Mediating a host cell signaling pathway linked to overwinter mortality offers a promising therapeutic approach for improving bee health

INTRODUCTION

Honey bees provides valuable pollination services for world food crops and wild flowering plants which are habitats of many animal species and remove carbon dioxide from the atmosphere, a powerful tool in the fight against climate change. Nevertheless, the honey bee population has been declining and the majority of colony losses occur during the winter.

OBJECTIVES

The goal of this study was to understand the mechanisms underlying overwinter colony losses and develop novel therapeutic strategies for improving bee health.

METHODS

First, pathogen prevalence in overwintering bees were screened between 2015 and 2018. Second, RNA sequencing (RNA-Seq) for transcriptional profiling of overwintering honey bees was conducted and qRT-PCR was performed to confirm the results of the differential expression of selected genes. Lastly, laboratory bioassays were conducted to measure the effects of cold challenges on bee survivorship and stress responses and to assess the effect of a novel medication for alleviating cold stress in honey bees.

RESULTS

We identified that sirtuin signaling pathway is the most significantly enriched pathway among the down-regulated differentially expressed genes (DEGs) in overwintering diseased bees. Moreover, we showed that the expression of SIRT1 gene, a major sirtuin that regulates energy and immune metabolism, was significantly downregulated in bees merely exposed to cold challenges, linking cold stress with altered gene expression of SIRT1. Furthermore, we demonstrated that activation of SIRT1 gene expression by SRT1720, an activator of SIRT1 expression, could improve the physiology and extend the lifespan of cold-stressed bees.

CONCLUSION

Our study suggests that increased energy consumption of overwintering bees for maintaining hive temperature reduces the allocation of energy toward immune functions, thus making the overwintering bees more susceptible to disease infections and leading to high winter colony losses. The novel information gained from this study provides a promising avenue for the development of therapeutic strategies for mitigating colony losses, both overwinter and annually.

A10 OVEREXPRESSION OF ASCL2 ALTERS DIFFERENTIATION, CELL CYCLE AND RESISTANCE TO ANTI-CANCER TREATMENT IN ESOPHAGEAL ORGANOIDS

Background

The esophagus is in constant contact with the austere environment caused by food and gastric reflux. It is protected by a squamous epithelium which maintenance is provided by a rare subpopulation of basal cells: Keratin 15+ (Krt15+) stem cells. However, little is known about the mechanisms underlying the expansion and the function of these stem cells. It was shown that the transcription factor ASCL2 is strongly upregulated in Krt15+ cells compared to Krt15- cells. Interestingly, ASCL2 is a gene target of the Wnt/β-catenin pathway, which acts as a regulator of proliferation and maintenance of the stemness state.

Purpose

The ultimate goal of my research project is to determine the role of ASCL2 in the maintenance of esophageal stem cells. To do so, I will investigate the role of ASCL2 in esophageal epithelial biology.

Method

Lentiviral infection approach was used to obtain mouse esophageal organoids overexpressing ASCL2 (ASCL2^OE). Organoid culture, immunostaining (such as IF and H&E), qPCR, WB, mass spectrometry and proliferation assay were used to characterize the effect of ASCL2^OE on morphology, differentiation, proliferation, self-renewal, and gene expression.

Result(s)

ASCL2^OE severely altered the morphology of organoids, which were smaller and less differentiated. Defects in differentiation was investigated by IF which showed that some cells expressed both p63 and K13, respectively basal and suprabasal markers. Thus, cells seem to be blocked in an intermediate state of differentiation suggesting a default in cell fate decision. Mass spectrometry analysis confirmed a change in biological processes related to differentiation of keratinocytes and of epithelial cells. We also investigated the role of ASCL2 in self-renewal and observed that organoid formation rate (OFR) was reduced in ASCL2^OE organoids. Furthermore, proliferation was also reduced in WST-1 and EdU assays. We then observed significant changes in the cell cycle by flow cytometry: there is an increased in the number of cells in G0/G1 and a major decrease in G2/M cells, suggesting a blockade in G1. Interestingly, CDNK2a (p16INK4a), an inhibitor of cell cycle progression, was increased in our mass spectrometry results. Finally, ASCL2 could also play a role in radio and chemoresistance of Krt15+ stem cells, as ASCL2^OE organoids are less sensitive to radiation and chemotherapy agents than control.

Conclusion(s)

ASCL2 could play a role in orchestrating cell fate decision in the esophageal epithelium as ASCL2^OE organoids showed alteration in differentiation, proliferation, and cell cycle.

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Other

Please indicate your source of funding;

NSERC, Canada Research Chairs and CRCHUS scolarship

Disclosure of Interest

None Declared

Left ventricular morphology in patients with aortic coarctation and bicuspid aortic valve: novel insights from a statistical shape modelling framework

Background

The functional implications of left ventricular (LV) morphological characterization in congenital heart disease (CHD) are not widely explored.

Purpose

This study qualitatively and quantitatively assessed LV shape associations with a) LV function and b) thoracic aortic morphology in patients with aortic coarctation (CoA) with/without bicuspid aortic valve (BAV).

Methods

A statistical shape modelling (SSM) framework was employed to analyse three-dimensional (3D) LV shapes from cardiac magnetic resonance (CMR) imaging data in n=110 cases including: isolated CoA (n=25), CoA+BAV (n=30), isolated BAV (n=30), and age-matched healthy controls (n=25). Average 3D templates (Picture 1) and deformations were computed. Correlations between shape data and CMR-derived morphometric parameters (i.e. sphericity, conicity) as well as CMR-derived global and apical strain values were assessed to elucidate possible functional implications. The relationship between LV shape features and arch architecture (i.e. gothicity, tortuosity) was also explored by means of regression analysis.

