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1.
J Urol ; 211(1): 55-62, 2024 01.
Article in English | MEDLINE | ID: mdl-37831635

ABSTRACT

PURPOSE: US states eased licensing restrictions on telemedicine during the COVID-19 pandemic, allowing interstate use. As waivers expire, optimal uses of telemedicine must be assessed to inform policy, legislation, and clinical care. We assessed whether telemedicine visits provided the same patient experience as in-person visits, stratified by in- vs out-of-state residence, and examined the financial burden. MATERIALS AND METHODS: Patients seen in person and via telemedicine for urologic cancer care at a major regional cancer center received a survey after their first appointment (August 2019-June 2022) on satisfaction with care, perceptions of communication during their visit, travel time, travel costs, and days of work missed. RESULTS: Surveys were completed for 1058 patient visits (N = 178 in-person, N = 880 telemedicine). Satisfaction rates were high for all visit types, both interstate and in-state care (mean score 60.1-60.8 [maximum 63], P > .05). More patients convening interstate telemedicine would repeat that modality (71%) than interstate in-person care (61%) or in-state telemedicine (57%). Patients receiving interstate care had significantly higher travel costs (median estimated visit costs $200, IQR $0-$800 vs median $0, IQR $0-$20 for in-state care, P < .001); 55% of patients receiving interstate in-person care required plane travel and 60% required a hotel stay. CONCLUSIONS: Telemedicine appointments may increase access for rural-residing patients with cancer. Satisfaction outcomes among patients with urologic cancer receiving interstate care were similar to those of patients cared for in state; costs were markedly lower. Extending interstate exemptions beyond COVID-19 licensing waivers would permit continued delivery of high-quality urologic cancer care to rural-residing patients.


Subject(s)
COVID-19 , Telemedicine , Urologic Neoplasms , Urology , Humans , Pandemics , COVID-19/epidemiology , Urologic Neoplasms/therapy , Patient Satisfaction
2.
Front Physiol ; 14: 1215535, 2023.
Article in English | MEDLINE | ID: mdl-37440997

ABSTRACT

Introduction: The response of the brain to space radiation is an important concern for astronauts during space missions. Therefore, we assessed the response of the brain to 28Si ion irradiation (600 MeV/n), a heavy ion present in the space environment, on cognitive performance and whether the response is associated with altered DNA methylation in the hippocampus, a brain area important for cognitive performance. Methods: We determined the effects of 28Si ion irradiation on object recognition, 6-month-old mice irradiated with 28Si ions (600 MeV/n, 0.3, 0.6, and 0.9 Gy) and cognitively tested two weeks later. In addition, we determined if those effects were associated with alterations in hippocampal networks and/or hippocampal DNA methylation. Results: At 0.3 Gy, but not at 0.6 Gy or 0.9 Gy, 28Si ion irradiation impaired cognition that correlated with altered gene expression and 5 hmC profiles that mapped to specific gene ontology pathways. Comparing hippocampal DNA hydroxymethylation following proton, 56Fe ion, and 28Si ion irradiation revealed a general space radiation synaptic signature with 45 genes that are associated with profound phenotypes. The most significant categories were glutamatergic synapse and postsynaptic density. Discussion: The brain's response to space irradiation involves novel excitatory synapse and postsynaptic remodeling.

3.
Cancer ; 129(18): 2887-2892, 2023 09 15.
Article in English | MEDLINE | ID: mdl-37221660

ABSTRACT

BACKGROUND: Patients residing in rural areas with urologic cancers confront significant obstacles in obtaining oncologic care. In the Pacific Northwest, a sizeable portion of the population lives in a rural county. Telehealth offers a potential access solution. METHODS: Patients receiving urologic care through telehealth or an in-person appointment at the Fred Hutchinson Cancer Center in Seattle, Washington, were surveyed to assess appointment-related satisfaction and travel costs. Patients' residences were classified as rural or urban based on their self-reported ZIP code. Median patient satisfaction scores and appointment-related travel costs were compared by rural versus urban residence within telehealth and in-person appointment groups using Wilcoxon signed-rank or χ2 testing. RESULTS: A total of 1091 patients seen for urologic cancer care between June 2019 and April 2022 were included, 28.7% of which resided in a rural county. Patients were mostly non-Hispanic White (75%) and covered by Medicare (58%). Among rural-residing patients, telehealth and in-person appointment groups had the same median satisfaction score (61; interquartile ratio, 58, 63). More rural-residing than urban-residing patients in the telehealth appointment groups strongly agreed that "Considering the cost and time commitment of my appointment, I would choose to meet with my provider in this setting in the future" (67% vs. 58%, p = .03). Rural-residing patients with in-person appointments carried a higher financial burden than those with telehealth appointments (medians, $80 vs. $0; p <.001). CONCLUSIONS: Appointment-related costs are high among rural-residing patients traveling for urologic oncologic care. Telehealth provides an affordable solution that does not compromise patient satisfaction.


