Superoxide dismutase expression in human cumulus oophorus cells

Abstract

Success in assisted reproductive techniques (ART) is influenced by gamete and embryo quality but the assessment of these parameters has been thwarted by the lack of reliable biomarkers. Follicular fluid and cumulus oophorus cells may provide biomarkers due to their close relationship to the oocyte. These cells produce antioxidants and thus protect the oocyte from oxidative damage exerted by reactive oxygen species (ROS). ROS and antioxidants are known to intervene in reproductive physiology and pathology, but their roles are unclear. It is hypothesized that superoxide dismutase (SOD), a first line antioxidant enzyme, is associated with oocyte quality. Cells obtained in the course of ART for the treatment of infertility due to male factor or female pathology were processed for SOD intracellular isoforms (CuZnSOD and MnSOD) immunodetection, total SOD activity and isoforms content. Cells presented strong positive staining for CuZnSOD and MnSOD. SOD activity decreased with increasing female age but was increased in endometriosis and in ovulatory dysfunction. When male factor was the cause for infertility, successful ART was associated with higher SOD activity. Variations in SOD emphasize the relevance of oxidative stress in the oocyte maturation process. These variations also suggest that SOD is a potential biomarker for ART success.

Differences in cumulus cells gene expression between modified natural and stimulated in vitro fertilization cycles

“…The correlation between patients' age and log2 expression values for genes related to oxidation-reduction process, regardless of therapy, is not statistically significant. A negative correlation between age and gene expression of genes involved in defense against reactive oxygen species (ROS) in follicles is well known and has been reported in several studies [28][29][30][31]. It seems that in our study we have controlled this effect by including patients of similar age and younger than 35 years, which is proved by a non-significant correlation (Table S3-Regardless of therapy).…”

Endometriosis and Infertility: The Role of Oxidative Stress

“…Data of a recently published study showed that SOD activity decreased with age in women, but increased in women with endometriosis and ovulatory dysfunction (Matos et al, 2009). When the cause of infertility was male factor, the success of ART was associated with increased SOD activity.…”

“…When the cause of infertility was male factor, the success of ART was associated with increased SOD activity. Variations in SOD activity emphasize the importance of oxidative stress in the oocyte maturation process, and are suggested to be a potential biomarker of ART success (Matos et al, 2009).…”

“…However, no studies have evaluated the expression of this enzyme or of the entire GSH redox system in COCs of patients with infertility related to endometriosis. Matos et al (2009) suggested a positive correlation between the SOD activity of COCs of infertile women submitted o ovarian stimulation for ART due to male factor and ART outcomes. In this same study an increase in SOD activity was observed in in vitro culture of COCs from infertile women with endometriosis.…”

Maternal obesity in mice not only affects fresh embryo quality but also aggravates injury due to vitrification

“…In our study, the significant downregulation of MnSOD in previously vitrified day-5 blastocysts from obese mice may be caused by decompensation to stress. Superoxide dismutase (SOD) activity has been shown to diminish with increasing female age, and successful ART was associated with higher SOD activity [47]. This implies that day-5 blastocysts previously vitrified on day 3 in the obese group are still in a stressed state.…”