Interferon restores replication fork stability and cell viability in BRCA-defective cells via ISG15

DNA replication and repair defects or genotoxic treatments trigger interferon (IFN)-mediated inflammatory responses. However, whether and how IFN signaling in turn impacts the DNA replication process has remained elusive. Here we show that basal levels of the IFN-stimulated gene 15, ISG15, and its conjugation (ISGylation) are essential to protect nascent DNA from degradation. Moreover, IFNβ treatment restores replication fork stability in BRCA1/2-deficient cells, which strictly depends on topoisomerase-1, and rescues lethality of BRCA2-deficient mouse embryonic stem cells. Although IFNβ activates hundreds of genes, these effects are specifically mediated by ISG15 and ISGylation, as their inactivation suppresses the impact of IFNβ on DNA replication. ISG15 depletion significantly reduces cell proliferation rates in human BRCA1-mutated triple-negative, whereas its upregulation results in increased resistance to the chemotherapeutic drug cisplatin in mouse BRCA2-deficient breast cancer cells, respectively. Accordingly, cells carrying BRCA1/2 defects consistently show increased ISG15 levels, which we propose as an in-built mechanism of drug resistance linked to BRCAness.

Exploration of T cell immune responses by expression of a dominant-negative SHP1 and SHP2

SHP1 and SHP2 are SH2 domain-containing proteins which have inhibitory phosphatase activity when recruited to phosphorylated ITIMs and ITSMs on inhibitory immune receptors. Consequently, SHP1 and SHP2 are key proteins in the transmission of inhibitory signals within T cells, constituting an important point of convergence for diverse inhibitory receptors. Therefore, SHP1 and SHP2 inhibition may represent a strategy for preventing immunosuppression of T cells mediated by cancers hence improving immunotherapies directed against these malignancies. Both SHP1 and SHP2 contain dual SH2 domains responsible for localization to the endodomain of inhibitory receptors and a protein tyrosine phosphatase domain which dephosphorylates and thus inhibits key mediators of T cell activation. We explored the interaction of the isolated SH2 domains of SHP1 and SHP2 to inhibitory motifs from PD1 and identified strong binding of both SH2 domains from SHP2 and more moderate binding in the case of SHP1. We next explored whether a truncated form of SHP1/2 comprising only of SH2 domains (dSHP1/2) could act in a dominant negative fashion by preventing docking of the wild type proteins. When co-expressed with CARs we found that dSHP2 but not dSHP1 could alleviate immunosuppression mediated by PD1. We next explored the capacity of dSHP2 to bind with other inhibitory receptors and observed several potential interactions. In vivo we observed that the expression of PDL1 on tumor cells impaired the ability of CAR T cells to mediate tumor rejection and this effect was partially reversed by the co-expression of dSHP2 albeit at the cost of reduced CAR T cell proliferation. Modulation of SHP1 and SHP2 activity in engineered T cells through the expression of these truncated variants may enhance T cell activity and hence efficacy in the context of cancer immunotherapy.

Blood-CNS barrier dysfunction in amyotrophic lateral sclerosis: Proposed mechanisms and clinical implications

There is strong evidence for blood-brain and blood-spinal cord barrier dysfunction at the early stages of many neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). Since impairment of the blood-central nervous system barrier (BCNSB) occurs during the pre-symptomatic stages of ALS, the mechanisms underlying this pathology are likely also involved in the ALS disease process. In this review, we explore how drivers of ALS disease, particularly mitochondrial dysfunction, astrocyte pathology and neuroinflammation, may contribute to BCNSB impairment. Mitochondria are highly abundant in BCNSB tissue and mitochondrial dysfunction in ALS contributes to motor neuron death. Likewise, astrocytes adopt key physical, transport and metabolic functions at the barrier, many of which are impaired in ALS. Astrocytes also show raised expression of inflammatory markers in ALS and ablating ALS-causing transgenes in astrocytes slows disease progression. In addition, key drivers of neuroinflammation, including TAR DNA-binding protein 43 (TDP-43) pathology, matrix metalloproteinase activation and systemic inflammation, affect BCNSB integrity in ALS. Finally, we discuss the translational implications of BCNSB dysfunction in ALS, including the development of biomarkers for disease onset and progression, approaches aimed at restoring BCNSB integrity and in vitro modelling of the neurogliovascular system.

