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A complex interplay between mRNA translation and cellular respiration has been recently unveiled, but its regulation in humans is poorly characterized in either health or disease. Cancer cells radically reshape both biosynthetic and bioenergetic pathways to sustain their aberrant growth rates. In this regard, we have shown that the molecular chaperone TRAP1 not only regulates the activity of respiratory complexes, behaving alternatively as an oncogene or a tumor suppressor, but also plays a concomitant moonlighting function in mRNA translation regulation. Herein, we identify the molecular mechanisms involved, showing that TRAP1 (1) binds both mitochondrial and cytosolic ribosomes, as well as translation elongation factors; (2) slows down translation elongation rate; and (3) favors localized translation in the proximity of mitochondria. We also provide evidence that TRAP1 is coexpressed in human tissues with the mitochondrial translational machinery, which is responsible for the synthesis of respiratory complex proteins. Altogether, our results show an unprecedented level of complexity in the regulation of cancer cell metabolism, strongly suggesting the existence of a tight feedback loop between protein synthesis and energy metabolism, based on the demonstration that a single molecular chaperone plays a role in both mitochondrial and cytosolic translation, as well as in mitochondrial respiration.
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Mitocôndrias , Proteínas Mitocondriais , Chaperonas Moleculares , Neoplasias , Biossíntese de Proteínas , Humanos , Proteínas de Choque Térmico HSP90/genética , Proteínas de Choque Térmico HSP90/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Biossíntese de Proteínas/genética , Biossíntese de Proteínas/fisiologia , Ribossomos/genética , Ribossomos/metabolismo , Elongação Traducional da Cadeia Peptídica/genética , Elongação Traducional da Cadeia Peptídica/fisiologia , Mitocôndrias/genética , Mitocôndrias/metabolismoRESUMO
During protein synthesis, nonsense mutations, resulting in premature stop codons (PSCs), produce truncated, inactive protein products. Such defective gene products give rise to many diseases, including cystic fibrosis, Duchenne muscular dystrophy (DMD), and some cancers. Small molecule nonsense suppressors, known as TRIDs (translational read-through-inducing drugs), stimulate stop codon read-through. The best characterized TRIDs are ataluren, which has been approved by the European Medicines Agency for the treatment of DMD, and G418, a structurally dissimilar aminoglycoside. Previously [1], we applied a highly purified in vitro eukaryotic translation system to demonstrate that both aminoglycosides like G418 and more hydrophobic molecules like ataluren stimulate read-through by direct interaction with the cell's protein synthesis machinery. Our results suggested that they might do so by different mechanisms. Here, we pursue this suggestion through a more-detailed investigation of ataluren and G418 effects on read-through. We find that ataluren stimulation of read-through derives exclusively from its ability to inhibit release factor activity. In contrast, G418 increases functional near-cognate tRNA mispairing with a PSC, resulting from binding to its tight site on the ribosome, with little if any effect on release factor activity. The low toxicity of ataluren suggests that development of new TRIDs exclusively directed toward inhibiting termination should be a priority in combatting PSC diseases. Our results also provide rate measurements of some of the elementary steps during the eukaryotic translation elongation cycle, allowing us to determine how these rates are modified when cognate tRNA is replaced by near-cognate tRNA ± TRIDs.
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Aminoglicosídeos/farmacologia , Códon sem Sentido/efeitos dos fármacos , Oxidiazóis/farmacologia , Elongação Traducional da Cadeia Peptídica/efeitos dos fármacos , Aminoglicosídeos/metabolismo , Animais , Artemia/genética , Códon sem Sentido/metabolismo , Códon de Terminação/efeitos dos fármacos , Códon de Terminação/metabolismo , Fibrose Cística/genética , Distrofia Muscular de Duchenne/genética , Oxidiazóis/metabolismo , Biossíntese de Proteínas/efeitos dos fármacos , Inibidores da Síntese de Proteínas , RNA de Transferência/efeitos dos fármacos , RNA de Transferência/genética , RNA de Transferência/metabolismo , Ribossomos/efeitos dos fármacos , Saccharomyces/genéticaRESUMO
Angiogenesis is a critical physiological response to ischemia but becomes pathological when dysregulated and driven excessively by inflammation. We recently identified a novel angiogenic role for tripartite-motif-containing protein 2 (TRIM2) whereby lentiviral shRNA-mediated TRIM2 knockdown impaired endothelial angiogenic functions in vitro. This study sought to determine whether these effects could be translated in vivo and to determine the molecular mechanisms involved. CRISPR/Cas9-generated Trim2-/- mice that underwent a periarterial collar model of inflammation-induced angiogenesis exhibited significantly less adventitial macrophage infiltration relative to wildtype (WT) littermates, concomitant with decreased mRNA expression of macrophage marker Cd68 and reduced adventitial proliferating neovessels. Mechanistically, TRIM2 knockdown in endothelial cells in vitro attenuated inflammation-driven induction of critical angiogenic mediators, including nuclear HIF-1α, and curbed the phosphorylation of downstream effector eNOS. Conversely, in a hindlimb ischemia model of hypoxia-mediated angiogenesis, there were no differences in blood flow reperfusion to the ischemic hindlimbs of Trim2-/- and WT mice despite a decrease in proliferating neovessels and arterioles. TRIM2 knockdown in vitro attenuated hypoxia-driven induction of nuclear HIF-1α but had no further downstream effects on other angiogenic proteins. Our study has implications for understanding the role of TRIM2 in the regulation of angiogenesis in both pathophysiological contexts.
