PE-22-28 Peptide: TREK-1 Channel Inhibition and Antidepressant Research
PE-22-28 is a synthetic fragment of spadin that inhibits TREK-1 two-pore-domain potassium channels. Preclinical data positions it as a rapid-onset antidepressant candidate with a novel mechanism distinct from SSRIs or ketamine.
Dr. Marcus Chen
Senior Research Scientist
PE-22-28 is a truncated, optimised fragment of spadin — a natural peptide released by cleavage of the NTSR3/sortilin receptor — that potently inhibits TREK-1 (TWIK-related K⁺ channel 1), a member of the two-pore-domain (K2P) potassium channel family. TREK-1 suppression has emerged as a mechanistically novel antidepressant strategy following the observation that TREK-1 knockout mice display a depression-resistant phenotype and enhanced serotonergic neurotransmission.
TREK-1 and Depression
TREK-1 channels regulate neuronal resting membrane potential and are abundantly expressed in the prefrontal cortex, hippocampus, and raphe nuclei — regions central to mood regulation:
- TREK-1 knockout mice show antidepressant-like behaviour in forced swim tests, tail suspension tests, and learned helplessness models.
- TREK-1 activity is modulated by serotonin (5-HT) receptors; its inhibition facilitates serotonergic firing in the dorsal raphe, creating an SSRI-like downstream effect via an upstream mechanism.
- Unlike SSRIs, TREK-1 inhibition may avoid the 2–4 week latency to antidepressant effect seen with serotonin reuptake inhibitors.
PE-22-28 Pharmacology
PE-22-28 was developed through systematic truncation and optimisation of the natural spadin sequence to improve potency and BBB permeability:
- In patch-clamp studies, PE-22-28 inhibits TREK-1 current with greater potency than full-length spadin, and shows selectivity over related K2P channels (TRAAK, TREK-2).
- Intranasal administration in mice achieves CNS concentrations sufficient to produce antidepressant-like effects in the forced swim test and open-field exploratory models.
- Antidepressant effects are absent in TREK-1 knockout mice, confirming on-target action.
- Hippocampal neurogenesis markers (BrdU incorporation, DCX expression) are increased in PE-22-28-treated mice, paralleling effects of established antidepressants.
Research teams studying TREK-1 pharmacology or novel antidepressant mechanisms can source PE-22-28 research vials from Myotrope in 10 mg lyophilised format.
Research Context
The TREK-1 inhibitor approach is mechanistically distinct from all currently approved antidepressants:
- No monoamine reuptake inhibition (vs. SSRIs, SNRIs)
- No NMDA receptor antagonism (vs. ketamine/esketamine)
- No direct serotonin receptor agonism (vs. psilocybin-related approaches)
This novelty makes PE-22-28 an attractive tool compound for dissecting the neurobiology of depression and for developing antidepressants in treatment-resistant populations.
Peptide Profile
| Property | Value |
|---|---|
| Origin | Truncated fragment of spadin (NTSR3/sortilin cleavage product) |
| Target | TREK-1 (K2P potassium channel) |
| Molecular weight | ~900 Da (fragment-dependent) |
| Route (research) | Intranasal, intraperitoneal |
| Development stage | Preclinical (rodent models) |
References
- Mazella J, et al. (2010). Spadin, a sortilin-derived peptide, targeting rodent TREK-1 channels: a new concept in the antidepressant drug design. PLOS Biology, 8(4), e1000355.
- Djillani A, et al. (2017). Shortened spadin analogs display better TREK-1 inhibition, in vivo stability and antidepressant activity. Frontiers in Pharmacology, 8, 643.
- Heurteaux C, et al. (2006). Deletion of the background potassium channel TREK-1 results in a depression-resistant phenotype. Nature Neuroscience, 9(9), 1134–1141.
