Engineered Bispecific Antibodies with Exquisite HIV-1-Neutralizing Activity.

While the search for an efficacious HIV-1 vaccine remains elusive, emergence of a new generation of virus-neutralizing monoclonal antibodies (mAbs) has re-ignited the field of passive immunization for HIV-1 prevention. However, the plasticity of HIV-1 demands additional improvements to these mAbs to better ensure their clinical utility. Here, we report engineered bispecific antibodies that are the most potent and broad HIV-neutralizing antibodies to date. One bispecific antibody, 10E8V2.0/iMab, neutralized 118 HIV-1 pseudotyped viruses tested with a mean 50% inhibitory concentration (IC50) of 0.002 µg/mL. 10E8V2.0/iMab also potently neutralized 99% of viruses in a second panel of 200 HIV-1 isolates belonging to clade C, the dominant subtype accounting for ∼50% of new infections worldwide. Importantly, 10E8V2.0/iMab reduced virus load substantially in HIV-1-infected humanized mice and also provided complete protection when administered prior to virus challenge. These bispecific antibodies hold promise as novel prophylactic and/or therapeutic agents in the fight against HIV-1.

Structures of rhodopsin in complex with G-protein-coupled receptor kinase 1.

G-protein-coupled receptor (GPCR) kinases (GRKs) selectively phosphorylate activated GPCRs, thereby priming them for desensitization1. Although it is unclear how GRKs recognize these receptors2-4, a conserved region at the GRK N terminus is essential for this process5-8. Here we report a series of cryo-electron microscopy single-particle reconstructions of light-activated rhodopsin (Rho*) bound to rhodopsin kinase (GRK1), wherein the N terminus of GRK1 forms a helix that docks into the open cytoplasmic cleft of Rho*. The helix also packs against the GRK1 kinase domain and stabilizes it in an active configuration. The complex is further stabilized by electrostatic interactions between basic residues that are conserved in most GPCRs and acidic residues that are conserved in GRKs. We did not observe any density for the regulator of G-protein signalling homology domain of GRK1 or the C terminus of rhodopsin. Crosslinking with mass spectrometry analysis confirmed these results and revealed dynamic behaviour in receptor-bound GRK1 that would allow the phosphorylation of multiple sites in the receptor tail. We have identified GRK1 residues whose mutation augments kinase activity and crosslinking with Rho*, as well as residues that are involved in activation by acidic phospholipids. From these data, we present a general model for how a small family of protein kinases can recognize and be activated by hundreds of different GPCRs.

Spatial spillovers of violent conflict amplify the impacts of climate variability on malaria risk in sub-Saharan Africa.

Africa carries a disproportionately high share of the global malaria burden, accounting for 94% of malaria cases and deaths worldwide in 2019. It is also a politically unstable region and the most vulnerable continent to climate change in recent decades. Knowledge about the modifying impacts of violent conflict on climate-malaria relationships remains limited. Here, we quantify the associations between violent conflict, climate variability, and malaria risk in sub-Saharan Africa using health surveys from 128,326 individuals, historical climate data, and 17,429 recorded violent conflicts from 2006 to 2017. We observe that spatial spillovers of violent conflict (SSVCs) have spatially distant effects on malaria risk. Malaria risk induced by SSVCs within 50 to 100 km from the households gradually increases from 0.1% (not significant, P>0.05) to 6.5% (95% CI: 0 to 13.0%). SSVCs significantly promote malaria risk within the average 20.1 to 26.9 °C range. At the 12-mo mean temperature of 22.5 °C, conflict deaths have the largest impact on malaria risk, with an approximately 5.8% increase (95% CI: 1.0 to 11.0%). Additionally, a pronounced association between SSVCs and malaria risk exists in the regions with 9.2 wet days per month. The results reveal that SSVCs increase population exposure to harsh environments, amplifying the effect of warm temperature and persistent precipitation on malaria transmission. Violent conflict therefore poses a substantial barrier to mosquito control and malaria elimination efforts in sub-Saharan Africa. Our findings support effective targeting of treatment programs and vector control activities in conflict-affected regions with a high malaria risk.

Structural and Molecular Mechanisms of Cytokine-Mediated Endocrine Resistance in Human Breast Cancer Cells.

