Pollen-expressed RLCKs control pollen tube burst.

In angiosperms, the pollen tube enters the receptive synergid cell, where they rupture to release its cytoplasm along with two sperm cells. Although this interaction is complex, the exact signal transducers that trigger the bursting of pollen tubes are not well understood. In this study, we identify three homologous Receptor-Like Cytoplasmic Kinase (RLCK) expressed in pollen tubes, named Delayed Burst 1/2/3 (DEB1/2/3) in Arabidopsis, which play a crucial role in this process. These genes produce proteins localized on the plasma membrane, and knockout of them causes delayed pollen tube burst and the entrance of additional pollen tubes into the embryo sac due to fertilization recovery. We show that DEBs interact with the Ca2+ pump ACA9, influencing the dynamics of cytoplasmic Ca2+ in pollen tubes through phosphorylation. These results highlight the importance of DEBs as key signal transducers and the critical function of the DEB-ACA9 axis in the timely pollen tube burst in synergids.

Targeting senescent HDF with the USP7 inhibitor P5091 to enhance DFU wound healing through the p53 pathway.

OBJECTIVE: The objective of this study was to examine the potential of USP7 as a target for senolytic therapy and to investigate the molecular mechanism by which its inhibitor selectively induced apoptosis in senescent HDF and enhanced DFU wound healing. METHODS: Clinical samples of DFU were collected to detect the expression of USP7 and aging-related proteins using immunohistochemistry and Western blot. In addition, ß-galactosidase staining, qPCR, flow cytometry, ROS and MMP kits, and Western blot were used to analyze the biological functions of P5091 on senescence, cycle, and apoptosis. RNAseq was employed to further analyze the molecular mechanism of P5091. Finally, the DFU rat model was established to evaluate the effect of P5091 on wound healing. RESULTS: The expression of USP7 and p21 were increased in DFU clinical samples. After treatment with d-glucose (30 mM, 7 days), ß-galactosidase staining was deepened, proliferation rate decreased. USP7 inhibitors (P5091) could reduce the release of SASP factors, activate the production of ROS, and reduce MMP. In addition, it induced apoptosis and selectively clears senescent cells through the p53 signaling pathway. Finally, P5091 can improve diabetic wound healing in rats. CONCLUSION: This study clarified the molecular mechanism of USP7 inhibitor (P5091) selectively inducing apoptosis of high glucose senescent HDF cells. This provides a new senolytics target and experimental basis for promoting DFU wound healing.

New insight into the catalytic mechanism of ester hydrogenation over the Cu/ZnO catalyst: the contribution of hydrogen spillover.

The dimethyl maleate hydrogenation activity of Cu, ZnO-X and physically mixed Cu+ZnO-X samples was systematically investigated to probe the essential role of ZnO in ester hydrogenation processes. Cu samples exhibited high CC bond hydrogenation ability with dimethyl succinate as the main product. Comparatively, ZnO was inactive in hydrogenation due to its weak ability to dissociate hydrogen while the CO group could be activated and adsorbed on the ZnO surface. Interestingly, physical mixing with ZnO significantly improved the CO hydrogenation activity of Cu samples. The H2-TPD results reveal the origin of "Cu-ZnO synergy": hydrogen atoms formed on the copper surface can spill over to the ZnO surface and react with the adsorbed CO group.

Virtual screening of natural products targeting ubiquitin-specific protease 7.

Ubiquitin-specific protease 7 (USP7) is a promising prognostic and druggable target for cancer therapy. Inhibition of USP7 can activate the MDM2-P53 signaling pathway, thereby promoting cancer cell apoptosis. This study based on watvina molecular docking of virtual screening method and biological evaluation found the new USP7 inhibitors targeting catalytic active site. Three hits were screened from 3760 natural products and validated as USP7 inhibitors by enzymatic and kinetic assays. The IC50 values of scutellarein (Scu), semethylzeylastera (DML) and salvianolic acid C (SAC) were 3.017, 6.865 and 8.495 µM, respectively. Further, we reported that the hits could downregulate MDM2 and activate p53 signal pathway in HCT116 cells. Molecular dynamics simulation was used to investigate the binding mechanism of USP7 to Scu, the compound with the best performance, which formed stable contact with Val296, Gln297, Phe409, Tyr465 and Tyr514. These interactions are essential for maintaining the biological activity of Scu. Three natural products are suitable as lead compounds for the development of novel USP7 inhibitors, especially anti-colon cancer drugs.Communicated by Ramaswamy H. Sarma.

