Regulatory effect of rapamycin on key genes of circadian rhythm in senescent cells

LIU Zuojun; LIU Baohua; MENG Fanbiao

doi:10.3969/j.issn.1002-266X.2017.42.007

Abstract：Objective To investigated the effect of rapamycin on the cell autonomous circadian rhythm of senescent cells. Methods We induced replicative senescence of human dermal fibroblasts by series passage. The senescent human dermal fibroblasts cells were identified by SA-β-gal staining. The senescent human dermal fibroblasts cells were synchro-nized by 50% horse serum,and treated with DMSO or 200 nmol/L rapamycin. The oscillation profiles of BMAL1,PER2, CRY1,Rev-erbα and Rorα were examined by fluorogenic quantitative PCR. The circadian rhythm of genes was analyzed by JTK-CYCLE software. The protein expression of BMA1,CRY1,and PER2 was detected by Western blotting. Results The mRNA expression of PER2,CRY1,Rev-erbα and Rorα in the observation group was higher than that of the control group (all P <0.05). The biorhythm cycle of BMAL1,CRY1,Rev-erbα,and Rorα genes in the control group was 24 h, and the biorhythm cycle of PER2 gene was 28 h. The biorhythm cycle of BMAL1,CRY1,and Rorα genes in the observa-tion group was 24 h,and the biorhythm cycle of Rev-erbα gene was 27.5h. The expression of CRY1 protein in the obser-vation group was significantly higher than that in the control group,while PER2 protein expression was significantly lower than that in the control group (both P < 0.05). No significant difference was found in BMAL1 mRNA and protein expres-sion between these two groups. Conclusion Rapamycin can increase the expression of BMAL1,PER2,CRY1,Rev-erbαand Rorα mRNA in the aging human dermal fibroblasts and shorten the rhythmic cycle of PER2,which plays a regulatory role in the disturbance of circadian clock function.