Kisspeptin-54 Research Articles

Chronic Nasal Administration of Kisspeptin-54 Regulates Mood-Related Disorders Via Amygdaloid GABA in Hemi-Parkinsonian Rats.

Depression and anxiety, the most prevalent neuropsychiatric manifestations in Parkinson's disease (PD), negatively impact their quality of life. To determine whether the chronic nasal administration of kisspeptin-54 (KP-54) could. alleviate symptoms of anxiety and depression in hemi-Parkinsonian rats. Experimental study. This study included adult Sprague Dawley male rats who were administered either a vehicle (artificial cerebrospinal fluid) or 6-hydroxydopamine (6-OHDA) unilaterally into the medial forebrain bundle. The vehicle, or KP-54 (3 nmol/kg, applied topically to the rhinarium), was administered daily for a seven-day period. The sucrose preference test (SPT), elevated plus maze test (EPMT), and open field test (OFT) were implemented to evaluate depression- and anxiety-like behaviors, respectively, seven days following the lesion surgery. Gamma-aminobutyric acid (GABA) concentrations in the amygdala were quantified using mass spectrometry. Tyrosine hydroxylase in substantia nigra was analyzed using immunohistochemistry. The nasal delivery of KP-54 significantly reduced depression- and anxiety-like behaviors that were induced by 6-OHDA, as indicated by the results of the SPT, OFT, and EPMT. Moreover, it was observed that nasal KP-54 effectively mitigated 6-OHDA-induced motor deficits and the loss of nigral dopaminergic neurons. The nasal administration of KP- 54 augmented the decline in GABA levels in the amygdala induced by 6-OHDA. Furthermore, effective correlations were established between GABA concentrations and behavioral parameters. The nasal delivery of KP-54 could function as a viable therapeutic alternative for treating mood-related disorders in PD.

Endocrine profile of the kisspeptin receptor agonist MVT-602 in healthy premenopausal women with and without ovarian stimulation: results from 2 randomized, placebo-controlled clinical tricals

Kisspeptin is an essential regulator of hypothalamic gonadotropin-releasing hormone release and is required for physiological ovulation. Native kisspeptin-54 (KP54) can induce oocyte maturation during in vitro fertilization treatment, including in women at high risk of ovarian hyperstimulation syndrome. MVT-602 is a potent kisspeptin receptor agonist with prospective utility to treat anovulatory disorders by triggering oocyte maturation and ovulation during medically assisted reproduction (MAR). Currently, the endocrine profile of MVT-602 during ovarian stimulation is unreported. ObjectiveTo determine the endocrine profile of MVT-602 in the follicular phase of healthy premenopausal women (Phase-1 trial), and after minimal ovarian stimulation to more closely reflect the endocrine milieu encountered during MAR (Phase-2a trial). DesignTwo randomized, placebo-controlled, parallel group, dose-finding trials. SettingClinical trials unit, Netherlands. ParticipantsHealthy women aged 18-35 years, either without (Phase-1; n=24), or with ovarian stimulation (Phase-2a; n=75). InterventionsPhase-1: Single subcutaneous dose of MVT-602 (0.3, 1.0, or 3.0 μg) or placebo, (n=6 per dose).Phase-2a: Single subcutaneous dose of MVT-602 (0.1, 0.3, 1.0, or 3.0 μg; n=16-17 per dose), triptorelin 0.2 mg (n=5; active comparator), or placebo (n=5). Main Objectives and Outcome MeasuresPhase-1: Safety/tolerability; pharmacokinetics; pharmacodynamics (LH and other reproductive hormones).Phase-2a: Safety/tolerability; pharmacokinetics; pharmacodynamics (LH and other reproductive hormones); time to ovulation assessed by transvaginal ultrasound. ResultsIn both trials, MVT-602 was safe and well-tolerated across the entire dose-range. It was rapidly absorbed and eliminated, with a mean elimination half-life of 1.3-2.2 hours.In the Phase-2a trial, LH concentrations increased dose-dependently; mean maximum change from baseline of 82.4 IU/L at 24.8 hours was observed after administration of 3μg MVT-602 and remained above 15 IU/L for 33 hours. Time to ovulation following drug administration was 3.3-3.9 days (MVT-602), 3.4 days (triptorelin), and 5.5 days (placebo). Ovulation occurred within 5 days of administration in 100% (3 μg), 88% (1μg), 82% (0.3μg), and 75% (0.1μg), of women after MVT-602, 100% after triptorelin, and 60% after placebo. ConclusionsMVT-602 induces LH concentrations of similar amplitude and duration as the physiological mid-cycle LH surge with potential utility for induction of oocyte maturation and ovulation during MAR. Trial RegistrationsEUDRA-CT: 2017-003812-38, 2018-001379-20