Research on Coix seed as a food and medicinal resource, it's chemical components and their pharmacological activities: A review.

ETHNOPHARMACOLOGICAL RELEVANCE: Coix lacryma-jobi var. ma-yuen (Romanet du Caillaud) Stapf is a plant of the genus Coix in the Gramineae family. Coix seed is cultivated in various regions throughout China. In recent years, with the research on the medicinal value of Coix seed, it has received more and more widespread attention from people. Numerous pharmacological effects of Coix seed have been demonstrated through modern pharmacological studies, such as hypoglycemia, improving liver function, anti-tumor, regulating intestinal microbiota, improving spleen function, and anti-inflammatory effects. AIMS OF THE STUDY: This article is a literature review. In recent years, despite the extensive research on Coix seed, there has yet to be a comprehensive review of its traditional usage, medicinal resources, chemical components, and pharmacological effects is still lacking. To fill this gap, the paper provides an overview of the latest research progress on Coix seed, aiming to offer guidance and references for its further development and comprehensive utilization. MATERIAL AND METHODS: To gather information on the traditional usage, phytochemical ingredients, and pharmacological properties of Coix seed, we conducted a literature search using both Chinese and English languages in five databases: PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), and Springer. RESULTS: This article is a literature review. The chemical constituents of Coix seed include various fatty acids, esters, polysaccharides, sterols, alkaloids, triterpenes, tocopherols, lactams, lignans, phenols, flavonoids and other constituents. Modern pharmacological research has indeed shown that Coix seed has many pharmacological effects and is a natural anti-tumor drug. In addition to its anti-tumor effect, it also has pharmacological effects such as hypoglycemia, improving liver function, regulating intestinal microbiota, improving spleen function, and anti-inflammatory effects. CONCLUSIONS: This article provides a brief overview of the traditional uses, biotechnological applications, chemical components, and pharmacological effects of Coix seed. It highlights the importance of establishing quality standards, discovering new active ingredients, and exploring pharmacological mechanisms in Coix seed research. The article also emphasizes the significance of clinical trials, toxicology studies, pharmacokinetics data, and multidisciplinary collaboration for further advancements in this field. Overall, it aims to enhance understanding of Coix seed and its potential in pharmaceutical development and wellness products.

Cell and rat serum, urine and tissue metabolomics analysis elucidates the key pathway changes associated with chronic nephropathy and reveals the mechanism of action of rhein.

BACKGROUND: Rhein can significantly delay the progression of chronic nephropathy. However, its mechanism of action has not been adequately elaborated, which hinders its extensive clinical application. In this work, the effects of rhein on models of TGF-ß-induced NRK-49F cellular fibrosis and rat renal ischemia-reperfusion fibrosis were evaluated using metabolomics and western blotting. METHODS: The metabolic profiles of NRK-49F cells and rat urine, serum, and kidney tissues in the control, model, and rhein groups were investigated using UPLC-QTOF-MS. The levels of p-P65, p-IKK, p-AKT, p-P38, p-JNK and AP-1 in NRK-49F cells were measured using western blotting and immunofluorescence methods. Molecular docking and network pharmacology methods were employed to explore the relationship between the potential targets of rhein and key proteins in the NF-κB and MAPK signaling pathways. RESULTS: Various potential metabolites, including sphingolipids, ceramides, phosphatidylcholine, and lysophosphatidylcholine,14-hydroxy-E4-neuroprostane E, and 5-HPETE, were present in the cell, tissue, urine, and serum samples; however, few metabolites matches exactly among the four type of biological samples. These differential metabolites can effectively differentiated between the control, model, and rhein groups. Pathway enrichment analysis of differential metabolites unveiled that sphingolipid metabolism, arachidonic acid metabolism, and glycerophospholipid metabolism were closely related to nephropathy. Phosphorylation levels of AKT, IKK, P65 and AP-1 in NRK-49F cells was reduced by rhein treatment. Network pharmacology and molecular docking showed that the potential targets of rhein might regulated the expression of MAPK and AKT in the NF-κB and MAPK signaling pathways. CONCLUSION: In brief, rhein might delays the progression of chronic nephropathy via the metabolic pathways, NF-κB and MAPKs signaling pathways, which provides the foundation for its development and clinical application.