Results

The LV template was shorter and more spherical in CoA patient (Picture 1), as also confirmed by statistical analysis of the SSM-derived shape modes. LV sphericity, which was higher in CoA, was associated (p≤0.04) with lower global longitudinal, radial and circumferential strain, irrespective of the presence of aortic stenosis and/or regurgitation. Conversely, neither LV morphology nor LV strain was not associated with arch architecture.

Conclusions

Differences in LV morphology were observed between CoA and BAV patients. Increasing LV sphericity was associated with reduced strain, independent of aortic arch architecture and functional aortic valve disease.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation and NIHR BRC

Outcomes After Transcatheter Edge-to-Edge Mitral Valve Repair According to Mitral Regurgitation Etiology and Cardiac Remodeling

BACKGROUND

Transcatheter edge-to-edge repair (TEER) has been increasingly used for selected patients with mitral regurgitation (MR), but limited data are available regarding clinical outcomes in patients with varied etiology and mechanism of MR.

OBJECTIVES

The aim of this study was to evaluate the outcomes of TEER according to etiology and left ventricular (LV) and left atrial remodeling.

METHODS

Consecutive patients who underwent TEER between 2007 and 2020 were included in the analysis. Among patients with functional MR (FMR), those with predominant LV remodeling were classified as having ventricular FMR (v-FMR), whereas those without LV remodeling but predominant left atrial remodeling were classified as having atrial FMR (a-FMR). The primary outcome was a composite of all-cause mortality and heart failure hospitalization at 2 years and was compared among patients with degenerative MR (DMR), a-FMR, and v-FMR.

RESULTS

A total of 1,044 patients (11% with a-FMR, 48% with v-FMR, and 41% with DMR) with a mean Society of Thoracic Surgeons score of 8.6 ± 7.8 underwent TEER. Patients with a-FMR had higher rates of atrial fibrillation and severe tricuspid regurgitation with larger left and right atria, whereas patients with v-FMR had lower LV ejection fractions with larger LV dimensions. Residual MR more than moderate at discharge was not significantly different among the 3 groups (5.2% vs 3.2% vs 2.6%; P = 0.37). Compared with patients with DMR, 2-year event rates of the primary outcome were significantly higher in patients with a-FMR and v-FMR (21.6% vs 31.5% vs 42.3%; log-rank P < 0.001).

CONCLUSIONS

Despite excellent procedural outcomes, patients with a-FMR and v-FMR had worse clinical outcomes compared with those with DMR.

O-135 Sperm-borne small ribonucleic acid profile significantly impacts embryo development

Study question

Do normozoospermic males with reduced pre-implantation embryo development have aberrant sperm small RNA profiles?

Summary answer

Small RNA sequencing suggests the small RNA profile may differ in normozoospermic males with low blastocyst development rates, compared to males with higher blastocyst progression.

What is known already

Current male factor infertility diagnostics are insufficient, with 30-50% of subfertile males having unknown etiology. Spermatozoa contain a complex, epigenetically-marked genome and a collection of RNAs and proteins, which are not adequately assessed by current diagnostic methods. The sperm small RNA payload is reportedly modified during epididymal transit and in response to paternal exposures, influencing which sperm small RNA species are delivered to the oocyte. Mechanistic animal studies and correlative human and animal studies have suggested that sperm small RNAs may be important for early embryonic development and health of offspring, though their diagnostic and therapeutic value are still unclear.

Study design, size, duration

Human semen samples were collected between April 2017 and August 2020 from a total of 56 male patients presenting to CReATe Fertility Centre for fertility evaluation. Clinical data was accessed retrospectively. All patients were normozoospermic, according to standard semen analysis and were using donor oocytes. Samples were divided into high (n = 20), average (n = 16), and low (n = 20) fertility groups based on their deviation (1 standard deviation) from the mean blastocyst rate.

Participants/materials, setting, methods

Semen analysis was undertaken immediately following sample collection and spermatozoa were isolated by centrifugation. Sperm small RNA was purified and eluted using the RNeasy and MiRNeasy Kits (Qiagen). Barcoded and amplified cDNA libraries were prepared from small RNA using the NEXTFLEX Small RNA-Seq Kit v3 (Bioo Scientific). Resulting libraries were pooled, size-selected to a range of 140-190 base pairs, denatured and diluted for sequencing. Single-end, 75 bp sequencing was performed using the NextSeq 550 (Illumina).

Main results and the role of chance

Sequencing generated approximately 300 million raw reads, with 30 samples exceeding 2 million reads included in the differential expression analysis. Most reads were mapped to rRNAs (69%), miRNAs (11%), and piRNAs (12%). However, transfer RNA fragments from tRNA-Gly-GCC and tRNA-Val-CAC were the most abundant sequences. Top annotated miRNAs include: miR-12136-5p; miR-21-5p; and miR-122-5p. Principal component analysis revealed 222 genes that were differentially expressed between the high (n = 14) and low (n = 11) fertility groups (p &lt; 0.05). Interestingly, the top 50 differentially expressed sRNAs are sufficient to effectively cluster sperm with poor blastocyst development rates.

Limitations, reasons for caution

The results are limited by a relatively low sequencing depth (mean of 4.1 million reads per sample) and sample size. Fertility groups were determined by blastocyst rates, which can be confounded by non-sperm-derived variables, including technical skill, embryo culturing conditions, and maternal factors (though donor oocytes were used).  

