Mechanism of cognitive impairment induced by d-galactose and l-glutamate through gut-brain interaction in tree shrews.

d-Galactose (d-gal) and l-glutamate (l-glu) impair learning and memory. The mechanism of interaction between the gut microbiome and brain remains unclear. In this study, a model of cognitive impairment was induced in tree shrews by intraperitoneal (ip) injection of d-gal (600 mg/kg/day), intragastric (ig) administration with l-glu (2000 mg/kg/day), and the combination of d-gal (ip, 600 mg/kg/day) and l-glu (ig, 2000 mg/kg/day). The cognitive function of tree shrews was tested by the Morris water maze method. The expression of Aß1-42 proteins, the intestinal barrier function proteins occludin and P-glycoprotein (P-gp), and the inflammatory factors NF-κB, TLR2, and IL-18 was determined by immunohistochemistry. The gut microbiome was analyzed by 16SrRNA high-throughput sequencing. After administering d-gal and l-glu, the escape latency increased (p < .01), and the times of crossing the platform decreased (p < .01). These changes were greater in the combined administration of d-gal and l-glu (p < .01). The expression of Aß1-42 was higher in the perinuclear region of the cerebral cortex (p < .01) and intestinal cell (p < .05). There was a positive correlation between the cerebral cortex and intestinal tissue. Moreover, the expression of NF-κB, TLR2, IL-18, and P-gp was higher in the intestine (p < .05), while the expression of occludin and the diversity of gut microbes were lower, which altered the biological barrier of intestinal mucosal cells. This study indicated that d-gal and l-glu could induce cognitive impairment, increase the expression of Aß1-42 in the cerebral cortex and intestinal tissue, decrease the gut microbial diversity, and alter the expression of inflammatory factors in the mucosal intestines. The dysbacteriosis may produce inflammatory cytokines to modulate neurotransmission, causing the pathogenesis of cognitive impairment. This study provides a theoretical basis to explore the mechanism of learning and memory impairment through the interaction of microbes in the gut and the brain.

Functional Guilds, Community Assembly, and Co-occurrence Patterns of Fungi in Metalliferous Mine Tailings Ponds in Mainland China.

Metalliferous mine tailings ponds are generally characterized by low levels of nutrient elements, sustained acidic conditions, and high contents of toxic metals. They represent one kind of extreme environments that are believed to resemble the Earth's early environmental conditions. There is increasing evidence that the diversity of fungi inhabiting mine tailings ponds is much higher than previously thought. However, little is known about functional guilds, community assembly, and co-occurrence patterns of fungi in such habitats. As a first attempt to address this critical knowledge gap, we employed high-throughput sequencing to characterize fungal communities in 33 mine tailings ponds distributed across 18 provinces of mainland China. A total of 5842 fungal phylotypes were identified, with saprotrophic fungi being the major functional guild. The predictors of fungal diversity in whole community and sub-communities differed considerably. Community assembly of the whole fungal community and individual functional guilds were primarily governed by stochastic processes. Total soil nitrogen and total phosphorus mediated the balance between stochastic and deterministic processes of the fungal community assembly. Co-occurrence network analysis uncovered a high modularity of the whole fungal community. The observed main modules largely consisted of saprotrophic fungi as well as various phylotypes that could not be assigned to known functional guilds. The richness of core fungal phylotypes, occupying vital positions in co-occurrence network, was positively correlated with edaphic properties such as soil enzyme activity. This indicates the important roles of core fungal phylotypes in soil organic matter decomposition and nutrient cycling. These findings improve our understanding of fungal ecology of extreme environments.

Remarkable effects of microbial factors on soil phosphorus bioavailability: A country-scale study.

