NIHRDataInsights/HRCSData huggingface dataset:
Title: Multi-parametric and super-resolution imaging of amyloidogenic proteins
Funder: Medical Research Council

Abstract: Amyloid proteins such as Abeta and tau are known to misfold and, eventually, to aggregate into insoluble deposits. Questions that remain unsolved include: What are the neurotoxic amyloid species? Can the misfolded state propagate from one cell to another and has this an impact on the neuropathology? Do extracellular chaperones impact on degradation or aggregation pathways of amyloid species? The applicant's group specialises in the development and application of advanced microscopy techniques for the functional study of protein self-assembly reactions in neurodegenerative disease. We will use these tools to address the following questions: - Abeta and tau aggregates are likely to be composed of ensembles of oligomers with different sizes and conformations and potentially differing neurotoxicity. We will use novel fluorescence-based sensors to: a) characterise the biophysical properties of these ensembles in live cells with a spatial resolution on the molecular scale; and b) correlate their biophysical properties with effects on neuropathology. - There is increasing evidence in the literature that intracellular Abeta plays an important role in disease. In addition, the propagation of tau pathology appears to be crucial in spreading the disease to non-affected brain areas. We aim to characterise the trafficking mechanisms responsible for amyloid proteins being taken up by cells and/or released in the extracellular space. - We will screen for different inhibitors of Abeta or tau mediated neuropathology. Firstly, we will investigate different inhibitors of amyloid proteins propagation. Secondly, we will test the potential of extracellular chaperones to interfere with amyloid protein degradation or aggregation.


Research activity codes: 2.1 BIOLOGICAL AND ENDOGENOUS FACTORS
Health categories: NEUROLOGICAL
Title: Imaging prognostic markers for surgical seizure control in medically intractable temporal lobe epilepsy
Funder: Medical Research Council

Abstract: The aim of this proposal is to identify the neuroanatomical factors that are associated with postsurgical epileptic seizures using high quality presurgical T1-weighted MRI and diffusion tensor imaging (DTI) in a large sample of people with temporal lobe epilepsy and hippocampal sclerosis, and to develop prognostic markers on the basis of these factors to predict postsurgical seizure control. Several hypotheses will be tested in patients who have undergone amygdalohippocampectomy, which are based on the concepts of (i) aberrant anatomy supporting epileptogenic activity that is not surgically resected, and which remains intact and functionally active postsurgically and (ii) distinct clinicopathological subtypes of patients with TLE. State-of-the-art MRI morphometric and DTI tractography techniques will be used that focus on the structure and connectivity of the affected and contralateral temporal lobes, extratemporal structures, and of the hippocampus deemed presurgically to be sclerotic. Standardised postsurgical outcome classification at one and three years will be used to compare brain structure, connections and networks between patients (i) rendered free from all seizures, (ii) rendered free from complex partial seizures but with continuation of simple partial seizures (i.e. reduced severity), and (iii) with no worthwhile postsurgical improvement. Comparison will also be made to brain structure, connections and networks in a large sample of healthy controls. Presurgical neuroimaging data will be combined with patient demographic, clinical and presurgical electrophysiological data to develop the most reliable predictors of postsurgical seizure outcome. In addition to the identification of neuroanatomical factors associated with poor postsurgical seizure control, the validity of a new hippocampal subfield mapping technique will be assessed in relation to quantitative histological assessment of resected specimens obtained from the same patients.