Human breast cancers that exhibit high proportions of immune cells and elevated levels of pro-inflammatory cytokines predict poor prognosis. Here, we demonstrate that treatment of human MCF-7 breast cancer cells with pro-inflammatory cytokines results in ERα-dependent activation of gene expression and proliferation, in the absence of ligand or presence of 4OH-tamoxifen (TOT). Cytokine activation of ERα and endocrine resistance is dependent on phosphorylation of ERα at S305 in the hinge domain. Phosphorylation of S305 by IKKß establishes an ERα cistrome that substantially overlaps with the estradiol (E2)-dependent ERα cistrome. Structural analyses suggest that S305-P forms a charge-linked bridge with the C-terminal F domain of ERα that enables inter-domain communication and constitutive activity from the N-terminal coactivator-binding site, revealing the structural basis of endocrine resistance. ERα therefore functions as a transcriptional effector of cytokine-induced IKKß signaling, suggesting a mechanism through which the tumor microenvironment controls tumor progression and endocrine resistance.

A tumor microenvironment-activated metal-organic framework-based nanoplatform for amplified oxidative stress-induced enhanced chemotherapy.

Engineering a highly tumor microenvironment-responsive nanoplatform toward effective chemotherapy has always been a challenge in targeted cancer treatment. Metal-organic frameworks are a promising delivery system to reformulate previously approved drugs for enhanced chemotherapy, such as disulfiram (DSF). Herein, a tumor microenvironment-activated metal-organic framework-based nanoplatform DSF@MOF-199@FA has been fabricated to realize amplified oxidative stress-induced enhanced chemotherapy. Our results unveil that the copper ions and DSF released by DSF@MOF-199@FA in an acidic environment can be converted into toxic bis(N, N-diethyl dithiocarbamate) copper and then induce cell apoptosis. Simultaneously, we determined that the apoptosis outcome is further promoted by amplified oxidative stress through effective generation of reactive oxygen species and GSH elimination. In conclusion, this work provides a promising platform for effective anticancer treatment.

Genome-wide identification and expression analysis of the SPL gene family and its response to abiotic stress in barley (Hordeum vulgare L.).

BACKGROUND: Squamosa promoter-binding protein-like (SPL) is a plant-specific transcription factor that is widely involved in the regulation of plant growth and development, including flower and grain development, stress responses, and secondary metabolite synthesis. However, this gene family has not been comprehensively evaluated in barley, the most adaptable cereal crop with a high nutritional value. RESULTS: In this study, a total of 15 HvSPL genes were identified based on the Hordeum vulgare genome. These genes were named HvSPL1 to HvSPL15 based on the chromosomal distribution of the HvSPL genes and were divided into seven groups (I, II, III, V, VI, VII, and VIII) based on the phylogenetic tree analysis. Chromosomal localization revealed one pair of tandem duplicated genes and one pair of segmental duplicated genes. The HvSPL genes exhibited the highest collinearity with the monocotyledonous plant, Zea mays (27 pairs), followed by Oryza sativa (18 pairs), Sorghum bicolor (16 pairs), and Arabidopsis thaliana (3 pairs), and the fewest homologous genes with Solanum lycopersicum (1 pair). The distribution of the HvSPL genes in the evolutionary tree was relatively scattered, and HvSPL proteins tended to cluster with SPL proteins from Z. mays and O. sativa, indicating a close relationship between HvSPL and SPL proteins from monocotyledonous plants. Finally, the spatial and temporal expression patterns of the 14 HvSPL genes from different subfamilies were determined using quantitative real-time polymerase chain reaction (qRT-PCR). Based on the results, the HvSPL gene family exhibited tissue-specific expression and played a regulatory role in grain development and abiotic stress. HvSPL genes are highly expressed in various tissues during seed development. The expression levels of HvSPL genes under the six abiotic stress conditions indicated that many genes responded to stress, especially HvSPL8, which exhibited high expression under multiple stress conditions, thereby warranting further attention. CONCLUSION: In this study, 15 SPL gene family members were identified in the genome of Hordeum vulgare, and the phylogenetic relationships, gene structure, replication events, gene expression, and potential roles of these genes in millet development were studied. Our findings lay the foundation for exploring the HvSPL genes and performing molecular breeding of barley.

Genome-wide identification, evolution, and role of SPL gene family in beet (Beta vulgaris L.) under cold stress.