Subject(s)
Telemedicine , Urologic Neoplasms , Humans , Aged , United States , Medicare , Patient Satisfaction , Urologic Neoplasms/therapy , Patient-Centered Care
4.
Front Genet ; 9: 404, 2018.
Article in English | MEDLINE | ID: mdl-30356920

ABSTRACT

Behavioral and cognitive traits have a genetic component even though contributions from individual genes and genomic loci are in many cases modest. Changes in the environment can alter genotype-phenotype relationships. Space travel, which includes exposure to ionizing radiation, constitutes environmental challenges and is expected to induce not only dramatic behavioral and cognitive changes but also has the potential to induce physical DNA damage. In this study, we utilized a genetically heterogeneous mouse model, dense genotype data, and shifting environmental challenges, including ionizing radiation exposure, to explore and quantify the size and stability of the genetic component of fear learning and memory-related measures. Exposure to ionizing radiation and other external stressors altered the genotype-phenotype correlations, although different behavioral and cognitive measures were affected to different extents. Utilizing an integrative genomic approach, we identified pathways and functional ontology categories associated with these behavioral and cognitive measures.

5.
Sci Rep ; 7(1): 10227, 2017 08 31.
Article in English | MEDLINE | ID: mdl-28860502

ABSTRACT

The brain's response to radiation exposure is an important concern for patients undergoing cancer therapy and astronauts on long missions in deep space. We assessed whether this response is specific and prolonged and is linked to epigenetic mechanisms. We focused on the response of the hippocampus at early (2-weeks) and late (20-week) time points following whole body proton irradiation. We examined two forms of DNA methylation, cytosine methylation (5mC) and hydroxymethylation (5hmC). Impairments in object recognition, spatial memory retention, and network stability following proton irradiation were observed at the two-week time point and correlated with altered gene expression and 5hmC profiles that mapped to specific gene ontology pathways. Significant overlap was observed between DNA methylation changes at the 2 and 20-week time points demonstrating specificity and retention of changes in response to radiation. Moreover, a novel class of DNA methylation change was observed following an environmental challenge (i.e. space irradiation), characterized by both increased and decreased 5hmC levels along the entire gene body. These changes were mapped to genes encoding neuronal functions including postsynaptic gene ontology categories. Thus, the brain's response to proton irradiation is both specific and prolonged and involves novel remodeling of non-random regions of the epigenome.


Subject(s)
DNA Methylation/radiation effects , Epigenomics/methods , Hippocampus/radiation effects , Whole-Body Irradiation/methods , 5-Methylcytosine/analogs & derivatives , 5-Methylcytosine/analysis , 5-Methylcytosine/radiation effects , Animals , Gene Expression Profiling , Gene Expression Regulation/radiation effects , Gene Regulatory Networks/radiation effects , Hippocampus/chemistry , Male , Maze Learning/radiation effects , Mice , Protons/adverse effects , Sequence Analysis, RNA , Spatial Learning/radiation effects , Time Factors
6.
Life Sci Space Res (Amst) ; 13: 39-44, 2017 May.
Article in English | MEDLINE | ID: mdl-28554508

