Why Do the Cosmic Rays Induce Aging?

Abstract

The increasing duration of space missions involves a progressively higher exposure of astronauts to cosmic rays, whose most hazardous component is made up of High-Atomic number and High-Energy (HZE) ions. HZE ions interact along their tracks with biological molecules inducing changes on living material qualitatively different from that observed after irradiation for therapeutic purposes or following nuclear accidents. HZE ions trigger in cells different responses initialized by DNA damage and mitochondria dysregulation, which cause a prolonged state of sterile inflammation in the tissues. These cellular phenomena may explain why spending time in space was found to cause the onset of a series of diseases normally related to aging. These changes that mimic aging but take place more quickly make space flights also an opportunity to study the mechanisms underlying aging. In this short review, we describe the biological mechanisms underlying cell senescence and aging; the peculiar characteristics of HZE ions, their interaction with living matter and the effects on the organism; the key role of mitochondria in HZE ion-induced health effects and aging-related phenomena.

A Longitudinal Epigenetic Aging and Leukocyte Analysis of Simulated Space Travel: The Mars-500 Mission

“…Researchers have long made efforts to study the impact of space travel on human aging ( Mohler, 1985 ). Crew members on a space mission and astronauts living on the International Space Station (ISS) can remain in space for many months at a time, where they experience a unique combination of stressors known to impact aging processes, including social isolation, confinement, microgravity, and cosmic radiation ( Giovanetti et al, 2020 ; Welsh et al, 2019 ; Kehler et al, 2019 ; Pantell et al, 2013 ; Tanskanen and Anttila, 2016 ). Although the potential negative impact of these stressors is well appreciated, the financial and physical demands of studying human aging biology in outer space have resigned some aspects of aging research to animal models or cell cultures ( Demontis et al, 2017 ; Patel et al, 2019 ).…”

Aging affects cognition and hippocampal ultrastructure in male Wistar rats

“…Such granules, which are one of the most common age‐related changes, represent the products of the lipofuscin and lysosome genesis and are directly dependent on mitochondrial function. It is believed that during aging, mutation in mitochondrial DNA initiates oxidative damage, which provokes further oxidative stress via oxidative phosphorylation resulting in a vicious cycle of damage (D'Anca et al., 2019; Giovanetti et al., 2020; Kowalska et al., 2020). However, downregulation of mitochondrial proteases compromises mitochondrial restoration system and prevents it from degrading oxidized proteins (Lee et al., 2011; Panel et al., 2018).…”

Understanding the Complexities and Changes of the Astronaut Microbiome for Successful Long-Duration Space Missions

“…The consequences of chronic exposure to radiation, and to CGR in particular, is concerning, due to the high energy, high penetrability and ionizing nature of their most hazardous components, the HZE particles [49]. These particles are so penetrating that shielding can only partially protect against exposure and the large emission of secondary neutrons that may follow, posing an additional hazard to the crew [50].…”