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The current study aimed to investigate the effects of ageing on oral immunity using ß-defensin (DEFB) 1/2 as a marker and evaluate the effects of curcumin (CUR) on these processes. The study sample included thirty male C57BL/6J mice divided into three groups based on the treatment method used. The young control (YC) and old control (OC) groups received 0·5 % methylcellulose-400 (CUR vehicle) orally for 5 days, whereas the CUR group of older mice received a CUR solution suspended in 0·5 % methylcellulose-400 (dose: 3·0 mg/kg body). DEFB1/2 and immune indicator levels were measured in the saliva and salivary glands post-treatment. The saliva volume and protein content were significantly reduced in the OC group compared with the YC group. CUR administration restored these parameters, decreased DEFB1 expression in the salivary gland and increased DEFB1/2 secretion and DEFB2 expression. These findings were supported by epigenetic gene regulation and partial cytokine activation from changes in WD40 repeat protein 5, TNF alpha and IL-1beta. CUR can partially restore age-related changes in oral immune responses and promote oral health, thereby preventing frailty in the older population through a nutritional therapeutic pathway.
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Since the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, we have established an archive system of livestock and wild animals from the surrounding ex-evacuation zone. Wildlife within the alert zone have been exposed to low-dose-rate (LDR) radiation for a long continuous time. In this study, we analysed the morphological characteristics of the testes and in vitro fertilization (IVF) capacity of cryopreserved sperm of racoons from the ex-evacuation zone of the FDNPP accident. The radioactivity of caesium-137 (137 Cs) was measured by gamma-ray spectrometry, and the measured radioactivity concentration was 300-6,630 Bq/kg in the Fukushima raccoons. Notably, normal spermatogenesis was observed in the seminiferous tubules of the testes, with the germinal epithelium composed of a spermatogenic cell lineage with no evident ultrastructural alterations; freeze-thawing sperm penetration ability was confirmed using the interspecific zona pellucida-free mouse oocytes IVF assays. This study revealed that the chronic and LDR radiation exposure associated with the FDNPP accident had no adverse effect on the reproductive characteristics and functions of male raccoons.
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Radioisótopos de Césio/efeitos adversos , Acidente Nuclear de Fukushima , Guaxinins/fisiologia , Testículo/efeitos da radiação , Animais , Radioisótopos de Césio/análise , Criopreservação/veterinária , Feminino , Fertilização in vitro , Espécies Introduzidas , Japão , Masculino , Camundongos Endogâmicos ICR , Guaxinins/anatomia & histologia , Preservação do Sêmen/veterinária , Espermatogênese/efeitos da radiação , Testículo/fisiologia , Testículo/ultraestruturaRESUMO
Cetaceans accumulate high levels of environmental pollutants, yet their toxicological studies have been difficult due to technical and ethical issues. It is essential to identify and fill the current knowledge gaps in the in vitro assays available for cetaceans. The present study establishes a novel in vitro assay that uses the fibroblasts of a finless porpoise (Neophocaena asiaeorientalis) (FF) stranded in the Seto Inland Sea (SIS) to answer questions about the cytotoxicity and risks of environmental pollutants. FF were treated with 17 compounds including polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane and their metabolites (DDTs) and evaluated for cytotoxicity, viability, and apoptosis. The results of FF were compared with those of human fibroblasts (HF). The relative potencies of the test compounds were comparable between the two species, as EC50 of these compounds significantly correlated for FF and HF. Exposure-activity ratios (EARs) revealed that accumulation of PCBs and DDTs are likely to pose adverse effects at the cellular level in the SIS finless porpoises, as their tissue concentrations exceeded EC50 values obtained in this study. This study successfully evaluated the risks of environmental pollutants using cetacean fibroblasts isolated by a non-invasive method that may be applied to various cetacean species and compounds.
