Inhibition by human embryos of mouse granulosa cell progesterone production: development of a sensitive bioassay

Abstract

Reproduction technologies could be improved by the development of methods to evaluate oocyte or embryo quality in a non-invasive, quantitative manner. Since human embryos secrete a factor that inhibits granulosa cell progesterone production, an interspecies bioassay was established to investigate whether the presence of this progesterone-inhibitory factor (PIF) in human embryo-conditioned (HEC) media is related to the health and developmental capacity of the embryos. Oocytes were microsurgically removed from oocyte-cumulus complexes isolated from superovulated mouse ovaries, and the oocytectomized complexes were cultured in HEC media in the presence of follicle stimulating hormone and testosterone. Progesterone accumulation in the media was determined by radioimmunoassay. Despite the potential limitations of very small volumes of HEC media to evaluate, and the need to freeze these media at the source, the bioassay was able to detect PIF activity in HEC media. Most embryos produced PIF activity, but the degree of inhibition was not correlated with the ability of oocytes to be fertilized, nor with embryo morphology or ability to cleave and develop after transfer. These results demonstrate that secretion of PIF by human embryos can be measured by this bioassay and that human PIF can inhibit murine granulosa cell steroidogenesis; however, PIF activity is not correlated with human embryo quality or developmental competence.

Use of novel silver nanoparticles with Hyaluronan as potential biological labels for determining the quality of embryos development

“…Therefore it is important for in vitro reproductive techniques to select the most viable gametes and embryos without interference with their functions and viability. The adequate determination of embryo's development quality can increase pregnancy rates and decrease the risk of early embryos losing with consequent obstetrical morbidity 4 . Modern qualitative and quantitative methods of embryos and gametes competence assessment use biochemical markers and visual observation.…”

Aromatase activity in granulosa cells as a predictor of pregnancy potential

“…Morphological evaluation and development rates [2] are the most commonly used methods to date. More recently, the development of micro-analytical methodologies has led to the investigation of several different biochemical markers [3] to predict the highest implantation potential of embryos within a given cohort. However, despite these different strategies, no reliable method has been developed.…”

Cumulus cells steroidogenesis is influenced by the degree of oocyte maturation

“…Moreover, soluble factors produced by germ cells can affect a variety of functions, namely granulosa cell proliferation [29,30], dimeric inhibin A and B secretion [31], inhibition of plasminogen activator production [32], and expression of LH receptors [33]. Finally, there is evidence that the oocyte plays an active role in the steroidogenic function of GC in many species [22,28,34-37]. Although the effects of these oocyte-secreted factors have been extensively studied and many of them can be mimicked by the growth differentiation factor-9 (GDF-9) [38,39], less is known about their nature [27,35] and their physiological role.…”