Kisspeptin-10 Research & Studies

To develop a protocol for chronic kisspeptin administration that persistently stimulates gonadotropin secretion. We evaluated the effects of acute and chronic subcutaneous kisspeptin-10 administration on reproductive hormones in healthy men to (1) characterize the acute dose--response relationship to subcutaneous kisspeptin-10 infusion, (2) assess the effects of continuous kisspeptin-10 infusion over 5 days, and (3) daily intermittent administration (8 h on, 16 h off) for 12 days.

In Osteoarthritis (OA), the senescence of chondrocytes plays a pivotal role, contributing to cartilage degradation and impairing tissue repair mechanisms. (Kp-10), a peptide hormone, exerts diverse biological functions across multiple cell types and tissues via its receptor Gpr54. However, its role in chondrocytes and OA has been understudied. This study investigates the role of Kp-10 in mitigating TNF-α- induced senescence in primary chondrocytes, a hallmark of OA pathogenesis. Gpr54 expression was confirmed in both primary chondrocytes and the ATDC5 chondrogenic cell line, with TNF-α treatment leading to a dose-dependent decrease in Gpr54 expression. Kp-10 treatment at concentrations of 50 and 100 nM effectively ameliorated TNF-α-induced senescence, as evidenced by diminished senescence-associated β-galactosidase staining and enhanced telomerase activity. Moreover, Kisspeptin-10 modulated the expression of key regulators involved in cellular aging, including hTERT and TERF2, and suppressed the activation of the p53/p21 pathway. Notably, Kp-10 restored SIRT1 expression, which was downregulated by TNF-α. Silencing SIRT1 abolished the protective effects of Kp-10, highlighting the essential role of SIRT1 in its anti-senescence action. These findings suggest that Kp-10 may be a promising therapeutic strategy for OA by mitigating chondrocyte senescence and improving cellular function by modulating the SIRT1 and p53/p21 pathways.

Gestational diabetes mellitus (GDM) is a common pregnancy complication that leads to insulin resistance (IR) and adversely affects both maternal and fetal health. Kisspeptin-10 (Kp-10), a peptide acting via G Protein-Coupled Receptor 54 (Gpr54), has shown potential in modulating insulin secretion, but its role in GDM remains unclear. This study explores Kp-10's therapeutic effects on GDM by targeting IR in placental tissues. We used GDM rat models (induced by a high-fat diet and streptozotocin) and high-glucose-treated HTR8/SVneo trophoblast cells to investigate Kp-10's effects on glucose metabolism, insulin signaling, and the cAMP/PKA pathway. Our results show that Gpr54 expression was significantly downregulated in the placental tissues of GDM rats, which was associated with impaired glucose uptake and IR. Kp-10 treatment improved fasting blood glucose (FBG) levels, insulin sensitivity, and fetal outcomes, including increased fetal weight and decreased fetal blood glucose. Moreover, Kp-10 restored the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling pathway and enhanced glucose uptake by upregulating Glut-4, Insr, and Irs1 expression in both placental tissues and HTR8/SVneo cells. The effects of Kp-10 were reversed by the cAMP inhibitor SQ22536, confirming the involvement of the cAMP/PKA pathway in its anti-IR effects. Our findings suggest that Kp-10 has the potential as a therapeutic agent for alleviating IR in GDM and improving maternal-fetal outcomes.

