GLP-2 Peptide Modified with Cell-Penetrating Sequences Delivered Nose-to-Brain Shows Antidepressant Effect
PAS-CPP-modified GLP-2 achieved nose-to-brain delivery with antidepressant effects within 20 minutes of intranasal administration at the same dose effective via direct brain injection, while intravenous delivery was ineffective.
Quick Facts
What This Study Found
PAS-CPP-GLP-2 showed antidepressant-like effects within 20 min of intranasal administration at the same dose effective by i.c.v. injection, while i.v. delivery was ineffective. The modification prevented degradation and enabled transcellular nose-to-brain transport.
Key Numbers
CPPs significantly enhanced nasal GLP-2 brain delivery; antidepressant effects in both depression and treatment-resistant depression models.
How They Did This
In vitro: cellular uptake mechanism (macropinocytosis via CPP), endosomal escape (via PAS), and transcellular transport studies. In vivo: depression model mice tested with intranasal, intravenous, and intracerebroventricular PAS-CPP-GLP-2 administration.
Why This Research Matters
Depression affects hundreds of millions of people, and treatment-resistant depression has few options. A nasal spray delivering an effective brain peptide within minutes could transform treatment — especially since GLP-2 works in treatment-resistant models where conventional antidepressants fail.
The Bigger Picture
Nose-to-brain delivery is one of the most promising routes for CNS drug delivery, bypassing the blood-brain barrier. This proof-of-concept with GLP-2 demonstrates that CPP/PAS modification can make neuropeptides clinically viable as nasal therapies for brain disorders.
What This Study Doesn't Tell Us
Mouse depression model — behavioral tests are proxies for human depression. Dose-response optimization and long-term efficacy not established. PAS-CPP modification adds manufacturing complexity. Safety profile of repeated intranasal delivery needs evaluation.
Questions This Raises
- ?Can PAS-CPP-GLP-2 nasal spray be advanced to human clinical trials for depression?
- ?Would this nose-to-brain delivery approach work for other neuropeptides?
- ?How does the antidepressant effect compare to rapid-acting treatments like ketamine?
Trust & Context
- Key Stat:
- 20 minutes onset of antidepressant effect from intranasal PAS-CPP-GLP-2, matching direct brain injection efficacy
- Evidence Grade:
- Innovative proof-of-concept with compelling evidence of nose-to-brain delivery (intranasal effective, IV ineffective). Mouse depression model is standard but limited in predicting human outcomes.
- Study Age:
- Published in 2021. Nose-to-brain peptide delivery for psychiatric conditions is an emerging field.
- Original Title:
- Usefulness of cell-penetrating peptides and penetration accelerating sequence for nose-to-brain delivery of glucagon-like peptide-2.
- Published In:
- Journal of controlled release : official journal of the Controlled Release Society, 335, 575-583 (2021)
- Authors:
- Akita, Tomomi, Kimura, Ryosuke, Akaguma, Saki, Nagai, Mio, Nakao, Yusuke, Tsugane, Mamiko, Suzuki, Hiroaki, Oka, Jun-Ichiro, Yamashita, Chikamasa
- Database ID:
- RPEP-05256
Evidence Hierarchy
Frequently Asked Questions
How does a nasal spray deliver drugs to the brain?
The nose has a direct connection to the brain through olfactory nerves. Specially designed peptides can travel along these nerve pathways, bypassing the blood-brain barrier and reaching the brain within minutes.
What is treatment-resistant depression?
Depression that doesn't respond to standard antidepressants, affecting about one-third of depression patients. GLP-2 showed effects in treatment-resistant depression models, suggesting it works through different mechanisms than conventional drugs.
Read More on RethinkPeptides
Cite This Study
https://rethinkpeptides.com/research/RPEP-05256APA
Akita, Tomomi; Kimura, Ryosuke; Akaguma, Saki; Nagai, Mio; Nakao, Yusuke; Tsugane, Mamiko; Suzuki, Hiroaki; Oka, Jun-Ichiro; Yamashita, Chikamasa. (2021). Usefulness of cell-penetrating peptides and penetration accelerating sequence for nose-to-brain delivery of glucagon-like peptide-2.. Journal of controlled release : official journal of the Controlled Release Society, 335, 575-583. https://doi.org/10.1016/j.jconrel.2021.06.007
MLA
Akita, Tomomi, et al. "Usefulness of cell-penetrating peptides and penetration accelerating sequence for nose-to-brain delivery of glucagon-like peptide-2.." Journal of controlled release : official journal of the Controlled Release Society, 2021. https://doi.org/10.1016/j.jconrel.2021.06.007
RethinkPeptides
RethinkPeptides Research Database. "Usefulness of cell-penetrating peptides and penetration acce..." RPEP-05256. Retrieved from https://rethinkpeptides.com/research/akita-2021-usefulness-of-cellpenetrating-peptides
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.