Murine Disease Models Research Articles

PD-1+CD8+ T Cell-Mediated Hepatocyte Pyroptosis Promotes Progression of Murine Autoimmune Liver Disease.

The specific mechanisms underlying effector pathways in autoimmune liver disease remain enigmatic and therefore constructing appropriate murine models to investigate disease pathogenesis becomes critical. A spontaneous severe murine model of autoimmune liver disease has been previously established in dnTGFβRII Aire-/- mice, exhibiting disease phenotypes that resemble both human primary biliary cholangitis (PBC) and autoimmune hepatitis (AIH). The data suggests that auto-reactive liver-specific CD8+ T cells are the primary pathogenic cells in liver injury. In this study, these data are advanced through the use of both single-cell sequencing and extensive in vitro analysis. The results identify a specific expanded pathogenic subset of PD-1+CD8+ T cells in the liver, exhibiting strong functional activity and cytotoxicity against target cells. Depletion of PD-1+CD8+ T cells using CAR-T cells effectively alleviates the disease. GSDMD-mediated pyroptosis is found to be aberrantly activated in the livers of model mice, and treatment with a GSDMD-specific inhibitor significantly inhibits disease progression. In vitro experiments reveal that PD-1+CD8+ T cells can induce the pyroptosis of hepatocytes through elevated production of granzyme B and perforin-1. These results provide a novel explanation for the cytotoxic activity of pathogenic liver PD-1+CD8+ T cells in autoimmune liver diseases and offer potential therapeutic targets.

Angiopoietin-1 attenuates lipopolysaccharide-induced endotoxemia in a Hirschsprung's disease murine model by improving intestinal vascular integrity: implications for treating postoperative Hirschsprung-associated enterocolitis.

Angiopoietin-1 (Ang1) mitigates inflammation as a proangiogenic growth factor. Action of Ang1 on lipopolysaccharide (LPS)-induced endotoxemic inflammation was investigated in endothelin receptor-B null Hirschsprung's disease mice (KO). LPS or saline was injected intraperitoneally in KO (KO-LPS; n = 9, KO-sal; n = 5) and wild-type (WT) (WT-LPS; n = 6, WT-sal; n = 6) pups obtained within 24h of birth. Normoganglionic terminal ileum harvested 6h after LPS was used for RNA extraction and histology. IL-1β, SELE, VEGFA, Ang1, Angiopoietin-2 (Ang2), and TIE2 expression analyzed by quantitative polymerase chain reaction (qPCR), vascular permeability assessed by the Miles assay, severity of inflammation, and immunofluorescence for phospho-TIE2 and VE-cadherin were used to assess endothelial cell contact integrity and compared with KO pups pretreated with intraperitoneal Ang1 [Ang1(KO-LPS); n = 5] or saline [sal(KO-LPS); n = 6] 2h before LPS. KO-LPS pups showed significantly increased inflammation (p < 0.05) and expression of IL-1β, SELE, VEGFA, and Ang2 (p = 0.019, 0.003, 0.008 and < 0.0001, respectively); expression of Ang1 and TIE2 remained unchanged when compared with KO-saline. In Ang1(KO-LPS) ileum, changes seen in sal(KO-LPS) were eliminated and phospho-TIE2 and VE-cadherin fluorescence increased. Ang1 successfully attenuated LPS-induced normoganglionic intestinal inflammation, downregulated pro-inflammatory genes, and improved vascular barrier integrity in KO pups.

A Novel Subset of Regulatory T Cells Induced by B Cells Alleviate the Severity of Immunological Diseases.