P–710 The possible relation between kisspeptin and apoptosis on granulosa cells of PCOS patients

Abstract Study question Does kisspeptin administration affect the apoptotic factors of granulosa cells of Polycystic Ovary Syndrome (PCOS) patients? Summary answer Kisspeptin administration significantly increased apoptosis related factors. What is known already Kisspeptin plays a critical role in central gonadotropin secretion by acting on GnRH neurons in the hypothalamus. Kisspeptin receptors are also expressed on the ovaries. Kisspeptin–54 has recently been known as a prominent agent in oocyte maturation. Although there are many studies on the possible roles of kisspeptin administration in vivo on hypothalamic gonadotropin secretion and ovarian function and the possible roles of these effects in the pathogenesis of PCOS, there is not enough information about the effect of in vitro application of kisspeptin on ovarian function and conditions that lead to the development of PCOS. Study design, size, duration This basic research study was an in vitro experimental approach involving the use of granulosa cell from a PCOS and normal cases between July to December in 2020. 32 women were included in both control and PCOS groups. Participants/materials, setting, methods Women with (n = 16) and without (n = 16) PCOS were included in the study. Granulosa cells, follicular fluids and blood samples were collected on oocyte pick-up day. Cells were isolated from follicular fluids. Kisspeptin–54 levels were determined by ELISA in serum and follicle fluids. Also, FSH and LH levels were determined in serum. Kisspeptin–54 administrated in vitro to the half of the samples. Fluorescence spectrophotometer and laser scanning confocal microscope were used to evaluate calcium concentrations Main results and the role of chance The serum kisspeptin level was found significantly higher in PCOS patients compared to the control group (p < 0.05). Also, the level of kisspeptin in follicular fluid was statistically significantly higher in PCOS patients compared to the control group (p < 0.05). The mean serum FSH level of PCOS patients was found to be significantly lower than the control group (p < 0.05). Furthermore, the mean serum LH level of PCOS patients was significantly higher than control groups (p < 0.05). The intracellular calcium concentration in granulosa cells obtained from PCOS patients was significantly lower than the control group (p < 0.05). Limitations, reasons for caution The KISS1, KISS1R, BCL–2, CASPASE–3, FSHR, LHCGR, STAR, ESR1, ESR2, INHBA gene expression levels of apoptotic process is still under analyses. The protein expression analyses of these genes may strength the results. Wider implications of the findings: Using kisspeptin antagonists may be supposed as an additional treatment for patients with PCOS. Trial registration number OMU KAEK 2019 /724

Kisspeptin-54 attenuates oxidative stress and neuronal apoptosis in early brain injury after subarachnoid hemorrhage in rats via GPR54/ARRB2/AKT/GSK3β signaling pathway

Oxidative stress-induced neuron apoptosis plays a crucial role in the early brain injury (EBI) after subarachnoid hemorrhage (SAH). Kisspeptin has been reported as antioxidant to reduce oxidative stress-induced neuronal cell death through G protein-coupled receptor 54 (GPR54). The goal of this study was to determine the neuroprotection of the Kisspeptin/GRP54 signaling pathway against EBI after SAH. Two hundred and ninety-two Sprague Dawley male rats were used and SAH was induced by the endovascular perforation. Exogenous Kisspeptin 54 (KP54) was delivered intranasally. Small interfering ribonucleic acid (siRNA) for endogenous KISS1, a selective GPR54 antagonist kisspeptin 234, or β-arrestin 2 siRNA for ARRB2 (a functional adaptor of GPR54) were administered intracerebroventricularly. Post-SAH evaluations included neurobehavioral tests, SAH grade, Western blot, immunofluorescence, Fluoro-Jade C, TUNEL, and Nissl staining. The results showed that endogenous KISS1 knockdown aggravated but exogenous KP54 (1.0 nmol/kg) treatment attenuated neurological deficits, brain oxidative stress, and neuronal apoptosis at 24 h after SAH. The benefits of KP54 persisted to 28 days after SAH, which significantly improved cognitive function in SAH rats. The GPR54 blockade or the ARRB2 knockout offset the neuroprotective effects of KP54 in SAH rats. In conclusion, our results suggested that administration of KP54 attenuated oxidative stress, neuronal apoptosis and neurobehavioral impairments through GPR54/ARRB2/AKT/GSK3β signaling pathway after SAH in rat. Thus, KP54 may provide an effective treatment strategy for SAH patients.

