Conservation and specialization of the Ycf2-FtsHi chloroplast protein import motor in green algae.

The protein import motor in chloroplasts plays a pivotal role in their biogenesis and homeostasis by driving the translocation of preproteins into chloroplasts. While the Ycf2-FtsHi complex serves as the import motor in land plants, its evolutionary conservation, specialization, and mechanisms across photosynthetic organisms are largely unexplored. Here, we isolated and determined the cryogenic electron microscopy (cryo-EM) structures of the native Ycf2-FtsHi complex from Chlamydomonas reinhardtii, uncovering a complex composed of up to 19 subunits, including multiple green-algae-specific components. The heterohexameric AAA+ ATPase motor module is tilted, potentially facilitating preprotein handover from the translocon at the inner chloroplast membrane (TIC) complex. Preprotein interacts with Ycf2-FtsHi and enhances its ATPase activity in vitro. Integrating Ycf2-FtsHi and translocon at the outer chloroplast membrane (TOC)-TIC supercomplex structures reveals insights into their physical and functional interplay during preprotein translocation. By comparing these findings with those from land plants, our study establishes a structural foundation for understanding the assembly, function, evolutionary conservation, and diversity of chloroplast protein import motors.

Plasmodium vivax serological exposure markers: PvMSP1-42-induced humoral and memory B-cell response generates long-lived antibodies.

Plasmodium vivax serological exposure markers (SEMs) have emerged as promising tools for the actionable surveillance and implementation of targeted interventions to accelerate malaria elimination. To determine the dynamic profiles of SEMs in current and past P. vivax infections, we screened and selected 11 P. vivax proteins from 210 putative proteins using protein arrays, with a set of serum samples obtained from patients with acute P. vivax and documented past P. vivax infections. Then we used a murine protein immune model to initially investigate the humoral and memory B cell response involved in the generation of long-lived antibodies. We show that of the 11 proteins, especially C-terminal 42-kDa region of P. vivax merozoite surface protein 1 (PvMSP1-42) induced longer-lasting long-lived antibodies, as these antibodies were detected in individuals infected with P. vivax in the 1960-1970s who were not re-infected until 2012. In addition, we provide a potential mechanism for the maintenance of long-lived antibodies after the induction of PvMSP1-42. The results indicate that PvMSP1-42 induces more CD73+CD80+ memory B cells (MBCs) compared to P. vivax GPI-anchored micronemal antigen (PvGAMA), allowing IgG anti-PvMSP1-42 antibodies to be maintained for a long time.

QTLbase2: an enhanced catalog of human quantitative trait loci on extensive molecular phenotypes.

Deciphering the fine-scale molecular mechanisms that shape the genetic effects at disease-associated loci from genome-wide association studies (GWAS) remains challenging. The key avenue is to identify the essential molecular phenotypes that mediate the causal variant and disease under particular biological conditions. Therefore, integrating GWAS signals with context-specific quantitative trait loci (QTLs) (such as different tissue/cell types, disease states, and perturbations) from extensive molecular phenotypes would present important strategies for full understanding of disease genetics. Via persistent curation and systematic data processing of large-scale human molecular trait QTLs (xQTLs), we updated our previous QTLbase database (now QTLbase2, http://mulinlab.org/qtlbase) to comprehensively analyze and visualize context-specific QTLs across 22 molecular phenotypes and over 95 tissue/cell types. Overall, the resource features the following major updates and novel functions: (i) 960 more genome-wide QTL summary statistics from 146 independent studies; (ii) new data for 10 previously uncompiled QTL types; (iii) variant query scope expanded to fit 195 QTL datasets based on whole-genome sequencing; (iv) supports filtering and comparison of QTLs for different biological conditions, such as stimulation types and disease states; (v) a new linkage disequilibrium viewer to facilitate variant prioritization across tissue/cell types and QTL types.

CCL5/CCR5/CYP1A1 pathway prompts liver cancer cells to survive in the combination of targeted and immunological therapies.

