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1.
Artif Organs ; 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39023289

RESUMO

Cardiogenic shock (CS) is a severe complication of peripartum cardiomyopathy (PPCM). Patients with deteriorating CS often require temporary mechanical circulatory support. In PPCM, this can be used as a bridge to postpartum recovery or bridge to decision. The outcomes are unclear, especially if prolonged utilization is required. We present a case series of three patients with PPCM in deteriorating CS who were successfully supported with a ventricular assist device or veno-arterial extracorporeal membrane oxygenation as a bridge to postpartum recovery.

2.
Angew Chem Int Ed Engl ; 63(18): e202401626, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38416546

RESUMO

Coenzyme B12 (AdoCbl; 5'-deoxy-5'-adenosylcobalamin), the quintessential biological organometallic radical catalyst, has a formerly unanticipated, yet extensive, role in photoregulation in bacteria. The light-responsive cobalt-corrin AdoCbl performs this nonenzymatic role by facilitating the assembly of CarH photoreceptors into DNA-binding tetramers in the dark, suppressing gene expression. Conversely, exposure to light triggers the decomposition of this AdoCbl-bound complex by a still elusive photochemical mechanism, activating gene expression. Here, we have examined AdoRhbl, the non-natural rhodium analogue of AdoCbl, as a photostable isostructural surrogate for AdoCbl. We show that AdoRhbl closely emulates AdoCbl in its uptake by bacterial cells and structural functionality as a regulatory ligand for CarH tetramerization, DNA binding, and repressor activity. Remarkably, we find AdoRhbl is photostable even when bound "base-off/His-on" to CarH in vitro and in vivo. Thus, AdoRhbl, an antivitamin B12, also represents an unprecedented anti-photoregulatory ligand, opening a pathway to precisely target biomimetic inhibition of AdoCbl-based photoregulation, with new possibilities for selective antibacterial applications. Computational biomolecular analysis of AdoRhbl binding to CarH yields detailed structural insights into this complex, which suggest that the adenosyl group of photoexcited AdoCbl bound to CarH may specifically undergo a concerted non-radical syn-1,2-elimination mechanism, an aspect not previously considered for this photoreceptor.


Assuntos
Fosfotreonina/análogos & derivados , Ródio , Ligantes , Cobamidas/química , Bactérias/metabolismo , DNA
3.
Circulation ; 143(21): 2091-2109, 2021 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-33709773

RESUMO

BACKGROUND: Marfan syndrome (MFS) is an autosomal dominant disorder of the connective tissue caused by mutations in the FBN1 (fibrillin-1) gene encoding a large glycoprotein in the extracellular matrix called fibrillin-1. The major complication of this connective disorder is the risk to develop thoracic aortic aneurysm. To date, no effective pharmacologic therapies have been identified for the management of thoracic aortic disease and the only options capable of preventing aneurysm rupture are endovascular repair or open surgery. Here, we have studied the role of mitochondrial dysfunction in the progression of thoracic aortic aneurysm and mitochondrial boosting strategies as a potential treatment to managing aortic aneurysms. METHODS: Combining transcriptomics and metabolic analysis of aortas from an MFS mouse model (Fbn1c1039g/+) and MFS patients, we have identified mitochondrial dysfunction alongside with mtDNA depletion as a new hallmark of aortic aneurysm disease in MFS. To demonstrate the importance of mitochondrial decline in the development of aneurysms, we generated a conditional mouse model with mitochondrial dysfunction specifically in vascular smooth muscle cells (VSMC) by conditional depleting Tfam (mitochondrial transcription factor A; Myh11-CreERT2Tfamflox/flox mice). We used a mouse model of MFS to test for drugs that can revert aortic disease by enhancing Tfam levels and mitochondrial respiration. RESULTS: The main canonical pathways highlighted in the transcriptomic analysis in aortas from Fbn1c1039g/+ mice were those related to metabolic function, such as mitochondrial dysfunction. Mitochondrial complexes, whose transcription depends on Tfam and mitochondrial DNA content, were reduced in aortas from young Fbn1c1039g/+ mice. In vitro experiments in Fbn1-silenced VSMCs presented increased lactate production and decreased oxygen consumption. Similar results were found in MFS patients. VSMCs seeded in matrices produced by Fbn1-deficient VSMCs undergo mitochondrial dysfunction. Conditional Tfam-deficient VSMC mice lose their contractile capacity, showed aortic aneurysms, and died prematurely. Restoring mitochondrial metabolism with the NAD precursor nicotinamide riboside rapidly reverses aortic aneurysm in Fbn1c1039g/+ mice. CONCLUSIONS: Mitochondrial function of VSMCs is controlled by the extracellular matrix and drives the development of aortic aneurysm in Marfan syndrome. Targeting vascular metabolism is a new available therapeutic strategy for managing aortic aneurysms associated with genetic disorders.


