Experimental Animals最新文献

The pathophysiology of endometriosis remains incompletely understood, necessitating the development of effective animal models for research. We generated and characterized a luminescent endometriosis mouse model utilizing luminescent B6-CAG-ELuc transgenic mice as uterine tissue donors and B6.Cg-c/c-hr/hr mice as recipients, enabling non-invasive in vivo imaging. Following transplantation of minced uterine tissue fragments into the peritoneal cavity of recipients, we monitored lesion growth via in vivo imaging system on 0, 14, 28, 42 days post transplantation. Morphology of the lesion was observed by dissecting microscopy, X-ray micro-computed tomography, and conventional histology. Inflammation-related serum cytokines were quantified using multiplex immunobeads assay. The growth of endometriotic lesions was efficiently observed by bioluminescence from day 0 through 42 days post transplantation. Comprehensive morphological observations revealed typical endometriotic lesions consisted of multiple fluid-filled cysts lined with single-layered epithelium, associated with glandular epithelial tissues and interstitial stroma. The level of IL-1β, IL-2, IL-6, IL-10, IL-12p70, IFN-γ, and TNF-α was quantified simultaneously in each serum sample to evaluate the temporal changes of each cytokine, showing four distinct patterns: IFN-γ and TNF-α showed continuous increase, IL-12p70 and IL-1β demonstrated gradual increase followed by marked elevation, IL-6 and IL-2 exhibited dramatic increase in later stages, while IL-10 showed transient increase followed by gradual decrease. In conclusion, this luminescent endometriosis mouse model using B6 luminescent transgenic mice as uterine tissue donor and B6.Cg-c/c-hr/hr recipient could be used to investigate comprehensive cytokine profiling in the development of endometriosis.

Rats (Rattus norvegicus) have been widely utilized as model animals due to their physiological characteristics, making them suitable for surgical and long-term studies. They have played a crucial role in biomedical research, complementing studies conducted in mice. The advent of genome editing technologies has facilitated the generation of genetically modified rat strains, advancing studies in experimental animals. Among these innovations, Cre-driver rat models have emerged as powerful tools for spatiotemporal control of gene expression. However, their development and characterization remain less advanced compared to mouse models. In this study, we developed liver-targeting Cre knock-in rats and reporter knock-in rats to evaluate Cre recombinase expression profiles in different genetic contexts. Our results revealed that insertion orientation and promoter origin significantly influence Cre expression patterns. Notably, forward insertion of the Albumin (Alb) promoter-driven Cre sequence at the ROSA26 locus resulted in ubiquitous Cre expression, while reverse insertion confined Cre expression predominantly to the liver. Interestingly, Cre expression under an endogenous Alb promoter unexpectedly induced expression in non-liver tissues, which may suggest a potential link to the in vivo dynamics of albumin. These findings underscore the importance of rigorous characterization in Cre-based transgenic systems. By elucidating the roles of promoter origin, insertion site, and orientation, our study provides valuable insights for optimizing Cre-driver rat models. These findings pave the way for refining genetic strategies to enhance tissue specificity and reliability in functional genomics and disease modeling.

In mammals, blastocyst-stage trophectoderm (TE) contacts the maternal body at the time of implantation and forms the placenta after implantation, which supports the development of the fetus. Studying gene function in TE and placenta is important to understand normal implantation and pregnancy processes and their dysfunction. However, genetically modified mice are commonly generated by manipulating pronuclear-stage zygotes, which modify both the genome of the fetus and the placenta. Therefore, we previously developed TE/placenta-specific gene expression technology by transducing blastocysts with lentiviral vectors. However, the zona pellucida (ZP) needed to be removed before transduction. In this study, we examined various adeno-associated viral (AAV) vectors to develop a new TE/placenta-specific gene transduction method. As AAV1 can path through ZP, we succeeded in trophoblast-specific gene expression without ZP removal. Furthermore, TE cells genetically modified by AAV1-Cre contributed uniformly to the placenta. Our new technology contributes to advances in implantation and placenta research and leads to the development of new assisted reproductive technology.

