Search Results (57,374)

Preclinical studies in virological research are pivotal to comprehend mechanisms of viral virulence and pathogenesis and evaluate antiviral therapies or vaccines. Mouse models, through access to various genetic strains and amenable reagents, along with their ease of implementation and cost-effectiveness, remain the gold standard for establishing go/no-go thresholds before advancing to non-human primate or clinical studies. In preclinical mouse studies, standardized weight loss thresholds (WLTs)—which correspond to an established percentage of weight change at which animals are humanely euthanized—are a routine metric to quantitatively evaluate the lethality of a viral pathogen and the effectiveness of antiviral countermeasures in preventing fatal viral disease. While it is recognized that WLTs can significantly impact the assessment of viral virulence, they are often established to meet existing ethical or methodological requirements, rather than being based on a specific scientific rationale. Here, we examine how various experimental variables—including mouse and viral strains and the sex ratio within a mouse cohort—influence the ability of a WLT to support the generation of robust mouse models of fatal viral infection. Using various mouse strains and viral pathogens, we report that variations in experimental conditions in mouse preclinical studies can significantly compromise the performance of a non-adjusted WLT to yield an accurate estimate of viral virulence. Our findings advocate for a robust adjustment of WLT to each experimental framework and associated variables to establish mouse models of fatal viral infection that can generate high-resolution data acquisition while upholding ethical standards. Overall, our study provides methodological insights to enhance the unbiased acquisition and benchmarking of viral virulence and antiviral efficacy data in mouse models. Full article

Polynucleotide (PN), a high-molecular-weight DNA fragment derived from salmon and other fish sources, shows promising anti-aging and regenerative effects on the skin. This study investigated how PN enhances collagen synthesis, focusing on its effect on phosphoenolpyruvate carboxykinase 1 (PCK1) in senescent macrophages and its downstream effects on fibroblasts. Using in vitro senescent cell models and in vivo aged animal models, PN significantly upregulated the adenosine 2A receptor (A2AR), adenylate cyclase (AC), cyclic AMP (cAMP), protein kinase A (PKA), and cAMP response element-binding protein (CREB) in senescent macrophages. This led to increased PCK1 expression, which reduced oxidative stress and promoted M2 macrophage polarization, associated with elevated levels of interleukin-10 and tumor growth factor-β. Conditioned media from PN-treated macrophages enhanced SMAD family member 2 and signal transducer and activator of transcription 3 phosphorylation in senescent fibroblasts, increasing collagen I and III synthesis and reducing nuclear factor-κB activity. In vivo, PN administration elevated expression of the A2AR/AC/PKA/CREB/PCK1 pathway, reduced oxidative stress, increased M2 macrophage markers, and significantly improved collagen density and skin elasticity over time. Use of a PCK1 inhibitor attenuated these effects, highlighting the pivotal role of PCK1. Overall, PN modulates macrophage-fibroblast interactions via the CREB/PCK1 axis, enhancing collagen synthesis and counteracting age-related skin changes. PN has emerged as a promising therapeutic agent for skin rejuvenation by targeting cellular senescence and promoting extracellular matrix restoration. Full article

Phenylketonuria (PKU) is an inherited disorder caused by mutations in the phenylalanine hydroxylase (PAH) gene that result in the amino acid phenylalanine (Phe) building up in the blood. Current therapies suggest low-Phe dietary management and (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin (BH₄) therapy, which are limited in efficacy and require lifelong treatment. Recent advances in gene therapy, including gene editing and viral-mediated gene delivery, produce therapeutic effects. Advancements in gene editing technologies, notably adenine base editors (ABEs) and CRISPR-based systems, in conjunction with enhanced delivery methods such as lipid nanoparticles (LNPs) and recombinant viruses, have demonstrated substantial promise in preclinical studies. This review details the pathophysiology of PKU treatment, and progress in preclinical and clinical gene therapy strategies. Emphasis is on adenine base editing using LNPs, recombinant adeno-associated virus (rAAV)-mediated gene transfer, and the translational challenges associated with these technologies. We also discuss future directions for therapeutic reach and ensuring long-term safety and efficacy. Full article

