RESUMO
Oxidative stress occurs during ex-situ heart perfusion (ESHP) and may negatively affect functional preservation of the heart. We sought to assess the status of key antioxidant enzymes during ESHP, and the effects of augmenting these antioxidants on the attenuation of oxidative stress and improvement of myocardial and endothelial preservation in ESHP. Porcine hearts were perfused for 6 hours with oxygen-derived free-radical scavengers polyethylene glycol (PEG)-catalase or PEG-superoxide dismutase (SOD) or with naive perfusate (control). The oxidative stress-related modifications were determined in the myocardium and coronary vasculature, and contractile function, injury, and endothelial integrity were compared between the groups. The activity of key antioxidant enzymes decreased and adding catalase and SOD restored the enzyme activity. Cardiac function and endothelial integrity were preserved better with restored catalase activity. Catalase and SOD both decreased myocardial injury and catalase reduced ROS production and oxidative modification of proteins in the myocardium and coronary vasculature. The activity of antioxidant enzymes decrease in ESHP. Catalase may improve the preservation of cardiac function and endothelial integrity during ESHP. While catalase and SOD may both exert cardioprotective effects, unbalanced SOD and catalase activity may paradoxically increase the production of reactive species during ESHP.
Assuntos
Catalase , Sequestradores de Radicais Livres , Estresse Oxidativo , Superóxido Dismutase , Animais , Suínos , Superóxido Dismutase/metabolismo , Catalase/metabolismo , Sequestradores de Radicais Livres/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Perfusão/métodos , Miocárdio/metabolismo , Polietilenoglicóis/farmacologia , Coração/fisiologia , Coração/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Antioxidantes/farmacologia , Preservação de Órgãos/métodosRESUMO
Importance: Prostate-specific membrane antigen (PSMA) demonstrates overexpression in prostate cancer and correlates with tumor aggressiveness. PSMA positron emission tomography (PET) is superior to conventional imaging for the metastatic staging of prostate cancer per current research but studies of second-generation PSMA PET radioligands for locoregional staging are limited. Objective: To determine the accuracy of fluorine-18 PSMA-1007 PET/computed tomography (18F-PSMA-1007 PET/CT) compared to multiparametric magnetic resonance imaging (MRI) in the primary locoregional staging of intermediate-risk and high-risk prostate cancers. Design, Setting, and Participants: The Next Generation Trial was a phase 2 prospective validating paired cohort study assessing the accuracy of 18F-PSMA-1007 PET/CT and MRI for locoregional staging of prostate cancer, with results of histopathologic examination as the reference standard comparator. Radiologists, nuclear medicine physicians, and pathologists were blinded to preoperative clinical, pathology, and imaging data. Patients underwent all imaging studies and radical prostatectomies at 2 tertiary care hospitals in Alberta, Canada. Eligible participants included men with intermediate-risk or high-risk prostate cancer who consented to radical prostatectomy. Participants who underwent radical prostatectomy were included in the final analysis. Patients were recruited between March 2022 and June 2023, and data analysis occurred between July 2023 and December 2023. Exposures: All participants underwent both 18F-PSMA-1007 PET/CT and MRI within 2 weeks of one another and before radical prostatectomy. Main Outcomes and Measures: The primary outcome was the correct identification of the prostate cancer tumor stage by each imaging test. The secondary outcomes were correct identification of the dominant nodule, laterality, extracapsular extension, and seminal vesical invasion. Results: Of 150 eligible men with prostate cancer, 134 patients ultimately underwent radical prostatectomy (mean [SD] age at prostatectomy, 62.0 [5.7] years). PSMA PET was superior to MRI for the accurate identification of the final pathological tumor stage (61 [45%] vs 38 [28%]; P = .003). PSMA PET was also superior to MRI for the correct identification of the dominant nodule (126 [94%] vs 112 [83%]; P = .01), laterality (86 [64%] vs 60 [44%]; P = .001), and extracapsular extension (100 [75%] vs 84 [63%]; P = .01), but not for seminal vesicle invasion (122 [91%] vs 115 [85%]; P = .07). Conclusions and Relevance: In this phase 2 prospective validating paired cohort study, 18F-PSMA-1007 PET/CT was superior to MRI for the locoregional staging of prostate cancer. These findings support PSMA PET in the preoperative workflow of intermediate-risk and high-risk tumors.
