Human charcoal-stripped serum supplementation enhances both the stearoyl-coenzyme a desaturase 1 activity of cumulus cells and the in vitro maturation of oocytes

Abstract

Obtaining a better outcome in assisted reproductive technology remains to be attained. In the case of in vitro fertilization (IVF), oocyte maturity is paramount for achieving a successful pregnancy. Maternal serum supplementation of in vitro maturation (IVM) medium can increase the rate of oocyte IVM. The aim of the present study was to compare the effect of whole and charcoal-stripped serum supplementation on IVM and the activity index of stearoyl-coenzyme A desaturase 1 (SCD1) in cumulus cells enclosing the oocyte as a molecular indicator of oocyte quality. Cumulus cells and germinal vesicle immature oocytes were collected from 76 women with polycystic ovarian syndrome during an IVF cycle. Serum samples were pooled from healthy women and were applied as whole or charcoal-stripped serum supplements. SCD1 expression and activity were measured by quantitative polymerase chain reaction (PCR) and gas-liquid chromatography, respectively. Charcoal-stripped serum at an amount of 10% showed a higher potency in increasing the SCD1 expression and activity index than whole serum (>1.5 fold, p < 0.001). An increase in the IVM rate was also observed in oocytes cultured in the presence of 10% charcoal-stripped serum compared to the control group (1.9 fold, p = 0.031). Therefore, charcoal-based lipid depletion as a simple and preparative strategy may increase the beneficial effect of serum supplementation in oocyte IVM culture.