Regulatory T (Treg) cells are crucial for maintaining immune tolerance by suppressing response to self-antigens and harmless antigens to prevent autoimmune diseases and uncontrolled immune responses. Therefore, using Treg cells is considered a therapeutic strategy treating inflammatory diseases. Based on their origin, Treg cells are classified into thymus-derived, peripherally induced, and in vitro induced Treg cells. Our group discovered a novel Treg cell subset, namely, Treg-of-B (Treg/B) cells, generated by culturing CD4+CD25- T cells with B cells, including Peyer's patch B cells, splenic B cells and peritoneal B1a cells, for 3days. Treg/B cells express CD44, OX40 (CD134), cytotoxic T-lymphocyte-associated antigen-4 (CD152), glucocorticoid-induced tumor necrosis factor receptor family-related protein (CD357), interleukin-10 receptor, lymphocyte activation gene-3 (CD223), inducible co-stimulator (CD278), programmed-death 1 (CD279), tumor necrosis factor receptor II, and high levels of IL-10, but not forkhead box protein P3, similar to type 1 Treg (Tr1) cells. However, unlike Tr1 cells, Treg/B cells do not express CD103, CD226, and latency-associated peptide. Treg/B cells have been applied for the treatment of some murine models of inflammatory diseases, including allergic asthma, inflammatory bowel disease, collagen-induced arthritis, gout, psoriasis and primary biliary cholangitis. This review summarizes the current knowledge of Treg/B cells.

Human-mouse proteomics reveals the shared pathways in Alzheimer's disease and delayed protein turnover in the amyloidome.

Murine models of Alzheimer's disease (AD) are crucial for elucidating disease mechanisms but have limitations in fully representing AD molecular complexities. We comprehensively profiled age-dependent brain proteome and phosphoproteome ( n > 10,000 for both) across multiple mouse models of amyloidosis. We identified shared pathways by integrating with human metadata, and prioritized novel components by multi-omics analysis. Collectively, two commonly used models (5xFAD and APP-KI) replicate 30% of the human protein alterations; additional genetic incorporation of tau and splicing pathologies increases this similarity to 42%. We dissected the proteome-transcriptome inconsistency in AD and 5xFAD mouse brains, revealing that inconsistent proteins are enriched within amyloid plaque microenvironment (amyloidome). Determining the 5xFAD proteome turnover demonstrates that amyloid formation delays the degradation of amyloidome components, including Aβ-binding proteins and autophagy/lysosomal proteins. Our proteomic strategy defines shared AD pathways, identify potential new targets, and underscores that protein turnover contributes to proteome-transcriptome discrepancies during AD progression.

Adeno-Associated Virus Gene Transfer Ameliorates Progression of Skeletal Lesions in Mucopolysaccharidosis IVA Mice.

Mucopolysaccharidosis type IVA (MPS IVA) is an autosomal congenital metabolic lysosomal disease caused by a deficiency of the N-acetyl-galactosamine-6-sulfate sulfatase (GALNS) gene, leading to severe skeletal dysplasia. The available therapeutics for patients with MPS IVA, enzyme replacement therapy and hematopoietic stem cell transplantation, revealed limitations in the impact of skeletal lesions. Our previous study, a significant leap forward in MPS IVA research, showed that liver-targeted adeno-associated virus (AAV) gene transfer of human GALNS (hGALNS) restored GALNS enzymatic activity in blood and multiple tissues and partially improved the aberrant accumulation of storage materials. This promising approach was further validated in our current study, where we delivered AAV8 vectors expressing hGALNS, under the control of a liver-specific or ubiquitous promoter, into MPS IVA murine disease models. The results were highly encouraging, with both AAV8 vectors leading to supraphysiological enzymatic activity in plasma and improved cytoplasmic vacuolization of chondrocytes in bone lesions of MPS IVA mice. Notably, the ubiquitous promoter constructs, a potential game-changer, resulted in significantly greater enzyme activity levels in bone and improved pathological findings of cartilage lesions in these mice than in a liver-specific one during the 12-week monitoring period, reinforcing the positive outcomes of our research in MPS IVA treatment.

Spatial memory in Alzheimer's disease 5XFAD mice is enhanced by XPO1 inhibitor KPT-330.