Research activity codes: 2.1 BIOLOGICAL AND ENDOGENOUS FACTORS;5.4 SURGERY
Health categories: NEUROLOGICAL
Title: Characterisation of a novel cell model for Huntington's disease: insights into pathogenesis
Funder: Medical Research Council

Abstract: Huntington's disease (HD) is a fatal, autosomal dominant inherited condition caused by a CAG repeat expansion in exon 1 of the gene encoding Huntingtin (Htt) protein. We aim to create a cell model of Huntington's disease using two different human neural stem cell (hNSC) lines and knocking the mutated exon 1 with various CAG repeat lengths (50, 80 and 120 repeats) into one of the Htt gene alleles to create heterozygous cell lines. This will be achieved using the rAAV vector, which triggers homologous recombination into the native gene locus, thus creating a model that is far more representative of the diseased cell. The two hNSC lines differentiate into dopaminergic and GABA-ergic neurons, a proportion of them specifically forming the medium spiny neurons which are preferentially destroyed in HD. We will then use this model to characterise the effect that the mutated gene has on the phenotype of the neurons. My hypothesis is that mutant HTT will cause CAG length dependent cellular dysfunction in MSNs. This will be tested using LDH and ATP assays, as well as the Cellomics fluorescence based cytotoxicity bioapplication. I will also use electrophysiology and quantitative PCR to assess synaptic function and transcriptional dysregulation, which are known problems in HD. The other hypothesis I wish to test is that wild type and mutant HTT have different cellular trafficking pathways, which impacts on cell function. This will be tested using immunofluorescence and confocal laser microscopy in conjunction with an existing panel of anti-HTT antibodies to different HTT epitopes. I will also use live cell imaging techniques to study the effect of mutant HTT on axonal transport.


Research activity codes: 1.1 NORMAL BIOLOGICAL DEVELOPMENT AND FUNCTIONING
Health categories: NEUROLOGICAL
Title: A gene therapy approach to childhood parkinsonism
Funder: Medical Research Council

Abstract: Dopamine transporter deficiency syndrome (DTDS) is a newly recognised autosomal recessive neurotransmitter disorder clinically characterised by progressive infantile parkinsonism dystonia. It is caused by loss-of-function mutations in the SLC6A3 gene that encodes for the dopamine transporter (DAT).This progressive condition does not respond to medical or surgical treatments leading to early death. Gene therapy is increasingly being considered as a realistic treatment option for human disorders including a number of successful clinical gene therapy trials. Indeed there has been a recent clinical gene therapy trial showing positive results in children with AADC deficiency. This is another devastating genetic neurotransmitter disorder lacking in medical treatment. This study demonstrated improvement in oculogyric crisis and motor abilities in all children treated and provides impetus to study potential gene therapy in DTDS. A proof of concept study would be required to describe expression of transgene delivery and restoration of DAT expression in the first instance. We aim to develop a gene therapy strategy in the knockout mouse model of DTDS. We hypothesise that by inserting human DAT through gene transfer to the DAT-KO mouse model will restore gene function and DAT expression and function. The key aims of the study are to: 1. Establish a DAT-KO mouse colony at UCL 2. Develop a safe and efficient vector for transgene delivery to the central nervous system in DAT- KO mouse model 3. Demonstrate efficacy through restoration or augmentation of DAT expression through locomotor phenotyping and tissue histological study. 4. Establish optimal time of administration of gene transfer 5. Establish optimal dosage and correlate dosage effects In the longer term this study would underpin future translation to clinical trials of gene therapy in DTDS. The expertise gained may also be applicable to other untreatable childhood neurological diseases.


Research activity codes: 1.1 NORMAL BIOLOGICAL DEVELOPMENT AND FUNCTIONING
Health categories: NEUROLOGICAL
Title: Unravelling Disease Mechanisms Causing Seizures and Cognitive Dysfunction in Early Infantile Epileptic Encephalopathy (EIEE)
Funder: Medical Research Council

