PGE2 Potentiates Orai1-Mediated Calcium Entry Contributing to Peripheral Sensitization

Peripheral sensitization is one of the primary mechanisms underlying the pathogenesis of chronic pain. However, candidate molecules involved in peripheral sensitization remain incompletely understood. We have shown that store-operated calcium channels (SOCs) are expressed in the dorsal root ganglion (DRG) neurons. Whether SOCs contribute to peripheral sensitization associated with chronic inflammatory pain is elusive. Here we report that global or conditional deletion of Orai1 attenuates Complete Freund's adjuvant (CFA)-induced pain hypersensitivity in both male and female mice. To further establish the role of Orai1 in inflammatory pain, we performed calcium imaging and patch-clamp recordings in wild-type (WT) and Orai1 knockout (KO) DRG neurons. We found that SOC function was significantly enhanced in WT but not in Orai1 KO DRG neurons from CFA- and carrageenan-injected mice. Interestingly, the Orai1 protein level in L3/4 DRGs was not altered under inflammatory conditions. To understand how Orai1 is modulated under inflammatory pain conditions, prostaglandin E2 (PGE2) was used to sensitize DRG neurons. PGE2-induced increase in neuronal excitability and pain hypersensitivity was significantly reduced in Orai1 KO mice. PGE2-induced potentiation of SOC entry (SOCE) was observed in WT, but not in Orai1 KO DRG neurons. This effect was attenuated by a PGE2 receptor 1 (EP1) antagonist and mimicked by an EP1 agonist. Inhibition of Gq/11, PKC, or ERK abolished PGE2-induced SOCE increase, indicating PGE2-induced SOCE enhancement is mediated by EP1-mediated downstream cascade. These findings demonstrate that Orai1 plays an important role in peripheral sensitization. Our study also provides new insight into molecular mechanisms underlying PGE2-induced modulation of inflammatory pain.Significance Statement Store-operated calcium channel (SOC) Orai1 is expressed and functional in dorsal root ganglion (DRG) neurons. Whether Orai1 contributes to peripheral sensitization is unclear. The present study demonstrates that Orai1-mediated SOC function is enhanced in DRG neurons under inflammatory conditions. Global and conditional deletion of Orai1 attenuates complete Freund's adjuvant (CFA)-induced pain hypersensitivity. We also demonstrate that prostaglandin E2 (PGE2) potentiates SOC function in DRG neurons through EP1-mediated signaling pathway. Importantly, we have found that Orai1 deficiency diminishes PGE2-induced SOC function increase and reduces PGE2-induced increase in neuronal excitability and pain hypersensitivity. These findings suggest that Orai1 plays an important role in peripheral sensitization associated with inflammatory pain. Our study reveals a novel mechanism underlying PGE2/EP1-induced peripheral sensitization. Orai1 may serve as a potential target for pathological pain.

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

INTRODUCTION

The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures.

METHODS

In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025.

FINDINGS

Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2-6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5-5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4-10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32-4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23-11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation.

INTERPRETATION

After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Working with Insulin, Carbohydrates, Ketones and Exercise to Manage Diabetes (WICKED): evaluation of a self-management course for young people with Type 1 diabetes

AIMS

To evaluate a 5-day self-management education course for young people with Type 1 diabetes and assess its effects on knowledge, self-efficacy, beliefs, distress, self-management behaviours and HbA_1c .

METHODS

This is an evaluation of a structured education course. Young people (aged 16-24 years) with Type 1 diabetes were recruited from three diabetes centres. In the first centre, participants completed self-report measures of knowledge, self-efficacy, positive and negative outcome expectancies, and hypoglycaemic worries at baseline (n=47) and the end of the course (n=42). In two additional centres, participants completed these and other measures assessing self-management behaviours, cognitive adaptation to diabetes and diabetes distress at baseline (n=32), the end of the course (n=27) and 3-month follow-up (n = 27). HbA_1c levels were recorded at baseline (n=79), 6 months (n=77) and 12 months (n=65).

