Search Results (337)

(1) Background: Epidemiological studies link ozone (O₃) exposure to diabetes risk, but mechanisms and early biomarkers remain unclear. (2) Methods: Female mice exposed to 0.5/1.0 ppm O₃ were assessed for glucose tolerance and HOMA (homeostasis model assessment) index. Genes related to impaired glucose tolerance and insulin resistance were screened through the Comparative Toxicogenomics Database (CTD), and verified using quantitative real-time PCR. In addition, liver histopathological observations and the determination of basic biochemical indicators were conducted, and targeted metabolomics analysis was performed on the liver to verify glycogen levels and gene expression. In vitro validation was conducted with HepG2 and Min6 cell lines. (3) Results: Fasting blood glucose and insulin resistance were elevated following O₃ exposure. Given that the liver plays a critical role in glucose metabolism, we further investigated hepatocyte apoptosis and alterations in glycogen metabolism, including reduced glycogen levels and genetic dysregulation. Metabolomics analysis revealed abnormalities in fructose metabolism and glycogen synthesis in the livers of the O₃-exposed group. In vitro studies demonstrated that oxidative stress enhances both liver cell apoptosis and insulin resistance in pancreatic islet β cells. (4) Conclusions: O₃ triggers prediabetes symptoms via hepatic metabolic dysfunction and hepatocyte apoptosis. The identified metabolites and genes offer potential as early biomarkers and therapeutic targets. Full article

Background/Objectives: An important new consideration when studying autism spectrum disorder (ASD) is the bioenergetic mechanisms underlying the relatively recent rapid evolutionary expansion of the human brain, which pose fundamental risks for mitochondrial dysfunction and calcium signaling abnormalities and their potential role in ASD, as recently highlighted by insights from the BTBR mouse model of ASD. The rapid brain expansion taking place as Homo sapiens evolved, particularly in the parietal lobe, led to increased energy demands, making the brain vulnerable to such metabolic disruptions as are seen in ASD. Methods: Mitochondrial dysfunction in ASD is characterized by impaired oxidative phosphorylation, elevated lactate and alanine levels, carnitine deficiency, abnormal reactive oxygen species (ROS), and altered calcium homeostasis. These dysfunctions are primarily functional, rather than being due to mitochondrial DNA mutations. Calcium signaling plays a crucial role in neuronal ATP production, with disruptions in inositol 1,4,5-trisphosphate receptor (ITPR)-mediated endoplasmic reticulum (ER) calcium release being observed in ASD patient-derived cells. Results: This impaired signaling affects the ER–mitochondrial calcium axis, leading to mitochondrial energy deficiency, particularly in high-energy regions of the developing brain. The BTBR mouse model, with its unique Itpr3 gene mutation, exhibits core autism-like behaviors and metabolic syndromes, providing valuable insights into ASD pathophysiology. Conclusions: Various interventions have been tested in BTBR mice, as in ASD, but none have directly targeted the Itpr3 mutation or its calcium signaling pathway. This review presents current genetic, biochemical, and neurological findings in ASD and its model systems, highlighting the need for further research into metabolic resilience and calcium signaling as potential diagnostic and therapeutic targets for ASD. Full article

The H1N1 swine influenza viruses CQ91 and CQ445, isolated from pigs in China, exhibited distinct virulence in mice despite sharing similar genomic constellations. CQ91 demonstrated higher pathogenicity (MLD₅₀: 5.4 log₁₀ EID₅₀) and replication efficiency in mice compared to CQ445 (MLD₅₀: 6.6 log₁₀ EID₅₀). Through reverse genetics, we found that the attenuation of CQ445 was due to a single substitution of glutamic acid (E) with lysine (K) at position 343 in the PB2 protein. Introducing the CQ445-PB2 (343K) into CQ91 significantly reduced viral replication and pathogenicity in mice, while replacing CQ445-PB2 with CQ91-PB2 (343E) restored virulence. In vitro studies showed that the K343E mutation impaired viral replication in MDCK and A549 cells and reduced polymerase activity in minigenome assays. Mechanistically, the amino acid at position 343 in the PB2 affects the transcription stage of the viral replication process. Structural modeling indicated that the charge reversal caused by E343K altered local electrostatic interactions without major conformational changes. Phylogenetic analysis revealed that PB2-343E is highly conserved (>99.9%) in human and swine H1/H3 influenza viruses, suggesting that PB2-343E confers an adaptive advantage. This study identifies PB2-343E as a critical determinant of influenza virus pathogenicity in mammals, highlighting its role in host adaptation. Full article