Wider implications of the findings

With additional validation, a clinically-useful panel of differentially expressed sperm small RNAs could be used to predict IVF success and evaluate therapies aimed at improving male reproductive health. Augmenting traditional semen analytics with diagnostic sperm small RNA analysis could reduce time to pregnancy and the psychosocial impacts of fertility treatment.

Trial registration number

Not applicable

Prognostic Value of Increased Mitral Valve Gradient After Transcatheter Edge-to-Edge Repair for Primary Mitral Regurgitation

OBJECTIVES

This study sought to evaluate the prognostic value of an increased mean mitral valve pressure gradient (MVG) in patients with primary mitral regurgitation (MR) after transcatheter edge-to-edge repair (TEER).

BACKGROUND

Conflicting data exist regarding impact of increased mean MVG on outcomes after TEER.

METHODS

This study included 419 patients with primary MR (mean age 80.6 ± 10.4 years; 40.6% female) who underwent TEER. Patients were divided into quartiles (Qs) based on discharge echocardiographic mean MVG. Primary outcome was the composite endpoint of all-cause mortality and heart failure hospitalization. Secondary outcomes included all-cause mortality and the secondary composite endpoint of all-cause mortality, heart failure hospitalization, and mitral valve reintervention.

RESULTS

The median number of MitraClips used was 2 per patient. MR reduction ≤moderate was achieved in 407 (97.1%) patients. Mean MVG was 1.9 ± 0.3 mm Hg, 3.0 ± 0.1 mm Hg, 4.0 ± 0.1 mm Hg, and 6.0 ± 1.2 mm Hg in Q1, Q2, Q3, and Q4, respectively. There was no significant differences across quartiles in the primary outcome (15.4%, 19.6%, 22.0%, and 21.9% in Q1-Q4, respectively; P = 0.63), all-cause mortality (15.9% vs 18.6% vs 19.4% vs 17.1%, respectively; P = 0.91), and the secondary composite endpoint at 2 years (33.3% vs 29.5% vs 22.0% vs 31.6%, respectively; P = 0.37). After multivariate adjustment for baseline clinical and procedural variables, the mean MVG in Q4 compared with Q1 to Q3 was not independently associated with the primary outcome (HR: 1.22; 95% CI: 0.82-1.83; P = 0.33), all-cause mortality, and the secondary composite endpoint.

CONCLUSIONS

Increased mean MVG was not independently associated with adverse events after TEER in patients with primary MR.

A21 OVEREXPRESSION OF ASCL2 ALTERS DIFFERENTIATION IN ESOPHAGEAL ORGANOIDS

Background

The first population of stem cells in the esophageal epithelium was recently identified with the marker Keratin 15 ( Krt15). However, little is known about the mechanisms underlying the expansion and the function of these stem cells. It was shown that the transcription factor ASCL2 is upregulated in Krt15+ cells compared to Krt15- cells. Interestingly, ASCL2 is a gene target of the Wnt/β-catenin pathway, which acts as a regulator of proliferation and maintenance of the stemness state. The ultimate goal of my research project is to determine the role of ASCL2 in the maintenance of esophageal stem cells and to identify its binding partners.

Aims

Investigate the role of ASCL2 in esophageal epithelial biology.

Methods

Lentiviral infection approach was used to obtain mouse esophageal organoids overexpressing ASCL2. Organoid culture, immunostaining (such as IF and H&E), qPCR, WB and proliferation assay were used to characterize the effect of ASCL2 overexpression on morphology, differentiation, proliferation, self-renewal and gene expression.

Results

First, ASCL2 overexpression was confirmed by WB. Interestingly, the morphology of organoid overexpressing ASCL2 was severely altered: organoids were smaller and less differentiated. Defect in differentiation was investigated by qPCR and IF using relevant markers such as p63, Krt13, Wnt5a and NT5E. Indeed, we observed an increase in basal marker ( p63), a decrease in suprabasal markers ( Krt13, Wnt5a) and in a stem cell marker ( NT5E). We also investigated the role of ASCL2 in self-renewal and observed that organoid formation capacity was reduced in ASCL2-overexpressing organoids. Furthermore, proliferation was also reduced in WST-1 assays. We also observed lower expression of the gene Top2a, a recently identified marker of the proliferative basal cell population in the human esophagus. Finally, we observed significant changes in the expression of genes associated with quiescent stem cells (Clu, ZFP36L2 and Anxa1).

Conclusions

ASCL2 overexpression alters differentiation and proliferation in organoids. ASCL2 could play a role in orchestrating cell fate decision in the esophageal epithelium.

Funding Agencies

NSERC, Canada Research Chair

Social inclusion, intersectionality, and profiles of vulnerable groups of young people seeking mental health support

BACKGROUND

headspace centres provide enhanced primary mental healthcare for young people. A priority is to provide services for all young people irrespective of a range of social disadvantages or social exclusion. The aims of this study were to: (i) delineate extent of social inclusion across domains of housing, studying/employment, functioning, alcohol, and other drug use; and (ii) map profiles of young people deemed vulnerable to experiencing additional barriers to accessing services based on their social inclusion domains (e.g., those living in unstable housing, not in employment/education, and/or experiencing intersecting or multiple forms of disadvantage or difficulties), including detailing their clinical characteristics.

METHODS

Young people were recruited from five headspace centres. Data relevant to social inclusion were examined. Multivariate logistic regression models were used to determine overlap between vulnerable groups, functional, social, clinical, and behavioural factors.

