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The direct one-pot conversion of furfural to 2-methyltetrahydrofuran (2-MTHF) was investigated in liquid phases using H2as a hydrogen source over a bimetallic Cu–Pd/HY catalyst. This catalyst showed excellent catalytic reactivity toward the formation of 2-MTHF with a yield of 83.1% under optimized reaction conditions. By adjusting the Cu/Pd ratio in the catalyst, the desired product could be obtained selectively. This was due to (1) selective catalysis of Cu toward C=O bonds in furfural, (2) excellent hydrogenation ability of Pd, and (3) the synergistic effects between Cu, Pd, and the acidic sites of the support HY. The influences of other parameters on conversion and selectivity were also investigated. Mechanism studies revealed that reactions mainly perform through the hydrogenation of furfural to furfuryl alcohol and then hydrodeoxygenation to 2-methylfuran followed by furan ring hydrogenation to 2-MTHF. Finally, after five recycling runs, this catalyst still displayed high catalytic behavior and stability, which provided a certain foundation for future research of furfural catalytic hydrogenation to 2-MTHF.

The human auditory system extracts rich linguistic abstractions from speech signals. Traditional approaches to understanding this complex process have used linear feature-encoding models, with limited success. Artificial neural networks excel in speech recognition tasks and offer promising computational models of speech processing. We used speech representations in state-of-the-art deep neural network (DNN) models to investigate neural coding from the auditory nerve to the speech cortex. Representations in hierarchical layers of the DNN correlated well with the neural activity throughout the ascending auditory system. Unsupervised speech models performed at least as well as other purely supervised or fine-tuned models. Deeper DNN layers were better correlated with the neural activity in the higher-order auditory cortex, with computations aligned with phonemic and syllabic structures in speech. Accordingly, DNN models trained on either English or Mandarin predicted cortical responses in native speakers of each language. These results reveal convergence between DNN model representations and the biological auditory pathway, offering new approaches for modeling neural coding in the auditory cortex.

The interaction between palladium(II)-chlorpromazine hydrochloride and sodium tungstate was investigated by ultraviolet-visible absorption, resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering (FDS) spectroscopy. In pH 5.3 Britton-Robinson (BR) buffer medium, chlorpromazine hydrochloride (CPZ) reacted with Pd(II) to form 2:1 cationic chelate, which further reacted with Na2WO4to form a 1:1 ternary ion-association complex ([Pd(CPZ)2]·WO4). As a result, the signal intensities of RRS, SOS and FDS were enhanced greatly, and the enhancements of scattering were proportional to the CPZ concentration in a certain range. Their maximum wavelengths were located at 310 nm, 570 nm and 391 nm, respectively and the detection limits (3σ) were 1.6 ng/mL (RRS method), 3.2 ng/mL (SOS method) and 5.6 ng/mL (FDS method). The optimum reaction conditions, the influences of coexisting substances and analytical application were mainly investigated by RRS method due to its highest sensitivity. A highly sensitive, simple, rapid and new method had been proposed to determine CPZ in the pharmaceutical form and residue of CPZ in pork. In addition, the Gibbs free energy change (δGf) of ion-association reaction was computed by using B3LYP/3-21g*/LanL2dz method. The formation of ion-association and the reasons for the enhancement of RRS were also discussed.

The pathogenesis of LPS-induced acute kidney injury (AKI) requires signaling through tumor necrosis factor-α (TNF) receptor 1 (TNFR1), which within the kidney is primarily located in the endothelium. We showed previously that caspase inhibition protected mice against LPS-induced AKI and in parallel significantly inhibited LPS-induced renal inflammation. Therefore we hypothesized that caspase activation amplifies TNF-induced inflammation in renal endothelial cells (ECs). In cultured renal ECs, TNF induced apoptosis through a caspase-8-dependent pathway. TNF caused translocation of the p65 subunit of NF-κB to the nucleus, resulting in upregulation of inflammatory markers such as adhesion molecules ICAM-1 and VCAM-1. However, the broad-spectrum caspase inhibitor Boc-d-fmk reduced NF-kB activation as assessed by gel shift assay, reduced phosphorylation of subunit IκBα, and significantly inhibited TNF-induced expression of ICAM-1 and VCAM-1 as assessed by both real-time PCR and flow cytometry. Broad-spectrum caspase inhibition markedly inhibited neutrophil adherence to the TNF-activated endothelial monolayer, supporting the functional significance of this effect. Specific inhibitors of caspases-8 and -3, but not of caspase-1, reduced TNF-induced NF-κB activation. Caspase inhibition also reduced TNF-induced myosin light chain (MLC)-2 phosphorylation, and activation of upstream regulator RhoA. Consistent with this, MLC kinase (MLCK) inhibitor ML-7 reduced TNF-induced NF-κB activation. Thus caspase activation influences NF-κB signaling via its affect on cytoskeletal changes occurring through RhoA and MLCK pathways. These cell culture experiments support a role for caspase activation in TNF-induced inflammation in the renal endothelium, a key event in LPS-induced AKI.

