Figure 4: In vivo delivery of miR-146a mimic using mellitin-derived cell permeable peptide (p5RHH) effectively reduced levels of TRAF6 and IRAK1 mRNAs and protein levels. Animals were subjected to controlled cortical impact injury (n = 6) and randomly assigned to receive an intrahippocampal injection of p5RHH + miR-146a mimic (n = 3) or scrambled RNA control (n = 3). The animals were then euthanatized at 48 hours after injection and the hippocampi removed for protein and RNA isolation and analysis. (A) TRAF6 and IRAK1 mRNA levels determined by RT-qPCR following TBI and nanoparticle injections. Data are expressed as the mean ± SD. The difference between miR-146a and scramble mimics was evaluated using Student’s t-test. *P < 0.05. (B) Western blot analysis for TRAF6 using hippocampal tissues that were injected with either miR-146a or scrambled control mimic. IRAK1: Interleukin-1 receptor-associated kinase 1; TRAF6: TNF receptor-associated factor 6.