Animal models and experimental medicine最新文献

Over 550 000 people in the U.S. require hemodialysis for management of end stage renal disease (ESRD). When anatomy restricts fistula creation, arteriovenous grafts (AVG) are implanted. AVGs have poor primary patency and high risk of infection, highlighting a need for better alternatives. Previous AVG large animal models were limited by high complication rates and short-term follow-up. This study investigates the safety and durability of an ovine bilateral carotid-jugular AVG model. Eight female sheep underwent bilateral carotid-jugular AVG implantation via a single longitudinal incision overlying the trachea. Ringed PTFE grafts were anastomosed in a “lazy-S” configuration to provide the laxity needed to prevent avulsion and minimize kinking with neck movement. Post-operatively, sheep were evaluated daily to monitor for complications. Duplex ultrasonography of the grafts was performed at regular intervals out to 6 months to evaluate patency. At 6 months, angiography and duplex was performed followed by explant for gross and histologic analysis. Technical success was achieved in 16 of 16 (100%) graft implants. No major complications, including stroke, anastomotic disruption, infection, wound breakdown, or death occurred. Primary patency of control PTFE grafts was 75% at 6 months, paralleling reported rates in humans. Bilateral carotid-jugular AVG implantation in sheep is a safe and durable model for self-controlled long-term evaluation of AVG conduit technology.

Background: Cancer-associated cardiac cachexia (CACC) refers to cardiac injury in cancer patients in a malignant state, but preclinical animal models remain inadequately developed.

Methods: This study established CACC models in C57BL/6J and BALB/c mice using orthotopic, intra-abdominal, and hematogenous metastatic tumor induction. Multimodal cardiac assessments, including echocardiography, transmission electron microscopy for myocardial ultrastructural and mitochondrial analysis, and ex vivo cardiomyocyte contractility assays, were systematically applied.

Results: Metastatic burden triggered CACC characterized by cardiac mass reduction, epicardial fat depletion, interstitial fibrosis, and electrocardiographic abnormalities. Histopathological analysis revealed cardiomyocyte atrophy, myofibrillar disarray, mitochondrial dysfunction, and ubiquitin-mediated Myh6 degradation via MuRF-1, accompanied by compensatory Myh7 upregulation. These findings mechanistically link tumor-induced cachexia to cardiac dysfunction through contractile protein remodeling.

Conclusion: This work establishes a preclinical framework for targeting ubiquitin pathways to mitigate the morbidity of cancer-related cardiopathy. Our integrated approach delineates a hierarchical progression from subcellular dysfunction to macroscopic cardiac deterioration.

Background: Allergic rhinitis (AR) is a kind of immune disease mediated by IgE. We are intrigued by the potential role of DEK proto-oncogene (DEK) in inflammation-related diseases. We investigated the effects and mechanisms of DEK in treating AR, aiming to identify potential new treatment targets for AR.

Methods: The AR mouse model was induced by house dust mite (HDM) (1 mg/mL). HNEpCs stimulated by HDM (1 mg/mL) were pretreated for 24 h with or without DEK lentivirus. The effect of DEK knockout or knockdown on AR was evaluated in vitro and in vivo using western blotting, ELISA, flow cytometry, real-time quantitative PCR, immunohistochemistry, HE staining, PAS staining, Diff staining, and immunofluorescence.

Results: After DEK knockdown, the inflammatory response of AR mice was reduced. In addition, DEK deletion mitigated nasal tissue damage and mitochondrial division. Our further studies showed that DEK deletion or inhibition led to the down-regulation of RhoA activity and decreased phosphorylation of Ezrin and Drp1 proteins, and inhibited mitochondrial division. Overall, DEK deficiency mitigated AR by down-regulating RhoA/Ezrin/Drp1 pathway activity.

Conclusion: DEK alleviates AR through RhoA/Ezrin/Drp1 signaling pathway, which provides a new perspective for developing improved therapies and understanding the pathogenesis of AR.

