A New Peptide Rescues Brain Function Deficits in a Genetic Autism Mouse Model

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.

Burgdorf, Jeffrey S et al.·Molecular psychiatry·2023·Strong EvidenceAnimal StudyAnimal Study
RPEP-06764Animal StudyStrong Evidence2023RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Animal Study
Evidence
Strong Evidence
Sample
Shank3 heterozygous mice (genetic model of Phelan-McDermid Syndrome/autism) and cultured neurons
Participants
Shank3 heterozygous mice (genetic model of Phelan-McDermid Syndrome/autism) and cultured neurons

What This Study 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.

Key Numbers

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 They Did This

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).

Why This Research 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 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.

What This Study Doesn't 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.

Questions This Raises

  • ?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?

Trust & Context

Key Stat:
Multi-domain rescue JB2 rescued deficits across synaptic function, learning, memory, vocalizations, motor function, seizure susceptibility, and EEG biomarkers in a single genetic autism model
Evidence Grade:
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.
Study Age:
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.
Original Title:
An IGFBP2-derived peptide promotes neuroplasticity and rescues deficits in a mouse model of Phelan-McDermid syndrome.
Published In:
Molecular psychiatry, 28(3), 1101-1111 (2023)
Database ID:
RPEP-06764

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal StudyOne case or non-human subjects
This study

Tests effects in animals (usually mice or rats), not humans.

What do these levels mean? →

Frequently Asked Questions

What is Phelan-McDermid Syndrome?

Phelan-McDermid Syndrome (PMS) is a rare genetic condition caused by a missing or mutated SHANK3 gene on chromosome 22. It causes autism, intellectual disability, delayed speech, poor motor coordination, and seizures. There is currently no approved treatment targeting the underlying biology.

How does the JB2 peptide help the brain?

JB2 mimics a natural growth factor (IGFBP2) and directly binds to synapses — the connections between brain cells. It activates pathways that promote synapse formation and strengthening (neuroplasticity), effectively restoring the brain's ability to make and maintain connections that are disrupted when SHANK3 is missing.

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Cite This Study

RPEP-06764·https://rethinkpeptides.com/research/RPEP-06764

APA

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

MLA

Burgdorf, Jeffrey S, et al. "An IGFBP2-derived peptide promotes neuroplasticity and rescues deficits in a mouse model of Phelan-McDermid syndrome.." Molecular psychiatry, 2023. https://doi.org/10.1038/s41380-022-01904-0

RethinkPeptides

RethinkPeptides Research Database. "An IGFBP2-derived peptide promotes neuroplasticity and rescu..." RPEP-06764. Retrieved from https://rethinkpeptides.com/research/burgdorf-2023-an-igfbp2derived-peptide-promotes

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.