Factors influencing organised faecal occult blood test screening participation in culturally and linguistically diverse populations: a scoping review

OBJECTIVE

This review aims to provide a comprehensive overview of the literature examining factors influencing participation in organised faecal occult blood test (FOBT) screening programmes in culturally and linguistically diverse populations. This article addresses gaps in the literature by providing a mixed methods review of the multilevel influences on FOBT screening in culturally and linguistically diverse (CALD) populations. This review was guided by the question "What are the factors influencing participation in organised FOBT screening programs in CALD populations?"

STUDY DESIGN

Scoping review.

METHODS

A scoping review methodology was used to summarise the available evidence. A thematic analysis of the included studies was undertaken to identify factors influencing organised FOBT screening participation in CALD populations from the literature.

RESULTS

FOBT screening participation was lower by ethnicity, religion, birthplace and language spoken. Barriers to screening included, faecal aversion, fatalism, fear of cancer, language and literacy barriers, difficulty accessing translated materials and low colorectal screening knowledge and awareness. CALD populations also had lower perceived benefits, susceptibility and cues to action, higher perceived barriers and greater perceived external health locus control than non-CALD populations. Facilitators of screening included positive attitudes to screening, general practitioner recommendations and social support. Group education sessions and narrative-based screening information were found to increase screening participation.

CONCLUSION

This review highlights the range of interrelated factors influencing participation in organised FOBT screening programmes in CALD populations and proposes multicomponent interventions to address low screening uptake. Features of successful community-level interventions should be explored further. Narratives show promise for engaging CALD populations. Accessibility of screening information should be addressed at the system level. Leveraging the general practitioner relationship in promoting FOBT screening programmes may also be an effective strategy to target 'hard-to-reach' populations.

Lactate promotes endothelial-to-mesenchymal transition via Snail1 lactylation after myocardial infarction

High levels of lactate are positively associated with the prognosis and mortality in patients with heart attack. Endothelial-to-mesenchymal transition (EndoMT) plays an important role in cardiac fibrosis. Here, we report that lactate exerts a previously unknown function that increases cardiac fibrosis and exacerbates cardiac dysfunction by promoting EndoMT following myocardial infarction (MI). Treatment of endothelial cells with lactate disrupts endothelial cell function and induces mesenchymal-like function following hypoxia by activating the TGF-β/Smad2 pathway. Mechanistically, lactate induces an association between CBP/p300 and Snail1, leading to lactylation of Snail1, a TGF-β transcription factor, through lactate transporter monocarboxylate transporter (MCT)-dependent signaling. Inhibiting Snail1 diminishes lactate-induced EndoMT and TGF-β/Smad2 activation after hypoxia/MI. The MCT inhibitor CHC mitigates lactate-induced EndoMT and Snail1 lactylation. Silence of MCT1 compromises lactate-promoted cardiac dysfunction and EndoMT after MI. We conclude that lactate acts as an important molecule that up-regulates cardiac EndoMT after MI via induction of Snail1 lactylation.

Peli1 deletion in macrophages attenuates myocardial ischemia/reperfusion injury by suppressing M1 polarization

The polarization of macrophages to the M1 or M2 phenotype has a pivotal role in inflammatory response following myocardial ischemia/reperfusion injury. Peli1, an E3 ubiquitin ligase, is closely associated with inflammation and autoimmunity as an important regulatory protein in the Toll-like receptor signaling pathway. We aimed to explore the function of Peli1 in macrophage polarization under myocardial ischemia/reperfusion injury and elucidate the possible mechanisms. We show here that Peli1 is upregulated in peripheral blood mononuclear cells from patients with myocardial ischemia/reperfusion, which is correlated with myocardial injury and cardiac dysfunction. We also found that the proportion of M1 macrophages was reduced and myocardial infarct size was decreased, paralleling improvement of cardiac function in mice with Peli1 deletion in hematopoietic cells or macrophages. Macrophage Peli1 deletion lessened M1 polarization and reduced the migratory ability in vitro. Mechanistically, Peli1 contributed to M1 polarization by promoting K63-linked ubiquitination and nuclear translocation of IRF5. Moreover, Peli1 deficiency in macrophages reduced the apoptosis of cardiomyocytes in vivo and in vitro. Together, our study demonstrates that Peli1 deficiency in macrophages suppresses macrophage M1 polarization and alleviates myocardial ischemia/reperfusion injury by inhibiting the nuclear translocation of IRF5, which may serve as a potential intervention target for myocardial ischemia/reperfusion injury.

Peli1 contributes to myocardial ischemia/reperfusion injury by impairing autophagy flux via its E3 ligase mediated ubiquitination of P62

Autophagy flux is impaired during myocardial ischemia/reperfusion (M-I/R) via the accumulation of autophagosome and insufficient clearance, which exacerbates cardiomyocyte death. Peli1 (Pellion1) is a RING finger domain-containing ubiquitin E3 ligase that could catalyze the polyubiquitination of substrate proteins. Peli1 has been demonstrated to play an important role in ischemic cardiac diseases. However, little is known about whether Peli1 is involved in the regulation of autophagy flux during M-I/R. The present study investigated whether M-I/R induced impaired autophagy flux could be mediated through Peli1 dependent mechanisms. We induced M-I/R injury in wild type (WT) and Peli1 knockout mice and observed that M-I/R significantly decreased cardiac function that was associated with increased cardiac Peli1 expression and upregulated autophagy-associated protein LC3II and P62. In contrast, Peli1 knockout mice exhibited significant improvement of M-I/R induced cardiac dysfunction and decreased LC3II and P62 expression. Besides, inhibitors of autophagy also increased the infarct size in Peli1 knockout mice after 24 h of reperfusion. Mechanistic studies demonstrated that in vivo I/R or in vitro hypoxia/reoxygenation (H/R) markedly increased the Peli1 E3 ligase activity which directly promoted the ubiquitination of P62 at lysine(K)7 via K63-linkage to inhibit its dimerization and autophagic degradation. Co-immunoprecipitation and GST-pull down assay indicated that Peli1 interacted with P62 via the Ring domain. In addition, Peli1 deficiency also decreased cardiomyocyte apoptosis. Together, our work demonstrated a critical link between increased expression and activity of Peli1 and autophagy flux blockage in M-I/R injury, providing insight into a promising strategy for treating myocardium M-I/R injury.

LACTATE IMPAIRS VASCULAR PERMEABILITY BY INHIBITING HSPA12B EXPRESSION VIA GPR81-DEPENDENT SIGNALING IN SEPSIS

ABSTRACT

Introduction: Sepsis impaired vascular integrity results in multiple organ failure. Circulating lactate level is positively correlated with sepsis-induced mortality. We investigated whether lactate plays a role in causing endothelial barrier dysfunction in sepsis. Methods: Polymicrobial sepsis was induced in mice by cecal ligation and puncture (CLP). Lactic acid was injected i.p. (pH 6.8, 0.5 g/kg body weight) 6 h after CLP or sham surgery. To elucidate the role of heat shock protein A12B (HSPA12B), wild-type, HSPA12B-transgenic, and endothelial HSPA12B-deficient mice were subjected to CLP or sham surgery. To suppress lactate signaling, 3OBA (120 μM) was injected i.p. 3 h before surgery. Vascular permeability was evaluated with the Evans blue dye penetration assay. Results: We found that administration of lactate elevated CLP-induced vascular permeability. Vascular endothelial cadherin (VE-cadherin), claudin 5, and zonula occluden 1 (ZO-1) play a crucial role in the maintenance of endothelial cell junction and vascular integrity. Lactate administration significantly decreased VE-cadherin, claudin 5, and ZO-1 expression in the heart of septic mice. Our in vitro data showed that lactate (10 mM) treatment disrupted VE-cadherin, claudin 5, and ZO-1 in endothelial cells. Mechanistically, we observed that lactate promoted VE-cadherin endocytosis by reducing the expression of HSPA12B. Overexpression of HSPA12B prevented lactate-induced VE-cadherin disorganization. G protein-coupled receptor 81 (GPR81) is a specific receptor for lactate. Inhibition of GPR81 with its antagonist 3OBA attenuated vascular permeability and reversed HSPA12B expression in septic mice. Conclusions: The present study demonstrated a novel role of lactate in promoting vascular permeability by decreasing VE-cadherin junctions and tight junctions in endothelial cells. The deleterious effects of lactate in vascular hyperpermeability are mediated via HSPA12B- and GPR81-dependent signaling.

