Ultrastructure of coarse granules in the perivitelline space and association with ovulation induction protocols

OBJECTIVE

To evaluate the origin and ultrastructure of the coarse granules in the perivitelline space (PVS) of oocytes of a group of couples attending assisted reproduction treatment.

METHODS

The ultrastructure of five oocytes with coarse granulues in the PVS obtained from three patients were evaluated by transmission electron microscopy (TEM). The influence of the ovulation induction regimen on the formation of granules in the PVS of the oocytes of 214 couples and the developmental capacity of these oocytes presenting granules in the PVS was analyzed retrospectively.

RESULTS

In TEM analysis, the microvilli structure was irregular, short, and loosely scattered through the oolemma in the oocytes presenting coarse granules in the PVS. Furthermore, dense lipid droplets were identified within the PVS and the surrounding cumulus cells. In retrospective analysis, the number of oocytes with coarse granules in the PVS was positively correlated with the duration of antagonist administration (r=0.23, p=0.013). Regardless of the type of granule, the presence of coarse or moderately coarse granules in the PVS was positively correlated with low-quality embryos on D3 (r=0.29, p=0.005) and the total number of arrested embryos up to D3 (r=0.33, p<0.001). Furthermore, the presence of coarse granules in the PVS severely exacerbated miscarriage rates.

CONCLUSIONS

Our findings suggest that the presence of especially coarse granules in the PVS is correlated with the reduction of further embryonic developmental capacity in post-implantation stages of embryonic development, indicating a negative impact from aggressive ovulation induction protocols on developing oocytes.

Identification of the pathogenic effects of missense variants causing PRKAG2 cardiomyopathy

BACKGROUND

Pathogenic missense variants in PRKAG2, the gene for the gamma 2 regulatory subunit of adenosine monophosphate-activated protein kinase (AMPK), cause severe progressive cardiac disease and sudden cardiac death, named PRKAG2 cardiomyopathy. In our previous study, we reported a E506K variant in the PRKAG2 gene that was associated with this disease. This study aimed to functionally characterize the three missense variants (E506K, E506Q, and R531G) of PRKAG2 and determine the possible effects on AMPK activity.

METHODS

The proband was clinically monitored for eight years. To investigate the functional effects of three missense variants of PRKAG2, in vitro mutagenesis experiments using HEK293 cells with wild and mutant transcripts and proteins were comparatively analyzed using quantitative RT-PCR, immunofluorescence staining, and enzyme-linked immunosorbent assay.

RESULTS

In the long-term follow-up, the proband was deceased due to progressive heart failure. In the in vitro experimental studies, PRKAG2 was overexpressed after 48 h of transfection in three mutated cells, after which the expression levels of PRKAG2 were regressed to the level of wild-type cells in 3-weeks stably transformed cells, except for the cells with E506K variant. E506K, E506Q, and R531G variants had caused a reduction in the AMPK activity and resulted in the formation of cytoplasmic glycogen deposits.

CONCLUSION

Three missense variants that alter AMPK activity affect a residue in the CBS4 domain associated with ATP/AMP-binding. Detailed information on the influence of PRKAG2 pathogenic variants on AMPK activity would be helpful to improve the treatment and management of patients with metabolic cardiomyopathy.

Higher follicular fluid glycodelin levels are negatively correlated with embryonic development in assisted reproduction

OBJECTIVE

To investigate the possible effect of follicular fluid glycodelin levels on the quality of developing oocytes and subsequent in vitro embryo development.

METHODS

Follicular fluid glycodelin levels of 145 patients undergoing assisted reproductive treatment were analyzed and the correlation between glycodelin levels and ART outcomes were evaluated.

RESULTS

We found that glycodelin levels were negatively correlated with the number of high quality embryos on day 3 (r=-0.20, p=0.05). Additionally, higher glycodelin levels were correlated with higher FSH levels (r=0.18, p=0.04). However, glycodelin levels were not predictive for implantation (p=0.67) or ongoing pregnancy rates (p=0.99).

CONCLUSION

Glycodelin in the follicular environment might be one of the factors that influence the competence of growing oocytes and affect the quality of subsequent in vitro embryo development.