Fig. 7

Protodioscin promotes NBR1 expression and binds to p62 and Keap1 to activate Nrf2. p62 direct-acting proteins were predicted using the STRING database (A). mRNA expression of WDFY3, CYLD, TRAF6, NBR1 and PRKCI was assessed by qRT-PCR (B). The mRNA and protein expression levels of NBR1 and PRKCI after incubation of primary mouse lung fibroblasts with varying concentrations of protodioscin were quantified by WB and qRT-PCR (C–E). mRNA and protein levels of NBR1 were determined by WB and qRT-PCR after NBR1 silencing (F, G). The effects of protodioscin on p62 and P-p62 after NBR1 silencing could be indicated by WB and qRT-PCR (H, I). Co-Ip experiments validate the direct interaction between NBR1, p62 and Keap1 (J–L). Expression of data was undertaken in form of mean ± standard deviation, and the experiments were replicated independently on a minimum of three occasions, * P < 0.05; *It is suggestive of statistical significance at the P threshold below 0.05; **Denotes heightened significance at the P threshold below 0.01; ***Reflects substantial significance at the P threshold below 0.001; ****Demonstrates remarkable significance at the P threshold below 0.0001