Assuntos
Aneurisma Aórtico/fisiopatologia , Síndrome de Marfan/genética , Mitocôndrias/metabolismo , Animais , Modelos Animais de Doenças , Humanos , Síndrome de Marfan/fisiopatologia , Camundongos
4.
J Cardiovasc Pharmacol ; 79(5): 646-649, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35058410

RESUMO

ABSTRACT: Left ventricular assist device (LVAD) implantation is increasingly utilized in patients with advanced heart failure and morbid obesity. Laparoscopic sleeve gastrectomy (LSG) can facilitate weight loss in this population and can ultimately change the pharmacokinetics of heart failure therapeutics. In this study, we aimed to explore the changes in cardiovascular pharmacotherapy post LSG intervention. We conducted a retrospective observational cohort study of morbidly obese LVAD patients between 2013 and 2019 at the University of Florida with available pharmacotherapeutic data at 1 and 6 months. Thirteen post-LSG patients and 13 control subjects were included in the final analysis. In the post-LSG group, the mean body mass index decreased significantly (44 ± 5 vs. 34 ± 4.9, P < 0.001), and 7 patients were successfully bridged to cardiac transplantation. Only 3 patients required adjustment of their LVAD speed. Mean return to flow decreased by 8 mm Hg, despite a 45% reduction in the mean number of vasodilators per patient (1.2 vs. 0.7, P = 0.03). Mean weekly warfarin dose decreased by 35% after 6 months (32.9 ± 20.9 vs. 50.7 ± 26.6, P = 0.01). The use of diuretics, vasodilators, and beta-blockers was significantly reduced by 50%, 45%, and 35%, respectively. None of these changes were observed in the control group at 6-month follow-up post LVAD. In this single-center experience, weight loss post LSG is associated with decreased vasodilator, diuretic, and anticoagulant medication requirements in LVAD patients.


Assuntos
Insuficiência Cardíaca , Coração Auxiliar , Laparoscopia , Obesidade Mórbida , Índice de Massa Corporal , Gastrectomia/efeitos adversos , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/terapia , Humanos , Laparoscopia/efeitos adversos , Obesidade Mórbida/diagnóstico , Obesidade Mórbida/cirurgia , Estudos Retrospectivos , Resultado do Tratamento , Vasodilatadores , Redução de Peso
5.
J Allergy Clin Immunol ; 147(5): 1855-1864.e9, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33385443

RESUMO

BACKGROUND: Anaphylaxis is a severe allergic reaction that can be lethal if not treated adequately. The underlying molecular mechanisms responsible for the severity are mostly unknown. OBJECTIVE: This study is based on a clinical case of a patient with extremely severe anaphylaxis to paper wasp venom. This patient has a mutation in the KARS gene, which encodes lysyl-tRNA synthetase (LysRS), a moonlight protein with a canonical function in protein synthesis and a noncanonical function in antigen dependent-FcεRI activation in mast cells. In this study, the objective was to characterize the mutation at the molecular level. METHODS: Analysis of the KARS mutation was carried out using biochemical and functional approaches, cell transfection, Western blot, confocal microscopy, cell degranulation, prostaglandin D2 secretion, and proteases gene transcription. Structural analysis using molecular dynamics simulations and well-tempered metadynamics was also performed. RESULTS: The mutation found, P542R (proline was replaced by arginine at aminoacid 542), affects the location of the protein as we show in biochemical and structural analyses. The mutation resembles active LysRS and causes a constitutive activation of the microphthalmia transcription factor, which is involved in critical mast cell functions such as synthesis of mediators and granule biogenesis. Moreover, the structural analysis provides insights into how LysRS works in mast cell activation. CONCLUSIONS: A link between the aberrant LysRS-P542R function and mast cell-exacerbated activation with increase in proinflammatory mediator release after antigen-IgE-dependent response could be established.


