Research Paper Volume 16, Issue 5 pp 4609—4630

Figure 4. Muscle satellite cells in the gastrocnemius muscle activate by MPC-Exo, MPC-Exo^140- or AAV-KO-140. Eight-week-old male wildtype C57BL/6 mice were treated with MPC-Exo and MPC-Exo¹⁴⁰⁻ 3 times. Five-week-old mice were injected with adeno-associated virus carrying miR-140-5p inhibitors. RT-qPCR was used to detect the expression (fold change) of miR-140-5p (A), Pax7 (B), MyoD (C) and MyoG (D). The amount of proteins for Pax 7, MyoD and myoD was analyzed by Western blot (E). Data: mean ± SEM (N = 5). ^*P < 0.05 by one-way ANOVA analysis. (F) presents the IF results: activated SCs are characterized by the coexpression of Pax7⁺/MyoD⁺. The marked locations in the figure indicate that in the control group, these cells are expressed only in the cell pool to maintain stem cell numbers. In the injected MPC-Exo group, there was a significant increase in activated SCs around the muscle fibers, indicating that muscle satellite cells were in a proliferative state. This proliferation of activated SCs was further augmented in the injected MPC-Exo¹⁴⁰⁻ group and AAV-KO-140 group (Scale bar in 100 μm).