RESUMEN
Rationale: Recent evidence highlights the pivotal role of mitochondrial dysfunction in mood disorders, but the mechanism involved remains unclear. We studied whether the Hippo/YAP/14-3-3η signaling pathway mediates mitochondrial abnormalities that result in the onset of major depressive disorder (MDD) in a mouse model. Methods: The ROC algorithm was used to identify a subpopulation of mice that were exposed to chronic unpredictable mild stress (CUMS) and exhibited the most prominent depressive phenotype (Dep). Electron microscopy, biochemical assays, quantitative PCR, and immunoblotting were used to evaluate synaptic and mitochondrial changes in the basolateral amygdala (BLA). RNA sequencing was used to explore changes in the Hippo pathway and downstream target genes. In vitro pharmacological inhibition and immunoprecipitation was used to confirm YAP/14-3-3η interaction and its role in neuronal mitochondrial dysfunction. We used virus-mediated gene overexpression and knockout in YAP transgenic mice to verify the regulatory effect of the Hippo/YAP/14-3-3η pathway on depressive-like behavior. Results: Transcriptomic data identified a large number of genes and signaling pathways that were specifically altered from the BLA of Dep mice. Dep mice showed notable synaptic impairment in BLA neurons, as well as mitochondrial damage characterized by abnormal mitochondrial morphology, compromised function, impaired biogenesis, and alterations in mitochondrial marker proteins. The Hippo signaling pathway was activated in Dep mice during CUMS, and the transcriptional regulatory activity of YAP was suppressed by phosphorylation of its Ser127 site. 14-3-3η was identified as an important co-regulatory factor of the Hippo/YAP pathway, as it can respond to chronic stress and regulate cytoplasmic retention of YAP. Importantly, the integrated Hippo/YAP/14-3-3η pathway mediated neuronal mitochondrial dysfunction and depressive behavior in Dep mice. Conclusion: The integrated Hippo/YAP/14-3-3η pathway in the BLA neuron is critical in mediating depressive-like behaviors in mice, suggesting a causal role for this pathway in susceptibility to chronic stress-induced depression. This pathway therefore may present a therapeutic target against mitochondrial dysfunction and synaptic impairment in MDD.
Asunto(s)
Complejo Nuclear Basolateral , Modelos Animales de Enfermedad , Vía de Señalización Hippo , Mitocondrias , Proteínas Serina-Treonina Quinasas , Transducción de Señal , Proteínas Señalizadoras YAP , Animales , Ratones , Mitocondrias/metabolismo , Proteínas Señalizadoras YAP/metabolismo , Complejo Nuclear Basolateral/metabolismo , Complejo Nuclear Basolateral/patología , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Masculino , Estrés Psicológico/complicaciones , Estrés Psicológico/metabolismo , Proteínas 14-3-3/metabolismo , Proteínas 14-3-3/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Trastorno Depresivo Mayor/metabolismo , Trastorno Depresivo Mayor/patología , Depresión/metabolismo , Ratones Endogámicos C57BL , Neuronas/metabolismo , Neuronas/patología , Ratones TransgénicosRESUMEN
During mesenchymal development, the sources of mechanical forces transduced by cells transition over time from predominantly cell-cell interactions to predominantly cell-extracellular matrix (ECM) interactions. Transduction of the associated mechanical signals is critical for development, but how these signals converge to regulate human mesenchymal stem cells (hMSCs) mechanosensing is not fully understood, in part because time-evolving mechanical signals cannot readily be presented in vitro. Here, we established a DNA-driven cell culture platform that could be programmed to present the RGD peptide from fibronectin, mimicking cell-ECM interactions, and the HAVDI peptide from N-cadherin, mimicking cell-cell interactions, through DNA hybridization and toehold-mediated strand displacement reactions. The platform could be programmed to mimic the evolving cell-ECM and cell-cell interactions during mesenchymal development. We applied this platform to reveal that RGD/integrin ligation promoted cofilin phosphorylation, while HAVDI/N-cadherin ligation inhibited cofilin phosphorylation. Cofilin phosphorylation upregulated perinuclear apical actin fibers, which deformed the nucleus and thereby induced YAP nuclear localization in hMSCs, resulting in subsequent osteogenic differentiation. Our programmable culture platform is broadly applicable to the study of dynamic, integrated mechanobiological signals in development, healing, and tissue engineering.
