ASI-Biomission VITA Inc. 51/52 NANOROS experiment: skeletal muscle cell protection against oxidative stress with cerium oxide nanoparticles in space

摘要

With low gravity conditions and high energy radiations, space environment exerts deleterious effects on the astronauts' musculoskeletal system, inducing/accelerating loss of skeletal muscle mass and force that are typical of aging or certain pathological conditions on Earth. In astronauts, these effects are partially reversible upon return on Earth, yet they hinder long-term permanence in space and interplanetary exploration. Oxidative stress is among the causes of the observed effects, and its onset both on Earth and in space is related to the unbalanced production/removal of highly reactive species (such as hydroxyl radical, superoxide and singlet oxygen, collectively termed as reactive oxygen species- ROS). These species are typically scavenged by endogenous antioxidant defenses (provided for instance by superoxide dismutase and catalase), in synergy with dietary intakes of natural antioxidants (like vitamins and polyphenols). Traditional antioxidants require constant supply due to their short biological activity, whereas novel materials such as cerium oxide nanoparticles (nanoceria, NC) exhibit a self-regenerative antioxidant property mimicking superoxide dismutase/catalase activity that was demonstrated in a number of cellular models and even in some disease animal models. Selected by the Agenzia Spaziale Italiana for implementation on board the International Space Station (ISS) with increment 51/52, our experiment entitled "Nanotechnology Solutions against Oxidative Stress in Muscle Tissue during Long-Term Microgravity Exposure" (NANOROS) aimed at assessing the protective role of NC as antioxidant agents on differentiating H9c2 myoblasts in space. Preliminary on-ground simulations of the whole experimental timeline (performed in hardware qualified to flight) enabled the identification of suitable cell density (30,000 cells/cm~2), NC size (30 nm on average) and coating (with fetal bovine serum) to obtain high RNA concentrations (~100 ng/ul) for transcriptional