RESUMEN
The safety, low cost, and high power density of aqueous Zn-based devices (AZDs) appeal to large-scale energy storage. Yet, the presence of hydrogen evolution reaction (HER) and chemical corrosion in the AZDs leads to local OH- concentration increasement and the formation of ZnxSOy(OH)zâ¢nH2O (ZHS) by-products at the Zn/electrolyte interface, causing instability and irreversibility of the Zn-anodes. Here, a strategy is proposed to regulate OH- by introducing a bio-sourced/renewable polypeptide (É-PL) as a pH regulator in electrolyte. The consumption of OH- species is evaluated through in vitro titration and cell in vivo in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy at a macroscopic and molecular level. The introduction of É-PL is found to significantly suppress the formation of ZHS and associated side reactions, and reduce the local coordinated H2O of the Zn2+ solvation shell, widening electrochemical stable window and suppressing OH- generation during HER. As a result, the inclusion of É-PL improves the cycle time of Zn/Zn symmetrical cells from 15 to 225 h and enhances the cycle time of aqueous Zn- I2 cells to 1650 h compared to those with pristine electrolytes. This work highlights the potential of kinetical OH- regulation for by-product and dendrite-free AZDs.
RESUMEN
Twenty-five seco-4-methyl-DCK derivatives were designed, synthesized and evaluated for chemoreversal activity when combined with paclitaxel or vincristine in two drug-resistant cancer cell lines (A2780/T and KB-V) respectively. Most of the new compounds displayed moderate to significant MDR reversal activities in the P-gp overexpressing A2780/T and KB-V cells. Especially, compounds 7o and 7y showed the most potent chemosensitization activities with more than 496 and 735 reversal ratios at a concentration of 10⯵M. Unexpectedly the newly synthesized compounds did not show chemosensitization activities observed in a non-P-gp overexpressing cisplatin resistant human ovarian cancer cell line (A2780/CDDP), implying that the MDR reversal effects might be associated with P-gp overexpression. Moreover, these compounds did not exhibit significant antiproliferative activities against nontumorigenic cell lines (HUVEC, HOSEC and T29) compared to the positive control verapamil at the tested concentration, which suggested better safety than verapamil. The pharmacological actions of the compounds will be studied further to explore their merit for development as novel candidates to overcome P-gp mediated MDR cancer.
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Antineoplásicos/farmacología , Resistencia a Múltiples Medicamentos/efectos de los fármacos , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Estructura Molecular , Relación Estructura-ActividadRESUMEN
Rapid clearance of adoptively transferred Cd47-null (Cd47(-/-)) cells in congeneic WT mice suggests a critical self-recognition mechanism, in which CD47 is the ubiquitous marker of self, and its interaction with macrophage signal regulatory protein α (SIRPα) triggers inhibitory signaling through SIRPα cytoplasmic immunoreceptor tyrosine-based inhibition motifs and tyrosine phosphatase SHP-1/2. However, instead of displaying self-destruction phenotypes, Cd47(-/-) mice manifest no, or only mild, macrophage phagocytosis toward self-cells except under the nonobese diabetic background. Studying our recently established Sirpα-KO (Sirpα(-/-)) mice, as well as Cd47(-/-) mice, we reveal additional activation and inhibitory mechanisms besides the CD47-SIRPα axis dominantly controlling macrophage behavior. Sirpα(-/-) mice and Cd47(-/-) mice, although being normally healthy, develop severe anemia and splenomegaly under chronic colitis, peritonitis, cytokine treatments, and CFA-/LPS-induced inflammation, owing to splenic macrophages phagocytizing self-red blood cells. Ex vivo phagocytosis assays confirmed general inactivity of macrophages from Sirpα(-/-) or Cd47(-/-) mice toward healthy self-cells, whereas they aggressively attack toward bacteria, zymosan, apoptotic, and immune complex-bound cells; however, treating these macrophages with IL-17, LPS, IL-6, IL-1ß, and TNFα, but not IFNγ, dramatically initiates potent phagocytosis toward self-cells, for which only the Cd47-Sirpα interaction restrains. Even for macrophages from WT mice, phagocytosis toward Cd47(-/-) cells does not occur without phagocytic activation. Mechanistic studies suggest a PKC-Syk-mediated signaling pathway, to which IL-10 conversely inhibits, is required for activating macrophage self-targeting, followed by phagocytosis independent of calreticulin Moreover, we identified spleen red pulp to be one specific tissue that provides stimuli constantly activating macrophage phagocytosis albeit lacking in Cd47(-/-) or Sirpα(-/-) mice.
