Stigmasterol alleviates neuropathic pain by reducing Schwann cell-macrophage cascade in DRG by modulating IL-34/CSF1R.

AIMS: This study aimed to investigate the potential therapeutic applications of stigmasterol for treating neuropathic pain. METHODS: Related mechanisms were investigated by DRG single-cell sequencing analysis and the use of specific inhibitors in cellular experiments. In animal experiments, 32 male Sprague-Dawley rats were randomly divided into the sham operation group, CCI group, ibuprofen group, and stigmasterol group. We performed behavioral tests, ELISA, H&E staining and immunohistochemistry, and western blotting. RESULTS: Cell communication analysis by single-cell sequencing reveals that after peripheral nerve injury, Schwann cells secrete IL-34 to act on CSF1R in macrophages. After peripheral nerve injury, the mRNA expression levels of CSF1R pathway and NLRP3 inflammasome in macrophages were increased in DRG. In vitro studies demonstrated that stigmasterol can reduce the secretion of IL-34 in LPS-induced RSC96 Schwann cells; stigmasterol treatment of LPS-induced Schwann cell-conditioned medium (L-S-CM) does not induce the proliferation and migration of RAW264.7 macrophages; L-S-CM reduces CSF1R signaling pathway (CSF1R, P38MAPK, and NFκB) activation, NLRP3 inflammasome activation, and ROS production. In vivo experiments have verified that stigmasterol can reduce thermal and cold hyperalgesia in rat chronic compressive nerve injury (CCI) model; stigmasterol can reduce IL-1ß, IL-6, TNF-α, CCL2, SP, and PGE2 in serum of CCI rats; immunohistochemistry and western blot confirmed that stigmasterol can reduce the levels of IL-34/CSF1R signaling pathway and NLRP3 inflammasome in DRG of CCI rats. CONCLUSION: Stigmasterol alleviates neuropathic pain by reducing Schwann cell-macrophage cascade in DRG by modulating IL-34/CSF1R axis.

Quantitative measurement of cell-surface displayed proteins based on split-GFP assembly.

BACKGROUND: Microbial cell surface display technology allows immobilizing proteins on the cell surface by fusing them to anchoring motifs, thereby endowing the cells with diverse functionalities. However, the assessment of successful protein display and the quantification of displayed proteins remain challenging. The green fluorescent protein (GFP) can be split into two non-fluorescent fragments, while they spontaneously assemble and emit fluorescence when brought together through complementation. Based on split-GFP assembly, we aim to: (1) confirm the success display of passenger proteins, (2) quantify the number of passenger proteins displayed on individual cells. RESULTS: In this study, we propose two innovative methods based on split-green fluorescent protein (split-GFP), named GFP1-10/GFP11 and GFP1-9/GFP10-11 assembly, for the purpose of confirming successful display and quantifying the number of proteins displayed on individual cells. We evaluated the display efficiency of SUMO and ubiquitin using different anchor proteins to demonstrate the feasibility of the two split-GFP assembly systems. To measure the display efficiency of functional proteins, laccase expression was measured using the split-GFP assembly system by co-displaying GFP11 or GFP10-11 tags, respectively. CONCLUSIONS: Our study provides two split-GFP based methods that enable qualitative and quantitative analyses of individual cell display efficiency with a simple workflow, thus facilitating further comprehensive investigations into microbial cell surface display technology. Both split-GFP assembly systems offer a one-step procedure with minimal cost, simplifying the fluorescence analysis of surface-displaying cells.

The use of amino acids and their derivates to mitigate against pesticide-induced toxicity.