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Angiogênese , Células Endoteliais , Animais , Camundongos , Células Endoteliais/metabolismo , Membro Posterior/irrigação sanguínea , Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Inflamação/metabolismo , Isquemia/metabolismo , Neovascularização Patológica/metabolismo , Neovascularização Fisiológica/genéticaRESUMO
BACKGROUND: Patients with angina and non-obstructive coronary arteries (ANOCA) frequently have coronary vasomotor disorders (CVaD), characterised by transient pathological vasoconstriction and/or impaired microvascular vasodilatation. Functional coronary angiography is the gold standard for diagnosing CVaD. Despite recommendations, testing is only available at a limited number of Australian and New Zealand centres. This study aimed to determine the prevalence of CVaDs in an Australian ANOCA population and identify predictive factors associated with specific endotypes. METHOD: Functional coronary angiography was performed in patients with suspected ANOCA. Vasoreactivity testing was performed using intracoronary acetylcholine provocation. A pressure-temperature sensor guidewire was used for coronary physiology assessment. Comprehensive clinical data on patient characteristics, cardiac risk factors, and symptom profiles was collected before testing. RESULTS: This prospective observational study at Royal Prince Alfred and Concord Repatriation General Hospital included 110 patients (58±13 years with 63.6% women), with 81.8% (90/110) having a CVaD. Regarding specific ANOCA endotypes, microvascular angina (MVA) occurred in 31.8% (35/110) of cases, vasospastic angina (VSA) in 25.5% (28/110) and a mixed presentation of MVA and VSA in 24.5% (27/110) of patients. Patients with CVaD were found to be older (59±11 vs 51±15, p=0.024), overweight (61.1% vs 15.0%, p<0.001) and had a worse quality of life (EuroQol 5 Dimensions-5 Levels; 0.61 vs 0.67, p=0.043). MVA was associated with being overweight (odds ratio [OR] 4.2 [95% confidence interval [CI] 1.9-9.3]; p=0.015) and ischaemia on stress testing (OR 2.4 [95% CI 1.1-4.3]; p=0.028), while VSA was associated with smoking (OR 9.1 [95% CI 2.21-39.3]; p=0.007). CONCLUSIONS: Coronary vasomotor disorders are highly prevalent among ANOCA patients. This study highlights the importance of increasing national awareness and the use of functional coronary angiography to evaluate and manage this unique cohort.
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BACKGROUND: Mitral valve transcatheter edge-to-edge repair (M-TEER) is an effective option for treatment of mitral regurgitation (MR). We previously reported favorable 2-year outcomes for the PASCAL transcatheter valve repair system. OBJECTIVES: We report 3-year outcomes from the multinational, prospective, single-arm CLASP study with analysis by functional MR (FMR) and degenerative MR (DMR). METHODS: Patients with core-lab determined MR ≥ 3+ were deemed candidates for M-TEER by the local heart team. Major adverse events were assessed by an independent clinical events committee to 1 year and by sites thereafter. Echocardiographic outcomes were evaluated by the core laboratory to 3 years. RESULTS: The study enrolled 124 patients, 69% FMR; 31% DMR (60% NYHA class III-IVa, 100% MR ≥ 3+). The 3-year Kaplan-Meier estimate for survival was 75% (66% FMR; 92% DMR) and freedom from heart failure hospitalization (HFH) was 73% (64% FMR; 91% DMR), with 85% reduction in annualized HFH rate (81% FMR; 96% DMR) (p < 0.001). MR ≤ 2+ was achieved and maintained in 93% of patients (93% FMR; 94% DMR) and MR ≤ 1+ in 70% of patients (71% FMR; 67% DMR) (p < 0.001). The mean left ventricular end-diastolic volume (181 mL at baseline) decreased progressively by 28 mL [p < 0.001]. NYHA class I/II was achieved in 89% of patients (p < 0.001). CONCLUSIONS: The 3-year results from the CLASP study demonstrated favorable and durable outcomes with the PASCAL transcatheter valve repair system in patients with clinically significant MR. These results add to the growing body of evidence establishing the PASCAL system as a valuable therapy for patients with significant symptomatic MR.
