Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 44
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Circ Arrhythm Electrophysiol ; 14(10): e009957, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34592837

RESUMO

Each heartbeat that pumps blood throughout the body is initiated by an electrical impulse generated in the sinoatrial node (SAN). However, a number of disease conditions can hamper the ability of the SAN's pacemaker cells to generate consistent action potentials and maintain an orderly conduction path, leading to arrhythmias. For symptomatic patients, current treatments rely on implantation of an electronic pacing device. However, complications inherent to the indwelling hardware give pause to categorical use of device therapy for a subset of populations, including pediatric patients or those with temporary pacing needs. Cellular-based biological pacemakers, derived in vitro or in situ, could function as a therapeutic alternative to current electronic pacemakers. Understanding how biological pacemakers measure up to the SAN would facilitate defining and demonstrating its advantages over current treatments. In this review, we discuss recent approaches to creating biological pacemakers and delineate design criteria to guide future progress based on insights from basic biology of the SAN. We emphasize the need for long-term efficacy in vivo via maintenance of relevant proteins, source-sink balance, a niche reflective of the native SAN microenvironment, and chronotropic competence. With a focus on such criteria, combined with delivery methods tailored for disease indications, clinical implementation will be attainable.

2.
Nat Biomed Eng ; 5(8): 880-896, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34426676

RESUMO

Fibroblasts can be directly reprogrammed into cardiomyocytes, endothelial cells or smooth muscle cells. Here we report the reprogramming of mouse tail-tip fibroblasts simultaneously into cells resembling these three cell types using the microRNA mimic miR-208b-3p, ascorbic acid and bone morphogenetic protein 4, as well as the formation of tissue-like structures formed by the directly reprogrammed cells. Implantation of the formed cardiovascular tissue into the infarcted hearts of mice led to the migration of reprogrammed cells to the injured tissue, reducing regional cardiac strain and improving cardiac function. The migrated endothelial cells and smooth muscle cells contributed to vessel formation, and the migrated cardiomyocytes, which initially displayed immature characteristics, became mature over time and formed gap junctions with host cardiomyocytes. Direct reprogramming of somatic cells to make cardiac tissue may aid the development of applications in cell therapy, disease modelling and drug discovery for cardiovascular diseases.


Assuntos
Células Endoteliais/transplante , Coração/fisiologia , Infarto do Miocárdio/terapia , Miócitos de Músculo Liso/transplante , Regeneração , Animais , Ácido Ascórbico/farmacologia , Proteína Morfogenética Óssea 4/farmacologia , Reprogramação Celular/efeitos dos fármacos , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Junções Comunicantes/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , Miocárdio/citologia , Miocárdio/metabolismo , Miocárdio/patologia , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/metabolismo , Cadeias Pesadas de Miosina/genética , Cadeias Pesadas de Miosina/metabolismo , Neovascularização Fisiológica , Transcriptoma
3.
IEEE Trans Biomed Circuits Syst ; 15(2): 221-234, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33760741

RESUMO

The paper presents a 256-pixel CMOS sensor array with in-pixel dual electrochemical and impedance detection modalities for rapid, multi-dimensional characterization of exoelectrogens. The CMOS IC has 16 parallel readout channels, allowing it to perform multiple measurements with a high throughput and enable the chip to handle different samples simultaneously. The chip contains a total of 2 × 256 working electrodes of size 44 µm × 52 µm, along with 16 reference electrodes of dimensions 56 µm × 399 µm and 32 counter electrodes of dimensions 399 µm × 106 µm, which together facilitate the high resolution screening of the test samples. The chip was fabricated in a standard 130nm BiCMOS process. The on-chip electrodes are subjected to additional fabrication processes, including a critical Al-etch step that ensures the excellent biocompatibility and long-term reliability of the CMOS sensor array in bio-environment. The electrochemical sensing modality is verified by detecting the electroactive analyte NaFeEDTA and the exoelectrogenic Shewanella oneidensis MR-1 bacteria, illustrating the chip's ability to quantify the generated electrochemical current and distinguish between different analyte concentrations. The impedance measurements with the HEK-293 cancer cells cultured on-chip successfully capture the cell-to-surface adhesion information between the electrodes and the cancer cells. The reported CMOS sensor array outperforms the conventional discrete setups for exoelectrogen characterization in terms of spatial resolution and speed, which demonstrates the chip's potential to radically accelerate synthetic biology engineering.

