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At least 19 recordsLinked to original sources

PubMed2025

Investigating the genomic landscape of mouse models of breast cancer metastasis.

Metastasis remains a major cause of cancer mortality. AbstractThis study, expanding upon previous findings in the MMTV-PyMT model, investigated four independent mouse models, representing luminal (MMTV-PyMT, MMTV-Myc), HER2-amplified (MMTV-Her2) and triple negative (C3(1)TAg) breast cancer subtypes. Consistent with previous results, limited evidence for metastasis-associated somatic point mutations was found for all models. We also found that oncogenic drivers significantly influenced the number and size of metastasis-specific copy number variations (MSCNVs), but common driver-independent MSCNVs were rare. Furthermore, analyzing a cohort with varying genetic backgrounds while maintaining a constant oncogenic driver (PyMT) revealed that genetic background profoundly impacts MSCNVs. Transcriptome analysis demonstrated that oncogenic drivers strongly shaped metastasis-specific gene expression (MSGE), with each driver exhibiting distinct expression profiles. In contrast, MSGE in the PyMT-F1 cohort was more variable across strains. Despite the diversity of MSCNV and MSGE, functional analysis revealed that both mechanisms converge on the modulation of key cellular processes, including immune responses, metabolism, and extracellular matrix interactions. These findings emphasize the complex interplay between oncogenic drivers and genetic background in shaping the genomic and transcriptional landscapes of metastatic lesions.

Journal Article↗

PubMed2025

Inhaled xenon modulates microglia and ameliorates disease in mouse models of amyloidosis and tauopathy.

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder. Antiamyloid antibody treatments modestly slow disease progression in mild dementia due to AD. Emerging evidence shows that homeostatic dysregulation of the brain immune system, especially that orchestrated by microglia, plays an important role in disease onset and progression. Thus, a major question is how to modulate the phenotype and function of microglia to treat AD. Xenon (Xe) gas is a noble gas used in human patients as an anesthetic and a neuroprotectant used for treating brain injuries. Xe penetrates the blood-brain barrier, which could make it an effective therapeutic. To assess the effect of Xe on microglia and AD pathology, we designed a custom Xe inhalation chamber and treated several mouse models of AD with Xe gas. Xe treatment induced mouse microglia to adopt an intermediate activation state that we have termed pre-neurodegenerative microglia (pre-MGnD). This microglial phenotypic transition was observed in mouse models of acute neurodegeneration and amyloidosis (APP/PS1 and 5xFAD mice) and tauopathy (P301S mice). This microglial state enhanced amyloid plaque compaction and reduced dystrophic neurites in the APP/PS1 and 5xFAD mouse models. Moreover, Xe inhalation reduced brain atrophy and neuroinflammation and improved nest-building behavior in P301S mice. Mechanistically, Xe inhalation induced homeostatic brain microglia toward a pre-MGnD state through IFN-γ signaling that maintained the microglial phagocytic response in APP/PS1 and 5xFAD mice while suppressing the microglial proinflammatory phenotype in P301S mice. These results support the translation of Xe inhalation as an approach for treating AD.

Animals↗

PubMed2024

Intrahepatic Exhausted Antiviral Immunity in an Immunocompetent Mouse Model of Chronic Hepatitis B.