Assuntos
Procedimentos Cirúrgicos Cardíacos , Implante de Prótese de Valva Cardíaca , Insuficiência da Valva Mitral , Humanos , Insuficiência da Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/cirurgia , Valva Mitral/diagnóstico por imagem , Valva Mitral/cirurgia , Estudos Prospectivos , Resultado do TratamentoRESUMO
Cardiometabolic disease is an increasing cause of morbidity and death in society. While M1-like macrophages contribute to metabolic inflammation and insulin resistance, those polarized to an M2-like phenotype exert protective properties. Building on our observations reporting M2-like macrophage exosomes in atherosclerosis control, we tested whether they could serve to control inflammation in the liver and adipose tissue of obese mice. In thinking of clinical translation, we studied human THP-1 macrophages exposed to interleukin (IL)-4 as a source of exosomes (THP1-IL4-exo). Our findings show that THP1-IL4-exo polarized primary macrophages to an anti-inflammatory phenotype and reprogramed their energy metabolism by increasing levels of microRNA-21/99a/146b/378a (miR-21/99a/146b/378a) while reducing miR-33. This increased lipophagy, mitochondrial activity, and oxidative phosphorylation (OXPHOS). THP1-IL4-exo exerted a similar regulation of these miRs in cultured 3T3-L1 adipocytes. This enhanced insulin-dependent glucose uptake through increased peroxisome proliferator activated receptor gamma (PPARγ)-driven expression of GLUT4. It also increased levels of UCP1 and OXPHOS activity, which promoted lipophagy, mitochondrial activity, and beiging of 3T3-L1 adipocytes. Intraperitoneal infusions of THP1-IL4-exo into obese wild-type and Ldlr-/- mice fed a Western high-fat diet reduced hematopoiesis and myelopoiesis, and favorably reprogramed inflammatory signaling and metabolism in circulating Ly6Chi monocytes. This also reduced leukocyte numbers and inflammatory activity in the circulation, aorta, adipose tissue, and the liver. Such treatments reduced hepatic steatosis and increased the beiging of white adipose tissue as revealed by increased UCP1 expression and OXPHOS activity that normalized blood insulin levels and improved glucose tolerance. Our findings support THP1-IL4-exo as a therapeutic approach to control cardiometabolic disease and diabetes in obesity.
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Doenças Cardiovasculares , Diabetes Mellitus , Exossomos , Resistência à Insulina , Interleucina-4/metabolismo , MicroRNAs , Tecido Adiposo/metabolismo , Animais , Doenças Cardiovasculares/metabolismo , Diabetes Mellitus/metabolismo , Dieta Hiperlipídica , Exossomos/metabolismo , Humanos , Inflamação/metabolismo , Insulina/metabolismo , Interleucina-4/genética , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , MicroRNAs/metabolismo , Obesidade/genética , Obesidade/terapiaRESUMO
Endothelial dysfunction, hallmarked by an imbalance between vasoconstriction and vasorelaxation, is associated with diabetes. Thioredoxin Interacting protein (TXNIP), controlled by an exquisitely glucose sensitive gene, is increasingly recognized for its role in diabetes. However, the role of TXNIP in modulating diabetes-related endothelial dysfunction remains unclear. To elucidate the role of TXNIP, we generated two novel mouse strains; endothelial-specific TXNIP knockout (EKO) and a Tet-O inducible, endothelial-specific TXNIP overexpression (EKI). Hyperglycemia was induced by streptozotocin (STZ) treatment in floxed control (fl/fl) and EKO mice. Doxycycline (DOX) was given to EKI mice to induce endothelial TXNIP overexpression. The ablation of endothelial TXNIP improved glucose tolerance in EKO mice. Acetylcholine-induced, endothelium-dependent vasorelaxation was impaired in STZ-treated fl/fl mice while this STZ impaired vasorelaxation was attenuated in EKO mice. Hyperglycemia induction of NLRP3 and reductions in Akt and eNOS phosphorylation were also mitigated in EKO mice. Overexpression of endothelial TXNIP did not impair glucose tolerance in DOX-treated EKI mice, however induction of endothelial TXNIP led to impaired vasorelaxation in EKI mice. This was associated with increased NLRP3 and reduced Akt and eNOS activation. In conclusion, deletion of endothelial TXNIP is protective against and overexpression of endothelial TXNIP induces endothelial dysfunction; thus, endothelial TXNIP plays a critical role in modulating endothelial dysfunction.
