RESUMEN
By harnessing structural hierarchical insights, plausibly simulate better ones imagination to figure out the best choice of methods for reaching out the unprecedented developments of the tissue engineering products as a next level. Constructing a functional tissue that incorporates two-dimensional (2D) or higher dimensions requires overcoming technological or biological limitations in order to orchestrate the structural compilation of one-dimensional and 2D sheets (microstructures) simultaneously (in situ). This approach enables the creation of a layered structure that can be referred to as an ensemble of layers or, after several days of maturation, a direct or indirect joining of layers. Here, we have avoided providing a detailed methodological description of three-dimensional and 2D strategies, except for a few interesting examples that highlight the higher alignment of cells and emphasize rarely remembered facts associated with vascular, peripheral nerve, muscle, and intestine tissues. The effective directionality of cells in conjunction with geometric cues (in the range of micrometers) is well known to affect a variety of cell behaviors. The curvature of a cell's environment is one of the factors that influence the formation of patterns within tissues. The text will cover cell types containing some level of stemness, which will be followed by their consequences for tissue formation. Other important considerations pertain to cytoskeleton traction forces, cell organelle positioning, and cell migration. An overview of cell alignment along with several pivotal molecular and cellular level concepts, such as mechanotransduction, chirality, and curvature of structure effects on cell alignments will be presented. The mechanotransduction term will be used here in the context of the sensing capability that cells show as a result of force-induced changes either at the conformational or the organizational levels, a capability that allows us to modify cell fate by triggering downstream signaling pathways. A discussion of the cells' cytoskeleton and of the stress fibers involvement in altering the cell's circumferential constitution behavior (alignment) based on exposed scaffold radius will be provided. Curvatures with size similarities in the range of cell sizes cause the cell's behavior to act as if it was in an in vivo tissue environment. The revision of the literature, patents, and clinical trials performed for the present study shows that there is a clear need for translational research through the implementation of clinical trial platforms that address the tissue engineering possibilities raised in the current revision. This article is categorized under: Infectious Diseases > Biomedical Engineering Neurological Diseases > Biomedical Engineering Cardiovascular Diseases > Biomedical Engineering.
Asunto(s)
Mecanotransducción Celular , Ingeniería de Tejidos , Mecanotransducción Celular/fisiología , Ingeniería de Tejidos/métodos , Intestinos , Fenómenos Mecánicos , MúsculosRESUMEN
One of the many effects of soft tissues under mechanical solicitation in the cellular damage produced by highly localized strain. Here, we study the response of peripheral stress fibers (SFs) to external stretch in mammalian cells, plated onto deformable micropatterned substrates. A local fluorescence analysis reveals that an adaptation response is observed at the vicinity of the focal adhesion sites (FAs) due to its mechanosensor function. The response depends on the type of mechanical stress, from a Maxwell-type material in compression to a complex scenario in extension, where a mechanotransduction and a self-healing process takes place in order to prevent the induced severing of the SF. A model is proposed to take into account the effect of the applied stretch on the mechanics of the SF, from which relevant parameters of the healing process are obtained. In contrast, the repair of the actin bundle occurs at the weak point of the SF and depends on the amount of applied strain. As a result, the SFs display strain-softening features due to the incorporation of new actin material into the bundle. In contrast, the response under compression shows a reorganization with a constant actin material suggesting a gliding process of the SFs by the myosin II motors.
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Actinas , Fibras de Estrés , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Animales , Adhesiones Focales/metabolismo , Mamíferos/metabolismo , Mecanotransducción Celular/fisiología , Miosina Tipo II/metabolismo , Fibras de Estrés/metabolismo , Estrés MecánicoRESUMEN
The role of Pannexin (PANX) channels during collective and single cell migration is increasingly recognized. Amongst many functions that are relevant to cell migration, here we focus on the role of PANX-mediated adenine nucleotide release and associated autocrine and paracrine signaling. We also summarize the contribution of PANXs with the cytoskeleton, which is also key regulator of cell migration. PANXs, as mechanosensitive ATP releasing channels, provide a unique link between cell migration and purinergic communication. The functional association with several purinergic receptors, together with a plethora of signals that modulate their opening, allows PANX channels to integrate physical and chemical cues during inflammation. Ubiquitously expressed in almost all immune cells, PANX1 opening has been reported in different immunological contexts. Immune activation is the epitome coordination between cell communication and migration, as leukocytes (i.e., T cells, dendritic cells) exchange information while migrating towards the injury site. In the current review, we summarized the contribution of PANX channels during immune cell migration and recruitment; although we also compile the available evidence for non-immune cells (including fibroblasts, keratinocytes, astrocytes, and cancer cells). Finally, we discuss the current evidence of PANX1 and PANX3 channels as a both positive and/or negative regulator in different inflammatory conditions, proposing a general mechanism of these channels contribution during cell migration.
