부산대학교 도서관

Circadian rhythms regulate diverse aspects of gastrointestinal physiology ranging from the composition of microbiota to motility. However, development of the intestinal circadian clock and detailed mechanisms regulating circadian physiology of the intestine remain largely unknown. In this report, we show that both pluripotent stem cell‐derived human intestinal organoids engrafted into mice and patient‐derived human intestinal enteroids possess circadian rhythms and demonstrate circadian phase‐dependent necrotic cell death responses to Clostridium difficile toxin B (TcdB). Intriguingly, mouse and human enteroids demonstrate anti‐phasic necrotic cell death responses to TcdB. RNA‐Seq analysis shows that ~3–10% of the detectable transcripts are rhythmically expressed in mouse and human enteroids. Remarkably, we observe anti‐phasic gene expression of Rac1, a small GTPase directly inactivated by TcdB, between mouse and human enteroids, and disruption of Rac1 abolishes clock‐dependent necrotic cell death responses. Our findings uncover robust functions of circadian rhythms regulating clock‐controlled genes in both mouse and human enteroids governing organism‐specific, circadian phase‐dependent necrotic cell death responses, and lay a foundation for human organ‐ and disease‐specific investigation of clock functions using human organoids for translational applications. SYNOPSIS: How rhythmicity of gene expression in the gut epithelium develops and which molecular mechanisms contribute to its maintenance remains unclear. This analysis of mouse and human organoid models uncovers species‐specific oscillatory behavior of circadian genes in the intestine. Maturation of pluripotent stem cell‐derived human intestinal organoids is required to develop robust circadian rhythms.Approximately 3–10% of transcripts in mouse and human intestinal enteroids are clock‐controlled genes.Phase set enrichment analysis uncovers eight conserved rhythmic signaling pathways.Rac1 small GTPase oscillations are anti‐phasic between mouse and human enteroids, regulating distinct necrotic cell death responses to Clostridium difficile toxin B. [ABSTRACT FROM AUTHOR]