Experimental Animals最新文献

Sepsis-induced acute lung injury represents a significant threat to human health and is frequently associated with pulmonary thrombosis due to dysregulation of the coagulofibrinolytic system. Plasmin, the major protease that degrades fibrin aggregates, is activated predominantly by tissue-plasminogen activator (tPA), whereas tPA is negatively regulated by plasminogen activator inhibitor (PAI-1). Under septic conditions, the imbalance between coagulation and fibrinolysis results in excessive microthrombosis. Pulmonary capillary endothelial cells serve as a primary source of tPA and PAI-1. The molecular pathways regulating their expression levels depend on the differential activity of transcription factors. In this study, we elucidated the role of the zinc-finger transcription factor GATA3 in response to sepsis-induced pulmonary embolism. Endothelial cell-specific GATA3-deficient mice (G3-ECKO) presented increased susceptibility to bacterial endotoxin-induced pulmonary embolism, which was associated with increased PAI-1 expression levels and decreased tPA expression levels in the lungs. Septic lung extracts from G3-ECKO mice consistently presented decreased plasmin activity, which likely underlies the increased coagulation. These results demonstrate that GATA3 plays a protective role against bacterial endotoxin-induced pulmonary vascular embolism. Our findings will contribute to understanding the molecular mechanisms involving GATA3 in preventing pulmonary embolism.

Royal jelly (RJ) is recognized due to its high nutritional value and potential health benefits. Previous research showed that RJ supplementation decreased fat accumulation, resulting in weight loss and improvements in hyperglycemia and insulin resistance in high-fat diet (HFD)-induced obese mice. To expand the weight-reducing properties of RJ, this study aimed to investigate the effects of RJ supplementation on HFD-induced obese mice with impaired sleep stabilization. Over a 20-week period, the C57BL/6J mice were divided into the following dietary groups: normal diet (ND), ND supplemented with 5% lyophilized RJ powder (ND + RJ), HFD, and HFD supplemented with 5% lyophilized RJ powder (HFD + RJ) groups. Compared with the HFD group, the HFD + RJ group exhibited a significant reduction in body weight via a decrease in fat mass. Moreover, much like the ND group, the HFD + RJ group demonstrated improvements in the fragmentation of non-rapid eye movement (NREM) sleep and wakefulness. These processes contributed to the reestablishment of sleep/wake continuity and restored the overall stability of sleep. In contrast, the ND + RJ and ND groups exhibited a similar sleep/wake architecture. Thus, RJ supplementation in the ND demonstrated no substantial effect on sleep/wake. According to these findings, dietary RJ improves the sleep/wake architecture and restores sleep stability. Hence, RJ is a promising dietary component for addressing obesity and restoring sleep stability.

Dietary supplementation with melinjo (Gnetum gnemon L.) seed extract (MSE) has been an integral part of an anti-obesity therapeutic regimen. To examine the relationship between anti-obesity and sleep, we explored the effect of MSE on sleep structure in high-fat diet (HFD)-induced obese mice. Although HFD did not alter the total amount of daily sleep, it significantly reduced the average duration of non-rapid eye movement (NREM) sleep and wakefulness episodes and significantly increased the number of these episodes. These findings indicate fragmented NREM sleep due to repeated brief awakenings in the HFD-fed mice. When 1% (w/v) MSE was given to HFD-fed mice, their weight or sleep structure were comparable to those of ND-fed mice, proving that dietary MSE completely hindered HFD-induced weight gain and sleep/wake fragmentation. Our data provide compelling evidence that MSE is a novel and promising dietary supplement that restores obesity-induced sleep architecture changes in mice.

