Resveratrol inhibits LPS-induced apoptosis in bovine mammary epithelial cells: the role of PGC1α-SIRT3 axis.

Resveratrol (Res) is a bioactive dietary component and alleviates apoptosis in multiple cell types. However, its effect and mechanism on lipopolysaccharide (LPS)-induced bovine mammary epithelial cells (BMEC) apoptosis, which commonly happens in dairy cows with mastitis, is unknown. We hypothesized that Res would inhibit LPS-induced apoptosis in BMEC through SIRT3, a NAD + -dependent deacetylase activated by Res. To test the dose-response effect on apoptosis, 0-50 μM Res were incubated with BMEC for 12 h, followed by 250 μg/mL LPS treatment for 12 h. To investigate the role of SIRT3 in Res-mediated alleviation of apoptosis, BMEC were pretreated with 50 μM Res for 12 h, then incubated with si-SIRT3 for 12 h and were finally treated with 250 μg/mL LPS for 12 h. Res dose-dependently promoted the cell viability and protein levels of Bcl-2 (Linear P < 0.001) but decreased protein levels of Bax, Caspase-3 and Bax/Bcl-2 (Linear P < 0.001). TUNEL assays indicated that cellular fluorescence intensity declined with the rising doses of Res. Res also dose-dependently upregulated SIRT3 expression, but LPS had the opposite effect. SIRT3 silencing abolished these results with Res incubation. Mechanically, Res enhanced the nuclear translocation of PGC1α, the transcriptional cofactor for SIRT3. Further molecular docking analysis revealed that Res could directly bind to PGC1α by forming a hydrogen bond with Tyr-722. Overall, our data suggested that Res relieved LPS-induced BMEC apoptosis through the PGC1α-SIRT3 axis, providing a basis for further in vivo investigations of applying Res to relieve mastitis in dairy cows.