Electrochemical Sensor for the Detection and Accurate Early Diagnosis of Ovarian Cancer

Ovarian cancer (OC) has the highest mortality rate among malignant tumors, primarily because it is difficult to diagnose early. Exosomes, a type of extracellular vesicle rich in parental information, have garnered significant attention in the field of cancer diagnosis and treatment. They play an important regulatory role in the occurrence, development, and metastasis of OC. Consequently, exosomes have emerged as noninvasive biomarkers for early cancer detection. Therefore, identifying cancer-derived exosomes may offer a novel biomarker for the early detection of OC. In this study, we developed a metal-organic frameworks assembled "double hook"-type aptamer electrochemical sensor, which enables accurate early diagnosis of OC. Under optimal experimental conditions, electrochemical impedance spectroscopy technology demonstrated a good linear relationship within the concentration range of 31-3.1 × 106 particles per microliter, with a detection limit as low as 12 particles per microliter. The universal exosome detection platform is constructed, and this platform can not only differentiate between high-grade serous ovarian cancer (HGSOC) patients and healthy individuals but also distinguish between HGSOC patients and nonhigh-grade serous OC (non-HGSOC). Consequently, it provides a novel strategy for the early diagnosis of OC and holds great significance in clinical differential diagnosis.

Levels, Distribution and Ecological Risk Assessment of PBDEs in Soils and Plants Around the Engineering Plastics Factory

This study systematically investigated the pollution levels and migration trends of PBDEs in soils and plants around engineering plastics factory, and identified the ecological risks of PBDEs in the environment around typical pollution sources.The results showed that 13 kinds of PBDEs were widely detected in the surrounding areas, and the concentration level was higher than the general environmental pollution level. The total PBDE concentrations (∑13PBDEs) in soils ranged from 14.6 to 278.4 ng/g dry weight (dw), and in plants ranged from 11.5 to 176 ng/g dw. Both soil and plant samples showed that BDE-209 was the most important congener, the pollution level in soil and plant was similar, and the composition of PBDEs congener was similar. In the soil column (50 cm), the radial migration of PBDEs was mainly concentrated in the 0-30 cm section. Except for BDE-66, which was mainly located in the 20-30 cm soil layer, the concentration of PBDEs was the highest in the 0-10 cm region. Furthermore, the environmental risks of PBDEs in soil and plants were evaluated by hazard quotient method, and the HQ values were all < 1, which did not exhibit any ecological risk. The evaluation results also showed that the ecological risk of PBDEs in soil was higher than that of plants, especially penta-BDE, which should be paid more attention.

Identification and Functional Analysis of Lysine 2-Hydroxyisobutyrylation in Cyanobacteria

Cyanobacteria are the oldest prokaryotic photoautotrophic microorganisms and have evolved complicated post-translational modification (PTM) machinery to respond to environmental stress. Lysine 2-hydroxyisobutyrylation (Khib) is a newly identified PTM that is reported to play important roles in diverse biological processes, however, its distribution and function in cyanobacteria have not been reported. Here, we performed the first systematic studies of Khib in a model cyanobacterium Synechococcus sp. strain PCC 7002 (Syn7002) using peptide prefractionation, pan-Khib antibody enrichment, and high-accuracy mass spectrometry (MS) analysis. A total of 1875 high-confidence Khib sites on 618 proteins were identified, and a large proportion of Khib sites are present on proteins in the cellular metabolism, protein synthesis, and photosynthesis pathways. Using site-directed mutagenesis and functional studies, we showed that Khib of glutaredoxin (Grx) affects the efficiency of the PS II reaction center and H2O2 resistance in Syn7002. Together, this study provides novel insights into the functions of Khib in cyanobacteria and suggests that reversible Khib may influence the stress response and photosynthesis in both cyanobacteria and plants.

Development of a CRISPR/Cas12a-mediated aptasensor for Mpox virus antigen detection

The emergence and rapid spread of Mpox (formerly monkeypox) have caused significant societal challenges. Adequate and appropriate diagnostics procedures are an urgent necessity. Herein, we discover a pair of aptamers through the systematic evolution of ligands by exponential enrichment (SELEX) that exhibit high affinity and bind to different sites towards the A29 protein of the Mpox virus. Subsequently, we propose a facile, sensitive, convenient CRISPR/Cas12a-mediated aptasensor for detecting the A29 antigen. The procedure employs the bivalent aptamers recognition, which induces the formation of a proximity switch probe and initiates subsequent cascade strand displacement reactions, then triggers CRISPR/Cas12a DNA trans-cleavage to achieve the sensitive detection of Mpox. Our method enables selective and ultrasensitive evaluation of the A29 protein within the range of 1 ng mL-1 to 1 μg mL-1, with a limit of detection (LOD) at 0.28 ng mL-1. Moreover, spiked A29 protein recovery exceeds 96.9%, while the detection activity remains above 91.9% after six months of storage at 4 °C. This aptasensor provides a novel avenue for exploring clinical diagnosis in cases involving Mpox as facilitating development in various analyte sensors.

Interactome Analysis of ClpX Reveals Its Regulatory Role in Metabolism and Photosynthesis in Cyanobacteria

Protein homeostasis is essential for cyanobacteria to maintain proper cellular function under adverse and fluctuating conditions. The AAA+ superfamily of proteolytic complexes in cyanobacteria plays a critical role in this process, including ClpXP, which comprises a hexameric ATPase ClpX and a tetradecameric peptidase ClpP. Despite the physiological effects of ClpX on growth and photosynthesis, its potential substrates and underlying mechanisms in cyanobacteria remain unknown. In this study, we employed a streptavidin-biotin affinity pull-down assay coupled with label-free proteome quantitation to analyze the interactome of ClpX in the model cyanobacterium Synechocystis sp. PCC 6803 (hereafter Synechocystis). We identified 503 proteins as potential ClpX-binding targets, many of which had novel interactions. These ClpX-binding targets were found to be involved in various biological processes, with particular enrichment in metabolic processes and photosynthesis. Using protein-protein docking, GST pull-down, and biolayer interferometry assays, we confirmed the direct association of ClpX with the photosynthetic proteins, ferredoxin-NADP+ oxidoreductase (FNR) and phycocyanin subunit (CpcA). Subsequent functional investigations revealed that ClpX participates in the maintenance of FNR homeostasis and functionality in Synechocystis grown under different light conditions. Overall, our study provides a comprehensive understanding of the extensive functions regulated by ClpX in cyanobacteria to maintain protein homeostasis and adapt to environmental challenges.

Deciphering the structure, function, and mechanism of lysine acetyltransferase cGNAT2 in cyanobacteria

Lysine acetylation is a conserved regulatory posttranslational protein modification that is performed by lysine acetyltransferases (KATs). By catalyzing the transfer of acetyl groups to substrate proteins, KATs play critical regulatory roles in all domains of life; however, no KATs have yet been identified in cyanobacteria. Here, we tested all predicted KATs in the cyanobacterium Synechococcus sp. PCC 7002 (Syn7002) and demonstrated that A1596, which we named cyanobacterial Gcn5-related N-acetyltransferase (cGNAT2), can catalyze lysine acetylation in vivo and in vitro. Eight amino acid residues were identified as the key residues in the putative active site of cGNAT2, as indicated by structural simulation and site-directed mutagenesis. The loss of cGNAT2 altered both growth and photosynthetic electron transport in Syn7002. In addition, quantitative analysis of the lysine acetylome identified 548 endogenous substrates of cGNAT2 in Syn7002. We further demonstrated that cGNAT2 can acetylate NAD(P)H dehydrogenase J (NdhJ) in vivo and in vitro, with the inability to acetylate K89 residues, thus decreasing NdhJ activity and affecting both growth and electron transport in Syn7002. In summary, this study identified a KAT in cyanobacteria and revealed that cGNAT2 regulates growth and photosynthesis in Syn7002 through an acetylation-mediated mechanism.

Azotobacter inoculation can enhance the resistance of Bt cotton to cotton bollworm, Helicoverpa armigera

The rising trend in the cultivation of Bacillus thuringiensis (Bt) transgenic crops may cause a destabilization of agroecosystems, thus increasing concerns about the sustainability of Bt crops as a valid pest management method. Azotobacter can be used as a biological regulator to increase environmental suitability and improve the soil nitrogen utilization efficiency of crops, especially Bt cotton. A laboratory test investigated effects on the development and food utilization of Helicoverpa armigera fed with different Cry1Ab/Cry1Ac proteins and nitrogen metabolism-related compounds from cotton (transgenic variety SCRC 37 vs non-Bt cotton cv. Yu 2067) inoculated with Azospirillum brasilense (Ab) and Azotobacter chroococcum (Ac). The findings indicate that inoculation with Azotobacter significantly decreased the partial development and food utilization indexes (pupal weight; pupation rate; adult longevity; fecundity; relative growth rate, RGR; efficiency of conversion of digested food, ECD; and efficiency of conversion of ingested food, ECI) of H. armigera fed on Bt cotton, but contrasting trends were found among these indexes in H. armigera fed on non-Bt cotton inoculated with Azotobacter, as a result of differences in Bt toxin production. Overall, the results showed that inoculation with Azotobacter had negative effects on the development and food utilization of H. armigera fed on Bt cotton, leading to enhanced target insect resistance. Presumably, Azotobacter inoculation can be used to stimulate plant soil nitrogen uptake to increase nitrogen metabolism-related compounds and promote plant growth for Bt and non-Bt cotton, simultaneously raising Bt protein expression and enhancing resistance efficacy against cotton bollworm in Bt cotton.

