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1.
Pediatrics ; 153(6)2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38770574

RESUMO

OBJECTIVES: Unplanned extubations (UEs) can be a frequent problem and are associated with adverse outcomes. This quality improvement initiative sought to reduce UEs from tube dislodgement in a level IV NICU utilizing methods applicable to other ICUs and performed with minimal monetary funds. METHODS: From January 2019 to July 2023, an interdisciplinary quality improvement team used the Model for Improvement and performed sequential interventions to improve the outcome measure of UEs per 100 ventilator days. Process measures included adherence to a modified, site-specific UE care bundle derived from the Solutions for Patient Safety network, whereas the number of endotracheal tube-related pressure injuries was used as a balancing measure. Statistical process control charts and established rules for special cause variation were applied to analyze data. RESULTS: Sequential interventions reduced the rate of UEs from a baseline of 2.3 to 0.6 UEs per 100 ventilator days. Greater than 90% adherence with the UE care bundle and apparent cause analysis form completion occurred since December 2020. There were no endotracheal tube-related pressure injuries. CONCLUSIONS: A sustained reduction in UEs was demonstrated. Leveraging a multidisciplinary team allowed for continuous UE analysis, which promoted tailored consecutive interventions. UE care bundle audits and the creation of a postevent debrief guide, which helped providers share a common language, were the most impactful interventions. Next steps include disseminating these interventions to other ICUs across our hospital enterprise. These low-cost interventions can be scalable to other NICUs and PICUs.


Assuntos
Extubação , Unidades de Terapia Intensiva Neonatal , Intubação Intratraqueal , Melhoria de Qualidade , Humanos , Recém-Nascido , Pacotes de Assistência ao Paciente
2.
bioRxiv ; 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38464133

RESUMO

Genetic variants can alter the profile of heritable molecules such as small RNAs in sperm and oocytes, and in this manner ancestral genetic variants can have a significant effect on offspring phenotypes even if they are not themselves inherited. Here we show that wild type female mice descended from ancestors with a mutation in the mammalian germ cell gene Khdc3 have hepatic metabolic defects that persist over multiple generations. We find that genetically wild type females descended from Khdc3 mutants have transcriptional dysregulation of critical hepatic metabolic genes, which persist over multiple generations and pass through both female and male lineages. This was associated with dysregulation of hepatically-metabolized molecules in the blood of these wild type mice with mutational ancestry. The oocytes of Khdc3-null females, as well as their wild type descendants, had dysregulation of multiple small RNAs, suggesting that these epigenetic changes in the gametes transmit the phenotype between generations. Our results demonstrate that ancestral mutation in Khdc3 can produce transgenerational inherited phenotypes, potentially indefinitely.

3.
J Stroke Cerebrovasc Dis ; 33(1): 107468, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38039801

RESUMO

INTRODUCTION: Tenecteplase has been compared to alteplase in acute stroke randomized trials, with similar outcomes and safety measures, but higher doses of tenecteplase have been associated with higher hemorrhage rates in some studies. Limited data are available on the safety of tenecteplase outside of clinical trials. METHODS: We examined the safety measures of intracranial hemorrhage, angioedema, and serious extracranial adverse events in a 21-hospital integrated healthcare system that switched from alteplase (0.9 mg/kg, maximum dose 90 mg) to tenecteplase (0.25 mg/kg, maximum dose 25 mg) for acute ischemic stroke. RESULTS: Among 3,689 subjects, no significant differences were seen between tenecteplase and alteplase in the rate of intracranial hemorrhage (ICH), parenchymal hemorrhage, or volume of parenchymal hemorrhage. Symptomatic hemorrhage (sICH) was not different between the two agents: sICH by NINDS criteria was 2.0 % for alteplase vs 2.3 % for tenecteplase (P = 0.57), and sICH by SITS criteria was 0.8 % vs 1.1 % (P = 0.39). Adjusted logistic regression models also showed no differences between tenecteplase and alteplase: the odds ratio for tenecteplase (vs alteplase) modeling sICH by NINDS criteria was 0.9 (95 % CI 0.33 - 2.46, P = 0.83) and the odds ratio for tenecteplase modeling sICH by SITS criteria was 1.12 (95 % CI 0.25 - 5.07, P = 0.89). Rates of angioedema and serious extracranial adverse events were low and did not differ between tenecteplase and alteplase. Elapsed door-to-needle times showed a small improvement after the switch to tenecteplase (51.8 % treated in under 30 min with tenecteplase vs 43.5 % with alteplase, P < 0.001). CONCLUSION: In use outside of clinical trials, complication rates are similar between tenecteplase and alteplase. In the context of a stroke telemedicine program, the rates of hemorrhage observed with either agent were lower than expected based on prior trials and registry data. The more easily prepared tenecteplase was associated with a lower door-to-needle time.


