Barriers and facilitators for the implementation and expansion of outpatient parenteral antimicrobial therapy: a systematic review

Outpatient parenteral antimicrobial therapy (OPAT) has been expanding in recent years and serves as a viable solution in reducing the shortage of hospital beds. However, the wider implementation of OPAT faces numerous challenges. This review aimed to assess implementation barriers and facilitators of OPAT services. Studies describing barriers and facilitators of the OPAT service were retrieved from PubMed, Scopus, MEDLINE, EMBASE, CINAHL, Cochrane Library, Web of Science Proceedings, International Pharmaceutical Abstracts and PsycINFO. All types of study designs published in the English language were included. Studies that did not mention any barrier or facilitator, did not differentiate OPAT and inpatient, focused on specific antimicrobials or diseases, and made no distinction between parenteral and other treatments were excluded. Qualitative analysis was performed using the 'best-fit' framework approach and the Consolidated Framework for Implementation Research (CFIR). The review was PROSPERO registered (CRD42023441083). A total of 8761 studies were screened for eligibility and 147 studies were included. Problems in patient selection, lack of awareness, poor communication and co-ordination, lack of support, lack of structured service and inappropriate prescriptions were identified. OPAT provides safe, effective and efficient treatment while maintaining patients' privacy and comfort, resulting in less daily life disruption, and reducing the risk of infection. Satisfaction and preference for OPAT were very high. Initiatives in strengthening OPAT such as antimicrobial stewardship and telemedicine are beneficial. Challenges to and facilitators of OPAT were identified among patients, health professionals, OPAT service providers and healthcare administrators. Understanding them is crucial to designing targeted initiatives for successful OPAT service implementation.

Potential Impact of SOD2 (rs4880; p.Val16Ala) Variant with the Susceptibility for Childhood Bronchial Asthma

Oxidative stress is a sophisticated situation that orignates from the accumulation of reactive free radicals within cellular compartments. The antioxidant mechanism of the MnSOD enzyme facilitates the removal of these lethal oxygen species from cellular components. The main goal of this pertained work is to study the contribution of the SOD2 (rs4880; p.Val16Ala) variant to the development of bronchial asthma among children. The study's design was carried out based on a total of 254 participants including 127 asthmatic children (91 atopic and 36 non-atopic) along with 127 unrelated healthy controls. Allelic discrimination analysis was executed using the T-ARMS-PCR protocol. This potential variant conferred a significant association with decreased risk of bronchial asthmatic children under allelic (OR = 0.56, P-value = 0.002), recessive (OR = 0.32, P-value = 0.011), and dominant (OR = 0.51, P-value = 0.040) models. Additionally, atopic and non-atopic asthmatic children indicated a protection against bronchial asthma development under allelic, and dominant models (p-value < 0.05). Our findings suggested that the SOD2*rs4880 variant was correlated with decreased risk of childhood bronchial asthma.

The histone methyltransferase SETD2 drives cardiometabolic heart failure with preserved ejection fraction

Background

Heart failure with preserved ejection fraction (HFpEF) is highly prevalent in patients with cardiometabolic disorders and associates with a poor outcome. Pathological gene expression in heart failure is accompanied by changes in active histone marks without major alterations in DNA methylation. Histone 3 trimethylation at lysine 36 (H3k36me3) – an active chromatin mark induced by the methyltransferase SETD2 – was recently found among the top epigenetic signatures in failing human hearts. Yet, the role of SETD2/H3k36me3 in heart failure is poorly understood.

Purpose

To investigate whether SETD2 participates in the transcriptional regulation of cardiometabolic HFpEF.

Methods

Mice with cardiomyocyte-specific deletion of SETD2 (c-SETD2−/−) and control littermates (SETD2fl/fl) were generated and subjected to high fat diet feeding and L-NAME treatment for 15 weeks to induce cardiometabolic HFpEF. Histology, mouse echocardiography (Vevo3100) and Treadmill exhaustion test were performed. ChIP-Seq datasets were employed to determine the biological pathways regulated by H3k36me3, whereas chromatin immunoprecipitation assays (ChIP) were performed to investigate SETD2/H3k36me3 enrichment on gene promoters. SETD2 gain- and loss-of-function experiments were performed in cultured cardiomyocytes (CMs) exposed to palmitic acid. Lipotoxic injury was assessed by mass spectrometry (MS)-based quantification of lipid species, autophagic flux (by Western blot) and apoptosis (by Caspase-3 activity assay). SETD2/H3k36me3 were also investigated in left ventricular myocardial specimens from patients with HFpEF and were correlated to passive stiffness.