BACKGROUND & AIMS: Targeting exhausted immune systems would be a promising therapeutic strategy to achieve a functional cure for HBV infection in patients with chronic hepatitis B (CHB). However, animal models recapitulating the immunokinetics of CHB are very limited. We aimed to develop an immunocompetent mouse model of CHB for intrahepatic immune profiling. METHODS: CHB mice were created by intrahepatic delivery of the Sleeping Beauty transposon vector tandemly expressing the hepatitis B virus (HBV) genome and fumarylacetoacetate hydrolase (FAH) cDNA into C57BL/6J congenic FAH knockout mice via hydrodynamic tail vein injection. We profiled the viral and intrahepatic immune kinetics in CHB mice with or without treatment with recombinant IFNα or the hepatotropic Toll-like receptor 7 agonist SA-5 using single-cell RNA-seq. RESULTS: CHB mice exhibited sustained HBV viremia and persistent hepatitis. They showed intrahepatic expansion of exhausted CD8+ T (Tex) cells, the frequency of which was positively associated with viral load. Recruited macrophages increased in number but impaired inflammatory responses in the liver. The cytotoxicity of mature natural killer (NK) cells also increased in CHB mice. IFNα and SA-5 treatment both resulted in viral suppression with mild hepatic flares in CHB mice. Although both treatments activated NK cells, SA-5 had the capacity to revitalize the impaired function of Tex cells and liver-recruited macrophages. CONCLUSIONS: Our novel CHB mouse model recapitulated the intrahepatic exhausted antiviral immunity in patients with CHB, which might be able to be reinvigorated by a hepatotropic TLR7 agonist.

Animals↗

PubMed2024

A novel mouse model recapitulates the effects of rs2254524 variant in the lanosterol synthase gene on salt sensitivity and organ damage.

OBJECTIVE: The blood pressure (BP) response to salt intake (salt sensitivity) shows great variability among individuals and is more frequent in hypertensive patients. Elevated levels of the steroid hormone Endogenous Ouabain (EO) are associated with hypertension (HT) and salt sensitivity. The lanosterol synthase gene ( LSS ) plays a key role in the biosynthesis of steroids and its rs2254524 variant (Val642Leu) is linked to salt sensitivity in humans. This study aims to investigate the pathophysiological significance of the Lss missense variation in a new knock-in mouse model of salt-sensitive HT onset. METHODS: We generated a mouse model carrying the murine homolog (Val643Leu) of the human LSS variant. C57BL/6N LssV643L/V643L mice were fed different NaCl diets (low-salt, LSD; normal-salt, NSD; high-salt, HSD) and were characterized at functional, histological, and molecular levels. RESULTS: At baseline, mutant mice showed an enlarged kidney compared to the wild-type (WT) counterpart, but the Lss V643L variant did not affect EO biosynthesis nor systolic BP at 3 and 12 months. In HSD, we observed an increased systolic BP only in 12-month-old LssV643L/V643L mice, compared to NSD. Moreover, only the HSD LssV643L/V643L mice showed cardiac hypertrophy and a higher incidence of cardiac fibrosis compared to WT at 12 months. Finally, the Lss mRNA level was differentially regulated by HSD in the adrenal gland, liver, and heart of LssV643L/V643L mice compared to WT. CONCLUSIONS: The novel Lss mouse model resembles the salt-sensitive HT phenotype observed in hypertensive patients and provides a good model of salt-sensitive HT and HT-mediated organ damage.

Animals↗

PubMed2024

Retinal Proteome Profiling of Inherited Retinal Degeneration Across Three Different Mouse Models Suggests Common Drug Targets in Retinitis Pigmentosa.

Inherited retinal degenerations (IRDs) are a leading cause of blindness among the population of young people in the developed world. Approximately half of IRDs initially manifest as gradual loss of night vision and visual fields, characteristic of retinitis pigmentosa (RP). Due to challenges in genetic testing, and the large heterogeneity of mutations underlying RP, targeted gene therapies are an impractical largescale solution in the foreseeable future. For this reason, identifying key pathophysiological pathways in IRDs that could be targets for mutation-agnostic and disease-modifying therapies (DMTs) is warranted. In this study, we investigated the retinal proteome of three distinct IRD mouse models, in comparison to sex- and age-matched wild-type mice. Specifically, we used the Pde6βRd10 (rd10) and RhoP23H/WT (P23H) mouse models of autosomal recessive and autosomal dominant RP, respectively, as well as the Rpe65-/- mouse model of Leber's congenital amaurosis type 2 (LCA2). The mice were housed at two distinct institutions and analyzed using LC-MS in three separate facilities/instruments following data-dependent and data-independent acquisition modes. This cross-institutional and multi-methodological approach signifies the reliability and reproducibility of the results. The large-scale profiling of the retinal proteome, coupled with in vivo electroretinography recordings, provided us with a reliable basis for comparing the disease phenotypes and severity. Despite evident inflammation, cellular stress, and downscaled phototransduction observed consistently across all three models, the underlying pathologies of RP and LCA2 displayed many differences, sharing only four general KEGG pathways. The opposite is true for the two RP models in which we identify remarkable convergence in proteomic phenotype even though the mechanism of primary rod death in rd10 and P23H mice is different. Our data highlights the cAMP and cGMP second-messenger signaling pathways as potential targets for therapeutic intervention. The proteomic data is curated and made publicly available, facilitating the discovery of universal therapeutic targets for RP.