Assuntos
Angioedema , Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Ativador de Plasminogênio Tecidual/efeitos adversos , Tenecteplase/efeitos adversos , Fibrinolíticos/efeitos adversos , AVC Isquêmico/diagnóstico , AVC Isquêmico/tratamento farmacológico , AVC Isquêmico/induzido quimicamente , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/induzido quimicamente , Hemorragias Intracranianas/induzido quimicamente , Hemorragias Intracranianas/tratamento farmacológico , Angioedema/induzido quimicamente , Resultado do Tratamento , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/induzido quimicamente
4.
Nat Cell Biol ; 25(4): 528-539, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37024683

RESUMO

Upon stimulation by extrinsic stimuli, stem cells initiate a programme that enables differentiation or self-renewal. Disruption of the stem state exit has catastrophic consequences for embryogenesis and can lead to cancer. While some elements of this stem state switch are known, major regulatory mechanisms remain unclear. Here we show that this switch involves a global increase in splicing efficiency coordinated by DNA methyltransferase 3α (DNMT3A), an enzyme typically involved in DNA methylation. Proper activation of murine and human embryonic and haematopoietic stem cells depends on messenger RNA processing, influenced by DNMT3A in response to stimuli. DNMT3A coordinates splicing through recruitment of the core spliceosome protein SF3B1 to RNA polymerase and mRNA. Importantly, the DNA methylation function of DNMT3A is not required and loss of DNMT3A leads to impaired splicing during stem cell turnover. Finally, we identify the spliceosome as a potential therapeutic target in DNMT3A-mutated leukaemias. Together, our results reveal a modality through which DNMT3A and the spliceosome govern exit from the stem state towards differentiation.


Assuntos
DNA (Citosina-5-)-Metiltransferases , DNA Metiltransferase 3A , Animais , Humanos , Camundongos , Diferenciação Celular/genética , DNA (Citosina-5-)-Metiltransferases/genética , DNA (Citosina-5-)-Metiltransferases/metabolismo , Metilação de DNA , Células-Tronco Hematopoéticas/metabolismo
5.
IEEE Open J Eng Med Biol ; 4: 141-147, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38274781

RESUMO

Assessment of coupling between transtibial sockets and users is historically based on clinicians' observations and experience, but can be inaccurate and unreliable. Therefore, we present a proof of concept, for five out of six possible degrees of freedom coupling metric system for a socket, using motion analysis calibrated on a 3D printed limb substitute. The method is compatible with any socket suspension method and does not require prior modifications to the socket. Calibration trials were used to locate the axis of rotation of the knee joint referenced against a marker cluster on the thigh; this allowed for the identification of the limb during test trials despite the entire residuum being obscured from view by the socket. The error in the technique was found to be within 0.7 mm in displacement and 0.7 degrees in rotation, based on the control data. Dynamic testing showed the Inter Quartile Range (IQR) of inter time step variance was <0.5 mm/deg for all metrics. The method can form a basis for objective socket evaluation, improve clinical practice and the quality of life for amputees.