TMBPF-induced neurotoxicity and oxidative stress in zebrafish larvae: impacts on central nervous system development and dopamine neurons

Bisphenol A (BPA), a common bisphenol molecule, is well known in the environment as an endocrine disruptor. Furthermore, BPs (BPA, BPS, BPF, and BPAF) have been shown in recent years to be neurotoxic to zebrafish. Tetramethyl bisphenol F (TMBPF) has recently been introduced as a substitute for bisphenol A (BPA) in various industries, including plastics and food contact coatings. However, a growing number of studies have demonstrated that the toxicity of some BPA substitutes is similar to or even stronger than BPA, posing potential harm to human health and the environment. In this study, we used zebrafish larvae as a model to investigate the neurodevelopmental effects of TMBPF at different concentrations (0, 0.25, 0.5, 1, 2, 4 and 8 mg/L). Our results showed that exposure to TMBPF at concentrations higher than 4 mg/L for 72 h post-fertilization (hpf) resulted in zebrafish mortality, whereas exposure to 2 mg/L for 144 hpf caused deformities. Furthermore, TMBPF exposure inhibited the development of the central nervous system, motor nerves, and dopamine neurons in zebrafish. Real-time polymerase chain reaction (PCR) analysis revealed that TMBPF exposure significantly down-regulated the expression of oxidative stress-related genes (Cu/Zn-SOD, Mn-SOD, and CAT) and neurodevelopmental genes (mbp, gafp, and syn2a), while up-regulated the expression of dopamine-related genes (th1, th2, and dat). Notably, treatment with the antioxidant N-acetylcysteine (NAC) alleviated TMBPF-induced toxicity. NAC can regulate the expression of genes related to oxidative stress, neurodevelopment and dopamine development, and make the nerve development of zebrafish normal. Overall, our research suggested that TMBPF may disrupt the development of the early central nervous system and dopamine neurons, leading to abnormal motor behavior in zebrafish larvae. These results highlight the potential risks associated with the use of TMBPF in various industries and the importance to evaluate its potential risks to human health and the environment.

Adhesion G Protein-Coupled Receptor G2 Promotes Hepatocellular Carcinoma Progression and Serves as a Neutrophil-Related Prognostic Biomarker

Adhesion G protein-coupled receptor G2 (ADGRG2) is an orphan adhesion G protein-coupled receptor (GPCR), which performs a tumor-promoting role in certain cancers; however, it has not been systematically investigated in hepatocellular carcinoma (HCC). In the current study, we utilized multiple databases to analyze the expression and diagnostic and prognostic value of ADGRG2 in HCC and its correlation with immune infiltration and inflammatory factors. The function and upstream regulatory miRNA of ADGRG2 were validated through qPCR, Western blot, CCK8, wound healing, and dual luciferase assays. It turned out that ADGRG2 was significantly higher in HCC and had a poor survival rate, especially in AFP ≤ 400 ng/mL subgroups. Functional enrichment analysis suggested that ADGRG2 may be involved in cancer pathways and immune-related pathways. In vitro, siRNA-mediated ADGRG2 silencing could inhibit the proliferation and migration of Huh7 and HepG2 cells. There was a highly significant positive correlation between ADGRG2 and neutrophils. Moreover, NET-related genes were filtered and confirmed, such as ENO1 and S100A9. Meanwhile, the high expression of ADGRG2 was also accompanied by the highest number of inflammatory cytokines, chemokines, and chemokine receptors and good immunotherapy efficacy. Finally, AGDGR2 may be sensitive to two drugs (PIK-93 and NPK76-II-72-1) and can be targeted by miR-326. In conclusion, ADGRG2 may serve as a novel biomarker and drug target for HCC diagnosis, immunotherapy, and prognosis and was related to neutrophils and the inflammatory process of liver cancer development.

[Lactate promotes HMGB1 phosphorylation and release via Akt signaling pathway in gastric cancer cells HGC-27]

Objective: To investigate the molecular mechanism of how lactate induces high mobility group box 1 (HMGB1) release. Methods: Gastric cancer HGC-27 cells were divided into the control group and the lactate group (The cells were treated with lactate for 6 h). The level of HMGB1 in the cell culture medium was detected by enzyme-linked immunosorbent assay (ELISA), the localization of HMGB1 was detected using laser confocal microscopy, and the nuclear translocation of HMGB1 was detected using the nucleoplasmic separation assay. The phosphorylation and acetylation levels of HMGB1 were determined by co-immunoprecipitation, and Western blot was used to measure the phosphorylation of Akt and protein kinase C (PKC). HGC-27 cells were first treated with lactate and LY294002, the inhibitor of Akt, and then the phosphorylation of HMGB1 and Akt was analyzed by co-immunoprecipitation and Western blot, respectively. The localization of HMGB1 in cells was detected by laser confocal microscopy. EdU and Transwell assays were used to detect the proliferation and migration abilities of HGC-27 cells, respectively. HGC-27 cells were then injected into the BALB/C null mice for subcutaneous tumor implantation. Mice in the lactate group were intraperitoneally injected with lactate (0.2 g/kg/2 d), while those in the control group were intraperitoneally injected with an equal amount of PBS for 20 consecutive days. ELISA was used to detect the HMGB1 levels in the blood samples taken from the medial canthus vein of the mice, while co-immunoprecipitation and Western blot were used to detect the phosphorylation of HMGB1 and Akt in tumor tissue proteins, respectively. Results: The release levels of HMGB1 in the lactate group were (2 995.00±660.91) pg/ml and (696.33±22.03) pg/ml, after lactate treatment for 6 h and 12 h, respectively, both higher than those in the control group (485.00±105.83) pg/ml (P<0.001 and P=0.028, respectively). After lactate treatment for 6 h, the relative expression of HMGB1 protein in the cytoplasm of HGC-27 cells was 1.13±0.09, higher than that of the control group (0.83±0.07, P=0.001), while the relative expression of HMGB1 in the nucleus was 0.79±0.06, lower than that of the control group (1.07±0.06, P=0.007). The phosphorylation level of HMGB1 reached 1.41±0.09, which was higher than that of the control group (0.97±0.10, P=0.031). The phosphorylation level of Akt was 11.16±0.06, higher than that of the control group (0.91±0.022, P=0.002). The phosphorylation level and nuclear translocation of HMGB1 induced by lactate decreased obviously after Akt inhibition; the proliferation and migration abilities induced by lactate were also obviously inhibited after Akt inhibition. In vivo, the HMGB1 level in the peripheral blood was (1 280.70±389.66) pg/ml in the lactate group, which was obviously higher than that in the control group (595.11±44.75) pg/ml (P=0.008), and the phosphorylation levels of HMGB1 and Akt in tumor tissues in the lactate group were obviously enhanced compared with the control group. Conclusion: Lactate induces HMGB1 release through enhancing HMGB1 phosphorylation via the Akt signaling pathway.

Extract latent features of single-particle trajectories with historical experience learning

Single-particle tracking has enabled real-time, in situ quantitative studies of complex systems. However, inferring dynamic state changes from noisy and undersampling trajectories encounters challenges. Here, we introduce a data-driven method for extracting features of subtrajectories with historical experience learning (Deep-SEES), where a single-particle tracking analysis pipeline based on a self-supervised architecture automatically searches for the latent space, allowing effective segmentation of the underlying states from noisy trajectories without prior knowledge on the particle dynamics. We validated our method on a variety of noisy simulated and experimental data. Our results showed that the method can faithfully capture both stable states and their dynamic switch. In highly random systems, our method outperformed commonly used unsupervised methods in inferring motion states, which is important for understanding nanoparticles interacting with living cell membranes, active enzymes, and liquid-liquid phase separation. Self-generating latent features of trajectories could potentially improve the understanding, estimation, and prediction of many complex systems.

Prussian blue analogues-derived zero valent iron to efficiently activate peroxymonosulfate for phenol degradation triggered via reactive oxygen species and high-valent iron-oxo complexes

It is of great significance to develop the effective technique to treat phenol-containing wastewater. Herein, Fe-based prussian blue analogues-derived zero valent iron (ZVI) was successfully synthesized by one-step calcination method. Owing to high specific surface area and rich active sites, ZVI-2 possessed excellent performance in charge transfer. Notably, in comparison with conventional ZVI and Fe2+, ZVI-2 can effectively activate peroxymonosulfate (PMS) for achieving rapid degradation of phenol, and the highest removal efficiency of phenol reached 94.9% within 24 min. More importantly, developed ZVI-2/PMS oxidation system with good stability displayed strong anti-interference capability. Interestingly, Fe0 loaded on the surface of ZVI-2 can efficiently break the O-O bond of PMS to generate reactive oxygen species (i.e., SO4•-, OH•, O2•- and 1O2). As main adsorption sites of PMS, the existence of oxygen vacancy promote the formation of high-valent transition metal complexes (namely ZVI-2≡Fe4+=O). Under the combined action of reactive oxygen species and ZVI-2≡Fe4+=O, phenol can be eventually degraded into CO2 and H2O. The possible degradation pathways of phenol were also investigated. Furthermore, proposed ZVI-2/PMS oxidation system displayed great potential for application in the field of wastewater treatment. All in all, current work provided a valuable reference for design and application of Fe-based catalysts in PS-AOPs.