Motor Neuron Disease Systematic Multi-Arm Adaptive Randomised Trial (MND-SMART): a multi-arm, multi-stage, adaptive, platform, phase III randomised, double-blind, placebo-controlled trial of repurposed drugs in motor neuron disease

INTRODUCTION

Motor neuron disease (MND) is a rapidly fatal neurodegenerative disease. Despite decades of research and clinical trials there remains no cure and only one globally approved drug, riluzole, which prolongs survival by 2-3 months. Recent improved mechanistic understanding of MND heralds a new translational era with many potential targets being identified that are ripe for clinical trials. Motor Neuron Disease Systematic Multi-Arm Adaptive Randomised Trial (MND-SMART) aims to evaluate the efficacy of drugs efficiently and definitively in a multi-arm, multi-stage, adaptive trial. The first two drugs selected for evaluation in MND-SMART are trazodone and memantine.

METHODS AND ANALYSIS

Initially, up to 531 participants (177/arm) will be randomised 1:1:1 to oral liquid trazodone, memantine and placebo. The coprimary outcome measures are the Amyotrophic Lateral Sclerosis Functional Rating Scale Revised (ALSFRS-R) and survival. Comparisons will be conducted in four stages. The decision to continue randomising to arms after each stage will be made by the Trial Steering Committee who receive recommendations from the Independent Data Monitoring Committee. The primary analysis of ALSFRS-R will be conducted when 150 participants/arm, excluding long survivors, have completed 18 months of treatment; if positive the survival effect will be inferentially analysed when 113 deaths have been observed in the placebo group. The trial design ensures that other promising drugs can be added for evaluation in planned trial adaptations. Using this novel trial design reduces time, cost and number of participants required to definitively (phase III) evaluate drugs and reduces exposure of participants to potentially ineffective treatments.

ETHICS AND DISSEMINATION

MND-SMART was approved by the West of Scotland Research Ethics Committee on 2 October 2019. (REC reference: 19/WS/0123) Results of the study will be submitted for publication in a peer-reviewed journal and a summary provided to participants.

TRIAL REGISTRATION NUMBERS

European Clinical Trials Registry (2019-000099-41); NCT04302870.

Clinical trials in amyotrophic lateral sclerosis: a systematic review and perspective

Amyotrophic lateral sclerosis is a progressive and devastating neurodegenerative disease. Despite decades of clinical trials, effective disease-modifying drugs remain scarce. To understand the challenges of trial design and delivery, we performed a systematic review of Phase II, Phase II/III and Phase III amyotrophic lateral sclerosis clinical drug trials on trial registries and PubMed between 2008 and 2019. We identified 125 trials, investigating 76 drugs and recruiting more than 15 000 people with amyotrophic lateral sclerosis. About 90% of trials used traditional fixed designs. The limitations in understanding of disease biology, outcome measures, resources and barriers to trial participation in a rapidly progressive, disabling and heterogenous disease hindered timely and definitive evaluation of drugs in two-arm trials. Innovative trial designs, especially adaptive platform trials may offer significant efficiency gains to this end. We propose a flexible and scalable multi-arm, multi-stage trial platform where opportunities to participate in a clinical trial can become the default for people with amyotrophic lateral sclerosis.

Experiences of remote consulting for patients and neurologists during the COVID-19 pandemic in Scotland

BACKGROUND

Remote consulting is an emerging model in managing chronic neurological conditions and has been widely implemented during the COVID-19 pandemic. The objective of this national survey was to investigate the initial experiences of remote consulting for neurologists and patients with established neurological conditions under follow-up during the first COVID-19 phase.

METHODS

In collaboration with the Scottish Association of Neurological Sciences and the Neurological Alliance of Scotland, we conducted a web-based survey of neurologists and patients between October and November 2020.

