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DOSE AND DOSE RATE EFFECTS OF IRRADIATION ON BLOOD COUNT AND CYTOKINE LEVEL IN BALB/c MICE
Son, Yeonghoon,Jung, Dong Hyuk,Kim, Sung Dae,Lee, Chang Geun,Yang, Kwangmo,Kim, Joong Sun The Korean Association for Radiation Protection 2013 방사선방어학회지 Vol.38 No.4
The biological effects of radiation are dependent on the dose rate and dose of radiation. In this study, effects of dose and dose rate using whole body radiation on plasma cytokines and blood count from male BALB/c mice were evaluated. We examined the blood and cytokine changes in mice exposed to a low (3.49m Gy $h^{-1}$) and high (2.6 Gy $min^{-1}$) dose rate of radiation at a total dose of 0.5 and 2 Gy, respectively. Blood from mice exposed to radiation were evaluated using cytokine assays and complete blood count. Peripheral lymphocytes and neutrophils decreased in a dose dependent manner following high dose rate radiation. The peripheral lymphocytes population remained unchanged following low dose rate radiation; however, the neutrophils population increased after radiation. The sera from these mice exhibited elevated levels of flt3 ligand and granulocyte-colony-stimulating factor (G-CSF), after high/low dose rate radiation. These results suggest that low-dose-rate radiation does not induce blood damage, which was unlike high-dose-rate radiation treatment; low-dose-rate radiation exposure activated the hematopoiesis through the increase of flt3 ligand and G-CSF.
Long-term RF exposure on behavior and cerebral glucose metabolism in 5xFAD mice
Son, Yeonghoon,Kim, Jin Su,Jeong, Ye Ji,Jeong, Youn Kyoung,Kwon, Jong Hwa,Choi, Hyung-Do,Pack, Jeong-Ki,Kim, Nam,Lee, Yun-Sil,Lee, Hae-June Elsevier 2018 Neuroscience Letters Vol.666 No.-
<P><B>Abstract</B></P> <P>Given the increased public concern about the deleterious biological consequences of radiofrequency electromagnetic fields (RF-EMFs), the involvement of RF-EMFs in neurodegenerative diseases, especially Alzheimer’s disease (AD), has received increased consideration. To investigate the effect of long-term RF-EMF exposure on AD progression, we exposed 5xFAD mice to 1950 MHz RF-EMF at a specific absorption rate of 5.0 W/kg for 2 h/day and 5 days/week for 8 months. Behavioral changes were assessed by an open field test and an object recognition memory task after RF exposure was terminated. In addition, cerebral glucose metabolism was analyzed in the brains of the 5xFAD mice using 18F-deoxyglucose positron emission tomography. The hyperactivity-like and anxiolytic behaviors of the 5xFAD mice in open field tests were rescued by RF exposure. Furthermore, long-term RF-EMF exposure improved the cognitive deficits of 5xFAD mice that were observed in the object recognition memory test. Consistent with the behavioral changes, glucose metabolism in the hippocampus and amygdala regions of the brains of 5xFAD mice following RF exposure was significantly increased compared to glucose metabolism in the brains of sham-exposed mice. These data suggest that long-term exposure to RF-EMF might exert beneficial effects on AD in 5xFAD mice.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Chronic RF-EMF exposure improved cognitive deficits in 5xFAD mice. </LI> <LI> Chronic RF-EMF exposure rescued locomotor defects in AD-transgenic mice. </LI> <LI> Glucose metabolism was increased in the brains of 5xFAD mice after RF-EMF. </LI> </UL> </P>
Treatment with granulocyte colony-stimulating factor aggravates thrombocytopenia in irradiated mice
Son, Yeonghoon,Bae, Min Ji,Lee, Chang Geun,Jo, Wol Soon,Kim, Sung Dae,Yang, Kwangmo,Jang, Hyosun,Kim, Joong Sun 대한독성유전단백체학회 2014 Molecular & cellular toxicology Vol.9 No.3
Ionizing radiation can damage the hematopoietic system, and treatment with cytokines, including granulocytecolony-stimulating factor (G-CSF), is used to enhance hematopoietic recovery. In the present study, mice were whole-body irradiated with a sublethal dose of 5 Gy to produce severe myelosuppression and to evaluate the hematologic consequences of G-CSF treatment following irradiation. G-CSF ($100{\mu}g/kg$ of body weight) was injected immediately after irradiation, and then every three days for 3 weeks. G-CSF significantly ameliorated the decrease in peripheral neutrophils typically observed after exposure to radiation, but it also aggravated the decrease in the number of peripheral platelets during days 3-14 following irradiation. In the histological analysis, while the number of megakaryocytes was significantly decreased in the bone marrow, a number of trapped megakaryocytes were observed in the spleen of G-CSF-treated and irradiated mice. These data suggest that radiation-induced thrombocytopenia is worsened by G-CSF administration, possibly due to a decrease in the number of megakaryocytes in the bone marrow and an increase in the trapping of megakaryocytes in the spleen.
