Abstract Background Obesity is often associated with elevated glucocorticoid (GC) levels mediated by melanocortin 2 receptor (MC2R), the adrenocorticotropic hormone (ACTH) receptor expressed in the adrenal gland. Meanwhile, previous in vitro studies in non-adrenal cells suggest a potential role for MC2R in lipid metabolism in murine primary adipocytes; however, the functional relevance of MC2R in vivo remains poorly understood. Here, we assessed the metabolic effects and therapeutic potential of MC2R in obesity and GC regulation in vivo by generating mice with adipocyte-specific MC2R overexpression using the adeno-associated virus doublef-floxed inverse orientation (AAV-DIO) system. Results Our findings show that under basal, high-fat diet (HFD), and stress-induced conditions, MC2R overexpression in adipocytes has minimal effects on thermogenic and lipolytic markers and is insufficient to promote weight reduction in mice. Moreover, adipocyte-specific overexpression of MC2R failed to sequester the ACTH and decrease elevated serum corticosterone levels after exogenous ACTH administration. Conclusions These findings demonstrate that adipocyte-specific MC2R overexpression does not induce strong metabolic benefits, suggesting that MC2R-directed gene therapy may not be an effective treatment strategy for obesity.
The natural history of osteoarthritis development in individuals with hip dysplasia diagnosed after skeletal maturity is difficult to predict. While reorienting acetabular osteotomy improves pain and function for those with pre-arthritic hip dysplasia, the impact of dysplastic deformity correction on cartilage health and future cartilage degeneration remains unknown. The rabbit has been used as a preclinical model of hip dysplasia for investigation of joint degeneration and surgical treatment, but there is variability among protocols used to induce and characterize dysplastic deformity. The aim of this narrative review was to summarize techniques for inducing hip dysplasia, the associated morphologic and histopathologic changes, and the ability of surgical correction to mitigate joint degeneration in order to guide future research using the rabbit as a model of hip dysplasia. We identified 21 studies that induced dysplastic deformity in the rabbit hip. The most common method to induce dysplastic deformity was immobilization of the knee in extension in skeletally immature rabbits. Immobilization initiated at a younger age and for longer duration resulted in more severe dysplasia. In the few studies that assessed surgical treatment of the dysplastic hip, cartilage degeneration was reduced with correction of dysplastic deformity. We concluded that immobilizing skeletally immature rabbit knees in extension reliably causes dysplastic deformity of the hip, replicating a shallow and abnormally oriented acetabulum, which can progress to full dislocation more characteristic of hip dysplasia in infants and children, or be present without complete femoral head dislocation more characteristic of human hip dysplasia that presents in young adults. This model thereby offers the opportunity to assess the tissue level effects of hip dysplasia and the effects of surgical correction across the age spectrum.Clinical trials number : Not applicable.
Pigmentary cutaneous disorders are characterized by abnormal decreases or increases in melanin production, leading to altered skin coloration. These conditions include vitiligo, melasma, and post-inflammatory hyperpigmentation. The etiology of these dermatological manifestations is multifactorial, encompassing environmental triggers, hormonal fluctuations, psychological stress, and physical trauma. Although generally non-life-threatening, these disorders significantly impact patients’ quality of life due to visible disfigurement and consequent psychosocial distress. This paper reviews the methods used to establish animal models for different types of pigmentary skin diseases and the research progress in this area. By examining published experimental studies, we have sorted out the modeling methods for these animal models and discussed their potential applications in clinical treatment research. Studies have shown that establishing appropriate animal models is beneficial for understanding the pathogenesis of pigmentary skin diseases and for conducting drug screening and dosage form optimization. Although no major breakthroughs have been made so far, the existing research results have provided an important foundation for future studies and supported the potential of these models in clinical treatment research. Establishing appropriate animal models for pigmentary skin diseases is both feasible and meaningful. With the continuous improvement of modeling techniques and a deeper understanding of the model mechanisms, animal models for pigmentary skin diseases will provide a powerful tool for verifying new treatment methods, thereby promoting progress in clinical treatment.