Asunto(s)
Células Madre Mesenquimatosas , Osteogénesis , Humanos , Integrinas/metabolismo , Cadherinas/metabolismo , Fosforilación , Adhesivos/metabolismo , Factores Despolimerizantes de la Actina/metabolismo , Células Madre Mesenquimatosas/metabolismo , Diferenciación Celular , Matriz Extracelular/metabolismo , ADN/metabolismoRESUMEN
Mesenchymal stem cells adopt differentiation pathways based upon cumulative effects of mechanosensing. A cell's mechanical microenvironment changes substantially over the course of development, beginning from the early stages in which cells are typically surrounded by other cells and continuing through later stages in which cells are typically surrounded by extracellular matrix. How cells erase the memory of some of these mechanical microenvironments while locking in memory of others is unknown. Here, we develop a material and culture system for modifying and measuring the degree to which cells retain cumulative effects of mechanosensing. Using this system, we discover that effects of the RGD adhesive motif of fibronectin (representative of extracellular matrix), known to impart what is often termed "mechanical memory" in mesenchymal stem cells via nuclear YAP localization, are erased by the HAVDI adhesive motif of the N-cadherin (representative of cell-cell contacts). These effects can be explained by a motor clutch model that relates cellular traction force, nuclear deformation, and resulting nuclear YAP re-localization. Results demonstrate that controlled storage and removal of proteins associated with mechanical memory in mesenchymal stem cells is possible through defined and programmable material systems.
Asunto(s)
Cadherinas/metabolismo , Núcleo Celular/metabolismo , Células Madre Mesenquimatosas/metabolismo , Proteínas Señalizadoras YAP/metabolismo , Secuencias de Aminoácidos , Fenómenos Biomecánicos , Cadherinas/química , Cadherinas/genética , Núcleo Celular/química , Núcleo Celular/genética , Humanos , Células Madre Mesenquimatosas/química , Transporte de ProteínasRESUMEN
Major depression is a prevalent and long-lasting psychiatric illness with severe functional impairment and high suicide rate. We have previously shown that the ventrolateral orbital cortex (VLO) plays a key role in the stress responses in mice, but the underlying mechanisms remains unclear. Here, we used proteomic method to identify differentially expressed proteins in VLO of chronic unpredictable mild stress (CUMS) mice. Of 4,953 quantified proteins, 45 proteins were differentially expressed following CUMS. The integrated pathway analyses identified 14-3-3ε and TrkB signaling as differentially downregulated in association with stress-induced depressive-like behaviors. 14-3-3ε overexpression in VLO relieved the depressive-like behaviors by rescue of Bad-mediated apoptosis. Moreover, treatment with the 14-3-3ε stabilizer FC-A precluded neuronal apoptotic signaling in VLO of depressed mice. Because 14-3-3ε provides significant protection against chronic stress, boosting 14-3-3ε expression, pharmacological stabilization of 14-3-3s (e.g. with FC-A) is identified as an exciting therapeutic target for major depression.
RESUMEN
Neurons are situated in a microenvironment composed of various mechanical cues, where stretching is thought to have a major impact on neurons, resulting in microstructural changes in neural tissue and further leading to abnormal electrophysiological function. In spite of significant experimental efforts, the underlying mechanism remains elusive, more works are needed to provide a detailed description of the process that leads to the observed phenomena. Here, we developed a mechanoelectrical coupling model of central neurons under stretching and specially considered the plastic deformation of neurons. With the model, we showed that the increasing axial strain induces a decreased membrane action potential and a more frequent neuronal firing, which agree well with experimental observations reported in the literature. The simulation results also showed a faster electrophysiological signal conduction. Our model provides a reference for the prediction and regulation of neuronal function under simplified conditions of mechanical loadings.
