6-Formylindolo(3,2-b)carbazole (FICZ) is a photoproduct of tryptophan and an endogenous high affinity ligand for aryl hydrocarbon receptor (AhR). It was previously reported that, in patient-derived ...HL-60 myeloblastic leukemia cells, retinoic acid (RA)-induced differentiation is driven by a signalsome containing c-Cbl and AhR. FICZ enhances RA-induced differentiation, assessed by expression of the membrane differentiation markers CD38 and CD11b, cell cycle arrest and the functional differentiation marker, inducible oxidative metabolism. Moreover, FICZ augments the expression of a number of the members of the RA-induced signalsome, such as c-Cbl, Vav1, Slp76, PI3K, and the Src family kinases Fgr and Lyn. Pursuing the molecular signaling responsible for RA-induced differentiation, we characterized, using FRET and clustering analysis, associations of key molecules thought to drive differentiation. Here we report that, assayed by FRET, AhR interacts with c-Cbl upon FICZ plus RA-induced differentiation, whereas AhR constitutively interacts with Cbl-b. Moreover, correlation analysis based on the flow cytometric assessment of differentiation markers and western blot detection of signaling factors reveal that Cbl-b, p-p38α and pT390-GSK3β, are not correlated with other known RA-induced signaling components or with a phenotypic outcome. We note that FICZ plus RA elicited signaling responses that were not typical of RA alone, but may represent alternative differentiation-driving pathways. In clusters of signaling molecules seminal to cell differentiation, FICZ co-administered with RA augments type and intensity of the dynamic changes induced by RA. Our data suggest relevance for FICZ in differentiation-induction therapy. The mechanism of action includes modulation of a SFK and MAPK centered signalsome and c-Cbl-AhR association.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The known collaboration between all‐transretinoic acid and interferon motivates this study of the dependence of RA‐induced leukemic cell differentiation on interferon regulatory factor‐1 (IRF‐1), a ...transcription factor that is the main mediator of interferon effects. In the HL‐60 acute myeloid leukemia (AML) model that represents a rare RA‐responsive subtype of AML, IRF‐1 is not expressed until RA induces its prominent expression, and ectopic IRF‐1 expression enhances RA‐induced differentiation, motivating interest in how IRF‐1 is putatively needed for RA response. Accordingly, we created CRISPR/Cas9‐mediated IRF‐1 knockout HL‐60 cells. Contrary to expectation, loss of IRF‐1 did not diminish RA‐induced cellular signaling that propels differentiation, and RA‐induced cell differentiation markers, including CD38 and CD11b expression and G1/G0cell cycle arrest, were unaffected. However, elimination of IRF‐1 inhibited RA‐induced p47phox expression and inducible oxidative metabolism detected by reactive oxygen species (ROS), suggesting IRF‐1 is essential for mature granulocytic inducible oxidative metabolism. In the case of 1,25‐Dihydroxyvitamin D3‐induced differentiation to monocytes, IRF‐1 loss did not affect D3‐induced expression of CD38, CD11b, and CD14, and G1/0 arrest; but inhibited ROS production. Our data suggest that IRF‐1 is inessential for differentiation but upregulates p47phox expression for mature‐cell ROS production.
Multi Jet Fusion (MJF) is a powder-bed fusion (PBF) additive manufacturing process that enables high-resolution, rapid fabrication of large-scale polymer parts. In particular, the MJF process enables ...direct printing of structures without the need for support material, enabling complex geometries such as lattices and scaffolds to be manufactured with minimal post-processing. The lattice structure is a highly tunable geometry that can form the stiff, strong backbone of larger-scale designs, facilitating time and material efficiency in the printing process compared to a solid body. While the benefits of lattice-based designs produced with powder-bed fusion processes are clear, there currently exist few studies that empirically characterize the mechanical performance of lattices printed using MJF. In this work, we treat each lattice as an assembly of components (beams and nodes), with each component defined by its nominal size and orientation. To study the effect of changing these parameters on material properties, lattice unit cells of structural interest are modeled with their beam diameters, node sizes, and unit cell geometries varied. Specimens are printed using polyamide (PA)-12 powder, then mechanically tested to determine strength and stiffness. The results are used to determine empirical fitting parameters to the Gibson-Ashby scaling model of lattices, previously unapplied to MJF-printed structures. To further develop a model of the structure's geometry-dependent behavior, the varying failure modes of printed lattices are also characterized. The results of this work provide a foundation for the design optimization of lattices printed using Multi Jet Fusion, in turn developing a fundamental model for a variety of large-scale printable structures.
Multi Jet Fusion (MJF) is a 3D-printing process capable of fabricating large-scale polymer structures. Herein, we present a framework for MJF-printed lattices with tunable stiffness and strength based on an empirical analysis of structural behavior.