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Poluentes Ambientais , Toninhas , Poluentes Químicos da Água , Animais , Fibroblastos , Medição de Risco , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidadeRESUMO
Biallelic germline mutations in the DNA mismatch repair gene MLH1 lead to constitutional mismatch repair-deficiency syndrome and an increased risk for childhood hematopoietic malignancies, including lymphoma and leukemia. To examine how Mlh1 dysfunction promotes lymphoma as well as the influence of ionizing radiation (IR) exposure, we used an Mlh1-/- mouse model and whole-exome sequencing to assess genomic alterations in 23 T-cell lymphomas, including 8 spontaneous and 15 IR-associated lymphomas. Exposure to IR accelerated T-cell lymphoma induction in the Mlh1-/- mice, and whole-exome sequencing revealed that IR exposure neither increased the number of mutations nor altered the mutation spectrum of the lymphomas. Frequent mutations were evident in genes encoding transcription factors (e.g. Ikzf1, Trp53, Bcl11b), epigenetic regulators (e.g. Suv420h1, Ep300, Kmt2d), transporters (e.g. Rangap1, Kcnj16), extracellular matrix (e.g. Megf6, Lrig1), cell motility (e.g. Argef19, Dnah17), protein kinase cascade (e.g. Ptpro, Marcks) and in genes involved in NOTCH (e.g. Notch1), and PI3K/AKT (e.g. Pten, Akt2) signaling pathways in both spontaneous and IR-associated lymphomas. Frameshift mutations in mononucleotide repeat sequences within the genes Trp53, Ep300, Kmt2d, Notch1, Pten and Marcks were newly identified in the lymphomas. The lymphomas also exhibited a few chromosomal abnormalities. The results establish a landscape of genomic alterations in spontaneous and IR-associated lymphomas that occur in the context of mismatch repair dysfunction and suggest potential targets for cancer treatment.
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Reparo de Erro de Pareamento de DNA/genética , Mutação da Fase de Leitura/genética , Mutação em Linhagem Germinativa/genética , Linfoma de Células T/genética , Proteína 1 Homóloga a MutL/genética , Animais , Epigênese Genética/genética , Proteínas de Membrana Transportadoras/genética , Camundongos , Camundongos Endogâmicos C57BL , Radiação Ionizante , Transdução de Sinais/genética , Fatores de Transcrição/genéticaRESUMO
Seasonally, bred wild mice provide a unique bioresource, with high genetic diversity that differs from wild-derived mice and laboratory mice. This study aimed to establish an alternative superovulation method using wild large Japanese field mice (Apodemus speciosus) as the model species. Specifically, we investigated how the application of inhibin antiserum and equine chorionic gonadotropin (IASe) during both the reproductive and non-reproductive seasons impact the ovulation rate and competence of embryo development after in vitro fertilization (IVF) with fresh and cryopreserved sperm. When the wild mice were superovulated by injecting eCG followed by human chorionic gonadotropin (hCG), few oocytes were collected during the reproductive and non-reproductive seasons. In comparison, the number of ovulated oocytes was dramatically enhanced by the administration of IASe, followed by isolation of ovulated oocytes 24 hr after 30 IU hCG administration. The IVF oocytes that were in vitro cultured (IVC) with medium containing serum further developed to the 2- and/or 4-cell stage using both fresh and frozen-thawed sperm. In conclusion, we successfully established an alternative protocol for collecting ovulated oocytes from wild large Japanese field mice by administering IASe and hCG during both the reproductive and non-reproductive seasons. This study is the first to develop IVF-IVC wild large Japanese field mice beyond the 2- and/or 4-cell stage in vitro using fresh and cryopreserved sperm. This approach could be used in other species of wild or endangered mice to reduce the number of animals used for experiments, or in maintaining stocks of germ cells or embryos.