Animals↗

PubMed2026

Revisiting endothelial tropism of SARS-CoV-2 using a cell-specific hACE2 mouse model.

UNLABELLED: Severe COVID-19 is frequently associated with vascular complications, raising ongoing debate about whether SARS-CoV-2 can directly infect endothelial cells and thereby contribute to disease pathogenesis. Although endothelial cells express angiotensin-converting enzyme 2 (ACE2), the in vivo relevance of endothelial-restricted viral tropism remains unclear. To directly assess the consequences of endothelial-restricted SARS-CoV-2 tropism in vivo, we generated a transgenic mouse model expressing human ACE2 under control of the endothelial-specific Cdh5 promoter (Cdh5-hACE2). Despite confirmed pulmonary endothelial expression and protein presence of hACE2, SARS-CoV-2 infection of Cdh5-hACE2 mice did not induce clinical illness, detectable viral replication, immune cell influx in the lung, or histopathological abnormalities in the lung or brain. These findings indicate that endothelial-restricted SARS-CoV-2 tropism alone is insufficient to drive productive infection and clinical disease in vivo, suggesting that endothelial involvement in COVID-19 likely arises in the context of broader cellular infection or systemic host responses rather than from primary endothelial infection. IMPORTANCE: Although SARS-CoV-2 primarily infects the upper and lower airways, COVID-19 was quickly recognized as a multi-organ disease, in which vascular complications are a recurring feature. This has raised the possibility that direct infection of endothelial cells contributes to disease pathogenesis. However, whether vascular injury arises from productive endothelial infection or instead represents a secondary consequence of systemic inflammation remains unresolved. To directly disentangle these possibilities and define the in vivo consequences of endothelial-restricted viral tropism, we generated a transgenic mouse model expressing human ACE2 under the control of the endothelial-specific Cdh5 promoter (Cdh5-hACE2).

Animals↗

PubMed2025

Profiling hippocampal neuronal populations reveals unique gene expression mosaics reflective of connectivity-based degeneration in the Ts65Dn mouse model of Down syndrome and Alzheimer's disease.

INTRODUCTION: Individuals with Down syndrome (DS) exhibit neurological deficits throughout life including the development of in Alzheimer's disease (AD) pathology and cognitive impairment. At the cellular level, dysregulation in neuronal gene expression is observed in postmortem human brain and mouse models of DS/AD. To date, RNA-sequencing (RNA-seq) analysis of hippocampal neuronal gene expression including the characterization of discrete circuit-based connectivity in DS remains a major knowledge gap. We postulate that spatially characterized hippocampal neurons display unique gene expression patterns due, in part, to dysfunction of the integrity of intrinsic circuitry. METHODS: We combined laser capture microdissection to microisolate individual neuron populations with single population RNA-seq analysis to determine gene expression analysis of CA1 and CA3 pyramidal neurons and dentate gyrus granule cells located in the hippocampus, a region critical for learning, memory, and synaptic activity. RESULTS: The hippocampus exhibits age-dependent neurodegeneration beginning at ~6 months of age in the Ts65Dn mouse model of DS/AD. Each population of excitatory hippocampal neurons exhibited unique gene expression alterations in Ts65Dn mice. Bioinformatic inquiry revealed unique vulnerabilities and differences with mechanistic implications coinciding with onset of degeneration in this model of DS/AD. CONCLUSIONS: These cell-type specific vulnerabilities may underlie degenerative endophenotypes suggesting precision medicine targeting of individual populations of neurons for rational therapeutic development.