Assuntos
Anafilaxia/genética , Lisina-tRNA Ligase/genética , Adulto , Anafilaxia/imunologia , Animais , Mordeduras e Picadas/complicações , Mordeduras e Picadas/genética , Mordeduras e Picadas/imunologia , Linhagem Celular , Humanos , Lisina-tRNA Ligase/imunologia , Masculino , Mastócitos/imunologia , Fator de Transcrição Associado à Microftalmia/genética , Fator de Transcrição Associado à Microftalmia/imunologia , Mutação , Ratos , Vespas
6.
Heart Fail Rev ; 26(2): 355-361, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32997214

RESUMO

Intravenous inotropic therapy can be used in patients with advanced heart failure, as palliative therapy or as a bridge to cardiac transplantation or mechanical circulatory support, as well as in cardiogenic shock. Their use is limited to increasing cardiac output in low cardiac output states and reducing ventricular filling pressures to alleviate patient symptoms and improve functional class. Many advanced heart failure patients have sinus tachycardia as a compensatory mechanism to maintain cardiac output. However, excessive sinus tachycardia caused by intravenous inotropes can increase myocardial oxygen consumption, decrease coronary perfusion, and at extreme heart rates decrease ventricular filling and stroke volume. The limited available hemodynamic studies support the hypothesis that adding ivabradine, a rate control agent without negative inotropic effect, may blunt inotrope-induced tachycardia and its associated deleterious effects, while optimizing cardiac output by increasing stroke volume. This review analyzes the intriguing pathophysiology of combined intravenous inotropes and ivabradine to optimize the hemodynamic profile of patients in advanced heart failure. Graphical abstract Illustration of the beneficial and deleterious hemodynamic effects of intravenous inotropes in advanced heart failure, and the positive effects of adding ivabradine.


Assuntos
Cardiotônicos , Insuficiência Cardíaca , Cardiotônicos/farmacologia , Insuficiência Cardíaca/tratamento farmacológico , Frequência Cardíaca , Hemodinâmica , Humanos , Ivabradina , Volume Sistólico
7.
Mar Drugs ; 19(9)2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34564172

RESUMO

Paralytic shellfish toxins (PST) are found in the hepatopancreas of Southern Rock Lobster Jasus edwardsii from the east coast of Tasmania in association with blooms of the toxic dinoflagellate Alexandrium catenella. Tasmania's rock lobster fishery is one of the state's most important wild capture fisheries, supporting a significant commercial industry (AUD 97M) and recreational fishing sector. A comprehensive 8 years of field data collected across multiple sites has allowed continued improvements to the risk management program protecting public health and market access for the Tasmanian lobster fishery. High variability was seen in toxin levels between individuals, sites, months, and years. The highest risk sites were those on the central east coast, with July to January identified as the most at-risk months. Relatively high uptake rates were observed (exponential rate of 2% per day), similar to filter-feeding mussels, and meant that lobster accumulated toxins quickly. Similarly, lobsters were relatively fast detoxifiers, losing up to 3% PST per day, following bloom demise. Mussel sentinel lines were effective in indicating a risk of elevated PST in lobster hepatopancreas, with annual baseline monitoring costing approximately 0.06% of the industry value. In addition, it was determined that if the mean hepatopancreas PST levels in five individual lobsters from a site were <0.22 mg STX equiv. kg-1, there is a 97.5% probability that any lobster from that site would be below the bivalve maximum level of 0.8 mg STX equiv. kg-1. The combination of using a sentinel species to identify risk areas and sampling five individual lobsters at a particular site, provides a cost-effective strategy for managing PST risk in the Tasmanian commercial lobster fishery.


