In vitro effects of simulated microgravity on Sertoli cell function

With the advent of space flights questions concerning the effects of microgravity (0G) on human reproductive physiology have received great attention. The aim of this study was to evaluate the influence of 0G on Sertoli cells. A Sertoli cell line from mouse testis (42GPA9) was analyzed for cytoskeletal and Sex Hormone Binding Globilin (SHBG) changes by immunohistochemistry, for antioxidant content by RT-PCR and for culture medium lactate concentrations by protein chemistry. Cells were cultured for 6, 24 and 48 h on a three-dimensional Random Positioning Machine (3D-RPM); static controls (1G) were positioned on the supporting frame. At the end of each experiment, cultured cells were either fixed in paraformaldehyde or lysed and RNA-extracted or used for culture medium lactate measurements as needed. At 0G, Sertoli cytoskeleton became disorganized, microtubules fragmented and SHBG undetectable already after 24 h, with alterations worsening by 48 h. It was evident that various antioxidant systems appreciably increased during the first 24 h but significantly decreased at 48 h. No changes occurred in the 1G samples. Initially, 0G seemed to disturb antioxidant pro- tection strategies allowing the testes to support sperm production, thus generating an aging-like state of oxidative stress. Lactate pro- duction at 0G slightly decreased after 24 h. Further experiments are needed in space to investigate upon steroidogenesis and germ cell differentiation within the testis, to rule out male infertility as a possible consequence, which could be a problem, as life expectancy increases.With the advent of space flights questions concerning the effects of microgravity (0G) on human reproductive physiology have 13 received great attention. The aim of this study was to evaluate the influence of 0G on Sertoli cells. A Sertoli cell line from mouse testis 14 (42GPA9) was analyzed for cytoskeletal and Sex Hormone Binding Globilin (SHBG) changes by immunohistochemistry, for antioxidant 15 content by RT-PCR and for culture medium lactate concentrations by protein chemistry. Cells were cultured for 6, 24 and 48 h on a 16 three-dimensional Random Positioning Machine (3D-RPM); static controls (1G) were positioned on the supporting frame. At the 17 end of each experiment, cultured cells were either fixed in paraformaldehyde or lysed and RNA-extracted or used for culture medium 18 lactate measurements as needed. At 0G, Sertoli cytoskeleton became disorganized, microtubules fragmented and SHBG undetectable 19 already after 24 h, with alterations worsening by 48 h. It was evident that various antioxidant systems appreciably increased during the 20 first 24 h but significantly decreased at 48 h. No changes occurred in the 1G samples. Initially, 0G seemed to disturb antioxidant pro- 21 tection strategies allowing the testes to support sperm production, thus generating an aging-like state of oxidative stress. Lactate pro- 22 duction at 0G slightly decreased after 24 h. Further experiments are needed in space to investigate upon steroidogenesis and germ 23 cell differentiation within the testis, to rule out male infertility as a possible consequence, which could be a problem, as life expectancy 24 increase