Type 2 Diabetes (T2D) is a growing global health issue, often aggravated by excessive sugar intake. Chronic high-sucrose diets contribute to insulin resistance, oxidative stress, and pancreatic dysfunction, worsening metabolic health. Sodium-glucose co-transporter 2 (SGLT2) inhibitors, like empagliflozin, show potential in improving glycemic control and metabolic parameters, but their effects on pancreatic efficiency in sugar-induced T2D are not well understood. This study aimed to explore the effects of empagliflozin on metabolic and pancreatic protection in a high-sucrose diet-induced T2D model. Male Wistar rats were divided into four groups: normal, normal-treated, diabetic, and diabetic-treated (n = 8 per group). Diabetes was induced with a 35% sucrose solution for 8 weeks, followed by a low-dose streptozotocin (STZ) injection. Treated groups received empagliflozin (15 mg/kg/day) for the duration. Biochemical markers, including fasting blood sugar (FBS), lipid profile, insulin levels, and oxidative stress markers, were measured. Insulin resistance (HOMA-IR) and pancreatic function (HOMA-B) were assessed. Histological analysis of pancreatic tissues was performed. The high-sucrose diet increased FBS, insulin resistance, and oxidative stress, while decreasing pancreatic function and islet diameter. Empagliflozin treatment lowered FBS (p = 0.001), improved insulin sensitivity (p = 0.001), reduced triglycerides (p = 0.001), and LDL (p = 0.05). It also enhanced antioxidant enzymes, reduced lipid peroxidation (MDA, p = 0.001), and preserved pancreatic islet structure (p = 0.001). A high-sucrose diet negatively affects metabolic health and pancreatic function. Empagliflozin mitigates these effects by improving metabolism, reducing oxidative stress, and preserving pancreatic integrity, suggesting its potential as a therapeutic agent in diabetes related to excessive sugar consumption.

Background: Constitutional mismatch repair deficiency (CMMRD) is a rare disorder resulting from biallelic germline pathogenic variants in mismatch repair genes. This study described the molecular profile of two metachronous brain tumors and a patient-derived xenograft (PDX) from a Brazilian child with CMMRD.

Methods: After PDX development, methylation array, whole exome sequencing, and NanoString techniques were applied to describe the genetic landscape of CMMRD.

Results: A 6½-year-old girl was diagnosed with Sonic Hedgehog (SHH)-activated medulloblastoma and somatic TP53-mutant. After surgery and radiochemotherapy, she remained free of disease progression. At 10 years and 3 months, she developed a diffuse pediatric-type high-grade glioma (dpHGG). The child had a family history of cancer, and subsequent investigation revealed a biallelic germline variant on MSH6 (c.3556+1G>A) with the absence of protein expression in both normal and tumor tissue. A PDX model of the dpHGG was developed. The methylation profile confirmed the diagnosis of both brain tumors and PDX, refining the classification of dpHGG, Rtk1 subtype, subclass A, with an actionable alteration on Platelet-derived growth factor receptor A (PDGFRA). Exome analysis showed high tumor mutational burden, with 3019, 540, and 1049 pathogenic variants in the medulloblastoma, dpHGG, and PDX, respectively. Only the medulloblastoma exhibited microsatellite instability. The CD24, CD47, and CD276 immune checkpoints had elevated messenger RNA levels, yet no programmed death ligand 1 expression was observed in CMMRD-derived tumors.

Conclusion: We report an extensive molecular profile of a CMMRD patient, and the developed PDX model can be applied to explore new therapeutic approaches for CMMRD-associated brain tumors.

Background: Endoplasmic reticulum (ER) stress is an important factor in the development of numerous cardiovascular disorders; nevertheless, the association between ER stress and mitral regurgitation (MR) remains inadequately characterized. The molecular mechanism of pimobendan (PIMO) that contributes to the delay in congestive heart failure (CHF) in MR associated with apoptosis and fibrosis is still unclear. Our aim was to examine the impact of PIMO on ER stress, apoptosis, and fibrosis in a chronic MR rat model.

Methods: MR was surgically induced in 10 Sprague-Dawley rats, with 5 serving as sham operation controls. At 8 weeks postsurgery, the MR animals were randomly allocated into two groups: MR and MR + PIMO groups. PIMO was administered twice daily through oral gavage for 4 weeks, whereas the sham and MR groups were administered similar quantities of drinking water. Echocardiography was conducted before the delivery of PIMO as a baseline measure and at the end of the study. At the end of the investigation, hearts were procured for histopathological and ER stress evaluations.