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Endotélio , Hiperglicemia , Tiorredoxinas , Vasodilatação , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Endotélio/metabolismo , Endotélio/fisiopatologia , Glucose , Hiperglicemia/metabolismo , Hiperglicemia/fisiopatologia , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Estreptozocina , Tiorredoxinas/genética , Tiorredoxinas/metabolismo , Vasodilatação/genética , Vasodilatação/fisiologiaRESUMO
OBJECTIVE: Hmox1 (heme oxygenase-1) is a stress-induced enzyme that catalyzes the degradation of heme to carbon monoxide, iron, and biliverdin. Induction of Hmox1 and its products protect against cardiovascular disease, including ischemic injury. Hmox1 is also a downstream target of the transcription factor HIF-1α (hypoxia-inducible factor-1α), a key regulator of the body's response to hypoxia. However, the mechanisms by which Hmox1 confers protection against ischemia-mediated injury remain to be fully understood. Approach and Results: Hmox1 deficient (Hmox1-/-) mice had impaired blood flow recovery with severe tissue necrosis and autoamputation following unilateral hindlimb ischemia. Autoamputation preceded the return of blood flow, and bone marrow transfer from littermate wild-type mice failed to prevent tissue injury and autoamputation. In wild-type mice, ischemia-induced expression of Hmox1 in skeletal muscle occurred before stabilization of HIF-1α. Moreover, HIF-1α stabilization and glucose utilization were impaired in Hmox1-/- mice compared with wild-type mice. Experiments exposing dermal fibroblasts to hypoxia (1% O2) recapitulated these key findings. Metabolomics analyses indicated a failure of Hmox1-/- mice to adapt cellular energy reprogramming in response to ischemia. Prolyl-4-hydroxylase inhibition stabilized HIF-1α in Hmox1-/- fibroblasts and ischemic skeletal muscle, decreased tissue necrosis and autoamputation, and restored cellular metabolism to that of wild-type mice. Mechanistic studies showed that carbon monoxide stabilized HIF-1α in Hmox1-/- fibroblasts in response to hypoxia. CONCLUSIONS: Our findings suggest that Hmox1 acts both downstream and upstream of HIF-1α, and that stabilization of HIF-1α contributes to Hmox1's protection against ischemic injury independent of neovascularization.
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Heme Oxigenase-1/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Isquemia/enzimologia , Proteínas de Membrana/metabolismo , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/enzimologia , Traumatismo por Reperfusão/prevenção & controle , Animais , Hipóxia Celular , Células Cultivadas , Modelos Animais de Doenças , Metabolismo Energético , Feminino , Fibroblastos/enzimologia , Fibroblastos/patologia , Glucose/metabolismo , Heme Oxigenase-1/deficiência , Heme Oxigenase-1/genética , Membro Posterior , Isquemia/genética , Isquemia/patologia , Masculino , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Camundongos Endogâmicos BALB C , Camundongos Knockout , Músculo Esquelético/patologia , Necrose , Estabilidade Proteica , Fluxo Sanguíneo Regional , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/patologiaRESUMO
BACKGROUND: Cardiac Society of Australia and New Zealand (CSANZ) guidelines recommend elective high-risk percutaneous coronary intervention (PCI) is not performed in sites greater than 1 hour from cardiac surgery. METHODS: In hospital outcomes for all patients from Orange Health Service (OHS) from January 2017 to January 2020 who were transferred electively to tertiary centres in Sydney for high risk PCI were examined. RESULTS: One hundred and fourteen (114) patients were identified, with 1,259 PCIs performed at OHS over the same period without transfer. The mean age of these 114 patients was 71 years, with 74.6% male. Receiving hospitals were Royal Prince Alfred Hospital, Sydney, NSW (66.7%), Concord Repatriation General Hospital, Concord, NSW (19.3%) and Strathfield Private Hospital, Strathfield, NSW (14%). The definition of high risk and indication for transfer included at least one of: moderate or greater calcification of the target lesion or proximal segment (34%), single or multiple target lesions that in aggregate jeopardised over 50% of remaining viable myocardium (27%), degenerated saphenous vein grafts (14.8%), chronic total occlusions (7.0%) and severe left ventricular (LV) impairment (3.9%). American Heart Society/American College of Cardiology (AHA/ACC) lesion types were A (1%), B1 (4.2%), B2 (40.2%), and C (54.6%). PCI was performed via the femoral route in 96.2%. The mean procedure duration was 72 minutes, mean combined fluoroscopy time was 19 minutes and mean radiation dose as defined by Reference Air Kerma was 1,630 mGy. Complications occurred in 13 patients and were: acute vessel dissection requiring stenting (4), perforation (2), acute vessel closure (4), puncture site related (1), and life-threatening arrhythmia (2). There were no cases of emergent coronary artery bypass graft (CABG) or death. CONCLUSION: This contemporary cohort of high-risk patients transferred electively from a regional PCI centre to a tertiary cardiac unit underwent lengthy PCI procedures, with high radiation doses, and a modest rate of peri-procedural complications, but had otherwise excellent procedural and clinical outcomes.