RESULTS

1107 young people participated, aged 12-25 years (M = 18.1 years, SD = 3.3), most living in stable housing (96.5%) and engaged in studying/employment (84.8%). Specific vulnerabilities were evident in young people with NEET status (15.2%); in unstable accommodation (3.5%); of culturally diverse backgrounds (CALD) (12.2%); living in regional areas (36.1%); and identifying as lesbian, gay, bisexual, transgender, intersex, queer/questioning, and asexual plus (LGBTIQA+; 28.2%). Higher levels of distress, substance use, functional impairment, and lower social support were reported by those who were NEET and/or in unstable housing. LGBTIQA+ status was associated with high distress, depressive symptoms, and suicidal ideation.

CONCLUSIONS

Most participants reported good social support, stable housing, and engagement in work or education. Those deemed vulnerable were likely to experience social exclusion across multiple domains and reported more mental health problems. The co-occurrence of mental ill-health and social exclusion highlights the importance of integrated mental healthcare.

Surgical management of superficial digital flexor tendon luxation in dogs: 48 cases (2005-2020)

OBJECTIVES

To report the outcome, frequency of complications and potential prognostic factors associated with surgical repair of superficial digital flexor tendon (SDFT) luxation in dogs.

MATERIALS AND METHODS

Medical records from 10 referral hospitals were reviewed retrospectively for cases of SDFT luxation in dogs that underwent surgical stabilisation. Signalment, clinical presentation, diagnostic imaging, surgical method, type and length of post-operative limb immobilisation, nature of and length of exercise restriction, presence of post-operative complications and outcomes were recorded. Data were summarised descriptively and prognostic risk factors assessed for association with surgical outcome using risk ratios.

RESULTS

Forty-eight cases were included. A successful surgical outcome was recorded in 35 of 48 (73%) cases. Re-luxation of the SDFT occurred in seven of 48 (15%). Six out of 48 (13%) had a persistent lameness despite a stable non-luxating SDFT. A high frequency of post-operative complications occurred (71%), with the majority resolved medically. The risk of surgical failure was 60% higher (risk ratio 1.6, 95% confidence interval 1.1 to 2.4) where absorbable suture material was used compared to non-absorbable suture material. Surgical failure was more common in cases managed with non-rigid immobilisation post-operatively (57% failure) compared to cases managed with rigid immobilisation (19% failure), although this result was not statistically significant. Limb immobilisation of 6 weeks or longer did not significantly affect surgical outcome, compared to shorter periods of exercise restriction or limb immobilisation.

CLINICAL SIGNIFICANCE

A good outcome can be expected following surgical stabilisation of SDFT luxation. The use of non-absorbable suture was associated with a more successful surgical outcome.

The psychometric characteristics of the Kessler Psychological Distress Scale (K6) in help-seeking youth: What do you miss when using it as an outcome measure?

This is the first study to describe psychometric properties of the Kessler Psychological Distress Scale (K6) in a large cohort of help-seeking young people presenting to primary mental health care services. The aim was to determine whether the K6 was appropriate for monitoring outcomes in such settings. 1067 young people were recruited from Australian headspace services. We examined dimensionality of the K6, measurement invariance, and how the K6 correlated with the the Patient Health Questionnaire-9 (PHQ-9)and the Generalised Anxiety Disorder-7 Scale (GAD-7). Standardised Response Mean (SRM) and Cohen's d effect size (ES) were used to examine 3-month stability of the K6. The best-fitting model was a two-factor model: (i) nervous and restlessness; and (ii) hopeless, worthless, depressed and effort. Measurement non-invariance was observed for sex and age groups. K6 strongly correlated with the PHQ-9 and GAD-7. The K6 was less sensitive to change compared to these other two measures. There was some support for the K6 being a screener for young people presenting to primary care; however, there issues arise with its use as an outcome measure. These issues include measurement non-invariance, concern about the dimensionality and focus of items, and its sensitivity to change.

Complement inhibition for prevention of antibody-mediated rejection in immunologically high-risk heart allograft recipients

Allosensitization represents a major barrier to heart transplantation (HTx). We assessed the efficacy and safety of complement inhibition at transplant in highly sensitized heart transplant recipients. We performed a single-center, single-arm, open-label trial (NCT02013037). Patients with panel reactive antibodies (PRA) ≥70% and pre-formed donor-specific antibodies (DSA) were eligible. In addition to standard of care, patients received nine infusions of eculizumab during the first 2 months posttransplant. The primary composite endpoint was antibody-mediated rejection (AMR) ≥pAMR2 and/or left ventricular dysfunction during the first year. Secondary endpoints included hemodynamic compromise, allograft rejection, and patient survival. Twenty patients were included. Median cPRA and mean fluorescence intensity of immunodominant DSA were 95% (90%-97%) and 6250 (5000-10 000), respectively. Retrospective B cell and T cell flow crossmatches were positive in 14 and 11 patients, respectively. The primary endpoint occurred in four patients (20%). Survival at 1 year was 90% with no deaths resulting from AMR. In a prespecified analysis comparing treated patients to matched control patients, we observed a dramatic reduction in the risk of biopsy-proven AMR in patients treated with eculizumab (HR = 0.36, 95% CI = 0.14-0.95, p = .032). Our findings support the prophylactic use of complement inhibition for heart transplantation at high immunological risk. ClinincalTrials.gov, NCT02013037.

Evaluating the Dynamic Performance of Interfacial Pressure Sensors at a Simulated Body-Device Interface

BACKGROUND

Pressure sensing at the body-device interface can help assess the quality of fit and function of assistive devices during physical activities and movement such as walking and running. However, the dynamic performance of various pressure sensor configurations is not well established.