Lactate induces vascular permeability via disruption of VE-cadherin in endothelial cells during sepsis

Circulating lactate levels are a critical biomarker for sepsis and are positively correlated with sepsis-associated mortality. We investigated whether lactate plays a biological role in causing endothelial barrier dysfunction in sepsis. We showed that lactate causes vascular permeability and worsens organ dysfunction in CLP sepsis. Mechanistically, lactate induces ERK-dependent activation of calpain1/2 for VE-cadherin proteolytic cleavage, leading to the enhanced endocytosis of VE-cadherin in endothelial cells. In addition, we found that ERK2 interacts with VE-cadherin and stabilizes VE-cadherin complex in resting endothelial cells. Lactate-induced ERK2 phosphorylation promotes ERK2 disassociation from VE-cadherin. In vivo suppression of lactate production or genetic depletion of lactate receptor GPR81 mitigates vascular permeability and multiple organ injury and improves survival outcome in polymicrobial sepsis. Our study reveals that metabolic cross-talk between glycolysis-derived lactate and the endothelium plays a critical role in the pathophysiology of sepsis.

Cardiovascular Dysfunction in COVID-19: Association Between Endothelial Cell Injury and Lactate

Coronavirus disease 2019 (COVID-19), an infectious respiratory disease propagated by a new virus known as Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), has resulted in global healthcare crises. Emerging evidence from patients with COVID-19 suggests that endothelial cell damage plays a central role in COVID-19 pathogenesis and could be a major contributor to the severity and mortality of COVID-19. Like other infectious diseases, the pathogenesis of COVID-19 is closely associated with metabolic processes. Lactate, a potential biomarker in COVID-19, has recently been shown to mediate endothelial barrier dysfunction. In this review, we provide an overview of cardiovascular injuries and metabolic alterations caused by SARS-CoV-2 infection. We also propose that lactate plays a potential role in COVID-19-driven endothelial cell injury.

Transverse bunch-by-bunch feedback system for time-resolved experiments at PLS-II

A description of the upgraded bunch-by-bunch feedback system for time-resolved experiments at Pohang Light Source II (PLS-II) is provided. The bunch-by-bunch feedback system has been upgraded to increase the single-bunch current in the hybrid fill pattern of the PLS-II facility. The project is part of the SPring-8 and PLS-II collaboration. The main features of the upgrade are to employ a single 500 MHz analog-to-digital converter (ADC) instead of the previous four 125 MHz interleaved ADCs for 500 MHz rate, to replace a single-loop two-dimensional feedback with two independent one-dimensional feedback loops, to implement the tune measurement function with a single bunch, and mainly to implement single-bunch and stretcher control. The realization of a 400 mA hybrid fill pattern including a 10 mA single bunch demonstrates the precision of the upgraded bunch-by-bunch feedback system.

Lactate Suppresses Macrophage Pro-Inflammatory Response to LPS Stimulation by Inhibition of YAP and NF-κB Activation via GPR81-Mediated Signaling

Recent evidence from cancer research indicates that lactate exerts a suppressive effect on innate immune responses in cancer. This study investigated the mechanisms by which lactate suppresses macrophage pro-inflammatory responses. Macrophages [Raw 264.7 and bone marrow derived macrophages (BMDMs)] were treated with LPS in the presence or absence of lactate. Pro-inflammatory cytokines, NF-κB and YAP activation and nuclear translocation were examined. Our results show that lactate significantly attenuates LPS stimulated macrophage TNF-α and IL-6 production. Lactate also suppresses LPS stimulated macrophage NF-κB and YAP activation and nuclear translocation in macrophages. Interestingly, YAP activation and nuclear translocation are required for LPS stimulated macrophage NF-κB activation and TNFα production. Importantly, lactate suppressed YAP activation and nuclear translocation is mediated by GPR81 dependent AMKP and LATS activation which phosphorylates YAP, resulting in YAP inactivation. Finally, we demonstrated that LPS stimulation induces an interaction between YAP and NF-κB subunit p65, while lactate decreases the interaction of YAP and NF-κB, thus suppressing LPS induced pro-inflammatory cytokine production. Our study demonstrates that lactate exerts a previously unknown role in the suppression of macrophage pro-inflammatory cytokine production via GPR81 mediated YAP inactivation, resulting in disruption of YAP and NF-κB interaction and nuclear translocation in macrophages.

Endothelial cell HSPA12B and yes-associated protein cooperatively regulate angiogenesis following myocardial infarction

Angiogenesis is essential for cardiac functional recovery after myocardial infarction (MI). HSPA12B is predominately expressed in endothelial cells and required for angiogenesis. Yes-associated protein (YAP) plays an important role in tumor angiogenesis. This study investigated the cooperative role of HSPA12B and YAP in angiogenesis after MI. Silencing of either HSPA12B or YAP impaired hypoxia-promoted endothelial cell proliferation and angiogenesis. Deficiency of HSPA12B suppressed YAP expression and nuclear translocation after hypoxia. Knockdown of YAP attenuated hypoxia-stimulated HSPA12B nuclear translocation and abrogated HSPA12B-promoted endothelial cell angiogenesis. Mechanistically, hypoxia induced an interaction between endothelial HSPA12B and YAP. ChIP assay showed that HSPA12B is a target gene of YAP/transcriptional enhanced associated domain 4 (TEAD4) and a coactivator in YAP-associated angiogenesis. In vivo studies using the MI model showed that endothelial cell-specific deficiency of HSPA12B (eHspa12b-/-) or YAP (eYap-/-) impaired angiogenesis and exacerbated cardiac dysfunction compared with WT mice. MI increased YAP expression and nuclear translocation in WT hearts but not eHspa12b-/- hearts. HSPA12B expression and nuclear translocation were upregulated in WT MI hearts but not eYap-/- MI myocardium. Our data demonstrate that endothelial HSPA12B is a target and coactivator for YAP/TEAD4 and cooperates with YAP to regulate endothelial angiogenesis after MI.

Hybrid team based learning-personalised education for teaching epidemiology in public health degrees

Background

University education in Australia and internationally involves teaching diverse students: in terms of age, life experience, previous degrees completed, and level of English competency. In Australia the Bachelors of Public Health (BPH) at The University of Wollongong, epidemiology is a core subject. It aims to equip students with the knowledge and skills needed to design, critique and interpret studies that investigate why different populations experience different health outcomes. A student-centred learning strategy; Hybrid Team Based Learning and Personalised Education teaching strategy (HTBL-PE) was created to maximise academic success. Each phase has a distinct purpose based on learning theories (e.g. TBL, Bloom's taxonomy and Vygotsky). HTBL-PE aims to systematically build students abilities; strengthen self-confidence and belief, by teaching the way students learn and harnessing the capabilities of the team to strengthen the individual.

Objectives

HTBL-PE was evaluated in spring 2019 in the BPH, where their experiences at the beginning and end of semester were measured.

Results

In total 73 out of 84 enrolled students provided data at both time-points (87%). At the end of the semester, the vast majority of students indicated their interest in epidemiology had increased (93%), critical thinking had improved (92%), and confidence as independent learners had increased (86%). Outcomes did not differ significantly by gender or across learning styles. More than two thirds of students had already applied learnings from this subject in other settings (67%). Students' final mark for this subject was significantly higher than their Weighted Average Mark (WAM) prior to the semester (+17.4, p < 0.001). Average scores for the subject were > 84/100 with a < 0.5% failure rate.