Combination therapy of anti-programmed cell death protein-1 (PD-1) antibodies and tyrosine kinase inhibitors (TKIs) has significantly improved the prognosis for hepatocellular carcinoma (HCC), but many patients still have unsatisfactory outcomes. CD8 T cells are known to exert a pivotal function in the immune response against tumors. Nevertheless, most CD8 T cells in HCC tissues are in a state of exhaustion, losing the cytotoxic activity against malignant cells. Cytokines, mainly secreted by immune cells, play an important role in the occurrence and development of tumors. Here, we demonstrated the changes in exhausted CD8T cells during combination therapy by single-cell RNA sequencing (scRNA-seq) analysis on tumor samples before and after treatment. Combination therapy exerted a substantial impact on the exhausted CD8T cells, particularly in terms of cytokine expression. CCL5 was the most abundantly expressed cytokine in CD8T cells and exhausted CD8T cells, and its expression increased further after treatment. Subsequently, we discovered the CCL5/CCR5/CYP1A1 pathway through RNA sequencing (RNA-seq) on CCL5-stimulated Huh7 cells and verified through a series of experiments that this pathway can mediate the resistance of liver cancer cells to lenvatinib. Tissue experiments showed that after combination therapy, the CCL5/CCR5/CYP1A1 pathway was activated, which can benefit the residual tumor cells to survive treatment. Tumor-bearing mouse experiments demonstrated that bergamottin (BGM), a competitive inhibitor of CYP1A1, can enhance the efficacy of both lenvatinib and combination therapy. Our research revealed one mechanism by which hepatoma cells can survive the combination therapy, providing a theoretical basis for the refined treatment of HCC.

Cyclophilin A regulates the apoptosis of A549 cells by stabilizing Twist1 protein.

Cyclophilin A (CypA, also known as PPIA) is an essential member of the immunophilin family. As an intracellular target of the immunosuppressive drug cyclosporin A (CsA) or a peptidyl-prolyl cis/trans isomerase (PPIase), it catalyzes the cis-trans isomerization of proline amidic peptide bonds, through which it regulates a variety of biological processes, such as intracellular signaling, transcription and apoptosis. In this study, we found that intracellular CypA enhanced Twist1 phosphorylation at Ser68 and inhibited apoptosis in A549 cells. Mechanistically, CypA could mediate the phosphorylation of Twist1 at Ser68 via p38 mitogen-activated protein kinase (also known as MAPK14), which inhibited its ubiquitylation-mediated degradation. In addition, CypA increased interaction between Twist1 and p65 (also known as RELA), as well as nuclear accumulation of the Twist1-p65 complex, which regulated Twist1-dependent expression of CDH1 and CDH2. Our findings collectively indicate the role of CypA in Twist1-mediated apoptosis of A549 cells through stabilizing Twist1 protein.

Intranasal Delivery of Pure Nanodrug Loaded Liposomes for Alzheimer's Disease Treatment by Efficiently Regulating Microglial Polarization.

The activated M1-like microglia induced neuroinflammation is the critical pathogenic event in Alzheimer's disease (AD). Microglial polarization from pro-inflammatory M1 toward anti-inflammatory M2 phenotype is a promising strategy. To efficiently accomplish this, amyloid-ß (Aß) aggregates as the culprit of M1 microglia activation should be uprooted. Interestingly, this study finds out that the self-reassembly of curcumin molecules into carrier-free curcumin nanoparticles (CNPs) exhibits multivalent binding with Aß to achieve higher inhibitory effect on Aß aggregation, compared to free curcumin with monovalent effect. Based on this, the CNPs loaded cardiolipin liposomes are developed for efficient microglial polarization. After intranasal administration, the liposomes decompose to release CNPs and cardiolipin in response to AD oxidative microenvironment. The CNPs inhibit Aß aggregation and promote Aß phagocytosis/clearance in microglia, removing roadblock to microglial polarization. Subsequently, CNPs are endocytosed by microglia and inhibit TLR4/NF-κB pathway for microglia polarization (M1→M2). Meanwhile, cardiolipin is identified as signaling molecule to normalize microglial dysfunction to prevent pro-inflammatory factors release. In AD transgenic mice, neuroinflammation, Aß burden, and memory deficits are relieved after treatment. Through combined attack by extracellularly eradicating roadblock of Aß aggregation and intracellularly inhibiting inflammation-related pathways, this nanotechnology assisted delivery system polarizes microglia efficiently, providing a reliable strategy in AD treatment.

The Respiratory Burst Oxidase Homologue OsRBOHE is crucial for root hair formation, drought resistance and tillering in rice.

