title: The impact of high and low dose ionising radiation on the central nervous system.
abstract: Responses of the central nervous system (CNS) to stressors and injuries, such as ionising radiation, are modulated by the concomitant responses of the brains innate immune effector cells, microglia. Exposure to high doses of ionising radiation in brain tissue leads to the expression and release of biochemical mediators of 'neuroinflammation', such as pro-inflammatory cytokines and reactive oxygen species (ROS), leading to tissue destruction. Contrastingly, low dose ionising radiation may reduce vulnerability to subsequent exposure of ionising radiation, largely through the stimulation of adaptive responses, such as antioxidant defences. These disparate responses may be reflective of non-linear differential microglial activation at low and high doses, manifesting as an anti-inflammatory or pro-inflammatory functional state. Biomarkers of pathology in the brain, such as the mitochondrial Translocator Protein 18kDa (TSPO), have facilitated in vivo characterisation of microglial activation and 'neuroinflammation' in many pathological states of the CNS, though the exact function of TSPO in these responses remains elusive. Based on the known responsiveness of TSPO expression to a wide range of noxious stimuli, we discuss TSPO as a potential biomarker of radiation-induced effects.
authors.affiliation: Bioanalytics group, Life Sciences, Australian Nuclear Science and Technology Organisation (ANSTO), New Illawarra Road, Lucas Heights, NSW 2234, Australia; Discipline of Medical Imaging & Radiation Sciences, Faculty of Health Sciences, The University of Sydney, 75 East Street, Lidcombe, NSW 2141, Australia.
authors.forename: Calina
authors.initials: C
authors.lastname: Betlazar
authors.affiliation: Bioanalytics group, Life Sciences, Australian Nuclear Science and Technology Organisation (ANSTO), New Illawarra Road, Lucas Heights, NSW 2234, Australia.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Middleton
authors.affiliation: Bioanalytics group, Life Sciences, Australian Nuclear Science and Technology Organisation (ANSTO), New Illawarra Road, Lucas Heights, NSW 2234, Australia; Discipline of Medical Imaging & Radiation Sciences, Faculty of Health Sciences, The University of Sydney, 75 East Street, Lidcombe, NSW 2141, Australia. Electronic address: rib@ansto.gov.au.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Banati
authors.affiliation: Bioanalytics group, Life Sciences, Australian Nuclear Science and Technology Organisation (ANSTO), New Illawarra Road, Lucas Heights, NSW 2234, Australia; Discipline of Medical Imaging & Radiation Sciences, Faculty of Health Sciences, The University of Sydney, 75 East Street, Lidcombe, NSW 2141, Australia. Electronic address: gdl@ansto.gov.au.
authors.forename: Guo-Jun
authors.initials: GJ
authors.lastname: Liu
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D002490:Central Nervous System / Q000378:metabolism* / Q000528:radiation effects*; D016207:Cytokines / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000209:etiology / Q000378:metabolism; D018836:Inflammation Mediators / Q000378:metabolism; D017628:Microglia / Q000378:metabolism / Q000528:radiation effects; D011829:Radiation Dosage; D011839:Radiation, Ionizing; D017382:Reactive Oxygen Species / Q000378:metabolism; D018079:Receptors, GABA / Q000378:metabolism; D013312:Stress, Physiological
chemical_list: D000975:Antioxidants; D016207:Cytokines; D018836:Inflammation Mediators; D017382:Reactive Oxygen Species; D018079:Receptors, GABA
keywords: Antioxidants; Ionizing radiation; Microglia; Neuroinflammation; Reactive oxygen species (ROS); Translocator Protein (TSPO)