Search Results (3,505)

Chikungunya virus (CHIKV) infection presents a wide spectrum of clinical outcomes, ranging from mild self-limiting disease to severe and fatal manifestations, which are influenced by both host and viral factors. Animal models are essential for elucidating CHIKV pathogenesis and for preclinical evaluation of antiviral strategies; however, a well-characterized model evaluating the effect of different viral doses in AG129 mice remains limited. In this study, we investigated the clinical, virological, and pathological outcomes of CHIKV infection in male AG129 mice inoculated intraperitoneally with different viral doses (10, 100, and 1000 PFU/mL) of a Brazilian strain belonging to the East/Central/South African (ECSA) lineage. Lower-dose inoculation (10 PFU/mL) resulted in a milder disease course, characterized by transient viremia, limited tissue viral dissemination, minimal histopathological alterations, partial survival, and viral clearance. In contrast, higher doses (≥100 PFU/mL) led to rapid systemic viral dissemination, severe histopathological damage in the spleen, liver, and kidneys, and uniform lethality. Viral RNA was detected in serum and multiple organs in a time-dependent manner, with limited differences among inoculum doses in most tissues. Notably, dose-related differences were observed in specific compartments and time points, particularly in hind-limb muscles at early time points and in serum at later stages. Full article

The purpose of this project was to define gene expression changes associated with the acquisition and loss of resilience to diabetic retinopathy (RDR) in individual retinal cell types. A non-immune form of type 1 diabetes mellitus (DM) was induced by injecting male C57Bl6J mice with streptozotocin. Single-cell RNA sequencing was performed on retinas from mice that experienced DM for 5 or 15 days, along with retinas from age-matched, non-DM mice. The resulting data sets were analyzed to identify DM-associated differentially expressed genes and pathway enrichments after each duration of DM. We observed that acquisition of RDR, previously shown to arise after 5 days of DM was linked to altered expression of genes in a subset of retinal cells, mainly Müller cells. Pathway analysis indicated enhancement of numerous modes of protection, including reinforced neurovascular and structural homeostasis through phagocytosis, integrin signaling, and interferon-mediated defense. After 15 days of DM, when we previously showed that RDR is waning this pro-protection surge in gene expression subsided. We conclude that a duration of DM that is too short to cause diabetic retinopathy (DR) nonetheless evoked a profound change in the gene expression profile within a subset of retinal cell types. The nature and timing of this molecular shift indicated that it was not the preamble to DM-related damage that eventually develops. Rather, DM engaged numerous defense programs within Müller cells. The temporal alignment between RDR and activation of Müller cell-based defense provides a molecular foundation for the retina’s transient ability to remain healthy in the face of DM. Full article

Purpose: To determine which age of mice should be used to compare the effects of ADAM8 mutation on intervertebral disc (IVD) responses to injury. Methods: IVDs of ADAM8 mutant (Adam8^EQ) and wild type (WT) mice, aged 3, 10 and 18 months were injured. IVD tissues were harvested 1 week post injury for histological and molecular studies. Results: Histological scores increased with aging in intact IVDs, and there were no differences between Adam8^EQ and WT mice (n = 11–28; p > 0.05). Safranin O-staining was less intense in 10-month than in 3-month-old mice, in both intact and injured IVDs (n = 3–15; p < 0.05). Cxcl1, Il6, and Adam8 gene expression levels were higher in the injured tail IVDs of 3-month-old Adam8^EQ than WT mice (n = 18–30; p < 0.05); the injury-related differences diminished with increasing age. Conclusions: No histological differences were found between Adam8^EQ and WT mouse IVDs at 3, 10 or 18 months of age, in the intact or injured discs. The differences in inflammatory marker gene expression were detectable at age 3 months, but were less evident when the injury occurred at age 10 or 18 months. Therefore, to identify differences in injury responses between WT and Adam8^EQ mouse IVDs, 3-month-old mice are superior to older mice. Full article