Results

ChIP-Seq in mouse CMs showed a strong enrichment of SETD2/H3k36me3 in pathways underpinning triglyceride synthesis. SETD2 and H3k36me3 were upregulated in HFpEF vs. control mouse hearts and were highly enriched on the promoter of sterol regulatory element-binding transcription factor 1 (SREBF1) gene. These changes were associated with SREBF1 upregulation, myocardial triglyceride accumulation and lipotoxic damage. In HFpEF mice, cardiomyocyte-specific deletion of SETD2 prevented hypertrophic remodeling, diastolic dysfunction and lung congestion while improving exercise tolerance. Moreover, SETD2 deletion blunted H3K36me3 enrichment on SREBF1 promoter thus preventing SREBF1-related lipid accumulation, impaired autophagic flux and apoptosis. In cultured CMs exposed to palmitic acid, SETD2 depletion prevented H3k36me3-driven SREBF1 upregulation, whereas SETD2 overexpression recapitulated lipotoxic damage. SREBF1 knockdown prevented lipotoxic injury in SETD2-overexpressing CMs, suggesting its direct role in SETD2 signalling. Finally, SETD2 was upregulated in myocardial samples from obese patients with HFpEF and positively correlated with cardiomyocyte stiffness, a major feature of HFpEF.

Conclusions

SETD2 may represent an attractive molecular target for the prevention of cardiometabolic HFpEF.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): University of Zürich

A methylation-dependent checkpoint by SETD7 promotes myocardial ischemic injury in mice and men

Background

Despite appropriate revascularization strategies, a significant number of patients with myocardial infarction (MI) develop ischemic heart failure suggesting that breakthrough therapies are yet to be approved in this setting. Methylation of non-histone proteins is emerging as a central regulatory mechanism in health and disease. The methyltransferase SETD7 has been shown to methylate and alter the function of a variety of proteins in vitro, however, its function in the heart is poorly understood.

Purpose

To determine the role of SETD7 in myocardial ischemic injury.

Methods

Neonatal rat ventricular myocytes (NRVM) were exposed to normal glucose levels or glucose deprivation (GD) for 15 h, in the presence of the selective SETD7 inhibitor (R)-PFI-2 or its inactive enantiomer (S)-PFI-2. Western blot and real-time PCR were employed to investigate the effects of energy stress on SETD7 and the Hippo pathway, while apoptosis and oxidative stress were assessed by Caspase-3 activity assay and mitoSOX staining. YAP transcriptional activity was assessed by chromatin immunoprecipitation assay (ChIP) while its localization and methylation were examined by confocal microscopy and immunoblotting, respectively. SETD7 knockout (SETD7−/−) mice and wild-type (WT) littermates underwent myocardial ischemia-reperfusion (I/R) injury (1h coronary ligation /24 h of reperfusion) followed by assessment of cardiac function by echocardiography. Left ventricular (LV) myocardial samples were collected from I/R mice and patients with ischemic cardiomyopathy (ICM), and isolated cardiomyocytes were treated with (R)-PFI-2. Finally, SETD7 expression was also assessed in peripheral blood mononuclear cells (PBMCs) from patients with ST-elevation MI (STEMI).

Results

SETD7 was activated upon energy deprivation in cultured NRVMs and methylated YAP, leading to its cytosolic retention and impaired transcription of antioxidant genes MnSOD and CAT. Pharmacological inhibition of SETD7 by (R)-PFI-2 restored YAP nuclear localization thus preventing mitochondrial reactive oxygen species (mtROS) and apoptosis. SETD7 deletion in mice attenuated I/R injury, mtROS and LV dysfunction by restoring YAP-dependent transcriptional programs. SETD7/YAP dysregulation was also observed in LV specimens from ICM patients. Moreover, in cardiomyocytes isolated from I/R mice and ICM patients, (R)-PFI-2 restored YAP nuclear localization, prevented mtROS accumulation while improving myofibrillar protein contractility and Ca2+ sensitivity. Finally, SETD7 was upregulated in PBMCs from STEMI patients and negatively correlated with the expression of MnSOD and CAT.

Conclusions

SETD7-dependent methylation of YAP is an important mechanism underpinning myocardial oxidative stress and apoptosis during ischemia. Pharmacological modulation of SETD7 by (R)-PFI-2 may represent a potential therapeutic approach to prevent myocardial ischemic damage through modulation of the Hippo pathway.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): University of Zurich

Targeting Neurofibromin 2 (NF2) prevents endothelial dysfunction in obesity: a study in mice and humans

Introduction

The mechanisms underlying endothelial dysfunction (ED) in obesity are poorly understood. Neurofibromin 2 (NF2) is a scaffold-like protein involved in cell growth and survival. However, its role in the vascular endothelium is unknown.

