Long noncoding RNA (lncRNA) have critical roles in various pathophysiological processes, and are frequently dysregulated in many diseases, particularly in cancer. The lncRNA glypican 3 antisense ...transcript 1 (GPC3‐AS1) has been reported to be a potential biomarker for hepatocellular carcinoma (HCC) screening. However, the exact biological functions of GPC3‐AS1 in HCC, and its roles and regulation mechanisms regarding GPC3 are still unknown. In this study, we observed a significant upregulation of GPC3‐AS1 in HCC. Increased expression of GPC3‐AS1 was associated with α‐fetoprotein, tumor size, microvascular invasion, encapsulation, Barcelona Clinic Liver Cancer stage, and worse prognosis of HCC patients. Furthermore, we found that GPC3‐AS1 physically associated with P300/CBP‐associated factor and recruited it to the GPC3 gene body region, consequently inducing an increase in euchromatic histone marks and activating GPC3 transcription. GPC3‐AS1 expression was strongly correlated with GPC3 in HCC tissues. Gain‐of‐function and loss‐of‐function analyses showed that GPC3‐AS1 overexpression enhanced HCC cell proliferation and migration in vitro and xenograft tumor growth in vivo. GPC3‐AS1 knockdown inhibited HCC cell proliferation and migration. Moreover, the effects of GPC3‐AS1 on HCC cell proliferation and migration were dependent on the upregulation of GPC3. Collectively, our studies indicate that GPC3‐AS1 significantly promotes HCC progression via epigenetically activating GPC3, and identifies GPC3‐AS1 as a potential therapeutic target for HCC.
The long noncoding RNA GPC3‐AS1 is significantly upregulated in hepatocellular carcinoma (HCC) and indicates poor prognosis of HCC patients. GPC3‐AS1 physically associates with P300/CBP‐associated factor (PCAF) and recruits it to the GPC3 gene body region, consequently inducing an increase in euchromatic histone marks and activating GPC3 transcription. GPC3‐AS1 overexpression enhances HCC cell proliferation and migration in vitro and xenograft tumour growth in vivo.
Allosteric modulation provides exciting opportunities for drug discovery of enzymes, ion channels, and G protein-coupled receptors. As cation channels gated by extracellular ATP, P2X receptors have ...attracted wide attention as new drug targets. Although small molecules targeting P2X receptors have entered into clinical trials for rheumatoid arthritis, cough, and pain, negative allosteric modulation of these receptors remains largely unexplored. Here, combining X-ray crystallography, computational modeling, and functional studies of channel mutants, we identified a negative allosteric site on P2X3 receptors, fostered by the left flipper (LF), lower body (LB), and dorsal fin (DF) domains. Using two structurally analogous subtype-specific allosteric inhibitors of P2X3, AF-353 and AF-219, the latter being a drug candidate under phase II clinical trials for refractory chronic cough and idiopathic pulmonary fibrosis, we defined the molecular interactions between the drugs and receptors and the mechanism by which allosteric changes in the LF, DF, and LB domains modulate ATP activation of P2X3. Our detailed characterization of this druggable allosteric site should inspire new strategies to develop P2X3-specific allosteric modulators for clinical use.
Resina Draconis is a traditional Chinese medicine, with the in-depth research, its medicinal value in anti-tumor has been revealed. Loureirin A is extracted from Resina Draconis, however, research on ...the anti-tumor efficacy of Loureirin A is rare. Herein, we investigated the function of Loureirin A in melanoma. Our research demonstrated that Loureirin A inhibited the proliferation of and caused G0/G1 cell cycle arrest in melanoma cells in a concentration-dependent manner. Further study showed that the melanin content and tyrosinase activity was enhanced after Loureirin A treatment, demonstrated that Loureirin A promoted melanoma cell differentiation, which was accompanied with the reduce of WNT signaling pathway. Meanwhile, we found that Loureirin A suppressed the migration and invasion of melanoma cells through the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway. Taken together, this study demonstrated for the first time the anti-tumor effects of Loureirin A in melanoma cells, which provided a novel therapeutic strategy against melanoma.
Quantifying plant carbon (C) allocation among different pools is critical for understanding and predicting how C turnover responds to global climate change in terrestrial ecosystems. A field ...experiment with increasing warming and nitrogen (N) was established to investigate interactive effects on plant C allocation in alpine meadows. Open-top chambers (OTCs) were used to simulate warming. In OTCs, daytime air and soil temperature at 5 cm depth increased by 2.0 and 1.6 °C, respectively, compared with ambient conditions, but soil moisture at 5 cm depth decreased by 4.95% (v/v) from 2012 to 2014. Warming reduced aboveground biomass by 38, 36, and 43% in 2012, 2013, and 2014, respectively, and increased belowground biomass by 64% and 29% in 2013 and 2014, respectively, and the root-to-shoot ratio was significantly increased. Specifically, warming increased the proportion of plant roots in the deep layers (10–20 cm). Both N addition and its combination with warming substantially enhanced belowground biomass. Pulse-labeling experiments for
13
C revealed that warming reduced the translocation of assimilated C to shoots by 8.8% (38.7% in warming, and 47.5% in the control CK), and increased the allocation to root by 12.2% (55.5% in warming, and 43.3% in CK) after 28 days labeling. However, N addition increased the proportion of assimilated C allocated to shoots by 6.5% (54.0% in N addition, and 47.5% in CK), whereas warming combined with N addition reduced this proportion by 10.9%. A decline in soil water content in the surface layer may be the main cause of plants allocating more newly fixed photosynthate to roots. Therefore, plants promoted root growth to draw water from deeper soil layers (10–20 cm). We concluded that climate warming will change the allocation patterns of plant photosynthates by affecting soil water availability, whereas N addition will increase plant photosynthates aboveground in alpine meadows and thus will significantly affect C turnover under future climate change scenarios.