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Intervenção Coronária Percutânea , Idoso , Estudos de Coortes , Ponte de Artéria Coronária , Feminino , Hospitais , Humanos , Masculino , Stents , Resultado do Tratamento , Estados UnidosRESUMO
BACKGROUND: Although transcatheter aortic valve implantation (TAVI) has become the standard treatment for severe aortic stenosis in high-risk patients in Australia, there is still limited data on long term survival. METHODS: All patients undergoing TAVI at a single tertiary institution between September 2009 and December 2015 were included. The primary outcome was survival, by linkage of patients with the National Death Index of the Australian Institute of Health and Welfare. Post-procedure data and echocardiographic measurements were retrospectively analysed for all patients. RESULTS: A total of 186 patients were included. It was a high-risk patient population (mean EuroSCORE 31.5±20.5, mean age 83.0±8.2 years). Valve prostheses used were Edwards SAPIEN (ES) (Edwards, Irvine, CA, USA) in 16.1%, Edwards SAPIEN XT (ESXT) in 74.2%, and Medtronic CoreValve (MCV) (Medtronic, Minneapolis, MN, USA) in 9.7%. Median survival time for the entire cohort was 68.2 months (95% Confidence Interval [CI]; Lower Limit [LL] 58.0 months, Upper Limit [UL] not defined). The 2- and 5-year estimates of survival were 85% (LL 80%, UL 90%) and 56% (LL 48%, UL 66%), respectively. There was no statistically significant difference in median survival between the ES and ESXT valves, or implantation approach. Survival was greater in patients with creatinine <200 µmol/L compared to >200 µmol/L (68.8 months [LL 61.4, UL n/a] vs 48.0 months [LL 25.5, UL n/a]). Over the study period, there was a statistically significant trend in increasing mean transvalvular gradient (ES: 1.66 mmHg/yr, p=0.0058; ESXT: 2.50 mmHg/yr, p≤0.001) and maximum velocity (ESXT: 0.16 m/s/yr, p=0.004) and decreasing valve area (ESXT: -0.07 cm2/yr, p<0.001). There was substantial attrition of patient echocardiographic follow-up (number of echocardiograms followed up at 5 years=6, number at risk=41). CONCLUSIONS: This study has demonstrated acceptable survival in a high-risk cohort of patients undergoing TAVI, with comparable results to larger international experiences. There was a trend for worsening haemodynamics that needs to be monitored. Future studies need to examine patient quality of life and the performance of newer generation prostheses.
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Estenose da Valva Aórtica , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter , Idoso , Idoso de 80 Anos ou mais , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/cirurgia , Austrália/epidemiologia , Humanos , Desenho de Prótese , Qualidade de Vida , Estudos Retrospectivos , Resultado do TratamentoRESUMO
BACKGROUND: Comparative costing studies using real-world data stratified by patient case-mix, are valuable to decision makers for making reimbursement decisions of new interventions. This study evaluated real-world hospital admissions and short-term costs of transcatheter aortic valve implantation (TAVI) and isolated surgical aortic valve replacement (SAVR) for patients with aortic stenosis, stratified by the Society of Thoracic Surgeons (STS) risk scores. METHODS: Retrospective analysis of consecutive patients with a principal diagnosis of aortic stenosis who underwent isolated valve replacement at a single tertiary hospital, January 2012-December 2017. Patients were followed-up for 30 days post-procedure or until hospital discharge if index hospitalisation was greater than 30 days. Intensive care unit (ICU) and hospital length of stay (days), and costs in 2018 Australian dollars for the index procedure and 30-day follow-up were assessed. Multivariable generalised linear and two-part models with gamma distribution and log link function adjusting for Society of Thoracic Surgeons (STS) risk group and key sociodemographic characteristics were used. RESULTS: Of 488 patients, 61% males, median age 78 years (IQR 14 years), 221 (45%) received transcatheter aortic valve replacement (TAVI) and 267 (55%) received surgical aortic valve replacement (SAVR). STS risk scores were low (28%), intermediate (46%) and high (26%) for TAVI patients, and low (85%), intermediate (12%) and high (3%) for SAVR patients. When adjusted, TAVI length of stay was 57% shorter than SAVR (95% CI 31-83%, p<0.001) for intensive care unit (ICU) admission, and 64% shorter (95% CI 47-81%, p<0.001) for hospital admissions. TAVI costs were 13% lower than SAVR (95% CI 4-22%, p=0.005). CONCLUSION: This data suggests short-term health care costs are lower for patients with aortic stenosis undergoing TAVI than SAVR. A further roll-out of the TAVI program in hospitals across Australia may result in savings to the health system.
