• Albright Drejer posted an update 1 week, 3 days ago

    MAPK1 or ERBB4 overexpression rescued the effects of miR-326 on proliferation, migration and invasion in PTC cells. Notably, miR-326 reduced tumorigenesis in vivo, including the decrease of tumor volume and weight, suppression of Ki-67, N-cadherin, MAPK1 and ERBB4. In all, these results might provide a new therapeutic target for the diagnosis of PTC.Proline is found in a cis conformation in proteins more often than other proteinogenic amino acids, where it influences structure and modulates function, being the focus of several high-resolution structural studies. However, until now, technical and methodological limitations have hampered the site-specific investigation of the conformational preferences of prolines present in poly proline (poly-P) homorepeats in their protein context. Here, we apply site-specific isotopic labeling to obtain high-resolution NMR data on the cis/trans equilibrium of prolines within the poly-P repeats of huntingtin exon 1, the causative agent of Huntington’s disease. Screening prolines in different positions in long (poly-P11) and short (poly-P3) poly-P tracts, we found that, while the first proline of poly-P tracts adopts similar levels of cis conformation as isolated prolines, a length-dependent reduced abundance of cis conformers is observed for terminal prolines. Interestingly, the cis isomer could not be detected in inner prolines, in line with percentages derived from a large database of proline-centered tripeptides extracted from crystallographic structures. These results suggest a strong cooperative effect within poly-Ps that enhances their stiffness by diminishing the stability of the cis conformation. This rigidity is key to rationalizing the protection toward aggregation that the poly-P tract confers to huntingtin. Furthermore, the study provides new avenues to probe the structural properties of poly-P tracts in protein design as scaffolds or nanoscale rulers.Ion migration has been recognized as a critical step in determining the performance of numerous devices in chemistry, biology, and material science. However, direct visualization and quantitative investigation of solid-phase ion migration among anisotropic nanostructures have been a challenging task. Here, we report an in-situ ChemTEM method to quantitatively investigate the solid-phase ion migration process among coassembled nanowires (NWs). This complicated process was tracked within a NW and between NWs with an obvious nanogap, which was revealed by both phase field simulation and ab initio modeling theoretical evaluation. A migration “bridge” between neighboring NWs was observed. Furthermore, these new observations could be applied to migration of other metal ions on semiconductor NWs. These findings provide critical insights into the solid-phase ion migration kinetics occurring in nanoscale systems with generality and offer an efficient tool to explore other ion migration processes, which will facilitate fabrication of customized and new heteronanostructures in the future.Designing highly efficient catalysts for use in fuel production is a highly attractive research area but still remains challenging. Herein, for the first time, ultrafine Ni nanoparticles (NPs) self-assembled on ceria nanowires (NWs) and then embedded in a microporous silica shell (denoted as Ni-CeO2@SiO2) are successfully designed and synthesized via a one-pot facile strategy. The average diameter of Ni-CeO2 NWs is just 2.9 nm, and the length is up to 102.7 nm. The resulting Ni-CeO2@SiO2 exhibits high performance and 100% hydrogen selectivity for H2 production from N2H4 and N2H4BH3 in aqueous solution. Unexpectedly, Ni-CeO2@SiO2 also has good catalytic performance and thermal stability for CO2 methanation. The high catalytic performance of Ni-CeO2@SiO2 can be attributed to the synergistic electronic effect and strong interaction between Ni NPs and CeO2 NWs with plenty of oxygen vacancies, as well as the unique structure effect. As an effective strategy, the present work provides an opportunity to embed ultrafine metal NPs-CeO2 NWs into a microporous silica shell, which has broad application prospects in various catalytic fields.Identification of peptides in species lacking fully-sequenced genomes is challenging due to the lack of prior knowledge. De novo sequencing is the method of choice, but its performance is less than satisfactory due to algorithmic bias and interference in complex MS/MS spectra. The task becomes even more challenging for endogenous peptides that do not involve an enzymatic digestion step, such as neuropeptides. However, many neuropeptides possess common sequence motifs that are conserved across members of the same family. Taking advantage of this feature to improve de novo sequencing of neuropeptides, we have developed a method named PRESnovo (prescreening precursors prior to de novo sequencing) to predict the motif from a MS/MS spectrum. A neuropeptide sequence is broken into a motif with conserved amino acid residues and the remaining partial sequence. By searching against a predefined motif database constructed from known homologous sequences, PRESnovo assigns the most probable motif to each precursor via a sophisticated scoring function. Performance analysis was conducted with 15 neuropeptide standards, and 11 neuropeptides were correctly identified with PRESnovo compared to 1 identification by PEAKS only. We applied PRESnovo to assign motifs to peptide sequences in conjunction with PEAKS for assigning the rest of the peptide sequence in order to discover neuropeptides in tissue samples of green crab, C. maenas, and Jonah crab, C. borealis. Collectively, a large number of neuropeptides were identified, including 13 putative neuropeptides identified in green crab brain, 77 in Jonah crab brain, and 47 in Jonah crab sinus glands for the first time. This PRESnovo strategy greatly simplifies de novo sequencing and enhances the accuracy and sensitivity of neuropeptide identification when common motifs are present.Metastasis is one of the ongoing challenges in cancer therapy which most treatments failed to address. Inspired by the upregulated