Massive seasonal high-altitude migrations of nocturnal insects above the agricultural plains of East China.

Long-distance migrations of insects contribute to ecosystem functioning but also have important economic impacts when the migrants are pests or provide ecosystem services. We combined radar monitoring, aerial sampling, and searchlight trapping, to quantify the annual pattern of nocturnal insect migration above the densely populated agricultural lands of East China. A total of ~9.3 trillion nocturnal insect migrants (15,000 t of biomass), predominantly Lepidoptera, Hemiptera, and Diptera, including many crop pests and disease vectors, fly at heights up to 1 km above this 600 km-wide region every year. Larger migrants (>10 mg) exhibited seasonal reversal of movement directions, comprising northward expansion during spring and summer, followed by southward movements during fall. This north-south transfer was not balanced, however, with southward movement in fall 0.66× that of northward movement in spring and summer. Spring and summer migrations were strongest when the wind had a northward component, while in fall, stronger movements occurred on winds that allowed movement with a southward component; heading directions of larger insects were generally close to the track direction. These findings indicate adaptations leading to movement in seasonally favorable directions. We compare our results from China with similar studies in Europe and North America and conclude that ecological patterns and behavioral adaptations are similar across the Northern Hemisphere. The predominance of pests among these nocturnal migrants has severe implications for food security and grower prosperity throughout this heavily populated region, and knowledge of their migrations is potentially valuable for forecasting pest impacts and planning timely management actions.

Integrin αvß1 facilitates ACE2-mediated entry of SARS-CoV-2.

Integrins have been suggested to be involved in SARS-CoV-2 infection, but the underlying mechanisms remain largely unclear. This study aimed to investigate how integrins facilitate the ACE2-mediated cellular entry of SARS-CoV-2. We first tested the susceptibility of a panel of human cell lines to SARS-CoV-2 infection using the spike protein pseudotyped virus assay and examined the expression levels of integrins in these cell lines by qPCR, western blot and flow cytometry. We found that integrin αvß1 was highly enriched in the SARS-CoV-2 susceptible cell lines. Additional studies demonstrated that RGD (403-405)→AAA mutant was defective in binding to integrin αvß1 compared to its wild type counterpart, and anti-αvß1 integrin antibodies significantly inhibited the entry of SARS-CoV-2 into the cells. Further studies using mouse NIH3T3 cells expressing human ACE2, integrin αv, integrin ß1, and/or integrin αvß1 suggest that integrin αvß1 was unable to function as an independent receptor but could significantly facilitate the cellular entry of SASR-CoV-2. Finally, we observed that the Omicron exhibited a significant increase in the ACE2-mediated viral entry. Our findings may enhance our understanding of the pathogenesis of SARS-CoV-2 infection and offer potential therapeutic target for COVID-19.

Two Microsatellite Types Within NAD6 Gene Help to Distinguish Populations and Infer the Migratory Route of the Invasive Fall Armyworm, Spodoptera frugiperda, (Lepidoptera, Noctuidae) in China.

Spodoptera frugiperda is a major agricultural pest that has invaded China since January 2019. Given that most of the individuals present in China carried the diagnostic rice-strain mtDNA (COI-RS), there was no efficient method to distinguish populations of S. frugiperda. In this study, we identified and characterized two variant microsatellite alleles in the mitochondrial NAD6 gene of S. frugiperda retrieved from the National Center for Biotechnology Center GenBank. We then sequenced partial NAD6 genes containing the microsatellite region and the diagnostic COI barcoding gene (used to distinguish the corn-strain and the rice-strain) of 429 invasive S. frugiperda individuals that were collected from the main infested regions in China during 2019-2020. Our data indicates that two kinds of interrupted repeat sequences, (ATA)4T(ATA)3 and (ATA)5T(ATA)3, exist in the microsatellite region which we defined as the deletion type (NAD6-D), and the insertion type (NAD6-I) based on the repeat units' differentiation, respectively. The presence of these two microsatellite types in the mtDNA genome of S. frugiperda was further confirmed with the sequencing results in 429 samples. Moreover, NAD6-I and NAD6-D types were both present in individuals with COI-RS, while only NAD6-D type was detected in the COI-CS individuals. Interestingly, the two microsatellite types suggested a possible geographic distribution: the western migratory route (Yunan and Chongqing) was comprised exclusively of NAD6-I type, while both NAD6-I and NAD6-D types were identified in the predicted eastern migration trajectories (Hainan, Guangxi, Shandong, etc.). These results suggested that NAD6-D and NAD6-I types may be useful in distinguishing between populations, analyzing the evolutionary mechanism of mtDNA microsatellite polymorphism, inferring the migratory route of S. frugiperda in China, and developing precise and integrated control strategies for S. frugiperda.

