Influence of age, gender characteristics, chronotype on the expression of core clock genes Per1, Clock, Bmal1 and Cry1 in buccal epithelium

The purpose of the study is to determine the expression of the core clock genes in buccal epithelial cells of healthy people with different chronotypes. Materials and methods. Fourteen healthy volunteers with a healthy periodontium and oral mucosa (7 women and 7 men) were selected for participation in the trial. The buccal epithelium sampling was performed at 07:00 am and 07:00 pm in one day by cytological brush. The surveyed patients were examined chronotypically using the Horn-Ostberg test. The determination of the mRNA expression of the Per1, Clock, Bmal1, Cry1 genes was performed by quantitative real-time PCR. Statistical analysis was performed using two-way analysis of variance followed by Bonferroni post hoc tests. Results. Per1 expression was higher in the morning, regardless of chronotype, age, and gender. The expression of the Clock demonstrated the prevalence of the evening in both chronotypes, in both men and women. Bmal1 was better expressed in the evening, regardless of age, gender, and chronotype. The expression of Cry1 did not show statistically significant differences between the indicators. Conclusions. The evening expression of Clock was higher in people with the evening chronotype than in people with the morning chronotype. The chronotype did not show any effect on the expression of Per1, Bmal1, and Cry1. Age and sex did not show any effect on the expression of the core clock genes.