BACKGROUND:NKX3.1 is a prostate-specific tumor suppressor that is frequently downregulated during the early stages of prostate cancer. Although NKX3.1 knockout (KO) mice develop spontaneous epithelial abnormalities, these lesions rarely progress beyond early neoplastic changes without additional oncogenic stimulus. Therefore, we investigated whether exogenous testosterone (TS) exacerbates early-stage, pre-neoplastic lesions in the prostate of NKX3.1 KO mice. Alterations in prostate weights of male reproductive organs (testis, seminal vesicles, and prostate lobes), histopathological lesion scores, apoptotic proteins, and angiogenic proteins were analyzed in C57BL/6 NKX3.1em1Hlee/Korl KO (NKX3.1 KO) mice injected with TS for six weeks. RESULTS:The weight of testis, seminal vesicles and ventral prostate was commonly changed in TS-treated mice of wild type (WT) and NKX3.1 KO group, while those of the dorsolateral and anterior prostate were only increased in TS-treated NKX3.1 KO group compared to those of WT. Histopathological lesion severity was greater in TS-treated NKX3.1 KO mice, with the highest lesion scores observed in the high-dose TS (HiTS)-treated KO group, and a similar pattern was observed for p53 staining. The expression levels of apoptotic and angiogenic proteins were significantly increased in TS-treated NKX3.1 KO mice compared to the same group of WT mice. CONCLUSIONS:These findings suggest that the exogenous TS exacerbates early-stage, pre-neoplastic lesions in the prostate of NKX3.1 KO mice, consistent with a gene-hormone synergistic interaction. The mechanistic basis of this synergy remains to be defined.
Abstract Background Gene targeting via CRISPR/Cas9 has become a powerful tool to create animal models for human genetic disorders. Although CRISPR/Cas9 mediated gene editing is relatively simple, factors such as mouse strain, breeding performance, and quality and recovery of the embryos, can limit the overall outcome. Genetic manipulations are commonly carried out using embryos from a well characterized C57BL6 strain of mouse however, the ability for direct gene editing in strains such as non-obese diabetic (NOD) mice, which is an important strain to create mouse models for autoimmune type 1 diabetes (TD1), immunology, cancer and infectious diseases, is quite limiting. Therefore, gene modification in NOD mice in one way is carried out via a time-consuming cross breeding with the transgenic animals created in a more permissive C57BL6 strain for several generations which can take long time and consume valuable resources. Direct gene manipulation in the NOD mouse background will greatly expedite the creation of genetically engineered mouse models bypassing the complicated steps of backcrossing thus saving almost two years and valuable resources and help promoting 3 R principles of refinement of animal welfare. Results We present improved and streamlined conditions for gene manipulation directly on the pure NOD background using embryos from NODShiLtJ mouse, a strain commonly used for studies on autoimmune TD1 and animal models for potential applications in cancer, immunology, and infectious disease research. High efficiency, 80–90% success rate, was achieved via CRISPR/Cas9 genome editing in pups born from embryos recovered from naturally mated 4-week-old NODShiLtJ females superovulated under specific time schedules. Conclusions We demonstrate that 4-week-old NODShiLtJ females superovulated and mated under specific time requirements can produce healthy and robust embryos for gene manipulation saving significant resources and maintenance costs that will help in 3R principles of refinement to improve animal welfare. Similar conditions may be applied to create new genetic modifications in complex NOD/SCID Gamma (NSG) and NOD/SCID Rag (NRG) mice for dissecting mechanisms of immunology as well as generation of mouse models for infectious diseases for underlying conditions in human patients.