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Gonadotropina Coriônica/farmacologia , Desenvolvimento Embrionário/efeitos dos fármacos , Gonadotropinas Equinas/farmacologia , Soros Imunes/farmacologia , Murinae , Indução da Ovulação/veterinária , Superovulação/efeitos dos fármacos , Animais , Criopreservação/veterinária , Embrião de Mamíferos , Feminino , Fertilização in vitro/veterinária , Cavalos , Humanos , Inibinas/antagonistas & inibidores , Masculino , Oócitos/citologia , Preservação do Sêmen/veterináriaRESUMO
BACKGROUND/AIM: Cancer remains a major global health challenge, with an estimated 10 million cancer-related deaths in 2020, hindering efforts to extend life expectancy. Cisplatin, an effective platinum-based chemotherapeutic agent used against various malignancies, has numerous side effects. Ganoderma lucidum is a traditional Chinese medicine with extensive historical use and proven biological activity. This study investigated the effects of G. lucidum on cisplatin-induced nephrotoxicity and gastrointestinal toxicity. MATERIALS AND METHODS: RAW264.7 cells were treated with cisplatin, G. lucidum, or both. Cytotoxicity and antioxidant capacity were measured. Slc:ICR (ICR) mice were treated with cisplatin, G. lucidum, or both. The survival rate and physiological data were measured. RESULTS: G. lucidum suppressed cisplatin-induced cytotoxicity and apoptosis in RAW264.7 cells. G. lucidum suppressed cisplatin-induced nephrotoxicity and gastrointestinal toxicity via its antioxidant effects in ICR mice. CONCLUSION: The suppressive mechanism of G. lucidum may be mediated via its antioxidant effects. These findings indicate its potential to reduce the side effects of cisplatin.
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Apoptose , Cisplatino , Reishi , Animais , Cisplatino/efeitos adversos , Camundongos , Reishi/química , Apoptose/efeitos dos fármacos , Células RAW 264.7 , Antineoplásicos/efeitos adversos , Antioxidantes/farmacologia , Camundongos Endogâmicos ICR , Masculino , Rim/efeitos dos fármacos , Rim/patologia , Gastroenteropatias/induzido quimicamente , Gastroenteropatias/patologiaRESUMO
Since the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, great attention has been paid to the impact of chronic low-dose-rate (LDR) radiation exposure on biological systems. The reproductive system is sensitive to radiation, with implications connected to infertility. We investigated the testis ultrastructure of the wild large Japanese field mouse (Apodemus speciosus) from three areas contaminated after the FDNPP accident, with different levels of LDR radiation (0.29 µSv/h, 5.11 µSv/h, and 11.80 µSv/h). Results showed good preservation of the seminiferous tubules, comparable to the unexposed animals (controls), except for some ultrastructural modifications. Increases in the numerical density of lipid droplet clusters in spermatogenic cells were found at high levels of LDR radiation, indicating an antioxidant activity rising due to radiation recovery. In all groups, wide intercellular spaces were found between spermatogenic cells, and cytoplasmic vacuolization increased at intermediate and high levels and vacuolated mitochondria at the high-level. However, these findings were also related to the physiological dynamics of spermatogenesis. In conclusion, the testes of A. speciosus exposed to LDR radiation associated with the FDNPP accident showed a normal spermatogenesis, with some ultrastructural changes. These outcomes may add information on the reproductive potential of mammals chronically exposed to LDR radiation.
