Cryo-EM structure of human HCN3 channel and its regulation by cAMP.

HCN channels are important for regulating heart rhythm and nerve activity and have been studied as potential drug targets for treating depression, arrhythmia, nerve pain, and epilepsy. Despite possessing unique pharmacological properties, HCN channels share common characteristics in that they are activated by hyperpolarization and modulated by cAMP and other membrane lipids. However, the mechanisms of how these ligands bind and modulate HCN channels are unclear. In this study, we solved structures of full-length human HCN3 using cryo-EM and captured two different states, including a state without any ligand bound and a state with cAMP bound. Our structures reveal the novel binding sites for cholesteryl hemisuccinate in apo state and show how cholesteryl hemisuccinate and cAMP binding cause conformational changes in different states. These findings explain how these small modulators are sensed in mammals at the molecular level. The results of our study could help to design more potent and specific compounds to influence HCN channel activity and offer new therapeutic possibilities for diseases that lack effective treatment.

Prokaryotic expression of soluble IFN-λ1 recombinant protein with cold-shock system.

Interferon (IFN)-λ1, a member of type III IFN, possesses unique antiviral, anti-tumor, and immune modulation properties. IFN-λ alone or combined with other drugs is considered an essential therapeutic regimen in the clinic. Obtaining high-quality, biologically-active recombinant human IFN-λ1 (rhIFN-λ1) is of great practical significance. In this study, pCold-II-IFN-λ1 expression plasmid was correctly constructed, the rhIFN-λ1 was expressed in BL21(DE3) E.coli and reached the highest level under the optimal condition of 15 °C culture temperature and at 1 µg/L IPTG induction for 12 h. The soluble rhIFN-λ1 was purified by Ni-NTA affinity chromatography. The purified rhIFN-λ1 can effectively activate the JAK1-STAT1 signaling pathway and induce the expression of a large number of interferon-stimulated genes (ISG) including ISG15, ISG54, ISG56, TRAIL, OAS1, MX1, IRF7 and IRF9. In addition, rhIFN-λ1 can effectively inhibit the growth/proliferation of cervical cancer HeLa cells in a dose-dependent pattern. Collectively, the soluble rhIFN-λ1 was successfully expressed in BL21(DE3) E.coli with the cold-shock system, and the purified rhIFN-λ1 demonstrated excellent biological activity. This study lays a solid basis for acquiring high-quality rhIFN-λ1 and its clinical application.

π-Stacking-Controlled Dearomatic Sulfur-Shifted Ene Reaction of Ketenes and Polycyclic Arylthiiranes: Access to Areno[d]-ε-thiolactones.

Electrophilic ring-expansion of polycyclic arylthiiranes and ketenes generated from alkoxy/aryloxyacetyl chlorides in the presence of triethylamine (TEA) is developed and provides a new strategy for the synthesis of areno[d]-ε-thiolactones, areno[d]thiepinones, directly without catalysts or additives. This strategy features atom- and step-economic one-pot characteristic via a tandem sequence of in situ ketene generation, π-stacking-controlled dearomatic sulfur-shifted ene, and aromatization. The current reaction is a novel strategy of electrophilic ring expansions of three-membered saturated heterocycles.

Interferon gamma regulates a complex pro-survival signal network in chronic lymphocytic leukemia.