Insight into the mechanisms of neuroendocrine toxicity induced by 6:2FTCA via thyroid hormone disruption

6:2 fluorotonic carboxylic acid (6:2 FTCA), a novel substitute for perfluorooctanoic acid (PFOA), is being used gradually in industrial production such as coatings or processing aids, and its detection rate in the aqueous environment is increasing year by year, posing a potential safety risk to aquatic systems and public health. However, limited information is available on the effects and mechanism of 6:2 FTCA. Therefore, this study was conducted to understand better the neuroendocrine effects of early exposure to 6:2 FTCA and the underlying mechanisms on zebrafish. In this study, zebrafish embryos were treated to varied doses of 6:2 FTCA (0, 0.08 μg/mL, 0.8 μg/mL and 8 μg/mL) at 4 h post-fertilization (hpf) for a duration of six days, which exhibited a pronounced inhibition of early growth and induced a disorganized swim pattern characterized by reduced total swim distance and average swim speed. Simultaneously, the thyroid development of zebrafish larvae was partially hindered, accompanied by decreased T3 levels, altered genes associated with the expression of thyroid hormone synthesis, transformation and transportation and neurotransmitters associated with tryptophan and tyrosine metabolic pathways. Molecular docking results showed that 6:2 FTCA has a robust binding energy with the thyroid hormone receptor (TRβ). Moreover, exogenous T3 supplementation can partially restore the adverse outcomes. Our findings indicated that 6:2 FTCA acts as a thyroid endocrine disruptor and can induce neuroendocrine toxic effects. Furthermore, our results show that targeting TRβ may be a potentially therapeutic strategy for 6:2 FTCA-induced neuroendocrine disrupting effects.

PP2C phosphatases Ptc1 and Ptc2 dephosphorylate PGK1 to regulate autophagy and aflatoxin synthesis in the pathogenic fungus Aspergillus flavus

IMPORTANCE

Aspergillus flavus is a model filamentous fungus that can produce aflatoxins when it infects agricultural crops. This study evaluated the protein phosphatase 2C (PP2C) family as a potential drug target with important physiological functions and pathological significance in A. flavus. We found that two redundant PP2C phosphatases, Ptc1 and Ptc2, regulate conidia development, aflatoxin synthesis, autophagic vesicle formation, and seed infection. The target protein phosphoglycerate kinase 1 (PGK1) that interacts with Ptc1 and Ptc2 is essential to regulate metabolism and the autophagy process. Furthermore, Ptc1 and Ptc2 regulate the phosphorylation level of PGK1 S203, which is important for influencing aflatoxin synthesis. Our results provide a potential target for interdicting the toxicity of A. flavus.

Cla4 phosphorylates histone methyltransferase Set1 to prevent its degradation by the APC/CCdh1 complex

H3K4 trimethylation (H3K4me3) is a conserved histone modification catalyzed by histone methyltransferase Set1, and its dysregulation is associated with pathologies. Here, we show that Set1 is intrinsically unstable and elucidate how its protein levels are controlled within cell cycle and during gene transcription. Specifically, Set1 contains a destruction box (D-box) that is recognized by E3 ligase APC/CCdh1 and degraded by the ubiquitin-proteasome pathway. Cla4 phosphorylates serine 228 (S228) within Set1 D-box, which inhibits APC/CCdh1-mediated Set1 proteolysis. During gene transcription, PAF complex facilitates Cla4 to phosphorylate Set1-S228 and protect chromatin-bound Set1 from degradation. By modulating Set1 stability and its binding to chromatin, Cla4 and APC/CCdh1 control H3K4me3 levels, which then regulate gene transcription, cell cycle progression, and chronological aging. In addition, there are 141 proteins containing the D-box that can be potentially phosphorylated by Cla4 to prevent their degradation by APC/CCdh1. We addressed the long-standing question about how Set1 stability is controlled and uncovered a new mechanism to regulate protein stability.

Corrigendum: Interferon-induced transmembrane protein 3 in the hippocampus: a potential novel target for the therapeutic effects of recombinant human brain natriuretic peptide on sepsis-associated encephalopathy

[This corrects the article DOI: 10.3389/fnmol.2023.1182005.].

Contact Toxicity, Antifeedant Activity, and Oviposition Preference of Osthole against Agricultural Pests

Osthole, the dominant bioactive constituent in the Cnidium monnieri, has shown acute pesticidal activities. However, its detailed toxicity, antifeedant, and oviposition preference effects against agricultural pests have not been fully understood, limiting its practical use. This study aimed to investigate the contact toxicity, antifeedant activity, and oviposition preference of osthole against three agricultural pests (Tetranychus urticae, Myzus persicae, and Bactrocera dorsalis). Our results showed that the Cnidium monnieri (L.) Cusson (CMC) has a high osthole content of 11.4 mg/g. Osthole exhibited a higher level of acute toxicity against the T. urticae to four other coumarins found in CMC. It showed significant pesticidal activity against T. urticae and M. persicae first-instar nymphs and adults in a dose-dependent manner but not against B. dorsalis adults. Osthole exposure reduced the fecundity and prolonged the developmental time of the T. urticae and M. persicae. Leaf choice bioassays revealed potent antifeedant activity in the T. urticae and M. persicae. Furthermore, the female B. dorsalis showed a distinct preference for laying eggs in mango juice with 0.02 mg/mL osthole at 48 h, a preference that persisted at 96 h. These results provide valuable insights into the toxicity, repellent activity, and attractant activity of osthole, thereby providing valuable insights into its potential efficacy in pest control.

Effects on the yield and fiber quality components of Bt cotton inoculated with Azotobacter chroococcum under elevated CO2

Background

The raising trend of cultivation of Bacillus thuringiensis (Bt)-transgenic cotton is faced with a new challenge what effects on the growth and yield of Bt cotton under elevated CO2.

Methods

Rhizobacteria is the significant biological regulator to increase environmental suitability and ameliorate soil-nitrogen utilization efficiency of crops, especially Bt cotton. Pot-culture experiments investigated the effects on the yield and fiber quality components of Bt cotton (transgenic Line SCRC 37) inoculated with Azotobacter chroococcum (AC) under elevated CO2.

Results

The findings indicated that the inoculation of azotobacter significantly improved the yield and fiber quality components of Bt cotton, the elevated CO2 significantly increased the soil density of A. chroococcum and the partial yield indexes (as cottonweightper 20 bolls, lint yield per 20 bolls and boll number per plant), and non-significant decrease the fiber quality components of Bt cotton except uniform.

Discussion

Overall results obviously depicted that the inoculation of azotobacter and the elevated CO2 had positive effects on the yield and fiber quality components of Bt cotton. Presumably, azotobacter inoculation can be used to stimulate plant soil-nitrogen uptake and promote plant growth for Bt cotton under elevated CO2 in the future.

Interferon-induced transmembrane protein 3 in the hippocampus: a potential novel target for the therapeutic effects of recombinant human brain natriuretic peptide on sepsis-associated encephalopathy

Objective

This study aims to explore whether interferon-induced transmembrane protein 3 (IFITM3) is involved in recombinant human brain natriuretic peptide (rhBNP)-mediated effects on sepsis-induced cognitive dysfunction in mice.

Methods

The cellular localization and expression level of IFITM3 in the hippocampus were detected. The IFITM3 overexpression was achieved using an intracranial stereotactic system to inject an adeno-associated virus into the hippocampal CA1 region of mice. Field experiments, an elevated plus maze, and conditioned fear memory tests assessed the cognitive impairment in rhBNP-treated septic mice. Finally, in the hippocampus of septic mice, terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining and Immunoblot were used to detect changes in the protein expression of cleaved Caspase-8 and cleaved Caspase-3 in apoptosis-related pathways, and toll-like receptor 4 (TLR4) and nuclear factor κB (NF-κB) p65 in inflammatory pathways.

Results

Fourteen days after cecal ligation and puncture (CLP) surgery, IFITM3 localized in the plasma membrane and cytoplasm of the astrocytes in the hippocampus of septic mice, partially attached to the perivascular and neuronal surfaces, but not expressed in the microglia. The expression of IFITM3 was increased in the astrocytes and neurons in the hippocampus of septic mice, which was selectively inhibited by the administration of rhBNP. Overexpression of IFITM3 resulted in elevated anxiety levels and long-term learning and memory dysfunction, completely abolished the therapeutic effect of rhBNP on cognitive impairment in septic mice, and induced an increase in the number of neuronal apoptosis in the hippocampal CA1 region. The expression levels of cleaved Caspase-3 and cleaved Caspase-8 proteins were significantly increased in the hippocampus, but the expression levels of TLR4 and NF-κB p65 were not increased.

Conclusion

The activation of IFITM3 may be a potential new target for treating sepsis-associated encephalopathy (SAE), and it may be one of the key anti-apoptotic mechanisms in rhBNP exerting its therapeutic effect, providing new insight into the clinical treatment of SAE patients.