The proteostatic decline in Alzheimer's disease is well established and improvement in proteostasis could potentially delay cognitive impairment. One emerging entry point to modulate proteostasis is the regulation of nucleo-cytoplasmic partitioning of proteins across the nuclear pore via karyopherins. The nuclear exportin XPO1 is a key regulator of proteostasis by driving the assembly of ribosomes and by modulating the process of autophagy. We recently found that XPO1 inhibitor KPT-330 (Selinexor), an FDA approved drug against multiple myelomas, enhances proteostasis, leading to benefits in models of neurodegenerative diseases in C. elegans and Drosophila . Here, we find that KPT-330 increases autophagy in murine neuronal cells and improves spatial memory performance in a murine model of Alzheimer's disease (5XFAD). Unexpectedly, general amyloid deposition in several brain regions was significantly increased by KPT-330, but specific regions, especially the thalamus, displayed significantly lower deposition, suggesting that XPO1 inhibition has regional-specific effects on proteostasis and amyloid plaque formation. Altogether, we conclude that XPO1 inhibition can improve cognition via spatially-specific reductions in amyloid deposition.

Divergent and Convergent TMEM106B Pathology in Murine Models of Neurodegeneration and Human Disease.

TMEM106B is a lysosomal/late endosome protein that is a potent genetic modifier of multiple neurodegenerative diseases as well as general aging. Recently, TMEM106B was shown to form insoluble aggregates in postmortem human brain tissue, drawing attention to TMEM106B pathology and the potential role of TMEM106B aggregation in disease. In the context of neurodegenerative diseases, TMEM106B has been studied in vivo using animal models of neurodegeneration, but these studies rely on overexpression or knockdown approaches. To date, endogenous TMEM106B pathology and its relationship to known canonical pathology in animal models has not been reported. Here, we analyze histological patterns of TMEM106B in murine models of C9ORF72 -related amyotrophic lateral sclerosis and frontotemporal dementia (C9-ALS/FTD), SOD1-related ALS, and tauopathy and compare these to postmortem human tissue from patients with C9-ALS/FTD, Alzheimer's disease (AD), and AD with limbic-predominant age-related TDP-43 encephalopathy (AD/LATE). We show that there are significant differences between TMEM106B pathology in mouse models and human patient tissue. Importantly, we also identified convergent evidence from both murine models and human patients that links TMEM106B pathology to TDP-43 nuclear clearance specifically in C9-ALS. Similarly, we find a relationship at the cellular level between TMEM106B pathology and phosphorylated Tau burden in Alzheimer's disease. By characterizing endogenous TMEM106B pathology in both mice and human postmortem tissue, our work reveals considerations that must be taken into account when analyzing data from in vivo mouse studies and elucidates new insights supporting the involvement of TMEM106B in the pathogenesis and progression of multiple neurodegenerative diseases.

Epigenetic regulation by polycomb repressive complex 1 promotes cerebral cavernous malformations.

Cerebral cavernous malformations (CCMs) are anomalies of the cerebral vasculature. Loss of the CCM proteins CCM1/KRIT1, CCM2, or CCM3/PDCD10 trigger a MAPK-Krüppel-like factor 2 (KLF2) signaling cascade, which induces a pathophysiological pattern of gene expression. The downstream target genes that are activated by KLF2 are mostly unknown. Here we show that Chromobox Protein Homolog 7 (CBX7), component of the Polycomb Repressive Complex 1, contributes to pathophysiological KLF2 signaling during zebrafish cardiovascular development. CBX7/cbx7a mRNA is strongly upregulated in lesions of CCM patients, and in human, mouse, and zebrafish CCM-deficient endothelial cells. The silencing or pharmacological inhibition of CBX7/Cbx7a suppresses pathological CCM phenotypes in ccm2 zebrafish, CCM2-deficient HUVECs, and in a pre-clinical murine CCM3 disease model. Whole-transcriptome datasets from zebrafish cardiovascular tissues and human endothelial cells reveal a role of CBX7/Cbx7a in the activation of KLF2 target genes including TEK, ANGPT1, WNT9, and endoMT-associated genes. Our findings uncover an intricate interplay in the regulation of Klf2-dependent biomechanical signaling by CBX7 in CCM. This work also provides insights for therapeutic strategies in the pathogenesis of CCM.