Dual-mode tunable absorber based on quasi-bound states in the continuum.

In this Letter, we propose a novel, to the best of our knowledge, dual-mode tunable absorber that utilizes quasi-bound states in the continuum (q-BIC) based on the periodically arranged silicon cylinders tetramer. By introducing asymmetry perturbation through manipulating the diameters of diagonal cylinders in the all-dielectric structure, the symmetry-protected BIC (SP-BIC) transforms into q-BIC, leading to the emergence of one transmission and one reflection Fano-like resonant mode. The relationship between the quality factor of each mode and the asymmetry parameter α is analyzed, revealing an exponential dependence with an exponent of -1.75, i.e., Q ∝ α-1.75. To explain the underlying physics, multipole decomposition analysis and Aleksandra's theory are applied. Subsequently, a monolayer graphene is introduced to the all-dielectric structure to demonstrate the application of the dual-mode tunable absorber. When the critical coupling condition is satisfied, each mode can achieve the theoretical maximum absorption, demonstrating the distinctive capability of our proposed absorber for tuning and efficient light absorption. This research provides valuable insights into light-matter interactions and opens up possibilities for optical modulation and the development of graphene-based devices.

Central-cell-produced attractants control fertilization recovery.

Animal fertilization relies on hundreds of sperm racing toward the egg, whereas, in angiosperms, only two sperm cells are delivered by a pollen tube to the female gametes (egg cell and central cell) for double fertilization. However, unsuccessful fertilization under this one-pollen-tube design can be detrimental to seed production and plant survival. To mitigate this risk, unfertilized-gamete-controlled extra pollen tube entry has been evolved to bring more sperm cells and salvage fertilization. Despite its importance, the underlying molecular mechanism of this phenomenon remains unclear. In this study, we report that, in Arabidopsis, the central cell secretes peptides SALVAGER1 and SALVAGER2 in a directional manner to attract pollen tubes when the synergid-dependent attraction fails or is terminated by pollen tubes carrying infertile sperm cells. Moreover, loss of SALs impairs the fertilization recovery capacity of the ovules. Therefore, this research uncovers a female gamete-attraction system that salvages seed production for reproductive assurance.

A dual-band hydrogen sensor based on Tamm plasmon polaritons.

Optical hydrogen sensors possess significant potential in various fields, including aerospace and fuel cell applications, which is due to their compact design and immunity to electromagnetic interference. However, commonly used sensors mostly use single-band sensing, which increases the risk of inaccurate measurements due to environmental interference or operational errors. To address this issue, this study proposes a dual-band hydrogen sensor comprising a Pd metal layer, a dielectric spacer layer, a defect layer, and a photonic crystal. By leveraging the interaction between the defect mode in the excitonic microcavity structure and the Tamm plasmon polaritons (TPPs) and Fabry-Perot (FP) resonances, the structure simultaneously generates two near-zero resonance valleys in the visible wavelength range. By adjusting the thickness of the defect layer, the coupling effect of the defect mode and TPPs together with FP resonance respectively is optimized. When the thickness is 0.27 µm, the sensitivities of the Tamm resonance band and FP resonance band are 239 and 21 RIU-1, respectively. Compared with the common sensors with a single band, its low-sensitivity wavelength can be used as a reference to assist the high-sensitivity wavelength for sensing. In addition, we find that the proposed sensor, through calculation, has good fault tolerance for both the thickness of the defect layer and the incident light angle. This study demonstrates a dual-band hydrogen sensor with TPPs, which is important for exploring new optical hydrogen sensors.

Correction: A redshifted photonic bandgap and wide-angle polarization selection in an all-hyperbolic-metamaterial one-dimensional photonic crystal.