Low soil phosphorus (P) bioavailability causes the widespread occurrence of P-limited terrestrial ecosystems around the globe. Exploring the factors influencing soil P bioavailability at large spatial scales is critical for managing these ecosystems. However, previous studies have mostly focused on abiotic factors. In this study, we explored the effects of microbial factors on soil P bioavailability of terrestrial ecosystems using a country-scale sampling effort. Our results showed that soil microbial biomass carbon (MBC) and acid phosphatase were important predictors of soil P bioavailability of agro- and natural ecosystems across China although they appeared less important than total soil P. The two microbial factors had a positive effect on soil P bioavailability of both ecosystem types and were able to mediate the effects of several abiotic factors (e.g., mean annual temperature). Meanwhile, we revealed that soil phytase could affect soil P bioavailability at the country scale via ways similar to those of soil MBC and acid phosphatase, a pattern being more pronounced in agroecosystems than in natural ecosystems. Moreover, we obtained evidence for the positive effects of microbial genes encoding these enzymes on soil P bioavailability at the country scale although their effect sizes varied between the two ecosystem types. Taken together, this study demonstrated the remarkable effects of microbial factors on soil P bioavailability at a large spatial scale, highlighting the importance to consider microbial factors in managing the widespread P-limited terrestrial ecosystems.

An area under the concentration-time curve threshold as a predictor of efficacy and nephrotoxicity for individualizing polymyxin B dosing in patients with carbapenem-resistant gram-negative bacteria.

BACKGROUND: Evidence supports therapeutic drug monitoring of polymyxin B, but clinical data for establishing an area under the concentration-time curve across 24 h at steady state (AUCss,24 h) threshold are still limited. This study aimed to examine exposure-response/toxicity relationship for polymyxin B to establish an AUCss,24 h threshold in a real-world cohort of patients. METHODS: Using a validated Bayesian approach to estimate AUCss,24 h from two samples, AUCss,24 h threshold that impacted the risk of polymyxin B-related nephrotoxicity and clinical response were derived by classification and regression tree (CART) analysis and validated by Cox regression analysis and logical regression analysis. RESULTS: A total of 393 patients were included; acute kidney injury (AKI) was 29.0%, clinical response was 63.4%, and 30-day all-cause mortality was 35.4%. AUCss,24 h thresholds for AKI of > 99.4 mg h/L and clinical response of > 45.7 mg h/L were derived by CART analysis. Cox and logical regression analyses showed that AUCss,24 h of > 100 mg h/L was a significant predictor of AKI (HR 16.29, 95% CI 8.16-30.25, P < 0.001) and AUCss,24 h of ≥ 50 mg h/L (OR 4.39, 95% CI 2.56-7.47, P < 0.001) was independently associated with clinical response. However, these exposures were not associated with mortality. In addition, the correlation between trough concentration (1.2-2.8 mg/L) with outcomes was similar to AUCss,24 h. CONCLUSIONS: For critically ill patients, AUCss,24 h threshold of 50-100 mg h/L was associated with decreased nephrotoxicity while assuring clinical efficacy. Therapeutic drug monitoring is recommended for individualizing polymyxin B dosing.

The chemokine system and its role in obesity.

The chemokine system is a complex arrangement of molecules that attract leukocytes to the site of injury or inflammation. This chemotactic behavior gives the system the name "Chemokine." The intricate and redundant nature of the chemokine system has made it a subject of ongoing scientific investigation. Obesity is characterized as low-grade systemic or chronic inflammation that is responsible for the release of cytokines, adipokines, and chemokines. Excessive tissue fat expansion triggers the release of chemokines, which in turn attract various leukocytes and activate the resident immune surveillance system, eventually leading to worsening of obesity and other related comorbidities. To date, 50 chemokines and 20 chemokine receptors that belong to the G-protein-coupled receptor family have been discovered, and over the past two decades, the physiological and pathological roles of many of these chemokines and their receptors have been elucidated. The objective of this review is to present an update on the link between chemokines and obesity under the light of recent knowledge.

Effects of sodium-glucose cotransporter (SGLT) inhibitors in addition to insulin therapy on glucose control and safety outcomes in adults with type 1 diabetes: A meta-analysis of randomized controlled trials.

