Search Results (924)

Curli fimbriae are a major component of biofilm formation in Escherichia coli, and their expression is regulated by numerous transcription factors and small regulatory RNAs (sRNAs). The RcsD-RcsC-RcsB phosphorelay system, which is involved in the envelope stress response, plays a role in this regulation. In this study, we report that DNase-I footprinting analysis revealed that the response regulator RcsB interacts with the −31 to +53 region of the promoter region of csgD, which encodes a major regulator of biofilm formation, and thus contributes to its transcriptional repression. Additionally, overexpression of RcsB or RcsB D56A that could not be phosphorylated by the histidine kinases RcsC and D both significantly reduced csgD expression and suppressed Curli formation. This indicates that the phosphorylation of RcsB has an insignificant impact on its affinity for its operator sites. Furthermore, we confirm that RcsB binds cooperatively to the csgD promoter region in the presence of the nucleoid-associated protein H-NS. Our study also confirms that RcsB positively regulates the expression of an sRNA, RprA, which is known to reduce mRNA csgD mRNA translation RprA via its binding to the 5′-untranslated region (UTR) of csgD. These findings indicate that, in E. coli, the RcsBCD system suppresses csgD expression through both direct transcriptional repression by the regulator RcsB and translational repression by the sRNA RprA. Full article

Maternal undernutrition (MUN) causes severe metabolic disruption in the offspring of mammals. Here we determined the role of histone modification in hepatic gene expression in late-gestation fetuses of nutritionally restricted cows, an established model using low-nutrition (LN) and high-nutrition (HN) conditions. The chromatin immunoprecipitation sequencing results show that genes with an altered trimethylation of histone 3 lysine 4 (H3K4me3) are associated with cortisol synthesis and secretion, the PPAR signaling pathway, and aldosterone synthesis and secretion. Genes with the H3K27me3 alteration were associated with glutamatergic synapse and gastric acid secretion. Compared to HN fetuses, promoter H3K4me3 levels in LN fetuses were higher in GDF15, IRF2BP2, PPP1R3B, and QRFPR but lower in ANGPTL4 and APOA5. Intriguingly, genes with the greatest expression changes (>1.5-fold) exhibited the anticipated up-/downregulation from elevated or reduced H3K4me3 levels; however, a significant relationship was not observed between promoter CpG methylation or H3K27me3 and the gene set with the greatest expression changes. Furthermore, the stress response genes EIF2A, ATF4, DDIT3, and TRIB3 were upregulated in the MUN fetal liver, suggesting activation by upregulated GDF15. Thus, H3K4me3 likely plays a crucial role in MUN-induced physiological adaptation, altering the hepatic gene expression responsible for the integrated stress response and systemic energy metabolism, especially circulating lipoprotein lipase regulation. Full article

Obstructive sleep apnea (OSA) is a sleep-related respiratory disorder characterized by partial or complete obstruction of the upper airway, typically resulting in a decrease in arterial oxygen saturation and repeated awakenings from sleep. It is the most common sleep-related respiratory disorder, affecting 9% to 38% of adults. OSA is associated with loss of tone, improper contraction of the tongue, and pharyngeal dilator muscles of the upper airway during sleep. The gold-standard treatment for moderate-to-severe OSA is continuous positive airway pressure (CPAP). However, many patients have poor long-term compliance with CPAP. Stimulation of the upper airway with electrical activation of the hypoglossal nerve has emerged as a promising treatment for patients with moderate-to-severe OSA who have failed CPAP therapy. Objectives: The present paper aims to review the literature regarding neurostimulation for the treatment of OSA. Conclusions: Hypoglossal nerve stimulation (HNS) has shown favorable success and low morbidity in the management of moderate-to-severe OSA. Full article