Introduction: Pathogenic mutations in leucine-rich repeat protein kinase-2 (LRRK2), particularly G2019S, constitute the most common cause of autosomal dominant PD. Methods: Mouse models encoding human mutant alpha-synuclein (SNCA A53T) and LRRK2 G2019S were treated with a brain-penetrant kinase inhibitor (BK40196). Behavior, nigrostriatal and mesolimbic dopamine (DA) pathways were examined. Results: Mice harboring LRRK2 G2019S do not show age-dependent motor symptoms, but mice encoding SNCA A53T display motor deficits, while both strains exhibit anxiety-like behavior and BK40196 improves motor and behavioral defects. BK40196, a multi-kinase inhibitor of Abelson (Abl), Discoidin domain receptor (DDR)-1, c-KIT and FYN, alters microglial morphology and alpha-synuclein levels in SNCA A53T mice and improves DA neurotransmission, primarily via the nigrostriatal system. BK40196 inhibits brain LRRK2 G2019S (IC₅₀ of 89nM) and does not affect phosphorylated or total peripheral LRRK2 levels (lungs, kidneys, liver, etc.). LRRK2 G2019S mice treated with BK40196 exhibit distinct increases in DA in mesolimbic neurons such as the nucleus accumbens (NAcc), suggesting differential mechanisms of DA neurotransmission in mutant alpha-synuclein and LRRK2 models of PD. Conclusions: LRRK2 G2019S may primarily involve mesolimbic pathways leading to nonmotor symptoms independent of the motor and behavioral manifestations associated with alpha-synuclein via the nigrostriatal system. BK40196 may provide a comprehensive and synergistic therapeutic approach that addresses multiple mechanisms to reduce the pathologies related to LRRK2 G2019S and/or SNCA in PD. The multiple pathologies of PD necessitate a holistic approach that simultaneously targets inflammation and autophagy and LRRK2 inhibition. Full article

Peripheral nerve injury is a leading cause of disability, which can result in partial or complete loss of motor, sensory, and autonomic function, and currently, there is no effective treatment for this incapacitating condition. It is important to identify new compounds that enable rapid and complete functional recovery. This study evaluated the effects of isorhamnetin (ISO) on functional rehabilitation in a mouse model of sciatic nerve injury. A total of 30 BALB/c mice, aged 8–10 weeks, were randomly assigned to three groups: sham, control, and treatment (n = 10/group). The mice in the ISO and Ctrl groups were operated on, whilst the animals in the sham group had their sciatic nerves exposed but left intact without crushing. The Ctrl and Sham groups received DMSO and normal saline intraperitoneally in equal volumes. In contrast, the ISO-treated group received ISO (10 mg/kg) dissolved in DMSO intraperitoneally from the day of nerve crush until the end of the study. All groups were fed regular chow and provided with sufficient water throughout the experiment. Behavioural analyses evaluated sensorimotor function recovery. Biochemical and haematological assays quantified oxidative stress markers and total blood count, while morphometric analysis determined structural recovery of muscle fibers. Nerve regeneration was indirectly evaluated by analyzing S100β protein levels and proinflammatory cytokines (IL-6 and TNF-α) expression. In the mouse model, ISO treatment resulted in substantial improvement in sensorimotor function recovery (p < 0.001). A substantial difference (p < 0.001) in blood glucose levels and oxidative stress markers was observed among all groups. The treated group displayed a remarkable improvement in the cross-sectional area of muscle fibers. At the end of the study, it was noted that ISO treatment significantly downregulated the expression of S100β, TNF-α, and IL-6, suggesting a positive impact of ISO on nerve regeneration. These findings indicate that ISO expedites the restoration of sensorimotor function following sciatic nerve injury by modulating S100β and proinflammatory cytokine expression and improving oxidative stress. Full article

