Estradiol and progesterone production by cultured granulosa cells cryopreserved from in vitro fertilization patients

Associations between microbial presence in follicular fluid with IVF outcomes: a systematic review and meta-analysis

PURPOSE

The aim of the study was to synthesize disparate studies to investigate potential impact of microbial presence in FF of infertile women on IVF outcomes.

METHODS

Following preliminary searches to find medical subject heading (MeSH) terms plus free terms, a systematic search was performed in the PubMed, Cochrane Library, Embase, Web of Science, and Clinicaltrials.gov databases from January 10, 2022, to July 5, 2023. Data collected for each study were analyzed using RevMan 5.4 software available on the Cochrane website.

RESULTS

After correcting for contamination from the vagina, the FFs of 289 women were detected positively by microbial culture and identification, ELISA, and IPA. The pregnancy rate of the FF-positive group was significantly lower than the FF-negative group (19.7% vs. 32.2%) and (OR: 0.57, 95% CI: 0.28-1.14, P=0.11; I2=56%) while the fertilization rate was almost equal (60.0% vs. 62.0%) and (OR: 1.03, 95% CI: 0.88-1.20, P=0.72; I2=0%). Evidence quality was very low.

CONCLUSIONS

The different species of microorganisms in FF of infertile women may have different effects on IVF outcomes. The Lactobacillus spp. may have a positive effect, while other microorganisms may have the opposite effect.

A rapid and robust method for the cryopreservation of human granulosa cells

Human primary granulosa cells (GCs) derived from women undergoing oocyte retrieval can be cultured and used as a cellular model for the study of human ovarian function. In vitro, they change rapidly, initially resembling cells of the preovulatory follicle and then cells of the corpus luteum. They are derived from individual patients, whose different medical history, lifestyle and age lead to heterogeneity. Thus, cells can rarely be ideally matched for cellular experiments or, if available, only in small quantities. We reasoned that cryopreservation of human GCs may be helpful to improve this situation. Previous studies indicated the feasibility of such an approach, but low survival of human GCs was reported, and effects on human GC functionality were only partially evaluated. We tested a slow freezing protocol (employing FCS and DMSO) for human GCs upon isolation from follicular fluid. We compared cryopreserved and subsequently thawed cells with fresh, non-cryopreserved cells from the same patients. About 80% of human GCs survived freezing/thawing. No differences were found in cell morphology, survival rate in culture, or transcript levels of mitochondrial (COX4, OPA1, TOMM20), steroidogenic (CYP11A1, CYP19A1) or cell-cell contact genes (GJA1) between the two groups in cells cultured for 1-5 days. A proteomic analysis revealed no statistically significant change in the abundance of a total of 5962 proteins. The two groups produced comparable basal levels of progesterone and responded similarly to hCG with elevation of progesterone. Taken together, our results show this to be a rapid and readily available method for the cryopreservation of human GCs. We anticipate that it will allow future large-scale experiments and may thereby improve cellular studies with human ovarian cells.

Low Doses of Resveratrol Protect Human Granulosa Cells from Induced-Oxidative Stress

Resveratrol is a phytoalexin present in plant-derived foods, including grape’s skin, cocoa, and peanuts. Evidence suggests that it has beneficial effects on human health because of its antioxidant properties. However, there is limited knowledge about the part played by resveratrol in ovarian function. In this paper, the influence of resveratrol on granulosa cells (GC) was evaluated. In addition to being the main estradiol producers, GC are in direct contact with the oocyte, playing a fundamental role in its growth and development. The cell line COV434 and human granulosa cells (hGC), obtained from women undergoing assisted reproductive technology (ART), were used. GC were treated with resveratrol (0.001–20 μM) at different times (24–72 h). Low concentrations of this compound suggest a protective role, as they tend to reduce ROS/RNS formation after inducement of stress. On the contrary, high concentrations of resveratrol affect GC viability and steroidogenic function. As it may act as a direct modulator of GC oxidative balance, this work may help to clarify the impact of resveratrol on GC and the usefulness of this antioxidant as adjunct to infertility treatments.

Effect of cryopreservation on human granulosa cell viability and responsiveness to gonadotropin

In human, the use of freshly recovered granulosa cells for experiments remains difficult. Because of the single use of human cells, the experiments cannot be repeated, and no additional conditions can be tested afterwards with the cells of the same patient. Therefore, granulosa cell cryopreservation could be a good alternative to keep part of these cells for later controls or experiments. The aim of this study is to compare the responsiveness to FSH of fresh and frozen-thawed human primary granulosa-lutein cells (hGLC) and determine if cryopreserved granulosa cells can be used in place of fresh cells. Two cryopreservation methods were also compared: a conventional versus a simplified freezing method. This experimental study was undertaken at Igyxos S.A., Nouzilly, France. Seventy women undergoing oocyte retrieval at the IVF Unit from Bretonneau University Hospital (Tours, France) were recruited in 2016. Fresh and frozen-thawed hGLC were cultured for 7 days and then stimulated by r-FSH for 48 h. To assess r-FSH efficacy and potency, extracellular cAMP accumulated in the supernatant for each stimulation point was measured. We demonstrated that hGLC remain responsive to FSH stimulation after freezing-thawing and 7 days of pre-culture. They are able to secrete cAMP with a similar EC50 value as fresh hGLC, but FSH efficacy is lowered. As our study did not show any significant difference between the two freezing methods concerning the sensitivity of hGLC to FSH, hGLC could be cryopreserved with the simplified freezing method without taking up too much time for IVF laboratories.