ABSTRACT

Long-term space mission exposes astronauts to a radiation environment with potential health hazards. High-energy charged particles (HZE), including 28Si nuclei in space, have deleterious effects on cells due to their characteristics with high linear energy transfer and dense ionization. The influence of 28Si ions contributes more than 10% to the radiation dose equivalent in the space environment. Understanding the biological effects of 28Si irradiation is important to assess the potential health hazards of long-term space missions. The hematopoietic system is highly sensitive to radiation injury and bone marrow (BM) suppression is the primary life-threatening injuries after exposure to a moderate dose of radiation. Therefore, in the present study we investigated the acute effects of low doses of 28Si irradiation on the hematopoietic system in a mouse model. Specifically, 6-month-old C57BL/6J mice were exposed to 0.3, 0.6 and 0.9Gy 28Si (600MeV) total body irradiation (TBI). The effects of 28Si TBI on BM hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) were examined four weeks after the exposure. The results showed that exposure to 28Si TBI dramatically reduced the frequencies and numbers of HSCs in irradiated mice, compared to non-irradiated controls, in a radiation dose-dependent manner. In contrast, no significant changes were observed in BM HPCs regardless of radiation doses. Furthermore, irradiated HSCs exhibited a significant impairment in clonogenic ability. These acute effects of 28Si irradiation on HSCs may be attributable to radiation-induced apoptosis of HSCs, because HSCs, but not HPCs, from irradiated mice exhibited a significant increase in apoptosis in a radiation dose-dependent manner. However, exposure to low doses of 28Si did not result in an increased production of reactive oxygen species and DNA damage in HSCs and HPCs. These findings indicate that exposure to 28Si irradiation leads to acute HSC damage.


Subject(s)
Apoptosis/radiation effects , Bone Marrow/pathology , Hematopoietic Stem Cells/pathology , Whole-Body Irradiation/adverse effects , Animals , Bone Marrow/radiation effects , Cell Cycle/radiation effects , Cells, Cultured , DNA Damage/radiation effects , Hematopoietic Stem Cells/radiation effects , Male , Mice , Mice, Inbred C57BL , Oxidative Stress/radiation effects , Reactive Oxygen Species/metabolism
7.
BMC Genomics ; 17(1): 825, 2016 10 24.
Article in English | MEDLINE | ID: mdl-27776477

ABSTRACT

BACKGROUND: Astronauts are exposed to 56Fe ions that may pose a significant health hazard during and following prolonged missions in deep space. We showed previously that object recognition requiring the hippocampus, a structure critical for cognitive function, is affected in 2-month-old mice irradiated with 56Fe ions. Here we examined object recognition in 6-month-old mice irradiated with 56Fe ions, a biological age more relevant to the typical ages of astronauts. Moreover, because the mechanisms mediating the detrimental effects of 56Fe ions on hippocampal function are unclear, we examined changes in hippocampal networks involved in synaptic plasticity and memory, gene expression, and epigenetic changes in cytosine methylation (5mC) and hydroxymethylation (5hmC) that could accompany changes in gene expression. We assessed the effects of whole body 56Fe ion irradiation at early (2 weeks) and late (20 weeks) time points on hippocampus-dependent memory and hippocampal network stability, and whether these effects are associated with epigenetic changes in hippocampal DNA methylation (both 5mC and 5hmC) and gene expression. RESULTS: At the two-week time point, object recognition and network stability were impaired following irradiation at the 0.1 and 0.4 Gy dose, but not following irradiation at the 0.2 Gy dose. No impairments in object recognition or network stability were seen at the 20-week time point at any irradiation dose used. Consistent with this pattern, the significance of pathways for gene categories for 5hmC was lower, though not eliminated, at the 20-week time point compared to the 2-week time point. Similarly, significant changes were observed for 5mC gene pathways at the 2-week time point, but no significant gene categories were observed at the 20-week time point. Only the 5hmC changes tracked with gene expression changes. CONCLUSIONS: Dose- and time-dependent epigenomic remodeling in the hippocampus following 56Fe ion exposure correlates with behavioral changes.


Subject(s)
Cognition/radiation effects , DNA Methylation/radiation effects , Epigenesis, Genetic/radiation effects , Gene Expression Regulation/radiation effects , Hippocampus/metabolism , Hippocampus/radiation effects , Iron , Radiation, Ionizing , Animals , CA1 Region, Hippocampal/metabolism , CA1 Region, Hippocampal/radiation effects , Cluster Analysis , Gene Expression Profiling , Gene Ontology , Immunohistochemistry , Male , Maze Learning , Mice , Psychomotor Performance/radiation effects
8.
J Proteomics ; 140: 24-36, 2016 05 17.
Article in English | MEDLINE | ID: mdl-27020882