Alzheimer’s disease (AD) is the most prevalent form of dementia and is characterized by abnormal aggregation of β-amyloid (Aβ) peptides, tau proteins, and neuroinflammation in the central nervous system (CNS). While most AD research has focused on the brain, the molecular pathology of the spinal cord remains poorly understood. In this study, we investigated amyloid pathology, neurodegeneration, neuroinflammation, and cholesterol metabolism across distinct regions of the spinal cord and examined sex-specific differences using a model of AD, 5xFAD mice. Our data reveal that Aβ accumulation was restricted to the cervical spinal cord at 3 months but was evident in all areas of the spinal cord by 9 months, with similar patterns in both female and male animals. Despite this early and progressive Aβ deposition, no significant neuronal loss was observed in the ventral horn of the cervical spinal cord in either sex at 3 or 9 months of age. In contrast, there was a significant positive correlation between Aβ deposition and Iba1+ cell density in the spinal cord of 5xFAD mice. The number of Iba1+ cells in both the grey and white matter was significantly increased in female and male 5xFAD mice compared with age-matched wild-type (WT) littermates at 9 months of age. Astrocytic responses, however, were sex-specific: female, but not male, 5xFAD mice exhibited a significant increase in GFAP+ astrocytes in the grey matter of the thoracic and lumber spinal cord at 9 months compared with 3 months and relative to age-matched WT controls in the cervical and thoracic spinal cord. Furthermore, GFAP+ area in the thoracic spinal cord was significantly higher in female 9-month-old 5xFAD mice compared with their male counterparts, indicating a female-specific astrocytic response in AD spinal cord pathology. Our data also show an increase in free cholesterol (Filipin+ area) in 5xFAD mice at 9 months relative to WT controls, accompanied by altered expression of cholesterol metabolism genes, including downregulation of Abca1, Cyp46a1 and Cyp27a1. Collectively, these findings provide new insights into AD progression in the spinal cord, highlighting molecular pathology of AD extending beyond the brain. Full article

Vaccinium bracteatum Thunb. leaves (VBTL), a traditional medicinal plant historically consumed as food in certain regions of China, have been documented to possess potent in vitro antioxidant activity. However, its in vivo anti-aging effects and underlying mechanisms remain to be fully elucidated. Therefore, this study aimed to evaluate its anti-aging efficacy to support its potential value as a functional food constituent for healthy aging. Anti-aging efficacy was systematically assessed using D-galactose-induced aging mice, a Caenorhabditis elegans model, and an H₂O₂-induced cellular senescence model. Key active constituents were identified via untargeted metabolomics. In D-galactose-induced aging mice, VBTL extracts effectively ameliorated oxidative stress, significantly increasing the activities of endogenous antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT), while reducing malondialdehyde (MDA) levels. In Caenorhabditis elegans, VBTL extended lifespan, reduced lipofuscin accumulation, and demonstrated no reproductive toxicity. Untargeted metabolomics identified xanthotoxol as a key active constituent, which was then selected for mechanistic investigation. In a cellular senescence model, xanthotoxol alleviated H₂O₂-induced oxidative stress, significantly enhanced SOD activity, reduced reactive oxygen species (ROS) and MDA levels, inhibited senescence-associated β-galactosidase (SA-β-gal) activity and the expression of senescence-associated secretory phenotype (SASP) factors (IL-6, MMP1, MMP3), and downregulated the expression of genes in the P53/P21/P16 signaling pathway. Mechanistically, xanthotoxol activated the Nrf2 signaling pathway, promoting the expression of its downstream targets heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase 1 (NQO1). This study demonstrates that VBTL and its active compound xanthotoxol exert anti-aging effects across multiple models by modulating the Nrf2 pathway, providing both theoretical and experimental foundations for developing VBTL as a novel, safe, and effective natural ingredient in anti-aging functional foods. Full article

Background: Postoperative neurocognitive disorders (PND) are frequent complications in the elderly surgical patients, with aging recognized as a major risk factor. This study aimed to identify electrophysiological markers and establish an exploratory machine learning framework for PND-related vulnerability prediction using anesthetic electroencephalography (EEG) features in aged mice. Methods: Young and aged mice underwent laparotomy under isoflurane anesthesia with EEG recording. Neurocognitive performance was quantified by 16 standardized behavioral fractions. A semi-supervised K-means algorithm, anchored on young-surgery mice, stratified aged-surgery mice into PND and non-PND clusters. EEG dynamics during anesthesia maintenance and emergence were analyzed, and machine learning models were trained to predict PND from EEG features. Results: At baseline, neurocognitive function was comparable across groups. After anesthesia/surgery, aged mice exhibited selective spatial and contextual memory impairments, with two-thirds classified as PND. During emergence, PND mice displayed elevated δ power and reduced α and β ratios. A Multi-layer Perceptron classifier showed discriminatory performance for PND classification in one evaluation setting (AUC = 0.94). Conclusions: This study identifies emergence-related EEG features associated with postoperative neurocognitive vulnerability in aged mice and provides an exploratory machine learning framework for preclinical risk stratification. These findings support further mechanistic investigation and warrant future validation in human perioperative EEG datasets. Full article