Purpose

To investigate NF2 function in obesity-related ED.

Methods

Human aortic endothelial cells (HAECs) were exposed to palmitic acid (PA, 200 uM) or vehicle for 48 hours. Gene silencing of NF2 was performed by small interfering RNA (siRNA). Gene and protein expression were assessed by real time PCR and Western blot, respectively. The interaction of NF2 with endothelial proteins was investigated by co-immunoprecipitation. A constitutive active mutant form of NF2 (Ala518) was employed to study the effects of NF2 gain-of-function. To specifically investigate NF2 role in the vascular endothelium, we generated mice with endothelium-specific deletion of NF2 (NF2 ECKO) by crossing NF2flox/flox mice with tamoxifen-inducible endothelial-specific Cre mice [Cdh5(PAC)-CreERT2]. Endothelium-dependent relaxations to acetylcholine (Ach) were assessed in aortas from NF2 ECKO and wild type (WT) littermates, fed a control and a high fat diet (60 kcal% fat) for 20 weeks. NF2 signalling and endothelial function were also assessed in small visceral fat arteries (VFA) isolated from 18 obese and 18 age-matched healthy subjects undergoing bariatric surgery and cholecystectomy, respectively. Gene in silencing of NF2 by siRNA was performed in VFA from obese patients.

Results

In HAECs, PA promoted NF2 activation by decreasing its phosphorylation at Ser518. Akt and MYPT-1 were responsible for NF2 dephosphorylation. In PA-treated HAECs, NF2 was mainly found in the plasma membrane as compared to other cell fractions. Among different membrane proteins implicated in endothelial homeostasis, NF2 binds and activates Caveolin 1 (Cav-1), a pivotal repressor of endothelial NO synthase (eNOS). NF2 knockdown in PA-treated HAECs prevented eNOS–Cav-1 interaction, thus preserving eNOS activity and NO levels. By contrast, HAECs expressing the constitutive active mutant form of NF2 displayed reduced eNOS activity. In aortas from obese mice, we found that NF2-Cav-1 interaction was responsible for impaired eNOS activity and ED. Cav-1 gene silencing in NF2-overexpressing aortas prevented ED, thus confirming the direct involvement of Cav-1 in NF2-induced ED. Interestingly, Ach-dependent vasorelaxation was preserved in obese NF2 ECKO mice as compared to WT littermates. Moreover, NO bioavailability was preserved in aortas from NF2 ECKO mice. In VFA from obese patients, NF2 was upregulated, and its activity negatively correlated with Ach-dependent vasorelaxation. Of note, NF2 gene silencing in VFA from obese patients rescued ED.

Conclusions

In human endothelial cells, mice with endothelium-specific deletion of NF2 and VFA from obese patients, we show that NF2 drives ED by repressing Cav-1. Targeting NF2 may prevent ED in obese patients.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Holcim Stiftung

Systemic GDF11 replenishment ignites myocardial injury through diminishing anti-apoptotic activity of cardiac progenitor cells

Background

Tissue damage due to acute myocardial infarction is caused by both the ischemic insult and subsequent reperfusion injury (I/R). Restoration of coronary blood flow accelerates cardiomyocyte death, a phenomenon referred to as reperfusion injury, the extent of which is partly modulated by cardiac progenitor cells (CPC). Development of novel therapies to reduce infarct size, the main determinant of outcome, represent a huge unmet medical need (1). Systemic levels of growth differentiation factor 11 (GDF11), a TGF-β superfamily member that shares 90% homology with myostatin, decline with age, and GDF11 replenishment by heterochronic parabiosis or systemic recombinant GDF11 (rGDF11) delivery was postulated to have rejuvenating effects (2).

Purpose

We aimed to probe the effects of systemic GDF11 replenishment on I/R injury and deepen insights into the molecular mechanisms involved.

Methods

We designed a vehicle-controlled study in which young (3–4 months) and old (22–24 months) C57Bl/6 mice were randomly assigned to either daily systemic rGDF11 or control treatment over 30 days before myocardial I/R injury was induced. Dissected hearts were subjected to in-depth profiling followed by IPA-guided -omics to identify key regulatory mechanisms. Finally, in vitro experiments on human CPCs and HL-1 cardiomyocytes were performed.