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Antígeno CD47/genética , Inflamación/genética , Interleucina-10/genética , Receptores Inmunológicos/genética , Animales , Citocinas/biosíntesis , Citocinas/genética , Endocitosis/genética , Humanos , Inflamación/patología , Macrófagos/metabolismo , Macrófagos/patología , Ratones , Ratones Noqueados , Fagocitosis/genética , Proteína Quinasa C/genética , Transducción de Señal/genéticaRESUMEN
Previous studies have suggested that CD47, an essential cell-surface protein, plays an important role in polymorphonuclear neutrophil (PMN) transmigration across tissue cells and extracellular matrix. In the current study, the role of CD47 in PMN transmigration and infiltration into tissues was further evaluated by investigating the function of CD47(-/-) PMN and inflammatory conditions induced in CD47(-/-) mice. Using in vitro time-course assays, we found that CD47(-/-) PMN exhibited no impediment, but slightly enhanced response to and transmigration toward, the chemoattractant fMLF. In vivo analysis in CD47(-/-) mice by inducing acute peritonitis and aggressive colitis observed consistent results, indicating that both PMN and monocytes effectively infiltrated inflammatory sites despite the absence of CD47 on these leukocytes or the surrounding tissue cells. Although PMN transmigration was not delayed in CD47(-/-) mice, fewer PMN were found in the intestine at the postacute/chronic stage of chronic colitis induced with sustained low-dose dextran sulfate sodium. Further analysis suggested that the paucity of PMN accumulation was attributable to attenuated granulopoiesis secondary to assessed lower levels of IL-17. Administration of exogenous IL-17A markedly increased PMN availability and rapidly rendered severe colitis in CD47(-/-) mice under dextran sulfate sodium treatment.
Asunto(s)
Antígeno CD47/genética , Quimiotaxis de Leucocito/inmunología , Colitis/inmunología , Granulocitos/inmunología , Mielopoyesis/inmunología , Neutrófilos/inmunología , Enfermedad Aguda , Animales , Antígeno CD47/fisiología , Inhibición de Migración Celular/genética , Inhibición de Migración Celular/inmunología , Quimiotaxis de Leucocito/genética , Enfermedad Crónica , Colitis/genética , Colitis/patología , Femenino , Granulocitos/metabolismo , Granulocitos/patología , Inflamación/genética , Inflamación/inmunología , Inflamación/patología , Ratones , Ratones Noqueados , Mielopoyesis/genética , Neutrófilos/citología , Neutrófilos/patologíaRESUMEN
Neutrophil (polymorphonuclear leukocytes [PMN]) infiltration plays a central role in inflammation and is also a major cause of tissue damage. Thus, PMN infiltration must be tightly controlled. Using zymosan-induced peritonitis as an in vivo PMN infiltration model, we show in this study that PMN response and infiltration were significantly enhanced in mice experiencing various types of systemic inflammation, including colitis and diabetes. Adoptive transfer of leukocytes from mice with inflammation into healthy recipients or from healthy into inflammatory recipients followed by inducing peritonitis demonstrated that both circulating PMN and tissue macrophages were altered under inflammatory conditions and that they collectively contributed to enhanced PMN infiltration. Detailed analyses of dextran sulfate sodium-elicited colitis revealed that enhancement of PMN infiltration and macrophage function occurred only at the postacute/chronic phase of inflammation and was associated with markedly increased IL-17A in serum. In vitro and ex vivo treatment of isolated PMN and macrophages confirmed that IL-17A directly modulates these cells and significantly enhances their inflammatory responses. Neutralization of IL-17A eliminated the enhancement of PMN infiltration and IL-6 production and also prevented severe tissue damage in dextran sulfate sodium-treated mice. Thus, IL-17A produced at the chronic stage of colitis serves as an essential feedback signal that enhances PMN infiltration and promotes inflammation.
