73 research outputs found

    The E2 ubiquitin-conjugating enzymes UBE2D1 and UBE2D2 regulate VEGFR2 dynamics and endothelial function

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    Vascular endothelial growth factor receptor 2 (VEGFR2, encoded by KDR) regulates endothelial function and angiogenesis. VEGFR2 undergoes ubiquitination that programs this receptor for trafficking and proteolysis, but the ubiquitin-modifying enzymes involved are ill-defined. Herein, we used a reverse genetics screen for the human E2 family of ubiquitin-conjugating enzymes to identify gene products that regulate VEGFR2 ubiquitination and proteolysis. We found that depletion of either UBE2D1 or UBE2D2 in endothelial cells caused a rise in steady-state VEGFR2 levels. This rise in plasma membrane VEGFR2 levels impacted on VEGF-A-stimulated signalling, with increased activation of canonical MAPK, phospholipase Cγ1 and Akt pathways. Analysis of biosynthetic VEGFR2 is consistent with a role for UBE2D enzymes in influencing plasma membrane VEGFR2 levels. Cell-surface-specific biotinylation and recycling studies showed an increase in VEGFR2 recycling to the plasma membrane upon reduction in UBE2D levels. Depletion of either UBE2D1 or UBE2D2 stimulated endothelial tubulogenesis, which is consistent with increased VEGFR2 plasma membrane levels promoting the cellular response to exogenous VEGF-A. Our studies identify a key role for UBE2D1 and UBE2D2 in regulating VEGFR2 function in angiogenesis

    E2 ubiquitin-conjugating enzymes, UBE2D1 and UBE2D2, regulate VEGFR2 dynamics and endothelial function

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    Vascular endothelial growth factor receptor 2 (VEGFR2) regulates endothelial function and angiogenesis. VEGFR2 undergoes ubiquitination which programs this receptor for trafficking and proteolysis but the ubiquitin-modifying enzymes involved are ill-defined. Herein, we used a reverse genetics screen of the human E2 family of ubiquitin-conjugating enzymes to identify gene products which regulate VEGFR2 ubiquitination and proteolysis. We find that depletion of either UBE2D1 or UBE2D2 in endothelial cells cause a rise in steady-state VEGFR2 levels. This rise in plasma membrane VEGFR2 levels impact on VEGF-A-stimulated signalling, with increased activation of canonical MAPK, phospholipase C1, and Akt pathways. Analysis of biosynthetic VEGFR2 is consistent with a role for UBE2D enzymes in influencing plasma membrane VEGFR2 levels. Cell surface biotinylation and recycling studies show an increase in VEGFR2 recycling to the plasma membrane upon reduction in UBE2D levels. Depletion of either UBE2D1 or UBE2D2 stimulates endothelial tubulogenesis which is consistent with increased VEGFR2 plasma membrane levels promoting the cellular response to exogenous VEGF-A. Our studies identify a key role for UBE2D1 and UBE2D2 in regulating VEGFR2 function in angiogenesis

    Rap1 binding and a lipid-dependent helix in talin F1 domain promote integrin activation in tandem.

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    Rap1 GTPases bind effectors, such as RIAM, to enable talin1 to induce integrin activation. In addition, Rap1 binds directly to the talin1 F0 domain (F0); however, this interaction makes a limited contribution to integrin activation in CHO cells or platelets. Here, we show that talin1 F1 domain (F1) contains a previously undetected Rap1-binding site of similar affinity to that in F0. A structure-guided point mutant (R118E) in F1, which blocks Rap1 binding, abolishes the capacity of Rap1 to potentiate talin1-induced integrin activation. The capacity of F1 to mediate Rap1-dependent integrin activation depends on a unique loop in F1 that has a propensity to form a helix upon binding to membrane lipids. Basic membrane-facing residues of this helix are critical, as charge-reversal mutations led to dramatic suppression of talin1-dependent activation. Thus, a novel Rap1-binding site and a transient lipid-dependent helix in F1 work in tandem to enable a direct Rap1-talin1 interaction to cause integrin activation

    “Affimer” synthetic protein scaffolds block oxidized LDL binding to the LOX-1 scavenger receptor and inhibit ERK1/2 activation