4.
Curr Cardiol Rep ; 22(5): 29, 2020 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-32232590

RESUMO

PURPOSE OF REVIEW: The goal of this paper is to review present knowledge regarding biological pacemakers created by somatic reprogramming as a platform for mechanistic and metabolic understanding of the rare subpopulation of pacemaker cells, with the ultimate goal of creating biological alternatives to electronic pacing devices. RECENT FINDINGS: Somatic reprogramming of cardiomyocytes by reexpression of embryonic transcription factor T-box 18 (TBX18) converts them into pacemaker-like. Recent studies take advantage of this model to gain insight into the electromechanical, metabolic, and architectural intricacies of the cardiac pacemaker cell across various models, including a surgical model of complete atrioventricular block (CAVB) in adult rats. The studies reviewed here reinforce the potential utility of TBX18-induced pacemaker myocytes (iPMS) as a minimally invasive treatment for heart block. Several challenges which must be overcome to develop a viable therapeutic intervention based on these observations are discussed.


Assuntos
Reprogramação Celular , Marca-Passo Artificial , Animais , Bloqueio Atrioventricular , Estimulação Cardíaca Artificial , Humanos , Miócitos Cardíacos , Ratos , Proteínas com Domínio T
5.
Stem Cells ; 38(3): 352-368, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31648393

RESUMO

Cardiac differentiation of embryonic stem cells (ESCs) can give rise to de novo chamber cardiomyocytes and nodal pacemaker cells. Compared with our understanding of direct differentiation toward atrial and ventricular myocytes, the mechanisms for nodal pacemaker cell commitment are not well understood. Taking a cue from the prominence of canonical Wnt signaling during cardiac pacemaker tissue development in chick embryos, we asked if modulations of Wnt signaling influence cardiac progenitors to bifurcate to either chamber cardiomyocytes or pacemaker cells. Omitting an exogenous Wnt inhibitor, which is routinely added to maximize cardiac myocyte yield during differentiation of mouse and human ESCs, led to increased yield of spontaneously beating cardiomyocytes with action potential properties similar to those of native sinoatrial node pacemaker cells. The pacemaker phenotype was accompanied by enhanced expression of genes and gene products that mark nodal pacemaker cells such as Hcn4, Tbx18, Tbx3, and Shox2. Addition of exogenous Wnt3a ligand, which activates canonical Wnt/ß-catenin signaling, increased the yield of pacemaker-like myocytes while reducing cTNT-positive pan-cardiac differentiation. Conversely, addition of inhibitors of Wnt/ß-catenin signaling led to increased chamber myocyte lineage development at the expense of pacemaker cell specification. The positive impact of canonical Wnt signaling on nodal pacemaker cell differentiation was evidenced in direct differentiation of two human ESC lines and human induced pluripotent stem cells. Our data identify the Wnt/ß-catenin pathway as a critical determinant of cardiac myocyte subtype commitment during ESC differentiation: endogenous Wnt signaling favors the pacemaker lineage, whereas its suppression promotes the chamber cardiomyocyte lineage.


Assuntos
Células-Tronco Embrionárias Humanas/metabolismo , Mesoderma/metabolismo , Células-Tronco Embrionárias Murinas/metabolismo , Via de Sinalização Wnt/genética , Animais , Diferenciação Celular , Humanos , Camundongos
7.
Adv Sci (Weinh) ; 6(22): 1901099, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31763140

RESUMO

Every heartbeat originates from a tiny tissue in the heart called the sinoatrial node (SAN). The SAN harbors only ≈10 000 cardiac pacemaker cells, initiating an electrical impulse that captures the entire heart, consisting of billions of cardiomyocytes for each cardiac contraction. How these rare cardiac pacemaker cells (the electrical source) can overcome the electrically hyperpolarizing and quiescent myocardium (the electrical sink) is incompletely understood. Due to the scarcity of native pacemaker cells, this concept of source-sink mismatch cannot be tested directly with live cardiac tissue constructs. By exploiting TBX18 induced pacemaker cells by somatic gene transfer, 3D cardiac pacemaker spheroids can be tissue-engineered. The TBX18 induced pacemakers (sphTBX18) pace autonomously and drive the contraction of neighboring myocardium in vitro. TBX18 spheroids demonstrate the need for reduced electrical coupling and physical separation from the neighboring ventricular myocytes, successfully recapitulating a key design principle of the native SAN. ß-Adrenergic stimulation as well as electrical uncoupling significantly increase sphTBX18s' ability to pace-and-drive the neighboring myocardium. This model represents the first platform to test design principles of the SAN for mechanistic understanding and to better engineer biological pacemakers for therapeutic translation.