8711 The Effect of Testosterone Therapy Upon Bone Remodelling in Testosterone Deficient APOE-/- Mice Fed a High Fat Diet

Abstract Disclosure: A. Williamson: None. L. Bateman: None. C. LeMaitre: None. T.H. Jones: None. N. Aberdein: None. D.M. Kelly: None. Introduction: Low testosterone can lead to bone loss in males, but the mechanisms are not fully characterised. This study investigates the effects of testosterone depletion, and subsequent testosterone treatment on parameters of bone remodeling in a murine model of cardiometabolic disease. Methods: At 8 weeks of age, high-fat diet-fed ApoE-/- mice were randomised into three groups: sham surgery + placebo treatment (control, n=9), orchidectomy + placebo treatment (n =8), and orchidectomy + testosterone treatment (n=10). 25 week old mice were sacrificed and tissues collected for analysis. Left tibiae were decalcified, paraffin embedded and sectioned prior to immunostaining of bone turnover markers including receptor activator of nuclear factor κB ligand (RANKL), Osteoprotegerin (OPG), runx2, Alkaline Phosphatase (ALP), adiponectin and marrow lipid content. Right tibiae underwent mechanical 3-point bend testing at 0.05mm/s using a CellScale Univert. Results: µCT demonstrated a significant decrease in trabecular bone volume, number, and bone mineral density (BMD) and increased trabecular thickness in orchidectomised mice compared to controls. These parameters returned to control levels in testosterone treated orchiectomised mice. No significant differences were observed in cortical bone. Lipid deposition within the bone marrow was significantly increased in testosterone deficient mice compared to testosterone replete mice. No significant differences in ALP immunopositivity were detected between groups, and runx2 was significantly decreased in orchiectomised mice treated with testosterone compared to controls. The ratio of RANKL/OPG immunopositivity was significantly increased in testosterone deficient mice compared to testosterone replete mice. 3-point bending demonstrated no significant differences in maximal force between groups despite a downward trend in orchiectomised groups compared to controls. Osteoclast number quantified from TRAP-stained sections was not different between groups. Discussion: Testosterone depletion accelerates trabecular bone loss, mediated by increased osteoclastogenesis via the RANKL/OPG pathway and increased bone marrow adiposity, an effect reversed by testosterone treatment. While this study highlights the benefits of testosterone upon trabecular bone health in male mice these changes may not alter fracture risk as 3-point-bend maximal force was not affected. Presentation: 6/2/2024

A Novel Preclinical Murine Model of Systemic Lupus Erythematosus-Like Cardiovascular Disease.

Systemic lupus erythematosus (SLE) affects nine women to every man worldwide, and these patients are at greater risk for cardiovascular disease (CVD) morbidity and mortality. Clinical studies have demonstrated that patients with SLE are more likely to develop CVD, including cardiac and vascular dysfunction. Although many preclinical models of SLE are available, including treatment with Toll-like receptor (TLR) 7/8 agonists, a consistent preclinical model of SLE-like CVD with systemic, cardiac, renal, and cerebral endothelial activation and cardiac dysfunction has yet to be described. Here, we hypothesize that acceleration of SLE with the TLR7/8 agonist resiquimod (R848) will promote cardiac and endothelial activation with subsequent end-stage organ damage in the SLE-prone B6.Nba2 mouse model. Female and male SLE-prone B6.Nba2 mice were treated with R848 or acetone, administered topically twice weekly over a four-week period, to accelerate the development of SLE-like pathophysiology. Echocardiography was performed at baseline, 4 weeks, and 16 weeks. At 16 weeks, tissues were harvested, weighed, and analyzed by histology, immunofluorescence, real-time quantitative polymerase chain reaction, and enzyme-linked immunosorbent assays. We found that female R848-treated mice had increased serum anti-Smith and immunoglobulin G complex deposition in the kidney, heart, and brain consistent with SLE-like etiology. Tissue analysis revealed significant enlargement of the spleen in both female and male R848-treated mice, with only cardiac and renal enlargement in females compared to their respective controls. Echocardiographic imaging revealed left ventricular wall thickening by 4 weeks that was followed by a progressive increase in left ventricular internal diameters and subsequent decrease in ejection fraction over the 16-week time course in female mice. We found that circulating levels of soluble vascular adhesion molecule-1 and soluble intracellular adhesion molecule-1 were increased in both female and male R848-treated mice, whereas cardiac and renal fibrosis were significantly increased in only female R848-treated mice. Our data demonstrate that R848 treatment of SLE-prone B6.Nba2 mice is a novel preclinical model to study the sex-dependent pathophysiologic mechanisms of SLE-like CVD.