Conclusions

HTBL-PE has positive learning outcomes; low failure rates, increased confidence in learning and themselves, increased interest in epidemiology and high overall scores in the subject.

Key messages

An effective new innovative teaching strategy resulted in a subject average score > 84/100 and <0.5% failure rate. The vast majority of students reported increased confidence as independent lifelong learners, critical thinking, confidence in epidemiology (knowledge, skills, and attitudes) and themselves.

Differences in Colorectal Cancer (CRC) patients who did and did not undergo screening

Background

The Australian National Bowel Cancer Screening Program (NBSCP) is a free population-based screening program which aims to identify precancerous lesions and early colorectal cancer (CRC) using an immunochemical faecal occult blood test in average risk Australians. Formally commencing in 2006, NBCSP participation rate in eligible 50-74-year-old people was 42% in 2018. The barriers and facilitators of participation in the NBCSP have been explored for the general, at-risk population but not in a population of CRC patients. This is the first study to assess a population of CRC patients, post diagnosis, who would have been eligible for CRC screening to determine the barriers and facilitators to screening.

Methods

A cross sectional study nested within a cohort study. Data from CRC patients who participated in the 45 and Up Study; the largest cohort study in Australia and southern hemisphere, were analysed to compare those who had and had not participated in CRC screening. Logistic regression analyses were conducted using RStudio (version 3.5.2, Boston, Massachusetts, USA.). Multiple Imputation (MI), was used to handle missing values assumed to be missing at random.

Results

A total of 339 CRC patients were included. Patients who were female, overweight (≥25kg/m2), consumed less than the recommended five servings of vegetables per day, consumed less than or equal to fourteen standard drinks per week (compared to non-drinkers) or did not meet physical activity guidelines were significantly less likely to have participated in screening.

Conclusions

Our study has taken a unique approach to identifying a high-risk group by exploring factors to screening participation in CRC patients. CRC patients with less healthy lifestyles were less likely to participate in screening. In contrast to previous studies, female patients were less likely to participate in screening than males were. This was an unexpected finding and should be replicated.

Key messages

Not surprising that those with less healthy lifestyle practices also reflected less than ideal screening practices. Surprising that female patients participated less in screening than males. Future interventions to improve CRC screening participation rates should consider specialised messaging for average-risk females who are overweight not meeting dietary or physical activity guidelines.

Percentage volume of delayed kinetics in computer-aided diagnosis of MRI of the breast to reduce false-positive results and unnecessary biopsies

AIM

To investigate the best cut-off percentage volume of delayed kinetics using magnetic resonance imaging (MRI) with computer-aided diagnosis (CAD) to reduce unnecessary biopsies in patients with newly diagnosed breast cancer.

MATERIALS AND METHODS

Between January 2017 and December 2018, 94 malignant and 56 benign masses were analysed using MRI CAD. All malignant and benign masses measured <2 cm and were confirmed histopathologically. The optimal cut-off values for washout, plateau, and persistent components were determined using the maximum Youden Index. The positive predictive value (PPV) was analysed using morphological descriptors and combining the percentage volume of delayed kinetics.

RESULTS

The area under the curve (AUC) was highest at ≤73% persistent component (AUC=0.759). In the subgroup analyses of masses <1 cm, the AUC was highest a plateau of >26% (AUC=0.697). When the persistent ≤73% criterion was applied to the lesions of C4a, the positive predictive value (PPV) increased from 61.9% to 72.44% with reduced false-negative cases and when applied to the lesions of C4a and C4b, the PPV increased from 61.9% to 78.1% with slightly increased false-negative cases. For subcentimetre lesions, the PPV increased from 46.77% to 54.72% with the same number of false-negative cases, when a plateau of >26% was applied to C4a, and the PPV increased from 46.77% to 61.36% with five false-negative cases when applied to C4a and C4b.

CONCLUSION

The percentage volume of delayed kinetics has the potential to improve the PPV of breast MRI. When suspicious masses <2 cm do not show ≤73% persistence, follow-up rather than biopsy could be considered; however, to avoid increasing false-negative cases, delayed kinetic information should be used with caution and accurate margin assessment is essential.

Novel Role of Endothelial Derived Exosomal HSPA12B in Regulating Macrophage Inflammatory Responses in Polymicrobial Sepsis

Endothelial cell dysfunction contributes to sepsis induced initiate immune response and the infiltration of immune cells into organs, resulting in organ injury. Heat shock protein A12B (HSPA12B) is predominantly expressed in endothelial cells. The present study investigated whether endothelial HSPA12B could regulate macrophage pro-inflammatory response during sepsis. Wild type (WT) and endothelial cell-specific HSPA12B deficient (HSPA12B^-/-) mice were subjected to CLP sepsis. Mortality and cardiac function were monitored. Higher mortality, worsened cardiac dysfunction, and greater infiltrated macrophages in the myocardium and spleen were observed in HSPA12B^-/- septic mice compared with the WT septic mice. The serum levels of TNF-α and IL-1β were higher and the levels of IL-10 were lower in HSPA12B^-/- septic mice than in WT septic mice. Importantly, endothelial exosomes contain HSPA12B which can be uptaken by macrophages. Interestingly, endothelial exosomal HSPA12B significantly increases IL-10 levels and decreases TNF-α and IL-1β production in LPS-stimulated macrophages. Mechanistic studies show that endothelial exosomal HSPA12B downregulates NF-κB activation and nuclear translocation in LPS stimulated macrophages. These data suggest that endothelial HSPA12B plays a novel role in the regulation of macrophage pro-inflammatory response via exosomes during sepsis and that sepsis induced cardiomyopathy and mortality are associated with endothelial cell deficiency of HSPA12B.

Endothelial HSPA12B Exerts Protection Against Sepsis-Induced Severe Cardiomyopathy via Suppression of Adhesion Molecule Expression by miR-126

Heat shock protein A12B (HSPA12B) is predominately expressed in endothelial cells (ECs) and has been reported to protect against cardiac dysfunction from endotoxemia or myocardial infarction. This study investigated the mechanisms by which endothelial HSPA12B protects polymicrobial sepsis–induced cardiomyopathy. Wild-type (WT) and endothelial HSPA12B knockout (HSPA12B^–/–) mice were subjected to polymicrobial sepsis induced by cecal ligation and puncture (CLP). Cecal ligation and puncture sepsis accelerated mortality and caused severe cardiac dysfunction in HSPA12B^–/– mice compared with WT septic mice. The levels of adhesion molecules and the infiltrated immune cells in the myocardium of HSPA12B^–/– septic mice were markedly greater than in WT septic mice. The levels of microRNA-126 (miR-126), which targets adhesion molecules, in serum exosomes from HSPA12B^–/– septic mice were significantly lower than in WT septic mice. Transfection of ECs with adenovirus expressing HSPA12B significantly increased miR-126 levels. Increased miR-126 levels in ECs prevented LPS-stimulated expression of adhesion molecules. In vivo delivery of miR-126 carried by exosomes into the myocardium of HSPA12B^–/– mice significantly attenuated CLP sepsis increased levels of adhesion molecules, and improved CLP sepsis–induced cardiac dysfunction. The data suggest that HSPA12B protects against sepsis-induced severe cardiomyopathy via regulating miR-126 expression which targets adhesion molecules, thus decreasing the accumulation of immune cells in the myocardium.