ABSTRACT

UNLABELLED: Recent advances in the field of biodosimetry have shown that the response of biological systems to ionizing radiation is complex and depends on the type and dose of radiation, the tissue(s) exposed, and the time lapsed after exposure. The biological effects of low dose radiation on learning and memory are not well understood. An ion mobility-enhanced data-independent acquisition (MS(E)) approach in conjunction with the ISOQuant software tool was utilized for label-free quantification of hippocampal proteins with the goal of determining protein alteration associated with low-dose whole body ionizing radiation (X-rays, 1Gy) of 5.5-month-old male C57BL/6J mice post contextual fear conditioning training. Global proteome analysis revealed deregulation of 73 proteins (out of 399 proteins). Deregulated proteins indicated adverse effects of irradiation on myelination and perturbation of energy metabolism pathways involving a shift from the TCA cycle to glutamate oxidation. Our findings also indicate that proteins associated with synaptic activity, including vesicle recycling and neurotransmission, were altered in the irradiated mice. The elevated LTP and decreased LTD suggest improved synaptic transmission and enhanced efficiency of neurotransmitter release which would be consistent with the observed comparable contextual fear memory performance of the mice following post-training whole body or sham-irradiation. SIGNIFICANCE: This study is significant because the biological consequences of low dose radiation on learning and memory are complex and not yet well understood. We conducted a IMS-enhanced MS(E)-based label-free quantitative proteomic analysis of hippocampal tissue with the goal of determining protein alteration associated with low-dose whole body ionizing radiation (X-ray, 1Gy) of 5.5-month-old male C57BL/6J mice post contextual fear conditioning training. The IMS-enhanced MS(E) approach in conjunction with ISOQuant software was robust and accurate with low median CV values of 0.99% for the technical replicates of samples from both the sham and irradiated group. The biological variance was as low as 1.61% for the sham group and 1.31% for the irradiated group. The applied data generation and processing workflow allowed the quantitative evaluation of 399 proteins. The current proteomic analysis indicates that myelination is sensitive to low dose radiation. The observed protein level changes imply modulation of energy metabolism pathways in the radiation exposed group, specifically changes in protein abundance levels suggest a shift from TCA cycle to glutamate oxidation to satisfy energy demands. Most significantly, our study reveals deregulation of proteins involved in processes that govern synaptic activity including enhanced synaptic vesicle cycling, and altered long-term potentiation (LTP) and depression (LTD). An elevated LTP and decreased LTD suggest improved synaptic transmission and enhanced efficiency of neurotransmitter release which is consistent with the observed comparable contextual fear memory performance of the mice following post-training whole body or sham-irradiation. Overall, our results underscore the importance of low dose radiation experiments for illuminating the sensitivity of biochemical pathways to radiation, and the modulation of potential repair and compensatory response mechanisms. This kind of studies and associated findings may ultimately lead to the design of strategies for ameliorating hippocampal and CNS injury following radiation exposure as part of medical therapies or as a consequence of occupational hazards.


Subject(s)
Hippocampus/radiation effects , Proteome/analysis , Radiation, Ionizing , Animals , Behavior, Animal , Fear/radiation effects , Gene Expression Regulation/radiation effects , Hippocampus/chemistry , Long-Term Potentiation/radiation effects , Male , Memory/radiation effects , Mice , Mice, Inbred C57BL , Proteome/radiation effects , Proteomics/methods , Synaptic Transmission/radiation effects
9.
Front Neurosci ; 9: 326, 2015.
Article in English | MEDLINE | ID: mdl-26441501

ABSTRACT

Methamphetamine (MA) consumption causes disruption of many biological rhythms including the sleep-wake cycle. This circadian effect is seen shortly following MA exposure and later in life following developmental MA exposure. MA phase shifts, entrains the circadian clock and can also alter the entraining effect of light by currently unknown mechanisms. We analyzed and compared immunoreactivity of the immediate early gene c-Fos, a marker of neuronal activity, to assess neuronal activation 2 h following MA exposure in the light and dark phases. We used network analyses of correlation patterns derived from global brain immunoreactivity patterns of c-Fos, to infer functional connectivity between brain regions. There were five distinct patterns of neuronal activation. In several brain areas, neuronal activation following exposure to MA was stronger in the light than the dark phase, highlighting the importance of considering circadian periods of increased effects of MA in defining experimental conditions and understanding the mechanisms underlying detrimental effects of MA exposure to brain function. Functional connectivity between the ventromedial hypothalamus (VMH) and other brain areas, including the paraventricular nucleus of the hypothalamus and basolateral and medial amygdala, was enhanced following MA exposure, suggesting a role for the VMH in the effects of MA on the brain.