Fungal skin infections caused by dermatophytes are of significant veterinary and zoonotic concern. This study investigated the prevalence, risk factors, and treatment outcomes of dermatophytosis in dogs and cats with skin lesions. A total of 140 animals (90 dogs and 50 cats) that presented with skin lesions (alopecia, crusts, pruritus, and scales) were examined. Identification of dermatophyte isolates relied on both phenotypic characteristics and molecular techniques. The molecular approach involved PCR and sequencing of ribosomal DNA regions (ITS1, ITS2, and 5.8S rDNA), complemented by Restriction Fragment Length Polymorphism (RFLP). Treatment regimens included topical clotrimazole, systemic itraconazole, supportive therapy, and a dermatophyte vaccine. Of the 90 dog samples examined, 47 (52.22%) were positive for fungal culture (p = 0.65). In cats, 35 samples (70%) were positive (p < 0.0001). Microsporum canis was the most significant (p < 0.0001) prevalent isolate (60%), followed by Trichophyton mentagrophytes (20%). This study reported the first isolation of T. indotineae in Egypt. Younger animals (<1 year) exhibited a significantly (p < 0.05) higher risk of infection compared with adults (>1 year). Indoor/outdoor housing in cats significantly reduced the risk of infection when compared with indoor housing (p < 0.0001; odds ratio = 0.05). Combination therapy using itraconazole, clotrimazole, supportive treatment, and a dermatophyte vaccine resulted in the fastest clinical recovery (p < 0.0001). These findings underscore the importance of accurate diagnosis and effective treatment strategies for managing dermatophytosis in pets and preventing zoonotic transmission. Full article

Background: Nettle is a potential non-conventional feed resource due to its high level of crude protein content, and ensiling is better for utilization in the animal industry. Previous integrated analysis (microbiome and metabolome) suggested that 4-pentenoic acid and malic acid in ensiled nettle may inhibit harmful microorganisms within the system. The present study investigated the effects of these two acids on nettle silage quality through the addition of 1% fresh weight of these acids, then analyzed the characteristics and bacterial communities during 60 days of nettle ensiling. Results: The addition of 4-pentenoic acid increased the content of crude protein (CP) and acetic acid (AA) compared with both control and malic acid-treated groups during 30 to 60 days of ensiling (p < 0.05). Lactic acid (LA) content was highest in the malic acid-treated group (4.21%, dry matter, DM based) compared to the control and 4-pentenoic acid-treated groups after 7 days of nettle ensiling (p < 0.05), but lower compared with the 4-pentenoic acid-treated group after 30 days of nettle ensiling (p < 0.05), and it was not detected in all groups after 60 days of silage. The contents of butyric acid (BA) and ammonia (AN) were the lowest (2.92–4.39% of DM and 9.94–24.28% of total nitrogen, respectively) in the 4-pentenoic-treated group compared with both control and malic acid-treated groups during 30 to 60 days of ensiling (p < 0.05). Both acids increased the relative abundance of Weissella after 30 days of nettle ensiling, with 4-pentenoic acid showing a higher inhibitory capacity. Both acids showed a trend to inhibit the relative abundance of Clostridium sensu stricto 15 after 30 days of nettle ensiling. Clostridium sensu stricto 15 showed significant positive correlation with BA and AN (p < 0.05). Conclusions: The results of the present study suggested that the addition of 4-pentenoic could improve the quality of silage by reducing levels of protein degradation, probably resulting from its inhibited activity against Clostridium spp. However, malic acid was less effective than 4-pentenoic acid in suppressing Clostridium spp. activity and the associated production of BA and AN, resulting in inferior preservation of CP. Full article