Exposure to pesticides induces oxidative stress and deleterious effects on various tissues in non-target organisms. Numerous models investigating pesticide exposure have demonstrated metabolic disturbances such as imbalances in amino acid levels within the organism. One potentially effective strategy to mitigate pesticide toxicity involves dietary intervention by supplementing exogenous amino acids and their derivates to augment the body's antioxidant capacity and mitigate pesticide-induced oxidative harm, whose mechanism including bolstering glutathione synthesis, regulating arginine-NO metabolism, mitochondria-related oxidative stress, and the open of ion channels, as well as enhancing intestinal microecology. Enhancing glutathione synthesis through supplementation of substrates N-acetylcysteine and glycine is regarded as a potent mechanism to achieve this. Selection of appropriate amino acids or their derivates for supplementation, and determining an appropriate dosage, are of the utmost importance for effective mitigation of pesticide-induced oxidative harm. More experimentation is required that involves large population samples to validate the efficacy of dietary intervention strategies, as well as to determine the effects of amino acids and their derivates on long-term and low-dose pesticide exposure. This review provides insights to guide future research aimed at preventing and alleviating pesticide toxicity through dietary intervention of amino acids and their derivates.

The global nitrogen regulator GlnR is a direct transcriptional repressor of the key gluconeogenic gene pckA in actinomycetes.

In most actinomycetes, GlnR governs both nitrogen and non-nitrogen metabolisms (e.g., carbon, phosphate, and secondary metabolisms). Although GlnR has been recognized as a global regulator, its regulatory role in central carbon metabolism [e.g., glycolysis, gluconeogenesis, and the tricarboxylic acid (TCA) cycle] is largely unknown. In this study, we characterized GlnR as a direct transcriptional repressor of the pckA gene that encodes phosphoenolpyruvate carboxykinase, catalyzing the conversion of the TCA cycle intermediate oxaloacetate to phosphoenolpyruvate, a key step in gluconeogenesis. Through the transcriptomic and quantitative real-time PCR analyses, we first showed that the pckA transcription was upregulated in the glnR null mutant of Amycolatopsis mediterranei. Next, we proved that the pckA gene was essential for A. mediterranei gluconeogenesis when the TCA cycle intermediate was used as a sole carbon source. Furthermore, with the employment of the electrophoretic mobility shift assay and DNase I footprinting assay, we revealed that GlnR was able to specifically bind to the pckA promoter region from both A. mediterranei and two other representative actinomycetes (Streptomyces coelicolor and Mycobacterium smegmatis). Therefore, our data suggest that GlnR may repress pckA transcription in actinomycetes, which highlights the global regulatory role of GlnR in both nitrogen and central carbon metabolisms in response to environmental nutrient stresses. IMPORTANCE: The GlnR regulator of actinomycetes controls nitrogen metabolism genes and many other genes involved in carbon, phosphate, and secondary metabolisms. Currently, the known GlnR-regulated genes in carbon metabolism are involved in the transport of carbon sources, the assimilation of short-chain fatty acid, and the 2-methylcitrate cycle, although little is known about the relationship between GlnR and the TCA cycle and gluconeogenesis. Here, based on the biochemical and genetic results, we identified GlnR as a direct transcriptional repressor of pckA, the gene that encodes phosphoenolpyruvate carboxykinase, a key enzyme for gluconeogenesis, thus highlighting that GlnR plays a central and complex role for dynamic orchestration of cellular carbon, nitrogen, and phosphate fluxes and bioactive secondary metabolites in actinomycetes to adapt to changing surroundings.

Creatine Acts as a Mediator of the Causal Effect of Obesity on Puberty Onset in Girls: Evidence from Mediation Mendelian Randomization Study.

Epidemiological studies have linked obesity to the onset of puberty, while its causality and the potential metabolite mediators remain unclear. We employed a two-sample Mendelian randomization (MR) design to evaluate the causal effects of obesity on puberty onset and its associated diseases including type 2 diabetes (T2D) and cardiovascular diseases (CVDs). The potential mediators in this pathway were further explored using a two-step MR design. The robustness of our findings was evaluated using sensitivity analyses. Our MR results revealed that childhood obesity/BMI were causally associated with an increased Tanner stage in girls, younger age at menarche, and increased risk of adulthood T2D and CVD. However, neither childhood BMI nor obesity had a causal effect on the Tanner stage in boys. Mediation analysis further indicated that increased creatine served as a mediator for the causal pathway from childhood obesity/BMI to the Tanner stage of girls, while early puberty onset in girls played a mediating role in the pathway linking childhood obesity to increased risk of adulthood T2D and CVD. This study indicated that the risk of early puberty onset in girls and its associated health issues can be potentially reduced by preventing childhood obesity. The involvement of creatine in this process needs to be further validated and explored.