BACKGROUND: SPL transcription factors play vital roles in regulating plant growth, development, and abiotic stress responses. Sugar beet (Beta vulgaris L.), one of the world's main sugar-producing crops, is a major source of edible and industrial sugars for humans. Although the SPL gene family has been extensively identified in other species, no reports on the SPL gene family in sugar beet are available. RESULTS: Eight BvSPL genes were identified at the whole-genome level and were renamed based on their positions on the chromosome. The gene structure, SBP domain sequences, and phylogenetic relationship with Arabidopsis were analyzed for the sugar beet SPL gene family. The eight BvSPL genes were divided into six groups (II, IV, V, VI, VII, and VIII). Of the BvSPL genes, no tandem duplication events were found, but one pair of segmental duplications was present. Multiple cis-regulatory elements related to growth and development were identified in the 2000-bp region upstream of the BvSPL gene start codon (ATG). Using quantitative real-time polymerase chain reaction (qRT-PCR), the expression profiles of the eight BvSPL genes were examined under eight types of abiotic stress and during the maturation stage. BvSPL transcription factors played a vital role in abiotic stress, with BvSPL3 and BvSPL6 being particularly noteworthy. CONCLUSION: Eight sugar beet SPL genes were identified at the whole-genome level. Phylogenetic trees, gene structures, gene duplication events, and expression profiles were investigated. The qRT-PCR analysis indicated that BvSPLs play a substantial role in the growth and development of sugar beet, potentially participating in the regulation of root expansion and sugar accumulation.

Susceptibility gene identification and risk evaluation model construction by transcriptome-wide association analysis for salt sensitivity of blood pressure.

BACKGROUND: Salt sensitivity of blood pressure (SSBP) is an intermediate phenotype of hypertension and is a predictor of long-term cardiovascular events and death. However, the genetic structures of SSBP are uncertain, and it is difficult to precisely diagnose SSBP in population. So, we aimed to identify genes related to susceptibility to the SSBP, construct a risk evaluation model, and explore the potential functions of these genes. METHODS AND RESULTS: A genome-wide association study of the systemic epidemiology of salt sensitivity (EpiSS) cohort was performed to obtain summary statistics for SSBP. Then, we conducted a transcriptome-wide association study (TWAS) of 12 tissues using FUSION software to predict the genes associated with SSBP and verified the genes with an mRNA microarray. The potential roles of the genes were explored. Risk evaluation models of SSBP were constructed based on the serial P value thresholds of polygenetic risk scores (PRSs), polygenic transcriptome risk scores (PTRSs) and their combinations of the identified genes and genetic variants from the TWAS. The TWAS revealed that 2605 genes were significantly associated with SSBP. Among these genes, 69 were differentially expressed according to the microarray analysis. The functional analysis showed that the genes identified in the TWAS were enriched in metabolic process pathways. The PRSs were correlated with PTRSs in the heart atrial appendage, adrenal gland, EBV-transformed lymphocytes, pituitary, artery coronary, artery tibial and whole blood. Multiple logistic regression models revealed that a PRS of P < 0.05 had the best predictive ability compared with other PRSs and PTRSs. The combinations of PRSs and PTRSs did not significantly increase the prediction accuracy of SSBP in the training and validation datasets. CONCLUSIONS: Several known and novel susceptibility genes for SSBP were identified via multitissue TWAS analysis. The risk evaluation model constructed with the PRS of susceptibility genes showed better diagnostic performance than the transcript levels, which could be applied to screen for SSBP high-risk individuals.

Peripheral blood MR1 tetramer-positive mucosal-associated invariant T-cell function is modulated by mammalian target of rapamycin complex 1 in patients with active tuberculosis.

Tuberculosis (TB) is still an urgent global public health problem. Notably, mucosal-associated invariant T (MAIT) cells play an important role in early anti-TB immune response. Targeted control of them may be an effective method to improve vaccine efficacy and TB treatment. However, the biology and signal regulation mechanisms of MAIT cells in TB patients are still poorly understood. Previous studies have been limited by the lack of reagents to specifically identify MAIT cells. In addition, the use of alternative markers may subsume non-MAIT cell into MAIT cell populations. In this study, the human MR1 tetramer which can specifically identify MAIT cells was used to further explore the effect and mechanism of MAIT cells in anti-TB immune response. Our results showed that the tetramer+ MAIT cells in peripheral blood of TB patients were mainly CD8+ or CD4-CD8- cells, and very few were CD4+ cells. After BCG infecting autologous antigen-presenting cells, MAIT cells in patients produced significantly higher levels of cytokines, lysis and proliferation compared with healthy controls. After suppression of mTORC1 by the mTORC1-specific inhibitor rapamycin, the immune response of MAIT cells in patients was significantly reduced. This study demonstrates that peripheral blood tetramer+ MAIT cells from TB patients have significant anti-TB immune effect, which is regulated by mTORC1. This could provide ideas and potential therapeutic targets for the development of novel anti-TB immunotherapy.

