Maternal Extracellular Vesicles During Pregnancy and Autism Risk in Children

Area of Science:

• Perinatal research
• Neurodevelopmental disorders
• Biomarker discovery

Background:

• Extracellular vesicles (EVs) are implicated in intercellular signaling and show differences in autism.
• The role of maternal EVs during pregnancy in offspring autism risk is largely unknown.
• This study investigates prenatal maternal EVs in relation to childhood autism likelihood.

Purpose of the Study:

• To evaluate the association between maternal EVs' concentration and RNA cargo in prenatal plasma and childhood autism likelihood.
• To identify specific RNA molecules within maternal EVs that may correlate with autism risk.
• To explore the biological pathways potentially affected by these RNA differences.

Main Methods:

• Maternal plasma collected during mid-pregnancy (15-23 weeks) from the Nulliparous Pregnancy Outcomes Study.
• EVs isolated via ultracentrifugation; characterized for concentration, size, and CD63 levels.
• Small RNA sequencing performed to analyze RNA cargo; Social Communication Questionnaire used for autism risk assessment at 4.5-6 years.

Main Results:

• No significant differences in EV concentration, mean size, or CD63 levels between groups.
• 145 RNAs were differentially contained, predominantly downregulated in pregnancies with high autism risk offspring.
• Affected RNAs mapped to pathways in immune signaling, intracellular trafficking, protein turnover, and neurodevelopment, with some linked to SFARI Gene database autism risk genes.

Conclusions:

• Preliminary evidence suggests maternal prenatal EV RNA cargo is associated with childhood autism likelihood.
• Further large-scale studies are needed to confirm the role of prenatal EVs in autism pathogenesis.
• Future research should include longitudinal EV sampling and source deconvolution for enhanced interpretability.