The bovine viral diarrhea virus (BVDV) infects a wide range of domestic and wild mammals. This review hypothesized that there might be cross-species transmission of BVDV. Therefore, the aim was to explore the BVDV-5′ UTR and N-pro sequence-based evidence to understand host plasticity among different animals. A total of 146 unique BVDV sequences retrieved from GenBank, originating from 12 distinct mammalian species that are submitted from 55 countries, were analyzed. The phylogenetic analysis revealed that all three BVDV species exhibited genetic relatedness infecting diverse animal species. BVDV-1 sequences obtained from cattle, buffalo, and pigs and BVDV-2 and HoBi-like pestivirus sequences from cattle, goats, and sheep showed a genetic resemblance. Surprisingly, cattle and buffalo in China, cattle and yak in Mongolia, cattle and wild boar in Serbia, cattle and deer in Mexico, cattle and alpacas in Canada, goats and pigs in the USA, and sheep and buffalo in Argentina were infected with BVDV-1 within the same county and strongly positioned in the same cluster, indicating potential spillover with host tropism. Moreover, BVDV sequences isolated from various neighboring countries clustered closely, suggesting potential cross-border transmission events. Based on genomic evidence, the BVDV transmission cycle could be depicted, where cattle act as a primary source of infection, while other domestic and wild animals maintain the infection ecology within their habitat due to virus tropism. Full article

The red-claw crayfish Cherax quadricarinatus has been widely introduced and cultured in China and has become a crucial economic freshwater species. However, individuals reared from the same batch of seedlings in uniform aquaculture systems exhibit significant size variation within and between genders, which notably impedes the optimization of both their quality and yield. Gut microbiota plays an important role in the metabolism, development, and immunity of aquatic animals. However, the knowledge on the intestinal microbiota of red-claw crayfish with various sizes and genders is poor. In this study, the intestinal microbiota of red-claw crayfish cultured in consistent farming conditions were separated to larger-sized female (GUBF), larger-sized male (GUBM), smaller-sized female (GUSF), and smaller-sized male (GUSM) groups based on their body size (weight) and gender, before being analyzed via high-throughput 16S rRNA gene sequencing. The intestinal microbiota results showed that alpha diversity tended to generally decrease in the order of GUBF, GUBM, GUSF, and GUSM, indicating that the richness and evenness of the gut flora were gradually improved with the increase in body weight or from male to female. Community richness and diversity were highest in the GUBF group, followed by the GUBM, GUSF, and GUSM groups, respectively. Beta diversity indicated significant differences in gut microbiota between the GUBF and GUSF, GUBM and GUSM, GUBF, and GUBM groups. Further analysis showed that the dominant phyla in the intestine of the red-claw crayfish were Firmicutes, Proteobacteria, Fusobacteriota, Bacteroidota, and Deinococcota, and the dominant genera were Vibrio, Tyzzerella, Candidatus Bacilloplasma, Citrobacter, and Candidatus Hepatoplasma. Moreover, nine phyla and 106 genera were identified to be significantly different in abundance among all four groups. Pairwise comparisons revealed that the phylum Dependentiae and Planctomycetota and genus Babeliaceae_unclassified were significantly abundant in the gut of female crayfishes, regardless of body size. On the other hand, irrespective of genders, the abundance of Novosphingobium, Piscinibacter, and Citrobacter was significantly increased or declined in the larger or smaller crayfishes, respectively. PICRUSt2 analysis based on the KEGG database suggested that the pathway bacterial secretion system, isoflavonoid biosynthesis, and pathway glycerolipid metabolism were significantly up- and down-regulated in female individuals, respectively, regardless of body sizes. Meanwhile, the adipocytokine signaling pathway, pyruvate metabolism, and pathway electron transfer carriers were significantly up- and down-regulated in larger individuals, respectively, regardless of gender. Gender differences may induce gut microbiota to exert a greater impact on hormonal regulation, whereas differences in individual size seem to lead gut microbiota to develop a preference for food intake and energy sources. In summary, this study revealed key differences in the intestinal microbiota of the crayfish with different sizes and genders, even in those which were cultured in the same environment and period, which potentially suggest that the intestinal microbiota may be influenced by some other factors in the culture system, such as hormone secretion, metabolism, and immunity. This study will contribute to improving growth performance and animal quality in the aquaculture of C. quadricarinatus. Full article

