RESUMEN
The rheological behavior of a xanthan gum (XG) suspension with Fe-based nanoparticles (Fe-NPs), e.g., nanoparticles of zerovalent iron (nZVI) and Fe3O4 (nFe3O4), needs to be understood for better injection of Fe-NPs for groundwater remediation. In this study, the rheological behavior of a XG suspension of nZVI and nFe3O4 was investigated at different particle concentrations. The Ostwald, Sisko, Williamson, and Cross models were employed to fit the rheological behavior of the suspensions for quantitatively describing the effect of the particles. The results showed that the viscosity of the XG solutions decreased with increasing particle concentrations and they maintained shear thinning properties. The Cross model was the best among the four models to describe the shear thinning behavior of the XG solution in the presence of the particles. According to Cross model analysis, increasing particle concentrations increased the degree of shear thinning behavior, as indicated by the increase of the power index (n). Also, the relaxation time (λ) decreased with increasing particle concentrations, which indicated an increase of molecule movement of XG. Compared with nFe3O4, nZVI resulted in a larger decrease in viscosity and a larger increase in the degree of shear thinning behavior. There was a good linear relation between n and λ for the suspensions (R2 = 0.85), which indicated that increasing molecule movement of XG was an important mechanism for the particles to intensify the shear thinning rheological behavior of the XG suspension of Fe-NPs. This study added insight into the knowledge of the rheological properties of the XG suspension of Fe-NPs, which is of importance for the field injection effort.
RESUMEN
The present study investigated the stability and efficacy of a biosurfactant produced by Klebsiella sp. KOD36 under extreme conditions and its potential for enhancing the solubilization and degradation of phenanthrene in various environmental matrices. Klebsiella sp. KOD36 produced a mono-rhamnolipids biosurfactant with a low critical micelle concentration (CMC) value. The biosurfactant was stable under extreme conditions (60 °C, pH 10 and 10% salinity) and could lower surface tension by 30% and maintained an emulsification index of > 40%. The emulsion index was also higher (17-43%) in the presence of petroleum hydrocarbons compared to synthetic surfactant Triton X-100. Investigation on phenanthrene degradation in three different environmental matrices (aqueous, soil-slurry and soil) confirmed that the biosurfactant enhanced the solubilization and biodegradation of phenanthrene in all matrices. The high functional stability and performance of the biosurfactant under extreme conditions on phenanthrene degradation show the great potential of the biosurfactant for remediation applications under harsh environmental conditions.
Asunto(s)
Biodegradación Ambiental , Klebsiella/fisiología , Fenantrenos/metabolismo , Tensoactivos/metabolismo , Medios de Cultivo , Emulsiones , Glucolípidos , Hidrocarburos/metabolismo , Klebsiella/metabolismo , Micelas , Petróleo/metabolismo , Suelo , Contaminantes del Suelo/metabolismoRESUMEN
Chemotherapy resistance is a major challenge to the effective treatment of cancer. Thus, a systematic pipeline for the efficient identification of effective combination treatments could bring huge biomedical benefit. In order to facilitate rational design of combination therapies, we developed a comprehensive computational model that incorporates the available biological knowledge and relevant experimental data on the life-and-death response of individual cancer cells to cisplatin or cisplatin combined with the TNF-related apoptosis-inducing ligand (TRAIL). The model's predictions, that a combination treatment of cisplatin and TRAIL would enhance cancer cell death and exhibit a "two-wave killing" temporal pattern, was validated by measuring the dynamics of p53 accumulation, cell fate, and cell death in single cells. The validated model was then subjected to a systematic analysis with an ensemble of diverse machine learning methods. Though each method is characterized by a different algorithm, they collectively identified several molecular players that can sensitize tumor cells to cisplatin-induced apoptosis (sensitizers). The identified sensitizers are consistent with previous experimental observations. Overall, we have illustrated that machine learning analysis of an experimentally validated mechanistic model can convert our available knowledge into the identity of biologically meaningful sensitizers. This knowledge can then be leveraged to design treatment strategies that could improve the efficacy of chemotherapy.