Results

Myocardial Gdf11 expression declined with age, whereas myostatin (Mstn) showed an opposing expression pattern (Fig. 1A), a trend similarly observed upon I/R (Fig. 1B). Surprisingly, after the 30-day study period (Fig. 1C), young and aged rGDF11-treated mice showed higher I/R-induced infarct size and serum cardiac troponin I levels than controls, despite comparable areas at risk (Fig. 1D). Importantly, while proxies of necroptosis/pyroptosis remained unchanged, rGDF11-treated animals showed reduced cardiomyocyte viability irrespective of their age (Fig. 2A). Targeted transcriptomics applied on cardiac tissues of both groups identified the CPC-marker Nkx2–5 to be differentially regulated (Fig. 2B-C), an expression pattern validated in an independent cohort at both mRNA and protein levels (Fig. 2D). In the adult myocardium, the expression of both Nkx2–5 and its cofactor Gata4 is mainly confined to CPCs; indeed, similar reductions in Nkx2–5 and Gata4 expression were observed in CPCs exposed to rGDF11 (Fig. 2E) which coincided with accelerated cardiomyocyte death if cultured in conditioned media obtained from CPCs treated with rGDF11 (Fig. 2F), pointing toward a paracrine signalling pathway.

Conclusions

Myocardial expression of GDF11 declines with age, and is blunted upon I/R injury, thereby opposing the expression pattern of myostatin. Surprisingly, however, systemic GDF11 replenishment by rGDF11 supplementation enhances rather than reduces myocardial infarct size through augmented apoptosis, a phenomenon mediated by diminished cardioprotective function of CPCs.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Foundation for Cardiovascular Research – Zurich Heart House

A chromatin mark by SETD7 regulates myocardial inflammation in obesity-related heart failure with preserved ejection fraction

Background

Obesity is a major risk factor for heart failure with preserved ejection fraction (HFpEF). Post-translational modification of histones by chromatin modifying enzymes (CMEs) are emerging as pivotal regulators of gene transcription in cardiovascular disease.

Purpose

To investigate the role of chromatin remodelling in obese HFpEF (obHFpEF).

Methods

Gene expression profiling of CMEs (PCR array) was performed in left ventricular (LV) myocardial specimens from obHFpEF patients and age-matched control donors (n=8/group). Among myocardial CMEs, the methyltransferase SETD7 showed the highest variation in gene expression. Hence, we investigated the role of SETD7 and its chromatin mark H3K4me1 in a murine model of obHFpEF. Mice with cardiomyocyte-specific deletion of SETD7 (c-SETD7−/−) and control littermates (SETD7fl/fl) were subjected to high fat diet feeding and L-NAME treatment for 15 weeks to induce obHFpEF. Echocardiography and Treadmill exhaustion test were performed. ChIP-Seq datasets were employed to determine the biological pathways regulated by SETD7, whereas chromatin immunoprecipitation assays (ChIP) were performed to investigate SETD7/H3k4me1 enrichment on target gene promoters. SETD7 gain- and loss-of-function experiments were performed in cultured neonatal rat ventricular myocytes (NRVMs) exposed to palmitic acid (200μM) for 48h. Selective inhibition of SETD7 by (R)-PFI-2 was performed in skinned cardiomyocytes isolated from left ventricular specimens of obHFpEF patients. Passive stiffness, a main feature of HFpEF, was assessed before and after (R)-PFI-2 treatment.

Results

CMEs profiling showed SETD7 as the top-ranking transcript (fold change, 7.36, P&lt;0.01) in myocardial specimens from obHFpEF patients as compared to controls. ChIP-Seq in CMs showed a strong enrichment of SETD7 and H3k4me1 on the promoter of NF-kB p65 gene, a master regulator of inflammation. SETD7 and H3k4me1 were upregulated in HFpEF vs. control mouse hearts, showed enrichment on NF-kB p65 promoter and were associated with IL-1β and IL-6 upregulation. In HFpEF mice, cardiomyocyte-specific deletion of SETD7 protected against LV hypertrophy, diastolic dysfunction (assessed by E/E' ratio) and lung congestion while improving exercise tolerance. At the molecular level, SETD7 deletion blunted H3K4me1 enrichment on p65 promoter thus preventing the upregulation of inflammatory genes and myocardial apoptosis. In cultured CMs exposed to PA, SETD7 inhibition by (R)-PFI-2 prevented H3k4me1-driven p65 upregulation, whereas SETD7 overexpression mimicked HFpEF features. Moreover, knockdown of NF-kB p65 prevented IL-1β/IL-6 transcription in SETD7-overexpressing CMs. Of clinical relevance, (R)-PFI-2 reduced passive stiffness in skinned CMs isolated from obHFpEF patients.

