Figure 7.

Age-related changes in miRNA expression from cortex-derived ECs following CCI injury. ECs were isolated from the cortex of 4 d sham and injured adult and juvenile mice using magnetic bead separation. a, Expression of miR-21–5p, miR-155, miR-31, miR-127, and miR-148a was quantified using qRT-PCR and is represented relative to adult sham. We found that miR-21–5p was increased in juvenile sham ECs (*p = 0.0270) and adult injured ECs (****p < 0.0001) compared with adult sham. We also observed that juvenile injured ECs had a greater increase in miR-21–5p compared with adult injured ECs (****p < 0.0001). Adult and juvenile injured ECs showed an increase in miR-155 over their respective sham controls (***p = 0.0009 and ***p = 0.0010, respectively) and miR-31 was increased in juvenile sham ECs compared adult (*p = 0.0461), which was reduced after injury (*p = 0.0383). No difference was seen in miR-127; however, miR-148a was increased only in juvenile injured ECs compared with adult injured ECs (**p = 0.0135). b, Using miRSystem pathway ranking scores, we identified significant biological processes predicted to be regulated by both miR-21 and miR-148a, which were enhanced in juvenile ECs compared with adult. c, We used KEGG pathway analysis to generate a graphical representation of cell signaling processes targeted by miR-21 and miR-148a in juvenile ECs, including apoptosis, vegf, and cytokine expression. Pathway components targeted by miR-21 and/or 148a are shown in red.