RESULTS

There were statistically significant increases in self-report knowledge, self-efficacy, positive outcome expectancies and self-management behaviours, and a statistically significant decrease in negative outcome expectances, between baseline and the end of the course. There were also statistically significant increases in self-report knowledge, self-efficacy, self-management behaviours and cognitive adaptation to diabetes between baseline and 3-month follow-up. Compared with baseline, HbA_1c levels decreased by a mean (sd) of 5.44 (19.93) mmol/mol (0.48%) at 6 months (P=0.019), and by 5.98 (23.32) mmol/mol (0.54%) at 12 months (P =0.043).

DISCUSSION

The results indicate the potential benefits of a self-management course designed to address the developmental needs and challenges faced by young people with Type 1 diabetes. Further studies with larger numbers and appropriate controls are required to confirm these initial findings.

Using the Medical Research Council framework to develop a complex intervention to improve delivery of care for young people with type 1 diabetes

AIMS

We describe how we have used the development phase of the Medical Research Council (MRC) Guidelines to construct a complex intervention to improve physical and psychological health among young people (16-21 years) with Type 1 diabetes.

METHODS

We consulted previous reviews where available and conducted systematic searches of electronic databases to determine physical and mental health among the population, audited medical records, surveyed self-reported psychological health among our clinic population; and interviewed staff (n = 13), young people (n = 27) and parents (n = 18) about their views of current care.

RESULTS

Our audit (n = 96) confirmed a high HbA1c [86 mmol/mol (10.0%)] and one third (36.1%) reported significant eating problems. Young people did not attend 12% of their clinic appointments. Staff described difficulties communicating with young people who wanted staff to take account of their individual lifestyle when giving information.

CONCLUSION

Based on the findings of the systematic reviews and our audit, we concluded that there was sufficient evidence to justify development of a model of care specific to this age group. The components of the complex intervention include changes to standard care, an optional 5-day self-management course directed at young people and a separate family communication programme. The MRC Guidelines provided a valuable structure to guide development and evaluation of this intervention.

Effect of visual perception, visual function, cognition, and personality on power wheelchair use in adults

The purpose of this study was to determine to what extent visual perception, visual function, cognition, and personality traits affect power wheelchair use in adults. It also proposes to establish baseline information to help clinicians determine or predict power wheelchair driving performance and to develop service plans to address those driving skills that need improvement or compensation. Sixty-two adult power wheelchair users were recruited. Standardized instruments were used to evaluate visual perceptual skills, visual function, cognitive skills, and personality traits. The results of these evaluations were then correlated with participants' scores on a power wheelchair performance test. Strong correlations were found between power wheelchair driving performance and visual perception (p = .000), ocular motor function (p = .000 and p < or = .001), stereodepth perception (p < or = .001), and alertness to the environment (p < or = .001). No significant correlations were found between personality traits and power wheelchair driving performance. These results indicate that good visual perceptual skills, visual function, and various aspects of cognition are necessary for proficient power wheelchair use. These data will assist clinicians in identifying significant factors to consider when evaluating and training clients for power wheelchair use.

The spectrum of category effects in object and action knowledge in dementia of the Alzheimer's type

The validity and origin of category effects in the anomia demonstrated by individuals with dementia of the Alzheimer's type (DAT) remains controversial. Twenty DAT subjects were tested with picture naming and semantic association judgment tests. Picture and word stimuli were drawn from biological, nonbiological, and actions-verbs categories, all of equal difficulty and previously normed on elderly controls. DAT subjects made significantly more naming and semantic judgment errors in the biological category than in the nonbiological category. They were relatively more accurate in naming and making judgments for actions-verbs when presented as words or as 5-s animations. When line drawings of actions were shown for naming, performance deteriorated significantly. Converging results from these 2 tasks provide strong evidence for a semantic memory impairment preferentially affecting biological items to a greater extent than nonbiological items or action verbs in DAT.

On the status of object concepts in aphasia

While verbal comprehension is often impaired in aphasia due to left hemispheric damage, the status of nonverbal conceptual knowledge of objects remains controversial. We tested 16 aphasic subjects for their comprehension of concrete single words. Eight showed significant impairment on word-to-picture matching, when distractors were semantically and not just perceptually confusable. These 8 also made errors in answering verbal probe questions concerning the same items. When tested on a nonverbal pictorial version of the same probe questions, however, 3 of these 8 improved their performance to the level of normal controls. The other 5 showed continuing impairment in indicating responses to pictorial probes. These 5 showed no evidence of generalized intellectual impairment, and it is concluded that they demonstrated a comprehension deficit not limited to the verbal domain. Unlike the other aphasic patients, these latter 5 also had CT scan lesions extending into the posterior left temporal lobe (involving Brodmann's areas 22, 21, and 37). They were also more impaired in terms of general aphasia severity. It is suggested that a nonverbal (as well as verbal) semantic memory deficit occurs in a subgroup of patients with single word comprehension disturbance due to aphasia, and this may reflect general severity of language impairment as well as damage to certain localized brain regions.