The emerging role of deubiquitylating enzymes as therapeutic targets in cancer metabolism.

Cancer cells must rewire cellular metabolism to satisfy the unbridled proliferation, and metabolic reprogramming provides not only the advantage for cancer cell proliferation but also new targets for cancer treatment. However, the plasticity of the metabolic pathways makes them very difficult to target. Deubiquitylating enzymes (DUBs) are proteases that cleave ubiquitin from the substrate proteins and process ubiquitin precursors. While the molecular mechanisms are not fully understood, many DUBs have been shown to be involved in tumorigenesis and progression via controlling the dysregulated cancer metabolism, and consequently recognized as potential drug targets for cancer treatment. In this article, we summarized the significant progress in understanding the key roles of DUBs in cancer cell metabolic rewiring and the opportunities for the application of DUBs inhibitors in cancer treatment, intending to provide potential implications for both research purpose and clinical applications.

In situ one-pot synthesis of Sn/lignite-based porous carbon composite for enhanced lithium storage.

To expand the variety of Sn/C composites, lignite-based porous carbon was initially prepared with Baoqing lignite as the raw material and K2CO3 as the extractant and activator. A novel Sn/lignite-based porous carbon composite was subsequently fabricated via an in situ one-pot synthesis method. In the nanocomposite, Sn nanoparticles are uniformly distributed on lignite-based porous carbon, improving the lithium-ion storage performance of the as-prepared material. Compared with pure Sn and bare lignite-based porous carbon, Sn/lignite-based porous carbon displayed a superior electrochemical performance. The composite material exhibits a high reversible capacity of 941 mAh g-1 after 200 cycles at 100 mA g-1. Even after 800 charge/discharge cycles at a high current density of 1000 mA g-1, the nanocomposite retains a reversible capacity of 573 mAh g-1. The enhanced lithium-ion storage performance can be attributed to the combined effect of Sn and lignite-based porous carbon.

Discovery of a natural fluorescent probe targeting the Plasmodium falciparum cysteine protease falcipain-2.

The Plasmodium falciparum cysteine protease falcipain-2 (FP-2) is an attractive antimalarial target. Here, we discovered that the natural compound NP1024 is a nonpeptidic inhibitor of FP-2 with an IC50 value of 0.44 µmol L-1. The most exciting finding is that both in vitro and in vivo, NP1024 directly targets FP-2 in malaria parasite-infected erythrocytes as a natural fluorescent probe, thereby paving the way for an integration of malaria diagnosis and treatment.

N/O co-doped porous interconnected carbon nanosheets from the co-hydrothermal treatment of soybean stalk and nickel nitrate for high-performance supercapacitors.

Porous interconnected carbon nanosheets (PICNs) with high electrochemical performance were prepared by doping urea and a co-hydrothermal precursor derived from soybean stalk (SS) and nickel nitrate. The specific surface area and average pore diameter of the as-synthesized PICNs are 2226.29 m2 g-1 and 1.89 nm, and their N and O contents are 5.08% and 9.4%, respectively, which is beneficial for increasing pseudocapacitance. Furthermore, the doping of the metal Ni increases the graphitization degree of the PICNs and promotes the conversion of pyridine-N to graphitized-N. Therefore, the PICNs possess a high specific capacitance of 407 F g-1 at a current density of 0.5 A g-1, a high capacitance retention of 78.62% even at 20 A g-1, and an outstanding cycling stability (over 93% retention rate after 10,000 charge/discharge cycles). Moreover, an energy density of 36.11 W h kg-1 is achieved at a power density of 517.8 W kg-1 during a two-electrode system test, and a retention rate of 87.5% is obtained after 10,000 cycles. This co-hydrothermal treatment as well as nitrogen-doping approach for preparing porous interconnected carbon from SS not only represents an alternative strategy for carbon-based supercapacitor materials but also provides a new option for the utilization of waste SS.