Biosynthesis of the highly oxygenated tetracyclic core skeleton of Taxol.

Taxol is a widely-applied anticancer drug that inhibits microtubule dynamics in actively replicating cells. Although a minimum 19-step biosynthetic pathway has been proposed and 16 enzymes likely involved have been characterized, stepwise biosynthetic reactions from the well-characterized di-oxygenated taxoids to Taxol tetracyclic core skeleton are yet to be elucidated. Here, we uncover the biosynthetic pathways for a few tri-oxygenated taxoids via confirming the critical reaction order of the second and third hydroxylation steps, unearth a taxoid 9α-hydroxylase catalyzing the fourth hydroxylation, and identify CYP725A55 catalyzing the oxetane ester formation via a cascade oxidation-concerted acyl rearrangement mechanism. After identifying a acetyltransferase catalyzing the formation of C7-OAc, the pathway producing the highly-oxygenated 1ß-dehydroxybaccatin VI with the Taxol tetracyclic core skeleton is elucidated and its complete biosynthesis from taxa-4(20),11(12)-diene-5α-ol is achieved in an engineered yeast. These systematic studies lay the foundation for the complete elucidation of the biosynthetic pathway of Taxol.

Nutritional, Textural, and Sensory Attributes of Protein Bars Formulated with Mycoproteins.

Research accumulated over the past decades has shown that mycoprotein could serve as a healthy and safe alternative protein source, offering a viable substitute for animal- and plant-derived proteins. This study evaluated the impact of substituting whey protein with fungal-derived mycoprotein at different levels (10%, 20%, and 30%) on the quality of high-protein nutrition bars (HPNBs). It focused on nutritional content, textural changes over storage, and sensory properties. Initially, all bars displayed similar hardness, but storage time significantly affected textural properties. In the early storage period (0-5 days), hardness increased at a modest rate of 0.206 N/day to 0.403 N/day. This rate dramatically escalated from 1.13 N/day to 1.36 N/day after 5 days, indicating a substantial textural deterioration over time. Bars with lower mycoprotein levels (10%) exhibited slower hardening rates compared with those with higher substitution levels (20% and 30%), pointing to a correlation between mycoprotein content and increased bar hardness during storage. Protein digestibility was assessed through in vitro gastric and intestinal phases. Bars with no or low-to-medium levels of mycoprotein substitution (PB00, PB10, and PB20) showed significantly higher digestibility (40.3~43.8%) compared with those with the highest mycoprotein content (PB30, 32.9%). However, digestibility rates for all mycoprotein-enriched bars were lower than those observed for whey-protein-only bars (PB00, 84.5%), especially by the end of the intestinal digestion phase. The introduction of mycoprotein enriched the bars' dietary fiber content and improved their odor, attributing a fresh mushroom-like smell. These findings suggest that modest levels of mycoprotein can enhance nutritional value and maintain sensory quality, although higher substitution levels adversely affect texture and protein digestibility. This study underscores the potential of mycoprotein as a functional ingredient in HPNBs, balancing nutritional enhancement with sensory acceptability, while also highlighting the challenges of textural deterioration and reduced protein digestibility at higher substitution levels.

Ginsenoside Rb1, Compound K and 20(S)-Protopanaxadiol Attenuate High-Fat Diet-Induced Hyperlipidemia in Rats via Modulation of Gut Microbiota and Bile Acid Metabolism.