Triad3A attenuates pathological cardiac hypertrophy involving the augmentation of ubiquitination-mediated degradation of TLR4 and TLR9

Activation of TLRs mediated the NF-κB signaling pathway plays an important pathophysiological role in cardiac hypertrophy. Triad3A, a ubiquitin E3 ligase, has been reported to negatively regulate NF-κB activation pathway via promoting ubiquitination and degradation of TLR4 and TLR9 in innate immune cells. The role of Triad3A in cardiac hypertrophic development remains unknown. The present study investigated whether there is a link between Triad3A and TLR4 and TLR9 in pressure overload induced cardiac hypertrophy. We observed that Triad3A levels were markedly reduced following transverse aortic constriction (TAC) induced cardiac hypertrophy. Similarly, stimulation of neonatal rat cardiac myocytes (NRCMs) with angiotensin-II (Ang II) significantly decreased Triad3A expression. To determine the role of Triad3A in TAC-induced cardiac hypertrophy, we transduced the myocardium with adenovirus expressing Triad3A followed by induction of TAC. We observed that increased expression of Triad3A significantly attenuated cardiac hypertrophy and improved cardiac function. To investigate the mechanisms by which Triad3A attenuated cardiac hypertrophy, we examined the Triad3A E3 ubiquitination on TLR4 and TLR9. We found that Triad3A promoted TLR4 and TLR9 degradation through ubiquitination. Triad3A mediated TLR4 and TLR9 degradation resulted in suppression of NF-κB activation. Our data suggest that Triad3A plays a protective role in the development of cardiac hypertrophy, at least through catalyzing ubiquitination-mediated degradation of TLR4 and TLR9, thus negatively regulating NF-κB activation.

Equivalence of Assurance® Gold Enzyme Immunoassay for Visual or Instrumental Detection of Motile and Nonmotile Salmonella in All Foods to AOAC Culture Method: Collaborative Study

Six foods representative of a wide variety of processed, dried powder processed, and raw food types were analyzed by the Assurance® Gold Salmonella Enzyme Immunoassay (EIA) and AOAC INTERNATIONAL culture method. Paired samples of each food type were simultaneously analyzed; one sample by the Assurance method and one by the AOAC culture method. The results for Assurance method were read visually and instrumentally with a microplate reader. A total of 24 laboratories representing federal government agencies and private industry, in the United States and Canada, participated in this collaborative study. Food types were inoculated with species of Salmonella with the exception of raw ground chicken, which was naturally contaminated. No statistical differences (p &lt; 0.05) were observed between Assurance Gold Salmonella EIA with either visual or instrumental interpretation and the AOAC culture method for any inoculation level of any food type or naturally contaminated food. The Assurance visual and instrumental options of reading sample reactions produced the same results for 1277 of the 1296 sample and controls analyzed.

MicroRNA-214 protects against hypoxia/reoxygenation induced cell damage and myocardial ischemia/reperfusion injury via suppression of PTEN and Bim1 expression

BACKGROUND

Myocardial apoptosis plays an important role in myocardial ischemia/reperfusion (I/R) injury. Activation of PI3K/Akt signaling protects the myocardium from I/R injury. This study investigated the role of miR-214 in hypoxia/reoxygenation (H/R)-induced cell damage in vitro and myocardial I/R injury in vivo.

METHODS AND RESULTS

H9C2 cardiomyoblasts were transfected with lentivirus expressing miR-214 (LmiR-214) or lentivirus expressing scrambled miR-control (LmiR-control) respectively, to establish cell lines of LmiR-214 and LmiR-control. The cells were subjected to hypoxia for 4 h followed by reoxygenation for 24 h. Transfection of LmiR-214 suppresses PTEN expression, significantly increases the levels of Akt phosphorylation, markedly attenuates LDH release, and enhances the viability of the cells subjected to H/R. In vivo transfection of mouse hearts with LmiR-214 significantly attenuates I/R induced cardiac dysfunction and reduces I/R-induced myocardial infarct size. LmiR-214 transfection significantly attenuates I/R-induced myocardial apoptosis and caspase-3/7 and caspase-8 activity. Increased expression of miR-214 by transfection of LmiR-214 suppresses PTEN expression, increases the levels of phosphorylated Akt, represses Bim1 expression and induces Bad phosphorylation in the myocardium. In addition, in vitro data shows transfection of miR-214 mimics to H9C2 cells suppresses the expression and translocation of Bim1 from cytosol to mitochondria and induces Bad phosphorylation.

CONCLUSIONS

Our in vitro and in vivo data suggests that miR-214 protects cells from H/R induced damage and attenuates I/R induced myocardial injury. The mechanisms involve activation of PI3K/Akt signaling by targeting PTEN expression, induction of Bad phosphorylation, and suppression of Bim1 expression, resulting in decreases in I/R-induced myocardial apoptosis.

TLR3 Mediates Repair and Regeneration of Damaged Neonatal Heart through Glycolysis Dependent YAP1 Regulated miR-152 Expression

The present study investigated whether TLR3 is required for neonatal heart repair and regeneration following myocardial infarction (MI). TLR3 deficient neonatal mice exhibited impaired cardiac functional recovery and a larger infarct size, while wild type neonatal mice showed cardiac functional recovery and small infarct size after MI. The data suggest that TLR3 is essential for the regeneration and repair of damaged neonatal myocardium. In vitro treatment of neonatal cardiomyocytes with a TLR3 ligand, Poly (I:C), significantly enhances glycolytic metabolism, YAP1 activation and proliferation of cardiomyocytes which were prevented by a glycolysis inhibitor, 2-deoxyglucose (2-DG). Administration of 2-DG to neonatal mice abolished cardiac functional recovery and YAP activation after MI, suggesting that TLR3-mediated regeneration and repair of the damaged neonatal myocardium is through glycolytic-dependent YAP1 activation. Inhibition of YAP1 activation abolished Poly (I:C) induced proliferation of neonatal cardiomyocytes. Interestingly, activation of YAP1 increases the expression of miR-152 which represses the expression of cell cycle inhibitory proteins, P27kip1 and DNMT1, leading to cardiomyocyte proliferation. We conclude that TLR3 is required for neonatal heart regeneration and repair after MI. The mechanisms involve glycolytic-dependent YAP1 activation, resulting in miR-152 expression which targets DNMT1/p27kip1.

Self-care educational intervention to reduce hospitalisations in heart failure: A randomised controlled trial

Background:

A variety of educational interventions have been implemented to assist patients with heart failure to maintain their own health, develop self-care behaviours and decrease readmissions.

Aims:

The purpose of this study was to determine the effectiveness of a multimedia educational intervention for patients with heart failure in reducing unplanned hospital readmissions.

Methods:

The study, a randomised controlled trial in a large tertiary referral hospital in Australia, recruited 200 patients. Patients diagnosed with heart failure were randomly allocated 1:1 to usual education or a multimedia educational intervention. The multimedia approach began with an individual needs assessment to develop an educational plan. The educational intervention included viewing a DVD, and verbal discussion supported by a written manual with a teach-back evaluation strategy. The primary outcome was all-cause unplanned hospital readmission at 28 days, three months and 12 months post-recruitment. The secondary outcomes were changes in knowledge and self-care behaviours at three months and 12 months post-recruitment.

Results:

At 12 months, data on 171 participants were analysed. There were 24 participants who had an unplanned hospital readmission in the intervention group compared to 44 participants in the control group ( p=0.005). The self-care educational intervention reduced the risk of readmission at 12 months by 30% (relative risk: 0.703; 95% confidence interval: 0.548–0.903).

Conclusion:

A targeted multimedia educational intervention can be effective in reducing all-cause unplanned readmissions for people with heart failure.

Enhanced Glycolytic Metabolism Contributes to Cardiac Dysfunction in Polymicrobial Sepsis

Background

Cardiac dysfunction is present in >40% of sepsis patients and is associated with mortality rates of up to 70%. Recent evidence suggests that glycolytic metabolism plays a critical role in host defense and inflammation. Activation of Toll-like receptors on immune cells can enhance glycolytic metabolism. This study investigated whether modulation of glycolysis by inhibition of hexokinase will be beneficial to septic cardiomyopathy.