Zebrafish MAP2K7 Simultaneously Enhances Host IRF7 Stability and Degrades Spring Viremia of Carp Virus P Protein via Ubiquitination Pathway

During viral infection, host defensive proteins either enhance the host immune response or antagonize viral components directly. In this study, we report on the following two mechanisms employed by zebrafish mitogen-activated protein kinase kinase 7 (MAP2K7) to protect the host during spring viremia of carp virus (SVCV) infection: stabilization of host IRF7 and degradation of SVCV P protein. In vivo, map2k7+/- (map2k7-/- is a lethal mutation) zebrafish showed a higher lethality, more pronounced tissue damage, and more viral proteins in major immune organs than the controls. At the cellular level, overexpression of map2k7 significantly enhanced host cell antiviral capacity, and viral replication and proliferation were significantly suppressed. Additionally, MAP2K7 interacted with the C terminus of IRF7 and stabilized IRF7 by increasing K63-linked polyubiquitination. On the other hand, during MAP2K7 overexpression, SVCV P proteins were significantly decreased. Further analysis demonstrated that SVCV P protein was degraded by the ubiquitin-proteasome pathway, as the attenuation of K63-linked polyubiquitination was mediated by MAP2K7. Furthermore, the deubiquitinase USP7 was indispensable in P protein degradation. These results confirm the dual functions of MAP2K7 during viral infection. IMPORTANCE Normally, during viral infection, host antiviral factors individually modulate the host immune response or antagonize viral components to defense infection. In the present study, we report that zebrafish MAP2K7 plays a crucial positive role in the host antiviral process. According to the weaker antiviral capacity of map2k7+/- zebrafish than that of the control, we find that MAP2K7 reduces host lethality through two pathways, as follows: enhancing K63-linked polyubiquitination to promote host IRF7 stability and attenuating K63-mediated polyubiquitination to degrade the SVCV P protein. These two mechanisms of MAP2K7 reveal a special antiviral response in lower vertebrates.

Panax notoginseng transcription factor WRKY15 modulates resistance to Fusarium solani by up-regulating osmotin-like protein expression and inducing JA/SA signaling pathways

BACKGROUND

Panax notoginseng (Burk) F. H. Chen is a valuable traditional Chinese medicinal plant, but its commercial production is seriously affected by root rot caused by some pathogenic fungi, including Fusarium solani. Nevertheless, the genetic breeding for disease resistance of P. notoginseng remains limited. The WRKY transcription factors have been revealed to play important roles in plant defense responses, which might provide an inspiration for resistance improvement in P. notoginseng.

RESULTS

In this study, the regulatory mechanism of transcription factor PnWRKY15 on P. notoginseng resistance to F. solani infection was revealed. The suppressed expression of PnWRKY15 via RNA interference increased the sensitivity of P. notoginseng to F. solani and decreased the expression levels of some defense-related genes, including PnOLP1, which encodes an osmotin-like protein that confers resistance to F. solani. Ectopic expression of PnWRKY15 in the model plant tobacco significantly enhanced the resistance to F. solani. Moreover, the transcriptome sequencing analysis discovered that some pathogenesis-related genes were expressed at higher levels in the PnWRKY15-overexpressing tobacco than that in the wild-type tobacco. In addition, the jasmonic acid (JA) and salicylic acid (SA) signaling pathways were evidently induced by PnWRKY15-overexpression, that was evidenced by that the JA and SA contents were significantly higher in the PnWRKY15-overexpressing tobacco than that in the wild-type. Furthermore, PnWRKY15, which was localized in the nucleus, can trans-activate and up-regulate PnOLP1 expression according to the EMSA, yeast one-hybrid and co-expression assays.

CONCLUSIONS

PnWRKY15 contributes to P. notoginseng resistance to F. solani by up-regulating the expression of resistance-related gene PnOLP1 and activating JA/SA signaling pathways. These findings will help to further elucidate the transcriptional regulatory mechanism associated with the P. notoginseng defense response to F. solani.

Functional evaluation of the insulin/insulin-like growth factor signaling pathway in determination of wing polyphenism in pea aphid

Wing polyphenism is a common phenomenon that plays key roles in environmental adaptation of insects. Insulin/insulin-like growth factor signaling (IIS) pathway is a highly conserved pathway in regulation of metabolism, development, and growth in metazoans. It has been reported that IIS is required for switching of wing morph in brown planthopper via regulating the development of the wing pad. However, it remains elusive whether and how IIS pathway regulates transgenerational wing dimorphism in aphid. In this study, we found that pairing and solitary treatments can induce pea aphids to produce high and low percentage winged offspring, respectively. The expression level of ILP5 (insulin-like peptide 5) in maternal head was significantly higher upon solitary treatment in comparison with pairing, while silencing of ILP5 caused no obvious change in the winged offspring ratio. RNA interference-mediated knockdown of FoxO (Forkhead transcription factor subgroup O) in stage 20 embryos significantly increased the winged offspring ratio. The results of pharmacological and quantitative polymerase chain reaction experiments showed that the embryonic insulin receptors may not be involved in wing polyphenism. Additionally, ILP4 and ILP11 exhibited higher expression levels in 1st wingless offspring than in winged offspring. We demonstrate that FoxO negatively regulates the wing morph development in embryos. ILPs may regulate aphid wing polyphenism in a developmental stage-specific manner. However, the regulation may be not mediated by the canonical IIS pathway. The findings advance our understanding of IIS pathway in insect transgenerational wing polyphenism.

Direct Observation of Nanotracer Transport in Swarming Bacteria during Antibiotic Adaptation

Microorganisms inevitably encounter environmental variations and thus need to develop necessary strategies to adjust the colonies for survival. Here, we use cooperating Serratia marcescens bacteria to reveal how the whole population responds to a gradually deteriorating habitat. When subjected to antibiotics with increasing doses, the swarming bacteria transform weak homogeneous turbulent flows to nematic jet flows with defects and vortices on a large scale, by which bacteria exploit these coherent flows to transfer material and/or information. We elucidate a complete view of detailed spatiotemporal transport behavior in such microscale active turbulence with single-nanoparticle tracking. The nanoparticles in these active flows are brought into the state with the up limit of superdiffusion by the bacterial collective response to the stronger antibiotic stimulation. Strikingly, we found that, under the strengthening stimulation from antibiotics, bacteria with only a small fraction of their community get elongated and facilitate the drastic turbulence transition and an enhanced superdiffusion. These findings imply a possible collective response mechanism against environmental variations.

[Aloin inhibits gastric cancer cell proliferation and migration by suppressing the STAT3/HMGB1 signaling pathway]

OBJECTIVE

To investigate the molecular mechanism underlying the inhibitory effect of aloin on the proliferation and migration of gastric cancer cells.

METHODS

Human gastric cancer MGC-803 cells treated with 100, 200 and 300 μg/mL aloin were examined for changes in cell viability, proliferation and migration abilities using CCK-8, EdU and Transwell assays. HMGB1 mRNA level in the cells was detected with RT-qPCR, and the protein expressions of HMGB1, cyclin B1, cyclin E1, E-cadherin, MMP-2, MMP-9 and p-STAT3 were determined using Western blotting. JASPAR database was used to predict the binding of STAT3 to HMGB1 promoter. In a BALB/c-Nu mouse model bearing subcutaneous MGC-803 cell xenograft, the effect of intraperitoneal injection of aloin (50 mg/kg) on tumor growth was observed. The protein expressions of HMGB1, cyclin B1, cyclin E1, E-cadherin, MMP-2, MMP-9 and p-STAT3 in the tumor tissue was examined using Western blotting, and tumor metastasis in the liver and lung tissues was detected using HE staining.

RESULTS

Treatment with aloin concentration-dependently inhibited the viability of MGC-803 cells (P < 0.05), significantly reduced the number of EdU-positive cells (P < 0.01), and attenuated the migration ability of the cells (P < 0.01). Aloin treatment dose-dependently down-regulated HMGB1 mRNA expression (P < 0.01), lowered the protein expressions of HMGB1, cyclin B1, cyclin E1, MMP-2, MMP-9 and p-STAT3, and up-regulated E-cadherin expression in MGC-803 cells. Prediction based on JASPAR database suggested that STAT3 could bind to the promoter region of HMGB1. In the tumor-bearing mice, aloin treatment significantly reduced the tumor size and weight (P < 0.01), lowered the protein expressions of cyclin B1, cyclin E1, MMP-2, MMP-9, HMGB1 and p-STAT3 and increased the expression of E-cadherin in the tumor tissue (P < 0.01).

CONCLUSION

Aloin attenuates the proliferation and migration of gastric cancer cells by inhibiting the STAT3/HMGB1 signaling pathway.

Management of heterotopic pregnancy: clinical analysis of sixty-five cases from a single institution

Objective

This retrospective study aims to analyze the influence of different treatment modalities on viable intrauterine pregnancy and to summarize the clinical features of heterotopic pregnancy (HP) patients.

Material and methods

All patients diagnosed with HP between January 2012 and December 2022 in Tianjin Central Obstetrics and Gynecology Hospital were reviewed retrospectively.

