Effects of growth hormone and insulin-like growth factor 1 on progesterone production in human luteinized granulosa cells

Clustering of multi-tissue transcriptomes in gilts with normal cyclicity or delayed puberty reveals genes related to pubertal development†

In gilts, puberty is marked by standing estrus in the presence of a boar. Delayed puberty (DP; failure to display pubertal estrus) is a major reason for gilt removal. To investigate the physiological determinants underlying DP in gilts, transcriptomic data from tissues relevant to estrus and puberty, such as mediobasal hypothalamus, anterior pituitary gland, ovarian cortex, olfactory bulb, amygdala, and hippocampus, were obtained from age-matched DP (n = 8) and cyclic control gilts at follicular phase (n = 8) and luteal phase (n = 8) of the estrous cycle. A gene expression module analysis via three-way gene × individual × tissue clustering using tensor decomposition identified pituitary and ovary gene modules contributing to regulation of pubertal development. Analysis of gene expression in the hypothalamic-pituitary-ovary axis identified reduced expression of hypothalamic genes critical for stimulating gonadotropin secretion (KISS1 and TAC3) and reduced expression of LHB in the anterior pituitary of DP gilts compared with their cyclic counterparts. Consequently, luteinizing hormone-induced genes in the ovary important for folliculogenesis (OXTR, RUNX2, and PTX3) were less expressed in DP gilts. Other intrafollicular genes (AHR, PTGS2, PTGFR, and IGFBP7) and genes in the steroidogenesis pathways (STAR and CYP11A1) necessary to complete the ovulatory cascade were also less expressed in DP gilts. This is the first clustering of multi-tissue expression data from DP and cyclic gilts to identify genes differentially expressed in gilts of similar ages but at different levels of sexual development. A critical lack of gonadotropin support and reduced ovarian responsiveness underlie DP in gilts.

Evaluation of growth hormone deficiency in women with unexplained infertility

PURPOSE

Growth hormone (GH) has been recognized to play a regulatory role in female reproduction. It has been reported that infertile GH deficient patients regained fertility after GH replacement. The frequency of GH deficiency is not established in patients diagnosed with unexplained infertility. Here, we aim to present the prevalence of GH deficieny in this patient group.

METHODS

We included patients diagnosed with unexplained infertility throughout 18 months. Insulin tolerance test (ITT) and glucagon stimulation tests (GST) were performed and insufficient response to both tests was required for the diagnosis of GH deficiency.

RESULTS

Twenty-five patients were included in the study, the mean age was 27.4 ± 4.5 years and the median duration of infertility was 60 months (min:14, max:120). Two patients were GH deficient according to GST and 14 to ITT. Two patients (8%) showed lack of response on both tests and were diagnosed with GH deficiency.

CONCLUSION

The rate of GH deficiency among women with unexplained infertility was 8% in this preliminary study. There is need for further studies with larger patient groups to verify the results.

Growth Hormone and Endometrial Receptivity

Administration of growth hormone (GH) during ovarian stimulation has shown beneficial effects on in vitro fertilization (IVF) outcomes. It is generally believed that this improvement is due to the stimulating effect of GH on oocyte quality. However, studies are emerging that show possible positive effect of GH administration on endometrial receptivity, thus suggesting an additional potential benefit at the level of the uterus, especially among women with recurrent implantation failure, thin endometrium, and older normal responders. This review summarizes recent data on GH co-treatment effects on endometrium and endometrial receptivity among infertile women undergoing IVF, and proposes possible mechanisms of GH actions in the endometrium.

Human umbilical cord mesenchymal stem cells improve the reserve function of perimenopausal ovary via a paracrine mechanism

Background

Human umbilical cord mesenchymal stem cells (hUCMSCs) are a type of pluripotent stem cell which are isolated from the umbilical cord of newborns. hUCMSCs have great therapeutic potential. We designed this experimental study in order to investigate whether the transplantation of hUCMSCs can improve the ovarian reserve function of perimenopausal rats and delay ovarian senescence.