This study demonstrated that application of the particular plant growth-promoting rhizobacteria (PGPR) strains Erwinia sp. and Serratia sp. (named C15 and C20, respectively) significantly enhanced tea plant resilience in Zn (zinc)-, Pb (lead)-, and Zn + Pb-contaminated soils by the improving survival rates (over 60%) and chlorophyll content of tea plants, and by reducing the accumulation of these metals in tea plants’ tissues (by 19–37%). The PGPRs elevated key soil nutrients organic carbon (OC), total nitrogen (TH), hydrolysable nitrogen (HN), and available potassium (APO) and phosphorus (APH) contents. Compared to non-PGPR controls, both strains consistently increased microbial α-diversity (Chao1 index: +28–42% in Zn/Pb soils; Shannon index: +19–33%) across all contamination regimes. PCoA/UniFrac analyses confirmed distinct clustering of PGPR-treated communities, with strain-specific enrichment of metal-adapted taxa, including Pseudomonas (LDA = 6) and Bacillus (LDA = 4) under Zn stress; Rhodanobacter (LDA = 4) under Pb stress; and Lysobacter (LDA = 5) in Zn + Pb co-contamination. Fungal restructuring featured elevated Mortierella (LDA = 6) in Zn soils and stress-tolerant Ascomycota dominance in co-contaminated soils. Multivariate correlations revealed that the PGPR-produced auxin was positively correlated with soil carbon dynamics and Mortierellomycota abundance (r = 0.729), while the chlorophyll content in leaves was closely associated with Cyanobacteria and reduced by Pb accumulation. These findings highlighted that PGPR could mediate and improve in tea plant physiology, soil fertility, and stress-adapted microbiome recruitment under heavy metal contaminated soil and stress. Full article

Recent advancements in deep learning have significantly enhanced brain tumor segmentation from MRI data, providing valuable support for clinical diagnosis and treatment planning. However, challenges persist in effectively integrating prior medical knowledge, capturing global multimodal features, and accurately delineating tumor boundaries. To address these challenges, the Hybrid Network for Multimodal Brain Tumor Segmentation (HN-MBTS) is proposed, which incorporates prior medical knowledge to refine feature extraction and boundary precision. Key innovations include the Two-Branch, Two-Model Attention (TB-TMA) module for efficient multimodal feature fusion, the Linear Attention Mamba (LAM) module for robust multi-scale feature modeling, and the Residual Attention (RA) module for enhanced boundary refinement. Experimental results demonstrate that this method significantly outperforms existing approaches. On the BraT2020 and BraT2023 datasets, the method achieved average Dice scores of 87.66% and 88.07%, respectively. These results confirm the superior segmentation accuracy and efficiency of the approach, highlighting its potential to provide valuable assistance in clinical settings. Full article

The main soil type in the Sanjiang Plain of Northeast China, dryland albic soil is of great significance for studying nutrient distribution characteristics. This study focuses on 852 Farm in the typical dryland albic soil area of the Sanjiang Plain, using a combination of paired t-test, geostatistics, correlation analysis, and principal component analysis to systematically reveal the spatial differentiation of soil nutrients in the black soil layer and white clay layer of dryland albic soil, and to clarify the impact mechanism of plow layer nutrient characteristics on crop productivity. The results show that the nutrient content order in both the black and white clay layers is consistent: total potassium (TK) > organic matter (OM) > total nitrogen (TN) > total phosphorus (TP) > alkali-hydrolyzable nitrogen (HN) > available potassium (AK) > available phosphorus (AP). Both layers exhibit a spatial pattern of overall consistency and local differentiation, with spatial heterogeneity dominated by altitude gradients—nutrient content increases with decreasing altitude. Significant differences exist in nutrient content and distribution between the black and white clay layers, with the comprehensive fertility of the black layer being significantly higher than that of the white clay layer, particularly for TN, TP, TK, HN, and OM contents (effect size > 8). NDVI during the full maize growth period is significantly positively correlated with TP, TN, AK, AP, and HN, and the NDVI dynamics (first increasing. then decreasing) closely align with the peak periods of available nitrogen/phosphorus and crop growth cycles, indicating a strong coupling relationship between vegetation biomass accumulation and nutrient availability. These findings provide important references for guiding rational fertilization, agricultural production layout, and ecological environmental protection, contributing to the sustainable utilization of dryland albic soil resources and sustainable agricultural development. Full article