Results

This study diagnosed 65 patients using transvaginal ultrasound (TVS), including two cases of natural pregnancy, seven cases of ovulation induction pregnancy, and 56 cases after in vitro fertilization and embryo transfer (IVF-ET). The gestational age was 50.2 ± 13.0 days at the time of diagnosis. The most frequent manifestations were abdominal pain (61.5%) and vaginal bleeding (55.4%), while 11 patients (16.9%) had no symptoms before the diagnosis. The primary treatment was expectant and surgical management, including laparotomy and laparoscopic surgery. In the expectant management group, four patients were transferred to surgery due to rupture of ectopic pregnancy or ectopic pregnancy mass gradually enlarged. In the surgical management group, 53 patients underwent laparoscopic surgery, and six underwent laparotomy. The laparoscopic group's mean operation time was 51.3 ± 14.2 min (range: 15-140 min), and the median intraoperative blood loss was 20 mL (range 5-200 mL). In contrast, the laparotomy group's mean operation time was 80.0 ± 25.3 min (range 50-120 min), and the median intraoperative blood loss was 22.5 mL (range 20-50 mL). Four patients had postoperative abortions. Sixty-one newborns had no birth abnormalities, and no developmental malformations were discovered after a median follow-up of 32 months.

Conclusion

Expectant treatment has a high failure rate in HP, and laparoscopic surgery is a safe and effective treatment for removing ectopic pregnancy without increasing the risk of abortion or newborn birth defects.

Customization of aptamer to develop CRISPR/Cas12a-derived ultrasensitive biosensor

The CRISPR/Cas systems have provided wide biosensing applications. Particularly, the aptamer-involved CRISPR/Cas sensor system powerfully expanded to non-nucleic-acid targets. However, tailoring the sequence of the aptamer to explore the relationship between affinity and the activation of CRISPR/Cas12a trans-cleavage activity has not been reported yet. Herein, we developed a series of new aptamers toward the spike protein 1(S1) of SARS-CoV-2. Surface plasmon resonance measurements showed that the affinity of these aptamers to S1 was at the nM level. Subsequently, a "SET" effect (Sequence Essential Trans-cleavage activity) is discovered for the activation of CRISPR/Cas12a trans-cleavage activity. That is, an aptamer, as the activator, sequence needs to be tailored to activate CRISPR/Cas12a efficiently. A balance should be reached between affinity and activation ability. On the one hand, high affinity ensures target recognition performance, and on the other hand, activation can achieve adequate amplification and output of recognition signals. The optimized sequence (with 27 nucleotides, for short 27-nt) not only recognizes the target with a high affinity and specificity but also can trigger the CRISPR/Cas12a trans-cleavage activity efficiently, showing an excellent detection performance in electrochemical biosensors. The detection limit for SARS-CoV-2 S1 can be low at 1.5 pg mL^-1. The new CRISPR/Cas12a-derived aptasensor also displays a remarkable ability to detect Beta, Delta, and Omicron variants but is selective toward other kinds of proteins. Above all, it is robust for point-of-care testing (POCT) in complex biological fluids, such as saliva, urine, and serum, and provides a universal and scalable detecting platform. Our results provide new insights into aptamer development and a different strategy for COVID-19 antigen detection and biosensor development.

Cnidium monnieri (L.) Cusson Flower as a Supplementary Food Promoting the Development and Reproduction of Ladybeetles Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae)

Predaceous ladybeetles are highly polyphagous predators that ingest supplementary food from flowering plants. Flowering plants widely grown in agroecosystems can sustain multiple natural enemies of agricultural pests, and the pollen and nectar resources from flowering plants may have a positive role in natural enemies. Cnidium monnieri (L.) Cusson, an annual herb with many flowers, blooms from May to July. C. monnieri can support several predatory natural enemies, and the addition of C. monnieri strips increases the density of Harmonia axyridis (Pallas) and improves the biological control of apple aphids in an apple orchard. H. axyridis is also the most important natural enemy in wheat aphid biocontrol and is attracted to healthy and aphid-infested C. monnieri plants. In addition, adult Propylaea japonica Thunberg survives significantly longer on C. monnieri flowers than on a water-only diet. In this study, a laboratory experiment was conducted to assess (i) the effect of nutritional supplements derived from C. monnieri flowers on the development and reproduction of H. axyridis under a wheat aphids-only diet; (ii) the effect of C. monnieri flowers on H. axyridis adult reproduction performance. We compared the larval durations, survival, weight, adult longevity, and reproduction of H. axyridis reared on wheat aphids-only and aphids plus C. monnieri flower diets. The results showed that H. axyridis larvae reared on aphids plus flowers had significantly greater weights and survival rates, shorter larval durations, and produced 1.62 times more eggs than those reared on wheat aphids-only diets. H. axyridis adults ingesting a C. monnieri flowers plus an aphid diet increased egg production 1.44 times compared to the aphids-only diet. Our study demonstrates that C. monnieri flowers as a supplementary food positively affect the survival, development, and reproduction performance of H. axyridis.

Salivary carbonic anhydrase II in winged aphid morph facilitates plant infection by viruses

Aphids are the most common insect vector transmitting hundreds of plant viruses. Aphid wing dimorphism (winged vs. wingless) not only showcases the phenotypic plasticity but also impacts virus transmission; however, the superiority of winged aphids in virus transmission over the wingless morph is not well understood. Here, we show that plant viruses were efficiently transmitted and highly infectious when associated with the winged morph of Myzus persicae and that a salivary protein contributed to this difference. The carbonic anhydrase II (CA-II) gene was identified by RNA-seq of salivary glands to have higher expression in the winged morph. Aphids secreted CA-II into the apoplastic region of plant cells, leading to elevated accumulation of H+. Apoplastic acidification further increased the activities of polygalacturonases, the cell wall homogalacturonan (HG)-modifying enzymes, promoting degradation of demethylesterified HGs. In response to apoplastic acidification, plants accelerated vesicle trafficking to enhance pectin transport and strengthen the cell wall, which also facilitated virus translocation from the endomembrane system to the apoplast. Secretion of a higher quantity of salivary CA-II by winged aphids promoted intercellular vesicle transport in the plant. The higher vesicle trafficking induced by winged aphids enhanced dispersal of virus particles from infected cells to neighboring cells, thus resulting in higher virus infection in plants relative to the wingless morph. These findings imply that the difference in the expression of salivary CA-II between winged and wingless morphs is correlated with the vector role of aphids during the posttransmission infection process, which influences the outcome of plant endurance of virus infection.

Aptamers dimerization inspired biomimetic clamp assay towards impedimetric SARS-CoV-2 antigen detection

Antigen-detecting rapid diagnostic testing (Ag-RDT) has contributed to containing the spread of SARS-CoV-2 variants of concern (VOCs). In this study, we proposed a biomimetic clamp assay for impedimetric SARS-CoV-2 nucleocapsid protein (Np) detection. The DNA biomimetic clamp (DNA-BC) is formed by a pair of Np aptamers connected via a T₂₀ spacer. The 5'- terminal of the DNA-BC is phosphate-modified and then anchored on the surface of the screen-printed gold electrode, which has been pre-coated with Au@UiO-66-NH₂. The integrated DNA-material sensing biochip is fabricated through the strong Zr-O-P bonds to form a clamp-type impedimetric aptasensor. It is demonstrated that the aptasensor could achieve Np detection in one step within 11 min and shows pronounced sensitivity with a detection limit of 0.31 pg mL^-1. Above all, the aptasensor displays great specificity and stability under physiological conditions as well as various water environments. It is a potentially promising strategy to exploit reliable Ag-RDT products to confront the ongoing epidemic.

A novel gene REPTOR2 activates the autophagic degradation of wing disc in pea aphid

Wing dimorphism in insects is an evolutionarily adaptive trait to maximize insect fitness under various environments, by which the population could be balanced between dispersing and reproduction. Most studies concern the regulatory mechanisms underlying the stimulation of wing morph in aphids, but relatively little research addresses the molecular basis of wing loss. Here, we found that, while developing normally in winged-destined pea aphids, the wing disc in wingless-destined aphids degenerated 30-hr postbirth and that this degeneration was due to autophagy rather than apoptosis. Activation of autophagy in first instar nymphs reduced the proportion of winged aphids, and suppression of autophagy increased the proportion. REPTOR2, associated with TOR signaling pathway, was identified by RNA-seq as a differentially expressed gene between the two morphs with higher expression in the thorax of wingless-destined aphids. Further genetic analysis indicated that REPTOR2 could be a novel gene derived from a gene duplication event that occurred exclusively in pea aphids on autosome A1 but translocated to the sex chromosome. Knockdown of REPTOR2 reduced autophagy in the wing disc and increased the proportion of winged aphids. In agreement with REPTOR's canonical negative regulatory role of TOR on autophagy, winged-destined aphids had higher TOR expression in the wing disc. Suppression of TOR activated autophagy of the wing disc and decreased the proportion of winged aphids, and vice versa. Co-suppression of TOR and REPTOR2 showed that dsREPTOR2 could mask the positive effect of dsTOR on autophagy, suggesting that REPTOR2 acted as a key regulator downstream of TOR in the signaling pathway. These results revealed that the TOR signaling pathway suppressed autophagic degradation of the wing disc in pea aphids by negatively regulating the expression of REPTOR2.

