Institute Of Cancer Research Mice Research Articles

Development of skin health test efficacy modules in vivo

Sunlight contains ultraviolet (UV) light that causes sunburn and makes the skin age faster, leading to more wrinkles as older. The UV light can come from the natural and artificial sources. Moreover, UV light has shorter wavelengths than the visible light. Therefore, people’ eyes can’t see UV, but people’ skin can feel it. In this study, the in vivo skin health test efficacy modules have been established via the detection of skin’s moisture retention (%), skin’s cytokine expression levels, enzymatic expressions in the skin, the expression levels of hyaluronic acid (HA), collagen type I, melanin, and malondialdehyde (MDA) in the skin, and the experimental mice’ skin thickness and lesions via histo-pathologic examination. According to the results, the clinical behavior observation indexes of Institute of Cancer Research (ICR) mice in each group were normal during the experiments. Moreover, all ICR mice were survival until the end of the experiments. The moisture retention (%) of skin in ICR mice in UVB group was significant decrease after D1, D3, and D5 of UVB irradiation compared to the normal control group. Based on the IL-1β, IL-6 and TNF-α analysis expressions, both IL-1β and IL-6 expressions in UVB group were significantly increase than the control group, while there was no significant difference in the TNF-α expression between the groups. ICR mice’ skin enzymatic expressions in each group presented that catalase (CAT) expression and superoxide dismutase (SOD) activity in UVB group were significantly lower than the control group. The MDA expression in UVB group were significantly higher than the control group. The HA and collagen type I expressions in UVB group were significantly lower than the control group. However, the melanin expressions in UVB group and the control groups were not significantly different. The matrix metalloproteinase 2 (MMP-2) expressions in UVB group was significantly higher than the control group. The skin epidermal thickness in UVB group was significantly thicker than the control group. The dermal thickness in two groups was not significantly different. The number of sunburn cells in the derma in UVB group was significantly increase than the control group. The solar elastosis in the derma in two groups was not significantly different. Based on the above results, we have successfully established in vivo skin health test efficacy modules to evaluate the status of skin health. We hope the modules should be provide for the research and development (R&D) of the effective treatment included drugs and therapeutic strategies.

Machine learning and murine models explain failures of clinical sepsis trials.

Multiple clinical trials failed to demonstrate the efficacy of hydrocortisone, ascorbic acid, and thiamine (HAT) in sepsis. These trials were dominated by patients with pulmonary sepsis and have not accounted for differences in the inflammatory responses across varying etiologies of injury/illness. Hydrocortisone, ascorbic acid, and thiamine have previously revealed tremendous benefits in animal peritonitis sepsis models (cecal ligation and puncture [CLP]) in contradiction to the various clinical trials. The impact of HAT remains unclear in pulmonary sepsis. Our objective was to investigate the impact of HAT in pneumonia, consistent with the predominate etiology in the discordant clinical trials. We hypothesized that, in a pulmonary sepsis model, HAT would act synergistically to reduce end-organ dysfunction by the altering the inflammatory response, in a unique manner compared with CLP. Using Pseudomonas aeruginosa pneumonia, a pulmonary sepsis model (pneumonia [PNA]) was compared directly to previously investigated intra-abdominal sepsis models. Machine learning applied to early vital signs stratified animals into those predicted to die (pDie) versus predicted to live (pLive). Animals were then randomized to receive antibiotics and fluids (vehicle [VEH]) vs. HAT). Vitals, cytokines, vitamin C, and markers of liver and kidney function were assessed in the blood, bronchoalveolar lavage, and organ homogenates. PNA was induced in 119 outbred wild-type Institute of Cancer Research mice (predicted mortality approximately 50%) similar to CLP. In PNA, interleukin 1 receptor antagonist in 72-hour bronchoalveolar lavage was lower with HAT (2.36 ng/mL) compared with VEH (4.88 ng/mL; p = 0.04). The remaining inflammatory cytokines and markers of liver/renal function showed no significant difference with HAT in PNA. PNA vitamin C levels were 0.62 mg/dL (pDie HAT), lower than vitamin C levels after CLP (1.195 mg/dL). Unlike CLP, PNA mice did not develop acute kidney injury (blood urea nitrogen: pDie, 33.5 mg/dL vs. pLive, 27.6 mg/dL; p = 0.17). Furthermore, following PNA, HAT did not significantly reduce microscopic renal oxidative stress (mean gray area: pDie, 16.64 vs. pLive, 6.88; p = 0.93). Unlike CLP where HAT demonstrated a survival benefit, HAT had no impact on survival in PNA. Hydrocortisone, ascorbic acid, and thiamine therapy has minimal benefits in pneumonia. The inflammatory response induced by pulmonary sepsis is unique compared with the response during intra-abdominal sepsis. Consequently, different etiologies of sepsis respond differently to HAT therapy.