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Estenose da Valva Aórtica , Implante de Prótese de Valva Cardíaca , Substituição da Valva Aórtica Transcateter , Idoso , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/diagnóstico , Estenose da Valva Aórtica/cirurgia , Austrália/epidemiologia , Feminino , Humanos , Masculino , Estudos Retrospectivos , Fatores de Risco , Resultado do TratamentoRESUMO
BACKGROUND: To determine the safety and performance of the SAPIEN XT transcatheter heart valve (THV) in Australian patients with severe aortic stenosis (AS) and intermediate surgical risk. METHODS: Eligible patients in this multi-centre, prospective, consecutively enrolled, non-randomised, clinical trial, received transcatheter aortic valve replacement via femoral artery access. Follow-up visits were at discharge, 30 days, and 6, 12, and 24 months. The primary endpoint was Valve Academic Research Consortium-2 composite safety at 30 days: all-cause mortality, all stroke, life-threatening bleeding, acute kidney injury-Stage 3, coronary artery obstruction requiring intervention, major vascular complication, and valve-related dysfunction requiring repeat procedure. Other endpoints were device success (successful vascular access, delivery, and deployment; correct position; intended performance mean aortic valve gradient <20 mmHg, mild or less paravalvular aortic regurgitation [PAR]; and only one valve implanted) and New York Heart Association functional class (NYHA). Kaplan-Meier (KM) estimates were calculated for the primary endpoint. RESULTS: At baseline, mean patient (N=199) age was 85.5 years, mean Society of Thoracic Surgeon score was 5.9, and 78.4% were in NYHA class III/IV. The primary composite endpoint KM estimate was 12.1%. Device success was 88.8%. SAPIEN XT was implanted in the proper location in 98.5% (n=2: valve-in-valve procedures, n=1: no implant due to left main coronary artery occlusion). No device malfunctions were reported. The post procedure PAR was mild or less in 93.8% of patients. Mean aortic gradient decreased from baseline (50.0 mmHg) to 2 years (10.3 mmHg). Most patients (90.9%) were in NYHA class I/II at 30 days. New permanent pacemaker rate was 8.1%. Stroke at 30 days was 3.5% (1.5% disabling). CONCLUSION: SAPIEN XT was safe and improved heart failure symptoms and valve haemodynamics in this cohort of Australian patients.
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Estenose da Valva Aórtica/cirurgia , Valva Aórtica/cirurgia , Cateterismo Cardíaco/métodos , Substituição da Valva Aórtica Transcateter/métodos , Idoso , Idoso de 80 Anos ou mais , Estenose da Valva Aórtica/diagnóstico , Austrália , Ecocardiografia , Feminino , Artéria Femoral , Humanos , Masculino , Estudos Prospectivos , Desenho de Prótese , Fatores de Risco , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
High-density lipoproteins augment hypoxia-induced angiogenesis by inducing the key angiogenic vascular endothelial growth factor A (VEGFA) and total protein levels of its receptor 2 (VEGFR2). The activation/phosphorylation of VEGFR2 is critical for mediating downstream, angiogenic signaling events. This study aimed to determine whether reconstituted high-density lipoprotein (rHDL) activates VEGFR2 phosphorylation and the downstream signaling events and the importance of VEGFR2 in the proangiogenic effects of rHDL in hypoxia. In vitro, rHDL increased VEGFR2 activation and enhanced phosphorylation of downstream, angiogenic signaling proteins ERK1/2 and p38 MAPK in hypoxia. Incubation with a VEGFR2-neutralizing antibody attenuated rHDL-induced phosphorylation of VEGFR2, ERK1/2, p38 MAPK, and tubule formation. In a murine model of ischemia-driven neovascularization, rHDL infusions enhanced blood perfusion and augmented capillary and arteriolar density. Infusion of a VEGFR2-neutralizing antibody ablated those proangiogenic effects of rHDL. Circulating Sca1+/CXCR4+ angiogenic progenitor cell levels, important for neovascularization in response to ischemia, were higher in rHDL-infused mice 3 d after ischemic induction, but that did not occur in mice that also received the VEGFR2-neutralizing antibody. In summary, VEGFR2 has a key role in the proangiogenic effects of rHDL in hypoxia/ischemia. These findings have therapeutic implications for angiogenic diseases associated with an impaired response to tissue ischemia.-Cannizzo, C. M., Adonopulos, A. A., Solly, E. L., Ridiandries, A., Vanags, L. Z., Mulangala, J., Yuen, S. C. G., Tsatralis, T., Henriquez, R., Robertson, S., Nicholls, S. J., Di Bartolo, B. A., Ng, M. K. C., Lam, Y. T., Bursill, C. A., Tan, J. T. M. VEGFR2 is activated by high-density lipoproteins and plays a key role in the proangiogenic action of HDL in ischemia.