Asunto(s)
Fenómenos Electrofisiológicos , Fenómenos Mecánicos , Modelos Neurológicos , Neuronas/citología , Fenómenos BiomecánicosRESUMEN
Engineered tissue constructs rely on biomaterials as support structures for tissue repair and regeneration. Among these biomaterials, polyester biomaterials have been widely used for scaffold construction because of their merits such as ease in synthesis, degradable properties, and elastomeric characteristics. To mimic the aligned structures of native extracellular matrix (ECM) in tissues such as nerve, heart and tendon, various polyester materials have been fabricated into aligned fibrous scaffolds with fibers ranging from several nanometers to several micrometers in diameter by electrospinning in a simple and reproducible manner. These aligned fibrous scaffolds, especially the three-dimensional (3D) aligned nanofibrous scaffolds have emerged as a promising solution for tissue regeneration. Compared with two-dimensional (2D) scaffolds, the 3D aligned nanofibrous scaffolds provide another dimension for cell behaviors such as morphogenesis, migration and cell-cell interactions, which is important in regulating the stem cell fate and tissue regeneration. In this review, we provide an extensive overview on recent efforts for constructing 3D aligned polyester nanofibrous scaffolds by electrospinning, then the results of cell-specific functions dependent on such physical and chemical cues, and discuss their potentials in improving or restoring damaged tissues.
Asunto(s)
Nanofibras/química , Ingeniería de Tejidos/métodos , Andamios del Tejido/química , Animales , Materiales Biocompatibles/química , Humanos , Tejido Nervioso/citología , Células Madre/citologíaRESUMEN
Stem cell therapy is promising for treating traumatic injuries of the central nervous system, where a major challenge is to effectively differentiate neural stem cells into neurons with uniaxial alignment. Recently, controlling stem cell fate by modulating biophysical cues (e.g., stiffness, conductivity, and patterns) has emerged as an attractive approach. Herein, we report a new heterostructure composite scaffold to induce cell-oriented growth and enhance the neuronal differentiation of SH-SY5Y cells. The scaffold is composed of aligned electrospinning silk nanofibers coated on reduced graphene paper with high conductivity and good biocompatibility. Our experimental results demonstrate that the composite scaffold can effectively induce the oriented growth and enhance neuronal differentiation of SH-SY5Y cells. Our study develops a novel scaffold for enhancing the differentiation of SH-SY5Y cells into neurons, which holds great potential in the treatment of neurological diseases and injuries.
RESUMEN
Electric field-induced micro-/nanopatterns in thin polymer films, sometimes referred as electrohydrodynamic patterning, is a promising technique to fabricate micro-/nanostructures. Extensive attention has been attracted because of its advantages in microcontact (easy demolding) and low cost. Although considerable work has been done on this technique, including both experimental and theoretical ones, there still appears a requirement for understanding the mechanism of electrohydrodynamic patterning. Thus, we systematically studied the effect of different parameters on electrohydrodynamic patterning with a numerical phase field model. Previous researchers usually employed lubrication approximation (i.e., long-wave approximation) to simplify the numerical model. However, this approximation would lose its validity if the structure height is on the same scale or larger than the wavelength, which occurs in most cases. Thus, we abandoned the lubrication approximation and solved the full governing equations for fluid flow and electric field. In this model, the deformation of polymer film is described by the phase field model. As to the electric field, the leaky dielectric model is adopted in which both electrical permittivity and conductivity are considered. The fluid flow together with electric field is coupled together in the framework of phase field. By this model, the effect of physical parameters, such as external voltage, template structure height, and polymer conductivity, is studied in detail. After that, the governing equations are nondimesionalized to analyze the relationship between different parameters. A dimensionless parameter, electrical Reynolds number ER, is defined, for which, a large value would simplify the electric field to perfect dielectric model and a small value leads it to steady leaky model. These findings and results may enhance our understanding of electrohydrodynamic patterning and may be a meaningful guide for experiments.