Auraptene ameliorates osteoporosis by inhibiting RANKL/NFATc1 pathway-mediated bone resorption based on network pharmacology and experimental evaluation.

AimsThe association of auraptene (AUR), a 7-geranyloxycoumarin, on osteoporosis and its potential pathway was predicted by network pharmacology and confirmed in experimental osteoporotic mice.MethodsThe network of AUR was constructed and a potential pathway predicted by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) terms enrichment. Female ovariectomized (OVX) Institute of Cancer Research mice were intraperitoneally injected with 0.01, 0.1, and 1 mM AUR for four weeks. The bone mineral density (BMD) level was measured by dual-energy X-ray absorptiometry. The bone microstructure was determined by histomorphological changes in the femora. In addition, biochemical analysis of the serum and assessment of the messenger RNA (mRNA) levels of osteoclastic markers were performed.ResultsIn total, 65.93% of the genes of the AUR network matched with osteoporosis-related genes. Osteoclast differentiation was predicted to be a potential pathway of AUR in osteoporosis. Based on the network pharmacology, the BMD and bone mineral content levels were significantly (p < 0.05) increased in the whole body, femur, tibia, and lumbar spine by AUR. AUR normalized the bone microstructure and the serum alkaline phosphatase (ALP), bone-specific alkaline phosphatase (bALP), osteocalcin, and calcium in comparison with the OVX group. In addition, AUR treatment reduced TRAP-positive osteoclasts and receptor activator of nuclear factor kappa-B ligand (RANKL)+nuclear factor of activated T cells 1 (NFATc1)+ expression in the femoral body. Moreover, the expressions of initiators for osteoclastic resorption and bone matrix degradation were significantly (p < 0.05) regulated by AUR in the lumbar spine of the osteoporotic mice.ConclusionAUR ameliorated bone loss by downregulating the RANKL/NFATc1 pathway, resulting in improvement of osteoporosis. In conclusion, AUR might be an ameliorative cure that alleviates bone loss in osteoporosis via inhibition of osteoclastic activity.Cite this article: Bone Joint Res 2022;11(5):304–316.

Detection and isolation of typical gut indigenous bacteria in mice fed corn starch, bread flour or whole wheat flour

AbstractWhole wheat flour (WWF) is regarded to have preventive effects on life‐style diseases. Detection, identification and isolation of WWF‐responsive gut indigenous bacteria (RIB) should reveal the gut microbiota‐mediated properties of WWF. To confirm the existence and roles of bread flour (BF)‐ and WWF‐RIB, Institute of Cancer Research mice were fed a diet containing corn starch (CS), BF or WWF as the starch source for 14 days. WWF increased in defecation. BF‐ and WWF‐RIB were detected using 16S rRNA(V4) gene amplicon sequencing. Amplicon sequence variants (ASVs) of Lactobacillus johnsonii‐like bacteria in both BF and WWF groups (respective relative abundance: 9.3% and 9.4%) were higher than those in the CS group (0.5%). While Lactobacillus intestinalis‐ and Limosilactobacillus reuteri‐like bacteria ASVs were high in the WWF group (0.8% and 1.7%, respectively), these were not detected in the CS group. In contrast, ASVs of Blautia‐, Clostridium saudiense/disporicum‐, Lactobacillus murinus‐, Muribaculaceae‐, Phocaeicola vulgatus‐ and Bifidobacterium pseudolongum‐like bacteria in CS‐fed mice were higher than those in the other mice. Among these BF‐ and WWF‐RIB, L. johnsonii and L. reuteri could be isolated. Further studies on the isolation of the RIB from the human gut are required.