Spinocerebellar Ataxia type 2 (SCA2) and Amyotrophic Lateral Sclerosis type 13 (ALS13) are triggered by polyglutamine expansion in Ataxin-2 (ATXN2). To understand these neurodegenerative disorders at the molecular level, the brains of 10-month-old Atxn2-CAG100-knockin mice were analyzed as microglial, astroglial and neuronal fractions via global RNA sequencing. Data were validated by comparison with the spinal cord oligonucleotide microarray profile or filtered by RNA-seq consistency. Here, we show that the mutation causes a massive inflammatory response in microglia and a reciprocal loss of neuronal transcripts in glial fractions, suggesting severe synapse loss. Beyond these general neurodegenerative signs, we identify pathognomonic changes in the machinery for protein translation and RNA splicing. Glial fractions showed upregulation of Gpnmb (to 2082%), Cst7, Clec7a, Axl, Csf1, Lgals3, Lgals3bp, Slc11a1, and Usp18 as an unspecific neuroinflammatory signature, versus downregulation of axonal Nefh (to <19%), and synaptic Scn4b, Camk2b, Rab15, and Grin1 mRNAs correlating with circuit disconnection. In all fractions, reductions in Kif5a, Rph3a, and Cplx1 were noted versus disease-specific inductions of ribosomal subunits, presumably mirroring the partial loss-of-function of ATXN2 as RNA translation modulator. Selective accumulations of embryonic factors Rnu1b2 and Eef1a1 versus downregulation of adult Eef1a2 specify the mutation impact on splicing and translation elongation. As a potential underpinning of toxic gain-of-function, the proteostasis transcript Rnf213 appeared increased in astroglial and microglial fractions. These transcriptome data suggest altered ribosomal and spliceosome machinery, with massive microgliosis versus mild astrogliosis, at the core of SCA2 and ALS13. Full article

Type 1 diabetes (T1D) is an autoimmune disease characterized by T-cell-mediated destruction of pancreatic β-cells. Antigen-specific peptide immunotherapy represents a promising strategy to restore immune tolerance. Reliable identification of relevant T-cell epitopes requires accurate prediction of peptide binding to disease-associated major histocompatibility complex (MHC) molecules. In this study, we developed and validated artificial intelligence (AI)-driven machine learning (ML) predictive models for peptides binding to the NOD mouse-specific MHC class I molecules H-2D^b and H-2K^d and the class II molecule I-A^g7. Balanced datasets of experimentally validated binders and non-binders were compiled, divided into training and test sets, and used to construct position-specific logo models and supervised ML classifiers based on z-scale physicochemical descriptors. External validation demonstrated moderate predictive performance for the logo models (ROC AUC 0.685–0.738), whereas AI models, including Random Forest, Support Vector Machine, and Gradient Boosting, achieved substantially improved discrimination (ROC AUC 0.888–0.906). The validated models were applied to the major T1D autoantigens glutamic acid decarboxylase 65, insulin-1, insulin-2 and zinc transporter 8 and predicted multiple binders, with some overlapping with previously reported immunodominant regions. Selected binders were prioritized for further synthesis and in vivo immunogenicity testing in NOD mice. Full article

