Pneumocystis (P.) carinii is known to cause fatal pneumonia in immunocompromised rats. Cases of P. carinii interstitialpneumonia in immunocompetent rats have been shown histologically to present with perivascular lymphoid cuffs, which have previously been attributed to rat respiratory virus. This study aimsto determine the prevalence and pathological characteristics of P. carinii in immunocompetent laboratory rats in experimental facilities in Japan. An epidemiological surveyfor this agent was performed using PCR to assess 1,981 immunocompetent rats from 594 facilities in Japan. We observed that 6 of the 1,981 rats (0.30%) from 4 out of 594 facilities (0.67%)were positive for P. carinii without infection of other known pathogens. Gross pulmonary lesions were found in 4 of the 6 affected rats. The lungs of these rats containedscattered dark red/gray foci. Histopathologically, the lungs exhibited interstitial pneumonia with lymphoid perivascular cuffs: Pneumocystis cysts were observed usingGrocott’s methenamine silver stain. To our knowledge, this report is the first to reveal the prevalence of natural P. carinii infection in immunocompetent laboratory rats inJapan.

Pathogens can affect physiological and immunological reactions in immunocompromised animals and genetically engineered mice. Specifically, murine norovirus (MNV), Helicobacter, and intestinal protozoa are prevalent in rodent laboratory facilities worldwide. In this study, microbiological test results of the soiled bedding of sentinel mice showed the prevalence of MNV (50.9%, 28/55), Helicobacter hepaticus (29.1%, 16/55), Trichomonas spp. (14.5%, 8/55), and Entamoeba spp. (32.7%, 18/55). No single infections were detected as all cases were confirmed to have complex infections with two or four pathogens. In previous studies, the success rate of the cross-fostering method was not perfect; therefore, in this study, the entire mouse strain of the SPF rodent facility was rederived using embryo transfer. For up to three years, we confirmed that the results were negative with regular health surveillance tests. Embryo transfer was, thus, determined to be an effective method for the rederivation of specific pathogen free (SPF) barrier mouse facilities. This is the report for the effectiveness of embryo transfer as an example of successful microbiological clean-up of a mouse colony with multiple infections in an entire SPF mouse facility and embryo transfer may be useful for rederiving.

Minocycline is a type of tetracycline antibiotic with broad-spectrum antibacterial activity that has been demonstrated to protect the brain against a series of central nervous system diseases. However, the precise mechanisms of these neuroprotective actions remain unknown. In the present study, we found that minocycline treatment significantly reduced HT22 cell apoptosis in a mechanical cell injury model. In addition, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining confirmed the neuroprotective effects of minocycline in vivo through the inhibition of apoptosis in a rat model of controlled cortical impact (CCI) brain injury. The western blotting analysis revealed that minocycline treatment significantly downregulated the pro-apoptotic proteins BAX and cleaved caspase-3 and upregulated the anti-apoptotic protein BCL-2. Furthermore, the beam-walking test showed that the administration of minocycline ameliorated traumatic brain injury (TBI)-induced deficits in motor function. Taken together, these findings suggested that minocycline attenuated neuronal apoptosis and improved motor function following TBI.

To observe the changes in NLR family pyrin domain containing 3 (NLRP3) inflammasome in a rat model of diabetes-induced lung injury, and investigate the effect of low-dose ethanol on the production of NLRP3 inflammasome. The type I diabetic mellitus (DM) rat model was established, and the rats were divided into four groups: normal control group (CON group), low-dose ethanol group (EtOH group), diabetes group (DM group) and DM+EtOH group. The rats were fed for 6 and 12 weeks, respectively. The ratio of lung wet weight/body weight (lung/body coefficient) was calculated, and the changes of pulmonary morphology and fibrosis were observed by HE and Masson staining. The changes in pulmonary ultra-structure were examined by electron microscopy. The expressions of mitochondrial acetaldehyde dehydrogenase 2 (ALDH2) and NLRP3 inflammasome key factors, NLRP3, ASC and caspase-1 proteins were detected by western blot. Compared with the CON group, the lung/body coefficient was increased (P<0.05), lung fibrosis occurred, ALDH2 protein expression was decreased, and NLRP3, ASC and caspase-1 protein expressions were increased in the DM rats (P<0.05). Compared with the DM group, the lung/body coefficient and fibrosis degree were decreased, ALDH2 protein expression was increased (P<0.05), and NLRP3, ASC and caspase-1 protein expressions were decreased in the DM+EtOH group (P<0.05). Hence, low-dose ethanol increased ALDH2 protein expression and alleviated diabetes-induced lung injury by inhibiting the production of NLRP3 inflammasome.