Unbalanced redox homeostasis leads to the production of reactive oxygen species and exacerbates inflammatory bowel disease. To investigate the role of the transcription factor Nrf2, a major antioxidative stress sensor, in intestinal epithelial cells (IECs), we generated IEC-specific Nrf2 gene knock-in mice (Nrf2-vRes), which express Nrf2 only in IECs, using the cre/loxp system. Colitis was induced in wild-type (WT) mice, whole-body Nrf2-knockout (Nrf2-KO) mice, and Nrf2-vRes mice by administering dextran sulfate sodium (DSS) for 1 week (acute model) or intermittently for 5 weeks (chronic model). The mRNA and protein levels of NAD(P)H:quinone oxidoreductase 1 (NQO1), which is involved in the oxidative stress response in a manner regulated by Nrf2, were reduced in Nrf2-KO compared with those in WT, while these decreases were reversed in Nrf2-vRes at all timepoints. Nrf2-KO mice administered DSS developed more severe colitis with higher disease activity index, higher leucine-rich α2 glycoprotein in serum, shorter colon length, and more severe epithelial damage and infiltration of inflammatory cells histopathologically than did WT mice in the acute model; moreover, these exacerbations of colitis were ameliorated in Nrf2-vRes mice. However, these differences were not observed among the three sets of mice in the chronic model. IEC-specific expression of Nrf2 ameliorated DSS-induced acute colitis. These results suggest that Nrf2 expression in IECs plays a protective role against early-stage colitis and undertakes important regulatory functions during intestinal inflammation.

In most cases, the diagnosis of diabetes in animal models is based solely on blood glucose levels. While hemoglobin A1c (HbA1c) is widely used in the diagnosis of diabetes in humans, it is rarely measured in mice in diabetes research. This is thought to be because there are no established reference values for mouse HbA1c, as well as the fact that there are very few reports on the variability and reproducibility of measurements taken using different devices. In this study, we measured HbA1c levels in diabetic mouse models using different devices based on different principles, including capillary electrophoresis, high-performance liquid chromatography, and enzymatic methods, and compared the results. A positive correlation was observed between blood glucose and HbA1c levels in all measurement methods, and high reproducibility was confirmed in the measurement of HbA1c. However, HbA1c levels measured using the enzymatic method were slightly higher than those measured using the other two methods. In addition, an examination of diabetic mice given a sodium-glucose cotransporter 2 inhibitor, which is used to treat diabetes, revealed that there was a 2-week difference in the fluctuation of mouse HbA1c levels compared with the fluctuation of blood glucose levels. Based on these results, it is thought that HbA1c can be a reliable indicator in diabetic mouse models, and it is expected to make the evaluation of abnormal glucose metabolism in mice more reliable.

Atrial fibrillation (AF) is a common arrhythmia in clinical. Its most important pathophysiological factor is atrial fibrosis. Transferrin receptor (TFRC) promotes ferroptosis by facilitating iron uptake. Its role in AF is unknown. TFRC expression in Angiotensin II (Ang II)-induced AF mice was significantly upregulated. TFRC knockdown significantly reduced AF occurrence. TFRC silence ameliorated myocardial fibrosis by inhibiting transforming growth factor-β1 (TGF-β1)/Smad2 pathway in vivo. TFRC interference reduced ferroptosis by inhibiting lipid oxidation product generation in vivo. Ang II-induced HL-1 cardiomyocyte model was employed to simulate an in vivo situation. The in vitro results were consistent with the in vivo results. Forkhead box O3 (FOXO3) was reported to protect atrium against fibrosis and participate in ferroptosis. FOXO3 exerted transcriptional repressive activity by binding to TFRC promoter. FOXO3 overexpression protected HL-1 cells against ferroptosis, which was reversed by TFRC overexpression. In summary, TFRC knockdown reduces AF occurrence by ameliorating atrial fibrosis through inhibiting cardiomyocyte ferroptosis under FOXO3 regulation.

The Cynomolgus monkey is the most widely used models in non-clinical studies. As factors like age, gender, and breeding province may affect hematologic and serum biochemical parameters, it is important to establish base values of these parameters by these three factors and to determine the effects of these factors on the parameters. In total, 1794 Cynomolgus monkeys (Male: 901, Female: 893) were selected. A total of 24 hematologic and 21 serum biochemical parameters were measured, and the effects of age, gender, and breeding province were analyzed. Base values for hematologic and serum biochemical parameters were established by age, gender, and breeding province. A significant neutrophil percent, alkaline phosphatase, and creatinine differences were observed between different ages; a significant alkaline phosphatase, gamma glutamyl transpeptidase, and creatinine differences were observed between males and females; a significant lymphocyte percent, neutrophil percent, reticulocyte count, alkaline phosphatase, gamma glutamyl transpeptidase, and creatinine differences were observed between different breeding provinces. The results emphasize the importance of improving base values by age, gender, and breeding provinces. There was no statistically significant difference in most of the above parameters, and Cynomolgus monkeys from different breeding provinces can be used in the same study.