Abstract Background Myopia is one of the most common refractive vision disorders. Recent studies have demonstrated that insufficient sleep correlates with myopia development in adolescents. However, the underlying mechanism for myopia progression is unclear. This study aimed to investigate the effect of sleep deprivation (SD) on the myopia development of guinea pigs. Results The experiment was divided into two parts. In the initial part, 45 animals were evenly divided into three groups, namely, the LIM(lens-induced myopia) group, LIM+SD20hr group, and LIM+SD21hr group. Thirty-six animals were used in the second part and divided into three groups: the LIM+SD20hr, LIM+SD20hr + NE-100 (Sigma-1 receptor antagonist), and LIM+SD20hr+saline groups. For animals of the LIM+SD20hr group, apart from wearing a concave lens on the right eye, they were deprived of sleep for 20 h daily. The LIM+SD21hr group was deprived of sleep for 21 h daily instead. For the LIM+SD20hr + NE-100 group, peribulbar injections of NE-100 60 µg were administered in the right eye. The LIM+SD20hr+saline group was administered with saline instead. The expression of retinal Sigma1R was measured using immunofluorescence staining and a Western blot. γ-aminobutyric acid (GABA) and glutamic acid (Glu) content in the retina was determined using the high-performance liquid chromatography electrochemical method. In the first set of experiments, SD alone did not induce myopia in control eyes but accelerated LIM progression, with increased myopic refraction (-3.14 ± 0.19 D vs. -1.93 ± 0.16 D in LIM alone, p < 0.001), axial elongation (8.34 ± 0.02 mm vs. 8.21 ± 0.01 mm, p < 0.01), and elevated retinal Glu/GABA ratio (p < 0.001). S1R expression was upregulated in LIM + SD eyes (p < 0.001). In the second set of experiments, intravitreal NE-100 administration partially reversed these effects, reducing myopic shift (-1.86 ± 0.20 D, vs. -3.21 ± 0.21 D In LIM + SD) and normalizing Glu/GABA levels (p < 0.001). Conclusions SD exacerbates LIM via S1R activation and neurotransmitter dysregulation. S1R antagonists like NE-100 may offer therapeutic potential for myopia control.
BACKGROUND:Ulcerative colitis (UC) is a chronic inflammatory disease of the colon with multifactorial aetiology involving genetic, immune, environmental, and microbial factors. Alterations in the gut microbiome are a consistent feature of UC, yet their causal contribution to disease onset and progression remains unresolved. Current animal models rely largely on chemical or genetic induction and fail to capture the complexity of host-microbiome interactions characteristic of human disease. To address this limitation and enhance the translational relevance of preclinical research, this study employed patient-derived microbiota to model UC-associated dysbiosis and investigated its effects alone and in combination with chemical induction. RESULTS:We compared three mouse models using different UC-induction triggers: dextran sulphate sodium (DSS), faecal microbiota transplantation (FMT) from a UC patient, and their combination (COMB). DSS and COMB treatments induced marked clinical symptoms, whereas FMT alone caused only mild changes, likely due to the short exposure period. Immunophenotyping revealed distinct immune profiles across all models, with leukocyte and neutrophil infiltration in the colonic mucosa of all groups, demonstrating that the microbiota alone can elicit localized immune activation. Transcriptomic analysis showed that FMT significantly modulated tight junction and mucin gene expression and induced microbiome shifts resembling those observed in human UC. In contrast, DSS triggered a strong pro-inflammatory transcriptional response and reduced microbial diversity, but with compositional changes mostly opposing those seen in UC patients. The COMB model combined features of both approaches - producing clinical symptoms and inflammatory activation similar to DSS and tight junction dysregulation resembling FMT. CONCLUSIONS:This study investigated novel experimental models of ulcerative colitis by incorporating patient-derived microbiota as an inducing factor. DSS induced strong clinical and inflammatory responses, FMT primarily altered barrier gene expression and microbiome composition, and their combination merged both inflammatory and epithelial characteristics. These microbiota-based models show promise for more accurately reproducing UC pathophysiology and thereby improving translational relevance. Further optimization is needed, including adjustment of exposure duration and sequence of induction, as well as validation for reproducibility.