10.
Transl Stroke Res ; 6(5): 390-8, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26040424

ABSTRACT

Vascular cognitive impairment (VCI) is the second most common cause of dementia. Reduced cerebral blood flow is thought to play a major role in the etiology of VCI. Therefore, chronic cerebral hypoperfusion has been used to model VCI in rodents. The goal of the current study was to determine the histopathological and neuroimaging substrates of neurocognitive impairments in a mouse model of chronic cerebral hypoperfusion induced by unilateral common carotid artery occlusion (UCCAO). Mice were subjected to sham or right UCCAO (VCI) surgeries. Three months later, neurocognitive function was evaluated using the novel object recognition task, Morris water maze, and contextual and cued fear-conditioning tests. Next, cerebral perfusion was evaluated with dynamic susceptibility contrast magnetic resonance imaging (MRI) using an ultra-high field (11.75 T) animal MRI system. Finally, brain pathology was evaluated using histology and T2-weighted MRI. VCI, but not sham, mice had significantly reduced cerebral blood flow in the right vs. left cerebral cortex. VCI mice showed deficits in object recognition. T2-weighted MRI of VCI brains revealed enlargement of lateral ventricles, which corresponded to areas of hippocampal atrophy upon histological analysis. In conclusion, our data demonstrate that the UCCAO model of chronic hypoperfusion induces hippocampal atrophy and ventricular enlargement, resulting in neurocognitive deficits characteristic of VCI.


Subject(s)
Behavior, Animal/physiology , Dementia, Vascular/pathology , Hippocampus/pathology , Animals , Atrophy/complications , Cerebral Cortex/blood supply , Conditioning, Classical/physiology , Dementia, Vascular/etiology , Disease Models, Animal , Fear/physiology , Magnetic Resonance Imaging , Male , Maze Learning/physiology , Mice , Mice, Inbred C57BL , Recognition, Psychology/physiology
11.
Radiat Res ; 183(6): 708-12, 2015 Jun.
Article in English | MEDLINE | ID: mdl-26010712

ABSTRACT

The space radiation environment consists of multiple species of charged particles, including (28)Si, (48)Ti and protons that may impact cognition, but their damaging effects have been poorly defined. In mouse studies, C57Bl6/J homozygous wild-type mice and genetic mutant mice on a C57Bl6/J background have typically been used for assessing effects of space radiation on cognition. In contrast, little is known about the radiation response of mice on a heterozygous background. Therefore, in the current study we tested the effects of (28)Si, (48)Ti and proton radiation on hippocampus-dependent contextual fear memory and hippocampus-independent cued fear memory in C57Bl6/J × DBA2/J F1 (B6D2F1) mice three months after irradiation. Contextual fear memory was impaired at a 1.6 Gy dose of (28)Si radiation, but not cued fear memory. (48)Ti or proton irradiation did not affect either type of memory. Based on earlier space radiation cognitive data in C57Bl6/J mice, these data highlight the importance of including different genetic backgrounds in studies aimed at assessing cognitive changes after exposure to space radiation.


Subject(s)
Fear/physiology , Memory/radiation effects , Silicon/adverse effects , Animals , Cognition/radiation effects , Fear/radiation effects , Female , Hippocampus/physiology , Hippocampus/radiation effects , Male , Mice
12.
Radiat Res ; 183(2): 240-8, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25635345

ABSTRACT

Space flight poses certain health risks to astronauts, including exposure to space radiation, with protons accounting for more than 80% of deep-space radiation. Proton radiation is also now being used with increasing frequency in the clinical setting to treat cancer. For these reasons, there is an urgent need to better understand the biological effects of proton radiation on the body. Such improved understanding could also lead to more accurate assessment of the potential health risks of proton radiation, as well as the development of improved strategies to prevent and mitigate its adverse effects. Previous studies have shown that exposure to low doses of protons is detrimental to mature leukocyte populations in peripheral blood, however, the underlying mechanisms are not known. Some of these detriments may be attributable to damage to hematopoietic stem cells (HSCs) that have the ability to self-renew, proliferate and differentiate into different lineages of blood cells through hematopoietic progenitor cells (HPCs). The goal of this study was to investigate the long-term effects of low-dose proton irradiation on HSCs. We exposed C57BL/6J mice to 1.0 Gy whole-body proton irradiation (150 MeV) and then studied the effects of proton radiation on HSCs and HPCs in the bone marrow (BM) 22 weeks after the exposure. The results showed that mice exposed to 1.0 Gy whole-body proton irradiation had a significant and persistent reduction of BM HSCs compared to unirradiated controls. In contrast, no significant changes were observed in BM HPCs after proton irradiation. Furthermore, irradiated HSCs and their progeny exhibited a significant impairment in clonogenic function, as revealed by the cobblestone area-forming cell (CAFC) and colony-forming cell assays, respectively. These long-term effects of proton irradiation on HSCs may be attributable to the induction of chronic oxidative stress in HSCs, because HSCs from irradiated mice exhibited a significant increase in NADPH oxidase 4 (NOX4) mRNA expression and reactive oxygen species (ROS) production. In addition, the increased production of ROS in HSCs was associated with a significant reduction in HSC quiescence and an increase in DNA damage. These findings indicate that exposure to proton radiation can lead to long-term HSC injury, probably in part by radiation-induced oxidative stress.