expression of both integrin β1 and heparan sulfate in metastatic tumors, we developed an integrin/HS dual-targeting peptide assembly that selectively inhibits cancer cell migration and invasion. Particularly, the dual-targeting peptide self-assembles into nanofibrous microdomains specifically on the cancer cell membrane, triggering spatial organization of integrins, which form clusters on the apical membrane. Via the actin cytoskeleton that physically connects to integrin clusters, the oncogene yes-associated protein, which regulates cancer metastasis, is deactivated. We showed that in multiple cancer cell lines, including the highly metastatic pancreatic cancer cells, the dual-targeting peptide exerts potent and dose-dependent antimetastatic effects. Our work illustrates how basic biochemical insights can be exploited as the basis for nano-biointerface fabrication, which is potentially a general design strategy for nanomedicine development.Microbial production of many lipophilic compounds is often limited by product toxicity to host cells. Engineering cell walls can help mitigate the damage caused by lipophilic compounds by increasing tolerance to those compounds. To determine if the cell wall engineering would be effective in enhancing lipophilic compound production, we used a previously constructed squalene-overproducing yeast strain (SQ) that produces over 600 mg/L of squalene, a model membrane-damaging lipophilic compound. This SQ strain had significantly decreased membrane rigidity, leading to increased cell lysis during fermentation. The SQ strain was engineered to restore membrane rigidity by activating the cell wall integrity (CWI) pathway, thereby further enhancing its squalene production efficiency. Maintenance of CWI was associated with improved squalene production, as shown by cell wall remodeling through regulation of Ecm33, a key regulator of the CWI pathway. Deletion of ECM33 in the SQ strain helped restore membrane rigidity and improve stress tolerance. Moreover, ECM33 deletion suppressed cell lysis and increased squalene production by approximately 12% compared to that by the parent SQ strain. Thus, this study shows that engineering of the yeast cell wall is a promising strategy for enhancing the physiological functions of industrial strains for production of lipophilic compounds.Aggregation of polypeptides and proteins is commonly associated with human and other vertebrate diseases. find more For example, amyloid plaques consisting of amyloid-β proteins are frequently identified in Alzheimer’s disease and islet amyloid formed by islet amyloid polypeptide (IAPP, amylin) can be found in most patients with type 2 diabetes (T2D). Although many fluorescent dyes have been developed to stain amyloid fibrils, very few examples have been designed for IAPP. In this study, a series of environmentally sensitive fluorescent probes using flavonoid as a scaffold design are rationally designed and synthesized. One of these probes, namely 3-HF-ene-4′-OMe, can bind to IAPP fibrils but not nonfibrillar IAPP by exhibiting a much stronger fluorescent enhancement at 535 nm. In addition, this probe shows better detection sensitivity to IAPP fibrils compared with that of conventionally used thioflavin-T. We demonstrate that 3-HF-ene-4′-OMe can be used to monitor the kinetics of IAPP fibril formation in vitro even in the presence an amyloid inhibitor. To test the specificity of the probe, we attempt to incubate this probe with amyloid fibrils formed from other amyloidogenic proteins. Interestingly, this probe shows different responses when mixed with these fibrils, suggesting the mode of binding of this probe on these fibrils could be different. Moreover, we show that this probe is not toxic to pancreatic mouse β-cells. Further structural optimization based on the structure of 3-HF-ene-4′-OMe may yield a specific probe for imaging islet amyloid in the pancreas. That would improve our understanding of the relationship between islet amyloid and T2D.As one of the representative metallic hollow nanostructures, Au nanoframes have shown fascinating properties such as strong localized surface plasmon resonance (LSPR) associated with the emerging application as surface-enhanced Raman scattering (SERS) sensors. In this study, it is demonstrated, for the first time, a facile one-pot synthetic approach for hollow Au nanoframes by directly etching Au nanoplates, i.e. so-called self-templates. A novel growth mechanism has been revealed that involves a synergistic function of Ag and Br ions. The presence of Ag+ lead to observed self-limiting of Au film thickness whereas Au 111 facets are preferentially attacked by the presence of Br- in the reaction ambient. More importantly, graphene is introduced to prevent/minimize aggregation during the formation of Au nanoframes. Combined simulation and experimental studies show that the hybrid platform made of graphene/Au nanoframes is capable of detecting analytes at concentration levels down to 10-9 M by using the SERS technique.For light-emitting polymers with a deep highest occupied molecular orbital energy level used for polymer light-emitting diodes (PLEDs), the hole injection barrier and hole transport of the anode buffer layer are of vital importance for optimized electroluminescent performance. In this study, high-work-function hole injection layers with nanotextures were achieved by modifying poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOTPSS) with a perfluorinated ionomer (PFI) and n-butyl alcohol, and were used to achieve a single-layer device without a hole transport layer. With such an interlayer, the PLEDs based on PPF-SO25 exhibit remarkable current efficiency over 13.0 cd A-1, which is significantly outperform the devices with regular PEDOTPSS. To our knowledge, this performance is among the best reported for single-layer blue PLEDs. The bias-dependent capacitance curves of these PLEDs suggest a nonuniform surface distribution of PFI. Our findings show that the PFI-modified PEDOTPSS not only operates as a high-work-function hole injection layer to facilitate hole injection, but also a potential inner scattering medium for light extraction.