BACKGROUND: It is known that the microenvironmental cytokine interferon gamma (IFN-γ) provides a survival advantage for chronic lymphocytic leukemia (CLL) cells. However, the mechanisms involved in this effect have not been properly investigated. METHODS: Herein, we conducted a comprehensive screening of the effects of IFN-γ on signaling pathways and gene expression profiles in CLL cells by using western blotting, real-time quantitative reverse transcription (RT-qPCR) and high-throughput RNA sequencing (RNA-seq). RESULTS: We found that IFN-γ not only activated the pro-survival signal transducer and activator of transcription 3 (STAT3), but also activated the protein kinase B and extracellular signal-regulated kinase signaling pathways. RNA-seq analysis showed that IFN-γ stimulation changed the expression profiles of more than 500 genes, with 391 being up-regulated and 123 down-regulated. These genes are involved in numerous biological processes, including anti-apoptosis, cell migration, and proliferation. IFN-γ significantly up-regulated the expression of CD38, BCL6, CXCL9, BCL2A1, SCOS3, IL-10, HGF, EGFR, THBS-1, FN1, and MUC1, which encode proteins potentially associated with disease progression, worse prognosis or poor response to treatment. Blocking janus kinases1/2 (JAK1/2) or STAT3 signal by specific inhibitors affected the expression of most genes, suggesting a pivotal role of the JAK1/2-STAT3 pathway in IFN-γ pro-survival effects in CLL. CONCLUSIONS: Our data demonstrate that IFN-γ regulates a complex pro-survival signal network in CLL through JAK1/2-STAT3, which provides a rational explanation for IFN-γ promoting CLL cells survival and drug resistance.

Theoretical mechanistic insights into the electrophilic addition of hydrogen halides to alkynes.

The electrophilic addition of hydrogen halides to alkynes, also called polar hydrohalogenation of alkynes, is one of the most classical and important organic reactions. Mechanistic and stereoselective insights into the hydrohalogenation of various structurally different distinct alkynes, including both alkyl and aryl substituted acetylenes, in acetic acid were investigated theoretically via density functional theory (DFT) calculations. The results indicate that π-complexes between hydrogen halides and alkynes are first formed, and then all alkynes can undergo a competitive bimolecular intimate ion-pair syn-addition process and a pentamolecular concerted anti-addition process through the cyclic proton transfer mechanism for proton transfer in the absence of tetraalkylammonium halides or a termolecular electrophilic addition (AdE3) process in the presence of tetraalkylammonium halides. All aliphatic alkynes undergo slightly to obviously predominant anti-addition in hydrohalogenations both in the absence and presence of tetraalkylammonium halides. Aromatic 1-arylalk-1-ynes favour syn-additions through bimolecular intimate ion-pair processes with asynchronous concerted characteristics in the absence of tetraalkylammonium halides, while most of them generally prefer anti-addition in the presence of tetraalkylammonium halides. The stereoselectivity is significantly affected by both the electronic and steric effects of 1-arylalk-1-ynes and halides in the reaction mixture. Strongly electron-rich and bulky 1-arylalk-1-ynes generally favour syn-addition in the presence of tetraalkylammonium halides, especially arylethynes in hydrochlorination. Anti-Markovnikov hydrohalogenations of 1-arylalk-1-ynes also prefer anti-addition both in the absence and presence of tetraalkylammonium halides even in small amounts due to high activation energies. The current investigation provides deep insights into the mechanism and stereoselectivity in polar hydrohalogenations of alkynes.

Reconstructing annual XCO2 at a 1 km×1 km spatial resolution across China from 2012 to 2019 based on a spatial CatBoost method.

Long-time-series, high-resolution datasets of the column-averaged dry-air mole fraction of carbon dioxide (XCO2) have great practical importance for mitigating the greenhouse effect, assessing carbon emissions and implementing a low-carbon cycle. However, the mainstream XCO2 datasets obtained from satellite observations have coarse spatial resolutions and are inadequate for supporting research applications with different precision requirements. Here, we developed a new spatial machine learning model by fusing spatial information with CatBoost, called SCatBoost, to fill the above gap based on existing global land-mapped 1° XCO2 data (GLM-XCO2). The 1-km-spatial-resolution dataset containing XCO2 values in China from 2012 to 2019 reconstructed by SCatBoost has stronger and more stable predictive power (confirmed with a cross-validation (R2 = 0.88 and RSME = 0.20 ppm)) than other traditional models. According to the estimated dataset, the overall national XCO2 showed an increasing trend, with the annual mean concentration rising from 392.65 ppm to 410.36 ppm. In addition, the spatial distribution of XCO2 concentrations in China reflects significantly higher concentrations in the eastern coastal areas than in the western inland areas. The contributions of this study can be summarized as follows: (1) It proposes SCatBoost, integrating the advantages of machine learning methods and spatial characteristics with a high prediction accuracy; (2) It presents a dataset of fine-scale and high resolution XCO2 over China from 2012 to 2019 by the model of SCatBoost; (3) Based on the generated data, we identify the spatiotemporal trends of XCO2 in the scale of nation and city agglomeration. These long-term and high resolution XCO2 data help understand the spatiotemporal variations in XCO2, thereby improving policy decisions and planning about carbon reduction.