Asunto(s)
Biología Computacional/métodos , Quimioterapia Combinada/métodos , Quimioterapia Asistida por Computador/métodos , Aprendizaje Automático , Modelos Biológicos , Algoritmos , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Cisplatino/farmacología , Cisplatino/uso terapéutico , Humanos , Neoplasias/tratamiento farmacológico , Transducción de Señal/efectos de los fármacos , Ligando Inductor de Apoptosis Relacionado con TNF/farmacología , Ligando Inductor de Apoptosis Relacionado con TNF/uso terapéuticoRESUMEN
Precise Ca cycling through the sarcoplasmic reticulum (SR), a Ca storage organelle, is critical for proper cardiac muscle function. This cycling initially involves SR release of Ca via the ryanodine receptor, which is regulated by its interacting proteins junctin and triadin. The sarco/endoplasmic reticulum Ca ATPase (SERCA) pump then refills SR Ca stores. Histidine-rich Ca-binding protein (HRC) resides in the lumen of the SR, where it contributes to the regulation of Ca cycling by protecting stressed or failing hearts. The common Ser96Ala human genetic variant of HRC strongly correlates with life-threatening ventricular arrhythmias in patients with idiopathic dilated cardiomyopathy. However, the underlying molecular pathways of this disease remain undefined. Here, we demonstrate that family with sequence similarity 20C (Fam20C), a recently characterized protein kinase in the secretory pathway, phosphorylates HRC on Ser96. HRC Ser96 phosphorylation was confirmed in cells and human hearts. Furthermore, a Ser96Asp HRC variant, which mimics constitutive phosphorylation of Ser96, diminished delayed aftercontractions in HRC null cardiac myocytes. This HRC phosphomimetic variant was also able to rescue the aftercontractions elicited by the Ser96Ala variant, demonstrating that phosphorylation of Ser96 is critical for the cardioprotective function of HRC. Phosphorylation of HRC on Ser96 regulated the interactions of HRC with both triadin and SERCA2a, suggesting a unique mechanism for regulation of SR Ca homeostasis. This demonstration of the role of Fam20C-dependent phosphorylation in heart disease will open new avenues for potential therapeutic approaches against arrhythmias.
Asunto(s)
Arritmias Cardíacas/metabolismo , Proteínas de Unión al Calcio/metabolismo , Quinasa de la Caseína I/metabolismo , Proteínas de la Matriz Extracelular/metabolismo , Secuencia de Aminoácidos , Animales , Arritmias Cardíacas/genética , Arritmias Cardíacas/prevención & control , Proteínas de Unión al Calcio/genética , Quinasa de la Caseína I/genética , Línea Celular Tumoral , Células Cultivadas , Proteínas de la Matriz Extracelular/genética , Humanos , Ratones Noqueados , Ratones Transgénicos , Mutación , Miocitos Cardíacos/metabolismo , Fosforilación , Ratas , Retículo Sarcoplasmático/metabolismo , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/genética , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/metabolismo , Serina/genética , Serina/metabolismoRESUMEN
Ischemia/reperfusion injury is associated with contractile dysfunction and increased cardiomyocyte death. Overexpression of the hematopoietic lineage substrate-1-associated protein X-1 (HAX-1) has been shown to protect from cellular injury but the function of endogenous HAX-1 remains obscure due to early lethality of the knockout mouse. Herein we generated a cardiac-specific and inducible HAX-1 deficient model, which uncovered an unexpected role of HAX-1 in regulation of sarco/endoplasmic reticulum Ca-ATPase (SERCA2a) in ischemia/reperfusion injury. Although ablation of HAX-1 in the adult heart elicited no morphological alterations under non-stress conditions, it diminished contractile recovery and increased infarct size upon ischemia/reperfusion injury. These detrimental effects were associated with increased loss of SERCA2a. Enhanced SERCA2a degradation was not due to alterations in calpain and calpastatin levels or calpain activity. Conversely, HAX-1 overexpression improved contractile