Asunto(s)
Movimiento Celular/fisiología , Conexinas/fisiología , Células Dendríticas/fisiología , Leucocitos/fisiología , Fagocitos/fisiología , Nucleótidos de Adenina/fisiología , Envejecimiento/inmunología , Envejecimiento/fisiología , Animales , Astrocitos/fisiología , Polaridad Celular , Quimiotaxis de Leucocito/fisiología , Citoesqueleto/fisiología , Fibroblastos/fisiología , Humanos , Inflamación/inmunología , Inflamación/fisiopatología , Queratinocitos/fisiología , Mecanotransducción Celular/fisiología , Neoplasias/inmunología , Degeneración Nerviosa/inmunología , Degeneración Nerviosa/fisiopatología , Proteínas del Tejido Nervioso/fisiología , Receptores Purinérgicos/fisiologíaRESUMEN
AIM: We aimed to evaluate the correlation between the polymorphism of the interleukin 1-Beta (IL1-ß, +3954 C>T) and tooth movement, in a group of Colombian patients undergoing surgically accelerated orthodontic tooth movement. METHODS: The study was nested to a controlled clinical trial. Blood samples were taken from 11 women and 29 healthy Colombian male volunteers between 18 and 40 years old, after 1 year of starting orthodontic treatment. The patients presented malocclusion class I, with grade II or III. To detect the genetic polymorphism of the nucleotide +3954 C to T in the IL-1ß gene, we used a real-time PCR assay. RESULTS: Eleven individuals presented the allele 2 (T) heterozygous with the allele 1 (T/C) and 19 individuals were homozygous for the allele 1 (C/C). When analyzing the presence of the SNP, no significant differences were found in any of the variables. The best treatment was reflected in Group 3 (selective upper and lower alveolar decortication and 3D collagen matrix) and Group 4 (only selective alveolar decortication in the upper arch, with 3D collagen matrix), with 27% and 35% more speed respectively than in the control group. CONCLUSIONS: Our analyses indicated that a reduction in the total treatment time can be mostly potentiated by using decortication and collagen matrices and not for the presence of the allele 2 in the IL-1ß. Nevertheless, it is important that further studies investigate if the polymorphism could be associated with the speed of tooth movement and analyze the baseline protein levels.
OBJETIVO: Evaluar la correlación entre el polimorfismo de la interleucina 1-Beta (IL1-ß, +3954 C> T) y el movimiento de los dientes, en un grupo de pacientes colombianos sometidos a un movimiento dental ortodóncico acelerado quirúrgicamente. MÉTODOS: Este fue un estudio secundario derivado de un ensayo clínico aleatorio controlado. Se tomaron muestras de sangre de 11 mujeres y 29 voluntarios varones colombianos sanos entre 18 y 40 años, después de 1 año de comenzar el tratamiento de ortodoncia. Los pacientes presentaron maloclusión clase I, con grado II o III. Para detectar el polimorfismo genético del nucleótido +3954 C a T en el gen IL-1ß, se usó un ensayo de PCR en tiempo real. RESULTADOS: 11 individuos presentaron el alelo 2 (T) heterocigoto con el alelo 1 (T / C) y 19 individuos fueron homocigotos para el alelo 1 (C / C). Al analizar la presencia del SNP, no se encontraron diferencias significativas en ninguna de las variables. El mejor tratamiento se reflejó en el Grupo 3 (decorticación alveolar superior e inferior selectiva y matriz de colágeno 3D) y el Grupo 4 (solo decorticación alveolar selectiva en el arco superior, con matriz de colágeno 3D), con un 27% y un 35% más de velocidad, respectivamente, que en el grupo de control. CONCLUSIONES: Los análisis indicaron que una reducción en el tiempo total de tratamiento puede potenciarse principalmente mediante el uso de decorticación y matrices de colágeno y no por la presencia del alelo 2 en la IL-1ß. Sin embargo, es importante que otros estudios investiguen si el polimorfismo podría estar asociado con la velocidad del movimiento de los dientes y analizar los niveles de proteína de referencia.
Asunto(s)
Interleucina-1beta/genética , Maloclusión/genética , Maloclusión/terapia , Polimorfismo de Nucleótido Simple , Técnicas de Movimiento Dental/métodos , Adulto , Alelos , Colombia , Análisis de Datos , Femenino , Heterocigoto , Homocigoto , Humanos , Estimación de Kaplan-Meier , Masculino , Maloclusión/clasificación , Mecanotransducción Celular/fisiología , Tempo Operativo , Factores de Tiempo , Adulto JovenRESUMEN
Abstract Aim: We aimed to evaluate the correlation between the polymorphism of the interleukin 1-Beta (IL1-β, +3954 C>T) and tooth movement, in a group of Colombian patients undergoing surgically accelerated orthodontic tooth movement. Methods: The study was nested to a controlled clinical trial. Blood samples were taken from 11 women and 29 healthy Colombian male volunteers between 18 and 40 years old, after 1 year of starting orthodontic treatment. The patients presented malocclusion class I, with grade II or III. To detect the genetic polymorphism of the nucleotide +3954 C to T in the IL-1β gene, we used a real-time PCR assay. Results: Eleven individuals presented the allele 2 (T) heterozygous with the allele 1 (T/C) and 19 individuals were homozygous for the allele 1 (C/C). When analyzing the presence of the SNP, no significant differences were found in any of the variables. The best treatment was reflected in Group 3 (selective upper and lower alveolar decortication and 3D collagen matrix) and Group 4 (only selective alveolar decortication in the upper arch, with 3D collagen matrix), with 27% and 35% more speed respectively than in the control group. Conclusions: Our analyses indicated that a reduction in the total treatment time can be mostly potentiated by using decortication and collagen matrices and not for the presence of the allele 2 in the IL-1β. Nevertheless, it is important that further studies investigate if the polymorphism could be associated with the speed of tooth movement and analyze the baseline protein levels.