OBJECTIVES

Two common commercially available thin-film pressure sensors were tested to determine the effects of clinically relevant setup configurations focusing on loading areas, interfacing elements (i.e. 'puck') and calibration methods.

METHODOLOGY

Testing was performed using a customized universal testing machine to simulate dynamic, mobility relevant loads at the body-device interface. Sensor performance was evaluated by analyzing accuracy and hysteresis.

FINDINGS

The results suggest that sensor calibration method has a significant effect on sensor performance although the difference is mitigated by using an elastomeric loading puck. Both sensors exhibited similar performance during dynamic testing that agree with accuracy and hysteresis values reported by manufacturers and in previous studies assessing mainly static and quasi-static conditions.

CONCLUSION

These findings suggest that sensor performance under mobility relevant conditions may be adequately represented via static and quasi-testing testing. This is important since static testing is much easier to apply and reduces the burden on users to verify dynamic performance of sensors prior to clinical application. The authors also recommend using a load puck for dynamic testing conditions to achieve optimal performance.

A novel method for the detection and diagnosis of virus infections in honey bees

In terms of infectious diseases caused by a variety of microorganisms, the ability to promptly and accurately identify the causative agents is the first step on the path to all types of effective management of such infections. Among the various factors that are affecting global bee health, viruses have often been linked to honey bee colony losses and they pose a serious threat to the fraction of agriculture that depends on the service of pollinators. Over the past few decades, PCR-based molecular methods have provided powerful tools for rapid, specific, and sensitive detection and the quantification of difficult-to-grow pathogenic microorganisms such as viruses in honey bees. However, PCR-based methods require nucleic acid extraction and purification, which can be quite laborious and time-consuming and they involve the use of organic solvents and chaotropic agents like phenol and chloroform which are volatile and highly toxic. In response, we developed a novel and non-sacrificial method for detecting viral infections in honey bees. As little as 1 μl of hemolymph was collected from adult workers, larvae, and queens of bee colonies by puncturing the soft inter-tergal integument between the second and third dorsal tergum with a fine glass capillary. The hemolymph was then diluted and subjected to RT-PCR analysis directly. The puncture wound caused by the glass capillary was found to heal automatically and rapidly without any trouble and the lifespan of the experimental workers remained unaffected. Using this method, we detected multiple viruses including Deformed wing virus (DWV), Black queen cell virus (BQCV), and Sacbrood virus (SBV) in infected bees. Furthermore, expressed transcripts that indicate the induction of innate immune response to the virus infections were also detected in the hemolymph of infected bees. The simplicity and cost-effectiveness of this innovative approach will allow it to be a valuable, time-saving, safer, and more environmentally friendly contribution to bee disease management programs.

A53 STUDYING THE ROLE OF ASCL2 IN THE ESOPHAGEAL EPITHELIUM USING ORGANOIDS

Background

The esophagus is lined with a stratified squamous epithelium that assure protection against the austere environment found in the esophageal lumen. The maintenance of this epithelium is ensured by a rare population of cells: stem cells. Those cells have increased capacity of self-renewal and multipotency, which is the capacity to give rise to every cell types of a tissue. The marker Krt15 was used to identify the first stem cell population in the esophagus. Krt15+ cells display an extended lifespan and they are radioresistant, multipotent and capable of self-renewal. Moreover, it was observed by RNA sequencing that the expression of the transcription factor ASCL2 is strongly increased in Krt15+ cells compared to Krt15- cells. Interestingly, ASCL2 is necessary to maintain the stemness of Lgr5+ intestinal stem cells. It is also a target of the Wnt/β-catenin pathway. The overall goal of this project is to determine the role of ACSL2 in the maintenance of esophageal stem cells and to identify its binding partners since ASCL2 needs to dimerize to efficiently bind DNA.

Aims

Confirm that esophageal organoids are adapted to study ASCL2 in the esophagus.

Methods

Esophageal organoids were established from esophageal epithelial cells from wildtype mice. Following this, organoids were treated with an inhibitor of the Notch pathway (DAPT) to induce hyperplasia or infected with lentiviruses to invalidate Ascl2 (CRISPR/Cas9 approach).

Results

To validate that Ascl2 plays an important role in esophageal cell proliferation, Notch pathway was inhibited through DAPT treatment in esophageal organoids to induce hyperplasia, which was confirmed by increased number of proliferative cells (Ki-67+). ASCL2 protein expression was also increased in DAPT-treated organoids supporting its role in proliferation and confirming that organoid is a good model to study ASCL2 role in esophageal epithelial cells. In this optic, organoids lines invalidated for Ascl2 (CRISPR/Cas9 approach) were established. Our preliminary results suggest that Ascl2 loss affects cell proliferation and organoid size under normal conditions.

Conclusions

The expression of ASCL2 correlates with hyperplasia which supports its role in esophageal epithelium homeostasis.