Kisspeptin is a neuropeptide recognised for a pivotal role within the reproductive system, but potentially important endocrine metabolic effects are less well understood. We examined effects of twice-daily intraperitoneal administration of saline vehicle or kisspeptin-10 (25 nmol/kg), for 21 days, on glucose homeostasis, energy balance, circulating hormones as well as the morphology-function of enteroendocrine and islet cells in high-fat diet (HFD) fed female mice, with normal diet (ND) mice as an additional control group. Kisspeptin-10 decreased body weight, blood glucose and energy intake to ND levels. HFD increased circulating follicle-stimulating hormone (FSH) levels, which were further enhanced by kisspeptin-10 along with luteinising hormone (LH) concentrations. Neither HFD nor kisspeptin-10 affected progesterone or corticosterone. In the ileum, kisspeptin-10 decreased crypt depth and restored villi length to ND control levels, as well as increasing the proportion of glucose-dependent insulinotropic polypeptide (GIP) positive cells when compared to HFD mice and glucagon-like peptide-1 (GLP-1) positive cells compared to ND mice. Peptide YY (PYY) immunoreactivity was unaltered by HFD or kisspeptin-10. Plasma GIP was unchanged but circulating GLP-1 and PYY were reduced to ND levels. Within the pancreas, total islet, beta- and alpha-cell areas were similar in all mice, but kisspeptin-10 intervention restored relative insulin area to ND levels. Glucagon radius, an indicator of peripherally located alpha-cells, was reduced in HFD mice but normalised by kisspeptin-10 alongside elevated glucagon-islet area. Notably, beta-cell proliferation was increased by kisspeptin-10 with no alteration in beta-cell apoptosis. Overall, we reveal a previously uncharacterised diverse metabolic role for kisspeptin in directly modulating the gut-pancreatic axis.

Cerebral aneurysms (CAs) are a prevalent brain condition with poorly understood pathological features. The Kisspeptin-10 (KP-10)/G protein-coupled receptor 54 (GPR54) system is a vital neuroendocrine pathway primarily implicated in the regulation of reproductive functions and energy metabolism. This research explores the role of the KP-10/GPR54 system in CAs.

The integrity of the Blood-Brain Barrier (BBB) is crucial in the pathophysiological progression of acute ischemic stroke (AIS). However, the potential of Kisspeptin-10 (Kp-10), with its antioxidant and anti-inflammatory properties, has not been explored experimentally in the context of stroke management. This study aimed to investigate the neurovascular protective effects of Kp-10 following cerebral ischemia using both in vivo and in vitro models. A middle cerebral artery occlusion (MCAO) model was established in C57BL/6 mice, followed by Kp-10 administration. Neurological deficits (Longa score), infarct volume (TTC staining), BBB permeability (14C-Sucrose), and Claudin-10 expression (qRT-PCR and immunohistochemistry) were assessed to evaluate the therapeutic effects of Kp-10. Human brain microvascular endothelial cells (HBMVECs) were subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) to mimic ischemic conditions. Endothelial permeability, oxidative stress (OS), and nuclear factor erythroid 2-related factor 2 (Nrf2) levels were evaluated. Nrf2 silencing was performed to validate its role in Kp-10-mediated protection. Initially, we observed a significant reduction in Kp-10 expression within the cortical tissue of mice subjected to MCAO. Subsequent administration of Kp-10 not only alleviated neurological deficits but also significantly mitigated blood-brain barrier (BBB) dysfunction following stroke induction, as evidenced by reduced 14C-sucrose leakage. Furthermore, Kp-10 treatment led to an upregulation of Claudin-10 expression in the post-stroke cortical region. In our in vitro experiments, we employed HBMVECs exposed to OGD/R to simulate ischemic conditions. We found that Kp-10 effectively reduced OGD/R-induced endothelial permeability by enhancing Claudin-10 expression. Additionally, Kp-10 exhibited antioxidant capabilities by decreasing mitochondrial reactive oxygen species (ROS) levels, increasing superoxide dismutase (SOD) activity, and upregulating nuclear factor erythroid 2-related factor 2 (Nrf2) expression. Notably, when Nrf2 was knocked down in HBMVECs, the protective effects of Kp-10 on endothelial permeability and Claudin-10 expression were abolished, indicating that the beneficial actions of Kp-10 are mediated through the Nrf2 pathway. In conclusion, our findings suggest that Kp-10 holds promise as a therapeutic strategy to preserve BBB integrity and promote neuroprotection following stroke, acting primarily via the Nrf2 signalling pathway. These findings suggest that Kp-10 may represent a promising therapeutic strategy for preserving BBB integrity following ischemic stroke.