Conclusions

Our results unveil a new epigenetic mechanism underpinning inflammation in obHFpEF. Targeting SETD7 may represent a novel therapeutic approach to prevent HFpEF in obesity.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Swiss National Science Foundation

O040 Patient reported outcomes and experiences following emergency laparotomy: a mixed methods patient survey

Introduction

Emergency laparotomy (EmLap) is a “life-saving” procedure, but little is known about how “life-changing” it can be. This study aims to establish the impact of EmLap on PROMs and PREMs.

Methods

All surviving patients who had an EmLap from 2016–2019 were included. Eligible patients were invited to complete a postal questionnaire. Responses underwent qualitative and logistical regression analysis.

Results

Response rate was 42.6% (n=310). 11.3% reported that they had not resumed intimacy post-op. Patients were less likely to resume intimacy if they were &gt;80 years (OR 10.500, p0.003), had a return to theatre (OR 5.111, p0.017), IBD diagnosis (OR 5.00, p0.009) or stoma (OR 4.906, p0.003). Patients were more likely to change employment if female (OR 2.858, p0.009), more comorbid (ASA3 OR 5.000, p0.024), had a stoma (OR 4.006, p&lt;0.001), or incisional hernia (OR 4.228, p&lt;0.001). Qualitative analysis revealed deconditioning, lack of employer support, and delays to reconstructive surgery were the main reasons for not returning to work. Qualitative analysis of experience exposed a number of unmet needs: surgical “debrief” and “what to expect” (33.6%), surgical aftercare (25.2%), mental-health support (22.6%) and timely restorative surgery (11.7%). 88.1% felt a specialist nurse would have improved their experience. Patients were more likely to have reported a negative experience if they had benign disease (p0.010).

Conclusion

This is the first study to describe PROMS and PREMS following EmLap, and also to identify patients at risk of poor outcome. It advocates the need for an EmLap specialist nurse to facilitate holistic care.

Bioengineered PLEKHA7 nanodelivery regularly induces behavior alteration and growth retardation of acute myeloid leukemia

Acute myeloid leukemia (AML) is the most lethal leukemia with an extremely poor prognosis and high relapse rates. In leukemogenesis, adhesion abnormalities can readily guide an imbalance between hematopoietic progenitor cells and bone marrow stromal cells, altering the normal hematopoietic bone marrow microenvironment into leukemic transformation that enhances leukemic proliferation. Here, we have firstly studied the PLEKHA7 expression in leukemic cells to assess their growth capability affected by the restoration of PLEKHA7 in the cells. The efficacy of PLEKHA7-loaded cRGD-mediated PEGylated cationic lipid nanoparticles for efficient PLEKHA7 delivery in leukemic cells as well as the effect of PLEKHA7 on the regulated induction of AML behavior and growth alterations were investigated. PLEKHA7 re-expression diminished colony-forming ability and reinforced the incidence of growth retardation without apoptosis in AML cell lines. PLEKHA7 regulated the restoration of cell surface adhesion and integrity during normal homeostasis. Our findings revealed that PLEKHA7 functions as a behavior and growth modulator in AML. To our knowledge, the role of PLEKHA7 in AML had not been studied previously and our data could be exploited for further mechanistic studies and insights into altering human AML behavior and growth.

P736Histone marks induced by the methyltransferase SETD7 modulate angiogenic response in diabetes

Introduction

Despite advances in revascularization strategies, type 2 diabetic (T2D) patients with peripheral artery disease (PAD) continue to have a high risk of limb amputation. Hence, strategies that promote vascularization can be considered as a novel therapeutic option in T2D patients with PAD. Epigenetic modifications of histones and DNA have emerged as key modulators of gene expression. Mono-methylation of histone 3 at lysine 4 (H3K4m1) – a specific epigenetic signature induced by the methyltransferase SETD7 – favours a chromatin conformation enabling the transcription of genes involved in inflammation and oxidative stress.

Purpose

To investigate whether SETD7 modulates angiogenesis in experimental diabetes.

