The United Kingdom Research study into Ethnicity And COVID-19 outcomes in Healthcare workers (UK-REACH): protocol for a prospective longitudinal cohort study of healthcare and ancillary workers in UK healthcare settings

INTRODUCTION

The COVID-19 pandemic has resulted in significant morbidity and mortality and devastated economies globally. Among groups at increased risk are healthcare workers (HCWs) and ethnic minority groups. Emerging evidence suggests that HCWs from ethnic minority groups are at increased risk of adverse COVID-19-related outcomes. To date, there has been no large-scale analysis of these risks in UK HCWs or ancillary workers in healthcare settings, stratified by ethnicity or occupation, and adjusted for confounders. This paper reports the protocol for a prospective longitudinal questionnaire study of UK HCWs, as part of the UK-REACH programme (The United Kingdom Research study into Ethnicity And COVID-19 outcomes in Healthcare workers).

METHODS AND ANALYSIS

A baseline questionnaire will be administered to a national cohort of UK HCWs and ancillary workers in healthcare settings, and those registered with UK healthcare regulators, with follow-up questionnaires administered at 4 and 8 months. With consent, questionnaire data will be linked to health records with 25-year follow-up. Univariate associations between ethnicity and clinical COVID-19 outcomes, physical and mental health, and key confounders/explanatory variables will be tested. Multivariable analyses will test for associations between ethnicity and key outcomes adjusted for the confounder/explanatory variables. We will model changes over time by ethnic group, facilitating understanding of absolute and relative risks in different ethnic groups, and generalisability of findings.

ETHICS AND DISSEMINATION

The study is approved by Health Research Authority (reference 20/HRA/4718), and carries minimal risk. We aim to manage the small risk of participant distress about questions on sensitive topics by clearly participant information that the questionnaire covers sensitive topics and there is no obligation to answer these or any other questions, and by providing support organisation links. Results will be disseminated with reports to Government and papers submitted to pre-print servers and peer reviewed journals.

TRIAL REGISTRATION NUMBER

ISRCTN11811602; Pre-results.

Amyloid binding and beyond: a new approach for Alzheimer's disease drug discovery targeting Aβo-PrPC binding and downstream pathways

Amyloid β oligomers (Aβo) are the main toxic species in Alzheimer's disease, which have been targeted for single drug treatment with very little success. In this work we report a new approach for identifying functional Aβo binding compounds. A tailored library of 971 fluorine containing compounds was selected by a computational method, developed to generate molecular diversity. These compounds were screened for Aβo binding by a combined 19F and STD NMR technique. Six hits were evaluated in three parallel biochemical and functional assays. Two compounds disrupted Aβo binding to its receptor PrPC in HEK293 cells. They reduced the pFyn levels triggered by Aβo treatment in neuroprogenitor cells derived from human induced pluripotent stem cells (hiPSC). Inhibitory effects on pTau production in cortical neurons derived from hiPSC were also observed. These drug-like compounds connect three of the pillars in Alzheimer's disease pathology, i.e. prion, Aβ and Tau, affecting three different pathways through specific binding to Aβo and are, indeed, promising candidates for further development.

Glucosylpolyphenols as Inhibitors of Aβ-Induced Fyn Kinase Activation and Tau Phosphorylation: Synthesis, Membrane Permeability, and Exploratory Target Assessment within the Scope of Type 2 Diabetes and Alzheimer's Disease