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Assessment of risks associated with childhood exposure to ionizing radiation when combined with chemical carcinogens is of great importance. We studied the age-dependence of the effect of combined exposure to ionizing radiation (IR) and a chemical carcinogen on lung carcinogenesis. Female 1-, 5-, and 22-week-old Wistar rats were locally irradiated on the thorax with X-rays (3.18 Gy) and/or were injected intraperitoneally with N-nitrosobis(2-hydroxypropyl)amine (BHP) (1g/kg body weight) 1 week after X-ray exposure or at 23 weeks of age. Rats were terminated at 90 weeks of age. We found that: (i) the incidence of lung tumors (adenoma and adenocarcinoma) increased slightly as a function of age at X-ray exposure, although this was not statistically significant, while the incidence induced by BHP decreased with increasing age at administration; (ii) combined exposure to X-rays at 5 or 22 weeks with BHP 1 week later enhanced the tumor incidence, and the effect at early-life stage (5 weeks irradiation) was more effective than that at late-life stage (22 weeks irradiation); (iii) combined exposure preferentially enhanced malignant transformation; (iv) although a longer interval between the X-ray and BHP treatments reduced the combined effect, risks of early-life irradiation at 1 or 5 weeks of age lasted into adulthood; (v) adenomas and adenocarcinomas induced by X-ray and/or BHP originated from surfactant apoprotein A-positive alveolar type II cells; and (vi), extracellular signal-regulated kinase pathway activation was observed in half the adenocarcinomas, regardless of the exposure schedule. In conclusion, combined exposure may enhance lung tumorigenesis more synergistically at early-life stage (5 weeks of age) than later-life stage.
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Carcinógenos/toxicidade , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/efeitos da radiação , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Induzidas por Radiação/induzido quimicamente , Nitrosaminas/toxicidade , Tórax/efeitos dos fármacos , Tórax/efeitos da radiação , Adenocarcinoma/induzido quimicamente , Adenocarcinoma/etiologia , Adenocarcinoma/patologia , Adenoma/induzido quimicamente , Adenoma/etiologia , Envelhecimento/efeitos dos fármacos , Envelhecimento/efeitos da radiação , Animais , Animais Recém-Nascidos , Transformação Celular Neoplásica/patologia , Feminino , Neoplasias Pulmonares/etiologia , Neoplasias Pulmonares/patologia , Neoplasias Induzidas por Radiação/patologia , Ratos , Ratos Wistar , Tórax/patologiaRESUMO
Multiple epidemiological studies have shown that obesity is a serious risk factor for cancer development. While the underlying mechanisms between obesity and cancer are still unknown, obesity disrupts the role of adipocytes in energy homeostasis, and the alteration of adipokine, insulin and sex steroid signaling. Recently, it has been identified that adipose tissue-derived exosome-like vesicles (ELVs) regulate metabolic homeostasis. In this study, we collected ELVs from adipose tissue of an obese mouse (ob/ob) strain and control mouse (C57BL/6) strain, and checked whether adipose ELVs influence radiation-induced cell death on mouse fibroblast cells (m5S). Furthermore, we analyzed the micronucleus (MN) frequency in survived cells after radiation exposure to investigate the effect of ELVs on radiation-induced genomic instability. We first observed that ELVs from control and obese mice showed enhanced colony forming ability in un-irradiated m5S cells. However, enhanced survival was observed only in 3 Gy-irradiated m5S cells with obese ELV treatment. Despite no ELV effect on colony size, interestingly, the frequency of MN in survived m5S cells after 3 Gy irradiation was elevated when treated obese ELVs compared to control ELVs. These results suggested that obese mouse adipose ELVs could enhance the survival of irradiated cells harboring increased radiation-induced genomic instability.
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Exossomos , Camundongos , Animais , Exossomos/metabolismo , Sobrevivência Celular , Camundongos Obesos , Camundongos Endogâmicos C57BL , Tecido Adiposo/metabolismo , ObesidadeRESUMO
BACKGROUND/AIM: We investigated the effects of chloroquine, an autophagy inhibitor, on doxorubicin-induced apoptosis in A549 cells. MATERIALS AND METHODS: A549 cells were treated with doxorubicin, chloroquine, or both. Then, cytotoxicity was measured. The expression levels of caspases and mitogen-activated protein kinases were also quantified. In addition, the levels of doxorubicin-derived reactive oxygen species were measured. RESULTS: Chloroquine enhanced doxorubicin-induced apoptosis and oxidative stress and suppressed the doxorubicin-induced extracellular-signal-regulated kinase activation. CONCLUSION: Chloroquine enhances doxorubicin-induced and oxidative stress-mediated apoptosis. This mechanism may involve the dephosphorylation of extracellular-signal-regulated kinases.
