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  • Heng Yang, Yang Liu, Yuqing Wang, Yuhua Wen, Yan Chen, Rui Fan, Jiayan Xu, Shunlian Hu, Hao Qian, Rui Jiang, Weijun Cao, Jinfu Xu
    Animal Models and Experimental Medicine. 2026, 9(7): 1409-1419.
    Background:

    Given the need to translate basic research into human therapies, the development and refinement of clinically relevant animal models for bronchiectasis are critically important. To date, there are no well-established animal models for bronchiectasis. Thus, our aim was to develop a novel animal model that accurately recapitulates bronchiectasis-like pathologies.

    Methods:

    To address this question, clinical strains of chronic Pseudomonas aeruginosa (CPA) were embedded in agar beads in vitro; then CPA-loaded agar beads and papain were repeatedly instilled intratracheally in female C57BL/6 J mice. Experimental assessments included micro-computed tomography (micro-CT) imaging, histological analysis, immune cell infiltration, cytokines, and lung function parameter measurements to evaluate structural damage, immune responses, and lung function impairments in the mouse model.

    Results:

    In this mouse model, we observed that lung micro-CT imaging revealed significant bronchiectasis, with visible airways in the periphery, cylindrical airway expansion, and an airway-to-artery ratio > 1. Histopathology highlighted immune cell infiltration around the trachea, including lymphocytes, neutrophils, and monocytes, along with Periodic acid-Schiff staining-positive hypermucinous secretion. Compared to controls, the bronchiectasis group exhibited elevated pro-inflammatory cytokines in bronchoalveolar lavage fluid and worse lung function.

    Conclusion:

    Our study presented a novel mouse model that better replicated the bronchiectasis-like phenotype than the CPA airway infection model, showing the advantages of the "CPA-loaded agar beads and papain"-driven approach in optimizing the disease models. The model mimicked the progression of bronchiectasis closely and could be used for studies on disease pathogenesis as well as the evaluation of novel therapies in the near future.

  • Sergio Recalde, Maite Moreno Orduña, Jaione Bezunartea, Idoia Belza, Ainara Chas, Laura Fernández-Sánchez, Nicolás Cuenca Navarro, Alfredo García-Layana, Patricia Fernández-Robredo, María Hernández
    Animal Models and Experimental Medicine. 2026, 9(7): 1420-1435.
    Background:

    Age-related macular degeneration (AMD) is a multifactorial retinal disease in which alterations in lipid metabolism and dysregulation of the complement system play a central role. The aim of this study was to characterize a novel double-knockout (DK) mouse model deficient in apolipoprotein E and complement factor H (ApoE−/−Cfh−/−) as an experimental model of early and intermediate AMD.

    Methods:

    ApoE−/−Cfh−/− mice and wild-type controls underwent comprehensive morphological, ultrastructural, biochemical, and molecular analyses. Retinal and retinal pigment epithelium (RPE) integrity, Bruch's membrane (BM) morphology, lipid accumulation, complement activation, angiogenic signaling, and synaptic organization were evaluated using histology, electron microscopy, immunohistochemistry, biochemical assays, and gene expression analyses.

    Results:

    DK mice exhibited significant RPE thinning, disruption of tight junctions, vacuolization, and BM thickening (p < 0.05). Lipid accumulation and plasma lipid levels significantly increased compared with controls (p < 0.01). Complement activation was significantly enhanced, as evidenced by increased C5b-9 deposition (p < 0.01). In addition, DK mice exhibited increased vascular endothelial growth factor expression (p < 0.05), altered matrix metalloproteinase activity (p < 0.05), and significant synaptic disorganization between photoreceptors and second-order neurons (p < 0.05).

    Conclusions:

    The ApoE−/−Cfh−/− mouse reproduces key molecular and structural features of early and intermediate retinal degeneration with statistically significant alterations. Although it does not progress to advanced disease stages, it represents a valuable model to investigate several factors of AMD pathogenesis and evaluate therapeutic strategies targeting early disease mechanisms.