Variations and reduction of plastome are associated with the evolution of parasitism in Convolvulaceae.

Parasitic lifestyle can often relax the constraint on the plastome, leading to gene pseudogenization and loss, and resulting in diverse genomic structures and rampant genome degradation. Although several plastomes of parasitic Cuscuta have  been reported, the evolution of parasitism in the family Convolvulaceae which is linked to structural variations and reduction of plastome has not been well investigated. In this study, we assembled and collected 40 plastid genomes belonging to 23 species representing four subgenera of Cuscuta and ten species of autotrophic Convolvulaceae. Our findings revealed nine types of structural variations and six types of inverted repeat (IR) boundary variations in the plastome of Convolvulaceae spp. These structural variations were associated with the shift of parasitic lifestyle, and IR boundary shift, as well as the abundance of long repeats. Overall, the degradation of Cuscuta plastome proceeded gradually, with one clade exhibiting an accelerated degradation rate. We observed five stages of gene loss in Cuscuta, including NAD(P)H complex → PEP complex → Photosynthesis-related → Ribosomal protein subunits → ATP synthase complex. Based on our results, we speculated that the shift of parasitic lifestyle in early divergent time promoted relaxed selection on plastomes, leading to the accumulation of microvariations, which ultimately resulted in the plastome reduction. This study provides new evidence towards a better understanding of plastomic evolution, variation, and reduction in the genus Cuscuta.

Reactive oxygen species (ROS) modulate nitrogen signaling using temporal transcriptome analysis in foxtail millet.

Reactive oxygen species (ROS) is a chemically reactive chemical substance containing oxygen and a natural by-product of normal oxygen metabolism. Excessive ROS affect the growth process of crops, which will lead to the decrease of yield. Nitrogen, as a critical nutrient element in plants and plays a vital role in plant growth and crop production. Nitrate is the primary nitrogen source available to plants in agricultural soil and various natural environments. However, the molecular mechanism of ROS-nitrate crosstalk is still unclear. In this study, we used the foxtail millet (Setaria italica L.) as the material to figure it out. Here, we show that excessive NaCl inhibits nitrate-promoted plant growth and nitrogen use efficiency (NUE). NaCl induces ROS accumulation in roots, and ROS inhibits nitrate-induced gene expression in a short time. Surprisingly, low concentration ROS slight promotes and high concentration of ROS inhibits foxtail millet growth under long-term H2O2 treatment. These results may open a new perspective for further exploration of ROS-nitrate signaling pathway in plants.

Biosynthesis of Enfumafungin-type Antibiotic Reveals an Unusual Enzymatic Fusion Pattern and Unprecedented C-C Bond Cleavage.

Enfumafungin-type antibiotics, represented by enfumafungin and fuscoatroside, belong to a distinct group of triterpenoids derived from fungi. These compounds exhibit significant antifungal properties with ibrexafungerp, a semisynthetic derivative of enfumafungin, recently gaining FDA's approval as the first oral antifungal drug for treating invasive vulvar candidiasis. Enfumafungin-type antibiotics possess a cleaved E-ring with an oxidized carboxyl group and a reduced methyl group at the break site, suggesting unprecedented C-C bond cleavage chemistry involved in their biosynthesis. Here, we show that a 4-gene (fsoA, fsoD, fsoE, fsoF) biosynthetic gene cluster is sufficient to yield fuscoatroside by heterologous expression in Aspergillus oryzae. Notably, FsoA is an unheard-of terpene cyclase-glycosyltransferase fusion enzyme, affording a triterpene glycoside product that relies on enzymatic fusion. FsoE is a P450 enzyme that catalyzes successive oxidation reactions at C19 to facilitate a C-C bond cleavage, producing an oxidized carboxyl group and a reduced methyl group that have never been observed in known P450 enzymes. Our study thus sets the important foundation for the manufacture of enfumafungin-type antibiotics using biosynthetic approaches.