Alzheimer’s disease↗

PubMed2026

Motor coordination and behavioural deficits in a mouse model of KMT2B-related dystonia.

INTRODUCTION: Pathogenic variants in KMT2B cause early-onset dystonia, but a mouse model that has undergone comprehensive, dystonia-oriented phenotyping is lacking. METHODS: We conducted detailed phenotyping on heterozygous Kmt2b constitutive knockout mice and wild-type littermates, assessing growth, neurobehavioural traits, motor coordination, sensorimotor gating, social behaviour and metabolic parameters, combined with striatal RNA sequencing. RESULTS: Kmt2b knockout mice of both sexes were viable but significantly smaller and lighter than littermate controls. Knockouts were hyperlocomotive in the open field and showed approximately two-fold larger acoustic startle responses; unexpectedly, prepulse inhibition was enhanced rather than reduced at all prepulse intensities. On the balance beam, knockouts crossed more slowly and paused more frequently; female knockouts also paused more on the ladder rung task. Frame-by-frame video analysis revealed a claw-like hindpaw posture characterized by abnormal inward flexion of the digits. Knockout mice spent less time investigating a novel conspecific, while social recognition memory remained intact. Striatal RNA sequencing confirmed reduction of Kmt2b transcript to approximately half of control levels and identified 177 differentially expressed genes, including Maob, encoding monoamine oxidase B; gene set enrichment analysis implicated neurodevelopmental, glial and mitochondrial processes. Nociception, vision, body-weight-adjusted grip strength, and clinical chemistry and haematological measures were largely unaffected. CONCLUSION: Heterozygous Kmt2b knockout mice show hyperlocomotion, altered sensorimotor gating, impaired motor coordination with dystonic-like paw posturing and reduced sociability, alongside a striatal transcriptomic signature implicating neurodevelopmental processes. The model mirrors aspects of human KMT2B-related dystonia and provides a platform for mechanistic study; environmental or pharmacological challenge may be needed to unmask overt dystonic features.

Dystonia↗

PubMed2026

Optimized AAV5-RPGR ORF15 Gene Therapy Rescues Photoreceptor Structure and Function in X-Linked Retinitis Pigmentosa Mouse Model.

PURPOSE: To develop and evaluate an rAAV5-based gene therapy vector expressing an optimized human RPGR ORF15 transgene (rAAV5-RPGR) for the treatment of X-linked retinitis pigmentosa caused by RPGR mutations, addressing the challenges of cloning the unstable wild-type ORF15 sequence. DESIGN: This was a prospective experimental study. SUBJECTS: This was an animal study. METHODS: An optimized RPGR ORF15 sequence was designed to eliminate problematic secondary structures and cryptic splice sites. In vitro expression was validated in HEK 293T and photoreceptor-like 661 W cells. A complete Rpgr knockout mouse model (Rpgr-knockout [KO]) was generated and characterized phenotypically. Therapeutic efficacy was assessed in Rpgr-KO mice via subretinal injection of rAAV5-RPGR at low (1 × 10⁹ vg/eye), medium (3 × 10⁹ vg/eye), or high (1 × 10¹⁰ vg/eye) doses. Structural and functional outcomes were evaluated at 12- and 14-month postinjection. Short-term safety was assessed in rabbits 1 month after subretinal injection. MAIN OUTCOME MEASURES: Level of RPGR protein expression and Protein isoform profile (elimination of truncated isoforms), Cellular localization of transgene expression and Dose-dependence of expression, outer nuclear layer thickness, and electroretinography parameters. RESULTS: (1) The optimized vector increased RPGR protein expression 3.3-fold in vitro compared to wild-type and eliminated truncated isoforms. (2) Subretinal delivery of rAAV5-RPGR in mice demonstrated dose-dependent transgene expression localized correctly to photoreceptor inner segments. (3) In Rpgr-KO mice, high-dose treatment significantly preserved outer nuclear layer thickness at the injection site (42% greater than controls at 14 months, P < .01) and central retina (P < .05), reduced aberrant rhodopsin mislocalization (P < .01), and partially restored retinal function. ERG showed significantly improved scotopic a-wave (≥100 vs <90 µV in controls at 10 cd·s/m²) and photopic b-wave amplitudes (49-66 vs 31-46 µV at 30 cd·s/m²) in treated mice. (4) No vector-related toxicity was observed in rabbits. CONCLUSIONS: rAAV5-RPGR mediated efficiently, targeted expression of optimized RPGR-ORF15, significantly preserved photoreceptor structure and function in a severe X-linked retinitis pigmentosa mouse model, and demonstrated a favorable safety profile. This study provides preclinical proof-of-concept for RPGR-targeted gene replacement therapy.