Osteoclasts are over-activated as we age, which results in bone loss. Src deficiency in mice leads to severe osteopetrosis due to a functional defect in osteoclasts, indicating that Src function is essential in osteoclasts. G-protein-coupled receptors (GPCRs) are the targets for ∼35% of approved drugs but it is still unclear how GPCRs regulate Src kinase activity. Here, we reveal that GPR54 activation by its natural ligand Kisspeptin-10 (Kp-10) causes Dusp18 to dephosphorylate Src at Tyr 416. Mechanistically, Gpr54 recruits both active Src and the Dusp18 phosphatase at its proline/arginine-rich motif in its C terminus. We show that Kp-10 binding to Gpr54 leads to the up-regulation of Dusp18. Kiss1, Gpr54 and Dusp18 knockout mice all exhibit osteoclast hyperactivation and bone loss, and Kp-10 abrogated bone loss by suppressing osteoclast activity in vivo. Therefore, Kp-10/Gpr54 is a promising therapeutic target to abrogate bone resorption by Dusp18-mediated Src dephosphorylation.

The hypothalamic neurohormone kisspeptin-10 (KP-10) was inherently implicated in cholinergic pathologies when aberrant fluctuations of expression patterns and receptor densities were discerned in neurodegenerative micromilieus. That said, despite variable degrees of functional redundancy, KP-10, which is biologically governed by its cognate G-protein-coupled receptor, GPR54, attenuated the progressive demise of α-synuclein (α-syn)-rich cholinergic-like neurons. Under explicitly modeled environments, in silico algorithms further rationalized the surface complementarities between KP-10 and α-syn when KP-10 was unambiguously accommodated in the C-terminal binding pockets of α-syn. Indeed, the neuroprotective relevance of KP-10's binding mechanisms can be insinuated in the amelioration of α-syn-mediated neurotoxicity; yet it is obscure whether these extenuative circumstances are contingent upon prior GPR54 activation. Herein, choline acetyltransferase (ChAT)-positive SH-SY5Y neurons were engineered ad hoc to transiently overexpress human wild-type or E46K mutant α-syn while the mitigation of α-syn-induced neuronal death was ascertained via flow cytometric and immunocytochemical quantification. Recapitulating the specificity observed on cell viability, exogenously administered KP-10 (0.1 µM) substantially suppressed wild-type and E46K mutant α-syn-mediated apoptosis and mitochondrial depolarization in cholinergic differentiated neurons. In particular, co-administrations with a GPR54 antagonist, kisspeptin-234 (KP-234), failed to abrogate the robust neuroprotection elicited by KP-10, thereby signifying a GPR54 dispensable mechanism of action. Consistent with these observations, KP-10 treatment further diminished α-syn and ChAT immunoreactivity in neurons overexpressing wild-type and E46K mutant α-syn. Overall, these findings lend additional credence to the previous notion that KP-10's binding zone may harness efficacious moieties of neuroprotective intent.

A simple method for producing pseudopregnant mice supports pup production. In this study, pregnant ICR were obtained mice without mating with vasectomized mice via administration of mouse Kisspeptin-10 (mKp-10) and transferring blastocysts to the uterus. Blastocyst transfer after mKp-10 administration to mice with gapping and reddish pink vagina resulted in 65.2% (15/23) pregnancies, and 39.1% (34/87) of the transferred blastocysts showed full-term growth. Vaginal smears were observed for accurate estrus cycle determination, and subsequent administration of mKp10 to mice during the estrus stage and blastocyst transfer resulted in 95.2% (20/21) pregnancies and 50.7% (104/205) birth rates. Regarding 2-cell transfer after administration of mKp-10, 100% (8/8) of the mice became pregnant, and 45.0% (36/80) of the embryos were born. Administration of mKp-10 to mice during the estrus stage is a convenient way to generate pseudopregnant mice.