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    In multicellular organisms, a variety of lipid-protein particles control the systemic flow of triacylglycerides, cholesterol and fatty acids between cells in different tissues. The chemical modification by oxidation of these particles can trigger pathological responses, mediated by a group of membrane proteins termed scavenger receptors. The lectin-like oxidised low-density lipoprotein (LOX-1) scavenger receptor binds to oxidized low density lipoprotein (oxLDL) and mediates both signaling and trafficking outcomes. Here, we identified 5 synthetic proteins termed Affimers from a phage display library, each capable of binding recombinant LOX-1 extracellular (oxLDL-binding) domain with high specificity. These Affimers, based on a phytocystatin scaffold with loop regions of variable sequence, were able to bind to the plasma membrane of HEK293T cells exclusively when human LOX-1 was expressed. Binding and uptake of fluorescently-labelled oxLDL by the LOX-1-expressing cell model was inhibited with sub-nanomolar potency by all 5 Affimers. ERK1/2 activation, stimulated by oxLDL binding to LOX-1, was also significantly inhibited (p<0.01) by pre-incubation with LOX-1-specific Affimers, but these Affimers had no direct agonistic effect. Molecular modeling indicated that the LOX-1-specific Affimers bound predominantly via their variable loop regions to the surface of the LOX-1 lectin-like domain that contains a distinctive arrangement of arginine residues previously implicated in oxLDL binding, involving interactions with both subunits of the native, stable scavenger receptor homodimer. These data provide a new class of synthetic tools to probe and potentially modulate the oxLDL/LOX-1 interaction that plays an important role in vascular disease

    A multicentre review comparing long term outcomes of endoscopic vein harvesting versus open vein harvesting for coronary artery bypass surgery [version 1; peer review: 1 approved, 2 approved with reservations]

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    Background: Utilisation of the Endoscopic Vein Harvesting (EVH) technique has been increasing for coronary artery bypass grafting (CABG) for the last two decades. Some surgeons remain concerned about the long-term patency of the long saphenous vein harvested endoscopically compared to traditional Open Vein Harvesting (OVH). The aim of this study was to perform a retrospective analysis of the outcomes between EVH and OVH from three UK centres with 10 years follow-up. Methods: 27,024 patients underwent CABG with long saphenous vein harvested by EVH (n=13,794) or OVH (n=13,230) in three UK centres between 2007 and 2019. Propensity modelling was used to calculate the Inverse Probability of Treatment Weights (IPTW). The primary endpoint was mortality from all causes and secondary endpoints were length of hospital stay, postoperative complications, and incidence of repeat coronary re-vascularisation for symptomatic patients. IPTW was used to balance the two intervention groups for baseline and preoperative co-morbidities. Results: Median follow-up time was 4.54 years for EVH and 6.00 years for OVH. Death from any cause occurred in 13.8% of the EVH group versus 20.8% in the OVH group over the follow-up period. The hazard ratio of death (EVH to OVH) was 0.823 (95% CI: 0.767, 0.884). Length of hospital stay was similar between the groups (p=0.86). Post-operative pulmonary complications were more common in EVH vs OVH (14.7% vs. 12.8%, p<0.001), but repeat coronary re-vascularisation was similar between the groups. Conclusion: This large retrospective multicentre analysis indicates that EVH has a lower risk of mortality compared with OVH during the follow-up period of the study. The observed benefits of EVH may outweigh the risks but should be considered on a case-by-case basis. We hope this review gives confidence to other cardiac centres that offering an EVH approach to conduit harvesting does not affect long term patient outcomes

    A multicentre review comparing long term outcomes of endoscopic vein harvesting versus open vein harvesting for coronary artery bypass surgery

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    Background: Utilisation of the Endoscopic Vein Harvesting (EVH) technique has been increasing for coronary artery bypass grafting (CABG) for the last two decades. Some surgeons remain concerned about the long-term patency of the long saphenous vein harvested endoscopically compared to traditional Open Vein Harvesting (OVH). The aim of this study was to perform a retrospective analysis of the outcomes between EVH and OVH from three UK centres with 10 years follow-up.Methods: 27,024 patients underwent CABG with long saphenous vein harvested by EVH (n=13,794) or OVH (n=13,230) in three UK centres between 2007 and 2019. Propensity modelling was used to calculate the Inverse Probability of Treatment Weights (IPTW). The primary endpoint was mortality from all causes and secondary endpoints were length of hospital stay, postoperative complications, and incidence of repeat coronary re-vascularisation for symptomatic patients. IPTW was used to balance the two intervention groups for baseline and preoperative co-morbidities.Results: Median follow-up time was 4.54 years for EVH and 6.00 years for OVH. Death from any cause occurred in 13.8% of the EVH group versus 20.8% in the OVH group over the follow-up period. The hazard ratio of death (EVH to OVH) was 0.823 (95% CI: 0.767, 0.884). Length of hospital stay was similar between the groups (p=0.86). Post-operative pulmonary complications were more common in EVH vs OVH (14.7% vs. 12.8%, p<0.001), but repeat coronary re-vascularisation was similar between the groups.Conclusion: This large retrospective multicentre analysis indicates that EVH has a lower risk of mortality compared with OVH during the follow-up period of the study. The observed benefits of EVH may outweigh the risks but should be considered on a case-by-case basis. We hope this review gives confidence to other cardiac centres that offering an EVH approach to conduit harvesting does not affect long term patient outcomes