Correction for 'A redshifted photonic bandgap and wide-angle polarization selection in an all-hyperbolic-metamaterial one-dimensional photonic crystal' by Feng Wu et al., Phys. Chem. Chem. Phys., 2023, 25, 10785-10794, https://doi.org/10.1039/D3CP00280B.

Angle-insensitive topological interface states in hybrid one-dimensional photonic crystal heterostructures containing all-dielectric metamaterials.

Topological interface states (TISs) in conventional one-dimensional (1D) photonic crystal (PhC) heterostructures strongly shift toward higher frequencies as the incident angle increases. This strong blueshift property of TISs intensively limits the operating angle ranges of TISs. Herein, we design two angle-insensitive photonic bandgaps (PBGs) in two hybrid 1D PhCs containing all-dielectric metamaterials. By cascading these two hybrid 1D PhCs to construct a hybrid 1D PhC heterostructure, we achieve an angle-insensitive TIS under transverse magnetic polarization. Empowered by the angle-insensitive property of the PBGs, the angular tolerance of the TIS reaches 69.65°, which is much higher than those of the TISs in conventional 1D PhC heterostructures. In addition, the angle-insensitive property of the TIS is robust against the layer thickness. Our work provides a viable route to achieving TISs with high angular tolerances and would facilitate the applications of photonic topological states.

A redshifted photonic bandgap and wide-angle polarization selection in an all-hyperbolic-metamaterial one-dimensional photonic crystal.

According to the Bragg scattering theory, photonic bandgaps (PBGs) in all-dielectric one-dimensional (1-D) photonic crystals (PhCs) are polarization-insensitive. This polarization-insensitive property of PBGs poses a challenge in wide-angle high-performance polarization selection. Herein, we theoretically investigate the angle dependence of the PBGs in a novel kind of 1-D PhC called all-hyperbolic-metamaterial (all-HMM) 1-D PhC entirely composed of HMMs. As the incident angle increases, the PBGs in all-HMM 1-D PhCs exhibit the redshift property under transverse magnetic polarization while exhibiting the blueshift property under transverse electric polarization. Empowered by the polarization-sensitive property of the PBGs, wide-angle high-performance polarization selection can be theoretically achieved. Such a wide-angle polarizer would be useful in liquid crystal displays, quantum interferometers, and Q-switched lasers.

Photonic spin-selective perfect absorptance on planar metasurfaces driven by chiral quasi-bound states in the continuum.

Optical metasurfaces with high-quality-factor resonances and selective chirality simultaneously are desired for nanophotonics. Here, an all-dielectric planar chiral metasurface is theoretically proposed and numerically proved to support the astonishing symmetry-protected bound state in the continuum (BIC), due to the preserved π rotational symmetry around the z axis and up-down mirror symmetry simultaneously. Importantly, such BIC is a vortex polarization singularity enclosed by elliptical eigenstate polarizations with non-vanishing helicity, owing to the broken in-plane mirror symmetry. Under the oblique incidence, companied by the BIC transforming into a quasi-BIC (Q-BIC), the strong extrinsic chirality manifests. Assisted by the single-port critical coupling, the planar metasurface can selectively and near-perfectly absorb one circularly polarized light but non-resonantly reflect its counterparts. The circular dichroism (CD) approaching 0.812 is achieved. Intriguingly, the sign of CD (namely, the handedness of the chiral metasurface) can be flexibly manipulated only via varying the azimuthal angle of incident light, due to the periodic helicity sign flip in eigen polarizations around the BIC. Numerical results are consistent with the coupled-mode theory and multipole decomposition method. The spin-selective metasurface absorber empowered by the physics of chiral Q-BICs undoubtedly may promise various applications such as optical filters, polarization detectors, and chiral imaging.

Topological plasmons in stacked graphene nanoribbons.

