Hydrogen Sulfide and/or Ammonia Reduces Spermatozoa Motility through AMPK/AKT Related Pathways

Abstract

A number of emerging studies suggest that air pollutants such as hydrogen sulfide (H ₂S) and ammonia (NH ₃) may cause a decline in spermatozoa motility. The impact and underlying mechanisms are currently unknown. Boar spermatozoa ( in vitro) and peripubertal male mice ( in vivo) were exposed to H ₂S and/or NH ₃ to evaluate the impact on spermatozoa motility. Na ₂S and/or NH ₄Cl reduced the motility of boar spermatozoa in vitro. Na ₂S and/or NH ₄Cl disrupted multiple signaling pathways including decreasing Na ⁺/K ⁺ ATPase activity and protein kinase B (AKT) levels, activating Adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK) and phosphatase and tensin homolog deleted on chromosome ten (PTEN), and increasing reactive oxygen species (ROS) to diminish boar spermatozoa motility. The increase in ROS might have activated PTEN, which in turn diminished AKT activation. The ATP deficiency (indicated by reduction in Na ⁺/K ⁺ ATPase activity), transforming growth factor (TGF _β) activated kinase-1 (TAK1) activation, and AKT deactivation stimulated AMPK, which caused a decline in boar spermatozoa motility. Simultaneously, the deactivation of AKT might play some role in the reduction of boar spermatozoa motility. Furthermore, Na ₂S and/or NH ₄Cl declined the motility of mouse spermatozoa without affecting mouse body weight gain in vivo. Findings of the present study suggest that H ₂S and/or NH ₃ are adversely associated with spermatozoa motility.