A synthetic peptide called JB2 rescued synaptic function, learning, vocalization, motor skills, and seizure susceptibility in mice modeling Phelan-McDermid Syndrome — a genetic form of autism.
Multi-domain rescueJB2 rescued deficits across synaptic function, learning, memory, vocalizations, motor function, seizure susceptibility, and EEG biomarkers in a single genetic autism model
What the researchers found
A synthetic peptide fragment called JB2, derived from insulin-like growth factor binding protein 2 (IGFBP2), rescued multiple deficits in a mouse model of Phelan-McDermid Syndrome (PMS) — a genetic form of autism. JB2 restored synaptic function and plasticity, improved learning and memory, normalized vocalizations and motor function, reduced seizure susceptibility, and corrected abnormal brainwave patterns (EEG measures) that are directly translatable to human testing.
Mechanistically, JB2 binds directly to synapses and dendrites, activating NMDA receptors and IGF2 receptors (but not IGF1 receptors) to trigger gene expression and extensive remodeling of the phosphoproteome. Among the affected proteins, autism risk factors and Shank3-associated networks were significantly enriched — suggesting JB2 directly targets the molecular pathways disrupted in PMS and broader ASD.
Why it matters
Phelan-McDermid Syndrome and many forms of autism have no approved treatments targeting the underlying biology — only symptom management. A peptide that rescues synaptic function, cognitive deficits, communication, motor problems, AND seizures in a genetic autism model is remarkable in its breadth. The fact that JB2 also normalized EEG biomarkers that can be measured in humans makes it especially promising for clinical translation.
The numbers in context
JB2 peptide · IGFBP2-derived · rescued learning, memory, vocalizations, motor function · normalized EEG: auditory evoked response latency, alpha peak frequency, SSVEP · Shank3 heterozygous mouse model
How the study worked
In vitro studies in cultured neurons and in vivo studies in Shank3 heterozygous mice (a model of Phelan-McDermid Syndrome). Assessed JB2's effects on synaptic structure, neuronal plasticity, phosphoproteome remodeling, behavior (learning, memory, vocalizations, motor function), neuronal excitability, seizure susceptibility, and electrophysiological biomarkers (EEG measures).
Who was studied
Shank3 heterozygous mice (genetic model of Phelan-McDermid Syndrome/autism) and cultured neurons
What this study cannot tell us
Preclinical study in mice — results may not fully translate to human PMS or ASD. The Shank3 heterozygous mouse models one specific genetic cause of autism, so JB2 may not be effective across the full heterogeneous spectrum of ASD. Long-term safety, dosing, and blood-brain barrier penetration in humans are unknown. The gap between rescued mouse behaviors and meaningful clinical outcomes in human autism can be substantial.
How to read the evidence
This is a rigorous preclinical study published in Molecular Psychiatry, a top-tier journal. The breadth of rescued phenotypes and mechanistic depth are impressive, but translation to human clinical benefit requires clinical trials.
When this study was published
Published in 2023 in Molecular Psychiatry. Very recent and represents the cutting edge of peptide-based approaches to neurodevelopmental disorders. Clinical development status of JB2 is not specified.
The bigger picture
Most autism research has focused on behavioral interventions because no drug targets the underlying synaptic dysfunction. JB2 represents a fundamentally different approach — a peptide that directly restores synapse function in a genetically defined form of autism. If it translates to humans, it could be the first treatment addressing the biology rather than just the symptoms of PMS. The normalized EEG biomarkers are particularly exciting because they provide measurable endpoints for clinical trials.
Questions still open
- Can JB2 cross the blood-brain barrier effectively enough for systemic administration in humans?
- Will JB2's benefits extend to forms of autism beyond SHANK3-related Phelan-McDermid Syndrome?
- What is the optimal dosing window — does JB2 need to be given during brain development, or can it rescue deficits in adults?
Common questions
What is Phelan-McDermid Syndrome?
How does the JB2 peptide help the brain?
Read the original research
An IGFBP2-derived peptide promotes neuroplasticity and rescues deficits in a mouse model of Phelan-McDermid syndrome.
Molecular psychiatry, 28(3), 1101-1111
Citation
Burgdorf, Jeffrey S; Yoon, Sehyoun; Dos Santos, Marc; Lammert, Catherine R; Moskal, Joseph R; Penzes, Peter. (2023). An IGFBP2-derived peptide promotes neuroplasticity and rescues deficits in a mouse model of Phelan-McDermid syndrome.. Molecular psychiatry, 28(3), 1101-1111. https://doi.org/10.1038/s41380-022-01904-0