Platinum (Pt) nanocatalysts as the best catalysts for direct methanol fuel cell (DMFC) still face a huge challenge such as high cost, low utilization rate, activity and stability to be improved. ...Adjusting the surface structure of Pt nanoparticles (NPs) to achieve high-index facets with more active sites is an effective method to resolve the problems. Furthermore, the controlled synthesis of high-index faceted Pt (HIF-Pt) nanocatalysts directly on carbon paper, which is an important component of membrane electrode, can greatly promote the practical application of HIF-Pt nanocatalysts in DMFC. Herein, the HIF-Pt nanocatalysts supported on carbon paper (HIF-Pt/CP) were realized by developing an electrochemically controlled synthesis method. The fishbone-like and concave cube shaped Pt NPs surrounded by some high-index facets such as (200), (220), and (311), were achieved by adjusting the frequency and treatment time of applied potential. Hence, these HIF-Pt/CPs exhibit excellent activity and stability towards methanol electrooxidation during both cyclic voltammetry characterization and potentiostatic test. Especially, the specific activities and mass activities of HIF-Pt/CP-1 Hz reached 3.78 mA·cm
−2
and 1.53 A·mg
−1
, which were 6.5 and 2.78 times higher than those of commercial Pt/C, respectively. And the direct growth of HIF-Pt NPs on carbon paper effectively improves the stability of the catalyst layer which shows great potential in the practical application in DMFC.
Graphical Abstract
P2X receptors are ATP-gated ion channels involved in many physiological functions, and determination of ATP-recognition (AR) of P2X receptors will promote the development of new therapeutic agents ...for pain, inflammation, bladder dysfunction and osteoporosis. Recent crystal structures of the zebrafish P2X4 (zfP2X4) receptor reveal a large ATP-binding pocket (ABP) located at the subunit interface of zfP2X4 receptors, which is occupied by a conspicuous cluster of basic residues to recognize triphosphate moiety of ATP. Using the engineered affinity labeling and molecular modeling, at least three sites (S1, S2 and S3) within ABP have been identified that are able to recognize the adenine ring of ATP, implying the existence of at least three distinct AR modes in ABP. The open crystal structure of zfP2X4 confirms one of three AR modes (named AR1), in which the adenine ring of ATP is buried into site S1 while the triphosphate moiety interacts with clustered basic residues. Why architecture of ABP favors AR1 not the other two AR modes still remains unexplored. Here, we examine the potential role of inherent dynamics of head domain, a domain involved in ABP formation, in AR determinant of P2X4 receptors. In silico docking and binding free energy calculation revealed comparable characters of three distinct AR modes. Inherent dynamics of head domain, especially the downward motion favors the preference of ABP for AR1 rather than AR2 and AR3. Along with the downward motion of head domain, the closing movement of loop139-146 and loop169-183, and structural rearrangements of K70, K72, R298 and R143 enabled ABP to discriminate AR1 from other AR modes. Our observations suggest the essential role of head domain dynamics in determining AR of P2X4 receptors, allowing evaluation of new strategies aimed at developing specific blockers/allosteric modulators by preventing the dynamics of head domain associated with both AR and channel activation of P2X4 receptors.
Significant progress has been made in understanding the roles of crucial residues/motifs in the channel function of P2X receptors during the pre-structure era. The recent structural determination of ...P2X receptors allows us to reevaluate the role of those residues/motifs. Residues Arg-309 and Asp-85 (rat P2X4 numbering) are highly conserved throughout the P2X family and were involved in loss-of-function polymorphism in human P2X receptors. Previous studies proposed that they participated in direct ATP binding. However, the crystal structure of P2X demonstrated that those two residues form an intersubunit salt bridge located far away from the ATP-binding site. Therefore, it is necessary to reevaluate the role of this salt bridge in P2X receptors. Here, we suggest the crucial role of this structural element both in protein stability and in channel gating rather than direct ATP interaction and channel assembly. Combining mutagenesis, charge swap, and disulfide cross-linking, we revealed the stringent requirement of this salt bridge in normal P2X4 channel function. This salt bridge may contribute to stabilizing the bending conformation of the β2,3-sheet that is structurally coupled with this salt bridge and the α2-helix. Strongly kinked β2,3 is essential for domain-domain interactions between head domain, dorsal fin domain, right flipper domain, and loop β7,8 in P2X4 receptors. Disulfide cross-linking with directions opposing or along the bending angle of the β2,3-sheet toward the α2-helix led to loss-of-function and gain-of-function of P2X4 receptors, respectively. Further insertion of amino acids with bulky side chains into the linker between the β2,3-sheet or the conformational change of the α2-helix, interfering with the kinked conformation of β2,3, led to loss-of-function of P2X4 receptors. All these findings provided new insights in understanding the contribution of the salt bridge between Asp-85 and Arg-309 and its structurally coupled β2,3-sheet to the function of P2X receptors.