Hyperlipidemia, characterized by elevated serum lipid concentrations resulting from lipid metabolism dysfunction, represents a prevalent global health concern. Ginsenoside Rb1, compound K (CK), and 20(S)-protopanaxadiol (PPD), bioactive constituents derived from Panax ginseng, have shown promise in mitigating lipid metabolism disorders. However, the comparative efficacy and underlying mechanisms of these compounds in hyperlipidemia prevention remain inadequately explored. This study investigates the impact of ginsenoside Rb1, CK, and PPD supplementation on hyperlipidemia in rats induced by a high-fat diet. Our findings demonstrate that ginsenoside Rb1 significantly decreased body weight and body weight gain, ameliorated hepatic steatosis, and improved dyslipidemia in HFD-fed rats, outperforming CK and PPD. Moreover, ginsenoside Rb1, CK, and PPD distinctly modified gut microbiota composition and function. Ginsenoside Rb1 increased the relative abundance of Blautia and Eubacterium, while PPD elevated Akkermansia levels. Both CK and PPD increased Prevotella and Bacteroides, whereas Clostridium-sensu-stricto and Lactobacillus were reduced following treatment with all three compounds. Notably, only ginsenoside Rb1 enhanced lipid metabolism by modulating the PPARγ/ACC/FAS signaling pathway and promoting fatty acid ß-oxidation. Additionally, all three ginsenosides markedly improved bile acid enterohepatic circulation via the FXR/CYP7A1 pathway, reducing hepatic and serum total bile acids and modulating bile acid pool composition by decreasing primary/unconjugated bile acids (CA, CDCA, and ß-MCA) and increasing conjugated bile acids (TCDCA, GCDCA, GDCA, and TUDCA), correlated with gut microbiota changes. In conclusion, our results suggest that ginsenoside Rb1, CK, and PPD supplementation offer promising prebiotic interventions for managing HFD-induced hyperlipidemia in rats, with ginsenoside Rb1 demonstrating superior efficacy.

dbCRAF: a curated knowledgebase for regulation of radiation response in human cancer.

Radiation therapy (RT) is one of the primary treatment modalities of cancer, with 40-60% of cancer patients benefiting from RT during their treatment course. The intrinsic radiosensitivity or acquired radioresistance of tumor cells would affect the response to RT and clinical outcomes in patients. Thus, mining the regulatory mechanisms in tumor radiosensitivity or radioresistance that have been verified by biological experiments and computational analysis methods will enhance the overall understanding of RT. Here, we describe a comprehensive database dbCRAF (http://dbCRAF.xialab.info/) to document and annotate the factors (1,677 genes, 49 proteins and 612 radiosensitizers) linked with radiation response, including radiosensitivity, radioresistance in cancer cells and prognosis in cancer patients receiving RT. On the one hand, dbCRAF enables researchers to directly access knowledge for regulation of radiation response in human cancer buried in the vast literature. On the other hand, dbCRAF provides four flexible modules to analyze and visualize the functional relationship between these factors and clinical outcome, KEGG pathway and target genes. In conclusion, dbCRAF serves as a valuable resource for elucidating the regulatory mechanisms of radiation response in human cancers as well as for the improvement of RT options.

Taxonomic and functional shifts of gut microbiome in immunoglobulin A vasculitis children and their mothers.

Objectives: To examine the gut microbiota characteristics in children with immunoglobulin A vasculitis and their interrelationships with the host, while evaluate the vertical inheritance of microbiota in the development and progression of IgA vasculitis. Methods: This study investigated the gut microbiome of 127 IgA vasculitis mother-child pairs and 62 matched healthy mother-child pairs, and compared the gut microbial composition of different groups. The pathway enrichment analysis evaluated potential gut microbiome-mediated pathways involved in the pathophysiology of IgA vasculitis. The Spearman correlation analysis illustrated the relationships between clinical variables and bacterial biomarkers. Results: This study identified distinct intestinal microbiome in IgA vasculitis children compared to healthy children, and further pointed out the association in gut microbiota between IgA vasculitis children's and their mother's. The relative abundance of Megamonas and Lactobacillus in IgAV children was positively correlated with that in their mothers. The pathway enrichment analysis found microbial biosynthesis of vitamins and essential amino acids was upregulated in children with IgA vasculitis. Correlation analysis showed bacterial biomarkers were correlated with indicators of blood coagulation. Conclusion: Children with IgA vasculitis have unique bacterial biomarkers and may affect coagulation function, and their gut microbiome was closely associated with that of their mothers. The observed association in gut microbiota between IgA vasculitis children and their mothers suggested a potential intergenerational influence of the maternal microbiota on the development or progression of IgA vasculitis in children.