Parkinson’s disease (PD) is a common neurodegenerative disorder marked by progressive loss of dopaminergic neurons in the substantia nigra pars compacta and the accumulation of Lewy bodies, intracellular inclusions enriched in α-synuclein. Synphilin-1 interacts with α-synuclein, localizes to Lewy bodies, and has been implicated in inclusion formation and neuroprotection in cellular and animal models; however, its physiological function in vivo remains poorly defined. Here, we generated and characterized a synphilin-1 knockout (Sph-1 KO) mouse by targeted genetic deletion of the Sph-1 locus and performed a comprehensive phenotyping battery including behavioral testing as well as biochemical, histological, structural, and ultrastructural analyses. Sph-1 KO mice survived to nearly two years of age and showed normal body weight, lifespan, motor performance, learning and memory, anxiety-like behavior, attention, and gross brain morphology. Western blot analyses indicated that levels of α-synuclein and synaptic proteins were largely unchanged. While outer mitochondrial membrane proteins were unaffected, the mitochondrial matrix protein HSP60 was reduced, consistent with altered mitochondrial proteostasis in the absence of synphilin-1. Strikingly, histochemical analyses, magnetic resonance imaging, and electron microscopy revealed early-onset hydrocephalus in Sph-1 KO mice associated with severe loss and disorganization of motile ependymal cilia in the ventricular lining, a cell type that normally expresses high levels of synphilin-1. Ultrastructural and immunohistochemical analyses revealed disrupted ependymal architecture, mislocalization of acetylated α-tubulin to the cytoplasm, cellular swelling, and enlarged, aberrant mitochondria, whereas cortical neurons appeared largely structurally unaffected. Together, these findings identify synphilin-1 as a key regulator of microtubule organization and cytoskeletal/organelle homeostasis in ependymal cells, required to maintain motile ciliogenesis, cerebrospinal fluid flow, and ventricular integrity. This unexpected role for synphilin-1 in ciliated brain epithelia, along with a reduction in the critical mitochondrial chaperone HSP60, broadens our understanding of synphilin-1 biology and provides a new framework for its potential relevance to PD-associated pathology. Full article

Bone marrow-derived mesenchymal stem cells (BMSCs), owing to their osteoblastogenic differentiation potential, are crucial for maintaining bone homeostasis and remodeling. Nevertheless, in aging and age-related bone diseases like osteoporosis, BMSCs show significantly diminished osteogenic potential, with a concomitant increase in adipogenic differentiation. The aged BMSCs also become desensitized to BMP2 stimulation to a large extent and exhibit aberrations in BMP2 signaling. However, the molecular mechanisms facilitating this shift in lineage commitment and mediating the cellular dysfunctions remain elusive. This knowledge gap hinders the development of regenerative strategies for skeletal aging and osteoporosis. This study employed an integrative tandem mass tag (TMT)-based phosphoproteomic and total proteomic profiling on BMSCs isolated from young (6-month) and aged (15-month) C57BL/6 (B6) mice to elucidate global alterations in both protein activity and expression. The analysis identified more than 500 proteins that underwent significant alterations (BH-adjusted p-value <0.05) either in phosphorylation or expression between young and aged BMSCs. Many lineage-specific markers also underwent changes in both phosphorylation and expression with aging. Additionally, key biological processes, including cellular metabolism, clathrin-mediated endocytosis, and nucleocytoplasmic transport mechanisms, were enriched for the deregulated proteins. Signaling proteins, ERK-1/2, had increased activating phosphorylation in the aged BMSCs, while transcription factors Lrrfip1, Ruvbl1, and Ruvbl2 also exhibited dysregulated activity and abundance in the aged BMSCs. The findings from the study adds significant mechanistic insights into how aging disrupts signal transduction, metabolism, and transcriptional program in BMSCs, contributing to age-associated loss of bone mass and reduced skeletal regenerative capabilities. Through the identification of key mediators of BMSC dysfunction seen in aging, this work offers a strong foundation in devising potential therapeutic strategies to restore diminished osteogenic potential and treat osteoporosis. Full article