Animals↗

PubMed2026

Phosphoproteomic analysis in a mouse model reveals ERK signaling as a key modulator of inflammatory response in nasal mucosa associated with childhood allergic rhinitis.

Childhood allergic rhinitis (AR) is a multifactorial condition arising from the interplay between genetic predisposition and environmental exposures. Although protein phosphorylation is widely recognized as a key regulator of gene expression across various physiological and pathological states, its global alterations in the nasal mucosa of pediatric patients with AR and their subsequent impact on mucosal function and inflammatory pathways remain incompletely characterized. Our study aimed to elucidate the molecular mechanisms underlying nasal mucosa dysfunction induced by pediatric AR. Our analysis revealed 3,861 proteins encompassing a total of 15,491 phosphorylation sites. Specifically, we detected 441 downregulated phosphorylation sites on 584 proteins and 531 upregulated phosphorylation sites on 722 proteins in the nasal mucosa of the AR group. Our proteomics findings suggest that the dysregulation of immune activation and metabolic regulation may contribute to AR pathophysiology. Through pathway analysis of the identified phosphorylation sites, we found Extracellular Signal-Regulated Kinase (ERK) signaling emerged as an important pathway; notably, upregulation of ERK1/2 phosphorylation was observed as a significant marker associated with AR. Importantly, targeting ERK inhibitors presents a potential therapeutic strategy for modulating key inflammatory response signaling pathways in the context of AR, although this finding is derived from preclinical mouse models and requires rigorous validation in human pediatric nasal mucosal tissues before any clinical translation can be considered. Collectively, these findings highlight that elucidating the molecular mechanisms underlying AR-induced nasal mucosal dysfunction in the mouse model may inform the novel therapeutic targets for pediatric allergy-related diseases. Overall, elucidating these mechanisms has substantial implications for developing targeted interventions aimed at mitigating inflammation associated with allergic rhinitis.

Animals↗

PubMed2025

Tracking HIV persistence across T cell lineages during early ART-treated HIV-1-infection using a reservoir-marking humanized mouse model.

Human immunodeficiency virus (HIV) infection depletes CD4 T-cells, and long-term persistence of latent virus prevents full clearance of HIV even in the presence of effective antiretroviral therapy (ART), Here we present the HIV-1-induced lineage tracing (HILT) system, a model that irreversibly marks infected cells within a humanized mouse model, which detects rare latently infected cells. Immunodeficient mice transplanted with genetically modified hematopoietic stem cells develop a human immune system, in which CD4 T-cells contain a genetic switch that permanently labels cells infected by HIV-1 expressing cre-recombinase. Through single-cell RNA sequencing of HILT-marked cells during acute infection and post-ART treatment, we identify distinct CD4+ T-cell transcriptional lineages enriched in either active or latent infections. Comparative gene expression analysis highlights common pathways modulated in both states, including EIF2, Sirtuin, and protein ubiquitination. Critical regulators of these pathways, including JUN, BCL2, and MDM2, change to opposite directions in the two states, highlighting gene expression programs that may support HIV persistence across T-cell lineages and states.

