Experimental Animals最新文献

The study aimed to evaluate the periodontal disease status in different age groups and clarify the relationship between aging and the severity of periodontal disease. The test animals were cynomolgus monkeys that were born and raised at Tsukuba Primate Research Center, National Institutes of Biomedical Innovation, Health and Nutrition. The participants were divided into three groups: young (5-10 years old), middle (10-19 years old), and old (≥20 years old). The Plaque Index (PLI), Gingival Index (GI), Probing pocket depth (PPD), and Bleeding on probing (BOP) were used for the periodontal examination. Representative teeth were also examined. Polymerase chain reaction (PCR) was used to identify Porphyromonas macacae in dental plaque. Multiple comparisons and regression analyses were used to analyze the relationship between each age group and each oral examination index. Statistically significant differences were found between the age groups and periodontal examination index. Multiple regression analysis revealed that age was strongly correlated with each oral examination index. Based on these results, oral examinations of cynomolgus monkeys kept in the same environment confirmed an association between aging and periodontal disease severity. Monkeys at this facility are expected to serve as new experimental models for elucidating the mechanisms underlying the progression of age-related periodontal disease.

The present study investigated the neural health benefit of beta-sitosterol (BSS) against trimethyltin (TMT)-induced neurodegeneration in mice. Forty male Institute of Cancer Research (ICR) mice were randomly divided into Sham-veh, TMT-veh, TMT-BSS50, and TMT-BSS100. A one-time intraperitoneal injection of 2.6 mg/kg of TMT was given to mice in TMT groups. Vehicle (veh), BSS 50 mg/kg or BSS 100 mg/kg were orally given for 2 weeks. Spatial learning and memory were evaluated. Brain oxidative status, hippocampal neuropathology, and reactive astrocytes were done. White matter pathology was also evaluated. The results indicated the massy effect of TMT on induced motor ability and spatial memory deficits in accordance with increased neuronal degeneration in Cornus ammonis (CA) 1, CA3, and dentate gyrus (DG) and internal capsule white matter damage. TMT also induced the reduction of reactive astrocytes in CA1 and DG. Brain's catalase activity was significantly reduced by TMT, but not in mice with BSS treatments. Both doses of BSS treatment exhibited improvement in motor ability and spatial memory deficits in accordance with the activation of reactive astrocytes in CA1, CA3, and DG. However, they successfully prevented the increase of neuronal degeneration in CA1 found only with the BSS dose of 100 mg/kg, and it was indicated as the effective dose for neuroprotection in the vulnerable brain area. This study demonstrated mitigative effects of BSS against motor ability and memory deficits with neural health benefits, including a protective effect against CA1 neurodegeneration and a nurturing effect on hippocampal reactive astrocytes.

Ischemia/reperfusion (I/R) is a pathological process that occurs in numerous organs and is often associated with severe cellular damage and death. Ectodysplasin-A2 receptor (EDA2R) is a member of the TNF receptor family that has anti-inflammatory and antioxidant effects. However, to the best of our knowledge, its role in the progression of myocardial I/R injury remains unclear. The present study aimed to investigate the role of EDA2R during myocardial I/R injury and the molecular mechanisms involved. In vitro, dexmedetomidine (DEX) exhibited a protective effect on hypoxia/reoxygenation (H/R)-induced cardiomyocyte injury and downregulated EDA2R expression. Subsequently, EDA2R silencing enhanced cell viability and reduced the apoptosis of cardiomyocytes. Furthermore, knockdown of EDA2R led to an elevated mitochondrial membrane potential (MMP), repressed the release of Cytochrome C and upregulated Bcl-2 expression. EDA2R knockdown also resulted in downregulated expression of Bax, and decreased activity of Caspase-3 and Caspase-9 in cardiomyocytes, reversing the effects of H/R on mitochondria-mediated apoptosis. In addition, knockdown of EDA2R suppressed H/R-induced oxidative stress. Mechanistically, EDA2R knockdown inactivated the NF-κB signaling pathway. Additionally, downregulation of EDA2R weakened myocardial I/R injury in mice, as reflected by improved left ventricular function and reduced infarct size, as well as suppressed apoptosis and oxidative stress. Additionally, EDA2R knockdown repressed the activation of NF-κB signal in vivo. Collectively, knockdown of EDA2R exerted anti-apoptotic and antioxidant effects against I/R injury in vivo and in vitro by suppressing the NF-κB signaling pathway.