Arsenic trioxide (As2O3) is highly effective for the treatment of acute promyelocytic leukemia, even in patients who are unresponsive to all-trans-retinoic acid therapy. As2O3is believed to function primarily by promoting apoptosis, but the underlying molecular mechanisms remain largely unknown. In this report, using cDNA arrays, we have examined the changes in gene expression profiles triggered by clinically achievable doses of As2O3in acute promyelocytic leukemia NB4 cells. CASPASE-10expression was found to be potently induced by As2O3. Accordingly, caspase-10 activity also substantially increased in response to As2O3treatment. A selective inhibitor of caspase-10, Z-AEVD-FMK, effectively blocked caspase-3 activation and significantly attenuated As2O3-triggered apoptosis. Interestingly, the treatment of NB4 cells with As2O3markedly increased histone H3 phosphorylation at serine 10, an event that is associated with acetylation of the lysine 14 residue. Chromatin immunoprecipitation assays revealed that As2O3potently enhances histone H3 phosphoacetylation at the CASPASE-10locus. These results suggest that the effect of As2O3on histone H3 phosphoacetylation at the CASPASE-10gene may play an important role in the induction of apoptosis and thus contribute to its therapeutic effects on acute promyelocytic leukemia.

Both the mitogen-activated protein kinase (MAPK) phosphatases MKP-1 and MKP-2 exert important feedback control of MAPK-mediated signaling events. The function of MKP-1 and MKP-2 is regulated via complex mechanisms, ranging from increased transcription of the MKP-1 and MKP-2 genes to post-translational catalytic activation of MKP-1 and MKP-2 proteins upon binding to their substrate MAPKs. In addition, MKP-1 stability increases upon ERK-dependent phosphorylation of two serine residues in its C-terminus. The C-terminal regions of MKP-1 and MKP-2, but not those of other MKPs, are homologous. To investigate the role of this domain, we have deleted the C-terminal tails from MKP-1 and MKP-2 and examined the effect of these deletions on their enzymatic activity. C-terminally truncated MKP-1 and MKP-2 exhibited, both in vivo and in vitro, substantially greater phosphatase activity towards their substrate MAPKs than did the full-length counterparts. However, C-terminal truncations did not significantly change either their substrate affinity, or their substrate-mediated catalytic activation. Basal phosphatase activity of the truncated proteins was also significantly higher than that of the wild-type counterparts. Collectively, these results suggest that the C-terminal domain may potentially play a role in the regulation of MKP-1 and MKP-2.

Mitogen-activated protein (MAP) kinase phosphatase-1 (MKP-1) is the archetypal member of the dual-specificity protein phosphatase family, the expression of which can be rapidly induced by a variety of growth factors and cellular stress. Since MKP-1 protein localizes in the nucleus, it has been suggested to play an important role in the feedback control of MAP kinase-regulated gene transcription. Recently it has been demonstrated that the interaction of several cytosolic MAP kinase phosphatases with MAP kinases can trigger the catalytic activation of the phosphatases. It is unclear whether such a regulatory mechanism can apply to nuclear MAP kinase phosphatases and serve as an additional apparatus for the feedback control of MAP kinase-mediated gene expression. Here we have shown that MKP-1 associates directly with p38 MAP kinase both in vivo and in vitro, and that this interaction enhances the catalytic activity of MKP-1. The point mutation Asp-316 → Asn in the C-terminus of p38, analogous to the ERK2 (extracellular-signal-regulated kinase 2) sevenmaker mutation, dramatically decreases its binding to MKP-1 and substantially compromises its stimulatory effect on the catalytic activity of this phosphatase. Consistent with its defective interaction with MKP-1, this p38 mutant also displays greater resistance to dephosphorylation by the phosphatase. Our studies provide the first example of catalytic activation of a nuclear MAP kinase phosphatase through direct binding to a MAP kinase, suggesting that such a regulatory mechanism may play an important role in the feedback control of MAP kinase signalling in the nuclear compartment.

Monitoring of mitochondrial redox states of the epicardium predicts impending myocardial dysfunction and cardiac arrest.