    The re-professionalization of the police in England and Wales

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    In this article contemporary police claims to professional status are analysed and related to a new structure of police regulation in England and Wales. It is argued that the notion of the police as a profession is not new and, unlike police and academic commentary, analysis of this subject, should draw on sociological understandings of professions. The wider policy context within which claims to professionalisation are made is also considered. It is argued that a new, loosely-coupled system of regulation has been developed in England and Wales. Policing’s professional body, the College of Policing, is central to this regulatory framework that has placed government at a distance from constabularies and police representative associations. Finally, some of the consequences of the hybrid system are considered and benefits of the framework of analysis proposed are discussed

    Counseling and surveillance of obstetric risks for female childhood, adolescent, and young adult cancer survivors: recommendations from the International Late Effects of Childhood Cancer Guideline Harmonization Group

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    Female childhood, adolescent, and young adult cancer survivors have an increased risk of adverse pregnancy outcomes related to their cancer- or treatment-associated sequelae. Optimal care for childhood, adolescent, and young adult cancer survivors can be facilitated by clinical practice guidelines that identify specific adverse pregnancy outcomes and the clinical characteristics of at-risk subgroups. However, national guidelines are scarce and vary in content. Here, the International Late Effects of Childhood Cancer Guideline Harmonization Group offers recommendations for the counseling and surveillance of obstetrical risks of childhood, adolescent, and young adult survivors. A systematic literature search in MEDLINE database (through PubMed) to identify all available evidence published between January 1990 and December 2018. Published articles on pregnancy and perinatal or congenital risks in female cancer survivors were screened for eligibility. Study designs with a sample size larger than 40 pregnancies in childhood, adolescent, and young adult cancer survivors (diagnosed before the age of 25 years, not pregnant at that time) were eligible. This guideline from the International Late Effects of Childhood Cancer Guideline Harmonization Group systematically appraised the quality of available evidence for adverse obstetrical outcomes in childhood, adolescent, and young adult cancer survivors using Grading of Recommendations Assessment, Development, and Evaluation methodology and formulated recommendations to enhance evidence-based obstetrical care and preconception counseling of female childhood, adolescent, and young adult cancer survivors. Healthcare providers should discuss the risk of adverse obstetrical outcomes based on cancer treatment exposures with all female childhood, adolescent, and young adult cancer survivors of reproductive age, before conception. Healthcare providers should be aware that there is no evidence to support an increased risk of giving birth to a child with congenital anomalies (high-quality evidence). Survivors treated with radiotherapy to volumes exposing the uterus and their healthcare providers should be aware of the risk of adverse obstetrical outcomes such as miscarriage (moderate-quality evidence), premature birth (high-quality evidence), and low birthweight (high-quality evidence); therefore, high-risk obstetrical surveillance is recommended. Cardiomyopathy surveillance is reasonable before pregnancy or in the first trimester for all female survivors treated with anthracyclines and chest radiation. Female cancer survivors have increased risks of premature delivery and low birthweight associated with radiotherapy targeting the lower body and thereby exposing the uterus, which warrant high-risk pregnancy surveillance

    The management and outcome for patients with chronic subdural hematoma: a prospective, multicenter, observational cohort study in the United Kingdom

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    Symptomatic chronic subdural hematoma (CSDH) will become an increasingly common presentation in neurosurgical practice as the population ages, but quality evidence is still lacking to guide the optimal management for these patients. The British Neurosurgical Trainee Research Collaborative (BNTRC) was established by neurosurgical trainees in 2012 to improve research by combining the efforts of trainees in each of the United Kingdom (UK) and Ireland's neurosurgical units (NSUs). The authors present the first study by the BNTRC that describes current management and outcomes for patients with CSDH throughout the UK and Ireland. This provides a resource both for current clinical practice and future clinical research on CSDH
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