Method

We selected naturally aging rats confirmed by vaginal smears as models of perimenopausal rats, divided into the control group and the treatment group, and selected young fertile female rats as normal controls. hUCMSCs were transplanted into rats of the treatment group through tail veins. Enzyme-linked immunosorbent assay (ELISA) detected serum levels of sex hormones, H&E staining showed ovarian tissue structure and allowed follicle counting, immunohistochemistry and western blot analysis revealed ovarian expression of hepatocyte growth factor (HGF), vascular endothelial cell growth factor (VEGF), and insulin-like growth factor-1 (IGF-1), polymerase chain reaction (PCR) and western blot analysis revealed hUCMSCs expression of HGF, VEGF, and IGF-1.

Results

At time points of 14, 21, and 28 days after hUCMSCs transplantation, estradiol (E₂) and anti-Müllerian hormone (AMH) increased while follicle-stimulating hormone (FSH) decreased; ovarian structure improved and follicle number increased; ovarian expression of HGF, VEGF, and IGF-1 protein elevated significantly. Meanwhile, PCR and western blot analysis indicated hUCMSCs have the capacity of secreting HGF, VEGF, and IGF-1 cytokines.

Conclusions

Our results suggest that hUCMSCs can promote ovarian expression of HGF, VEGF, and IGF-1 through secreting those cytokines, resulting in improving ovarian reserve function and withstanding ovarian senescence.

The effects of growth hormone on clinical outcomes after frozen-thawed embryo transfer

OBJECTIVE

To evaluate the effects of recombinant human growth hormone (rhGH) on clinical outcomes of frozen-thawed embryo transfer (FET).

METHODS

A prospective study was conducted among 240 patients (aged ≤38years) who underwent FET cycles at a center in Hefei, China, between November 2011 and October 2012. Patients were divided into three groups on the basis of visit order: those in group A received hormone-replacement therapy (HRT) for endometrial preparation, those in group B received HRT plus simultaneous rhGH, and those in group C received rhGH on day8 of HRT.

RESULTS

Ten cycles were cancelled; 230 FET cycles were analyzed (77 in group A, 77 in group B, 76 in group C). The rates of clinical pregnancy, embryo implantation, and live birth were significantly higher in group B than in group A, as were the serum levels of estradiol and insulin-like growth factor-1 (P≤0.033 for all comparisons). Endometrial thickness and serum levels of vascular endothelial growth factor were significantly higher in group B than in groups A and C, whereas pulsatility index, resistance index, and peak systolic velocity/end diastolic velocity of the uterine arcuate artery were significantly lower (P≤0.017 for all comparisons).

CONCLUSION

Simultaneous administration of rhGH with HRT could improve clinical outcomes after FET by increasing endometrial blood perfusion and expression of cytokines related to endometrial receptivity.

Growth hormone and reproduction: a review of endocrine and autocrine/paracrine interactions

The somatotropic axis, consisting of growth hormone (GH), hepatic insulin-like growth factor I (IGF-I), and assorted releasing factors, regulates growth and body composition. Axiomatically, since optimal body composition enhances reproductive function, general somatic actions of GH modulate reproductive function. A growing body of evidence supports the hypothesis that GH also modulates reproduction directly, exerting both gonadotropin-dependent and gonadotropin-independent actions in both males and females. Moreover, recent studies indicate GH produced within reproductive tissues differs from pituitary GH in terms of secretion and action. Accordingly, GH is increasingly used as a fertility adjunct in males and females, both humans and nonhumans. This review reconsiders reproductive actions of GH in vertebrates in respect to these new conceptual developments.