6.
Pediatrics ; 150(2)2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35909148

RESUMO

OBJECTIVES: Liquid medication dosing errors are common in pediatrics. Our outpatient clinic identified gaps in caregiver education based on a 2015 American Academy of Pediatrics policy statement on prescribing liquid medications. This quality improvement (QI) initiative sought to improve caregiver's understanding of liquid acetaminophen administration at the 2-month well-child visit from 30% to 70% over a 32-month period. METHODS: A resident-led interdisciplinary QI team performed sequential interventions to improve our outcome measure: the percentage of caregivers with an adequate understanding of 4 essential components of liquid acetaminophen administration (name, indication, dose, and frequency). Outcome data were collected via a 4-item verbal assessment of caregiver's understanding by nursing staff, with correct answers to all items considered adequate understanding. Process measures (medications prescribed and education provided), and balancing measures (anticipatory guidance items discussed) were gathered via electronic health record review. Shewhart "P" charts and established rules for detecting special cause variation were used to analyze data. Scatter plots assessed the association between the provision of syringes and caregiver understanding of medication administration. RESULTS: In 636 caregivers, overall understanding of medication use improved from 39.8% to 74%. Knowledge of accurate dosage improved from 50.9% to 76.8%. Correlation between syringe provision and caregiver understanding was strong (R = .84). CONCLUSIONS: Resident-led QI improved caregiver's understanding of liquid acetaminophen administration in infants. The most impactful interventions were implementation of English and Spanish pictograms and provision of dose-demarcated oral syringes, coupled with teach-back. Future interventions will examine generalizability to other medications and expansion to other services.


Assuntos
Acetaminofen , Cuidadores , Criança , Educação em Saúde , Humanos , Lactente , Erros de Medicação , Preparações Farmacêuticas , Atenção Primária à Saúde
7.
Sensors (Basel) ; 21(24)2021 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-34960503

RESUMO

The fit of a lower limb prosthetic socket is critical for user comfort and the quality of life of lower limb amputees. Sockets are conventionally produced using hand-crafted patient-based casting techniques. Modern digital techniques offer a host of advantages to the process and ultimately lead to improving the lives of amputees. However, commercially available scanning equipment required is often expensive and proprietary. Smartphone photogrammetry could offer a low cost alternative, but there is no widely accepted imaging technique for prosthetic socket digitisation. Therefore, this paper aims to determine an optimal imaging technique for whole socket photogrammetry and evaluate the resultant scan measurement accuracy. A 3D printed transtibial socket was produced to create digital and physical twins, as reference models. The printed socket was photographed from 360 positions and simplified genetic algorithms were used to design a series of experiments, whereby a collection of photos were processed using Autodesk ReCap. The most fit technique was used to assess accuracy. The accuracy of the socket wall volume, surface area and height were 61.63%, 99.61% and 99.90%, respectively, when compared to the digital reference model. The scanned model had a wall thickness ranging from 2.075 mm at the top to 7.758 mm towards the base of the socket, compared to a consistent thickness of 2.025 mm in the control model. The technique selected did not show sufficient accuracy for clinical application due to the degradation of accuracy nearer to the base of the socket interior. However, using an internal wall thickness estimation, scans may be of sufficient accuracy for clinical use; assuming a uniform wall thickness.


Assuntos
Membros Artificiais , Smartphone , Humanos , Fotogrametria , Desenho de Prótese , Qualidade de Vida
9.
Int J Pharm ; 609: 121115, 2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34547393