Methods

Male C57B6/J mice were treated with a hexokinase inhibitor (2-deoxy-d-glucose [2-DG], 0.25-2 g/kg, n = 6-8) before cecal ligation and puncture (CLP) induced sepsis. Untreated septic mice served as control. Sham surgically operated mice treated with or without the 2-DG inhibitor served as sham controls. Cardiac function was assessed 6 hours after CLP sepsis by echocardiography. Serum was harvested for measurement of inflammatory cytokines and lactate.

Results

Sepsis-induced cardiac dysfunction was significantly attenuated by administration of 2-DG. Ejection fraction and fractional shortening in 2-DG-treated septic mice were significantly (P < .05) greater than in untreated CLP mice. 2-DG administration also significantly improved survival outcome, reduced kidney and liver injury, attenuated sepsis-increased serum levels of tumor necrosis factor α and interleukin 1β as well as lactate, and enhanced the expression of Sirt1 and Sirt3 in the myocardium, which play an important role in mitochondrial function and metabolism. In addition, 2-DG administration suppresses sepsis-increased expression of apoptotic inducers Bak and Bax as well as JNK phosphorylation in the myocardium.

Conclusions

Glycolytic metabolism plays an important role in mediating sepsis-induced septic cardiomyopathy. The mechanisms may involve regulation of inflammatory response and apoptotic signaling.

Direct Visualization of Helicase Dynamics Using Fluorescence Localization and Optical Trapping

Helicases control the accessibility of single-stranded (ss) nucleic acid (NA) generated as a transient intermediate during almost every step in cells related to nucleic acid metabolisms. For subsequent processing, however, helicases need to adjust the pace of unwinding adequately to avoid ssNA exposure to nucleases. Therefore, understanding how the unwinding process of helicases is regulated is crucial to address genome integrity and repair mechanisms. Using single-molecule fluorescence-force spectroscopy with fluorescence localization, we recently observed the stoichiometry of UvrD helicase, which determines the functions of UvrD: translocation and unwinding. For the first time, we provide direct evidence that a UvrD dimer is required to initiate the unwinding pathway. Moreover, with subpixel precision of fluorescence localization, the dynamic parameters of helicases can be obtained directly. Here, we present detailed single-molecule assays for observing the biochemical activities of helicases in real time and revealing how mechanical forces are involved in protein-nucleic acid interactions. These single-molecule approaches are generally applicable to many other protein-nucleic acid systems.

MicroRNA-125b Prevents Cardiac Dysfunction in Polymicrobial Sepsis by Targeting TRAF6-Mediated Nuclear Factor κB Activation and p53-Mediated Apoptotic Signaling

BACKGROUND

 This study examined the effect of microRNA-125b (miR-125b) on sepsis-induced cardiac dysfunction.

METHODS

 Mouse hearts were transfected with lentivirus expressing miR-125b (LmiR-125b) 7 days before cecal ligation and puncture (CLP)-induced sepsis. Cardiac function was examined by echocardiography before and 6 hours after CLP (n = 6/group). Survival was monitored following CLP-induced sepsis (n = 12/group).

RESULTS

 LmiR-125b transfection significantly attenuated cardiac dysfunction due to CLP-induced sepsis. Fractional shortening and ejection fraction values were significantly (P < .05) higher in the LmiR-125b-treated CLP group than in the untreated CLP group. Survival outcome in LmiR-125b-transfected septic mice was markedly improved, compared with mice with CLP-induced sepsis. Transfection of LmiR-125b into the heart significantly suppressed the expression of ICAM-1 and VCAM-1, decreased the accumulation of macrophages and neutrophils in the myocardium, and decreased serum levels of tumor necrosis factor α and interleukin 1β by targeting tumor necrosis factor receptor-associated factor 6 (TRAF6)-mediated nuclear factor κB (NF-κB) activation. In addition, sepsis-induced myocardial apoptosis was markedly attenuated by LmiR-125b transfection through suppression of p53, Bax, and Bak1 expression. In vitro transfection of endothelial cells with miR-125b mimics attenuate LPS-induced ICAM-1 and VCAM-1 expression by suppressing TRAF6 and NF-κB activation.

CONCLUSIONS

 Increased myocardial miR-125b expression attenuates sepsis-induced cardiac dysfunction and improves survival. miR-125b may be a target for septic cardiomyopathy.

Abstract 117: Poly (i:c) Attenuates Myocardial I/R Injury via Glycolytic Dependent Yap Activation and by Suppression of MiR-143

Glycolytic metabolism plays a critical role in ischemia/reperfusion (I/R) injury. The Yes associated protein (YAP) is a core effector of the Hippo pathway that regulates cell proliferation and apoptosis. We observed that poly (I:C) enhanced glycolysis and Yap activation in neonatal cardiomyocytes. This study investigated whether poly (I:C) will attenuate myocardial I/R injury via a glycolytic dependent mechanism. Mice (n=6/group) were treated with poly (I:C) (10 μg/25g body weight) one h before the hearts were subjected to ischemia (45 min) followed by reperfusion (24 h). Sham surgery served as sham control. Poly (I:C) treatment significantly reduced infarct size by 35% and enhanced EF% by 20.5% and FS% by 24.9% compared with I/R group. The expression of miR-143 was markedly reduced and Yap levels were significantly increased in poly (I:C) treated hearts. In vitro data show that poly (I:C) treatment enhanced extracellular acidification rate (ECAR) and lactate production in HL-1 cardiomyocytes. In vivo inhibition of hexokinase 2 abolished poly (I:C)-induced cardioprotection. To determine the role of miR-143 in regulation of glycolysis, we transfected HL-1 cardiomyocytes with anti-miR-143 mimics before the cells were subjected to hypoxia/reoxygenation. We observed that anti-miR-143 significantly enhanced cell viability, reduced LDH release, and increased hexokinase 2 levels and extracellular acidification rate (ECAR). To determine whether suppression of miR-143 will induce protection against myocardial I/R injury, we loaded anti-miR-143 on exosomes (Exo-antimiR-143) by transection of bone marrow stromal cells with anti-miR-143 mimics. MiR-control mimics served as control (Exo-miR-control). Exo-miR-143 was delivered into the myocardium through the right carotid artery immediately before the hearts (n=6/group) were subjected to I/R. We observed that delivery of Exo-antimiR-143 significantly enhanced EF% by 20.5% and FS% by 26.4% and decreased infarct size by 42.2%, when compared with untreated I/R group. Delivery of Exo-miR-control did not alter I/R-induced cardiac dysfunction and infarct size. We conclude that poly (I:C) attenuates myocardial I/R injury via glycolytic dependent YAP mechanism and suppression of miR-143 expression.

Attenuation of cardiac dysfunction and remodeling of myocardial infarction by microRNA-130a are mediated by suppression of PTEN and activation of PI3K dependent signaling

OBJECTIVE

Activation of PI3K/Akt signaling protects the myocardium from ischemia/reperfusion injury. MicroRNAs have been demonstrated to play an important role in the regulation of gene expression at the post-transcriptional level. In this study, we examined whether miR-130a will attenuate cardiac dysfunction and remodeling after myocardial infarction (MI) via PI3K/Akt dependent mechanism.

APPROACHES AND RESULTS

To determine the role of miR-130a in the proliferation and migration of endothelial cells, HUVECs were transfected with miR-130a mimics before the cells were subjected to scratch-induced wound injury. Transfection of miR-130a mimics stimulated the migration of endothelial cells into the wound area and increased phospho-Akt levels. To examine the effect of miR-130a on cardiac dysfunction and remodeling after MI, Lentivirus expressing miR-130a (LmiR-130a) was delivered into mouse hearts seven days before the mice were subjected to MI. Cardiac function was assessed by echocardiography before and for up to 21 days after MI. Ejection fraction (EF%) and fractional shortening (FS%) in the LmiR-130a transfected MI hearts were significantly greater than in LmiR-control and untransfected control MI groups. LmiR-130a transfection increased capillary number and VEGF expression, and decreased collagen deposition in the infarcted myocardium. Importantly, LmiR-130a transfection significantly suppressed PTEN expression and increased the levels of phosphorylated Akt in the myocardium. However, treatment of LmiR-130a-transfected mice with LY294002, a PI3K inhibitor, completely abolished miR-130a-induced attenuation of cardiac dysfunction after MI.