Preparation of Porous Activated Carbons for High Performance Supercapacitors from Taixi Anthracite by Multi-Stage Activation.

Coal-based porous materials for supercapacitors were successfully prepared using Taixi anthracite (TXA) by multi-stage activation. The characterization and electrochemical tests of activated carbons (ACs) prepared in different stages demonstrated that the AC from the third-stage activation (ACIII) shows good porous structures and excellent electrochemical performances. ACIII exhibited a fine specific capacitance of 199 F g-1 at a current density of 1 A g-1 in the three-electrode system, with 6 mol L-1 KOH as the electrolyte. The specific capacitance of ACIII remained 190 F g-1 even despite increasing the current density to 5 A g-1, indicating a good rate of electrochemical performance. Moreover, its specific capacitance remained at 98.1% of the initial value after 5000 galvanostatic charge-discharge (GCD) cycle tests at a current density of 1 A g-1, suggesting that the ACIII has excellent cycle performance as electrode materials for supercapacitors. This study provides a promising approach for fabricating high performance electrode materials from high-rank coals, which could facilitate efficient and clean utilization of high-rank coals.

Potentiometric titration for the high precision determination of active components in six types of chemical disinfectants.

Chemical disinfectants effectively kill pathogenic microorganisms, eliminating routes of transmission for infectious diseases. Accurate quantification of the active ingredients can help make a more effective use of disinfectants. In this study, the active ingredients in six different types of chemical disinfectants were systematically quantified with great precision and accuracy using potentiometric titration. The coefficient of variations fell in the range of 0.04%-0.46%. The recovery rates of samples were all above 95% and the extended uncertainty was 0.32g/L. This method can be broadly applied to the analysis of disinfectants in the future.

Small-Conductance Ca2+-Activated K+ Channel 2 in the Dorsal Horn of Spinal Cord Participates in Visceral Hypersensitivity in Rats.

Visceral hypersensitivity is a highly complex and subjective phenomenon associated with multiple levels of the nervous system and a wide range of neurotransmission. The dorsal horn (DH) in spinal cord relays the peripheral sensory information into the brain. Small conductance Ca2+-activated K+ (SK) channels regulate neuronal excitability and firing by allowing K+ to efflux in response to increase in the intracellular Ca2+ level. In this study, we examined the influence of SK2 channels in the spinal DH on the pathogenesis of visceral hypersensitivity induced by colorectal distension (CRD) in rats. Electrophysiological results showed that rats with visceral hypersensitivity presented a decrease in the SK channel-mediated afterhyperpolarization current (IAHP), and an increase in neuronal firing rates and c-Fos positive staining in the spinal DH. Western blot data revealed a decrease in the SK2 channel protein in the membrane fraction. Moreover, intrathecal administration of the SK2 channel activator 1-EBIO or CyPPA alleviated visceral hypersensitivity, reversed the decrease in IAHP and the increase in neuronal firing rates in spinal DH in rats that experienced CRD. 1-EBIO or CyPPA effect could be prevented by SK2 channel blocker apamin. CRD induced an increase in c-Fos protein expression in the spinal DH, which was prevented by 1-EBIO. Together, these data suggest that visceral hypersensitivity and pain is associated with a decrease in the number and function of membrane SK2 channels in the spinal DH. Pharmacological manipulation of SK2 channels may open a new avenue for the treatment of visceral hypersensitivity and pain. Highlights: -Neonatal colorectal distension induced visceral hypersensitivity in rats.-Visceral hypersensitivity rats presented a decrease in afterhyperpolarization current (IAHP) and membrane SK2 channel protein in the spinal dorsal horn.-Visceral hypersensitivity rats presented an increase in neuronal firing rate in the spinal dorsal horn.-Intrathecal administration of SK2 channel activator 1-EBIO or CyPPA prevented visceral hypersensitivity and decrease in IAHP.