Sodium-glucose cotransporter (SGLT) inhibitors added to insulin therapy have been proposed as treatment strategy for type 1 diabetes (T1D). We thus conducted a meta-analysis of randomized controlled trials (RCTs) to assess the efficacy and adverse effects of this combination in T1D. We searched the PubMed, EMBASE, and Cochrane Library databases and ClinicalTrials.gov for RCTs. Statistical analyses were performed using STATA 15. Ten eligible placebo-controlled trials involving 5961 patients were included. Compared with placebo, SGLT inhibitors were associated with a reduction in HbA1c of -0.39% (95% CI, -0.43 to -0.36), an improved mean amplitude of glucose excursion (MAGE) of -14.81 mg/dL (95% CI, -19.08 to -10.54), and a reduction in body weight of -3.47% (95% CI, -3.78 to -3.16), as well as no increased relative risk of hypoglycaemia (1.01; 95% CI, 0.99-1.02) or severe hypoglycaemia (0.91; 95% CI, 0.77-1.07). SGLT inhibitors decreased fasting plasma glucose and insulin requirement but increased the risk of genital infection (3.57; 95% CI, 2.97-4.29) and diabetic ketoacidosis (3.11; 95% CI, 2.11-4.58). However, the very low dose empagliflozin (2.5 mg) did not increase the risk of diabetic ketoacidosis (risk ratio [RR] 0.67; 95% CI, 0.11-3.95). SGLT inhibitors had no effect on overall adverse events, urinary tract infection, or bone fracture but slightly increased the risk of serious adverse events (1.35; 95% CI, 1.16-1.58), severe adverse events (1.84; 95% CI, 1.20-2.84), adverse events leading to discontinuation (1.50; 95% CI, 1.22-1.84), drug-related adverse events (1.78; 95% CI, 1.44-2.19), and diarrhoea (1.54; 95% CI, 1.15-2.05). Although adverse events exist, the available data provide evidence that the combination of SGLT inhibitors with basal insulin treatment is beneficial in patients with T1D.

Bushenshugan Formula Attenuates the Development of Lung Cancer by Inhibiting Epithelial-Mesenchymal Transition.

BACKGROUND/AIMS: BushenShugan Formula (BSF) is a traditional Chinese medicine that has therapeutic effects on middle- and late-stage lung adenocarcinoma in clinical application. It was reported that Bushen Chinese medicine suppressed the onset of pre-metastatic niches in a murine model of spontaneous lung metastasis. However, the mechanisms of BSF on human lung adenocarcinoma remain unknown. METHODS: Cell proliferation was determined by CCK8 and colony formation. Cell apoptosis and cell cycle were detected by flow cytometry. Cancer stem cells properties were examined by spheroid body formation. The migration and invasion abilities were analyzed by wound healing assay and transwell invasion assay. The mRNA expressions were determined by qRT-PCR. Western blotting analysis showed the protein levels. RESULTS: BSF was shown to inhibit the proliferation of A549 cells in time- and concentration-dependent manners. Colony formation assays also indicated the antiproliferative effect of BSF against A549 cells. Cellular mechanistic studies demonstrated that BSF arrested the cell cycle in G2/M phase and induced apoptosis. Importantly, BSF could inhibit the epithelial-mesenchymal transition(EMT) of A549 cells through PI3K/AKT/NF-κB pathway. CONCLUSIONS: BSF effectively inhibited tumour growth, suggesting that it is a promising anticancer treatment for further clinical development.

Alkannin Inhibited Hepatic Inflammation in Diabetic Db/Db Mice.