Subject(s)
Cell Differentiation/radiation effects , Cosmic Radiation , Hematopoietic Stem Cells/metabolism , Hematopoietic Stem Cells/radiation effects , Oxidative Stress/physiology , Reactive Oxygen Species/metabolism , Whole-Body Irradiation/adverse effects , Animals , Cells, Cultured , Dose-Response Relationship, Radiation , Hematopoietic Stem Cells/pathology , Longitudinal Studies , Male , Mice , Mice, Inbred C57BL , Oxidative Stress/radiation effects , Protons , Radiation Dosage
13.
Radiat Res ; 182(1): 92-101, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24960414

ABSTRACT

There is an increasing need to better understand the long-term health effects of high-linear energy transfer (LET) radiation due to exposure during space missions, as well as its increasing use in clinical treatments. Previous studies have indicated that exposure to (56)Fe heavy ions increases the incidence of acute myeloid leukemia (AML) in mice but the underlying molecular mechanisms remain elusive. Epigenetic alterations play a role in radiation-induced genomic instability and the initiation and progression of AML. In this study, we assessed the effects of low-dose (56)Fe-ion irradiation on epigenetic alterations in bone marrow mononuclear cells (BM-MNCs) and hematopoietic progenitor and stem cells (HPSCs). Exposure to (56)Fe ions (600 MeV, 0.1, 0.2 and 0.4 Gy) resulted in significant epigenetic alterations involving methylation of DNA, the DNA methylation machinery and expression of repetitive elements. Four weeks after irradiation, these changes were primarily confined to HPSCs and were exhibited as dose-dependent hypermethylation of LINE1 and SINE B1 repetitive elements [4.2-fold increase in LINE1 (P < 0.001) and 7.6-fold increase in SINE B1 (P < 0.01) after exposure to 0.4 Gy; n = 5]. Epigenetic alterations were persistent and detectable for at least 22 weeks after exposure, when significant loss of global DNA hypomethylation (1.9-fold, P < 0.05), decreased expression of Dnmt1 (1.9-fold, P < 0.01), and increased expression of LINE1 and SINE B1 repetitive elements (2.8-fold, P < 0.001 for LINE1 and 1.9-fold, P < 0.05 for SINE B1; n = 5) were observed after exposure to 0.4 Gy. In contrast, exposure to (56)Fe ions did not result in accumulation of increased production of reactive oxygen species (ROS) and DNA damage, exhibited as DNA strand breaks. Furthermore, no significant alterations in cellular senescence and apoptosis were detected in HPSCs after exposure to (56)Fe-ion radiation. These findings suggest that epigenetic reprogramming is possibly involved in the development of radiation-induced genomic instability and thus, may have a causative role in the development of AML.


Subject(s)
Epigenesis, Genetic/radiation effects , Hematopoietic Stem Cells/metabolism , Hematopoietic Stem Cells/radiation effects , Iron/adverse effects , Animals , Apoptosis/genetics , Apoptosis/radiation effects , Cellular Senescence/genetics , Cellular Senescence/radiation effects , DNA Damage/genetics , DNA Methylation/radiation effects , Dose-Response Relationship, Radiation , Gene Dosage/radiation effects , Male , Mice , Mice, Inbred C57BL , Reactive Oxygen Species/metabolism , Repetitive Sequences, Nucleic Acid/radiation effects , Time Factors
14.
J Radiat Res ; 55(4): 823-8, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24585548

