Executive, language and fluency dysfunction are markers of localised TDP-43 cerebral pathology in non-demented ALS

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Neuronal clusterin expression is associated with cognitive protection in amyotrophic lateral sclerosis

Research Funding Medical Research Council. Grant Number: MR/L016400/1 Academy of Medical Sciences. Grant Number: 210JMG 3102 R45620 MND Scotland Motor Neurone Disease Association Amyotrophic Lateral Sclerosis AssociationPeer reviewedPublisher PD

NLRP3 inflammasome as a key molecular target underlying cognitive resilience in amyotrophic lateral sclerosis

Funding Pathological Society of Great Britain and Ireland. Grant Number: Jean Shanks Foundation Clinical Lecturer Support G OR is funded by a Wellcome Trust PhD fellowship (108890/Z/15/Z). JMG is funded by a starter grant for clinical lecturers from the AMS (210JMG 3102 R45620) and a Clinical Lecturer Support Grant from The Pathological Society/Jean Shanks Foundation, and brain bank funding from the MRC (MR/L016400/1). EE is funded by a PhD fellowship from the CSO and MND Scotland: 217ARF R45951.Peer reviewedPublisher PD

Gallin; an antimicrobial peptide member of a new avian defensin family, the ovodefensins, has been subject to recent gene duplication

Background: Egg white must provide nutrients and protection to the developing avian embryo. One way in which this is achieved is an arsenal of antimicrobial proteins and peptides which are essentially extensions of the innate immune system. Gallin is a recently identified member of a family of peptides that are found in egg white. The function of this peptide family has not been identified and they are potentially antimicrobial. Results: We have confirmed that there are at least 3 forms of the gallin gene in the chicken genome in 3 separate lines of chicken, all the forms are expressed in the tubular cells of the magnum region of the oviduct, consistent with its presence in egg white. mRNA expression levels are in the order 10,000 times greater in the magnum than the shell gland. The conservation between the multiple forms of gallin in the chicken genome compared with the conservation between gallin and other avian gallin like peptides, suggests that the gene duplication has occurred relatively recently in the chicken lineage. The gallin peptide family contains a six cysteine motif (C-X-5-C-X-3-C-X-11-CX3-C-C) found in all defensins, and is most closely related to avian beta-defensins, although the cysteine spacing differs. Further support for the classification comes from the presence of a glycine at position 10 in the 41 amino acid peptide. Recombinant gallin inhibited the growth of Escherischia coli (E. coli) at a concentration of 0.25 mu M confirming it as part of the antimicrobial innate immune system in avian species. Conclusions: The relatively recent evolution of multiple forms of a member of a new defensin related group of peptides that we have termed ovodefensins, may be an adaptation to increase expression or the first steps in divergent evolution of the gene in chickens. The potent antimicrobial activity of the peptide against E. coli increases our understanding of the antimicrobial strategies of the avian innate immune system particularly those of the egg white and the evolution of the defensin family. The potential of this peptide and others in the family can now be investigated in a number of novel antimicrobial role

Nrf2 activation in the human brain after stroke due to supratentorial intracerebral haemorrhage: a case–control study

AIMS: Pharmacological activation of the antioxidative transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) improves outcomes in experimental models of intracerebral haemorrhage (ICH). However, the Nrf2 pathway has not been previously studied in humans after ICH. Our study aims to address this gap. METHODS: We selected cases with fatal ICH from a prospective community-based inception cohort study and age-matched and sex-matched controls who died suddenly of non-neurological disease. We used immunohistochemistry to quantify Nrf2 (% total area stained overall and % of nuclei stained) and CD68 expression in controls and perihaematomal, ipsilateral and contralateral brain tissue from cases. We measured downstream haem oxygenase-1 (HMOX1) and NAD(P)H dehydrogenase quinone 1 [NQO1] expression using RNA in situ hybridisation. RESULTS: 26 ICH cases (median age: 82 (IQR 76–86); 13 (50%) male) and eight controls (median age: 79 (IQR 77–80); 3 (37.5%) male) were included. We found no significant differences in overall % of Nrf2 staining between ICH cases and controls. However, the mean % of nuclei staining for Nrf2 seemed higher in perihaematomal compared with contralateral regions, although this was only statistically significant >60 days after ICH (25% (95% CI 17% to 33%) vs 14% (95% CI 11% to 17%), p=0.029). The percentage of perihaematomal tissue staining for CD68 was higher >60 days after ICH (6.75%, 95% CI 2.78% to 10.73%) compared with contralateral tissue (1.45%, 95% CI 0.93% to 1.96%, p=0.027) and controls (1.08%, 95% CI 0.20% to 1.97%, p=0.0008). RNA in situ hybridisation suggested increased abundance of HMOX1 and NQO1 transcripts in perihaematomal versus distant ipsilateral brain tissue obtained <7 days from onset of ICH. CONCLUSIONS: We found evidence of Nrf2 activation in human brain tissue after ICH. Pharmacological augmentation of Nrf2 activation after ICH might be a promising therapeutic approach

Clusterin protects neurons against intracellular proteotoxicity.

