Kisspeptin-10 Peptide

Kisspeptin-10 is a naturally occurring peptide derived from the KISS1 gene.(2) The KISS1 gene encodes a 145–amino acid precursor protein that is cleaved into smaller active peptides, including Kisspeptin-54 and ultimately Kisspeptin-10 (amino acids 45–54).(6)

Initially identified as a metastasis suppressor in cancers such as melanoma and breast carcinoma, Kisspeptin was later found to play a significant role in the hypothalamic–pituitary–gonadal (HPG) axis and reproductive regulation.(3)

Kisspeptin-10 acts as a ligand for the G-protein coupled receptor GPR54 (KISS1R), which is involved in regulating reproductive hormone signaling.(5)

Overview

Kisspeptin-10 is thought to influence reproductive function by interacting with GPR54 receptors, potentially stimulating the release of gonadotropin-releasing hormone (GnRH). This may activate downstream release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which regulate reproductive processes.(1)(7)

Research suggests Kisspeptin-10 may:

• Stimulate GnRH and gonadotropin release

• Influence reproductive function in low-fertility models

• Exhibit dose-dependent effects, including possible desensitization at higher concentrations(8)

Mechanistically, Kisspeptin peptides may trigger intracellular signaling pathways involving calcium mobilization, arachidonic acid release, and protein kinase activation, potentially modulating GnRH neuron activity.(7)(9)

Chemical Makeup

• Molecular Formula: C63H83N17O14

• Molecular Weight: 1302.4 g/mol

• Other Name: Kisspeptin 45–54

Research and Clinical Studies

Kisspeptin-10 and Reproduction

A 2017 literature review suggested that the Kisspeptin system (KISS1 gene, peptides, and GPR54 receptors) may regulate gonadotropin hormone release.(10)

Studies in animal models of hypogonadotropic hypogonadism (HH) and polycystic ovary syndrome (PCOS) suggest dysfunction in the KISS1/GPR54 system may contribute to reproductive disorders. Kisspeptin-10 is therefore considered a potential regulator of GnRH secretion.

Kisspeptin-10 and Delayed Hormonal Development

In studies of delayed development, Kisspeptin-10 exposure resulted in increased LH levels in ~47% of experimental models, with partial or no response in others.(13)

These findings suggest variable responsiveness and a possible role in stimulating reproductive hormone activity.

Kisspeptin-10 and Emotional Modulation

Research examining brain activity found that Kisspeptin-10 may influence limbic system function. Neuroimaging studies suggested increased responses to sexual and bonding stimuli following exposure.(14)

Kisspeptin-10 and Reproductive Hormone Release

Studies in male and female models suggest:

• Increased LH and FSH levels in males

• In females, hormone increases primarily during the preovulatory phase(15)

These findings indicate a phase-dependent hormonal response.

Kisspeptin-10 and Food Intake

Kisspeptin-10 is widely distributed in brain regions involved in appetite regulation, including the hypothalamus.

Studies in mice suggest it may:

• Reduce food intake initially (3–12 hours post-exposure)

• Increase intervals between meals without altering meal size

• Influence appetite-related signaling pathways(11)

Mechanistic findings suggest:

• Increased neuropeptide Y (NPY) expression (associated with hunger)

• Decreased brain-derived neurotrophic factor (BDNF) expression

• Reduced serotonin and dopamine levels, with stable norepinephrine(12)

These changes suggest a complex role in appetite and energy regulation.

Studies in Impaired Kisspeptin-10 Systems

As part of this study,⁽¹³⁾ the energetic and metabolic potential of Kisspeptin-10 was compared between control mice and mice with impaired Kisspeptin systems. Results suggested that female mice with impaired Kisspeptin systems exhibited dramatic increases in body weight and significantly impaired glucose tolerance levels. While the peptide exposed and impaired female mice ate less than the control female mice, they were more obese, with reduced locomotor activity and respiratory rate. No reported difference was found between control male mice and male mice with impaired Kisspeptin systems. Both exhibited normal body weight and glucose levels.

Kisspeptin-10 and Neuroprotection

The accumulation of amyloid-beta (Aβ) and alpha-synuclein (α-syn) within cholinergic neurons is believed to damage and potentially cause dysfunction within important central nervous system structures. However, it has been proposed that Kisspeptin-10 may attach to Aβ on the outside of cells, which may, in turn, possibly reduce the harmful actions of Aβ.⁽¹⁶⁾ Studies have suggested that Kisspeptin-10 peptides may counteract the damaging actions of Aβ, prion protein (PrP), and Islet Amyloid Polypeptide (IAPP) without being hindered by the antagonists of the kisspeptin receptor (GPR-54) or the neuropeptide FF (NPFF) receptor. Given the resemblance between the non-amyloid-β component (NAC) of α-syn and the C-terminus of Aβ, it has been speculated that Kisspeptin-10 might also lessen the toxicity caused by α-syn in cholinergic neurons.⁽¹⁷⁾ Research involving cholinergic cells has indicated that while high concentrations of Kisspeptin-10 may increase toxicity, lower concentrations may potentially decrease the toxicity induced by both the wild-type and the E46K mutant forms of α-syn. Computational studies have supported these observations by suggesting a potentially actionable interaction between Kisspeptin-10 and the C-terminal residues of α-syn. The molecular dynamics simulations indicated that the complexes formed between Kisspeptin-10 and α-syn appeared to have demonstrated good stability.

Researchers have also delved into investigating whether the activation of GPR54 (the receptor for the Kisspeptin gene) is crucial for the potential of Kisspeptin-10 to bind to the C-terminal pockets of α-syn. In one study, ChAT-positive SH-SY5Y neurons were genetically modified to produce either the wild-type or the E46K mutant version of α-syn, and the actions of Kisspeptin-10 on the neuronal damage caused by α-syn were assessed through flow cytometry and immunocytochemistry methods.⁽¹⁸⁾ Results suggested that Kisspeptin-10 may have lessened both apoptosis and mitochondrial damage in cholinergic neurons affected by either form of α-syn. Notably, the seeming protective action of Kisspeptin-10 did not appear to be impacted when introduced alongside a GPR54 antagonist, kisspeptin-234 (KP-234), implying that the activation of GPR54 may not be necessary for the actions of Kisspeptin-10. Additionally, it was observed that Kisspeptin-10 may have reduced the presence of α-syn and choline acetyltransferase (ChAT) in neurons that overexpressed the wild-type and E46K mutant α-syn, further highlighting its potential neuroprotective capacity.