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This study investigated the effects of chronic low-dose-rate radiation exposure on gene expression related to immunological defense mechanisms and epigenetic regulation in the testis of male mice. The study found that radiation exposure (4.5 mGy/hr until 4000 mGy) led to a significant decrease in the expression of genes involved in epigenetic regulation and a significant increase in the expression of several genes linked to innate and acquired immunity, suggesting a noticeable effect on the immune response. In addition, there was a significant increase in the expression of SRY-box transcription factor 9, which plays a crucial role in testicular development, indicating a response to irradiation. These findings provide insights into the biological effects of chronic low-dose-rate radiation exposure on innate immunity and epigenetic regulation in the testis. [ABSTRACT FROM AUTHOR]

The current study aimed to investigate the effects of ageing on oral immunity using β -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. [ABSTRACT FROM AUTHOR]

Simple Summary: In 2011, the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident resulted in the release of vast quantities of radioactive substances. In this study, we performed an ultrastructural analysis of the testis of the wild large Japanese field mouse (Apodemus speciosus), inhabiting the area near the ex-evacuation zones of the FDNPP and chronically exposed to various levels of low-dose-rate (LDR) radiation, to evaluate the effects of ionizing radiation on the male reproductive system and the possible consequences for future generations. Our results showed a preserved morphology of seminiferous tubules. However, ultrastructural changes, such as wide intercellular spaces, cytoplasmic vacuolization, vacuolated mitochondria, and increased lipid droplet clusters, were found, which could be linked to the mechanisms related to spermatogenesis. Long-term chronic LDR radiation exposure associated with the FDNPP accident had no pronounced adverse effect on spermatogenesis in A. speciosus, even if testis presented some ultrastructural changes. Our findings could be used in future studies to evaluate the effects of radiation on reproductive health in wild animals. 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. [ABSTRACT FROM AUTHOR]

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. 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. 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. These findings suggest that chromosome aberration analysis is useful to evaluate and monitor radiation effects in wild animals. [ABSTRACT FROM AUTHOR]

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). 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. 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. Our study suggests that low dose-rate radiation of more than 200 Gy/d reduced HPCs, possibly eliminating genomically unstable HPCs. [ABSTRACT FROM AUTHOR]

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. 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. >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. 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Purpose: In order to establish suitable protocols of blood culture to obtain sufficient numbers of metaphases for dicentric chromosome assay (DCA), we have examined the effect of storage temperature, storage time, and anticoagulant type. Materials and methods: Peripheral blood was collected from five healthy donors with lithium heparin and ethylenediaminetetraacetic acid dipotassium salt (EDTA-2K). These samples were irradiated with X-rays at 3 Gy or sham; the samples were further divided into groups that were either stored at room temperature (RT) or 5.2 ± 1.0 °C. After 6, 24, 48, 72, and 168 h of storage, both blood counts and the mitotic index (MI) were analyzed. Results: Heparinized blood samples stored under cold conditions exhibited low white blood cell, lymphocyte, and platelet counts. EDTA-treated blood samples did not show such obvious changes in cell counts. After 6 h of storage, heparinized blood samples stored at RT had MI of 21.5-29.3%. Similar MI was obtained in the EDTA-washed group stored for 6, 24, 48, and 72 h. Conclusions: Our study confirms that heparinized blood samples should be stored at RT to get sufficient metaphases for DCA, and that EDTA blood samples also can be used for blood culture after washing and storage under 5.2 ± 1.0 °C. [ABSTRACT FROM AUTHOR]