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Indutores da Angiogênese/metabolismo , Isquemia/metabolismo , Lipoproteínas HDL/metabolismo , Sistema de Sinalização das MAP Quinases , Neovascularização Fisiológica , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Animais , Anticorpos Neutralizantes/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Isquemia/patologia , Isquemia/fisiopatologia , Lipoproteínas HDL/antagonistas & inibidores , Camundongos , Fosforilação/efeitos dos fármacosRESUMO
Angiogenesis, the process of forming new blood vessels, is crucial in the physiological response to ischemia, though it can be detrimental as part of inflammation and tumorigenesis. We have previously shown that high-density lipoproteins (HDL) modulate angiogenesis in a context-specific manner via distinct classical signalling pathways, enhancing hypoxia-induced angiogenesis while suppressing inflammatory-driven angiogenesis. Whether additional novel targets exist to account for these effects are unknown. A microarray approach identified two novel genes, cyclic-adenosine-monophosphate-response-element-binding protein 3 regulatory factor (CREBRF) and tripartite motif-containing protein 2 (TRIM2) that were upregulated by reconstituted HDL (rHDL). We measured CREBRF and TRIM2 expression in human coronary artery endothelial cells following incubation with rHDL and exposure to either hypoxia or an inflammatory stimulus. We found that CREBRF and TRIM2 mRNA were significantly upregulated by rHDL, particularly in response to its phospholipid component 1-palmitoyl-2-linoleoyl-phosphatidylcholine, however, protein expression was not significantly altered. Knockdown of TRIM2 impaired endothelial cell tubulogenesis in vitro in both hypoxia and inflammation, implying a necessary role in angiogenesis. Furthermore, TRIM2 knockdown attenuated rHDL-induced tubule formation in hypoxia, suggesting that it is important in mediating the pro-angiogenic action of rHDL. Our study has implications for understanding the regulation of angiogenesis in both of these pathophysiological contexts by HDL.
Assuntos
Lipoproteínas HDL/genética , Neovascularização Patológica/genética , Proteínas Nucleares/genética , Proteínas Supressoras de Tumor/genética , Carcinogênese/genética , Hipóxia Celular/genética , Linhagem Celular , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Inflamação/genética , Inflamação/patologia , Lipoproteínas HDL/farmacologia , Neovascularização Patológica/patologia , Fosfatidilcolinas/farmacologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologiaRESUMO
The oxidation of ethyl tert-butyl ether (ETBE), a widely used fuel oxygenated additive, is investigated using Cl atoms as initiators in the presence of oxygen. The reaction is carried out at 293, 550, and 700 K. Reaction products are probed by a multiplexed chemical kinetics photoionization mass spectrometer coupled with the synchrotron radiation produced at the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory. Products are identified on the basis of mass-to-charge ratio, ionization energies, and shape of photoionization spectra. Reaction pathways are proposed together with detected primary products.
RESUMO
We report a case of asceptic sialadenitis that occurred in a patient with end-stage renal failure following administration of iodinated contrast for coronary and carotid angiography. This is a rare but important complication of iodinated contrast. Early diagnosis of iodide mumps following angiography avoids unnecessary investigations and treatment. In this case the patient underwent haemodialysis with subsequent complete resolution of the sialadenitis, a treatment that has previously not been reported for this condition.
Assuntos
Artérias Carótidas/diagnóstico por imagem , Meios de Contraste , Angiografia Coronária , Vasos Coronários/diagnóstico por imagem , Falência Renal Crônica , Sialadenite , Idoso , Meios de Contraste/administração & dosagem , Meios de Contraste/efeitos adversos , Angiografia Coronária/efeitos adversos , Feminino , Humanos , Falência Renal Crônica/diagnóstico por imagem , Falência Renal Crônica/terapia , Sialadenite/induzido quimicamente , Sialadenite/diagnóstico por imagem , Sialadenite/terapiaRESUMO
Accurate translation of the genetic code depends on mRNA:tRNA codon:anticodon base pairing. Here we exploit an emissive, isosteric adenosine surrogate that allows direct measurement of the kinetics of codon:anticodon University of California base formation during protein synthesis. Our results suggest that codon:anticodon base pairing is subject to tighter constraints at the middle position than at the 5'- and 3'-positions, and further suggest a sequential mechanism of formation of the three base pairs in the codon:anticodon helix.