The rational design of artificial lighting systems in pig housing can enhance animal welfare, thereby boosting gilt health and reproductive performance while improving economic metrics for swine farms. To identify the optimal light environments for gilts under artificial illumination, we conducted self-selection-based photic preference testing, ultimately providing actionable insights for welfare-centric precision lighting protocols in modern pig production. In this study, a dynamic multi-chromatic self-selection system was developed, integrating programmable RGBW-LED arrays for spectral control, inter-compartment access channels for autonomous gilt movement, and real-time image recognition technology to investigate light color preferences. Twenty-four gilts (nulliparous female pigs) were housed for five weeks in pens with white, yellow, green, blue, or red light (100 lux), and they were given free access to all of the chromatic zones through inter-compartment channels. A YOLOv8n-based deep learning framework was used to quantify their spatiotemporal distribution, activity levels, and eating behavior. The key findings were the following: (1) a significant preference for green light environments (21.29 ± 3.77% distribution proportion) (p < 0.05), peaking at 6:00–13:00 and 18:00–20:00; (2) the average activity was the highest in a white light environment (25.49 ± 0.77%), significantly exceeding yellow (22.69 ± 0.63%) and green light (21.55 ± 0.61%) (p < 0.05); and (3) the daily feed consumption under green light was the lowest, significantly lower than that under white, blue, and red light (p < 0.05). The findings from this study offer insights into the light environment preferences of gilts, which could improve animal welfare. Full article

Hepatitis E virus (HEV) is one of the pathogens that cause viral hepatitis, and its clinical symptoms can manifest as acute, chronic viral hepatitis, or asymptomatic infection. Among them, swines are the main animal source of HEV. Open reading frame 3 (ORF3) is a multifunctional protein essential for swine hepatitis E virus (SHEV) infection and release, involved in biological processes such as intracellular signal transduction regulation. In our preliminary research, we utilized adenovirus-mediated overexpression of type IV SHEV ORF3 in HepG2 cells, extracted total RNA, and performed high-throughput long non coding RNAs (lncRNAs) and transcriptome sequencing. In this study, we screened and analyzed lncRNAs involved in the GO pathway: viral process (GO: 0016032), and combined them with differentially expressed mRNAs for target gene prediction. We identified two lncRNAs—lncRNA AL137002 (MSTRG. 7478) and lncRNA AL049840 (MSTRG. 8427)—that are associated with viral progression and have p ≤ 0.05 in HepG2 cells expressing ORF3 of porcine hepatitis E virus type IV. We predicted their five lncRNA-mRNA networks, which are lncRNA AL137002 (MSTRG. 7478)-ENST0000375440, lncRNA AL137002 (MSTRG. 7478)-ENST0000375441, lncRNA AL049840(MSTRG. 8427)-ENST0000246489, lncRNA AL049840 (MSTRG. 8427)-ENST0000554280 and lncRNA AL049840 (MSTRG. 8427)-ENST0000452929, and were used to predict their lncRNA mRNA binding sites and construct relevant molecular models. This will lay a solid foundation for further revealing the function of SHEV ORF3 and elucidating the mechanism of SHEV infection. Full article

