FAIM Enhances the Efficacy of Mesenchymal Stem Cell Transplantation by Inhibiting JNK-Induced c-FLIP Ubiquitination and Degradation

Figure 5

FAIM stabilizes the c-FLIP protein in MSCs by inhibiting its ubiquitination. (a) mRNA expression of c-FLIP in MSCs_Vec and MSCs_FAIM challenged with OGD. (b) Representative immunoblots showing c-FLIP protein expression in MSCs_Vec and MSCs_FAIM treated with 10 μM CHX for the indicated times under OGD conditions. The results of densitometric quantitation are shown on the right, and the line chart shows c-FLIP protein levels (normalized to GAPDH) as a percentage of the c-FLIP protein expression of MSCs_Vec at 0 h (). (c) Representative immunoblots showing c-FLIP protein levels in MSCs_si-scr and MSCs_si-FAIM treated with 10 μM CHX for the indicated times under OGD conditions. The results of densitometric quantitation are shown on the right (). (d) Representative Western blotting results showing c-FLIP protein expression after siRNA-mediated knockdown of FAIM or scrambled siRNA administration followed by treatment with chloroquine (CQ, 50 nM) or MG132 (10 μM) under OGD conditions. The results of densitometric quantitation are shown below (). (e) MSCs_Vec and MSCs_FAIM were treated with MG132 (10 μM) under OGD conditions for 6 h. Whole-cell lysates were immunoprecipitated with anti-FLIP antibodies, followed by immunoblotting with anti-ubiquitin antibodies. The input (10% of the total) was analyzed by Western blotting using anti-FLIP and anti-FAIM antibodies. The data are shown as the . indicates not significant; denotes ; .

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