CONCLUSIONS

miR-130a plays a critical role in attenuation of cardiac dysfunction and remodeling after MI. The mechanisms involve activation of PI3K/Akt signaling via suppression of PTEN expression.

Attenuation of Cardiac Dysfunction in Polymicrobial Sepsis by MicroRNA-146a Is Mediated via Targeting of IRAK1 and TRAF6 Expression

Cardiac dysfunction is a major consequence of sepsis/septic shock and contributes to the high mortality of sepsis. Innate and inflammatory responses mediated by TLRs play a critical role in sepsis-induced cardiac dysfunction. MicroRNA-146 (miR-146) was first identified as a negative regulator in innate immune and inflammatory responses induced by LPS. This study examined whether miR-146a will have a protective effect on sepsis-induced cardiac dysfunction. Lentivirus-expressing miR-146a (LmiR-146a) or lentivirus-expressing scrambled miR (LmiR-control) was delivered into the myocardium via the right carotid artery. Seven days after transfection, mice were subjected to cecal ligation and puncture (CLP). Untransfected mice were also subjected to CLP-induced sepsis. Cardiac function was examined by echocardiography before and 6 h after CLP. In vitro studies showed that increased miR-146a levels suppress LPS-induced IκBα phosphorylation and inflammatory cytokine production in both H9C2 cardiomyocytes and J774 macrophages. In vivo transfection of LmiR-146a attenuated sepsis-induced cardiac dysfunction. The values for percent ejection fraction and percent fractional shortening in LmiR-146a-transfected CLP mice were significantly greater than in untransfected CLP control. LmiR-146a transfection prevented sepsis-induced NF-κB activity, suppressed IRAK and TRAF6 expression in the myocardium, and attenuated sepsis-induced inflammatory cytokine production in both plasma and peritoneal fluid. In addition, LmiR-146a transfection decreased sepsis-induced infiltration of neutrophils and macrophages into the myocardium. LmiR-146a can also transfect macrophages in the periphery. We conclude that miR-146a attenuates sepsis-induced cardiac dysfunction by preventing NF-κB activation, inflammatory cell infiltration, and inflammatory cytokine production via targeting of IRAK and TRAF6 in both cardiomyocytes and inflammatory monocytic cells.

Pellino1-mediated TGF-β1 synthesis contributes to mechanical stress induced cardiac fibroblast activation

Activation of cardiac fibroblasts is a key event in the progression of cardiac fibrosis that leads to heart failure. However, the molecular mechanisms underlying mechanical stress-induced cardiac fibroblast activation are complex and poorly understood. This study demonstrates that Pellino1, an E3 ubiquitin ligase, was activated in vivo in pressure overloaded rat hearts and in cultured neonatal rat cardiac fibroblasts (NRCFs) exposed to mechanical stretch in vitro. Suppression of the expression and activity of Pellino1 by adenovirus-mediated delivery of shPellino1 (adv-shpeli1) attenuated pressure overload-induced cardiac dysfunction and cardiac hypertrophy and decreased cardiac fibrosis in rat hearts. Transfection of adv-shpeli1 also significantly attenuated mechanical stress-induced proliferation, differentiation and collagen synthesis in NRCFs. Pellino1 silencing also abrogated mechanical stretch-induced polyubiquitination of tumor necrosis factor-alpha receptor association factor-6 (TRAF6) and receptor-interacting protein 1 (RIP1) and consequently decreased the DNA binding activity of nuclear factor-kappa B (NF-κB) in NRCFs. In addition, Pellino1 silencing prevented stretch-induced activation of p38 and activator protein 1 (AP-1) binding activity in NRCFs. Chromatin Immunoprecipitation (ChIP) and luciferase reporter assays showed that Pellino1 silencing prevented the binding of NF-κB and AP-1 to the promoter region of transforming growth factor-β1 (TGF-β1) thus dampening TGF-β1 transactivation. Our data reveal a previously unrecognized role of Pellino1 in extracellular matrix deposition and cardiac fibroblast activation in response to mechanical stress and provides a novel target for treatment of cardiac fibrosis and heart failure.

Poly (I:C) therapy decreases cerebral ischaemia/reperfusion injury via TLR3-mediated prevention of Fas/FADD interaction

Toll-like receptor (TLR)-mediated signalling plays a role in cerebral ischaemia/reperfusion (I/R) injury. Modulation of TLRs has been reported to protect against cerebral I/R injury. This study examined whether modulation of TLR3 with poly (I:C) will induce protection against cerebral I/R injury. Mice were treated with or without Poly (I:C) (n = 8/group) 1 hr prior to cerebral ischaemia (60 min.) followed by reperfusion (24 hrs). Poly (I:C) pre-treatment significantly reduced the infarct volume by 57.2% compared with untreated I/R mice. Therapeutic administration of Poly (I:C), administered 30 min. after cerebral ischaemia, markedly decreased infarct volume by 34.9%. However, Poly (I:C)-induced protection was lost in TLR3 knockout mice. In poly (I:C)-treated mice, there was less neuronal damage in the hippocampus compared with untreated I/R mice. Poly (I:C) treatment induced IRF3 phosphorylation, but it inhibited NF-κB activation in the brain. Poly (I:C) also decreased I/R-induced apoptosis by attenuation of Fas/FasL-mediated apoptotic signalling. In addition, Poly (I:C) treatment decreased microglial cell caspase-3 activity. In vitro data showed that Poly (I:C) prevented hypoxia/reoxygenation (H/R)-induced interaction between Fas and FADD as well as caspase-3 and -8 activation in microglial cells. Importantly, Poly (I:C) treatment induced co-association between TLR3 and Fas. Our data suggest that Poly (I:C) decreases in cerebral I/R injury via TLR3 which associates with Fas, thereby preventing the interaction of Fas and FADD, as well as microglial cell caspase-3 and -8 activities. We conclude that TLR3 modulation by Poly (I:C) could be a potential approach for protection against ischaemic stroke.

The TLR9 ligand, CpG-ODN, induces protection against cerebral ischemia/reperfusion injury via activation of PI3K/Akt signaling

Background

Toll‐like receptors (TLRs) have been shown to be involved in cerebral ischemia/reperfusion (I/R) injury. TLR9 is located in intracellular compartments and recognizes CpG‐DNA. This study examined the effect of CpG‐ODN on cerebral I/R injury.

Methods and Results

C57BL/6 mice were treated with CpG‐ODN by i.p. injection 1 hour before the mice were subjected to cerebral ischemia (60 minutes) followed by reperfusion (24 hours). Scrambled‐ODN served as control‐ODN. Untreated mice, subjected to cerebral I/R, served as I/R control. The effect of inhibitory CpG‐ODN (iCpG‐ODN) on cerebral I/R injury was also examined. In addition, we examined the therapeutic effect of CpG‐ODN on cerebral I/R injury by administration of CpG‐ODN 15 minutes after cerebral ischemia. CpG‐ODN administration significantly decreased cerebral I/R‐induced infarct volume by 69.7% (6.4±1.80% vs 21.0±2.85%, P<0.05), improved neurological scores, and increased survival rate, when compared with the untreated I/R group. Therapeutic administration of CpG‐ODN also significantly reduced infarct volume by 44.7% (12.6±2.03% vs 22.8±2.54%, P<0.05) compared with untreated I/R mice. Neither control‐ODN, nor iCpG‐ODN altered I/R‐induced cerebral injury or neurological deficits. Nissl staining showed that CpG‐ODN treatment preserved neuronal morphology in the ischemic hippocampus. Immunoblot showed that CpG‐ODN administration increased Bcl‐2 levels by 41% and attenuated I/R‐increased levels of Bax and caspase‐3 activity in ischemic brain tissues. Importantly, CpG‐ODN treatment induced Akt and GSK‐3β phosphorylation in brain tissue and cultured microglial cells. PI3K inhibition with LY294002 abolished CpG‐ODN‐induced protection.