HM-PAO (CERETEC) SPECT brain scanning in the diagnosis of Alzheimer's disease

OBJECTIVE

To evaluate the accuracy of Single Photon Emission Computed Tomography (SPECT) scanning in the diagnosis of Alzheimer's Disease (AD) and its capacity to improve the diagnostic accuracy of conventional clinical evaluation.

DESIGN

Comparison of SPECT scanning of AD and normal subjects with the criterion standard of clinical diagnosis confirmed by 1-year repeated evaluation.

SETTING

A memory clinic in a tertiary care university hospital.

PATIENTS

One hundred twenty patients were evaluated upon entering the Jewish General Hospital (McGill University) Memory Clinic. Fifty-eight patients were diagnosed as having AD and 17 as having vascular dementia. Twenty unmatched controls (recruited mainly through newspaper advertisements) were normal, and 25 had cognitive impairment without dementia (not included in the statistical analysis).

MAIN OUTCOME MEASURES

Comparison of visual inspection of SPECT, based on the system of classification developed by Holman et al., using B pattern alone as positive or B (bilateral posterior temporal and/or parietal cortex deficits) or C (bilateral posterior temporal and/or parietal deficits with additional defects) pattern and B or C or D (unilateral posterior temporal and/or parietal defects with or without additional defects) as positive compared with clinical diagnosis after repeated evaluations. Sensitivity and specificity, as well as positive predictive value (PPV) and negative predictive value (NPV) based on the prevalence of AD in a memory clinic setting of 30% or 50%, were calculated.

RESULTS

With B pattern as positive, the sensitivity of SPECT was 21% whereas the specificity was 80%. With B or C as positive, the sensitivity was 29% and the specificity was 75%. With B or C or D as positive, the sensitivity was 55% and the specificity was 65%. With a 30% prevalence, the PPV with B pattern as positive was 31% whereas the NPV was 30%. The PPV with B or C as positive was 33% while the NPV was 29%, and the PPV with B or C or D as positive was 40% whereas the NPV was 23%. With a 50% prevalence, the PPV with B pattern as positive was 51% and the NPV 49.6%; the PPV with B or C as positive was 54% and the NPV 48.6%; the PPV with B or C or D as positive was 61% while NPV was 41%.

CONCLUSION

The sensitivity and specificity were too low for SPECT to be useful as a diagnostic test for AD. The poor positive and negative predictive values in our tertiary care clinic mean that SPECT is not useful in "ruling-in" or "ruling-out" AD in that setting. In fact, clinical evaluation is more accurate.

Controlled study of eating concerns and psychopathological traits in relatives of eating-disordered probands: do familial traits exist?

To examine the extent to which first-degree relatives of eating-disordered (ED) probands endorse maladaptive eating attitudes and personality/affective traits, we compared self-reported eating concerns (Restraint, Emotional Eating, Body Dissatisfaction, and maladaptive eating attitudes) and psychopathological traits (Affective Instability, Anxiousness, Compulsivity, and Narcissism) across groups of restricter (n = 19), binger (n = 56), psychiatric control (PC, n = 38), normal dieter (ND, n = 29), and nondieter control (NC, n = 28) probands, and then across participating nuclear family members. Results among probands were as anticipated: ED probands showed expected elevations in both areas, and predicted restricter/binger differences were obtained. However, corresponding differences were not obtained on measures of mothers', fathers', or siblings' eating concerns and traits. Our findings corroborate the notion that EDs represent a convergence of eating, affective, and personality disturbances, but not that such a clustering of features exists as a familial trait. We discuss normal trait and attitudinal variations observed in ED probands' relatives in light of findings showing EDs and other psychiatric syndromes to aggregate within families.