BACKGROUND/AIMS: The current study was designed to investigate the protective role of alkannin (ALK) on liver injury in diabetic C57BL/KsJ-db/db mice and explore its potential mechanisms. METHODS: An oral glucose tolerance test (OGTT) was performed. The levels of insulin, alanine aminotransferase (ALT), aspartate aminotransaminase (AST), total cholesterol (TC) and triglyceride (TG) were determined by commercial kits. The pro-inflammatory cytokines interleukin (IL)-1ß, IL-6 and tumour necrosis factor (TNF)-α were determined by ELISA. The levels of the ROCK/NF-κB pathway were determined by Western blotting. RESULTS: The contents of pro-inflammatory cytokines interleukin (IL)-1ß, IL-6 and tumour necrosis factor (TNF)-α were inhibited by ALK, metformin or fasudil in diabetic db/db mice. Further, Western blotting analysis showed that the expression of Rho, ROCK1, ROCK2, p-NF-κBp65, and p-IκBα was significantly reversed by ALK treatment. In human hepatic HepG2 cells, the hepatoprotective effects of ALK were further characterized. With response to palmitic acid-challenge, increased amounts of insulin, ALT, AST, TG, and TC were observed, whereas ALK pretreatment significantly inhibited their leakage in HepG2 cells without appreciable cytotoxic effects. The inflammation condition was recovered with ALK treatment as shown by changes of IL-1ß, IL-6 and TNF-α. Further, Western blotting analysis also suggested that ALK improves hepatic inflammation in a Rho-kinase pathway. CONCLUSION: The present study successfully investigated the role of Rho-kinase signalling in diabetic liver injury. ALK exhibited hepatoprotective effects in diabetic db/db mice, and it might act through improving hepatic inflammation through the Rho-kinase pathway.

Identification of an early diagnostic biomarker of lung adenocarcinoma based on co-expression similarity and construction of a diagnostic model.

BACKGROUND: The purpose of this study was to achieve early and accurate diagnosis of lung cancer and long-term monitoring of the therapeutic response. METHODS: We downloaded GSE20189 from GEO database as analysis data. We also downloaded human lung adenocarcinoma RNA-seq transcriptome expression data from the TCGA database as validation data. Finally, the expression of all of the genes underwent z test normalization. We used ANOVA to identify differentially expressed genes specific to each stage, as well as the intersection between them. Two methods, correlation analysis and co-expression network analysis, were used to compare the expression patterns and topological properties of each stage. Using the functional quantification algorithm, we evaluated the functional level of each significantly enriched biological function under different stages. A machine-learning algorithm was used to screen out significant functions as features and to establish an early diagnosis model. Finally, survival analysis was used to verify the correlation between the outcome and the biomarkers that we found. RESULTS: We screened 12 significant biomarkers that could distinguish lung cancer patients with diverse risks. Patients carrying variations in these 12 genes also presented a poor outcome in terms of survival status compared with patients without variations. CONCLUSIONS: We propose a new molecular-based noninvasive detection method. According to the expression of the stage-specific gene set in the peripheral blood of patients with lung cancer, the difference in the functional level is quantified to realize the early diagnosis and prediction of lung cancer.

Effect of metformin on glycaemic control in patients with type 1 diabetes: A meta-analysis of randomized controlled trials.

BACKGROUND: For type 1 diabetes (T1D) patients, adding metformin to insulin therapies is thought to improve blood glucose levels, but current evidence does not support this clinical benefit. Additional data from large clinical trials are now available; therefore, we conducted a meta-analysis of studies on assessing the efficacy and adverse effects of metformin. METHODS: We searched the MEDLINE, EMBASE, and Cochrane Library databases for data from randomized controlled trials. We performed statistical analyses by using Review Manager 5.2. RESULTS: Thirteen randomized controlled trials that compared metformin versus placebo met our inclusion criteria and were included in the study. The final meta-analysis included a total of 1183 participants with T1D. Metformin was associated with reductions in BMI (-1.14, 95% CI -2.05 to -0.24, P = .01), insulin requirements (-0.47, 95% CI -0.70 to -0.23, P = .0001), total cholesterol (-0.23, 95% CI -0.34 to -0.12, P < .0001), and low-density lipoprotein cholesterol (-0.20, 95% CI -0.29 to -0.11, P < .0001) in T1D patients. No clear evidence indicated that metformin improved HbA1c, triglyceride, or high-density lipoprotein cholesterol levels. A safety analysis showed that metformin slightly increased the risk of severe hypoglycaemia (1.23, 95% CI 1.00 to 1.52, P = .05) and mainly gastrointestinal adverse events (2.67, 95% CI 2.06 to 3.45, P < .00001). No evidence showed that metformin increased diabetic ketoacidosis events. CONCLUSIONS: Compared with placebo, metformin was not associated with glycaemic control in T1D patients. Although it exhibited other benefits, such as lower BMI and reduced insulin requirements, total cholesterol, and low-density lipoprotein cholesterol, negative outcomes, such as gastrointestinal adverse effects and severe hypoglycaemia, should also be considered in the use of metformin for T1D patients.