8.
Exp Mol Med ; 51(9): 1-12, 2019 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-31519870

RESUMO

Cardiac pacemaker cells of the sinoatrial node initiate each and every heartbeat. Compared with our understanding of the constituents of their electrical excitation, little is known about the metabolic underpinnings that drive the automaticity of pacemaker myocytes. This lack is largely owing to the scarcity of native cardiac pacemaker myocytes. Here, we take advantage of induced pacemaker myocytes generated by TBX18-mediated reprogramming (TBX18-iPMs) to investigate comparative differences in the metabolic program between pacemaker myocytes and working cardiomyocytes. TBX18-iPMs were more resistant to metabolic stresses, exhibiting higher cell viability upon oxidative stress. TBX18-induced pacemaker myocytes (iPMs) expensed a lower degree of oxidative phosphorylation and displayed a smaller capacity for glycolysis compared with control ventricular myocytes. Furthermore, the mitochondria were smaller in TBX18-iPMs than in the control. We reasoned that a shift in the balance between mitochondrial fusion and fission was responsible for the smaller mitochondria observed in TBX18-iPMs. We identified a mitochondrial inner membrane fusion protein, Opa1, as one of the key mediators of this process and demonstrated that the suppression of Opa1 expression increases the rate of synchronous automaticity in TBX18-iPMs. Taken together, our data demonstrate that TBX18-iPMs exhibit a low metabolic demand that matches their mitochondrial morphology and ability to withstand metabolic insult.


Assuntos
GTP Fosfo-Hidrolases/genética , Miócitos Cardíacos/metabolismo , Marca-Passo Artificial , Proteínas com Domínio T/genética , Animais , Reprogramação Celular/genética , Regulação da Expressão Gênica/genética , Glicólise/genética , Humanos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Dinâmica Mitocondrial/genética , Membranas Mitocondriais/metabolismo , Estresse Oxidativo/genética , Ratos , Nó Sinoatrial/metabolismo , Nó Sinoatrial/patologia , Estresse Fisiológico/genética
9.
Adv Sci (Weinh) ; 6(17): 1900939, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31508289

RESUMO

Commercially available health monitors rely on rigid electronic housing coupled with aggressive adhesives and conductive gels, causing discomfort and inducing skin damage. Also, research-level skin-wearable devices, while excelling in some aspects, fall short as concept-only presentations due to the fundamental challenges of active wireless communication and integration as a single device platform. Here, an all-in-one, wireless, stretchable hybrid electronics with key capabilities for real-time physiological monitoring, automatic detection of signal abnormality via deep-learning, and a long-range wireless connectivity (up to 15 m) is introduced. The strategic integration of thin-film electronic layers with hyperelastic elastomers allows the overall device to adhere and deform naturally with the human body while maintaining the functionalities of the on-board electronics. The stretchable electrodes with optimized structures for intimate skin contact are capable of generating clinical-grade electrocardiograms and accurate analysis of heart and respiratory rates while the motion sensor assesses physical activities. Implementation of convolutional neural networks for real-time physiological classifications demonstrates the feasibility of multifaceted analysis with a high clinical relevance. Finally, in vivo demonstrations with animals and human subjects in various scenarios reveal the versatility of the device as both a health monitor and a viable research tool.

10.
Biosens Bioelectron ; 144: 111626, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31494510

RESUMO

Intracellular action potential signals reveal enriched physiological information. Patch clamp techniques have been widely used to measure intracellular potential. Despite their high signal fidelity, they suffer from low throughput. Recently, 3D nanoelectrodes have been developed for intracellular potential recording. However, they are limited by scalability, yield, and cost, directly constraining their use in monitoring large number of cells and high throughput applications. In this paper, we demonstrate intracellular potential monitoring of cardiomyocytes using simple 2D planar electrode array in a standard CMOS process without patch clamps or post fabricated 3D nanoelectrodes. This is enabled by our unique cardiomyocytes/fibroblasts co-culturing technique and electroporation. The co-cultured fibroblasts promote tight sealing of cardiomyocytes on electrodes and enable high-fidelity intracellular potential monitoring based on 2D planar electrode. Compared to existing technologies, our platform has a unique potential to achieve an unprecedented combination of throughput, spatiotemporal resolution, and a tissue-level field-of-view for cellular electrophysiology monitoring.


