EVALUATION OF THE ANTIAPOPTOTIC EFFECT OF COENZYME Q10 AS A COUNTERMEASURE AGAINST EYE LESIONS ENDURED DURING LONG DURATION SPACE FLIGHT

Understanding human space exploration-related dam- ages, whose main causes are microgravity and cosmic irradiations, is an essential goal for  mission  design and risk assessment. One main target of space related damaging agents is the retina, which cells are known to undergo apoptosis in the response to space irradia- tion and microgravity. This review summarises the most relevant results we have achieved by developing the project RA (“ Ra diation, microgravity and Ap optosis”) funded by Agenzia Spaziale Italiana (ASI), in which we proposed a peculiar countermeasure aimed to inhibit retinal cell apoptosis: the Coenzyme Q10 (CoQ10). We previously recognised CoQ10, the well-known free radi- cal scavenger, as a potent, general antiapoptotic mol- ecule, being a gatekeeper of the mitochondrial perme- ability transition pore whose opening is the main trigger of apoptosis. We have carried out studies on retina-cul- tured cells subjected to a plethora of damaging stimuli, including radiations and microgravity (by using a Rota- tor Wall Vessel Bioreactor), and on animal models of radiation- or excitotoxicity-induced retinal damage. Our results clearly indicated that CoQ10 signifcantly coun- teracted apoptosis in response to all tested damaging stimuli, both in vitro and in vivo . This supports the pos- sibility that CoQ10 treatment could be evaluated as an optimal countermeasure against retinal lesions during space explorations. Furthermore, our observation that CoQ10 administered as eye drops reaches the choroid/ retina area strongly suggests that it could be simply and effciently administered in this form.