  • Sahar Rahimi, Seyedeh Mahdieh Khoshnazar, Ali Derakhshani, Nader Shahrokhi
    Animal Models and Experimental Medicine. 2026, 9(7): 1436-1453.
    Background:

    Excessive extracellular matrix accumulation, primarily as a result of hepatic stellate cell activation, is a hallmark of hepatic fibrosis, a progressive outcome of chronic liver injuries. Recent research studies suggest that stem cells, hepatocytes, and extracellular vesicles may provide therapeutic advantages due to their anti-inflammatory, antioxidative, and regenerative activities. This study aimed to comparatively evaluate the therapeutic efficacy of these agents in a rat model of carbon tetrachloride (CCl4)-induced hepatic fibrosis.

    Methods:

    Liver fibrosis was induced in male Wistar rats via intraperitoneal CCl4 injections for 8 weeks. Then the animals were intravenously administrated stem cells, hepatocytes, hepatocyte-derived exosomes, or stem cell-derived exosomes. Also, a fibrosis, a sham, a intact, and a PBS-treated group were consider the controls. After treatment, protein expression (alpha-smooth muscle actin (α-SMA), desmin), oxidative stress markers (superoxide dismutase, glutathione peroxidase, malondialdehyde), serum biochemical parameters (aspartate aminotransferase, alanine aminotransferase, glucose, uric acid, cholesterol, triglycerides), and fibrosis-related gene expression (matrix metalloproteinase 2 (MMP2), platelete-derived growth factor receptor beta (PDGFRB), transforming growth factor-beta (TGF-β), thymosin beta-10 (TMSB10) and transmembrane protein 176B (TMEM176B)) were assessed.

    Results:

    Significant liver damage, changed metabolic parameters, increased oxidative stress, and upregulated fibrosis markers were all observed in the fibrosis group. On the contrary, all treatments caused considerable improvements, though exosomes derived from stem cells demonstrated the most significant effects. Along with improved histopathological features, this group exhibited significant decreases in oxidative damage, liver enzymes, and profibrotic marker expression.

    Conclusion:

    Liver fibrosis was considerably reduced by stem cells, hepatocytes, and particularly their exosomes. Exosomes made from stem cells demonstrated the strongest therapeutic effect, confirming their potential as a viable noncellular hepatic fibrosis treatment approach.

  • Huidong Chen, Yunlong Zhang, Huanzhi Wan, Bingqian Yang, Tianyi Liu, Jie Wang, Hua Liao, Yuanyuan Zhang, Zhijian Zhang, Qingquan Hua
    Animal Models and Experimental Medicine. 2026, 9(7): 1454-1468.
    Background:

    Stem cell therapy offers promise for the neurodegenerative diseases and has been explored for sensorineural hearing loss (SNHL). However, effective cell delivery strategies remain a critical challenge for SNHL treatment.

    Methods:

    To address this need, we established an ouabain-induced SGN injured hearing loss model in rat and evaluated a novel transplantation strategy targeting the cochlear nerve surface via posterior occipital approach, designed to minimize cochlear structural damage and facilitate targeted cell delivery to Rosenthal's canal (RC). The temporal changes in glial cell densities within RC revealed a progressively deteriorating neural microenvironment, supporting early-stage intervention. Accordingly, hair follicle-derived neural crest stem cell (HFNCSC) transplantation was performed 3 or 4 days after modeling via two approaches: cochlear nerve surface transplantation (CNT) and round window transplantation (RWT).

