The circular RNA Edis regulates neurodevelopment and innate immunity

Area of Science:

• Molecular Biology
• Immunology
• Neuroscience

Background:

• Circular RNAs (circRNAs) are prevalent in eukaryotes, but their functions are often uncharacterized.
• Understanding the roles of specific circRNAs is crucial for deciphering complex biological processes.

Purpose of the Study:

• To identify and functionally characterize novel circRNAs in Drosophila.
• To investigate the role of the brain-enriched circRNA Edis (circ_Ect4) in innate immunity and neurodevelopment.

Main Methods:

• Identification and validation of Drosophila circRNAs.
• RNA interference (RNAi) for gene depletion and ectopic expression studies.
• Assessment of innate immunity responses in vitro and in vivo.
• Analysis of locomotor activity, lifespan, and neurodevelopmental phenotypes.
• Investigation of the interaction between Edis and the immune transcription factor Relish.

Main Results:

• Depletion of Edis leads to hyperactivated innate immunity and increased resistance to bacterial infection.
• Ectopic Edis expression suppresses innate immunity signaling.
• Edis inactivation causes impaired locomotor activity, shortened lifespan, and defective neurodevelopment, particularly with neuron-specific depletion.
• Edis encodes a functional protein that inhibits Relish processing and activation.
• Restoring Edis expression or its encoded protein rescues the observed phenotypes.

Conclusions:

• Edis is a key regulator of both innate immunity and neurodevelopment in Drosophila.
• The Edis-encoded protein plays a critical role in modulating the Relish immune pathway.
• This study highlights the multifaceted roles of circRNAs in fundamental biological processes.