Resumen Objetivo: Evaluar la correlación entre el polimorfismo de la interleucina 1-Beta (IL1-β, +3954 C> T) y el movimiento de los dientes, en un grupo de pacientes colombianos sometidos a un movimiento dental ortodóncico acelerado quirúrgicamente. Métodos: Este fue un estudio secundario derivado de un ensayo clínico aleatorio controlado. Se tomaron muestras de sangre de 11 mujeres y 29 voluntarios varones colombianos sanos entre 18 y 40 años, después de 1 año de comenzar el tratamiento de ortodoncia. Los pacientes presentaron maloclusión clase I, con grado II o III. Para detectar el polimorfismo genético del nucleótido +3954 C a T en el gen IL-1β, se usó un ensayo de PCR en tiempo real. Resultados: 11 individuos presentaron el alelo 2 (T) heterocigoto con el alelo 1 (T / C) y 19 individuos fueron homocigotos para el alelo 1 (C / C). Al analizar la presencia del SNP, no se encontraron diferencias significativas en ninguna de las variables. El mejor tratamiento se reflejó en el Grupo 3 (decorticación alveolar superior e inferior selectiva y matriz de colágeno 3D) y el Grupo 4 (solo decorticación alveolar selectiva en el arco superior, con matriz de colágeno 3D), con un 27% y un 35% más de velocidad, respectivamente, que en el grupo de control. Conclusiones: Los análisis indicaron que una reducción en el tiempo total de tratamiento puede potenciarse principalmente mediante el uso de decorticación y matrices de colágeno y no por la presencia del alelo 2 en la IL-1β. Sin embargo, es importante que otros estudios investiguen si el polimorfismo podría estar asociado con la velocidad del movimiento de los dientes y analizar los niveles de proteína de referencia.
Asunto(s)
Adulto , Femenino , Humanos , Masculino , Adulto Joven , Técnicas de Movimiento Dental/métodos , Polimorfismo de Nucleótido Simple , Interleucina-1beta/genética , Maloclusión/genética , Maloclusión/terapia , Factores de Tiempo , Colombia , Mecanotransducción Celular/fisiología , Alelos , Estimación de Kaplan-Meier , Tempo Operativo , Análisis de Datos , Heterocigoto , Homocigoto , Maloclusión/clasificaciónRESUMEN
BACKGROUND: Cardiac physiology depends on coupling and electrical and mechanical coordination through the intercalated disc. Focal adhesions offer mechanical support and signal transduction events during heart contraction-relaxation processes. Talin links integrins to the actin cytoskeleton and serves as a scaffold for the recruitment of other proteins, such as paxillin in focal adhesion formation and regulation. Chagasic cardiomyopathy is caused by infection by Trypanosoma cruzi and is a debilitating condition comprising extensive fibrosis, inflammation, cardiac hypertrophy and electrical alterations that culminate in heart failure. OBJECTIVES: Since mechanotransduction coordinates heart function, we evaluated the underlying mechanism implicated in the mechanical changes, focusing especially in mechanosensitive proteins and related signalling pathways during infection of cardiac cells by T. cruzi. METHODS: We investigated the effect of T. cruzi infection on the expression and distribution of talin/paxillin and associated proteins in mouse cardiomyocytes in vitro by western blotting, immunofluorescence and quantitative real-time polymerase chain reaction (qRT-PCR). FINDINGS: Talin and paxillin spatial distribution in T. cruzi-infected cardiomyocytes in vitro were altered associated with a downregulation of these proteins and mRNAs levels at 72 h post-infection (hpi). Additionally, we observed an increase in the activation of the focal adhesion kinase (FAK) concomitant with increase in ß-1-integrin at 24 hpi. Finally, we detected a decrease in the activation of FAK at 72 hpi in T. cruzi-infected cultures. MAIN CONCLUSION: The results suggest that these changes may contribute to the mechanotransduction disturbance evidenced in chagasic cardiomyopathy.