Abstract Background Sepsis remains a critical challenge in intensive care, necessitating reliable animal models that accurately mimic human pathophysiological responses. While cecal ligation and puncture (CLP) is widely considered the gold standard, its inherent variability often limits reproducibility. This study aimed to optimize a fecal intraperitoneal injection (FIP) murine model by evaluating the impact of fecal preparation (fresh vs. lyophilized) and dosage (0.5–1.0 g/kg) on model stability. We systematically compared the optimized FIP model with the conventional CLP method in male BALB/c mice to define their respective pathophysiological characteristics and suitability for therapeutic screening. Results Fresh fecal suspensions significantly enhanced model reproducibility compared to dried preparations, which exhibited inconsistent virulence. An optimized FIP dose of 0.7 g/kg induced a hyperacute sepsis phenotype, characterized by rapid systemic bacterial dissemination and severe acute organ damage within 24 h. Crucially, semi-quantitative histological scoring confirmed that FIP triggered a synchronized, hyperacute injury spike across the lung, kidney, liver, and heart, whereas the CLP model exhibited a more protracted, progressive exacerbation of organ dysfunction through 48 h. Hematological analysis further revealed that while both models induced systemic inflammation, the FIP model provided a much sharper and predictable onset of severe leukopenia and multi-organ failure. Conclusions The optimized FIP model, characterized by its procedural simplicity, high controllability, and superior reproducibility, serves as a robust platform for investigating the early, fulminant pathophysiological mechanisms of unmitigated sepsis. Conversely, the CLP model remains the preferred choice for studies focusing on protracted infection and chronic organ dysfunction. These findings provide a methodological framework for selecting appropriate sepsis models based on specific research objectives in experimental medicine. Clinical trial number Not applicable.
Abstract Background This study investigated the therapeutic potential of exosomes derived from human umbilical cord mesenchymal stem cells (hUCMSCs-exos) in an Ovalbumin (OVA) -induced mouse model of allergic asthma, comparing their efficacy to budesonide, a standard asthma treatment. hUCMSCs-exos were characterized by their typical morphology, size, and marker expression (CD9, CD63, and HSP70) using transmission electron microscopy (TEM), Nanosight 300, and Western blot analysis. Results Treatment with hUCMSCs-exos significantly decreased lung inflammation by detecting plasma IL-4 and IgE levels, as well as white blood cells and eosinophils counts in Bronchoalveolar lavage fluid (BALF), the M1 and M2 type of macrophages, Regulatory T Cells (Tregs) in lung tissues, paralleling the effects of budesonide therapy. Notably, hUCMSCs -exos achieved a greater reduction in the percentage of eosinophils in BALF and a significant increase M2 macrophages and Tregs in lung tissues. Conclusions These findings suggest hUCMSCs-exos may offer comparable or superior therapeutic benefits to budesonide, warranting further investigation into their molecular mechanisms to support clinical application.
Abstract Background Sepsis is a common complication of parenteral nutrition therapy for infants with intestinal failure, due to the presence of a central venous catheter and impairment of gut barrier function. Intestinal failure-associated liver disease (IFALD) is another complication, often attributed to the type of intravenous lipid emulsion delivered and this is commonly studied in pre-clinical animal models. Animal studies frequently overlook sepsis as a confounding factor, potentially biasing the results. We retrospectively reviewed 14-day studies of total parenteral nutrition (TPN) in piglets in our laboratory from 2011 to 2025, to determine if sepsis is an independent predictor of key liver outcomes relevant to IFALD research. Sepsis was defined as positive blood culture. Results A total of 86 piglets (76 male; aged 2–5 days) were eligible for inclusion across four experimental studies. In total, 44 (51%) were suspected to have sepsis on the basis of clinical signs, 4 had missing blood cultures, and of these 28/40 (70%) had a positive blood culture. Septic piglets had higher mortality compared to those not suspected to be septic or having a negative blood culture (43% vs. 9%, p < 0.001). Septic piglets showed significantly lower bile flow (p < 0.001) and higher serum total bilirubin (p < 0.001) compared to non-septic piglets. The risk of developing sepsis was reduced in piglets with older age (OR = 0.42, p = 0.007) and increased when given a pure soy-oil compared to pure fish-oil emulsion (OR = 10.77, p = 0.05). Multivariate analysis showed the independent predictors of bile flow were both sepsis (negative) and higher body weight at study entry (positive) (R2 = 0.42, p < 0.001), while sepsis and use of a soy-based lipid emulsion were independent positive predictors of total bilirubin (R2 = 0.34, p < 0.001). Conclusions Sepsis is associated with reduced bile flow, elevated total bilirubin and increased mortality in PN fed neonatal piglets. As sepsis can be a confounding factor in liver outcomes, researchers should both introduce refinements to mitigate sepsis as well as consistently report on the number of animals with sepsis within treatment groups and their outcomes.