Urban outdoor thermal comfort (OTC) has become an increasingly critical issue under the pressures of urbanization and climate change. Comparative analyses of urban blocks with distinct spatial morphologies are essential for identifying OTC issues and proposing targeted optimization strategies. However, existing studies predominantly rely on microclimate numerical simulations, while comparative assessments of OTC from the human thermal perception perspective remain limited. This study employs the thermal walk method, integrating microclimatic measurements with thermal perception questionnaires, to conduct on-site OTC investigations across three urban blocks with contrasting spatial morphologies—a business district (BD), a residential area (RA), and a historical neighborhood (HN)—in Beijing, a hot summer and cold winter climate city. The results reveal substantial OTC differences among the blocks. However, these differences demonstrated great seasonal and temporal variations. In summer, BD exhibited the best OTC (mTSV = 1.21), while HN performed the worst (mTSV = 1.72). In contrast, BD showed the poorest OTC in winter (mTSV = −1.57), significantly lower than HN (−1.11) and RA (−1.05). This discrepancy was caused by the unique morphology of different blocks. The sky view factor emerged as a more influential factor affecting OTC over building coverage ratio and building height, particularly in RA (r = 0.689, p < 0.01), but its impact varied by block, season, and sunlight conditions. North–South streets generally perform better OTC than East–West streets, being 0.26 units cooler in summer and 0.20 units warmer in winter on the TSV scale. The study highlights the importance of incorporating more applicable physical parameters to optimize OTC in complex urban contexts and offering theoretical support for designing climate adaptive urban spaces. Full article

Newcastle disease virus (NDV) genotype VI from pigeon origin is an important causative agent for serious disease in pigeons. Although the biological characteristics of genotype VI NDV have been extensively studied, the understanding of the thermostability of this genotype is still incomplete. In this study, an NDV strain, designated P0506, was isolated from a diseased pigeon in China and classified as genotype VI. Phylogenetic analysis on the basis of the Fusion gene coding sequence indicated that P0506 belonged to sub-genotype VI.2.1.1.2.2 of class II. The thermostability may be a universal characteristic of genotype VI NDV. Thus, the thermostability of two strains, including P0506 identified in this study and P0713 identified previously, belonging to VI.2.1.1.2.2, and another previously isolated strain, P0813, in VI.2.1.1.2.1, was investigated. It was indicated that all three viruses presented resistance to heat treatment, but P0713 was more robust than P0813 and P0506. By constructing a series of HN protein mutants, amino acid residues at both residues 365 and 497 in HN protein were found to be involved in the heat resistance. Furthermore, the effects of residues 365 and 497 in HN protein on the thermostability of the virus were further evaluated by using recombinant viruses generated by the reverse genetic system. Our results showed that residue at position 365 in HN protein was the key thermostable determinant of sub-genotype VI.2.1.1.2.2 NDV. These findings will help us better understand the thermostable mechanism of NDV and serve as a foundation for the further development of novel thermostable vaccines. Full article

Accurate modeling of the power–cadence relationship is essential for assessing maximal anaerobic power (Pmax) of the lower limbs. Experimental data points from Force–Velocity tests during cycling do not always reflect the maximal and cadence-specific power individuals can produce. The quality of the models and the accuracy of Pmax estimation is potentially compromised by the inclusion of non-maximal data points. This study evaluated a novel residual-based filtering method that selects five strategically located, maximal data points to improve model fit and Pmax prediction. Twenty-three recreationally active male participants (age: 26 ± 5 years; height: 178 ± 5 cm; body mass: 73 ± 11 kg) completed a Force–Velocity test consisting of multiple maximal cycling efforts on a stationary ergometer. Power and cadence data were used to generate third-order polynomial models: from all data points (High Number, HN), from the highest power value in each 5-RPM interval (Moderate Number, MN), and from five selected data points (Low Number, LN). The LN model yielded the best goodness of fit (R² = 0.995 ± 0.008; SEE = 29 ± 15 W), the most accurate estimates of experimentally measured peak power (mean absolute percentage error = 1.45%), and the highest Pmax values (1220 ± 168 W). Selecting a limited number of maximal data points improves the modeling of individual power–cadence relationships and Pmax assessment. Full article

