Ciart, the circadian-associated repressor of transcription, is involved in the regulation of the circadian clock. The circadian clock is a fundamental biological mechanism that controls various physiological processes and biological rhythms in organisms. Ciart is associated with pathways related to cortisol secretion, and its expression can be influenced in different tissues [2].

In the context of SARS-CoV-2 infection, lung airway organoids, lung alveolar organoids and cardiomyocytes derived from isogenic CIART-/-human pluripotent stem cells were significantly resistant to the infection, independently of viral entry. This indicates that Ciart plays a key role in SARS-CoV-2 infection, and it may control the infection at least in part through the regulation of NR4A1 [1]. In a study on spinal cord injury-induced immunodeficiency, the upregulated genes in the adrenal glands including Ciart were enriched in cortisol secretion and circadian rhythm changes [2]. In hypertensive rats, ARB-modified fecal microbiota transplantation led to increased intestinal Ciart levels, which was associated with beneficial effects on vascular remodeling, injury, and metabolic and intestinal functions [3].

In conclusion, Ciart is an important gene in the regulation of the circadian clock, and its function is closely related to various physiological and disease processes. Gene knockout models, such as the CIART-/-human pluripotent stem cells, have been crucial in revealing its role in SARS-CoV-2 infection. Understanding Ciart's functions in different biological processes may provide potential therapeutic targets for related diseases like COVID-19, and also offer insights into the underlying mechanisms of spinal cord injury-induced immunodeficiency and hypertension-related complications [1,2,3].

References:

1. Tang, Xuming, Xue, Dongxiang, Zhang, Tuo, Evans, Todd, Chen, Shuibing. 2023. A multi-organoid platform identifies CIART as a key factor for SARS-CoV-2 infection. In Nature cell biology, 25, 381-389. doi:10.1038/s41556-023-01095-y. https://pubmed.ncbi.nlm.nih.gov/36918693/

2. Zeng, Hong, Cheng, Li, Lu, De-Zhi, Zhou, Mou-Wang, Wang, Jin-Wu. 2023. Unbiased multitissue transcriptomic analysis reveals complex neuroendocrine regulatory networks mediated by spinal cord injury-induced immunodeficiency. In Journal of neuroinflammation, 20, 219. doi:10.1186/s12974-023-02906-7. https://pubmed.ncbi.nlm.nih.gov/37775760/

3. Li, Jing, Wang, Si-Yuan, Yan, Kai-Xin, Dong, Ying, Zhong, Jiu-Chang. 2024. Intestinal microbiota by angiotensin receptor blocker therapy exerts protective effects against hypertensive damages. In iMeta, 3, e222. doi:10.1002/imt2.222. https://pubmed.ncbi.nlm.nih.gov/39135690/