Gradient Design of Vacancies and Their Positive Correlation with Electrochemical Anticorrosion Protection.

The contribution of defects to electrochemistry is a controversial but practically applicable subject. Meanwhile, it is challenging to obtain precisely a certain nonchemometric single phase in mixed-valence compounds. The precise design of nonchemometric single-phase WO3-x (x = 0, 0.1, 0.28, and 1) mixed-valence metal oxides (MVMOs) was achieved by the gradient intrinsic reduction method, and the correlation between oxygen vacancies and electrochemical anticorrosion protection was explored systematically. Then, the decisive role of periodic oxygen vacancies in electrochemical anticorrosion was confirmed. And the origin was the synergistic reaction of oxygen vacancy-upgraded photocathodic protection, vacancy-induced passivation, and mixed-valence reductive protection, which were brought about by the high oxygen vacancy concentration. Integrating the above three aspects, the WO2.72 MVMO showed the best electrochemical anticorrosion performance by increasing the resistance value to 7.67 times that of the epoxy resin coating. The establishment of a positive correlation between oxygen vacancy and corrosion protection in WO3-x (x = 0, 0.1, 0.28, and 1) materials can not only guide the design of MVMOs but also make an important contribution to the rapid precorrosion performance of the materials.

PML-II regulates ERK and AKT signal activation and IFNα-induced cell death.

BACKGROUND: The requirement of promyelocytic leukaemia protein (PML) in interferon (IFN)-induced cell apoptosis is well-established. However, the exact mechanisms by which the multiple isoforms of PML protein participate in this process remain not well-understood. We previously demonstrated that PML isoform II (PML-II) positively regulates induced gene expression during a type I IFN response and evaluate here how PML-II contributes to IFNα-induced cell death. METHODS: HeLa cells were transiently depleted of PML-II by siRNA treatment and the response of these cells to treatment with IFNα assessed by molecular assays of mRNA and proteins associated with IFN and apoptosis responses. RESULTS: In HeLa cells, death during IFNα stimulation was reduced by prior PML-II depletion. PML-II removal also considerably decreased the induced expression of pro-apoptotic ISGs such as ISG54 (IFIT2), and substantially impaired or prevented expression of PUMA and TRAIL, proteins that are associated with the intrinsic and extrinsic apoptotic pathways respectively. Thirdly, PML-II depletion enhanced ERK and AKT pro-survival signaling activation suggesting that PML-II normally suppresses signaling via these pathways, and that lack of PML-II hence led to greater than normal activation of AKT signaling upon IFNα stimulation and consequently increased resistance to IFNα-induced apoptosis. CONCLUSIONS: The positive contribution of PML-II to the expression of various IFNα-induced pro-apoptotic proteins and its inhibition of pro-survival signaling together provide a mechanistic explanation for reduced apoptosis under conditions of PML deficiency and may account for at least part of the role of PML as a tumor suppressor gene. Video Abstract.

Status of arsenic accumulation in agricultural soils across China (1985-2016).