Phosphoglycerate dehydrogenase activates PKM2 to phosphorylate histone H3T11 and attenuate cellular senescence

Vascular endothelial cells (ECs) senescence correlates with the increase of cardiovascular diseases in ageing population. Although ECs rely on glycolysis for energy production, little is known about the role of glycolysis in ECs senescence. Here, we report a critical role for glycolysis-derived serine biosynthesis in preventing ECs senescence. During senescence, the expression of serine biosynthetic enzyme PHGDH is significantly reduced due to decreased transcription of the activating transcription factor ATF4, which leads to reduction of intracellular serine. PHGDH prevents premature senescence primarily by enhancing the stability and activity of pyruvate kinase M2 (PKM2). Mechanistically, PHGDH interacts with PKM2, which prevents PCAF-catalyzed PKM2 K305 acetylation and subsequent degradation by autophagy. In addition, PHGDH facilitates p300-catalyzed PKM2 K433 acetylation, which promotes PKM2 nuclear translocation and stimulates its activity to phosphorylate H3T11 and regulate the transcription of senescence-associated genes. Vascular endothelium-targeted expression of PHGDH and PKM2 ameliorates ageing in mice. Our findings reveal that enhancing serine biosynthesis could become a therapy to promote healthy ageing.

The AMP-Activated Protein Kinase (AMPK) Positively Regulates Lysine Biosynthesis Induced by Citric Acid in Flammulina filiformis

Flammulina filiformis, the most produced edible mushroom species in China, is rich in lysine. Further enhancing its lysine biosynthesis is vital for improving its quality in industrialized cultivation. Citric acid induction significantly increases both the biomass and growth rate of F. filiformis hyphae, as well as the lysine content. The genes encoding enzymes in the lysine biosynthesis pathway were detected under the optimal induction, revealing that the expression levels of hcs, hac, and hah were 2.67, 1.97, and 1.90 times greater, respectively, relative to the control, whereas no significant difference was seen for hdh, aat, sr, and shd, and the expression of aar decreased. Furthermore, the transcriptional levels of Ampk, GCN2, GCN4, and TOR were found significantly upregulated, with the most upregulated, Ampk, reaching a level 42.68 times greater than that of the control, while the phosphorylation of AMPK rose by nearly 54%. In AMPK-silencing strains under the optimal induction, however, the phosphorylation increment dropped to about 16% and the lysine content remained at the same level as in the WT. Thus, AMPK is presented as the critical intermediary in citric acid's regulation of lysine biosynthesis in F. filiformis.

The TORC1 activates Rpd3L complex to deacetylate Ino80 and H2A.Z and repress autophagy

Autophagy is a critical process to maintain homeostasis, differentiation, and development. How autophagy is tightly regulated by nutritional changes is poorly understood. Here, we identify chromatin remodeling protein Ino80 and histone variant H2A.Z as the deacetylation targets for histone deacetylase Rpd3L complex and uncover how they regulate autophagy in response to nutrient availability. Mechanistically, Rpd3L deacetylates Ino80 K929, which protects Ino80 from being degraded by autophagy. The stabilized Ino80 promotes H2A.Z eviction from autophagy-related genes, leading to their transcriptional repression. Meanwhile, Rpd3L deacetylates H2A.Z, which further blocks its deposition into chromatin to repress the transcription of autophagy-related genes. Rpd3-mediated deacetylation of Ino80 K929 and H2A.Z is enhanced by the target of rapamycin complex 1 (TORC1). Inactivation of TORC1 by nitrogen starvation or rapamycin inhibits Rpd3L, leading to induction of autophagy. Our work provides a mechanism for chromatin remodelers and histone variants in modulating autophagy in response to nutrient availability.

Improving the genome and proteome annotations of the marine model diatom Thalassiosira pseudonana using a proteogenomics strategy

Diatoms are unicellular eukaryotic phytoplankton that account for approximately 20% of global carbon fixation and 40% of marine primary productivity; thus, they are essential for global carbon biogeochemical cycling and climate. The availability of ten diatom genome sequences has facilitated evolutionary, biological and ecological research over the past decade; however, a complimentary map of the diatom proteome with direct measurements of proteins and peptides is still lacking. Here, we present a proteome map of the model marine diatom Thalassiosira pseudonana using high-resolution mass spectrometry combined with a proteogenomic strategy. In-depth proteomic profiling of three different growth phases and three nutrient-deficient samples identified 9526 proteins, accounting for ~ 81% of the predicted protein-coding genes. Proteogenomic analysis identified 1235 novel genes, 975 revised genes, 104 splice variants and 234 single amino acid variants. Furthermore, our quantitative proteomic analysis experimentally demonstrated that a considerable number of novel genes were differentially translated under different nutrient conditions. These findings substantially improve the genome annotation of T. pseudonana and provide insights into new biological functions of diatoms. This relatively comprehensive diatom proteome catalog will complement available diatom genome and transcriptome data to advance biological and ecological research of marine diatoms.

Supplementary Information

The online version contains supplementary material available at 10.1007/s42995-022-00161-y.

Lysine Succinylation of VBS Contributes to Sclerotia Development and Aflatoxin Biosynthesis in Aspergillus flavus

Aspergillus flavus is a common saprophytic and pathogenic fungus, and its secondary metabolic pathways are one of the most highly characterized owing to its aflatoxin (AF) metabolite affecting global economic crops and human health. Different natural environments can cause significant variations in AF synthesis. Succinylation was recently identified as one of the most critical regulatory post-translational modifications affecting metabolic pathways. It is primarily reported in human cells and bacteria with few studies on fungi. Proteomic quantification of lysine succinylation (Ksuc) exploring its potential involvement in secondary metabolism regulation (including AF production) has not been performed under natural conditions in A. flavus. In this study, a quantification method was performed based on tandem mass tag labeling and antibody-based affinity enrichment of succinylated peptides via high accuracy nano-liquid chromatography with tandem mass spectrometry to explore the succinylation mechanism affecting the pathogenicity of naturally isolated A. flavus strains with varying toxin production. Altogether, 1240 Ksuc sites in 768 proteins were identified with 1103 sites in 685 proteins quantified. Comparing succinylated protein levels between high and low AF-producing A. flavus strains, bioinformatics analysis indicated that most succinylated proteins located in the AF biosynthetic pathway were downregulated, which directly affected AF synthesis. Versicolorin B synthase is a key catalytic enzyme for heterochrome B synthesis during AF synthesis. Site-directed mutagenesis and biochemical studies revealed that versicolorin B synthase succinylation is an important regulatory mechanism affecting sclerotia development and AF biosynthesis in A. flavus. In summary, our quantitative study of the lysine succinylome in high/low AF-producing strains revealed the role of Ksuc in regulating AF biosynthesis. We revealed novel insights into the metabolism of AF biosynthesis using naturally isolated A. flavus strains and identified a rich source of metabolism-related enzymes regulated by succinylation.

[The common morphology and clinical significance of the axillary arch]

Axillary arch is the most common type of axillary muscle fiber variation, with about 10.8% incidence in the Chinese population. Its natural forms are varied and fluid, with different starting points and terminations, and clinicians frequently lack recognition. Under commonly applicated sentinel lymph node biopsy, the axillary arch has been endowed with more clinical significance. The fabric of axillary arch will not only block lymphatic drainage in axilla and unclear anatomical level of axillary dissection, but also compress the axillary neurovascular bundle, causing upper limb venous thrombosis, lymphedema and nerve entrapment. The intumescent axillary arch may also show abnormal axillary bulge. In addition to finding axillary arch during cadaveric study and operation, several of imaging methods availably diagnose axillary arch preoperative, which can create new way for detection of axillary arch and extension of the surgical plan of sentinel lymph node biopsy. Although embryology and comparative anatomy have been used to explain the origin of the axillary arch, most of the ideas are still hypotheses and need further study.

How Neighborhood Structural and Individual Characteristics Affect Frailty Progression: Evidence from the China Health and Retirement Longitudinal Study

OBJECTIVES

(1) To characterize the average trajectories of frailty over time in Chinese community-dwelling older adults; (2) To assess the effects of neighborhood structural and individual characteristics on frailty progression.

DESIGN

A nationally representative prospective cohort study.

SETTING

Communities in 28 provinces, China.

PARTICIPANTS

6238 respondents aged 60 and above in 447 communities from four waves of the China Health and Retirement Longitudinal Study.

MEASUREMENTS

Frailty was measured using the 61-item Frailty Index (FI).

RESULTS

The trajectory of FI was nonlinear, with an average growth rate of 0.025 that significantly slows down at the rate of 0.002 per year. Older, male, and uninsured respondents showed faster rates of growth in FI over time than younger, female, and insured counterparts. Respondents living in neighborhoods with a higher percentage of the older population and rural villages showed slower rates of growth in FI over time.

CONCLUSION

Expanding health insurance coverage and keeping a high clustering of the elderly in neighborhoods may be the potential strategies for population-level frailty prevention and interventions.

