KissPeptin-10

Kisspeptin-10 Peptide

Kisspeptin-10 is a naturally occurring peptide protein that researcher suggest is encoded by the KISS1 gene ⁽²⁾. Kisspeptin is a product of the KISS1 gene, which is produced due to the cleavage of the original 145 amino acid peptide to a smaller peptide composed of 54 amino acids ⁽⁶⁾.

KISS1 is a gene that is considered to suppress metastases of melanomas and breast carcinomas, thereby inhibiting abnormal cell growth and preventing cancer ⁽²⁾. Initially thought to be a metastasis suppressor, Kisspeptin-10 was later suggested to possess a different expression profile which may possibly allow it to function on the hypothalamus and pituitary gland, thereby possibly impacting the reproductive system ⁽³⁾.

Several independent studies in the mid-2000s suggested that Kisspeptin-10 may play a role in hypogonadotropic hypogonadism as Kisspeptin-10 is considered to be a ligand of the G-protein coupled receptor 54 (GPR54)⁽⁵⁾. Research continues to date to explore this potential aspect of the Kisspeptin-10 peptide.

Hypogonadism is system disorder where reproductive organs produce less or no sex hormones. One of the forms of hypogonadism is called hypogonadotropic hypogonadism where the organism suffers from hypogonadism due to under-functioning of the pituitary gland or hypothalamus ⁽¹⁾. GnRH is considered to stimulate the pituitary gland to release follicle stimulating hormone (FSH) and luteinizing hormone (LH). Both FSH and LH are considered to regulate reproductive function ⁽¹⁾. Lack of these hormones, i.e. GnRH, FSH, and LH, are considered to be main factors of hypogonadotropic hypogonadism.

Kisspeptin-10 Overview

GPR54, also called KISS1 receptor (KISS1R)⁽⁷⁾, has been suggested by researchers to be an important GnRH receptor ⁽¹⁾. They further suggest that Kisspeptin-10 exhibits action by possibly binding to GPR54 receptors which may activate the reproductive axis by stimulating the release of GnRH and gonadotropin neurons. ⁽⁷⁾.

Kisspeptin-10 is a 54 amino acid peptide which is considered to be a product of the KISS1 gene. Researchers have isolated smaller peptide fragments such as Kisspeptin 10, 13, and 14, which all have been suggested to possess some biological activity towards GPR54 ⁽⁷⁾. These smaller peptides have been posited to bind with a low affinity to the GPR54 receptors and possibly stimulate calcium mobilization, arachidonic acid release, and extracellular protein kinase phosphorylation ⁽⁷⁾. These events may depolarize the Kisspeptin-10 neurons, which might lead to the depolarization of the GnRH neurons, possibly modulating gonadotropin release to some extent ⁽⁹⁾.

Research studies on Kisspeptin-10 have explored its potential in a wide variety of functions and impacts, and several hypotheses have been presented on the peptide’s possible mechanisms of action ⁽⁸⁾:

• May potentially stimulate GnRH release
• May potentially stimulate endogenous gonadotropin release in lesser fertile test models
• Peptide concentrations may possibly induce desensitization and suppression of the hypothalamus, pituitary gland, and gonadal axis