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Interleucina-17/sangre , Infiltración Neutrófila/inmunología , Neutrófilos/inmunología , Neutrófilos/patología , Enfermedad Aguda , Animales , Enfermedad Crónica , Colitis/inmunología , Colitis/metabolismo , Colitis/patología , Modelos Animales de Enfermedad , Retroalimentación Fisiológica , Inflamación/sangre , Inflamación/inmunología , Inflamación/patología , Mediadores de Inflamación/sangre , Ratones , Ratones Endogámicos C57BL , Neutrófilos/metabolismo , Peritonitis/inducido químicamente , Peritonitis/inmunología , Peritonitis/patología , Zimosan/toxicidadRESUMEN
The ß(2)-integrin CD11b/CD18 mediates the firm adhesion of neutrophils (PMNs) to epithelial monolayers, a key step in PMN transepithelial migration. To complete the transmigration process, adherent PMNs must detach from epithelial monolayer surfaces to move forward. The mechanism that governs the detachment of adherent PMNs, however, is not clear. Here, we present evidence that cleavage of the CD11b extracellular domain containing the ligand-binding I-domain by 3 structural and functional related serine proteases (elastase, proteinase-3 and cathepsin G) serves as a novel mechanism for PMN detachment after the initial cell adhesion. Kinetic studies showed that the cleavage of CD11b is positively correlated with PMN detachment and subsequent transmigration. Moreover, the results demonstrated that elastase, proteinase-3 and cathepsin G all cleaved the purified, functionally active form of CD11b in a pattern similar to the CD11b shedding that occurs during PMN transmigration. Their cleavage sites on purified CD11b were located at (761)Thr-Ala(762) (elastase/proteinase-3) and (760)Phe-Thr(761) (cathepsin G), respectively. CD11b cleavage and PMN detachment and chemotaxis, were impaired in elastase/cathepsin G-deficient Beige mice; this defect could be restored by the addition of extracellular elastase. By illustrating CD11b shedding by elastase, proteinase-3 and cathepsin G as a novel mechanism for PMN detachment, our study provides novel therapeutic targets for controlling inflammation.
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Antígeno CD11b/metabolismo , Quimiotaxis de Leucocito/fisiología , Neutrófilos/fisiología , Serina Proteasas/metabolismo , Animales , Sitios de Unión , Antígeno CD11b/química , Antígenos CD18/metabolismo , Catepsina G/metabolismo , Adhesión Celular/fisiología , Humanos , Técnicas In Vitro , Elastasa de Leucocito/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Mieloblastina/metabolismo , Estructura Terciaria de ProteínaRESUMEN
Advanced glycation end products (AGEs) delay spontaneous apoptosis of monocytes and contribute to the development of inflammatory responses. However, the mechanism by which AGEs affect monocyte apoptosis is unclear. We studied the role of microRNA-214 (miR-214) and its target gene in AGE-induced monocytic apoptosis delay. Using microRNA (miRNA) microarray and stem-loop, quantitative RT-PCR assay, we studied genome-wide miRNA expression in THP-1 cells treated with or without AGEs. Significant upregulation of miR-214 was consistently observed in THP-1 and human monocytes treated with various AGEs, and AGE-induced monocytic miR-214 upregulation was likely through activation of receptor for AGEs. A striking increase in miR-214 was also detected in monocytes from patients with chronic renal failure. Luciferase reporter assay showed that miR-214 specifically binds to the phosphatase and tensin homolog (PTEN) mRNA 3'-untranslated region, implicating PTEN as a target gene of miR-214. PTEN expression is inversely correlated with miR-214 level in monocytes. Compared with normal monocytes, AGE-treated monocytes and monocytes from chronic renal failure patients exhibited lower PTEN levels and delayed apoptosis. Overexpression of pre-miR-214 led to impaired PTEN expression and delayed apoptosis of THP-1 cells, whereas knockdown of miR-214 level largely abolished AGE-induced cell survival. Our findings define a new role for miR-214-targeting PTEN in AGE-induced monocyte survival.