Asunto(s)
Cardiomiopatía Chagásica/metabolismo , Miocitos Cardíacos/parasitología , Paxillin/metabolismo , Talina/metabolismo , Trypanosoma cruzi/fisiología , Animales , Western Blotting , Técnica del Anticuerpo Fluorescente Indirecta , Immunoblotting , Mecanotransducción Celular/fisiología , Ratones , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
Shear stress changes are associated with a repertory of signaling cascade modulating vascular phenotype. As shear stress-related tensional forces might be associated with pathophysiological susceptibility, a more comprehensive molecular map needs to be addressed. Thus, we subjected human umbilical vein endothelial cells (HUVECs) to a circuit of different tensional forces in vitro considering the following three groups: (a) physiological blood flow shear stress condition (named Normo), (b) a hypertensive blood flow shear stress (named Hyper), and (c) these hyper-stressed cells were returned to Normo condition (named Return). The samples were properly collected to allow different methodologies analysis. Our data showed a pivotal involvement of c-Src on driving the mechanotransduction cascade by modulating signaling related with adhesion, survival (PI3K/Akt) and proliferative phenotype. Moreover, c-Src seems to develop important role during extracellular matrix remodeling. Additionally, proteomic analysis showed strong involvement of heat shock protein 70 (HSP70) in the hypertensive-stressed cells; it being significantly decreased in return phenotype. This result prompted us to investigate 20S proteasome as an intracellular proteolytic alternative route to promote the turnover of those proteins. Surprisingly, our data reveled significant overexpression of sets of proteasome subunit α-type (PSMA) and ß-type (PSMB) genes. In conjunction, our data showed c-Src as a pivotal protein to drive mechanotransduction in endothelial cells in a HSP70-dependent turnover scenario. Because shear patterns is associated with pathophysiological changes, such as atherosclerosis and hypertension, these results paved new road to understand the molecular mechanism on driving mechanotransduction in endothelial cells and, if drugable, these targets must be considered within pharmacological treatment optimization.
Asunto(s)
Proteína Tirosina Quinasa CSK/metabolismo , Proteínas HSP70 de Choque Térmico/metabolismo , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Mecanotransducción Celular/fisiología , Flujo Sanguíneo Regional/fisiología , Adhesión Celular/fisiología , Células Cultivadas , Hemodinámica/fisiología , Humanos , Hipertensión/fisiopatología , Complejo de la Endopetidasa Proteasomal/metabolismo , Transducción de Señal/fisiología , Estrés Mecánico , Estrés Fisiológico/fisiologíaRESUMEN
Endothelial cells participate in extracellular ATP release elicited by mechanosensors. To characterize the dynamic interactions between mechanical and chemical factors that modulate ATP secretion by the endothelium, we assessed and compared the mechanisms participating in the spontaneous (basal) and mechanically stimulated secretion using primary cultures of rat mesentery endothelial cells. ATP/metabolites were determined in the cell media prior to (basal) and after cell media displacement or a picospritzer buffer puff used as mechanical stimuli. Mechanical stimulation increased extracellular ATP that peaked within 1 min, and decayed to basal values in 10 min. Interruption of the vesicular transport route consistently blocked the spontaneous ATP secretion. Cells maintained in media lacking external Ca2+ elicited a spontaneous rise of extracellular ATP and adenosine, but failed to elicit a further extracellular ATP secretion following mechanical stimulation. 2-APB, a TRPV agonist, increased the spontaneous ATP secretion, but reduced the mechanical stimulation-induced nucleotide release. Pannexin1 or connexin blockers and gadolinium, a Piezo1 blocker, reduced the mechanically induced ATP release without altering spontaneous nucleotide levels. Moreover, thrombin or related agonists increased extracellular ATP secretion elicited by mechanical stimulation, without modifying spontaneous release. In sum, present results allow inferring that the spontaneous, extracellular nucleotide secretion is essentially mediated by ATP containing vesicles, while the mechanically induced secretion occurs essentially by connexin or pannexin1 hemichannel ATP transport, a finding fully supported by results from Panx1-/- rodents. Only the latter component is modulated by thrombin and related receptor agonists, highlighting a novel endothelium-smooth muscle signaling role of this anticoagulant.
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Adenosina Trifosfato/metabolismo , Células Endoteliales/metabolismo , Mecanotransducción Celular/fisiología , Canales Catiónicos TRPV/metabolismo , Trombina/metabolismo , Animales , Células Cultivadas , Masculino , Mesenterio/citología , Mesenterio/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratas , Ratas Sprague-DawleyRESUMEN
Various approaches have been taken to improve our knowledge of the microenvironmental regulation of limbal epithelial stem cells. Researchers have extensively investigated the roles of growth factors, survival factors, cytokines, enzymes, and permeable molecules secreted by the limbal cells. However, recent evidence suggests that stem cell fate (i.e., self-renewal or differentiation) can also be influenced by biophysical and mechanical cues related to the supramolecular organization and the liquid crystalline (mesophase) nature of the stromal extracellular matrix. These cues can be sensed by stem cells and transduced into intracellular biochemical and functional responses, a process known as mechanotransduction. The objective of this review is to offer perspectives on the supramolecular microenvironmental regulation of limbal epithelial stem cells and the differentiation of their progeny.