Abstract: The early infantile epileptic encephalopathy (EIEE) syndromes are characterised by severe drug-resistant seizures, a poor neurodevelopmental outcome and increased mortality. Several age-dependent electroclinical syndromes are described, including Migrating Partial Seizures in Infancy (MPSI). The disease basis of these disorders is poorly understood. I have recently identified a novel cause of MPSI due to mutations in an ion transporter gene, MPSI-X. The residues mutated in MPSI-X are highly conserved throughout species and the mutations are not present in ethnically-matched controls. Both the drosophila and mouse knock-out models display an epilepsy phenotype. I hypothesise that in infants with mutations in MPSI-X, there is loss of transporter function, leading to disrupted ion homeostasis, loss of GABA-mediated inhibition and epileptogenesis. In my proposed fellowship, I will investigate (i) the spectrum of infantile epilepsies caused by MPSI-X (ii) how mutations in MPSI-X cause epilepsy and its associated co-morbidities. A variety of laboratory techniques including immunoblotting, immunofluorescence, confocal microscopy and a functional transporter assay will be used to study the effects of identified mutations in a cellular disease model. Using an already established knock-out mouse model, in vivo electrophysiological systems and behavioural approaches will be used to phenotype and study the mechanisms of cognitive impairments in MPSI-X knock-out mice.


Research activity codes: 1.1 NORMAL BIOLOGICAL DEVELOPMENT AND FUNCTIONING
Health categories: NEUROLOGICAL
Title: Combining imaging and genomics to study brain development in preterm infants.
Funder: Medical Research Council

Abstract: Background: Despite reductions in mortality among preterm infants, 30-50% of those born very preterm are cognitively impaired, 10% have cerebral palsy, and 5% have autistic spectrum disorders. The underlying processes remain unclear but magnetic resonance imaging (MRI) and candidate gene studies suggest correlates for imaging and functional abnormalities. New mathematical approaches allow imaging and genomic data to be combined, taking advantage of the multivariate nature of the datasets. Aims: To develop and implement new methods uniting imaging and genomic data to identify determinants of abnormal neurodevelopment in preterm infants. Objectives: To analyse a previously collected data library for 500 preterm infants, and explore the relationship between pathway and network based genetic variation and neuroanatomical features. Methods: Data previously collected from 500 preterm infants as part of the ePrime study will be analysed. This includes brain MRI at term equivalent age, and follow-up at 2 years for saliva sample collection and neurodevelopmental assessment. SNP genotyping in exomic regions will be done using the Illumina HumanCoreExome chip. Genetic architecture will be investigated using network and pathway approaches based on SNP, gene and protein interactions. Neuroinformatics tools including tract-based spatial statistics, whole-brain connectivity approaches and cortical diffusion will be used to extract differences in tissue injury and neuroanatomical connectivity. Using a pathways sparse reduced-rank regression model informed by prior knowledge, SNP data grouped in pathways and sets will be compared with voxel-level MRI data to identify gene pathways associated with imaging endophenotypes and correlated with outcome. Scientific and medical opportunities: With this multi-modal approach we expect to uncover pathological mechanisms that previously eluded detection, and that could be used to guide development of novel targeted therapies.


Research activity codes: 2.1 BIOLOGICAL AND ENDOGENOUS FACTORS;4.2 EVALUATION OF MARKERS AND TECHNOLOGIES
Health categories: NEUROLOGICAL
Title: The pathophysiological role of TDP43 in amyotrophic lateral sclerosis due to C9orf72 mutations
Funder: Medical Research Council

Abstract: Amyotrophic lateral sclerosis (ALS) is a progressive degenerative neurological disorder that predominantly affects the motor system and results in death within 1-5 years of onset. There are no effective treatments. Its pathophysiology is poorly understood and multiple hypotheses exist. There is abundant evidence that RNA splicing is defective in ALS. This is supported by the fact that the signature protein found in the inclusions in ALS, TDP-43, is an RNA binding protein. The most common mutation in ALS patients is a hexanucleotide repeat in the intron of C9orf72, found in 40% of familial and 7% of sporadic cases. Patients with C9orf72 mutations have a characteristic clinical picture and have TDP-43 positive inclusions, such as those found in the majority of ALS patients, but also have atypical TDP43 negative inclusions. The function of C9orf72 as well as its relationship with TDP-43 are still unknown. We will investigate this using the two following hypotheses: Hypothesis 1: Motor neurons with the C9orf72 mutation have different physiology and pathology from sporadic ALS cells and controls. This will be tested using motor neurons derived from iPS cells derived from relevant patients and controls from the ALS clinic. I will analyse survival, TDP43 pathology, neurophysiology and response to cellular stress. Results will be validated using the TDP43 mouse model available in the host laboratory, a C9orf72 mouse model in development and human autopsy findings. Hypothesis 2: The C9orf72 mutation interferes with splicing of Mr.NA species normally targeted by TDP-43. I will extract RNA from the above cell lines and look for splicing abnormalities using RNA sequencing. I will then create antisense oligonucleotides to silence the mutation and analyse for reversal of the effects identified.