recovery and maintained SERCA2a levels. The regulatory effects of HAX-1 on SERCA2a degradation were observed at multiple levels, including intact hearts, isolated cardiomyocytes and sarcoplasmic reticulum microsomes. Mechanistically, HAX-1 ablation elicited increased production of reactive oxygen species at the sarco/endoplasic reticulum compartment, resulting in SERCA2a oxidation and a predisposition to its proteolysis. This effect may be mediated by NAPDH oxidase 4 (NOX4), a novel binding partner of HAX-1. Accordingly, NOX inhibition with apocynin abrogated the effects of HAX-1 ablation in hearts subjected to ischemia/reperfusion injury. Taken together, our findings reveal a role of HAX-1 in the regulation of oxidative stress and SERCA2a degradation, implicating its importance in calcium homeostasis and cell survival pathways.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas/metabolismo , Proteolisis , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Anciano , Animales , Calpaína/metabolismo , Retículo Endoplásmico/metabolismo , Femenino , Eliminación de Gen , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/patología , Insuficiencia Cardíaca/fisiopatología , Humanos , Péptidos y Proteínas de Señalización Intracelular , Masculino , Ratones Endogámicos C57BL , Persona de Mediana Edad , Contracción Miocárdica , Daño por Reperfusión Miocárdica/patología , Daño por Reperfusión Miocárdica/fisiopatología , Miocardio/patología , Miocitos Cardíacos/metabolismo , NADPH Oxidasa 4/metabolismo , Oxidación-Reducción , Estrés Oxidativo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Recuperación de la Función , Retículo Sarcoplasmático/metabolismoRESUMEN
Heat shock protein 20 (Hsp20) has been shown to be a critical regulator of cardiomyocyte survival upon cardiac stress. In this study, we investigated the functional significance of a novel human Hsp20 mutation (S10F) in peripartum cardiomyopathy. Previous findings showed that cardiac-specific overexpression of this mutant were associated with reduced autophagy, left ventricular dysfunction and early death in male mice. However, this study indicates that females have normal function with no alterations in autophagy but died within a week after 1-4 pregnancies. Further examination of mutant females revealed left ventricular chamber dilation and hypertrophic remodelling. Echocardiography demonstrated increases in left ventricular end-systolic volume and left ventricular end-diastolic volume, while ejection fraction and fractional shortening were depressed following pregnancy. Subsequent studies revealed that cardiomyocyte apoptosis was elevated in mutant female hearts after the third delivery, associated with decreases in the levels of Bcl-2/Bax and Akt phosphorylation. These results indicate that the human S10F mutant is associated with dysregulation of cell survival signalling, accelerated heart failure and early death post-partum.
RESUMEN
The objective of this review is to provide a comprehensive overview of the advances in the applications of rhamnolipids biosurfactants in soil and ground water remediation for removal of petroleum hydrocarbon and heavy metal contaminants. The properties of rhamnolipids associated with the contaminant removal, that is, solubilization, emulsification, dispersion, foaming, wetting, complexation, and the ability to modify bacterial cell surface properties, were reviewed in the first place. Then current remediation technologies with integration of rhamnolipid were summarized, and the effects and mechanisms for rhamnolipid to facilitate contaminant removal for these technologies were discussed. Finally rhamnolipid-based methods for remediation of the sites co-contaminated by petroleum hydrocarbons and heavy metals were presented and discussed. The review is expected to enhance our understanding on environmental aspects of rhamnolipid and provide some important information to guide the extending use of this fascinating chemical in remediation applications.