Marine-derived compounds represent a rich source of structurally diverse molecules with therapeutic potential for cancer, renal disorders, metabolic-associated fatty liver disease (MAFLD), and atherosclerosis. This review systematically evaluates recent advances, highlighting compounds such as Microcolin H, Benzosceptrin C, S14, HN-001, Equisetin, glycosides (e.g., cucumarioside A₂-2), ilimaquinone, and Aplidin (plitidepsin). Key mechanisms include autophagy modulation, immune checkpoint inhibition, anti-inflammatory effects, and mitochondrial homeostasis. Novel findings reveal glycosides’ dual role in cytotoxicity and immunomodulation, ilimaquinone’s induction of the DNA damage response, and Aplidin’s disruption of protein synthesis via eEF1A2 binding. Pharmacokinetic challenges and structure–activity relationships are critically analyzed, emphasizing nanodelivery systems and synthetic analog development. This review bridges mechanistic insights with translational potential, offering a cohesive framework for future drug development. Full article

The gut microbiota critically influences lipid metabolism and fat deposition in pigs, processes that underpin pork quality preferences and differentiate the meat traits of Chinese indigenous breeds (fat-type) from those of Western commercial breeds (lean-type). To explore the mechanisms underlying breed-specific fatty acid absorption, we compared the rectal and colonic microbiota and metabolite profiles of Huainan and Large White pigs using 16S rRNA sequencing and untargeted metabolomics. HN pigs exhibited enriched Lactobacillus johnsonii and Lactobacillus amylovorus, along with a significantly higher Firmicutes/Bacteroidetes ratio. Functional predictions further revealed elevated microbial pathways related to glycolysis, pyruvate metabolism, and ABC transporters in HN pigs. Conversely, LW pigs showed increased abundance of potentially pro-inflammatory bacteria and enriched pathways for lipopolysaccharide (LPS) biosynthesis. Metabolites such as 4-ethyl-2-heptylthiazole and picolinic acid were significantly upregulated in HN pigs and served as robust biomarkers (Area Under the Curve, AUC = 1.0),with perfect discrimination observed in both rectal and colonic samples. Integrative analysis identified 52 co-enriched microbial and metabolic pathways in HN pigs, including short-chain fatty acid (SCFA) production, lipid biosynthesis and transport, amino acid metabolism, ABC transporter activity, and the PPAR signaling pathway, supporting a microbiota–metabolite axis that enhances fatty acid absorption and gut immune balance. These findings provide mechanistic insight into breed-specific fat deposition and offer candidate biomarkers for improving pork quality via precision nutrition and breeding. Full article

Accurate quantification of Bifidobacterium animalis subsp. lactis HN019, a clinically validated probiotic strain conferring immune modulation, gastrointestinal health, and gut barrier integrity benefits, is essential for diverse applications. To address the critical need for strain-specific detection, we developed a quantitative PCR (qPCR) assay targeting a unique single-nucleotide polymorphism (SNP) within the galK gene, identified through comparative whole-genome sequencing (WGS) analysis of 31 B. animalis subsp. lactis strains. The assay exhibited exceptional specificity, distinguishing HN019 from 19 other Bifidobacterium strains. Sensitivity tests indicated a detection limit of 0.5 pg of DNA and 10³ CFU/mL of bacterial cells, making it suitable for industrial-scale applications. Additionally, the method exhibited strong repeatability, reproducibility across different qPCR platforms, and resistance to interference from high cell density of B. animalis subsp. lactis DSMZ 10140. Successful quantification of HN019 in complex multi-strain probiotic powders confirmed its practical reliability. This work establishes a rapid, robust, and scalable tool for precise probiotic strain tracking, addressing critical quality control and regulatory compliance needs within the rapidly expanding probiotic industry. Full article