Assuntos
Radioisótopos de Flúor , Imageamento por Ressonância Magnética Multiparamétrica , Estadiamento de Neoplasias , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Neoplasias da Próstata , Humanos , Masculino , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Neoplasias da Próstata/cirurgia , Imageamento por Ressonância Magnética Multiparamétrica/métodos , Pessoa de Meia-Idade , Idoso , Estudos Prospectivos , Compostos Radiofarmacêuticos , Niacinamida/análogos & derivados , Oligopeptídeos , Glutamato Carboxipeptidase II/metabolismo , Antígenos de Superfície/metabolismoRESUMO
BACKGROUND: The tumor suppressor and proapoptotic transcription factor P53 is induced (and activated) in several forms of heart failure, including cardiotoxicity and dilated cardiomyopathy; however, the precise mechanism that coordinates its induction with accessibility to its transcriptional promoter sites remains unresolved, especially in the setting of mature terminally differentiated (nonreplicative) cardiomyocytes. METHODS: Male and female control or TRIM35 (tripartite motif containing 35) overexpression adolescent (aged 1-3 months) and adult (aged 4-6 months) transgenic mice were used for all in vivo experiments. Primary adolescent or adult mouse cardiomyocytes were isolated from control or TRIM35 overexpression transgenic mice for all in vitro experiments. Adenovirus or small-interfering RNA was used for all molecular experiments to overexpress or knockdown, respectively, target genes in primary mouse cardiomyocytes. Patient dilated cardiomyopathy or nonfailing left ventricle samples were used for translational and mechanistic insight. Chromatin immunoprecipitation and DNA sequencing or quantitative real-time polymerase chain reaction (qPCR) was used to assess P53 binding to its transcriptional promoter targets, and RNA sequencing was used to identify disease-specific signaling pathways. RESULTS: Here, we show that E3-ubiquitin ligase TRIM35 can directly monoubiquitinate lysine-120 (K120) on histone 2B in postnatal mature cardiomyocytes. This epigenetic modification was sufficient to promote chromatin remodeling, accessibility of P53 to its transcriptional promoter targets, and elongation of its transcribed mRNA. We found that increased P53 transcriptional activity (in cardiomyocyte-specific Trim35 overexpression transgenic mice) was sufficient to initiate heart failure and these molecular findings were recapitulated in nonischemic human LV dilated cardiomyopathy samples. CONCLUSIONS: These findings suggest that TRIM35 and the K120Ub-histone 2B epigenetic modification are molecular features of cardiomyocytes that can collectively predict dilated cardiomyopathy pathogenesis.
Assuntos
Insuficiência Cardíaca , Histonas , Camundongos Transgênicos , Miócitos Cardíacos , Proteína Supressora de Tumor p53 , Ubiquitinação , Animais , Feminino , Humanos , Masculino , Camundongos , Cardiomiopatia Dilatada/metabolismo , Cardiomiopatia Dilatada/genética , Cardiomiopatia Dilatada/patologia , Células Cultivadas , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/patologia , Histonas/metabolismo , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/metabolismo , Regiões Promotoras Genéticas , Proteína Supressora de Tumor p53/metabolismo , Proteína Supressora de Tumor p53/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genéticaRESUMO
Oxidative stress occurs during ex-situ heart perfusion (ESHP) and may negatively affect functional preservation of the heart. We sought to assess the status of key antioxidant enzymes during ESHP, and the effects of augmenting these antioxidants on the attenuation of oxidative stress and improvement of myocardial and endothelial preservation in ESHP. Porcine hearts were perfused for 6 hours with oxygen-derived free-radical scavengers polyethylene glycol (PEG)-catalase or PEG-superoxide dismutase (SOD) or with naive perfusate (control). The oxidative stress-related modifications were determined in the myocardium and coronary vasculature, and contractile function, injury, and endothelial integrity were compared between the groups. The activity of key antioxidant enzymes decreased and adding catalase and SOD restored the enzyme activity. Cardiac function and endothelial integrity were preserved better with restored catalase activity. Catalase and SOD both decreased myocardial injury and catalase reduced ROS production and oxidative modification of proteins in the myocardium and coronary vasculature. The activity of antioxidant enzymes decrease in ESHP. Catalase may improve the preservation of cardiac function and endothelial integrity during ESHP. While catalase and SOD may both exert cardioprotective effects, unbalanced SOD and catalase activity may paradoxically increase the production of reactive species during ESHP.