Methods

Human aortic endothelial cells (HAECs) were cultured in growth factor-free medium and exposed either to normal glucose (NG, 5 mM) or high glucose (HG, 25 mM) for 48 hours. SETD7 protein and H3K4me1 levels were investigated by Western blot and chromatin immunoprecipitation (ChIP). Knockdown of SETD7 was achieved by small interfering RNA (siRNA). Pharmacological blockade of SETD7 was performed by using the highly selective inhibitor (R)-PFI-2, while its inactive enantiomer, (S)-PFI-2, was used as a control. Scratch and tube formation assays were performed to investigate the impact of SETD7 on angiogenic properties of HAECs. RNA sequencing (RNA-seq) and Ingenuity Pathway Analysis (IPA) were employed to unveil putative genes regulated by SETD7 in HG-treated HAECs. SETD7 expression was also investigated in muscular specimens isolated from type 2 diabetic (db/db) mice and non-diabetic mice undergoing hindlimb ischemia for 21 days.

Results

HG exposure in HAECs led to a time-dependent increase of both SETD7 gene and protein expression, as compared to NG. SETD7 upregulation in HG-treated HAECs was associated with an increase of H3K4me1 levels as well as with impaired endothelial cell migration and tube formation. Of interest, both gene silencing and pharmacological blockade of SETD7 rescued hyperglycemia-induced impairment of angiogenic properties in HAECs. RNA-seq in HG-treated HAECs with and without SETD7 depletion unveiled an array of differentially expressed genes, which were mainly involved in blood vessel growth and angiogenic response, as assessed by IPA analysis. Among dysregulated genes, ChIP assays showed that SETD7-dependent chromatin changes enabled the transcription of Semaphorin 3G (SEMA-3G), a negative regulator of endothelial cell migration. Indeed, gene silencing of SETD7 blunted SEMA-3G expression in HAECs exposed to HG. Consistent with our in vitro observations, SETD7 was upregulated in adductor muscle specimens from db/db mice undergoing hindlimb ischemia as compared to non-diabetic animals.

Conclusions

Pharmacological blockade of SETD7 by (R)-PFI-2 may represent a potential therapeutic approach to boost post-ischemic vascularization in T2D patients with PAD.

2162Neurofibromin 2 (NF2) drives obesity-related endothelial dysfunction by targeting Caveolin-1: a study in mice and humans

Introduction

Endothelial dysfunction (ED) is a key underpinning of cardiovascular disease in obesity, but the underlying molecular mechanisms remain elusive. Neurofibromin 2 (NF2) is a scaffold-like protein implicated in various cellular processes, namely growth, differentiation and survival. NF2 is inactivated by Akt-dependent phosphorylation at Ser518, whereas its dephosphorylation by the myosin phosphatase target subunit 1 (MYPT-1) leads to an active conformation. The role of NF2 in obesity-related alterations of endothelial phenotype remains elusive.

Purpose

To investigate whether NF2 participates to ED in obesity.

Methods

Human aortic endothelial cells (HAECs) were exposed to palmitic acid (PA, 200 uM) or vehicle for 48 hours. Gene silencing of NF2 was performed by small interfering RNA (siRNA). Protein expression was assessed by Western blot. Nitric oxide (NO) levels were measured by using a colorimetric assay. The interaction of NF2 with endothelial proteins was investigated by co-immunoprecipitation. To specifically determine NF2 role in the endothelium, we generated mice with endothelium-specific deletion of NF2 (NF2 ECKO) by crossing NF2flox/flox mice with tamoxifen-inducible endothelial-specific cre mice [Cdh5(PAC)-CreERT2]. Endothelium-dependent relaxations to acetylcholine (Ach, 10–9 to 10–5 mol/L) were assessed in aortas isolated from male NF2 ECKO and wild type littermates, fed a control (10 kcal% fat) and a high fat diet (60 kcal% fat) for 20 weeks. NF2 signalling and endothelial function were also assessed in small visceral fat arteries (VFA) isolated from 18 obese and 18 age-matched healthy subjects undergoing bariatric surgery and cholecystectomy, respectively.

Results

Exposure of HAECs to PA decreased NF2 phosphorylation at Ser518, thus leading to an active protein conformation. Blunted NF2 phosphorylation was explained by a reduction of Akt phosphorylation at Ser473 and a concomitant increase of MYPT-1 phosphorylation at Thr696. Pull-down experiments revealed that NF2 binds and activates Caveolin 1 (Cav-1), a pivotal repressor of endothelial NO synthase (eNOS). NF2 knockdown in PA-treated HAECs prevented eNOS–Cav-1 interaction, thus preserving eNOS activity and NO levels. In aortas from obese mice, we found that NF2-Cav-1 interaction was responsible for impaired eNOS activity, reduced NO levels and endothelial dysfunction. By contrast, Ach-dependent vasorelaxation were preserved in obese mice with endothelium-specific deletion of NF2. Moreover, we found that NF2 is activated in VFA from obese patients as compared to healthy controls, and its activity negatively correlated with Ach-dependent vasorelaxation of isolated VFA, as assessed by organ chamber experiments.