FINDINGS

Data was available for 62 neurologists and 201 patients. The consensus among neurologists was that remote consulting is a satisfactory way of delivering healthcare in selected groups of patients. For practical and technical reasons, there was preference for phone over video consultations (phone 63% vs video 33%, p=0.003). The prevailing opinion among clinicians was that considerable training interventions for remote consultation skills are required ('yes' 63% vs 'no' 37%, p=0.009) to improve clinician consultation skills and successfully embed this new model of care.Most patients perceived remote consultations as safe, effective and convenient, with 89% of patients being satisfied with their remote consultation experience. Although traditional face-to-face consultations were the favoured way of interaction for 62% of patients, a significant proportion preferred that some of their future consultations be remote.

INTERPRETATION

Although not a replacement for face-to-face consultations, this survey illustrates that remote consulting can be an acceptable adjunct to traditional face-to-face consultations for doctors and patients. More research is required to identify overall safety and applicability.

Antisense oligonucleotide activity in tumour cells is influenced by intracellular LBPA distribution and extracellular vesicle recycling

Next generation modified antisense oligonucleotides (ASOs) are commercially approved new therapeutic modalities, yet poor productive uptake and endosomal entrapment in tumour cells limit their broad application. Here we compare intracellular traffic of anti KRAS antisense oligonucleotide (AZD4785) in tumour cell lines PC9 and LK2, with good and poor productive uptake, respectively. We find that the majority of AZD4785 is rapidly delivered to CD63+late endosomes (LE) in both cell lines. Importantly, lysobisphosphatidic acid (LBPA) that triggers ASO LE escape is presented in CD63+LE in PC9 but not in LK2 cells. Moreover, both cell lines recycle AZD4785 in extracellular vesicles (EVs); however, AZD4785 quantification by advanced mass spectrometry and proteomic analysis reveals that LK2 recycles more AZD4785 and RNA-binding proteins. Finally, stimulating LBPA intracellular production or blocking EV recycling enhances AZD4785 activity in LK2 but not in PC9 cells thus offering a possible strategy to enhance ASO potency in tumour cells with poor productive uptake of ASOs.

Kapustin et al. investigate the intracellular trafficking of anti-KRAS antisense oligonucleotides. They show that the oligonucleotide AZD4785 is recycled via late endosomes in extracellular vesicles in both cells with poor and good oligo productive uptake, and that inducing lysobisphosphatidic acid in late endosomes or blocking EV recycling enhance AZD4785 activity in cells with poor productive uptake, potentially offering improved treatment strategies.

National audit of cognitive assessment in people with pwMND A national audit of cognitive assessment in people with motor neurone disease (pwMND) in Scotland

Cognitive and behavioral abnormalities are recognized as an integral part of Motor Neurone Disease (MND) and occur at all stages of the disease. The early detection of cognitive and behavioral symptoms in MND is critical. Such symptoms are only reported when we explicitly ask, evaluate, document, and assess. In the National Institute for Health and Care Excellence (NICE) MND guideline (2016), formal cognitive and behavioral assessment is incorporated in MND management and is fundamental to providing appropriate care to pwMND. Cognition is explicitly stated in 14 separate recommendations in the guidelines. The NICE guidelines therefore constitute pre-defined standards which we audited. This audit highlights that health professionals increasingly recognize the significance of cognitive screening in MND and follow more structured approaches in implementing this compared to previous years.

Case report: meningitis as a presenting feature of anti-NMDA receptor encephalitis

Background

Meningitis is a very rare atypical presenting feature of anti-NMDA receptor encephalitis. In our case report, we describe an unusual clinical presentation of anti-NMDA receptor encephalitis with a biphasic pattern of meningitis followed by encephalitis and discuss potential mechanisms underlying this presentation. We aim to widen the differential diagnosis to be considered in a patient presenting with clinical meningitis and pyrexia.

Case presentation

This is a case of a 33-year old Caucasian woman who initially presented with a lymphocytic meningitis attributed to a viral infection. She subsequently developed fluctuating consciousness, agitation, visual hallucinations, dyskinetic movements, a generalized tonic-clonic seizure, and autonomic instability. Investigations revealed a diagnosis of anti-NMDA receptor encephalitis secondary to a previously unidentified ovarian teratoma. She made an excellent recovery with immunotherapy and removal of the teratoma.

Conclusion

Clinicians should consider autoimmune encephalitides in individuals with meningitis, particularly where extensive investigations fail to identify a causative pathogen and there is rapid development of an encephalitic phenotype.