Here, we report the identification of causative genes for limb-shortening in individuals repeatedly found in a population of severely immunodeficient NOG mice maintained via sibling mating. First, we conducted a pedigree survey to determine whether limb-shortening was a recessive genetic trait and then identified it using a crossing test. Simultaneously, the symptoms were identified in detail using pathological analysis. Accordingly, a mouse strain exhibiting a recessive trait caused by a single gene trait and similar symptoms was identified, suggesting growth differentiation factor 5 (Gdf5) as a causative gene. Genome walking via PCR and sequence analysis of Gdf5 revealed a deletion of approximately 1.1 kb from the latter half of exon 2 of Gdf5. Furthermore, we established NOG-Gdf5^bpJic by removing other modified genes and confirmed that the inheritance pattern was reconfirmed semi-dominant. In recent years, regenerative medicine research using immunodeficient mice has been actively conducted, and this murine strain is expected to contribute to niche stem cell analysis and transplantation research.

Hamsters are valuable rodent models that are distinct from mice and rats. Currently, the main hamster species used for experimental research are the Syrian golden hamster and Chinese hamster, in addition to hamster species from other countries. Chinese hamsters are small, easy to run and feed, and inexpensive. They are prominent species found only in China and are part of the experimental animal resources of Chinese specialty. Chinese hamsters are distinguished by a black stripe on their back, short tail, pair of easily retractable cheek pouches, and pair of large drooping testes in males with 22 chromosomes. Due to their unique anatomical structure and biological features, Chinese hamsters have been used as a model in biomedical research. Moreover, the breeding and use of Chinese hamsters was comprehensively studied in 1958, with significant breakthroughs. We present a thorough review of the current developments and applications of Chinese hamsters and support the use of this species as a suitable and innovative experimental research model. With the success of Chinese hamster transgenic technology, this species will become more commonly employed in biological and medical research in the future.

The dense nerve and thin vascular structure of the corneal tissue provide the refractive function in healthy eyes. Diabetes mellitus causes ocular complications including corneal opacification because of corneal nerve degeneration. Diabetic neurotrophic keratopathy is characterized by reduced corneal sensitivity, delayed corneal wound healing, and nerve degeneration. Neurotization and vascularization inhibit each other in the cornea. Macrophages contribute to the corneal neovascularization. To investigate the role of macrophage in neurotrophic keratopathy, clodronate liposome was subconjunctivally injected into diabetic db/db mice with neurotrophic keratopathy. The clodronate liposome treatment decreased F4/80⁺ macrophage infiltration into the corneal epithelium, and improved corneal nerve involvement in diabetic db/db mice. Furthermore, we found that Il1b and Il34 mRNA expression was increased in the corneal epithelium of clodronate-treated diabetic db/db mice. These cytokines contribute to the maintenance of nerve tissues via microglia and nerve regeneration; however, their role in corneal nerve involvement remains unknown. Notably, the intraocular injection of recombinant IL-1β and IL-34 promoted nerve regeneration in the cornea of diabetic db/db mice. These results suggest that clodronate liposome treatment contributes to nerve regeneration during corneal involvement via IL-1β and IL-34 signaling.

Daphnetin has been demonstrated to exert beneficial effects on diabetes mellitus and renal complications. However, the role and molecular mechanism of daphnetin in diabetic cardiomyopathy (DCM) remain unclear. In this study, rats were injected with streptozotocin (STZ) to induce diabetes. The diabetic rats were then administered daphnetin (1 and 4 mg/kg) or dimethyl sulfoxide (DMSO) daily for 12 weeks. The results demonstrated that the diabetic rats exhibited elevated blood glucose levels, which were dose-dependently ameliorated by daphnetin. At 13 weeks following STZ injection, the rats exhibited typical diabetic signs, cardiac dysfunction, and evident pathological alterations in myocardial tissues. The administration of daphnetin to diabetic rats resulted in improvement in cardiac function, reductions in myocardial injury biomarkers, and the inhibition of myocardial fibrosis. Furthermore, daphnetin treatment suppressed inflammation and endoplasmic reticulum stress-induced apoptosis in a dose-dependent manner. Additionally, daphnetin exhibited partial blockade of the activation of mitogen-activated protein kinase pathways induced by diabetes. These findings indicate that daphnetin may be a promising therapeutic agent for the treatment of DCM.