Preparation of porous carbon spheres from 2-keto-l-gulonic acid mother liquor by oxidation and activation for electric double-layer capacitor application.

A novel strategy is proposed for the increase of specific surface area (SSA) of porous carbon sphere (PCS) by oxidation and activation. 2-keto-l-gulonic acid mother liquor (GAML) as a high-pollution waste has a relatively high value of reutilization. For its high value-added utilization, GAML is used as the precursor for preparation of PCS as carbon-based electrode materials for electric double-layer capacitor. PCS is prepared by hydrothermal carbonization, carbonization and KOH activation, and Fe(NO3)3 9H2O is used as an oxidizing agent during carbonization. The as-prepared PCS has excellent porosity and high SSA of 2478 m2 g-1. Meanwhile, the pore structure of PCS can be controlled by the adjustment of carbonization parameters (carbonization temperature and the loading of Fe(NO3)3 9H2O). Besides, the SSA and specific capacitance of PCS can be increased remarkably when Fe(NO3)3 9H2O is added in carbonization. The specific capacitance of PCS can reach 303.7 F g-1 at 40 mA g-1. PCSs as electrode material have superior electrochemical stability. After 8000 cycles, the capacitance retention is 98.3% at 2 A g-1. The electric double-layer capacitance of PCS is improved when CS is carbonized with Fe(NO3)3 9H2O, and the economic and environmental benefits are achieved by the effective recycle of GAML.

Veratramine modulates AP-1-dependent gene transcription by directly binding to programmable DNA.

Because the transcription factor activator protein-1 (AP-1) regulates a variety of protein-encoding genes, it is a participant in many cellular functions, including proliferation, transformation, epithelial mesenchymal transition (EMT), and apoptosis. Inhibitors targeting AP-1 have potential use in the treatment of cancer and other inflammatory diseases. Here, we identify veratramine as a potent natural modulator of AP-1, which selectively binds to a specific site (TRE 5'-TGACTCA-3') of the AP-1 target DNA sequence and regulates AP-1-dependent gene transcription without interfering with cystosolic signaling cascades that might lead to AP-1 activation. Moreover, RNA-seq experiments demonstrate that veratramine does not act on the Hedgehog signaling pathway in contrast to its analogue, cyclopamine, and likely does not harbor the same teratogenicity and toxicity. Additionally, veratramine effectively suppresses EGF-induced AP-1 transactivation and transformation of JB6 P+ cells. Finally, we demonstrate that veratramine inhibits solar-ultraviolet-induced AP-1 activation in mice. The identification of veratramine and new findings in its specific regulation of AP-1 down stream genes pave ways to discovering and designing regulators to regulate transcription factor.

Structural analysis of recombinant human ubiquitin-conjugating enzyme UbcH5c.

UbcH5c belongs to the ubiquitin-conjugating enzyme family and plays an important role in catalyzing ubiquitination during TNF-α--triggered NF-κB activation. Therefore, UbcH5c is a potent therapeutic target for the treatment of inflammatory and autoimmune diseases induced by aberrant activation of NF-κB. In this study, we established a stable expression system for recombinant UbcH5c and solved the crystal structure of UbcH5c belonging to space group P22121 with one molecule in the asymmetric unit. This study provides the basis for further study of UbcH5c including the design of UbcH5c inhibitors.

Activation of corticotropin-releasing factor neurons and microglia in paraventricular nucleus precipitates visceral hypersensitivity induced by colorectal distension in rats.