Mutant C9orf72 human iPSC-derived astrocytes cause non-cell autonomous motor neuron pathophysiology

Mutations in C9orf72 are the most common genetic cause of amyotrophic lateral sclerosis (ALS). Accumulating evidence implicates astrocytes as important non‐cell autonomous contributors to ALS pathogenesis, although the potential deleterious effects of astrocytes on the function of motor neurons remains to be determined in a completely humanized model of C9orf72‐mediated ALS. Here, we use a human iPSC‐based model to study the cell autonomous and non‐autonomous consequences of mutant C9orf72 expression by astrocytes. We show that mutant astrocytes both recapitulate key aspects of C9orf72‐related ALS pathology and, upon co‐culture, cause motor neurons to undergo a progressive loss of action potential output due to decreases in the magnitude of voltage‐activated Na⁺ and K⁺ currents. Importantly, CRISPR/Cas‐9 mediated excision of the C9orf72 repeat expansion reverses these phenotypes, confirming that the C9orf72 mutation is responsible for both cell‐autonomous astrocyte pathology and non‐cell autonomous motor neuron pathophysiology.

Neuromyelitis optica spectrum disorder presenting as rhomboencephalitis

Rhomboencephalitis, at least in its acute phase, is often a severely disabling syndrome, and can be life threatening. A range of underlying conditions can lead to this clinical syndrome. Rapid diagnosis to initiate treatment early is key to a beneficial outcome. We report the case of a 22 year old Afro-Caribbean woman, who presented with a two -week history of walking difficulties, upper limb incoordination and slurred speech. Her brainstem function deteriorated at pace, and she developed hypersomnia. A broad diagnostic approach led to prophylactic treatment for the most common infectious causes. This did not improve her symptoms. Non-infectious inflammatory causes were therefore considered and plasma exchange treatment was initiated leading to marked improvement within days. Screening for autoimmune conditions confirmed aquaporin-4 positive neuromyelitis optica spectrum disorder (NMOSD) as the underlying cause. Immunotherapy with rituximab was started. So far, no relapse has been observed. While the definition of NMOSD continues to be refined, aquaporin-4 testing should be considered early in patients presenting with rhomboencephalitis who do not respond to antibiotic and antiviral treatment. Vigilance and early intervention are key to limit morbidity and mortality from NMOSD.

A Rapamycin-Activated Caspase 9-Based Suicide Gene

Engineered T cell therapies show considerable promise in the treatment of refractory malignancies. Given the ability of engineered T cells to engraft and persist for prolonged periods along with unpredicted toxicities, incorporation of a suicide gene to allow selective depletion after administration is desirable. Rapamycin is a safe and widely available immunosuppressive pharmaceutical that acts by heterodimerization of FKBP12 with the FRB fragment of mTOR. The apical caspase caspase 9 is activated by homodimerization through its CARD domain. We developed a rapamycin-induced caspase 9 suicide gene. First, we showed that caspase 9 could be activated by a two-protein format with replacement of the CARD domain with both FRB and FKBP12. We next identified an optimal compact single-protein rapamycin caspase 9 (rapaCasp9) by fusing both FRB and FKBP12 with the catalytic domain of caspase 9. Functionality of rapaCasp9 when co-expressed with a CD19 CAR was demonstrated in vitro and in vivo.

Commuting, Life-Satisfaction and Internet Addiction

The focus of the present work was on the association between commuting (business and private), life satisfaction, stress, and (over-) use of the Internet. Considering that digital devices are omnipresent in buses and trains, no study has yet investigated if commuting contributes to the development of Internet addiction. Overall, N = 5039 participants (N = 3477 females, age M = 26.79, SD = 10.68) took part in an online survey providing information regarding their commuting behavior, Internet addiction, personality, life satisfaction, and stress perception. Our findings are as follows: Personality seems to be less suitable to differentiate between commuter and non-commuter groups, which is possibly due to commuters often not having a choice but simply must accept offered job opportunities at distant locations. Second, the highest levels of satisfaction were found with income and lodging in the group commuting for business purposes. This might be related to the fact that commuting results in higher salaries (hence also better and more expensive housing style) due to having a job in another city which might exceed job opportunities at one’s own living location. Third, within the business-commuters as well as in the private-commuter groups, females had significantly higher levels of stress than males. This association was not present in the non-commuter group. For females, commuting seems to be a higher burden and more stressful than for males, regardless of whether they commute for business or private reasons. Finally, we observed an association between higher stress perception (more negative attitude towards commuting) and Internet addiction. This finding suggests that some commuters try to compensate their perceived stress with increased Internet use.