Assuntos
Catalase , Sequestradores de Radicais Livres , Estresse Oxidativo , Superóxido Dismutase , Animais , Suínos , Superóxido Dismutase/metabolismo , Catalase/metabolismo , Sequestradores de Radicais Livres/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Perfusão/métodos , Miocárdio/metabolismo , Polietilenoglicóis/farmacologia , Coração/fisiologia , Coração/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Antioxidantes/farmacologia , Preservação de Órgãos/métodosRESUMO
Pyruvate kinase M2 (PKM2) is a glycolytic enzyme that translocates to the nucleus to regulate transcription factors in different tissues or pathologic states. Although studied extensively in cancer, its biological role in the heart remains unresolved. PKM1 is more abundant than the PKM2 isoform in cardiomyocytes, and thus, we speculated that PKM2 is not genetically redundant to PKM1 and may be critical in regulating cardiomyocyte-specific transcription factors important for cardiac survival. Here, we showed that nuclear PKM2 (S37P-PKM2) in cardiomyocytes interacts with prosurvival and proapoptotic transcription factors, including GATA4, GATA6, and P53. Cardiomyocyte-specific PKM2-deficient mice (Pkm2 Mut Cre+) developed age-dependent dilated cardiac dysfunction and had decreased amounts of GATA4 and GATA6 (GATA4/6) but increased amounts of P53 compared to Control Cre+ hearts. Nuclear PKM2 prevented caspase-1-dependent cleavage and degradation of GATA4/6 while also providing a molecular platform for MDM2-mediated reduction of P53. In a preclinical heart failure mouse model, nuclear PKM2 and GATA4/6 were decreased, whereas P53 was increased in cardiomyocytes. Loss of nuclear PKM2 was ubiquitination dependent and associated with the induction of the E3 ubiquitin ligase TRIM35. In mice, cardiomyocyte-specific TRIM35 overexpression resulted in decreased S37P-PKM2 and GATA4/6 along with increased P53 in cardiomyocytes compared to littermate controls and similar cardiac dysfunction to Pkm2 Mut Cre+ mice. In patients with dilated left ventricles, increase in TRIM35 was associated with decreased S37P-PKM2 and GATA4/6 and increased P53. This study supports a previously unrecognized role for PKM2 as a molecular platform that mediates cell signaling events essential for cardiac survival.
Assuntos
Cardiopatias , Insuficiência Cardíaca , Animais , Camundongos , Proteínas Reguladoras de Apoptose/metabolismo , Fator de Transcrição GATA4/metabolismo , Cardiopatias/metabolismo , Insuficiência Cardíaca/metabolismo , Miócitos Cardíacos/metabolismo , Piruvato Quinase/metabolismo , Fatores de Transcrição/metabolismo , Proteína Supressora de Tumor p53/metabolismoRESUMO
Fasting increases susceptibility to acute myocardial ischaemia/reperfusion injury (IRI) but the mechanisms are unknown. Here, we investigate the role of the mitochondrial NAD+-dependent deacetylase, Sirtuin-3 (SIRT3), which has been shown to influence fatty acid oxidation and cardiac outcomes, as a potential mediator of this effect. Fasting was shown to shift metabolism from glucose towards fatty acid oxidation. This change in metabolic fuel substrate utilisation increased myocardial infarct size in wild-type (WT), but not SIRT3 heterozygous knock-out (KO) mice. Further analysis revealed SIRT3 KO mice were better adapted to starvation through an improved cardiac efficiency, thus protecting them from acute myocardial IRI. Mitochondria from SIRT3 KO mice were hyperacetylated compared to WT mice which may regulate key metabolic processes controlling glucose and fatty acid utilisation in the heart. Fasting and the associated metabolic switch to fatty acid respiration worsens outcomes in WT hearts, whilst hearts from SIRT3 KO mice are better adapted to oxidising fatty acids, thereby protecting them from acute myocardial IRI.