A novel liquid chromatography Orbitrap mass spectrometry method with full scan for simultaneous determination of multiple bioactive constituents of Shenkang injection in rat tissues: Application to tissue distribution and pharmacokinetic studies.

Shenkang injection is a traditional Chinese formula with good curative effect on chronic renal failure. In this paper, a novel, rapid and sensitive ultra-high-performance liquid chromatography coupled with Q Exactive hybrid quadrupole Orbitrap high-resolution accurate mass spectrometry was developed and validated for simultaneous determination of seven bioactive constituents of Shenkang injection in rat plasma and tissues after intravenous administration. Acetonitrile was used as a protein precipitation agent in biological samples disposal with carbamazepine as internal standard. The chromatographic separation was carried out on a C18 column with a gradient mobile phase consisting of acetonitrile and water (containing 0.1% formic acid). The MS analysis was performed in the full-scan positive and negative ion mode. The lower limits of quantification for the seven analytes in rat plasma and tissues were 0.1-10 ng/mL. The validated method was successfully applied to tissue distribution and pharmacokinetic studies of Shenkang injection after intravenous administration. The results of the tissue distribution study showed that the high concentrations of seven constituents were primarily in the kidney tract. This is the first report of the application of Q-Orbitrap with full-scan mass spectrometry in tissue distribution and pharmacokinetic studies of Shenkang injection.

'Repair' Treg Cells in Tissue Injury.

Studies in mice and humans have elucidated an important role for Tregs in promoting tissue repair and restoring tissue integrity. Emerging evidence has revealed that Tregs promoted wound healing and repair processes at multiple tissue sites, such as the heart, liver, kidney, muscle, lung, bone and central nervous system. The localization of repair Tregs in the lung, muscle and liver exhibited unique phenotypes and functions. Epidermal growth factor receptor, amphiregulin, CD73/CD39 and keratinocyte growth factor are important repair factors that are produced or expressed by repair Tregs; these factors coordinate with parenchymal cells to limit injury and promote repair. In addition, repair Tregs can be modulated by IL-33/ST2, TCR signals and other cytokines in the context of injured microenvironment cues. In this review, we provide an overview of the emerging knowledge about Treg-mediated repair in damaged tissues and organs.

Phenotype and function of tissue-resident unconventional Foxp3-expressing CD4(+) regulatory T cells.

It is becoming increasingly clear that regulatory T cells (Treg cells) in specific tissues are important parts of immune system. Tissue-resident Treg cells, which are largely Foxp3-expressing CD4(+) Treg cells, are distinct from one another and conventional Treg cells, and have tissue-specific phenotype and function. They have roles in improving insulin sensitivity in adipose tissue, promoting muscle repair, limiting inflammation in intestine, skin and central nervous system. In this Review, we discuss the current understanding of phenotype and function of tissue-resident Treg cells. Understanding phenotypic and functional diversity in different tissues could provide new insight into Treg cells development and investigation.

Multiple mechanisms involved in diabetes protection by lipopolysaccharide in non-obese diabetic mice.