Respiratory Burst Oxidase Homologues (RBOHs) are involved in plant growth, development, and stress adaptation. How OsRBOHs affect root hair formation and consequently nutrient acquisition and drought resistance in rice is not well understood. We knocked out six OsRBOH genes in rice that were expressed in roots and identified OsRBOHE as the only one affecting root hair formation. OsRBOHE was strongly expressed in the root epidermis, root hairs and tiller buds. OsRBOHE is localised at the plasma membrane. Knockout of OsRBOHE decreased reactive oxygen species generation in the root hairs and tiller buds, downregulated genes involved in cell wall biogenesis, and decreased root hair length and tillering by 90% and 30%, respectively. Knockout of OsRBOHE decreased phosphorus acquisition only in low available P soil under aerobic conditions, but not in high P soil or under flooded conditions when P was likely not limited by diffusion. Knockout of OsRBOHE markedly decreased drought resistance of rice plants through the effect on root hair formation and the associated rhizosheath. Taken together, OsRBOHE is crucial for root hair formation and tillering and consequently on drought resistance in rice. The contribution of root hairs to P acquisition in rice is limited to aerobic soil.

Coordination Assistance: A Powerful Strategy for Metal-Catalyzed Regio- and Enantioselective Hydroalkynylation of Internal Alkenes.

ConspectusAlkenes are versatile compounds that are readily available on a large scale from industry or through organic synthesis. The widespread occurrence of alkenes provides the continuous impetus for the development of catalytic asymmetric alkene hydrofunctionalizations, which enables expeditious construction of complex chiral molecules from readily available starting materials. Catalytic asymmetric hydrofunctionalization of internal alkenes presents a notable challenge, due to their low reactivity, many potential side reactions, and the simultaneous control of the regio-, diastereo-, and enantioselectivities.Dehydroamino acids and enamides are among the first substrates that provide notable enantioselectivities in catalytic asymmetric hydrogenation. The crucial importance of an amide coordinating group is established by a series of classical mechanistic studies. This initial success greatly stimulated further development for catalytic hydrogenation and hydrofunctionalization. Building on these pioneering works in asymmetric hydrogenation as well as related hydrofunctionalizations, we have adopted coordination assistance as a powerful tool to address the challenges associated with the asymmetric hydrofunctionalization of internal alkenes. Using a functional group on the alkene substrate as a native coordinating group, a two-point binding mode of the substrate to the metal center effectively enhances the reactivity and facilitates the control of regio-, diastereo- and enantioselectivities. Through this strategy, we have developed a number of alkene hydrofunctionalization methods with excellent regio-, diastereo-, and enantiocontrols.In this Account, we summarize the recent advance in our lab using coordination assistance as a key element to achieve regio- and enantioselective hydroalkynylation of internal alkenes. First, we describe our early work aimed at controlling the regio- and enantioselectivity of hydroalkynylation using disubstituted enamide as the substrate. Both α- and ß-alkynylation were achieved by channeling the reaction pathway into a Chalk-Harrod or modified Chalk-Harrod mechanism. Next, we discuss the further development of catalysts to achieve regiodivergent and enantioselective hydroalkynylation of trisubstituted enamide to access vicinal stereocenters and quaternary carbon stereocenters. We also discuss the hydroalkynylation of α,ß-unsaturated amides to achieve unconventional site-selectivity through a combination of alkene isomerization and regioselective hydroalkynylation. This provides the basis for the construction of a remote quaternary carbon stereocenter through catalytic hydroalkynylation of trisubstituted ß,γ-unsaturated amides. We further show that this controlling principle is applicable to terminal alkene with a coordinating group as well. A ligand-controlled mechanism shift is discussed for the enantioselective alkynylation at the terminal and internal position of 1,1,-disubstituted alkenes. Finally, we briefly mention the application of coordination assistance to other hydrofunctionalizations such as hydroboration and hydrosilylation, where previously inaccessible reactivity and selectivity were achieved. Collectively, these catalytic methods demonstrate the power of coordination assistance for enantioselective hydrofunctionalizations. We anticipate that this strategy will create a platform to enable diverse enantioselective alkene transformations.

High efficiency and stability of perovskite solar cells prepared by alkali metal interfacial modification.