A quantitative proteomic approach to evaluate the efficacy of carnosine in a murine model of chronic obstructive pulmonary disease (COPD)

The aim of the work was to study a dose-dependent effect of inhaled carnosine (10, 50 or 100 mg/kg/day) in mice exposed to cigarette smoke as a model of chronic obstructive pulmonary disease (COPD). A dose-dependent loading of the dipeptide in lung tissue and bronchoalveolar lavage (BAL) was firstly demonstrated by LC-ESI-MS analysis. Cigarette smoke exposure induced a significant lung inflammation and oxidative stress in mice which was dose-dependently reduced by carnosine. Inflammation was firstly evaluated by measuring the cytokines content in the BAL. All the measured cytokines were found significantly higher in the smoke group in respect to control, although the data are affected by a significant variability. Carnosine was found effective only at the highest dose tested and significantly only for keratinocyte-derived cytokine (KC). Due to the high variability of cytokines, a quantitative proteomic approach to better understand the functional effect of carnosine and its molecular mechanisms was used. Proteomic data clearly indicate that smoke exposure had a great impact on lung tissue with 692 proteins differentially expressed above a threshold of 1.5-fold. Protein network analysis identified the activation of some pathways characteristic of COPD, including inflammatory response, fibrosis, induction of immune system by infiltration and migration of leukocyte pathways, altered pathway of calcium metabolism and oxidative stress. Carnosine at the tested dose of 100 mg/kg was found effective in reverting all the pathways evoked by smoke. Only a partial reverse of the dysregulated proteins was evident at low- and mid-tested doses, although, for some specific proteins, indicating an overall dose-dependent effect. Regarding the molecular mechanisms involved, we found that carnosine upregulated some key enzymes related to Nrf2 activation and in particular glutathione peroxidase, reductase, transferase, SOD, thioredoxins, and carbonyl reductase. Such mechanism would explain the antioxidant and anti-inflammatory effects of the dipeptide.

Meibomian gland lipid alterations and ocular surface sequela in Awat2 knockout murine model of meibomian gland dysfunction and evaporative dry eye disease

PurposeThere is an urgent need for animal models of meibomian gland dysfunction (MGD) and evaporative dry eye disease (EDED) to understand their pathophysiology and investigate novel therapeutics. This study sought to further define the acyl-CoA: wax alcohol acyltransferase 2 knockout (Awat2 KO) mouse as a model of EDED using a combination of novel clinical, biochemical, and biophysical endpoints. MethodsWildtype and Awat2 KO mice between 1 and 18 months of age were used. Ocular examinations and advanced imaging were performed. The lipidomic composition and in situ melting temperature of meibum were determined. qPCR was performed to define ocular surface gene and pro-inflammatory transcript expression. Dynamic contact angle goniometry was performed to assess the adherence capability of the ocular surface. ResultsAwat2 KO mice have mild, white, hyperreflective corneal opacities of the anterior stroma and significantly enlarged apical epithelial cells (P=0.0004). In Awat2 KO meibum, wax esters were 9-10 times lower than in wildtype meibum. Additionally, meibum melting temperature increased from 32° to 47°C (P<0.0001), leading to impaired meibum secretion and dilation of the central duct. Awat2 KO corneal epithelia had significantly decreased mucin expression (Muc1 and Muc4, P=0.0043) and increased interferon-γ production (P=0.0303). Awat2 KO globes have a significantly shortened time of droplet adherence to their ocular surface (P=0.0053), indicating a decreased tear film adherence capacity. Wildtype corneal epithelia does not express Awat2, indicating that the EDED phenotype is secondary to the loss of Awat2 from the meibomian glands. ConclusionsAwat2 KO mice recapitulate many of features of human MGD and EDED, representing a model to test novel therapeutics.