Asunto(s)
Diferenciación Celular/fisiología , Epitelio Corneal/citología , Matriz Extracelular/fisiología , Limbo de la Córnea/citología , Mecanotransducción Celular/fisiología , Células Madre/fisiología , Epitelio Corneal/fisiología , Humanos , Nicho de Células Madre/fisiologíaRESUMEN
ABSTRACT Various approaches have been taken to improve our knowledge of the microenvironmental regulation of limbal epithelial stem cells. Researchers have extensively investigated the roles of growth factors, survival factors, cytokines, enzymes, and permeable molecules secreted by the limbal cells. However, recent evidence suggests that stem cell fate (i.e., self-renewal or differentiation) can also be influenced by biophysical and mechanical cues related to the supramolecular organization and the liquid crystalline (mesophase) nature of the stromal extracellular matrix. These cues can be sensed by stem cells and transduced into intracellular biochemical and functional responses, a process known as mechanotransduction. The objective of this review is to offer perspectives on the supramolecular microenvironmental regulation of limbal epithelial stem cells and the differentiation of their progeny.
RESUMO Muitas abordagens têm sido utilizadas para ampliar entendimentos sobre a regulação microambiental das células tronco epiteliais limbais. Neste contexto, pesquisadores têm exaustivamente investigado a participação de fatores de crescimento, fatores de sobrevida, citocinas, enzimas e moléculas permeáveis secretadas pelas células limbais. Entretanto, evidências recentes sugerem que o destino (ie. autorrenovação ou recrutamento para a via de diferenciação) das células tronco também sofre influência de estímulos biofísicos ou mecânicos relacionados à organização supramolecular e à natureza liquido-cristalina (mesofases) da matriz extracelular estromal. Esses estímulos podem ser percebidos e traduzidos pelas células tronco em sinais bioquímicos que geram respostas funcionais, através de um processo designado de mecanotransdução. Objetiva-se, com a presente revisão, oferecer ao leitor perspectivas supramoleculares sobre a regulação microambiental das células tronco epiteliais limbais e a diferenciação de sua progênie.
Asunto(s)
Humanos , Células Madre/fisiología , Diferenciación Celular/fisiología , Limbo de la Córnea/citología , Epitelio Corneal/citología , Mecanotransducción Celular/fisiología , Matriz Extracelular/fisiología , Epitelio Corneal/fisiología , Nicho de Células Madre/fisiologíaRESUMEN
Recent evidence suggests that ß-arrestins, which are involved in G protein-coupled receptors desensitization, may influence mechanotransduction. Here, we observed that nitric oxide (NO) production was abrogated in human saphenous vein endothelial cells (SVECs) transfected with siRNA against ß-arrestin 1 and 2 subjected to shear stress (SS, 15 dynes/cm2, 10 min). The downregulation of ß-arrestins 1/2 in SVECs cells also prevented the SS-induced rise in levels of phosphorylation of Akt and endothelial nitric oxide synthase (eNOS, Serine 1177). Interestingly, immunoprecipitation revealed that ß-arrestin interacts with Akt, eNOS and caveolin-1 and these interactions are not influenced by SS. Our data indicate that ß-arrestins and Akt/eNOS downstream signaling are required for early SS-induced NO production in SVECs, which is consistent with the idea that ß-arrestins and caveolin-1 are part of a pre-assembled complex associated with the cellular mechanotransduction machinery.
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Células Endoteliales/metabolismo , Óxido Nítrico Sintasa de Tipo III/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , beta-Arrestina 1/metabolismo , Arrestina beta 2/metabolismo , Caveolina 1/metabolismo , Células Cultivadas , Regulación hacia Abajo , Humanos , Mecanotransducción Celular/fisiología , Fosforilación , ARN Interferente Pequeño/genética , Transducción de Señal , Estrés Mecánico , beta-Arrestina 1/antagonistas & inhibidores , beta-Arrestina 1/genética , Arrestina beta 2/antagonistas & inhibidores , Arrestina beta 2/genéticaRESUMEN
The lipid bilayer component of biological membranes is important for the distribution, organization, and function of bilayer spanning proteins. These physical barriers are subjected to bilayer perturbations. As a consequence, nature has evolved proteins that are able to sense changes in the bilayer properties and transform these lipid-mediated stimuli into intracellular signals. A structural feature that most signal-transducing membrane-embedded proteins have in common is one or more α-helices that traverse the lipid bilayer. Because of the interaction with the surrounding lipids, the organization of these transmembrane helices will be sensitive to membrane properties, like hydrophobic thickness. The helices may adapt to the lipids in different ways, which in turn can influence the structure and function of the intact membrane proteins. We review recent insights into the molecular basis of thermosensing via changes in membrane thickness and consider examples in which the hydrophobic matching can be demonstrated using reconstituted membrane systems. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon.
Asunto(s)
Respuesta al Choque por Frío/fisiología , Membrana Dobles de Lípidos/química , Membrana Dobles de Lípidos/metabolismo , Mecanotransducción Celular/fisiología , Lípidos de la Membrana/metabolismo , Animales , Humanos , Lípidos de la Membrana/química , Membranas/metabolismo , Transducción de Señal/fisiología , Sensación Térmica/fisiologíaRESUMEN
Mechanical ventilation is an essential method of patient support, but it may induce lung damage, leading to ventilator-induced lung injury (VILI). VILI is the result of a complex interplay among various mechanical forces that act on lung structures, such as type I and II epithelial cells, endothelial cells, macrophages, peripheral airways, and the extracellular matrix (ECM), during mechanical ventilation. This article discusses ongoing research focusing on mechanisms of VILI in previously healthy lungs, such as in the perioperative period, and the development of new ventilator strategies for surgical patients. Several experimental and clinical studies have been conducted to evaluate the mechanisms of mechanotransduction in each cell type and in the ECM, as well as the role of different ventilator parameters in inducing or preventing VILI. VILI may be attenuated by reducing the tidal volume; however, the use of higher or lower levels of positive end-expiratory pressure (PEEP) and recruitment maneuvers during the perioperative period is a matter of debate. Many questions concerning the mechanisms of VILI in surgical patients remain unanswered. The optimal threshold value of each ventilator parameter to reduce VILI is also unclear. Further experimental and clinical studies are necessary to better evaluate ventilator settings during the perioperative period in different types of surgery.