Evaluation of genotoxicity of ethanolic extracts of Platostoma palustre by micronucleus assay

Platostoma palustre (Pp) jelly is a traditional food. Pp has been used as folk medicine and is effective against heat-shock, hypertension and diabetes. Therefore, the aim of this study was to evaluate the ethanolic extracts of Pp’ genotoxicity. The ethanolic extracts of Pp by using 40% ethanol for extraction. Evaluation of genotoxicity of ethanolic extracts of Pp by micronucleus assay was performed in vivo. During the in vivo genotoxicity-evaluated experiment, the experimental animal’s clinical behavior, body weight (BW), food consumption, and the percentage of RET/RBCs (reticulocytes/red blood cells) and MN-RET/RETs (micronucleated reticulocytes/reticulocytes) after the treatments of Pp ethanolic extracts were evaluated. Both sexes Institute of Cancer Research (ICR) mice were given three daily treatments by intraperitoneal injection of 2 mg/kg of mitomycin C (genotoxicity induction) or by oral route of 200 μL of PBS (normal control group). Until 48 h after the last treatment, K2-EDTA-anticoagulated peripheral blood specimens were collected. These blood samples were processed for the microscopy-based analysis using Giemsa stain and the percentage of reticulocytes and micronucleated reticulocytes was determined. The results were shown that the experimental animal’s clinical behaviors were normal in all groups. The BW and food consumption were no significant difference between all groups. RET/RBCs (‰) in male or female ICR mice in the negative control group, the normal control group, the high dose of Pp ethanolic extract group, the middle dose of Pp ethanolic extract group, and the low dose of Pp ethanolic extract group were respectively 7.8 ± 0.8 / 8.6 ± 0.8, 23.2 ± 1.5 / 22.1 ± 1.3, 22.8 ± 1.6 / 22.1 ± 1.7, 23.2 ± 1.5 / 22.6 ± 1.0 and 22.2 ± 1.9 / 23.9 ± 1.9; MN-RET/RETs (‰) in male or female ICR mice in the negative control group, the normal control group, the high dose of Pp ethanolic extract group, the middle dose of Pp ethanolic extract group, and the low dose of Pp ethanolic extract group were 2.0 ± 0.0 / 2.0 ± 0.0, 43.2 ± 10.6 / 39.6 ± 10.9, 1.8 ± 0.4 / 1.6 ± 0.5, 1.6 ± 0.5 / 1.4 ± 0.5, and 1.8 ± 0.4 / 1.6 ± 0.5, respectively. Both RET/RBCs (‰) and MN-RET/RETs (‰) in male or female ICR mice in the negative control group were significantly difference than the other groups (p &lt; 0.001). Taken all results together, Pp ethanolic extracts were without genotoxicity. Therefore, Pp ethanolic extracts were safety.

Timely and Appropriate Administration of Inhaled Argon Provides Better Outcomes for tMCAO Mice: A Controlled, Randomized, and Double-Blind Animal Study.

Inhaled argon (iAr) has shown promising therapeutic efficacy for acute ischemic stroke and has exhibited impressive advantages over other inert gases as a neuroprotective agent. However, the optimal dose, duration, and time point of iAr for acute ischemic stroke are unknown. Here, we explored variable iAr schedules and evaluated the neuroprotective effects of acute iAr administration on lesion volume, brain edema, and neurological function in a mouse model of cerebral ischemic/reperfusion injury. Adult ICR (Institute of Cancer Research) mice were randomly subjected to sham, moderate (1.5h), or severe (3h) transient middle cerebral artery occlusion (tMCAO). One hour after tMCAO, the mice were randomized to variable iAr protocols or air. General and focal deficit scores were assessed during double-blind treatment. Infarct volume, overall recovery, and brain edema were analyzed 24h after cerebral ischemic/reperfusion injury. Compared with those in the tMCAO-only group, lesion volume (p < 0.0001) and neurologic outcome (general, p < 0.0001; focal, p < 0.0001) were significantly improved in the group administered iAr 1h after stroke onset (during ischemia). Short-term argon treatment (1 or 3h) significantly improved the infarct volume (1 vs. 24h, p < 0.0001; 3 vs. 24h, p < 0.0001) compared with argon inhalation for 24h. The concentration of iAr was confirmed to be a key factor in improving focal neurological outcomes relative to that in the tMCAO group, with higher concentrations of iAr showing better effects. Additionally, even though ischemia research has shown an increase in cerebral damage proportional to the ischemia time, argon administration showed significant neuroprotective effects on infarct volume (p < 0.0001), neurological deficits (general, p < 0.0001; focal, p < 0.0001), weight recovery (p < 0.0001), and edema (p < 0.0001) in general, particularly in moderate stroke. Timely iAr administration during ischemia showed optimal neurological outcomes and minimal infarct volumes. Moreover, an appropriate duration of argon administration was important for better neuroprotective efficacy. These findings may provide vital guidance for using argon as a neuroprotective agent and moving to clinical trials in acute ischemic stroke.