It is now widely accepted in the field that the normally secreted chaperone clusterin is redirected to the cytosol during endoplasmic reticulum (ER) stress, although the physiological function(s) of this physical relocation remain unknown. We have examined in this study whether or not increased expression of clusterin is able to protect neuronal cells against intracellular protein aggregation and cytotoxicity, characteristics that are strongly implicated in a range of neurodegenerative diseases. We used the amyotrophic lateral sclerosis-associated protein TDP-43 as a primary model to investigate the effects of clusterin on protein aggregation and neurotoxicity in complementary in vitro, neuronal cell and Drosophila systems. We have shown that clusterin directly interacts with TDP-43 in vitro and potently inhibits its aggregation, and observed that in ER stressed neuronal cells, clusterin co-localized with TDP-43 and specifically reduced the numbers of cytoplasmic inclusions. We further showed that the expression of TDP-43 in transgenic Drosophila neurons induced ER stress and that co-expression of clusterin resulted in a dramatic clearance of mislocalized TDP-43 from motor neuron axons, partially rescued locomotor activity and significantly extended lifespan. We also showed that in Drosophila photoreceptor cells, clusterin co-expression gave ER stress-dependent protection against proteotoxicity arising from both Huntingtin-Q128 and mutant (R406W) human tau. We therefore conclude that increased expression of clusterin can provide an important defense against intracellular proteotoxicity under conditions that mimic specific features of neurodegenerative disease

Random forest modelling demonstrates microglial and protein misfolding features to be key phenotypic markers in C9orf72 ‐ALS

Acknowledgments We gratefully acknowledge Professor Tom Gillingwater for his helpful comments and support. This work would not have been possible without the resources of the Edinburgh Brain Bank, and the people with ALS and their families who have generously donated tissue. This research was funded in part by a studentship from the Wellcome Trust (108890/Z/15/Z) to OMR and MDES, a Pathological Society and Jean Shanks foundation grant (217CHA R46564) to JMG and JO, and a Sir Henry Dale fellowship jointly funded by the Wellcome Trust and the Royal Society (215454/Z/19/Z) to CRS.Peer reviewedPublisher PD

Mitochondrial bioenergetic deficits in C9orf72 amyotrophic lateral sclerosis motor neurons cause dysfunctional axonal homeostasis

ARM is a Lady Edith Wolfson Clinical Fellow and is jointly funded by the Medical Research Council (MRC) and the Motor Neurone Disease Association (MR/R001162/1). He also acknowledges support from the Rowling Scholars scheme, administered by the Anne Rowling Regenerative Neurology Clinic (ARRNC), University of Edinburgh, and a seedcorn grant from The Chief Scientist Office and the RS Macdonald Charitable Trust via the Scottish Neurological Research Fund, administered by the University of St Andrews. JMG is funded by a starter grant for clinical lecturers from the Academy of Medical Sciences. CS is supported by a Medical Research Council grant (MR/L016400/1). NMM was funded by a Wellcome Trust New Investigator Award (100981/Z/13/Z). RNC and NMM are funded by a Diabetes UK grant (17/0005697). The Hardingham and Chandran laboratories are supported by the Euan MacDonald Centre for Motor Neurone Disease Research, and the UK Dementia Research Institute (DRI), which receives its funding from UK DRI Ltd, funded by the MRC, Alzheimer's Society and Alzheimer's Research UK. SC also acknowledges funding from the ARRNC, My Name’5 Doddie Foundation, and an MRC Dementias Platform UK Stem Cell Partnership grant (MR/N013255/1). BTS is a Rowling-DRI Fellow.Peer reviewedPublisher PD

Cell-autonomous immune dysfunction driven by disrupted autophagy in C9orf72-ALS iPSC-derived microglia contributes to neurodegeneration

Although microglial activation is widely found in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), the underlying mechanism(s) are poorly understood. Here, using human-induced pluripotent stem cell-derived microglia-like cells (hiPSC-MG) harboring the most common ALS/FTD mutation (C9orf72, mC9-MG), gene-corrected isogenic controls (isoC9-MG), and C9orf72 knockout hiPSC-MG (C9KO-MG), we show that reduced C9ORF72 protein is associated with impaired phagocytosis and an exaggerated immune response upon stimulation with lipopolysaccharide. Analysis of the C9ORF72 interactome revealed that C9ORF72 interacts with regulators of autophagy and functional studies showed impaired initiation of autophagy in mC9-MG and C9KO-MG. Coculture studies with motor neurons (MNs) demonstrated that the autophagy deficit in mC9-MG drives increased vulnerability of mC9-MNs to excitotoxic stimulus. Pharmacological activation of autophagy ameliorated both cell-autonomous functional deficits in hiPSC-MG and MN death in MG-MN coculture. Together, these findings reveal an important role for C9ORF72 in regulating immune homeostasis and identify dysregulation in myeloid cells as a contributor to neurodegeneration in ALS/FTD.</p