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Apoptose , Cloroquina , Células A549 , Cloroquina/farmacologia , Doxorrubicina/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismoRESUMO
BACKGROUND/AIM: We examined the inhibitory effect of mulberry leaf (ML) (Morus alba L.) administration on the development of hepatocellular carcinoma (HCC) in stelic animal model (STAM) mice. This STAM mouse model of nonalcoholic steatohepatitis (NASH) closely resembles the progression from NASH to HCC in human clinical practice. MATERIALS AND METHODS: Streptozotocin (STZ, 200 µg) was administered to C57L/6J mice that were fed a high-fat diet (HFD; STAM mice) with 1% ML ad libitum. After sacrificing, the liver and blood were collected. Biochemical tests of plasma and histologic examination of the liver were performed. RESULTS: Pathologic examination of all (6/6) liver samples of the STAM mice showed HCC. On the contrary, in STAM mice that received ML, fat deposition and adenoma were observed in 6/6 and 2/6 of the liver samples, respectively, but there was no HCC. CONCLUSION: Administration of ML in STAM mice inhibited the progression from nonalcoholic hepatitis (NASH) to HCC. ML may be effective in preventing the development of HCC.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Morus , Administração Oral , Animais , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/prevenção & controle , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/prevenção & controle , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/patologia , Folhas de Planta , Pós , EstreptozocinaRESUMO
PURPOSE: To study the environmental radiation effects of wild animals after the Fukushima Dai-ichi nuclear power plant accident, we assessed effects on hematopoietic progenitor cells (HPCs) in large Japanese field mice (Apodemus speciosus). MATERIALS AND METHODS: A. speciosus were collected from three contaminated sites and control area. The air dose-rates at the control and contaminated areas were 0.96 ± 0.05 µGy/d (Hirosaki), 14.4 ± 2.4 µGy/d (Tanashio), 208.8 ± 31.2 µGy/d (Ide), 470.4 ± 93.6 µGy/d (Omaru), respectively. We investigated possible DNA damage and pro-inflammatory markers in the bone marrow (BM) cells. The colony-forming potential of BM cells was estimated by the number of HPC colony-forming cells. Radiation-induced genomic instability (RIGI) in HPCs was also analyzed by quantifying delayed DNA damage in CFU-GM clones. RESULTS: Although no significant differences in DNA damage and inflammation markers in BM cells from control and contaminated areas, the number of HPC colonies exhibited an inverse correlation with air dose-rate. With regard to RIGI, no significant differences in DNA damage of CFU-GM clones between the mice from the control and the three contaminated areas. CONCLUSIONS: Our study suggests that low dose-rate radiation of more than 200 Gy/d reduced HPCs, possibly eliminating genomically unstable HPCs.
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Acidente Nuclear de Fukushima , Animais , Arvicolinae , Instabilidade Genômica , Células-Tronco Hematopoéticas/efeitos da radiação , Camundongos , MurinaeRESUMO
PURPOSE: After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in Japan on March 11 2011, the surroundings became contaminated with radionuclides. To understand the possible biological effects after chronic low dose-rate radiation in contaminated areas of Fukushima, we assessed the effects in large Japanese field mice (Apodemus speciosus) by means of chromosome aberration analysis. MATERIALS AND METHODS: We collected A. speciosus in five sites around Namie Town, Fukushima (contaminated areas) and in two sites in Hirosaki City, Aomori (control areas, 350 km north of FDNPP) from autumn 2011 to 2013. The number of mice captured and ambient dose-rates were as follows: high (n = 11, 10.1-30.0 µGy h-1), moderate (n = 10, 5.7-15.6 µGy h-1), low (n = 12, 0.23-1.14 µGy h-1) and control (n = 20, 0.04-0.07 µGy h-1). After spleen extraction from rodents, spleen cell culture was performed to obtain metaphase spreads. Chromosome aberrations were assessed on Giemsa-stained metaphase spreads. RESULTS: Although the mice in the contaminated areas were chronically exposed, there was no radiation-specific chromosome aberrations observed, such as dicentric chromosomes and rings. Some structural aberrations such as gaps and breaks were observed, and these frequencies decreased annually in mice from Namie Town. CONCLUSION: These findings suggest that chromosome aberration analysis is useful to evaluate and monitor radiation effects in wild animals.