RESUMEN
Existing studies on the mechanism of cell volume regulation are mainly relevant to ion channels and osmosis in extracellular fluid. Recently, accumulating evidence has shown that cellular mechanical microenvironment also influences the cell volume. Herein, we investigated the regulation of substrate stiffness on the cell volume homeostasis of MCF-7 cells and their following migration behaviors. We found that cell volume increases with increasing substrate stiffness, which could be affected by blocking the cell membrane anion permeability and dopamine receptor. In addition, the cell migration is significantly inhibited by decreasing the cell volume using tamoxifen and such inhibition effect on migration is enhanced by increasing substrate stiffness. The cell membrane anion permeability might be the linker between cellular mechanical microenvironment and cellular volume homeostasis regulation. This work revealed the regulation of substrate stiffness on cell volume homeostasis for the first time, which would provide a new perspective into the understanding of cancer metastasis and a promising anti-cancer therapy through regulation of cell volume homeostasis.
Asunto(s)
Resinas Acrílicas/química , Neoplasias de la Mama/metabolismo , Membrana Celular/metabolismo , Tamaño de la Célula , Osmorregulación , Ácido 4,4'-Diisotiocianostilbeno-2,2'-Disulfónico/farmacología , Proteínas de Transporte de Anión/antagonistas & inhibidores , Proteínas de Transporte de Anión/metabolismo , Antineoplásicos Hormonales/farmacología , Benzazepinas/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Adhesión Celular , Membrana Celular/efectos de los fármacos , Membrana Celular/patología , Permeabilidad de la Membrana Celular , Movimiento Celular , Tamaño de la Célula/efectos de los fármacos , Colágeno/metabolismo , Femenino , Humanos , Hidrogeles , Soluciones Hipotónicas/farmacología , Células MCF-7 , Osmorregulación/efectos de los fármacos , Porosidad , Receptores de Dopamina D1/antagonistas & inhibidores , Receptores de Dopamina D1/metabolismo , Tamoxifeno/farmacología , Microambiente TumoralRESUMEN
Propofol lipid emulsion (PLE) is a nanosized sedative, and it is used with a combination of salted antalgic prodrug, fentanyl citrate (FC). To illustrate the synergistic effect of mixing, we compared the sedation/analgesia resulting from simultaneous and sequential administration in surgically induced abortion (No. ChiCTR-IPC-15006153). Simultaneous group showed lower bispectral index, blood pressure, and heart rate, when cannula was inserted into the uterus. It also showed less frequency of hypertension, sinus tachycardia, movement, pain at the injection site, and additional FC. Therefore, premixing of PLE and FC enhanced the sedation and analgesia; stabilized the hemodynamics; lessened the incidence of movement and injection pain; and reduced the requirement of drugs.
Asunto(s)
Aborto Inducido , Fentanilo/administración & dosificación , Fentanilo/farmacología , Hipnóticos y Sedantes/administración & dosificación , Hipnóticos y Sedantes/farmacología , Propofol/administración & dosificación , Propofol/farmacología , Adulto , Presión Sanguínea/efectos de los fármacos , Monitores de Conciencia , Femenino , Fentanilo/efectos adversos , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Hipnóticos y Sedantes/efectos adversos , Embarazo , Propofol/efectos adversos , Factores de TiempoRESUMEN
A novel strategy of rapid transport across the blood-brain barrier (BBB) via phosphatidylethanolamine-triggered release is developed through both molecular dynamics (MD) simulation and experiments. Hydrophobic drugs, namely, propofol, iodine, and 1,1'-dioctadecyltetramethyl indotricarbocyanine iodide, were loaded with propionylated amylose helix (HLPAH) nanoclusters to form PLPAH, ILPAH, and DLPAH nanoclusters, respectively. These clusters were subjected to MD simulation, structure measurement, in vitro triggered study, in vivo DLPAH imaging, and analysis of PLPAH sedative effects on rabbits. Results indicated that HLPAH nanoclusters were initially located on the BBB, and the helix was unfolded to release the loaded hydrophobic drugs. The released drugs crossed the BBB and performed their functions in the central nervous system (CNS) through concentration gradient and hydrophobicity. This mechanism of HLPAH across the BBB featured high membrane permeability and specificity, rapid onset, short maintenance, rapid recovery, and lower dosage of drugs. Hence, this novel strategy is very meaningful for the development of CNS drug carriers and the proposed system could be used to improve the therapeutic effects of CNS diseases.
