EIF4A3‐Induced Circular RNA CircDdb1 Promotes Muscle Atrophy through Encoding a Novel Protein CircDdb1‐867aa

• Published in: Advanced science 2024-12, Vol.11 (45), p.e2406986-n/a
• Main Authors: Zhu, Xiaolan, Yang, Tingting, Zheng, Yongjun, Nie, Qiumeng, Chen, Jingying, Li, Qian, Ren, Xinyi, Yin, Xiaohang, Wang, Siqi, Yan, Yuwei, Liu, Zhengyu, Wu, Ming, Lu, Dongchao, Yu, Yan, Chen, Lei, Chatterjee, Emeli, Li, Guoping, Cretoiu, Dragos, Bowen, T Scott, Li, Jin, Xiao, Junjie
• Format: Article
• Language: English
• Subjects: Aging; Animals; Atrophy; Autophagy; circDdb1; Denervation; Disease Models, Animal; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; eEF2; Eukaryotic Initiation Factor-3 - genetics; Eukaryotic Initiation Factor-3 - metabolism; Humans; Male; Mice; Mice, Inbred C57BL; Mitochondrial DNA; muscle aging; muscle atrophy; Muscular Atrophy - genetics; Muscular Atrophy - metabolism; Muscular Atrophy - pathology; Musculoskeletal system; Myogenesis; Physiology; Protein synthesis; Proteins; RNA, Circular - genetics; RNA, Circular - metabolism; translation
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202406986

Little is known about if and how circular RNAs (circRNAs) are involved in skeletal muscle atrophy. Here a conserved circular RNA Damage‐specific DNA binding protein 1 (circDdb1), derived from the host gene encoding Damage‐specific DNA binding protein 1 (DDB1), as a mechanism of muscle atrophy is identified. circDdb1 expression is markedly increased in a variety of muscle atrophy types in vivo and in vitro, and human aging muscle. Both in vivo and in vitro, ectopic expression of circDdb1 causes muscle atrophy. In contrast, multiple forms of muscle atrophy caused by dexamethasone, tumor necrosis factor‐alpha (TNF‐α), or angiotensin II (Ang II) in myotube cells, as well as by denervation, angiotensin II, and immobility in mice, are prevented by circDdb1 inhibition. Eukaryotic initiation factor 4A3 (EIF4A3) is identified as a regulator of circDdb1 expression in muscle atrophy, whereas circDdb1 encodes a novel protein, circDdb1‐867aa. circDdb1‐867aa binds with and increases the phosphorylation level of eukaryotic elongation factor 2 (eEF2) at Thr56 to reduce protein translation and promote muscle atrophy. In summary, these findings establish circDdb1 as a shared regulator of muscle atrophy across multiple diseases and a potential therapeutic target. circDdb1 is increased in muscle atrophy models and aged muscle. Overexpression of circDdb1 promotes muscle atrophy, while knockdown of circDdb1 attenuates that. circDdb1 promotes muscle atrophy by encoding a novel protein circDdb1‐867aa. circDdb1‐867aa binds with and increases the phosphorylation level of eukaryotic elongation factor 2 (eEF2) at Thr56 to reduce protein translation and promote muscle atrophy. Collectively, these findings establish circDdb1 as a shared regulator of muscle atrophy across multiple diseases and a potential therapeutic target.