Assuntos
Acidente Nuclear de Fukushima , Monitoramento de Radiação , Animais , Arvicolinae , Radioisótopos de Césio , Aberrações Cromossômicas , Camundongos , Murinae/genética , Centrais NuclearesRESUMO
Wild large Japanese field mice (Apodemus speciosus) responses to cyclic seasonal changes are associated with physiological and behavioral changes. However, the detailed regulation of oogenesis in the ovary during the seasonal reproductive cycle in wild large Japanese field mice has not been studied. We assessed the dynamics and changes in ovarian morphology and hormone concentrations associated with reproductive seasonality throughout the year. The stages of the ovarian morphological breeding cycle of wild large Japanese field mice were classified as breeding, transition, and non-breeding periods during the annual reproductive cycle. Measurement of blood estradiol concentrations throughout the year showed that the levels in September and October were higher than those in other months. It is presumed that follicle development starts from a blood estradiol concentration of 38.4 ± 27.1 pg/mL, which marks a shift from the transitional season to the breeding season, followed by the transition to the non-breeding season at 26.1 ± 11.6 pg/mL. These results suggest that seasonal follicle development in wild rodents is correlated with estradiol regulation. We consider this species to be an alternative animal model for studying seasonal reproductive changes and the effects of environmental changes.
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BACKGROUND/AIM: We investigated the effect of Kumaizasa leaf extract (KLE) on innate immunity using the HEK293 and RAW 264.7 cell lines. MATERIALS AND METHODS: KLE, lipopolysaccharides (LPS), or KLE with LPS were added to RAW 264.7 cells. The TNF-α and IL-1ß mRNA expression was then quantified. The expression of MAPKs, NFĸB, TNF-α and IL-1ß proteins was also quantified. In addition, KLE was added to HEK293 cells and the IL-8 concentration was measured. RESULTS: In RAW 264.7 cells, KLE increased the levels of TNF-α and IL-1ß mRNA. By contrast, when KLE and LPS were added to RAW 264.7 cells, the increase in TNF-α and IL-1ß mRNA was ameliorated. Similarly, the expression of JNK and ERK proteins was reduced. The addition of KLE to HEK293 cells induced IL-8 production. CONCLUSION: Based on these results, a KLE-mediated mechanism may regulate immunity by suppressing the expression of JNK and ERK, which are involved in inflammatory signal transduction.
Assuntos
Imunidade Inata/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Sasa , Animais , Citocinas/genética , Citocinas/imunologia , MAP Quinases Reguladas por Sinal Extracelular/imunologia , Células HEK293 , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/imunologia , Lipopolissacarídeos/farmacologia , Macrófagos/imunologia , Camundongos , Folhas de Planta , Células RAW 264.7RESUMO
Alopecia is one of the common symptoms after high-dose radiation exposure. In our experiments, neonatal mice that received 7 Gy X-ray exhibited defects in overall hair growth, except for their cheeks. This phenomenon might suggest that some substances were secreted and prevented hair follicle loss in the infant tissues around their cheeks after radiation damage. In this study, we focused on exosome-like vesicles (ELV) secreted from cheek skin tissues and back skin tissues, as control, and examined their radiation protective effects on mouse fibroblast cell lines. We observed that ELV from irradiated cheek skin showed protective effects from radiation. Our results suggest that ELV from radiation-exposed cheek skin tissue is one of the secreted factors that prevent hair follicle loss after high-dose radiation.