Research activity codes: 2.1 BIOLOGICAL AND ENDOGENOUS FACTORS
Health categories: NEUROLOGICAL
Title: Spinal inhibitory interneurons that suppress itch
Funder: Medical Research Council

Abstract: Itch, a distressing symptom of many diseases, is often difficult to treat. Noxious stimuli suppress itch through GABAergic and glycinergic inhibition in the spinal cord. A major breakthrough in our understanding of itch came from the Bhlhb5 knockout mouse, which shows exaggerated itch and sensitivity to formalin (but otherwise normal pain responses), resulting from loss of dorsal horn inhibitory interneurons. It is therefore important to identify these interneurons and the circuits through which they act. We have recently shown that four non-overlapping neurochemical populations of GABAergic neurons can be identified, and in pilot studies we find that two of these: cells expressing nNOS or galanin, are substantially depleted in the Bhlhb5 knockout. Since nNOS (but not galanin) neurons are thought to use GABA and glycine as co-transmitters, we predict that these cells inhibit itch. We will test this hypothesis and investigate the underlying neuronal circuitry. We will first check whether loss of inhibitory interneurons in the knockout is restricted to nNOS and galanin cells. We will then use two approaches to kill or inactivate inhibitory interneuron populations in normal animals and test the effect on itch and pain. We will target either sst2A-expressing inhibitory interneurons (which include all nNOS and galanin cells) or only the nNOS cells. We will then test whether the inhibition acts directly on projection neurons by looking for loss of inhibitory synapses on itch-activated cells in knockout mice. Finally, we will test the prediction that giant cells in lamina I (which lose inhibitory synapses in the knockout) are involved in the increased response to formalin. The project will provide important information about the organisation of somatosensory pathways in spinal cord. This will improve our understanding of pathological itch and pain, and should assist in the identification of targets for new antipruritic and analgesic drugs.


Research activity codes: 2.1 BIOLOGICAL AND ENDOGENOUS FACTORS
Health categories: NEUROLOGICAL
Title: Functional significance of neuronal sodium channel splicing in epilepsy and pain
Funder: Medical Research Council

Abstract: While it has been known for decades that sodium channels are subject to highly conserved alternative splicing in their voltage sensing paddles, the functional role and adaptive significance of this splicing has been obscured by the challenge of expressing, clamping and comparing these channels in neurons. The sensitivity of the channels to the intracellular modulation, and their specialisation for neuronal functions, means that heterologous expression is severely limited, and even over-expression of cDNAs in neurons may not recapitulate the roles of these highly similar variants. We have recently established tools that enable us to ask, in neurons, the functional consequences of selectively manipulating splice variants. We have developed shRNA sequences that can significantly alter the proportion of each splice variant in neurons. Using our lentiviral-delivered shRNAs we have shown in vitro, that reducing each of the two variants of SCN8A leads to distinct effects, with reducing the 'neonatal' variant significantly altering resting membrane potential, while reducing the 'adult' variant disrupts regular firing, and appears to reduce the contribution of the axon initial segment to action potentials. We have developed four parallel approaches for measuring the functional roles and distribution of splice variants in neurons. In addition we have two models of clinically-important disease (epilepsy and pain) that are strongly associated with altered sodium channel activity. We will test whether key drugs that modulate sodium channels can distinguish between the functions of splice variants, and whether the changes in this voltage sensing paddle may be a potential target for rationally-designed drugs. Finally we will return to the question of how a human polymorphism that changes splicing might lead to altered dosage of drugs to ask how splicing impacts drug response.