Abstract Background Age-related diseases are medical conditions whose incidence or severity increases with advancing age. Among them, musculoskeletal diseases, like osteoarthritis, are associated with postmenopausal hormonal shifts. Ovariectomy (OVX) is a widely used animal model to mimic the decline of ovarian hormones after menopause. Most preclinical studies rely on ovariectomized young animals, questioning their relevance to faithfully replicate the complexities of the human conditions. This study examines the long-term effects of OVX on motor performance, nociceptive response, and joint morphology in adult mice, all of which are osteoarthritis-related characteristics. Seven-month-old female mice underwent OVX or sham surgery and were monitored longitudinally until 18 months of age. Motor ability was assessed using rotarod and open field tests, pain sensitivity was evaluated via Von Frey testing, and bone integrity was analyzed through micro-computed tomography (µCT). Histological evaluation of articular cartilage was performed using Safranin-O staining. Results A transient increase in mechanical pain sensitivity was observed between 10 and 13 months post-OVX. Despite this change, OVX did not exacerbate the age-related decline in motor function. µCT revealed reduced bone mineral density in the subchondral cortical and vertebral trabecular bone in OVX mice, without significant changes in trabecular volume. Articular cartilage degeneration was similar in both experimental groups. Conclusions These findings suggest that hormonal depletion alone may not be sufficient to drive the full osteoarthritic phenotype in aging mice. Importantly, longitudinal studies allow the capture of subtle differences in the aging process.
Streptozotocin (STZ) is a commonly administered chemical via the intracerebroventricular (ICV) route in rodents to induce Alzheimer’s disease (AD)-like symptoms. Unfortunately, available research articles from different laboratories suggest inconsistency in doses, administration schedules, and target brain regions. For instance, ICV dose varies from 1.5 to 5 mg/kg either unilaterally or bilaterally, for 7 days to 21 days, as a single or multiple injections. Therefore, it is challenging for novice investigators to select the optimal doses, treatment durations, and targeted molecular pathways while employing STZ to induce AD-like conditions in experimental animals. In this background, the information related to the STZ-induced animal model of AD should be available on a single platform to aid researchers in selecting the suitable doses and regimens that suit their research objectives. The literature search was carried out by employing search engines such as PubMed and Google Scholar with keywords such as streptozotocin, intracerebroventricular, dosage optimization, Alzheimer’s disease, neuroinflammation, and oxidative stress. The present review highlights the articles published up to May 2025, with predefined inclusion (ICV-STZ model, cognitive/biochemical outcomes) and exclusion criteria (non-peer-reviewed papers, studies lacking behavioral or molecular endpoints, and studies older than 20 years). We have attempted to present the optimal dose, administration regimen, and biological process for inducing ICV-STZ AD models based on their advantages and limitations. According to the comparative quantitative evaluation of preclinical investigations, bilateral ICV administration of STZ at a cumulative dose of 3 mg/kg (1.5 mg/kg on days 1 and 3) displays the most reliable and physiologically relevant regimen. Studies also demonstrated that between 14 and 21 days after injection, this regimen reliably causes oxidative stress, neuroinflammation, cholinergic dysfunction, and progressive cognitive impairments, offering a balanced picture of physiological, histological, and behavioral alterations. However, unlike transgenic models, the ICV-STZ paradigm generally fails to develop extensive amyloid-beta plaque deposition or well-formed neurofibrillary tangles. Hence, more quantitative investigations are necessary to validate this optimization.