Toll-like receptor 4 (TLR4) activation has been proposed to be important for islet cell inflammation and eventually ß cell loss in the course of type 1 diabetes (T1D) development. However, according to the "hygiene hypothesis", bacterial endotoxin lipopolysaccharide (LPS), an agonist on TLR4, inhibits T1D progression. Here we investigated possible mechanisms for the protective effect of LPS on T1D development in non-obese diabetic (NOD) mice. We found that LPS administration to NOD mice during the prediabetic state neither prevented nor reversed insulitis, but delayed the onset and decreased the incidence of diabetes, and that a multiple-injection protocol is more effective than a single LPS intervention. Further, LPS administration suppressed spleen T lymphocyte proliferation, increased the generation of CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs), reduced the synthesis of strong Th1 proinflammatory cytokines, and downregulated TLR4 and its downstream MyD88-dependent signaling pathway. Most importantly, multiple injections of LPS induced a potential tolerogenic dendritic cell (DC) subset with low TLR4 expression without influencing the DC phenotype. Explanting DCs from repeated LPS-treated NOD mice into NOD/SCID diabetic mice conferred sustained protective effects against the progression of diabetes in the recipients. Overall, these results suggest that multiple mechanisms are involved in the protective effects of LPS against the development of diabetes in NOD diabetic mice. These include Treg induction, down-regulation of TLR4 and its downstream MyD88-dependent signaling pathway, and the emergence of a potential tolerogenic DC subset.

Metabolomics-based promising candidate biomarkers and pathways in Alzheimer's disease.

Pathologically, loss of synapses and neurons, extracellular senile plaques and intracellular neurofibrillary tangles (NFTs) are observed in the brains of patients with Alzheimer's disease (AD). These features are associated with changes Aß (amyloid ß) 40, Aß42, total tau and phosphorylated tau (p-tau), which are as definitely biomarkers for severe AD state. However, biomarkers for effectively diagnosing AD in the pre-clinical state for directing therapeutic strategies are lacking. Metabolic profiling as a powerful tool to identify new biomarkers is receiving increasing attention in AD. This review will focus on metabolomics-based detection of promising candidate biomarkers and pathways in AD to facilitate the discovery of new medicines and disease pathways.

Effect of electrohydrodynamic (EHD) drying on active ingredients, textural properties and moisture distribution of yam (Dioscorea opposita).

This paper systematically investigates the changes in material properties during electrohydrodynamic (EHD) drying, the discharge characteristics of the EHD system as well as the active ingredients, textural properties (hardness, adhesiveness, etc.) and moisture distribution of yam under EHD, air drying and hot air drying were investigated. The results showed that the active particles and the ionized wind generated during the discharge process of the electrohydrodynamic drying device had a significant effect on the drying. Compared to thermal drying, 21 kV drying resulted in the most complete cellular structure, the best internal bound water content as well as textural properties of yam. It played a positive role in the retention of internal nutrients in yam, and the total phenol and allantoin contents were increased by 25.74% and 81.99%, respectively. These results elucidate the advantages of electrohydrodynamic drying in yam drying and provide a reference for the application of EHD in drying.

Study on the thawing characteristics of beef in ultrasound combined with plasma-activated water.

The effects of deionized water thawing (DT), plasma-activated water thawing (PT), ultrasound (150 W, 40 kHz) combined with deionized water thawing (UDT), and ultrasound combined with plasma-activated water thawing (UPT) on the thawing characteristics and the physicochemical properties of the beef were investigated. The results showed that the UPT group had a faster thawing rate (38 % higher compared to the PT group) and good bactericidal ability (75 % higher compared to the UDT group), and had no adverse effect on the color and pH value of the beef. Plasma-activated water (PAW) can maintain the stability of the beef fiber, improve the water holding capacity (WHC), inhibit lipid oxidation, and reduce the loss of soluble substances such as protein. Therefore, UPT thawing is a promising meat thawing technology, which provides practical guidance and methods for the wide application of UPT in the field of meat thawing.

Unraveling the habitat preferences, ecological drivers, potential hosts, and auxiliary metabolism of soil giant viruses across China.

