Circadian reprogramming of inflammation and metabolism in chronic kidney disease

BACKGROUND: Chronic kidney disease (CKD) is driven by inflammation, fibrosis, and metabolic dysfunction. While circadian rhythm dysregulation is well documented in chronic disorders, its specific impact on CKD pathogenesis remains elusive. METHODS: We performed four-hour interval time-series RNA sequencing on renal tissues from control and CKD mice. We used the JTK_CYCLE algorithm to identify rhythmic genes and categorize them as lost, acquired, or sustained in CKD; we subsequently performed focused bioinformatic analyses. RESULTS: The renal circadian profile was substantially altered; acquired rhythmicity emerged as the dominant pattern, and core clock gene expression was disrupted. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that upregulated acquired-rhythmic genes in CKD were enriched in immune-inflammatory pathways; the expression of these genes peaked at Zeitgeber time (ZT) 12-16, consistent with a higher level of renal macrophage infiltration at ZT16 than at ZT0. Conversely, genes associated with nutrient and energy metabolism pathways were downregulated but acquired rhythmicity in CKD. Dapagliflozin improved renal function and restored the circadian expression rhythms of NR1D1 and p-BMAL1. CONCLUSIONS: CKD profoundly remodels the renal circadian transcriptome, driving immune-inflammatory and metabolic pathways into maladaptive rhythmicity. Furthermore, dapagliflozin can partially restore the expression of renal core clock genes.