Chronic Wound Infection Model of Acinetobacter baumannii in Outbred Mice.

We established a murine wound infection model with doxycycline treatment against multidrug-resistant Acinetobacter baumannii (AB5075) in Institute of Cancer Research (ICR) outbred mice. Using three groups of neutropenic ICR mice, two full-thickness dorsal dermal wounds (6 mm diameter) were made on each mouse. In two groups, wounds were inoculated with 7.0 × 104 colony-forming units of AB5075. Of these two groups, one received a 6-day regimen of doxycycline while the other was sham treated with phosphate-buffered saline as placebo control. Another uninfected/untreated group served as a control. Wound closure, clinical symptoms, bacterial burden in wound beds and organs, and wound histology were investigated. Doxycycline-treated wounds completely healed by day 21, but untreated, infected wounds failed to heal. Compared to controls, wound infections without treatment resulted in significant reductions in body weight and higher bacterial loads in wound beds, lung, liver, and spleen by day 7. Histological evaluation of wounds on day 21 revealed ulcerated epidermis, muscle necrosis, and bacterial presence in untreated wounds, while wounds treated with doxycycline presented intact epidermis. Compared to the previously developed BALB/c dermal wound model, this study demonstrates that the mouse strain selected impacts wound severity and resolution. Furthermore, this mouse model accommodates two dorsal wounds rather than only one. These variations offer investigators increased versatility when designing future studies of wound infection. In conclusion, ICR mice are a viable option as a model of dermal wound infection. They accommodate two simultaneous dorsal wounds, and upon infection, these wounds follow a different pattern of resolution compared to BALB/c mice.

Inhibition of Hedgehog Delays Liver Regeneration through Disrupting the Cell Cycle

Liver regeneration is a complicated biological process orchestrated by various liver resident cells. Hepatic cell proliferation and reconstruction of the hepatic architecture involve multiple signaling pathways. It has been reported that the Hh signal is involved in liver regeneration. However, the signal transduction pathways and cell types involved are ill studied. This study aimed to investigate hedgehog signal response cell types and the specific molecular mechanism involved in the process of liver regeneration. Partial hepatectomy (PH) of 70% was performed on ICR (Institute of Cancer Research) mice to study the process of liver regeneration. We found that the hedgehog signal was activated significantly after PH, including hedgehog ligands, receptors and intracellular signaling molecules. Ligand signals were mainly expressed in bile duct cells and non-parenchymal hepatic cells, while receptors were expressed in hepatocytes and some non-parenchymal cells. Inhibition of the hedgehog signal treated with vismodegib reduced the liver regeneration rate after partial hepatectomy, including inhibition of hepatic cell proliferation by decreasing Cyclin D expression and disturbing the cell cycle through the accumulation of Cyclin B. The current study reveals the important role of the hedgehog signal and its participation in the regulation of hepatic cell proliferation and the cell cycle during liver regeneration. It provides new insight into the recovery of the liver after liver resection.