RESUMO

In the past two decades, biopharmaceuticals have been a breakthrough in improving the quality of lives of patients with various cancers, autoimmune, genetic disorders etc. With the growing demand of biopharmaceuticals, the need for reducing manufacturing costs is essential without compromising on the safety, quality, and efficacy of products. Batch Freeze-drying is the primary commercial means of manufacturing solid biopharmaceuticals. However, Freeze-drying is an economically unfriendly means of production with long production cycles, high energy consumption and heavy capital investment, resulting in high overall costs. This review compiles some potential, innovative drying technologies that have not gained popularity for manufacturing parenteral biopharmaceuticals. Some of these technologies such as Spin-freeze-drying, Spray-drying, Lynfinity® Technology etc. offer a paradigm shift towards continuous manufacturing, whereas PRINT® Technology and MicroglassificationTM allow controlled dry particle characteristics. Also, some of these drying technologies can be easily scaled-up with reduced requirement for different validation processes. The inclusion of Process Analytical Technology (PAT) and offline characterization techniques in tandem can provide additional information on the Critical Process Parameters (CPPs) and Critical Quality Attributes (CQAs) during biopharmaceutical processing. These processing technologies can be envisaged to increase the manufacturing capacity for biopharmaceutical products at reduced costs.


Assuntos
Produtos Biológicos , Tecnologia Farmacêutica , Dessecação , Liofilização
10.
Biol Reprod ; 105(3): 747-760, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34159361

RESUMO

It is well established that environmental exposures can modify the profile of heritable factors in an individual's germ cells, ultimately affecting the inheritance of phenotypes in descendants. Similar to exposures, an ancestor's genotype can also affect the inheritance of phenotypes across generations, sometimes in offspring who do not inherit the genetic aberration. This can occur via a variety of prenatal, in utero, or postnatal mechanisms. In this review, we discuss the evidence for this process in mammals, with a focus on examples that are potentially mediated through the germline, while also considering alternate routes of inheritance. Noninherited ancestral genotypes may influence descendant's disease risk to a much greater extent than currently appreciated, and focused evaluation of this phenomenon may reveal novel mechanisms of inheritance.


Assuntos
Epigênese Genética , Genótipo , Células Germinativas/metabolismo , Padrões de Herança , Fenótipo , Animais , Humanos , Camundongos , Ratos
11.
J Pharm Sci ; 110(10): 3395-3402, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34118253

RESUMO

Near-infrared (NIR) and frequency modulated spectroscopy (FMS) were employed, for non-invasive moisture determination of a lyophilized biologic drug product (DP). Development of NIR and FMS provides a rapid non-invasive means of residual moisture measurement, and would be beneficial compared with traditional time consuming, product destructive methods such as Karl Fischer (KF). A model therapeutic enzyme in a sucrose-based formulation was employed for proof of concept studies, and NIR and FMS methods were compared side by side for residual moisture analysis. Moisture models were created using lyophilized vials and comparisons were made between the methods using different moisture preparation approaches:1) direct water droplet addition to the vial headspace, 2) use of elevated temperature (80°C), and 3) using various levels of moisture in stoppers generated during the washing and drying procedures, then lyophilizing using the stoppers and placing the sealed vials on stability. The results for direct water addition gave an average percent error for residual moisture of 5.7% for NIR and 9.4% for FMS when compared to KF. The elevated temperature method resulted in an average percent error for residual moisture of 54% for NIR and 43% for FMS compared to KF. The stopper moisture stability study, for FMS, provided an average percent error for residual moisture of 31% compared to KF. The error was greater for the elevated temperature and stopper methods, due to the low moisture values, which resulted in greater error. At this lower range of moisture (<1%) both NIR and FMS were less accurate, but from 1 to 5% their accuracy increased, based on the models used in this study. NIR and FMS methods can be used to complement KF at these lower moisture levels and models could be further improved with additional data points. NIR and FMS methods have advantages and disadvantages for residual moisture analysis when compared to each other, but both provided an accurate measurement of drug product moisture (depending on the method used for moisture increase), they can be used as process analytical technology (PAT), and both can be used for fast non-invasive moisture determination.