Based on 1677 published studies, 1648 sites across China collected from 1985 to 2016 were used to research the concentrations of arsenic in agricultural soils. In order to understand the status of arsenic pollution in agricultural soils in China over the past three decades, and to learn about the arsenic stocks in agricultural soils in various regions, and compared the relationship with annual arsenic emissions in China, and finally evaluated the potential ecological risks and human health risks. The median arsenic concentration in the surface agricultural soils of China was 10.40 mg Kg-1, and it ranged from 0.4 mg Kg-1 to 175.8 mg Kg-1. The inventory of arsenic in Chinese agricultural surface soils was estimated to be 3.71 × 106 t. In this study, the arsenic concentrations were found to be higher in Central, South, and Southwest China than those in other regions. The trend of arsenic pollution in agricultural soils has gradually increased over the past three decades. However, the growth rate of arsenic concentrations pollution in farmlands agricultural in China slowed during 2012-2016. The ecological risk index and geoaccumulation index revealed that arsenic in Chinese agricultural soil poses a low risk to the ecosystem. For human health assessment, the dietary pathway was the main pathway of exposure to arsenic in farmland soil of China. However, children's soil intake also contributed 34.48% to the exposure to arsenic, owing to their behavior. This study can provide a reference for the management of arsenic agricultural pollution in farmland soils in China.

CUDC-907 blocks multiple pro-survival signals and abrogates microenvironment protection in CLL.

CUDC-907, a dual PI3K/HDAC inhibitor, has been proposed to have therapeutic potential in hematopoietic malignancies. However, the molecular mechanisms of its effects in chronic lymphocytic leukaemia (CLL) remain elusive. We show that CLL cells are sensitive to CUDC-907, even under conditions similar to the protective microenvironment of proliferation centres. CUDC-907 inhibited PI3K/AKT and HDAC activity, as expected, but also suppressed RAF/MEK/ERK and STAT3 signalling and reduced the expression of anti-apoptotic BCL-2 family proteins BCL-2, BCL-xL, and MCL-1. Moreover, CUDC-907 downregulated cytokines BAFF and APRIL and their receptors BAFFR, TACI, and BCMA, thus blocking BAFF-induced NF-κB signalling. T cell chemokines CCL3/4/17/22 and phosphorylation of CXCR4 were also reduced by CUDC-907. These data indicated that CUDC-907 abrogates different protective signals and suggested that it might sensitize CLL cells to other drugs. Indeed, combinations of low concentrations of CUDC-907 with inhibitors of BCL2, BTK, or the NF-κB pathway showed a potent synergistic effect. Our data indicate that, apart from its known functions, CUDC-907 blocks multiple pro-survival pathways to overcome microenvironment protection in CLL cells. This provides a rationale to evaluate the clinical relevance of CUDC-907 in combination therapies with other targeted inhibitors.

A Cerato-Platanin Family Protein FocCP1 Is Essential for the Penetration and Virulence of Fusarium oxysporum f. sp. cubense Tropical Race 4.

Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4) is well-known as the causal agent of Fusarium wilt of banana and is one of the most destructive phytopathogens for banana plants. The molecular mechanisms underlying Foc TR4 virulence remain elusive. Here, we demonstrate that a cerato-platanin (CP) protein, FocCP1, functions as a virulence factor that is required by Foc TR4 for penetration and full virulence. The FocCP1 gene was expressed in every condition studied, showing a high transcript level in planta at the early stage of infection. Infiltration of the recombinant FocCP1 protein induced significant cell death and upregulated defence-related gene expression. FocCP1 knock-out strains showed a significant decrease in aerial growth rather than aqueous growth, which is reminiscent of hydrophobins. Furthermore, deletion of FocCP1 significantly reduced virulence and dramatically reduced infective growth in banana roots, likely resulting from a defective penetration ability. Taken together, the results of this study provide novel insight into the function of the recently identified FocCP1 as a virulence factor in Foc TR4.

Precise carbon isotopic ratio analyses of micro amounts of carbonate and non-carbonate in basalt using continuous-flow isotope ratio mass spectrometry.