An Ultramicroelectrode Electrochemistry and Surface Plasmon Resonance Coupling Method for Cell Exocytosis Study.

Exocytosis of a single cell has been extensively researched in recent years due to its close association with numerous diseases. However, current methods only investigate exocytosis at either the single-cell or multiple-cell level, and a method for simultaneously studying exocytosis at both levels has yet to be established. In this study, a combined device incorporating ultramicroelectrode (UME) electrochemistry and surface plasmon resonance (SPR) was developed, enabling the simultaneous monitoring of single-cell and multiple-cell exocytosis. PC12 cells were cultured directly on the SPR sensing Au film, with a carboxylated carbon nanopipette (c-CNP) electrode employed for electrochemical detection in the SPR reaction cell. Upon exocytosis, the released dopamine diffuses onto the inner wall of c-CNP, undergoing an electrochemical reaction to generate a current peak. Concurrently, exocytosis can also induce changes in the refractive index of the Au film surface, leading to the SPR signal. Consequently, the device enables real-time monitoring of exocytosis from both single and multiple cells with a high spatiotemporal resolution. The c-CNP electrode exhibited excellent resistance to protein contamination, high sensitivity for dopamine detection, and the capability to continuously monitor dopamine exocytosis over an extended period. Analysis of both SPR and electrochemical signals revealed a positive correlation between changes in the SPR signal and the frequency of exocytosis. This study introduces a novel method and platform for the simultaneous investigation of single-cell and multiple-cell exocytosis.

Genome-wide identification, structural characterization and gene expression analysis of the WRKY transcription factor family in pea (Pisum sativum L.).

BACKGROUND: The WRKY gene family is one of the largest families of transcription factors in higher plants, and WRKY transcription factors play important roles in plant growth and development as well as in response to abiotic stresses; however, the WRKY gene family in pea has not been systematically reported. RESULTS: In this study, 89 pea WRKY genes were identified and named according to the random distribution of PsWRKY genes on seven chromosomes. The gene family was found to have nine pairs of tandem duplicates and 19 pairs of segment duplicates. Phylogenetic analyses of the PsWRKY and 60 Arabidopsis WRKY proteins were performed to determine their homology, and the PsWRKYs were classified into seven subfamilies. Analysis of the physicochemical properties, motif composition, and gene structure of pea WRKYs revealed significant differences in the physicochemical properties within the PsWRKY family; however, their gene structure and protein-conserved motifs were highly conserved among the subfamilies. To further investigate the evolutionary relationships of the PsWRKY family, we constructed comparative syntenic maps of pea with representative monocotyledonous and dicotyledonous plants and found that it was most recently homologous to the dicotyledonous WRKY gene families. Cis-acting element analysis of PsWRKY genes revealed that this gene family can respond to hormones, such as abscisic acid (ABA), indole-3-acetic acid (IAA), gibberellin (GA), methyl jasmonate (MeJA), and salicylic acid (SA). Further analysis of the expression of 14 PsWRKY genes from different subfamilies in different tissues and fruit developmental stages, as well as under five different hormone treatments, revealed differences in their expression patterns in the different tissues and fruit developmental stages, as well as under hormone treatments, suggesting that PsWRKY genes may have different physiological functions and respond to hormones. CONCLUSIONS: In this study, we systematically identified WRKY genes in pea for the first time and further investigated their physicochemical properties, evolution, and expression patterns, providing a theoretical basis for future studies on the functional characterization of pea WRKY genes during plant growth and development.

Boosted Near-Infrared Photothermal Conversion in Rare Earth Ions-Doped 2D SnSe Nanosheets for Solar-Powered Water Evaporation Systems.