BACKGROUND: Soil giant viruses are increasingly believed to have profound effects on ecological functioning by infecting diverse eukaryotes. However, their biogeography and ecology remain poorly understood. RESULTS: In this study, we analyzed 333 soil metagenomes from 5 habitat types (farmland, forest, grassland, Gobi desert, and mine wasteland) across China and identified 533 distinct giant virus phylotypes affiliated with nine families, thereby greatly expanding the diversity of soil giant viruses. Among the nine families, Pithoviridae were the most diverse. The majority of phylotypes exhibited a heterogeneous distribution among habitat types, with a remarkably high proportion of unique phylotypes in mine wasteland. The abundances of phylotypes were negatively correlated with their environmental ranges. A total of 76 phylotypes recovered in this study were detectable in a published global topsoil metagenome dataset. Among climatic, geographical, edaphic, and biotic characteristics, soil eukaryotes were identified as the most important driver of beta-diversity of giant viral communities across habitat types. Moreover, co-occurrence network analysis revealed some pairings between giant viral phylotypes and eukaryotes (protozoa, fungi, and algae). Analysis of 44 medium- to high-quality giant virus genomes recovered from our metagenomes uncovered not only their highly shared functions but also their novel auxiliary metabolic genes related to carbon, sulfur, and phosphorus cycling. CONCLUSIONS: These findings extend our knowledge of diversity, habitat preferences, ecological drivers, potential hosts, and auxiliary metabolism of soil giant viruses. Video Abstract.

Hidden diversity and potential ecological function of phosphorus acquisition genes in widespread terrestrial bacteriophages.

Phosphorus (P) limitation of ecosystem processes is widespread in terrestrial habitats. While a few auxiliary metabolic genes (AMGs) in bacteriophages from aquatic habitats are reported to have the potential to enhance P-acquisition ability of their hosts, little is known about the diversity and potential ecological function of P-acquisition genes encoded by terrestrial bacteriophages. Here, we analyze 333 soil metagenomes from five terrestrial habitat types across China and identify 75 viral operational taxonomic units (vOTUs) that encode 105 P-acquisition AMGs. These AMGs span 17 distinct functional genes involved in four primary processes of microbial P-acquisition. Among them, over 60% (11/17) have not been reported previously. We experimentally verify in-vitro enzymatic activities of two pyrophosphatases and one alkaline phosphatase encoded by P-acquisition vOTUs. Thirty-six percent of the 75 P-acquisition vOTUs are detectable in a published global topsoil metagenome dataset. Further analyses reveal that, under certain circumstances, the identified P-acquisition AMGs have a greater influence on soil P availability and are more dominant in soil metatranscriptomes than their corresponding bacterial genes. Overall, our results reinforce the necessity of incorporating viral contributions into biogeochemical P cycling.

Identification and quantification of total coumarins from Urtica dentata Hand and its roles in promoting immune tolerance via TLR4-mediated dendritic cell immaturation.

Urtica dentata Hand (UDH) is traditionally used in the Alpine region as a herbal medicine. Immunotherapy using total coumarins (TC) of UDH has been proposed, yet the cellular and molecular mechanisms remain incompletely characterized. Additionally, there is no method available for the quantification of the main coumarins in UDH. We describe maturation-resistant, TC-conditioned dendritic cell (DC), which expressed much lower MHC class II (I-Ak) and CD86, showed reduced capacity to stimulate effector T cell responses and upregulated PD-Ll (programmed death ligand-1). TC-DC-stimulated regulatory cells (Treg) were superior alloantigen-specific suppressor of the T effector response as compared to those stimulated by control (CTR)-DC. Furthermore, TC-conditioned DC increased the levels of Foxp3 and CTLA-4 in the CD25 T cell population. TC-DC downregulated toll like receptor 4 (TLR4) protein expression in response to LPS. This indicates that down-regulation of TLR4 in response to TC on DC is a critical signaling pathway that regulates the phenotype and function of DC. We also established a sensitive and specific high-performance liquid chromatography-diodearray detection-mass spectrometry (HPLC-DAD-MS) method for simultaneous identification of its main coumarins, 6,6',7,7'-tetramethoxyl-8,8'-biscoumarin (1), 7,7'-dihydroxy-6,6'-dimethoxy-8,8'-biscoumarin (2), 7,7'-dimethoxy-6,6'-biscoumarin (3), and scoparone (4). A demonstration of this mechanism and the method for identification and quantification of TC in UDH endorsed their potential as a tolerance-promoting herbal medicine to prevent or treat transplantation rejection and autoimmune diseases.