Primary cilia shape postnatal astrocyte development through Sonic Hedgehog signaling.

Area of Science:

• Neuroscience
• Cell Biology
• Developmental Biology

Background:

• Primary cilia act as signaling hubs regulating cellular processes, including neuron and glia development.
• Astrocytes, crucial glial cells, possess cilia, yet their developmental role is poorly understood.
• Cilia and astrocyte dysfunction are implicated in neurodevelopmental disorders.

Purpose of the Study:

• To investigate the function of cilia in astrocyte development and their role in Sonic Hedgehog (Shh) signaling.
• To determine the impact of astrocyte cilia loss on astrocyte proliferation and maturation.

Main Methods:

• Utilized genetic ablation of astrocyte cilia in vivo at distinct developmental stages.
• Analyzed changes in Shh transcriptional targets and astrocyte morphology.
• Assessed astrocyte proliferation rates.

Main Results:

• A subpopulation of developing astrocytes in the prefrontal cortex expresses ciliary protein ARL13B and is ciliated.
• Loss of astrocyte cilia led to decreased Shh signaling in both immature and mature astrocytes.
• Ablation of cilia in immature astrocytes reduced proliferation, while in mature astrocytes, it caused enlarged morphology.

Conclusions:

• Astrocytes require cilia for proper Shh signaling throughout development.
• Astrocyte cilia play essential roles in regulating astrocyte proliferation and maturation.
• Findings enhance understanding of astrocyte development, cilia function, and neurodevelopmental disorders.