Perovskite solar cells (PSCs) have attracted much attention at home and abroad due to their excellent photoelectric properties. Defects in the electron transport layer (ETL) and ETL/perovskite interface greatly affect the power conversion efficiency (PCE) and stability of PSCs. In the paper, the surface of tin dioxide (SnO2) ETL was modified by an alkali metal salt (NaBr, KBr, and RbBr) solution to optimize electron transport and passivate SnO2/perovskite. The results show that the photovoltaic performance of the PSCs is significantly improved after interfacial modification, especially the KBr-modified PSC has the highest PCE, which is 7.8% higher than that of the unmodified device, and the open-circuit voltage, short-circuit current density and fill factor are all greatly improved. This improvement is attributed to the fact that interfacial modification reduces the trap density of the SnO2 films, increases the mobility of the SnO2 films film, effectively passivates defects, and significantly inhibits the recombination at the SnO2/perovskite interface. This method aims to use simple and low-cost inorganic materials for effective interface modification.

Vector-guided Fourier single-pixel imaging.

The Fourier single-pixel imaging technique exhibits great potential for compressive imaging. However, the utilization of low sampling ratio can introduce unwanted ringing artifacts, thereby compromising the fidelity of reconstructed image detail. To address this issue, Vector guided Fourier single-pixel imaging (V-FSI) has been proposed. We analyze the statistical properties in the edge vector field derived from images with low sampling ratio. Based on this information, a tailored sampling map is designed to acquire the significant high-frequency components for image reconstruction. Experimental results demonstrate the remarkable effectiveness of the proposed V-FSI method in enhancing image quality. Notably, V-FSI exhibits exceptional capabilities in perceiving and preserving the details of the objects, particularly for objects characterized by pronounced periodicity and directionality.

Extended depth of field for Fresnel zone aperture camera via fast passive depth estimation.

The lensless camera with incoherent illumination has gained significant research interest for its thin and flexible structure. However, it faces challenges in resolving scenes with a wide depth of field (DoF) due to its depth-dependent point spread function (PSF). In this paper, we present a single-shot method for extending the DoF in Fresnel zone aperture (FZA) cameras at visible wavelengths through passive depth estimation. The improved ternary search method is utilized to determine the depth of targets rapidly by evaluating the sharpness of the back propagation reconstruction. Based on the depth estimation results, a set of reconstructed images focused on targets at varying depths are derived from the encoded image. After that, the DoF is extended through focus stacking. The experimental results demonstrate an 8-fold increase compared with the calibrated DoF at 130 mm depth. Moreover, our depth estimation method is five times faster than the traversal method, while maintaining the same level of accuracy. The proposed method facilitates the development of lensless imaging in practical applications such as photography, microscopy, and surveillance.

Address model mismatch and defocus in FZA lensless imaging via model-driven CycleGAN.

Mask-based lensless imaging systems suffer from model mismatch and defocus. In this Letter, we propose a model-driven CycleGAN, MDGAN, to reconstruct objects within a long distance. MDGAN includes two translation cycles for objects and measurements respectively, each consisting of a forward propagation and a backward reconstruction module. The backward module resembles the Wiener-U-Net, and the forward module consists of the estimated image formation model of a Fresnel zone aperture camera (FZACam), followed by CNN to compensate for the model mismatch. By imposing cycle consistency, the backward module can adaptively match the actual depth-varying imaging process. We demonstrate that MDGAN based on either a simulated or calibrated imaging model produces a higher-quality image compared to existing methods. Thus, it can be applied to other mask-based systems.

Hybrid Membrane Composed of Nickel Diselenide Nanosheets with Carbon Nanotubes for Catalytic Conversion of Polysulfides in Lithium-Sulfur Batteries.

Lithium-sulfur batteries demonstrate enormous energy density are promising forms of energy storage. Unfortunately, the slow redox kinetics and polysulfides shuttle effect are some of the factors that prevent the its development. To address these issues, the hybrid membrane with combination of nickel diselenide nanosheets modified carbon nanotubes (NSN@CNTs) and utilized Li2 S6 catholyte for lithium sulfur battery. The conductive CNTs facilitates fast electronic/ionic transport, while the polarity of NSN as a strong affinity to lithium polysulfides, effectively anchoring them, facilitating the redox conversion of polysulfide species, and effectively diminishing reaction barriers. The cell with NSN@CNTs delivers the first discharge capacity of 1123.8 mAh g-1 and maintains 786.5 mAh g-1 after 300 cycles (0.2 C) at the sulfur loading 5.4 mg. Its rate capability is commendable, enabling it to sustain a capacity of 559.8 mAh g-1 even at a high discharge rate of 2 C. In addition, its initial discharge capacity can remain 8.33 mAh even at 10.8 mg for duration of 100 cycles. This research indicates the potential application of NSN@CNTs hybrid materials in lithium-sulfur batteries.