Detection and isolation of typical gut indigenous bacteria in ICR mice fed wheat bran and wheat straw fibre

Wheat bran (WB) and wheat straw fibre (WSF) are by-products of the wheat flour industry. To prove the existence of indigenous gut bacteria responsible for WB and WSF, the Institute of Cancer Research (ICR) mice were fed a diet containing no fibre (CS), 10% WB, or 5% WSF for 14 d. The caecal microbiome was analysed by 16S rDNA (V4 region) amplicon sequencing. Typical colonies were isolated and estimated by 16S rRNA gene BLASTn analysis. The predominant amplicon sequence variants in all diet groups belonged to Bifidobacterium pseudolongum- and Faecalibaculum rodentium-like bacteria. Lactobacillus johnsonii- and Limosilactobacillus reuteri-like bacteria were high in the WB group compared with those in the CS group. Lactobacillus johnsonii Wheat-1 and L. reuteri Wheat-12 strains could be isolated. Lactobacillus johnsonii Wheat-1 exhibited good fermentation activity in 10% (w/v) WB suspension. Superoxide anion radical scavenging capacity of the WB suspension was significantly increased by the fermentation.

Neutrophil Recruitment in Arterial Thrombus and Characteristics of Stroke Patients with Neutrophil-Rich Thrombus.

Neutrophils contribute to thrombosis. However, there is limited information on the temporal course of neutrophil recruitment in thrombosis, the contribution of neutrophils to thrombus growth, and the characteristics of stroke patients with neutrophil-rich thrombi. After inducing carotid artery thrombosis in Institute of Cancer Research mice using ferric chloride, aged thrombi were produced by ligating the distal portion of the carotid artery in mice for 0.5, 1, 2, 3, 6, or 24 h. For thrombus analysis in stroke patients, we used registry data and thrombi that were obtained during intra-arterial thrombectomy. Immunohistochemistry was performed to determine thrombus composition. In the thrombi of 70 mice, Ly6G positive cell counts (neutrophils) and histone H3-positive cell counts increased in a time-dependent manner (both p<0.001). Ly6G-positive cell count was strongly correlated with histone H3-positive cell counts (r=0.910, p<0.001), but not with thrombus size (p=0.320). In 75 stroke patients, atrial fibrillation and cardioembolism were more frequent in the higher neutrophil group (32/37, 86.5%) than in the lower neutrophil group (19/38, 50%) (p=0.002). The median erythrocyte fraction was higher [52.0 (interquartile range 39.9-57.8)] in the higher neutrophil group than in the lower neutrophil group [40.3 (interquartile range 23.5-53.2)]. The fraction of neutrophils was positively correlated with that of erythrocytes (R=0.35, p=0.002). Neutrophils were recruited and increased in arterial thrombosis in a time-dependent manner; however, they were not associated with the growth of formed thrombi. Neutrophil fractions in the thrombi of stroke patients appeared to be associated with atrial fibrillation and erythrocyte fraction.

Autologous transplantation of fresh ovarian tissue in the ICR mice model

SUMMARY&#x0D; During the past 20 years, autologous transplantation of either frozen ovarian tissue for cancer patients or ovarian tissue pretreated with curative medications for premature ovarian insufficiency (POI) patients have been achieved worldwide. POI is characterized by amenorrhea before 40 years of age. As a result, juvenile cancer patients and POI patients have increased chances to give healthy birth based on this achievement. It also indicates that mastering the skills of ovarian auto-transplantation is required for researchers and doctors. In this study, we performed orthotopic auto-transplantation of fresh ovarian tissues by transplanting unilateral half ovarian tissue to the contralateral ovary in the ICR (Institute of Cancer Research) strain of outbred, heterogeneous mice to determine if the transplanted tissue could be functional. The transplantation surgery entailed taking partial ovarian tissue from the unilateral ovary of the adult ICR female mouse and then transplanting into the ovarian sac of the contralateral ovary, in which part of the ovarian tissue had been removed in advance. One week after surgery, we found that the freshly transplanted mouse ovarian tissue survived and functional, as histochemical and immunofluorescence assays have shown that not only both follicles at different developing stages and corpus luteum are available, but the morphology of them are properly maintained within the transplanted tissue. This study approved that for those who are interested in ovarian transplantation study, applying mouse model to practice ovarian tissue auto-transplantation is reliable and easy handled.