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by restricted social communication and repetitive behaviors. Prenatal stress is critical in neurodevelopment and increases risk for ASD, particularly in those with greater genetic susceptibility to stress. Docosahexaenoic acid (DHA) is one of the most abundant ω-3 fatty acids in the membrane phospholipids of the mammalian brain, and dietary DHA plays an important role in brain development and maintenance of brain structure. In this study, we investigated whether peri-natal supplementation of DHA can alleviate autistic-like behaviors in a genetic risk/stress mouse model and how it alters lipid peroxidation activity and GABAergic system gene expression in the forebrain. Pregnant heterozygous serotonin transporter knockout (SERT-KO) and wild-type (WT) dams were placed in either non-stressed control conditions or chronic variable stress (CVS) conditions and fed either a control diet or a DHA-rich (1% by weight) diet. Offspring of each group were assessed for anxiety and autism-associated behavior at post-natal day 60 using an open field test, elevated plus maze test, repetitive behavior, and the 3-chamber social approach test. A liquid chromatography-mass spectrometry (LC-MS)-based method was used to follow changes in levels of lipid peroxidation products in the cerebral cortex. Male offspring of prenatally stressed SERT-het KO dams exhibited decreased social preference behaviors and increased repetitive grooming behaviors compared to WT control offspring. Moreover, DHA supplementation in male SERT-het mice decreased frequency of grooming behaviors albeit showing no associated effects on social behaviors. Regardless of stress conditions, supplementation of DHA to the WT mice did not result in alterations in grooming nor social interaction in the offspring. Furthermore, no apparent changes were observed in the lipid peroxidation products comparing the stressed and non-stressed brains. Gad2 was downregulated in the cortex of female offspring of prenatally stressed SERT-KO dams, and this change appeared to be rescued by DHA supplementation in offspring. Gad2 was upregulated in the striatum of male offspring of prenatally stressed SERT-KO dams, but DHA did not significantly alter the expression compared to the control diet condition. Full article

(1) Background: Vascular mural cells reside in the media and outer layers of the vessel wall. Their ability to proliferate and migrate or to change phenotype in response to external cues is a central feature of the vascular response to injury. Genetically engineered mice are used for loss- or gain-of-function analyses or lineage tracing in vivo, their primary cells for mechanistic studies in vitro. Whether and how cultivation conditions affect their phenotype and function is often overlooked. (2) Methods: Here, we systematically studied how the cultivation of primary mural cells isolated from the aorta of adult wild-type mice in either basal medium (DMEM) or special media formulated for the cultivation of fibroblasts or pericytes affects their phenotype and function. (3) Results: Medium composition did not alter cell viability, but the mRNA levels of differentiated smooth muscle cell markers were highest in vascular mural cells expanded in DMEM. Conversely, significantly higher numbers of proliferating and migrating cells were observed in cells expanded in Pericyte medium, and cytoskeletal rearrangements supported increased migratory capacities. Significantly reduced telomere lengths and metabolic reprogramming was observed in aortic mural cells cultured in Fibroblast medium. (4) Conclusions: Our findings underline the plasticity of primary aortic mural cells and highlight the importance of the culture media composition during their expansion, which could be exploited to interrogate their responsiveness to external stimuli or conditions observed in vivo or in patients. Full article