Human amnion mesenchymal stem cells promote endometrial repair via paracrine, preferentially than transdifferentiation.

BACKGROUND: Intrauterine adhesion (IUA) is one of the most severe causes of infertility in women of childbearing age with injured endometrium secondary to uterine performance. Stem cell therapy is effective in treating damaged endometrium. The current reports mainly focus on the therapeutic effects of stem cells through paracrine or transdifferentiation, respectively. This study investigates whether paracrine or transdifferentiation occurs preferentially in treating IUA. METHODS: Human amniotic mesenchymal stem cells (hAMSCs) and transformed human endometrial stromal cells (THESCs) induced by transforming growth factor beta (TGF-ß1) were co-cultured in vitro. The mRNA and protein expression levels of Fibronectin (FN), Collagen I, Cytokeratin19 (CK19), E-cadherin (E-cad) and Vimentin were detected by Quantitative real-time polymerase chain reaction (qPCR), Western blotting (WB) and Immunohistochemical staining (IHC). The Sprague-Dawley (SD) rats were used to establish the IUA model. hAMSCs, hAMSCs-conditional medium (hAMSCs-CM), and GFP-labeled hAMSCs were injected into intrauterine, respectively. The fibrotic area of the endometrium was evaluated by Masson staining. The number of endometrium glands was detected by hematoxylin and eosin (H&E). GFP-labeled hAMSCs were traced by immunofluorescence (IF). hAMSCs, combined with PPCNg (hAMSCs/PPCNg), were injected into the vagina, which was compared with intrauterine injection. RESULTS: qPCR and WB revealed that FN and Collagen I levels in IUA-THESCs decreased significantly after co-culturing with hAMSCs. Moreover, CK19, E-cad, and Vimentin expressions in hAMSCs showed no significant difference after co-culture for 2 days. 6 days after co-culture, CK19, E-cad and Vimentin expressions in hAMSCs were significantly changed. Histological assays showed increased endometrial glands and a remarkable decrease in the fibrotic area in the hAMSCs and hAMSCs-CM groups. However, these changes were not statistically different between the two groups. In vivo, fluorescence imaging revealed that GFP-hAMSCs were localized in the endometrial stroma and gradually underwent apoptosis. The effect of hAMSCs by vaginal injection was comparable to that by intrauterine injection assessed by H&E staining, MASSON staining and IHC. CONCLUSIONS: Our data demonstrated that hAMSCs promoted endometrial repair via paracrine, preferentially than transdifferentiation.

IUA is the crucial cause of infertility in women of childbearing age, and no satisfactory treatment measures have been found in the clinic. hAMSCs can effectively treat intrauterine adhesions through paracrine and transdifferentiation mechanisms. This study confirmed in vitro and in vivo that amniotic mesenchymal stem cells preferentially inhibited endometrial fibrosis and promoted epithelial repair through paracrine, thus effectively treating intrauterine adhesions. The level of fibrosis marker proteins in IUA-THESCs decreased significantly after co-culturing with hAMSCs for 2 days in vitro. However, the level of epithelial marker proteins in hAMSCs increased significantly, requiring at least 6 days of co-culture. hAMSCs-CM had the same efficacy as hAMSCs in inhibiting fibrosis and promoting endometrial repair in IUA rats, supporting the idea that hAMSCs promoted endometrial remodeling through paracrine in vivo. In addition, GFP-labeled hAMSCs continuously colonized the endometrial stroma instead of the epithelium and gradually underwent apoptosis. These findings prove that hAMSCs ameliorate endometrial fibrosis of IUA via paracrine, preferentially than transdifferentiation, providing the latest insights into the precision treatment of IUA with hAMSCs and a theoretical basis for promoting the "cell-free therapy" of MSCs.

Analysis of antimicrobial biological activity of a marine Bacillus velezensis NDB.