Assuntos
Potenciais de Ação/fisiologia , Técnicas Biossensoriais , Avaliação Pré-Clínica de Medicamentos , Miócitos Cardíacos/fisiologia , Animais , Técnicas de Cocultura/métodos , Eletrodos , Fibroblastos/fisiologia , Humanos , Técnicas de Patch-Clamp , Ratos
11.
Sci Rep ; 9(1): 11893, 2019 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-31417144

RESUMO

The cardiac action potential (AP) is vital for understanding healthy and diseased cardiac biology and drug safety testing. However, techniques for high throughput cardiac AP measurements have been limited. Here, we introduce a novel technique for reliably increasing the coupling of cardiomyocyte syncytium to planar multiwell microelectrode arrays, resulting in a stable, label-free local extracellular action potential (LEAP). We characterized the reliability and stability of LEAP, its relationship to the field potential, and its efficacy for quantifying AP morphology of human induced pluripotent stem cell derived and primary rodent cardiomyocytes. Rise time, action potential duration, beat period, and triangulation were used to quantify compound responses and AP morphology changes induced by genetic modification. LEAP is the first high throughput, non-invasive, label-free, stable method to capture AP morphology from an intact cardiomyocyte syncytium. LEAP can accelerate our understanding of stem cell models, while improving the automation and accuracy of drug testing.


Assuntos
Potenciais de Ação/fisiologia , Coração/fisiologia , Microeletrodos , Animais , Animais Recém-Nascidos , Eletroporação , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Canais Iônicos/antagonistas & inibidores , Canais Iônicos/metabolismo , Miócitos Cardíacos/fisiologia , Ratos , Processamento de Sinais Assistido por Computador , Fatores de Tempo
12.
Sci Rep ; 9(1): 6930, 2019 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-31061413

RESUMO

Complete atrioventricular block (CAVB) is a life-threatening arrhythmia. A small animal model of chronic CAVB that properly reflects clinical indices of bradycardia would accelerate the understanding of disease progression and pathophysiology, and the development of therapeutic strategies. We sought to develop a surgical model of CAVB in adult rats, which could recapitulate structural remodeling and arrhythmogenicity expected in chronic CAVB. Upon right thoracotomy, we delivered electrosurgical energy subepicardially via a thin needle into the atrioventricular node (AVN) region of adult rats to create complete AV block. The chronic CAVB animals developed dilated and hypertrophied ventricles with preserved systolic functions due to compensatory hemodynamic remodeling. Ventricular tachyarrhythmias, which are difficult to induce in the healthy rodent heart, could be induced upon programmed electrical stimulation in chronic CAVB rats and worsened when combined with ß-adrenergic stimulation. Focal somatic gene transfer of TBX18 to the left ventricular apex in the CAVB rats resulted in ectopic ventricular beats within days, achieving a de novo ventricular rate faster than the slow atrioventricular (AV) junctional escape rhythm observed in control CAVB animals. The model offers new opportunities to test therapeutic approaches to treat chronic and severe CAVB which have previously only been testable in large animal models.


Assuntos
Bloqueio Atrioventricular/fisiopatologia , Bloqueio Atrioventricular/terapia , Bradicardia/fisiopatologia , Bradicardia/terapia , Animais , Bloqueio Atrioventricular/diagnóstico , Bloqueio Atrioventricular/mortalidade , Biópsia , Bradicardia/diagnóstico , Bradicardia/mortalidade , Ablação por Cateter/métodos , Terapia Combinada , Gerenciamento Clínico , Modelos Animais de Doenças , Ecocardiografia , Eletrocardiografia , Feminino , Frequência Cardíaca , Imuno-Histoquímica , Masculino , Ratos , Fatores de Tempo , Remodelação Ventricular
13.
Am J Physiol Heart Circ Physiol ; 317(7): H13-H25, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30925072