Results: PIMO significantly maintained heart function and structural remodeling in the MR animals. PIMO significantly reduced MR-induced myocyte apoptosis (p = 0.044) and fibrosis (p = 0.002) by reducing the messenger RNA expression of genes associated with ER stress (GRP78 [glucose-regulated protein 78], ATF4 [activating transcription factor 4], and CHOP [C/ERP homologous protein]) compared to the MR group (p < 0.05, p < 0.01, and p < 0.001, respectively).

Conclusion: PIMO demonstrated cardioprotective benefits on heart function, myocyte apoptosis, and fibrosis by regulating ER stress in an MR-induced CHF rat model.

Background: Ketamine is a widely used anesthetic in animal research, but its use is strictly regulated in several countries, including Japan and China. As an alternative, the medetomidine-midazolam-butorphanol (MMB) combination is commonly used in Japan. However, medetomidine is a racemic mixture containing the inactive R-enantiomer, which may reduce anesthetic predictability and safety.

Objective: The aim of the study was to evaluate the efficacy and safety of a modified anesthetic combination (dMMB), in which dexmedetomidine replaces medetomidine, across three commonly used mouse strains (ICR, C57BL/6, BALB/c).

Methods: Male and female mice were administered either MMB or dMMB subcutaneously. Anesthetic depth, recovery profiles, heart rate, SpO₂, body temperature, ocular opacity, and blood glucose levels were assessed. Atipamezole was used to reverse anesthesia, and thermoregulatory recovery was monitored postinjection.

Results: dMMB produced similar anesthetic depth to MMB, with faster and more consistent recovery, particularly in males. Body temperature recovery was significantly enhanced in dMMB-treated B6 males. No significant differences in side effects (ocular opacity or blood glucose levels) were observed between protocols, though strain-specific glucose elevations were noted in dMMB-treated males.

Conclusion: dMMB is a safe, effective, and ketamine-free injectable anesthetic protocol, offering advantages in recovery and thermoregulation. It may be a valuable alternative in research settings where ketamine is restricted and medetomidine may become unavailable.

As one of the most prevalent gastrointestinal malignancies in humans, gastric cancer (GC) is often detected at an advanced stage, resulting in a poor prognosis and ranking it the fifth leading cause of cancer-related deaths. Due to their high genomic correlation with humans, mice are ideal in vivo models for investigating GC-related pathogenesis and therapeutic interventions. This review provides an overview of different GC models, including genetically engineered, transplantation-based models, and chemically or biologically induced models, and discusses the recent advancements for each type, highlighting their unique contributions to the field. In addition, it summarizes the strengths, limitations, and typical applications of these models and offers a critical assessment of their applicability in research while acknowledging their current limitations in fully mirroring human GC progression. Furthermore, we analyze how each model accurately recapitulates the complexities of human GC and evaluate their potential for clinical translation. This review provides a reference for model selection in future GC research.

Vitamin D, with its diverse molecular pathways and immunomodulatory properties, has become a crucial tool in the prevention and treatment of various cancers. It controls angiogenesis, apoptosis, differentiation, and cellular proliferation, inhibiting cancer through immune surveillance, DNA repair, and tumor suppression genes. Additionally, vitamin D signaling impacts tumor growth and metastasis in various cancer types by interacting with key oncogenic pathways like Wnt/β-catenin, NF-κB, PI3K/Akt, and p53. This review demonstrates the molecular and therapeutic implications of vitamin D in oncology, focusing on its potential as a safe, adjuvant treatment method. It emphasizes the role of vitamin D in epigenetic modification, its impact on tumor microenvironment, and its synergistic benefits when combined with immune checkpoint inhibitors and chemotherapeutic drugs. Despite promising results, genetic variations in the VDR gene continue to cause issues with bioavailability, ideal dosage, and interindividual response variability. The review also proposes future research on vitamin D's potentiality as a therapeutic adjuvant in various malignancies, including colorectal, prostate, and breast cancers, and suggests the development of non-calcemic vitamin D analogs and the incorporation of vitamin D-based methods into personalized oncology treatments.