PE-22-28 is a synthetic heptapeptide derived from the FGFR1 (fibroblast growth factor receptor 1) binding domain of the neural cell adhesion molecule (NCAM). It activates FGFR1 directly — producing antidepressant-like effects in rodent models through a mechanism entirely distinct from BDNF/TrkB (the pathway of classical antidepressants and ketamine), GABA-A (benzodiazepines), serotonin reuptake inhibitors, or monoamine oxidase inhibitors. This novel MoA makes PE-22-28 the primary research tool for studying FGFR1-mediated neuroplasticity, synaptogenesis, and antidepressant biology independent of the BDNF signalling axis.
Synaptogenesis: FGFR1/ERK → dendritic spine density increase, PSD-95/synapsin upregulation — structural plasticity without BDNF/TrkB
Hippocampal neurogenesis: FGFR1 promotes proliferation of hippocampal neural progenitor cells
BrdU/Ki67 proliferation: Dentate gyrus neurogenesis measurable within days of PE-22-28 administration
Why TrkB-independence matters for antidepressant research
Most current antidepressant research focuses on BDNF/TrkB — ketamine, esketamine, and many novel agents work through this pathway. PE-22-28 provides a BDNF/TrkB-independent antidepressant mechanism for studying whether neuroplasticity effects require TrkB signalling. Running PE-22-28 alongside TrkB inhibitors allows dissection of FGFR1 vs TrkB contributions to any neuroplasticity readout.
Key Research Studies & Data
Study
Model
Finding
Bhatt et al. 2020 (ACS Chem Neurosci)
Forced swim test + tail suspension, mice
PE-22-28 produced antidepressant-like effects at 1-10 mg/kg IP — TrkB inhibitor did not block effect
Bhatt et al. 2020 (same)
Hippocampal synaptogenesis
Dendritic spine density increased; PSD-95 and synapsin elevated — FGFR1 dependent
Bhatt et al. 2020 (same)
BrdU hippocampal neurogenesis
Increased BrdU+ cells in dentate gyrus — neurogenic antidepressant mechanism
PE-22-28 1-10 mg/kg IP 30min pre-test in C57BL/6 mice. FST immobility, TST immobility vs vehicle, imipramine positive control, TrkB inhibitor (ANA-12) arm to confirm TrkB-independence. Open field test for locomotion confound.
Protocol 2: Hippocampal synaptogenesis
PE-22-28 10 mg/kg IP daily × 7 days. Golgi stain (dendritic spine density/morphology), PSD-95/synapsin WB, Sholl analysis of dendritic complexity. FGFR1 inhibitor (SU5402) arm to confirm receptor dependence.
PE-22-28 is a synthetic heptapeptide FGFR1 agonist with antidepressant-like effects in rodent models via a mechanism independent of BDNF/TrkB, serotonin reuptake, or GABA-A signalling.
How is PE-22-28 different from other antidepressant peptides?
Most antidepressant peptides act on TrkB. PE-22-28 activates FGFR1 — a receptor tyrosine kinase in the FGF signalling family — producing antidepressant and synaptogenic effects through ERK/CREB without requiring BDNF or TrkB.
What does FGFR1 activation do in the brain?
FGFR1 in neurons activates PLCg/PI3K/MAPK/ERK1/2 → CREB → neuroplasticity gene expression. It promotes dendritic spine density, synaptic protein synthesis, and hippocampal neurogenesis — all implicated in antidepressant neurobiological mechanisms.
Can PE-22-28 be combined with Dihexa or Semax?
Dihexa activates HGF/MET for synaptogenesis; Semax activates BDNF/TrkB. PE-22-28 activates FGFR1 independently of both. Running all three allows comparison of three distinct neuroplasticity-promoting receptor pathways.
What formats does QSC supply PE-22-28 in?
QSC supplies PE-22-28 as lyophilised research vials, ≥99% purity HPLC verified with Janoshik COA. Ships from domestic warehouses in USA, EU, UK, Canada, and Australia.