1950 MHz radiofrequency electromagnetic fields do not aggravate memory deficits in 5xFAD mice
Son, Yeonghoon,Jeong, Ye Ji,Kwon, Jong Hwa,Choi, Hyung‐,Do,Pack, Jeong‐,Ki,Kim, Nam,Lee, Yun‐,Sil,Lee, Hae‐,June Alan R. Liss 2016 Bioelectromagnetics Vol.37 No.6
<P>The increased use of mobile phones has generated public concern about the impact of radiofrequency electromagnetic fields (RF‐EMF) on health. In the present study, we investigated whether RF‐EMFs induce molecular changes in amyloid precursor protein (APP) processing and amyloid beta (Aβ)‐related memory impairment in the 5xFAD mouse, which is a widely used amyloid animal model. The 5xFAD mice at the age of 1.5 months were assigned to two groups (RF‐EMF‐ and sham‐exposed groups, eight mice per group). The RF‐EMF group was placed in a reverberation chamber and exposed to 1950 MHz electromagnetic fields for 3 months (SAR 5 W/kg, 2 h/day, 5 days/week). The Y‐maze, Morris water maze, and novel object recognition memory test were used to evaluate spatial and non‐spatial memory following 3‐month RF‐EMF exposure. Furthermore, Aβ deposition and APP and carboxyl‐terminal fragment β (CTFβ) levels were evaluated in the hippocampus and cortex of 5xFAD mice, and plasma levels of Aβ peptides were also investigated. In behavioral tests, mice that were exposed to RF‐EMF for 3 months did not exhibit differences in spatial and non‐spatial memory compared to the sham‐exposed group, and no apparent change was evident in locomotor activity. Consistent with behavioral data, RF‐EMF did not alter APP and CTFβ levels or Aβ deposition in the brains of the 5xFAD mice. These findings indicate that 3‐month RF‐EMF exposure did not affect Aβ‐related memory impairment or Aβ accumulation in the 5xFAD Alzheimer's disease model. Bioelectromagnetics. 37:391–399, 2016. © 2016 The Authors <I>Bioelectromagnetics</I> published by Wiley Periodicals, Inc. on behalf of Bioelectromagnetics Society.</P>
Kang, Sohi,Son, Yeonghoon,Lee, Sueun,Kim, Juhwan,Kim, Jong-Choon,Kim, Joong-Sun,Jung, Uhee,Kim, Sung-Ho,Yang, Miyoung,Moon, Changjong Elsevier/North-Holland 2017 Neuroscience letters Vol.657 No.-
<P><B>Abstract</B></P> <P>Brain exposure to ionizing radiation can cause functional deficits in the hippocampus, including memory impairment. However, the specific molecular mechanisms underlying irradiation-induced cognitive impairments are largely unknown. Changes in DNA methyltransferases (DNMTs) and histone deacetylases (HDACs), which are involved in DNA methylation and histone remodeling, may be associated with behavioral changes in learning and memory. We assessed changes in the levels of enzymes associated with the epigenetic modification of gene expression, including DNMT1, HDAC1, HDAC2, Sirtuin 1 (SIRT1), and acetylated histone H3 (Ace-H3) in the mouse hippocampus 1 and 30days after a single exposure to cranial irradiation (0 or 10Gy). mRNA levels of HDAC1 were significantly downregulated 1day after irradiation with 10Gy, and those of DNMT1, HDAC1, and HDAC2 were significantly downregulated 30days post-irradiation. Western blot analysis revealed significant decreases in DNMT1, HDAC1, and HDAC2 protein levels 1 and 30days after irradiation with 10Gy. Furthermore, protein levels of SIRT1 and Ace-H3 were significantly downregulated in the mouse hippocampus 1 and 30days after cranial irradiation. Our findings suggest that the reduction in epigenetic gene expression is associated with hippocampal dysfunction in mice exposed to cranial irradiation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Epigenetic modification plays an important role during hippocampal memory processing. </LI> <LI> Cranial irradiation inhibited hippocampal epigenetic modification signals in mice. </LI> <LI> Decreased epigenetic modification signals may be involved in radiation-induced hippocampal dysfunctions. </LI> </UL> </P>
Neuropharmacological Potential of <i>Gastrodia elata</i> Blume and Its Components
Jang, Jung-Hee,Son, Yeonghoon,Kang, Seong Soo,Bae, Chun-Sik,Kim, Jong-Choon,Kim, Sung-Ho,Shin, Taekyun,Moon, Changjong Hindawi Publishing Corporation 2015 Evidence-based Complementary and Alternative Medic Vol.2015 No.-
<P>Research has been conducted in various fields in an attempt to develop new therapeutic agents for incurable neurodegenerative diseases. <I>Gastrodia elata</I> Blume (GE), a traditional herbal medicine, has been used in neurological disorders as an anticonvulsant, analgesic, and sedative medication. Several neurodegenerative models are characterized by oxidative stress and inflammation in the brain, which lead to cell death via multiple extracellular and intracellular signaling pathways. The blockade of certain signaling cascades may represent a compensatory therapy for injured brain tissue. Antioxidative and anti-inflammatory compounds isolated from natural resources have been investigated, as have various synthetic chemicals. Specifically, GE rhizome extract and its components have been shown to protect neuronal cells and recover brain function in various preclinical brain injury models by inhibiting oxidative stress and inflammatory responses. The present review discusses the neuroprotective potential of GE and its components and the related mechanisms; we also provide possible preventive and therapeutic strategies for neurodegenerative disorders using herbal resources.</P>