A new strain of Bacillus velezensis NDB was isolated from Xiangshan Harbor and antibacterial test revealed antibacterial activity of this strain against 12 major pathogenic bacteria. The whole genome of the bacterium was sequenced and found to consist of a 4,214,838 bp circular chromosome and a 7410 bp circular plasmid. Furthermore, it was predicted by AntiSMASH and BAGEL4 to have 12 clusters of secondary metabolism genes for the synthesis of the inhibitors, fengycin, bacillomycin, macrolactin H, bacillaene, and difficidin, and there were also five clusters encoding potentially novel antimicrobial substances, as well as three bacteriocin biosynthesis gene clusters of amylocyclicin, ComX1, and LCI. qRT-PCR revealed significant up-regulation of antimicrobial secondary metabolite synthesis genes after 24 h of antagonism with pathogenic bacteria. Furthermore, MALDI-TOF mass spectrometry revealed that it can secrete surfactin non-ribosomal peptide synthase and polyketide synthase to exert antibacterial effects. GC-MS was used to analyze methanol extract of B. velezensis NDB, a total of 68 compounds were identified and these metabolites include 16 amino acids, 17 acids, 3 amines, 11 sugars, 11 alcohols, 1 ester, and 9 other compounds which can inhibit pathogenic bacteria by initiating the antibiotic secretion pathway. A comparative genomic analysis of gene families showed that the specificity of B. velezensis NDB was mainly reflected in environmental adaptability. Overall, this research on B. velezensis NDB provides the basis for elucidating its biocontrol effect and promotes its future application as a probiotic.

Efficient production of guanosine in Escherichia coli by combinatorial metabolic engineering.

BACKGROUND: Guanosine is a purine nucleoside that is widely used as a raw material for food additives and pharmaceutical products. Microbial fermentation is the main production method of guanosine. However, the guanosine-producing strains possess multiple metabolic pathway interactions and complex regulatory mechanisms. The lack of strains with efficiently producing-guanosine greatly limited industrial application. RESULTS: We attempted to efficiently produce guanosine in Escherichia coli using systematic metabolic engineering. First, we overexpressed the purine synthesis pathway from Bacillus subtilis and the prs gene, and deleted three genes involved in guanosine catabolism to increase guanosine accumulation. Subsequently, we attenuated purA expression and eliminated feedback and transcription dual inhibition. Then, we modified the metabolic flux of the glycolysis and Entner-Doudoroff (ED) pathways and performed redox cofactors rebalancing. Finally, transporter engineering and enhancing the guanosine synthesis pathway further increased the guanosine titre to 134.9 mg/L. After 72 h of the fed-batch fermentation in shake-flask, the guanosine titre achieved 289.8 mg/L. CONCLUSIONS: Our results reveal that the guanosine synthesis pathway was successfully optimized by combinatorial metabolic engineering, which could be applicable to the efficient synthesis of other nucleoside products.

Electrophile-Arene Affinity: An Energy Scale for Evaluating the Thermodynamics of Electrophilic Dearomatization Reactions.

Rational design and development of organic reactions are lofty goals in synthetic chemistry. Quantitative description of the properties of molecules and reactions by physical organic parameters plays an important role in this regard. In this Article, we report an energy scale, namely, electrophile-arene affinity (EAA), for evaluating the thermodynamics of electrophilic dearomatization reactions, a class of important transformations that can rapidly build up molecular complexity and structural diversity by converting planar aromatic compounds into three-dimensional cyclic molecules. The acquisition of EAA data can be readily achieved by theoretically calculating the enthalpy changes (ΔH) of the hypothetical reactions of various (cationic) electrophiles with aromatic systems (taking the 1-methylnaphthalen-2-olate ion as an example in this study). Linear correlations are found between the calculated ΔH values and established physical organic parameters such as the percentage of buried volume %VBur (steric effect), Hammett's σ or Brown's σ+ (electronic effect), and Mayr's E (reaction kinetics). Careful analysis of the ΔH values leads to the rational design of a dearomative alkynylation reaction using alkynyl hypervalent iodonium reagents as the electrophiles.

Editing Silicon Transporter Genes to Reduce Arsenic Accumulation in Rice.