Funding Agencies

Canada research chair et NSERC

Transferrin-mediated iron sequestration suggests a novel therapeutic strategy for controlling Nosema disease in the honey bee, Apis mellifera

Nosemosis C, a Nosema disease caused by microsporidia parasite Nosema ceranae, is a significant disease burden of the European honey bee Apis mellifera which is one of the most economically important insect pollinators. Nevertheless, there is no effective treatment currently available for Nosema disease and the disease mechanisms underlying the pathological effects of N. ceranae infection in honey bees are poorly understood. Iron is an essential nutrient for growth and survival of hosts and pathogens alike. The iron tug-of-war between host and pathogen is a central battlefield at the host-pathogen interface which determines the outcome of an infection, however, has not been explored in honey bees. To fill the gap, we conducted a study to investigate the impact of N. ceranae infection on iron homeostasis in honey bees. The expression of transferrin, an iron binding and transporting protein that is one of the key players of iron homeostasis, in response to N. ceranae infection was analysed. Furthermore, the functional roles of transferrin in iron homeostasis and honey bee host immunity were characterized using an RNA interference (RNAi)-based method. The results showed that N. ceranae infection causes iron deficiency and upregulation of the A. mellifera transferrin (AmTsf) mRNA in honey bees, implying that higher expression of AmTsf allows N. ceranae to scavenge more iron from the host for its proliferation and survival. The suppressed expression levels of AmTsf via RNAi could lead to reduced N. ceranae transcription activity, alleviated iron loss, enhanced immunity, and improved survival of the infected bees. The intriguing multifunctionality of transferrin illustrated in this study is a significant contribution to the existing body of literature concerning iron homeostasis in insects. The uncovered functional role of transferrin on iron homeostasis, pathogen growth and honey bee's ability to mount immune responses may hold the key for the development of novel strategies to treat or prevent diseases in honey bees.

Personalized treatments for depressive symptoms in patients with advanced heart failure: A pragmatic randomized controlled trial

Objectives

Heart Failure is a chronic syndrome affecting over 5.7 million in the US and 26 million adults worldwide with nearly 50% experiencing depressive symptoms. The objective of the study is to compare the effects of two evidence-based treatment options for adult patients with depression and advanced heart failure, on depressive symptom severity, physical and mental health related quality of life (HRQoL), heart-failure specific quality of life, caregiver burden, morbidity, and mortality at 3, 6 and 12-months.

Methods

Trial design. Pragmatic, randomized, comparative effectiveness trial.

Interventions. The treatment interventions are: (1) Behavioral Activation (BA), a patient-centered psychotherapy which emphasizes engagement in enjoyable and valued personalized activities as selected by the patient; or (2) Antidepressant Medication Management administered using the collaborative care model (MEDS).

Participants. Adults aged 18 and over with advanced heart failure (defined as New York Heart Association (NYHA) Class II, III, and IV) and depression (defined as a score of 10 or above on the PHQ-9 and confirmed by the MINI International Neuropsychiatric Interview for the DSM-5) selected from all patients at Cedars-Sinai Medical Center who are admitted with heart failure and all patients presenting to the outpatient programs of the Smidt Heart Institute at Cedars-Sinai Medical Center. We plan to randomize 416 patients to BA or MEDS, with an estimated 28% loss to follow-up/inability to collect follow-up data. Thus, we plan to include 150 in each group for a total of 300 participants from which data after randomization will be collected and analyzed.

Conclusions

The current trial is the first to compare the impact of BA and MEDS on depressive symptoms, quality of life, caregiver burden, morbidity, and mortality in patients with depression and advanced heart failure. The trial will provide novel results that will be disseminated and implemented into a wide range of current practice settings.

Registration

ClinicalTrials.Gov Identifier: NCT03688100.

Heart Transplantation for Giant Cell Myocarditis: A Case Series

BACKGROUND

Giant cell myocarditis (GCM) has a poor prognosis without heart transplant, but post-transplant survival is unknown.

PURPOSE

To describe the post-transplant survival of patients with GCM at a large transplant center.

METHODS

Seven patients underwent heart transplant for histologically confirmed GCM of the explanted heart. The median age was 59 years, and 43% (3 of 7) were female. All patients had cardiogenic shock, multiorgan failure, elevated troponin, and recurrent ventricular tachycardia, and some required mechanical circulatory support. All patients received rabbit antithymocyte globulin (rATG) in the perioperative period at a dose of 1.5 mg/kg daily for 1 to 5 days and 4 received intravenous immunoglobulin 1 g/kg daily for 2 days after rATG. All patients had early initiation of tacrolimus by first to third postoperative day depending on renal function, early mycophenolate, and high dose steroid. All were maintained using tacrolimus, mycophenolate, and prednisone.

RESULTS

One patient had asymptomatic recurrence of GCM at 3 months, managed by up-titration of tacrolimus, and had asymptomatic 2R cellular rejection at 4 months, managed with steroid bolus. No patient had high-grade rejection. One patient died at 267 days, possibly of GCM. Six of 7 (86%) remain alive at a median of 842 days (2.3 years) post transplant.

CONCLUSIONS

Patients with GCM have excellent post-transplant survival with use of rATG and triple drug immunosuppressive therapy; however, some patients remain at risk for GCM recurrence after transplant, which may respond to augmented immunosuppression.

The impact of antidepressants on depressive symptom severity, quality of life, morbidity, and mortality in heart failure: a systematic review

OBJECTIVE

The purpose of this paper is to review the literature on the impact of antidepressants on depressive symptom severity, quality of life (QoL), morbidity, and mortality in patients with heart failure (HF).

METHODS

Following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) Reporting Items for Systematic Reviews and Meta-Analyses guidelines, studies published from December 1969 to December 2019 that pertain to depression and HF were identified through the use of the PubMed and PsycINFO databases, using the keywords: 'antidepressant*' and 'heart failure.' Two authors independently conducted a focused analysis and reached a final consensus on 17 studies that met the specific selection criteria and passed the study quality checks.