Abstract Inflammatory bowel disease (IBD) represents a group of chronic inflammatory conditions that extend beyond the gastrointestinal tract, with profound systemic effects on the musculoskeletal system. This review comprehensively examines the experimental models that have elucidated the intricate relationship between intestinal inflammation and the development of osteosarcopenia—the concurrent deterioration of bone and muscle tissues. We analyze chemically-induced models (DSS, TNBS), genetically engineered models (T-cell transfer, IL-10 knockout, IL-2 knockout), and the Winnie mouse model of spontaneous colitis, highlighting their contributions to our understanding of IBD-associated musculoskeletal complications. The review emphasizes how these models have revealed critical molecular mediators, particularly gut-derived serotonin and vitamin D signaling pathways, that connect intestinal pathology to distant skeletal deterioration. Notably, pro-inflammatory cytokines including TNF-α, IL-6, and IL-17 emerge as central regulators affecting both bone and muscle homeostasis, explaining the synchronized pattern of deterioration observed clinically. The findings from these experimental models highlight potential therapeutic targets and intervention strategies beyond conventional approaches, including gut-derived serotonin inhibition and vitamin D modulation. This review underscores the value of chronic colitis models in elucidating the complex pathophysiology of IBD-associated osteosarcopenia and provides direction for translational research to develop integrated treatment approaches for this debilitating extraintestinal manifestation.
BACKGROUND: Metabolic dysfunction-associated steatohepatitis (MASH) is a progressive fibrotic liver disease, the underlying mechanisms of which have not been fully elucidated. Most MASH research relies on diet-induced models, particularly inbred mouse strains such as C57BL/6J. Although inbred strains are commonly used, outbred mice more accurately reflect the genetic diversity of human populations. It was reported that ICR mice were resistant to developing MASH after high-fat diet feeding. However, the effects of choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) on ICR mice remain unexplored. The CDAHFD is a widely adopted diet-induced model for MASH. In this study, C57BL/6J and ICR mice were fed either a normal diet (ND) or a CDAHFD for 10 weeks. Metabolism-related phenotypes and liver histology assessments were conducted to establish MASH models. RNA transcriptome sequencing of liver samples was performed to identify differentially expressed genes, which were then aligned to the human MASH transcriptome. RESULTS: We successfully established MASH models via CDAHFD in both C57BL/6J and ICR mouse strains. ICR mice presented transcriptional profiles comparable to those of the C57BL/6J strain and effectively replicated the inflammatory and fibrotic features observed in patients with MASH. CONCLUSIONS: This study revealed that ICR mice are as suitable as inbred C57BL/6J mice for CDAHFD-induced MASH models.
Abstract Background Several blood withdrawal techniques are employed for biochemical research. However, these techniques fail to fulfil the desired requirement of blood volume. We invented the alternative method of blood collection through the thoracic aorta in an anesthetized rat. Under anesthesia, the rat was placed supine, and a transverse abdominal incision was made. The diaphragm was carefully cut, and a vertical thoracic incision was performed. The rat was held upright, creating a diaphragm sac, as a natural reservoir for blood collection. The thoracic aorta was identified and cut, allowing a large volume of blood to accumulate and be collected in sample tubes. The purity of the blood samples was determined using the plasma protein concentration, hemolysis index and lactate dehydrogenase (LDH) activity. Results A maximum blood volume of approximately 10–15 mL was successfully collected from the thoracic aorta using the diaphragm sac in a single rat. This method provided a higher blood yield compared to traditional techniques, such as retro-orbital bleeding, tail vein sampling, and cardiac puncture, all of which typically yield smaller volumes and require multiple collections. The blood collected using this method demonstrated comparable quality to that obtained via cardiac puncture, with no significant differences observed in plasma protein concentration, hemolysis index and LDH activity, supporting its suitability for high-quality plasma collection. Conclusions Existing blood collection methods often fall short of volume requirements, leading to repeated needle and capillary use and causing animal stress. In contrast, the proposed method is simpler, designed for rats sacrificed post-procedure. The new blood collection method through the thoracic aorta efficiently provides large blood volumes, ideal for biochemical investigations.