Rats were the first mammals to be domesticated for scientific research, and abundant physiological data are available on them. Rats are expected to continue to play an important role as experimental animals, especially with advancements such as CRISPR/Cas9 technology. Environmental enrichment aims to promote species-specific behaviors and psychological well-being. In the present study, we designed a double-decker (DD) cage, which utilizes two stacked plastic cages for rat enrichment, and investigated the influence of housing in the DD cage on rat mating behavior. The results indicated that mount frequency, total mount counts, and total ejaculation latency were significantly lower in the DD cages than in the single-decker (SD) cages. Notably, in the DD cages, the body weight loss of male rats after mating behavior was lower than that observed in the SD cage. Water consumption per day during mating behavior was also significantly lower in the DD cages, although no significant differences were observed in daily food intake during mating behavior. In addition, reproductive performance, including pregnancy rate and birth rate, did not change in the DD cages. In summary, our study demonstrated that DD cages reduce mount frequency and ejaculation latency during rat mating, resulting in decreased water consumption and weight loss in male rats. Therefore, housing in DD cages may serve as a beneficial enrichment for rats.

Histopathological features of hepatocellular carcinoma (HCC) induced by diethylnitrosamine (DEN) in mice display strong similarities with those seen in humans, including the higher tumor prevalence in males than in females. Previous studies have demonstrated that continual production of the pro-inflammatory IL-6 by Kupffer cells is involved in the initiation and progression of DEN-induced HCC and that estrogen-mediated reduction of IL-6 secretion would decrease its incidence in females. Given the predominant utilization of male mice in hepatic carcinogenesis research, the objective of this study was to examine histopathological and immunological parameters in the DEN-induced liver carcinogenesis model in female C3H mice. We observed a significant prevalence of hepatocellular hyperplasias and adenomas alongside a minimal infiltration of inflammatory cells and a scarcity of senescent areas in females. Further, a low expression of immunosuppression markers is observed in females - such as neutrophil/lymphocyte ratio, PD-1 expression in CD8 T cells, and PD-L1 in myeloid cells - compared to males. Comparative studies between susceptible and resistant hosts to chemical carcinogenesis may help to unveil novel therapeutic strategies against cancer.

The complement active product, C3a, and the receptor C3aR comprise an axis that exerts various biological functions, such as protection against infection. C3a is highly expressed in the inflamed skin and blood from patients with psoriasiform dermatitis. However, the role of the C3a/C3aR axis in psoriasiform dermatitis remains unclear because conflicting results using C3^-/- mice have been published. In this study, to elucidate the contribution of commensal microbiota in C3^-/- and wild-type (WT) mice were subjected to imiquimod-induced psoriasiform dermatitis under different housing conditions. C3^-/- mice showed increased epidermal thickness and keratinocyte proliferation markers in the inflamed ear compared to WT mice upon treatment with IMQ. These inflamed phenotypes were observed in both cohoused and separately housed conditions, and antibiotic treatment did not abolish the aggravation of IMQ-induced psoriasiform dermatitis in C3^-/- mice. These results suggested that the difference of commensal microbiota is not important for the C3-involved psoriasiform dermatitis. Keratinocyte hyperproliferation is a major feature of the inflamed skin in patients with psoriasiform dermatitis. In vitro experiments showed that C3a and C3aR agonists inhibited keratinocyte proliferation, which was abolished by introduction of a C3aR antagonist. Collectively, these results suggest that the C3a/C3aR axis plays a critical role in psoriasiform dermatitis development by inhibiting keratinocyte proliferation, regardless of the regulation of the commensal microbiota.

Acupuncture has obvious therapeutic effect on intracerebral hemorrhage (ICH). miR-34a-5p regulated by acupuncture was found to attenuate neurological deficits in ICH. However, the underlying mechanisms are unclear. Ubiquitin-like 4A (UBL4A) has not been studied in ICH. SD rats were injected with autologous blood to induce ICH and treated with Baihui-penetrating-Qubin acupuncture. Acupuncture resulted in an increase in forelimb placing test scores, and a decrease in corner test scores and brain water content of ICH rats. Histopathological examination showed that acupuncture inhibited ICH-induced inflammation, decreased damaged neurons and increased UBL4A expression. UBL4A overexpression increased cell viability, inhibited apoptosis, reduced reactive oxygen species (ROS) level and increased manganese superoxide dismutase (MnSOD) activity, mitochondrial membrane potential and mtDNA level in rat embryonic primary cortical neurons. miR-34a-5p knockdown increased UBL4A expression, apoptosis rate and ROS level in hemin-treated neurons. Dual luciferase assays showed that miR-34a-5p bound to UBL4A. Apoptotic cells and ROS level were increased in hemin-treated neurons with UBL4A and miR-34a-5p knockdown. We firstly demonstrate the inhibitory effect of UBL4A on neuronal apoptosis, and the regulation relationship between UBL4A and miR-34a-5p. This study provides a new candidate target for ICH treatment and more basis for elucidating the molecular mechanism of acupuncture. In the future, we will conduct a deeper exploration of the effects of UBL4A on ICH.

