Exposure of Triclosan in Porcine Oocyte Leads to Superoxide Production and Mitochondrial-Mediated Apoptosis during In Vitro Maturation

Abstract

While triclosan (TCS) exerts detrimental effects on female reproduction, the effect of TCS-derived toxins on porcine oocytes during in vitro maturation (IVM) is unclear. This study investigated the effects of TCS on mitochondrion-derived reactive oxygen species (ROS) production and apoptosis pathways during porcine oocyte maturation. Porcine oocytes were treated with TCS (1, 10, and 100 μM) and triphenylphosphonium chloride (Mito-TEMPO; 0.1 μM), and matured cumulus oocyte complexes (COCs) were stained with orcein, dichlorofluorescein diacetate (DCF-DA), and Mito-SOX. Proteins and mRNA levels of factors related to cumulus expansion and mitochondrion-mediated apoptosis and antioxidant enzymes were analyzed by western blotting and reverse-transcription polymerase chain reaction (RT-PCR), respectively. Meiotic maturation and cumulus cell expansion significantly decreased for COCs after TCS treatment along with an increase in mitochondrial superoxide levels at 44 h of IVM. Further, mitochondrion-related antioxidant enzymes and apoptosis markers were significantly elevated in porcine COCs following TCS-mediated oxidative damage. The protective effect of Mito-TEMPO as a specific superoxide scavenger from TCS toxin improved the maturation capacity of porcine COCs. Mito-TEMPO downregulated the mitochondrial apoptosis of TCS-exposed porcine COCs by reducing superoxide level. In conclusion, our data demonstrate that TCS mediates toxicity during porcine oocyte maturation through superoxide production and mitochondrion-mediated apoptosis.

Induction of Oxidative Stress and Mitochondrial Dysfunction by Juglone Affects the Development of Bovine Oocytes

“…This confirms previous studies that showed activation of caspase-3 and procaspase-9 in HL-60, SGC-7901, SKOV3, Hela, and B16F1 cells post-juglone treatment [ 2 , 3 , 5 , 47 ]. It also corroborates our above-mentioned records regarding juglone-induced damage in bovine oocytes as well as other studies documenting the induction of cellular apoptosis and reduction of oocyte quality during meiotic progression following the successive accumulation of ROS [ 32 , 39 , 40 ]. Collectively, these results indicated that juglone induces the accumulation of ROS, which in turn can reduce oocyte maturation and induce apoptosis, which can eventually impair the embryo development.…”

“…Generally, the degree of cumulus expansion correlates with the competence of in vitro oocyte maturation that can eventually predict the developmental competence of embryos [ 31 ]. Similar to our observations, previous studies on porcine COCs showed a significant reduction in cumulus expansion and/or downregulation of HAS2, TNFAIP6, and PTX3 following treatment with juglone and the pro-oxidant molecules atrazine and triclosan [ 25 , 32 , 33 ].…”

“…Since the linkage between apoptosis and reduced embryo development has been discussed in several studies, we moved forward to assess the levels of apoptosis following juglone treatment. Exposure of oocytes to toxic compounds significantly impaired the development of embryos through induction of ROS-derived oxidative stress, apoptosis, and cell death [ 32 , 33 , 48 , 49 ]. Staining of oocytes with annexin V showed a higher incidence of apoptosis after juglone treatment.…”

Effects of Mito-TEMPO on the survival of vitrified bovine blastocysts in vitro

“…According to previous study, reduction of superoxidederived oxidative stress by Mito-TEMPO improved oocyte maturation rate and developmental competence in porcine and bovine embryos (Yang et al, 2018;Park et al, 2020;Yousefian et al, 2021). Moreover, freezing medium with Mito-TEMPO supplementation assisted conservation of post-thawed sperm quality and survival competence in human (Lu et al, 2018;Masoudi et al, 2021).…”

A Review on the Fate of Legacy and Alternative Antimicrobials and Their Metabolites during Wastewater and Sludge Treatment

“…TCS has structural similarities to several thyroid hormones and has been shown to have dose-dependent effects on thyroid hormone production in animal studies [149]. Kim et al [150] and Park et al [151] both showed that perinatal TCS exposure caused porcine mitochondrial disruption and oxidative stress. Tran et al [152] demonstrated that perinatal TCS exposure induced neurodevelopment disorders in mice, leading to significant social, cognitive and learning defects in offspring mice.…”