RESUMO

Engineered cardiac tissue and cardiomyocyte cell cultures offer wide opportunities for improved therapeutic intervention and laboratory heart models. Electrical field excitation is a common intervention in the production of engineered tissue and the investigation of the electrical properties of in vitro cell cultures. In this work, we use strength-duration relationships to investigate systematically factors influencing electrical excitability of two- (2D) and three-dimensional (3D) neonatal rat ventricular myocyte cultures. We find that the strength of the voltage pulse is negatively correlated with the threshold duration, as predicted by the Lapicque-Hill equation, and show that higher pacing frequencies require higher thresholds to capture paced cultures. We also study the impact of properties intrinsic to the 2D and 3D cultures on strength-duration relationships. We show that a smaller culture dimension, perpendicular anisotropic culture orientation with respect to electrical field, higher proportion of added fibroblasts, and TBX18-induced pacemaker reprogramming independently result in higher stimulation thresholds. These properties reflect the characteristics of the well-insulated endogenous pacemaking tissue in the heart (sinoatrial node) and should guide the engineering of biological pacemakers for improved outcomes. NEW & NOTEWORTHY Gaps exist in the availability of in vitro functional assessment tools that can emulate the integration of regenerative cells and tissues to the host myocardium. We use strength-duration relationships of electrically stimulated two- and three-dimensional myocardial constructs to study the effects of pacing frequency, culture dimensions, anisotropic cell alignment, fibroblast content, and pacemaker phenotype on electrical excitability. Our study delivers electrical strength-duration as a quantifiable parameter to evaluate design parameters of engineered cardiac tissue constructs.


Assuntos
Potenciais de Ação , Contração Miocárdica , Miócitos Cardíacos/fisiologia , Engenharia Tecidual/métodos , Animais , Células Cultivadas , Fibroblastos/fisiologia , Ventrículos do Coração/citologia , Periodicidade , Cultura Primária de Células/métodos , Ratos , Ratos Sprague-Dawley
14.
J Cardiovasc Dev Dis ; 5(4)2018 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-30347716

RESUMO

Bradycardia arising from pacemaker dysfunction can be debilitating and life threatening. Electronic pacemakers serve as effective treatment options for pacemaker dysfunction. They however present their own limitations and complications. This has motivated research into discovering more effective and innovative ways to treat pacemaker dysfunction. Gene therapy is being explored for its potential to treat various cardiac conditions including cardiac arrhythmias. Gene transfer vectors with increasing transduction efficiency and biosafety have been developed and trialed for cardiovascular disease treatment. With an improved understanding of the molecular mechanisms driving pacemaker development, several gene therapy targets have been identified to generate the phenotypic changes required to correct pacemaker dysfunction. This review will discuss the gene therapy vectors in use today along with methods for their delivery. Furthermore, it will evaluate several gene therapy strategies attempting to restore biological pacing, having the potential to emerge as viable therapies for pacemaker dysfunction.

15.
Lab Chip ; 18(19): 3037-3050, 2018 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-30168827

RESUMO

Cells are complex systems with concurrent multi-physical responses, and cell physiological signals are often encoded with spatiotemporal dynamics and further coupled with multiple cellular activities. However, most existing electronic sensors are only single-modality and cannot capture multi-parametric cellular responses. In this paper, a 1024-pixel CMOS quad-modality cellular interfacing array that enables multi-parametric cell profiling for drug development is presented. The quad-modality CMOS array features cellular impedance characterization, optical detection, extracellular potential recording, and biphasic current stimulation. The fibroblast transparency and surface adhesion are jointly monitored by cellular impedance and optical sensing modalities for comprehensive cell growth evaluation. Simultaneous current stimulation and opto-mechanical monitoring based on cardiomyocytes are demonstrated without any stimulation/sensing dead-zone. Furthermore, drug dose-dependent multi-parametric feature extractions in cardiomyocytes from their extracellular potentials and opto-mechanical signals are presented. The CMOS array demonstrates great potential for fully automated drug screening and drug safety assessments, which may substantially reduce the drug screening time and cost in future new drug development.