Assuntos
Bivalves , Monitoramento Ambiental , Toxinas Marinhas/análise , Palinuridae , Intoxicação por Frutos do Mar/prevenção & controle , Animais , Demografia , Ecossistema , Pesqueiros , Humanos , Doenças Profissionais/prevenção & controle , Reprodutibilidade dos Testes , Tasmânia
8.
Opt Express ; 28(6): 8156-8168, 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-32225446

RESUMO

Vibrational Raman effect is widely used in atmospheric lidar systems, but rotational Raman present several advantages. We have implemented a new setup in the ultraviolet branch of an existing multiwavelength lidar system to collect signal from rotational Raman lines of Oxygen and Nitrogen. We showed that, with an appropriate filter wavelength selection, the systematic error introduced in the particle optical properties due to temperature dependence was less than 4%. With this new setup, we have been able to retrieve aerosol extinction and backscatter coefficients profiles at 355 nm with 1-h time resolution during daytime and up to 1-min time resolution during nighttime.

9.
Pacing Clin Electrophysiol ; 43(9): 1048-1050, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32394443

RESUMO

There is limited known safety and efficacy of leadless pacemaker device use in patients with durable left ventricular assist devices (LVADs). We present a case of a pacemaker-dependent LVAD patient with infection of permanent transvenous pacemaker who underwent successful implantation of Micra transcatheter pacing system (Medtronic).


Assuntos
Fibrilação Atrial/terapia , Cardiomiopatias/terapia , Bloqueio Cardíaco/terapia , Coração Auxiliar , Marca-Passo Artificial , Idoso , Fibrilação Atrial/diagnóstico por imagem , Cardiomiopatias/diagnóstico por imagem , Bloqueio Cardíaco/diagnóstico por imagem , Humanos , Masculino , Desenho de Prótese
10.
J Card Surg ; 35(3): 710-712, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31971286

RESUMO

As patient survival after cardiac transplantation has improved over the course of the last several decades, clinicians are now faced with late complications. This includes aortic stenosis which, traditionally, has been treated with reoperative sternotomy and aortic valve replacement. Transcather aortic valve replacement (TAVR) offers a minimally invasive alternative in this high-risk population. A small but growing number of cases of TAVR after heart transplantation in high-risk patients have been reported in the last 10 years; we now present a case of aortic valve replacement via a transcatheter approach 24 years after cardiac transplantation.


Assuntos
Valva Aórtica/cirurgia , Transplante de Coração , Complicações Pós-Operatórias/cirurgia , Substituição da Valva Aórtica Transcateter , Idoso de 80 Anos ou mais , Estenose da Valva Aórtica/cirurgia , Humanos , Masculino , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Reoperação , Esternotomia , Fatores de Tempo , Resultado do Tratamento
11.
J Card Surg ; 35(10): 2529-2538, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32741013

RESUMO

OBJECTIVES: Renal function may improve after left ventricular assist device (LVAD) implant, however, some patients develop postoperative acute kidney injury (AKI). Randomized trials showed benefit for early renal replacement therapy (RRT) in critically ill patients with AKI, but this practice has not been studied in LVAD patients. METHODS: We performed a single-center, retrospective cohort study of all adults (>18 years) who underwent LVAD placement from 1/2010 to 12/2018. We collected preoperative, hemodynamic, echocardiographic, intraoperative, and postoperative data. AKI was defined according to Kidney Disease: Improving Global Outcomes definition. Early (E) RRT was considered treatment at AKI stage II or below. Standard (S) RRT was considered treatment at AKI stage III. Outcomes and Kaplan-Meier analysis were compared between groups. RESULTS: A total of 184 patients were included (mean age 56.10 years, 81% males, 30.4% African-American race). A total of 71 (38.6%) developed AKI and 17 (9.24%) needed RRT (11 E vs 6 S). A total of 11 remained hemodialysis-dependent at discharge (5 [45.5%] in E vs 6 [100%] in S, P = .043). There was a trend toward shorter intensive care unit stay and ventilation time in E group, and overall hospital stay was significantly less in the E group (48.18 ± 25.95 vs 94.00 ± 53.07 days, P = .028). Thirty-day mortality was similar between groups (E 18% vs S 16%, P = .9), but there was a trend toward improved overall survival in the E group. CONCLUSION: This is the first study to examine early initiation of RRT after LVAD implant. Early RRT was associated with shorter hospital stay, lower need for permanent RRT, and a trend toward improved survival. This practice may provide significant cost savings and should be examined further.


