Follicular GH and IGF1 Levels Are Associated With Oocyte Cohort Quality: A Pilot Study

Chronic psychosocial stress affects insulin-like growth factor 1 and its receptors in mouse ovaries

Context Chronic psychosocial stress negatively affects folliculogenesis and oogenesis. Intraovarian mechanisms mediating these effects are poorly understood. Aims This work aimed to find out how chronic psychosocial stress affects ovarian IGF1 and its receptor (IGF1R), as well as Igf1 and Igf1r gene expression in cumulus-oocyte complexes (COCs). It also aimed to address possible protective effects of gonadotropin stimulation on IGF1 ovarian signalling. Methods Female CD1 mice experienced chronic psychosocial stress of 11-day isolation followed by overcrowding for 10days. To verify the model, blood corticosterone levels and the quality of oocytes were evaluated in stressed females. The levels of IGF1/IGF1R, blood IGF1 concentration, and expression of Igf1 /Igf1r in the ovaries were compared in stressed and unstressed females. Key results Psychosocial stress caused an elevation of corticosterone level, which was alleviated by gonadotropin treatment. The stressed mice showed a decreased IGF1 level in the ovaries and a decreased expression of Igf1 and Igf1r in COCs. In the unstressed females, gonadotropin injection decreased the expression of Igf1 and Igf1r ; in the stressed females, the same treatment increased Igf1r expression. Neither stress nor ovarian stimulation with gonadotropins affected the serum IGF1 level. Conclusions Psychosocial stress suppresses IGF1 signalling in the ovaries. Gonadotropin treatment modulates these effects differently in stressed and unstressed animals. Implications The results may have translational value for human reproduction. Ovarian IGF1 can be considered a candidate for further improvement of IVF results in women under conditions of chronic stress.

Up-regulated mitochondrial biogenesis associated with GH/IGF axis in the ovaries of muskrats (Ondatra zibethicus)

Mitochondria play a critical role in follicular development and ovulation, at least in part through the actions of growth hormone (GH)/insulin-like growth factor-1 (IGF-1) on mitochondrial biogenesis. This study aimed to identify seasonal alterations in the GH/IGF-1 system and mitochondrial biogenesis in muskrat (Ondatra zibethicus) ovaries. We utilized the muskrat, a typical seasonal breeder, to clarify the potential impact of the GH/IGF-1 system on mitochondrial biogenesis across different breeding seasons using immunohistochemistry, gene expression and high-throughput sequencing. Alterations in follicular development existed in muskrat ovaries between the breeding season (BS) and non-breeding season (NBS), accompanied by a striking decrease in circulating and ovarian GH and IGF-1 concentrations. GH, GHR, IGF-1, IGF-1R, and mitochondrial biogenesis markers were localized in the ovarian cells of muskrats during both seasons. In contrast, Gh, Ghr, Igf-1, Igf-1r, Ppargc1a, Ppargc1b, Tfam, and Nrf1/2 mRNA levels were higher in BS. The relative levels of GH and IGF-1 in circulation and ovaries were positively associated with mitochondrial biogenesis markers. Additionally, RNA-seq analysis demonstrated that differentially expressed genes might be associated with insulin and PI3K/Akt signaling pathways, as well as mitochondrial function-related pathways. These findings suggest that the intra-ovarian GH/IGF-1 system, which is associated with seasonal changes in mitochondrial biogenesis, is activated in muskrat ovaries in BS.

Does insulin-like growth factor-I level associate with pregnancy outcomes in primary and secondary infertile women undergoing in vitro fertilization? A prospective cohort study

BACKGROUND

Infertility, which affects 8%-12% of couples worldwide and 21.9% of couples in Pakistan in particular, is a major reproductive health issue. In vitro fertilization (IVF) has emerged as a prevalent therapeutic intervention. Recent studies have identified insulin-like growth factor-I (IGF-I) as a promising biomarker for assessing embryo viability and predicting implantation outcomes in IVF procedures.

Unravelling the role of HAS2, GREM1, and PTGS2 gene expression in cumulus cells: implications for human oocyte development competency - a systematic review and integrated bioinformatic analysis

The leading indicator for successful outcomes in in-vitro fertilization (IVF) is the quality of gametes in oocytes and sperm. Thus, advanced research aims to highlight the parameter in assessing these qualities - DNA fragmentation in sperm and oocyte development capacity (ODC) via evaluation of microenvironments involving its maturation process. Regarding oocytes, most evidence reveals the role of cumulus cells as non-invasive methods in assessing their development competency, mainly via gene expression evaluation. Our review aims to consolidate the evidence of GDF-9 derivatives, the HAS2, GREM1, and PTGS2 gene expression in cumulus cells used as ODC markers in relevant publications and tailored to current IVF outcomes. In addition to that, we also added the bioinformatic analysis in our review to strengthen the evidence aiming for a better understanding of the pathways and cluster of the genes of interest - HAS2, GREM1, and PTGS2 in cumulus cell level. Otherwise, the current non-invasive method can be used in exploring various causes of infertility that may affect these gene expressions at the cumulus cell level. Nevertheless, this method can also be used in assessing the ODC in various cohorts of women or as an improvement of markers following targeted tools or procedures by evaluating the advancement of these gene expressions following the targeted intervention.