Conclusions

The present findings – obtained in human endothelial cells, conditional mouse models and visceral fat arteries from obese patients – suggest that targeting NF2 may represent a potential therapeutic strategy to prevent ED in patients with obesity.

P5378The methyltransferase SETD7 promotes myocardial ischemic injury by activating Hippo signalling

Introduction

Despite significant advances in coronary revascularization, acute myocardial infarction remains the leading cause of heart failure and death worldwide. The Hippo pathway is a master regulator of cell survival during myocardial ischemia. Upon cellular stress, activation of Hippo signaling leads to cytosolic retention and degradation of the pro-survival transcription factor YAP. Post-translational modifications, namely methylation, critically affect protein functionality in conditions of cellular stress. The SET domain-containing lysine methyltransferase 7 (SETD7) - which induces a specific mono-methylation of both histone and non-histone proteins - has recently emerged as key player in the pathogenesis of vascular disease. However, the role of SETD7 in the heart is largely unknown.

Purpose

The present study investigates whether SETD7 regulates the Hippo pathway during myocardial ischemia.

Methods

Neonatal rat ventricular myocytes (NRVM) were exposed to normal glucose levels or glucose deprivation (GD) for 15 h, in the presence of the selective SETD7 inhibitor [(R)-PFI-2] or its inactive enantiomer [(S)-PFI-2]. Western blot and real time PCR were employed to investigate the effects of energy stress on SETD7 and the Hippo pathway, while apoptosis was assessed by Caspase-3 activity assay. YAP localization was examined by confocal microscopy while its mono-methylation was assessed by immunoblotting. SETD7 knockout (SETD7−/−) mice and wild-type (WT) littermates (male, 8–12 weeks old) underwent 1 h of left anterior descending (LAD) coronary artery ligation followed by 24 h of reperfusion. Infarct size was assessed by TTC staining and shown as infarct size per ventricle surface (I/V). Cardiac function was investigated at 24h by conventional and Tissue Doppler Imaging echocardiography (Vevo 3100, Visualsonics).

Results

GD for 15h in NRVMs led to both YAP phosphorylation and mono-methylation, and subsequent cytosolic retention, as assessed by confocal microscopy. Reduced nuclear content of YAP was confirmed by downregulation of YAP-dependent pro-survival genes, namely Ctgf and Fgf2. GD-induced YAP inactivation was associated with an increase in SETD7 expression. Interestingly, pharmacological inhibition of SETD7 by (R)-PFI-2 blunted YAP mono-methylation, thus restoring nuclear retention of YAP and transcription of pro-survival genes in GD-treated NRVMs. Moreover, (R)-PFI-2 prevented NRVMs apoptosis. In line with our in vitro findings, SETD7−/− mice showed decreased infarct size as compared to WT littermates (I/V: 16.27%±2 vs. 20.54%±3, p<0.005, respectively). Consistently, cardiac function, as assessed by ejection fraction (EF: 46%±2 vs. 38%±5, p<0.001), fractional shortening (FS: 22%±1 vs. 18%±3, p<0.001) as well as by TDI, was preserved in mice lacking SETD7 as compared to WT animals.

Conclusions

Pharmacological modulation of SETD7 by (R)-PFI-2 may represent a novel therapeutic approach to prevent myocardial ischemic damage.

Antitumor activity of intratracheal inhalation of temozolomide (TMZ) loaded into gold nanoparticles and/or liposomes against urethane-induced lung cancer in BALB/c mice

The current study aimed to develop gold nanoparticles (GNPs) and liposome-embedded gold nanoparticles (LGNPs) as drug carriers for temozolomide (TMZ) and investigate the possible therapeutic effects of intratracheal inhalation of nanoformulation of TMZ-loaded gold nanoparticles (TGNPs) and liposome-embedded TGNPs (LTGNPs) against urethane-induced lung cancer in BALB/c mice. Physicochemical characters and zeta potential studies for gold nanoparticles (GNPs) and liposome-embedded gold nanoparticles (LGNPs) were performed. The current study was conducted by inducing lung cancer chemically via repeated exposure to urethane in BALB/C mice. GNPs and LGNPs were exhibited in uniform spherical shape with adequate dispersion stability. GNPs and LGNPs showed no significant changes in comparison to control group with high safety profile, while TGNPs and LTGNPs succeed to improve all biochemical data and histological patterns. GNPs and LGNPs are promising drug carriers and succeeded in the delivery of small and efficient dose of temozolomide in treatment lung cancer. Antitumor activity was pronounced in animal-treated LTGNPs, these effects may be due to synergistic effects resulted from combination of temozolomide and gold nanoparticles and liposomes that may improve the drug distribution and penetration.