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Bochecha/fisiologia , Bochecha/efeitos da radiação , Vesículas Extracelulares/metabolismo , Animais , Animais Recém-Nascidos , Sobrevivência Celular/efeitos da radiação , Ensaio de Unidades Formadoras de Colônias , Reparo do DNA/efeitos da radiação , Relação Dose-Resposta à Radiação , Vesículas Extracelulares/efeitos da radiação , Feminino , Fibroblastos/efeitos da radiação , Cabelo/crescimento & desenvolvimento , Masculino , Pele/efeitos da radiação , Raios XRESUMO
The intergenerational effects from chronic low-dose exposure are matters of concern. It is thus important to elucidate the radiation-induced effects of germ cell maturation, fertilization and embryonic development. It is well known that DNA methylation levels in CpG sites in gametes are reprogrammed in stages during their maturity. Furthermore, the binding of Izumo on the surface of sperm and Juno on the surface of oocytes is essential for fertilization. Thus, there is a possibility that these genes are useful indicators to evaluate fertility in mice after irradiation exposure. Therefore, in this study, we analyzed global DNA methylation patterns in the testes and gene expression of Izumo1 and Izumo1r (Juno) in the gonads of mice after neonatal acute high-dose ionizing radiation (HDR) and chronic low-dose ionizing radiation (LDR). One-week-old male and female mice were irradiated with a total dose of 4 Gy, with acute HDR at 7 days at a dose rate of 30 Gy/h and LDR continuously at a dose rate of 6 mGy/h from 7 to 35 days. Their gonads were subsequently analyzed. The results of global DNA methylation patterns in the testes showed that methylation level increased with age in the control group, the LDR group maintained its DNA methylation level, and the HDR group showed decreased DNA methylation levels with age. In the control group, the gene expression level of Izumo1 in the testis did not show age-related changes, although there was high expression at 100 days of age. However, in the LDR group, the expression level recovered after the end of irradiation, while it remained low regardless of age in the HDR group. Conversely, gene expression of Izumo1r (Izumo1 receptor) in the ovary decreased with age in the control group. Although the gene expression of Izumo1r decreased with age in the LDR group, it remained low in the HDR group. Our results indicate that LDR can induce different DNA methylation patterns, and both high- and low-dose radiation before sexual maturity might affect gametogenesis and fertility.
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We investigated the internal contamination by radioactive cesium associated with the FDNPP accident, in the testes or uterus and ovaries of free-roaming cats (Felis silvestris catus), which were protected by volunteers in the Namie Town, Fukushima. A total of 253 samples (145 testes and 108 uterus and ovaries) obtained from adult cats and 15 fetuses from 3 pregnant female cats were measured. Free-roaming cats in Namie Town had a higher level of radioactive contamination in comparison to the control group in Tokyo, as the 134Cs + 137Cs activity concentration ranged from not detectable to 37,882 Bq kg-1 in adult cats. Furthermore, the radioactivity in the fetuses was almost comparable to those in their mother's uterus and ovaries. The radioactivity was also different between several cats protected in the same location, and there was no significant correlation with ambient dose-rates and activity concentrations in soil. Moreover, radioactive cesium levels in cats decreased with each year. Therefore, it is likely that decontamination work in Namie Town and its surroundings could affect radioactive cesium accumulation, and thus possibly reduce the internal radiation exposure of wildlife living in contaminated areas. It is hence necessary to continue radioactivity monitoring efforts for the residents living in Namie Town.