Asunto(s)
Apoptosis/inmunología , Marcación de Gen , Productos Finales de Glicación Avanzada/fisiología , MicroARNs/biosíntesis , Monocitos/inmunología , Monocitos/patología , Fosfohidrolasa PTEN/metabolismo , Albúmina Sérica/fisiología , Proteínas Supresoras de Tumor/metabolismo , Apoptosis/genética , Muerte Celular/genética , Muerte Celular/inmunología , Línea Celular Tumoral , Supervivencia Celular/genética , Supervivencia Celular/inmunología , Células Cultivadas , Regulación de la Expresión Génica/inmunología , Productos Finales de Glicación Avanzada/antagonistas & inhibidores , Productos Finales de Glicación Avanzada/genética , Humanos , Fallo Renal Crónico/enzimología , Fallo Renal Crónico/metabolismo , Fallo Renal Crónico/patología , MicroARNs/antagonistas & inhibidores , MicroARNs/genética , Monocitos/metabolismo , Fosfohidrolasa PTEN/antagonistas & inhibidores , Fosfohidrolasa PTEN/genética , Interferencia de ARN/inmunología , Albúmina Sérica/antagonistas & inhibidores , Albúmina Sérica/genética , Albúmina Sérica Humana , Factores de Tiempo , Proteínas Supresoras de Tumor/antagonistas & inhibidores , Proteínas Supresoras de Tumor/genéticaRESUMEN
Aqueous Zn-metal batteries (AZMBs) are promising large-scale energy storage devices for their high safety and theoretical capacity. However, unstable Zn-electrolyte interface and severe side reactions have excluded AZMBs from long cycling required by practically reversible energy storage. Traditional high-concentration electrolyte is an effective strategy to suppress dendrites growth and resolve the poor electrochemical stability and reversibility of Zn-metal anodes, yet how scientifically universal such strategy is for hybrid electrolyte of different concentrations remains unclear. Herein, we studied the electrochemical behaviors of AZMBs comprising a ZnCl2 -based DMSO/H2 O electrolyte of two distinct concentrations (1 m vs. 7 m). The electrochemical stability/reversibility of Zn anodes in both symmetric and asymmetric cells with high-concentration electrolytes are unusually inferior to the ones with low-concentration electrolyte. It was found that more DMSO components in the solvation sheath of low-concentration electrolyte exist at the Zn-electrolyte interface than in high-concentration counterpart, enabling higher organic compositions in solid-electrolyte-interface (SEI). The rigid inorganic and flexible organic compositions of SEI decomposed from the low-concentration electrolyte is accounted for improved cycling and reversibility of Zn metal anodes and the respective batteries. This work reveals the critical role of SEI than the high concentration itself in delivering stable electrochemical cycling in AZMBs.
RESUMEN
Neutrophil (polymorphonuclear leukocyte; PMN) inflammatory functions, including cell adhesion, diapedesis, and phagocytosis, are dependent on the mobilization and release of various intracellular granules/vesicles. In this study, we found that treating PMN with damnacanthal, a Ras family GTPase inhibitor, resulted in a specific release of secondary granules but not primary or tertiary granules and caused dysregulation of PMN chemotactic transmigration and cell surface protein interactions. Analysis of the activities of Ras members identified Ral GTPase as a key regulator during PMN activation and degranulation. In particular, Ral was active in freshly isolated PMN, whereas chemoattractant stimulation induced a quick deactivation of Ral that correlated with PMN degranulation. Overexpression of a constitutively active Ral (Ral23V) in PMN inhibited chemoattractant-induced secondary granule release. By subcellular fractionation, we found that Ral, which was associated with the plasma membrane under the resting condition, was redistributed to secondary granules after chemoattractant stimulation. Blockage of cell endocytosis appeared to inhibit Ral translocation intracellularly. In conclusion, these results demonstrate that Ral is a critical regulator in PMN that specifically controls secondary granule release during PMN response to chemoattractant stimulation.
