Biology-Basel最新文献

The intestinal barrier undergoes profound changes with age, impacting local immunity and systemic health, yet the mechanisms coordinating immune and microbial dynamics across the lifespan remain incompletely understood. Toll-like receptor 4 (TLR4) serves as a key mediator of host-microbiota interactions. This study investigated age-related changes in barrier function and the role of TLR4 using C57BL/6J and TLR4 knockout (TLR4^-/-) mice across key developmental stages: pups (postnatal day 9), adults (2-4 months), middle-aged (7-9 months), and old (16-19 months). Through a multi-layered approach integrating histology, microbiome profiling, short-chain fatty acid (SCFA) analysis, cytokine quantification, ex vivo functional assays, and transcriptomics, we identified a multi-phase process of intestinal remodeling. Pup-P9 mice exhibited immature colonic structure, a simple microbiota dominated by Firmicutes and Proteobacteria, and undetectable acetic acid level. Adults reached peak diversity and SCFA concentrations, marked by a rise in Bacteroidota and the emergence of Akkermansia. In middle and old age, pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) increased, Bacteroidota declined while Firmicutes, Actinobacteria, and Turicibacter expanded, and aged colons showed blunted ex vivo responses to IL-1β. This age-associated functional decline phenotype was absent in TLR4^-/- mice, supporting the involvement of TLR4 signaling. Transcriptomics further revealed biphasic PI3K/Akt activation in both pups-P9 and old mice. Together, these findings suggest a systemic rewiring of host metabolic and immune signaling pathways in response to an aging microbiota, highlighting this dynamic, lifespan-wide microbiota-host signaling axis as a potential intervention target.

Pigs are a major source of animal protein and an important model for studying domestication, adaptation, and the genetics of complex traits. Over the past decade, pig genomics has progressed from generating reference assemblies and variant catalogues toward reconstructing population history and interpreting phenotypic divergence with greater resolution. Improvements in reference continuity, breed-matched assemblies, and pangenome/graph representations reduce reference bias in repeat-rich and structural-variant-prone regions, strengthening cross-population comparisons and fine-mapping across cohorts. Time-stratified ancient genomes provide an explicit temporal framework for evaluating lineage turnover and gene flow and support a multi-stage, network-based view of domestication. In parallel, genetic analyses of growth, carcass composition, meat quality, and disease resilience increasingly integrate association signals with regulatory annotation, gene expression, and tissue- or stage-specific context. Across these lines of work, maintaining comparability across reference frameworks remains central, including stable coordinate systems, robust imputation resources, and reproducible approaches for structural-variant genotyping. Together, these developments support more consistent inference and interpretation while providing a clearer basis for translation in breeding and biomedical research with attention to genetic diversity.

Botulinum toxin (BoNT) is a highly specific molecular enzyme whose therapeutic action is based on the proteolytic cleavage of SNARE proteins, most notably SNAP-25. Despite the deterministic nature of this molecular mechanism, the clinical effects of BoNT exhibit substantial variability in efficacy, spatial extent, and duration that cannot be fully explained by dose-response relationships or diffusion-based models. In this work, we propose the Molecular Probability Field (MPF-BoNT) as a conceptual framework that bridges discrete molecular events and emergent functional outcomes. The MPF is defined as the spatial-temporal distribution of the probability that presynaptic terminals reach a functional silencing state (operationalized via SNAP-25 cleavage exceeding a threshold), shaped by exposure, uptake, target density, and temporal dynamics following toxin exposure. Within this framework, clinical effects arise from the integration of probabilistic molecular events across space and time, rather than from toxin presence or concentration alone. The MPF-BoNT framework accounts for key features of botulinum toxin action, including spread, nonlinearity of dose effects, variability in duration, and differences between technical and biological non-response. By explicitly incorporating molecular variables such as local concentration, exposure time, terminal density, internalization probability, and functional silencing thresholds, the framework provides an integrative interpretation of tissue-level behavior grounded in molecular biology. The MPF-BoNT offers a formal language to describe how established enzymatic events generate observable spatial, temporal, and functional patterns. As a generative framework grounded in explicit testable structure, it establishes a foundation for future experimental and clinical research.

Orthohalarachne attenuata and O. diminuata mites are parasites of the respiratory system of Pinnipeds. During hosts' dives, mites must cope with changing conditions of oxygen availability in the nasal cavity. Adults and nymphs live inside the host, but larvae are active and responsible for colonizing new hosts. Hence, larvae are also exposed to environmental conditions with variable temperature and pressure, as well as to dehydration and changes in salinity. Although both species live within the respiratory tract of hosts, adults attach to different sections. Also, larvae have differential thermal tolerances and locomotion capacities. In this study, we show the effect of hypoxia, humidity and salinity on survival of O. attenuata and O. diminuata mite larvae. We found that both species are highly tolerant to hypoxia and can withstand it for long periods. In turn, both species showed low survival when exposed to direct air. Finally, hyperosmotic solution was highly harmful for O. attenuata, but not for O. diminuata. Our results show that humidity rather than oxygen availability is a constraint for survival and a limitation for dispersal when searching for new hosts. The present study expands our knowledge of ecophysiology and adaptations to changing conditions experienced during the dispersal of these marine parasite species.