Assuntos
Produtos Biológicos , Espectroscopia de Luz Próxima ao Infravermelho , Liofilização , Sacarose , Água
12.
Mol Ther Methods Clin Dev ; 20: 191-203, 2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33426146

RESUMO

Galactosialidosis is a rare lysosomal storage disease caused by a congenital defect of protective protein/cathepsin A (PPCA) and secondary deficiency of neuraminidase-1 and ß-galactosidase. PPCA is a lysosomal serine carboxypeptidase that functions as a chaperone for neuraminidase-1 and ß-galactosidase within a lysosomal multi-protein complex. Combined deficiency of the three enzymes leads to accumulation of sialylated glycoproteins and oligosaccharides in tissues and body fluids and manifests in a systemic disease pathology with severity mostly correlating with the type of mutation(s) and age of onset of the symptoms. Here, we describe a proof-of-concept, preclinical study toward the development of enzyme replacement therapy for galactosialidosis, using a recombinant human PPCA. We show that the recombinant enzyme, taken up by patient-derived fibroblasts, restored cathepsin A, neuraminidase-1, and ß-galactosidase activities. Long-term, bi-weekly injection of the recombinant enzyme in a cohort of mice with null mutation at the PPCA (CTSA) locus (PPCA -/- ), a faithful model of the disease, demonstrated a dose-dependent, systemic internalization of the enzyme by cells of various organs, including the brain. This resulted in restoration/normalization of the three enzyme activities, resolution of histopathology, and reduction of sialyloligosacchariduria. These positive results underscore the benefits of a PPCA-mediated enzyme replacement therapy for the treatment of galactosialidosis.

13.
Stroke ; 51(9): 2697-2704, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32757749

RESUMO

BACKGROUND AND PURPOSE: In large artery occlusion stroke, both intravenous (IV) tPA (tissue-type plasminogen activator) and endovascular stroke treatment (EST) are standard-of-care. It is unknown how often tPA causes distal embolization, in which a procedurally accessible large artery occlusion is converted to a more distal and potentially inaccessible occlusion. METHODS: We analyzed data from a decentralized stroke telemedicine program in an integrated healthcare delivery system covering 21 hospitals, with 2 high-volume EST centers. We captured all cases sent for EST and examined the relationship between IV tPA administration and the rate of distal embolization, the rate of target recanalization (modified Treatment in Cerebral Infarction scale 2b/3), clinical improvement before EST, and short-term and long-term clinical outcomes. RESULTS: Distal embolization before EST was quite common (63/314 [20.1%]) and occurred more often after IV tPA before EST (57/229 [24.9%]) than among those not receiving IV tPA (6/85 [7.1%]; P<0.001). Distal embolization was associated with an inability to attempt EST: after distal embolization, 26/63 (41.3%) could not have attempted EST because of the new clot location, while in cases without distal embolization, only 8/249 (3.2%) were unable to have attempted EST (P<0.001). Among patients who received IV tPA, 13/242 (5.4%) had sufficient symptom improvement that a catheter angiogram was not performed; 6/342 (2.5%) had improvement to within 2 points of their baseline NIHSS. At catheter angiogram, 2/229 (0.9%) of patients who had received tPA had complete recanalization without distal embolization. Both IV tPA and EST recanalization were associated with improved long-term outcome. CONCLUSIONS: IV tPA administration before EST for large artery occlusion is associated with distal embolization, which in turn may reduce the chance that EST can be attempted and recanalization achieved. At the same time, some IV tPA-treated patients show symptomatic improvement and complete recanalization. Because IV tPA is associated with both distal embolization and improved long-term clinical outcome, there is a need for prospective clinical trials testing the net benefit or harm of IV tPA before EST.


Assuntos
Embolização Terapêutica/efeitos adversos , Procedimentos Endovasculares/métodos , Fibrinolíticos/efeitos adversos , Acidente Vascular Cerebral/cirurgia , Ativador de Plasminogênio Tecidual/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Angiografia , Arteriopatias Oclusivas/complicações , Infarto Cerebral/cirurgia , Feminino , Fibrinolíticos/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Medição de Risco , Ativador de Plasminogênio Tecidual/uso terapêutico , Tomografia Computadorizada por Raios X , Resultado do Tratamento
14.
Mol Genet Metab ; 130(1): 65-76, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32192868

