Experimental Animals最新文献

This study aimed to determine the feasibility of using perfusion computed tomography (CT) to assess blood flow in different regions of the stomach in dogs. Dynamic perfusion CT scans were conducted on five beagle dogs, and blood flow analysis was performed using the maximum slope and Patlak plot methods. The findings revealed significant variations in blood flow among the fundus, body, and pylorus of the stomach. Specifically, the body showed approximately 1.3 times higher blood flow than the fundus and approximately 5 times higher blood flow than the pylorus. There were no significant differences in blood flow between the two analysis algorithms. The findings suggest that gastric perfusion CT can accurately detect variations in blood flow within the stomach. Using the maximum slope method for analysis allows for noninvasive and rapid measurement of gastric blood flow. This technique may have clinical applications in detecting submucosal diseases that are challenging to identify with endoscopies and serve as a valuable noninvasive tool for longitudinal observations in experimental animal studies.

This study evaluated the therapeutic potential of omentin-1 in preeclampsia (PE). A PE-like mouse model received recombinant human omentin-1 protein (rh-omentin) from gestation day (gd) 13.5 to 16.5. On gd 17.5, fetuses and placentas were weighed, and soluble fms-like tyrosine kinase-1 (sFlt-1) levels were measured. Maternal aortic rings were used for ex vivo vascular reactivity assays. Inflammatory factors and Krüppel-like factor 2 (KLF2) expression in placental and aortic tissues were assessed using qPCR. Human umbilical vein endothelial cells (HUVECs) were exposed to plasma from PE patients or healthy pregnant individuals to evaluate omentin-1 and KLF2 expression by qPCR, with additional evaluation of KLF2 after rh-omentin treatment. Rh-omentin treatment reduced blood pressure in the PE-like model, accompanying by increased fetal and placental weights and higher fetal/placental weight ratios compared to untreated PE mice. Additionally, rh-omentin enhanced endothelial function in maternal aortic rings, as well as reduced placental necrosis and promoted CD31-positive vasculature in the labyrinth zone. Moreover, rh-omentin decreased pro-inflammatory factors in aortic and placental tissues of PE mice. KLF2 expression was restored in both aortic and placental tissues of PE mice and in HUVECs exposed to PE plasma following rh-omentin treatment. Rh-omentin improved fetal and placental outcomes in PE-like mice, enhancing vascular function and reducing inflammation in aortic and placental tissues. It also restored KLF2 expression in PE tissues and HUVECs exposed to PE plasma, suggesting therapeutic potential for addressing endothelial dysfunction in PE.

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.

Allele-specific, monoallelic expression in diploid organisms represents an extreme case of allelic imbalance resulting from incompatibility between cis- and trans-elements. Due to haploinsufficiency, such monoallelic expression can lead to sporadic genetic diseases. In mice, allelic imbalances can be introduced into F1 offspring from inbred strains. Previously, we established F1 hybrid embryonic stem (ES) cell lines derived from four different mouse strains, each belonging to a different subspecies with substantial genetic polymorphisms. In this study, we investigated the neural differentiation capacity of the established ES cell lines. By introducing different culture conditions, which kept the ES cells undifferentiated under various pluripotencies, we succeeded in differentiating the majority of ES cell lines (eight out of eleven) with our default neural differentiation paradigm. Still, three lines exhibited insufficient differentiation despite combining culture conditions promoting undifferentiated as well as differentiated status. In addition, Ube3a imprinting was seen in two lines. Our findings contribute to the methodological understanding of mouse ES cell pluripotency and lead to the practical utility of F1 hybrid ES cells as a model for studying phenotypes resulting from gene locus interactions.

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 K⁺-Cl^- cotransporter 2 (KCC2) and Na⁺-K⁺-Cl^- cotransporter 1 (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.

Aging is a complex biological process. Several animal models, including nematodes, Drosophila, and rodents, have been used in research on aging mechanisms and the extension of healthy life expectancy. The present study investigated the physiological and anatomical changes associated with aging in two sub-strains of aged C57BL/6 mice used in aging research: C57BL/6NCrSlc (B6N) and C57BL/6J (B6J). The survival rate before 24 months old (mo) was higher in B6J mice than in B6N mice; however, after 24 mo, it was markedly lower in the former than in the latter. Body weight increased in male C57BL/6 mice until 15-18 mo and in females until 21-24 mo and then began to decrease. Body temperature was lower in B6N mice than in B6J mice until 24 mo. Food and water intakes increased from 18 mo in both strains. The incidence of alopecia was higher in female C57BL/6J mice from 3 mo. Necropsy findings showed a high rate of spontaneous tumors in both sub-strains. The incidence of cutaneous ulcerative infections and hepatic pathologies was significantly higher in the B6N strain. A high incidence of renal lesions was also observed in B6J mice, particularly in males. These results provide insights into the characteristics of these sub-strains and the phenotypic changes associated with aging, which will facilitate the use of aged mice as a quality resource for geriatric and gerontological research.

