MiRNAs in ischemic tolerance. (A) MiRNA screening reveals that the predominant response of miRNAs after preconditioning (P) is upregulation, versus downregulation in ischemia (I) and tolerance (T). (B) MeCP2 (methyl-CpG binding protein) immunostaining shows induction in the cortex 8 h after preconditioning, consistent with decreased expression of MeCP2 miRNA. (C) Infarct is larger in tolerized MeCP2-null mice than in tolerized wildtype (WT) mice. Adapted, with permission, from Lusardi et al, 2010.