Retinal dysfunction is emerging as a potential early marker of neurodegenerative diseases. Within the retina, the dopaminergic circuit, comprising dopaminergic amacrine cells, dopamine synthesis and turnover, and dopamine receptor signalling, is essential for visual processing, particularly colour contrast perception. Disruption of this circuit may underline early retinal alterations observed in Huntington’s disease (HD) and Alzheimer’s disease (AD). In this study, we systematically analysed retinal dopaminergic dysfunction in murine models of HD (genetic origin) and AD (sporadic), across different disease stages. We assessed dopamine levels, turnover, tyrosine hydroxylase expression, D1 and D2 receptor gene expression, and neurotransmitter balance. HD mice showed early and marked alterations: reduced dopamine content, decreased tyrosine hydroxylase, increased turnover, and downregulation of D1 receptor expression—all preceding motor symptoms and detectable brain pathology. In contrast, AD mice showed only mild changes at later stages; however, clinical evidence suggests that similar dysfunction may occur earlier in human AD. These findings position retinal dopaminergic disruption as a potential early biomarker in HD and possibly in AD. While the current study relies on invasive techniques in animal models, it lays the groundwork for non-invasive retinal assessments, such as electroretinography or optical coherence tomography, as promising tools for early diagnosis and disease monitoring in neurodegeneration. Full article

Background/Objectives: Sweet taste receptor TAS1R2 is expressed in skeletal muscle, yet its role in muscle metabolism remains poorly understood. Methods: Here, we leverage the BXD recombinant inbred mouse panel and Tas1r2 whole-body knockout (bKO) models to investigate the transcriptional impact of Tas1r2 deficiency on skeletal muscle function. Results: A gene network analysis revealed significant overlap in transcriptomic signatures between BXD strains with low Tas1r2 expression (BXD L_Tas1r2) and bKO muscle, particularly in pathways regulating oxidative phosphorylation, cytoplasmic ribosome function, and proteostasis. Notably, Tas1r2 expression negatively correlated with genes involved in fatty acid metabolism, suggesting its role in lipid utilization. Under high-fat diet (HFD) conditions, BXD_HFD L_Tas1r2 mice exhibited further enrichment in pathways linked to proteasome degradation, oxidative stress, and interleukin signaling, amplifying the transcriptomic convergence with bKO models. Key transcription factors (Mlxipl, Nfic, Rxrb) exhibited altered regulatory patterns under dietary stress, indicating that TAS1R2 influences metabolic adaptability through transcriptional reprogramming. Conclusions: Given that human TAS1R2 variants rarely result in complete loss of function (LOF), the BXD panel provides an effective dose-dependent model to bridge the gap between knockout phenotypes and human SNP carriers. Our findings establish TAS1R2 as a metabolic regulator in skeletal muscle and highlight the utility of genetically diverse mouse populations in dissecting gene-diet interactions relevant to human metabolic diseases. Full article

Background: Hippocampal sclerosis (HS) is a hallmark of mesial temporal lobe epilepsy (MTLE). However, genetic studies on MTLE patients with HS (MTLE-HS) remain limited, especially in East Asian populations. This study aimed to identify genetic variants associated with MTLE-HS and elucidate their biological relevance through integrative genomic and transcriptomic analyses. Methods: We conducted a genome-wide association study (GWAS) on 157 Korean epilepsy patients, including 52 MTLE-HS subjects and 105 non-acquired focal epilepsy individuals without HS as controls. The splicing and expression quantitative trait locus (sQTL and eQTL, respectively) effects of significant variants were analyzed using GTEx datasets. Transcriptomic data from the hippocampi of MTLE-HS subjects and an epilepsy mouse model were examined to assess TMEM14A expression. Gene correlation enrichment analysis was performed to investigate potential associations with epilepsy-related phenotypes. Results: The GWAS identified rs6924849, located downstream of TMEM14A, as significantly associated with MTLE-HS. The sQTL analysis revealed that rs6924849 induces abnormal TMEM14A splicing in hippocampal tissue. Transcriptomic analyses showed reduced TMEM14A expression in MTLE-HS hippocampi, while mice with pilocarpine-induced epilepsy exhibited a transient increase in TMEM14A expression during the acute phase post-status epilepticus. Gene correlation enrichment analyses linked TMEM14A to seizure-related phenotypes in both humans and mice. Conclusions: This study identifies rs6924849 as a novel genetic variant associated with MTLE-HS in an East Asian population. The dysfunctional splicing and altered expression of TMEM14A may contribute to the neuronal loss characteristic of HS, as TMEM14A regulates apoptosis. These findings emphasize the potential role of TMEM14A in MTLE-HS pathogenesis from genomic and transcriptomic perspectives. Full article