Wistar-SD Hypercholesterolemia (WSHc) Rat is a novel hyperlipidemia-susceptible rat that we discovered and bred earlier, which can be used as an ideal animal model for the study of non-alcoholic fatty liver disease (NAFLD). However, its pathogenesis of hyperlipidemia and genetic and biological characteristics need to be further investigated. In the current study, WSHc rats were fed a high-fat diet (HFD) and standard chow (SC), with age-matched Wistar rats as the control group undergoing the same treatment, followed by serum lipid level measurement. It was found that HFD-fed WSHc rats developed dyslipidemia. Transcriptomic analysis was performed to detect genes associated with cholesterol metabolism in the liver, and 119 differentially expressed genes were discovered through bioinformatics analysis and molecular biology verification. Additionally, Srebf1 was identified as a HUB gene and Nr1d1 as an independent key gene using the protein-protein interaction network and one-cluster clustering analysis. The two genes had also been further validated in molecular biology experiments and were consistent with transcriptomic results. Serum lipid metabolomics analysis identified 7 lipid subclasses and 84 lipid molecules using UHPLC-Q-TOF/MS. There were 62 and 70 lipid molecules with significant differences in the metabolic profiles of serum lipid mediators in the WSHc+HFD group compared to the WSHc+SC and Wistar+HFD groups, respectively, and the differential metabolites were mainly produced via sphingolipid and glycerophospholipid metabolism. In sum, the hypercholesterolemia model can be established with WSHc rats after the HFD induction, and the pathogenesis involves the Srebf1 and Nr1d1 genes and the sphingolipid and glycerophospholipid metabolism pathways.

An unconventional myosin, myosin VI gene (MYO6), contributes to recessive and dominant hearing loss in humans and mice. The Kumamoto shaker/waltzer (ksv) mouse is a model of deafness resulting from a splice-site mutation in Myo6. While ksv/ksv homozygous mice are deaf due to cochlear hair cell stereocilia fusion at the neonatal stage, the hearing phenotypes of ksv/+ heterozygous mice have been less clear. Due to this splicing error, most MYO6 protein expression is lost in ksv mice; however, MYO6 with a single amino acid mutation (p.E461K) remains expressed. In this study, we investigated the hearing phenotypes and effect of a p.E461K mutation in ksv/+ heterozygous mice. Hearing tests indicated that hearing loss in ksv/+ mice arises concurrently at both low and high frequencies. In the low-frequency region, stereocilia fusions were detected in the inner hair cells of ksv/+ mice. Expression analysis revealed abnormal MYO6 expression and localization, along with atypical expression of proteins in the basal region of the stereocilia, suggesting that these abnormalities may contribute to stereocilia fusion in ksv/+ mice. Conversely, although the expression patterns of MYO6 and stereociliary basal-region proteins appeared normal in the cochlear area corresponding to high-frequency sounds, stereocilia loss in the outer hair cells was observed in ksv/+ mice. These findings suggest that the ksv/+ mice exhibit distinct mechanisms underlying hearing loss across areas responsible for low- and high-frequency hearing, differing from those previously reported in heterozygous Myo6 mice with loss-of-function and missense mutant alleles.

Streptozotocin (STZ) is widely used as a pancreatic beta-cell toxin to induce experimental diabetes in rodents. Strain-dependent variations in STZ-induced diabetes susceptibility have been reported in mice. Differences in STZ-induced diabetes susceptibility are putatively related to pancreatic beta-cell fragility via DNA damage response. In this study, we identified two STZ-induced diabetes susceptibility regions in chromosome 11 (Chr11) of Nagoya-Shibata-Yasuda (NSY) mice via congenic mapping using the C3H-11^NSY consomic strains, in which the entire Chr11 of STZ-resistant C3H/He (C3H) mice was replaced with that of NSY mice, and named them STZ susceptibility region for NSY (Ssnsy)-1 and -2, respectively. Screening for variants in the Ssnsy1 region revealed that NSY mice exhibited a characteristic missense c.599G>T (p.G200V) variant in a highly conserved region within the DNA repair gene, RAD50 double-strand break repair protein (Rad50). Subsequently, we generated R2B1-Rad50 knock-in mice, in which c.599T in Rad50 of STZ-susceptible C3H.NSY-R2B1 subcongenic mice was replaced with c.599G via genome editing. Compared with C3H.NSY-R2B1 mice, and R2B1-Rad50 knock-in mice showed suppressed hyperglycemia, incidence of diabetes, and decrease in plasma insulin levels following single high-dose and multiple low-dose injections of STZ. Our results suggest Rad50 as a susceptibility gene for STZ-induced diabetes that is involved in pancreatic beta-cell fragility. Forward genetic approaches using inbred mouse strains with STZ susceptibility as a phenotypic indicator will further elucidate the molecular mechanisms of pancreatic beta-cell destruction via DNA damage response.

In humans, cerebral malaria is the most common cause of malaria-related mortality. Mouse C57BL/6 (B6) sub-strains are the major model system for experimental cerebral malaria (ECM) as they show similar pathophysiology to human cerebral malaria after infection with the rodent malaria parasite Plasmodium berghei ANKA. This model system has been used to analyze the molecular mechanisms of cerebral malaria. To develop new mouse models, we analyzed the ECM susceptibility of NOD/Shi (NOD) and NSY/Hos (NSY) strains established from the non-inbred ICR strain. Both NOD and NSY strains exhibited clinical symptoms and pathologies similar to ECM in C57BL/6J (B6J) mice and died within 11 days of infection. Thus, the NOD and NSY strains are susceptible to ECM and may be useful as new ECM models. The ECM susceptibility of both strains is suggested to be due to homozygosity for the cerebral malaria susceptibility allele of the ECM susceptible ICR strain. Although analyses using B6 sub-strains have proposed that complement component 5 (C5) plays an important role in ECM pathogenesis, we found that C5 was not essential as the ECM susceptible NOD strain is C5 deficient. Thus, results obtained from B6 sub-strains may not reflect the full picture of ECM in mice. Comparative analyses of multiple ECM models will contribute to a more accurate identification of the factors essential for ECM.