RESUMO

Mucopolysaccharidosis VII (MPS VII) is a rare lysosomal storage disease characterized by a deficiency in the enzyme ß-glucuronidase that has previously been successfully treated in a mouse model with enzyme replacement therapy. Here, we present the generation of a novel, highly sialylated version of recombinant human ß-glucuronidase (rhGUS), vestronidase alfa, that has high uptake, resulting in an improved enzyme replacement therapy for the treatment of patients with MPS VII. In vitro, vestronidase alfa has 10-fold more sialic acid per mole of rhGUS monomer than a prior rhGUS version (referred to as GUS 43/44) and demonstrated very high affinity at ~1 nM half maximal uptake in human MPS VII fibroblasts. Vestronidase alfa has a longer enzymatic half-life after uptake into fibroblasts compared with other enzymes used as replacement therapy for MPS (40 days vs 3 to 4 days, respectively). In pharmacokinetic and tissue distribution experiments in Sprague-Dawley rats, intravenous administration of vestronidase alfa resulted in higher serum rhGUS levels and enhanced ß-glucuronidase activity distributed to target tissues. Weekly intravenous injections of vestronidase alfa (0.1 mg/kg to 20 mg/kg) in a murine model of MPS VII demonstrated efficient enzyme delivery to all tissues, including bone and brain, as well as reduced lysosomal storage of glycosaminoglycans (GAGs) in a dose-dependent manner, resulting in increased survival after 8 weeks of treatment. Vestronidase alfa was well-tolerated and demonstrated no toxicity at concentrations that reached 5-times the proposed clinical dose. In a first-in-human phase 1/2 clinical trial, a dose-dependent reduction in urine GAG levels was sustained over 38 weeks of treatment with vestronidase alfa. Together, these results support the therapeutic potential of vestronidase alfa as an enzyme replacement therapy for patients with MPS VII.


Assuntos
Terapia de Reposição de Enzimas/métodos , Glucuronidase/administração & dosagem , Glucuronidase/metabolismo , Lisossomos/enzimologia , Mucopolissacaridose VII/enzimologia , Mucopolissacaridose VII/terapia , Administração Intravenosa , Adulto , Animais , Células CHO , Criança , Cricetulus , Feminino , Fibroblastos/metabolismo , Glucuronidase/sangue , Glucuronidase/genética , Glucuronidase/farmacocinética , Glicosaminoglicanos/metabolismo , Glicosaminoglicanos/urina , Humanos , Lisossomos/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Distribuição Tecidual/efeitos dos fármacos
15.
Dev Cell ; 52(6): 714-730.e5, 2020 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-32109381

RESUMO

Inflammation triggered by infection or cellular necrosis is initiated by a battery of pattern-recognition receptors, such as Toll-like receptors or IL-1 family receptors. Diverse forms of cell stress, such as ER stress or mitochondrial stress, can also promote inflammatory responses that contribute to the chronic inflammation observed in cancer, obesity, and other conditions. However, the molecular mechanisms of cell-stress-induced inflammation are poorly understood. Here, we show that ER stress initiated NF-κB activation and inflammation through transcriptional upregulation and ligand-independent activation of TRAIL receptors. ER-stress-induced TRAIL receptor activation resulted in caspase-8/FADD/RIPK1-dependent NF-κB activation and inflammatory cytokine production. Silencing or deletion of TRAIL receptors, or their downstream effectors caspase-8, FADD, or RIPK1, suppressed ER-stress-induced inflammation. Furthermore, chemotherapeutic stress-induced inflammatory responses were blunted in DR5/TRAIL-R null animals. We propose that, upon ER stress, TRAIL receptors serve as "stress-associated molecular patterns (SAMPs)" coupling ER stress to NF-κB-dependent inflammation.


