Kisspeptin as autocrine/paracrine regulator of human ovarian cell functions: Possible interrelationships with FSH and its receptor

The novel stimulators of feline ovarian granulosa cell functions: Monocyte chemoattractant protein-1 and plasminogen activator inhibitor-1

The aim of the present study was to determine whether adipokines monocyte chemoattractant protein-1 (MCP-1) and plasminogen activator inhibitor-1 (PAI-1) can affect the functions of ovarian cells in cats. The addition of either MCP-1 or PAI-1 increased viability; promoted the accumulation of proliferation markers and progesterone and estradiol release; and decreased the accumulation of apoptosis markers in cultured feline granulosa cells. The present observations suggest that MCP-1 or PAI-1 can be physiological stimulators of ovarian granulosa cell functions.

Does the miR-105-1-Kisspeptin Axis Promote Ovarian Cell Functions?

The objective of this study was to elucidate the intricate interplay among miR-105-1, kisspeptin, and their synergistic influence on basic ovarian granulosa cell functions. The effects of miR-105-1 mimics or miR-105-1 inhibitor, kisspeptin (0, 1, and 10 ng/ml), and its combinations with miR-105-1 mimics on porcine granulosa cells were assessed. The expression levels of miR-105-1, viability, proliferation (accumulation of PCNA, cyclin B1, XTT-, and BrdU-positive cells), apoptosis (accumulation of bcl-2, bax, caspase 3, p53, TUNEL-positive cells), proportion of kisspeptin-positive cells, and the release of steroid hormones and IGF-I were analyzed. Transfection of cells with miR-105-1 mimics promoted cell viability and proliferation, the occurrence of kisspeptin, and the release of progesterone and IGF-I; in contrast, miR-105-1 mimics inhibited apoptosis and estradiol output. MiR-105-1 inhibitor had the opposite effect. Kisspeptin amplified the expression of miR-105-1, cell viability, proliferation, steroid hormones, and IGF-I release and reduced apoptosis. Furthermore, the collaborative action of miR-105-1 mimics and kisspeptin revealed a synergistic relationship wherein miR-105-1 mimics predominantly supported the actions of kisspeptin, while kisspeptin exhibited a dual role in modulating the effects of miR-105-1 mimics. These findings not only affirm the pivotal role of kisspeptin in regulating basic ovarian cell functions but also represent the inaugural evidence underscoring the significance of miR-105-1 in this regulatory framework. Additionally, our results show the ability of kisspeptin to promote miR-105-1 expression and the ability of miR-105-1 to promote the occurrence and effects of kisspeptin and, therefore, indicate the existence of the self-stimulating kisspeptin-miR-105-1 axis.

Involvement of circular RNAs in the control of porcine ovarian cell functions: Upregulation by ciR-00596 and downregulation by ciR-00646

The current understanding of the role of circular RNAs (circRNAs) in regulating ovarian functions is inadequate. To assess the impact of ciR-00596 and ciR-00646 on the regulation of basic porcine ovarian granulosa cell functions, we conducted upregulation (utilizing overexpressing vectors) and downregulation (utilizing shRNA vectors) of these circRNAs. The relative expression of both circRNAs, cell viability and proliferation (accumulation of PCNA, cyclin B1, and XTT-positive cells), cytoplasmic (accumulation of bax and caspase-3) and nuclear (DNA fragmentation) apoptosis, and the release of progesterone, testosterone, estradiol, IGF-I, and oxytocin were evaluated. Transfection of cells with the ciR-00596 overexpression vector resulted in increases in cell viability and proliferation and the release of progesterone and IGF-I, while it decreased the cytoplasmic and nuclear apoptosis, testosterone, estradiol, and oxytocin output. CiR-00596 inhibition had the opposite effects. The overexpression of ciR-00646 decreased cell viability and proliferation, and the release of progesterone, IGF-I, and oxytocin, while increasing cytoplasmic and nuclear apoptosis and the output of testosterone and estradiol. Our findings are the first to show the stimulatory action of ciR-00596 and the inhibitory effect of ciR-00646 on ovarian cell functions, including the cell cycle, apoptosis, and secretory activity.

