Figure 3. MSC restored the NMU-disrupted circadian expression of Per2 mRNA in mammary glands of NMU-treated rats in vivo.

Three rats in each group were sacrificed every 4 hours over a 24-hour period, beginning at 7 AM. Per2 mRNA expression levels were determined using RT-qPCR with total RNA samples extracted from rat mammary glands, and the results were analyzed with a comparative Ct method. Results were normalized with endogenous control, β-actin, and then with the expression level of the first sample at ZT0. X-axis: Zeitgeber Time (ZT), empty bar indicates light-on from ZT0 (7 AM) and black bar indicates light-off from ZT12 (7 PM); Y-axis: relative mRNA level, shown in mean ± SE (n = 3). A. NMU-treated rats were sacrificed at day 0 (control, diamond), 2 (square), or 30 (triangle) post-treatment. B. NMU-treated rats were maintained on control diet (triangle) or MSC-enriched diet (square) for 30 days post-exposure to NMU; rats untreated and maintained on control diet were used as control group (diamond).