Assuntos
Injúria Renal Aguda/etiologia , Injúria Renal Aguda/terapia , Coração Auxiliar/efeitos adversos , Terapia de Substituição Renal/métodos , Injúria Renal Aguda/economia , Injúria Renal Aguda/mortalidade , Estudos de Coortes , Redução de Custos , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Terapia de Substituição Renal/economia , Estudos Retrospectivos , Índice de Gravidade de Doença , Taxa de Sobrevida , Fatores de Tempo , Resultado do Tratamento
12.
J Card Surg ; 35(4): 854-859, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32115823

RESUMO

OBJECTIVE: The index for mortality prediction after cardiac transplantation (IMPACT) risk score incorporates 12 preoperative recipient-specific variables, and has been validated as an accurate predictor of short- and long-term mortality after orthotopic heart transplantation (OHTx). We believe it can also be used to predict hospital costs, and we hypothesize that higher preoperative IMPACT risk scores are associated with increased hospital resource consumption. METHODS: All OHTx patients ≥18 years of age at our institution were reviewed from 1 January 2000 to 31 December 2014. Total index hospitalization costs post-transplant were extracted and presented in 2014 consumer price index inflation-adjusted US dollars. Patients were stratified into quartiles (Q) according to IMPACT risk scores. Logarithmic transformation normalized cost data, and linear regression assessed for correlation. A comparison of cost between Q of IMPACT risk score was performed using rank-sum and Kruskal-Wallis tests. Survival was estimated using the Kaplan-Meier method. RESULTS: Three hundred fifty-six (n = 356) OHTx were performed during the study period. The median IMPACT score for the cohort was five (interquartile range [IQR] 3-6). Eight (2.2%) patients died within 30-days and 1-year Kaplan-Meier survival was 88.3%. The median length of stay (LOS) was 16 (IQR 14-24) days. The median hospital cost for index admission was $222 200 (IQR:$169 200-$313 700). Median LOS was longer in Q4 vs Q1 (18 days vs 15 days, P = .01) and index hospital costs in Q4 were significantly higher compared to Q1 patients ($280 400 vs $205 000, P < .01). There was a significant positive correlation between IMPACT risk score and cost (regression coefficient .04, P < .01). CONCLUSION: This is the first study in adult cardiac transplantation to identify a positive correlation between hospital cost and recipient risk using the IMPACT risk score. Cost and resource consumption for the index admission after OHTx were significantly higher in the highest IMPACT risk Q compared with patients in the lowest Q.


Assuntos
Economia/estatística & dados numéricos , Recursos em Saúde/economia , Recursos em Saúde/estatística & dados numéricos , Insuficiência Cardíaca/economia , Insuficiência Cardíaca/cirurgia , Transplante de Coração/economia , Transplante de Coração/mortalidade , Custos Hospitalares , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Período Pré-Operatório , Qualidade da Assistência à Saúde/estatística & dados numéricos , Risco , Taxa de Sobrevida , Fatores de Tempo , Adulto Jovem
13.
J Biol Chem ; 293(46): 17888-17905, 2018 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-30262667

RESUMO

Newly discovered bacterial photoreceptors called CarH sense light by using 5'-deoxyadenosylcobalamin (AdoCbl). They repress their own expression and that of genes for carotenoid synthesis by binding in the dark to operator DNA as AdoCbl-bound tetramers, whose light-induced disassembly relieves repression. High-resolution structures of Thermus thermophilus CarHTt have provided snapshots of the dark and light states and have revealed a unique DNA-binding mode whereby only three of four DNA-binding domains contact an operator comprising three tandem direct repeats. To gain further insights into CarH photoreceptors and employing biochemical, spectroscopic, mutational, and computational analyses, here we investigated CarHBm from Bacillus megaterium We found that apoCarHBm, unlike monomeric apoCarHTt, is an oligomeric molten globule that forms DNA-binding tetramers in the dark only upon AdoCbl binding, which requires a conserved W-X9-EH motif. Light relieved DNA binding by disrupting CarHBm tetramers to dimers, rather than to monomers as with CarHTt CarHBm operators resembled that of CarHTt, but were larger by one repeat and overlapped with the -35 or -10 promoter elements. This design persisted in a six-repeat, multipartite operator we discovered upstream of a gene encoding an Spx global redox-response regulator whose photoregulated expression links photooxidative and general redox responses in B. megaterium Interestingly, CarHBm recognized the smaller CarHTt operator, revealing an adaptability possibly related to the linker bridging the DNA- and AdoCbl-binding domains. Our findings highlight a remarkable plasticity in the mode of action of B12-based CarH photoreceptors, important for their biological functions and development as optogenetic tools.