Advance typing of Vibrio parahaemolyticus through the mtlA and aer gene: A high-resolution, cost-effective approach.

Vibrio parahaemolyticus is a significant cause of foodborne illness, and its incidence worldwide is on the rise. It is thus imperative to develop a straightforward and efficient method for typing strains of this pathogen. In this study, we conducted a pangenome analysis of 75 complete genomes of V. parahaemolyticus and identified the core gene mtlA with the highest degree of variation, which distinguished 44 strains and outperformed traditional seven-gene-based MLST when combined with aer, another core gene with high degree of variation. The mtlA gene had higher resolution to type strains with a close relationship compared to the traditional MLST genes in the phylogenetic tree built by core genomes. Strong positive selection was also detected in the gene mtlA (ω > 1), representing adaptive and evolution in response to the environment. Therefore, the panel of gene mtlA and aer may serve as a tool for the typing of V. parahaemolyticus, potentially contributing to the prevention and control of this foodborne disease.

Multifunctional Liposomes Co-Modified with Ginsenoside Compound K and Hyaluronic Acid for Tumor-Targeted Therapy.

Liposomes show promise for anti-cancer drug delivery and tumor-targeted therapy. However, complex tumor microenvironments and the performance limitations of traditional liposomes restrict clinical translation. Hyaluronic acid (HA)-modified nanoliposomes effectively target CD44-overexpressing tumor cells. Combination therapy enhances treatment efficacy and delays drug resistance. Here, we developed paclitaxel (PTX) liposomes co-modified with ginsenoside compound K (CK) and HA using film dispersion. Compared to cholesterol (Ch), CK substantially improved encapsulation efficiency and stability. In vitro release studies revealed pH-responsive behavior, with slower release at pH 7.4 versus faster release at pH 5. In vitro cytotoxicity assays demonstrated that replacing Ch with CK in modified liposomes considerably decreased HCT-116 cell viability. Furthermore, flow cytometry and fluorescence microscopy showed a higher cellular uptake of PTX-CK-Lip-HA in CD44-high cells, reflected in the lower half maximal inhibitory concentrations. Overall, CK/HA-modified liposomes represent an innovative, targeted delivery system for enhanced tumor therapy via pH-triggered drug release and CD44 binding.

Metagenomic characterization of a novel non-ammonia-oxidizing Thaumarchaeota from hadal sediment.

BACKGROUND: The hadal sediment, found at an ocean depth of more than 6000 m, is geographically isolated and under extremely high hydrostatic pressure, resulting in a unique ecosystem. Thaumarchaeota are ubiquitous marine microorganisms predominantly present in hadal environments. While there have been several studies on Thaumarchaeota there, most of them have primarily focused on ammonia-oxidizing archaea (AOA). However, systematic metagenomic research specifically targeting heterotrophic non-AOA Thaumarchaeota is lacking. RESULTS: In this study, we explored the metagenomes of Challenger Deep hadal sediment, focusing on the Thaumarchaeota. Functional analysis of sequence reads revealed the potential contribution of Thaumarchaeota to recalcitrant dissolved organic matter degradation. Metagenome assembly binned one new group of hadal sediment-specific and ubiquitously distributed non-AOA Thaumarchaeota, named Group-3.unk. Pathway reconstruction of this new type of Thaumarchaeota also supports heterotrophic characteristics of Group-3.unk, along with ABC transporters for the uptake of amino acids and carbohydrates and catabolic utilization of these substrates. This new clade of Thaumarchaeota also contains aerobic oxidation of carbon monoxide-related genes. Complete glyoxylate cycle is a distinctive feature of this clade in supplying intermediates of anabolic pathways. The pan-genomic and metabolic analyses of metagenome-assembled genomes belonging to Group-3.unk Thaumarchaeota have highlighted distinctions, including the dihydroxy phthalate decarboxylase gene associated with the degradation of aromatic compounds and the absence of genes related to the synthesis of some types of vitamins compared to AOA. Notably, Group-3.unk shares a common feature with deep ocean AOA, characterized by their high hydrostatic pressure resistance, potentially associated with the presence of V-type ATP and di-myo-inositol phosphate syntheses-related genes. The enrichment of organic matter in hadal sediments might be attributed to the high recruitment of sequence reads of the Group-3.unk clade of heterotrophic Thaumarchaeota in the trench sediment. Evolutionary and genetic dynamic analyses suggest that Group-3 non-AOA consists of mesophilic Thaumarchaeota organisms. These results indicate a potential role in the transition from non-AOA to AOA Thaumarchaeota and from thermophilic to mesophilic Thaumarchaeota, shedding light on recent evolutionary pathways. CONCLUSIONS: One novel clade of heterotrophic non-AOA Thaumarchaeota was identified through metagenome analysis of sediments from Challenger Deep. Our study provides insight into the ecology and genomic characteristics of the new sub-group of heterotrophic non-AOA Thaumarchaeota, thereby extending the knowledge of the evolution of Thaumarchaeota. Video Abstract.