Titanium elastic nailing in femoral diaphyseal fractures in children of 6-14 years age

PURPOSE

The purpose of this study is to report our experience of fractures in children riding Hoverboards.

METHODS

We undertook a prospective review of all children attending our hospital who sustained fractures whilst riding a Hoverboard. Data such as patient demographics, type of fracture sustained, treatment received, complications and outcome were collected.

RESULTS

Twelve children, 5 males and 7 females with ages ranging from 5.5 to 15.3 years were included in this study. All patients sustained upper limb fractures and the distal radius was the commonest fracture site (30%). Surgery was required in 6 (50%) out of the 12 patients because the respective fractures were displaced. No patient had any ongoing complaints or disability at the last clinic review.   Conclusion : Children riding Hoverboards are predisposed to upper limb fractures and parents who purchase Hoverboards should be warned about this.

Association of IL-1β +3954 C/T and IL-10-1082 G/A cytokine gene polymorphisms with susceptibility to tuberculosis

Tuberculosis (TB) constitutes the major cause of death due to infectious diseases. Cytokines play a major role in defence against Mycobacterium tuberculosis infection. Polymorphisms in the genes encoding various cytokines have been associated with tuberculosis susceptibility. Household contacts (HHC) are at increased risk of developing the disease. In this study, we examined the association of IL-1β and IL-10 cytokine gene polymorphisms with risk of developing tuberculosis in TB patients, their HHC and healthy controls (HC) using JavaStat and SPSS. Multifactor dimensionality reduction (MDR) analyses were performed to explore the potential gene-gene interactions. The genotype and allele frequencies of IL-1β +3954C/T polymorphism did not vary significantly between TB patients and HC. GG (P < 0.005, OR = 0.219 and 95% CI = 0.059-0.735) and GA (P < 0.0001, OR = 2.938 and 95% CI = 1.526-5.696) genotypes of IL-10-1082 G/A polymorphism were found to be significantly associated with patients versus HC. HHC with CC (P < 0.03, OR = 1.833 and 95% CI = 1.1-3.35) genotype in IL-1β and GA (P < 0.0001, OR = 4.612 and 95% CI = 2.225-9.702) genotype in IL-10 were at increased risk of developing tuberculosis. MDR tests revealed high-risk genotypes in IL-1β and IL-10 based on the association model. Our results demonstrate that the polymorphisms of IL-1β and IL-10 genes may be valuable markers to predict the risk for the development of TB in household contacts.

Pentachlorophenol and phenanthrene biodegradation in creosote contaminated aquifer material

Contamination of the subsurface environment at the Libby Superfund Site, Montana, includes polycyclic aromatic hydrocarbons and f1p4achlorophenol due to accidental spills and improper disposal of wood preserving wastes. Biodegradation is a treatment technology gaining wide application in the treatment of hazardous waste sites. A microcosm study was conducted to evaluate the effect of temperature, sampling depth, nutrient addition, and oxygen on the biodegradation potential of phenanthrene and pentachlorophenol in aquifer samples using radiolabeled chemicals. Mineralization of phenanthrene reached 14% but was less than 1% for pentachlorophenol over the 56 day incubation period. Phenanthrene mineralization in microcosms at 10 degrees C was not significantly different from those at 20 degrees C. This may have been due to microbial community acclimation to lower temperatures at the site. Average volatilization was less than 2% for both phenanthrene and pentachlorophenol. After 56 days, most of the radiolabeled chemical was either solvent extractable or soil bound.

Keys for identification of species of family Calliphoridae (Diptera) in Egypt

The present taxonomic study assists in the recognition of all known Egyptian species of Calliphoridae by keys to genera and species accompanied by synonyms in the light of modern taxonomic concepts. Eight genera are recorded in A.R. Egypt including 14 species. Hemipyrellia pulchra (Wied) is recorded for the first time in Egypt. Chrysomyia chloropyga (Wied) was recorded by Pont (1979) in his study of Synanthropic flies in Saudi Arabia, this species was not recorded or mentioned before him in Egypt and is not represented in our collections.