a feline analog of the inhibitory avoidance task and recorded BLA unit activity before and after a single inescapable footshock. Single-unit recordings revealed that the firing rate of many BLA neurons gradually increased after the footshock, peaking 30-50 min post-shock and then subsiding to baseline levels 2 h later. During this period of increased activity, the discharges of simultaneously recorded BLA cells were more synchronized than before the shock. Although it was known that pairing innocuous (conditioned stimulus, CS) and noxious stimuli modifies the responsiveness of BLA neurons to the CS, our results constitute the first demonstration that emotional arousal produces lasting increases in the spontaneous firing rates of BLA neurons. We propose that these changes in BLA activity may promote Hebbian interactions between coincident but spatially distributed activity patterns in BLA targets, facilitating the consolidation of emotional memories.

Characterization of Lef-1 promoter segments that facilitate inductive developmental expression in skin

Lymphoid Enhancer Factor 1 (Lef-1) is an important developmental transcription factor required for the inductive formation of several epithelial-derived organs including hair follicles. Inductive expression of Lef-1 mRNA is tightly regulated during embryo development, suggesting the involvement of a highly regulated promoter. In vitro analysis of the Lef-1 gene has demonstrated the existence of at least two spatially distinct promoters with multiple transcriptional start sites that are responsive to the canonical Wnt/beta-catenin pathway. Regions of the Lef-1 promoter required for inductive regulation in vivo, however, have yet to be determined. To this end, we utilized LacZ-reporter transgenic mice to define segments of the human Lef-1 promoter capable of reproducing mesenchymal- or epithelial-restricted transcriptional patterns of Lef-1 expression during hair and vibrissa follicle development. These studies have revealed that a 110 bp Wnt/beta-catenin-responsive element, contained within a minimal 2.5 kb Lef-1 promoter, plays an important role in regulating mesenchymal, and potentially epithelial, expression during follicle development in mouse embryos. This 2.5 kb Lef-1 promoter also demonstrated inductive mesenchymal expression during postnatal anagen stage hair-follicle cycling. Additionally, analysis of Lef-1 promoter expression revealed previously uncharacterized regions of endogenous Lef-1 expression seen in the sebaceous glands of vibrissa and hair follicles in transgenic lines harboring the minimal Lef-1 promoter and additional intronic sequences. In summary, these studies have begun to dissect the transcriptional diversity of the human Lef-1 promoter during the hair/vibrissa follicle and sebaceous gland formation.

Wnt-responsive element controls Lef-1 promoter expression during submucosal gland morphogenesis

Regulated expression of lymphoid enhancer factor 1 (Lef-1) plays an obligatory role in the transcriptional control of epithelial bud formation during airway submucosal gland and mammary gland development. However, regions of the Lef-1 promoter required for spatial and temporal regulation during glandular development have yet to be defined. We hypothesized that a previously reported 110-bp Wnt-responsive element (WRE) in the Lef-1 promoter, which can be induced by Wnt-3a/beta-catenin signals, may also play a role in regulating Lef-1 expression during airway and mammary gland development. Here we show that the Lef-1 promoter is also responsive to Wnt-1 signals in both airway and mammary epithelial cell lines. To better understand the importance of the WRE in dynamically regulating Lef-1 promoter activation in these two types of epithelia in vivo, we utilized LacZ reporter transgenic mice to evaluate the significance of Wnt-responsive sequences in the Lef-1 promoter during glandular bud formation. A 2.5-kb Lef-1 promoter fragment partially reproduced endogenous Lef-1 expression patterns in a subset of cell types involved in both mammary gland and submucosal glandular bud development. Interestingly, removal of the 110-bp WRE from the Lef-1 promoter ablated expression in nasal and tracheal submucosal glandular buds while having no significant effect on developmental expression in mammary glandular buds. These findings suggest that Wnt regulation of the Lef-1 promoter at the WRE may play an important role during airway submucosal glandular bud formation.

Stimulation-induced inhibition of neuronal firing in human subthalamic nucleus

The subthalamic nucleus (STN) is an important component of the basal ganglia (BG) and plays a major role in the pathogenesis of Parkinson's disease (PD). Hyperactivity of STN as a consequence of the loss of dopaminergic inputs to the BG is believed to be a major factor in producing the motor symptoms of PD. High-frequency (HF) deep brain stimulation (DBS) of the STN has recently become an important treatment in PD patients where medications no longer provide satisfactory therapy. However, the mechanisms underlying DBS therapy are unknown, and there is seemingly conflicting data suggesting inhibition or excitation of STN neurons. This study directly examined the effects of stimulation in STN on the activity of STN neurons in PD patients during functional stereotactic mapping prior to insertion of DBS electrodes. Electrical stimulation in STN was investigated in twelve PD patients by recording the neural activity of a cell in STN with one electrode while applying current pulses through a second electrode located about 600 microm away. Stimulation at high frequencies (100-300 Hz) was found to produce inhibition following the stimulus train in 42% of the 60 cells tested. Inhibition during the train was seen in 13 of 15 neurons where it was possible to detect such activity. Furthermore, in 44% of the cases where HF stimulation produced inhibition there was an early inhibition followed by rebound excitation and a further inhibitory period, suggesting that the inhibitions observed are due to hyperpolarization. In eight of the 25 neurons inhibited by HF stimulation, the effects of single stimuli were determined and revealed that in seven of these there was an inhibitory period of 15-20 ms following each stimulus. Thus, the present findings suggest that local HF stimulation inhibits many STN neurons. However, these studies could not determine whether the stimulus also directly excited the cell and/or its axon, but other recent findings suggest that this is likely the case. Therefore, the overall effects of DBS stimulation in STN are likely to be inhibition of intrinsic and synaptically mediated activity, and its replacement by regular high-frequency firing.