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Pulmón/patología , Respiración Artificial/efectos adversos , Lesión Pulmonar Inducida por Ventilación Mecánica/fisiopatología , Animales , Humanos , Mecanotransducción Celular/fisiología , Respiración con Presión Positiva , Respiración Artificial/métodosRESUMEN
A cell mechanical stimulation equipment, based on cell substrate deformation, and a more sensitive method for measuring adhesion of cells were developed. A probe, precisely positioned close to the cell, was capable of a vertical localized mechanical stimulation with a temporal frequency of 207 Hz, and strain magnitude of 50%. This setup was characterized and used to probe the response of Human Umbilical Endothelial Vein Cells (HUVECs) in terms of calcium signaling. The intracellular calcium ion concentration was measured by the genetically encoded Cameleon biosensor, with the Transient Receptor Potential cation channel, subfamily M, member 7 (TRPM7) expression inhibited. As TRPM7 expression also regulates adhesion, a relatively simple method for measuring adhesion of cells was also developed, tested and used to study the effect of adhesion alone. Three adhesion conditions of HUVECs on polyacrylamide gel dishes were compared. In the first condition, the substrate is fully treated with Sulfo-SANPAH crosslinking and fibronectin. The other two conditions had increasingly reduced adhesion: partially treated (only coated with fibronectin, with no use of Sulfo-SANPAH, at 5% of the normal amount) and non-treated polyacrylamide gels. The cells showed adhesion and calcium response to the mechanical stimulation correlated to the degree of gel treatment: highest for fully treated gels and lowest for non-treated ones. TRPM7 inhibition by siRNA on HUVECs caused an increase in adhesion relative to control (no siRNA treatment) and non-targeting siRNA, but a decrease to 80% of calcium response relative to non-targeting siRNA which confirms the important role of TRPM7 in mechanotransduction despite the increase in adhesion.
Asunto(s)
Señalización del Calcio/fisiología , Adhesión Celular/fisiología , Mecanotransducción Celular/fisiología , Proteínas Serina-Treonina Quinasas/genética , Canales Catiónicos TRPM/genética , Técnicas Biosensibles , Calcio/metabolismo , Señalización del Calcio/genética , Adhesión Celular/genética , Células Cultivadas , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Fenómenos Mecánicos , Proteínas Serina-Treonina Quinasas/metabolismo , Interferencia de ARN , ARN Interferente Pequeño , Canales Catiónicos TRPM/metabolismoRESUMEN
Introduction Schwannoma of the olfactory groove is an extremely rare tumor that can share a differential diagnosis with meningioma or neuroblastoma. Objectives The authors present a case of giant schwannoma involving the anterior cranial fossa and ethmoid sinuses. Case Report The patient presented with a 30-month history of left nasal obstruction, anosmia, and sporadic ipsilateral bleeding. Computed tomography of the paranasal sinuses revealed expansive lesion on the left nasal cavity extending to nasopharynx up to ethmoid and sphenoid sinuses bilaterally with intraorbital and parasellar extension to the skull base. Magnetic resonance imaging scan confirmed the expansive tumor without dural penetration. Biopsy revealed no evidence of malignancy and probable neural cell. Bifrontal craniotomy was performed combined with lateral rhinotomy (Weber-Ferguson approach), and the lesion was totally removed. The tumor measured 8.0 4.3 3.7 cm and microscopically appeared as a schwannoma composed of interwoven bundles of elongated cells (Antoni A regions)mixed with less cellular regions (Antoni B). Immunohistochemical study stained intensively for vimentin and S-100. Conclusion Schwannomas of the olfactory groove are extremely rare, and the findings of origin of this tumor is still uncertain but recent studies point most probably to the meningeal branches of trigeminal nerve or anterior ethmoidal nerves. .