In veterinary clinical medicine, evaluating the balance between nociception and antinociception presents a great challenge for anesthesiologists during canine surgeries. Heart rate (HR) and mean arterial pressure (MAP) are suitable indexes for monitoring noxious stimuli during anesthesia. Frontal electroencephalography (EEG) records, including processed parameters, are recommended for evaluating nociceptive balance in anesthetized unconscious human patients, which is unexplored in veterinary medicine. Therefore, the objective is to explore the response of processed EEG parameters to noxious stimulation and elucidate the impact of noxious stimulation on frontal cortical activity in dogs anesthetized with 1.5% isoflurane. Fourteen dogs were included and underwent frontal EEG monitoring, measuring the patient state index (PSI) and spectral edge frequency (SEF) before and after administering noxious stimulation using the towel clamp method on the tail of each 1.5% isoflurane-anesthetized dog. As the noxious stimulation was applied, there was a simultaneous increase in PSI, HR, and MAP, with PSI exhibiting a drastic response. SEF, especially on the left side, also increased with noxious stimulation. In EEG power spectral analysis, the delta band was decreased, and the alpha and beta bands showed an increase following noxious stimulation, with a more profound elevation of beta band on the left side. This study suggests that noxious stimulation brings asymmetric frontal cortical arousal, changing brain activity by suppressing delta wave and augmenting alpha and beta waves. Consequently, PSI seems to be a potential indicator for detecting stimuli in canine isoflurane anesthesia.

Status epilepticus is linked to cognitive decline due to damage to the hippocampus, a key structure involved in cognition. The hippocampus's high vulnerability to epilepsy-related damage is the main reason for this impairment. Convulsive seizures, such as those observed in status epilepticus, can cause various hippocampal pathologies, including inflammation, abnormal neurogenesis, and neuronal death. Interestingly, substantial evidence points to the therapeutic potential of the sedative/hypnotic agent zolpidem for neurorehabilitation in brain injury patients, following the unexpected discovery of its paradoxical awakening effect. In this study, we successfully established an ideal lithium-pilocarpine rat model of status epilepticus, which displayed significant deficits in hippocampal-dependent learning and memory. The Morris water maze test was used to assess zolpidem's potential to improve learning and memory, as well as its impact on anxiety-like behavior and motor function. Immunohistochemical staining and fluorescence analysis were used to examine the effect of zolpidem on KCC2 and NKCC1 protein expression in the hippocampal CA1 and CA3. Our findings showed that zolpidem did not improve learning and memory in status epilepticus rats. Additionally, its sedative/hypnotic effects were not apparent in the status epilepticus condition. However, immunohistochemical results revealed that zolpidem significantly restored altered NKCC1 levels in the CA1 and CA3 to levels similar to those seen in normal rats. These findings suggest that zolpidem may contribute to molecular restoration, particularly through its impact on NKCC1 protein expression in the hippocampus, which is crucial for proper inhibitory neurotransmission in the brain.

Atopic dermatitis (AD) is a chronic skin disease that causes itching and is characterized by recurrent flares and remissions. The interactions among type 2 inflammation, skin barrier dysfunction, and pruritus play important roles in the pathogenesis of AD. AD symptoms persist for a long period; thus, it is desirable to have disease models that reproduce a prolonged AD-like phenotype. Although MC903-induced AD model mice reportedly exhibit type 2 inflammation, skin barrier dysfunction, and pruritus, the effects of long-term application of MC903 on the changes in these symptoms over time are not fully understood. To clarify this point, we conducted a long-term time course analysis of these symptoms by applying MC903 to the ears of mice every other day for four weeks. Increased ear thickness, transepidermal water loss, number of scratching events, and serum IgE levels were observed in the MC903 model. Histological analysis revealed the infiltration of granulocytes and CD3-positive T cells and an increase in mast cells in the dermis. Furthermore, analyses of mRNA and protein expression in ear tissue revealed increased expression of thymic stromal lymphopoietin, IL-4, IL-13, and IL-33, which are involved in type 2 inflammation. All these changes were observed within two weeks after the initial application of MC903 and thereafter persisted throughout the experimental period. In conclusion, our data indicate that the long-term application of MC903 prolongs the duration of the three major symptoms of AD.