Study on the nicotine regulating the circadian clock gene expression rhythm in vascular smooth muscle cells

ObjectiveTo study the effects of nicotine on the circadian clock gene expression rhythm in primary rat aortic vascular smooth muscle cells(VSMCs).

MethodsThe primary VSMCs were extracted using adherent method.The expression level of marker α-SMA of VSMCs was detected using immunofluorescence method, the viability was detected using MTT assay, and the expression rhythm of Bmal1, CLOCK, Per1 and Cry1 genes in VSMCs cells was detected using RT-PCR.The data were fitted using the cosine method to calculate circadian parameters.

ResultsThe 100 nmol/L of nicotine could induce the best proliferation of VSMCs for 48 hours.Compared with the control group, the median value of Bmal1 and CLOCK genes expression were down-regulated(P < 0.05 and P < 0.01), the median value of Per1 and Cry1 genes expression were up-regulated, the amplitude of Per1 and Cry1 genes expression were down-regulated, the amplitude of Per1 and Cry1 genes expression were up-regulated, and the differences of which were statistically significant(P < 0.05 to P < 0.01).

ConclusionsNicotine can change the circadian clock gene expression in VSMCs within 48 hours, and induce specific proliferation of VSMCs, and produce phenotypic differentiation.