Assuntos
Traumatismo por Reperfusão Miocárdica , Sirtuína 3 , Animais , Camundongos , Jejum , Ácidos Graxos , Glucose , Camundongos Knockout , Traumatismo por Reperfusão Miocárdica/genética , Sirtuína 3/genéticaRESUMO
Metastasis is the primary cause of cancer patient death and the elevation of SLC2A5 gene expression is often observed in metastatic cancer cells. Here we evaluated the importance of SLC2A5 in cancer cell motility by silencing its gene. We discovered that CRISPR/Cas9-mediated inactivation of the SLC2A5 gene inhibited cancer cell proliferation and migration in vitro as well as metastases in vivo in several animal models. Moreover, SLC2A5-attenuated cancer cells exhibited dramatic alterations in mitochondrial architecture and localization, uncovering the importance of SLC2A5 in directing mitochondrial function for cancer cell motility and migration. The direct association of increased abundance of SLC2A5 in cancer cells with metastatic risk in several types of cancers identifies SLC2A5 as an important therapeutic target to reduce or prevent cancer metastasis.
RESUMO
Targeting cell fate may be the most promising approach to treat, reverse, and cure pulmonary arterial hypertension (Zhang et al.).
Assuntos
Artéria Pulmonar , Hipertensão Pulmonar Primária Familiar , HumanosRESUMO
An epithelial-to-mesenchymal transition (EMT) phenotype with cancer stem cell-like properties is a critical feature of aggressive/metastatic tumors, but the mechanism(s) that promote it and its relation to metabolic stress remain unknown. Here we show that Collapsin Response Mediator Protein 2A (CRMP2A) is unexpectedly and reversibly induced in cancer cells in response to multiple metabolic stresses, including low glucose and hypoxia, and inhibits EMT/stemness. Loss of CRMP2A, when metabolic stress decreases (e.g., around blood vessels in vivo) or by gene deletion, induces extensive microtubule remodeling, increased glutamine utilization toward pyrimidine synthesis, and an EMT/stemness phenotype with increased migration, chemoresistance, tumor initiation capacity/growth, and metastatic potential. In a cohort of 27 prostate cancer patients with biopsies from primary tumors and distant metastases, CRMP2A expression decreases in the metastatic versus primary tumors. CRMP2A is an endogenous molecular brake on cancer EMT/stemness and its loss increases the aggressiveness and metastatic potential of tumors.
Assuntos
Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neoplasias da Próstata , Semaforina-3A , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal/genética , Humanos , Masculino , Células-Tronco Neoplásicas/metabolismo , Neoplasias da Próstata/patologia , Semaforina-3A/metabolismo , Estresse FisiológicoRESUMO
The mitochondrial pyruvate dehydrogenase complex (PDC) translocates into the nucleus, facilitating histone acetylation by producing acetyl-CoA. We describe a noncanonical pathway for nuclear PDC (nPDC) import that does not involve nuclear pore complexes (NPCs). Mitochondria cluster around the nucleus in response to proliferative stimuli and tether onto the nuclear envelope (NE) via mitofusin-2 (MFN2)-enriched contact points. A decrease in nuclear MFN2 levels decreases mitochondria tethering and nPDC levels. Mitochondrial PDC crosses the NE and interacts with lamin A, forming a ring below the NE before crossing through the lamin layer into the nucleoplasm, in areas away from NPCs. Effective blockage of NPC trafficking does not decrease nPDC levels. The PDC-lamin interaction is maintained during cell division, when lamin depolymerizes and disassembles before reforming daughter nuclear envelopes, providing another pathway for nPDC entry during mitosis. Our work provides a different angle to understanding mitochondria-to-nucleus communication and nuclear metabolism.