Animals↗

PubMed2026

A mouse model of autosomal dominant spastic ataxia and myopathy caused by a mutation in Tuba4a.

Hereditary ataxias are a heterogeneous group of neurodegenerative disorders characterized by impaired balance and coordination, often due to cerebellar dysfunction. Despite advances in identifying genetic causes, animal models remain essential for dissecting underlying mechanisms and testing therapeutic strategies. Here we describe a mouse model of spastic ataxia and myopathy caused by a missense mutation in Tuba4a (n.A626C, p.Gln176Pro). In an ENU mutagenesis screen, a male C57BL/6 J mouse exhibiting muscle wasting and an intention tremor starting at approximately 4 weeks-of-age was identified. The male was bred by in vitro fertilization to BALB/cByJ oocyte donors. Genetic mapping determined dominant inheritance and localized the mutation to Chromosome 1. Genome sequencing revealed single nucleotide polymorphisms (SNPs) in serine threonine kinase 36 (Stk36Y1003N) and alpha-tubulin 4A (Tuba4aQ176P) in the mapping interval. These SNPs were CRISPR-engineered into C57BL/6 J mice, which confirmed the Tuba4aQ176P variant as the causative mutation. Mutant mice are normal at 3 weeks, except for decrement in muscle response following repetitive nerve stimulation. However, by 30 days these mice have overt ataxia, Purkinje neuron degeneration, and extensive skeletal muscle defects, which contribute to a decreased lifespan. Dominant TUBA4A mutations in humans are associated with spastic ataxia type 11 (SPAX11), congenital myopathy type 26 (CMYO26), and frontotemporal dementia/amyotrophic lateral sclerosis type 9 (FTDALS9). Our mice exhibit hallmark features of SPAX11 and CMYO26, but do not show motor neuron degeneration. This specificity makes this model a valuable tool for studying cell-type selective effects of TUBA4A mutations in neurodegeneration and myopathy.

Animals↗

PubMed2026

Progressive HNF1A-MODY pathophysiology revealed by a translational mouse model.

HNF1A-MODY, the most common monogenic diabetes, exhibits progressive β cell dysfunction, but existing mouse models fail to recapitulate human disease progression, limiting understanding of pathogenic mechanisms. We developed mice with heterozygous deletion of the Hnf1a transactivation domain (Hnf1a+/Δe4-10) to model human HNF1A haploinsufficiency, conducted cross-sectional metabolic characterization, and validated our findings in HNF1A-deficient human islets. Unlike previous models, Hnf1a+/Δe4-10 mice successfully recapitulated temporal HNF1A-MODY progression. Male mice developed sequential pathophysiology: early insulin resistance in young adults (7 weeks), followed by testosterone deficiency and fasting hyperglycemia in adult mice (10 weeks). Glucose intolerance emerged in middle-aged mice (30 weeks), progressing to multi-organ dysfunction in aged mice (44-70 weeks), characterized by elevated hepatic gluconeogenesis, impaired renal glucose handling, and hepatic steatosis/fibrosis. This dual pathophysiology involving β cell dysfunction and peripheral insulin resistance was associated with dysregulated hormone secretion from both α and β cells in aged mice (40-70 weeks). Human islet studies with HNF1A knockdown confirmed translational relevance, demonstrating reduced SGLT2 protein expression and inappropriate glucagon and insulin secretion. This work established a physiologically relevant HNF1A-MODY model, identified early insulin resistance as a key mechanism triggering hormonal dysfunction, and revealed HNF1A's role in multi-organ pathophysiology beyond traditional β cell dysfunction.

Animals↗

PubMed2026

Evaluating the pathogenic significance of unique chromosomal variants in craniosynostosis using patient-derived induced pluripotent stem cells and mouse modelling.