    Results:

    CNT resulted in significant improvements in auditory function, as evidenced by reduced auditory brainstem response (ABR) thresholds, shortened wave I latencies, and preserved wave I amplitudes post-transplantation. Transplanted cells were distributed along the nerve trunk and within RC. In contrast, RWT failed to improve auditory function and caused cochlear structural damage, with widespread cell dispersion in cochlear fluids. Notably, the CNT group exhibited significantly higher densities of TUJ1-positive neuron-like cells and glial cells in the RC, accompanied by enhanced myelin basic protein expression suggestive of remyelination. No such improvements were observed in the RWT group.

    Conclusions:

    These findings suggest that cochlear nerve surface transplantation enhances stem cell survival and auditory function recovery, and represents a promising delivery approach for stem cell-based therapy of SGN-related hearing loss.

  • Nicolina Südkamp, Marlena Rohm, Gabriele Russo, Xavier Helluy, Abdulhadi Kocabas, Martijn Froeling, Felix Kleefeld, Denise Manahan-Vaughan, Tobias Ruck, Frank Jacobsen, Matthias Vorgerd, Johannes Forsting, Lara Schlaffke
    Animal Models and Experimental Medicine. 2026, 9(7): 1469-1479.

    Calpainopathy is a rare genetic myopathy without causal treatment available. Recent advances have produced promising treatment strategies, including genetic treatment and immunomodulation, that are currently being tested pre-clinically in murine models. Traditional behavioral assays frequently fail to detect early motor deficits in corresponding mouse models. Thus, this study investigated whether more sophisticated measures, such as quantitative magnetic resonance imaging (qMRI) and automated motor assessments can reveal early pathological changes in a mouse model of calpainopathy, particularly in the subclinical stages. In this study, Calpain 3-deficient mice (Capn3-deficient) and wild-type controls underwent a standardized qMRI protocol on a 7T scanner at 5 and 15 months of age. Fat fraction (FF), water T2 relaxation time (wT2), and diffusion metrics were analyzed across selected hindlimb muscles. Additionally, voluntary motor activity was monitored using an intelligent phenotyping housing system. Motor activity assays revealed minimal and inconsistent genotype effects. Sex significantly affected qMRI measures, altering fat distribution and wT2 at 5 and 15 months. At 5 months, no significant differences were detected between genotypes. At 15 months, Capn3-deficient mice exhibited elevated wT2 in the soleus and gastrocnemius muscles, correlating with endomysial immune cell infiltration. Diffusion parameters and FF remained unchanged. Taken together, the results show that muscle qMRI, particularly T2 mapping, can sensitively detect subclinical muscle changes in aging Capn3-deficient mice, pointing towards inflammatory processes. Pronounced sex differences and measurement variability underscore the need for larger, sex-balanced cohorts. Extending follow-up beyond 15 months will likely increase sensitivity for later-stage pathology.

  • Jianghong Lu, Yicun Hu, Xin Yao
    Animal Models and Experimental Medicine. 2026, 9(7): 1480-1486.

    This study aims to establish a theoretical foundation for selecting and constructing animal models in clinical research on spine-related diseases. By establishing surgical models in three experimental animal species—mice, rats, and rabbits—we compare their respective advantages and disadvantages. First, three experimental animals of each of the three species were selected in good health. Subsequently, the experimental animals were dissected and several indices of the designated intervertebral discs and the height of the adjacent vertebrae were measured. At the same time, the ease of the surgical operation was assessed intraoperatively (in terms of the ease of preoperative localization, the clarity of the intraoperative structures, and the length of the surgical operation). In addition, the animal type most suitable for the construction of a spinal fusion surgery model was evaluated. Finally, a rabbit spinal fusion surgical model was constructed and evaluated by palpation and gross view of the tissue to assess the degree of spinal fusion. The data on the disc structure of rabbits have more advantages than those of mice and rats in constructing surgical models, with easier preoperative localization, more precise intraoperative structure, and shorter surgery time. Spinal fusion surgery in rabbits was successful, with a significant trend toward fusion at 4 weeks postoperatively. Rabbits were superior to mice and rats as experimental animals for establishing spinal fusion surgery models, and the fusion models were effective.