Temporal development and potential interactions between the gut microbiome and resistome in early childhood.

Antimicrobial resistance-associated infections have become a major threat to global health. The gut microbiome serves as a major reservoir of bacteria with antibiotic resistance genes; whereas, the temporal development of gut resistome during early childhood and the factors influencing it remain unclear. Moreover, the potential interactions between gut microbiome and resistome still need to be further explored. In this study, we found that antibiotic treatment led to destabilization of the gut microbiome and resistome structural communities, exhibiting a greater impact on the resistome than on the microbiome. The composition of the gut resistome at various developmental stages was influenced by the abundance and richness of different core microbes. First exposure to antibiotics led to a dramatic increase in the number of opportunistic pathogens carrying multidrug efflux pump encoding genes. Multiple factors could influence the gut microbiome and resistome formation. The data may provide new insights into early-life research.IMPORTANCEIn recent years, the irrational or inappropriate use of antibiotics, an important life-saving medical intervention, has led to the emergence and increase of drug-resistant and even multidrug-resistant bacteria. It remains unclear how antibiotic exposure affects various developmental stages of early childhood and how gut core microbes under antibiotic exposure affect the structural composition of the gut resistome. In this study, we focused on early antibiotic exposure and analyzed these questions in detail using samples from infants at various developmental stages. The significance of our research is to elucidate the impact of early antibiotic exposure on the dynamic patterns of the gut resistome in children and to provide new insights for early-life studies.

Navigating the B vitamins: Dietary diversity, microbial synthesis, and human health.

B vitamins are intricately involved in various physiological processes vital for health. Their significance is complicated by the heterogeneous landscape of B vitamin distribution in diets and the contributions of the gut microbiota. Here, we delve into the impact of these factors on B vitamins and introduce strategies, with a focus on microbiota-based therapeutic options, to enhance their availability for improved well-being. Additionally, we provide an ecological and evolutionary perspective on the importance of B vitamins to human-microbiota interactions. In the dynamic realms of nutrition and microbiome science, these essential micronutrients continue to play a fundamental role in our understanding of disease development.

Plastic Waste Conversion by Leveraging Renewable Photo/Electro-Catalytic Technologies.

Plastics have revolutionized our lives; however, the exponential growth of their usage has led to a global crisis. More sustainable strategies are needed to address this dilemma and transform the plastics economy from a linearity to a circular model. Herein, we systematically summarize the recent progress in renewable energy-driven plastic conversion strategies, including photocatalysis, electrocatalysis, and their integration. By introducing the significant works, the design principles, mechanisms, and system regulations, we decipher and compare the various aspects of plastic conversion. These approaches show high reactivity and selectivity under environmentally benign conditions and provide alternative reaction pathways for plastic conversion. Plastic upcycling as a chemical feedstock can yield value-added chemicals and fuels, contributing to the establishment of a sustainable and circular economy. Additionally, several innovations in reaction engineering and system designs are presented. Finally, the challenges and perspectives of sustainable energy-driven plastic conversion technologies are comprehensively discussed.