Assuntos
Citocinas/metabolismo , Estresse do Retículo Endoplasmático , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Transdução de Sinais , Células A549 , Animais , Caspase 8/metabolismo , Células Cultivadas , Citocinas/genética , Proteína de Domínio de Morte Associada a Fas/metabolismo , Células HCT116 , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética
16.
Cell Rep ; 28(9): 2275-2287.e5, 2019 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-31461645

RESUMO

Necroptosis is a form of programmed cell death that is defined by activation of the kinase RIPK3 and subsequent cell membrane permeabilization by the effector MLKL. RIPK3 activation can also promote immune responses via production of cytokines and chemokines. How active cytokine production is coordinated with the terminal process of necroptosis is unclear. Here, we report that cytokine production continues within necroptotic cells even after they have lost cell membrane integrity and irreversibly committed to death. This continued cytokine production is dependent on mRNA translation and requires maintenance of endoplasmic reticulum integrity that remains after plasma membrane integrity is lost. The continued translation of cytokines by cellular corpses contributes to necroptotic cell uptake by innate immune cells and priming of adaptive immune responses to antigens associated with necroptotic corpses. These findings imply that cell death and production of inflammatory mediators are coordinated to optimize the immunogenicity of necroptotic cells.


Assuntos
Membrana Celular/metabolismo , Necroptose , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Fator de Necrose Tumoral alfa/biossíntese , Células 3T3 , Animais , Retículo Endoplasmático/metabolismo , Feminino , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/genética
17.
Elife ; 82019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30644360

RESUMO

Direct reprogramming of fibroblasts to neurons induces widespread cellular and transcriptional reconfiguration. Here, we characterized global epigenomic changes during the direct reprogramming of mouse fibroblasts to neurons using whole-genome base-resolution DNA methylation (mC) sequencing. We found that the pioneer transcription factor Ascl1 alone is sufficient for inducing the uniquely neuronal feature of non-CG methylation (mCH), but co-expression of Brn2 and Mytl1 was required to establish a global mCH pattern reminiscent of mature cortical neurons. Ascl1 alone induced promoter CG methylation (mCG) of fibroblast specific genes, while BAM overexpression additionally targets a competing myogenic program and directs a more faithful conversion to neuronal cells. Ascl1 induces local demethylation at its binding sites. Surprisingly, co-expression with Brn2 and Mytl1 inhibited the ability of Ascl1 to induce demethylation, suggesting a contextual regulation of transcription factor - epigenome interaction. Finally, we found that de novo methylation by DNMT3A is required for efficient neuronal reprogramming.


Assuntos
Reprogramação Celular/genética , Metilação de DNA/genética , Fibroblastos/citologia , Neurônios/citologia , Animais , DNA (Citosina-5-)-Metiltransferases/metabolismo , DNA Metiltransferase 3A , Regulação para Baixo/genética , Regulação da Expressão Gênica no Desenvolvimento , Inativação Gênica , Camundongos Endogâmicos C57BL , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo , Transcrição Gênica
18.
Genome Biol ; 19(1): 88, 2018 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-30001199

RESUMO

BACKGROUND: DNA methylation is a heritable epigenetic mark, enabling stable but reversible gene repression. In mammalian cells, DNA methyltransferases (DNMTs) are responsible for modifying cytosine to 5-methylcytosine (5mC), which can be further oxidized by the TET dioxygenases to ultimately cause DNA demethylation. However, the genome-wide cooperation and functions of these two families of proteins, especially at large under-methylated regions, called canyons, remain largely unknown. RESULTS: Here we demonstrate that DNMT3A and TET1 function in a complementary and competitive manner in mouse embryonic stem cells to mediate proper epigenetic landscapes and gene expression. The longer isoform of DNMT3A, DNMT3A1, exhibits significant enrichment at distal promoters and canyon edges, but is excluded from proximal promoters and canyons where TET1 shows prominent binding. Deletion of Tet1 increases DNMT3A1 binding capacity at and around genes with wild-type TET1 binding. However, deletion of Dnmt3a has a minor effect on TET1 binding on chromatin, indicating that TET1 may limit DNA methylation partially by protecting its targets from DNMT3A and establishing boundaries for DNA methylation. Local CpG density may determine their complementary binding patterns and therefore that the methylation landscape is encoded in the DNA sequence. Furthermore, DNMT3A and TET1 impact histone modifications which in turn regulate gene expression. In particular, they regulate Polycomb Repressive Complex 2 (PRC2)-mediated H3K27me3 enrichment to constrain gene expression from bivalent promoters. CONCLUSIONS: We conclude that DNMT3A and TET1 regulate the epigenome and gene expression at specific targets via their functional interplay.