Solar-powered water evaporation as a clean and abundant renewable energy-efficient desalination technology provides a promising strategy to solve the shortage of freshwater resources. However, the development and application of solar vapor technology are hindered by the relatively low near-infrared photothermal conversion efficiency of existing materials and the lack of effective improvement strategies. In this work, the conductivity characteristics of 2D semiconductors are capitalized on the high visible light absorption and ultra-low thermal. Specifically, rare-earth ion dopants into SnSe nanosheets, significantly boosting their near-infrared photothermal conversion efficiency and solar water evaporation performance are introduced. Remarkably, the photothermal conversion efficiency of the doped SnSe nanosheets surged from 51.56% to 82.11%, surpassing many previously reported photothermal materials. Furthermore, leveraging these nanosheets with enhanced photothermal conversion efficiency, a solar interfacial evaporation system is constructed. The evaporation rate of 2.17 kg m-2 h-1 and the efficiency of 96.5% can be achieved at one solar irradiance, and it also has good salt-resistance properties. The findings demonstrate the potential of rare earth ion-doped 2D semiconductor nanosheets in solar water evaporation, paving the way for future sustainable desalination solutions.

Medical radiation exposure in inflammatory bowel disease: an updated meta-analysis.

BACKGROUND: There have been previous studies and earlier systematic review on the relationship between inflammatory bowel disease (IBD) and radiation exposure. With the diversification of current test methods, this study intended to conduct a meta-analysis to evaluate the IBD radiation exposure in recent years. METHODS: Three databases (PUBMED, EMBASE, and MEDICINE) for relevant literature up to May 1, 2023 were searched. The statistical data meeting requirements were collated and extracted. RESULTS: 20 papers were enrolled. The overall high radiation exposure rate was 15% (95% CI = [12%, 19%]) for CD and 5% (95% CI = [3%, 7%]) for UC. The pooled result found that high radiation exposure rate was 3.44 times higher in CD than in UC (OR = 3.44, 95% CI = [2.35, 5.02]). Moreover, the average radiation exposure level in CD was 12.77 mSv higher than that in UC (WMD = 12.77, 95% CI = [9.93, 15.62] mSv). Furthermore, radiation exposure level of CD after 2012 was higher than those before 2012 (26.42 ± 39.61vs. 23.76 ± 38.46 mSv, P = 0.016), while UC did not show similar result (11.99 ± 27.66 vs. 10.01 ± 30.76 mSv, P = 0.1). Through subgroup analysis, it was found that disease duration (WMD = 2.75, 95% CI = [0.10, 5.40] mSv), complications (OR = 5.09, 95% CI = [1.50, 17.29]), and surgical history (OR = 5.46, 95% CI = [1.51, 19.69]) significantly increased the proportion of high radiation exposure. CONCLUSION: This study found that radiation exposure level of IBD patients was high, which revealed the radiation risk in the process of diagnosis and treatment of IBD patients. In the future, longer follow-up and prospective studies are needed to reveal the relationship between high radiation exposure and solid tumorigenesis.

Targeted Discovery of a Natural ortho-Quinone Methide Precursor and Green Generation of Its Oligomers.

ortho-Quinone methides (o-QMs) are a class of highly reactive intermediates that serve as important nonisolable building blocks (NBBs) in organic synthesis and small-molecule library construction. Because of their instability and nonisolability, most reported o-QMs are generated through in situ chemical synthesis, and only a few natural o-QMs have been reported due to the lack of directed discovery strategies. Herein, a new natural o-QM precursor (trichophenol A, 2) was identified from the fungal strain of Trichoderma sp. AT0167 through genome mining, which was generated by trilA (nonreducing polyketide synthase) and trilB (2-oxoglutarate dependent dioxygenase). Combinatorial biosynthesis via two other known NRPKS genes with trilA and trilB was performed, leading to the generation of five new trichophenol o-QM oligomers (trichophenols D-H, 5-9). The strategy combining genome mining with combinatorial biosynthesis not only targetedly uncovered a new natural o-QM precursor but also produced various new molecules through oligomerization of the new o-QM and its designated o-QM acceptors without chemical synthesis and isolation of intermediates, which was named NBB genome mining-combinatorial biosynthesis strategy for o-QM molecule library construction. This study provides a new strategy for the targeted discovery of natural o-QMs and small-molecule library construction with natural o-QMs.

Effects of photodegradation on the composition characteristics and metal binding behavior of sediment-derived dissolved organic matter (SDOM) in nansi lake, China.