Inhibition of vinculin activity has an adverse effect on porcine ovarian cells

The existing knowledge of the involvement of vinculin (VCL) in the control of ovarian cell functions is insufficient. To understand the role of VCL in the control of basic porcine ovarian granulosa cell functions, we decreased VCL activity by small interfering RNA (VCL siRNA). The expression of VCL, accumulation of VCL protein, cell viability, proliferation (accumulation of PCNA and cyclin B1), proportion of proliferative active cells, apoptosis (accumulation of bax, caspase 3, p53, antiapoptotic marker bcl2, and bax/bcl-2 ratio), DNA fragmentation, and release of steroid hormones and IGF-I were analyzed by RT‒qPCR, Trypan blue exclusion test, quantitative immunocytochemistry, XTT assay, TUNEL assay, and ELISA. The suppression of VCL activity inhibited cell viability, the accumulation of the proliferation-related proteins PCNA and cyclin B1, the antiapoptotic protein bcl2, and the proportion of proliferative active cells. Moreover, VCL siRNA inhibited the release of progesterone, estradiol, and IGF-1. VCL siRNA increased the proportion of the proapoptotic proteins bax, caspase 3, p53, the proportion of DNA fragmented cells, and stimulated testosterone release. Taken together, the present study is the first evidence that inhibition of VCL suppresses porcine granulosa cell functions. Moreover, the results suggest that VCL can be a potent physiological stimulator of ovarian functions.

Rfamide-related peptide-3(RFRP-3) receptor gene is expressed in mouse ovarian granulosa cells: Potential role of RFRP-3 in steroidogenesis and apoptosis

RFRP-3 is a functional ortholog of avian GnIH and regulates reproductive activities in the gonads of animals. However, the role of RFRP-3 in the function of ovarian granulosa cells in mice remains unclear. First, we detected the expression of the RFRP-3 receptor (GPR147) in the ovarian granulosa cells of mice. Second, the effect of RFRP-3 treatment on estradiol and progesterone secretions from granulosa cells was tested by ELISA. Meanwhile, the expression of genes and proteins regulating steroid hormone synthesis was respectively examined by qPCR and western blot. Furthermore, the effect of RFRP-3 treatment on the apoptosis of granulosa cells was analyzed. The results revealed that the GPR147 protein (a RFRP-3 receptor) was expressed in the ovarian granulosa cells of mice. Low and medium doses RFRP-3 treatment significantly reduced progesterone secretion in the granulosa cells (P < 0.05), while RFRP-3 suppressed p450scc, 3β-HSD, StAR, and FSHR expression in a non-dose-dependent manner. Moreover, RFRP-3 treatment might induce the apoptosis of granulosa cells. Additionally, low doses RFRP-3 significantly reduced p-ERK1/2 protein expression (P < 0.05) in the ovarian granulosa cells. We here, for the first time, confirmed that GPR147 was expressed in the ovarian granulosa cells of mice. Our findings suggested that and RFRP-3 regulates the granulosa cell function through the ERK signaling pathway, which will lay the foundation for uncovering molecular mechanisms by which RFRP-3 regulates follicle development in future.

Kisspeptin stimulates oestradiol biosynthesis by upregulating steroidogenic transcripts and proliferation markers in the bubaline granulosa cells in vitro

Kisspeptin (Kp), an upstream regulator of GnRH release, is essential for the development and function of reproductive axis. Previously, we demonstrated the localization of Kp and its receptor (Kiss1r) in the active follicle in the bubaline ovary. Present study aimed to determine the effect of Kp on granulosa cell (GCs) functions, especially oestradiol (E2 ) and progesterone (P4 ) production, and differential expression of genes regulating the proliferation, apoptosis and steroidogenesis in the buffalo. The ovaries with 6-10 mm size follicles obtained from the cyclic buffaloes after slaughtering were used for isolation of GCs for in vitro study. The primary GCs culture was treated with Kp (0, 10, 50 and 100 nM) and incubated for 48 h. Production of E2 and P4 was estimated in the culture supernatant by ELISA. The expression of gonadotropin receptors (FSHR and LHR), steroidogenic genes (STAR, 3β-HSD, CYP19A1), proliferation marker (PCNA), apoptotic factors (CASP3 and BCL2) and Kp signalling molecule (extracellular signal-regulated kinase 1/2, ERK1/2 and p-ERK1/2) was studied in the GCs by qPCR. Significant E2 production was found in the Kp 50 and 100 nM groups (p < .05), whereas P4 production was reduced in Kp 100 nM group (p < .05). There was concomitant upregulation of FSHR, ERK1/2, STAR and CYP19A1 in the Kp 100 nM treated GCs. In addition, Kp at 100 nM stimulated the proliferation of GCs by upregulating the expression of BCL2 (5.0 fold) and PCNA (94.9 fold). Further, high immunoreactivity of p-ERK1/2 was observed in the Kp-treated GCs. It was concluded that Kp at 100 nM concentration stimulated E2 production by upregulating the steroidogenic pathway through ERK1/2, STAR and CYP19A1 and modulating PCNA and BCL2 expressions in the GCs. Further experiments are warranted using Kp antagonist in different combinations to establish the signalling pathway in Kp-mediated steroidogenesis in the GCs for developing strategies to control ovarian functions.