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Acidente Nuclear de Fukushima , Monitoramento de Radiação , Radioatividade , Animais , Gatos , Césio , Radioisótopos de Césio/análise , Feminino , Genitália/química , Japão , Centrais Nucleares , TóquioRESUMO
PURPOSE: In suspected radiation exposures, cytokinesis-block micronucleus (CBMN) assay is used for biodosimetry by detecting micronuclei (MN) in binucleated (BN) cells in whole blood and isolated peripheral blood mononuclear cell (PBMC) cultures. Standardized harvest protocols for whole blood were published by the International Atomic Energy Agency (IAEA) in 2001 (Technical report no. 405) and 2011 (EPR-Biodosimetry). For isolated PBMC harvest, cytocentrifugation of fresh cells is recommended to preserve cytoplasmic boundaries for MN scoring. However, cytocentrifugation utilizes specialized equipment and long-term cell suspension storage is difficult. In this study, an alternative CBMN harvest protocol is proposed for laboratories interested in culturing PBMCs and storing fixed cells with routine biodosimetry methods. MATERIALS AND METHODS: Peripheral blood from 4 males (24, 34, 41, 51 y.o.) and females (26, 37, 44, 56 y.o.) was irradiated with 0 and 2 Gy X-rays. For cells harvested with IAEA 2001 and 2011 protocols, whole blood was used. For cells harvested with our protocol (CRG), isolated PBMCs were used. CRG protocol was validated in DAPI, acridine orange and Giemsa stain, and in three other laboratories. Cytoplasm status, nuclear division index (NDI) and induced MN frequency (MN frequency at 2 Gy - background MN frequency at 0 Gy) (MN/1000 BN) of Giemsa-stained BN cells were compared in IAEA 2001, IAEA 2011, IAEA 2011 + formaldehyde (FA) and CRG protocols. Effects of low and high humidity spreading were evaluated. RESULTS: >94% of 1000 BN cells were scorable with clear cytoplasmic boundaries in all donors harvested with CRG protocol. FA addition in IAEA 2011 protocol reduced cell rupture in whole blood cultures, but cell rupture was affected by age, sex and humidity. Almost all cells harvested with IAEA 2001 protocol had cytoplasm loss. PBMCs harvested with CRG protocol stained well in DAPI, acridine orange and Giemsa, and showed high scorable BN frequency in all laboratories. A higher NDI and a lower induced MN frequency were seen in 2 Gy isolated PBMC than whole blood cultures. CONCLUSION: This quick CBMN harvest protocol for isolated PBMCs is a viable alternative to cytocentrifugation, as many scorable BN cells were obtained with routine biodosimetry reagents and equipment. IAEA 2011 + FA protocol should be used to improve CBMN harvest in whole blood cultures. Humidity during spreading should be optimized depending on the harvest protocol. NDI and MN frequency should be separately evaluated for whole blood and isolated PBMC cultures.
Assuntos
Separação Celular/métodos , Leucócitos Mononucleares/efeitos da radiação , Testes para Micronúcleos/métodos , Adulto , Citocinese , Feminino , Humanos , Umidade , Leucócitos Mononucleares/ultraestrutura , Masculino , Pessoa de Meia-Idade , Doses de RadiaçãoRESUMO
The aim of this study was to investigate the proliferation and apoptosis of male germ cells during the seasonal reproductive cycle of the large Japanese field mice (Apodemus speciosus). Male mice residing in their natural habitat were captured in Niigata, Japan. Testis sections were stained with haematoxylin and eosin, and mitotic male germ cells were identified using immunofluorescence staining for proliferating cell nuclear antigen (PCNA). Apoptosis was analysed using terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick end labelling (TUNEL) assay. The phases of spermatogenesis during the seasonal reproductive cycle were classified as active, transitional, and inactive based on the diameter of the seminiferous tubules. The number of PCNA-positive germ cells was less during the inactive than other phases. The percentage of TUNEL-positive germ cells per seminiferous tubule was greater during the inactive than active and transitional phases. Spermatogenesis during the seasonal reproductive cycle is controlled by proliferation and apoptosis in male germ cells. This species of undomesticated mice could be used as an animal model to study spermatogenesis as a valuable indicator of the effects of ecological and anthropogenic factors on animal reproduction.