Asunto(s)
Restauración y Remediación Ambiental/métodos , Metales Pesados/aislamiento & purificación , Ramnosa/química , Contaminantes del Suelo/aislamiento & purificación , Tensoactivos/química , Contaminantes Químicos del Agua/aislamiento & purificación , Conformación de Carbohidratos , Agua Subterránea/química , Hidrocarburos/química , Hidrocarburos/aislamiento & purificación , Metales Pesados/química , Ramnosa/análogos & derivados , Suelo/química , Contaminantes del Suelo/química , Contaminantes Químicos del Agua/químicaRESUMEN
The major underpinning of massive cell death associated with myocardial infarction involves opening of the mitochondrial permeability transition pore (mPTP), resulting in disruption of mitochondria membrane integrity and programmed necrosis. Studies in human lymphocytes suggested that the hematopoietic-substrate-1 associated protein X-1 (HAX-1) is linked to regulation of mitochondrial membrane function, but its role in controlling mPTP activity remains obscure. Herein we used models with altered HAX-1 expression levels in the heart and uncovered an unexpected role of HAX-1 in regulation of mPTP and cardiomyocyte survival. Cardiac-specific HAX-1 overexpression was associated with resistance against loss of mitochondrial membrane potential, induced by oxidative stress, whereas HAX-1 heterozygous deficiency exacerbated vulnerability. The protective effects of HAX-1 were attributed to specific down-regulation of cyclophilin-D levels leading to reduction in mPTP activation. Accordingly, cyclophilin-D and mPTP were increased in heterozygous hearts, but genetic ablation of cyclophilin-D in these hearts significantly alleviated their susceptibility to ischemia/reperfusion injury. Mechanistically, alterations in cyclophilin-D levels by HAX-1 were contributed by the ubiquitin-proteosomal degradation pathway. HAX-1 overexpression enhanced cyclophilin-D ubiquitination, whereas proteosomal inhibition restored cyclophilin-D levels. The regulatory effects of HAX-1 were mediated through interference of cyclophilin-D binding to heat shock protein-90 (Hsp90) in mitochondria, rendering it susceptible to degradation. Accordingly, enhanced Hsp90 expression in HAX-1 overexpressing cardiomyocytes increased cyclophilin-D levels, as well as mPTP activation upon oxidative stress. Taken together, our findings reveal the role of HAX-1 in regulating cyclophilin-D levels via an Hsp90-dependent mechanism, resulting in protection against activation of mPTP and subsequent cell death responses.
Asunto(s)
Ciclofilinas/metabolismo , Proteínas de Transporte de Membrana Mitocondrial/metabolismo , Miocardio/metabolismo , Proteínas/metabolismo , Adenoviridae/metabolismo , Animales , Calcio/metabolismo , Muerte Celular , Peptidil-Prolil Isomerasa F , Proteínas HSP90 de Choque Térmico/metabolismo , Heterocigoto , Humanos , Técnicas In Vitro , Péptidos y Proteínas de Señalización Intracelular , Masculino , Ratones , Membranas Mitocondriales/metabolismo , Poro de Transición de la Permeabilidad Mitocondrial , Miocitos Cardíacos/metabolismo , Estrés Oxidativo , Unión Proteica , Transporte de Proteínas , Proteolisis , Ratas Sprague-Dawley , UbiquitinaciónRESUMEN
The effect of low-concentrations of monorhamnolipid biosurfactant on transport of Pseudomonas aeruginosa ATCC 9027 in natural porous media (silica sand and a sandy soil) was studied with miscible-displacement experiments using artificial groundwater as the background solution. Transport of two types of cells was investigated, glucose- and hexadecane-grown cells with lower and higher cell surface hydrophobicity (CSH), respectively. The effect of hexadecane presence as a residual non-aqueous phase liquid (NAPLs) on transport was also examined. A clean-bed colloid deposition model was used to calculate deposition rate coefficients (k) for quantitative assessment. Significant cell retention was observed in the sand (81% and 82% for glucose- and hexadecane-grown cells, respectively). Addition of a low-concentration rhamnolipid solution enhanced cell transport, with 40 mg/L of rhamnolipid reducing retention to 50% and 60% for glucose- and hexadecane-grown cells, respectively. The k values for both glucose- and hexadecane-grown cells correlate linearly with rhamnolipid-dependent CSH represented as bacterial-adhesion-to-hydrocarbon rate of cells. Retention of cells by the soil was nearly complete (>99%). Addition of 40 mg/L rhamnolipid solution reduced retention to 95%. The presence of NAPLs in the sand increased the retention of hexadecane-grown cells with higher CSH. Transport of cells in the presence of the NAPL was enhanced by rhamnolipid at all concentrations tested, and the relative enhancement was greater than in was in the absence of NAPL. This study shows the importance of hydrophobic interaction on bacterial transport in natural porous media and the potential of using low-concentration rhamnolipid for facilitating the transport in subsurface for bioaugmentation efforts.