Abstract Background Preeclampsia is a multisystem pregnancy disorder that is a major contributor to maternal and neonatal morbidity and mortality worldwide. An animal model facilitates further understanding of the disorder and allows for the investigation of targeted therapies prior to first in-human studies. Although there are several animal models for studying preeclampsia, the utero-placental ischemia (UPI) model is thought to best replicate the placental ischemia that develops as preeclampsia evolves in humans. An established non-human primate (NHP) model of UPI resembles human preeclampsia and has been important in understanding and finding cures for this disorder. To date the ischemia in most animal models has been undertaken by surgical ligation of a uterine artery. There are however alternate means to reduce arterial blood flow via endovascular means. This study aimed to investigate the difference between the surgical reduction in flow (surgical UPI) to the use of percutaneously delivered intra-arterial coils (coils UPI). Results There was no significant difference between the two methods of inducing UPI for the measured parameters: circulating soluble fms-like tyrosine kinase-1(sFLT-1), blood pressure (BP) and proteinuria (p < 0.05). The results showed a percentage change from baseline in sFLT-1 of 3176 ± 1558% for the embolization and 2040 ± 1645% for the ligation group p = 0.11, three days post-UPI induction. Moreover, there was no difference between the two models in terms of preeclampsia-defining features. Conclusions No statistically significant difference was found between the two methods, coils for endovascular embolization and surgical UPI. However, since endovascular embolization is a less invasive technique compared to ligation it may be preferred for induction of UPI in the NHP model.
BACKGROUND: In vivo imaging is one of the analytical technologies that has been rapidly growing in demand in recent years to non-invasively observe the behavior of molecules such as genes and proteins in vivo and perform quantitative and qualitative analysis. Since the hair blocks and absorbs the fluorescence, Nude and Hairless mice have been used for in vivo imaging. Nude mice have been used for in vivo imaging for a long time; however, more efficient mice are needed for the next generation of imaging. RESULTS: We established a novel Hairless Rag2/Jak3 KO mice (Hairless R/J mice) model that exhibits hairlessness and a lack of T, B, and NK cell phenotypes. Hairless R/J mice exhibit thinner skin than that of Nude R/J mice. These mice also showed superior optical properties compared with Nude R/J mice, as demonstrated by green fluorescent beads and the mCherry-expressing human cholangiocarcinoma cell line M213, following subcutaneous transplantation. Furthermore, we show that Ihara cells, a human malignant melanoma cell line, can be used to facilitate live imaging of the growth of transplanted tumors. CONCLUSIONS: This novel mouse model will be a valuable tool for noninvasive tumor monitoring and evaluation of anticancer therapies.