RATIONALE: Continuous-flow isotope ratio mass spectrometry (CF-IRMS) is a specialized technique used to quickly analyze very small amounts of sample. We have used CF-IRMS to assess the influences of sample weight and relative carbon content on the accuracy and precision of the δ13 C values of micro amounts of carbonate and non-carbonate in silicate rocks. METHODS: The analytical work was performed on a Gasbench II (GB) sample preparation device and on an Elemental Analyzer (EA), which were both interfaced to CF-IRMS instruments. Potential silicate matrix effects on the carbon isotopic analyses were investigated by measuring mixtures of calibrated carbon reference materials and quartz powder. The calibration lines, established by the measured raw values and the known values of three reference materials mixed with quartz powder, were used to calibrate the δ13 C values of basalt samples from eastern China. RESULTS: The δ13 C values measured by GB-CF-IRMS of one national carbonate reference material, GBW04416, deviate slightly from the known value for approximately 20-70 µg of carbonate contained in 4.5-mL vials; the smaller the sample size, the lower the measured δ13 C values. External precision better than 0.1‰ (1σ, n = 26) is achieved at a signal intensity for mass 44 of between 868 and 1614 mV, corresponding to a sample weight of 30.8-50.2 µg, whereas it is reduced to 0.27‰ (1σ, n = 34) at a signal intensity between 519 and 1614 mV, corresponding to a sample weight of 21.1-50.2 µg. In the EA-CF-IRMS experiments for non-carbonate carbon, at high carbon concentration (greater than 800 ppm) and at optimum sample weights, the accuracy and precision are both better than 0.2‰. For carbon concentrations less than 500 ppm, the measured δ13 C values deviate from the average by up to -1.2‰ and the precision is 0.74‰. CONCLUSIONS: The measured δ13 C values decrease substantially at lower carbon concentration and higher sample weights, and poorer precision is obtained. Suggestions are made to measure repeatedly the same carbon concentration of sample and reference materials in order to obtain not only reproducible, but also accurate carbon isotope ratios.

Pro-survival signal inhibition by CDK inhibitor dinaciclib in Chronic Lymphocytic Leukaemia.

Dinaciclib is a cyclin-dependent kinase inhibitor with clinical potential in different cancers, including chronic lymphocytic leukaemia (CLL). In order to better understand its cytotoxic action, we characterized its effects on signalling pathways important for the survival of CLL cells. We found that dinaciclib induced apoptosis through the activation of caspases 8 and 9, which was independent of the presence of cytokines to mimic the environment of proliferation centres or IGVH mutation status. Moreover, treatment with dinaciclib led to the inhibition of oncogenic pathways normally activated in stimulated CLL cells, such as STAT3, NF-κB, p38, PI3K/AKT and RAF/MEK/ERK. Dinaciclib was also able to block the expression of anti-apoptotic proteins of the BCL2 family such as MCL1 and BCL-xL (also termed BCL2L1). Finally, we showed that low concentrations of dinaciclib enhanced cell sensitivity to ibrutinib and the BCL2 inhibitor ABT-199, two drugs with known effects on CLL. Taken together, our data show that dinaciclib targets multiple pro-survival signalling pathways in CLL, which provides a mechanistic explanation for its potent induction of apoptosis. They also support a therapeutic application of cyclin-dependent kinase inhibitors in CLL in combination with other relevant targeted therapies.

Double-image encryption without information disclosure using phase-truncation Fourier transforms and a random amplitude mask.

We present a study about information disclosure in phase-truncation-based cryptosystems. The main information of the original image to be encoded can be obtained by using a decryption key in the worst case. The problem cannot be thoroughly solved by imaginary part truncating, keeping the encryption keys as private keys, or applying different phase keys for different plaintexts during each encryption process as well as the phase modulation in the frequency domain. In order to eliminate the risk of unintended information disclosure, we further propose a nonlinear spatial and spectral encoding technique using a random amplitude mask (RAM). The encryption process involving two security layers can be fully controlled by a RAM. The spatial encoding of the plaintext images and the simultaneous encryption of the plaintext images and the encryption key greatly enhance the security of system, avoiding several attacks that have cracked the phase-truncation-based cryptosystems. Besides, the hybrid encryption system retains the advantage of a trap door one-way function of phase truncation. Numerical results have demonstrated the feasibility and effectiveness of the proposed encryption algorithm.