RESULTS

Studies varied in types of antidepressants used as well as in study designs. Ten studies were analyzed for the impact of antidepressant medications on depressive symptom severity. Five of these were randomized controlled trials (RCTs), out of which sertraline and paroxetine showed a significant reduction in depressive symptoms despite the small samples utilized. Four of the 17 studies addressed QoL as part of their outcomes showing no difference for escitalopram (RCT), significantly greater improvements for paroxetine controlled release (RCT), statistical significance for sertraline compared to control (pilot study), and showing significant improvement before and after treatment (open-label trial) for nefazodone. Thirteen of the 17 studies included measures of morbidity and mortality. Although early analyses have pointed to an association of antidepressant use and mortality particularly with fluoxetine, the reviewed studies showed no increase in mortality for antidepressants, and secondary analyses showed improved mortality in patients who achieved remission of depressive symptoms.

CONCLUSION

Out of the various antidepressants studied, which included sertraline, paroxetine, escitalopram, citalopram, bupropion, nefazodone, and nortriptyline, selective serotonin reuptake inhibitors seem to be a safe treatment option for patients with depression and HF. However, due to the variety of study designs as well as the mixed results for each antidepressant, more information for reducing depression severity, morbidity, and mortality and improving quality of life in patients with HF should be examined using robust large sample RCTs.

cBIN1 Score (CS) Identifies Ambulatory HFrEF Patients and Predicts Cardiovascular Events

BACKGROUND

Cardiac Bridging Integrator 1 (cBIN1) is a membrane deformation protein that generates calcium microdomains at cardiomyocyte t-tubules, whose transcription is reduced in heart failure, and is released into blood. cBIN1 score (CS), an inverse index of plasma cBIN1, measures cellular myocardial remodeling. In patients with heart failure with preserved ejection fraction (HFpEF), CS diagnoses ambulatory heart failure and prognosticates hospitalization. The performance of CS has not been tested in patients with heart failure with reduced ejection fraction (HFrEF).

METHODS AND RESULTS

CS was determined from plasma of patients recruited in a prospective study. Two comparative cohorts consisted of 158 ambulatory HFrEF patients (left ventricular ejection fraction (LVEF) ≤ 40%, 57 ± 10 years, 80% men) and 115 age and sex matched volunteers with no known history of HF. N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations were also analyzed for comparison. CS follows a normal distribution with a median of 0 in the controls, which increases to a median of 1.9 (p < 0.0001) in HFrEF patients. CS correlates with clinically assessed New York Heart Association Class (p = 0.007). During 1-year follow-up, a high CS (≥ 1.9) in patients predicts increased cardiovascular events (43% vs. 26%, p = 0.01, hazard ratio 1.9). Compared to a model with demographics, clinical risk factors, and NT-proBNP, adding CS to the model improved the overall continuous net reclassification improvement (NRI 0.64; 95% CI 0.18-1.10; p = 0.006). Although performance for diagnosis and prognosis was similar to CS, NT-proBNP did not prognosticate between patients whose NT-proBNP values were > 400 pg/ml.

CONCLUSION

CS, which is mechanistically distinct from NT-proBNP, successfully differentiates myocardial health between patients with HFrEF and matched controls. A high CS reflects advanced NYHA stage, pathologic cardiac muscle remodeling, and predicts 1-year risk of cardiovascular events in ambulatory HFrEF patients. CS is a marker of myocardial remodeling in HFrEF patients, independent of volume status.

Depression in Heart Failure: A Systematic Review

Objective: This paper sought to identify the instruments used to measure depression in heart failure (HF) and elucidate the impact of treatment interventions on depression in HF. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed. Studies published from 1988 to 2018 covering depression and HF were identified through the review of the PubMed and PsycINFO databases using the keywords: "depres*" AND "heart failure." Two authors independently conducted a focused analysis, identifying 27 studies that met the specific selection criteria and passed the study quality checks. Results: Patient-reported questionnaires were more commonly adopted than clinician-rated questionnaires, including the Beck Depression Inventory, the Patient Health Questionnaire (PHQ-9), and the Hospital Anxiety and Depression Scale. Six common interventions were observed: antidepressant medications, collaborative care, psychotherapy, exercise, education, and other nonpharmacological interventions. Except for paroxetine, selective serotonin reuptake inhibitors failed to show a significant difference from placebo. However, the collaborative care model including the use of antidepressants showed a significant decrease in PHQ-9 score after one year. All of the psychotherapy studies included a variation of cognitive behavioral therapy and patients showed significant improvements. The evidence was mixed for exercise, education, and other nonpharmacological interventions. Conclusion: This study suggests which types of interventions are more effective in addressing depression in heart failure patients.

P1502 A clinical case of mitral annulus disjunction syndrome revealed by cardiac MRI

A 39year old female patient with a family history of probable sudden cardiac death/long QT syndrome (sister died aged 36) was referred to our Arrhythmia/inherited cardiac conditions clinic. Patient was fit and well. She described occasional postural presyncope and some chest pain with stress. Not on any medication that could prolong QT. On examination she appeared well with normal heart sounds and no clinical signs of heart failure.

Her ECG in clinic confirmed sinus rhythm with normal QTc at 418msec. There were U waves which may reflect late repolarisation of His Purkinje system.

Diagnostic techniques and findings

A 24-hour ECG tape to look at the average QT interval, an exercise tolerance test to look for appropriate shortening of QT interval with exercise and an echocardiogram to exclude significant structural abnormality were requested.

The 24-hour ECG tape confirmed underlying sinus rhythm with multi-focal aberrant beats &lt;1% of total. One symptom demonstrated short run of ventricular bigeminy.

During the exercise tolerance test, QT interval was not obviously prolonged. There were frequent bifocal ventricular ectopic beats in recovery.

The echocardiogram showed minor abnormality with mild left ventricular dilatation, otherwise normal findings.

Patient referred for cardiac MRI In order to rule out any cardiomyopathy.

