CircSARS-CV2-N1368 from SARS-CoV-2 impairs endothelial cell function through the upregulation of ATF7 to activate TLR4/NF-κB/ROS signaling, 2025, Wen+

CircSARS-CV2-N1368 from SARS-CoV-2 impairs endothelial cell function through the upregulation of ATF7 to activate TLR4/NF-κB/ROS signaling
Wen, Yi-hong; Zhao, Heng-li; Wu, Shao-yu; Jiang, Jia-xue; Gao, Yuan; Wang, Zi-fan; Liu, Xiao-yao; Yu, Fei; Ou, Tao; Zhao, An-zhi; Chen, Li-wen; Fang, Jin-hua; Wu, Hua-yan; Zhu, Jie-ning; Ma, Ning; Sun, Jiu-feng; Fang, Xian-hong; Shan, Zhi-xin

SARS-CoV-2 can encode circular RNAs (circRNAs); however, the potential effects of exogenous SARS-CoV-2 circRNAs on cardiovascular sequelae remain unknown. Three circRNAs derived from the nucleocapsid (N) gene of SARS-CoV-2, namely, circSARS-CV2-Ns, were identified for functional studies. In particular, circSARS-CV2-N1368 was shown to enhance platelet adhesiveness to endothelial cells (ECs) and inhibit EC-dependent vascular relaxation. Moreover, exogenous expression of circSARS-CV2-N1368 suppressed EC proliferation and migration and decreased angiogenesis and cardiac organoid beating.

Mechanistically, we elucidated that circSARS-CV2-N1368 sponged the microRNA miR-103a-3p, which could reverse circSARS-CV2-N1368-induced EC damage. Additionally, activating transcription factor 7 (ATF7) was identified as a target gene of miR-103a-3p, and Toll-like receptor 4 (TLR4) was verified as a downstream gene of ATF7 that mediates circARS-CV2-N1368-induced activation of nuclear factor kappa B (NF-κB) signaling and ROS production in ECs. Importantly, the reactive oxygen species (ROS) scavenger NAC mitigated the circSARS-CV2-N1368-promoted EC impairment.

Our findings reveal that the TLR4/NF-κB/ROS signal pathway is critical for mediating circSARS-CV2-N1368-promoted oxidative damage in ECs, providing insights into the endothelial impairment caused by circSARS-CV2-Ns.

Link | PDF (Nature Acta Pharmacologica Sinica) [Open Access]