Asunto(s)
Animales , Femenino , Masculino , Ratones , Permeabilidad de la Membrana Celular/fisiología , Células Ciliadas Auditivas/fisiología , Canales Iónicos/fisiología , Mecanotransducción Celular/fisiología , Animales Recién Nacidos , Cadherinas/genética , Permeabilidad de la Membrana Celular/genética , Quelantes/farmacología , Sulfato de Dihidroestreptomicina/farmacología , Embrión de Mamíferos , Ácido Egtácico/análogos & derivados , Ácido Egtácico/farmacología , Células Ciliadas Auditivas/citología , Células Ciliadas Auditivas/efectos de los fármacos , Técnicas In Vitro , Canales Iónicos/efectos de los fármacos , Ratones Transgénicos , Mecanotransducción Celular/efectos de los fármacos , Mecanotransducción Celular/genética , Potenciales de la Membrana/efectos de los fármacos , Potenciales de la Membrana/genética , Miosinas/genética , Órgano Espiral/citología , Precursores de Proteínas/genéticaRESUMEN
Mechanosensitive channels are present in almost every living cell, yet the evidence for their functional presence in T lymphocytes is absent. In this study, by means of the patch-clamp technique in attached and inside-out modes, we have characterized cationic channels, rapidly activated by membrane stretch in Jurkat T lymphoblasts. The half-activation was achieved at a negative pressure of ~50mm Hg. In attached mode, single channel currents displayed an inward rectification and the unitary conductance of ~40 pS at zero command voltage. In excised inside-out patches the rectification was transformed to an outward one. Mechanosensitive channels weakly discriminated between mono- and divalent cations (PCa/PNa~1) and were equally permeable for Ca²âº and Mg²âº. Pharmacological analysis showed that the mechanosensitive channels were potently blocked by amiloride (1mM) and Gd³âº (10 µM) in a voltage-dependent manner. They were also almost completely blocked by ruthenium red (1 µM) and SKF 96365 (250 µM), inhibitors of transient receptor potential vanilloid 2 (TRPV2) channels. At the same time, the channels were insensitive to 2-aminoethoxydiphenyl borate (2-APB, 100 µM) or N-(p-amylcinnamoyl)anthranilic acid (ACA, 50 µM), antagonists of transient receptor potential canonical (TRPC) or transient receptor potential melastatin (TRPM) channels, respectively. Human TRPV2 siRNA virtually abolished the stretch-activated current. TRPV2 are channels with multifaceted functions and regulatory mechanisms, with potentially important roles in the lymphocyte Ca²âº signaling. Implications of their regulation by mechanical stress are discussed in the context of lymphoid cells functions.
Asunto(s)
Calcio/metabolismo , Activación del Canal Iónico/fisiología , Mecanotransducción Celular/fisiología , Canales Catiónicos TRPV/metabolismo , Amilorida/farmacología , Compuestos de Boro/farmacología , Expresión Génica , Humanos , Imidazoles/farmacología , Transporte Iónico/efectos de los fármacos , Transporte Iónico/fisiología , Células Jurkat , Leucemia de Células T/genética , Leucemia de Células T/metabolismo , Leucemia de Células T/fisiopatología , Magnesio/metabolismo , Potenciales de la Membrana/genética , Potenciales de la Membrana/fisiología , Técnicas de Placa-Clamp , Potasio/metabolismo , Interferencia de ARN , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Rojo de Rutenio/farmacología , Sodio/metabolismo , Canales Catiónicos TRPV/antagonistas & inhibidores , Canales Catiónicos TRPV/genéticaRESUMEN
The functional demand imposed on bone promotes changes in the spatial properties of osteocytes as well as in their extensions uniformly distributed throughout the mineralized surface. Once spatial deformation is established, osteocytes create the need for structural adaptations that result in bone formation and resorption that happen to meet the functional demands. The endosteum and the periosteum are the effectors responsible for stimulating adaptive osteocytes in the inner and outer surfaces. Changes in shape, volume and position of the jaws as a result of skeletal correction of the maxilla and mandible require anchorage to allow bone remodeling to redefine morphology, esthetics and function as a result of spatial deformation conducted by orthodontic appliances. Examining the degree of changes in shape, volume and structural relationship of areas where mini-implants and miniplates are placed allows us to classify mini-implants as devices of subabsolute anchorage and miniplates as devices of absolute anchorage.
Asunto(s)
Placas Óseas , Implantes Dentales , Métodos de Anclaje en Ortodoncia/instrumentación , Matriz Ósea/fisiología , Remodelación Ósea/fisiología , Resorción Ósea/fisiopatología , Humanos , Mandíbula/citología , Maxilar/citología , Mecanotransducción Celular/fisiología , Miniaturización , Diseño de Aparato Ortodóncico , Osteoblastos/fisiología , Osteoclastos/fisiología , Osteocitos/fisiología , Osteogénesis/fisiología , Periostio/fisiología , Técnicas de Movimiento Dental/instrumentaciónRESUMEN
Extracellular matrix and costamere proteins transmit the concentric, isometric, and eccentric forces produced by active muscle contraction. The expression of these proteins after application of passive tension stimuli to muscle remains unknown. This study investigated the expression of laminin and dystrophin in the soleus muscle of rats immobilized with the right ankle in plantar flexion for 10 days and subsequent remobilization, either by isolated free movement in a cage or associated with passive stretching for up to 10 days. The intensity of the macrophage response was also evaluated. One hundred and twenty-eight female Wistar rats were divided into 8 groups: free for 10 days; immobilized for 10 days; immobilized/free for 1, 3, or 10 days; or immobilized/stretched/free for 1, 3, or 10 days. After the experimental procedures, muscle tissue was processed for immunofluorescence (dystrophin/laminin/CD68) and Western blot analysis (dystrophin/laminin). Immobilization increased the expression of dystrophin and laminin but did not alter the number of macrophages in the muscle. In the stretched muscle groups, there was an increase in dystrophin and the number of macrophages after 3 days compared with the other groups; dystrophin showed a discontinuous labeling pattern, and laminin was found in the intracellular space. The amount of laminin was increased in the muscles treated by immobilization followed by free movement for 10 days. In the initial stages of postimmobilization (1 and 3 days), an exacerbated macrophage response and an increase of dystrophin suggested that the therapeutic stretching technique induced additional stress in the muscle fibers and costameres.