The aim of the study was to evaluate the role of kisspeptin-10 (KiSS-10) in the regulation of collagen content in cardiac fibroblasts. An attempt was also made to describe the mechanism of the effect of KiSS-10 on collagen metabolism. The studies indicate that kisspeptin-10 significantly increases the content of intracellular collagen in the myocardium. KiSS-10 also elevates the level of phosphorylated focal adhesion kinase (FAK) in human cardiac fibroblasts. The inhibition of FAK negates the stimulatory effect of KiSS-10 on collagen deposition in vitro. These changes correlate with an increase in the level of propeptides of procollagen type I (PICP) and III (PIIICP) in fibroblast culture medium and mouse PIIICP in serum. Moreover, this hormone inhibits the release of metalloproteinases (MMP-1,-2,-9) and elevates the secretion of their tissue inhibitors (TIMP-1,-2,-4). KiSS-10 also enhances the expression of α1 chains of procollagen type I and III in vitro. Thus, KiSS-10 is involved in the regulation of collagen metabolism and cardiac fibrosis. Augmentation of collagen deposition by KiSS-10 is dependent on the protein synthesis elevation, inhibition of MMPs activity (increase of TIMPs release) or decrease of MMPs concentration. The profibrotic activity of KiSS-10 is mediated by FAK and is not dependent on TGF-β1.

Recently, two different molecules have been discovered to play an important role in reproduction: kisspeptin (Kp) and gonadotropin inhibiting hormone (GnIH). The aim of this study was to establish the trend of kisspeptin 10 (Kp‑10) and GnIH concentrations, during all phases of pregnancy in cattle, in order to understand their possible role in the physiology of pregnancy. To examine the correlation between these hormones and steroid hormones, cortisol and oestradiol 17β (E2) were also analyzed. Eighty pregnant cows were enrolled and the pregnancy was divided into 8 periods of 30 days each (from 30‑60 days to 240‑270 days). Blood samples were collected from all cows, once only for cow. Kp‑10, GnIH, cortisol and E2 were measured in sera. After an initial plateau, Kp‑10 concentrations increased at 90‑120 days and then decreased until 180‑210 days, undergoing a further increase until 240‑270 days. GnIH concentrations decreased until 90‑120 days, then increased until the end of gestation. These trends were opposing until 180‑210 days, whereat concentrations of both increased until the end of gestation. Cortisol concentrations were homogenous at all times, except at the final period, in which they were higher. E2 showed two peaks, at 90‑120 days and 240‑270 days. The trends in Kp‑10 and GnIH concentrations suggest that these two hormones might act to maintain the delicate endocrine equilibrium of pregnancy.

The neuropathological substrate of dementia with Lewy bodies (DLB) is defined by the inextricable cross-seeding accretion of amyloid-β (Aβ) and α-synuclein (α-syn)-laden deposits in cholinergic neurons. The recent revelation that neuropeptide kisspeptin-10 (KP-10) is able to mitigate Aβ toxicity via an extracellular binding mechanism may provide a new horizon for innovative drug design endeavors. Considering the sequence similarities between α-syn's non-amyloid-β component (NAC) and Aβ's C-terminus, we hypothesized that KP-10 would enhance cholinergic neuronal resistance against α-syn's deleterious consequences through preferential binding. Here, human cholinergic SH-SY5Y cells were transiently transformed to upsurge the mRNA expression of α-syn while α-syn-mediated cholinergic toxicity was quantified utilizing a standardized viability-based assay. Remarkably, the E46K mutant α-syn displayed elevated α-syn mRNA levels, which subsequently induced more cellular toxicity compared with the wild-type α-syn in choline acetyltransferase (ChAT)-positive cholinergic neurons. Treatment with a high concentration of KP-10 (10 µM) further decreased cholinergic cell viability, while low concentrations of KP-10 (0.01-1 µM) substantially suppressed wild-type and E46K mutant α-syn-mediated toxicity. Correlating with the in vitro observations are approximations from in silico algorithms, which inferred that KP-10 binds favorably to the C-terminal residues of wild-type and E46K mutant α-syn with CDOCKER energy scores of -118.049 kcal/mol and -114.869 kcal/mol, respectively. Over the course of 50 ns simulation time, explicit-solvent molecular dynamics conjointly revealed that the docked complexes were relatively stable despite small-scale fluctuations upon assembly. Taken together, our findings insinuate that KP-10 may serve as a novel therapeutic scaffold with far-reaching implications for the conceptualization of α-syn-based treatments.