This study was the first report about complete chloroplast genome of Aster hypoleucus (Asteraceae, Astereae), an endemic species in Xizang (China). The circular whole cp genome of A. hypoleucus was ...152,300 bp in length, contained a large single-copy (LSC) region of 84,031 bp and a small single-copy (SSC) region of 18,269 bp. These two regions were separated by a pair of inverted repeat regions (IRa and IRb), each of them 25,000 bp in length. A total of 134 functional genes were encoded, consisted of 89 protein-coding genes, 37 tRNA genes, and eight rRNA genes. The overall GC content of the chloroplast genome sequence was 37.3%, and the GC contents of the LSC, SSC, and IR regions were 35.2%, 31.2%, and 43.0%, respectively.
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•The deformed Co-N4 sites are anchored on the in-situ grown CNTs.•The deformed Co-N4 sites on CNTs can enhance O2 activation.•The CNTs effectively slows down the oxidation of carbon ...carrier.•The PEMFC assembled by Co-N/C-1/4.4 cathode shows a potential application value.
Cobalt-nitrogen/carbon (Co-N/C) was considered as the promising catalyst for oxygen reduction reaction (ORR). The combination of dense single-atom active site density and serviceable proton electronic conductivity is the key to improve the activity and stability of the catalyst in proton exchange membrane fuel cells. Herein, we achieved the in-situ growth of massive carbon nanotubes (CNTs) during the synthesis of Co-N/C catalysts by precisely regulating the ratio of reactants in the metal–organic framework precursors. Notably, the dense deformed Co-N4 sites were anchored on the in-situ grown CNTs, improving the triple-phase boundary and proton electronic conductivity of membrane electrode assemblies (MEA). Benefiting from the unique structure of dense Co-N4 sites anchored on CNTs, the target catalyst Co-N/C-1/4.4 exhibited high activity in both ORR (half-wave potential: 0.781 V, kinetic current@0.80 V = 2.25 mA cm−2) and fuel cell (H2-Air: 0.49 W cm−2) tests. And the in-situ grown CNTs with high graphitization degree led to a significant improvement in the stability of the catalyst (10 mV decay of half-wave potential after 30,000 cycles). We believe this research may provide new understanding into the development of non-PGM electrocatalysts with high performance at the atomic scale.
The aim of this study was to evaluate the diagnostic performance of serum HA and LN as serum markers for predicting significant fibrosis in CHB patients.
Serum HA and LN levels of 87 patients with ...chronic hepatitis B and 19 blood donors were assayed by RIA. Liver fibrosis stages were determined according to the Metavir scoring-system. The diagnostic performances of all indexes were evaluated by the receiver operating characteristic (ROC) curves.
Serum HA and LN concentrations increased significantly with the stage of hepatic fibrosis, which showed positive correlation with the stages of liver fibrosis (HA: r =0.875, p <0.001; LN: r =0.610, p <0.001). There were significant differences of serum HA and LN levels between F2-4 group in comparison with those in F0-F1 group (p < 0.001) and controls (p < 0.001), respectively. From ROC curves, 185.3ng/mL as the optimal cut-off value of serum HA for diagnosis of significant fibrosis, giving its sensitivity, specificity, PPV, NPV, LR+, LR- and AC of 84.2%, 83.3%, 90.6%, 73.5%, 5.04, 0.19 and 83.9, respectively. While 132.7 ng/mL was the optimal cut-off value of serum LN, the sensitivity, specificity, PPV, NPV, LR+, LR-and AC were 71.9%, 80.0%, 87.2%, 60.0%, 3.59%, 0.35% and 74.7, respectively. Combinations of HA and LN by serial tests showed a perfect specificity and PPV of 100%, at the same time sensitivity declined to 63.2% and LR+ increased to 18.9, while parallel tests revealed a good sensitivity of 94.7%, NPV to 86.4%, and LR- declined to 0.08.
Serum HA and LN concentrations showed positive correlation with the stages of liver fibrosis. Detection of serum HA and LN in predicting significant fibrosis showed good diagnostic performance, which would be further optimized by combination of the two indices. HA and LN would be clinically useful serum markers for predicting significant fibrosis in patients with chronic hepatitis B, when liver biopsy is contraindicated.
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