Asphaltenes are typically defined by their solubility in benzene and insolubility in pentane or heptane. They are believed to exist in petroleum crude oil as a colloidal suspension, stabilized by ...surface-adsorbed resins. Their normal equilibrium under reservoir conditions may be disrupted during production by pressure reduction, crude oil chemical composition changes, introduction of miscible gases and liquids, and mixing with diluents and other oils, as well as by acid stimulation, hot oiling, and other oilfield operations. Electrospray ionization preferentially ionizes polar N-, S-, and O-containing compounds, and its combination with ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry makes a powerful tool for the compositional analysis of petroleum-derived materials such as asphaltenes. In this work, we compare the compositional differences between heptane-precipitated asphaltenes and asphaltenes collected by live oil depressurization. Negative- and positive-ion electrospray yield the acidic and basic species, respectively. We find that the heptane-precipitated asphaltenes contain higher double bond equivalents (number of rings plus double bonds) compared to the asphaltenes induced by pressure drop. On the other hand, the pressure-drop product exhibits a higher abundance of species containing sulfur. Thus, the solubility criterion for asphaltenes defines a significantly different chemical composition than the (more field-relevant) pressure-drop criterion.
In smokers, the lung parenchyma is characterized by inflammation and emphysema, processes that can result in local gain and loss of lung tissue. CT measures of lung density might reflect lung tissue ...changes; however, longitudinal data regarding the effects of CT lung tissue on FEV1 in smokers with and without COPD are scarce.
The 15th percentile of CT lung density was obtained from the scans of 3,390 smokers who completed baseline and 5-year follow-up of the Genetic Epidemiology of COPD (COPDGene) study visits. The longitudinal relationship between total lung capacity-adjusted lung density (TLC-PD15) and FEV1 was assessed by using multivariable mixed models. Separate models were performed in smokers at risk, smokers with preserved ratio and impaired spirometry (PRISm), and smokers with COPD according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) staging system.
The direction of the relationship between lung density and lung function was GOLD stage dependent. In smokers with PRISm, a 1-g/L decrease in TLC-PD15 was associated with an increase of 2.8 mL FEV1 (P = .02). In contrast, among smokers with GOLD III to IV COPD, a 1-g/L decrease in TLC-PD15 was associated with a decrease of 4.1 mL FEV1 (P = .002).
A decline in TLC-PD15 was associated with an increase or decrease in FEV1 depending on disease severity. The associations are GOLD stage specific, and their presence might influence the interpretation of future studies that use CT lung density as an intermediate study end point for a decline in lung function.
ClinicalTrials.gov; No.: NCT00608764; URL: www.clinicaltrials.gov.
In the present study, we determined the effects of the Src family kinase (SFK) inhibitor, Bosutinib, and the engineered loss of the Lyn SFK on all-trans retinoic acid-induced leukemic cell ...differentiation. Retinoic acid (RA) is an embryonic morphogen and dietary factor that demonstrates chemotherapeutic efficacy in inducing differentiation of a non-APL AML cell model, the HL-60 human myeloblastic (FAB-M2) leukemia cell line, via activation of a novel signalsome containing an ensemble of signaling molecules that drive differentiation. Bosutinib is an inhibitor of SFKs used to treat myeloid leukemias where prominent high expression of SFKs, in particular Lyn, has been observed. Using either Bosutinib or loss of Lyn expression due to shRNA promoted RA-induced phenotypic differentiation, G0 arrest, and respiratory burst (functional differentiation) of HL-60 cells. Signaling events putatively seminal to RA-induced differentiation, the expression of Fgr, Cbl, Slp-76 and Vav, and the phosphorylation of c-Raf (pS259), Vav (p-tyr), and Slp76 (p-tyr) were not inhibited by Bosutinib or loss of Lyn. Nor was RA-induced upregulation of p-tyr phosphorylation of p47phox, a member of the NADPH complex that produces ROS, a putative phosphorylation dependent signaling regulator. Surprisingly, Bosutinib still works in the absence of Lyn to enhance RA-induced differentiation and neither compromised RA-induced expression, nor phosphorylation of signaling molecules that drive differentiation. These findings suggested there is a novel, off-target, Lyn-independent effect of Bosutinib that is of therapeutic significance to differentiation therapy.
Calcium and sodium naphthenates are solid deposits and emulsions formed by the interaction of naphthenic acids with divalent (Ca2+, Mg2+) or monovalent (Na+, K+) ions in produced waters. Calcium ...naphthenate formation, an interfacial phenomenon, is thought to depend largely on tetraprotic naphthenic acids known as “ARN” acids (∼C80) in the crude oil, whereas sodium naphthenates originate from lower molecular weight (C15 to C35) monoprotic naphthenic acids. Here we present detailed chemical heteroatom class composition analyses of calcium and sodium naphthenates from the field based on high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). In all cases, calcium naphthenate deposits consist predominately of tetraprotic acids with a C80 hydrocarbon skeleton whereas sodium naphthenate emulsions consist mainly of specific monoprotic saturated carboxylic acids. Furthermore, low molecular weight tetraprotic (ARN) acids with C60−77 hydrocarbon skeletons were identified in the calcium naphthenate deposit. The high resolution and mass accuracy of FT-ICR MS provide detailed acidic speciation for the analyzed deposits and emulsions.
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