Primary culture of ovarian cells for research on cell interactions in the hormonal control of steroidogenesis

Ovary is a polymorphic complex structure in which the cells are arranged in two essential endocrine mini glands: the follicle (F) and the corpus luteum (CL). Their secretory function creates an optimal milieu for growth, maturation, and selection of follicles and oocytes competent for ovulation. Monoculture of isolated ovarian cells has identified the secretory potential of the different cell types functioning in this complex gland in vivo. Primary culture of isolated ovarian cells is a good tool for the investigation of cell interactions and its impact on steroidogenesis, dynamics of steroidogenic enzymes, hormone receptors, changes in the cytoskeleton in granulosa cell populations, regulatory mechanisms, and the intracellular pathways of gonadotropin signaling in steroidogenic ovarian cells. Since the granulosa cell number recovered during isolation from the follicle is substantial, this makes primary culture fairly easy and enables many kinds of studies in vitro. Ovarian cells are highly differentiated and express characteristic functional specificity dependent on the dynamics of the sexual cycle. This is important so as not to produce artifacts in vitro.

Protective role of melatonin in progesterone production by human luteal cells

This study investigated whether melatonin protects luteinized granulosa cells from reactive oxygen species (ROS) as an antioxidant to enhance progesterone production in the follicle during ovulation. Follicular fluid was sampled at the time of oocyte retrieval in women undergoing in vitro fertilization and embryo transfer (IVF-ET). Melatonin concentrations in the follicular fluid were positively correlated with progesterone concentrations (r = 0.342, P < 0.05) and negatively correlated with the concentration of 8-hydroxy-2'-deoxyguanosine (8-OHdG), an oxidative stress marker (r = -0.342, P < 0.05). The progesterone and 8-OHdG concentrations were negatively correlated (r = -0.246, P < 0.05). Luteinized granulosa cells were obtained at the time of oocyte retrieval in women undergoing IVF-ET. Cells were incubated with H(2)O(2) (30, 50, 100 μm) in the presence or absence of melatonin (1, 10, 100 μg/mL). Progesterone production by luteinized granulosa cells was significantly inhibited by H(2)O(2). Melatonin treatment overcame the inhibitory effect of H(2) O(2) . Twenty-five patients who had luteal phase defect (serum progesterone concentrations <10 ng/mL during the mid-luteal phase) were divided into two groups during the next treatment cycle: 14 women were given melatonin (3 mg/day at 22:00 hr) throughout the luteal phase and 11 women were given no medication as a control. Melatonin treatment improved serum progesterone concentrations (>10 ng/mL during the mid-luteal phase) in nine of 14 women (64.3%), whereas only two of 11 women (18.1%) showed normal serum progesterone levels in the control group. In conclusion, melatonin protects granulosa cells undergoing luteinization from ROS in the follicle and contributes to luteinization for progesterone production during ovulation.

Endometrial growth and uterine blood flow: a pilot study for improving endometrial thickness in the patients with a thin endometrium

OBJECTIVE

To examine whether thin endometria can be improved by increasing uterine radial artery (uRA) blood flow.

DESIGN

A prospective observational study.

SETTING

University hospital and city general hospital.

PATIENT(S)

Sixty-one patients with a thin endometrium (endometrial thickness [EM] <8 mm) and high radial artery-resistance index of uRA (RA-RI >or=0.81).

INTERVENTION(S)

Vitamin E (600 mg/day, n = 25), l-arginine (6 g/day, n = 9), or sildenafil citrate (100 mg/day, intravaginally, n = 12) was given.

MAIN OUTCOME MEASURE(S)

EM and RA-RI were assessed by transvaginal color-pulsed Doppler ultrasound.

RESULT(S)

Vitamin E improved RA-RI in 18 (72%) out of 25 patients and EM in 13 (52%) out of 25 patients. L-arginine improved RA-RI in eight (89%) out of nine patients and EM in six (67%) patients. Sildenafil citrate improved RA-RI and EM in 11 (92%) out of 12 patients. In the control group (n = 10), who received no medication to increase uRA-blood flow, only one (10%) patient improved in RA-RI and EM. The effect of vitamin E was histologically examined in the endometrium (n = 5). Vitamin E improved the glandular epithelial growth, development of blood vessels, and vascular endothelial growth factor protein expression in the endometrium.

CONCLUSION(S)

Vitamin E, l-arginine, or sildenafil citrate treatment improves RA-RI and EM and may be useful for the patients with a thin endometrium.