Assuntos
Avaliação Pré-Clínica de Medicamentos/instrumentação , Metais/química , Óxidos/química , Semicondutores , Análise Serial de Tecidos/instrumentação , Automação , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos
16.
IEEE Trans Biomed Circuits Syst ; 12(1): 80-94, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29377798

RESUMO

This paper presents a fully integrated CMOS multimodality joint sensor/stimulator array with 1024 pixels for real-time holistic cellular characterization and drug screening. The proposed system consists of four pixel groups and four parallel signal-conditioning blocks. Every pixel group contains 16 × 16 pixels, and each pixel includes one gold-plated electrode, four photodiodes, and in-pixel circuits, within a pixel footprint. Each pixel supports real-time extracellular potential recording, optical detection, charge-balanced biphasic current stimulation, and cellular impedance measurement for the same cellular sample. The proposed system is fabricated in a standard 130-nm CMOS process. Rat cardiomyocytes are successfully cultured on-chip. Measured high-resolution optical opacity images, extracellular potential recordings, biphasic current stimulations, and cellular impedance images demonstrate the unique advantages of the system for holistic cell characterization and drug screening. Furthermore, this paper demonstrates the use of optical detection on the on-chip cultured cardiomyocytes to real-time track their cyclic beating pattern and beating rate.


Assuntos
Impedância Elétrica , Processamento de Imagem Assistida por Computador , Dispositivos Lab-On-A-Chip , Potenciais da Membrana , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Animais , Técnicas de Cultura de Células , Avaliação Pré-Clínica de Medicamentos/instrumentação , Avaliação Pré-Clínica de Medicamentos/métodos , Eletrodos , Processamento de Imagem Assistida por Computador/instrumentação , Processamento de Imagem Assistida por Computador/métodos , Ratos , Ratos Sprague-Dawley
19.
Sci Rep ; 6: 30956, 2016 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-27492371

RESUMO

Efficient generation of cardiomyocytes from human pluripotent stem cells is critical for their regenerative applications. Microgravity and 3D culture can profoundly modulate cell proliferation and survival. Here, we engineered microscale progenitor cardiac spheres from human pluripotent stem cells and exposed the spheres to simulated microgravity using a random positioning machine for 3 days during their differentiation to cardiomyocytes. This process resulted in the production of highly enriched cardiomyocytes (99% purity) with high viability (90%) and expected functional properties, with a 1.5 to 4-fold higher yield of cardiomyocytes from each undifferentiated stem cell as compared with 3D-standard gravity culture. Increased induction, proliferation and viability of cardiac progenitors as well as up-regulation of genes associated with proliferation and survival at the early stage of differentiation were observed in the 3D culture under simulated microgravity. Therefore, a combination of 3D culture and simulated microgravity can be used to efficiently generate highly enriched cardiomyocytes.


Assuntos
Simulação por Computador , Mioblastos Cardíacos/fisiologia , Miócitos Cardíacos/fisiologia , Células-Tronco Pluripotentes/fisiologia , Diferenciação Celular , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Humanos , Técnicas de Cultura de Órgãos , Engenharia Tecidual , Simulação de Ausência de Peso
20.
Cell ; 166(3): 624-636, 2016 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-27374331

RESUMO

Degradation of Gram-positive bacterial cell wall peptidoglycan in macrophage and dendritic cell phagosomes leads to activation of the NLRP3 inflammasome, a cytosolic complex that regulates processing and secretion of interleukin (IL)-1ß and IL-18. While many inflammatory responses to peptidoglycan are mediated by detection of its muramyl dipeptide component in the cytosol by NOD2, we report here that NLRP3 inflammasome activation is caused by release of N-acetylglucosamine that is detected in the cytosol by the glycolytic enzyme hexokinase. Inhibition of hexokinase by N-acetylglucosamine causes its dissociation from mitochondria outer membranes, and we found that this is sufficient to activate the NLRP3 inflammasome. In addition, we observed that glycolytic inhibitors and metabolic conditions affecting hexokinase function and localization induce inflammasome activation. While previous studies have demonstrated that signaling by pattern recognition receptors can regulate metabolic processes, this study shows that a metabolic enzyme can act as a pattern recognition receptor. PAPERCLIP.


Assuntos
Hexoquinase/metabolismo , Inflamassomos/metabolismo , Peptidoglicano/metabolismo , Receptores Imunológicos/metabolismo , Acetilação , Acetilglucosamina/metabolismo , Animais , Bacillus anthracis/metabolismo , Parede Celular/metabolismo , Células Dendríticas/metabolismo , Glicólise , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Modelos Biológicos , Monócitos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Potássio/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...