Figure 6. In vitro dynamic effects of edaravone and diethyl maleate (DEM) treatments of human umbilical cord mesenchymal stem cells (hUCMSCs) on Nrf2 expression and its upstream/downstream pathway after lipopolysaccharide (LPS)/H₂O₂ intoxication (n = 4).

(a) The activity change of Nrf2 of hUCMSCs was measured by a commercial kit from nuclear protein. (b,c) The mRNA expressional change of NAD(P)H:quinone oxidoreductase-1 (NQO-1) and malic enzyme-1 (ME-1) measured by quantitative PCR. (d) After the application MAPK inhibitor PD98059 (25 μM) and PKC inhibitor staurosporine (10 nM), the beneficial effects of 20 μM edaravone on cell viability were partially abolished. (e) Silence of Keap1 by specific siRNA significantly increased the Nrf2 activity. (f) Enhancement of Nrf2 activity by Keap1 silence partially reversed the detrimental effects of DEM on cell viability. “*” “**” “***” mean significant changes (P < 0.05, 0.01, 0.001) between control and treatments, respectively; “#” “##” “###” mean significant changes (P < 0.05, 0.01, 0.001) between edaravone treatment group (10 μM or 20 μM) and LPS/H₂O₂ group, respectively; “@” “@@” mean significant change (P < 0.05, 0.01) between DEM-treated group and LPS/H₂O₂ group, respectively. LPS, LPS/H₂O₂ challenge; Eda10, 10 μM edaravone; Eda20, 20 μM edaravone; PD, PD98059; STA, staurosporine.