Asunto(s)
Amilosa/química , Barrera Hematoencefálica/metabolismo , Portadores de Fármacos/química , Hipnóticos y Sedantes/administración & dosificación , Nanopartículas/química , Propofol/administración & dosificación , Animales , Barrera Hematoencefálica/efectos de los fármacos , Sistemas de Liberación de Medicamentos , Interacciones Hidrofóbicas e Hidrofílicas , Hipnóticos y Sedantes/farmacocinética , Masculino , Simulación de Dinámica Molecular , Nanopartículas/ultraestructura , Propofol/farmacocinética , ConejosRESUMEN
Understanding interactions between cell-penetrating peptides and biomembrane under tension can help improve drug delivery and elucidate mechanisms underlying fundamental cellular events. As far as the effect of membrane tension on translocation, it is generally thought that tension should disorder the membrane structure and weaken its strength, thereby facilitating penetration. However, our coarse-grained molecular dynamics simulation results showed that membrane tension can restrain polyarginine translocation across the asymmetric membrane and that this effect increases with increasing membrane tension. We also analyzed the structural properties and lipid topology of the tensed membrane to explain the phenomena. Simulation results provide important molecular information on the potential translocation mechanism of peptides across the asymmetric membrane under tension as well as new insights in drug and gene delivery.
Asunto(s)
Membrana Celular/química , Péptidos de Penetración Celular/metabolismo , Péptidos/química , Péptidos/metabolismo , Membrana Celular/metabolismo , Péptidos de Penetración Celular/química , Membrana Dobles de Lípidos/química , Simulación de Dinámica Molecular , Fosfatidilserinas/química , Transporte de Proteínas , Electricidad EstáticaRESUMEN
Titanium dioxide (TiO2 ) nanomaterials (NMs) have found widespread applications owing to their attractive physical and chemical properties. As a result, the potential adverse impacts of nano-TiO2 exposure on humans have become a matter of concern. This review presents the state-of-the-art advances on the investigations of the adverse effects of NMs, including the potential exposure routes of nano-TiO2 (e.g. respiratory system, skin absorption and digestive system), the physico-chemical characterizations of nano-TiO2 (e.g. crystal structure, shape,size, zeta potential, treatment media, aggregation and agglomeration tendency, surface characteristics and coatings), risk evaluation of nanotoxicity (e.g. cytotoxicity, ecotoxicity, phototoxicity, and phytotoxicity) and potential mechanisms of adverse effects (e.g. generation of reactive oxygen species, oxidative stress and organelle dysfunction). The review aims to facilitate scientific assessments of health risks to nano-TiO2 , which would guide the safe applications of NMs in our daily life.
Asunto(s)
Nanopartículas del Metal/toxicidad , Titanio/toxicidad , Animales , Exposición a Riesgos Ambientales/efectos adversos , Humanos , Estrés Oxidativo , Titanio/farmacocinéticaRESUMEN
Though starch has been a common material used for drug delivery, it has not been used as an encapsulation material for hemoglobin-based oxygen carriers. In this study, cationic amylose (CA) was synthesized by an etherification reaction. The interaction behaviors between CA and hemoglobin (Hb) were measured by zeta potential, size, and UV-Vis absorption spectra at different pH values. Cationic starch encapsulated Hb by electrostatic adhesion, reverse micelles, and cross-linking, and showed a core shell structure with a size of around 100 nm, when measured immediately after dispersing in PBS solution. However, we found that it was prone to swell, aggregate, and leak Hb with a longer duration of dispersal in PBS.
Asunto(s)
Amilosa/química , Sustitutos Sanguíneos/química , Hemoglobinas/química , Proteínas Inmovilizadas/química , Animales , BovinosRESUMEN
The association between the rs498872 single nucleotide polymorphism (SNP) and glioma risk has been studied, but these studies have yielded conflicting results. In order to explore this association, we performed a meta-analysis. A comprehensive literature search was performed using PubMed and EMBASE database, with the last search up to August 23, 2013. Six articles including 10 case-control studies in English with 18 002 controls and 8434 cases were eligible for the meta-analysis. Subgroup analyses were conducted by source of controls and ethnicity. The combined results showed that rs498872 polymorphism was significantly associated with glioma risks (TTâ vsâ CC: OR = 1.337, 95% CI = 1.222-1.462; TCâ vsâ CC: OR = 1.173, 95% CI = 1.081-1.272; dominant model: OR = 1.199, 95% CI = 1.101-1.306; recessive model: OR = 1.237, 95% CI = 1.135-1.347; additive model: OR = 1.156, 95% CI = 1.085-1.232). Moreover, there was increased cancer risk in all genetic models after stratification of the SNP data by the source of controls and ethnicity, and no evidence of publication bias was produced. Our meta-analysis suggested that rs498872 polymorphism was associated with increased risk of glioma. However, additional studies exploring the combined effects of rs498872 polymorphisms in Asian population should be investigated.