RESUMEN
A hallmark of human and experimental heart failure is deficient sarcoplasmic reticulum (SR) Ca-uptake reflecting impaired contractile function. This is at least partially attributed to dephosphorylation of phospholamban by increased protein phosphatase 1 (PP1) activity. Indeed inhibition of PP1 by transgenic overexpression or gene-transfer of constitutively active inhibitor-1 improved Ca-cycling, preserved function and decreased fibrosis in small and large animal models of heart failure, suggesting that inhibitor-1 may represent a potential therapeutic target. We recently identified a novel human polymorphism (G109E) in the inhibitor-1 gene with a frequency of 7% in either normal or heart failure patients. Transgenic mice, harboring cardiac-specific expression of G109E inhibitor-1, exhibited decreases in contractility, Ca-kinetics and SR Ca-load. These depressive effects were relieved by isoproterenol stimulation. Furthermore, stress conditions (2Hz +/- Iso) induced increases in Ca-sparks, Ca-waves (60% of G109E versus 20% in wild types) and after-contractions (76% of G109E versus 23% of wild types) in mutant cardiomyocytes. Similar findings were obtained by acute expression of the G109E variant in adult cardiomyocytes in the absence or presence of endogenous inhibitor-1. The underlying mechanisms included reduced binding of mutant inhibitor-1 to PP1, increased PP1 activity, and dephosphorylation of phospholamban at Ser16 and Thr17. However, phosphorylation of the ryanodine receptor at Ser2808 was not altered while phosphorylation at Ser2814 was increased, consistent with increased activation of Ca/calmodulin-dependent protein kinase II (CaMKII), promoting aberrant SR Ca-release. Parallel in vivo studies revealed that mutant mice developed ventricular ectopy and complex ventricular arrhythmias (including bigeminy, trigeminy and ventricular tachycardia), when challenged with isoproterenol. Inhibition of CaMKII activity by KN-93 prevented the increased propensity to arrhythmias. These findings suggest that the human G109E inhibitor-1 variant impairs SR Ca-cycling and promotes arrhythmogenesis under stress conditions, which may present an additional insult in the compromised function of heart failure carriers.
Asunto(s)
Arritmias Cardíacas/genética , Arritmias Cardíacas/fisiopatología , Polimorfismo de Nucleótido Simple/genética , Proteínas/genética , Animales , Calcio/metabolismo , Señalización del Calcio/genética , Proteínas de Unión al Calcio/metabolismo , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/metabolismo , Catecolaminas/farmacología , Diástole/efectos de los fármacos , Corazón/efectos de los fármacos , Corazón/fisiopatología , Humanos , Isoproterenol/farmacología , Cinética , Ratones Transgénicos , Contracción Miocárdica/efectos de los fármacos , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Fosforilación/efectos de los fármacos , Proteínas/metabolismo , Ratas , Retículo Sarcoplasmático/efectos de los fármacos , Retículo Sarcoplasmático/metabolismo , Intercambiador de Sodio-Calcio/metabolismoRESUMEN
The chemokine (C-X-C motif) receptor 4 (CXCR4) is expressed on native cardiomyocytes and can modulate isolated cardiomyocyte contractility. This study examines the role of CXCR4 in cardiomyocyte response to ischaemia-reperfusion (I/R) injury. Isolated adult rat ventricular cardiomyocytes were subjected to hypoxia/reoxygenation (H/R) to simulate I/R injury. In response to H/R injury, the decrease in CXCR4 expression was associated with dysfunctional energy metabolism indicated by an increased adenosine diphosphate/adenosine triphosphate (ADP/ATP) ratio. CXCR4-overexpressing cardiomyocytes were used to determine whether such overexpression (OE) can prevent bio-energetic disruption-associated cell death. CXCR4 OE was performed with adenoviral infection with CXCR4 encoding-gene or non-translated nucleotide sequence (Control). The increased CXCR4 expression was observed in cardiomyocytes post CXCR4-adenovirus transduction and this OE significantly reduced the cardiomyocyte contractility under basal conditions. Although the same extent of H/R-provoked cytosolic calcium overload was measured, the hydrogen peroxide-induced decay of mitochondrial membrane potential was suppressed in CXCR4 OE group compared with control group, and the mitochondrial swelling was significantly attenuated in CXCR4 group, implicating that CXCR4 OE prevents permeability transition pore opening exposure to overload calcium. Interestingly, this CXCR4-induced mitochondrial protective effect is associated with the enhanced signal transducer and activator of transcription 3 (expression in mitochondria. Consequently, in the presence of H/R, mitochondrial dysfunction was mitigated and cardiomyocyte death was decreased to 65% in the CXCR4 OE group as compared with the control group. I/R injury leads to the reduction in CXCR4 in cardiomyocytes associated with the dysfunctional energy metabolism, and CXCR4 OE can alleviate mitochondrial dysfunction to improve cardiomyocyte survival.