Assuntos
Proteínas de Bactérias/metabolismo , Cobamidas/metabolismo , DNA Bacteriano/metabolismo , Fotorreceptores Microbianos/metabolismo , Proteínas Repressoras/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Bacillus megaterium , Proteínas de Bactérias/genética , Sítios de Ligação , DNA Bacteriano/genética , Regulação Bacteriana da Expressão Gênica , Regiões Operadoras Genéticas , Fotorreceptores Microbianos/genética , Regiões Promotoras Genéticas , Ligação Proteica , Domínios Proteicos , Multimerização Proteica , Proteínas Repressoras/genética , Raios Ultravioleta
14.
Environ Microbiol ; 21(10): 3577-3600, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31087616

RESUMO

Peñahueca is an athalassohaline hypersaline inland ephemeral lake originated under semiarid conditions in the central Iberian Peninsula (Spain). Its chemical composition makes it extreme for microbial life as well as a terrestrial analogue of other planetary environments. To investigate the persistence of microbial life associated with sulfate-rich crusts, we applied cultivation-independent methods (optical and electron microscopy, 16S rRNA gene profiling and metagenomics) to describe the prokaryotic community and its associated viruses. The diversity for Bacteria was very low and was vastly dominated by endospore formers related to Pontibacillus marinus of the Firmicutes phylum. The archaeal assemblage was more diverse and included taxa related to those normally found in hypersaline environments. Several 'metagenome assembled genomes' were recovered, corresponding to new species of Pontibacillus, several species from the Halobacteria and one new member of the Nanohaloarchaeota. The viral assemblage, although composed of the morphotypes typical of high salt systems, showed little similarity to previously isolated/reconstructed halophages. Several putative prophages of Pontibacillus and haloarchaeal hosts were identified. Remarkably, the Peñahueca sulfate-rich metagenome contained CRISPR-associated proteins and repetitions which were over 10-fold higher than in most hypersaline systems analysed so far.


Assuntos
Archaea/genética , Bactérias/genética , Lagos/microbiologia , Vírus/genética , Archaea/classificação , Bactérias/classificação , Biodiversidade , Exobiologia , Filogenia , RNA Ribossômico 16S/genética , Cloreto de Sódio/metabolismo , Espanha , Sulfatos/metabolismo , Vírus/classificação
15.
J Cell Sci ; 128(17): 3197-209, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26163491

RESUMO

Small non-coding RNAs (microRNAs) are important regulators of gene expression that modulate many physiological processes; however, their role in regulating intracellular transport remains largely unknown. Intriguingly, we found that the dynamin (DNM) genes, a GTPase family of proteins responsible for endocytosis in eukaryotic cells, encode the conserved miR-199a and miR-199b family of miRNAs within their intronic sequences. Here, we demonstrate that miR-199a and miR-199b regulate endocytic transport by controlling the expression of important mediators of endocytosis such as clathrin heavy chain (CLTC), Rab5A, low-density lipoprotein receptor (LDLR) and caveolin-1 (Cav-1). Importantly, miR-199a-5p and miR-199b-5p overexpression markedly inhibits CLTC, Rab5A, LDLR and Cav-1 expression, thus preventing receptor-mediated endocytosis in human cell lines (Huh7 and HeLa). Of note, miR-199a-5p inhibition increases target gene expression and receptor-mediated endocytosis. Taken together, our work identifies a new mechanism by which microRNAs regulate intracellular trafficking. In particular, we demonstrate that the DNM, miR-199a-5p and miR-199b-5p genes act as a bifunctional locus that regulates endocytosis, thus adding an unexpected layer of complexity in the regulation of intracellular trafficking.