Assuntos
Núcleo Celular , Complexo Piruvato Desidrogenase , Acetilcoenzima A/metabolismo , Núcleo Celular/genética , Núcleo Celular/metabolismo , Laminas/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Membrana Nuclear/metabolismo , Complexo Piruvato Desidrogenase/genética , Complexo Piruvato Desidrogenase/metabolismoRESUMO
In diabetes, glucagon secretion from pancreatic α cells is dysregulated. The underlying mechanisms, and whether dysfunction occurs uniformly among cells, remain unclear. We examined α cells from human donors and mice using electrophysiological, transcriptomic, and computational approaches. Rising glucose suppresses α cell exocytosis by reducing P/Q-type Ca2+ channel activity, and this is disrupted in type 2 diabetes (T2D). Upon high-fat feeding of mice, α cells shift toward a "ß cell-like" electrophysiological profile in concert with indications of impaired identity. In human α cells we identified links between cell membrane properties and cell surface signaling receptors, mitochondrial respiratory chain complex assembly, and cell maturation. Cell-type classification using machine learning of electrophysiology data demonstrated a heterogenous loss of "electrophysiologic identity" in α cells from donors with type 2 diabetes. Indeed, a subset of α cells with impaired exocytosis is defined by an enrichment in progenitor and lineage markers and upregulation of an immature transcriptomic phenotype, suggesting important links between α cell maturation state and dysfunction.
Assuntos
Diabetes Mellitus Tipo 2 , Células Secretoras de Glucagon , Ilhotas Pancreáticas , Animais , Diabetes Mellitus Tipo 2/metabolismo , Exocitose/fisiologia , Glucagon/metabolismo , Células Secretoras de Glucagon/metabolismo , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , CamundongosRESUMO
Oral treprostinil has been shown to improve exercise capacity and delay disease progression in patients with pulmonary arterial hypertension (PAH), but its effects on hemodynamics are not well-characterized. The FREEDOM-EV trial was a Phase III, international, placebo-controlled, double-blind, event-driven study in 690 participants with PAH who were taking a single oral PAH therapy. FREEDOM-EV demonstrated a significantly reduced risk for clinical worsening with oral treprostinil taken three times daily and did not uncover new safety signals in PAH patients. Sixty-one participants in the FREEDOM-EV trial volunteered for a hemodynamics sub-study. Pulmonary artery compliance (PAC), a ratio of stroke volume to pulmonary pulse pressure, significantly increased from Baseline to Week 24 in the oral treprostinil group compared with the placebo group (geometric mean 26.4% active vs. -6.0% placebo; ANCOVA p=0.007). There was a significant increase in cardiac output in the oral treprostinil group compared to the placebo group (geometric mean 11.3% active vs. -6.4% placebo; ANCOVA p=0.005) and a corresponding significant reduction in pulmonary vascular resistance (PVR) (geometric mean -21.5 active vs. -1.8% placebo; ANCOVA p=0.02) from Baseline to Week 24. These data suggest that increased compliance contributes to the physiological mechanism by which oral treprostinil improves exercise capacity and delays clinical worsening for patients with PAH.