Asunto(s)
Mitocondrias Cardíacas/metabolismo , Daño por Reperfusión Miocárdica/metabolismo , Miocitos Cardíacos/metabolismo , Receptores CXCR4/metabolismo , Adenoviridae/metabolismo , Animales , Calcio/farmacología , Cardiotónicos/farmacología , Muerte Celular/efectos de los fármacos , Hipoxia de la Célula/efectos de los fármacos , Citosol/efectos de los fármacos , Citosol/metabolismo , Mitocondrias Cardíacas/efectos de los fármacos , Mitocondrias Cardíacas/patología , Daño por Reperfusión Miocárdica/patología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Estrés Oxidativo/efectos de los fármacos , Ratas Sprague-Dawley , Factor de Transcripción STAT3/metabolismoRESUMEN
Exosomes, nano-vesicles naturally released from living cells, have been well recognized to play critical roles in mediating cell-to-cell communication. Given that diabetic hearts exhibit insufficient angiogenesis, it is significant to test whether diabetic cardiomyocyte-derived exosomes possess any capacity in regulating angiogenesis. In this study, we first observed that both proliferation and migration of mouse cardiac endothelial cells (MCECs) were inhibited when co-cultured with cardiomyocytes isolated from adult Goto-Kakizaki (GK) rats, a commonly used animal model of type 2 diabetes. However, GK-myocyte-mediated anti-angiogenic effects were negated upon addition of GW4869, an inhibitor of exosome formation/release, into the co-cultures. Next, exosomes were purified from the myocyte culture supernatants by differential centrifugation. While exosomes derived from GK myocytes (GK-exosomes) displayed similar size and molecular markers (CD63 and CD81) to those originated from the control Wistar rat myocytes (WT-exosomes), their regulatory role in angiogenesis is opposite. We observed that the MCEC proliferation, migration and tube-like formation were inhibited by GK-exosomes, but were promoted by WT-exosomes. Mechanistically, we found that GK-exosomes encapsulated higher levels of miR-320 and lower levels of miR-126 compared to WT-exosomes. Furthermore, GK-exosomes were effectively taken up by MCECs and delivered miR-320. In addition, transportation of miR-320 from myocytes to MCECs could be blocked by GW4869. Importantly, the exosomal miR-320 functionally down-regulated its target genes (IGF-1, Hsp20 and Ets2) in recipient MCECs, and overexpression of miR-320 inhibited MCEC migration and tube formation. GK exosome-mediated inhibitory effects on angiogenesis were removed by knockdown of miR-320. Together, these data indicate that cardiomyocytes exert an anti-angiogenic function in type 2 diabetic rats through exosomal transfer of miR-320 into endothelial cells. Thus, our study provides a novel mechanism underlying diabetes mellitus-induced myocardial vascular deficiency which may be caused by secretion of anti-angiogenic exosomes from cardiomyocyes.