Investigation of subfertility in the female Nsmf knockout mouse

OBJECTIVE

To study if a pituitary or ovarian defect contributes to subfertility of the female Nsmf knockout (KO) mouse, an animal model of the hypogonadotropic hypogonadism gene NSMF.

DESIGN

Analysis of hypothalamic, pituitary and ovarian gene expression at baseline, serum gonadotropin levels before and after gonadotropin-releasing hormone (GnRH) stimulation, ovarian response and implantation after superovulation, gonadotropin effects after ovariectomy, and ovarian NSMF protein expression.

SETTING

University research laboratory.

PATIENTS

None; mice were used.

INTERVENTIONS

Gonadotropin-releasing hormone stimulation, superovulation, and ovariectomy in separate experiments.

MAIN OUTCOME MEASURES

Gene expression in the hypothalamus, pituitary, and ovary; ovarian response and implantation after superovulation; serum gonadotropins after GnRH stimulation and ovariectomy; Western blot to measure ovarian NSMF expression.

RESULTS

We found increased hypothalamic Kiss1, Gnrh1, and Jak2 mRNA expression in female Nsmf KO vs. wild type (WT) mice. However, pituitary gonadotropin, and GnRH receptor gene expression was not affected, and serum gonadotropin levels were normal. Gonadotropins increased after ovariectomy for both groups. Baseline Kiss1, Fshr, Prkaca, Prkar1a, and Gdf9 ovarian mRNA expression was increased and Cyp19a1 expression was decreased in Nsmf KO mice, while superovulated Nsmf KO mice had reduced ovarian Kiss1r, Prkar1a, and Fshr mRNA expression, 50% less oocytes, and normal implantation. Western blot demonstrated NSMF protein expression in the ovary of WT mice.

CONCLUSIONS

Altered hypothalamic and ovarian gene expression was demonstrated in female Nsmf KO mice. It is possible that increased hypothalamic Gnrh1 and Kiss1 mRNA expression could compensate for reduced NSMF enabling a normal pituitary gonadotropin response. Impaired superovulation response, altered ovarian gene expression, and decreased number of oocytes indicate ovarian dysfunction, but a uterine factor cannot be excluded. These findings provide an anatomic basis for future mechanistic studies of subfertility in female Nsmf KO mice.

Role of kisspeptin-10 and betacellulin in control of feline ovarian cell functions

The action of betacellulin (BTC) on basic ovarian cell functions and interrelationships with kisspeptin (KISS) was investigated. For this purpose, we examined (1) the effect of the addition of BTC (0, 1, 10, and 100 ng/ml) given alone or in combination with KISS (10 ng/ml) on cultured feline ovarian fragments or granulosa cells. Viability, proliferation (accumulation of cyclin B1) and apoptosis (accumulation of bax), and the release of steroid hormones (progesterone, testosterone, and estradiol) were analyzed by using the Trypan blue exclusion test, quantitative immunocytochemistry, and ELISA. The addition of KISS alone increased proliferation, apoptosis, progesterone, estradiol release, and decreased testosterone but did not affect viability. The addition of BTC alone decreased cell proliferation, apoptosis, progesterone, testosterone, and estradiol release but did not influence viability. Furthermore, BTC mainly inhibited the stimulatory action of KISS on feline ovarian functions. The findings of our study suggest the effects of KISS on basic ovarian functions. We also observed the influence of BTC on these functions and its ability to modify the effects of KISS on these processes.