Assuntos
Dinaminas/metabolismo , Endocitose/fisiologia , MicroRNAs/metabolismo , Animais , Células COS , Caveolina 1/genética , Caveolina 1/metabolismo , Chlorocebus aethiops , Cadeias Pesadas de Clatrina/genética , Cadeias Pesadas de Clatrina/metabolismo , Dinaminas/genética , Regulação da Expressão Gênica/fisiologia , Células HeLa , Humanos , MicroRNAs/genética , Proteínas rab5 de Ligação ao GTP/genética , Proteínas rab5 de Ligação ao GTP/metabolismo
16.
Dig Dis Sci ; 62(1): 161-174, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27510753

RESUMO

BACKGROUND: Gastrointestinal bleeding (GIB) is a common adverse event after mechanical circulatory support device implantation. However, the majority of the reported data were obtained from small single-center studies. Our aim was to study the prevalence and predictors of GIB during the index hospitalization of mechanical circulatory support devices implantation using a nationwide database. METHODS: Nationwide inpatient sample (2009-2011) was used to perform a retrospective cross-sectional study. Adult patients with discharge diagnosis codes of congestive heart failure and procedure codes of left-ventricular assist device (LVAD) or intra-aortic balloon pump (IABP) implantation or orthotopic heart transplant (OHT, reference group) were identified. Our outcome was GIB during the index hospitalization when the device was implanted. Predictors that achieved statistical significance on the univariate analysis were included in a multivariable logistic-regression analysis. RESULTS: A total of 87,462 patients were included, 87 % of the patients received an IABP, 6 % received LVAD, and 5 % underwent OHT. Prevalence of GIB was 8, 5, and 3 % among those who had LVAD, IABP implantation, and OHT recipients, respectively (p < 0.001). Patients who underwent LVAD implantation had twofold increase in the prevalence of GIB (OR 2.1, 1.7-2.5, p < 0.001) when using IABP or OHT groups as a reference. This increase in the prevalence was not demonstrated among IABP recipients on a multivariate level. CONCLUSION: Prevalence of GIB was higher among LVAD compared to OHT and IABP recipients and could occur as early as the index admission of the device implantation.


Assuntos
Hemorragia Gastrointestinal/epidemiologia , Insuficiência Cardíaca/terapia , Coração Auxiliar , Balão Intra-Aórtico , Complicações Pós-Operatórias/epidemiologia , Implantação de Prótese , Idoso , Anticoagulantes/efeitos adversos , Estudos Transversais , Bases de Dados Factuais , Feminino , Hemorragia Gastrointestinal/induzido quimicamente , Transplante de Coração , Hospitalização , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Complicações Pós-Operatórias/induzido quimicamente , Prevalência , Estudos Retrospectivos , Fatores de Risco , Estados Unidos
17.
Chemistry ; 22(35): 12358-62, 2016 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-27440482

RESUMO

Oxidatively generated DNA lesions are numerous and versatile, and have been the subject of intensive research since the discovery of 8-oxoguanine in 1984. Even for this prototypical lesion, the precise mechanism of formation remains elusive due to the inherent difficulties in characterizing high-energy intermediates. We have probed the stability of the guanine endoperoxide in B-DNA as a key intermediate and determined a unique activation free energy of around 6 kcal mol(-1) for the formation of the first C-O covalent bond upon the attack of singlet molecular oxygen ((1) O2 ) on the central guanine of a solvated 13 base-pair poly(dG-dC), described by means of quantum mechanics/molecular mechanics (QM/MM) simulations. The B-helix remains stable upon oxidation in spite of the bulky character of the guanine endoperoxide. Our modeling study has revealed the nature of the versatile (1) O2 attack in terms of free energy and shows a sensitivity to electrostatics and solvation as it involves a charge-separated intermediate.