Assuntos
Hipertensão Arterial Pulmonar , Anti-Hipertensivos , Epoprostenol/análogos & derivados , Epoprostenol/uso terapêutico , Humanos , Hipertensão Arterial Pulmonar/tratamento farmacológico , Resultado do Tratamento , Resistência VascularRESUMO
Background Isolated loss-of-function single nucleotide polymorphisms (SNPs) for SIRT3 (a mitochondrial deacetylase) and UCP2 (an atypical uncoupling protein enabling mitochondrial calcium entry) have been associated with both pulmonary arterial hypertension (PAH) and insulin resistance, but their collective role in animal models and patients is unknown. Methods and Results In a prospective cohort of patients with PAH (n=60), we measured SNPs for both SIRT3 and UCP2, along with several clinical features (including invasive hemodynamic data) and outcomes. We found SIRT3 and UCP2 SNPs often both in the same patient in a homozygous or heterozygous manner, correlating positively with PAH severity and associated with the presence of type 2 diabetes and 10-year outcomes (death and transplantation). To explore this mechanistically, we generated double knockout mice for Sirt3 and Ucp2 and found increasing severity of PAH (mean pulmonary artery pressure, right ventricular hypertrophy/dilatation and extensive vascular remodeling, including inflammatory plexogenic lesions, in a gene dose-dependent manner), along with insulin resistance, compared with wild-type mice. The suppressed mitochondrial function (decreased respiration, increased mitochondrial membrane potential) in the double knockout pulmonary artery smooth muscle cells was associated with apoptosis resistance and increased proliferation, compared with wild-type mice. Conclusions Our work supports the metabolic theory of PAH and shows that these mice exhibit spontaneous severe PAH (without environmental or chemical triggers) that mimics human PAH and may explain the findings in our patient cohort. Our study offers a new mouse model of PAH, with several features of human disease that are typically absent in other PAH mouse models.
Assuntos
Diabetes Mellitus Tipo 2 , Polimorfismo de Nucleotídeo Único , Hipertensão Arterial Pulmonar , Sirtuína 3 , Proteína Desacopladora 2 , Animais , Diabetes Mellitus Tipo 2/genética , Modelos Animais de Doenças , Humanos , Resistência à Insulina/genética , Camundongos , Estudos Prospectivos , Hipertensão Arterial Pulmonar/genética , Hipertensão Arterial Pulmonar/terapia , Índice de Gravidade de Doença , Sirtuína 3/genética , Resultado do Tratamento , Proteína Desacopladora 2/genéticaRESUMO
INTRODUCTION: The anti-inflammatory effect of macrolides prompted the study of oral clarithromycin in moderate COVID-19. METHODS: An open-label non-randomized trial in 90 patients with COVID-19 of moderate severity was conducted between May and October 2020. The primary endpoint was defined at the end of treatment (EOT) as no need for hospital re-admission and no progression into lower respiratory tract infection (LRTI) for patients with upper respiratory tract infection and as at least 50% decrease of the respiratory symptoms score without progression into severe respiratory failure (SRF) for patients with LRTI. Viral load, biomarkers, the function of mononuclear cells and safety were assessed. RESULTS: The primary endpoint was attained in 86.7% of patients treated with clarithromycin (95% CIs 78.1-92.2%); this was 91.7% and 81.4% among patients starting clarithromycin the first 5 days from symptoms onset or later (odds ratio after multivariate analysis 6.62; p 0.030). The responses were better for patients infected by non-B1.1 variants. Clarithromycin use was associated with decreases in circulating C-reactive protein, tumour necrosis factor-alpha and interleukin (IL)-6; by increase of production of interferon-gamma and decrease of production of interleukin-6 by mononuclear cells; and by suppression of SARS-CoV-2 viral load. No safety concerns were reported. CONCLUSIONS: Early clarithromycin treatment provides most of the clinical improvement in moderate COVID-19. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04398004.
RESUMO
Stiffness in the tissue microenvironment changes in most diseases and immunological conditions, but its direct influence on the immune system is poorly understood. Here, we show that static tension impacts immune cell function, maturation, and metabolism. Bone-marrow-derived and/or splenic dendritic cells (DCs) grown in vitro at physiological resting stiffness have reduced proliferation, activation, and cytokine production compared with cells grown under higher stiffness, mimicking fibro-inflammatory disease. Consistently, DCs grown under higher stiffness show increased activation and flux of major glucose metabolic pathways. In DC models of autoimmune diabetes and tumor immunotherapy, tension primes DCs to elicit an adaptive immune response. Mechanistic workup identifies the Hippo-signaling molecule, TAZ, as well as Ca2+-related ion channels, including potentially PIEZO1, as important effectors impacting DC metabolism and function under tension. Tension also directs the phenotypes of monocyte-derived DCs in humans. Thus, mechanical stiffness is a critical environmental cue of DCs and innate immunity.