Asunto(s)
Pueblo Asiatico/genética , Predisposición Genética a la Enfermedad , Glioma/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Proteínas del Tejido Nervioso/genética , Polimorfismo de Nucleótido Simple/genética , Estudios de Casos y Controles , Humanos , PronósticoRESUMEN
A novel method for fabricating a three-layer SU-8 mould with inverted T-shaped cavities is presented. The first two SU-8 layers were spin coated and exposed separately, and simultaneously developed to fabricate the bottom and the horizontal part of the inverted T-shaped cavity. Then, a positive photoresist was filled into the cavity, and a wet lapping process was performed to remove the excess photoresist and make a temporary substrate. The third SU-8 layer was spin coated on the temporary substrate to make the vertical part of the inverted T-shaped cavity. The sacrificial photoresist layer can prevent the first two SU-8 layers from being secondly exposed, and make a temporary substrate for the third SU-8 layer at the same time. Moreover, the photoresist can be easily removed with the development of the third SU-8 layer. A polydimethylsiloxane (PDMS) microchip with arrays of T-shaped cantilevers for studying the mechanics of cells was fabricated by using the SU-8 mould.
Asunto(s)
Dimetilpolisiloxanos/química , Nylons/química , Análisis de Matrices Tisulares/instrumentación , Línea Celular , HumanosRESUMEN
Extensive studies have shown that titanium dioxide (TiO2 ) nanomaterials (NMs) can cause toxicity in vitro and in vivo under normal conditions. However, an adverse effect induced by nano-TiO2 in many diseased conditions, typically characterized by oxidative stress (OS), remains unknown. We investigated the toxicity of nano-TiO2 in rat liver cells (BRL-3A) and Sprague-Dawley (SD) rat livers under OS conditions, which were generated using hydrogen peroxide (H2 O2 ) in vitro and alloxan in vivo, respectively. In vitro results showed that cell death ratios after nano-TiO2 exposure were significantly enhanced (up to 2.62-fold) in BRL-3A cells under OS conditions, compared with normal controls. Significant interactions between OS conditions and nano-TiO2 resulted in the rapid G0/G1 to S phase transition and G2/M arrest, which were opposite to G0/G1 phase arrest in cells after NMs exposure only. In vivo results showed that obvious pathological changes in rat livers and the increased activities of four enzymes (i.e. aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase and alkaline phosphatase) owing to liver damage after nano-TiO2 exposure under OS conditions, compared with their healthy controls. In addition, compared with increased hepatotoxicity after nano-TiO2 exposure, micro-TiO2 showed no adverse effects to cells and rat livers under OS conditions. Our results suggested that OS conditions synergistically increase nano-TiO2 induced toxicity in vitro and in vivo, indicating that the evaluation of nanotoxicity under OS conditions is essentially needed prior to various applications of NMs in foods, cosmetics and potential treatment of diseases.
Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Hígado/efectos de los fármacos , Nanopartículas/química , Estrés Oxidativo/efectos de los fármacos , Titanio/toxicidad , Aloxano/administración & dosificación , Aloxano/toxicidad , Animales , Técnicas de Cultivo de Célula , Línea Celular , Supervivencia Celular/efectos de los fármacos , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Peróxido de Hidrógeno/administración & dosificación , Peróxido de Hidrógeno/toxicidad , Hígado/citología , Masculino , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Tamaño de la Partícula , Ratas , Ratas Sprague-Dawley , Propiedades de Superficie , Titanio/administración & dosificaciónRESUMEN
To develop standard in vitro chondrosarcoma models, we synthesized three hydrogels (i. e., PDMAAm, PNaAMPS and PMETAC) and investigated the influence of Young's modulus, swelling ratio and electric charges on the behavior of chondrosarcoma cells seeded on the hydrogels, including morphology, adhesion and aggregation. Results showed that the morphology of chondrosarcoma cells at 6h was dependent on the charges of hydrogels; cells present spindle-shaped and round-shaped morphology on negative charged and neutral hydrogel, respectively, while no cells spreaded on positive charged hydrogel. Chondrosarcoma cells formed aggregates on neutral PDMAAm after further culture. The hydrogels can be synthesized easily and has the characteristics of ease at use with defined components, which holds great potential for developing standard chondrosarcoma models in vitro.
Asunto(s)
Neoplasias Óseas/patología , Proliferación Celular/efectos de los fármacos , Condrosarcoma/patología , Hidrogeles/farmacología , Línea Celular Tumoral , Humanos , Hidrogeles/química , Metacrilatos/farmacología , Nylons/farmacología , Electricidad EstáticaRESUMEN
Heart diseases, which are related to oxidative stress (OS), negatively affect millions of people from kids to the elderly. Titanium dioxide (TiO2) has widespread applications in our daily life, especially nanoscale TiO2. Compared to the high risk of particulate matter (≤2.5µm) in air to heart disease patients, related research of TiO2 on diseased body is still unknown, which suggest us to explore the potential effects of nanoscale and microscale TiO2 to heart under OS conditions. Here, we used alloxan to induce OS conditions in rat, and investigated the response of heart tissue to TiO2 in healthy and alloxan treated rats. Compared with NMs treatment only, the synergistic interaction between OS conditions and nano-TiO2 significantly reduced the heart-related function indexes, inducing pathological changes of myocardium with significantly increased levels of cardiac troponin I and creatine kinase-MB. In contrast with the void response of micro-TiO2 to heart functions in alloxan treated rats, aggravation of OS conditions might play an important role in cardiac injury after alloxan and nano-TiO2 dual exposure. Our results demonstrated that OS conditions enhanced the adverse effects of nano-TiO2 to heart, suggesting that the use of NMs in stressed conditions (e.g., drug delivery) needs to be carefully monitored.
Asunto(s)
Lesiones Cardíacas/inducido químicamente , Corazón/efectos de los fármacos , Nanopartículas del Metal , Estrés Oxidativo , Titanio/toxicidad , Animales , Biomarcadores/metabolismo , Microscopía Electrónica de Transmisión , RatasRESUMEN
Osteosarcoma and chondrosarcoma are malignant bone tumors, and they significantly affect the life quality of patients including children and adults. The main treatment method is surgical amputation of the malignant lesion, despite that recurrence often occurs. Recently, it has been observed that TiO2 NPs killed HeLa cells effectively via photocatalysis in vitro, which indicates titanium dioxide (TiO2) nanoparticles (NPs) might be used to reduce the recurrence of osteosarcoma and chondrosarcoma by inducing cytotoxicity to bone tumor cells. In this study, we investigated the potential effects of TiO2 NPs in two cancer cell lines in vitro: U-2 OS (osteosarcoma) and SW 1353 (chondrosarcoma). We assessed cell viability, the levels of reactive oxygen species (ROS) and glutathione (GSH) after exposure to TiO2 NPs at different concentrations (0.1-100 microg/ml) for varying exposure periods (12-48 hours). Compared to the NP-free control, TiO2 NPs induced cell death in a dosage-dependent and time-dependent manner. The median inhibitory concentration (IC50) of TiO2 NPs at 24 hours was 211.3 +/- 15.2 microg/ml and 5408.8 +/- 45.9 microg/ml for SW 1353 and U-2 OS cell lines, respectively. TiO2 NPs concentrations above 1 microg/ml were more efficient to reduce the cell viability of SW 1353 than U-2 OS of NPs at all exposure times. The increased ROS and reduced GSH levels indicated that TiO2 NPs killed cancer cells through oxidative stress. These results suggested that the TiO2 NPs can be potentially used to minimize/prevent the recurrence of osteosarcoma and chondrosarcoma.