Asunto(s)
Membrana Celular/enzimología , Activación Neutrófila/fisiología , Neutrófilos/enzimología , Vesículas Secretoras/metabolismo , Proteínas de Unión al GTP ral/metabolismo , Sustitución de Aminoácidos , Membrana Celular/genética , Factores Quimiotácticos/farmacología , Quimiotaxis/efectos de los fármacos , Quimiotaxis/fisiología , Endocitosis/efectos de los fármacos , Endocitosis/fisiología , Humanos , Mutación Missense , Activación Neutrófila/efectos de los fármacos , Transporte de Proteínas/efectos de los fármacos , Transporte de Proteínas/fisiología , Proteínas de Unión al GTP ral/genéticaRESUMEN
OBJECTIVE: Previous studies demonstrated that uncoupling protein 2 (UCP2) plays a negative role in modulating leukocyte inflammatory responses. The mechanism underneath the role of UCP2 in modulating leukocyte inflammatory responses, however, is incompletely understood. Here, we investigated the effect of UCP2 in polymorphonuclear leukocyte (PMN) chemotaxis. METHODS AND RESULTS: First, we assessed PMN chemotaxis in zymosan-induced murine peritonitis and found that UCP2(-/-) mice had significantly more migrated PMN in peritoneal lavage compared to their wild-type littermates. In vitro transmigration assays using isolated PMN also showed that PMN from UCP2(-/-) mice migrated faster than those from wild-type mice in response to N-formyl-methionyl-leucyl-phenylalanine (fMLP). Second, in supporting an inhibitory role of UCP2 in PMN transmigration, migrated PMN had a decreased UCP2 expression compared to nonmigrated PMN. In contrast, in streptozotocin-induced diabetic mice in which UCP2 expression was enhanced, PMN chemotaxis was reduced. Third, comparing to UCP2(+/+) PMN, UCP2(-/-) PMN had a stronger upregulation of fMLP-induced surface CD11b/CD18 and CD11a/CD18. Finally, UCP2(-/-) PMN showed a quicker and larger fMLP-triggered intracellular calcium mobilization compared to UCP2(+/+) PMN. CONCLUSIONS: Our study demonstrates that UCP2 serves as a brake in controlling PMN chemotaxis and that the effect of UCP2 on PMN chemotaxis may be through modulating calcium influx.
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Calcio/metabolismo , Quimiotaxis/fisiología , Citoplasma/metabolismo , Canales Iónicos/metabolismo , Proteínas Mitocondriales/metabolismo , Neutrófilos/metabolismo , Animales , Antígeno CD11b/metabolismo , Antígenos CD18/metabolismo , Movimiento Celular/efectos de los fármacos , Movimiento Celular/fisiología , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patología , Modelos Animales de Enfermedad , Canales Iónicos/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas Mitocondriales/genética , N-Formilmetionina Leucil-Fenilalanina/farmacología , Neutrófilos/inmunología , Neutrófilos/patología , Peritonitis/inducido químicamente , Peritonitis/metabolismo , Peritonitis/patología , Estreptozocina , Proteína Desacopladora 2 , Zimosan/efectos adversosRESUMEN
OBJECTIVE: Monocyte migration across the vascular endothelium of blood vessels is a key early event in atherosclerosis. The mechanisms underlying monocyte transendothelial migration (TEM), however, are still not completely understood. Here we studied the role of junctional adhesion molecule-like protein (JAML) in regulating monocyte TEM. METHODS AND RESULTS: Firstly, by Western blot and flow cytometry, we showed that JAML was strongly expressed in monocytes and monocyte surface expression of JAML was upregulated by monocyte chemotaxis protein-1 stimulation. Both monocyte adhesion to and migration across tumor necrosis factor-alpha (TNFalpha) preactivated human microvascular endothelial cell (HMEC-1) monolayers were dose-dependently reduced by anti-JAML antiserum or soluble extracellular JAML recombinant. Secondly, short-term exposure of human monocytes and THP-1 cells to advanced glycation end products increased cell surface JAML expression, which was correlated with enhanced cell adhesion and TEM. In contrast, knockdown of JAML in THP-1 monocytes decreased both adhesion and transmigration of THP-1 monocytes. Finally, direct binding assay of the soluble JAML to HMEC-1 monolayers suggested that endothelial coxsackie and adenovirus receptor (CAR) may serve as one of the ligands for JAML. CONCLUSIONS: Monocytic JAML plays a critical role in regulating monocyte TEM probably via binding to the endothelial CAR and other tight junction-associated adhesive molecules.
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Moléculas de Adhesión Celular/genética , Movimiento Celular/fisiología , Endotelio Vascular/fisiología , Monocitos/fisiología , Adenoviridae/fisiología , Aterosclerosis/patología , Aterosclerosis/fisiopatología , Moléculas de Adhesión Celular/metabolismo , Permeabilidad de la Membrana Celular , Quimiocina CCL2/fisiología , Cartilla de ADN , Endotelio Vascular/citología , Endotelio Vascular/ultraestructura , Enterovirus/fisiología , Citometría de Flujo , Regulación de la Expresión Génica , Humanos , Moléculas de Adhesión de Unión , Microscopía Confocal , Receptores Virales/fisiología , Proteínas Recombinantes/metabolismo , Uniones Estrechas/fisiología , Túnica Íntima/patología , Túnica Íntima/fisiologíaRESUMEN
In this paper, a regulation method through torsional strain effect is proposed for carbon nanotube linear thermal actuators. The effects of torsional strain effect on the linear driven performance of linear actuators are systematically studied by molecular dynamics method, and the effect mechanism is revealed as well. It was found that the torsional strain affects the thermal driving force and the friction effect by changing the spacing between the carbon tubes and lattice vibration modes, then further affects the linear driving characteristics. The influence mechanism of torsional strain on the driving characteristics is analyzed and the valuable conclusions for nanoscale strain engineering application are obtained. The work of this paper provides a new idea for performance regulation for nano-driving by using strain effect, and has important guiding significance for nanoscale strain engineering.