Growth Hormone Promotes Oocyte Maturation In Vitro by Protecting Mitochondrial Function and Reducing Apoptosis

Some studies have been conducted to explore the influence of growth hormone (GH) on oocytes in in vitro maturation (IVM); however, previous studies reporting showed different results, and the specific mechanisms were not clear. In the present study, GH supplementation improved oocyte maturation rate. The rate of germinal vesicle breakdown (GVBD) in the GH group was 83.9%, which was significantly higher than that (72.1%) in the control group (p = 0.001). The maturation rate of the GH group (79.2%) was significantly higher than that (65.4%) of the control group (p = 0.000). The fertilization (68.6 vs. 59.3%) and blastocyst (30 vs. 25.3%) rates showed an increasing trend in the GH group compared to those in controls. The dynamic parameters of nuclear maturation of oocytes were recorded by time-lapse monitoring system; oocytes in the GH group completed nuclear maturation earlier than did those in the control group. GH reduced cAMP levels to promote oocyte maturation. Single-cell RNA sequencing analysis revealed that the majority of differentially expressed genes (DEGs) involved in mitochondrial oxidative phosphorylation was upregulated in the GH group. Furthermore, the mitochondrial membrane potential of oocytes significantly increased, and the levels of intracellular reactive oxygen species (ROS) and Ca2+ largely decreased in the GH group. Finally, single-oocyte transcriptome analysis indicated that GH decreased the expression of apoptosis-related genes in oocytes. GH treatment reduced the expression of γH2AX and caspase-3. Therefore, GH improves the developmental potential of immature oocytes by reducing cAMP levels more rapidly within 0.5 h, protecting mitochondrial function, and reducing DNA damage and apoptosis.

Pleiotropic Effects of IGF1 on the Oocyte

A woman’s endocrine system plays a crucial role in orchestrating cellular interactions throughout her life. The growth hormone (GH) and insulin-like growth factor (IGF) system appears to impact crucial reproductive events and cell types of the ovary, such as granulosa cells, theca cells, and oocytes. Further, IGF1 is a cornerstone during embryonic development and influences predominantly developing and pre-antral follicles. In this commentary, we will emphasize the pleiotropic effects of IGF1 on physiological processes inside the egg. Herein, we will provide a brief overview on IGF1 related cell signal transduction pathways during the maturation and aging of oocytes. We aim to elucidate from a molecular and biochemical point of view if IGF1 in women with metabolic imbalances such as obesity or diabetes could be used in clinics as a novel, reliable estimator for the developmental competence of an oocyte.

Aging conundrum: A perspective for ovarian aging

Progressive loss of physiological integrity and accumulation of degenerative changes leading to functional impairment and increased susceptibility to diseases are the main features of aging. The ovary, the key organ that maintains female reproductive and endocrine function, enters aging earlier and faster than other organs and has attracted extensive attention from society. Ovarian aging is mainly characterized by the progressive decline in the number and quality of oocytes, the regulatory mechanisms of which have yet to be systematically elucidated. This review discusses the hallmarks of aging to further highlight the main characteristics of ovarian aging and attempt to explore its clinical symptoms and underlying mechanisms. Finally, the intervention strategies related to aging are elaborated, especially the potential role of stem cells and cryopreservation of embryos, oocytes, or ovarian tissue in the delay of ovarian aging.

Growth hormone in fertility and infertility: Mechanisms of action and clinical applications

Secreted by the anterior pituitary gland, growth hormone (GH) is a peptide that plays a critical role in regulating cell growth, development, and metabolism in multiple targeted tissues. Studies have shown that GH and its functional receptor are also expressed in the female reproductive system, including the ovaries and uterus. The experimental data suggest putative roles for GH and insulin-like growth factor 1 (IGF-1, induced by GH activity) signaling in the direct control of multiple reproductive functions, including activation of primordial follicles, folliculogenesis, ovarian steroidogenesis, oocyte maturation, and embryo implantation. In addition, GH enhances granulosa cell responsiveness to gonadotropin by upregulating the expression of gonadotropin receptors (follicle-stimulating hormone receptor and luteinizing hormone receptor), indicating crosstalk between this ovarian regulator and the endocrine signaling system. Notably, natural gene mutation of GH and the age-related decline in GH levels may have a detrimental effect on female reproductive function, leading to several reproductive pathologies, such as diminished ovarian reserve, poor ovarian response during assisted reproductive technology (ART), and implantation failure. Association studies using clinical samples showed that mature GH peptide is present in human follicular fluid, and the concentration of GH in this fluid is positively correlated with oocyte quality and the subsequent embryo morphology and cleavage rate. Furthermore, the results obtained from animal experiments and human samples indicate that supplementation with GH in the in vitro culture system increases steroid hormone production, prevents cell apoptosis, and enhances oocyte maturation and embryo quality. The uterine endometrium is another GH target site, as GH promotes endometrial receptivity and pregnancy by facilitating the implantation process, and the targeted depletion of GH receptors in mice results in fewer uterine implantation sites. Although still controversial, the administration of GH during ovarian stimulation alleviates age-related decreases in ART efficiency, including the number of oocytes retrieved, fertilization rate, embryo quality, implantation rate, pregnancy rate, and live birth rate, especially in patients with poor ovarian response and recurrent implantation failure.