Background/Objectives: Hyperexcitable neuronal activity associated with seizures may disrupt brain homeostasis resulting in abnormal glucose and nutrient management and metabolism. Specialized ependymal cells known as tanycytes line the third ventricle wall bridging communication between the brain, CSF, and blood. Despite their positional importance, whether tanycytes are impacted by epilepsy is unknown. Here, known protein markers of tanycytes were assessed in the Kcna1-null mouse model of genetic epilepsy with spontaneous recurrent seizures (SRS mice). Further, whether an anti-seizure metabolic ketogenic diet (KD), previously proven effective in SRS mice, restored protein levels was determined. Methods: Known tanycyte proteins, including glucose transporter 1 (GLUT1), glial fibrillary acidic protein (GFAP), and doublecortin (DCX, to determine potential neurogenic differences) were examined throughout the anterior–posterior axis of the third ventricle using immunofluorescent histochemistry. Results: Decreased GLUT1 immunoreactivity and elevated GFAP levels were found in the SRS cohorts. The number of neurogenic DCX-expressing cells did not differ. Two weeks of KD treatment reduced GFAP to WT levels. GLUT1 remained low in KD-treated SRS mice. Conclusions: These data suggest that the expression of proteins important for the structure and function of tanycytes is altered in preclinical epilepsy and is differentially restored with KD treatment. Whether tanycytes actively participate in the pathophysiology of epilepsy or associated comorbidities is an intriguing possibility given their integral role in brain homeostasis. Full article

Background/objective: Mucinous borderline tumors of the ovary (MBOTs) are characterized by their unique histological features and intermediate malignant potential; however, the factors underlying their molecular carcinogenesis and tumor biology remain largely unknown. Developing cell lines from these tumors presents an ongoing challenge. The purpose of this study is to establish MBOT cell lines and characterize their biological features. Methods: Epithelial cells were collected and purified from surgically removed MBOT samples and then stably maintained with an extended life span by overexpressing CyclinD1/CDK4 in combination with human telomerase reverse transcriptase. The characterization of resulting cell lines was defined by morphology, growth kinetics, functional analysis, whole-exome sequencing, and tumorigenicity in mice. Results: Two independent cell lines, HMucBOT-1 and HMucBOT-2, were successfully established from the tissues of a patient with an MBOT, with the latter showing more aggressive growth capacity. In the patient-derived xenograft model, HMucBOT-1 cells retained the original morphological characteristics of the MBOT, whereas HMucBOT-2 cells displayed a transition to mucinous carcinoma accompanying undifferentiated carcinoma, suggestive of dedifferentiated carcinoma. Genetic analysis of the original tumor sample and HMucBOT-2 cells revealed shared oncogenic mutations. However, KRAS amplification and certain copy number alterations were uniquely observed in the HMucBOT-2 cells. Conclusions: The above results indicate that HMucBOT-1 can serve as a preclinical model for investigating the biological behavior of and potential targeted therapies for human MBOTs, with HMucBOT-2 serving as a valuable tool for studying the heterogeneity and genetic diversity of this tumor and explaining the potential causes of treatment failure or relapse. Full article