Retroviral transfer for a chimeric antigen receptor to generate regulatory T-like cells for the suppression of undesired immune responses. (VAC7P.1036)

Adoptive transfer of antigen specific regulatory T (Treg) cells was shown to be beneficial for the suppression of autoimmunity and Graft versus Host Disease (GvHD). To create a cellular regimen for the targeted suppression of unwanted immune responses, we engineered mouse MHC-class II specific Treg-like cells. The restricted expression of MHCII to professional antigen presenting cells and presence at high levels at all inflammatory sites, allow the employment of MHCII specific Treg-like cells for suppression in various inflammatory settings. A mouse MHCII-specific Chimeric Antigen Receptor (CAR) was used to redirect the specificity of T cells via retroviral transduction, while Foxp3 gene transfer into purified CD4+ cells leads to the acquisition of the Treg-like phenotype. Incorporation of a suicide mechanism within the engineered Treg-like cells, for their in vivo selective deletion, when desired, will ensure the short-term nature of suppression. The functionality of the generated CAR and the specificity of responses elicited by CAR bearing T cells were validated in vitro. In subsequent preliminary in vivo experiments, intravenous injection of C57BL/6 mice with syngeneic mouse MHCII-specific CD4+ T cells, led to GvHD-like toxicity, while no signs of toxicity were observed when Treg-like cells of the same specificity were transferred alone or in 1:1 mix with mouse MHCII specific CD4+ T cells. These data suggest the suppressive potential of the engineered Treg-like cells.

Review article: Treatment for Achilles tendon ruptures in athletes

Treatment for Achilles tendon ruptures in athletes is controversial. Surgical fixation has lower rates of re-rupture and confers increased strength and function, whereas conservative treatment has lower risks of wound complications. We review the literature on the optimal treatment for Achilles tendon rupture in athletes.

A rare case of perforated caecum after acute pancreatitis

Isolated caecal perforation following pancreatitis is a rare event. We report a case of severe non-necrotising pancreatitis complicated by caecal perforation that was managed successfully.

Relation of preoperative sialographic findings with histopathological diagnosis in cases of obstructive sialadenitis of the parotid and submandibular glands: retrospective study

The clinical records, preoperative sialograms and histopathological slides of 33 patients who had been operated on for symptoms of obstructive salivary gland disease were reviewed. Twenty patients had had superficial parotidectomy and 13 excision of the submandibular gland. Among those who had required parotidectomy, preoperative sialograms tended to suggest more architectural damage than was actually noted on definitive histopathological examination. Patients whose symptoms had been present for longer had more severe sialographic and histopathological changes. In the submandibular group, there was a closer relation between sialographic and histopathological changes, and a positive correlation between a short history and the severity of histopathological grading. These differences may reflect the different aetiology and course of obstructive disease in the two types of gland.

Primary carcinoid tumor of the mesentery

A primary carcinoid tumor of the mesentery was associated with intestinal obstruction in a 74-year-old man. Increased levels of plasma pancreatic polypeptide were subsequently demonstrated. An autopsy performed four years later showed carcinoid metastatic dissemination and confirmed the primary mesenteric origin of the carcinoid tumor initially resected at surgery.

Cystadenoma of the pancreas: a histological, histochemical and ultrastructural study of seven cases

Seven cases of cystadenoma of the pancreas were examined in detail histologically and histochemically and two variants were identified: a microcyst type lined by glycogen-rich cuboidal epithelium which also secretes some neutral mucins; and macrocystic type lined exclusively by mucus-secreting columnar cells which secrete predominantly sulphated acidic mucins with some neutral mucins. Electron microscopy of two cases of the microcystic variant showed neoplastic cells with an ultrastructure comparable to that of centroacinar cells of the normal exocrine pancreas.