Fucoidan Protects Against High-Fat Diet-Induced Obesity and Modulates Gut Microbiota in Institute of Cancer Research Mice.

Fucoidan possesses various biological activities, such as anticoagulant, immunomodulatory, anti-inflammatory, potential antioxidant, and others. In this study, we investigated the effect of fucoidan on high-fat diet-induced obesity, inflammation, and gut microbiota in Institute of Cancer Research mice. Mice were gavaged with 50 mg/(kg·d) (Fuc0.5 group) or 250 mg/(kg·d) (Fuc2.5 group) of fucoidan for 5 weeks. Fucoidan alleviated obesity and tissue damage by decreasing body weight and body mass index, decreasing body weight gain, improved organ index, liver steatosis, and improved the structure of the small intestine. In addition, fucoidan decreased total cholesterol, triglyceride, and low-density lipoprotein cholesterol, and increased high-density lipoprotein cholesterol. Moreover, fucoidan reduced serum lipopolysaccharide concentrations, tumor necrosis factor-α, and total bile acid. Furthermore, fucoidan improved the structure of gut microbiota and significantly increased the abundance (Shannon diversity index, evenness, and Faecalibacterium prausnitzii) determined by denaturing gradient gel electrophoresis and quantitative PCR. In conclusion, our study provides a scientific basis for fucoidan as a functional food for modulating the gut microbiota and protecting against obesity.

Wedelolactone protects against cisplatin-induced nephrotoxicity in mice via inhibition of organic cation transporter 2.

The balance of cisplatin uptake and efflux, mediated mainly by organic cation transporter 2 (OCT2) and multidrug and toxin extrusion 1 (MATE1), respectively, determines the renal accumulation and nephrotoxicity of cisplatin. Using transporter-mediated cellular uptake assay, we identified wedelolactone (WEL), a medicinal plant-derived natural compound, is a competitive inhibitor of OCT2 and a noncompetitive inhibitor of MATE1. Wedelolactone showed a selectivity to inhibit OCT2 rather than MATE1. Cytotoxicity studies revealed that wedelolactone alleviated cisplatin-induced cytotoxicity in OCT2-overexpressing HEK293 cells, whereas it did not alter the cytotoxicity of cisplatin in various cancer cell lines. Additionally, wedelolactone altered cisplatin pharmacokinetics, reduced kidney accumulation of cisplatin, and ameliorated cisplatin-induced acute kidney injury in the Institute of Cancer Research mice. In conclusion, these findings suggest a translational potential of WEL as a natural therapy for preventing cisplatin-induced nephrotoxicity and highlight the need for drug-drug interaction investigations of WEL with other treatments which are substrates of OCT2 and/or MATE1.

Lactate administration does not affect denervation-induced loss of mitochondrial content and muscle mass in mice.

Lactate is considered to be a signaling molecule that induces mitochondrial adaptation and muscle hypertrophy. The purpose of this study was to examine whether lactate administration attenuates denervation‐induced loss of mitochondrial content and muscle mass. Eight‐week‐old male Institute of Cancer Research mice underwent unilateral sciatic nerve transection surgery. The contralateral hindlimb served as a sham‐operated control. From the day of surgery, mice were injected intraperitoneally with PBS or sodium lactate (equivalent to 1 g·kg−1 body weight) once daily for 9 days. After 10 days of denervation, gastrocnemius muscle weight decreased to a similar extent in both the PBS‐ and lactate‐injected groups. Denervation significantly decreased mitochondrial enzyme activity, protein content, and MCT4 protein content in the gastrocnemius muscle. However, lactate administration did not have any significant effects. The current observations suggest that daily lactate administration for 9 days does not affect denervation‐induced loss of mitochondrial content and muscle mass.