Follicular development is recognized as a highly complex biological process regulated by multiple factors. Thyroid hormone (TH) is considered one of the key regulators of female reproduction, and its dysregulation can significantly impair follicular development. Epigallocatechin gallate (EGCG), the main active component of green tea, possesses strong antioxidant properties. Numerous studies have demonstrated that EGCG positively influences reproductive function in both humans and animals. However, whether EGCG directly affects follicular development under conditions of TH dysregulation remains poorly understood. The primary objective of this study was to investigate the impact of hyperthyroidism on ovarian development, examine whether EGCG could mitigate the adverse effects of TH dysregulation, and elucidate the underlying molecular mechanisms. In the T₄-induced hyperthyroidism rat model, ovarian tissues were serially sectioned for Hematoxylin-Eosin (HE) and Masson’s trichrome staining to assess morphological changes, and follicle numbers were quantified at each developmental stage. Granulosa cell (GC) viability, proliferation, and apoptosis induced by T₃ were evaluated using CCK8, EdU, and TUNEL assays, respectively. Antioxidant enzyme activity was measured, and the expression levels of related proteins were analyzed via Western blotting. Results showed that hyperthyroidism altered ovarian structure, significantly increasing the number of atretic follicles. Levels of antioxidant enzymes, including Superoxide Dismutase (SOD), Glutathione Peroxidase (GSH-PX), and Catalase (CAT), were markedly decreased, whereas the lipid peroxidation product malondialdehyde (MDA) was significantly elevated. Furthermore, all ERS-related proteins, phosphorylated Eukaryotic Initiation Factor 2 Alpha (p-eIF2α), Activating Transcription Factor 4 (ATF4), C/EBP homologous protein (CHOP), and Caspase-3, were upregulated, accompanied by decreased glucose-regulated protein 78 (GRP78) expression. Treatment with EGCG alleviated these detrimental effects of hyperthyroidism. At the cellular level, high concentrations of T₃ reduced GC viability and proliferation while increasing apoptosis. Reactive oxygen species levels were elevated, and GRP78 expression was decreased. Notably, all T₃-induced effects were reversed by EGCG treatment. In summary, this study demonstrates that hyperthyroidism induces oxidative stress in GCs, which triggers endoplasmic reticulum stress via the eIF2α/ATF4 pathway and leads to apoptosis. EGCG mitigates apoptosis by enhancing antioxidant capacity, thereby preserving ovarian function. These findings establish EGCG as a protective agent for maintaining ovarian health and fertility. Full article

Striatum can be described as a brain region containing a general neuronal mechanism to associate actions or events with reward. In particular, neural activity in the human striatum is modulated by social actions and, critically, by the conjunction of social actions and own reward. To perform this function, dopamine and oxytocin signaling reaching the striatum represent a key factor. These neurotransmitters, in both humans and animals, are released in response to afferent vagal and sensory stimulation, as well as sexual and social interactions, conveying information related to reward and pleasure associated with an event. Dopamine and oxytocin have several effects in common, but of particular interest is evidence indicating that they can mutually modulate their action. The present review focuses on available data delineating interactions between dopaminergic and oxytocinergic signaling in the striatum. In this context, recent data on the possible role played by striatal astrocytes and microglia as key modulators of this crosstalk will be briefly discussed. Full article

Antimicrobial resistance (AMR) represents a threat to human, animal, and environmental health. This study evaluated the potential role of birds as AMR dispersers in white storks as a model species investigating dispersal between locations connected by their movements. Throughout a year, 346 samples were collected from two landfills (225 fecal samples) and two wetlands (93 fecal/28 water samples) based on satellite tracking data that confirmed continuous stork movements between foraging (landfill) and nighttime roosting (wetlands) locations. Samples were seeded in selective media with antibiotics for the isolation of antibiotic-resistant bacteria. A total of 313 isolates from 35 different bacterial species were obtained, with an AMR prevalence of 43.1% in fecal samples from landfills, 7.5% in fecal samples from wetlands, and 21.4% in water from wetlands. Multidrug resistant bacteria were only found in fecal samples (19.6% landfills/4.3% wetlands) and extended-spectrum beta-lactamase producing-bacteria were found exclusively in fecal samples from landfills with a marked presence during the fall migration period. Our study reveals marked differences in AMR prevalence and resistance phenotypes between study locations and fecal and water samples throughout the year, thus not supporting a clear role of storks as AMR dispersers. Nevertheless, similar changes in AMR phenotype prevalences during fall migration in stork faecal samples from one of the tested landfills and its paired wetland, and the significant increase in ESBL-producing Enterobacterales prevalence matching the arrival of migratory white storks in fall, underline the need for more in-depth genome-based studies to elucidate the role of white storks as dispersers or sentinels of AMR. Full article