PURPOSE: Unravelling causal links between unique structural/copy-number variants (SV/CNV) and associated phenotypes is essential for correct genetic counselling. We investigated two families in which patients with craniosynostosis had SV/CNV potentially dysregulating a fibroblast growth factor (FGF)-encoding gene; a 730 kb dup(4)(q21.21) including FGF5; and a complex 568 kb interspersed 13q12.11 duplication, located 841 kb from FGF9. METHODS: We combined bioinformatic predictions of altered topologically-associating domain (TAD) structure, with experimental analysis (RNA- and ATAC- [assay for transposase-accessible chromatin] sequencing) of patient induced pluripotent stem cell lines (iPSCs) differentiated to neural crest (NCC) and osteoprogenitor (OPC) identities. For the dup(4)(q21.21) we generated a mouse bearing an equivalent rearrangement using CRISPR-Cas9 targeting. RESULTS: TAD analysis suggested potential dysregulation of the FGF5/FGF9 gene by bringing it into a novel genomic milieu. The RNA- and ATAC-seq assays demonstrated FGF5/FGF9 upregulation (2.7-18x) and local opening of chromatin, in 3/4 cell lines. For the dup(4)(q21.21), a causal role was supported by the mouse model, whereas interpretation of the 13q12.11 SV is confounded by a co-existing FOXP2 pathogenic variant. CONCLUSION: Patient iPSC-differentiated NCC and OPC lines, combined with TAD-based modelling to generate testable functional hypotheses, provide valuable functional evidence when evaluating causation of unique SV/CNV in craniosynostosis.

copy-number variant↗

PubMed2025

Optimized genomic editing of a common Duchenne muscular dystrophy mutation in patient-derived muscle cells and a new humanized mouse model.

Duchenne muscular dystrophy (DMD) is a fatal X-linked, recessive disease caused by mutations in the DMD gene encoding dystrophin, a membrane-associated protein necessary for maintaining muscle structure and function. One of the common DMD mutations is the deletion of exon 52 (Δ52), which introduces a premature stop codon in exon 53, preventing the expression of functional dystrophin protein. Patients with this mutation could benefit from skipping or reframing exon 53 to restore the dystrophin open reading frame. In this study, we investigated the efficacy of single-cut CRISPR gene editing with Staphylococcus pyogenes Cas9 (SpCas9)-LRVQR to restore dystrophin expression in patient-derived induced pluripotent stem cells (iPSCs) and a newly generated humanized DMD mouse model. We compared two injection routes for adeno-associated virus (AAV) serotype 9 to deliver gene-editing components to neonatal mice: intraperitoneal (IP) and facial vein (FV) injection. We observed efficient restoration of dystrophin protein expression across multiple skeletal muscle groups and the heart. The AAV9-mediated CRISPR single-cut approach ameliorated key DMD hallmarks, including histopathological phenotypes, impaired grip strength, and elevated serum creatine kinase levels. Our optimized strategies for dystrophin restoration in humanized DMD mice with exon 52 deletion represent a promising treatment for DMD.

AAV↗

PubMed2026

Construction and evaluation of an independently generated transgenic mouse model carrying mutated human HRAS genes for short-term carcinogenicity assessment.

The study aimed to construct and evaluate an independently generated transgenic mouse model applied to the short-term carcinogenicity assessment. Mutated human HRAS fragment containing an intron point-mutation was inserted into C57BL/6JGpt mice via bacterial artificial chromosome transgenic technology, eventually generating BALB/c;B6J-Tg(hHRAS)16/Gpt mice, abbreviated as HRAS mice. The inserted human HRAS fragment in HRAS mice was characterized, revealing five tandem copies at chromosome 19. Baseline profiles, including biochemical, hematological, immunophenotypic, survival, and carcinogenic data of HRAS mice, were collected. To evaluate the tumor susceptibility in HRAS mice, we applied N-Nitroso-N-methylurea (MNU) to HRAS mice in a short-term carcinogenicity assessment conducted according to Good Laboratory Practice. The genetic characteristics of HRAS mice include five tandem arrays of mutated human HRAS fragments located in genomic coordinate 7,755,606 on chromosome 19 and the duplication of a 9-kilobase genome sequence (genomic coordinate 7,755,606-7,746,509) located on chromosome 19. HRAS mice showed a relatively lower incidence and range of spontaneous tumor formation during long-term observation compared to CByB6F1-Tg(HRAS)2Jic (Tg.rasH2) transgenic mice. The short-term carcinogenicity assessment showed a strong tumor response to MNU, with high incidences of lymphoma (≥ 90%) and stomach squamous cell papilloma (≥ 90%) in both male and female HRAS mice. The HRAS mice showed susceptibility to MNU and exhibited baseline characteristics distinct from those of Tg.rasH2 mice. The co-expression of HRAS and MKI67 at the cellular localization level was found in neoplasms of HRAS mice. These findings preliminarily evaluated the feasibility of HRAS mice applied to the short-term carcinogenicity assessment.