Kisspeptin-54 Accurately Identifies Hypothalamic Gonadotropin-Releasing Hormone Neuronal Dysfunction in Men with Congenital Hypogonadotropic Hypogonadism

Background: Hypogonadotropic hypogonadism (HH) is hypogonadism due to either hypothalamic or pituitary dysfunction. While gonadotropin-releasing hormone (GnRH) can directly test pituitary function, no specific test of hypothalamic function exists. Kisspeptin-54 (KP54) is a neuropeptide that directly stimulates hypothalamic GnRH release and thus could be used to specifically interrogate hypothalamic function. Congenital HH (CHH) is typically due to variants in genes that control hypothalamic GnRH neuronal migration or function. Thus, we investigated whether KP54 could accurately identify hypothalamic dysfunction in men with CHH. Methods: Men with CHH (n = 21) and healthy eugonadal men (n = 21) received an intravenous bolus of either GnRH (100 μg) or KP54 (6.4 nmol/kg), on 2 occasions, and were monitored for 6 h after administration of each neuropeptide. Results: Maximal luteinizing hormone (LH) rise after KP54 was significantly greater in healthy men (12.5 iU/L) than in men with CHH (0.4 iU/L; p < 0.0001). KP54 more accurately differentiated CHH men from healthy men than GnRH (area under receiver operating characteristic curve KP54: 1.0, 95% CI 1.0–1.0; GnRH: 0.88, 95% CI 0.76–0.99). Indeed, all CHH men had an LH rise <2.0 iU/L following KP54, whereas all healthy men had an LH rise >4.0 iU/L. Anosmic men with CHH (i.e., Kallmann syndrome) had even lower LH rises after KP54 than did normosmic men with CHH (p = 0.017). Likewise, men identified to have pathogenic/likely pathogenic variants in CHH genes had even lower LH rises after KP54 than other men with CHH (p = 0.035). Conclusion: KP54 fully discriminated men with CHH from healthy men. Thus, KP54 could be used to specifically interrogate hypothalamic GnRH neuronal function in patients with CHH.

LIM-homeodomain transcription factor Isl-1 mediates kisspeptin's effect on insulin secretion in mice.

Kisspeptin and the G protein-coupled receptor 54 (GPR54) are highly abundant in the pancreas. In addition, circulating kisspeptin directly influences insulin secretion through GPR54. However, the mechanisms by which kisspeptin affects insulin release are unclear. The LIM-homeodomain transcription factor, Isl-1, is expressed in all pancreatic islet cells and is involved in regulating both islet development and insulin secretion. We therefore investigated potential interactions between kisspeptin and Isl-1. Our results demonstrate that Isl-1 and GPR54 are coexpressed in mouse pancreatic islet β-cells and NIT cells. Both in vitro and in vivo results demonstrate that kisspeptin-54 (KISS-54) inhibits Isl-1 expression and insulin secretion and both the in vivo and in vitro effects of KISS-54 on insulin gene expression and secretion are abolished when an Isl-1-inducible knockout model is used. Moreover, our results demonstrate that the direct action of KISS-54 on insulin secretion is mediated by Isl-1. Our results further show that KISS-54 influences Isl-1 expression and insulin secretion through the protein kinase C-ERK1/2 pathway. Conversely, insulin has a feedback loop via the Janus kinase-phosphatidylinositol 3-kinase pathway regulating kisspeptin expression and secretion. These findings are important in understanding mechanisms of insulin secretion and metabolism in diabetes.