Identification of distinct stool metabolites in women with endometriosis for non-invasive diagnosis and potential for microbiota-based therapies.

Endometriosis, a poorly studied gynecological condition, is characterized by the presence of ectopic endometrial lesions resulting in pelvic pain, inflammation, and infertility. These associated symptoms contribute to a significant burden, often exacerbated by delayed diagnosis. Current diagnostic methods involve invasive procedures, and existing treatments provide no cure. Microbiome-metabolome signatures in stool samples from individuals with and without endometriosis were determined using unbiased metabolomics and 16S bacteria sequencing. Functional studies for selected microbiota-derived metabolites were conducted invitro using patient-derived cells and invivo by employing murine and human xenograft pre-clinical disease models. We discovered a unique bacteria-derived metabolite signature intricately linked to endometriosis. The altered fecal metabolite profile exhibits a strong correlation with that observed in inflammatory bowel disease (IBD), revealing intriguing connections between these two conditions. Notably, we validated 4-hydroxyindole, a gut-bacteria-derived metabolite that is lower in stool samples of endometriosis. Extensive invivo studies found that 4-hydroxyindole suppressed the initiation and progression of endometriosis-associated inflammation and hyperalgesia in heterologous mouse and in pre-clinical models of the disease. Our findings are the first to provide a distinct stool metabolite signature in women with endometriosis, which could serve as stool-based non-invasive diagnostics. Further, the gut-microbiota-derived 4-hydroxyindole poses as a therapeutic candidate for ameliorating endometriosis. This work was funded by the NIH/NICHD grants (R01HD102680, R01HD104813) and a Research Scholar Grant from the American Cancer Society to R.K.

Failure of colonization following gut microbiota transfer exacerbates DSS-induced colitis.

To study the impact of differing specific pathogen-free gut microbiomes (GMs) on a murine model of inflammatory bowel disease, selected GMs were transferred using embryo transfer (ET), cross-fostering (CF), and co-housing (CH). Prior work showed that the GM transfer method and the microbial composition of donor and recipient GMs can influence microbial colonization and disease phenotypes in dextran sodium sulfate-induced colitis. When a low richness GM was transferred to a recipient with a high richness GM via CH, the donor GM failed to successfully colonize, and a more severe disease phenotype resulted when compared to ET or CF, where colonization was successful. By comparing CH and gastric gavage for fecal material transfer, we isolated the microbial component of this effect and determined that differences in disease severity and survival were associated with microbial factors rather than the transfer method itself. Mice receiving a low richness GM via CH and gastric gavage exhibited greater disease severity and higher expression of pro-inflammatory immune mediators compared to those receiving a high richness GM. This study provides valuable insights into the role of GM composition and colonization in disease modulation.