Conclusion

CpG‐ODN significantly reduces cerebral I/R injury via a PI3K/Akt‐dependent mechanism. Our data also indicate that CpG‐ODN may be useful in the therapy of cerebral I/R injury.

MicroRNA-125b protects against myocardial ischaemia/reperfusion injury via targeting p53-mediated apoptotic signalling and TRAF6

AIMS

The present study examined the role of microRNA-125b (miR-125b) in myocardial ischaemia/reperfusion (I/R) injury. We constructed lentivirus-expressing miR-125b (LmiR-125b) and developed transgenic mice with overexpression of miR-125b.

METHODS AND RESULTS

LmiR-125b was transfected into mouse hearts through the right common carotid artery. Lentivirus vector (LmiR-Con) served as vector control. Untreated mice served as I/R control. Sham operation served as sham control. Seven days after transfection, the hearts were subjected to ischaemia (45 min) followed by reperfusion (4 h). Myocardial infarct size was analysed by 2,3,5-triphenyltetrazolium chloride staining. In separate experiments, hearts were subjected to ischaemia (45 min) followed by reperfusion for up to 7 days. Cardiac function was measured by echocardiography before, as well as 3 and 7 days after myocardial I/R. Increased expression of miR-125b significantly decreased I/R-induced myocardial infarct size by 60% and prevented I/R-induced decreases in ejection fraction (EF%) and fractional shortening (%FS). Transgenic mice with overexpression of miR-125b also showed the protection against myocardial I/R injury. Increased expression of miR-125b attenuated I/R-induced myocardial apoptosis and caspase-3/7 and -8 activities. Western blot showed that increased expression of miR-125b suppresses p53 and Bak1 expression in the myocardium. In addition, transfection of LmiR-125b decreased the levels of TNF receptor-associated factor 6 (TRAF6) and prevented I/R-induced NF-κB activation.

CONCLUSION

miR-125 protects the myocardium from I/R injury by preventing p53-mediated apoptotic signalling and suppressing TRAF6-mediated NF-κB activation.

Experimental demonstration of energy-chirp control in relativistic electron bunches using a corrugated pipe

The first experimental study is presented of a corrugated wall device that uses wakefields to remove a linear energy correlation in a relativistic electron beam (a "dechirper"). Time-resolved measurements of both longitudinal and transverse wakefields of the device are presented and compared with simulations. This study demonstrates the feasibility to employ a dechirper for precise control of the beam phase space in the next generation of free-electron-lasers.

Toll-like receptor 3 plays a role in myocardial infarction and ischemia/reperfusion injury

Innate immune and inflammatory responses mediated by Toll like receptors (TLRs) have been implicated in myocardial ischemia/reperfusion (I/R) injury. This study examined the role of TLR3 in myocardial injury induced by two models, namely, myocardial infarction (MI) and I/R. First, we examined the role of TLR3 in MI. TLR3 deficient (TLR3(-/-)) and wild type (WT) mice were subjected to MI induced by permanent ligation of the left anterior descending (LAD) coronary artery for 21days. Cardiac function was measured by echocardiography. Next, we examined whether TLR3 contributes to myocardial I/R injury. TLR3(-/-) and WT mice were subjected to myocardial ischemia (45min) followed by reperfusion for up to 3days. Cardiac function and myocardial infarct size were examined. We also examined the effect of TLR3 deficiency on I/R-induced myocardial apoptosis and inflammatory cytokine production. TLR3(-/-) mice showed significant attenuation of cardiac dysfunction after MI or I/R. Myocardial infarct size and myocardial apoptosis induced by I/R injury were significantly attenuated in TLR3(-/-) mice. TLR3 deficiency increases B-cell lymphoma 2 (BCL2) levels and attenuates I/R-increased Fas, Fas ligand or CD95L (FasL), Fas-Associated protein with Death Domain (FADD), Bax and Bak levels in the myocardium. TLR3 deficiency also attenuates I/R-induced myocardial nuclear factor KappaB (NF-κB) binding activity, Tumor necrosis factor alpha (TNF-α) and Interleukin-1 beta (IL-1β) production as well as I/R-induced infiltration of neutrophils and macrophages into the myocardium. TLR3 plays an important role in myocardial injury induced by MI or I/R. The mechanisms involve activation of apoptotic signaling and NF-κB binding activity. Modulation of TLR3 may be an effective approach for ameliorating heart injury in heart attack patients.

The cardioprotection induced by lipopolysaccharide involves phosphoinositide 3-kinase/Akt and high mobility group box 1 pathways

Objective

The mechanisms by which lipopolysaccharide (LPS) pretreatment induces cardioprotection following ischaemia/reperfusion (I/R) have not been fully elucidated. We hypothesized that activation of phosphoinositide 3-kinase (PI3K)/Akt and high mobility group box 1 (HMGBx1) signaling plays an important role in LPS-induced cardioprotection.

Methods

In in vivo experiments, age- and weight- matched male C57BL/10Sc wild type mice were pretreated with LPS before ligation of the left anterior descending coronary followed by reperfusion. Infarction size was examined by triphenyltetrazolium chloride (TTC) staining. Akt, phospho-Akt, and HMGBx1 were assessed by immunoblotting with appropriate primary antibodies. In situ cardiac myocyte apoptosis was examined by the TdT-mediated dUTP nick-end labeling (TUNEL) assay. In an in vitro study, rat cardiac myoblasts (H9c2) were subdivided into two groups, and only one was pretreated with LPS. After pretreatment, the cells were transferred into a hypoxic chamber under 0.5% O₂. Levels of HMGBx1 were assessed by immunoblot.

Results

In the in vivo experiment, pretreatment with LPS reduced the at risk infarct size by 70.6% and the left ventricle infarct size by 64.93% respectively. Pretreatment with LPS also reduced cardiac myocytes apoptosis by 39.1% after ischemia and reperfusion. The mechanisms of LPS induced cardioprotection involved increasing PI3K/Akt activity and decreasing expression of HMGBx1. In the in vitro study, pretreatment with LPS reduced the level of HMGBx1 in H9c2 cell cytoplasm following hypoxia.

Conclusion

The results suggest that the cardioprotection following I/R induced by LPS pretreatment involves PI3K/Akt and HMGBx1 pathways.

Increased expression of microRNA-146a decreases myocardial ischaemia/reperfusion injury

AIMS

We have reported that either toll-like receptor 4 deficiency (TLR4(-/-)) or TLR2 modulation protects against myocardial ischaemia/reperfusion (I/R) injury. The mechanisms involve attenuation of I/R-induced nuclear factor KappaB (NF-κB) activation. MicroRNA-146a (miR-146a) has been reported to target interleukin-1 receptor-associated kinase 1 (IRAK1) and tumor necrosis factor (TNF) receptor associated factor 6 (TRAF6), resulting in inhibiting NF-κB activation. This study examined the role of microRNA-146a in myocardial I/R injury.

METHODS AND RESULTS

We constructed lentivirus expressing miR-146a (LmiR-146a). LmiR-146a was transfected into mouse hearts through the right common carotid artery. The lentivirus vector (LmiR-Con) served as vector control. Untransfected mice served as I/R control. Sham operation served as sham control. Seven days after transfection, the hearts were subjected to ischaemia (60 min) followed by reperfusion (4 h). Myocardial infarct size was analysed by triphenyltetrazolium chloride (TTC) staining. In separate experiments, the hearts were subjected to ischaemia (60 min) followed by reperfusion for up to 7 days. Cardiac function was measured by echocardiography prior to I/R, 3 and 7 days after myocardial I/R. LmiR-146a transfection significantly decreased I/R-induced myocardial infarct size by 55% and prevented I/R-induced decreases in ejection fraction (EF%) and fractional shortening (%FS). LmiR-146a transfection attenuated I/R-induced myocardial apoptosis and caspase-3/7 and -8 activities. LmiR-146a transfection suppresses IRAK1 and TRAF6 expression in the myocardium. In addition, transfection of LmiR-146a prevented I/R-induced NF-κB activation and inflammatory cytokine production.