Discussion and a new attack of the optical asymmetric cryptosystem based on phase-truncated Fourier transform.

A discussion and a cryptanalysis of the optical phase-truncated Fourier-transform-based cryptosystem are presented in this paper. The concept of an optical asymmetric cryptosystem, which was introduced into the optical image encryption scheme based on phase-truncated Fourier transforms in 2010, is suggested to be retained in optical encryption. A new method of attack is also proposed to simultaneously obtain the main information of the original image, the two decryption keys from its cyphertext, and the public keys based on the modified amplitude-phase retrieval algorithm. The numerical results illustrate that the computing efficiency of the algorithm is improved and the number of iterations is much less than that by the specific attack, which has two iteration loops.

Porphyromonas gingivalis Vaccine: Antigens and Mucosal Adjuvants.

Porphyromonas gingivalis (Pg), a Gram-negative anaerobic bacterium found in dental plaque biofilm within periodontal pockets, is the primary pathogenic microorganism responsible for chronic periodontitis. Infection by Pg significantly impacts the development and progression of various diseases, underscoring the importance of eliminating this bacterium for effective clinical treatment. While antibiotics are commonly used to combat Pg, the rise of antibiotic resistance poses a challenge to complete eradication. Thus, the prevention of Pg infection is paramount. Research suggests that surface antigens of Pg, such as fimbriae, outer membrane proteins, and gingipains, can potentially be utilized as vaccine antigens to trigger protective immune responses. This article overviews these antigens, discusses advancements in mucosal adjuvants (including immunostimulant adjuvants and vaccine-delivery adjuvants), and their application in Pg vaccine development. Furthermore, the review examines the advantages and disadvantages of different immune pathways and common routes of Pg vaccine immunization. By summarizing the current landscape of Pg vaccines, addressing existing challenges, and highlighting the potential of mucosal vaccines, this review offers new insights for the advancement and clinical implementation of Pg vaccines.

The clinical regimens and cell membrane camouflaged nanodrug delivery systems in hematologic malignancies treatment.

Hematologic malignancies (HMs), also referred to as hematological or blood cancers, pose significant threats to patients as they impact the blood, bone marrow, and lymphatic system. Despite significant clinical strategies using chemotherapy, radiotherapy, stem cell transplantation, targeted molecular therapy, or immunotherapy, the five-year overall survival of patients with HMs is still low. Fortunately, recent studies demonstrate that the nanodrug delivery system holds the potential to address these challenges and foster effective anti-HMs with precise treatment. In particular, cell membrane camouflaged nanodrug offers enhanced drug targeting, reduced toxicity and side effects, and/or improved immune response to HMs. This review firstly introduces the merits and demerits of clinical strategies in HMs treatment, and then summarizes the types, advantages, and disadvantages of current nanocarriers helping drug delivery in HMs treatment. Furthermore, the types, functions, and mechanisms of cell membrane fragments that help nanodrugs specifically targeted to and accumulate in HM lesions are introduced in detail. Finally, suggestions are given about their clinical translation and future designs on the surface of nanodrugs with multiple functions to improve therapeutic efficiency for cancers.

Settlement on asphalt concrete pavement in permafrost regions under the dynamic load of aircraft.

The settlement in permafrost regions has a significant effect on the safety of the aircraft. Therefore, a numerical model of asphalt concrete pavement and subgrade in permafrost regions is proposed and verified by comparing with previous studies. Numerical models under the dynamic load of aircraft are used to analyze the settlement nephogram, time-dependent curve, and settlement curve. Results show that the influences of different parameters on settlements decrease slowly at the depth of 0-1.45m, then decrease quickly at the depth of 1.45-2m, finally tend to be stable. The peaks of settlements increase with the growth of international roughness index, taxiing speed, and aircraft's weight. The settlement increases little when the international roughness index is more than 3. The settlement varies significantly when the taxiing speed is from 30m/s to 70m/s. The study provides a theoretical basis for the construction and maintenance of asphalt concrete pavement and subgrade in permafrost.