Tissue localization of GM-CSF receptor in bovine ovarian follicles and its role on glucose uptake by mural granulosa cells

In vitro effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on the expression of genes related to sperm motility and energy metabolism and intracytoplasmic sperm injection outcomes in obstructive azoospermic patients

BACKGROUND

The presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) and its receptor in various testicular cells and spermatozoa suggests a potential role in enhancing spermatogonial and postmeiotic cell development. Moreover, GM-CSF activates the pivotal pathways implicated in sperm motility regulation and glucose metabolism. However, the impact of GM-CSF on testicular biopsies from patients with obstructive azoospermia (OA) remains unexplored. Therefore, this study aimed to investigate the in vitro effects of GM-CSF on the expression of genes related to glucose transporters and signaling pathways, sperm motility, and viability in testicular biopsies.

METHODS AND RESULTS

Following testicular sperm extraction from 20 patients diagnosed with OA, each sample was divided into two parts: the experimental samples were incubated with medium containing 2 ng/ml GM-CSF at 37 °C for 60 min, and the control samples were incubated with medium without GM-CSF. Subsequently, the oocytes retrieved from the partner were injected with sperm from the treatment and control groups. The sperm parameters (motility and viability), the expression levels of sperm motility-related genes (PIK3R1, PIK3CA, and AKT1), and the expression levels of sperm energy metabolism-related genes (GLUT1, GLUT3, and GLUT14) were assessed. Furthermore, the fertilization and day 3 embryo development rate and embryo quality were evaluated. Compared with those in the nontreated group, the motility parameters and the mRNA expression levels of PIK3R1, AKT1, and GLUT3 in testicular sperm supplemented with GM-CSF were significantly greater (p < 0.05). However, no significant differences in the mRNA expression of PIK3CA, GLUT1, or GLUT14 were detected. According to the ICSI results, compared with the control group, the GM-CSF treatment group exhibited significantly greater fertilization rates (p = 0.027), Day 3 embryo development rate (p = 0.001), and proportions of good-quality embryos (p = 0.002).

CONCLUSIONS

GM-CSF increased the expression of genes related to motility and the energy metabolism pathway and effectively promoted the motility of testis-extracted spermatozoa, consequently yielding positive clinical outcomes.

Resveratrol improves follicular development of PCOS rats via regulating glycolysis pathway and targeting SIRT1

Polycystic ovary syndrome (PCOS) is a disease characterized by metabolic disorders. This study aimed to examine the effects of resveratrol treatment on ovulation in the PCOS rat model. Quantitative real-time PCR and immunohistochemistry were used to determine the mRNA and protein expression levels. TNUEL assay was used to evaluate cell apoptosis in ovary. The metabolites were evaluated by liquid chromatography with tandem mass spectrometry. Resveratrol alleviated disrupted estrous cycle and improved granular cell layers, and reversed the decreased proliferation and increased cell apoptosis of granulosa cells in the ovarian tissues of PCOS rats. Resveratrol restored the changes in the mRNA expression levels in the rate-limiting genes of glycolysis in the PCOS ovary. The expression of lactate dehydrogenase A (LDH-A), pyruvate kinase isozyme M2 (PKM2), and sirtuin 1 (SIRT1) was significantly downregulated in ovarian tissues of the PCOS rats; while the resveratrol treatment significantly increased the expression of LDH-A, PKM2, and SIRT1 in the ovarian tissues of PCOS rats. Collectively, the protective effects of resveratrol in the PCOS rats may be associated with the regulation of glycolysis-related mediators including PKM2, LDH-A, and SIRT1. Resveratrol may represent a good candidate in alleviating the development of PCOS.

GM-CSF (granulocyte-macrophage colony-stimulating factor) treatment improves sperm parameters in men with oligoasthenoteratospermia via PI3K/AKT pathway

Poor sperm quality in oligoasthenoteratospermia patients negatively affects assisted reproductive technology outcomes. Therefore, the development of sperm media is necessary to improve sperm parameters. This study investigated the effect of GM-CSF via PI3K/AKT pathway on sperm quality in OAT patients. Semen samples were collected from 20 OAT patients, and each sample was divided into two groups: Experiment and Control. In the experimental group, the samples were incubated with medium containing GM-CSF, and control samples were incubated without GM-CSF. Sperm parameters, mitochondrial membrane potential, acrosome reaction and DFI were studied; in addition, gene expression of PI3KR1, PI3KCA, GLUT1, GLUT3 and AKT1 was analysed, evaluation of PAKT/TAKT, and expression of GLUT 1, 3 was examined; subsequent fertilization rate and embryo quality were assessed. Our data showed that GM-CSF supplementation could significantly increase motility, mitochondrial activity, gene expression of PI3KCA, AKT1, the protein level of PAKT/TAKT and expression of GLUT 1, 3 while it decreases DNA fragmentation. The fertilization rate and embryo quality significantly improved in the treatment group. LY294002 had adverse effects on sperm motility and the PAKT/TAKT ratio. GM-CSF can improve in vitro sperm quality and could be a suitable supplement to sperm media for OAT patients.