Visceral hypersensitivity is a major contributor to irritable bowel syndrome and other disorders with visceral pain. Substantial evidence has established that glial activation and neuro-glial interaction play a key role in the establishment and maintenance of visceral hypersensitivity. We recently demonstrated that activation of spinal microglial toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear factor κB (NF-κB) signaling facilitated the development of visceral hypersensitivity in a rat model developed by neonatal and adult colorectal distensions (CRDs). Hypothalamic paraventricular nucleus (PVN) plays a pivotal role in the pathogenesis of chronic pain. In this study, we examined the mechanism by which microglia and neurons in PVN establish and maintain visceral hypersensitivity and the involvement of TLR4 signaling. Visceral hypersensitivity was precipitated by adult colorectal distension (CRD) only in rats that experienced neonatal CRDs. Visceral hypersensitivity was associated with an increase in the expression of c-fos, corticotropin-releasing factor (CRF) protein and mRNA in PVN, which could be prevented by intra-PVN infusion of lidocaine or small interfering RNA targeting the CRF gene. These results suggest PVN CRF neurons modulate visceral hypersensitivity. Adult CRD induced an increase in the expression of Iba-1 (a microglial marker), TLR4 protein, and its downstream effectors MyD88, NF-κB, as well as proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) only in rats that experienced neonatal CRDs. Intra-PVN infusion of minocycline, a nonselective microglial inhibitor, attenuated the hyperactivity of TLR4 signaling cascade, microglial activation, and visceral hypersensitivity. Taken together, these data suggest that neonatal CRDs induce a glial activation in PVN. Adult CRD potentiates the glial and CRF neuronal activity, and precipitates visceral hypersensitivity and pain. TLR4 signaling and proinflammatory cytokines TNF-α and IL-1ß may participate in neuro-glial interaction during the pathogenesis of visceral hypersensitivity.

Rational Design of Benzylidenehydrazinyl-Substituted Thiazole Derivatives as Potent Inhibitors of Human Dihydroorotate Dehydrogenase with in Vivo Anti-arthritic Activity.

Human dihydroorotate dehydrogenase (hDHODH) is an attractive therapeutic target for the treatment of rheumatoid arthritis, transplant rejection and other autoimmune diseases. Based on the X-ray structure of hDHODH in complex with lead compound 7, a series of benzylidenehydrazinyl-substituted thiazole derivatives as potent inhibitors of hDHODH were designed and synthesized, of which 19 and 30 were the most potent with IC50 values in the double-digit nanomolar range. Moreover, compound 19 displayed significant anti-arthritic effects and favorable pharmacokinetic profiles in vivo. Further X-ray structure and SAR analyses revealed that the potencies of the designed inhibitors were partly attributable to additional water-mediated hydrogen bond networks formed by an unexpected buried water between hDHODH and the 2-(2-methylenehydrazinyl)thiazole scaffold. This work not only elucidates promising scaffolds targeting hDHODH for the treatment of rheumatoid arthritis, but also demonstrates that the water-mediated hydrogen bond interaction is an important factor in molecular design and optimization.

Design, synthesis, X-ray crystallographic analysis, and biological evaluation of thiazole derivatives as potent and selective inhibitors of human dihydroorotate dehydrogenase.

Human dihydroorotate dehydrogenase (HsDHODH) is a flavin-dependent mitochondrial enzyme that has been certified as a potential therapeutic target for the treatment of rheumatoid arthritis and other autoimmune diseases. On the basis of lead compound 4, which was previously identified as potential HsDHODH inhibitor, a novel series of thiazole derivatives were designed and synthesized. The X-ray complex structures of the promising analogues 12 and 33 confirmed that these inhibitors bind at the putative ubiquinone binding tunnel and guided us to explore more potent inhibitors, such as compounds 44, 46, and 47 which showed double digit nanomolar activities of 26, 18, and 29 nM, respectively. Moreover, 44 presented considerable anti-inflammation effect in vivo and significantly alleviated foot swelling in a dose-dependent manner, which disclosed that thiazole-scaffold analogues can be developed into the drug candidates for the treatment of rheumatoid arthritis by suppressing the bioactivity of HsDHODH.