Background/Objectives: Previous research demonstrates higher sodium retention with increasing levels of dietary salt in some populations. Our objective was to determine whole-body sodium retention and sodium distribution on high and low salt diets using rodent models. Methods: Whole body retention of orally dosed Na-22, a gamma emitter, was measured in female growing and adult Sprague-Dawley rats on high (3.1% by wt. of diet) and low salt (0.13% by wt. of diet) diets. In a second study, whole-body sodium retention was compared between destructive inductively coupled plasma optical emission spectroscopy (ICP-OES) and neutron activation analysis (NAA) in adult male and female C57BL/6 mice. Results: Whole body retention of Na-22 was not different due to the age of rats on a high salt diet, but rats fed the high salt diet excreted Na-22 much more rapidly than rats fed a low salt diet. In mice, neither sodium retention nor tissue distribution was affected by dietary salt. Bland–Altman analysis indicated overall agreement between NAA and ICP-OES measurements, with observed systematic positive bias. Conclusions: Dietary salt had little effect on retention in normotensive rodents and should be studied in hypertensive models. Full article

Chronic exposure to artificial light at night (ALAN) is increasingly recognized as an environmental risk factor that disrupts circadian regulation of endocrine and metabolic systems. In this study, we investigated the effects of extreme ALAN on oxidative stress and gut microbiota composition in mice using two complementary experiments. In Experiment 1, adult female mice were maintained under either as a standard 12 h light/12 h dark cycle (12 h group) or continuous 24 h light exposure (24 h group) throughout pregnancy and lactation. In Experiment 2, the offspring from the 12 h group were maintained under the same photoperiod, whereas offspring from the 24 h group were divided into a 12 h light/12 h dark group or a continuous 24 h light group, with treatments initiated on postnatal day 19 and continued until 2 months of age. For all 12 h groups, light exposure occurred from 8:00 to 20:00. Compared with dams in the 12 h group, dams exposed to continuous light exhibited significantly increased catalase activity, while their offspring maintained under the 12 h photoperiod showed elevated glutathione levels. No significant changes were detected in immune organ indices. These results suggest that extreme ALAN modulates antioxidant defenses, potentially reflecting adaptive responses to oxidative stress. Moreover, offspring exposed early to extreme ALAN showed significantly reduced gut microbial α-diversity, accompanied by decreased abundances of Firmicutes, Bacteroidota, Campylobacterota, and Desulfobacterota, and an increase in Proteobacteria. Notably, Verrucomicrobiota and Akkermansia failed to recover following photoperiod normalization, indicating persistent microbiota dysbiosis. Overall, these findings demonstrate that extreme ALAN induces oxidative stress and long-lasting alterations in gut microbiota composition, highlighting potential health risks associated with night-time light pollution. Full article

Cold exposure is an unavoidable stressor in cold regions, leading to growth retardation, oxidative damage, and endocrine disruption. This study investigated changes in blood parameters and antioxidant function in the brown adipose tissue (BAT) of mice exposed to cold. Sixteen naturally mated female mice (aged 70 days) were selected and divided into a control group (CON, n = 8, 25 ± 1 °C) and a cold exposure group (CE, n = 8, 4 ± 1 °C). Each pregnant female gave birth to approximately 12 pups, and the litter (dams and pups co-housed) served as the independent experimental unit, with both euthanized for sampling when the pups reached 20 days of age. Results showed that cold exposure increased ADFI and ADG but decreased the feed conversion rate (FCR) in lactating mice. It also decreased platelet count (PLT) and mean corpuscular hemoglobin concentration (MCHC), elevated lactate dehydrogenase (LDH) activity, and decreased TG and non-esterified fatty acid (NEFA) levels. Hormonal changes included increased adrenocorticotropic hormone (ACTH), apelin 12 (AP12), INS, NE, decreased cortisol (COR), LEP, and thyroid-stimulating hormone (TSH). In pups, cold exposure inhibited growth, reduced PLT, plateletcrit (PCT), red blood cells (RBC), and hemoglobin (HGB), altered lipid profiles, and induced hormonal shifts. Notably, cold exposure enhanced the BAT antioxidant capacity in pups, increasing the total antioxidant capacity (T-AOC) and antioxidant enzyme activities, as supported by gene expression. These findings suggest that, despite growth suppression, mice maintain homeostasis by modulating blood parameters and enhancing BAT antioxidant function to mitigate cold-induced damage. Full article