Protective effects of folic acid on colon carcinogenesis induced by azoxymethane in mice

Colon cancer has been considered a leading cause of cancer-associated death. Folic acid is a vitamin necessary for cellular physiological functions and cell viability. However, the association between folic acid intake and colon cancer has been examined in several prospective cohort studies are controversial. This study investigated the effects of folate intake on colon carcinogenesis and oxidative stress in an azoxymethane (AOM)/dextran sodium sulfate (DSS) institute for cancer research (ICR) mouse model. Thirty male ICR mice (5 weeks old) were divided into the control group and the experimental group supplied 0.03% folic acid via drinking water (50 mL/week/mouse) for 6 weeks. To induce colonic pre-neoplastic lesions, the animals were subcutaneously injected three times weekly with AOM (10 mg/kg body weight), followed by 2% DSS in drinking water for a week. Folic acid supplementation significantly suppressed the total number of aberrant crypt foci and aberrant crypts. Histological image data showed that folic acid supplementation attenuated neoplastic change. In addition, we measured the thiobarbituric acid reactive substances concentration of dry feces samples to identify the effect of folic acid on reactive oxygen accumulation. The folic acid supplementation group had reduced reactive oxygen species levels in dry feces compared to the control group. In conclusion, these findings indicate that folic acid suppresses colon carcinogenesis and oxidative stress in an AOM/DSS mouse model.

Effect of leukopenia induced by cyclophosphamide on the initial stage of arterial thrombosis in mice

IntroductionLeukocytes are found in organizing thrombi and are associated with thrombus growth. However, their role in the initial stage of thrombus formation is not well known. We investigated the role of leukocytes in the early stage of arterial thrombosis by inducing leukopenia. MethodsIn this double-blind, randomized, placebo-controlled study, 72 Institute of Cancer Research mice were randomly treated with intraperitoneal 100 mg/kg cyclophosphamide or normal saline. The primary outcome was time to occlusion after FeCl3 treatment. We also compared thrombus size, histological composition, and association with peripheral blood cell counts between cyclophosphamide and control groups. ResultsCyclophosphamide treatment significantly decreased leukocyte counts by 82.8% compared to placebo (P < 0.001). The time to occlusion was significantly longer in the cyclophosphamide group (3.31 ± 1.59 min) than in the control group (2.30 ± 1.14 min; P = 0.003). The immunoreactivity for Ly6G-positive cells, intracellular histone H3, and released histone H3 in thrombi was significantly reduced in the cyclophosphamide group by 92.8%, 50.2%, and 34.3%, respectively. Time to occlusion had a moderate negative correlation with leukocyte count in peripheral blood (r = −0.326, P = 0.022) in the entire group. ConclusionsCyclophosphamide-induced leukopenia attenuated thrombus formation during the early stage of arterial thrombosis. Our findings suggest the potential role of leukocytes in the initial stage of arterial thrombosis.

ClbG in Avian Pathogenic Escherichia coli Contributes to Meningitis Development in a Mouse Model.

Colibactin is a complex secondary metabolite that leads to genotoxicity that interferes with the eukaryotic cell cycle. It plays an important role in many diseases, including neonatal mouse sepsis and meningitis. Avian pathogenic Escherichia coli (APEC) is responsible for several diseases in the poultry industry and may threaten human health due to its potential zoonosis. In this study, we confirmed that clbG was necessary for the APEC XM strain to produce colibactin. The deletion of clbG on APEC XM contributed to lowered γH2AX expression, no megalocytosis, and no cell cycle arrest in vitro. None of the 4-week Institute of Cancer Research mice infected with the APEC XM ΔclbG contracted meningitis or displayed weakened clinical symptoms. Fewer histopathological lesions were observed in the APEC XM ΔclbG group. The bacterial colonization of tissues and the relative expression of cytokines (IL-1β, IL-6, and TNF-α) in the brains decreased significantly in the APEC XM ΔclbG group compared to those in the APEC XM group. The tight junction proteins (claudin-5, occludin, and ZO-1) were not significantly destroyed in APEC XM ΔclbG group in vivo and in vitro. In conclusion, clbG is necessary for the synthesis of the genotoxin colibactin and affects the development of APEC meningitis in mice.

