Fig. 1

The intracellular validation of candidate circRNAs in C1 and C4. Validation of intracellular circRNA was performed using quantitative polymerase chain reaction (qPCR; in triplicate) in three randomly selected RNA samples. The level of intracellular expression of the validated circRNA was the average of these three samples. Prior to determination of the average, the normalized intracellular expression was calculated by the ratio of intracellular expression to microarray expression. Four up-regulated circRNAs (circRNA100550, circRNA100783, circRNA101328 and circRNA102592) and two down-regulated circRNAs with Top-2 Degree (circRNA103741 and circRNA101318) were validated in C1, respectively (a). Simultaneously, the same four up-regulated circRNAs and another two down-regulated circRNAs with Top-2 degree (circRNA104096 and circRNA100264) were validated in C4, respectively (b). Shown from the figure, only circRNA100783 is significantly differentially-expressed in both C1 and C4. Therefore, we supposed circRNA 1000783 might be a potential biomarker of immunosenescence