Assuntos
DNA (Citosina-5-)-Metiltransferases/genética , Proteínas de Ligação a DNA/genética , Epigênese Genética/genética , Células-Tronco Embrionárias Murinas/metabolismo , Regiões Promotoras Genéticas/genética , Proteínas Proto-Oncogênicas/genética , 5-Metilcitosina/metabolismo , Animais , Linhagem Celular , Cromatina/genética , Metilação de DNA/genética , DNA Metiltransferase 3A , Dioxigenases/genética , Epigenômica/métodos , Camundongos
19.
Stroke ; 49(2): 458-460, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29321339

RESUMO

BACKGROUND AND PURPOSE: Large artery occlusion (LAO) in ischemic stroke requires recognition and triage to an endovascular stroke treatment center. Noninvasive LAO detection is needed to improve triage. METHODS: Prospective study to test whether noninvasive cerebral oximetry can detect anterior circulation LAO in acute stroke. Interhemispheric ΔBrSO2 in LAO was compared with controls. RESULTS: In LAO stroke, mean interhemispheric ΔBrSO2 was -8.3±5.8% (n=19), compared with 0.4±5.8% in small artery stroke (n=17), 0.4±6.0% in hemorrhagic stroke (n=14), and 0.2±7.5% in subjects without stroke (n=19) (P<0.001). Endovascular stroke treatment reduced the ΔBrSO2 in most LAO subjects (16/19). Discrimination of LAO at a -3% ΔBrSO2 cut had 84% sensitivity and 70% specificity. Addition of the G-FAST clinical score (gaze-face-arm-speech- time) to the BrSO2 measure had 84% sensitivity and 90% specificity. CONCLUSIONS: Noninvasive cerebral oximetry may help detect LAO in ischemic stroke, particularly when combined with a simple clinical scoring system.


Assuntos
Isquemia Encefálica/diagnóstico , Circulação Cerebrovascular/fisiologia , Oximetria , Acidente Vascular Cerebral/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Artérias/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oximetria/métodos , Estudos Prospectivos , Terapia Trombolítica/métodos , Doenças Vasculares/diagnóstico , Adulto Jovem
20.
Nat Rev Immunol ; 17(4): 262-275, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28287107

RESUMO

Dying cells have an important role in the initiation of CD8+ T cell-mediated immunity. The cross-presentation of antigens derived from dying cells enables dendritic cells to present exogenous tissue-restricted or tumour-restricted proteins on MHC class I molecules. Importantly, this pathway has been implicated in multiple autoimmune diseases and accounts for the priming of tumour antigen-specific T cells. Recent data have revealed that in addition to antigen, dying cells provide inflammatory and immunogenic signals that determine the efficiency of CD8+ T cell cross-priming. The complexity of these signals has been evidenced by the multiple molecular pathways that result in cell death and that have now been shown to differentially influence antigen transfer and immunity. In this Review, we provide a detailed summary of both the passive and active signals that are generated by dying cells during their initiation of CD8+ T cell-mediated immunity. We propose that molecules generated alongside cell death pathways - inducible damage-associated molecular patterns (iDAMPs) - are upstream immunological cues that actively regulate adaptive immunity.


Assuntos
Apresentação de Antígeno/imunologia , Linfócitos T CD8-Positivos/imunologia , Morte Celular/imunologia , Apresentação Cruzada/imunologia , Animais , Humanos
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