The Adriamycin-induced nephropathy (AN) model plays a crucial role in advancing our understanding of and research on chronic kidney disease (CKD). This review outlines methodologies for generating AN models in mice and rats, discusses their pathophysiologic and molecular characteristics, highlights their advantages and limitations, describes therapeutic interventions that have been evaluated in these models, and presents future research perspectives. The AN model replicates key features observed in human CKD, such as proteinuria, podocyte injury, glomerulosclerosis, and tubulointerstitial fibrosis. Notably, genetic factors significantly influence the onset and severity of AN, with mutations in the Prkdc gene linked to nephrotoxicity and systemic toxicity. To evaluate therapeutic interventions for CKD, agents such as ACE inhibitors, corticosteroids, and SGLT2 inhibitors have been tested in the AN model, demonstrating promising renoprotective effects. However, the systemic toxicity of Adriamycin and variability across models pose limitations, highlighting the need for caution when translating findings to human CKD. Future advancements in genetic engineering and the application of CRISPR-Cas9 technology are expected to improve the fidelity of AN models to human disease. Additionally, discovery of biomarkers by using the AN model enables us to improve early diagnosis. These efforts are anticipated to deepen our understanding of CKD pathophysiology and contribute to developing more effective diagnostic tools and targeted therapies.

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.

There are few ultrasonographic studies on the spontaneous type 2 diabetes mellitus db/db mouse. Our objective was to dynamically investigate and assess renal morphological and hemodynamic changes in spontaneous T2DM db/db mice through high-frequency ultrasound. Eighteen male db/db mice (the model group) and twelve male db/+ mice (the control group) were included. Body weight and fasting blood glucose were measured at the ages of 8, 16 and 32 weeks. High-frequency ultrasound examinations were conducted at the same ages. Compared with those in the control group, hematoxylin-eosin and Masson staining revealed pathological changes in the renal tissue of the db/db mice at 16 weeks of age, and the lesions were significantly aggravated at 32 weeks of age. The body mass of the mice in the model group increased significantly at 8, 16 and 32 weeks of age, and the kidney volume measured by ultrasound also increased with age. Compared with those of the control group, the blood flow scores determined via power Doppler were significantly different. The peak systolic velocity (PSV), end diastolic velocity (EDV), and resistive index (RI) of the renal artery and the PSV, EDV, and RI of the segmental artery were significantly different at the sixteenth week compared with those that at the eighth week. The results of high-frequency ultrasound revealed that the renal hemodynamics of db/db mice changed at the sixteenth weeks.

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.

Gracile axonal dystrophy (gad) mutant mice present with autosomal recessive inherited sensory ataxia in the early stages, followed by age-dependent motor ataxia. This phenotype is caused by a mutation in the ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCH-L1) gene and leads to a lack of expression of UCH-L1 protein, ubiquitin-proteasome which is related to the autophagy pathway and the ubiquitin–proteasome system (UPS). To elucidate the pathophysiology of abnormal protein accumulation in gad mice, we focused on macroautophagy. Using electron microscopy, we detected a double-membrane structure, which was characteristic of autophagosomes, in gad mice. In addition, in immunohistochemistry to investigate the expression levels of autophagy-related proteins in the gracile nuclei of the gad mouse, we found upregulation of LC3 and p62 but not LAMP-2A. These results suggested that a lack of UCH-L1 expression might induce the formation of autophagosomes, but the resulting autophagy flux might be disturbed.

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.

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.

At present, there lacks a definitive pharmaceutical intervention or therapeutic approach for diabetes-associated cognitive impairment. Herein, we delved into the impact of electroacupuncture on cognitive function in high-fat diet/streptozocin (HFD/STZ)-induced type 2 diabetes mellitus (T2DM) mice and underlying mechanisms. Hippocampal insulin resistance was determined by western blot analysis. Cognitive function was evaluated by Morris water maze test. The morphology of the hippocampal neurons was observed through hematoxylin & eosin staining and Nissl staining. Synaptic plasticity was assessed by western blot analysis. Immunofluorescence, immunohistochemistry, western blot and real-time PCR were employed to detect the levels of ferroptosis markers, autophagy markers, and netrin-1. Electroacupuncture treatment exhibited ameliorative outcomes on hippocampal insulin resistance, spatial learning, memory function, neuronal damage, and synaptic plasticity in T2DM mice. Furthermore, it effectively suppressed neuronal ferroptosis in the hippocampus by upregulating GPX4 and SLC7A11 expression, and reducing 4-HNE expression. Meanwhile, electroacupuncture intervention increased the levels of Beclin1 and LC3II/LC3I, as well as decreased the levels of p62 and phosphorylated-mTOR in the hippocampus of T2DM mice, suggesting that electroacupuncture facilitated autophagy activation by inhibiting mTOR activity. 3-MA-mediated autophagy inhibition undermined the beneficial effects of electroacupuncture on neuronal ferroptosis and cognitive deficits in T2DM mice. Additionally, the beneficial effects of electroacupuncture on autophagy and ferroptosis was achieved by upregulation of netrin-1 in the hippocampus. Our study revealed that electroacupuncture therapy inhibited neuronal ferroptosis via the activation of autophagy, thereby ameliorating cognitive deficits in T2DM mice.

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.

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.

Beige adipocytes arise from white adipocytes in response to cold or other stimuli, known as browning of white adipose. Beige adipocytes play a role similar to that of brown adipocytes, express high levels of uncoupling protein 1 (UCP1), and are responsible for energy consumption via heat production, thus aiding in fat loss. Although histidine (His) and soy isoflavones (Iso) co-ingestion reportedly reduces food intake, body weight, and fat accumulation in female rats, the underlying mechanism remains unclear. Therefore, this study aimed to elucidate the mechanisms whereby histidine and soy isoflavones (His-Iso) co-ingestion suppresses fat accumulation. Female rats were fed a control diet or diet containing Iso, His, or His-Iso for 2 weeks, followed by sampling of periovarian white adipose tissue (poWAT) and retroperitoneal white adipose tissue (rWAT) and adipocyte morphology analysis. Additionally, the expression of browning- and lipid metabolism-related genes was examined. Histochemical analysis revealed the presence of multilocular lipid droplets, representative of beige adipocytes, in the poWAT and rWAT of rats in the His-Iso co-ingestion group. Quantitative PCR analysis showed that His-Iso co-ingestion upregulated brown adipocyte and beige adipocyte markers, including UCP1, indicating that His-Iso intake induces beige adipocytes. Moreover, His-Iso co-ingestion upregulated genes related to fatty acid oxidation (carnitine palmitoyl transferase 1A) and lipolysis (adipose triglyceride lipase) in WATs. In conclusion, His-Iso co-ingestion increases UCP1 expression and morphological changes to beige adipocytes, and suppresses fat accumulation by promotion of lipolysis and fatty acid oxidation in WAT.

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.

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.

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.

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.