Approximately 20 percent of the world’s population suffers from depression. Antidepressants, despite their demonstrated effectiveness, have a slow beginning of action and substantial side effects. Spadin (PE-22-28), a potential endogenous peptide with antidepressant effects, was first identified seven years ago. Spadin significantly blocks the TREK-1 channel. Spadin activity was previously shown to diminish after 7 hours in vivo by researchers. They looked for analogs and derivatives of spadin to see if they may increase in vivo stability and bioavailability.
Table of Contents
TREK-1: What Is It?
TREK-1 is the central receptor for spadin and, by extension, PE-22-28. K+ channels, such as the two-pore TREK-1, are controlled by several different molecules. Potassium channels with two pores, like this one, play a crucial role in controlling neuronal excitability. Transcription factor 1 (TREK-1) has been linked to mood, memory, and studying. The prefrontal cortex, the amygdala, and the hippocampus are all part of it. Reduced TREK-1 function increases excitability and the chance of a depolarization event when TREK-1 activity is stimulated. TREK-1 may aid in protecting neurons from excitotoxicity by lowering their excitability.
What is PE 22-28?
PE 22-28 is a seven-amino acid peptide derived from a research of spadin blood breakdown products. PE 22-28 demonstrated a greater affinity and selectivity for TREK-1 than spadin, with an IC50 of 0.12 nM vs. 40-60 nM for spadin in patch-clamp tests on hTREK-1/HEK cells. They also found that TREK-1 channel activity could be maintained or obliterated by distinct changes of its N or C-terminal ends without impacting PE 22-28 affinity. Using behavioral depression models like the forced swimming test, researchers were able to show the antidepressant effects of PE 22-28 and its variants in vivo.
Immobility time decreased significantly in mice treated with spadin analogs. Furthermore, in the novelty suppressed feeding test, PE 22-28 dramatically shortened the latency to consume the food pellet following a 4-day sub-chronic therapy. After just a 4-day therapy, PE 22-28 and its analogs were able to stimulate neurogenesis, with the G/A-PE 22-28 exerting the most influence. PE 22-28 and its derivatives improved synaptogenesis in mouse cortical neurons, as shown by increased PSD-95 expression. Finally, compared to spadin, the active duration of PE 22-28 and its analogs has been much enhanced, reaching up to 23 hours instead of 7 hours. Researchers found that PE 22-28 and its derivatives might be an option to spadin in the treatment of depression, findings.
Structures
Spadin Sequence:YAPLPRWSGPIGVSWGLR
Molecular Formula:C96H142N26O22
Molecular Weight: 2012.3492 g/mol
PE-22-28 Sequence:GVSWGLR
Molecular Formula:C35H55N11O9
Molecular Weight:773.8947 g/mol
The Work of Muscles
TREK-1 may have a significant role in muscles’ capacity to react to mechanical stimulation, according to new studies. In particular, TREK-1 blockage seems to improve muscular contractility, whereas stimulation of the channel promotes muscle tissue relaxation. While the TREK-1 channel is still in its infancy, one specific feature is becoming more critical. New therapeutic options for illnesses such as myogenic bladder dysfunction may be found in the study of molecules such as PE-22-28 and their roles in muscle contraction and relaxation. This research may also lead to new insights into the physiology of muscle functioning.
Depression after a traumatic event like a stroke
Post-stroke depression (PSD) is a frequent but difficult-to-treat complication of brain ischemia. Recent studies suggest that TREK-1 overexpression may contribute to this illness. SSRI antidepressants and TREK-1 blockers like spadin effectively reverse this increase in experimental animal models. It’s also worth noting that SSRIs take longer to take action and have several adverse effects. This shows that further research into the treatment of PSD with PE-22-28 may be fruitful.
