Effect of sodium fluoride on male mouse fertility

Abstract

SUMMARYSodium fluoride (NaF), an environmental pollutant, has been tested for its impact on fertility in several species of laboratory animals. A literature demonstrated that NaF adversely affects sperm motility, morphology, capacitation, and the acrosome reaction. However, the molecular mechanisms underlying these alterations have not yet been elucidated. Therefore, present study was designed to evaluate the regulatory pathways involved in the effect of NaF on sperm function and fertilization. In this in vitro study, mouse spermatozoa were incubated with a range of concentrations (2.5, 5, and 10 mM) of NaF for 90 min in media that support in vitro fertilization. Our results showed that NaF was associated with reduced intracellular ATP generation, motility, and motion kinematics. Likewise, short-term exposure of spermatozoa to NaF significantly reduced the intracellular calcium concentration, protein kinase-A activity, and tyrosine phosphorylation of sperm proteins, which were associated with a significant decrease in the rate of capacitation and the acrosome reaction. Finally, NaF significantly reduced the fertilization and blastocyst formation during early embryonic development. On the basis of these results, we propose that NaF reduces sperm motility, capacitation, and the acrosome reaction leading to poor fertilization and suppressed embryonic development.

Analysis of the small non-protein-coding RNA profile of mouse spermatozoa reveals specific enrichment of piRNAs within mature spermatozoa

“…13 Although unequivocal evidence of whether such effects are adaptive is presently lacking, 14 the premise that environmental experience can influence the RNA profile of spermatozoa is gaining growing acceptance. 15,16 Indeed, compelling evidence now exists that exposure of the paternal linage to a wide range of environmental stressors, including: dietary perturbations, [17][18][19] corticosterone administration, 20 psychological stress, [21][22][23] cigarette smoke, 24 and environmental pollutants such as sodium fluoride, 25 can alter the RNA profile that the exposed spermatozoa carry, with significant implications for post-fertilization functions, including the transmission of transgenerational inheritance phenotypes to the offspring.…”

Sodium fluoride disturbs DNA methylation of NNAT and declines oocyte quality by impairing glucose transport in porcine oocytes

“…In general, mice or rats were treated with drinking water with 100-200 mg/L NaF to detect the genotoxicity of NaF in vivo (Fu et al, 2014;Zhu et al, 2014). For the in vitro genotoxicity test, cells, sperms or embryos were incubated with a range of concentrations (0-10 mM) of NaF in medium (Niu et al, 2012;Kim et al, 2015). As we know, oocyte quality determined the embryo's developmental potential after fertilization (Wang and Sun 2007).…”

“…In the male, NaF destroyed the structure of testes, decreased the production of sperm and the expression of related important genes, like Ssty2, Sly and HSF2 . Besides, NaF reduced the intracellular calcium concentration, protein kinase‐A activity, and tyrosine phosphorylation of sperm proteins (Kim et al, ; Cao et al, ).…”

Elevated aminopeptidase N affects sperm motility and early embryo development

“…Briefly, the cauda epididymides were collected and transferred to cell culture dishes containing 2 mL of BM. After a 12-min preincubation, spermatozoa were incubated in BM media with 0.4% BSA for inducing capacitation [ 19 , 21 ] (with/without APN) for 90 min at 7°C in an atmosphere of 5% CO 2 . For each experiment, three male mice per replicate were used.…”