A structure-property study for konjac glucomannan and guar galactomannan: Selective carboxylation and scale inhibition

The effect of structural difference for konjac glucomannan (KGM) and guar galactomannan (GGM) on their physicochemical properties including selective carboxylation, biodegradation and scale inhibition was firstly investigated. Compared with GGM, KGM can be specially modified by amino acid to prepare carboxyl-functionalized polysaccharides. The structure-activity relationship explaining the difference in carboxylation activity and the anti-scaling abilities of polysaccharides and carboxylated derivatives were explored by static anti-scaling, iron oxide dispersion and biodegradation tests coupled with structural and morphological characterizations. KGM with linear structure was preferred for carboxylated modification by glutamic acid (KGMG) and aspartic acid (KGMA) while GGM with branched structure failed to accomplish that due to steric hindrance. GGM and KGM showed limited scale inhibition performance, which was probably attributed to the moderate adsorption and isolation effect of macromolecular stereoscopic structure. While KGMA and KGMG performed as effective and degradable inhibitors for CaCO₃ scale with inhibitory efficiencies > 90 %.

SESAME-catalyzed H3T11 phosphorylation inhibits Dot1-catalyzed H3K79me3 to regulate autophagy and telomere silencing

The glycolytic enzyme, pyruvate kinase Pyk1 maintains telomere heterochromatin by phosphorylating histone H3T11 (H3pT11), which promotes SIR (silent information regulator) complex binding at telomeres and prevents autophagy-mediated Sir2 degradation. However, the exact mechanism of action for H3pT11 is poorly understood. Here, we report that H3pT11 directly inhibits Dot1-catalyzed H3K79 tri-methylation (H3K79me3) and uncover how this histone crosstalk regulates autophagy and telomere silencing. Mechanistically, Pyk1-catalyzed H3pT11 directly reduces the binding of Dot1 to chromatin and inhibits Dot1-catalyzed H3K79me3, which leads to transcriptional repression of autophagy genes and reduced autophagy. Despite the antagonism between H3pT11 and H3K79me3, they work together to promote the binding of SIR complex at telomeres to maintain telomere silencing. Furthermore, we identify Reb1 as a telomere-associated factor that recruits Pyk1-containing SESAME (Serine-responsive SAM-containing Metabolic Enzyme) complex to telomere regions to phosphorylate H3T11 and prevent the invasion of H3K79me3 from euchromatin into heterochromatin to maintain telomere silencing. Together, these results uncover a histone crosstalk and provide insights into dynamic regulation of silent heterochromatin and autophagy in response to cell metabolism.

Target of Rapamycin Mediated Ornithine Decarboxylase Antizyme Modulate Intracellular Putrescine and Ganoderic Acid Content in Ganoderma lucidum

Putrescine (Put) has been shown to play an important regulatory role in cell growth in organisms. As the primary center regulating the homeostasis of polyamine (PA) content, ornithine decarboxylase antizyme (AZ) can regulate PA content through feedback. Nevertheless, the regulatory mechanism of Put is poorly understood in fungi. Here, our analysis showed that GlAZ had a modulate effect on intracellular Put content by interacting with ornithine decarboxylase (ODC) proteins and reducing its intracellular protein levels. In addition, GlAZ upregulated the metabolic pathway of ganoderic acid (GA) biosynthesis in Ganoderma lucidum by modulating the intracellular Put content. However, a target of rapamycin (TOR) was found to promote the accumulation of intracellular Put after the GlTOR inhibitor Rap was added exogenously, and unbiased analyses demonstrated that GlTOR may promote Put production through its inhibitory effect on the level of GlAZ protein in GlTOR-GlAZ-cosilenced strains. The effect of TOR on fungal secondary metabolism was further explored, and the content of GA in the GlTOR-silenced strain after the exogenous addition of the inhibitor Rap was significantly increased compared with that in the untreated wild-type (WT) strain. Silencing of TOR in the GlTOR-silenced strains caused an increase in GA content, which returned to the WT state after replenishing Put. Moreover, the content of GA in GlTOR-GlAZ-cosilenced strains was also not different from that in the WT strain. Consequently, these results strongly indicate that GlTOR affects G. lucidum GA biosynthesis via GlAZ. IMPORTANCE Research on antizyme (AZ) in fungi has focused on the mechanism by which AZ inhibits ornithine decarboxylase (ODC). Moreover, there are existing reports on the regulation of AZ protein translation by TOR. However, little is known about the mechanisms that influence AZ in fungal secondary metabolism. Here, both intracellular Put content and GA biosynthesis in G. lucidum were shown to be regulated through protein interactions between GlAZ and GlODC. Furthermore, exploration of upstream regulators of GlAZ suggested that GlAZ was regulated by the upstream protein GlTOR, which affected intracellular Put levels and ganoderic acid (GA) biosynthesis. The results of our work contribute to the understanding of the upstream regulation of Put and provide new insights into PA regulatory systems and secondary metabolism in fungi.

Proteomic analysis of the regulatory networks of ClpX in a model cyanobacterium Synechocystis sp. PCC 6803

Protein homeostasis is tightly regulated by protein quality control systems such as chaperones and proteases. In cyanobacteria, the ClpXP proteolytic complex is regarded as a representative proteolytic system and consists of a hexameric ATPase ClpX and a tetradecameric peptidase ClpP. However, the functions and molecular mechanisms of ClpX in cyanobacteria remain unclear. This study aimed to decipher the unique contributions and regulatory networks of ClpX in the model cyanobacterium Synechocystis sp. PCC 6803 (hereafter Synechocystis). We showed that the interruption of clpX led to slower growth, decreased high light tolerance, and impaired photosynthetic cyclic electron transfer. A quantitative proteomic strategy was employed to globally identify ClpX-regulated proteins in Synechocystis cells. In total, we identified 172 differentially expressed proteins (DEPs) upon the interruption of clpX. Functional analysis revealed that these DEPs are involved in diverse biological processes, including glycolysis, nitrogen assimilation, photosynthetic electron transport, ATP-binding cassette (ABC) transporters, and two-component signal transduction. The expression of 24 DEPs was confirmed by parallel reaction monitoring (PRM) analysis. In particular, many hypothetical or unknown proteins were found to be regulated by ClpX, providing new candidates for future functional studies on ClpX. Together, our study provides a comprehensive ClpX-regulated protein network, and the results serve as an important resource for understanding protein quality control systems in cyanobacteria.

Physical activity patterns, genetic susceptibility, and risk of hip/knee osteoarthritis: a prospective cohort study based on the UK Biobank

OBJECTIVES

The effect of physical activity on hip/knee osteoarthritis (OA) and how it varies by genetic susceptibility to OA remains inconclusive.

METHODS

In a cohort study of UK Biobank, 436,166 OA-free participants were recruited in 2006-2010 and followed for knee/hip OA until the end of 2020. 28 physical activity-related items were collected at baseline. Cox regression was used to estimate associations between physical activity behaviors, as well as major activity patterns (i.e., significant principal components[PCs] identified by principal component analysis), and risk of OA, adjusting for multiple confounders. We further stratified the analyses by polygenic risk score (PRS) for OA to examine the impact of genetic susceptibility to OA on the studied association.

RESULTS

During a mean follow-up of 11.15 years, 13,227 hip and 21,119 knee OA cases were identified. 19, out of 28, studied items showed associations with increased OA risk. Compared with low adherence group(<1^st tertile of PC score for each pattern), individuals with high adherence to five identified patterns were associated with increased risk of OA. The moderate adherence to "strenuous sports"(HR = 0.93, 95%CI: 0.89-0.97) and "walking for pleasure"(HR = 0.93, 95%CI: 0.89-0.98) patterns was associated with reduced OA. Similar risk patterns were obtained in the stratified analysis by PRS levels for OA.

CONCLUSION

High intensity of most activity patterns were associated with increased OA. However, a protective effect was suggested for moderate adherence to patterns of "strenuous sports" and "walking for pleasure" that consistent across different genetic susceptibilities, underscoring the potential benefits of moderate-intensity physical activity on OA.

Chitosan Increases Lysine Content through Amino Acid Transporters in Flammulina filiformis

Highlights

Abstract

Lysine content is considered an important indicator of the quality of Flammulina filiformis. In this study, chitosan was used to improve lysine content of F. filiformis. Optimal design conditions were obtained using central combination design (CCD): treatment concentration was 14.61 μg/mL, treatment time was 52.90 h, and the theoretical value of lysine content was 30.95 mg/g. We used Basic Local Alignment Search Tool Protein (BLASTP) to search the F. filiformis genome database using known AATs in the NCBI database. There were 11 members of AAT in F. filiformis. The expression levels of AAT3 and AAT4 genes increased significantly with chitosan treatment. Subsequently, AAT3 and AAT4 silencing strains were constructed using RNAi technology. The lysine content of the wild-type (WT) strain treated with chitosan increased by 26.41%. Compared with the chitosan-induced WT strain, chitosan-induced lysine content decreased by approximately 24.87% in the AAT3 silencing strain, and chitosan-induced lysine content in the AAT4 silencing strain increased by approximately 13.55%. The results indicate that AAT3 and AAT4 are involved in the regulation of the biosynthesis of lysine induced by chitosan in F. filiformis. AAT3 may participate in the absorption of lysine, and AAT4 may be involved in the excretion of lysine with chitosan treatment.

