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In vitro follicle growth under non-attachment conditions and decreased FSH levels reduces Lhcgr expression in cumulus cells and promotes oocyte developmental competence.

ABSTRACT: PURPOSE: The in-vitro environment influences oocyte competence and gene expression in cumulus cells and oocytes. Effects of culturing under non-attachment conditions and varying follicle exposure to FSH were investigated at the mRNA level and on oocyte developmental capacity. METHODS: Quantitative PCR analysis of Gdf9, Mater, Nmp2 (in oocytes), Lhcgr and Amh (in cumulus cells), and oocyte developmental competence after in vitro follicle culture were evaluated. RESULTS: Follicle survival (98.7%) and polar body rate (94%) were similar for all conditions. Estradiol and progesterone production were significantly lower in non-attachment follicles (10-fold and 3-fold, respectively). Under non-attachment conditions, a higher two-cell rate (69.9%) and total blastocyst yield (48.5%) were obtained and, by decreasing FSH levels during culture, Lhcgr transcripts were significantly reduced to levels similar to in-vivo. Levels of oocyte-specific transcripts were not significantly influenced by in-vitro conditions. CONCLUSION: Non-attachment conditions influence follicle steroid secretory capacity and, together with dynamic FSH doses, positively influence cumulus cell gene expression and oocyte developmental competence.

SUBMITTER: Sanchez F

PROVIDER: S-EPMC3270142 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature

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In vitro follicle growth under non-attachment conditions and decreased FSH levels reduces Lhcgr expression in cumulus cells and promotes oocyte developmental competence.

Sánchez Flor F Romero Sergio S Albuz Firas K FK Smitz Johan J

Journal of assisted reproduction and genetics 20111222 2

<h4>Purpose</h4>The in-vitro environment influences oocyte competence and gene expression in cumulus cells and oocytes. Effects of culturing under non-attachment conditions and varying follicle exposure to FSH were investigated at the mRNA level and on oocyte developmental capacity.<h4>Methods</h4>Quantitative PCR analysis of Gdf9, Mater, Nmp2 (in oocytes), Lhcgr and Amh (in cumulus cells), and oocyte developmental competence after in vitro follicle culture were evaluated.<h4>Results</h4>Follicl ...[more]

PMID: 22190081

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Project description:BackgroundSingle embryo transfer (SET) is the most successful way to reduce the frequency of multiple pregnancies following in vitro fertilisation. However, selecting the embryo for SET with the highest chances of pregnancy remains a difficult challenge since morphological and kinetics criteria provide poor prediction of both developmental and implantation ability. Partly through the expression of specific genes, the oocyte-cumulus interaction helps the oocyte to acquire its developmental competence. Our aim was therefore to identify at the level of cumulus cells (CCs) genes related to oocyte developmental competence.Methodology/principal findings197 individual CCs were collected from 106 patients undergoing an intra-cytoplasmic sperm injection procedure. Gene expression of CCs was studied using microarray according to the nuclear maturity of the oocyte (immature vs. mature oocyte) and to the developmental competence of the oocyte (ability to reach the blastocyst stage after fertilisation). Microarray study was followed by a meta-analysis of the behaviour of these genes in other datasets available in Gene Expression Omnibus which showed the consistency of this list of genes. Finally, 8 genes were selected according to oocyte developmental competence from the 308 differentially expressed genes (p<0.0001) for further validation by quantitative PCR (qPCR). Three of these 8 selected genes were validated as potential biomarkers (PLIN2, RGS2 and ANG). Experimental factors such as inter-patient and qPCR series variability were then assessed using the Generalised Linear Mixed Model procedure, and only the expression level of RGS2 was confirmed to be related to oocyte developmental competence. The link between biomarkers and pregnancy was finally evaluated and level of RGS2 expression was also correlated with clinical pregnancy.Conclusion/significanceRGS2, known as a regulator of G protein signalling, was the only gene among our 8 selected candidates biomarkers of oocyte competence to cover many factors of variability, including inter-patient factors and experimental conditions.

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Dataset Information

In vitro follicle growth under non-attachment conditions and decreased FSH levels reduces Lhcgr expression in cumulus cells and promotes oocyte developmental competence.

Publications

In vitro follicle growth under non-attachment conditions and decreased FSH levels reduces Lhcgr expression in cumulus cells and promotes oocyte developmental competence.

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