Rice is a dominant source of inorganic arsenic (As) exposure for populations consuming rice as a staple food. Decreasing As accumulation in rice grain is important for improving food safety. Arsenite [As(III)], the main form of As in paddy soil porewater, is taken up inadvertently by OsLsi1 and OsLsi2, the two key transporters for silicon (Si) uptake in rice roots. Here, we investigated whether editing OsLsi1 or OsLsi2 can decrease As accumulation in rice grain without compromising grain yield. We used the CRISPR-Cas9 technology to edit the promoter region of OsLsi1 and the C-terminal coding sequence of OsLsi1 and OsLsi2, and we generated a total of 27 mutants. Uptake and accumulation of Si and As were evaluated in both short-term hydroponic experiments and in a paddy field. Deletion of 1.2-2 kb of the OsLsi1 promoter suppressed OsLsi1 expression in roots and Si uptake markedly and did not affect As(III) uptake or grain As concentration. Some of the OsLsi1 and OsLsi2 coding sequence mutants showed large decreases in the uptake of Si and As(III) as well as large decreases in Si accumulation in rice husks. However, only OsLsi2 mutants showed significant decreases (by up to 63%) in the grain total As concentration. Editing OsLsi2 mainly affected the accumulation of inorganic As in rice grain with little effect on the accumulation of dimethylarsenate (DMA). Grain yields of the OsLsi2 mutants were comparable to those of the wild type. Editing OsLsi2 provides a promising way to reduce As accumulation in rice grain without compromising the grain yield.

Effects of silencing hsa_circ_0015326 on proliferation, migration, invasion, and apoptosis of epithelial ovarian cancer cells.

Although the treatment of ovarian cancer has made great progress, there are still many patients who are not timely detected and given targeted therapy due to unknown pathogenesis. Recent studies have found that hsa_circ_0015326 is upregulated in ovarian cancer and is involved in the proliferation, invasion, and migration of ovarian cancer cells. However, whether hsa_circ_0015326 can be used as a new target of ovarian cancer needs further investigation. Therefore, the effect of hsa_circ_0015326 on epithelial ovarian cancer was investigated in this study. At first, si-hsa_circ_0015326 lentivirus was transfected into epithelial ovarian cancer cells. Then real-time fluorescence quantitative PCR (qRT-PCR) was used to detect hsa_circ_0015326 level. The proliferation of ovarian cancer cells was detected by CCK-8 assay. The horizontal and vertical migration abilities of the cells were detected by wound-healing assay and Transwell assay, respectively. Transwell assay was also used to determine the invasion rate. As for the apoptosis rate, it was assessed by flow cytometry. As a result, the expression level of hsa_circ_0015326 in A2780 and SKOV3 was found to be higher than that in IOSE-80. However, after transfecting si-hsa_circ_0015326 and si-NC into the cells, the proliferation, migration, and invasion abilities of A2780 and SKOV3 cells in the si-hsa_circ_0015326 group were significantly reduced in comparison to those in the si-NC and mock groups, while their apoptosis rates were elevated. Collectively, silencing hsa_circ_0015326 bears the capability of inhibiting the proliferation, migration, and invasion of ovarian cancer cells while increasing apoptosis rate. It can be concluded that hsa_circ_0015326 promotes the malignant biological activities of epithelial ovarian cancer cells.

Synthesis, biological activities and mechanistic studies of C20-ketone pachysandra alkaloids as anti-hepatocellular carcinoma agents.

The pachysandra alkaloids found in Sarcococca ruscifolia demonstrate notable anti-hepatocellular carcinoma activity. Despite their efficacy, the structural diversity of these compounds remains limited, and their precise antitumor mechanism is still unclear. In pursuit of identifying novel lead compounds with high efficacy and low toxicity for combating hepatocellular carcinoma, twenty-three compounds of C20-ketone pachysandra alkaloid derivatives were designed and synthesized by using 3-dimethylamine pachysandra alkaloids as scaffolds. Subsequent in vitro anticancer activity experiments showed that synthetic pachysandra alkaloids had a stronger effect on HepG2 cells than did their natural counterparts, with low toxicity and high selectivity. The most potent derivative, 6k, had an IC50 value of 0.75 µM, demonstrating 25.7-fold greater anticancer activity than sarcovagine D against HepG2 cells. Through network pharmacology and molecular docking analysis, it was revealed that synthetic pachysandra alkaloids may exert their effects by inhibiting the JAK2/STAT3 pathway, thereby preventing the proliferation of liver cancer cells. Further research through scratch tests, immunofluorescence experiments, and Western blot analysis revealed that compound 6k effectively inhibited the migration of HepG2 cells and induced mitochondria-mediated intrinsic apoptosis of HepG2 cells by regulating the JAK2/STAT3 signaling pathway. The aforementioned results indicate that compound 6k could be developed as a potential candidate for the treatment of hepatocellular carcinoma.