Panax notoginseng WRKY Transcription Factor 9 Is a Positive Regulator in Responding to Root Rot Pathogen Fusarium solani

Panax notoginseng (Burk) F.H. Chen is a rare and valuable Chinese herb, but root rot mainly caused by Fusarium solani severely affects the yield and quality of P. notoginseng herbal materials. In this study, we isolated 30 P. notoginseng WRKY transcription factors (TFs), which were divided into three groups (I, II, and III) on the basis of a phylogenetic analysis. The expression levels of 10 WRKY genes, including PnWRKY9, in P. notoginseng roots increased in response to a methyl jasmonate (MeJA) treatment and the following F. solani infection. Additionally, PnWRKY9 was functionally characterized. The PnWRKY9 protein was localized to the nucleus. The overexpression of PnWRKY9 in tobacco (Nicotiana tabacum) considerably increased the resistance to F. solani, whereas an RNAi-mediated decrease in the PnWRKY9 expression level in P. notoginseng leaves increased the susceptibility to F. solani. The RNA sequencing and hormone content analyses of PnWRKY9-overexpression tobacco revealed that PnWRKY9 and the jasmonic acid (JA) signaling pathway synergistically enhance disease resistance. The PnWRKY9 recombinant protein was observed to bind specifically to the W-box sequence in the promoter of a JA-responsive and F. solani resistance-related defensin gene (PnDEFL1). A yeast one-hybrid assay indicated that PnWRKY9 can activate the transcription of PnDEFL1. Furthermore, a co-expression assay in tobacco using β-glucuronidase (GUS) as a reporter further verified that PnWRKY9 positively regulates PnDEFL1 expression. Overall, in this study, we identified P. notoginseng WRKY TFs and demonstrated that PnWRKY9 positively affects plant defenses against the root rot pathogen. The data presented herein provide researchers with fundamental information regarding the regulatory mechanism mediating the coordinated activities of WRKY TFs and the JA signaling pathway in P. notoginseng responses to the root rot pathogen.

Establishment of CRISPR/Cas9 Genome-Editing System Based on Dual sgRNAs in Flammulina filiformis

Flammulina filiformis, previously known as Asian Flammulina velutipes, is one of the most commercially important edible fungi, with nutritional value and medicinal properties worldwide. However, precision genome editing using CRISPR/Cas9, which is a revolutionary technology and provides a powerful tool for molecular breeding, has not been established in F. filiformis. Here, plasmids harboring expression cassettes of Basidiomycete codon-optimized Cas9 and dual sgRNAs targeting pyrG under the control of the gpd promoter and FfU6 promoter, respectively, were delivered into protoplasts of F. filiformis Dan3 strain through PEG-mediated transformation. The results showed that an efficient native U6 promoter of F. filiformis was identified, and ultimately several pyrG mutants exhibiting 5-fluorooric acid (5-FOA) resistance were obtained. Additionally, diagnostic PCR followed by Sanger sequencing revealed that fragment deletion between the two sgRNA target sites or small insertions and deletions (indels) were introduced in these pyrG mutants through the nonhomologous end joining (NHEJ) pathway, resulting in heritable changes in genomic information. Taken together, this is the first report in which a successful CRISPR/Cas9 genome-editing system based on dual sgRNAs was established in F. filiformis, which broadens the application of this advanced tool in Basidiomycetes.

Sinhcaf‐dependent histone deacetylation is essential for primordial germ cell specification

Primordial germ cells (PGCs) are the progenitor cells that give rise to sperm and eggs. Sinhcaf is a recently identified subunit of the Sin3 histone deacetylase complex (SIN3A-HDAC). Here, we provide evidence that Sinhcaf-dependent histone deacetylation is essential for germ plasm aggregation and primordial germ cell specification. Specifically, maternal-zygotic sinhcaf zebrafish mutants exhibit germ plasm aggregation defects, decreased PGC abundance and male-biased sex ratio, which can be rescued by re-expressing sinhcaf. Overexpression of sinhcaf results in excess PGCs and a female-biased sex ratio. Sinhcaf binds to the promoter region of kif26ab. Loss of sinhcaf epigenetically switches off kif26ab expression by increasing histone 3 acetylation in the promoter region. Injection of kif26ab mRNA could partially rescue the germ plasm aggregation defects in sinhcaf mutant embryos. Taken together, we demonstrate a role of Sinhcaf in germ plasm aggregation and PGC specialization that is mediated by regulating the histone acetylation status of the kif26ab promoter to activate its transcription. Our findings provide novel insights into the function and regulatory mechanisms of Sinhcaf-mediated histone deacetylation in PGC specification.

An MYB Transcription Factor Modulates Panax notoginseng Resistance Against the Root Rot Pathogen Fusarium solani by Regulating the Jasmonate Acid Signaling Pathway and Photosynthesis

Root rot of Panax notoginseng, a precious Chinese medicinal plant, seriously impacts its sustainable production. However, the molecular regulatory mechanisms employed by P. notoginseng against root rot pathogens, including Fusarium solani, are still unclear. In this study, the PnMYB2 gene was isolated, and its expression was affected by independent treatments with four signaling molecules (methyl jasmonate, ethephon, salicylic acid, and hydrogen peroxide) as assessed by quantitative real-time PCR. Moreover, the PnMYB2 expression level was induced by F. solani infection. The PnMYB2 protein localized to the nucleus and may function as a transcription factor. When overexpressed in transgenic tobacco, the PnMYB2 gene conferred resistance to F. solani. Jasmonic acid (JA) metabolism and disease resistance-related genes were induced in the transgenic tobacco, and the JA content significantly increased compared with in the wild type. Additionally, transcriptome sequencing, Kyoto Encyclopedia of Genes and Genomes annotation enrichment, and metabolic pathway analyses of the differentially expressed genes in the transgenic tobacco revealed that JA metabolic, photosynthetic, and defense response-related pathways were activated. In summary, PnMYB2 is an important transcription factor in the defense responses of P. notoginseng against root rot pathogens that acts by regulating JA signaling, photosynthesis, and disease-resistance genes.

Simulation of Water Flow in a Nanochannel with a Sudden Contraction or Expansion

Water flow in a nanoscale channel is known to be affected by strong water-wall interactions; as a result, the flow considerably deviates from the conventional continuum flow. Nanochannel with a sudden contraction or expansion is the most fundamental morphological nanostructure in many nanoporous systems such as shale matrix, mudrock, membrane, etc. However, the nanoconfinement effects of water flow in nanoporous systems and its effect on macroscopic flow behavior are still evolving research topics. In this work, our recently developed pore-scale lattice Boltzmann method (LBM) considering the nanoscale effects is extended to directly simulate water flow in nanoporous systems. The results show that the flow rate is dramatically decreased in hydrophobic nanopores because of additional flow resistances at the contraction and expansion junctions. This indicates that the bundle of capillary models or the permeability averaging method overestimates the water flow rate in nanoporous media if the contraction/expansion effects between different nanopores are ignored. This work highlights the importance of wettability of the nanochannel in the determination of dynamic water flow behaviors in the contraction/expansion nanosystem. Other important aspects, including velocity distribution, flow patterns, and vortex characteristics as well as pressure variation along the flow direction, are for the first time revealed and quantified. Large differences can be found comparing gas or larger-scale water flows through the same system. A new type of pressure variation curve along the axis of flow direction is found in the hydrophobic nanochannel with a sudden contraction/expansion. This work provides the fundamental understanding of water transport through the nanoscale system with contraction and expansion effects, giving implications to a wide range of industry applications.

Direct Observation of Endocytosis Dynamics of Anti-ErbB Modified Single Nanocargoes

The ErbB receptor family, including the epidermal growth factor receptor (EGFR) and ErbB2/3/4, regulate cell proliferation, differentiation, apoptosis, motility, etc., and their abnormalities can cause cancer and other diseases. Ligand-induced endocytosis of ErbB receptors is the key to various cancer treatment strategies, and different techniques have been developed to study this important process. Among them, single particle tracking (SPT) can reveal the spatiotemporal heterogeneity of ErbB receptors on the live cell membrane and has been used to characterize the EGFR dimerization process. Herein, we studied the endocytosis dynamics of two different ErbB receptors using dark-field microscopy. With anti-ErbB modified plasmonic gold nanorods (AuNRs) as probes, we compared the trajectories of individual anti-EGFR AuNRs (cAuNRs) and anti-ErbB AuNRs (tAuNRs) interacting with MCF-7 cells in situ in real time. The results revealed that the internalization rate of cAuNRs was faster than that of tAuNRs. Detailed SPT analysis suggests that cAuNRs enter cells through EGFR endocytosis pathway, and multiple intracellular transport modes sort the cAuNRs away from the transmembrane site. In contrast, the endocytosis resistance of ErbB2 slows down the cellular uptake rate of tAuNRs and causes some tAuNRs-ErbB2 complexes to be confined on the membrane with "circular" and "rolling circle" motions for a much longer time. Our results provide insights into the endocytosis process of the ErbB receptor family at the nanometer scale and could be potentially useful to develop cancer treatment strategies.

Apoptosis and autophagy coordinately shape vector tolerance to arbovirus infection

ABBREVIATIONS

CP: coat protein; MAPK: mitogen-activated protein kinase; PEBP: phosphatidylethanolamine binding protein; TYLCV: tomato yellow leaf curl virus.