Effect Of Microgravity On Aromatase Expression In Sertoli Cells

Area of Science:

• Reproductive Biology
• Cell Biology
• Space Medicine

Background:

• Cytochrome P450-aromatase is crucial for estrogen biosynthesis from C19 steroids.
• Sertoli cells in the testis are the primary source of estrogen during prepuberal development.
• Understanding the impact of microgravity on testicular function is vital for space exploration.

Purpose of the Study:

• To investigate the effects of simulated microgravity (SM) on aromatase expression in primary mouse Sertoli cells.
• To analyze biological properties of Sertoli cells cultured under SM conditions.
• To assess the potential consequences of SM-induced hormonal changes on male reproductive health.

Main Methods:

• Primary mouse Sertoli cells were cultured in a Rotary Cell Culture System (RCCS) to simulate microgravity.
• Cell viability, cell cycle, cytoskeletal protein expression, and growth factor levels were analyzed.
• Aromatase mRNA and protein expression were quantified, and 17β-estradiol levels were measured.

Main Results:

• Simulated microgravity did not affect Sertoli cell viability, proliferation, or expression of key cytoskeletal proteins and growth factors (KL, GDNF).
• SM significantly upregulated both mRNA and protein expression of P450 aromatase in Sertoli cells.
• Increased 17β-estradiol was detected in the culture medium, confirming functional aromatase activity, and this activity was not inducible by 8-Br-cAMP under SM.

Conclusions:

• Simulated microgravity induces significant upregulation of aromatase gene expression in Sertoli cells.
• This leads to increased 17β-estradiol secretion, potentially impacting male fertility and increasing testicular cancer risk.
• Further research is needed to elucidate the long-term effects of microgravity on testicular function and male reproductive health.