Chronic inflammation plays a central role in the pathogenesis of lung diseases including asthma, long COVID, chronic obstructive pulmonary disease (COPD), and lung cancer. Lipopolysaccharide (LPS) is a potent inflammatory agent produced by Gram-negative bacteria and also found in cigarette smoke. Our earlier study revealed that the intranasal exposure of A/J mice to LPS for 7 days altered gene expression levels in alveolar Type II epithelial cells (AECIIs), which serve as precursors to lung adenocarcinoma and are also preferentially targeted by SARS-CoV-2. In the present work, we employed a comprehensive multi-omics approach to characterize changes in DNA methylation/hydroxymethylation, gene expression, and global protein abundances in the AECIIs of A/J mice following the sub-chronic exposure to LPS and after a 4-week recovery period. Exposure to LPS led to hypermethylation at regulatory elements within the genome such as enhancer regions and expression changes in genes known to play a role in lung cancer tumorigenesis. Changes in protein abundance were consistent with an inflammatory phenotype and also included tumor suppressor proteins. Integration of the multi-omics data resulted in a model where LPS-driven inflammation in AECIIs triggers epigenetic changes that, along with genetic mutations, may contribute to lung cancer development. Full article

Salmonella enterica serovar Typhi (S. Typhi) produces outer membrane vesicles (OMVs) that remain comparatively underexplored as potential biotechnological tools. Here, we investigated how hypervesiculating S. Typhi mutants (ΔtolR and ΔdegS) can be engineered to load and deliver the fluorescent reporter protein mCherry, targeting human epithelial cells and the murine immune system. Deletions in tolR and degS led to distinct OMV phenotypes characterized by higher vesicle production and altered cargo composition, underscoring the impact of disrupted membrane integrity and envelope stress on OMV biogenesis. By fusing mCherry with the S. Typhi OmpA signal peptide (SP_ompA), we achieved robust and functionally intact intravesicular packaging in all strains. Flow cytometry and confocal microscopy revealed that the ΔtolR mutant exhibited particularly high cargo loading in the OMV fraction and pronounced mCherry delivery to epithelial cells, highlighting the potential of hypervesiculation to enhance OMV-based protein transport. However, immunization studies in mice showed that wild-type OMVs, despite carrying less mCherry than their hypervesiculating counterparts, induced the strongest anti-mCherry IgG responses. These findings indicate that, at least under these conditions, antigen loading alone is not sufficient to fully determine immunogenicity. Instead, the intrinsic composition or adjuvant-like properties of OMVs play a pivotal role in driving robust immune activation. Our results establish S. Typhi OMVs, especially when genetically modified with a Sec-dependent targeting signal (SP_ompA), as versatile platforms for heterologous protein delivery. Although hypervesiculation facilitates increased protein encapsulation and delivery to epithelial cells, native OMVs appear to better preserve and/or present antigens for effective immunogenic responses in vivo. These insights set the stage for further optimization of S. Typhi OMVs in vaccine development and protein therapeutics, where balancing cargo loading with immunostimulatory features may be key to achieving maximal efficacy. Full article