Kisspeptin is a peptide encoded by the Kiss 1 gene and is also called metastin. Previous studies have generally focused on several functions of this peptide, including metastasis, puberty, vasoconstriction and reproduction. However, few studies have focused on the cardiac functions of kisspeptin. In the present study, cardiac histomorphology was observed via TEM (transmission electron microscope) and HE and Masson staining to observe instinctive changes. Serum metabolites levels were also measured and analyzed using GC/TOF-MS after injection with kisspeptin-10. A gene chip was employed to screen the potential genes and pathways in the myocardium at the transcriptional leve, while RT-PCR and Western Blot were conducted to verify the relevant mRNA and protein expression, respectively. Histopathological findings demonstrated that there were many irregular wavy contractions through HE staining and increased fibrosis around the heart cells through Masson staining after treatment with kisspeptin-10. Additionally, the main changes in ultrastructure, including changes in mitochondrial and broken mitochondrial cristae, could be observed with TEM after treatment with kisspeptin-10. The PCA scores plot of the serum metabolites was in the apparent partition after injection of kisspeptin-10. Twenty-six obviously changed metabolites were detected and classified as amino acids, carbohydrate metabolites, organic acids and other metabolites. Furthermore, gene chip analysis showed 1112 differentially expressed genes after treatment with kisspeptin-10, including 330 up-regulated genes and 782 down-regulated genes. These genes were enriched in several signaling pathways related to heart diseases. The RT-PCR result for ITGB8, ITGA4, ITGB7, MYL7, HIF1-α and BNP corresponded with the gene chip assay. Moreover, the upregulated genes ITGB8, ITGA4 and BNP also displayed consistent protein levels in Western Blot results. In summary, these findings suggest that kisspeptin-10 could alter the morphology and structure of myocardial cells, serum metabolite levels, and expression of genes and proteins in heart tissues. Our work determined the profound effects of kisspeptin-10 on the heart, which could further lead to the development of therapeutics related to kisspeptin-10, including antagonists and analogs.

Kisspeptin is the natural ligand of the G protein-coupled receptor -54 and plays a major role in gonadotropin-releasing hormone secretion in the hypothalamus. Kisspeptin-10 is an endogenous derivative of kisspeptin and has 10 -amino acids. Previous studies have demonstrated that central administration of kisspeptin-10 stimulates the secretion of arginine vasopressin (AVP) in male rats. We examined the effects of kisspeptin-10 on- excitatory synaptic inputs to magnocellular neurosecretory cells (MNCs) including AVP neurons in the supraoptic nucleus (SON) by obtaining in vitro whole-cell patch-clamp recordings from slice preparations of the rat brain. The application of kisspeptin-10 (100 nM-1 μM) significantly increased the frequency of miniature excitatory postsynaptic currents (mEPSCs) in a dose-related manner without affecting the amplitude. The kisspeptin-10-induced potentiation of the mEPSCs was significantly attenuated by previous exposure to the kisspeptin receptor antagonist kisspeptin-234 (100 nM) and to the protein kinase C inhibitor bisindolylmaleimide I (20 nM). These results suggest that kisspeptin-10 participates in the regulation of synaptic inputs to the MNCs in the SON by interacting with the kisspeptin receptor.

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](1)KP-10, bound to KISS1R with lower affinity to KP-10 and exhibited similar bioactivity in vitro. However, in vivo peripheral administration of [dY](1)KP-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](1)KP-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](1)KP-10 may have greater therapeutic potential than endogenous forms of kisspeptin.