CONCLUSIONS

MicroRNA-146a protects the myocardium from I/R injury. The mechanisms may involve attenuation of NF-κB activation and inflammatory cytokine production by suppressing IRAK1 and TRAF6.

Abstract WP112: The TLR9 Ligand, CpG-ODN, Induces Protection Against Cerebral Ischemia/reperfusion Injury Via A PI3K/Akt Dependent Mechanism

Background: Toll-like receptors (TLRs) are involved in the pathophysiology of cerebral ischemia/reperfusion injury. TLR9 is an intracellular TLR which is located in the endosome and recognizes CpG-DNA. The role of TLR9 in ischemic stroke has not been investigated. We hypothesized that TLR9 activation would induce protection against cerebral I/R injury.

Methods: To evaluate our hypothesis, we treated C57BL/6 mice with CpG-ODN (10 μg/mouse, n=8), by i.p. injection one hr before the mice were subjected to cerebral ischemia (60 min) followed by reperfusion (24 hrs). Scrambled-ODN served as control-ODN (10 μg/mouse, n=8). Untreated mice, subjected to cerebral I/R, served as I/R control (n=8). We also examined the effect of inhibitory CpG-ODN (iCpG-ODN), a TLR9 antagonist, on cerebral I/R injury (n=8). In addition, the therapeutic effect of CpG-ODN on cerebral I/R injury was investigated by i.v. injection of CpG-OND 15 min after cerebral ischemia.

Results: CpG-ODN administration significantly attenuated cerebral I/R induced infarct volume (↓ 75.8%, p<0.05) improved neurological scores and increased survival rate when compared with the untreated I/R group. Of greater significance, therapeutic administration of CpG-ODN also significantly reduced infarct volume by 52.6% (p<0.05) compared with untreated I/R mice. Neither control-ODN, nor iCpG-ODN altered I/R-induced cerebral injury or neurological deficits. Nissl staining showed preservation of neuronal morphology in the ischemic hippocampus in CpG-ODN treated mice. Immunoblot showed that CpG-ODN administration increased Bcl-2 levels and attenuated Bax, Fas-L, TNF-α, and caspase-3 activity in ischemic brain tissues. CpG-ODN treatment also significantly increased the levels of p-Akt and p-GSK-3β. PI3K inhibition with LY29004 abolished CpG-ODN-induced protection against cerebral I/R injury.

Conclusion: The data suggest that the TLR9 ligand, CpG-ODN, significantly reduces focal cerebral I/R injury via a PI3K/Akt-dependent mechanism. The data also indicates that therapeutic administration of CpG-ODN during cerebral ischemia is effective in reducing cerebral I/R injury.

The Toll-like receptor 9 ligand, CpG oligodeoxynucleotide, attenuates cardiac dysfunction in polymicrobial sepsis, involving activation of both phosphoinositide 3 kinase/Akt and extracellular-signal-related kinase signaling

BACKGROUND

Toll-like receptors (TLRs) play a role in the pathophysiology of sepsis and multiple organ failure. This study examined the effect of CpG oligodeoxynucleotide (CpG-ODN), the TLR9 ligand, on polymicrobial sepsis-induced cardiac dysfunction.

METHODS

Male C57BL/6 mice were treated with CpG-ODN, control CpG-ODN (control-ODN), or inhibitory CpG-ODN (iCpG-ODN) 1 hour prior to cecal ligation and puncture (CLP)-induced sepsis. Mice that underwent sham surgery served as sham controls. Cardiac function was examined by echocardiography before and 6 hours after CLP.

RESULTS

Cardiac function was significantly decreased 6 hours after CLP. CpG-ODN prevented CLP-induced cardiac dysfunction, as evidenced by maintenance of the ejection fraction and fractional shortening. Control-ODN or iCpG-ODN did not alter CLP-induced cardiac dysfunction. CpG-ODN significantly attenuated CLP-induced myocardial apoptosis and increased myocardial Akt and extracellular-signal-related kinase (ERK) phosphorylation levels following CLP. In vitro experiments demonstrated that CpG-ODN promotes an association between TLR9 and Ras, resulting in Akt and ERK phosphorylation. Inhibition of phosphoinositide 3-kinase (PI3K) by Ly294002 or inhibition of ERK by U0126 in vivo abolished CpG-ODN attenuation of CLP-induced cardiac dysfunction.

CONCLUSIONS

CpG-ODN prevents CLP-induced cardiac dysfunction, in part through activation of PI3K/Akt and ERK signaling. Modulation of TLR9 could be an effective approach for treatment of cardiovascular dysfunction in patients with sepsis or septic shock.

Abstract P3-05-06: Automated analysis of Her2 FISH using combined Immunofluorescence and FISH signals

Introduction: Qualifying patients for Her2 targeted therapy is currently done by detecting Her2 protein overexpression or gene amplification using immunohistochemistry and/or FISH. We have recently developed a method for detecting both signals on the same tissue section allowing direct correlation of protein expression and gene copy number on a cell by cell basis. Accurate assessment of Her2 gene copy number is critical and can pose a challenge due to tumor heterogeneity. This paper reports the accuracy of a proprietary FISH dot counting algorithm on a cell-by-cell basis, potentially allowing analysis of thousands instead of dozens of tumor cells.

Method: Automatic FISH signal counts were compared to manual counts of 888 cells selected from 19 invasive ductal breast carcinoma samples exhibiting varying degrees of Her2 expression collected between June 2011 and March 2012. Tissue sections (4 µm) were mounted on positively charged slides, baked and processed through deparaffinization, rehydration and antigen retrieval, then stained for immunofluorescence (IF) using Cy5 labeled Her2 and Cy3 labeled cytokeratin antibodies, counterstained with DAPI, and imaged using InCell 2000 analyzer with GE-proprietary acquisition and processing software. Images were collected at 10x magnification and digitally stitched to span the entire tissue section. A pathologist then selected separate tumor and adjacent normal epithelium regions for subsequent imaging at 40x magnification. Slides were subsequently processed for FISH by pepsin digestion and then subjected to FISH by using PathVysion kit (Abbott Molecular, Des Plaines, IL). After hybridization and subsequent high stringency washes, samples were DAPI stained and mounted for microscopy. Samples were imaged at 40x at the same regions recorded for 40x IF acquisition, using filtersets appropriate for FISH fluorophores and DAPI.

A proprietary automated processing algorithm was used to analyze combined IF and FISH signals and derive case specific Her2 score from the tumor and/or adjacent normal epithelium. Cell-level dot counting accuracy was assessed using two metrics comparing automated counts to manual counts: cell classification agreement, where a normal cell was defined as having 3 or less Her2 and Cep17 dots; and dot-counting match, where a difference of more than 20% in absolute counts was considered an error.

Result: Our automatic results gave an overall cell-by-cell classification agreement of 88% (range 71% to 98% by case). Combining classification agreement and counting match, our algorithm gave an overall accuracy of 81% (range 63% to 97% by case). Restricting to tumor tissues (as judged by pathologist review of IF) classification agreement and accuracy were 84% and 72%, respectively.

Conclusion: The observed variability in algorithm performance between the different cases was due to the fact that error root causes were case dependent. For instance, the main cause of over-counting errors was image noise and artifacts. On the other hand, the main cause of under-counting was low image contrast, especially in highly amplified cases. These results are an early indication of the promise of automatic dot counting applied to breast cancer slides multiplexed for Her2 IF and FISH.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-05-06.