Despite the rapidly increasing number of patients suffering from type 2 diabetes, Alzheimer's disease, and diabetes-induced dementia, there are no disease-modifying therapies that are able to prevent or block disease progress. In this work, we investigate the potential of nature-inspired glucosylpolyphenols against relevant targets, including islet amyloid polypeptide, glucosidases, and cholinesterases. Moreover, with the premise of Fyn kinase as a paradigm-shifting target in Alzheimer's drug discovery, we explore glucosylpolyphenols as blockers of Aβ-induced Fyn kinase activation while looking into downstream effects leading to Tau hyperphosphorylation. Several compounds inhibit Aβ-induced Fyn kinase activation and decrease pTau levels at 10 μM concentration, particularly the per-O-methylated glucosylacetophloroglucinol and the 4-glucosylcatechol dibenzoate, the latter inhibiting also butyrylcholinesterase and β-glucosidase. Both compounds are nontoxic with ideal pharmacokinetic properties for further development. This work ultimately highlights the multitarget nature, fine structural tuning capacity, and valuable therapeutic significance of glucosylpolyphenols in the context of these metabolic and neurodegenerative disorders.

Discovery of N-methylpiperazinyl flavones as a novel class of compounds with therapeutic potential against Alzheimer’s disease: synthesis, binding affinity towards amyloid β oligomers (Aβo) and ability to disrupt Aβo-PrPC interactions

With no currently available disease-modifying drugs, Alzheimer’s disease is the most common type of dementia affecting over 47 million people worldwide. In light of the most recent discoveries placing the cellular prion protein (PrPC) as a key player in amyloid β oligomer (Aβo)-induced neurodegeneration, we investigated whether the neuroprotective potential of nature-inspired flavonoids against Aβ-promoted toxicity would translate into the ability to disrupt PrPC-Aβo interactions. Hence, we synthesized a small library of flavones and studied their binding affinity towards Aβo by STD-NMR. C-glucosyl flavones exhibited improved binding affinity with morpholine, thiomorpholine or N-methylpiperazine rings attached to the flavone skeleton in ring B para position. Moreover, a N-methylpiperazinyl flavone displayed suitable physicochemical properties and optimal water solubility even without the sugar moiety, and a high interaction with Aβo involving the whole flavone core. Its C-glucosyl derivative, was, however, the best compound to inhibit PrPC-Aβo interactions in a dose-dependent manner, with 41 % of inhibition capacity at 10 μM. The potential of C-glucosyl flavones and their aglycones as protein-protein interaction inhibitors able to tackle PrPC-Aβo interactions is here presented for the first time, and supports this class of compounds as new prototypes for further development in the treatment of Alzheimer’s disease.

A neuronal DNA damage response is detected at the earliest stages of Alzheimer's neuropathology and correlates with cognitive impairment in the Medical Research Council's Cognitive Function and Ageing Study ageing brain cohort

AIMS

Population-based studies have shown that approximately 20% of the ageing population (aged 65 years and over) with dementia have little or no classical Alzheimer-type neuropathology. Cumulative DNA damage and a reduced capacity of DNA repair may result in neuronal dysfunction and contribute to cognitive impairment independent of Alzheimer-type pathology in the ageing brain.

METHODS

We investigated expression of the DNA damage response (DDR)-associated molecules γH2AX and DNA-PKcs using immunohistochemistry and western blotting, and senescence-associated β-galactosidase in the frontal association neocortex of cases with low levels of Alzheimer-type pathology (Braak & Braak stage 0-II), and explored their relationship to cognitive impairment in a population-representative sample from the Medical Research Council's Cognitive Function and Ageing Study cohort.

RESULTS

Increases in both γH2AX(+) (r(s)  = -0.36, P = 0.025) and DNA-PKcs(+) (r(s)  = -0.39, P = 0.01) neuronal counts were associated with a lower Mini-Mental State Examination score. Increasing levels of senescence associated-β-gal(+) pyramidal neurones were weakly associated with the total number of DNA-PKcs(+) neurones (P = 0.08), but not with traditional senescence-associated signalling molecules, including p53 and p16.

CONCLUSION

The association between the neuronal DDR and cognitive impairment, independent of AD pathology in the ageing brain, may be suggestive of a causal link via neuronal dysfunction.