Internal tandem duplication (ITD) mutations in the FLT3 juxtamembrane domain lead to constitutive activation of FLT3 tyrosine kinase activity and cooperate in the oncogenic transformation of hematopoietic cells. Although numerous signaling molecules are known to be involved in FLT3/ITD signaling, the sites of interaction and mechanisms are not fully understood. In this study, FLT3/ITD protein was immunoprecipitated from TF-1/ITD cells and subjected to nanoLC-MS/MS analysis for determination of tyrosine phosphorylation sites. We found that tyrosine residue 842 (Y842) in the FLT3/ITD activation loop is constitutively phosphorylated. Mutation of this tyrosine residue to phenylalanine (FLT3/ITDY842F) reduces FLT3/ITD phosphorylation and activation of FLT3 downstream targets, including STAT5, AKT and ERK/MAPK. CEP-701, a selective FLT3 inhibitor, inhibits the proliferation of BaF3 cells expressing FLT3/ITD or FLT3/ITDY842F mutant with a similar potency. This implies CEP-701 targets FLT3/ITDY842F as effectively as FLT3/ITD. To identify the signaling pathway(s) initiated by FLT3/ITD Y842, SHP-2 and other molecules downstream of FLT3 were investigated. SHP-2 is known to be activated by FLT3 signaling and its interaction with Gab2 regulates the ERK/MAPK pathway. Previous studies also suggested that SHP-2 is possibly involved in STAT5 activation. Co-immunoprecipitation experiments revealed that SHP-2 association with the FLT3/ITDY842F mutant was considerably diminished as compared to the FLT3/ITD receptor. In addition, the interaction of SHP-2 with Gab2 adaptor protein was greatly compromised in FLT3/ITDY842F expressing BaF3 cells. Taken together, our data suggests that SHP-2 binds FLT3/ITD, either directly or indirectly, and contributes to the signaling pathways activated by mutant FLT3.

Internal tandem duplication (ITD) mutations in the FLT3 juxtamembrane domain lead to constitutive activation of FLT3 tyrosine kinase activity and cooperate in the oncogenic transformation of hematopoietic cells. Although numerous signaling molecules are known to be involved in FLT3/ITD signaling, the sites of interaction and mechanisms are not fully understood. In this study, FLT3/ITD protein was immunoprecipitated from TF-1/ITD cells and subjected to nanoLC-MS/MS analysis for determination of tyrosine phosphorylation sites. We found that tyrosine residue 842 (Y842) in the FLT3/ITD activation loop is constitutively phosphorylated. Mutation of this tyrosine residue to phenylalanine (FLT3/ITDY842F) reduces FLT3/ITD phosphorylation and activation of FLT3 downstream targets, including STAT5, AKT and ERK/MAPK. CEP-701, a selective FLT3 inhibitor, inhibits the proliferation of BaF3 cells expressing FLT3/ITD or FLT3/ITDY842F mutant with a similar potency. This implies CEP-701 targets FLT3/ITDY842F as effectively as FLT3/ITD. To identify the signaling pathway(s) initiated by FLT3/ITD Y842, SHP-2 and other molecules downstream of FLT3 were investigated. SHP-2 is known to be activated by FLT3 signaling and its interaction with Gab2 regulates the ERK/MAPK pathway. Previous studies also suggested that SHP-2 is possibly involved in STAT5 activation. Co-immunoprecipitation experiments revealed that SHP-2 association with the FLT3/ITDY842F mutant was considerably diminished as compared to the FLT3/ITD receptor. In addition, the interaction of SHP-2 with Gab2 adaptor protein was greatly compromised in FLT3/ITDY842F expressing BaF3 cells. Taken together, our data suggests that SHP-2 binds FLT3/ITD, either directly or indirectly, and contributes to the signaling pathways activated by mutant FLT3.