ABSTRACT

Despite significant progress, the long-term health effects of exposure to high charge (Z) and energy (E) nuclei (HZEs) and the underlying mechanisms remain poorly understood. Mouse studies show that space missions can result in pulmonary pathological states. The goal of this study was to evaluate the pro-fibrotic and pro-carcinogenic effects of exposure to low doses of heavy iron ions ((56)Fe) in the mouse lung. Exposure to (56)Fe (600 MeV; 0.1, 0.2 and 0.4 Gy) resulted in minor pro-fibrotic changes, detected at the beginning of the fibrotic phase (22 weeks post exposure), which were exhibited as increased expression of chemokine Ccl3, and interleukin Il4. Epigenetic alterations were exhibited as global DNA hypermethylation, observed after exposure to 0.4 Gy. Cadm1, Cdh13, Cdkn1c, Mthfr and Sfrp1 were significantly hypermethylated after exposure to 0.1 Gy, while exposure to higher doses resulted in hypermethylation of Cdkn1c only. However, expression of these genes was not affected by any dose. Congruently with the observed patterns of global DNA methylation, DNA repetitive elements were hypermethylated after exposure to 0.4 Gy, with minor changes observed after exposure to lower doses. Importantly, hypermethylation of repetitive elements coincided with their transcriptional repression. The findings of this study will aid in understanding molecular determinants of pathological states associated with exposure to (56)Fe, as well as serve as robust biomarkers for the delayed effects of irradiation. Further studies are clearly needed to investigate the persistence and outcomes of molecular alterations long term after exposure.


Subject(s)
Epigenesis, Genetic/radiation effects , Heavy Ions/adverse effects , Iron/toxicity , Lung/radiation effects , Animals , DNA Methylation/radiation effects , Humans , Iron/administration & dosage , Lung Injury/etiology , Lung Injury/genetics , Lung Neoplasms/etiology , Lung Neoplasms/genetics , Male , Mice , Mice, Inbred C57BL , Neoplasms, Radiation-Induced/etiology , Neoplasms, Radiation-Induced/genetics , Pulmonary Fibrosis/etiology , Pulmonary Fibrosis/genetics , Radiation Injuries, Experimental/etiology , Radiation Injuries, Experimental/genetics , Space Flight
15.
Neuropharmacology ; 66: 365-72, 2013 Mar.
Article in English | MEDLINE | ID: mdl-22884897

ABSTRACT

Group III metabotropic glutamate receptors (mGluRs), which are generally located presynaptically, modulate synaptic transmission by regulating neurotransmitter release. Previously we showed enhanced amygdala-dependent cued fear conditioning in mGluR4(-/-) mice 24 h following training involving two tone-shock pairings. In this study, we assessed the effects of modulating mGluR4 signaling on acquisition and extinction of conditioned fear. mGluR4(-/-) and wild-type female and male mice received 10 tone-shock pairings during training. Compared to wild-type mice, mGluR4(-/-) mice showed enhanced acquisition and extinction of cued fear. Next, we assessed whether acute pharmacological stimulation of mGluR4 with the specific orthosteric mGluR4 agonist LSP1-2111 also affects acquisition and extinction of cued fear. Consistent with the enhanced acquisition of cued fear in mGluR4(-/-), LSP1-2111, at 2.5 and 5 mg/kg, inhibited acquisition of cued fear conditioning in wild-type male mice. The drug's effect on extinction was less clear and only a subtle effect was seen at 5 mg/kg. Finally, analysis of microarray data of amygdala tissues from mGluR4(-/-) versus wild-type and from wild-type mice treated with a mGluR4 agonist versus saline revealed a significant overlap in pattern of gene expression. Together, these data support a role for mGluR4 signaling in acquisition of fear learning and memory. This article is part of a Special Issue entitled 'Metabotropic Glutamate Receptors'.


Subject(s)
Conditioning, Psychological/physiology , Fear/physiology , Memory/physiology , Receptors, Metabotropic Glutamate/physiology , Aminobutyrates/pharmacology , Amygdala/drug effects , Amygdala/physiology , Animals , Conditioning, Psychological/drug effects , Excitatory Amino Acid Agonists/pharmacology , Extinction, Psychological/drug effects , Extinction, Psychological/physiology , Fear/drug effects , Female , Gene Expression/drug effects , Gene Expression/physiology , Male , Memory/drug effects , Mice , Mice, Inbred C57BL , Mice, Knockout , Phosphinic Acids/pharmacology , Receptors, Metabotropic Glutamate/agonists , Receptors, Metabotropic Glutamate/genetics
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