Role of Ionizing Radiation in Neurodegenerative Diseases

Abstract

Ionizing radiation (IR) from terrestrial sources is continually an unprotected peril to human beings. However, the medical radiation and global radiation background are main contributors to human exposure and causes of radiation sickness. At high-dose exposures acute radiation sickness occurs, whereas chronic effects may persist for a number of years. Radiation can increase many circulatory, age related and neurodegenerative diseases. Neurodegenerative diseases occur a long time after exposure to radiation, as demonstrated in atomic bomb survivors, and are still controversial. This review discuss the role of IR in neurodegenerative diseases and proposes an association between neurodegenerative diseases and exposure to IR.

Mitochondrial Degeneration and Autophagy Associated With Delayed Effects of Radiation in the Mouse Brain

“…Population studies from Hiroshima documented various neurodegenerative, cancer, and cerebrovascular diseases as delayed effects in survivors. They documented that depending upon the density of exposure and age of exposure to radiation from the atomic bombing, there was a several-fold increase in the risk of certain diseases with age (Douple et al, 2011;Jordan, 2016;Sharma et al, 2018). Previously, it was reported that mitochondria are the target organelles for IR.…”

“…BBT-059 protects the hematopoietic system and attenuates radiationinduced upregulation of hematopoietic cytokine (Epo, TPO, Flt3L) expression, thereby preventing lethal radiation injury as determined in 30-day survival studies (Kumar et al, 2018). Animals surviving exposure to lethal doses of radiation might experience delayed effects of acute radiation exposure (DEARE) which may manifest after recovery from acute radiation syndrome (Williams et al, 2010) and contribute to an increased incidence of many circulatories, age-related, and neurodegenerative diseases (Sharma et al, 2018). Many neurodegenerative diseases are related to mitochondrial dysfunction and DEARE may disrupt mitochondrial function through several mechanisms.…”

Risk of Alzheimer’s Disease in Cancer Patients: Analysis of Mortality Data from the US SEER Population-Based Registries

“…Ionizing radiation has been speculated as a possible risk factor for AD mostly based on (i) analogy with cognitive dysfunctions observed in cancer patients who received radiation therapy by cranial irradiation, (ii) cellular and molecular changes in animal and in vitro studies that implied endothelial damage, impaired neurogenesis, and (iii) plausible mechanistic links, such as shared molecular mechanisms between AD and some pathological conditions induced by ionizing radiation (e.g., the damage induced by reactive oxygen species, ROS) (reviewed in References [90][91][92]). Contrary to the expectations raised by these mechanistic inferences, evidence from the animal models did not support the etiological role of ionizing radiation in the AD.…”

Sex-Specific Effects of a Wartime-Like Radiation Exposure on Cognitive Function

“…If cognitive impairments manifest at lower doses and progress over time they could clearly impact an individual's ability to adapt and respond in stressful situations. As impairments continue to manifest or worsen, they present a clear and adverse effect on longerterm quality of life, including increased risks of developing mood disorders, learning and memory impairments, as well as progressive neurodegenerative disease-like symptoms (13)(14)(15). For these reasons adult male and female mice were used in this study to evaluate the brain for the delayed effects of a whole-body gamma-ray exposure that would not induce acute radiation syndromes.…”