Optical mapping, nanotechnology-based multielectrode arrays and automated patch-clamp allow transmembrane voltage mapping with high spatial resolution, as well as L-type calcium and inward rectifier currents measurements using native mammalian cardiomyocytes. However, these methods are limited to in vitro and ex vivo experiments, while magnetocardiography (MCG) might offer a novel approach for non-invasive preclinical safety assessments of new drugs in intact and even conscious rodents by reconstructing the ventricular action potential waveform (rVAPw) from MCG signals. Objective: This study aims to assess the feasibility of rVAPw reconstruction from MCG signals in Guinea pigs (GPs) and validate the results by comparison with simultaneously recorded epicardial ventricular monophasic action potentials (eVMAP). Methods: Unshielded MCG (uMCG) data of 18 GPs, investigated anaesthetized and awake at ages of 5, 14, and 26 months using a 36-channel DC-SQUID system, were analyzed to calculate rVAPw from MCG’s current arrow map. Results: Successful rVAPw reconstruction from averaged MCG showed good alignment with eVMAP waveforms. However, some rVAPw displayed incomplete or distorted repolarization at sites with lower MCG amplitude. Conclusions: 300-s uMCG averaging allowed rVAPw reconstruction in intact GPs. Occasionally distorted rVAPw suggests the need for dedicated MCG devices development, with higher density of optimized vector sensors, and modelling tailored for small animal hearts. Full article

Imbalance in fatty acid (FA) metabolism is a critical factor in the development of type 2 diabetes (T2D). This study examined fatty acid composition and desaturase activities in the liver and spinal cord of male Zucker diabetic fatty (ZDF) rats, a genetic model of T2D. Heterozygous lean ZDF fa/+ animals served as controls, while homozygous obese ZDF fa/fa animals represented the diabetic group. FA profiles were determined by gas chromatography, and the activities of Δ5-desaturase (FADS1), Δ6-desaturase (FADS2), Δ9-desaturase (SCD1), and elongase of very long-chain fatty acids (ELOVL) were estimated. T2D rats displayed significantly elevated levels of monounsaturated fatty acids (MUFAs) and increased SCD1 activity in both the liver and spinal cord. In contrast, polyunsaturated fatty acids (PUFAs), particularly arachidonic acid (AA, C20:4 n-6), were reduced. Since AA plays a fundamental role in neuronal membrane structure and signaling pathways, these alterations have particular relevance to nervous system function. Tissue-specific alterations further suggested impaired FADS1 activity in the liver and reduced elongase/FADS2 activity in the spinal cord. These findings suggest that desaturase imbalance and FA remodeling in the spinal cord might represent characteristic features of T2D and that altered FA metabolism within the nervous system may potentially serve as an early indicator of neuropathy or a predictor of increased susceptibility to diabetes-related complications. Full article

Stress can alter neurochemical signalling, affecting memory processing, but its underlying neurobiological mechanism remains unclear. Here, we investigate the effect of acute restraint stress (ARS) on long-term retention of aversive memory in rats. We exposed the animals to either handling or an ARS protocol and tested the rats in the plus-maze discriminative avoidance task (PMDAT). Also, we performed immunohistochemistry assays to unveil the effect of stress on neuronal activity. We found that ARS immediately after training does not impair memory formation but hinders retention. Training triggers a peak of C-fos 1 h later and a delayed 18 h increase in Zif268 in dorsal CA1. The same does not occur when ARS is experienced immediately after training. We demonstrated that the crucial role of Zif268 and C-fos signalling in maintaining PMDAT LTM. ARS is more relevant for memory retention than for the formation of discriminative aversive memory. Full article