Asunto(s)
Animales , Femenino , Distrofina/metabolismo , Inmovilización/métodos , Laminina/metabolismo , Macrófagos/metabolismo , Ejercicios de Estiramiento Muscular/métodos , Músculo Esquelético/fisiología , Western Blotting , Distrofina/aislamiento & purificación , Matriz Extracelular/metabolismo , Técnica del Anticuerpo Fluorescente , Espacio Intracelular/metabolismo , Laminina/aislamiento & purificación , Mecanotransducción Celular/fisiología , Músculo Esquelético/lesiones , Ratas WistarRESUMEN
The functional demand imposed on bone promotes changes in the spatial properties of osteocytes as well as in their extensions uniformly distributed throughout the mineralized surface. Once spatial deformation is established, osteocytes create the need for structural adaptations that result in bone formation and resorption that happen to meet the functional demands. The endosteum and the periosteum are the effectors responsible for stimulating adaptive osteocytes in the inner and outer surfaces.Changes in shape, volume and position of the jaws as a result of skeletal correction of the maxilla and mandible require anchorage to allow bone remodeling to redefine morphology, esthetics and function as a result of spatial deformation conducted by orthodontic appliances. Examining the degree of changes in shape, volume and structural relationship of areas where mini-implants and miniplates are placed allows us to classify mini-implants as devices of subabsolute anchorage and miniplates as devices of absolute anchorage.
Uma demanda funcional sobre o osso promove alterações na forma espacial da rede de osteócitos e seus prolongamentos, distribuídos uniformemente na estrutura mineralizada. A partir da deformação espacial captada, os osteócitos comandam a necessidade de adaptações estruturais, formando osso em novas áreas e reabsorvendo em outras, para que sejam atendidas as demandas funcionais. O endósteo e o periósteo são os verdadeiros efetores desses estímulos osteocíticos adaptativos, nas superfícies internas e externas. As alterações de forma, volume e posição dos ossos maxilares, nas correções esqueléticas da maxila e mandíbula, requerem uma ancoragem para que a remodelação óssea redefina a morfologia, a estética e as funções, a partir de deformações espaciais dirigidas por aparelhos. Verificar o grau de alterações na forma, volume e relações estruturais das áreas onde se fixaram os mini-implantes e as miniplacas poderá levar à classificação dos mini-implantes como dispositivos de ancoragem subabsoluta e as miniplacas, como de ancoragem absoluta.
Asunto(s)
Humanos , Placas Óseas , Implantes Dentales , Métodos de Anclaje en Ortodoncia/instrumentación , Matriz Ósea/fisiología , Remodelación Ósea/fisiología , Resorción Ósea/fisiopatología , Miniaturización , Mandíbula/citología , Maxilar/citología , Mecanotransducción Celular/fisiología , Diseño de Aparato Ortodóncico , Osteoblastos/fisiología , Osteoclastos/fisiología , Osteocitos/fisiología , Osteogénesis/fisiología , Periostio/fisiología , Técnicas de Movimiento Dental/instrumentaciónRESUMEN
Extracellular matrix and costamere proteins transmit the concentric, isometric, and eccentric forces produced by active muscle contraction. The expression of these proteins after application of passive tension stimuli to muscle remains unknown. This study investigated the expression of laminin and dystrophin in the soleus muscle of rats immobilized with the right ankle in plantar flexion for 10 days and subsequent remobilization, either by isolated free movement in a cage or associated with passive stretching for up to 10 days. The intensity of the macrophage response was also evaluated. One hundred and twenty-eight female Wistar rats were divided into 8 groups: free for 10 days; immobilized for 10 days; immobilized/free for 1, 3, or 10 days; or immobilized/stretched/free for 1, 3, or 10 days. After the experimental procedures, muscle tissue was processed for immunofluorescence (dystrophin/laminin/CD68) and Western blot analysis (dystrophin/laminin). Immobilization increased the expression of dystrophin and laminin but did not alter the number of macrophages in the muscle. In the stretched muscle groups, there was an increase in dystrophin and the number of macrophages after 3 days compared with the other groups; dystrophin showed a discontinuous labeling pattern, and laminin was found in the intracellular space. The amount of laminin was increased in the muscles treated by immobilization followed by free movement for 10 days. In the initial stages of postimmobilization (1 and 3 days), an exacerbated macrophage response and an increase of dystrophin suggested that the therapeutic stretching technique induced additional stress in the muscle fibers and costameres.