Asunto(s)
Diabetes Mellitus Experimental/genética , Células Endoteliales/metabolismo , Exosomas/metabolismo , MicroARNs/genética , Miocitos Cardíacos/metabolismo , Compuestos de Anilina/farmacología , Animales , Compuestos de Bencilideno/farmacología , Transporte Biológico , Biomarcadores/metabolismo , Movimiento Celular , Proliferación Celular , Técnicas de Cocultivo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patología , Células Endoteliales/efectos de los fármacos , Células Endoteliales/patología , Exosomas/efectos de los fármacos , Exosomas/patología , Regulación de la Expresión Génica , Proteínas del Choque Térmico HSP20/genética , Proteínas del Choque Térmico HSP20/metabolismo , Humanos , Factor I del Crecimiento Similar a la Insulina/genética , Factor I del Crecimiento Similar a la Insulina/metabolismo , MicroARNs/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Neovascularización Fisiológica , Proteína Proto-Oncogénica c-ets-2/genética , Proteína Proto-Oncogénica c-ets-2/metabolismo , Ratas , Ratas Wistar , Transducción de SeñalRESUMEN
While the cotransport of carbon nanoparticles (CNPs) and clay colloids in porous media has been widely studied, the influence of the cation exchange capacity (CEC) of clay colloids on the transport process remains unclear. In this study, batch adsorption and column transport experiments were conducted to investigate the fate and transport of CNPs and clay colloids in quartz sand, with respect to the effect of monovalent-cation exchange capacity (mono-CEC), divalent-cation exchange capacity (di-CEC) and total CEC of clays. Fullerene nanoparticles (nC60) and six types of montmorillonite (ML) with different CEC were selected as modeled CNPs and clay colloids, respectively. Transport behavior of nC60 and ML was characterized using breakthrough curves (BTCs) and fitted with two-kinetic-sites colloid transport model. Results of the adsorption experiments showed a good linear correlation between the deposition of nC60 on the sand surface and the di-CEC of ML. Transport of ML and nC60 was inhibited by each other. The calculated mass recovery of nC60, as well as the fitted maximum deposition capacity and attachment rate coefficients of nC60 exhibited a strong linear relationship with the di-CEC of ML. These results indicate that divalent cations in ML interlayers play a significant role in aggregation between nC60 and ML and their cotransport. Through measurements of the particle size and zeta potentials of sole nC60 and mixtures of ML and nC60, FTIR and XPS analysis of nC60 under different conditions, and a release experiment of nC60 in a sand column, it demonstrated cation bridging (Ca2+-π) between nC60 and ML mediated by the divalent cations in ML interlayers. The study highlighted the potential of using di-CEC of clays as an indicator to predict the mobility of nC60 in clay-containing porous media and added insights to the transport behavior of CNPs in porous media.
RESUMEN
Enhanced kinetic stability of Fe-NPs in groundwater is a focus in application of Fe-NPs for groundwater remediation. The effect of surfactants (Triton X-100 and SDBS) and polymers (XG, SA, CCS, PSS and PVP) on the kinetic stability of Fe-NPs were studied with sedimentation experiments. Polymers improved stability of nFe3O4 and XG had the best effect, while surfactants had minimal effect. There was a critical concentration (CSC) for XG to stabilize nFe3O4, which was 2.0 g/L. At such a concentration nFe3O4, nFe2O3, and nCuO did not settled in 10 h, while the settlement occurred below the concentration and increased with decreasing XG concentration. At CSC XG could stabilize 20 g/L of nFe3O4 for >30 days and 8.0 g/L of nZVI for 13 days. Rheology studies indicated that the enhanced stability was due to the entanglement of XG molecules in the concentration range of 0.5-2.8 g/L and the formation of a uniform entangled network at CSC concentration was responsible for non-sedimentation of Fe-NPs. At hyper-CSC concentrations under the regime of concentrated network (>2.8 g/L), the stability of nFe3O4 and nFe2O3 decreased due to depletion interaction. The rules for XG to stabilize particles and information about the critical concentration will improve XG application in groundwater remediation using Fe-NPs.
Asunto(s)
Hierro , Polisacáridos Bacterianos , Reología , Polisacáridos Bacterianos/química , Cinética , Hierro/química , Nanopartículas del Metal/química , Tensoactivos/químicaRESUMEN
In this study, column experiments were conducted to explore on the method of emplacement of magnetite nanoparticles (MNPs) for in situ activation of persulfate (PS) in sand porous media to degrade 1,2-dichloroethane (DCA), a typical recalcitrant chlorinated compound. Different molar ratios between PS and DCA (0:1, 2:1, 5:1 and 20:1) and mass contents of MNPs in the sand (0 %, 1.9 % and 5.4 %) were tested. In the absence of MNPs, degradation of DCA was negligible for a hydraulic retention time of 7 h. Presence of MNPs at the content of 1.9 % enhanced degradation of DCA and the highest removal efficiency (34.2 %) was observed at the PS-to-DCA molar ratio of 5:1. At the MNPs content of 5.4 %, increase of the PS-to-DCA molar ratio from 2:1 to 20:1 lead to not only increase in DCA removal efficiency but also substantial enhancement in chloride production, indicating that high PS concentration could cause significant degradation of the Cl-containing intermediates. In contrast to MNPs, Fe3O4 solids with much larger size (â¼1 µm) were much less effective in activating PS for DCA removal even at a significantly higher content in the medium. The transport data could be well fitted by the one-site chemical nonequilibrium model, which showed kinetic DCA sorption to the MNPs as a key process for the transport. In the long-term injection experiment, a stable and significant removal of DCA (â¼50 %) was observed for 254 days at the MNP content of 1.9 %. The results of this study show the potential of MNPs as a sustainable PS activator in injection-based in situ chemical oxidation for groundwater remediation.