Male and female gonadal ageing: its impact on health span and life span

Ageing is linked to changes in the hypothalamic-pituitary-gonadal axis and a progressive decline in gonadal function. While women become infertile when they enter menopause, fertility decline in ageing men does not necessarily involve a complete cessation of spermatogenesis. Gonadal dysfunction in elderly people is characterized by morphological, endocrine and metabolic alterations affecting the reproductive function and quality of life. With advancing age, sexuality turns into a critical emotional and physical factor actually defining the number of years that ageing people live a healthy life. Gonadal ageing correlates with comorbidities and an increased risk of age-related diseases including diabetes, kidney problems, cardiovascular failures and cancer. This article briefly summarizes the current state of knowledge on ovarian and testicular senescence, explores the experimental models used in the study of gonadal ageing, and describes the local pro-inflammatory, oxidative and apoptotic events and the associated signalling pathways that take place in the gonads while people get older. Overall, literature reports that ageing exacerbates a mutual crosstalk among oxidative stress, apoptosis and the inflammatory response in the gonads leading to detrimental effects on fertility. Data also highlight the clinical implications of novel therapeutic interventions using antioxidant, anti-apoptotic and anti-inflammatory drugs on health span and life span.

Combined use of Diane-35 and metformin improves the ovulation in the PCOS rat model possibly via regulating glycolysis pathway

BACKGROUND

Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disease with unknown pathogenesis. However, the treatment of Diane-35 combined with metformin can improve the endocrine and ovulation of PCOS. In this study, we investigated the effects of Diane-35 combined with metformin (DM) treatment on ovulation and glucose metabolism in a PCOS rat model.

METHODS

Sprague Dawley rats were divided into 3 groups, control group, model group (PCOS group) and Diane-35 combined with metformin (PCOS + DM group). The mRNA expression levels were determined by qRT-PCR. The hormone levels were determined by enzyme-linked immunosorbent assay. Immunostaining detected the protein levels of lactate dehydrogenase A (LDH-A), pyruvate kinase isozyme M2 (PKM2) and sirtuin 1 (SIRT1) in the ovarian tissues. TNUEL assay was performed to determine cell apoptosis in the PCOS rats. The metabolites in the ovarian tissues were analyzed by liquid chromatography with tandem mass spectrometry.

RESULTS

PCOS rats showed an increased in body weight, levels of luteinizing hormone and testosterone and insulin resistance, which was significantly attenuated by the DM treatment. The DM treatment improved disrupted estrous cycle and increased the granulosa cells of the ovary in the PCOS rats. The decreased proliferation and increased cell apoptosis of granulosa cells in the ovarian tissues of PCOS rats were significantly reversed by the DM treatment. The analysis of metabolics revealed that ATP and lactate levels were significantly decreased in PCOS rats, which was recovered by the DM treatment. Furthermore, the expression of LDH-A, PKM2 and SIRT1 was significantly down-regulated in ovarian tissues of the PCOS rats; while the DM treatment significantly increased the expression of LDH-A, PKM2 and SIRT1 in the ovarian tissues of the PCOS rats.

CONCLUSION

In conclusion, our study demonstrated that Diane-35 plus metformin treatment improved the pathological changes in the PCOS rats. Further studies suggest that Diane-35 plus metformin can improve the energy metabolism of the ovary via regulating the glycolysis pathway. The mechanistic studies indicated that the therapeutic effects of Diane-35 plus metformin treatment in the PCOS rats may be associated with the regulation of glycolysis-related mediators including PKM2, LDH-A and SIRT1.

Apoptosis of bovine granulosa cells: Intracellular pathways and differentiation

Follicular atresia in granulosa and theca cells occurs by apoptosis through weak hormonal stimulation. We have previously proposed an in vitro model to study this process by inducing apoptosis in BGC-1, a bovine granulosa cell line, and in primary cultures from ovaries with or without corpus luteum (CPGB+ and CPGB-, respectively), with different doses of gonadotropin releasing hormone (GnRH) analogs (leuprolide acetate (LA) as agonist and antide as antagonist). BGC-1 represent immature granulosa cells, whereas CPGB represent different degrees of luteinization. Our aim was to evaluate the intracellular pathways involved in the GnRH regulation of apoptosis in BGC-1. Treatment with LA 100nM but not with antide led to an increase in BAX over BCL-2 expression, showing antagonism of antide. All treatments inhibited phospholipase-D (PLD) activity compared to control, implying agonist behavior of antide. Progesterone in vitro production and 3β-hydroxysteroid dehydrogenase (3β-HSD) expression revealed different degrees of luteinization: BGC-1 were immature, whereas CPGB+ were less differentiated than CPGB-. We concluded that LA-induced apoptosis in BGC-1 occurs by activation of the mitochondrial pathway and by inhibition of PLD activity and that antide might work both as an antagonist of the intrinsic pathway and as an agonist of the extrinsic protection pathway by inhibiting PLD activity.