The TIFY family, known as a novel group of transcription factors unique to the plant, plays a number of roles and has been functionally characterized in numerous plant species. However, TIFY proteins remain unexplored in litchi. Here, we identified 14 TIFY genes in litchi, which were unevenly located on 8 of 15 chromosomes. All of the LcTIFY proteins were predicted to be nuclear-localized and were phylogenetically categorized into four subfamilies (TIFY, PPD, ZML, and JAZ). Duplication analysis detected no tandem duplications but identified one segmental duplication event with LcTIFY genes, suggesting that segmental duplication served as the primary driving force for the expansion of LcTIFY genes. Comparative collinear analysis revealed 12, 5, and 27 collinear gene pairs between litchi and Arabidopsis, rice, and apple, respectively, providing valuable clues for understanding the evolution of the LcTIFY genes. RNA-Seq and qRT-PCR analyses indicated tissue-preferential expression patterns among LcTIFY genes. Notably, LcPPD1 and LcJAZ5 expressions were negatively correlated with anthocyanin accumulation in the 'Feizixiao' variety, except that LcJAZ5 displayed a positive correlation under CPPU treatment. In contrast, LcJAZ7 expression showed a positive correlation across all treatments, implicating these genes in the regulation of pericarp pigmentation. Collectively, these findings lay the groundwork for future investigations into the functional roles of TIFY genes in litchi and offer valuable genetic resources for elucidating the mechanisms underlying litchi pigmentation, thereby providing fresh perspectives for subsequent research into the molecular mechanisms of color formation in plants.

Climate warming is an important driver influencing soil microbial involvement in carbon cycling. To clarify the responses of carbon-fixing microorganisms in alpine lakeshore wetlands, we conducted a warming experiment using open-top chambers (OTCs) in the Qinghai Lake lakeshore wetland and applied high-throughput sequencing of the cbbM gene. The results indicated that warming significantly increased soil temperature and reduced soil moisture, but had no significant effects on soil pH, total carbon, or total nitrogen content. Despite the stability of community α-diversity, warming markedly reshaped the community composition and significantly elevated the relative abundances of dominant taxa including Ensifer and Hydrogenovibrio. In addition, warming significantly strengthened the assembly process of the cbbM-bearing carbon-fixing microbial community, in which heterogeneous selection played a leading role. Redundancy analysis revealed that soil total nitrogen and pH were major drivers influencing the composition of the microbial community. Notably, despite significant fluctuations in taxonomic composition, the functional profile dominated by sulfur oxidation and phototrophy remained unchanged, indicating strong functional redundancy. Overall, cbbM carbon-fixing microorganisms in alpine lakeshore wetlands effectively buffered environmental disturbances through functional redundancy and maintained stable carbon metabolic functions, providing scientific evidence for the short-term resilience of carbon sink functions in alpine wetlands under climate warming.

Breast cancer is a leading cause of cancer-related mortality in women, necessitating new treatment strategies. Curcumin (Cur), a natural polyphenol, and gemcitabine (Gem), a standard chemotherapeutic, were investigated for their combined anticancer effects. We hypothesized that Cur sensitizes breast cancer cells to Gem via reactive oxygen species (ROS)-mediated apoptosis, and that this effect is associated with selective oxidative vulnerability in malignant cells compared to normal breast epithelial cells. MCF-7 (hormone receptor-positive) and MDA-MB-231 (triple-negative) cells were treated with Cur and Gem alone or in combination. Normal breast epithelial MCF-10A cells were included to evaluate therapeutic selectivity. Cell viability (MTT), apoptosis (Annexin V/PI), oxidative stress (TOS/TAS), intracellular ROS generation (DCFH-DA assay), mitochondrial membrane potential (ΔΨm) (JC-1 staining), caspase activation, synergy (Bliss/HSA/Chou-Talalay), VEGF secretion (ELISA), and transcriptomic changes (RNA-Seq) were assessed. Cur and Gem showed dose-dependent cytotoxicity. Combination treatment demonstrated strong synergistic activity, significantly enhancing apoptosis, oxidative stress, and caspase activation. Direct quantification of intracellular ROS revealed marked ROS accumulation in MCF-7 and MDA-MB-231 cells following combination treatment, whereas MCF-10A cells exhibited only modest oxidative changes. JC-1 analysis demonstrated substantial mitochondrial depolarization in breast cancer cells, which was largely reversible by ROS scavenging and minimal in MCF-10A cells. VEGF secretion was markedly suppressed. Transcriptomic analysis revealed profound alterations in apoptosis, cell cycle, and angiogenesis-related pathways, with more pronounced transcriptional reprogramming observed in the triple-negative subtype. Cur synergistically enhances Gem's efficacy in breast cancer cells through ROS-mediated apoptosis and anti-angiogenic effects, characterized by cancer-selective ROS amplification and mitochondrial membrane depolarization, supporting its potential as a combination therapy, particularly for triple-negative breast cancer.

