Fig. 4

Upregulation of the transcription factor XBP1s in GA-MSCs promoted miR-21 expression

(A) miR-21 expression in human BM-MSCs and GA-MSCs was measured using miRNA sequencing. (B) The upregulated genes in GA-MSCs were filtered by overlapping them with predicted miR-21 transcription factors (determined with the transmiR and mirTrans databases). (C) The expression of miR-21 was measured in human BM-MSCs with TP53, XBP1, or EGR1 knockdown. (D) miR-21 expression was measured in control and XBP1 knockdown human BM-MSCs-derived exosomes. (E) Transcriptome variable shear analysis showed the expression of XBP1s in human BM-MSCs and GA-MSCs. (F) XBP1s expression in human BM-MSCs and GA-MSCs was measured using western blotting. Quantification of the fold change in the XBP1s/β-actin ratio (normalized to BM-MSCs) is shown. (G) The XBP1 binding site in the miR-21 promoter region was predicted using Jaspar, and ChIP‒qPCR was used to confirm the binding in BM-MSCs. (H) The luciferase activity of the wild-type and mutant-type plasmids in human BM-MSCs transfected with si-NC or si-XBP1 was measured. The data are presented as the mean ± SD; *p < 0.05, **p < 0.01, and ***p < 0.001