Abstract Background Chronic kidney disease (CKD) markedly accelerates atherosclerosis, driving the excess cardiovascular morbidity and mortality in these patients. While rodent models have been indispensable for mechanistic studies, their small vessel size limits the use of non-invasive vascular imaging to monitor disease progression. Therefore, large-animal models are needed to bridge experimental insights with clinical applicability. We aimed to establish a novel minipig model of CKD to characterize the temporal changes of CKD-driven atherosclerosis. Six female Yucatan minipigs overexpressing a human gain-of-function PCSK9 mutant were randomized to CKD (n = 3) or control (n = 3) groups. CKD was induced by selective clamping of the left renal artery branches combined with contralateral nephrectomy using a minimally invasive laparoscopic approach. All animals were fed with a high-fat, high-cholesterol diet and followed for 15 months. Longitudinal assessments included vascular and renal ultrasound, computed tomography, plasma iohexol clearance for glomerular filtration rate (GFR) determination, and biochemical profiling of ions, cytokines, chemokines, and lipids, including advanced lipoprotein, lipidomic and fatty acid analyses. Between-groups differences were evaluated using effect sizes with 95% confidence intervals. Results CKD pigs exhibited a significant reduction in GFR and increased blood creatinine. They exhibited accelerated atherogenesis, reflected by enhanced progressive adventitial vasa vasorum neovascularization in both carotid and iliac arteries, a higher burden of arterial calcifications in abdominal aorta and iliac arteries and postmortem larger atherosclerotic plaques and calcified areas in coronary arteries. CKD also altered the systemic inflammation profile (elevated IL-1ra, IL-2, IL-4, IL-8, and IL-10), promoted a proatherogenic lipoprotein phenotype with triglyceride-enriched VLDL, LDL, and IDL particles, increased VLDL particle number, and reduced LDL particle size. Lipidomic analyses revealed increased circulating and renal palmitic acid and distinct lesion-specific fatty acid signatures. Fatty streaks were enriched in palmitic acid and 10,16-dihydroxy-palmitic acid, and mature carotid plaques accumulated polyunsaturated fatty acids. Conclusions This minimally invasive CKD model in gentically modified minipigs accelerates atherosclerosis and induces a unique lipidomic remodelling, providing a valuable translational platform to study kidney-vascular interactions and to test therapeutic interventions targeting CKD-driven atherosclerosis.
Abstract Background Malignant pleural effusion (MPE), a common complication of advanced cancers, is associated with poor prognosis and reduced quality of life. Although host–tumor interactions are known to drive MPE development, the associated immune dynamics during disease progression remain unclear. Using a Lewis lung carcinoma-induced MPE model in C57BL/6JNidfc mice, we systematically evaluated general parameters and immune cell changes at two-day intervals throughout disease progression. Results The day of Lewis lung carcinoma cell injection into the pleural space was designated as day 0. By day 10 post-injection (p.i.), MPE-bearing mice exhibited ~ 10% body weight loss, marking the experimental endpoint. Pleural tumor mass and pleural effusion volume were minimal up to day 4 p.i. but increased sharply from day 6 onward. CD45⁺ immune cell counts rose over time, and days 6, 8, and 10 p.i. marked key stages of MPE progression. On day 6, B cells, T cells, and natural killer cells, but not macrophages and neutrophils, increased significantly compared to earlier timepoints. By day 8, all immune cell subsets except T cells exceeded day 6 levels, and at day 10, natural killer cell numbers declined while others continued to increase. Besides, the numbers of CD8⁺ T cells, Th1 cells, regulatory T cells, and M2 macrophages progressively increased from day 6 to 10. Based on these data, days 6 and 10 were defined as early and advanced MPE stages, respectively, with distinct immune phenotypes. In advanced MPE, CD8⁺ T cells displayed reduced IFN-γ, TNF-α, Granzyme B, Perforin, FasL, and Ki-67, but upregulated PD-1 and CTLA-4 relative to early stage. Similarly, Th1 cells showed decreased IFN-γ, TNF-α, and IL-2 production along with reduced Ki-67 expression. Advanced-stage M2 macrophages exhibited lower MHC-II levels and impaired phagocytosis, but higher PD-L1 and IL-10 production, while neutrophils showed reduced TNF-α release and phagocytic activity. Conclusions Our findings characterize the temporal immune dynamics associated with MPE progression in a mouse model, revealing a transition from an early immunostimulatory state to a late immunosuppressive state. This study enhances our understanding of MPE immunopathogenesis and provides a foundation for developing precise, stage-specific therapeutic strategies.
