Research Paper Volume 16, Issue 5 pp 4609—4630

Figure 7. MPC-Exo promote muscle development by activating satellite cells and fiber type transformation. Eight-week-old male wildtype C57BL/6 mice were treated with MPC-Exo 3 times. (A) uses laminin immunofluorescence staining to mark the changes in the cross-sectional area of the gastrocnemius muscle after injection (Scale bar in 200 μm). (B) presents a statistical analysis of its fiber area frequency distribution. (C, D) show WB results, revealing increased expression of muscle regeneration-related proteins and muscle protein synthesis metabolic proteins, as well as decreased expression of muscle protein breakdown metabolic proteins after three injections. (E) and (F) show IF results, indicating a decrease in MyHC I (green fluorescence) and an increase in MyHC IIx (red fluorescence) after injection (Scale bar in 100 μm). (G–I) show WB and RT-PCR results, indicating a transition of muscle fiber type from slow-twitch to fast-twitch. Different letters between bars mean P ≤ 0.05 analyses followed by non-paired Student’s t-test. ^nsp > 0.05, ^*p < 0.05, ^**p < 0.01 and ^***p < 0.001 vs. Sham.