Animals↗

PubMed2025

Quantitative proteomic analysis of the brain reveals the potential antidepressant mechanism of Jiawei Danzhi Xiaoyao San in a chronic unpredictable mild stress mouse model of depression.

OBJECTIVE: To reveal the antidepressant mechanisms of Jiawei DanZhiXiaoYaoSan (,JD) in chronic unpredictable mild stress (CUMS)-induced depression in mice. METHODS: Using the CUMS mouse model of depression, the antidepressant effects of JD were assessed using the sucrose preference test (SPT), forced swimming test (FST), and tail suspension test (TST). Tandem mass tag (TMT)-based quantitative proteomic analysis of the brain was performed following JD treatment. Hierarchical clustering, Gene Ontology function annotation, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and protein-protein interactions (PPIs) were used to analyze differentially expressed proteins (DEPs), which were further validated using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. RESULTS: Behavioral tests confirmed the anti-depressant effects of JD, and bioinformatics analysis revealed 59 DEPs, including 33 up-regulated and 26 down-regulated proteins, between the CUMS and JD-M groups. KEGG and PPI analyses revealed that neuro-filament proteins and the Ras signaling pathway may be key targets of JD in the treatment of depression. qRT-PCR and Western blotting results demonstrated that CUMS reduced the protein expression of neurofilament light (NEFL) and medium (NEFM) and inhibited the phosphorylation of extracellular regulated kinase 1/2 (ERK1/2), whereas JD promoted the phosphorylation of ERK1/2 and up-regulated the protein expression of NEFL and NEFM. CONCLUSIONS: The antidepressant mechanism of JD may be related to the up-regulation of p-ERK1/2 and neurofilament proteins.

Animals↗

PubMed2025

Development of a new flippase-dependent mouse model for red fluorescence-based isolation of KRASG12D oncogene-expressing tumor cells.

Proto-oncogene KRAS, GTPase (KRAS) is one of the most intensively studied oncogenes in cancer research. Although several mouse models allow for regulated expression of mutant KRAS, selective isolation and analysis of transforming or tumor cells that produce the KRAS oncogene remains a challenge. In our study, we present a knock-in model of oncogenic variant KRASG12D that enables the "activation" of KRASG12D expression together with production of red fluorescent protein tdTomato. Both proteins are expressed from the endogenous Kras locus after recombination of a transcriptional stop box in the genomic DNA by the enzyme flippase (Flp). We have demonstrated the functionality of the allele termed RedRas (abbreviated KrasRR) under in vitro conditions with mouse embryonic fibroblasts and organoids and in vivo in the lung and colon epithelium. After recombination with adenoviral vectors carrying the Flp gene, the KrasRR allele itself triggers formation of lung adenomas. In the colon epithelium, it causes the progression of adenomas that are triggered by the loss of tumor suppressor adenomatous polyposis coli (APC). Importantly, cells in which recombination has successfully occurred can be visualized and isolated using the fluorescence emitted by tdTomato. Furthermore, we show that KRASG12D production enables intestinal organoid growth independent of epidermal growth factor (EGF) signaling and that the KRASG12D function is effectively suppressed by specific inhibitor MRTX1133.

Animals↗