A sesquiterpene lactone from a medicinal herb inhibits proinflammatory activity of TNF-α by inhibiting ubiquitin-conjugating enzyme UbcH5.

UbcH5 is the key ubiquitin-conjugating enzyme catalyzing ubiquitination during TNF-α-triggered NF-κB activation. Here, we identified an herb-derived sesquiterpene lactone compound IJ-5 as a preferential inhibitor of UbcH5 and explored its therapeutic value in inflammatory and autoimmune disease models. IJ-5 suppresses TNF-α-induced NF-κB activation and inflammatory gene transcription by inhibiting the ubiquitination of receptor-interacting protein 1 and NF-κB essential modifier, which is essential to IκB kinase activation. Mechanistic investigations revealed that IJ-5 preferentially binds to and inactivates UbcH5 by forming a covalent adduct with its active site cysteine and thereby preventing ubiquitin conjugation to UbcH5. In preclinical models, pretreatment of IJ-5 exhibited potent anti-inflammatory activity against TNF-α- and D-galactosamine-induced hepatitis and collagen-induced arthritis. These findings highlight the potential of UbcH5 as a therapeutic target for anti-TNF-α interventions and provide an interesting lead compound for the development of new anti-inflammation agents.

Identification of diverse natural products as falcipain-2 inhibitors through structure-based virtual screening.

Ten natural compounds are successfully identified as falcipain-2 (FP-2) inhibitors from our in-house natural products database using structure-based virtual screening, which show moderate inhibitory activities against FP-2 with IC50 values ranging from 3.18 to 68.19 µM. While one of the inhibitors (compound 5) also exhibits in vitro antiplasmodial activity against chloroquine sensitive strain (3D7) and chloroquine resistant strain (Dd2) of Plasmodium falciparum in the micromolar range (IC50s=5.54 µM and 4.05 µM against 3D7 cells and Dd2 cells, respectively). Furthermore, the predicted binding poses are analyzed to explain the structure-activity relationships, which will be helpful for further structural modifications.

Novel selective and potent inhibitors of malaria parasite dihydroorotate dehydrogenase: discovery and optimization of dihydrothiophenone derivatives.

Taking the emergence of drug resistance and lack of effective antimalarial vaccines into consideration, it is of significant importance to develop novel antimalarial agents for the treatment of malaria. Herein, we elucidated the discovery and structure-activity relationships of a series of dihydrothiophenone derivatives as novel specific inhibitors of Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH). The most promising compound, 50, selectively inhibited PfDHODH (IC50 = 6 nM, with >14,000-fold species-selectivity over hDHODH) and parasite growth in vitro (IC50 = 15 and 18 nM against 3D7 and Dd2 cells, respectively). Moreover, an oral bioavailability of 40% for compound 50 was determined from in vivo pharmacokinetic studies. These results further indicate that PfDHODH is an effective target for antimalarial chemotherapy, and the novel scaffolds reported in this work might lead to the discovery of new antimalarial agents.

The efficient expression of human fibroblast collagenase in Escherichia coli and the discovery of flavonoid inhibitors.

Human skin fibroblast collagenase also known as Matrix Metalloproteinase-1 (MMP-1) is a key enzyme in remodeling and degradation of extracellular matrix, and the inhibitors of human MMP-1 are effective drug candidates for the treatment of cancer. In this study, we report an improved method for high-level expression of soluble human MMP-1 catalytic domain (cd-MMP-1) in E.coli. The enzymatic activity is found maximum at pH 7.5 and temperature 40°C with a Km value of 13.02 µM. Effects of 17 structure-related flavonoids on MMP-1 activity are evaluated using a fluorescent assay, 6 inhibitors are identified with IC50 < 10 µM. Fisetin is the most active agent with an IC50 value of 1.35 µM and is identified as a mixed type inhibitor. Our improved soluble cd-MMP-1 expression method provides a basis for inhibitors identification and may be beneficial to discover novel anti-cancer agent targeting human MMP-1.