Constitutively activating internal tandem duplication (ITD) mutations of the receptor tyrosine kinase FLT3 play an important role in leukemogenesis. They are the most common genetic alteration in AML and their presence is associated with poor prognosis. To better understand FLT3 signaling in leukemogenesis, we have examined the changes in gene expression induced by FLT3/ITD or constitutively activated wild type FLT3 signaling by cDNA microarray analysis. In order to minimize gene expression changes that might be drug specific and not related to FLT3 inhibition or might be cell-type specific, we used three different FLT3 inhibitors, CEP-701, CEP-5214, and AG1296, and three different constitutively activated FLT3-expressing leukemia-derived cell lines, EOL-1, MOLM-14 and MV4-11. We considered to be FLT3 responsive only those genes whose expression consistently changed in response to FLT3 inhibition by each of the three FLT3 inhibitors in all of the cell lines. RNA for hybridization to the microarrays was harvested from cells both before and after increasing times of FLT3 inhibition to determine genes which decreased or increased in response to FLT3 signaling. In addition, because the inhibitors are all reversible, RNA was also harvested from the cells at increasing times after release from FLT3 inhibition. This enabled us to confirm that, for example, genes whose expression appeared FLT3 dependent and were thus down-regulated by FLT3 inhibition, returned towards normal levels after FLT3 signaling was allowed to resume. Statistical analysis of the microarray results indicated a limited set of genes are highly and consistently affected by FLT3 inhibition and return toward pretreatment levels after release from inhibitor. We confirmed the cDNA microarray data using quantitative real-time PCR. Several of the most significantly affected genes are involved in the Ras/MAPK pathway including DUSP6, DUSP7, MAPK6, TNF, and cMyc. Other sets of genes are involved in JAK/STAT or Wnt signaling pathways including Pim-1, cMyc, Cyclin D3, IL4 receptor, and CISH. These genes are all consistently down-regulated after FLT3 inhibition. These data further confirm the role of constitutively activating FLT3 in mediating multiple signal transduction pathways. We also found several transcriptional factors (RUNX1/AML1, MAFG, XBP1, TGFBI4, and BRD8), several genes involved in receptor-mediated signaling (IL1RAP, CDC42EP3, PLAUR, LY64), and several genes involved in cell proliferation, metabolism, or structure (BCL7A, APTX, GHRH, SET7, ATAD2, CLIC1, CRIP2, MRPL12, VIM) to be consistently differentially expressed. In summary, we have found by cDNA microarray analysis and confirmed by QPCR, a consistent pattern of FLT3 dependent gene expression. The alteration of the gene expression profile in these cells is likely the mechanism of FLT3-mediated leukemogenisis.

Constitutively activating internal tandem duplication (ITD) mutations of the receptor tyrosine kinase FLT3 play an important role in leukemogenesis. They are the most common genetic alteration in AML and their presence is associated with poor prognosis. To better understand FLT3 signaling in leukemogenesis, we have examined the changes in gene expression induced by FLT3/ITD or constitutively activated wild type FLT3 signaling by cDNA microarray analysis. In order to minimize gene expression changes that might be drug specific and not related to FLT3 inhibition or might be cell-type specific, we used three different FLT3 inhibitors, CEP-701, CEP-5214, and AG1296, and three different constitutively activated FLT3-expressing leukemia-derived cell lines, EOL-1, MOLM-14 and MV4-11. We considered to be FLT3 responsive only those genes whose expression consistently changed in response to FLT3 inhibition by each of the three FLT3 inhibitors in all of the cell lines. RNA for hybridization to the microarrays was harvested from cells both before and after increasing times of FLT3 inhibition to determine genes which decreased or increased in response to FLT3 signaling. In addition, because the inhibitors are all reversible, RNA was also harvested from the cells at increasing times after release from FLT3 inhibition. This enabled us to confirm that, for example, genes whose expression appeared FLT3 dependent and were thus down-regulated by FLT3 inhibition, returned towards normal levels after FLT3 signaling was allowed to resume. Statistical analysis of the microarray results indicated a limited set of genes are highly and consistently affected by FLT3 inhibition and return toward pretreatment levels after release from inhibitor. We confirmed the cDNA microarray data using quantitative real-time PCR. Several of the most significantly affected genes are involved in the Ras/MAPK pathway including DUSP6, DUSP7, MAPK6, TNF, and cMyc. Other sets of genes are involved in JAK/STAT or Wnt signaling pathways including Pim-1, cMyc, Cyclin D3, IL4 receptor, and CISH. These genes are all consistently down-regulated after FLT3 inhibition. These data further confirm the role of constitutively activating FLT3 in mediating multiple signal transduction pathways. We also found several transcriptional factors (RUNX1/AML1, MAFG, XBP1, TGFBI4, and BRD8), several genes involved in receptor-mediated signaling (IL1RAP, CDC42EP3, PLAUR, LY64), and several genes involved in cell proliferation, metabolism, or structure (BCL7A, APTX, GHRH, SET7, ATAD2, CLIC1, CRIP2, MRPL12, VIM) to be consistently differentially expressed. In summary, we have found by cDNA microarray analysis and confirmed by QPCR, a consistent pattern of FLT3 dependent gene expression. The alteration of the gene expression profile in these cells is likely the mechanism of FLT3-mediated leukemogenisis.