In this Letter, we theoretically study the topological plasmons in Su-Schrieffer-Heeger (SSH) model-based graphene nanoribbon (GNR) layers. We find that for the one-dimensional (1D) stacked case, only two topological modes with the field localized in the top or bottom layer are predicted to exist by the Zak phase. When we further expand the stacked 1D GNR layers to two-dimensional (2D) arrays in the in-plane direction, the topology is then characterized by the 2D Zak phase, which predicts the emergence of three kinds of topological modes: topological edge, surface, and corner modes. For a 2D ribbon array with Nx × Ny units, there are 4(Ny - 1), 4(Nx - 1), and 4 topological edge, surface, and corner modes, and the field is highly localized at the edge/surface/corner ribbons. This work offers a platform to realize topological modes in GNRs and could be important for the design of topological photonic devices such as lasers and sensors.

Ginkgo Biflavones Cause p53 Wild-Type Dependent Cell Death in a Transcription-Independent Manner of p53.

Ginkgo biloba, as a medicinal plant in both traditional and western medicine, emerged as a potential therapeutic agent for the management of a variety of diseases, but ginkgo biflavones (bilobetin, isoginkgetin, and ginkgetin) application in cancer therapy and underlying mechanisms of action remained elusive. In the present study, we identified ginkgo biflavones as potential p53 activators that could enhance p53 protein expression level by inhibiting MDM2 protein expression. At the same time, they induced cell death independent of p53 transcriptional activity. Moreover, ginkgetin was a standout among ginkgo biflavones that reduced the survival of HCT-116 cells by induction of apoptosis and G2/M phase arrest. Furthermore, ginkgo biflavones induced ROS generation significantly, which resulted in ferroptosis. Finally, we provide evidence that ginkgetin strengthened the antitumor effect of fluorouracil (5-FU) in the HCT-116 colon cancer xenograft model. To sum up, ginkgo biflavones represent a new class of p53 activator that depends on the p53 wild-type status and warrants further exploration as potential anticancer agents.

Physiological and metabolic analyses provide insight into soybean seed resistance to fusarium fujikuroi causing seed decay.

Seed-borne pathogens cause diverse diseases at the growth, pre- and post-harvest stage of soybean resulting in a large reduction in yield and quality. The physiological and metabolic aspects of seeds are closely related to their defense against pathogens. Recently, Fusarium fujikuroi has been identified as the dominant seed-borne fungi of soybean seed decay, but little information on the responses of soybean seeds induced by F. fujikuroi is available. In this study, a time-course symptom development of seed decay was observed after F. fujikuroi inoculation through spore suspension soaking. The germination rate and the contents of soluble sugar and soluble protein were significantly altered over time. Both chitinase and ß-1,3-glucanase as important fungal cell wall-degrading enzymes of soybean seeds were also rapidly and transiently activated upon the early infection of F. fujikuroi. Metabolic profile analysis showed that the metabolites in glycine, serine, and threonine metabolism and tryptophan metabolism were clearly induced by F. fujikuroi, but different metabolites were mostly enriched in isoflavone biosynthesis, flavone biosynthesis, and galactose pathways. Interestingly, glycitein and glycitin were dramatically upregulated while daidzein, genistein, genistin, and daidzin were largely downregulated. These results indicate a combination of physiological responses, cell wall-related defense, and the complicated metabolites of soybean seeds contributes to soybean seed resistance against F. fujikuroi, which are useful for soybean resistance breeding.

Ultra-sensitive refractive index sensing enabled by a dramatic ellipsometric phase change at the band edge in a one-dimensional photonic crystal.

Surface plasmon polaritons (SPPs) and Bloch surface waves (BSWs) have been widely utilized to design sensitive refractive index sensors. However, SPP- and BSW-based refractive index sensors require additional coupling component (prism) or coupling structure (grating or fiber), which increases the difficulty to observe ultra-sensitive refractive index sensing in experiments. Herein, we realize dramatic ellipsometric phase change at the band edges in an all-dielectric one-dimensional photonic crystal for oblique incidence. By virtue of the dramatic ellipsometric phase change at the long-wavelength band edge, we design an ultra-sensitive refractive index sensor at near-infrared wavelengths. The minimal resolution of the designed sensor reaches 9.28×10-8 RIU. Compared with SPP- and BSW-based refractive index sensors, the designed ultra-sensitive refractive index sensor does not require any additional coupling component or coupling structure. Such ultra-sensitive refractive index sensor would possess applications in monitoring temperature, humidity, pressure, and concentration of biological analytes.