Sediment-derived dissolved organic matter (SDOM) is instrumental in the cycling of nutrients and heavy metals within lakes, influencing ecological balance and contaminant distribution. Given the influence of photodegradation on the alteration and breakdown of SDOM, further understanding of this process is essential. In this research, the properties of the SDOM photodegradation process and its metal-binding reactions in Nansi Lake were analyzed using the EEM-PARAFAC and 2D-SF/FTIR-COS techniques. Our study identified three sorts of humic-like components and one protein-like component in SDOM, with the humic-like material accounting for 71.3 ± 5.19% of the fluorescence intensity (Fmax). Photodegradation altered the abundance and structure of SDOM, with a 41.6 ± 5.82% decrease in a280 and a 29.1 ± 9.31% reduction in Fmax after 7 days, notably reducing the protein-like component C4 by 54.0 ± 5.17% and the humic-like component C2 by 48.5 ± 2.54%, which led to SDOM being formed with lower molecular weight and aromaticity. After photodegradation, the LogKCu values for humic-like and protein-like substances decreased (humic-like C2: LogKCu: 1.35 ± 0.10-1.11 ± 0.15, protein-like C4: 1.49 ± 0.14-1.29 ± 0.34), yet the preferential binding sequence of protein-like materials and specific functional groups with Cu2+ such as aliphatic C-OH, amide (I) C=O and polysaccharide C-O groups remained unaltered. Our results enhance the knowledge of light-induced SDOM alterations and offer insights into SDOM-metal interactions in aquatic ecosystems.

Lignans from Sambucus williamsii Protect Bone Via Microbiome.

PURPOSE OF REVIEW: Traditional Chinese Medicine has a unique system to diagnose and treat bone diseases with symptoms similar to those of osteoporosis. Sambucus williamsii Hance (SWH), a folk medicine in northern part of China for fractures healing and pain alleviation, has been demonstrated to exert bone anabolic effects in ovariectomized (OVX) rat and mice models in our previous studies. Lignans were identified to be the main bioactive fractions of SWH. However, pharmacokinetics study showed that the levels of lignan were too low to be detected in rat serum even upon taking 15 times of the effective dose of lignan-rich fraction from SWH. We hypothesize that lignans from SWH might exert its bone protective effect via the gut microbiome. RECENT FINDINGS: Our study revealed that the lignan-rich fraction of SWH did not influence the diversity of gut microbiota in OVX rats, but significantly increased the abundance of a few phyla, in particular, the restoration of the abundance of several genera that was directly correlated with bone mineral density (BMD). In addition, a subsequent metabolomic study indicated that serotonin, a neurotransmitter synthesized in the intestine and influenced by gut microbiota, may be involved in mediating the bone protective action of the lignans. Gut-derived serotonin is thought to inhibit bone growth. Based on this finding, several inhibitors that suppressed the synthesis of serotonin were identified from the lignans of SWH. Our studies suggested that microbiome is an indispensable factor for lignans derived from S. willimasii to exert bone beneficial effects.

Identification of systemic nitrogen signaling in foxtail millet (Setaria italica) roots based on split-root system and transcriptome analysis.

KEY MESSAGE: The study established split-root system (SRS) in foxtail millet, and identified the molecular regulatory mechanisms and metabolic pathways related to systemic nitrogen signaling based on this system and transcriptome analysis. The growth of crops is primarily constrained by the availability of nitrogen (N), an essential nutrient. Foxtail millet (Setaria italica L.) is a significant orphan crop known for its strong tolerance to barren conditions. Despite this, the signaling pathway of nitrogen in foxtail millet remains largely unexplored. Identifying the candidate genes responsible for nitrogen response in foxtail millet is crucial for enhancing its agricultural productivity. This study utilized the split-root system (SRS) in foxtail millet to uncover genes associated with Systemic Nitrogen Signaling (SNS). Transcriptome analysis of the SRS revealed 2158 differentially expressed genes (DEGs) implicated in SNS, including those involved in cytokinin synthesis, transcription factors, E3 ubiquitin ligase, and ROS metabolism. Silencing of SiIPT5 and SiATL31 genes through RNAi in transgenic plants resulted in reduced SNS response, indicating their role in the nitrogen signaling pathway of foxtail millet. Furthermore, the induction of ROS metabolism-related genes in response to KNO3 of the split-root System (Sp.KNO3) suggests a potential involvement of ROS signaling in the SNS of foxtail millet. Overall, this study sheds light on the molecular regulatory mechanisms and metabolic pathways of foxtail millet in relation to SNS.