RESUMEN
Thirty-four seco-3'R,4'R-disubstituted-2',2'-dimethyldihydropyrano[2,3-f]chromone (seco-DSP) derivatives were designed, synthesized and evaluated for chemo-reversal activity when combined with paclitaxel or vincristine in P-gp overexpressing A2780/T and KB-VIN drug-resistant cancer cell lines. Most of the compounds displayed moderate to significant MDR reversal activities. Compound 7e showed the most potent chemo-sensitization activity with more than 1471 reversal ratio at a concentration of 10 µM, which was higher than verapamil (VRP) (212-fold). Unexpectedly the newly synthesized compounds did not show chemosensitization activities in a non-P-gp overexpressing cisplatin resistant human ovarian cancer cell line (A2780/CDDP), implying that the MDR reversal effects might be associated with P-gp overexpression. Moreover, the compounds did not exhibit significant anti-proliferative activities against non-tumorigenic cell lines (HUVEC, HOSEC and T29) compared to VRP at the tested concentration and might be safer than VRP. In preliminary pharmacological mechanism studies, the compounds increased accumulation of DOX and promoted P-gp ATPase activity in A2780/T cell lines. Western blot analysis indicated they did not affect the expression level of P-gp in the tested MDR cell lines. Thus, further studies on these seco-DSP derivatives are merited with the goal of developing a desirable chemosensitizer drug candidate.
Asunto(s)
Cromonas/química , Cromonas/farmacología , Diseño de Fármacos , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Antineoplásicos/farmacología , Línea Celular Tumoral , Cromonas/síntesis química , Relación Dosis-Respuesta a Droga , Resistencia a Múltiples Medicamentos/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Sinergismo Farmacológico , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , HumanosRESUMEN
Adhesion of Shiga toxin-producing Enterohemorrhagic Escherichia coli (EHEC) O157:H7 to human colonic epithelium is a critical step for infection by this type of bacteria. Here, we demonstrate that adherence of EHEC O157:H7 to cultured human colonic T84 epithelial monolayers can be blocked by heparin and heparan sulfate in a dose-dependent fashion. In doing this, heparin and heparan sulfate also prevent dysfunction of the T84 barrier and disorganization of epithelial tight junction protein ZO-1 caused by EHEC O157:H7. This inhibition by heparin and heparan sulfate seems to result from a block in the binding interactions of bacteria intimin with epithelial beta(1) integrins. This study provides evidence, for the first time, that heparin and heparan sulfate can serve as novel effective blockers in preventing EHEC O157:H7 infection.
Asunto(s)
Adhesión Bacteriana/efectos de los fármacos , Colon/microbiología , Escherichia coli O157/fisiología , Heparina/farmacología , Heparitina Sulfato/farmacología , Adhesinas Bacterianas/metabolismo , Células Cultivadas , Colon/citología , Colon/metabolismo , Células Epiteliales/metabolismo , Células Epiteliales/microbiología , Escherichia coli O157/metabolismo , Proteínas de Escherichia coli/metabolismo , Humanos , Integrina beta1/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologíaRESUMEN
A GH30-8 endoxylanase was identified from an environmental Bacillus subtilis isolate following growth selection on aspen wood glucuronoxylan. The putative endoxylanase was cloned for protein expression and characterization in the Gram-positive protease deficient protein expression host B. subtilis WB800. The extracellular activity obtained was 55â¯U/mL, which was 14.5-fold higher than that obtained with the native species. The apparent molecular mass of BsXyn30 was estimated as 43â¯kDa by SDS-PAGE. BsXyn30 showed an optimal activity at pHâ¯7.0 and 60⯰C. Recombinant BsXyn30 displayed maximum activity against aspen wood xylan, followed by beechwood xylan but showed no catalytic activity on arabinose-substituted xylans. Analysis of hydrolyzed products of beechwood xylan by thin-layer chromatography and mass spectroscopy revealed the presence of xylooligosaccharides with a single methyl-glucuronic acid residue. BsXyn30 exhibited very low activity for hydrolysis xylotetraose and xylopentaose, but had no detectable activity against xylobiose and xylotriose. Using BsXyn30 as an additive in breadmaking, a decrease in water-holding capacity, an increase in dough expansion as well as improvements in volume and specific volume of the bread were recorded. Thus, the present study provided the basis for the application of GH30 xylanase in breadmaking.