International Union of Basic and Clinical Pharmacology. LXXVII. Kisspeptin Receptor Nomenclature, Distribution, and Function

Kisspeptins are members of the Arg-Phe amide family of peptides, which have been identified as endogenous ligands for a G-protein-coupled receptor encoded by a gene originally called GPR54 (also known as AXOR12 or hOT7T175). After this pairing, the gene has been renamed KISS1R. The International Union of Basic and Clinical Pharmacology Committee on Receptor Nomenclature and Drug Classification recommends that the official name for the receptor is the kisspeptin receptor to follow the convention of naming the receptor protein after the endogenous ligand. The endogenous ligand was initially called metastin, after its role as a metastasis suppressor, and is now referred to as kisspeptin-54 (KP-54), a C-terminally amidated 54-amino acid peptide cleaved from the 145-amino acid gene product. Shorter C-terminal cleavage fragments [KP-14, KP-13 and KP-10 (the smallest active fragment)] are also biologically active. Both receptor and peptide are widely expressed in human, rat, and mouse; the receptor sequence shares more than 80% homology in these species. Activation of the kisspeptin receptor by kisspeptin is via coupling to G(q/11) and the phospholipase C pathway, causing Ca(2+) mobilization. Mutations in the KISS1R gene result in hypogonadotropic hypogonadotropism, and targeted disruption of Kiss1r in mice reproduces this phenotype, which led to the discovery of the remarkable ability of the kisspeptin receptor to act as a molecular switch for puberty. In addition to regulating the reproductive axis, the kisspeptin receptor is also implicated in cancer, placentation, diabetes, and the cardiovascular system.

Twice-Weekly Administration of Kisspeptin-54 for 8 Weeks Stimulates Release of Reproductive Hormones in Women With Hypothalamic Amenorrhea

Kisspeptin is a novel therapeutic target for infertility. A single kisspeptin-54 (KP-54) injection acutely stimulates the release of reproductive hormones in women with hypothalamic amenorrhea (HA), a commonly occurring condition characterized by absence of menstruation; however, twice-daily administration of KP-54 results in tachyphylaxis. We determined the time course of desensitization to twice-daily KP-54 injections, compared the effects of twice-daily and twice-weekly administration regimens of KP-54, and studied the effects of long-term twice-weekly administration of KP-54 on the release of reproductive hormones in women with HA. When KP-54 was administered twice daily, responsiveness to luteinizing hormone (LH) diminished gradually, whereas responsiveness to follicle-stimulating hormone (FSH) was nearly abolished by day 2. Twice-weekly KP-54 administration resulted in only partial desensitization, in contrast to the complete tolerance achieved with twice-daily administration. Women with HA who were treated with twice-weekly KP-54 injections had significantly elevated levels of reproductive hormones after 8 weeks as compared with treatment with saline. No adverse effects were observed. This study provides novel pharmacological data on the effects of KP-54 on the release of reproductive hormones in women with HA.

A kisspeptin-10 analog with greater in vivo bioactivity than kisspeptin-10

The kisspeptins are neuropeptides that stimulate the hypothalamo-pituitary-gonadal (HPG) axis. The smallest endogenous kisspeptin, kisspeptin-10 (KP-10), binds to the receptor KISS1R with a similar affinity to the full-length peptide, kisspeptin-54 (KP-54), but is less effective in vivo, possibly because of increased enzymatic breakdown or clearance. The kisspeptin system may have therapeutic potential in the treatment of reproductive disorders and endocrine cancers. We have rationally modified the structure of KP-10 and tested the binding affinity of these analogs for the KISS1R. Those analogs that bound with relatively high affinity to KISS1R were tested for ability to stimulate ERK1/2 phosphorylation in vitro and for their ability to stimulate the HPG axis in vivo. One analog, [dY]1KP-10, bound to KISS1R with lower affinity to KP-10 and exhibited similar bioactivity in vitro. However, in vivo peripheral administration of [dY]1KP-10 increased plasma LH and testosterone more potently than KP-10 itself at 20 min postinjection in mice. In addition, 60 min postinjection, 0.15 nmol [dY]1KP-10 significantly increased total testosterone levels in mice whereas the same dose of KP-10 had no significant effect. Should manipulation of the kisspeptin/KISS1R signaling system prove therapeutically useful, long-lasting analogs such as [dY]1KP-10 may have greater therapeutic potential than endogenous forms of kisspeptin.