Spinocerebellar ataxia (SCA), an autosomal dominant neurodegenerative condition, is marked by a gradual deterioration of cerebellar function. To date, more than 40 distinct SCA subtypes have been identified, with some attributed to CAG repeat expansions and others to point mutations or deletions. Among these, spinocerebellar ataxia type 14 (SCA14) stems from missense mutations or deletions within the PRKCG gene, encoding protein kinase C gamma (PKCγ), a pivotal signaling molecule abundant in Purkinje cells. Despite its significance, the precise mechanisms underlying how genetic alterations trigger Purkinje cell malfunction and degeneration remain elusive. Given the prominent role and high expression of PKCγ in Purkinje cells, SCA14 presents a unique opportunity to unravel the underlying pathogenesis. A straightforward hypothesis posits that alterations in the biological activity of PKCγ underlie the disease phenotype, and there are hints that mutated PKCγ proteins exhibit altered enzymatic function. Our prior research focused on the PKCγ-G118D mutation, commonly found in SCA14 patients, located in the regulatory domain of the protein. While cellular assays demonstrated enhanced enzymatic activity for PKCγ-G118D, transgenic mice carrying this mutation failed to exhibit suppressed dendritic development in cerebellar cultures, raising questions about its impact within living Purkinje cells. One hypothesis is that endogenous PKCγ might interfere with the expression or effect of PKCγ-G118D. To further investigate, we leveraged CRISPR-Cas9 technology to generate a PKCγ knockout mouse model and integrated it with an L7-based, Purkinje cell-specific transfection system to analyze the effects of G118D protein expression on the dendritic morphology of developing Purkinje cells. Our findings reveal that, utilizing this approach, PKCγ-G118D exerts a detrimental effect on Purkinje cell growth, confirming its negative influence, indicating that the potential of the G118D mutation to contribute to SCA14 pathogenesis. Full article

Choroideremia is a rare X-linked recessive retinal disorder characterized by progressive vision loss caused by retinal degeneration resulting from mutations in the CHM gene, which encodes Rab escort protein 1 (REP-1). In humans and mice, the Rab escort protein (REP) family consists of two members, REP-1 and REP-2, with REP-2 hypothesized to compensate for REP-1 deficiency in tissues outside the eye in choroideremia. In this study, we conducted a systematic mutational analysis of the mouse orthologs of REP-1 and REP-2. Blood analyses revealed metabolic abnormalities in the mutant mice deficient for REP-1, resembling the systemic metabolic disturbances observed in individuals with choroideremia, such as altered lipid and hemoglobin metabolism. We also observed an elevation in systemic inflammatory biomarkers in these mutant mice. Interestingly, these systemic abnormalities emerged before retinal degeneration became detectable in REP-1-deficient mice. Transcriptomic analysis of retinas isolated from REP-1 deficient mice revealed enrichment of proinflammatory signaling pathways. These results suggest important similarities between choroideremia and some forms of retinitis pigmentosa. While engineered loss of REP-2 alone caused no detectable phenotypic changes, dual deficiency in REP-1 and REP-2 resulted in lethality under both in vivo and in vitro conditions. Our findings offer novel insights into REPs and deepen our understanding of choroideremia, which may contribute to the development of new treatments for this genetic condition. Full article

Inflammatory bowel disease (IBD) is a chronic disease influenced by a complex interplay of factors, including genetics, environmental, and gut microbiota. This study aimed to explore the therapeutic potential of the natural polyphenolic compound hydroxytyrosol (HT) in modulating dextran sodium sulfate (DSS)-induced colitis in mice. The findings demonstrate that oral administration of HT significantly alleviated colitis symptoms, as evidenced by a reduction in the disease activity index and improvements in colonic pathology. HT was found to inhibit the release of pro-inflammatory cytokines, enhance antioxidant status, and mitigate oxidative stress. Furthermore, HT contributed to the restoration of the gut barrier by reinstating tight junction proteins, reducing the inflammatory marker lipopolysaccharide (LPS), and suppressing inflammation-related genes. This compound also modulated the NLRP3-Cas-1-GSDMD-IL-1β inflammatory pathway and inhibited the NF-κB (nuclear factor kappa B) pathway, thereby alleviating colitis. Gut microbial analysis revealed that HT enriched the abundance of Bacteroidota and altered the balance between Bacteroidota and Firmicutes in mice. Correlation analysis between bacterial microbiota and inflammatory factors suggested that HT may alleviate colitis by modulating the relative abundance of Alistipes, Bacteroides, and unclassified_f__Muribaculaceae. These findings underscore the potential of HT as a therapeutic agent in the treatment of colitis. Full article