Kisspeptin-10, also called Metastin (45-54), is a 10 amino acid peptide that corresponds to the bioactive C-terminal 45-54 amino acids of metastin, a metastasis suppressor gene product. It acts as a potent agonist of GPR54 (OT7T175, AXOR12), with approximately 8-fold higher binding affinity than metastin (Ki values of 0.042 and 0.34 nM, respectively, for displacement of metastin (40-54)). Metastin (45-54) induces calcium mobilization in GPR54-transfected cells (EC50 = 0.18-1.1 nM). It inhibits the migration of GPR54-transfected CHO cells at concentrations of 10-100 nM, equaling the potency of full length metastin.
Kisspeptin 10 (human) is a powerful and specific activator for AXOR12 and hOT7T175 receptors. The Kisspeptin 10 (human) amide has been utilized in studies involving progesterone release from MA-10 cells and in experiments to induce gonadal differentiation in clownfish.
Kisspeptin-10 (human), a member of the kisspeptin family, is a neuropeptide that regulates gonadotropin secretion. It has anti-angiogenic effects, a concentration-dependent inhibition of HUVEC proliferation and migration, and is highly expressed in the placenta, which may help to regulate angiogenesis in this tissue. Kisspeptin-10 (human) is currently undergoing clinical studies with insulin secretion in men. It is also a potential drug target for the treatment of infertility.
Metastin serves as a tumor suppressor by hindering the growth of secondary tumors. When KISS1R (KISS1 receptor) is activated upon binding with KISS1, it boosts intracellular calcium levels and activates MAPKs, which in turn limit cell mobility and proliferation. Metastin is a potential therapeutic target for various cancers, including melanoma, thyroid, bladder, squamous cell carcinoma of the esophagus, gastric, hepatocellular, and breast cancers.
In addition to its role in cancer suppression, metastin plays a critical role in reproduction. It regulates the hypothalamic-pituitary-gonadal axis by modulating gonadotropin-releasing hormone (GnRH) secretion, which influences the onset of puberty. Gene mutations can lead to central precocious puberty (CPP) in males, while impaired metastin signaling can result in isolated hypogonadotropic hypogonadism (IHH) in both humans and mice. Metastin can also elevate plasma levels of gonadotropins (follicle-stimulating hormone and luteinizing hormone) and promote ovulation in prepubescent female rats.
Metastin is also known as kisspeptin 1 (KISS1). It is encoded by KISS1 gene, that is mapped to human chromosome 1q32. Metastin is a tumor suppressor protein, made up of 145 amino acids. The protein fragments contain RFamide motif at the C- terminal end. The encoded protein is expressed in the human hypothalamus, gonads, placenta, liver and pancreas. This novel?peptide?is mainly isolated from the human placenta.
The study revealed that the down regulation of galactose and up regulation of glycogenic amino acids (GAAs), including L-alanine, L-glutamic acid, L-methionine, L-proline and L-valine, in the kisspeptin-10 group suggests the accelerated carbohydrate metabolism, which indicates a negative energy balance. Moreover, in the kisspeptin-10-treated rats, high levels of GAAs that were possibly derived from protein decomposition might cause a negative nitrogen balance. It was found that increases of ketogenic amino acids such as tyrosine indicate a disturbance in glucose use, which might be induced by kisspeptin-10 in this study. In contrast, cholesterol increased significantly in the rats treated with kisspeptin-10, suggesting disrupted lipid metabolism, which might result from a lipolysis blockade[1].
Kisspeptin 10 (human) is a highly effective natural ligand for the Kisspeptin receptor (KISS1, GPR54). It exhibits strong binding affinity to rat and human KISS1 receptors, with Ki values of 1.59 and 2.33 nM respectively. This peptide inhibits metastasis and invasion in mouse melanomas and triggers gonadotropin release upon intracerebroventricular administration.
The kisspeptin (Kp) precursor contains 145 amino acids and can be hydrolyzed into Kp-54, Kp-14, Kp-13 and Kp-10. Kp-10, the shortest subtype with high activity, plays a vital role in many tissues. Kisspeptin 10 inhibited the expression of vascular endothelial growth factor (VEGF) in human umbilical vein endothelial cells, the main inducer of high vascular permeability (VP). Moreover, Kp-10 also promotes follicle maturation, ovulation and progesterone production. Exogenous Kp-10 injection decreased VP and VEGF by enhancing Kiss1r in OHSS rats without affecting ovulation [3].
Clinical claims and research
Kisspeptin-10 level is useful in assessing the severity of preeclampsia and can be a novel marker downregulated in pregnant women with preeclampsia, especially in those who also developed impaired uteroplacental perfusion or intrauterine growth restriction[2].
[1] Zhang Y, et al. The effects of kisspeptin-10 on serum metabolism and myocardium in rats. PLOS ONE, 2017; 12: e0179164.
[2] Ziyaraa M, et al. Correlation of Kisspeptin-10 level and fetal well-being in preeclamptic patients. Taiwanese Journal of Obstetrics and Gynecology, 2016; 55: 840-846.
[3] Zhai J, et al. Kisspeptin-10 inhibits OHSS by suppressing VEGF secretion. Reproduction, 2017; 154: 355–362.