This study aimed to investigate the effect and underlying mechanism of Taxus cuspidata seed oil (TCSO) on carbon tetrachloride (CCl₄)-induced hepatic fibrosis in mice. A mouse model of hepatic fibrosis was established by CCl₄ induction, and the model mice were subsequently treated orally with high dose or low dose TCSO for eight weeks. The degree of liver fibrosis and the mechanism of action were assessed through organ indices, serum biochemical markers, oxidative stress levels, histopathological examination, and molecular biological analyses. The results demonstrated that TCSO significantly reduced serum levels of alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP). Concurrently, it decreased the concentrations of liver fibrosis markers, including procollagen III (PC III), collagen IV (IV-C), hyaluronic acid (HA), and laminin (LN), and reduced hepatic collagen deposition. Furthermore, TCSO enhanced the activities of the antioxidants superoxide dismutase (SOD) and glutathione (GSH) while inhibiting the production of the lipid peroxidation product malondialdehyde (MDA), and it ameliorated histopathological alterations in liver tissue. Additionally, TCSO markedly downregulated the expression of key fibrogenic proteins, such as transforming growth factor-β1 (TGF-β1), matrix metalloproteinase-2 (MMP-2), and tissue inhibitor of metalloproteinases-1 (TIMP-1), thereby effectively suppressing the progression of hepatic fibrosis. In conclusion, TCSO ameliorates hepatic fibrosis in mice by reducing hepatotoxic enzyme activity and collagen deposition, enhancing antioxidant capacity, and downregulating the expression of fibrosis-related proteins.

Canine monocytotropic ehrlichiosis (CME), caused by the intracellular bacterium Ehrlichia canis, is a significant tick-borne disease in dogs that requires effective vaccination strategies. This study aimed to evaluate recombinant TRP19 (rTRP19), a highly conserved immunodominant antigen, as a promising vaccine candidate against experimental E. canis infection in dogs, following its success in a mouse model. Fifteen E. canis-negative beagles were immunized intramuscularly with either 50-µg or 100-µg of rTRP19 in alum adjuvant or a PBS control, on days 0, 30, and 60. All dogs were then exposed intravenously to E. canis on day 90 and monitored for 120 days for clinical signs, hematological changes (platelet count, hematocrit, and body temperature), and antibody titers. The rTRP19 vaccine prototypes induced strong antigen-specific humoral responses. They caused a significant reduction in rickettsial load, with complete elimination observed in the 100-µg group by day 7 and in both vaccinated groups by day 14 of exposure. Furthermore, the mean body temperature in the 100-µg rTRP19 group was significantly lower than that of the control group, suggesting that the higher-dose vaccine mitigated febrile response. Collectively, these results suggest that rTRP19 vaccine prototypes hold promise in overcoming the clinical signs and hematological abnormalities of E. canis infection by inducing a strong antigen-specific antibody response.

The transition from Sanger to next-generation sequencing (NGS) for HIV-1 drug resistance testing offers enhanced sensitivity but also introduces bioinformatic variability. This study evaluated four strategies: the commercial Exatype platform, the academic Stanford HIVdb-NGS, the open-source Quasitools (HyDRA) suite, and a custom de novo assembly workflow, iLunaR. Using 85 clinical HIV-1 pol MiSeq sequencing datasets, concordance was assessed at a 2% mutation detection threshold. A majority consensus standard defined true presence if a mutation was detected by at least three pipelines and supported by Sanger sequencing. While the datasets were successfully processed by all pipelines, discordances emerged in detecting low-abundance mutations and a specific case of structural mutation. iLunaR achieved perfect agreement (Cohen's kappa = 1.000; 95% CI: 1.000-1.000). Quasitools demonstrated the lowest agreement (Cohen's kappa = 0.901; 95% CI: 0.807-0.995) due to consistent reporting of mutations at lower abundance levels and aligner-induced reference bias misclassifying a deletion as a point mutation. Exatype (Cohen's kappa = 0.951; 95% CI: 0.884-1.000) and Stanford (Cohen's kappa = 0.926; 95% CI: 0.846-1.000) exhibited specific failures, including an omitted integrase mutation and codon translation errors, respectively. These findings confirm that bioinformatic algorithm choice remains a critical clinical variable despite NGS advancements in HIV-1 drug resistance testing.