Reproducibility in animal research is crucial for its reliance and translational relevance. The 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced model ofinflammatory bowel disease (IBD) is widely used but inconsistently and incompletely characterized throughout the literature. This hinders comparisons betweenstudies and influences the low rate of translation of effective preclinical molecules. The purpose of this study was to categorize TNBS-induced colitis, basedon macroscopic and microscopic scoring systems, and to identify basic routine parameters that could anticipate those categories. We retrospectively analysedmale Wistar Rattus norvegicus (n=28 for the control group and n=87 for the TNBS group) and categorized TNBS-induced colitis in threephenotypes: Mild, Moderate and Severe colitis, as for human IBD. Also, we showed that the time course of food intake and fecal excretion (but not body weight,fluid intake or welfare scores) could foresee those categories. So, routine evaluation of food intake and fecal excretion may guide researchers in planningtheir experiments, selecting the animals with the severity of colitis that better matches their aims, or applying early humane endpoints to animals that willnot be used in the experiments. In conclusion, categorizing TNBS-induced colitis enhances the reproducibility of data gathered with this experimental model andstrengths its translational relevance.

Malignant peritoneal mesothelioma (MPM) is a rare malignancy with few experimental models. This study used the human surgical specimen to establish MPMpatient-derived xenograft (PDX) models and primary cell lines to provide a study platform for MPM in vitro and in vivo, andconducted histopathological analysis. Our study used the experimental peritoneal cancer index (ePCI) score to evaluate gross pathology, and the results showedthat the ePCI score of the female and male nude mice were 8.80 ± 1.75 and 9.20 ± 1.81 (P=0.6219), respectively. The Hematoxylin and eosin (HE)staining of animal models showed that the tumor was epithelioid mesothelioma and invaded multiple organs. Immunohistochemistry (IHC) staining showed thatCalretinin, Cytokeratin 5/6, WT-1 and Ki-67 were all positive. The Swiss-Giemsa and Immunofluorescence (IF) staining of primary cell lines were also consistentwith the pathological characteristics of mesothelioma. We also performed the whole-exome sequencing (WES) to identify the mutant genes between models and thepatient. And the results showed that 21 mutant genes were shared between the two groups, and the genes related to tumorigenesis and development includingBAP1, NF2, MTBP, NECTIN2, CDC23, LRPPRC,TRIM25, and DHRS2. In conclusion, the PDX models and primary cell lines of MPM were successfully established with theepithelioid mesothelioma identity confirmed by histopathological evidence. Moreover, our study has also illustrated the shared genomic profile between modelsand the patient.

The risk of neurodegenerative disorders is increase during senescence. Understanding the mechanism of brain aging can contribute to the development of prevention. We study on the free radical theory of aging. This theory is shown to accumulation of oxidative damage. The cognitive function of mice gradually attenuates in an age-dependent manner. Interestingly, vitamin E-deficient mice showed significantly lower than the age-matched controls. After trials, lipid peroxidative products were significantly increased and we found apoptosis in hippocampus. Because it was found same phenomena on the normal aged-mice, accumulation of oxidative damage may deeply relate to dysfunction of cognition. It is difficult to recovery neuronal network after apoptosis, we observed early neuronal change prior to the induction of cell death. Treatment with a hydrogen peroxide to cultured cells, we found axonal degeneration occurred prior to the cell death. Axonal degeneration related to collapse of calcium homeostasis, induction of microtubule destabilization and autophagy dysfunction. Our results show that age-related cognitive dysfunction is oxidative damage-derived axonal degeneration. Calorie restriction is induced lifespan extension in mice and Rhesus monkeys, and one reason of lifespan extension relates to SIRT-2 expression. However, oxygen consumption also relates to lifespan extension. We are studying whether high-fat diet-treated mice induce cognitive dysfunction via acceleration of brain oxidation or not. I introduce laboratory data on this session.

is "Specific or broad: Outcome of Host-range". It seems that many pathogens infect specific hosts while some affect broad range of hosts. What is Host-range? Is this a right strategy for them to survive? This is one of fundamental questions and relates to set animal model experiments.We introduce four active speakers who are working at the frontline of infectious disease research. Dr. Horiguchi (Research Institute for Microbial Diseases, Osaka University (RIMD)) will talk about the title "Analyses of Bordetella pathogenicity through utilizing experimental animal models". Dr. Mimuro (RIMD) will present "Helicobacter pylori and laboratory animals". First two speakers are bacteriologists and they use animal models to study. Then, Dr. Iida (RIMD) gives us a talk named "Microbial Virulence: An approach from Genomics" from the viewpoint of microbiology and genomics. Final speaker is Dr. Miyazawa (Research Center for Infectious Diseases, Kyoto University) talking about "Endogenous retroviruses drive mammalian evolution including antiretroviral functions". Mammalian (=placental) development was accomplished by retrovirus-based genome reconstitution. His lecture will give us a lot of hints to think about "infection" on the meaning of life.This symposium will be performed in Japanese language.

In this study, we investigated the hair growth stimulating activity of propolis derived from Philippine endemic stingless bee (Tetragonula biroi, Friese). The crude ethanol extracted Philippine stingless bee propolis (EEP) was applied to the shaved dorsal skin of telogenic C57BL/6N mice. The anagen stage of C57BL/6N mice was determined by the degree of melanization, hair length and immunochemistry in dorsal skin. We found that not only the number of hair follicles was increased but also the expression of -catenin and proliferation of cells in hair follicles were significantly higher in EEP treated mice. These results suggest that Philippine stingless bee propolis stimulate hair growth by inducing anagen phase in resting hair follicles.