Animal models and experimental medicine最新文献

This study developed an animal model with internal and external urethral sphincter insufficiency by bypassing the sphincter without major damage so that the animal under study can return to normal life after the study. There is a need for a reliable, applicable, and reproducible animal model for studying urinary incontinency disease due to incorrect sphincter function. Seven adult male dogs were used for this study. The urethral sphincter was bypassed by inserting a catheter between the bladder neck and the distal sphincter. The animals' physical condition was closely monitored for 9 weeks, and standard urodynamic and radiologic studies were performed before and 1–2 months after surgery. The animals were killed at 9 weeks after surgery for pathological assessment. Catheter placement caused complete incontinence in the animal, with urodynamic assessments indicating that the animal was unable to control urination and radiological assessments indicating an empty bladder with a residual volume of 50 ± 10 cc. Tissue analysis did not show significant histological damage and inflammation. The study shows that by bypassing the urethral sphincter, which is a reliable and reproducible method, an animal model of urinary incontinence can be developed, which can be used in various studies such as assessing the adequacy of artificial sphincter function. The animals under study did not have any permanent defect, so they were able to return to their normal life.

Cardiac injury initiates repair mechanisms and results in cardiac remodeling and fibrosis, which appears to be a leading cause of cardiovascular diseases. Cardiac fibrosis is characterized by the accumulation of extracellular matrix proteins, mainly collagen in the cardiac interstitium. Many experimental studies have demonstrated that fibrotic injury in the heart is reversible; therefore, it is vital to understand different molecular mechanisms that are involved in the initiation, progression, and resolution of cardiac fibrosis to enable the development of antifibrotic agents. Of the many experimental models, one of the recent models that has gained renewed interest is isoproterenol (ISP)–induced cardiac fibrosis. ISP is a synthetic catecholamine, sympathomimetic, and nonselective β-adrenergic receptor agonist. The overstimulated and sustained activation of β-adrenergic receptors has been reported to induce biochemical and physiological alterations and ultimately result in cardiac remodeling. ISP has been used for decades to induce acute myocardial infarction. However, the use of low doses and chronic administration of ISP have been shown to induce cardiac fibrosis; this practice has increased in recent years. Intraperitoneal or subcutaneous ISP has been widely used in preclinical studies to induce cardiac remodeling manifested by fibrosis and hypertrophy. The induced oxidative stress with subsequent perturbations in cellular signaling cascades through triggering the release of free radicals is considered the initiating mechanism of myocardial fibrosis. ISP is consistently used to induce fibrosis in laboratory animals and in cardiomyocytes isolated from animals. In recent years, numerous phytochemicals and synthetic molecules have been evaluated in ISP-induced cardiac fibrosis. The present review exclusively provides a comprehensive summary of the pathological biochemical, histological, and molecular mechanisms of ISP in inducing cardiac fibrosis and hypertrophy. It also summarizes the application of this experimental model in the therapeutic evaluation of natural as well as synthetic compounds to demonstrate their potential in mitigating myocardial fibrosis and hypertrophy.

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.

Rheumatoid arthritis (RA) is a chronic autoimmune disease that affects approximately 0.46% of the global population. Conventional therapeutics for RA, including disease-modifying antirheumatic drugs (DMARDs), nonsteroidal anti-inflammatory drugs (NSAIDs), and corticosteroids, frequently result in unintended adverse effects. Dexamethasone (DEX) is a potent glucocorticoid used to treat RA due to its anti-inflammatory and immunosuppressive properties. Liposomal delivery of DEX, particularly when liposomes are surface-modified with targeting ligands like peptides or sialic acid, can improve drug efficacy by enhancing its distribution to inflamed joints and minimizing toxicity. This study investigates the potential of liposomal drug delivery systems to enhance the efficacy and targeting of DEX in the treatment of RA. Results from various studies demonstrate that liposomal DEX significantly inhibits arthritis progression in animal models, reduces joint inflammation and damage, and alleviates cartilage destruction compared to free DEX. The liposomal formulation also shows better hemocompatibility, fewer adverse effects on body weight and immune organ index, and a longer circulation time with higher bioavailability. The anti-inflammatory mechanism is associated with the downregulation of pro-inflammatory cytokines like tumor necrosis factor-α (TNF-α) and B-cell–activating factor (BAFF), which are key players in the pathogenesis of RA. Additionally, liposomal DEX can induce the expression of anti-inflammatory cytokines like interleukin-10 (IL-10), which has significant anti-inflammatory and immunoregulatory properties. The findings suggest that liposomal DEX represents a promising candidate for effective and safe RA therapy, with the potential to improve the management of this debilitating disease by providing targeted delivery and sustained release of the drug.