Unraveling non-cancer effects of spaceflight: how are the brain and skin affected in astronauts?

Lamers Greta

Promoter

Baatout Sarah, (UGent), sbaatout@SCKCEN.BE

SCK•CEN Mentor

Moreels Marjan
marjan.moreels@sckcen.be
+32 14 33 28 16

SCK•CEN Co-mentor

Verslegers Mieke
mieke.verslegers@sckcen.be
+32 14 33 28 67

Expert group

Radiobiology

PhD started

2017-10-25

Short project description

Astronauts on long duration, exploration missions outside low Earth orbit (LEO) are exposed to a unique and complex radiation environment that is quite different from exposures received on Earth. In addition, they are continuously exposed to low gravity conditions. This extreme environment has a clear impact on the crew health. Moreover, it is believed that the stressful conditions of psychological nature such as confinement, isolation and heavy workload also negatively affect the human body and can impair over time astronauts’ performance. Well-known effects include bone and muscle loss, and cardiovascular changes, but also neurological disorders are described including space motion sickness, visual disturbances, nausea and headaches, and neuromuscular fatigue and weakness. These pathological changes affect both motor and sensory functions, and the effects can be long lasting. Furthermore, it has been suggested that these changes could be the signs of an active process of neuroplasticity, which is the ability of the brain to change and adapt in response to environmental changes. In addition, spaceflight induced changes in skin are becoming an important matter of concern as well. Previous studies have shown that the astronauts’ skin becomes thinner in space, up to 20% during a six-month stay. This skin ageing mechanisms are slow on earth, but very much accelerated in weightlessness.

Previous findings from the Radiobiology Unit of SCK•CEN using  in vitro space analogs on Earth, indicate a strong impact of radiation and simulated microgravity on the neural network and survival (Pani, 2013; Pani, 2016). Furthermore, data from FOTON-M3 mission, in which human skin fibroblast were investigated that stayed in space for up to 10 days, showed a significant increase in DNA damage as well as increase in several secreted proteins, which are key players in the process of inflammation (Dieriks, 2009).

Objective

The main objective of this PhD project is to investigate how neural cells and behaviour, and skin cells, are affected by factors associated with the spaceflight environment (microgravity, radiation, psychological stress). A specific focus will be placed on further elucidating the morphological and signaling pathways that control cellular alterations to space flight stressors using both in vitro and in vivo models (hindlimb unloading mouse model).

A second purpose of this PhD project is to develop effective countermeasures to preserve neural activity and to prevent skin ageing. Thus, beyond the obvious space-related applications, the results delivered by this project can also provide a better understanding of certain aspects of human health, such as ageing, trauma and disease (e.g. neurological disorders), and are therefore highly relevant to improve human health on earth as well.

To achieve the objectives described above, the PhD candidate will use in vitro and in vivo ground-based experiments using space simulating devices available at SCK•CEN. For the latter, two Random Positioning Machines are available at the Radiobiology Unit. In order to simulate cosmic radiation, experiments with low-linear energy transfer (LET) photons or high-LET neutrons can be performed at the irradiation facility available at SCK•CEN. Moreover, we will apply for high-LET beam time at international accelerator facilities (GANIL, GSI, iThemba …). Psychological stress can be mimicked by adding different stress hormones (e.g. cortisol) to cell cultures. Finally, an ESA call (IBER-4: Investigating Biological Effects of Radiation) will be launched at the end of 2017 for which we will apply for extra financement.

To investigate the morphological changes and molecular events behind brain and skin alterations to space stressors, various immune parameters will be analyzed using high-throughput technologies available within the microscopic, genomic and Luminex platform at SCK•CEN: whole genome analysis of neural and skin cells, morphological analysis, high-throughput quantitative analysis of inflammatory proteins (cytokines) using the Luminex Technology, …