Calpain-5/CAPN5 is a calcium-activated, non-lysosomal cysteine (thiol) protease. The substrate repertoire of CAPN5 is not known. Calpains catalyze limited proteolysis of their substrates, generating neo-N-termini that correspond to internal residues of their nascent substrate proteins. To identify such neo-N-termini generated by CAPN5, we employed an N-terminomics approach called TAILS (Terminal amine isotopic labeling of substrates) to quantitatively compare the N-terminal peptides detected in parental and CAPN5-deficient SH-SY5Y neuroblastoma cells. Thirty neo-N-termini corresponding to 29 protein groups and 24 unique proteins were detected to be depleted in the CAPN5^−/− cells. A subset of the identified putative substrates was further studied with CAPN5 co-immunoprecipitation, in vitro calcium-induced CAPN5 proteolysis assay, and their cellular fragmentation patterns were compared in parental and CAPN5-deficient SH-SY5Y cells. Here, we provide evidence for CAPN5-mediated proteolysis of the synaptic proteins DLGAP4, IQSEC1 and MPDZ, the neurodegeneration-related EWS, hnRNPU, TFG and UGP2, the DNA replication regulator MCM3, and the neuronal differentiation regulator LMTK1. Our data provide new relevance for neovascular inflammatory vitreoretinopathy (NIV), a progressive eye disease caused by pathogenic mutations in CAPN5. Data are available via ProteomeXchange with identifier PXD064313. Full article

Background: Treacher Collins Syndrome (TCS) is a rare, congenital craniofacial syndrome. Its most characteristic feature is mandibular and midface hypoplasia. Due to malformations of the facial skeleton, airway abnormalities can also be observed, predisposing individuals to obstructive sleep apnoea (OSA). OSA in TCS may contribute to significant morbidity, including developmental delays, cardiovascular disorders and reduced quality of life. Objectives: This narrative review aims to present the true prevalence of OSA and the treatment options for TCS patients. Additionally, the pathophysiology and diagnostic tools for this condition were briefly outlined. Methods: The literature search included publications from PubMed, Scopus, Web of Science and Cochrane Library. The chosen period of time for these publications was 2000–2024. Results: The results showed that OSA is a serious problem among TCS patients. Although there is no standardised treatment protocol, the primary methods often include mandibular distraction osteogenesis (MDO) and continuous positive airway pressure (CPAP). Approaches such as hypoglossal nerve stimulation (HNS) need further investigation, especially with longitudinal observations. Conclusions: The development of treatment options seems to be promising, suggesting a favourable outlook for standardising the treatment protocols. Full article

Ornithine decarboxylase (ODC) is the rate-limiting enzyme in the biosynthesis of polyamines and plant alkaloids, including medicinal tropane alkaloids (TAs). Due to its key role, ODC has been utilized as an effective molecular tool in metabolic engineering. However, to date, only a limited number of plant ODCs have been characterized. Among the reported ODCs, Erythroxylum coca ODC (EcODC) exclusively has ODC activity, while Nicotiana glutinosa ODC (NgODC) exhibits dual ODC and lysine decarboxylase (LDC) activities. The potential LDC activity of ODCs from TA-producing plants remains unknown. Here, we characterized AlODC and DsODC from Anisodus luridus and Datura stramonium, along with two previously reported ODCs from Atropa belladonna (AbODC) and Hyoscyamus niger (HnODC), in Escherichia coli to investigate their enzyme kinetics and substrate specificity. Enzymatic assays revealed that both AlODC and DsODC catalyzed the conversion of ornithine to putrescine, confirming their ODC activity, with AlODC exhibiting a higher catalytic efficiency, comparable to established ODCs. Furthermore, all four ODCs also displayed LDC activity, albeit at significantly lower efficiency (<1% of ODC activity). This study provides a comprehensive analysis of the enzyme kinetics of ODCs from TA-producing plants, identifying promising candidate genes for metabolic engineering for the biomanufacturing of putrescine-derived alkaloids. Moreover, this is the first report of LDC activity in ODCs from Solanaceae TA-producing plants, shedding light on the evolutionary relationship between ODC and LDC. Full article