The ErbB2-Dock7 Signaling Axis Mediates Excessive Cell Morphogenesis Induced by Autism Spectrum Disorder- and...

Area of Science:

• Neuroscience
• Genetics
• Cell Biology

Background:

• Autism spectrum disorder (ASD) is a neurodevelopmental condition marked by social communication deficits and restricted behaviors.
• Genetic mutations are strongly linked to ASD, impacting protein function and neuronal development, but specific molecular pathways remain unclear.

Purpose of the Study:

• To investigate the molecular mechanisms underlying aberrant neuronal morphology in ASD, specifically focusing on the semaphorin-5A (Sema5A) p.Arg676Cys variant.
• To identify novel signaling pathways involved in the excessive neuronal process elongation associated with ASD and intellectual disability (ID).

Main Methods:

• Utilized short hairpin RNA to knock down Dock7 expression in primary cortical neurons.
• Employed a specific chemical inhibitor to block ErbB2 kinase signaling.
• Examined effects on neuronal process elongation and downstream signaling molecules Rac1 and Cdc42 in neuronal cell models.

Main Results:

• Demonstrated that signaling through Dock7 and its upstream activator ErbB2 drives excessive neuronal process elongation linked to the Sema5A p.Arg676Cys variant.
• Showed that inhibiting ErbB2 or knocking down Dock7 significantly reduced this excessive elongation.
• Confirmed that ErbB2-Dock7 signaling inhibition decreased the overactivation of Rac1 and Cdc42.

Conclusions:

• The ErbB2-Dock7 signaling axis is implicated in mediating aberrant neuronal morphology associated with the ASD- and ID-linked Sema5A p.Arg676Cys variant.
• This pathway represents a potential therapeutic target for addressing molecular and cellular challenges in ASD.