Allele-specific monoallelic gene expression is a unique phenomenon and a great resource for analyzing gene regulation. To study this phenomenon, we established new embryonic stem (ES) cell lines derived from F1 hybrid blastocysts from crosses between four mouse subspecies (Mus musculus domesticus, C57BL/6; M. musculus molossinus, MSM/Ms; M. musculus musculus, PWK; M. musculus castaneus, HMI/Ms) and analyzed the expression levels of undifferentiated pluripotent stem cell markers and karyotypes of each line. To demonstrate the utility of our cell lines, we analyzed the allele-specific expression pattern of the Inpp5d gene as an example. The allelic expression depended on the parental alleles; this dependence could be a consequence of differences in compatibility between cis- and trans-elements of the Inpp5d gene from different subspecies. The use of parental mice from four subspecies greatly enhanced genetic polymorphism. The F1 hybrid ES cells retained this polymorphism not only in the Inpp5d gene, but also at a genome-wide level. As we demonstrated for the Inpp5d gene, the established cell lines can contribute to the analysis of allelic expression imbalance based on the incompatibility between cis- and trans-elements and of phenotypes related to this incompatibility.

Progranulin (PGRN) may have two opposing effects-inflammation and anti-inflammation-in different diseases. Although previous studies have reported that PGRN is involved in liver fibrosis, its involvement in tubulointerstitial fibrosis remains to be fully elucidated. Herein, we investigated these issues using PGRN-knockout (KO) mice treated with unilateral ureteral obstruction (UUO). Eight-week-old male PGRN-KO and wild-type (WT) mice were euthanized 3 and 7 days following UUO, and their kidneys were harvested for histopathological analysis. The renal expression of PGRN was evaluated by immunohistochemical and/or western blot analyses. The renal mRNA levels of markers related to inflammation (Il1b, Tnf, Il6, Ccl2, and Adgre1) and fibrosis (Tgfb1, Acta2, Fn1, and Col1a2) were evaluated using quantitative PCR. Histological changes such as renal tubular atrophy, urinary casts, and tubulointerstitial fibrosis were significantly improved in UUO-KO mice compared with UUO-WT mice. Quantitative PCR revealed that the mRNA expression levels of all inflammation- and fibrosis-related markers were lower in UUO-KO mice than in UUO-WT mice at 3 and/or 7 days after UUO. Moreover, PGRN and GRN protein levels were higher in the kidneys of UUO-WT mice than in mice that did not undergo UUO. Elevated GRN levels associated with excess PGRN levels may be involved in the occurrence of renal inflammation and fibrosis in UUO mice.

Dehydroepiandrosterone (DHEA) is frequently integrated as an adjuvant in over a quarter of controlled ovarian hyperstimulation (COH) protocols, despite the ongoing debate regarding its impact. This study aimed to evaluate the efficacy and mechanism of action of DHEA on ovarian follicular development and ovarian response in rats with varying ovarian reserves. The study involved 75 rats categorized into 15 distinct groups. The ovarian tissues of rats in both the normal ovarian reserve group and the premature ovarian insufficiency (POI) group, induced by 4-vinylcyclohexene diepoxide (VCD) injection, were subjected to histomorphological and biochemical analyses following the administration of DHEA, either alone or in combination with COH. Follicle counting was performed on histological sections obtained from various tissues. Serum concentrations of anti-Müllerian hormone (AMH) and the quantification of specific proteins in ovarian tissue, including phosphatase and tensin homolog of chromosome 10 (PTEN), phosphoinositide 3-kinase (PI3K), phosphorylated protein kinase B (pAKT), cyclooxygenase 2 (COX-2), caspase-3, as well as assessments of total antioxidant status and total oxidant status, were conducted employing the ELISA method. The impact of DHEA exhibited variability based on ovarian reserve. In the POI model, DHEA augmented follicular development and ovarian response to the COH protocol by upregulating the PTEN/PI3K/AKT signaling pathway, mitigating apoptosis, inflammation, and oxidative stress, contrary to its effects in the normal ovarian reserve group. In conclusion, it has been determined that DHEA may exert beneficial effects on ovarian stimulation response by enhancing the initiation of primordial follicles and supporting antral follicle populations.