Assuntos
DNA de Forma B/química , Guanina/análogos & derivados , Polidesoxirribonucleotídeos/química , Oxigênio Singlete/química , Pareamento de Bases , DNA de Forma B/metabolismo , Guanina/química , Simulação de Dinâmica Molecular , Oxirredução
18.
FASEB J ; 29(2): 597-610, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25392271

RESUMO

Atherosclerosis is the major cause of death and disability in diabetic and obese subjects with insulin resistance. Akt2, a phosphoinositide-dependent serine-threonine protein kinase, is highly express in insulin-responsive tissues; however, its role during the progression of atherosclerosis remains unknown. Thus, we aimed to investigate the contribution of Akt2 during the progression of atherosclerosis. We found that germ-line Akt2-deficient mice develop similar atherosclerotic plaques as wild-type mice despite higher plasma lipids and glucose levels. It is noteworthy that transplantation of bone marrow cells isolated from Akt2(-/-) mice to Ldlr(-/-) mice results in marked reduction of the progression of atherosclerosis compared with Ldlr(-/-) mice transplanted with wild-type bone marrow cells. In vitro studies indicate that Akt2 is required for macrophage migration in response to proatherogenic cytokines (monocyte chemotactic protein-1 and macrophage colony-stimulating factor). Moreover, Akt2(-/-) macrophages accumulate less cholesterol and have an alternative activated or M2-type phenotype when stimulated with proinflammatory cytokines. Together, these results provide evidence that macrophage Akt2 regulates migration, the inflammatory response and cholesterol metabolism and suggest that targeting Akt2 in macrophages might be beneficial for treating atherosclerosis.


Assuntos
Aterosclerose/fisiopatologia , Proteínas Proto-Oncogênicas c-akt/deficiência , Proteínas Proto-Oncogênicas c-akt/genética , Animais , Glicemia/metabolismo , Células da Medula Óssea/citologia , Transplante de Medula Óssea , Movimento Celular , Colesterol/metabolismo , Citocinas/metabolismo , Progressão da Doença , Inflamação , Insulina/química , Leucócitos/citologia , Lipídeos/sangue , Lipoproteínas LDL/metabolismo , Macrófagos/citologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia Confocal , Microscopia de Fluorescência , Placa Aterosclerótica , Receptores de LDL/genética
19.
J Card Surg ; 31(2): 120-2, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26749254

RESUMO

Obesity poses significant challenges in advanced heart failure patients who otherwise meet criteria for listing for heart transplant. We present a patient who underwent bariatric surgery while on LVAD support that subsequently lost weight and was successfully bridged to heart transplantation.


Assuntos
Cirurgia Bariátrica , Transplante de Coração , Coração Auxiliar , Implantação de Prótese , Disfunção Ventricular Esquerda/cirurgia , Listas de Espera , Redução de Peso , Adulto , Índice de Massa Corporal , Ventrículos do Coração , Humanos , Masculino , Assistência Perioperatória , Fatores de Tempo
20.
P R Health Sci J ; 35(4): 224-227, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27898170

RESUMO

OBJECTIVE: Peripartum cardiomyopathy is a rare type of heart failure to which only pregnant women are susceptible. In Puerto Rico there is a paucity of information regarding this condition. In this report we describe our experience with peripartum cardiomyopathy. METHODS: This was a descriptive retrospective study. We conducted a chart review of all the patients with peripartum cardiomyopathy managed at our institution from January 2006 through December 2012. A total of 12 patients qualified for our analysis. RESULTS: The mean age of our population was 27 (± 8) years. Eight of the twelve (67%) patients were multigravid women, with a mean parity of 2.6 (± 1.6). Most patients (75%) showed clinical evidence of anemia while pregnant, and more than half (58%) delivered prematurely. Six patients (50%) had a prior history of preeclampsia. Cardiac imaging detected a mean ejection fraction of 35% (± 8%) at the time of diagnosis. Only 1 maternal death was documented. CONCLUSION: Our study cohort was very similar to those in most case series in which the same condition has been studied. In order to better understand the pathophysiology of this entity and, thus, improve treatment for these patients, prospective studies are needed.


Assuntos
Insuficiência Cardíaca , Transtornos Puerperais , Adolescente , Adulto , Feminino , Insuficiência Cardíaca/diagnóstico , Humanos , Transtornos Puerperais/diagnóstico , Porto Rico , Estudos Retrospectivos , Centros de Atenção Terciária , Adulto Jovem
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