Spinocerebellar ataxia 13 (SCA13) is an autosomal dominant neurological disorder caused by mutations in KCNC3. Our previous studies revealed that KCNC3 (Potassium Voltage-Gated Channel Subfamily C Member 3) mutation R423H results in an early-onset form of SCA13. Previous biological models of SCA13 include zebrafish and Drosophila but no mammalian systems. More recently, mouse models with Kcnc3 mutations presented behavioral abnormalities but without obvious pathological changes in the cerebellum, a hallmark of patients with SCA13. Here, we present a novel transgenic mouse model by bacterial artificial chromosome (BAC) recombineering to express the full-length mouse Kcnc3 expressing the R424H mutation. This BAC-R424H mice exhibited behavioral and pathological changes mimicking the clinical phenotype of the disease. The BAC-R424H mice (homologous to R423H in human) developed early onset clinical symptoms with aberrant gait, tremor, and cerebellar atrophy. Histopathological analysis of the cerebellum in BAC-R424H mice showed progressive Purkinje cell loss and thinning of the molecular cell layer. Additionally, Purkinje cells of BAC-R424H mice showed significantly lower spontaneous firing frequency with a corresponding increase in inter-spike interval compared to that of wild-type mice. Our SCA13 transgenic mice recapitulate both neuropathological and behavioral changes manifested in human SCA13 R423H patients and provide an advantageous approach to understanding the role of voltage-gated potassium channel in cerebellar morphogenesis and function. This mammalian in vivo model will lead to further understanding of the R423H allelic form of SCA13 from the molecular to the behavioral level and serve as a platform for testing potential therapeutic compounds.

After in vitro maturation (IVM) of porcine germinal vesicle (GV) oocytes, those that matured to the metaphase II (MII) stage were selected for further culture over a period of 24-48 h. Subsequently, these oocytes were either parthenogenetically activated or used for somatic cell nuclear transfer (SCNT) to evaluate their in vitro developmental competence. Parthenogenetically activated MII oocytes developed to the blastocyst stage after 42 h of continuous culture, whereas SCNT oocytes reached the blastocyst stage within 30 h of culture. These findings suggest that porcine MII oocytes retain their developmental competence after extended in vitro culture exceeding 30 h. This study highlights the potential of prolonged culture in enhancing the utility of MII-stage oocytes for livestock applications and possibly for future advancements in human infertility treatments.

Medetomidine, midazolam, and butorphanol (MMB) anesthesia is the preferred choice for rodents but requires excess volume of intramuscular injection in rabbits, which can lead to muscular damage. This study aimed to evaluate a dual-route MMB administration via the intravenous and subcutaneous routes in rabbits. MMB was administered to male Kbs:JW rabbits with an intravenous injection of 0.2 ml/kg followed by a subcutaneous injection of 0.8 ml/kg, totaling 0.2 mg/kg medetomidine, 2.0 mg/kg midazolam, and 2.0 mg/kg butorphanol. We compared the anesthetic effects of this dual-route method with those of intramuscular administration. The dual-route method resulted in a shorter induction time and similar anesthetic duration compared with those of the intramuscular route. While it induced a temporary decrease in body temperature within 30 min post-injection, other vital signs, such as respiration rate, heart rate, and O₂ saturation, remained similar. Notably, unlike intramuscular administration, dual-route administration did not increase tissue injury marker levels. This dual-route MMB administration provided sufficient anesthetic depth during surgery, eliminating pain reflexes. Double-dose administration extended anesthetic duration but resulted in rare fatalities, indicating room for protocol improvement. In conclusion, the novel anesthetic method is preferable for injectable anesthesia in rabbits, providing rapid induction and sufficient anesthetic duration, while potentially minimizing muscle injury. This technique may be beneficial for both laboratory and companion animals and significantly enhance animal welfare in anesthesia by reducing the pain associated with injectable anesthesia.