Microorganisms within human follicular fluid: effects on IVF

Our previous study reported microorganisms in human follicular fluid. The objective of this study was to test human follicular fluid for the presence of microorganisms and to correlate these findings with the in vitro fertilization (IVF) outcomes. In this study, 263 paired follicular fluids and vaginal swabs were collected from women undergoing IVF cycles, with various causes for infertility, and were cultured to detect microorganisms. The cause of infertility and the IVF outcomes for each woman were correlated with the microorganisms detected within follicular fluid collected at the time of trans-vaginal oocyte retrieval. Microorganisms isolated from follicular fluids were classified as: (1) ‘colonizers’ if microorganisms were detected within the follicular fluid, but not within the vaginal swab (at the time of oocyte retrieval); or (2) ‘contaminants’ if microorganisms detected in the vagina at the time of oocyte retrieval were also detected within the follicular fluid. The presence of Lactobacillus spp. in ovarian follicular fluids was associated with embryo maturation and transfer. This study revealed microorganisms in follicular fluid itself and that the presence of particular microorganisms has an adverse affect on IVF outcomes as seen by an overall decrease in embryo transfer rates and pregnancy rates in both fertile and infertile women, and live birth rates in women with idiopathic infertility. Follicular fluid microorganisms are a potential cause of adverse pregnancy outcomes in IVF in both infertile women and in fertile women with infertile male partners.

Cryopreservation of pig granulosa cells: effect of FSH addition to freezing medium

We cryopreserved swine granulosa cells by a slow cooling rate system; FSH was added to the freezing medium to test its effectiveness in protecting the cells. After thawing, proliferative activity, viability, steroidogenesis and apoptosis were tested; moreover, we determined heat shock protein (HSP70) production, to investigate the recovery from stress and superoxide dismutase (SOD) and catalase activity to evaluate a possible impairment of the antioxidant pathway. E2 production was enhanced by cryopreservation in particular with FSH; on the contrary, P4 production was inhibited by the freezing process in particular without FSH. Only the higher FSH concentration (10 ng/ml) stimulated steroid secretion in freshly collected cells; P4 production by cells cryopreserved in the presence and in absence of FSH was increased by both 5 and 10 ng/ml while the lowest concentration was effective in stimulating E2 production only when FSH was added to freezing medium. Freezing did not modify proliferative activity, while apoptosis was higher in frozen than in fresh cells. HSP70 production was lower in cells cryopreserved in presence of FSH, whose antioxidant metabolism was also conserved: SOD and catalase activities were similar to control. In conclusion, cryopreservation does not seem to markedly affect granulosa cells, in particular if they are frozen in presence of FSH; the gonadotrophin somehow improves their performances after thawing, probably stimulating E2 production and the antioxidant metabolism.

Live offspring by in vitro fertilization of oocytes from cryopreserved primordial mouse follicles after sequential in vivo transplantation and in vitro maturation

The objectives of the present study were to achieve 1) oocyte maturation, 2) oocyte competence of fertilization, and 3) oocyte competence of embryogenesis with oocytes from primordial follicles obtained from cryopreserved newborn mouse ovaries by using a two-step method. In the first step, frozen-thawed newborn mouse ovaries were transplanted under the kidney capsule of recipients for the initiation of growth from the primordial follicle stage on. In the second step, growing preantral follicles in the ovarian grafts were recovered and cultured. The results demonstrated that primordial follicles were able to be recruited to preantral follicles during the period of transplantation, and preantral follicles could be mechanically isolated from ovarian grafts. Under the present in vitro culture conditions, 85.8% of the isolated follicles (n = 332) from ovarian grafts survived the 12-day in vitro culture process, 84.9% of the recovered oocytes (n = 285) were germinal vesicle breakdown (GVBD)-competent, and 76% of the oocytes that underwent GVBD (n = 242) developed to the metaphase II (MII) stage. In the in vitro fertilization experiments, 75.4% of 142 inseminated MII oocytes underwent fertilization and cleavage to the 2-cell stage. Subsequently, 79.7% of the 2-cell-stage embryos (n = 69) progressed to the late morula-early blastocyst stage. Transfer of late morula-early blastocyst embryos resulted in the production of live offspring. From our experiments, it may be concluded that in vivo maturation by grafting followed by in vitro maturation of frozen-thawed primordial follicles can restore fertility in mice. This model could be useful for a similar application in the human.