Nicotine-induced Disturbances of Meiotic Maturation in Cultured Mouse Oocytes: Alterations of Spindle Integrity and Chromosome Alignment

Abstract

We investigated whether nicotine exposure in vitro of mouse oocytes affects spindle and chromosome function during meiotic maturation (M-I and M-II). Oocytes in germinal vesicle (GV) stage were cultured in nicotine for 8 h or for 16 h, to assess effects in M-I and in metaphase II (M-II). The latter culture setting used the three protocols: 8 h nicotine then 8 h medium (8N + 8M); 16 h nicotine (16N); 8 h medium then 8 h nicotine (8M + 8N). Non-toxic concentrations of nicotine at 1.0, 2.5, 5.0 and 10.0 mmol/L were used. Spindle-chromosome configurations were analyzed with wide-field optical sectioning microscopy. In 8 h cultures, nicotine exposure resulted in dose-related increased proportions of M-I oocytes with defective spindle-chromosome configurations. A dose-related delayed entry into anaphase I was also detected. In 16 h cultures, nicotine exposure for the first 8 h (8N + 8M), or for 16 h (16N), resulted in dose- and time-related increased proportions of oocytes arrested in M-I (10 mmol/L; 8 h: 53.2%, controls 9.6%; 16 h: 87.6%, controls 8.5%). Defects in M-I spindles and chromosomes caused M-I arrest leading to dose-related decreased proportions of oocytes that reached metaphase-II (10 mmol/L 8 h: 46.8%, controls 90.4%;16 h: 12.4%, controls 91.5%). A delayed anaphase-I affected the normal timing of M-II, leading to abnormal oocytes with dispersed chromosomes, or with double spindles and no polar body. Nicotine exposure during the second 8 h (8M + 8N) resulted in dose-related, increased proportions of M-II oocytes with defective spindles and chromosomes (10 mmol/L: 42.9%, controls 2.0%). Nicotine has no adverse effects on GV break down, but induces spindle and chromosome defects compromising oocyte meiotic maturation and development.

Reproductive Effects of Two Neonicotinoid Insecticides on Mouse Sperm Function and Early Embryonic Development In Vitro

“…To illustrate in vitro effects on reproduction and the underlying mechanism, reproductive toxicity study of nicotine exposure on mammalian spermatozoa or oocytes has been conducted for years [13], [14], [15], [16]. However, studies are rarely reported for the in vitro effects of IMI and ACE on mammalian reproduction, especially on their direct actions upon fertilization and preimplantation embryonic development.…”

Nicotine induces multinuclear formation and causes aberrant embryonic development in bovine

“…Studies have showed that nicotine, the dominate factor in cigarette tobacco, affects almost the whole process of reproduction such as oocyte maturation, fertilization and embryonic development (Zenzes, 2000). Nicotine has been shown to interfere with oocyte meiosis and chromosome disjunction (Racowsky et al, 1989;Mailhes et al, 2000) and alters spindle integrity and chromosome alignment (Zenzes and Bielecki, 2004;Liu et al, 2006). Data from in vitro fertilization and gamete intra-fallopian transfer in the human infers that maternal smoking affects oocyte maturation (Zenzes et al, 1995), increases the zona pellucida thickness of oocytes and embryos (Shiloh et al, 2004) and thereby decreases fertilization and pregnancy rates (Klonoff-Cohen et al, 2001).…”

Mode‐of‐action analysis of the effects induced by nicotine in the in vitro micronucleus assay

“…These lines of evidence again point toward an aneugenic MoA, as these molecular changes have been causally linked with aneugenic agents previously (Degrassi and Tanzarella ; Miller and Adler ; Johnson and Parry ; Bryce et al , ; Hernández et al ; Stock et al ). Although the nicotine‐aneugenicity relationship has been reported before (Racowsky et al ; Zenzes and Bielecki ; Liu et al ; Demirhan et al ), this is the first study to identify a specific molecular change that has the biological plausibility to lead to these effects. Only oxidative stress‐based MoAs have been suggested before, and while it is also possible especially at high concentrations, this mechanism is unlikely to result in these specific manifestations of toxicity (Yildiz ; Wu et al ; Prabhulkar and Li ; Ginzkey et al ; Schweitzer et al ).…”

“…Moreover, in vitro organotypic cell cultures (e.g., nasal, gingival, and respiratory cells) that partially recapitulate the cellular environment that is first exposed in human nicotine consumers have been shown to contain various forms of DNA damage following nicotine exposure (Argentin and Cicchetti 2004;Kleinsasser et al 2005;Sassen et al 2005;Ginzkey et al 2009Ginzkey et al , 2010Demirhan et al 2011;Ginzkey et al 2012Ginzkey et al , 2014aGinzkey et al , 2014b. There is also some evidence to suggest that nicotine may have aneugenic properties, as revealed by data from studies that examined numerical and structural chromosome changes in exposed human and rodent cells (Racowsky et al 1989;Zenzes and Bielecki 2004;Liu et al 2007;Demirhan et al 2011). In contrast, a minority of studies reports nongenotoxic findings in mammalian cells (Bishun et al 1972;Altmann et al 1984;Doolittle et al 1995), including one in vitro MN study conducted in human lymphocytes up to a concentration of 10 mM (European Chemical Agency (ECHA).…”