Comparison of intrinsic exercise capacity and response to acute exercise in ICR (Institute of Cancer Research) mice derived from three different lineages

BackgroundAs a laboratory animal resource, the ICR mouse is commonly used in a variety of research fields. However, information on differences in exercise-related characteristics in ICR mice derived from different lineages and the underlying mechanisms remains to be elucidated. In this study, we investigated the intrinsic exercise capacity and a magnitude of response to acute exercise, and sought to identify mechanisms contributing to difference in Korl:ICR (a novel ICR lineage recently established by the National Institute of Food and Drug Safety Evaluation, Korea) and two commercialized ICR lineages derived from different origins (viz., A:ICR mouse from Orient Bio Com, the United States, and B:ICR mouse from Japan SLC Inc., Japan).ResultsResults showed that despite no significant difference in body weight and weight-proportioned tissue mass of heart and skeletal muscles among groups, the relatively low intrinsic exercise capacity and exaggerated response to acute exercise were identified in B:ICR comparted with Korl:ICR and A:ICR, as reflected by total work and lactate threshold (LT). Also, the mitochondrial efficiency expressed as the complex 1 and complex 1 + 2 respiratory control ratio (RCR) values for cardiac mitochondrial O2 consumption in B:ICR was significantly lower than that in Korl:ICR with higher level of state 2 respiration by glutamate/malate and UCP3 expression in cardiac muscle.ConclusionsTaken together, these results indicate that the intrinsic exercise capacity of ICR mouse varies according to lineages, suggesting the role of cardiac mitochondrial coupling efficiency as a possible mechanism that might contribute to differences in the intrinsic exercise capacity and magnitude of response to exercise.

Single-Dose Toxicity Study on ML171, a Selective NOX1 Inhibitor, in Mice.

Background ML171 is a potent nicotinamide adenine dinucleotide phosphate oxidase (NOX) inhibitor with isoform selectivity only for NOX1. This study is aimed at investigating the safety of ML171 after a single intraperitoneal (IP) injection in mice. Methods The toxicity of a single dose of ML171 was evaluated in 6-week-old Institute of Cancer Research (ICR) mice in a good laboratory practice (GLP) laboratory. Twenty-five mice of each sex were assigned to five groups: negative control, vehicle control, and 125, 250, and 500 mg/kg of ML171. All mice were acclimatized for one week before beginning the study. Mice received an IP injection of ML171 or vehicle. The general condition and mortality of the animals were observed. The mice were sacrificed to evaluate histopathology 14 days after the administration of ML171 or vehicle. Results Bodyweights were not significantly different in any group. Three males and one female died due to ML171 administration in the 500 mg/kg dose group. Autopsies of the surviving mice did not reveal any significant abnormalities after the injection of 125 mg/kg of ML171. However, the anterior lobe edge of the liver was thickened and adhesions between the liver and adjacent organs were observed in mice treated with 250 or 500 mg/kg of ML171. In addition, hypertrophy of centrilobular hepatocytes and inflammatory cell infiltration were observed after injection of 250 and 500 mg/kg of ML171. Conclusion Our results indicate that the lethal IP injection dose of ML171 is 500 mg/kg for both males and females. Mortality were not observed for lower doses of ML171. The safe dose of single IP ML171 in ICR mice was 250 mg/kg or less. Further studies are needed to confirm the safety of ML171 in the human body.

Effects of feeder cells on proliferation of inducible pluripotent stem cells in chicken

ABSTRACT Although inducible pluripotent stem cells (iPSC) have been identified in poultry, the induction efficiency is low, because different culture media, feeder cells and feeder layer treatments affect the efficiency of somatic cell reprogramming. We investigated improvement of the feeder culture system for induction of chicken iPSC by comparing the effects of different types and treatments of feeder cells on the growth and proliferation of chicken iPSC. Mouse embryo fibroblasts (MEF), but not Sandoz inbred mouse-derived thioguanine-resistant and ouabain-buffalo rat cells, were suitable feeder cells that supported proliferation of chicken iPSC. Institute of Cancer Research (ICR) mice, but not Kunming mice, were suitable for preparing MEF that support cell proliferation. Also, MEF feeder cells that had been inactivated by mitomycin C were effective. Leukemia inhibitory factor was not required for chicken iPSC culture when MEF feeder cells were used. The optimal feeder culture system for growth and proliferation of chicken iPSC consisted of MEF feeder cells derived from ICR mice that were inactivated by mitomycin C combined with embryonic germ cell culture medium.