Cardiac MRI did not show any prolapse on the 3 chamber cine. In addition, the inferior and inferolateral annulus showed thinning passing into the LV, which is a feature of some patients with mitral annulus disjunction syndrome.

We went through the echocardiogram and in one single frame images are suspicious of focal P2 prolapse.

Learning points:

Mitral annulus disjunction (MAD) is an abnormal atrial displacement of the mitral valve leaflet hinge point. It has been associated with mitral valve prolapse and sudden cardiac death.

MAD is usually revealed with echocardiogram.

In this case report we showed that CMR revealed a MAD previously missed by echo.

Abstract P1502 Figure.

P707 Positive rest and negative adenosine stress perfusion in typical angina

Learning points

Resting perfusion is often considered an integral part of adenosine perfusion imaging in order to overcome dark ring artefact, but it requires an additional contrast injection, prolongs imaging time and adds to cost. Some experts suggest that resting perfusion does not add to clinical interpretation and is not required.

Our case is interesting, showing a previously unreported phenomenon. We cannot explain the reason for it but do not believe that the stress/rest order was reversed (as this would require two radiographers to go off protocol, and they and the supervising physician to be lying) and the physiological response is as expected. It therefore suggests that a rest study may occasionally provide helpful diagnostic information.

Abstract P707 Figure.

Association of a Novel Diagnostic Biomarker, the Plasma Cardiac Bridging Integrator 1 Score, With Heart Failure With Preserved Ejection Fraction and Cardiovascular Hospitalization

Importance

Transverse tubule remodeling is a hallmark of heart failure. Cardiac bridging integrator 1 (cBIN1) is a circulating membrane scaffolding protein that is essential for transverse tubule health, and its plasma level declines with disease.

Objective

To determine if a cBIN1-derived score can serve as a diagnostic biomarker of heart failure with preserved ejection fraction (HFpEF).

Design, Setting, and Participants

In this cohort study, the cBIN1 score (CS) was determined from enzyme-linked immunoabsorbent assay-measured plasma cBIN1 concentrations from study participants in an ambulatory heart failure clinic at Cedars-Sinai Medical Center. Consecutive patients with a confirmed diagnosis of heart failure with preserved ejection fraction (HFpEF; defined by a left ventricular ejection fraction ≥50%) were recruited from July 2014 to November 2015 and compared with age-matched and sex-matched healthy volunteers with no known cardiovascular diagnoses and participants with risk factors for heart failure but no known HFpEF. Baseline characteristics and 1-year longitudinal clinical information were obtained through electronic medical records. Data analysis occurred from November 2016 to November 2017.

Main Outcomes and Measures

The analysis examined the ability of the CS and N-terminal pro-B-type natriuretic peptide (NT-proBNP) results to differentiate among patients with HFpEF, healthy control participants, and control participants with risk factors for heart failure. We further explored the association of the CS with future cardiovascular hospitalizations.

Results

A total of 52 consecutive patients with a confirmed diagnosis of HFpEF were enrolled (mean [SD] age, 57 [15] years; 33 [63%] male). The CS values are significantly higher in the patients with HFpEF (median [interquartile range (IQR)], 1.85 [1.51-2.28]) than in the 2 control cohorts (healthy control participants: median [IQR], -0.03 [-0.48 to 0.41]; control participants with risk factors only: median [IQR], -0.08 [-0.75 to 0.42]; P < .001). For patients with HFpEF, the CS outperforms NT-proBNP when the comparator group was either healthy control participants (CS: area under curve [AUC], 0.98 [95% CI, 0.96-1.00]; NT-proBNP level: AUC, 0.93 [95% CI, 0.88-0.99]; P < .001) or those with risk factors (CS: AUC, 0.98 [95% CI, 0.97-1.00]; NT-proBNP: AUC, 0.93 [95% CI, 0.88-0.99]; P < .001). Kaplan-Meier analysis of 1-year cardiovascular hospitalizations adjusted for age, sex, body mass index, and NT-proBNP levels reveals that patients with HFpEF with CS greater than or equal to 1.80 have a hazard ratio of 3.8 (95% CI, 1.3-11.2; P = .02) for hospitalizations compared with those with scores less than 1.80.

Conclusions and Relevance

If further validated, the plasma CS, a marker of transverse tubule dysfunction, may serve as a biomarker of cardiomyocyte remodeling that has the potential to aide in the diagnosis of HFpEF.

Social-ecological network analysis for sustainability sciences: a systematic review and innovative research agenda for the future

Social-ecological network (SEN) concepts and tools are increasingly used in human-environment and sustainability sciences. We take stock of this budding research area to further show the strength of SEN analysis for complex human-environment settings, identify future synergies between SEN and wider human-environment research, and provide guidance about when to use different kinds of SEN approaches and models. We characterize SEN research along a spectrum specifying the degree of explicit network representation of system components and dynamics. We then systematically review one end of this spectrum, what we term "fully articulated SEN" studies, which specifically model unique social and ecological units and relationships. Results show more focus on methodological advancement and applied ends. While there has been some development and testing of theories, this remains an area for future work and would help develop SENs as a unique field of research, not just a method. Authors have studied diverse systems, while mainly focused on the problem of social-ecological fit alongside a scattering of other topics. There is strong potential, however, to engage other issues central to human-environment studies. Analyzing the simultaneous effects of multiple social, environmental, and coupled processes, change over time, and linking network structures to outcomes are also areas for future advancement. This review provides a comprehensive assessment of (fully articulated) SEN research, a necessary step that can help scholars develop comparable cases and fill research gaps.