Chrono-Specific Calcium Intervention Disrupts Hepatic Lipid Metabolism via the PER1-PPARα Axis

Morning calcium intervention (MCI) in mice significantly increased serum and hepatic total cholesterol (TC), triglyceride (TG), and low-density lipoprotein (LDL) levels, and induced lipid droplet deposition and swelling in hepatocytes. Transcriptome and validation experiments showed upregulated hepatic PER1 expression in the MCI group, while PPARα and its downstream lipid metabolism genes (CPT1A, APOA5) were downregulated. In HepG2 cells, nighttime calcium incubation (NC) significantly increased intracellular TG and LDL contents, upregulated PER1 expression, and inhibited PPARα, CPT1A, and APOA5 expressions. Knocking down PER1 reversed the abnormal gene expression and lipid-elevating effects in the NC group. Collectively, our findings demonstrate that the circadian timing of calcium intake critically regulates hepatic lipid homeostasis <i>via</i> the PER1-PPARα axis, highlighting the importance of chrono-nutrition in metabolic health.