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Bacillus subtilis/enzimología , Pan , Endo-1,4-beta Xilanasas/metabolismo , Xilanos/metabolismo , Secuencia de Aminoácidos , Bacillus subtilis/aislamiento & purificación , Endo-1,4-beta Xilanasas/química , Endo-1,4-beta Xilanasas/genética , Estabilidad de Enzimas , Harina , Regulación Enzimológica de la Expresión Génica , Concentración de Iones de Hidrógeno , Oligosacáridos/análisis , Especificidad por Sustrato , TemperaturaRESUMEN
In this work, five new hybrids of phenylsulfonylfuroxan merging 3-benzyl coumarin and their seco-B-ring derivatives 2-6 were designed and synthesized. Among them, compound 3 showed the most potent antiproliferation activities with IC50 values range from 0.5 to 143 nM against nine drug-sensitive and four drug-resistant cancer cell lines. Preliminary pharmacologic studies showed that these compounds displayed lower toxicities than that of lead compound 1. Compound 3 obviously induced the early apoptosis and hardly affected the cell cycle of A2780, which was significantly different from compound 1. Especially, it gave 559- and 294-fold selectivity antiproliferation activity in P-gp overexpressed drug-resistant cancer cell lines MCF-7/ADR and KB-V compared to their drug-sensitive ones MCF-7 and KB, implying that compounds 2-6 might have an extra mechanism of anti-MDR-cancer with P-gp overexpression.
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BACKGROUND: Lung adenocarcinoma is the most primary histologic subtype of non-small cell lung cancer (NSCLC). Compound 8b, a novel coumarin derivative with phenylsulfonylfuroxan group, shows significant antiproliferation activity against lung adenocarcinoma cell with low toxicity. PURPOSE: This study aims to uncover the potential of compound 8b in relation to apoptosis as well as autophagy induction in lung adenocarcinoma cells. STUDY DESIGN: The cytotoxicity and apoptosis of A549 and H1299 cells induced by compound 8b were detected by MTT, microscope and western blot analysis. Autophagy was determined by TEM, confocal microscopy and western blot analysis. Akt/mTOR and Erk signaling pathway were also examined by western blot analysis. RESULTS: First, significant growth inhibition and caspase-dependent apoptosis were observed in compound 8b-treated A549 and H1299 cells. Then, we confirmed compound 8b-induced autophagy by autophagosomes formation, upregulated expression of autophagy-related protein LC3-II and autophagic flux. Importantly, abolishing autophagy using inhibitors and ATG5 siRNA enhanced the cytotoxicity of compound 8b, indicating the cytoprotective role of autophagy in lung adenocarcinoma. Further mechanistic investigations suggested that Akt/mTOR and Erk signaling pathways contributed to autophagy induction by compound 8b. CONCLUSION: This results demonstrate that compound 8b induces caspase-dependent apoptosis as well as cytoprotective autophagy in lung adenocarcinoma cells, which may provide scientific evidence for developing this furoxan-based NO-releasing coumarin derivative as a potential anti-lung adenocarcinoma therapeutic agents.
Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Antineoplásicos/química , Antineoplásicos/farmacología , Autofagia/efectos de los fármacos , Neoplasias Pulmonares/tratamiento farmacológico , Oxadiazoles/química , Células A549 , Adenocarcinoma/patología , Adenocarcinoma del Pulmón , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Proteína 5 Relacionada con la Autofagia/genética , Proteína 5 Relacionada con la Autofagia/metabolismo , Caspasas/metabolismo , Línea Celular Tumoral , Cumarinas/química , Humanos , Neoplasias Pulmonares/patología , Óxido Nítrico/metabolismo , Transducción de Señal/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
An alkali tolerant xylanase gene from Bacillus subtilis Lucky9 was cloned and extracellular expressed in E. coli BL21. Xylanase amino acid sequence showed 99% identity with xylanase sequence from Bacillus subtilis 168, and was belonged to glycoside hydrolase family 11. The recombinant E. coli (pET-pelB-xynLC9) containing pelB signal peptide produced extracellular xylanase of 436.5U/mL for 8h, which was used arabinose as extra carbon source and inducer for enhancing extracellular production. The extracellular xylanase was determined by SDS-PAGE with a relative molecular mass of 21kDa. The recombinant xylanase was optimally activity at pH 6.5 and 60°C. The xylanase exhibited 80% residual activity over a broad pH range of 6.0-9.0 for 24h. Thermostability studies showed that xylanase retained 60% residual activity after 2h at 60°C. The main end-products of hydrolysis of beech-wood xylan and corncob by the extracellular xylanase were xylobiose and xylotriose. This extracellular xylanase without purification is a suitable candidate for application in the industrial production of xylooligosaccharides from agro-industrial waste for use as prebiotics.
Asunto(s)
Agricultura , Álcalis/farmacología , Bacillus subtilis/enzimología , Endo-1,4-beta Xilanasas/genética , Escherichia coli/genética , Glucuronatos/química , Residuos Industriales , Oligosacáridos/química , Arabinosa/farmacología , Bacillus subtilis/genética , Endo-1,4-beta Xilanasas/metabolismo , Estabilidad de Enzimas/efectos de los fármacos , Escherichia coli/citología , Escherichia coli/efectos de los fármacos , Espacio Extracelular/efectos de los fármacos , Espacio Extracelular/genética , Fagus/química , Expresión Génica , Concentración de Iones de Hidrógeno , Hidrólisis , Metales/farmacología , Análisis de Secuencia de ADN , Especificidad por Sustrato , Temperatura , Zea mays/químicaRESUMEN
Xylooligosaccharides (XOS) are high value-added ingredients for functional foods and they have potential use as prebiotics. In order to reduce the production cost of XOS, we constructed a fusion enzyme consisting of expansin and endo-xylanase from B. subtilis Lucky9 to produce high-pure XOS with affinity adsorption-enzymatic reaction integrated approach. By optimization of inserting linker, the specific xylanase activity of fusion enzyme with R2 linker was increased 1.28-fold than that of native xylanase. Electrophoretic pure fusion enzyme was separated from crude enzyme extracts by affinity adsorption on corncob substrate, with 90.3% recovery in optimized conditions. Then, the fusion enzyme-corncob mixture was directly hydrolyzed. The yield of XOS reached 6.91mg/mL. The production of XOS with high purity of 91.7% was obtained by one step of centrifugation. This affinity adsorption-enzymatic reaction integrated XOS production approach provides a green route to alternative XOS traditional enzymatic production.
Asunto(s)
Glucuronatos , Oligosacáridos , Adsorción , Reactores BiológicosRESUMEN
Thirteen novel furoxan-based nitric oxide (NO) releasing hybrids (14a-e, 15a-e, 17b-d) of 16,17-pyrazo-annulated steroidal derivatives were synthesized and evaluated against the MDA-MB-231, HCC1806, SKOV-3, DU145, and HUVEC cell lines for their in vitro anti-proliferative activity. Most of the compounds displayed potent anti-proliferative effects. Among them, 17c exhibited the best activity with IC50 values of 20-1.4nM against four cell lines (MDA-MB-231, SKOV-3, DU145, and HUVEC), and 1.03µM against a tamoxifen resistant breast cancer cell line (HCC1806). Furthermore, five compounds (14a, 15a, 17b-d) were selected to screen for VEGF inhibitory activity. Compounds 15a, 17b,c showed obviously better activity than 2-Methoxyestradiol (2-ME) on reducing levels of VEGF secreted by MDA-MB-231 cell line. In a Capillary-like Tube Formation Assay, compounds 17b,c exhibited a significant suppression of the tubule formation in the concentration of 1.75nM and 58nM, respectively. The preliminary SAR showed that steroidal scaffolds with a linker in 3-position were favorable moieties to evidently increase the bioactivities of these hybrids. Overall, these results implied that 17c merited to be further investigated as a promising anti-cancer candidate.