Ethanol with thioacetamide murine model of alcoholic liver disease identifies hepatic pathways as targets for the human disease

Introduction and ObjectivesHepatic proteome and gut microbiota alterations are known in alcohol-associated hepatitis (AAH). Current animal models sparsely mimic human AAH. We aimed to develop an murine model that closely resembled human AAH. Materials and MethodsMale C57BL/6N mice were pair-fed control/incremental ethanol Lieber-DeCarli diets and thioacetamide (TAA) for 12-weeks to induce AAH. Hepatic proteome was analyzed using LC-MS/MS. Gut-bacteria was determined using 16s-rRNA sequencing. ResultsMice exposed to EtOH+TAA displayed higher expression of liver triglycerides (1.5-fold, p = 0.001), pro-inflammatory (IL6, 1.5-fold, p = 0.002 and TNFα, 1.7-fold, p = 0.01), fibrotic (TGF-β, 2.7-fold, p = 0.01 and Col1α1, 2-fold, p = 0.01) and oxidative markers (GSH and SOD (-1.5 fold, p = 0.004 & 0.005 respectively)) as compared to EtOH alone. Histology of EtOH+TAA liver displayed pericellular liver fibrosis, increased steatosis, and neutrophil infiltration, which resembled human AAH. In the 12wk EtOH+TAA group, Desulfobacteria, Campylobacteria, and Patescibacteria increased by 2-fold (p = 0.02). Pathway combined score (CS, log10) in EtOH+TAA treatment showed upregulated hepatic ethanol oxidation (CS=1.93), fatty acid biosynthesis (CS=2.48), necrosis (CS=1.59), collagen formation (CS=1.28) and hypoxia (CS=0.68) and downregulated fatty acid beta-oxidation (CS=2.37), PPAR signaling (CS=1.35) fatty acid degradation (CS=2.35), bile acid metabolism (CS=1.87), and oxidative phosphorylation (CS=1.50), as observed in human disease. ConclusionsUsing an ethanol-thioacetamide combination in mice results in a faster establishment of AAH with fibrosis than previously known models. Differential protein expression strongly correlates with pathways found altered in human AAH, thus making the model mimic human disease better than other known models., respectively. Thioacetamide (TAA) was administered to enhance liver fibrosis and mimic human AAH.

Inhibition of Amyloid β Accumulation by Protease-Digested Whitebait (Shirasu) in a Murine Model of Alzheimer's Disease.

The number of people with dementia is increasing annually worldwide. Alzheimer's disease (AD), which accounts for the highest percentage of dementia-causing diseases, remains difficult to cure, and prevention of its onset is important. We aimed to discover new AD-preventive ingredients and investigate the inhibitory effects of ten different species of seafood digests prepared by protease treatment on β-secretase 1 (BACE1) activity. Substantial inhibition of BACE1 activity was observed in five species of seafood, and protease-digested whitebait (WPD) showed the highest inhibitory effect among the ten marine samples. We further examined the potential of WPD as an AD preventive component using a familial AD strain (5xFAD) murine model. The intraperitoneal administration of WPD for 28 days substantially decreased the insoluble amyloid β1-42 content and the expression of glial fibrillary acidic protein, a marker of astrogliosis, in the cerebral cortex of the 5xFAD mice. These results strongly suggest that WPD is a novel functional food-derived ingredient with preventive effects against AD.

Realistic Aspects of Cardiac Ultrasound in Rats: Practical Tips for Improved Examination.

Echocardiography is a reliable and non-invasive method for assessing cardiac structure and function in both clinical and experimental settings, offering valuable insights into disease progression and treatment efficacy. The successful application of echocardiography in murine models of disease has enabled the evaluation of disease severity, drug testing, and continuous monitoring of cardiac function in these animals. However, there is insufficient standardization of echocardiographic measurements for smaller animals. This article aims to address this gap by providing a guide and practical tips for the appropriate acquisition and analysis of echocardiographic parameters in adult rats, which may also be applicable in other small rodents used for scientific purposes, like mice. With advancements in technology, such as ultrahigh-frequency ultrasonic transducers, echocardiography has become a highly sophisticated imaging modality, offering high temporal and spatial resolution imaging, thereby allowing for real-time monitoring of cardiac function throughout the lifespan of small animals. Moreover, it allows the assessment of cardiac complications associated with aging, cancer, diabetes, and obesity, as well as the monitoring of cardiotoxicity induced by therapeutic interventions in preclinical models, providing important information for translational research. Finally, this paper discusses the future directions of cardiac preclinical ultrasound, highlighting the need for continued standardization to advance research and improve clinical outcomes to facilitate early disease detection and the translation of findings into clinical practice.