Assuntos
Nucleotídeos/genética , Ribossomos/genética , Pareamento de Bases , Código Genético , Cinética , Modelos Moleculares , RNA Mensageiro/genética , RNA de Transferência/genéticaRESUMO
BACKGROUND: The average population age is increasing and the incidence of age-related vascular complications is rising in parallel. Impaired wound healing and disordered ischemia-mediated angiogenesis are key contributors to age-impaired vascular complications that can lead to amputation. High-density lipoproteins (HDL) have vasculo-protective properties and augment ischemia-driven angiogenesis in young animals. We aimed to determine the effect of reconstituted HDL (rHDL) on aged mice in a murine wound healing model and the hindlimb ischemia (HLI) model. METHODS: Murine wound healing model-24-month-old aged mice received topical application of rHDL (50 µg/wound/day) or PBS (vehicle control) for 10 days following wounding. Murine HLI model-Femoral artery ligation was performed on 24-month-old mice. Mice received rHDL (40 mg/kg) or PBS, intravenously, on alternate days, 1 week pre-surgery and up to 21 days post ligation. For both models, blood flow perfusion was determined using laser Doppler perfusion imaging. Mice were sacrificed at 10 (wound healing) or 21 (HLI) days post-surgery and tissues were collected for histological and gene analyses. RESULTS: Daily topical application of rHDL increased the rate of wound closure by Day 7 post-wounding (25 %, p < 0.05). Wound blood perfusion, a marker of angiogenesis, was elevated in rHDL treated wounds (Days 4-10 by 22-25 %, p < 0.05). In addition, rHDL increased wound capillary density by 52.6 %. In the HLI model, rHDL infusions augmented blood flow recovery in ischemic limbs (Day 18 by 50 % and Day 21 by 88 %, p < 0.05) and prevented tissue necrosis and toe loss. Assessment of capillary density in ischemic hindlimb sections found a 90 % increase in rHDL infused animals. In vitro studies in fibroblasts isolated from aged mice found that incubation with rHDL was able to significantly increase the key pro-angiogenic mediator vascular endothelial growth factor (VEGF) protein (25 %, p < 0.05). CONCLUSION: rHDL can promote wound healing and wound angiogenesis, and blood flow recovery in response to ischemia in aged mice. Mechanistically, this is likely to be via an increase in VEGF. This highlights a potential role for HDL in the therapeutic modulation of age-impaired vascular complications.
Assuntos
Envelhecimento/efeitos dos fármacos , Isquemia/tratamento farmacológico , Lipoproteínas HDL/administração & dosagem , Neovascularização Patológica/tratamento farmacológico , Envelhecimento/metabolismo , Animais , Modelos Animais de Doenças , Artéria Femoral/efeitos dos fármacos , Artéria Femoral/patologia , Membro Posterior/efeitos dos fármacos , Membro Posterior/metabolismo , Membro Posterior/patologia , Humanos , Isquemia/metabolismo , Isquemia/patologia , Lipoproteínas HDL/metabolismo , Camundongos , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Fluxo Sanguíneo Regional/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/metabolismo , Cicatrização/efeitos dos fármacosAssuntos
Implante de Prótese de Valva Cardíaca , Insuficiência da Valva Tricúspide , Prolapso da Valva Tricúspide , Cateterismo Cardíaco , Humanos , Resultado do Tratamento , Valva Tricúspide/diagnóstico por imagem , Valva Tricúspide/cirurgia , Insuficiência da Valva Tricúspide/diagnóstico por imagem , Insuficiência da Valva Tricúspide/cirurgiaRESUMO
Cellular junctions are essential to the normal functioning of the endothelium and control angiogenesis, tissue leak, and inflammation. From a screen of micro RNAs (miRNAs) altered in in vitro angiogenesis, we selected a subset predicted to target junctional molecules. MiR-27a was rapidly downregulated upon stimulation of in vitro angiogenesis, and its level of expression is reduced in neovessels in vivo. The downregulation of miR-27a was essential for angiogenesis because ectopic expression of miR-27a blocked capillary tube formation and angiogenesis. MiR-27a targets the junctional, endothelial-specific cadherin, VE-cadherin. Consistent with this, vascular permeability to vascular endothelial growth factor in mice is reduced by administration of a general miR-27 inhibitor. To determine that VE-cadherin was the dominant target of miR-27a function, we used a novel technology with "Blockmirs," inhibitors that bind to the miR-27 binding site in VE-cadherin. The Blockmir CD5-2 demonstrated specificity for VE-cadherin and inhibited vascular leak in vitro and in vivo. Furthermore, CD5-2 reduced edema, increased capillary density, and potently enhanced recovery from ischemic limb injury in mice. The Blockmir technology offers a refinement in the use of miRNAs, especially for therapy. Further, targeting of endothelial junctional molecules by miRNAs has clinical potential, especially in diseases associated with vascular leak.