The circular RNA Edis regulates neurodevelopment and innate immunity

• Published in: PLoS genetics 2022-10, Vol.18 (10), p.e1010429
• Main Authors: Xiong, Xiao-Peng, Liang, Weihong, Liu, Wei, Xu, Shiyu, Li, Jian-Liang, Tito, Antonio, Situ, Julia, Martinez, Daniel, Wu, Chunlai, Perera, Ranjan J, Zhang, Sheng, Zhou, Rui
• Format: Article
• Language: English
• Subjects: Aging; Alzheimer's disease; Alzheimers disease; Animals; Bacterial infections; Biology and Life Sciences; Brain diseases; Circular RNA; Drosophila - genetics; Drosophila - metabolism; E coli; Ectopic expression; Gene expression; Genetic aspects; Genetic regulation; Genetic research; Gram-positive bacteria; Immune clearance; Immunity, Innate - genetics; Infections; Innate immunity; Insects; Kinases; Life span; Locomotor activity; Medicine and Health Sciences; Neurodegeneration; Neurodevelopment; Neurogenesis; Pathogens; Peptides; Phenotypes; Physiology; Properties; Proteins; Research and Analysis Methods; RNA; RNA - genetics; RNA, Circular - genetics; Signal Transduction; Transcription activation; Transcription Factors - genetics
• ISSN: 1553-7404; 1553-7390; 1553-7404
• DOI: 10.1371/journal.pgen.1010429

Circular RNAs (circRNAs) are widely expressed in eukaryotes. However, only a subset has been functionally characterized. We identify and validate a collection of circRNAs in Drosophila, and show that depletion of the brain-enriched circRNA Edis (circ_Ect4) causes hyperactivation of antibacterial innate immunity both in cultured cells and in vivo. Notably, Edis depleted flies display heightened resistance to bacterial infection and enhanced pathogen clearance. Conversely, ectopic Edis expression blocks innate immunity signaling. In addition, inactivation of Edis in vivo leads to impaired locomotor activity and shortened lifespan. Remarkably, these phenotypes can be recapitulated with neuron-specific depletion of Edis, accompanied by defective neurodevelopment. Furthermore, inactivation of Relish suppresses the innate immunity hyperactivation phenotype in the fly brain. Moreover, we provide evidence that Edis encodes a functional protein that associates with and compromises the processing and activation of the immune transcription factor Relish. Importantly, restoring Edis expression or ectopic expression of Edis-encoded protein suppresses both innate immunity and neurodevelopment phenotypes elicited by Edis depletion. Thus, our study establishes Edis as a key regulator of neurodevelopment and innate immunity.