Identifying biochemical changes in the kidney using proton nuclear magnetic resonance in an adenine diet chronic kidney disease mouse model.

This study aimed to investigate the metabolic changes in the kidneys in a murine adenine-diet model of chronic kidney disease (CKD). Kidney fibrosis is the common pathological manifestation across CKD aetiologies. Sustained inflammation and fibrosis cause changes in preferred energy metabolic pathways in the cells of the kidney. Kidney cortical tissue from mice receiving a control or adenine-supplemented diet for 8weeks (late inflammation and fibrosis) and 12 weeks (8weeks of treatment followed by 4weeks recovery) were analysed by 2D-correlated nuclear magnetic resonance spectroscopy and compared with histopathology and biomarkers of kidney damage. Tissue metabolite and lipid levels were assessed using the MestreNova software. Expression of genes related to inflammation, fibrosis, and metabolism were measured using quantitative polymerase chain reaction. Animals showed indicators of severely impaired kidney function at 8 and 12 weeks. Significantly increased fibrosis was present at 8weeks but not in the recovery group suggesting some reversal of fibrosis and amelioration of inflammation. At 8weeks, metabolites associated with glycolysis were increased, while lipid signatures were decreased. Genes involved in fatty acid oxidation were decreased at 8weeks but not 12 weeks while genes associated with glycolysis were significantly increased at 8weeks but not at 12 weeks. In this murine model of CKD, kidney fibrosis was associated with the accumulation of triglyceride and free lactate. There was an up-regulation of glycolytic enzymes and down-regulation of lipolytic enzymes. These metabolic changes reflect the energy demands associated with progressive kidney disease where there is a switch from fatty acid oxidation to that of glycolysis.

Aspergillus fumigatus conidial surface-associated proteome reveals factors for fungal evasion and host immunity modulation.

Aspergillus fumigatus causes aspergillosis and relies on asexual spores (conidia) for initiating host infection. There is scarce information about A. fumigatus proteins involved in fungal evasion and host immunity modulation. Here we analysed the conidial surface proteome of A. fumigatus, two closely related non-pathogenic species, Aspergillus fischeri and Aspergillus oerlinghausenensis, as well as pathogenic Aspergillus lentulus, to identify such proteins. After identifying 62 proteins exclusively detected on the A. fumigatus conidial surface, we assessed null mutants for 42 genes encoding these proteins. Deletion of 33 of these genes altered susceptibility to macrophage, epithelial cells and cytokine production. Notably, a gene that encodes a putative glycosylasparaginase, modulating levels of the host proinflammatory cytokine IL-1β, is important for infection in an immunocompetent murine model of fungal disease. These results suggest that A. fumigatus conidial surface proteins are important for evasion and modulation of the immune response at the onset of fungal infection.

Conserved moonlighting protein pyruvate dehydrogenase induces robust protection against Staphylococcus aureus infection

Developing an effective Staphylococcus aureus (S. aureus) vaccine has been a challenging endeavor, as demonstrated by numerous failed clinical trials over the years. In this study, we formulated a vaccine containing a highly conserved moonlighting protein, the pyruvate dehydrogenase complex E2 subunit (PDHC), and showed that it induced strong protective immunity against epidemiologically relevant staphylococcal strains in various murine disease models. While antibody responses contributed to bacterial control, they were not essential for protective immunity in the bloodstream infection model. Conversely, vaccine-induced systemic immunity relied on γδ T cells. It has been suggested that prior S. aureus exposure may contribute to the reduction of vaccine efficacy. However, PDHC-induced protective immunity still facilitated bacterial clearance in mice previously exposed to S. aureus. Collectively, our findings indicate that PDHC is a promising serotype-independent vaccine candidate effective against both methicillin-sensitive and methicillin-resistant S. aureus isolates.