Assuntos
Células Dendríticas/imunologia , Imunidade Inata/imunologia , Imunoterapia/métodos , Rigidez Vascular/imunologia , Humanos , Transdução de SinaisRESUMO
BACKGROUND/AIM: To investigate the efficacy (prognosis, coagulation/inflammation biomarkers) and safety (bleeding events) of different anticoagulation dosages in COVID-19 inpatients. PATIENTS AND METHODS: COVID-19 inpatients (Athens, Greece) were included. The "Enhanced dose THRomboprophylaxis in Admissions (ETHRA)" protocol was applied in certain Departments, suggesting the use of intermediate anticoagulation dosage. The primary endpoint was a composite of intubation/venous thromboembolism/death. Inflammation/coagulation parameters were assessed. RESULTS: Among 127 admissions, 95 fulfilled the inclusion criteria. Twenty-one events (4 deaths, 17 intubations) were observed. Regression analysis demonstrated significant reduction of events with intermediate or therapeutic dosage [HR=0.16 (95%CI=0.05-0.52) p=0.002; HR=0.17 (0.04-0.71) p=0.015, respectively]. D-Dimer values were higher in those who met the composite endpoint. Intermediate dosage treatment was associated with decreased values of ferritin. Three patients (3%) had minor hemorrhagic complications. CONCLUSION: Anticoagulation treatment (particularly intermediate dosage) appears to have positive impact on COVID-19 inpatients' prognosis by inhibiting both coagulation and inflammatory cascades.
Assuntos
Anticoagulantes/uso terapêutico , Coagulação Sanguínea/efeitos dos fármacos , COVID-19/prevenção & controle , Hospitalização/estatística & dados numéricos , SARS-CoV-2/isolamento & purificação , Tromboembolia Venosa/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/administração & dosagem , COVID-19/sangue , COVID-19/virologia , Relação Dose-Resposta a Droga , Feminino , Grécia , Humanos , Pacientes Internados/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , SARS-CoV-2/fisiologia , Resultado do Tratamento , Tromboembolia Venosa/sangueAssuntos
Antibióticos Antineoplásicos/efeitos adversos , Receptores de Apelina/metabolismo , Doxorrubicina/efeitos adversos , Miocárdio/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Animais , Cardiotoxicidade , Metabolismo Energético/efeitos dos fármacos , Ácidos Graxos/metabolismo , Coração/efeitos dos fármacos , Humanos , Masculino , Camundongos , Camundongos Nus , Transdução de Sinais/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismoRESUMO
The von Hippel-Lindau (VHL) protein binds and degrades hypoxia-inducible factors (HIF) hydroxylated by prolyl-hydroxylases under normoxia. Although originally described as a tumor suppressor, there is growing evidence that VHL may paradoxically promote tumor growth. The significance of its described interactions with many other proteins remains unclear. We found that VHL interacts with p53, preventing its tetramerization, promoter binding and expression of its target genes p21, PUMA, and Bax. VHL limited the decrease in proliferation and increase in apoptosis caused by p53 activation, independent of prolyl-hydroxylation and HIF activity, and its presence in tumors caused a resistance to p53-inducing chemotherapy in vivo. We propose that VHL has both anti-tumor function, via HIF degradation, and a new pro-tumor function via p53 target (p21, PUMA, Bax) inhibition. Because p53 plays a critical role in tumor biology, is activated by many chemotherapies, and because VHL levels vary among different tumors and its function can even be lost by mutations in some tumors, our results have important clinical applications. KEY MESSAGES: VHL and p53 physically interact and VHL inhibits p53 activity by limiting the formation of p53 tetramers. VHL attenuates the expression of p53 target genes in response to p53 stimuli. The inhibition of p53 by VHL is independent of HIF and prolyl-hydroxylation.