Research activity codes: 5.1 PHARMACEUTICALS;2.1 BIOLOGICAL AND ENDOGENOUS FACTORS
Health categories: NEUROLOGICAL
Title: Investigation of the mechanism by which huntingtin fragments are produced and their pathogenic relevance to Huntington's disease
Funder: Medical Research Council

Abstract: Huntington's disease (HD) is an inherited late onset neurodegenerative disorder caused by a CAG repeat expansion in the HTT gene that leads to an extra long polyglutamine tract in the huntingtin (HTT) protein. Considerable evidence has accumulated to indicate that N-terminal fragments of mutant HTT are pathogenic and may trigger the disease process. We have recently identified a novel mechanism by which a small HTT fragment is generated. We found that the HD mutation leads to incomplete splicing of HTT exon 1 to exon 2, resulting in a small polyadenylated exon 1-intron 1 mRNA that is translated to produce an exon 1 HTT protein. This may have considerable implications for HD pathogenesis as exon 1 HTT fragments have been found to be highly pathogenic in multiple model systems SRSF6 is a splicing factor that recognises a CAG repeat sequence and modulates splicing and premature polyadenylation. We shall use molecular biology approaches to further investigate the role of SRSF6 in the aberrant splicing of HTT and identify other splicing factors that may contribute to this process. We shall use zinc finger nuclease technology to produce a model in which the exon 1 HTT protein cannot be generated by mis-splicing and use this to determine the extent to which this small HTT fragment contributes to HD pathogenesis. Finally, we shall use chemical modification and mass spectrometry to determine the identity of additional larger HTT fragments. Huntingtin is a validated therapeutic target for HD. Understanding the contribution that exon 1 HTT makes to disease pathogenesis is essential. A considerable effort is currently being directed at using gene therapy approaches to lower the levels of HTT, not all of which prevent the production of the exon 1-intron 1 mRNA. A complete understanding of HTT gene processing and the production of HTT fragments is a basic requisite to unraveling HD pathogenesis and may lead to novel therapeutic strategies.


Research activity codes: 2.1 BIOLOGICAL AND ENDOGENOUS FACTORS
Health categories: NEUROLOGICAL
Title: Investigating the neurophysiological basis of sleep quality
Funder: Medical Research Council

Abstract: Sleep disorders present a considerable burden on public health and the economy. Diagnostics and treatment of sleep disorders are often based on the assessment of "sleep quality", but, despite its high clinical relevance, this concept has not been rigorously defined. The subjective experience of having poor sleep correlates weakly with objective measures, such as sleep duration, latency or efficiency, which vary between patients, and depend on such factors as age, sex, ethnicity or co-morbidities. In order to establish objective markers of sleep quality, we will make use of the recent concept that sleep and waking are not global all-or-none phenomena, but have a local aspect, which is not well represented in the scalp EEG. Specifically, it was found that the main defining characteristic of non-rapid eye movement sleep - EEG slow waves and the underlying active (ON) and inactive (OFF) neuronal states often occur locally, and their incidence is determined by preceding sleep-wake history. We will record cortical neuronal activity in freely-behaving mice during spontaneous and experimentally disrupted (by pharmacological agents, local cortical microstimulation or by the delivery of auditory tones) sleep, and test the animals in a visual discrimination task during subsequent waking. First, we will test the hypothesis that sleep quality, as measured by cognitive performance during subsequent waking, is defined by the proportion of local and global neuronal OFF periods. We suggest that sleep of poor quality corresponds to a state with mostly localised asynchronous patterns of neuronal firing. Second, we will address whether isolated neuronal OFF-periods during waking are directly responsible for poor waking quality, as defined by reduced cognitive performance. Finally, we will test whether waking and sleep quality are interrelated, as manifested in a compensatory increase in "local sleep" during waking after disrupted or insufficient sleep.


Research activity codes: 1.1 NORMAL BIOLOGICAL DEVELOPMENT AND FUNCTIONING
Health categories: NEUROLOGICAL