Calcium dysregulation in relation to Alzheimer-type pathology in the ageing brain

AIMS

Calcium dyshomeostasis is implicated in the pathogenesis of several neurodegenerative disorders including Alzheimer's disease. However, much of the previous research has focused on changes in neuronal calcium signalling. In a recent microarray study we identified dysregulation of several key signalling pathways including the Ca(2+) signalling pathway in astrocytes as Alzheimer-type pathology developed. In this study we sought to determine the expression of calpain-10 and calcium/calmodulin-dependent kinase alpha (CamKIIα) in relation to Alzheimer-type pathology in a population-based study.

METHODS

Using post mortem temporal cortex samples derived from the Medical Research Council Cognitive Function and Ageing Study (MRC-CFAS) ageing brain cohort we examined calpain-10 and CamKIIα gene and protein expression using quantitative polymerase chain reaction and immunohistochemistry.

RESULTS

We demonstrate that astrocytic expression of calpain-10 is up-regulated, and CamKIIα down-regulated with increasing Braak stage. Using immunohistochemistry we confirm protein expression of calpain-10 in astrocytes throughout the temporal cortex and demonstrate that calpain-10 immunoreactivity is correlated with both local and global measures of Alzheimer-type pathology. In addition, we identify a subpopulation of calpain-10 immunoreactive interlaminar astrocytes that extend processes deep into the cortex. CamKIIα is predominantly neuronal in localization and is associated with the presence of diffuse plaques in the ageing brain.

DISCUSSION

Dysregulated expression of key calcium signalling molecules occurs with progression of Alzheimer-type pathology in the ageing brain, highlighting the need for further functional studies of astrocytic calcium signalling with respect to disease progression.

Kinase activities increase during the development of tauopathy in htau mice

Hyperphosphorylated tau aggregates are the core constituent of neurofibrillary tangles. Recent research has shown a division between the presence of tangles, neurodegeneration and subsequent memory impairment, raising the possibility that an earlier pre-aggregated form of tau may be toxic. To gain further insight into the relationship between abnormal forms of tau, we have analyzed pathological changes in tau during tauopathy development in tangle-forming transgenic mice. In addition, we have quantified changes in the endogenous levels of a panel of protein kinases. We show progressive increases in aggregated tau and disease-specific conformational change, with hyperphosphorylation occurring in an age-dependent manner at specific sites. There were significant correlations between specific phosphorylation changes and amounts of aggregated tau and and abnormal tau conformations. Of the protein kinases tested, we found increases in phosphorylated (activated) p38 and the cyclin-dependent kinase-5 neuronal activators, p35 and p25, with aging, in the htau line, but not in non-tangle-forming control mice. Changes in tau kinases correlated with the amount of tau present in abnormal conformations and with insoluble tau in htau mice. These data suggest that cdk5 and p38 may be associated with pathological changes in wild-type human tau during the progressive development of tauopathy.

Attitudes and access to electronic exchange of information on occupational disease

BACKGROUND

THOR is a network of work-related disease surveillance schemes dependent on volunteer case reporting by medical specialists. Data collection and dissemination has hitherto been paper-based.

AIMS

To elicit the opinion of existing reporters in THOR on electronic exchange of information and to assess the practical capabilities of the same reporters to participate in electronic communication.

METHODS

A mail-based questionnaire of randomly selected THOR reporters using closed format questions.

RESULTS

The response rate to the questionnaire was 66% (253/383). Almost half (47%) of the responders wanted dissemination of information solely in an electronic form, 35% favoured paper-based reports, while 16% wanted both paper and electronic reports. Two-thirds (66%) would make use of electronic archives of reports and 59% would use this facility to resolve questions by accessing accumulated data. The majority (82%) read e-mail more than once a week and 34% browsed the web as frequently. However, 5% did not have e-mail and 6% never browsed the web. Most responders judged their internet connectivity to be rapid (68%) and convenient (83%), and 91% could receive e-mail attachments.

CONCLUSIONS

Most responders have the skills and infrastructure required to engage in electronic information exchange, and are favourably disposed to electronic means of communication. However it is also relevant to note that one-third of responders have a preference for the existing paper-based system.