RESUMEN
The number of quantitative systems pharmacology (QSP) submissions to the U.S. Food and Drug Administration has continued to increase over the past decade. This report summarizes the landscape of QSP submissions as of December 2023. QSP was used to inform drug development across various therapeutic areas and throughout the drug development process of small molecular drugs and biologics and has facilitated dose finding, dose ranging, and dose optimization studies. Though the majority of QSP submissions (>66%) focused on drug effectiveness, QSP was also utilized to simulate drug safety including liver toxicity, risk of cytokine release syndrome (CRS), bone density, and others. This report also includes individual contexts of use from a handful of new drug applications (NDAs) and biologics license applications where QSP modeling was used to demonstrate the utility of QSP modeling in regulatory drug development. According to the models submitted in QSP submissions, an anonymous case was utilized to illustrate how QSP informed development of a bispecific monoclonal antibody with respect to CRS risk. QSP submissions for informing pediatric drug development were summarized along with highlights of a case in inborn errors of metabolism. Furthermore, simulations of response variability with QSP were described. In summary, QSP continues to play a role in informing drug development.
RESUMEN
On September 30, 2022, the FDA granted accelerated approval to futibatinib for the treatment of adult patients with previously treated, unresectable, locally advanced or metastatic intrahepatic cholangiocarcinoma (iCCA) with FGFR2 fusions or other rearrangements. Approval was based on Study TAS-120-101, a multicenter open-label, single-arm trial. Patients received futibatinib 20-mg orally once daily. The major efficacy outcome measures were overall response rate (ORR) and duration of response (DoR) as determined by an independent review committee (IRC) according to RECIST v1.1. ORR was 42% (95% confidence interval, 32%-52%). Median DoR was 9.7 months. Adverse reactions occurring in ≥30% patients were nail toxicity, musculoskeletal pain, constipation, diarrhea, fatigue, dry mouth, alopecia, stomatitis, and abdominal pain. The most common laboratory abnormalities (≥50%) were increased phosphate, increased creatinine, decreased hemoglobin, and increased glucose. Ocular toxicity (including dry eye, keratitis, and retinal epithelial detachment) and hyperphosphatemia are important risks of futibatinib, which are listed under Warnings and Precautions. This article summarizes the FDA's thought process and data supporting the approval of futibatinib.
Asunto(s)
Neoplasias de los Conductos Biliares , Colangiocarcinoma , Pirazoles , Pirroles , Adulto , Humanos , Pirimidinas/efectos adversos , Colangiocarcinoma/tratamiento farmacológico , Neoplasias de los Conductos Biliares/tratamiento farmacológico , Neoplasias de los Conductos Biliares/genética , Conductos Biliares Intrahepáticos , Aprobación de Drogas , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/genéticaAsunto(s)
Fibrilación Atrial , Remodelación Atrial , Proteínas Proto-Oncogénicas c-sis/metabolismo , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/metabolismo , Fibrilación Atrial/metabolismo , Fibrilación Atrial/fisiopatología , Humanos , Transducción de Señal , Regulación hacia ArribaRESUMEN
A critical step to evaluate the potential in vivo antiviral activity of a drug is to connect the in vivo exposure to its in vitro antiviral activity. The Anti-SARS-CoV-2 Repurposing Drug Database is a database that includes both in vitro anti-SARS-CoV-2 activity and in vivo pharmacokinetic data to facilitate the extrapolation from in vitro antiviral activity to potential in vivo antiviral activity for a large set of drugs/compounds. In addition to serving as a data source for in vitro anti-SARS-CoV-2 activity and in vivo pharmacokinetic information, the database is also a calculation tool that can be used to compare the in vitro antiviral activity with in vivo drug exposure to identify potential anti-SARS-CoV-2 drugs. Continuous development and expansion are feasible with the public availability of this database.